Author name code: dircontent
ADS astronomy entries on 2022-09-14
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Title: Polarization angle dependence of vertically propagating
radio-frequency signals in South Polar ice
Authors: Besson, Dave Z.; Kravchenko, Ilya; Nivedita, Krishna
Bibcode: 2023APh...14402766B
Altcode:
To better understand the effect of ice properties on the capabilities
of radio experiments designed to measure ultra-high energy neutrinos
(UHEN), we recently considered the timing and amplitude characteristics
of radio-frequency (RF) signals propagating along multi-kilometer,
primarily horizontal trajectories through cold Polar ice at the South
Pole. That analysis indicated satisfactory agreement with a model
of ice birefringence based on ice crystal (c ˆ -axis) data culled
from the South Pole Ice Core Experiment (SPICE). Here we explore the
geometrically complementary case of signals propagating along primarily
vertical trajectories, using extant data from the Askaryan Radio Array
(ARA) experiment, supplemented by a refined analysis of older RICE
experimental data. The timing characteristics of the South Polar data
are in general agreement with the same birefringence model, although a
several nanosecond discrepancy is found in comparison to Taylor Dome
data. Re-analysis of older RICE data also confirm the correlation of
signal amplitudes reflected from internal-layers with the direction
of ice flow, similar to previous observations made along a traverse
from Dome Fuji to the Antarctic coast. These results have two important
implications for radio-based UHEN experiments: (i) if birefringence can
be locally calibrated, the timing characteristics of signals propagating
from neutrino-ice interactions to a distant receiver might be used
to infer the distance-to-vertex, which is necessary to estimate the
energy of the progenitor neutrino, (ii) the measured reflectivity of
internal layers may result in previously-unanticipated backgrounds to
UHEN searches, requiring significantly more modeling and analysis.
Title: Gravitational lensing in Kerr-Newman anti de Sitter spacetime
Authors: Mangut, Mert; Gürsel, Huriye; Sakallı, İzzet
Bibcode: 2023APh...14402763M
Altcode:
The method of Rindler and Ishak enables one to study how light is
bent in the vicinity of a non-rotating and spherically symmetric
gravitational lens. This method mainly aims to investigate the role
of cosmological constant in the consequent path. In this paper, we
use the extension of Rindler-Ishak method (RIM) in order to evaluate
the deflection angle of null geodesics in the equatorial plane of
Kerr-Newman anti de Sitter (KNAdS) spacetime. We then use astrophysical
data to see the effect of rotation and charge on the bending angle of
light for seven distinct stars and two black holes under the assumption
of having a KNAdS background with a negative cosmological constant Λ.
Title: Do pulsar and Fast Radio Burst dispersion measures obey
Benford's law?
Authors: Mamidipaka, Pragna; Desai, Shantanu
Bibcode: 2023APh...14402761M
Altcode: 2022arXiv220709696M
We check if the first significant digit of the dispersion measure of
pulsars and Fast Radio Bursts (using the CHIME catalog) is consistent
with the Benford distribution. We find a large disagreement with
Benford's law with χ2 close to 80 for 8 degrees of
freedom for both these aforementioned datasets. This corresponds to a
discrepancy of about 7 σ. Therefore, we conclude that the dispersion
measures of pulsars and FRBs do not obey Benford's law.
Title: Reconstruction of multiple Compton scattering events in
MeV gamma-ray Compton telescopes towards GRAMS: The physics-based
probabilistic model
Authors: Yoneda, Hiroki; Odaka, Hirokazu; Ichinohe, Yuto; Takashima,
Satoshi; Aramaki, Tsuguo; Aoyama, Kazutaka; Asaadi, Jonathan; Fabris,
Lorenzo; Inoue, Yoshiyuki; Karagiorgi, Georgia; Khangulyan, Dmitry;
Kimura, Masato; Leyva, Jonathan; Mukherjee, Reshmi; Nakasone, Taichi;
Perez, Kerstin; Sakurai, Mayu; Seligman, William; Tanaka, Masashi;
Tsuji, Naomi; Yorita, Kohei; Zeng, Jiancheng
Bibcode: 2023APh...14402765Y
Altcode:
Aimed at progress in mega-electron volt (MeV) gamma-ray astronomy,
which has not yet been well-explored, Compton telescope missions with
a variety of detector concepts have been proposed so far. One of the
key techniques for these future missions is an event reconstruction
algorithm that is able to determine the scattering orders of multiple
Compton scattering events and to identify events in which gamma rays
escape from the detectors before they deposit all of their energies. We
revisit previous event reconstruction methods and propose a modified
algorithm based on a probabilistic method. First, we present a
general formalism of the probabilistic model of Compton scattering
describing physical interactions inside the detector and measurement
processes. Then, we also introduce several approximations in the
calculation of the probability functions for efficient computation. For
validation, the developed algorithm has been applied to simulation
data of a Compton telescope using a liquid argon time projection
chamber, which is a new type of Compton telescope proposed for the
GRAMS project. We have confirmed that it works successfully for up to
8-hit events, including correction of incoming gamma-ray energies for
escape events. The proposed algorithm can be used for next-generation
MeV gamma-ray missions featured by large-volume detectors, e.g., GRAMS.
Title: Static cylindrically symmetric wormhole models in f(R ,
T) gravity
Authors: Bhatti, M. Z.; Yousaf, Z.; Nazir, M.
Bibcode: 2023NewA...9801897B
Altcode:
In this manuscript, we will examine thin-shell wormholes in the
framework of f(R , T) theory. In this gravitational theory, f is a
function of Ricci scalar invariant R and the trace of the stress-energy
tensor T. Also, wormholes that appeared as special solutions to
Einstein's field equations, are now being tackled in a variety of ways
and are being viewed as viable interstellar objects. By selecting a
minimally coupled f(R , T) function, we will reduce modified field
equations to their corresponding Lanczos equations. The junction
conditions are also manipulated and the generalized Chaplygin gas
(GCG) is used to find exact solutions for traversable wormholes. We
investigate the stability of these wormholes when they are perturbed
while maintaining their symmetry. From the comparison of the obtained
graphical solutions, it is found that only unstable solutions to
thin-shell wormholes exist.
Title: Orbit classification in the restricted three-body problem
with the effect of three-body interaction
Authors: Suraj, Md Sanam; Alhowaity, Sawsan; Aggarwal, Rajiv; Asique,
Md Chand
Bibcode: 2023NewA...9801894S
Altcode:
The modified circular restricted three-body problem is numerically
investigated to classify the orbits of the test particle. We perform
a numerical analysis on the various two-dimensional plane, i.e., (x ,
C) -plane, (y , C) -plane, and (x , y) -plane to classify the initial
conditions on the these planes and distinguish following four types
of orbits: (i) the bounded orbits, (ii) collision with the primary
m1, (iii) collision with the primary m2, and
(iv) escaping orbits. The motion of the test particle are evaluated
numerically, by illustrating the color-coded diagrams (CCDs), where
the starting conditions are linked to the orbit type and numerically
evaluated as a function of the Jacobian constant C, the initial value
of the x - co-ordinate and the Jacobian constant C or the x , y -
co-ordinates, or the y - co-ordinate and Jacobian constant. Moreover, in
the mean time we have also noted the associated time for classifications
of each of the starting conditions on the various 2D-planes.
Title: Short and long period periodic orbits around a stable collinear
equilibrium point in the circular restricted three-body problem with
a three-body interaction
Authors: Ragos, Omiros
Bibcode: 2023NewA...9801900R
Altcode:
We deal with a modification of the circular restricted three-body
problem (CR3BP), which incorporates an additional effect of a
three-body interaction. The parameters determining the configuration
of the corresponding dynamical system are the mass ratio μ of the
primary bodies and the constant k that scales the contribution of
the aforementioned interaction. We are interested in the families of
short and long period planar symmetric periodic orbits, which emanate
from the collinear equilibrium point L3 in the case that
this point is neutrally stable. First, we numerically investigate the
correlation between the values of μ and k that result such kinds of
families. Subsequently, these families are numerically constructed
and presented for an indicative case of these parameters. It is found
that both families terminate on some members of the family of short
period orbits.
Title: Three scenarios for shaping 'ears' in planetary nebulae
Authors: Akashi, Muhammad
Bibcode: 2023NewA...9801916A
Altcode:
We present three scenarios for shaping planetary nebulae (PNe) with
ears : (i) Ejection of early and short-duration jets into a spherical
wind. (ii) Fast wind ejection into a slow dense wind and then jet
ejection into the hot bubble. (iii) Interaction of fast wind with two
opposite punctured regions. We find that all three scenarios can lead
to the formation of ears. Ears are two opposite polar protrusions from
the main nebula that are smaller than the main nebula and with a cross
section that decreases monotonically from the base of each ear at the
shell to its far end. Ears are generally indicative of the operation
of jets, but in a rich spectrum of flow structures, jet properties
and time and duration of activity.
Title: Spectroscopic and photometric study of the new δ Scuti star
ASAS J063309+1810.8
Authors: Nouh, Mohamed I.; Abdel-Sabour, Mohamed; Shokry, Ahmed;
Hamed, Gamal M.; Fouda, Diaa A.; Takey, Ali
Bibcode: 2023NewA...9801898N
Altcode: 2022arXiv220807429N
We present BVR observations and low-resolution spectra collected by
the Kottamia Astronomical Observatory 1.88 m telescope (KAO) for the
new pulsating star ASAS J063309+1810.8 (hereafter it will be called
ASAS06+18). The photometric analysis revealed that the star is a δ
Scuti star with low amplitude (a=0.054-0.099 in V mag.) and a short
period (102.604 min). Fourier analysis of the light curves reveals the
fundamental mode with two harmonics. The photometric analysis yielded
a new value of the updated frequency of 13.0035232 cd-1
with an amplitude of 49.93 mmag at phases 0.326 and S/N 21.75 and two
frequencies (20.2099237cd-1, 5.9130945cd-1). Given
the available data, 37 new times of maximum light are presented,
and an updated ephemeris for the star and its O-C data. Assuming its
period decreases and changes smoothly, a new value of (1 / P)dP /dt
is determined. We calculated the effective temperature and surface
gravity as Teff = 7125 ± 250 K and logg = 4.0 ± 0.2 dex
from model atmosphere analysis of the star's spectra at different
phases. The bolometric magnitude Mbol=2.798±0.016, radius
R=1.577±0.077Rʘ, luminosity L=5.714±1.066Lʘ,
the mass is M=1.595 Mʘ, and pulsation constant
Q=0m.0338±0.0003. The star's locations in the evolutionary
mass-luminosity and mass-radius relationships are discussed.
Title: 44 Boo - A unified integrated light curve analysis
Authors: Nelson, R. H.
Bibcode: 2023NewA...9801901N
Altcode:
Radial velocity (RV) data from Lu et al. (2001) were combined
with light curve (LC) data from the Transiting Exoplanet Survey
Satellite (TESS) in an integrated Wilson-Devinney analysis to
yield fundamental parameters. Obtained were masses M 1
= 0.526 (5), M ʘ, and M 2 = 1.063 (7) M
ʘ, stellar radii R1 = 0.65 (2) Rʘ,
and R2 = 0.90 (1) Rʘ, and luminosities
L1 = 0.40 (4) Lʘ and L2 = 0.62 (5)
Lʘ. These are in reasonable agreement with the values
from Hill et al. (1989). Additional analyses were carried out also
using the same RV data but substituting, in turn, the LC datasets
of Binnendijk (1955), Duerbeck (1978), Robb and Milone (1982) and
Genet et al. (1982). While the four Earthbound LC datasets were of
much lower precision than the satellite data, they still yielded
reasonable agreement in the final parameters. Additionally, they
yielded some insight as to the behaviour of the dark spot (on star 1)
over some 75 years. The B and V light curve data of Duerbeck (1978)
suggested that the unresolved companion is hot. An updated period
study originally presented in Nelson et al. (2014) but now with a
Light Time Effect (LiTE) fit is presented. Fifteen new times of minimum
from the TESS data were added, requiring only a modest refinement of
the LiTE parameters. The intrinsic rate of period change (that is,
with the LiTE component removed) is dP/dt = 1.80 (20) x 10-7
seconds/year. If dP/dt can be attributed to conservative mass exchange,
the rate would be dM1/dt = -2.33 (26) x 10-7
Mʘ/year. When the fundamental parameters for each star
were added to the Log L vs Log T plot for EW-type binaries from Yakut
and Eggleton (2005), the results suggested that star 1 of the W-type
binary is under-luminous, while the cooler but larger secondary is
somewhat evolved. Both are in a marginal contact, typical of W-type
eclipsing binaries.
Title: Stability and velocity sensitivities of libration points
in the elliptic restricted synchronous three-body problem under an
oblate primary and a dipole secondary
Authors: Singh, Jagadish; Tyokyaa, Richard K.
Bibcode: 2023NewA...9801917S
Altcode:
The study investigates the stability and velocity sensitivities of
libration points in the elliptic restricted synchronous three-body
problem under an oblate primary and a dipole secondary for Luhman-16 and
HD188753 systems. We have observed that the position of L4
moves away from the centre of origin for both systems as the oblateness
and the half mass dipole distance increases. As the oblateness
and the half mass dipole distance increase, there is a shift in the
position of L5 closer to the centre of the origin for both
systems. The Poincare Surfaces of Section (PSS) for both systems have
revealed that the behaviour of the system changes significantly with
a bit change in the initial conditions, oblateness and the half mass
dipole distance. We have observed that the sensitivity of both systems
to change in position and velocities results in either regular orbits
or irregular orbits. Hence, the dynamical behaviour of the systems is
chaotic. Considering the range of a stable and unstable libration points
for the problem under study given as 0 < ν <νc and
νc ≤ ν ≤1/4 respectively, our study has revealed that,
the triangular libration points are stable and unstable for some values
of oblateness for the binary systems. In the absence of oblateness, the
νc* indicates that triangular points are stable
for Luhman-16 system. When the parameters are varied differently with
order of commensurability k, the critical mass parameters show that the
triangular points are stable for Luhman-16 and unstable for HD188753
system. Using binary systems in our study, the results obtained can be
used as springboards for broading the scope of interest in Celestial
Mechanics and its investigations have shown significant improvement
in the study of this longstanding problem.
Title: On the fraction of particles involved in magneto-centrifugally
generated ultra-high energy electrons in the Crab pulsar
Authors: Osmanov, Z. N.; Mahajan, S. M.
Bibcode: 2023NewA...9801903O
Altcode: 2022arXiv220801988O
The earthward journey of ultra high energy electrons (∼
600 TeV) produced in the Pulsar atmosphere by Landau damping of
magneto-centrifugally excited Langmuir waves (drawing energy form the
rotational slowdown) on primary electrons, is charted. It is shown,
that just as they escape the light cylinder zone, the ultra-high
energy particles, interacting with the medium of the Crab nebula,
rapidly loose their energy via the quantum synchrotron process,
producing highly energetic gamma rays ∼ 0 . 6 PeV. Interacting with
the cosmic background radiation in the interstellar medium, only a tiny
fraction of these ultra high energy photons (via the γγ channel) are,
then transformed into electron-positron pairs. Detected flux of these
photons imposes an upper limit on the fraction (4 × 10-7)
of the magnetospheric particles involved in the process of generation
of ultra-high energy photons (up to 600 TeV).
Title: The first photometric and spectroscopic analysis of the
neglected totally eclipsing contact binary NSVS 2536063
Authors: Xia, Qi-Qi; Li, Kai; Gao, Xing; Sun, Guo-You; Wang, Xi; Yin,
Shi-Peng; Liu, Fei
Bibcode: 2023NewA...9801914X
Altcode:
We firstly studied the neglected totally eclipsing contact binary NSVS
2536063 using the newly observed g'r'i'
light curves of 60 cm Ningbo Bureau of Education and Xinjiang
Observatory Telescope (NEXT) and some public data, which come from the
Transiting Exoplanet Survey Satellite (TESS), the All-Sky Automated
Survey for SuperNovae (ASAS-SN), the Zwicky Transient Facility (ZTF)
survey, and the Large sky Area Multi-Object fiber Spectroscopic
Telescope (LAMOST). NSVS 2536063 is determined as an A-type median
contact binary with a mass ratio of q=0.308 ± 0.001 and the contact
degree of f=26 ± 2%. The absolute parameters of the two components were
calculated using the photometric parameters and Gaia distance. Then
the diagrams of mass-radius and mass-luminosity indicate that the
more massive star is a main sequence star and the less massive star is
over-sized and over-luminous. Both the hot spot added on the primary
star and magnetic emission lines of spectra indicate the possible
magnetic activity of NSVS 2536063. The orbital period of NSVS 2536063
may be long-term increasing with a rate of dp/dt = 1.24(±0.19)
×10-7d yr-1, which is often explained by the
mass transfer from the less massive star to the more massive one. Mass
transfer may also be responsible for the hot spot on the primary star.
Title: Chromospheric activity and period variations of the contact
binary EE Cet from TESS
Authors: Yang, Yuangui; Wang, Shuang
Bibcode: 2023NewA...9801919Y
Altcode:
From the 100-day TESS observations, we comprehensively studied the
variations of the light curve and orbital period for EE Cet. It is found
that an 83.2-day oscillation occurs in the differences between two light
maxima, which identifies the existence of chromospheric activity. Using
the 2016-version Wilson-Devinney code, we obtained three sets of
photometric solutions from TIC1432, TIC2449
and TIC2495. Results imply a dark spot immigrating from
longitude 217 . 9(± 2 . 2) ∘ in BJD 2459449 into
longitude 61 . 6(± 0 . 7) ∘ in BJD 2459495. From the
eclipse timing residuals (i.e., observed minus computed), the orbital
period of EE Cet may be undergoing a long-term period increase with
a periodic variation. The 15.95-yr periodic oscillation with A =
0 . 0038(1) d may result from the light-time effect due to the third
body. Meanwhile, the orbital period increases at a rate of dP / dt =
1 . 74(± 0 . 02) × 10-7dyr-1 , which may result
from the conserved mass transfer from the less massive component to
the more massive one. With mass transferring, EE Cet will evolve into
the broken-contact configuration, as predicted by the TRO theory.
Title: Regular black hole solution in PFDM environment to explain
the radiative efficiency of black hole candidates
Authors: Narzilloev, Bakhtiyor; Ahmedov, Bobomurat
Bibcode: 2023NewA...9801922N
Altcode:
This work is the continuation of our preceding work where we have
shown that regular Bardeen black hole surrounded by perfect fluid
dark matter (PFDM) can be an alternative solution to explain the
radiative efficiency of the astronomical source A0620-00. Here we
expand the number of X-ray sources containing black hole candidates
with GROJ1655-40, XTEJ1550-564, H1743-322, and GRS1124-683. The
black hole solution explored contains in addition to the total mass
M two spacetime parameters as the magnetic charge of a black hole and
parameter that describes the properties of dark matter around a black
hole. It is observed that combination of these two additional spacetime
parameters can be very efficient to interpret the observational
radiative efficiency of most astronomical sources studied.
Title: A method for mixed additive and multiplicative random error
models with inequality constraints in geodesy
Authors: Wang, Leyang; Chen, Tao
Bibcode: 2022EP&S...74..125W
Altcode:
In the geodetic data processing field, most methods for dealing with
inequality constraints model are based on additive random error
(ARE) models, and there have been few studies on mixed additive
and multiplicative random error (MAAMRE) models with inequality
constraints. To address this problem, a MAAMRE model with inequality
constraints is first established based on the definition of inequality
constraint equations, and then, a corresponding parameter estimation
algorithm is proposed based on the idea of an exhaustive search
method. In addition, considering a MAAMRE model for an ill-posed
problem, an iterative regularization solution for an ill-posed MAAMRE
model is first derived, and then, a specific parameter estimation
algorithm for an ill-posed MAAMRE model with inequality constraints is
further proposed by applying the exhaustive search approach. Finally,
the feasibility and advantages of the proposed algorithms are verified
by global positioning system (GPS) elevation fitting model and digital
terrain model (DTM) examples.
Title: Experiments on seepage-triggered cliff landslides using
cohesive wet sand
Authors: Shibuya, Fumi; Sumita, Ikuro
Bibcode: 2022PEPS....9...43S
Altcode:
Unsaturated wet sand possesses capillary cohesion that is lost
when it becomes saturated. Thus, it can form a cliff, but a slide
may be triggered upon saturation. Here we conduct cliff landslide
experiments using cohesive wet sand where the groundwater seeps
in from the hydraulic head hw located at the rear of a
cliff (height H) and vary these parameters. Importantly, we measure
both the total stress σ and pore water pressure u to obtain the
effective stress σ'=σ -u . The experiments show that for
a fixed H (≃20 cm), a slide is triggered when the hw
exceeds a critical level. The slide occurs nearly simultaneous or
after the groundwater seeps out from the cliff toe and the vertical
velocity increases approximately exponentially during the slide. As
hw rises, 2 slides are triggered that progress downslope,
and for the highest hw, the whole cliff is pushed forward
after the first slide. On the other hand, when the H is high, the slide
becomes deep seated. The time needed for the water to seep out from the
cliff toe decreases with the hw and increases with the H,
as modeled by a permeable flow with a permeability that decreases with
the σ'. The σz (vertical) is initially uneven
and deviates from the lithostatic value by arching. For tall cliffs,
the σz near the cliff toe falls precipitously soon after
the seepage starts prior to the rise in u, indicating that a stress
redistribution occurred as the wet sand loses cohesion and slip plane
develops. This also indicates the efficacy of σ measurement because
the changes are detected before the groundwater arrives. A stability
analysis that models the drop in cohesion and a rise in u explains
the cliff becoming unstable with hw and the slide becoming
deep seated with H. However, it overestimates the factor of safety
Fs because it does not include the capillary rise and the
fall in σz.
Title: Role of the contribution of higher orders corrections on dust
acoustic solitons in polarized space dusty plasma
Authors: Kaur, Manveet; Saini, N. S.
Bibcode: 2022JApA...43...52K
Altcode:
In this paper, we have studied the dust acoustic (DA) solitons and
dressed solitons under the influence of polarization force in a dusty
plasma composed of negatively charged dust fluid, Maxwellian electrons
and generalized (r, q) distributed ions. The expression of polarization
force is modified due to the presence of generalized (r, q) distributed
ions hence the effect of polarization force. By imposing the reductive
perturbation method, the KdV equation and KdV type inhomogeneous
equation are derived to study DA solitons and dressed solitons. The
stationary solutions of these equations have been derived using the
renormalization method. The stability analysis of solitons has also
been carried out. The contribution of higher-order corrections and
(r, q) distributed ions on the propagation properties of DA solitons,
dressed solitons and energy of solitons in the presence of polarization
force has been scrutinized.
Title: Remote sensing and DC electrical investigations in the Figuil
area (North-Cameroon): structural and geological implications
Authors: Gouet, Daniel Hervé; Kana, Janvier Domra; Guimbous, Jean
Jacques Kouoh; Ewembe, Fontama Yuka; Mbabi, André; Ngos, Simon, III
Bibcode: 2022JAsGe..11..147G
Altcode:
No abstract at ADS
Title: Prediction and validation of short-to-long-term earthquake
probabilities in inland Japan using the hierarchical space-time ETAS
and space-time Poisson process models
Authors: Ogata, Yosihiko
Bibcode: 2022EP&S...74..110O
Altcode:
A hierarchical space-time version of the epidemic-type aftershock
sequence (HIST-ETAS) model was constructed for an optimally adapted fit
to diverse seismicity features characterized by anisotropic clustering
as well as regionally distinct parameters. This manuscript validates
this elaborate model for short-term prediction based on several
years of recent inland Japan earthquakes as a testing data set,
by evaluating the results using a log-likelihood ratio score. To
consider intermediate- and long-term performance, several types of
space-time Poisson models are compared with the background seismicity
rate of the HIST-ETAS model. Results show first that the HIST-ETAS
model has the best short-term prediction results for earthquakes in
the range of magnitudes from M4.0 to M5.0, although, for the larger
earthquakes, sufficient recent earthquake data is lacking to evaluate
the performance. Second, for intermediate-term predictions, the optimal
spatial nonuniform Poisson intensity model has a better forecast
performance than the seismic background intensity of the HIST-ETAS
model, while the uniform rate Poisson model throughout all of inland
Japan has the worst forecast performance. For earthquakes of M6 or
larger, the performance of retrospective long-term forecasts was tested
in two ways. First, a retrospective forecasting experiment divided the
entire period from 1885 to the present into two parts, with the recent
~ 30 years as the forecast period. Second, the historical damaging
earthquake data (599-1884) were spatially validated using century data
from 1885 to the present. In both validations, it was determined that
the spatial intensity of the inland background seismic activity of the
HIST-ETAS model is much better than the best-fit nonuniform Poisson
spatial model, leading to the best results. The findings of this study
will be critical for regional earthquake hazard planning in Japan and
similar locations worldwide.
Title: Preface for the article collection "Stratigraphy and
paleoclimatic/paleoenvironmental evolution across the Early-Middle
Pleistocene transition in the Chiba composite section, Japan, and
other reference sections in East Asia"
Authors: Suganuma, Yusuke; Head, Martin J.; Sagawa, Takuya
Bibcode: 2022PEPS....9....9S
Altcode:
No abstract at ADS
Title: Correction to: Seismicity distribution in the Tonankai and
Nankai seismogenic zones and its spatiotemporal relationship with
interplate coupling and slow earthquakes
Authors: Yamamoto, Yojiro; Yada, Shuichiro; Ariyoshi, Keisuke; Hori,
Takane; Takahashi, Narumi
Bibcode: 2022PEPS....9...36Y
Altcode:
No abstract at ADS
Title: Climatic zonation of Egypt based on high-resolution dataset
using image clustering technique
Authors: Hamed, Mohammed Magdy; Nashwan, Mohamed Salem; Shahid,
Shamsuddin
Bibcode: 2022PEPS....9...35H
Altcode:
Egypt, a predominantly arid and hyper-arid country, is one of the
environmentally most fragile regions of the world. The country became
a hot spot for climatic extremes and aridity change in the global
warming context. The unavailability of a detailed and reliable climate
zonation map is a major hindrance to climatic studies in Egypt. This
study attempted to generate a high-resolution climate zone map of Egypt
based on a novel image analysis technique. For this purpose, a colored
image representing Egypt's composite climatology was developed using
three high-resolution (1-km) climate variables: rainfall, maximum
temperature and minimum temperature during 1979-2013. A spherical
evolution algorithm was used to classify the image into different
climate zones. Subsequently, the climate zones representing similar
climate distribution were merged to generate the climate map of
Egypt. The study revealed that Egypt's distinguishable climate zones
could be recognized when the land area was classified into nine zones
using the image analysis technique. The statistical analysis of climate
variables of each zone revealed similar climatology only in two pairs
of zones. The merging of similar climate zones yielded seven climate
zones having distinct climate characteristics. The validation of climate
zonation using various statistical tests revealed the robustness of the
proposed method in classifying climate. The climate zone map generated
in the study can be used as a reference for climate change analysis
in Egypt.
Title: 3D geophysical mapping of the subsurface to support urban
water planning: a case study from Simawa, Nigeria
Authors: Fadakinte, Ifedayo
Bibcode: 2022JAsGe..11..120F
Altcode:
No abstract at ADS
Title: Refining the contribution of riverine particulate release to
the global marine Nd budget
Authors: Che, Hong; Zhang, Jing; Liu, Qian; He, Huijun; Zhao, Zhi-Qi
Bibcode: 2022PEPS....9...22C
Altcode:
The release of neodymium (Nd) from particles along continental margins
may contribute to losses in the global of Nd budget. The Changjiang
River, which carries a heavy load of total suspended matter, empties
into the East China Sea, and a strong particulate-seawater interaction
process occurs along the salinity gradient. In the low-salinity region
(S < 2.0), strong removal of dissolved rare earth elements (dREEs)
occurs, but the Nd isotope values are uniform. At mid- and high-salinity
(S = 2.0-28.0 and S > 28.0) areas, the dREE concentrations increase
slightly. An Nd isotope mass balance indicates that the release of
particulate matter is a source of dREEs in the Changjiang estuary. The
release rate of particulate Nd (NdSPM) to the dissolved
Nd pool in Changjiang estuary is higher than other estuaries, such as
Amazon estuary. Composite all river data available from the previous
studies indicate that 5800-9200 Mg per year of Nd is released to global
marine waters from riverine particles. This estimated quantity is on
the same order of magnitude as the calculated global Nd release flux
based on the case study in the Amazon estuary. Our study indicates that
to better constrain the global Nd budget, it is required to consider
the release rate of NdSPM in different rivers due to the
significant difference among various rivers, but with very limited
available data as of now.
Title: Analysis of dual band and survey photometry of two low mass
ratio contact binary systems
Authors: Wadhwa, Surjit S.; de Horta, Ain Y.; Filipović, Miroslav D.;
Totohill, F. H. Nick
Bibcode: 2022JApA...43...42W
Altcode: 2022arXiv220209120W
The study presents photometric analysis of the completely eclipsing
contact binary systems TYC 8351-1081-1 and ASAS J210406-0522.3. TYC
8351-1081-1 is an extremely low mass ratio (q =0.086 ) system with a
high degree of contact (f =0.66 ) while ASAS J210406-0522.3 is found to
be in marginal contact (f =0.08 ) with a relatively low-mass ratio of
0.272. There is good thermal contact in both systems with only a small
difference in the temperature of the components. The systems have been
observed by a number sky surveys over the past 20 years. We compare the
light curve solutions from up to three of these surveys and find that
survey photometric data manually analysed is robust and yields results
comparable to dedicated ground-based photometry. There is evidence of
significant luminosity transfer from the primary to the secondary,
on the order of 0.5 L⊙ for TYC 8351-1081-1 and 0.06
L⊙ for ASAS J210406-0522.3. There appears to be no change
in the period of either system over the past 20 years and theoretical
angular momentum loss is below current measurement threshold in both
cases. We also show that the mass ratio and separation are well above
the theoretical values for orbital instability in both cases. As would
be expected, the density of the secondary components is significantly
higher relative to the primary.
Title: Analyzing non-thermal steady solar plasmas in the κ-modified
polytropic GES model framework
Authors: Sarma, Pankaj; Karmakar, Pralay Kumar
Bibcode: 2022JApA...43...46S
Altcode:
The gravito-electrostatic sheath (GES) model, originally formulated
to see the surface origin of solar wind plasma (SWP) originating from
the solar interior plasma (SIP) through the quasi-linear coupling
non-rigid solar surface boundary (SSB), is revisited. The model
genesis is the application of laboratory plasma-wall coupling and
cross-border effects on the astrophysical spatiotemporal scales. In this
investigation, we consider the non-thermal (κ-distributed) electrons
and inertial ions as the constitutive fluids of the entire solar
plasma system. It is under the action of magnetic field in a turbulent
background describable with the Larson logabarotropic law in spherical
geometry. The structuring equations for both the SIP and SWP scales
are methodologically developed. It includes a new type of κ-modified
polytropic equation of state constructed herein for the first time. A
numerical illustrative platform is presented to characterize the new
κ-polytropic GES structure formation and subsequent evolution. The
reliability of our model study is validated on the grounds that the new
SSB is formed at a heliocentric radial distance of 3.5 (on Jeans scale)
for the thermal (Boltzmannian) electrons, which exactly matches the
previous GES prediction. It is interesting to see that the SSB location
gradually shifts radially inward with reduced non-thermality index (κ),
and so forth. The new solar plasma potential, flow and other relevant
characteristics are analyzed elaborately. The applicability of the
results in the real solar plasma environs is lastly indicated concisely.
Title: Extremely large flares/multiple large flares expected from
sunspot groups with large area
Authors: Watari, Shinichi
Bibcode: 2022EP&S...74..115W
Altcode:
The possible occurrence of major space weather events, such as large
solar flares within one hundred years, is studied anticipating their
effects on our social facilities. However, the continuous soft X-ray
(SXR) observation of flares by Geostationary Operational Environmental
Satellites (GOES) started in 1975, and the period of data collection
is less than 50 years. On the other hand, ground-based sunspot
observations have a long history. Their duration of data collection
exceeds 100 years. The possibility of the occurrence of extremely
large flares is estimated using the daily sunspot area data of
individual sunspot groups between 1879 and 2016 using the catalogue
complied by the Debrecen Heliophysical Observatory in Hungary and the
catalogue updated by Mandal, Krivova, Solanki, Shinha, and Banerjee in
2020. It had become clear that large sunspot groups with the potential
to produce Carrington-class flares (areas of more than 3000 MSH)
have appeared on a total of 119−139 days between 1879 and 2016,
and a sunspot group with the potential to produce an X100-class flare
appeared between March and April 1947. According to the past major space
weather events, the large sunspot groups caused a series of multiple
large flares instead of just one large flare. We tried to estimate
the probabilities of occurrence of a SXR flare ≥ X100 for 30-, 50-,
and 100-year periods to be 0.70−0.76, 0.87−0.91, and 0.98−0.99,
respectively, using the complementary cumulative distribution function
(CCDF) of sunspot areas for the 138-year data.
Title: Chinese sunspot drawings and their digitization - (V) the
phase relation between Hα flare index and sunspot activity
Authors: Li, Yang-Yang; Zheng, Sheng; Zeng, Shu-Guang; Zhou, Tuan-Hui;
Lin, Gang-Hua
Bibcode: 2022JApA...43...41L
Altcode:
Hα flare index is one of the solar activity indicators to
describe the physical properties of the active regions in the solar
atmosphere. Sunspot number is a representative indicator of the magnetic
activity in the photosphere, which is associated with the energy supply
rate to the corona. Thus, it is significant to investigate the phase
relationship between Hα flare activity and sunspot activity. In the
present work, monthly Hα flare index (FIm), monthly sunspot
activity (sunspot numbers (Rs) and group sunspot numbers
(Rg)) compiled from the Purple Mountain Observatory are
used to find their phase relationship using the cross-correlation
analysis. For solar cycles 20-23, there is a very pronounced time lag
of about 9, 4, 4.5 and 10 months between the monthly FIm
and Rs, respectively. Furthermore, there is a noticeable
time lag of about 7, 8, 4.5 and 9 months between FIm and
Rg for the same cycles, respectively. If we take the whole
time series together, we notice that FIm has a time lag of
about 4 months with regard to both Rs and Rg. The
possible physical mechanisms for their observed phase lag are discussed.
Title: Comparison of shadow models and their impact on precise orbit
determination of BeiDou satellites during eclipsing phases
Authors: Zhang, Yan; Wang, Xiaoya; Xi, Kewei; Li, Zhen
Bibcode: 2022EP&S...74..126Z
Altcode:
Solar radiation pressure (SRP) is an extremely critical perturbative
force that affects the GNSS satellites' precise orbit determination
(POD). Its imperfect modelling is one of the main error sources of POD,
whose magnitude is even to10−9 m/s2. The shadow
factor (i.e., eclipse factor) is one crucial parameter of SRP, generally
estimated by the cylindrical model, the conical model, or shadow models
considering the Earth's oblateness and the atmospheric effect, such as
the Perspective Projection Method atmosphere (PPMatm) model and Solar
radiation pressure with Oblateness and Lower Atmospheric Absorption,
Refraction, and Scattering Curve Fit (SOLAARS-CF) model. This paper
applies the former four shadow models to determine the corresponding
precise orbit using BeiDou satellites' ground-based observation, and
then compared and assessed the orbit accuracy through Satellite Laser
Ranging (SLR) validation and Inter-Satellite Link (ISL) check. The
results show that the PPMatm model's accuracy is equivalent to
the SOLAARS-CF model. Compared with the conical shadow model, SLR
validations show the orbit accuracy from the PPMatm and SOLAARS-CF
model can be generally improved by 2-10 mm; ISL range check shows
that the Root Mean Square (RMS) can be decreased by 2-7 mm. These
results show that the shadow model in GNSS POD should fully consider
the Earth's oblateness and the atmospheric effect, especially for the
perturbative acceleration higher than 10-10 m/s2.
Title: Different representations of a partially ionized plasma
Authors: Krishan, Vinod
Bibcode: 2022JApA...43...43K
Altcode:
It is economical to devise ways and means to simplify a multi-species
particle system. A partially ionized plasma consisting of electrons,
ions and neutral particles can be described as a three-fluid, a
two-fluid or a single-fluid system by appropriately combining the
dynamics of each of the species. Here, one of the three possible
two-fluid descriptions is discussed wherein the electron fluid and
the neutral fluid are combined into one fluid, christened as ENe
fluid, and treat the ions as the second fluid. It is found that
the process of combining the electrons and the neutrals endows the
neutrals with a negative electric charge. Hence, here is a plasma
with heavy (with nearly the mass of the neutral particle) negatively
charged particles along with the positively charged ions. After
establishing the framework for the two-fluid, the ENe-ion, system,
the characteristic electrostatic wave mode of this novel unmagnetized
plasma is determined. A new mode of frequency ω =ωEN
emerges in the limit (2 γen+γei) ≫ω,
where γen and γei are, respectively, the
electron-neutral and the electron-ion collision frequencies. This is
identified as a collective mode of the ENe fluid, a counterpart of
the electron plasma mode in a fully ionized plasma.
Title: Pre-foundation geophysical investigation of a site for
structural development in Oka, Nigeria
Authors: Ademila, Omowumi
Bibcode: 2022JAsGe..11...81A
Altcode:
No abstract at ADS
Title: Quantitative logging data clustering with hidden Markov model
to assist log unit classification
Authors: Yabe, Suguru; Hamada, Yohei; Fukuchi, Rina; Nomura, Shunichi;
Shigematsu, Norio; Kiguchi, Tsutomu; Ueki, Kenta
Bibcode: 2022EP&S...74...93Y
Altcode:
Revealing subsurface structures is a fundamental task in geophysical and
geological studies. Logging data are usually acquired through drilling
projects, which constrain the subsurface structure, and together
with the description of drill core samples, are used to distinguish
geological units. Clustering is useful for interpreting logging data
and making log unit classification and is usually performed by manual
inspection of the data. However, the validity of clustering results
with such subjective criteria may be questionable. This study proposed
the application of a statistical clustering method, the hidden Markov
model, to conduct unsupervised clustering of logging data. As logging
data are aligned along the drilled hole, they and the geological
structure hidden behind such sequential datasets can be regarded as
observables and hidden states in the hidden Markov model. When log
unit classification is manually conducted, depth dependency of logging
data is usually focused. Therefore, we included depth information
as observables to explicitly represent depth dependency of logging
data. The model was applied to the following geological settings:
the accretionary prism at the Nankai Trough, the onshore fault zone
at the Kii Peninsula (southwest Japan), and the forearc basin at the
Japan Trench. The optimum number of clusters were searched using a
quantitative index. The clustering results using the hidden Markov
model were consistent with previously reported classifications or
lithological descriptions; however, our method allowed a more detailed
division of logging data, which is useful to interpret geological
structures, such as a fault or a fault zone. Therefore, the use of the
hidden Markov model enabled us to clarify assumptions quantitatively
and conduct clustering consistently for the entire depth range, even
for different geological sites. The proposed method is expected to
have wider applicability and extensibility for other types of data,
including geochemical and structural geological data.
Title: Spatial and temporal influence of sea level on inland stress
based on seismic velocity monitoring
Authors: Andajani, Rezkia Dewi; Tsuji, Takeshi; Snieder, Roel; Ikeda,
Tatsunori
Bibcode: 2022EP&S...74...97A
Altcode:
Earth's crust responds to perturbations from various environmental
factors. To evaluate this response, seismic velocity changes offer an
indirect diagnostic, especially where velocity can be monitored on an
ongoing basis from ambient seismic noise. Investigating the connection
between the seismic velocity changes and external perturbations could be
useful for characterizing dynamic activities in the crust. The seismic
velocity is known to be sensitive to variations in meteorological
signals such as temperature, snow, and precipitation as well as changes
in sea level. Among these perturbations, the impact of variations in
sea level on velocity changes inferred from seismic interferometry of
ambient noise is not well known. This study investigates the influence
of the ocean in a 3-year record of ambient noise seismic velocity
monitoring in the Chugoku and Shikoku regions of southwest Japan. First,
we applied a bandpass filter to determine the optimal period band for
discriminating among different influences on seismic velocity. Then,
we applied a regression analysis between the proximity of seismic
station pairs to the coast and the ocean influence, as indicated
by the correlation of sea level to seismic velocity changes between
pairs of stations. Our study suggests that for periods between 0.0036
to 0.0155 cycle/day (64-274 days), the ocean's influence on seismic
velocity decreases with increasing distance of station pairs from the
coast. The increasing sea level deforms the ocean floor, affecting the
stress in the adjacent coast. The stress change induced by the ocean
loading may extend at least dozens of kilometers from the coast. The
correlation between sea level and inland seismic velocity changes is
negative or positive. Although it is difficult to clearly interpret
the correlation based on a simple model, they could depend on the
in situ local stress, orientation of dominant crack, and hydraulic
conductivity. Our study shows that seismic monitoring may be useful
for evaluating the perturbation in the crust associated with an
external load.
Title: On the performance of position-domain sidereal filter for
30-s kinematic GPS to mitigate multipath errors
Authors: Itoh, Yuji; Aoki, Yosuke
Bibcode: 2022EP&S...74...23I
Altcode:
The noise level of kinematic Global Positioning System (GPS)
coordinates is much higher than static daily coordinates. Therefore,
it needs to be improved to capture details of small sub-daily tectonic
deformation. Multipath is one of the dominant error sources of kinematic
GPS, which the sidereal filter can mitigate. With increasing interest
in applying kinematic GPS to early postseismic deformation studies, we
investigate the characteristics of multipath errors and the performance
of the position-domain sidereal filter using 30-s kinematic coordinates
with a length of nearly 5 days. Experiments using three very short
baselines mostly free from atmospheric disturbances show that multipath
signature in position-domain has better repeatability at longer periods,
and sidereal filtering without low-pass filtering yields a lift of
power spectral density (PSD) at periods shorter than 200 s. These
results recommend an empirical practice of low-pass filtering to a
sidereal filter. However, a moderate cut-off period maximizes the
performance of the sidereal filter because of the smaller multipath
signature at longer periods. The amplitude of post-sidereal-filtered
fluctuation is less than 6 mm in standard deviation, which demonstrates
the nearly lowest noise level of kinematic GPS used for postseismic
and other tectonic deformation studies. Our sidereal filter is proven
to mitigate several peaks of power spectral density at periods up to
100,000 s, but the period dependency of PSD is not fully alleviated
by sidereal filtering, which needs future investigation.
Title: Time-independent forecast model for large crustal earthquakes
in southwest Japan using GNSS data
Authors: Nishimura, Takuya
Bibcode: 2022EP&S...74...58N
Altcode:
In this study, we developed a regional likelihood model for crustal
earthquakes using geodetic strain-rate data from southwest Japan. First,
the smoothed strain-rate distributions were estimated from continuous
Global Navigation Satellite System (GNSS) measurements. Second, we
removed the elastic strain rate attributed to interplate coupling on
the subducting plate boundary, including the observed strain rate,
under the assumption that it is not attributed to permanent loading
on crustal faults. We then converted the geodetic strain rates to
seismic moment rates and calculated the 30-year probability for M ≥ 6
earthquakes in 0.2 × 0.2° cells, using a truncated Gutenberg-Richter
law and time-independent Poisson process. Likelihood models developed
using different conversion equations, seismogenic thicknesses, and
rigidities were validated using the epicenters and moment distribution
of historical earthquakes. The average seismic moment rate of crustal
earthquakes recorded during 1586-2020 was only 13-20% of the seismic
moment rate converted from the geodetic data, which suggests that
the observed geodetic strain rate includes considerable inelastic
strain. Therefore, we introduced an empirical coefficient to calibrate
the moment rate converted from geodetic data with the moment rate of the
earthquakes. Several statistical scores and the Molchan diagram showed
all models could predict real earthquakes better than the reference
model, in which earthquakes occur uniformly in space. Models using
principal horizontal strain rates exhibited better predictive skill
than those using the maximum horizontal shear strain rate. There were
no significant differences in predictive skill between uniform and
variable distributions for seismogenic thickness and rigidity. The
preferred models suggested high 30-year probability in the Niigata-Kobe
Tectonic Zone and central Kyushu, exceeding 1% in more than half of
the analyzed region. The model predictive skill was also verified by
a prospective test using earthquakes recorded during 2010-2020. This
study suggests that the proposed forecast model based on geodetic data
can improve the regional likelihood model for crustal earthquakes in
Japan in combination with other forecast models based on active faults
and seismicity.
Title: Latitudinal and interhemispheric differences of the ionospheric
semi-diurnal lunitidal perturbations during the 2009 Arctic sudden
stratospheric warming event in the eastern Asia-Australia sector
Authors: Liu, Jing; Zhang, Donghe; Sun, Shuji; Hao, Yongqiang;
Xiao, Zuo
Bibcode: 2022EP&S...74...22L
Altcode:
The ionosphere exhibits some characteristic perturbations during
sudden stratospheric warming (SSW) events, of which the mechanism is
not thoroughly understood. This study focuses on the latitudinal and
interhemispheric differences of the enhanced semi-diurnal lunitidal
(M2) perturbations related to SSW using total electron content
calculated from the network of Global Navigation Satellite System
and ionosonde data in the eastern Asia-Australia sector during
the January 2009 SSW. Our results show that the most distinct M2
perturbations in the northern and southern hemispheres occur near
the Equatorial Ionization Anomaly crest regions around ± 15°
geomagnetic latitudes, but corresponds to different moon phases,
respectively. Clear M2 perturbations extend to middle latitudes
only in the southern hemisphere and have another local maximum in
the southern middle latitude. Such latitudinal and interhemispheric
features of ionospheric M2 perturbations in the low latitude in the
eastern Asia-Australia sector are similar as those in the American
sector during the same SSW event. This supports previous suggestion that
such latitudinal and interhemispheric differences in the low latitude
can be primarily explained by the summer-winter thermospheric wind
modulation on equatorial plasma fountain and thus emphasize its role in
the vertical coupling process of M2 perturbation. The clear differences
of M2 perturbations in the southern middle latitude between the eastern
Asia-Australia and American sectors indicate that the thermospheric
circulation related to the Weddell Sea Anomaly may have influence on
the lower atmosphere-ionosphere coupling.
Title: Construction of nominal ionospheric gradient using satellite
pair based on GNSS CORS observation in Indonesia
Authors: Supriadi, Slamet; Abidin, Hasanuddin Zainal; Wijaya, Dudy
Darmawan; Abadi, Prayitno; Saito, Susumu; Prabowo, Dwiko Unggul
Bibcode: 2022EP&S...74...71S
Altcode:
Ground-Based Augmentation System (GBAS) is a GNSS augmentation system
that meets International Civil Aviation Organization (ICAO) requirements
to support precision approach and landing. GBAS is based on local
differential GNSS technique with reference stations located around an
airport to provide necessary integrity and accuracy. The performance
of the GBAS system can be affected by gradient in the ionospheric
delay between aircraft and reference stations. A nominal ionospheric
gradient, which is bounded by a conservative error bound, is represented
by a parameter σvig. The parameter σvig is
commonly determined using station pair to GNSS Continuous Operating
Reference Station (CORS) data. The station-pair method is susceptible
to doubling of the estimation error of receiver inter-frequency bias
(IFB) and is not suitable with the CORS conditions in Indonesia. We
propose a satellite-pair method that is found to be more suitable
for the CORS network over Indonesia which is centered in Java and
Sumatra islands. An overall value of σvig (5.21 mm/km)
was obtained using this method along with preliminary results of a
comparison of σvig from Java and Sumatra islands.
Title: Relationship between topography, tropospheric wind, and
frequency of mountain waves in the upper mesosphere over the Kanto
area of Japan
Authors: Ishii, Satoshi; Tomikawa, Yoshihiro; Okuda, Masahiro;
Suzuki, Hidehiko
Bibcode: 2022EP&S...74....6I
Altcode:
Imaging observations of OH airglow were performed at Meiji University,
Japan (35.6° N, 139.5° E), from May 2018 to December 2019. Mountainous
areas are located to the west of the imager, and westerly winds
are dominant in the lower atmosphere throughout the year. Mountain
waves (MWs) are generated and occasionally propagate to the upper
atmosphere. However, only four likely MW events were identified,
which are considerably fewer than expected. There are two possible
reasons for the low incidence: (1) MWs do not propagate easily to the
upper mesosphere due to background wind conditions, and/or (2) the
frequency of MW excitation was low around the observation site. Former
possibility is found not to be a main reason to explain the frequency
by assuming typical wind profiles in troposphere and upper mesosphere
over Japan. Thus, frequency and spatial distribution of orographic wavy
clouds were investigated by analyzing images taken by the Himawari-8
geostationary meteorological satellite in 2018. The number of days when
wavy clouds were detected in the troposphere around the observation site
(Kanto area) was about a quarter of that around the Tohoku area. This
result indicates that frequency of over-mountain flow which is thought
to be a source of excitation of MWs is low in Kanto area. We also found
that the angle between the horizontal wind direction in troposphere and
the orientation of the mountain ridge is a good proxy for the occurrence
of orographic wavy clouds, i.e., excitation of MWs. We applied this
proxy to the topography around the world to investigate regions where
MWs are likely to be excited frequently throughout the year to discuss
the likelihood of "MW hotspots" at various spatial scale.
Title: Estimating errors in autocorrelation functions for reliable
investigations of reflection profiles
Authors: Maeda, Yuta; Watanabe, Toshiki
Bibcode: 2022EP&S...74...48M
Altcode:
Autocorrelation functions (ACFs) of vertically incident seismic waves
are used to image subsurface reflectors. However, the reflection
responses derived from ACFs usually contain many false signals. We
present a method to quantify the errors in ACFs and extract true
reflectors with high reliability. We estimated the errors for each
earthquake at each station as follows. We calculated the amplitude
of the observed waveform within the noise window and generated 1000
random noise traces that have this amplitude. By subtracting the
random noise traces from the observed waveform, we created 1000
candidate earthquake waveforms. We computed the ACF for each of
the 1000 waveforms and calculated the ensemble average and standard
deviation of the 1000 different ACF amplitudes at each lag time. Then,
we applied weighted stacking to the ACFs of many earthquakes to obtain
the reflection response at the station. We calculated the standard
deviation of the weighted stack to estimate errors in the reflection
response. We evaluated the method by applying it to seismic data from
the metropolitan area of Japan. The subsurface structure of the study
area has been studied extensively and consists of a strong velocity
discontinuity between sedimentary and basement layers. Following our
method, the discontinuity was imaged as a clear reflector with an
amplitude that was substantially greater than three times the standard
deviation, which corresponds to statistical significance at the 99%
confidence level. At other depths where reflectors are not expected
to be present, the amplitudes of the peaks were less than or close to
three times the standard deviation. The signal of the discontinuity
was clearly visible at frequencies below 10 Hz and was less prominent
at higher frequencies.
Title: Influence of geomagnetic storms on the quality of
magnetotelluric impedance
Authors: Chen, Hao; Mizunaga, Hideki; Tanaka, Toshiaki
Bibcode: 2022EP&S...74..111C
Altcode:
Magnetotelluric (MT) field data contain natural electromagnetic
signals and artificial noise sources (instrumental, anthropogenic,
etc.). Not all available time-series data contain usable information
on the electrical conductivity distribution at depth with a low
signal-to-noise ratio. If variations in the natural electromagnetic
signal increase dramatically in a geomagnetic storm, the signal-to-noise
ratio increases. A more reliable impedance may be obtained using
storm data in a noisy environment. The field datasets observed at
mid-latitudes were used to investigate the effect of geomagnetic
storms on MT impedance quality. We combined the coherence between
the electric and magnetic fields and the result of the MT sounding
curve to evaluate the MT impedance quality across all periods and
combined the phase difference among the electric and magnetic fields,
the polarization direction, and the hat matrix to discuss the data
quality for a specific period simultaneously. The case studies showed
that the utilization of the data observed during the geomagnetic storm
could overcome the local noise and bring a more reliable impedance.
Title: Waveform inversion of the ultra-long-period seismic event
associated with ground tilt motion during an eruption of Mount
Kusatsu-Shirane, Japan, on January 23, 2018
Authors: Takahashi, Ryohei; Maeda, Yuta; Watanabe, Toshiki
Bibcode: 2022EP&S...74...85T
Altcode:
We conducted waveform inversions of an ultra-long-period (~ 240-s)
event associated with the phreatic eruption of Mount Kusatsu-Shirane
on January 23, 2018. We used broadband seismic and tilt records
from three stations surrounding the eruption site. The horizontal
components of the broadband seismic records were severely contaminated
by tilt motions. We applied a waveform inversion algorithm to account
for both the translational and tilt motions. To reduce the number of
free parameters, we assumed a tensile crack source and conducted grid
searches for the centroid location and orientation of the crack. The
results showed a rapid inflation of 105 m3 of the
crack, followed by a slow deflation starting 8-11 s prior to the onset
of the eruption. The source location and crack orientation were not
uniquely determined. The most likely source is a north-south-opening
sub-vertical crack near the eruptive craters. This ultra-long-period
event may represent volcanic fluid migration from depth to the surface
through a vertical crack during the eruption.
Title: Environmental assessment in the prelaunch phase of Hayabusa2
for safety declaration of returned samples from the asteroid (162173)
Ryugu: background monitoring and risk management during development
of the sampler system
Authors: Sakamoto, Kanako; Takano, Yoshinori; Sawada, Hirotaka;
Okazaki, Ryuji; Noguchi, Takaaki; Uesugi, Masayuki; Yano, Hajime;
Yada, Toru; Abe, Masanao; Tachibana, Shogo; Hayabusa2 Project Team
Bibcode: 2022EP&S...74...90S
Altcode:
We report ground-based environmental assessments performed during
development of the sampler system until the launch of the Hayabusa2
spacecraft. We conducted static monitoring of potential contaminants
to assess the environmental cleanliness during (1) laboratory work
performed throughout the development and manufacturing processes of
the sampler devices, (2) installation of the sampler system on the
spacecraft, and (3) transportation to the launch site at the Japan
Aerospace Exploration Agency's (JAXA's) Tanegashima Space Center. Major
elements and ions detected in our inorganic analyses were sodium
(Na), potassium (K), and ionized chloride (Cl-); those
elements and ions were positively correlated with the total organic
content and with exposure duration in the range from 101
to 103 nanograms per monitor coupon within an ~ 30-mm
diameter scale. We confirmed that total deposits on the coupon were
below the microgram-scale order during manufacturing, installation,
and transportation in the prelaunch phase. The present assessment
yields a nominal safety declaration for analysis of the pristine sample
(> 5.4 g) returned from asteroid (162173) Ryugu combined with a
highly clean environmental background level. We expect that the sample
returned from Ryugu by Hayabusa2 will be free of severe and/or unknown
contamination and will allow us to provide native profiles recorded
for the carbonaceous asteroid history.
Title: Detailed S-wave velocity structure of sediment and crust off
Sanriku, Japan by a new analysis method for distributed acoustic
sensing data using a seafloor cable and seismic interferometry
Authors: Fukushima, Shun; Shinohara, Masanao; Nishida, Kiwamu; Takeo,
Akiko; Yamada, Tomoaki; Yomogida, Kiyoshi
Bibcode: 2022EP&S...74...92F
Altcode:
The S-wave velocity (Vs) structure of sediments and the uppermost crust
in the landward slope of a subduction zone are important for determining
the dynamics of the overriding plate. Although distributed acoustic
sensing (DAS) measurements have improved the horizontal resolution of
Vs structure in marine areas, the estimations have been limited to the
uppermost sedimentary layers. In the present study, we applied seismic
interferometry to DAS data of 13 h duration to image the sedimentary
and crustal structure offshore of Sanriku, Japan with a spatial
horizontal resolution of 2.5 km and > 3.0 km depth. We grouped the
DAS data into 10 km long subarrays with 75% overlaps. We first applied
a frequency-wavenumber filter to the DAS data to remove DAS instrumental
noise and to allow effective extraction of surface waves from short-time
records. We then applied a seismic interferometry method and estimated
the phase velocities at each subarray. The estimated phase velocities
of the fundamental-mode and first higher-mode Rayleigh waves were then
used to determine one-dimensional Vs structures for each subarray. The
resultant 2-D Vs structure was interpreted as representing sediments
and crust. The upper sedimentary layers thicken seaward, while the
entire sedimentary unit shows complex lateral variations in depth. The
boundary between the sedimentary layers and the uppermost crust varies
in depth from 1.8 to 6.8 km and is the deepest in the middle of the
profile. Combining this result with the P-wave velocity (Vp) structure
along the nearest survey line, determined in previous studies, allowed
us to estimate Vp/Vs = 3.12, on average, for the lower sedimentary
layers. Our method of applying seismic interferometry to marine DAS
data broadens the techniques for estimating Vs and Vp/Vs structure of
sedimentary layers and the upper crust across subduction zones. These
results show that application of the frequency-wavenumber filtering
and seismic interferometry to marine DAS data can estimate the Vs
structure and the Vp/Vs structure, together with standard marine
geophysical surveys of sedimentary layers and the upper crust across
subduction zones.
Title: Characteristics of the foreshock occurrence for
Mj3.0 to 7.2 shallow onshore earthquakes in Japan
Authors: Peng, Hong; Mori, James
Bibcode: 2022EP&S...74...40P
Altcode:
We use the Japan Meteorological Agency (JMA) earthquake catalogue from
January, 2001 to February, 2021 to investigate the spatiotemporal
foreshock occurrence for shallow (within 30 km depth) onshore
earthquakes (Mj3.0 to 7.2). We find clear peaks for
the numbers of small earthquakes within 10 days and 3 km prior to
the larger earthquakes, which are considered as our definition of
foreshocks. After removing the aftershocks, earthquake swarms and
possible triggered earthquakes by the 2011 Mw9.0 Tohoku-oki
earthquake, we find that for the 2066 earthquakes (mainshocks), 783
(38%) have one or more foreshocks. There is a decreasing trend of
foreshock occurrence rate with mainshock depth. Also, normal faulting
earthquakes have higher foreshock occurrence rate than reverse faulting
earthquakes. We calculate the earthquake occurrence rate as a function
of the magnitudes of foreshocks and mainshocks, and we have found no
clear trend between the magnitudes of foreshocks and mainshocks.
Title: Surface wave imaging using deep reflection seismic data:
a study on the Cuonadong dome
Authors: Wang, Guangwen; Lu, Zhanwu; Li, Wenhui; Xue, Shuai; Wang,
Haiyan; Cheng, Yongzhi; Chen, Si; Cai, Wei
Bibcode: 2022EP&S...74..122W
Altcode:
As interference waves in deep reflection data processing, surface waves
are often suppressed as noise, but surface waves carry considerable
underground media information, including structural information
and the physical properties of rocks. Reasonable extraction and
use of surface wave signals are of great significance when studying
shallow characteristics. Deep reflection data are collected using
large offsets, trail spacing, and explosive sources. The surface
wave energy tends to be stronger, and the high-frequency surface wave
signal is abundant. After extraction and inversion, the shallow shear
wave velocity structure can be obtained. Near the Cuonadong dome
in the southern Tibetan detachment system (STDS), a large number
of leucogranites are developed in the core, containing important
rare metal minerals and high metallogenic potential. However, studies
regarding the shallow structure in this region are rare. In this paper,
we use deep reflection data from a profile through the Cuonadong dome to
obtain the S-wave velocity structure of the study area by extracting the
surface wave fundamental-mode dispersion curve and inversion. Combined
with regional geological and magnetotelluric data, we supposed that
the thickness of the Cuonadong dome sediment layer (< 1.4 km/s)
varies greatly from east to west, the thickness of the sediment layer
is the deepest near the Cuona fault and Jisong fault (more than 1 km),
and the core of the dome is the thinnest. Under the Cuonadong dome,
there are obvious high-velocity anomalies (> 2.2 km/s), and the
horizontal S-wave velocity changes greatly, which is mainly related
to the destruction of magmatic activity since the Miocene. These
understandings of the structure and velocity field of the Cuonadong
dome can provide a powerful geophysical basis for establishing the
dome structure model and searching for hidden ore bodies.
Title: XYtracker: a new approach to estimate fault rupture extent
in real time for large earthquakes
Authors: Xiao, Ying; Yamada, Masumi
Bibcode: 2022EP&S...74...77X
Altcode:
We present a methodology for estimating fault geometry and utilizing
the distance to the fault for the shaking estimation to improve the
accuracy of real-time shaking estimates for large earthquakes. Most
of the earthquake early warning system currently estimates the
seismic intensity with the ground-motion prediction equations (GMPE)
as a function of the hypocenter distance. However, using the fault
distance computed from a finite source model can improve the accuracy
of the shaking intensity estimation for large earthquakes. This study
proposes a novel methodology, XYtracker, to estimate the surface
projection of the fault extent and real-time seismic intensity. For
large earthquakes, high-frequency ground motions tend to saturate over
the magnitude range and strongly correlate with fault distance. As a
result, this work can achieve the fault extent using seismic intensity
and GMPE. We considered three types of fault models: point-source,
line-source, and rectangle-source model. We found the most probable
model parameters for each model by minimizing the residual sum of
squares between the observed and estimated seismic intensities. The
Akaike Information Criterion selected the most probable model among
them. The strong motion data set of the 2008 Wenchuan, 2011 Tohoku,
and 2016 Kumamoto earthquakes was used to test our methodology. The new
method for estimating the fault geometry can obtain the ongoing rupture
length and direction using the strong motion data. The model selection
scheme with the Akaike Information Criterion selected the finite-source
model to explain the shaking distribution. Results revealed that this
new approach performed well in estimating the fault dimension. The
method can promote the accuracy of the seismic intensity estimation
for future large earthquakes, including the subduction earthquakes.
Title: Migrating solar diurnal tidal variability during Northern
and Southern Hemisphere Sudden Stratospheric Warmings
Authors: Siddiqui, Tarique A.; Chau, Jorge L.; Stolle, Claudia;
Yamazaki, Yosuke
Bibcode: 2022EP&S...74..101S
Altcode:
In this study, the variability of the migrating solar diurnal
(DW1) tide in the mesosphere-lower thermosphere (MLT) region during
Northern and Southern Hemisphere (NH & SH) Sudden Stratospheric
Warmings (SSWs) is investigated using Sounding of the Atmosphere
using Broadband Emission Radiometry (SABER) temperature observations
and reanalysis-driven Whole Atmosphere Community Climate Model with
thermosphere and ionosphere extension (WACCM-X) simulations. The
periods examined include four major NH SSWs that occurred in 2006, 2009,
2010 and 2013 and two SH SSWs that were observed in 2002 and 2019. Our
analysis shows that the DW1 tide in both observations and simulations
displays a reduction of amplitude at low-latitudes after the onset of
NH and SH SSWs. As WACCM-X simulations qualitatively reproduce this
feature of DW1 tidal variability common to both NH and SH SSWs, they
have been used to examine the possible mechanism that could explain
these observations in the DW1 tide. It is known that changes in the
latitudinal shear of zonal winds at low-latitudes strongly affect
the seasonal variation of the DW1 tide in the MLT. We show that
SSW-associated changes in the latitudinal shear in the MLT could
explain the observed variability of the DW1 tide during NH and SH SSWs.
Title: Impact of crustal deformation detection by the DSI (difference
of split-band interferograms) method with PALSAR-2 data: a case
study on the 2016 Kumamoto Earthquake
Authors: Ozawa, Taku; Himematsu, Yuji
Bibcode: 2022EP&S...74...72O
Altcode:
Interferometric synthetic aperture radar (InSAR) is a useful tool for
detecting surface deformations at high spatial resolutions. When InSAR
is applied to large surface deformations, clear fringes with complicated
phase gaps often appear in the interferograms. Although the surface
deformations in such areas provide valuable data for earthquake research
and disaster investigation, it is difficult to convert the complicated
interferometric phase to surface deformation information because of
the difficulties associated with phase unwrapping. To resolve these
difficulties, we created multiple SAR pairs with different frequencies
using a bandpass filter and calculated the difference between the
interferograms generated from these SAR pairs (referred to as the DSI
analysis in this study). Generally, the obtained difference corresponds
to SAR observations using long-wavelength radar. Therefore, phase wrap
is less likely to occur, simplifying phase unwrapping. We applied the
DSI analysis to PALSAR-2 data pairs for the 2016 Kumamoto Earthquake
and successfully identified large crustal deformations with complicated
phase gaps in the vicinity of the surface ruptures. Comparing these
results with the crustal deformations observed with global navigation
satellite system measurements, the root-mean-squares of the differences
were found to be approximately 4 cm. Although this accuracy was
lower than that of conventional InSAR, it was nearly equivalent to
that of offset-tracking analysis. It should be noted that the spatial
resolution of the DSI analysis was significantly improved compared to
that of offset-tracking analysis. A disadvantage of this method is
that its detection accuracy is significantly degraded in zones with
low coherence owing to noise amplification. The standard deviation of
the noise component was approximately 2 cm for pixels with coherence
> 0.7. However, for pixels with a coherence < 0.2, the standard
deviation was > 10 cm, and the noise component occasionally exceeded
1 m. Despite its disadvantages, this method is effective for detecting
large crustal deformations with high spatial resolution in areas where
conventional InSAR processing is inappropriate.
Title: Geoelectric characterisation of furnace and slag trench
structures: Case study Obafemi Awolowo University ancient iron
smelting site, Ile-Ife, southwest Nigeria
Authors: Olorunfemi, Martins Olusola; Oni, Ademakinwa George; Fadare,
Taiwo Kazeem
Bibcode: 2022JAsGe..11....1O
Altcode:
No abstract at ADS
Title: Solar and geomagnetic activity dependence of 150-km echoes
observed by the Equatorial Atmosphere Radar in Indonesia
Authors: Yokoyama, Tatsuhiro; Takagi, Rieko; Yamamoto, Mamoru
Bibcode: 2022EP&S...74..113Y
Altcode:
The occurrence characteristics of 150-km echoes in low-latitude
regions are studied using the Equatorial Atmosphere Radar (EAR) in
Indonesia. The long-term observation of the 150-km echoes by the EAR
enables us to study the occurrence characteristics of 150-km echoes
statistically. It is shown that the occurrence rate of the 150-km
echoes observed by the EAR shows a semiannual variation with two peaks
in solstices and a negative correlation with both the EUV flux and Σ
Kp index, that is, the solar and the geomagnetic activity. Geomagnetic
activity correlates with the occurrence rate of 150-km echoes observed
one day after when the Σ Kp was measured. However, the occurrence
rate is always low during the high solar activity period regardless of
the geomagnetic activity. While the seasonal variation and the solar
activity dependence of the occurrence of 150-km echoes are consistent
with previous studies, this is the first time a negative correlation
with geomagnetic activity is reported.
Title: Ionospheric disturbances observed over Japan following the
eruption of Hunga Tonga-Hunga Ha'apai on 15 January 2022
Authors: Saito, Susumu
Bibcode: 2022EP&S...74...57S
Altcode:
Traveling ionospheric disturbances (TIDs) were observed over Japan by
using Global Navigation Satellite System (GNSS) receiver network data
after the eruption of Hunga Tonga-Hunga Ha'apai in Tonga on 15 January
2022. Two types of TIDs with different characteristics were observed as
perturbation in the total electron content (TEC). The first one arrived
at Japan which are located about 7800 km away from Hunga Tonga-Hunga
Ha'apai about 3 h after the eruption. The amplitude was about ± 0.5
TECU. The wavefronts was in the NNE-SSW direction and propagated in
the WNW direction (- 69∘ counter-clockwise from the north) at 250
m s-1. The wavelength was estimated as 400 km. The second
one arrived at Japan about 7 h after the eruption. The amplitude
was about ± 1.0 TECU. The wavefronts was in the NE-SW direction and
propagated in the NW direction (- 53∘ counter-clockwise from the
north) at 270 m s-1. The wavelength was longer than the
first one and was estimated as 800 km. The first one were associated
with ionospheric irregularities represented by the rate of TEC index
(ROTI). In contrast, the second one did not have irregularities all
over the TIDs, but in only a limited region. The arrival of the first
TID was too early for the atmospheric acoustic waves to arrive, while
the arrival of the second TIDs approximately coincided with the arrival
of surface pressure enhancement. To understand the mechanisms of the
TIDs, further studies with wide-area observations as well as numerical
calculations are necessary. TIDs and ionospheric irregularities after
volcanic eruption could be threats to GNSS-based systems especially
for those which utilize carrier-phase measurements.
Title: Spatio-temporal distribution of shallow very-low-frequency
earthquakes between December 2020 and January 2021 in Kumano-nada,
Nankai subduction zone, detected by a permanent seafloor seismic
network
Authors: Yamamoto, Yojiro; Ariyoshi, Keisuke; Yada, Shuichiro; Nakano,
Masaru; Hori, Takane
Bibcode: 2022EP&S...74...14Y
Altcode:
We estimate the hypocenter locations and the centroid moment tensor
solutions of the shallow very-low-frequency earthquake (sVLFE) activity
that occurred in the Kumano-nada region of the Nankai Trough megathrust
zone in central Japan from December 2020 to January 2021. Using
seafloor observation data, we examined the detailed spatio-temporal
distribution of the sVLFE activity. During this episode, the activity
area was within the vicinity in which the sVLFE activity has been
observed in the past and can be divided into two major parts. The
sVLFE activity started from the eastern side and remained there for
the first 5 days and then migrated to the western side via secondary
expansion. The eastern active area is located just below the outer
ridge and coincides with the location where the paleo-Zenith Ridge
subducted. The western activity area is centered between the outer
wedge and the outer ridge with the primary active area being at the
outer wedge. Comparing the activity in the eastern and western areas,
the eastern side is more active, but the individual moment releases
on this side are smaller than those on the western side. This may
indicate a difference in the fluid pressure along the plate boundary
between the eastern and western areas. After the second expansion of
the active area, we observed several migration patterns within the
expanded area with a faster velocity than those of the initial and
second expansions. The direction of these migrations is opposite to
that of the first and second expansions. This indicates that the fluid
pressure and/or stress level in the sVLFE generation region changed
with time within this episode. Furthermore, many waveforms with sVLFE
characteristics were observed at only one or a few observation points
near the trough axis in the middle to latter half of January 2021. This
indicates the occurrence of small-scale sVLFEs in the vicinity of the
trough axis at the end of this sVLFE episode.
Title: Nonlinear triggering process of whistler-mode emissions in
a homogeneous magnetic field
Authors: Fujiwara, Yuya; Nogi, Takeshi; Omura, Yoshiharu
Bibcode: 2022EP&S...74...95F
Altcode:
We perform an electromagnetic particle simulation of triggered emissions
in a uniform magnetic field for understanding of nonlinear wave-particle
interaction in the vicinity of the magnetic equator. A finite length
of a whistler-mode triggering wave packet with a constant frequency is
injected by oscillating an external current at the equator. We find
that the first subpacket of triggered emissions is generated in the
homogeneous magnetic field. By analyzing resonant currents and resonant
electron dynamics in the simulation, we find that the formation of an
electron hole in a velocity phase space results in resonant currents,
and the currents cause wave amplification and frequency increase. We
obtain the interaction time of counter-streaming resonant electrons
in a triggering wave packet with a finite width. By changing the
duration time of the triggering pulse, we evaluate the interaction
time necessary for formation of an electron hole. We conduct 4 runs
with different duration times of the triggering pulse, 980, 230,
105, 40 Ωe-1, which correspond to cases with
interaction times, 370%, 86%, 39%, and 15% of the nonlinear trapping
period, respectively. We find generation of triggered emissions in the
three cases of 370%, 86%, and 39%, which agrees with the conventional
nonlinear model that the nonlinear transition time, which is necessary
for formation of resonant currents, is about a quarter of the nonlinear
trapping period.
Title: Geomagnetic conjugacy of plasma bubbles extending to
mid-latitudes during a geomagnetic storm on March 1, 2013
Authors: Sori, Takuya; Otsuka, Yuichi; Shinbori, Atsuki; Nishioka,
Michi; Perwitasari, Septi
Bibcode: 2022EP&S...74..120S
Altcode:
This study, for the first time, reports the geomagnetically conjugate
structure of a plasma bubble extending to the mid-latitudes and the
asymmetrical structure of the decay of the plasma bubble during a
geomagnetic storm. We investigated the temporal and spatial variations
of plasma bubbles in the Asian sector during a geomagnetic storm on
March 1, 2013, using Global Navigation Satellite System-total electron
content data with high spatiotemporal resolutions. The first important
point of our data analysis results is that the plasma bubble extended
from the equator to the mid-latitudes with geomagnetic conjugacy along
the magnetic field lines. The total electron content data showed that
the plasma bubbles appeared in the equatorial regions near 150° E
after sunset during the main phase of the geomagnetic storm. From
ionosonde data over both Japan and Australia, they suggest that a
large eastward electric field existed in the Asian sector. Finally,
the plasma bubbles extended up to the mid-latitudes (~ 43° geomagnetic
latitude) in both hemispheres, maintaining geomagnetic conjugacy. The
second point is that the mid-latitude plasma bubble disappeared 1-2
h earlier in the northern hemisphere than in the southern hemisphere
at close to midnight. In the northern hemisphere, the ionospheric
virtual height decreased near midnight, followed by a rapid decrease
in the total electron content and a rapid increase in the ionospheric
virtual height. These results imply that the mid-latitude plasma
bubble disappeared as the background plasma density decreased after
midnight due to the recombination resulting from the descent of the F
layer. Therefore, we can conclude that mid-latitude plasma bubbles can
be asymmetric between the northern and southern hemispheres because
of the rapid decay of plasma bubbles in one of the hemispheres.
Title: Ionospheric signatures of repeated passages of atmospheric
waves by the 2022 Jan. 15 Hunga Tonga-Hunga Ha'apai eruption detected
by QZSS-TEC observations in Japan
Authors: Heki, Kosuke
Bibcode: 2022EP&S...74..112H
Altcode:
A large eruption occurred on Jan. 15, 2022, at the submarine volcano
Hunga Tonga-Hunga Ha'apai, southern Pacific, and the atmospheric Lamb
wave was observed to have traveled round the Earth multiple times
with a speed of ~ 0.3 km/s. Here, I compare their ionospheric and
atmospheric signatures using data from dense arrays of barometers and
GNSS stations in Japan. I confirmed that the ionospheric disturbances
passed over Japan at least four times, first from SE to NW, then from NW
to SE, again from SE to NW, and finally from NW to SE. The propagation
velocity of the ionospheric disturbances was as fast as the atmospheric
Lamb wave, suggesting their origin as upward energy leakage from the
troposphere. The first passage of the ionospheric disturbance started
prior to the arrival of the Lamb pulse, but its physical mechanism
is yet to be explored. Unlike the barometric records, waveforms and
amplitudes of ionospheric disturbances exhibit large diversity along
the wavefront, suggesting their turbulent nature.
Title: Simple topographic parameter reveals the along-trench
distribution of frictional properties on shallow plate boundary fault
Authors: Koge, Hiroaki; Ashi, Juichiro; Park, Jin-Oh; Miyakawa, Ayumu;
Yabe, Suguru
Bibcode: 2022EP&S...74...56K
Altcode:
The critical taper model best describes the first-order mechanics of
subduction zone wedges. The wedge geometry, which is conventionally
defined by two parameters, slope angle and basal dip angle, accounts
for the strength of megathrust. By applying this theoretical model,
fault frictional properties and earthquake occurrences can be compared
among subduction zones, and within a single subduction zone, and
the spatial distribution or temporal change of fault strength can be
investigated. Slope angle can be accurately estimated from bathymetry
data, but basal dip angle must be inferred from subsurface structure,
which requires highly accurate depth-migrated seismic reflection
profiles. Thus, application of the critical taper model is often
limited by an insufficient number of highly accurate profiles, and
the spatial distribution of frictional coefficients must be inferred
from relatively few data. To improve this situation, we revisited
the theoretical formula of the critical taper model. We found that
the effect of basal dip angle on the critical taper model is small,
and slope angle can be a proxy for the effective friction when the
pore fluid pressure ratio is high, internal friction is small, or
both. These conditions are met in many subduction zones. The validity of
the approximation can be checked with a parameter newly introduced in
this study. Therefore, this finding allows use of variations in slope
angle, which could be obtained accurately from only the bathymetry as
an approximation for relative variations in the effective coefficient
of basal friction, if the targeted subduction meets the validity. We
applied this approximation to the Japan Trench and estimated the
variations in the friction coefficient distribution on the shallow
plate boundary fault from 71 data points. We found that the area where
the friction coefficient was smaller than the mean corresponded to
a segment, where a large coseismic shallow rupture occurred during
the 2011 Tohoku-Oki earthquake (Mw 9.0). Thus, by approximating
tapered wedge geometry with a simple topographic parameter that can
be obtained from existing global bathymetry, we can quickly estimate
the distribution of frictional properties on a plate boundary fault
along a trench and related seismic activity.
Title: The revised method for retrieving daytime distributions
of atomic oxygen and odd-hydrogens in the mesopause region from
satellite observations
Authors: Kulikov, Mikhail Yu.; Belikovich, Mikhail V.; Grygalashvyly,
Mykhaylo; Sonnemann, Gerd R.; Feigin, Alexander M.
Bibcode: 2022EP&S...74...44K
Altcode:
Atomic oxygen (O) and atomic hydrogen (H) in the mesopause region
are critical species, governing chemistry, airglow, and energy
budget. However, they cannot be directly measured by satellite remote
sensing techniques and so inference techniques, by airglow observations,
are used. In this work, we retrieved daytime O and H distributions at
~ 77 km-100 km from the data of observations by the SABER (Sounding
of the Atmosphere using Broadband Emission Radiometry) instrument
at the TIMED (Thermosphere Ionosphere Mesosphere Energetics and
Dynamics) satellite in 2003-2015. The retrieval approach considered
the reaction H + O3 → O2 + OH in the ozone
balance equation. Moreover, we revised all quenching and spontaneous
emission coefficients according to latest published data. We then
calculated daytime distributions of OH and HO2 at these
altitudes with the use of their conditions of photochemical equilibrium.
Title: Microtremor array surveys and development of the velocity
model in the Hakodate Plain, Hokkaido, Japan
Authors: Asano, Kimiyuki; Iwata, Tomotaka; Yoshida, Kunikazu; Inoue,
Naoto; Somei, Kazuhiro; Miyakoshi, Ken; Ohori, Michihiro
Bibcode: 2022EP&S...74...94A
Altcode:
The Hakodate Plain in the southern part of the Oshima Peninsula,
Hokkaido, Japan, is a sedimentary basin surrounded by mountains. The
vertical displacements caused by active faults along the western margin
of the Hakodate Plain increased the basin depth in the western part of
the Hakodate Plain. Small-to-large-sized microtremor array surveys were
conducted at five sites in the Hakodate Plain to estimate the S-wave
velocity structure down to the seismic bedrock for each site to develop
a detailed velocity structure model. A new three-dimensional velocity
structure model of the Hakodate Plain was developed by integrating the
results of microtremor array surveys and other existing geophysical
explorations data. This three-dimensional velocity model was modeled as
a stack of homogeneous isotropic layers to facilitate its incorporation
into the present nation-wide three-dimensional velocity model for
ground motion prediction. The bottom depth of the Quaternary sediments
is deep along the western margin of the Hakodate Plain. The total
thickness of the Quaternary and Neogene sedimentary layers reaches
2.9 km in the western Hakodate Plain. The proposed velocity model was
validated by gravity anomaly modeling and ground motion simulation of
a moderate-sized inland earthquake. The location of the low-gravity
anomaly around the coastline of the Hakodate Bay was improved using
the new model. The numerical ground motion simulation using FDM also
demonstrated that the amplification and long duration observed in
the western part of the Hakodate Plain were reproduced effectively
using this velocity model. The spatial variation in long-period ground
motion amplifications (period > 1 s) is discussed based on numerical
simulations utilizing our three-dimensional velocity model. The highest
amplifications at periods of 4 and 5 s were expected in the southwestern
Hakodate Plain. The amplification at a period of 3 s was relatively
high near the western margin of the plain. Conversely, the spatial
characteristics below 2 s were quite complex due to interference of
the seismic wavefield inside the basin structure. Variation due to the
source location was also relatively high in the shorter period range.
Title: Detecting multiscale periodicity from the secular effusive
activity at Santiaguito lava dome complex (Guatemala)
Authors: Massaro, Silvia; Costa, Antonio; Sulpizio, Roberto; Coppola,
Diego; Soloviev, Anatoly
Bibcode: 2022EP&S...74..107M
Altcode:
Santiaguito, Guatemala, represents one of the best cases of active
lava dome complex in the world, producing lava flow effusion, weak
explosive activity, and cycles of lava dome extrusion over varying
timescales. Since the inception in 1922, it has shown a remarkable
constant eruptive activity, characterized by effusion of blocky domes
and lava flows punctuated by moderate explosions of gas-and-ash and
pyroclastic flows. In this study, we reconstruct the time evolution
of discharge rates of Santiaguito across one entire century, from
1922 to 2021, combining, for the more recent activity, new satellite
thermal data. By using discrete Fourier transform (DFT) and Morlet
wavelet analyses, we identify three fundamental periodicities in
subsets of the 1922-2021 time-series: (i) long term (ca. 10 years),
(ii) intermediate term (ca. 3.5 years), and (iii) short term (from
ca. 1 year to ca. 3 months), which are comparable with those observed
at other lava dome eruptions at calc-alkaline volcanoes. Such inferred
periodicities provide a powerful tool for the interpretation of the
non-linear eruptive behaviour and represent a pivotal benchmark for
numerical modelling aimed to reconstruct the dynamics of the magma
feeding system based on a time-averaged discharge rate dataset.
Title: Effective unwrapping of complicated phases by exploiting
multiple interferograms: a case study of the 2016 Kumamoto earthquake
Authors: Morishita, Yu
Bibcode: 2022EP&S...74...33M
Altcode:
Synthetic aperture radar (SAR) interferometry can measure ground
surface deformation with high accuracy and spatial resolution, in
the form of phase change in an interferogram. The phase is observed
modulo 2π (i.e., wrapped), and unwrapping is necessary to obtain the
absolute amount of deformation. Although several advanced automatic
unwrapping algorithms and approaches have been proposed, unwrapping
errors can occur, especially in complicated phases. Manual adjustment
of the integration path in the unwrapping may improve the unwrapping
result. However, sometimes, it tends to be challenging even for an
expert. In this report, I describe an effective unwrapping approach
for complicated phases to obtain a reliable unwrapping result using
multiple interferograms. A common integration path guide is created
from geocoded interferograms and their phase noise coherence estimates,
which reduces/eliminates the effort involved in manual adjustment and
greatly reduces unwrapping errors. The remaining unwrapping errors
were detected from residuals between the unwrapped phases of multiple
interferograms and corrected based on isolated components. A case study
was taken up in the northwest of the outer rim of the Aso caldera. Here,
plenty of displacement lineaments were generated by the 2016 Kumamoto
earthquake, resulting in severely complicated interferometric phases to
correctly unwrap by any existing approaches. Therefore, the proposed
approach effectively and efficiently retrieves reliable unwrapped
phases and subsequent significant interpretations of the displacement
lineaments. This effective unwrapping approach may reveal complicated
deformations and unrecognized mechanisms in future earthquakes or
other deformation-causing geophysical phenomena.
Title: Investigation of geomagnetic reference models based on the
Iridium® constellation
Authors: Califf, Samuel; Alken, Patrick; Chulliat, Arnaud; Anderson,
Brian; Rock, Kenneth; Vines, Sarah; Barnes, Robin; Liou, Kan
Bibcode: 2022EP&S...74...37C
Altcode:
The World Magnetic Model (WMM) is a geomagnetic main field model
that is widely used for navigation by governments, industry and the
general public. In recent years, the model has been derived using
high accuracy magnetometer data from the Swarm mission. This study
explores the possibility of developing future WMMs in the post-Swarm
era using data from the Iridium satellite constellation. Iridium
magnetometers are primarily used for attitude control, so they are
not designed to produce the same level of accuracy as magnetic data
from scientific missions. Iridium magnetometer errors range from 30 nT
quantization to hundreds of nT errors due to spacecraft contamination
and calibration uncertainty, whereas Swarm measurements are accurate
to about 1 nT. The calibration uncertainty in the Iridium measurements
is identified as a major error source, and a method is developed to
calibrate the spacecraft measurements using data from a subset of the
INTERMAGNET observatory network producing quasi-definitive data on a
regular basis. After calibration, the Iridium data produced main field
models with approximately 20 nT average error and 40 nT maximum error
as compared to the CHAOS-7.2 model. For many scientific and precision
navigation applications, highly accurate Swarm-like measurements are
still necessary, however, the Iridium-based models were shown to meet
the WMM error tolerances, indicating that Iridium is a viable data
source for future WMMs.
Title: Tsunami inundation characteristics along the Japan Sea
coastline: effect of dunes, breakwaters, and rivers
Authors: Yamanaka, Yusuke; Shimozono, Takenori
Bibcode: 2022EP&S...74...19Y
Altcode:
For Japanese coastal communities along the Japan Sea, where the risk
of earthquake-induced tsunamis is deemed lower than that along the
Pacific Ocean, tsunami disaster mitigation strategies have not been
sufficiently developed. This study estimated the tsunami inundation
characteristics for three major Japanese coastal cities along the
Japan Sea. Based on tsunami simulations for representative coastal
areas, we aimed to identify common vulnerabilities, which included
those suggested by previous studies and local governments, to develop
disaster mitigation strategies. Comprehensive simulations for tsunami
propagation and inundation were performed for coastal areas in Akita
City, Sakata City, and Niigata City based on earthquake and tsunami
source scenarios developed by the Japanese Government for the Japan
Sea area. To demonstrate the effectiveness of the estimated inundation
characteristics, tsunami inundation was simulated for each coastal
area under varying tsunami source conditions (including excessive
tsunami magnitude) with a high resolution of the topography and
infrastructure. Natural sand dunes, ports with man-made breakwaters, and
rivers with levees are typical topographical features found in urbanized
and densely populated areas along the Japan Sea coastline. According
to the simulated results, the dunes and port breakwaters contribute
significantly to decreasing the total amount of tsunami inundation
for the areas behind them. However, the presence of the breakwaters
also increases the tsunami heights in the areas immediately beyond
the ports. Additionally, even the areas protected by the dunes might
be exposed to an inundation risk in which the tsunamis invade a river
channel, causing it to overflow. These findings were common to the
coastal areas, and could be generally applicable to tsunami inundation
for all coastal areas along the Japan Sea. Based on these results, the
enhancement of existing infrastructure such as breakwaters and river
levees should be the priority measure within tsunami risk-mitigation
strategies; these, combined with natural resources such as dunes,
can effectively mitigate tsunami disasters.
Title: Atmospheric modes excited by the 2021 August eruption of the
Fukutoku-Okanoba volcano, Izu-Bonin Arc, observed as harmonic TEC
oscillations by QZSS
Authors: Heki, Kosuke; Fujimoto, Tatsuya
Bibcode: 2022EP&S...74...27H
Altcode:
Continuous Plinian eruptions of volcanoes often excite atmospheric
resonant oscillations with several distinct periods of a few minutes. We
detected such harmonic oscillations by the 2021 August eruption of
the Fukutoku-Okanoba volcano, a submarine volcano in the Izu-Bonin
arc, in ionospheric total electron content (TEC) observed from Global
Navigation Satellite System (GNSS) stations deployed on three nearby
islands, Chichijima, Hahajima, and Iwojima. Continuous records with
the geostationary satellite of Quasi-Zenith Satellite System (QZSS)
presented four frequency peaks of such atmospheric modes. The harmonic
TEC oscillations commenced at ~ 5:16 UT with a large amplitude but
decayed in a few hours.
Title: Electrical Geophysical method and GIS in Agricultural Crop
Productivity in a Typical Sedimentary Environment
Authors: Ozegin, K. O.; Salufu, S. O.
Bibcode: 2022JAsGe..11...69O
Altcode:
No abstract at ADS
Title: Rheological properties of halloysite soil slurry: a case
study of weathered tephra involved in a shallow landslide triggered
by the 2018 Eastern Iburi earthquake in Hokkaido, Japan
Authors: Kameda, Jun
Bibcode: 2022EP&S...74...70K
Altcode:
The 6.7 Mw Eastern Iburi earthquake of 6 September 2018
triggered destructive landslides in southern Hokkaido, Japan, many
of which were characterized by the flow-like downslope movement of
volcanic soils formed from weathered tephra containing halloysite. This
study aims to elucidate the mechanism of landslide generation through
rheological characterization of halloysite soil slurries. The examined
slurries were prepared from either oven-dried or moist soil. Both
slurries showed a power-law correlation between measured yield stress
and moisture content. However, at a given water content, slurry made
from dried soil showed stresses that are one-to-two orders of magnitude
lower than those of slurry made from moist soil. Compared with the
measurements for the slurry of dried soil, those for the slurry of moist
soil are closer to prior numerical modeling of a specific landslide,
indicating that the soils involved were moist. The yield stress also
varied with slurry pH, generally increasing with decreasing pH, which is
in part explained by the DLVO force model based on the electrical double
layer and van der Waals forces between the colloidal particles. The pH
dependence is more prominent in the slurry of moist soil, and thus
the mechanical state of the slope appears to vary significantly
with rainfall-induced changes in subsurface chemistry. Dynamic
viscoelasticity measurement indicated that both initially solid-like
slurries can become fluid under an applied oscillatory strain of 0.5
to 10 Hz: the susceptibility to fluidization depends greatly on water
content and frequency. The ground motion during the earthquake easily
fluidized the slurry, indicating this was a factor contributing to
the observed flow-like landslides.
Title: Characteristics of landslides triggered by the 2013
ML6.5 Nantou, Taiwan, earthquake
Authors: Wu, Bing Sheng; Chuang, Ray Y.; Chen, Yi-Chin; Lin, Ya-Shien
Bibcode: 2022EP&S...74....7W
Altcode:
Earthquake-triggered landslides are common disasters of active mountain
belts. Due to the lack of earthquake-triggered landslide inventory
in Taiwan, it is not intuitive to observe spatial relationships
and discover unique patterns between landslides and essential
triggers. We examined strong earthquake events in Taiwan after
the 1999 Mw7.6 Chi-Chi earthquake and targeted the 2013
ML6.5 Nantou earthquake to create the landslide inventory. We
adopted two Landsat-8 satellite images before and after the event to
detect landslides, and incorporated a 20-m DEM and rock type data of
Taiwan to represent key factors triggering earthquake-induced landslides
such as peak ground acceleration (PGA), lithology, slope roughness,
slope, and aspect. Based on the analysis of the density of landslides,
there are strong correlations between the landslide occurrence and
seismic and geomorphic factors. Furthermore, we noticed that the
landslide aspects have a systematic tendency towards the northeast,
which is not correlated with the dip directions and wave propagation
directions. Instead, we found that the northeastward landslide aspect
is more associated with the westward-southwestward surface movement at
the landslides. We found that the included angles between the landslide
aspects and the displacement directions for all the landslides are ~
100°-180°. The relationship indicated that the coseismic deformation
of the Nantou earthquake may play a role in the landslide distribution.
Title: Temporal change in seismic wave attenuation using highly
stable vibration sources
Authors: Tsuji, Shuhei; Yamaoka, Koshun; Ikuta, Ryoya
Bibcode: 2022EP&S...74...15T
Altcode:
We developed a method to detect attenuation changes during seismic
wave propagation excited by precisely controlled artificial seismic
sources, namely Accurately Controlled Routinely Operated Signal System
(ACROSS), and applied it to monitor the temporal changes for in situ
data collected by previous studies. Our method, together with the use
of the ACROSS sources, is less susceptible to noise level changes, from
which conventional methods such as envelope calculation suffer. The
method utilizes the noise level that is independently estimated in
the frequency domain and eliminates the influence of the noise from
the observed signal. For performance testing, we applied this method
to a dataset that was obtained in an experiment at Awaji Island,
Japan, from 2000 to 2001. We detected a change in amplitude caused by
rainfall, variation in atmospheric temperature, and coseismic ground
motions. Among them, coseismic changes are of particular interest
because there are limited studies on coseismic attenuation change, in
contrast to many studies on coseismic velocity decrease. At the 2000
Western Tottori earthquake (MW = 6.6, epicenter distance of
165 km), a sudden decrease in amplitude of up to 5% was observed. The
coseismic amplitude reduction and its anisotropic characteristics,
which showed a larger reduction in the direction of the major axis of
velocity decrease, were consistent with the opening of fluid-filled
cracks, as proposed by previous studies. The Δ Q-1
corresponding to the amplitude change gives similar values to those
reported in previous studies using natural earthquakes.
Title: Solar and lunar daily geomagnetic variations and their
equivalent current systems observed by Swarm
Authors: Yamazaki, Yosuke
Bibcode: 2022EP&S...74...99Y
Altcode:
This paper describes solar and lunar daily variations of the geomagnetic
field over low- and mid-latitude regions, using vector magnetometer
data from Swarm satellites at altitudes of ∼500 km during the
solar minimum years of 2017-2020. The average solar variation of
the geomagnetic field is within the range of ±14 nT, while the lunar
variation is within ±2 nT. The latter is comparable to the ocean tidal
field. A spherical harmonic analysis is performed on the solar and lunar
variations to evaluate their internal and external equivalent current
systems. The results show that both the solar and lunar variations are
mainly of internal origin, which can be attributed to combined effects
of ionospheric dynamo currents and induced underground currents. Global
patterns of the internal solar and lunar current systems are consistent
with the corresponding external current systems previously reported
based on ground observations. The Swarm external currents are
mainly in the meridional direction, and are likely associated with
interhemispheric field-aligned currents. Both the internal and external
current systems depend on the season and longitude.
Title: Effects of uncertainty in fault parameters on deterministic
tsunami hazard assessment: examples for active faults along the
eastern margin of the Sea of Japan
Authors: Satake, Kenji; Ishibe, Takeo; Murotani, Satoko; Mulia,
Iyan E.; Gusman, Aditya Riadi
Bibcode: 2022EP&S...74...36S
Altcode:
We investigated the effects of fault parameter uncertainty on the
deterministic assessment of tsunami hazards for the submarine and
coastal active faults in the Sea of Japan that were recently modeled
by the Integrated Research Project on Seismic and Tsunami Hazards
around the Sea of Japan. A key parameter in scenario-based tsunami
assessment is the fault slip amount, which is usually calculated
from empirical scaling relations that relate the fault size to the
slip. We examined four methods to estimate the fault slip amounts and
compared the coastal tsunami heights from the slip amounts obtained
by two different empirical relations. The resultant coastal tsunami
heights were strongly affected by the choice of scaling relation,
particularly the fault aspect ratio (fault length/fault width). The
geometric means of the coastal tsunami heights calculated from the
two methods ranged from 0.69 to 4.30 with an average of 2.01. We also
evaluated the effects of fault slip angles, which are also important
parameters for controlling coastal tsunami heights, by changing the
slip angles for faults in the southwestern and central parts of the
Sea of Japan, where the strike-slip faults are concentrated. The
effects of uncertainty of the fault slip angles (± 30° from the
standard) on the coastal tsunami heights were revealed to be equal to
or greater than those resulting from the choice of scaling relations;
the geometric means of the coastal tsunami heights from the modified
fault slip angles relative to the standard fault slip angles ranged from
0.23 to 5.88. Another important characteristic is that the locations
of the maximum coastal tsunami height and the spatial pattern of the
coastal tsunami heights can change with varying fault slip angles.
Title: Potential for crustal deformation monitoring using a dense
cell phone carrier Global Navigation Satellite System network
Authors: Ohta, Yusaku; Ohzono, Mako
Bibcode: 2022EP&S...74...25O
Altcode:
Monitoring of crustal deformation provides essential information for
seismology and volcanology. For such earth science fields and other
purposes, various Global Navigation Satellite System (GNSS) networks
have been constructed at the national and regional levels. In Japan,
the continuous nationwide GNSS network, the GNSS Earth Observation
Network System (GEONET), is operated by the Geospatial Information
Authority of Japan. Although GEONET has made a substantial contribution
to earth science research, the large spacing of GEONET sites makes it
difficult to accurately understand crustal deformation phenomena in
some cases. However, cell phone carriers in Japan have constructed
independent GNSS networks to improve their positioning services
in recent years. In this study, we examine the performance of a
GNSS network operated by SoftBank Corp. for crustal deformation
monitoring. The network has more than 3300 sites throughout Japan,
which is approximately 2.5 times the number of the GEONET sites. To
assess the quality of SoftBank's GNSS data, we first analyzed data
from Miyagi Prefecture and evaluated the stability of the coordinate
time series for nine consecutive days during a quiet (interseismic)
period. The calculated standard deviations were approximately the same
for both networks. Furthermore, we calculated the displacement between
September 2020 and March 2021. The results reveal that almost all
SoftBank sites showed a consistent displacement with their surrounding
GEONET sites. Next, we analyzed the coseismic deformation associated
with the off-Fukushima earthquake (MJMA 7.3) on February
13, 2021, in both static and kinematic modes. We obtained a westward
coherent displacement along the coastline in both networks, although
several outliers were observed for the SoftBank sites. Based on these
initial assessments, we conclude that these private sector GNSS sites
are useful for crustal deformation monitoring with appropriate data
quality control.
Title: A regional geomagnetic field model over Southern Africa
derived with harmonic splines from Swarm satellite and ground-based
data recorded between 2014 and 2019
Authors: Nahayo, Emmanuel; Korte, Monika
Bibcode: 2022EP&S...74....8N
Altcode:
A regional harmonic spline geomagnetic main field model, Southern
Africa Core Field Model (SACFM-3), is derived from Swarm satellite and
ground-based data for the southern African region, in the eastern part
of the South Atlantic Anomaly (SAA) where the field intensity continues
to decrease. Using SACFM-3 and the global CHAOS-6-×9 model, a detailed
study was conducted to shed light on the high spatial and temporal
geomagnetic field variations over Southern Africa between 2014 and
2019. The results show a steady decrease of the radial component Z in
almost the entire region. In 2019, its rate of decrease in the western
part of the region has reached high values, 76 nT/year and 78 nT/year
at Tsumeb and Keetmanshoop magnetic observatories, respectively. For
some areas in the western part of the region the radial component Z
and field intensity F have decreased in strength, from 1.0 to 1.3%
and from 0.9 to 1.2%, respectively, between the epochs 2014.5 and
2019.5. There is a noticeable decrease of the field intensity from
the south-western coast of South Africa expanding towards the north
and eastern regions. The results show that the SAA area is continuing
to grow in the region. Abrupt changes in the linear secular variation
in 2016 and 2017 are confirmed in the region using ground-based data,
and the X component shows an abrupt change in the secular variation in
2018 at four magnetic observatories (Hermanus, Hartebeesthoek, Tsumeb
and Keetmanshoop) that needs further investigation. The regional model
SACFM-3 reflects to some extent these fast core field variations in the
Z component at Hermanus, Hartebeesthoek and Keetmanshoop observatories.
Title: Evolution of the magma plumbing system of Miyakejima volcano
with periodic recharge of basaltic magmas
Authors: Geshi, Nobuo; Oikawa, Teruki; Weller, Derek J.; Conway,
Chris E.
Bibcode: 2022EP&S...74...20G
Altcode:
Defining the variations in petrological characteristics of erupted
magmas within a high-resolution chronostratigraphy provides a
necessary framework for monitoring the long-term activity and eruption
potential of an active volcano. Here, we investigate the evolution
of the magmatic system of Miyakejima volcano, Japan, between the
last two caldera-forming eruptions, at ~ 2.3 ka and AD 2000, based
on new stratigraphic constraints, radiocarbon ages, and whole-rock
geochemical data. The activity of Miyakejima during this interval
can be divided into three magmatic periods based on cyclic whole-rock
compositional trends. Period 1 spans the interval between ~ 2.3 ka and
the 7th century, from the Hatchodaira eruption with caldera collapse
to immediately before the Suoana-Kazahaya eruption. Period 2 spans the
time period between the seventh century and the fourteenth century, from
the Suoana-Kazahaya to the Sonei-bokujyo eruptions. Period 3 covers
the period from the two major flank eruptions that occurred in the
sixteenth century to the end of the twentieth century until the last
caldera-collapse event in AD 2000. The eruption rate decreased from
0.5 km3 per 1000 years in Period 1 to ~ 0.2 km3
per 1000 years in Period 2 and 3. Recharge of primitive basaltic magmas
into shallower crustal systems triggered extensive basaltic fissure
eruptions at the beginning of each period. Progressively increasing
whole-rock SiO2 contents of the hybrid magmas in subsequent
eruptions indicates continuous fractional crystallization in small
shallow magma chambers which formed at the start of each magmatic
period. Intermittent injections of basaltic magma into shallow magma
chambers induced magma mixing that caused eruption of hybrid basaltic
andesite in each period. We suggest that some basaltic magmas formed
isolated magma reservoirs at shallow depth, in which rapid fractionation
was able to occur. Rupturing of these isolated magma storage regions
filled with gas-rich evolved magma can lead to violent ejection of
andesitic magmas, such as for the Suoana-Kazahaya eruption in the
seventh century. Our results suggest two main scenarios of eruption for
the basaltic magma system at Miyakejima and similar mafic volcanoes
in the northern Izu-Bonin arc; (1) eruption of voluminous basaltic
lavas after the recharge of primitive basaltic magmas into the shallow
magmatic system, and (2) explosive fissure eruption by rupturing of
isolated magma bodies filled with gas-rich evolved magmas.
Title: Spatiotemporal evolution of tremor activity near the Nankai
Trough trench axis inferred from the spatial distribution of seismic
amplitudes
Authors: Ogiso, Masashi; Tamaribuchi, Koji
Bibcode: 2022EP&S...74...49O
Altcode:
Slow earthquakes have gained importance due to their proximity to
the focal regions of megathrust earthquakes. Among slow earthquakes,
tectonic tremors have the highest dominant frequency and are thus best
resolved. Here, we estimated the locations of tectonic tremors off the
Kii Peninsula, southwestern Japan, from December 2020 through January
2021 using the seismograms of the Dense Oceanfloor Network system
for Earthquakes and Tsunamis (DONET). The study area is adjacent to
the Nankai Trough, where large megathrust earthquakes are known to
occur. We successfully estimated the locations of 3578 tectonic tremor
events within an area of ∼130 km in northeast-southwest and ∼50
km in northwest-southeast directions along the trench axis. Tremor
activity differed between the northeastern and southwestern areas
of the focal region, which were separated by a central region of
markedly low activity. During the study period, tremor activity began
at the northeastern edge of the focal region, and expanded to the
southwest along the trench axis until reaching the central low-activity
region. Renewed tremor activity later began at the southwestern edge
of the low-activity region and migrated southwest along the trench
axis. We also detected two distinct events similar to rapid tremor
reversals that migrated to the northeast, the first of which may have
been triggered by the combined effects of teleseismic surface waves
and Earth's tides. Such detailed locations of tectonic tremors can be
used as a proxy of the stress state in the accretionary prism and/or
along the plate boundary in the Nankai Trough.
Title: Trophic niche separation of two non-spinose planktonic
foraminifers Neogloboquadrina dutertrei and Pulleniatina
obliquiloculata
Authors: Toue, Ryuji; Fujita, Kazuhiko; Tsuchiya, Masashi; Chikaraishi,
Yoshito; Sasaki, Yoko; Ohkouchi, Naohiko
Bibcode: 2022PEPS....9...20T
Altcode:
Based on laboratory observations, planktonic foraminifers are
omnivorous, feeding zooplankton and phytoplankton. Spinose species tend
toward greater dependence on zooplankton prey than on phytoplankton
prey, while non-spinose species are more adapted to herbivorous
diets. However, the trophic activity of planktonic foraminifers in
the natural environment and their trophic positions in the marine
food web have not yet been fully understood. The trophic position
(TP) of two non-spinose species, Neogloboquadrina dutertrei and
Pulleniatina obliquiloculata, was determined by differences in the
nitrogen isotopic composition between two amino acids (glutamic acid
and phenylalanine). Results show that TP values of N. dutertrei were
~ 2.4, indicating dependence on omnivorous (mixed herbivorous and
carnivorous) diets, while those of P. obliquiloculata were ~ 2.1,
indicating dependence on herbivorous diets. Together with previous
laboratory observations, these TP values suggest that N. dutertrei
is a detritivore or scavenger, while P. obliquiloculata is generally
a herbivore. This trophic niche separation likely allows these two
planktonic foraminiferal species to live within a similar depth zone
in the open water column and provides a clue for understanding causes
of spatial and temporal changes in their relative abundances in living
and sediment assemblages.
Title: Numerical experiments on tsunami flow depth prediction for
clustered areas using regression and machine learning models
Authors: Kamiya, Masato; Igarashi, Yasuhiko; Okada, Masato; Baba,
Toshitaka
Bibcode: 2022EP&S...74..127K
Altcode:
Emergency responses during a massive tsunami disaster require
information on the flow depth of land for rescue operations. This
study aims to predict tsunami flow depth distribution in real
time using regression and machine learning. Training data of 3480
earthquake-induced tsunamis in the Nankai Trough were constructed
by numerical simulations. Initially, the k-means method was used to
discriminate the areas with approximately the same flow depth. The
number of clustered areas was 18, and the standard deviation of the
flow depth data in a cluster was 0.46 m on average. The objective
variables were the mean and standard deviation of the flow depth in the
clustered areas. The explanatory variables were the maximum deviation
of the water pressure at the seafloor observation points of the DONET
observatory. We generated multiple regression equations for a power
law using these datasets and the conjugate gradient method. Further,
we employed the multilayer perceptron method, a machine learning
technique, to evaluate the prediction performance. Both methods
accurately predicted the tsunami flow depth calculated by testing
11 earthquake scenarios in the cabinet office of the government of
Japan. The RMSE between the predicted and the true (via forward tsunami
calculations) values of the mean flow depth ranged from 0.34-1.08 m. In
addition to large-scale tsunami prediction systems, prediction methods
with a robust and light computational load as used in this study are
essential to prepare for unforeseen situations during large-scale
earthquakes and tsunami disasters.
Title: Two current systems in the preliminary phase of sudden
commencements in the magnetosphere
Authors: Fujita, Shigeru; Tanaka, Takashi
Bibcode: 2022EP&S...74...66F
Altcode:
The preliminary impulse of the sudden commencement is simply explained
by the generation of the compressional wave due to sudden compression
of the dayside magnetopause and mode conversion from the compressional
wave to the Alfvén wave in the magnetosphere. However, this simple
model cannot explain a time delay of the peak displacement and longer
duration time in the higher latitudes in the pre-noon and post-noon
sectors of the polar region. Based on the global magnetohydrodynamic
simulation of the magnetosphere-ionosphere system reveals that this
peculiar behavior of the geomagnetic variation of the preliminary
impulse is associated with temporal deformation of the ionospheric
field-aligned current distribution of the preliminary impulse
into a crescent shape; its lower-latitude edge extends toward the
anti-sunward direction, and its higher-latitude edge almost stays
on the same longitude near noon. Numerical simulations revealed that
the deformation of the field-aligned current distribution is derived
from different behaviors of the two current systems of the preliminary
impulse. The first current system consists of the field-aligned current
connected to the field-aligned current of the preliminary impulse
in the lower latitude side of the ionosphere, the cross-magnetopause
current, and the magnetosheath current (type L current system). The
cross-magnetopause current is the inertia current generated in the
acceleration front of the solar wind due to the sudden compression of
the magnetosheath. Thus, the longitudinal speed of the type L current
system in the ionosphere is the solar wind speed in the magnetosheath
projected into the ionosphere. In contrast, the current system of
the preliminary impulse connected to the field-aligned current of the
preliminary impulse at higher latitude (type H current system) consists
of the upward/downward field-aligned current in the pre-noon/post-noon
sector, respectively, and dawn-to-dusk field-perpendicular current
along the dayside magnetopause. The dawn-to-dusk field-perpendicular
current moves to the higher latitudes in the outer magnetosphere
over time. The field-aligned current of the type H current system
is converted from the field-perpendicular current due to convergence
of the return field-perpendicular current heading toward the sunward
direction in the outer magnetosphere; the return field-perpendicular
current is the inertia current driven by the magnetospheric plasma
flow associated with compression of the magnetopause behind the
front region of the accelerated solar wind. The acceleration front
spreads concentrically from the subsolar point. Consequently,
as the return field-perpendicular current is converted to the
field-aligned current of the type H current system, it does not move
much in the longitudinal direction over time because the dawn-to-dusk
field-perpendicular current of the type H current system moves to the
higher latitudes. Therefore, the high-latitude edge of the current
distribution of the preliminary impulse in the ionosphere moves
only slightly. Finally, we clarified that the conversion between
field-perpendicular current and field-aligned current of the type L
current system mainly occurs in the region where the Alfvén speed
starts to increase toward the Earth. A region with a steep gradient
of the Alfvén speed like the plasmapause is not always necessary for
conversion from the field-perpendicular current to the field-aligned
current. We also suggest the possible field-aligned structure of the
standing Alfvén wave that may occur in the preliminary impulse phase.
Title: Performance assessment of radio occultation data from GeoOptics
by comparing with COSMIC data
Authors: Chang, Hyeyeon; Lee, Jiyun; Yoon, Hyosang; Morton, Y. Jade;
Saltman, Alex
Bibcode: 2022EP&S...74..108C
Altcode:
Responding to the ever-growing demand for environmental information, the
National Oceanic and Atmospheric Administration (NOAA) seeks to enter
into contracts to purchase Global Navigation Satellite System (GNSS)
radio occultation (RO) observations produced by commercial vendors at
a low-cost. GeoOptics is one commercial vendor awarded a contract with
NOAA. GeoOptics operates the Community Initiative for Cellular Earth
Remote Observation (CICERO) constellation of low-earth-orbiting (LEO) 6U
CubeSats. The 6U-sized CICERO will enable the deployment of GNSS array
consisting of RO satellites in the Earth's atmosphere to obtain many
atmospheric observations which can improve weather forecasting. Applying
GeoOptics RO data to reliable weather forecasting requires an assessment
of its performance. This study analyzes the performance of GeoOptics
CubeSats measurements by comparing it with the Constellation Observing
System for Meteorology, Ionosphere, and Climate (COSMIC) missions
(COSMIC-1 and COSMIC-2). The performance analysis was carried on data
coverage capabilities and measurement quality. The analysis of data
coverage confirmed that GeoOptics can acquire global observational
coverage with adequate low-altitude penetration capability, while there
should be updated in local time coverage. The analysis of RO measurement
quality showed that GeoOptics RO measurements are comparable to those
of COSMIC-2, even though GeoOptics exhibited a lower signal-to-noise
ratio (SNR). The potential of GeoOptics allows for the development of
a GNSS array in the Earth's atmosphere and a large amount of effective
RO measurements to be obtained for reliable weather forecasting.
Title: Issues related to velocity structure estimation in small
coastal sedimentary plains: case of Tottori plain facing the Sea
of Japan
Authors: Kagawa, Takao; Noguchi, Tatsuya
Bibcode: 2022EP&S...74...74K
Altcode:
Issues of predominant period of ground motion and derived underground
velocity structure model are investigated in the coastal plains affected
by the shallow soft sedimentary layer after the last ice age. It is
found that two predominant periods due to the shallow soft layer and
deeper drastic sedimentary boundaries are close in a small plain such
as the Tottori plain, Japan as an example. This study analyzes the
underground velocity structure derived from EHVSR (H/V spectrum ratio
of earthquake ground motions) with the diffuse field theory. It is
considered that the interaction of close predominant periods due to the
different layer boundaries with high contrast may amplify the seismic
ground motion in the period range that affects building structures in
small plains in coastal area.
Title: Recent advances in the study of the prompt emission of
gamma-ray bursts
Authors: Iyyani, Shabnam
Bibcode: 2022JApA...43...37I
Altcode:
Gamma-ray bursts are the most energetic transients occurring in the
distant cosmos. They are produced by either the collapse of massive
stars or the merger of compact objects like neutron stars or black
holes. Currently, gamma-ray burst is the only astrophysical event
successfully observed in different messengers such as gravitational and
electromagnetic waves. Despite several decades of extensive observations
and research, gamma-ray bursts still remain largely elusive in terms
of their central engine, jet composition and radiation process. In
this article, the author will review the recent observational and
theoretical advancements made in the direction to resolve some of
these enigmas and the future outlook.
Title: Seismic reflection imaging of deep crustal structures via
reverse time migration using offshore wide-angle seismic data on
the eastern margin of the Sea of Japan
Authors: Shiraishi, Kazuya; No, Tetsuo; Fujie, Gou
Bibcode: 2022EP&S...74...28S
Altcode:
We applied reverse time migration (RTM) to offshore wide-angle seismic
data acquired with airgun shots and sparsely deployed ocean bottom
seismographs (OBSs) for reflection imaging of the Moho discontinuity
in the eastern margin of the Sea of Japan. While seismic tomography is
generally applied to wide-angle seismic data for estimating regional
velocity, reflection imaging is uncommon due to the low folds from
wide-spacing OBS deployment. The long offset reflection data obtained by
airgun-OBS surveys are promising for profiling deep crustal structures,
which may be able to add constraints on the velocity structures
estimated by tomographic inversion. Furthermore, reflection imaging
from wide-angle seismic data is useful when only airgun-OBS data are
acquired without any MCS data due to weather conditions or restrictions
of using streamer cables. In this study, we validated the feasibility
of RTM, which is an effective reflection imaging method based on
wavefield modelling with the two-way wave equation, using offshore
wide-angle seismic data acquired along two crossing survey lines off
Niigata-Yamagata. Airgun shot intervals were 200 m in both surveys,
and the OBS spacings were 5 km along a 297-km-long line and 8 km or
16 km along a 366-km-long line, except for OBSs near the coast. By
applying RTM with velocity models estimated by traveltime tomography
of the same OBS data, we successfully imaged clear reflections
around depths of 20-30 km. We confirmed that reflections observed in
the long offset range were effective in imaging the deep structures
that were not imaged by the MCS survey in this region. The depths of
reflectors were traced from approximately 20 km in the offshore area
to approximately 30 km near the coast, which corresponds to the Moho
discontinuity. The depth variation is consistent with the crustal
classification that was inferred based on tomography analyses: thick
oceanic crust in the Yamato Basin and rifted continental or island
arc crust beneath the areas from the Sado Ridge to the coast. Our
results from two surveys with different OBS spacings suggested the
high potential of the application to a wide variety of wide-angle
seismic data for crustal-scale seismic exploration.
Title: Electromagnetic conjugacy of ionospheric disturbances after
the 2022 Hunga Tonga-Hunga Ha'apai volcanic eruption as seen in
GNSS-TEC and SuperDARN Hokkaido pair of radars observations
Authors: Shinbori, Atsuki; Otsuka, Yuichi; Sori, Takuya; Nishioka,
Michi; Perwitasari, Septi; Tsuda, Takuo; Nishitani, Nozomu
Bibcode: 2022EP&S...74..106S
Altcode:
To elucidate the characteristics of electromagnetic conjugacy of
traveling ionospheric disturbances just after the 15 January 2022 Hunga
Tonga-Hunga Ha'apai volcanic eruption, we analyze Global Navigation
Satellite System-total electron content data and ionospheric plasma
velocity data obtained from the Super Dual Auroral Radar Network
Hokkaido pair of radars. Further, we use thermal infrared grid data
with high spatial resolution observed by the Himawari 8 satellite
to identify lower atmospheric disturbances associated with surface
air pressure waves propagating as a Lamb mode. After 07:30 UT on 15
January, two distinct traveling ionospheric disturbances propagating
in the westward direction appeared in the Japanese sector with the
same structure as those at magnetically conjugate points in the
Southern Hemisphere. Corresponding to these traveling ionospheric
disturbances with their large amplitude of 0.5 - 1.1 × 1016
el/m2 observed in the Southern Hemisphere, the plasma flow
direction in the F region changed from southward to northward. At this
time, the magnetically conjugate points in the Southern Hemisphere were
located in the sunlit region at a height of 105 km. The amplitude and
period of the plasma flow variation are ~ 100-110 m/s and ~ 36-38 min,
respectively. From the plasma flow perturbation, a zonal electric field
is estimated as ~ 2.8-3.1 mV/m. Further, there is a phase difference
of ~ 10-12 min between the total electron content and plasma flow
perturbations. This result suggests that the external electric field
variation generates the traveling ionospheric disturbances observed in
both Southern and Northern Hemispheres. The origin of the external
electric field is an E-region dynamo driven by the neutral wind
oscillation associated with atmospheric acoustic waves and gravity
waves. Finally, the electric field propagates to the F region and
magnetically conjugate ionosphere along magnetic field lines with
the local Alfven speed, which is much faster than that of Lamb mode
waves. From these observational facts, it can be concluded that
the E-region dynamo electric field produced in the sunlit Southern
Hemisphere is a main cause of the two distinct traveling ionospheric
disturbances appearing over Japan before the arrival of the air
pressure disturbances.
Title: Space-to-space very low frequency radio transmission in the
magnetosphere using the DSX and Arase satellites
Authors: McCollough, James P.; Miyoshi, Yoshizumi; Ginet, Gregory P.;
Johnston, William R.; Su, Yi-Jiun; Starks, Michael J.; Kasahara,
Yoshiya; Kojima, Hirotsugu; Matsuda, Shoya; Shinohara, Iku; Song,
Paul; Reinisch, Bodo W.; Galkin, Ivan A.; Inan, Umran S.; Lauben,
David S.; Linscott, Ivan; Ling, Alan G.; Allgeier, Shawn; Lambour,
Richard; Schoenberg, Jon; Gillespie, William; Stelmash, Stephen;
Roche, Kevin; Sinclair, Andrew J.; Sanchez, Jenny C.; Pedinotti,
Gregory F.; Langhals, Jarred T.
Bibcode: 2022EP&S...74...64M
Altcode:
Very low frequency (VLF) waves (about 3-30 kHz) in the Earth's
magnetosphere interact strongly with energetic electrons and are
a key element in controlling dynamics of the Van Allen radiation
belts. Bistatic very low frequency (VLF) transmission experiments
have recently been conducted in the magnetosphere using the high-power
VLF transmitter on the Air Force Research Laboratory's Demonstration
and Science Experiments (DSX) spacecraft and an electric field
receiver onboard the Japan Aerospace Exploration Agency's Arase (ERG)
spacecraft. On 4 September 2019, the spacecraft came within 410 km
of each other and were in geomagnetic alignment. During this time,
VLF signals were successfully transmitted from DSX to Arase, marking
the first successful reception of a space-to-space VLF signal. Arase
measurements were consistent with field-aligned propagation as expected
from linear cold plasma theory. Details of the transmission event and
comparison to VLF propagation model predictions are presented. The
capability to directly inject VLF waves into near-Earth space provides
a new way to study the dynamics of the radiation belts, ushering in
a new era of space experimentation.
Title: Role of hard X-ray emission in ionospheric D-layer disturbances
during solar flares
Authors: Briand, Carine; Clilverd, Mark; Inturi, Srivani; Cecconi,
Baptiste
Bibcode: 2022EP&S...74...41B
Altcode:
Any disturbance of the ionosphere may affect operational activities
based on HF communication. The electron density is a critical parameter
that controls levels of HF-signal absorption. A significant part
of the HF absorption takes place in the D-layer. The increase of X
radiations during solar flares generates noticeable perturbations of
the electron density of the D-layer. However, the ionosphere reacts
with some delay to the solar forcing. Several studies have addressed
this question of ionospheric sluggishness from the time delay between
VLF narrow-band transmissions and soft X-ray emissions during solar
flares. Our study initially considers the interpretation of the VLF
amplitude time profile. In particular, we show that the maximum of
X-ray emission can be associated with a reversal in the VLF amplitude
variation with time, i.e. exhibiting a peak or a trough. Then,
building on this insight, we perform estimates of the time delay
between VLF and soft X-rays during 67 events between 2017 and 2021,
thus including the major flares of 2017. We show that the time delay
can become negative for flares above X2, proving that soft X-rays are
not the initial source of ionization in the case of major flares. From
a careful analysis of RHESSI data for some events of September 2017,
we demonstrate that radiation above 40 keV (i.e. hard X-rays) is an
important forcing source of the ionosphere. This is of crucial interest
in the frame of space weather forecasting since the hard X-rays are
produced several minutes before the peak of soft X-rays.
Title: A broadband magnetotelluric survey for Mt. Meakandake volcano
with special attention to the unrest during 2016-2017
Authors: Inoue, Tomohiro; Hashimoto, Takeshi; Tanaka, Ryo; Yamaya,
Yusuke
Bibcode: 2022EP&S...74..114I
Altcode:
We performed a broadband magnetotelluric (BBMT) survey and
three-dimensional resistivity modeling for the Meakandake volcano
in eastern Hokkaido, Japan, where remarkable ground deformation
suggests a sill-like intrusion on the northeastern flank from 2016 to
2017. The volcano remained unerupted, and therefore the volcanological
meaning of the deformation was unclear, making the evaluation of the
"unrest" event difficult. Our 3D MT model has revealed a subvertical
low-resistivity column C1 (approximately 1-10 Ωm) extending from
0.5 km BSL (below sea level) to a deeper part of Mt. Meakandake. The
conductor C1 was not right on the presumed sill but just beneath the
summit craters offset southwest. We performed a sensitivity test in
which the bottom limit of C1 was varied, and confirmed that C1 was
meaningful down to approximately 30 km BSL. The vertical reach in
depth was necessary to reproduce the impedance phases out of quadrant
at some sites west of Mt. Meakandake. In addition, we interpreted that
the uppermost part of C1 was probably connected to the active vents of
Mt. Meakandake through presumed subvertical pathways of heat and fluids,
corresponding to the alignment of microearthquakes. On the other hand,
we found no remarkable conductivity anomalies beneath the northeastern
flank, where the sill-like inflation source was presumed. While our
MT data do not suggest a thin sill at depth, it does not exclude the
possibility that the ground inflation has been caused by a lateral
magmatic or hydrothermal intrusion that branched from a certain depth
of the subvertical conductor C1.
Title: A novel Bayesian approach for disentangling solar and
geomagnetic field influences on the radionuclide production rates
Authors: Nguyen, Long; Suttie, Neil; Nilsson, Andreas; Muscheler,
Raimund
Bibcode: 2022EP&S...74..130N
Altcode:
Cosmogenic radionuclide records (e.g., 10Be and
14C) contain information on past geomagnetic dipole
moment and solar activity changes. Disentangling these signals is
challenging, but can be achieved by using independent reconstructions
of the geomagnetic dipole moment. Consequently, solar activity
reconstructions are directly influenced by the dipole moment
uncertainties. Alternatively, the known differences in the rates of
change of these two processes can be utilized to separate the signals in
the radionuclide data. Previously, frequency filters have been used to
separate the effects of the two processes based on the assumption that
millennial-scale variations in the radionuclide records are dominated
by geomagnetic dipole moment variations, while decadal-to-centennial
variations can be attributed to solar activity variations. However, the
influences of the two processes likely overlap on centennial timescales
and possibly millennial timescales as well, making a simple frequency
cut problematic. Here, we present a new Bayesian model that utilizes
the knowledge of solar and geomagnetic field variability to reconstruct
both solar activity and geomagnetic dipole moment from the radionuclide
data at the same time. This method allows for the possibility that solar
activity and geomagnetic dipole moment exhibit variations on overlapping
timescales. The model was tested and evaluated using synthetic data
with realistic noise and then used to reconstruct solar activity and
the geomagnetic dipole moment from the 14C production record
over the last two millennia. The results agree with reconstructions
based on independent geomagnetic field models and with solar activity
inferred from the Group Sunspot number. Our Bayesian model also has the
potential to be developed further by including additional confounding
factors, such as climate influences on the radionuclide records.
Title: Local time dependence of earthquakes occurrence and its
possible connection with geomagnetic diurnal variations
Authors: Takla, E. M.
Bibcode: 2022JAsGe..11..132T
Altcode:
No abstract at ADS
Title: An event study on broadband electric field noises and electron
distributions in the lunar wake boundary
Authors: Nishino, Masaki N.; Kasahara, Yoshiya; Harada, Yuki; Saito,
Yoshifumi; Tsunakawa, Hideo; Kumamoto, Atsushi; Yokota, Shoichiro;
Takahashi, Futoshi; Matsushima, Masaki; Shibuya, Hidetoshi; Shimizu,
Hisayoshi; Miyashita, Yukinaga; Goto, Yoshitaka; Ono, Takayuki
Bibcode: 2022EP&S...74....9N
Altcode:
Wave-particle interactions are fundamental processes in space plasma,
and some plasma waves, including electrostatic solitary waves (ESWs),
are recognised as broadband noises (BBNs) in the electric field spectral
data. Spacecraft observations in recent decades have detected BBNs
around the Moon, but the generation mechanism of the BBNs is not fully
understood. Here, we study a wake boundary traversal with BBNs observed
by Kaguya, which includes an ESW event previously reported by Hashimoto
et al. Geophys Res Lett 37:L19204 https://doi.org/10.1029/2010GL044529
(2010). Focusing on the relation between BBNs and electron pitch-angle
distribution functions, we show that upward electron beams from the
nightside lunar surface are effective for the generation of BBNs, in
contrast to the original interpretation by Hashimoto et al. Geophys
Res Lett 37:L19204 https://doi.org/10.1029/2010GL044529 (2010)
that high-energy electrons accelerated by strong ambipolar electric
fields excite ESWs in the region far from the Moon. When the BBNs were
observed by the Kaguya spacecraft in the wake boundary, the spacecraft's
location was magnetically connected to the nightside lunar surface,
and bi-streaming electron distributions of downward-going solar wind
strahl component and upward-going field-aligned beams (at ∼124 eV)
were detected. The interplanetary magnetic field was dominated by
a positive BZ (i.e. the northward component), and strahl
electrons travelled in the antiparallel direction to the interplanetary
magnetic field (i.e. southward), which enabled the strahl electrons to
precipitate onto the nightside lunar surface directly. The incident
solar wind electrons cause negative charging of the nightside lunar
surface, which generates downward electric fields that accelerate
electrons from the nightside surface toward higher altitudes along
the magnetic field. The bidirectional electron distribution is not a
sufficient condition for the BBN generation, and the distribution of
upward electron beams seems to be correlated with the BBNs. Ambipolar
electric fields in the wake boundary should also contribute to the
electron acceleration toward higher altitudes and further intrusion of
the solar wind ions into the deeper wake. We suggest that solar wind
ion intrusion into the wake boundary is also an important factor that
controls the BBN generation by facilitating the influx of solar wind
electrons there.
Title: Matuyama-Brunhes geomagnetic reversal record and associated key
tephra layers in Boso Peninsula: extraction of primary magnetization
of geomagnetic fields from mixed magnetic minerals of depositional,
diagenesis, and weathering processes
Authors: Oda, Hirokuni; Nakazato, Hiroomi; Nanayama, Futoshi;
Harigane, Yumiko
Bibcode: 2022EP&S...74...80O
Altcode:
We report paleomagnetic records of Matuyama-Brunhes geomagnetic
polarity reversal and associated key tephra layers from the Early-Middle
Pleistocene marine sedimentary succession in the Boso Peninsula. The
outcrop is in Terasaki, Chiba, Japan and ~ 25 km northeast of the Chiba
section. The sediment succession consists of a massive siltstone layer
of the Kokumoto Formation, Kazusa Group. A tephra layer was identified
in the middle of the outcrop with chemical composition comparable to
that of the Byk-E tephra layer from the Chiba section defining the base
of the Chibanian Stage. Oriented paleomagnetic samples were collected
at intervals of 1-10 cm from the siltstone. To identify the primary
remanent magnetization, progressive alternating field demagnetization
(PAFD) and progressive thermal demagnetization (PThD) were conducted
on pilot samples. Identification of primary magnetization with PAFD
was not successful, especially for reversely magnetized samples. In
addition, magnetization during PThD showed sharp drops around 175 °C,
which decreased gradually between 175 °C and ~ 300 °C, and became
unstable above ~ 350 °C. To extract the primary remanent magnetization
while avoiding laboratory alteration by heating, a PThD up to 175 °C
followed by PAFD was conducted. Combined analysis of remagnetization
circles enables extraction of primary magnetization with improved
reliability. Rock magnetic experiments were conducted during stepwise
heating to understand the magnetic minerals involved and to evaluate
the influence of laboratory heating. During heating, FORC-PCA revealed
significant changes of magnetic minerals at 200 °C, 400 °C, 450 °C
and 550 °C. Rock magnetic analyses and electron microscopy indicate
that titanomagnetite/magnetite are magnetic minerals contributing to
primary remanent magnetization. Greigite was also identified preserving
secondary magnetizations during sub-seafloor diagenesis. The presence
of feroxyhyte is suggested as secondary magnetization through the
weathering of pyrite by exposure to the air after the Boso Peninsula
uplift. The correlation of relative paleointensity with the Chiba
section provides an age model with sedimentation rates of 30 cm/kyr
and 18 cm/kr for the intervals above and below the Byk-E tephra. VGP
latitudes are highly consistent with those from the Chiba section
based on the age model, which assigns the main directional swing from
reversed to normal polarities as 772.8 ± 0.5 ka.
Title: Characterization of water masses around the southern Ryukyu
Islands based on isotopic compositions
Authors: Cruz Salmeron, Andros Daniel; Takayanagi, Hideko; Wakaki,
Shigeyuki; Ishikawa, Tsuyoshi; Miyajima, Toshihiro; Wakaki, Hitomi;
Itaki, Takuya; Iryu, Yasufumi
Bibcode: 2022PEPS....9...44C
Altcode:
We investigated the water-mass structure on the Okinawa Trough
and Pacific sides of the southern Ryukyu Island Arc (Yonaguni,
Iriomote, and Ishigaki subareas) using the Nd isotope composition
(143Nd/144Nd ratios; expressed as εNd values)
of benthic foraminiferal tests in surface sediments, which reflect
bottom-water composition, along with hydrogen and oxygen isotope
compositions (δD and δ18O values, respectively) and
physical properties (temperature and salinity) of seawater. The
Okinawa Trough side has lower εNd values than the Pacific side due to
continental/island material inputs characterized by relatively low εNd
values. Moreover, within the Okinawa Trough, other processes control the
Nd behavior of seawater and primarily affect the Yonaguni and Iriomote
subareas, as follows. (1) Surface and subsurface waters are influenced
by Taiwanese river discharge combined with temporospatial variations in
oceanographic conditions including Kuroshio Current meandering. (2)
Intermediate water is characterized by low εNd values (down to
− 8.2), possibly attributable to sediment plumes and turbiditic
fluxes. (3) The εNd values of bottom water indicate upwelling and
vertical mixing, with composition therefore being similar to those
of intermediate water. The εNd profiles are better defined on the
Pacific side. High εNd values occur in surface and subsurface (<
300 m depth, potential density < 25.0 kg m−3) waters,
and low values (down to − 7.0) occur in subsurface-core-intermediate
water (400-600 m depth, 26-27 kg m−3). εNd values increase
slightly to − 4.0 below 750 m depth and remain constant down to
about 2000 m depth, below which deep water shows a slight decrease
in εNd values. Intermediate and bottom/deep waters are distinguished
from upper layers by their lower δD and δ18O values.
Title: Restricted 2 +2 body problem with oblateness and straight
segment
Authors: Kumar, Dinesh; Aggarwal, Rajiv
Bibcode: 2022JApA...43...36K
Altcode:
The present study investigates the combined effects of the oblateness
and straight segment on the positions and linear stability of the
equilibrium points in the restricted 2 +2 body problem. The present
model holds fourteen equilibrium points, out of which six are collinear
with the centers of the primaries and the rest are non-collinear. It
has been observed that the positions of all the equilibrium points are
subsequently affected by the oblateness and length of the primary
bodies. The linear stability of the equilibrium points is also
presented by slightly perturbing the position of the equilibrium
points. It is observed that for a considered set of parameters, all
the fourteen equilibrium points are unstable. An application of the
present model is also studied, for which the position and stability of
the equilibrium points are investigated for the Earth-22 Kalliope-dual
satellite system. It has been observed that for this system, all the
equilibrium points are unstable except for two non-collinear equilibrium
points that are found to be stable.
Title: Rates of compact object coalescences
Authors: Mandel, Ilya; Broekgaarden, Floor S.
Bibcode: 2022LRR....25....1M
Altcode: 2021arXiv210714239M
Gravitational-wave detections are enabling measurements of the rate of
coalescences of binaries composed of two compact objects—neutron stars
and/or black holes. The coalescence rate of binaries containing neutron
stars is further constrained by electromagnetic observations, including
Galactic radio binary pulsars and short gamma-ray bursts. Meanwhile,
increasingly sophisticated models of compact objects merging through
a variety of evolutionary channels produce a range of theoretically
predicted rates. Rapid improvements in instrument sensitivity, along
with plans for new and improved surveys, make this an opportune time
to summarise the existing observational and theoretical knowledge of
compact-binary coalescence rates.
Title: 2D electrical resistivity imaging of tantalite-bearing veins
in Kaiama, Nigeria
Authors: Raji, Wasiu Olanrewaju; Bale, Rafiu Babatunde
Bibcode: 2022JAsGe..11..306R
Altcode:
No abstract at ADS
Title: Hadean/Eoarchean tectonics and mantle mixing induced by
impacts: a three-dimensional study
Authors: Borgeat, Xavier; Tackley, Paul J.
Bibcode: 2022PEPS....9...38B
Altcode:
The timing of the onset of plate tectonics on Earth remains a topic of
strong debate, as does the tectonic mode that preceded modern plate
tectonics. Understanding possible tectonic modes and transitions
between them is also important for other terrestrial planets such as
Venus and rocky exoplanets. Recent two-dimensional modelling studies
have demonstrated that impacts can initiate subduction during the early
stages of terrestrial planet evolution—the Hadean and Eoarchean in
Earth's case. Here, we perform three-dimensional simulations of the
influence of ongoing multiple impacts on early Earth tectonics and its
effect on the distribution of compositional heterogeneity in the mantle,
including the distribution of impactor material (both silicate and
metallic). We compare two-dimensional and three-dimensional simulations
to determine when geometry is important. Results show that impacts can
induce subduction in both 2-D and 3-D and thus have a great influence
on the global tectonic regime. The effect is particularly strong in
cases that otherwise display stagnant-lid tectonics: impacts can shift
them to having a plate-like regime. In such cases, however, plate-like
behaviour is temporary: as the impactor flux decreases the system
returns to what it was without impacts. Impacts result in both greater
production of oceanic crust and greater recycling of it, increasing
the build-up of subducted crust above the core-mantle boundary and
in the transition zone. Impactor material is mainly located in the
upper mantle, at least at the end of the modelled 500-million-year
period. In 2-D simulations, in contrast to 3-D simulations, impacts
are less frequent but each has a larger effect on surface mobility,
making the simulations more stochastic. These stronger 2-D subduction
events can mix both recycled basalt and impactor material into the
lower mantle. These results thus demonstrate that impacts can make
a first-order difference to the early tectonics and mantle mixing of
Earth and other large terrestrial planets, and that three-dimensional
simulations are important to obtain less stochastic results, and also
to not over- or under-predict the amount of impactor material mixed into
the mantle and the time during which a specific tectonic regime acts.
Title: Toward a long-term atmospheric CO2 inversion
for elucidating natural carbon fluxes: technical notes of
NISMON-CO2 v2021.1
Authors: Niwa, Yosuke; Ishijima, Kentaro; Ito, Akihiko; Iida, Yosuke
Bibcode: 2022PEPS....9...42N
Altcode:
Accurate estimates of the carbon dioxide (CO2)
fluxes at the earth's surface are imperative for comprehending
the carbon cycle mechanisms and providing reliable global
warming predictions. Furthermore, they can also provide valuable
science-based information that will be helpful in reducing human-induced
CO2 emissions. Inverse analysis is a prominent method of
quantitatively estimating spatiotemporal variations in CO2
fluxes; however, it involves a certain level of uncertainty and
requires technical refinement, specifically to improve the horizontal
resolution so that local fluxes can be compared with other estimates
made at the regional or national level. In this study, a novel set of
inversion schemes was incorporated into a state-of-the-art inverse
analysis system named NISMON-CO2. The introduced schemes
include a grid conversion, observational weighting, and anisotropic
prior error covariance, the details of which are described. Moreover,
pseudo-observation experiments were performed to examine the effect of
the new schemes and to assess the reliability of NISMON-CO2
for long-term analysis with practical inhomogeneous observations. The
experiment results evidently demonstrate the advantages of the grid
conversion scheme for high-resolution flux estimates (1° × 1°),
with notable improvements being achieved through the observational
weighting and anisotropic prior error covariance. Furthermore, the
estimated seasonal and interannual variations in regional CO2
fluxes were confirmed to be reliable, although some potential bias
in terms of global land-ocean partitioning was observed. Thus, these
results are useful for interpreting the flux variations that result from
real-observation inverse analysis by NISMON-CO2 ver. 2021.1.
Title: Effect of projectile shape and interior structure on crater
size in strength regime
Authors: Kadono, T.; Arakawa, M.; Tsujido, S.; Yasui, M.; Hasegawa,
S.; Kurosawa, K.; Shirai, K.; Okamoto, C.; Ogawa, K.; Iijima, Y.;
Shimaki, Y.; Wada, K.
Bibcode: 2022EP&S...74..132K
Altcode: 2022arXiv220811568K
Experiments on crater formation in the strength regime were conducted
using projectiles of various shapes with an aspect ratio of ~ 1,
including both solid and hollow interiors. The surface diameter, inner
(pit) diameter, and depth of the craters on basalt and porous gypsum
targets were measured. Using the bulk density of the projectile,
the surface diameter and depth for basalt and the pit diameter and
depth for porous gypsum were scaled using the pi-scaling law for
crater formation in the strength regime. The numerical code iSALE
was used to simulate the impact of projectiles of various shapes and
interior structure with similar bulk densities. Results show that the
distributions of the maximum (peak) pressure experienced and particle
velocity in the targets were similar regardless of projectile shape
and interior structure, implying that the dimensions of the final
craters were almost identical. This is consistent with the experimental
results. Thus, we conclude that the size of the craters formed by the
impact of projectiles with different shape and interior structure can
be scaled using a conventional scaling law in the strength regime,
using bulk density as projectile density.
Title: Simulation of great earthquakes along the Nankai Trough:
reproduction of event history, slip areas of the Showa Tonankai and
Nankai earthquakes, heterogeneous slip-deficit rates, and long-term
slow slip events
Authors: Hirose, Fuyuki; Maeda, Kenji; Fujita, Kenichi; Kobayashi, Akio
Bibcode: 2022EP&S...74..131H
Altcode:
Great earthquakes have occurred repeatedly along the Nankai Trough,
but only for recent events are details known, such as rupture areas
and time lags between paired events. It is meaningful for disaster
prevention to consider in advance what kind of phenomena are likely
after an earthquake that partially ruptures a seismogenic zone in
this region. We constructed three-dimensional simulations to partially
reproduce the spatial and temporal distribution of seismic or aseismic
slip and the heterogeneous distribution of the slip-deficit rate beneath
the seafloor on the plate boundary along the Nankai Trough. We found it
necessary to assign spatial heterogeneity to two friction parameters,
the effective normal stress and characteristic distance, based on
a hierarchical asperity model. Our model produced many event pairs
consisting of events east and west of Cape Shiono (Tokai/Tonankai and
Nankai events, respectively), nearly all of them either simultaneous
or separated by less than 3 years. The rupture areas of these event
pairs were rich in variation, and even when the rupture areas were the
same, the magnitudes and maximum displacements differed. The Tonankai
earthquakes rarely occurred alone. Our model also simulated recurring
long-term slow slip events in deeper parts of the seismogenic zone,
and these events were caused by stress disturbance and heterogeneous
stress distributions associated with non-ruptured portions of the
seismogenic zone.
Title: NuSTAR and AstroSat observations of thermonuclear X-ray bursts
with short-recurrence times in 4U 1636−536
Authors: Roy, Pinaki; Beri, Aru; Mondal, Aditya S.
Bibcode: 2022JApA...43...45R
Altcode: 2022arXiv220207379R
We report results from the spectro-timing analysis of the atoll
source 4U 1636−536 observed with NuSTAR and AstroSat during its
hard spectral state. In three observations of 207 ks total exposure,
we identify 31 thermonuclear X-ray bursts including five doublets and
a triplet. Recurrence time as short as 3.8 min is seen in one of the
doublets. To the best of our knowledge, this is the shortest recurrence
time known for this source. Our time-averaged spectroscopy during the
bursts indicates the presence of an additional power-law or a blackbody
component in a few cases, perhaps due to varying temperatures during
bursts or plausible deviation from ideal blackbody behavior; however,
it is difficult to probe this using the time-resolved spectroscopy
owing to limited statistics. Time-resolved bursts are well fit using
an absorbed blackbody model with temperatures varying between 1.7
and 2.2 keV. Burst oscillations around 581 Hz are detected with 3σ
confidence during the decay phase in two of the X-ray bursts. One of
the burst oscillations is seen at 582 Hz, a frequency observed during
the 2001 superburst in this source.
Title: Assessment of the performance of GPS/Galileo PPP-RTK
convergence using ionospheric corrections from networks with
different scales
Authors: Yan, Zhongbao; Zhang, Xiaohong
Bibcode: 2022EP&S...74...47Y
Altcode:
The rapid convergence of precise point positioning real-time kinematics
(PPP-RTK) with centimeter-level accuracy is of utmost importance
for many applications. One way of accelerating this convergence
is to explore the use of ionospheric models and multiple global
navigation satellite system (GNSS) observations, e.g., Global
Positioning System (GPS) and Galileo Satellite Navigation System
(Galileo) observations. Because the temporal and spatial variations
of the ionosphere are significant, convergence analysis of PPP-RTK
should be investigated in networks with different scales, especially
networks with large differences in their scales. This study describes
the convergence performance of PPP-RTK using GPS/Galileo observations
derived from networks with different scales under medium ionospheric
conditions. Slant ionospheric corrections were first estimated from the
reference network and then imported as virtual observations to enhance
the convergence performance of PPP-RTK at the user interface. The
results show that for the 165-km reference site spacing, the portions
of single-differenced (SD) ionospheric residuals within 0.3 total
electron content units (TECU) were 85.2% and 81.7% for the GPS and
Galileo observations, respectively. Considering the 90th percentile of
horizontal position errors, the PPP-RTK convergence time within the
network with 165-km spacing was shortened from 2.5 min for GPS-only
observations to 2.0 min for integrated GPS + Galileo observations. For
the network of about 50 km, the proportions of the SD ionospheric
residuals of the GPS and Galileo constellation within 0.3 TECU
were 95.9% and 82.8%, respectively. The PPP-RTK convergence time of
the 90th percentile horizontal positioning errors based on GPS-only
observations was 2.0 min but 1.5 min based on integrated GPS + Galileo
observations. Using GPS and Galileo observations, the convergence time
could be reduced by 25% for the network with 50-km spacing. Our results
suggest that the convergence time of PPP-RTK depends on the scale of
the reference network and becomes shorter as the scale of the network
decreases. Compared with the GPS-only PPP-RTK, the GPS/Galileo PPP-RTK
could shorten the convergence time further.
Title: Short-wave run-ups of the 1611 Keicho tsunami along the
Sanriku Coast
Authors: Yamanaka, Yusuke; Tanioka, Yuichiro
Bibcode: 2022PEPS....9...37Y
Altcode:
A tsunami generated by an earthquake that occurred off the east coast
of Japan in 1611 was predominantly concentrated along the Sanriku
Coast. The 1611 event produced its greatest observed tsunami height at
Koyadori, 28.8 m, higher than that produced by other representative
tsunamis at the same location such as the 2011 Tohoku and 1896 Meiji
Sanriku tsunamis. The characteristics of the source that resulted in
the remarkable tsunami height at Koyadori have been widely debated. In
this study, we simulated the local intensification mechanism of the
1611 tsunami and derived some key characteristics of the earthquake that
produced the intensification at Koyadori based on these results. First,
we investigated the topographical inundation characteristics in
representative areas on the Sanriku Coast, including Koyadori, by
numerical means. By comparing the numerical results with the observed
heights for the 1611 tsunami, we found that a simulated tsunami that was
dominated by short-wave components yielded a promising reproduction of
the observed heights. The development of a local resonance seemed a more
likely cause for the observed local intensification at Koyadori than
a single-pulse wave. These results suggested that the 1611 earthquake
produced a tsunami dominated by short-wave components. Furthermore,
the source must have been located far off the Tohoku coast near the
Japan Trench axis to have had substantial short-wave components along
the Sanriku Coast. Based on these findings, we constructed a source
scenario for local intensification by investigating the characteristics
of Green's functions from single-point sources. The scenario involves
two separate earthquake sources in shallow crustal areas at the plate
interface of the subduction zone, resulting in a moment magnitude of
8.5. The tsunami produced by this source model, which reflected the
characteristics of a tsunami earthquake, effectively reproduced the
local intensification observed on the Sanriku Coast.
Title: Space weathering signatures in sulfide and silicate minerals
from asteroid Itokawa
Authors: Chaves, Laura C.; Thompson, Michelle S.
Bibcode: 2022EP&S...74..124C
Altcode:
Transmission electron microscopy analyses of the polymineralic
regolith particle RC-MD01-0025 show microstructural and microchemical
characteristics indicative of space weathering on the surface of
asteroid Itokawa. The depletion of sulfur and nickel was identified
in space weathered rims on troilite and pentlandite minerals. This
corresponds to the first report of nickel depletion in samples returned
from asteroid Itokawa by the Hayabusa mission. Microstructurally,
the sulfide minerals present crystalline rims and the olivine presents
both crystalline and amorphous zones in the rim. These results suggest
that sulfides might be more resistant to amorphization caused by
solar wind irradiation. The space weathering features identified in
the regolith particle analyzed here are likely formed via solar wind
irradiation. Additionally, the differences in the space weathering
features in olivine, pentlandite, and troilite suggest that silicates
and sulfides respond differently to the same space weathering conditions
in interplanetary space.
Title: Earthquake probability in the National Seismic Hazard Maps for
Japan and people's risk perceptions: the search for more effective
expression
Authors: Saito, Sayaka; Yasumoto, Shinya; Sekiya, Naoya
Bibcode: 2022EP&S...74...82S
Altcode:
This study summarizes the findings of an attitude survey focused on
people's perceptions of seismic hazard maps, which illustrate the risk
of an earthquake in each location throughout Japan. These seismic hazard
maps depict the likelihood of an earthquake with a seismic intensity
of "6 Lower" or more within 30 years, with 3.0% being considered a
high possibility. The 3.0% occurrence probability within 30 years
can be reworded to 2.0% occurrence probability within 20 years, 0.1%
occurrence probability within a year, 4.9% occurrence probability
within 50 years, or 39.4% occurrence probability within 500 years when
being converted according to a Poisson distribution. In this study,
we convert the occurrence probability within 30 years in the seismic
hazard maps to obtain that within a year up to that within 1000 years,
present the involved risk and demonstrate the yearly probability
of the people who see the maps becoming most convinced of the need
for countermeasures. Although those are shorter than the occurrence
probability within 30 years anyway, it is a characteristic that the
peaks existed at the occurrence probability within 10-20 years, not
at the occurrence probability within one year or five years. However,
the results changed according to the age of the people viewing the maps,
and it was when the risk was presented as the occurrence probabilities
within 20 and 30 years for the people in their 20-40 s, while it
was when the risk was presented the occurrence probabilities within
10 years for the people in their 50-60 s, the perception toward the
need of countermeasures increased the most. In addition, regardless
of gender and place of residence (coast of the Sea of Japan or the
Pacific coast), the perception toward the need of countermeasures
peaked at the occurrence probabilities within 10 and 20 years.
Title: Effects of vertical nonlinearity on the superconducting
gravimeter CT #036 at Ishigakijima, Japan
Authors: Imanishi, Yuichi; Nawa, Kazunari; Tamura, Yoshiaki; Ikeda,
Hiroshi
Bibcode: 2022EP&S...74...73I
Altcode:
One of the characteristic features of the gravity recordings produced
by the superconducting gravimeter CT #036 at Ishigakijima, Japan,
is that it indicates gravity increase when a typhoon (hurricane)
approaches the island. Since we are trying to detect small gravity
signals associated with the long-term slow slip events in this region,
it is very important in the interpretation of the observed data whether
such gravity changes are of natural or instrumental origin. In this
paper, we investigate whether or not nonlinearity in the sensor of the
superconducting gravimeter is responsible for this phenomenon. Here we
take the same theoretical approach as taken by our previous study which
investigated the effect of coupling between horizontal and vertical
components of the gravity sensor in order to understand the noise
caused by the movements of a nearby VLBI antenna. From theoretical and
experimental approaches, we prove that the gravity increase observed
by CT #036 at the times of high background noise level cannot be
explained by instrumental effects, such as the nonlinearity in the
vertical component or the coupling between horizontal and vertical
components of the gravity sensor. This implies that the observed
gravity increases are real gravity signals of natural origin.
Title: A confirmation of vertical acoustic resonance and field-aligned
current generation just after the 2022 Hunga Tonga Hunga Ha'apai
volcanic eruption
Authors: Iyemori, Toshihiko; Nishioka, Michi; Otsuka, Yuichi;
Shinbori, Atsuki
Bibcode: 2022EP&S...74..103I
Altcode:
A strong volcanic eruption caused a clear vertical acoustic resonance
between the sea surface and the thermosphere. Its effects are observed
as geomagnetic and GPS-TEC oscillations near the volcano and its
geomagnetic conjugate area. The geomagnetic oscillations are observed
at Apia and Honolulu geomagnetic observatories with amplitude of about
2 nT and 0.2 nT, respectively. The volcanic eruption started around
04:14 UT on January 15, 2022. The oscillations appeared at 04:21UT at
Apia, Samoa, only about 7 min after the start of eruption. Because the
distance between the volcano and Apia is about 841 km, it takes about 40
min for a sound wave to propagate from the volcano to Apia. Therefore,
it is more plausible to assume that the magnetic oscillation observed
at Apia about 7 min after the eruption is caused by the sound waves
propagated vertically upward to the ionosphere and generated an electric
current. The coherent appearance of geomagnetic oscillation at Honolulu
located near the geomagnetic conjugate point of the volcano strongly
support the idea that the ionospheric current generated over the
volcano diverted as a field-aligned current which flew to the opposite
hemisphere and caused the geomagnetic oscillation at Honolulu. The
earliest start of GPS-TEC oscillation was around 04:15UT near the
volcanic eruption, and it was around 04:20 UT at KOKV station in
Hawaii. The time-lag of the TEC variations between Samoa and Hawaii
obtained by a cross-correlation analysis is 4.5 min or 8.5 min. These
time differences are much smaller than the travel time of the seismic
waves from the volcano to Hawaii islands. Therefore, it is suggested
that the electric field transmitted along geomagnetic field caused
the TEC variation observed over Hawaii Islands. A sawtooth waveform
of geomagnetic oscillation observed at Apia and Honolulu is analyzed
and a possible generation mechanism is discussed.
Title: Spatiotemporal functional modeling of postseismic deformations
after the 2011 Tohoku-Oki earthquake
Authors: Fujiwara, Satoshi; Tobita, Mikio; Ozawa, Shinzaburo
Bibcode: 2022EP&S...74...13F
Altcode:
Postseismic deformations continue to occur for a long period after
major earthquakes. Temporal changes in postseismic deformations can
be approximated using simple functions. Since the 2011 Tohoku-Oki
earthquake, operating global navigation satellite system stations have
been continuously accumulating a remarkable amount of relevant data. To
verify the functional model, we performed statistical data processing
on postseismic deformations due to this earthquake and obtained their
spatiotemporal distribution. Moreover, we approximated the postseismic
deformations over a relatively wide area with a standard deviation
of residuals of 1 cm for approximately 10 years using a combined
functional model of two logarithmic and one exponential functions;
however, the residuals from the functional model exhibited a marked
deviation since 2015. Although the pattern of postseismic deformations
remained unaltered after the earthquake, a change in the linear
deformation occurred from 2015 to date. We reduced the overall standard
deviation of the residuals of > 200 stations distributed over >
1000 km to < 0.4 cm in the horizontal component by enhancing the
functional model to incorporate this linear deformation. Notably,
time constants of the functions were similarly applicable for all
stations and components. Furthermore, the spatial distribution of the
coefficients of each time constant were nonrandom, and the distribution
was spatially smooth, with minute changes in the short wavelengths in
space. Thus, it is possible to obtain a gridded model in terms of a
spatial function. The spatial distributions of short- and long-period
components of the functional model and afterslip and viscoelastic
relaxation calculated using the physical model were similar to each
other, respectively. Each time function revealed a connotation regarding
the physical processes, which provided an understanding of the physical
phenomena involved in seismogenesis. The functional model can be used
to practical applications, such as discerning small variations and
modeling for precise positioning.
Title: Interaction between historical earthquakes and the 2021 Mw7.4
Maduo event and their impacts on the seismic gap areas along the
East Kunlun fault
Authors: Dong, Peiyu; Zhao, Bin; Qiao, Xuejun
Bibcode: 2022EP&S...74...42D
Altcode:
On May 21, 2021 (UTC time), an Mw7.4 earthquake struck Maduo County,
Qinghai Province, China. The rupture of this typical strike-slip
event and its aftershocks along the Kunlun-Jiangcuo fault (JCF)
propagated approximately 170 km from the epicenter. In this study,
we calculated the coseismic and postseismic Coulomb stress changes
induced by 14 historical earthquakes and investigated their impacts
on the 2021 Maduo source area. We found that the JCF is in the stress
shadow of these historical events with a combined ΔCFS range of
approximately − 400 to − 200 kPa. Since the seismogenic fault of
the 1937 event is nearly parallel and close to the JCF, the rupture
of the 1937 event had the greatest inhibitory effect on Maduo source
area. We hypothesize that the actual loading rate at the depth of
the seismogenic layer in the Maduo source area is much higher than
the simulated value (0.3 kPa/a). Consequently, the Maduo earthquake
still occurred despite the considerable delaying effect of these
historical earthquakes (especially the 1937 event). Our findings also
indicate that the tectonic stress in the eastern Bayanhar block is
still rapidly accumulating and adjusting. Our investigation further
reveals the enhanced stress induced by the historical and Maduo events
with ΔCFS values of approximately 30-300 kPa and 50-300 kPa on the
Xidatan-Dongdatan segment (XDS) and the eastern end of the East Kunlun
Fault (EKF), respectively, not only on the Maqin-Maqu segment (MMS)
but also at the eastern end of each branch segment of the EKF. Hence,
considering the accumulation of tectonic stress, we suggest that the
seismic hazard in these two regions has been promoted.
Title: Propagation characteristics of sporadic E and medium-scale
traveling ionospheric disturbances (MSTIDs): statistics using HF
Doppler and GPS-TEC data in Japan
Authors: Matsushima, Ryo; Hosokawa, Keisuke; Sakai, Jun; Otsuka,
Yuichi; Ejiri, Mitsumu K.; Nishioka, Michi; Tsugawa, Takuya
Bibcode: 2022EP&S...74...60M
Altcode:
We carried out a statistical analysis of the propagation characteristics
of Es and Medium-Scale Traveling Ionospheric Disturbances (MSTIDs)
by combining data of HF Doppler (HFD) sounder and Total Electron
Content (TEC) obtained from the GPS receivers of GEONET (GPS-TEC)
for 4 years from 2014 to 2017. We made use of Es reflection data
from the HFD receivers in Sugito, Saitama (36.0°N, 139.7°E),
Fujisawa, Kanagawa (35.3°N, 139.5°E), and Sugadaira, Nagano
(36.4°N, 138.3°E) in Japan. By using this triangle observation,
we succeeded in deriving the horizontal speed and direction of the
motion of Es. In addition, we estimated the phase velocity of MSTIDs
observed in the simultaneously obtained maps of GPS-TEC with the
same triangle observation procedure. The speeds of Es and MSTIDs
were commonly less than 100 m/s in most cases and their propagation
direction was predominantly southwestward. This result is consistent
with the statistical characteristics of nighttime MSTIDs observed in
the previous studies. More importantly, good correspondence between
the propagation characteristics of the two phenomena at two different
altitudes confirms that Es and MSTIDs move in tandem with each other,
further suggesting that Es in the E region plays an important role in
the generation and propagation of MSTIDs in the F region.
Title: Data agreement analysis and correction of comparative
geomagnetic vector observations
Authors: He, Zhaobo; Hu, Xingxing; Teng, Yuntian; Zhang, Xiuxia;
Shen, Xiaoyu
Bibcode: 2022EP&S...74...29H
Altcode:
Geomagnetism, similar to other areas of geophysics, is an
observation-based science. Data agreement between comparative
geomagnetic vector observations is one of the most important evaluation
criteria for high-quality geomagnetic data. The main influencing factors
affecting the agreement between comparative observational data are the
attitude angle, scale factor, long-term time drift, and temperature. In
this paper, we propose a method based on a genetic algorithm and linear
regression to correct for these effects and use the distribution pattern
of points in Bland-Altman plots with a 95% confidence interval length
to qualitatively and quantitatively evaluate the agreement between
the comparative observational data. In Bland-Altman plots with better
agreement, that is, with the corrected data, more than 95% of the
points are distributed within the 95% confidence interval and there
is no obvious pattern in the distribution of the points. Meanwhile,
the length of 95% confidence interval decreased significantly after
the correction. The method presented here has positive effects on the
vector instrumentation detection and would enhance the robustness of
geomagnetic observatory by bringing the data quality of the backup
variometer data in line with the primary variometer.
Title: Frequency spectra of horizontal winds in the mesosphere and
lower thermosphere region from multistatic specular meteor radar
observations during the SIMONe 2018 campaign
Authors: Charuvil Asokan, Harikrishnan; Chau, Jorge L.; Marino,
Raffaele; Vierinen, Juha; Vargas, Fabio; Urco, Juan Miguel; Clahsen,
Matthias; Jacobi, Christoph
Bibcode: 2022EP&S...74...69C
Altcode:
In recent years, multistatic specular meteor radars (SMRs) have been
introduced to study the Mesosphere and Lower Thermosphere (MLT)
dynamics with increasing spatial and temporal resolution. SMRs,
compared to other ground-based observations, have the advantage of
continuously measuring the region between 80 and 100 km independent of
weather, season, or time of day. In this paper, frequency spectra of
MLT horizontal winds are explored through observations from a campaign
using the SIMONe (Spread-spectrum Interferometric Multistatic meteor
radar Observing Network) approach conducted in northern Germany in 2018
(hereafter SIMONe 2018). The 7-day SIMONe 2018 comprised of fourteen
multistatic SMR links and allows us to build a substantial database
of specular meteor trail events, collecting more than one hundred
thousand detections per day within a geographic area of ∼ 500 km
× 500 km. We have implemented two methods to obtain the frequency
spectra of the horizontal wind components: (1) Mean Wind Estimation
(MWE) and (2) Wind field Correlation Function Inversion (WCFI), which
utilizes the mean and the covariances of the line of sight velocities,
respectively. Monte Carlo simulations of a gravity wave spectral
model were implemented to validate and compare both methods. The
simulation analyses suggest that the WCFI helps us to capture the
energy of smaller scale wind fluctuations than those capture with
MWE. Characterization of the spectral slope of the horizontal wind
at different MLT altitudes has been conducted on the SIMONe 2018, and
it provides evidence that gravity waves with periods smaller than 7 h
and greater than 2 h dominate with horizontal structures significantly
larger than 500 km. In the future, these analyses can be extended to
understand the significance of small-scale fluctuations in the MLT,
which were not possible with conventional MWE methods.
Title: Dynamic earthquake sequence simulation with an SBIEM accounting
for interseismic poroelastic rebound
Authors: Noda, Hiroyuki
Bibcode: 2022EP&S...74...89N
Altcode:
Afterslip inside a coseismic slip patch is rarely observed, though
some previous studies suggest that it is driven by poroelastic
rebound (PER). These studies assume constant frictional strength,
whereas time-dependent strengthening (healing) of a fault is expected
from laboratory experiments, which provide a basis for a rate-
and state-dependent friction law (RSF). In this study, quasistatic
poroelasticity (PE) was implemented in a dynamic earthquake sequence
simulation using a spectral boundary integral equation method,
and the effect of PER on the behavior of a fault governed by RSF was
examined. Spatio-temporal convolution for PE would significantly affect
the resolution of the numerical simulation affordable. This problem
has been resolved by numerical approximation of the time dependency
of Green's function of PE in the wavenumber domain, definition of
memory variables, and reformulation of the temporal convolution into
ordinary differential equations of them. In the novel method, the
additional numerical costs due to PE are negligible. A planar fault
with a rate-weakening patch embedded in the rate-strengthening region
was simulated. Because it is the healing of the fault that competes
against PER, both the aging law and slip law were examined, which have
different characteristics in the evolution of the fault strength. The
simulation results indicate that PER causes postseismic loading to the
patch, but the healing efficiently suppresses afterslip not only for
the aging law, but also for the slip law. When cases with different
friction laws are compared, the healing is more significant for the
aging law, which has log-t strengthening at a limit of V →0 . However,
the effect of PER on the slip rate is minor for the slip law. The slip
law yields additional healing if the fault is accelerated by loading
owing to PER. The simulation results are consistent with the absence
of afterslip within the coseismic slip patches in the observations.
Title: Paleotsunami history of Hachinohe, northern Japan: a multiproxy
analysis and numerical modeling approach
Authors: Velasco-Reyes, Erick R.; Goto, Kazuhisa; Sugawara, Daisuke;
Nishimura, Yuichi; Shinohara, Takahiro; Chiba, Takashi
Bibcode: 2022PEPS....9...19V
Altcode:
Paleotsunami studies along the Pacific coast of Tohoku, northern Japan,
have been considerably developed recently, particularly after the
massive impact of the 2011 Tohoku-oki tsunami. Nevertheless, in the
southernmost Shimokita Peninsula, studies pertaining to paleotsunami are
underdeveloped, leading to a vague understanding of the tsunamigenic
sources northward of the Tohoku region, along with incomplete hazard
evaluation. Paleotsunami deposits in Shimokita can be related not
only to the Japan Trench along the Sanriku coast but also to the Kuril
trench along the Pacific coast of Hokkaido. In this study, we unveiled
the paleotsunami history of Hachinohe in northern Tohoku. Using a
combination of sedimentological, geochemical, paleontological, and
mineralogical proxies, we characterized seven sand layers that dated
from ca. 2700 to ca. 5500 yr BP based on radiocarbon (14C)
ages as event deposits of marine origin. Sedimentological and
paleontological evidence coupled with ground-penetrating radar imagery
revealed a marsh environment comprising successive extinct ponds,
controlling the depositional environment. Numerical modeling ruled out
the possibility of storms as genetic sources, leading to the conclusion
that the presence of event deposits with marine sediments in the study
area would be associated with tsunami inundation episodes. Based on
14C dating, the mean frequency of recurrence of tsunamis
is estimated as 384 years (320-450 yr, 95% confidence interval)
and a coefficient of variation of 0.78 (0.68-0.99, 95% confidence
interval). The previously recorded limited paleotsunami evidence and
absence of an estimated recurrence interval in the Shimokita Peninsula
reaffirm the importance of Hachinohe as a tsunami record site for the
activity of both trenches.
Title: Assessing and projecting surface air temperature conditions
required to sustain permafrost in Japan
Authors: Yokohata, Tokuta; Iwahana, Go; Saito, Kazuyuki; Ishizaki,
Noriko N.; Matsushita, Taiga; Sueyoshi, Tetsuo
Bibcode: 2022PEPS....9...39Y
Altcode:
Permafrost covers a wide area of the Northern Hemisphere, including
high-altitude mountainous areas and even at mid-latitudes. There
is concern that the thawing of mountain permafrost can cause slope
instability and substantially impact alpine ecosystems, and because
permafrost in mountainous areas is difficult to observe, detailed
analyses have not been performed on its current distribution and
future changes. Although previous studies have observed permafrost
only at a limited number of points in Japan (e.g., Daisetsu Mountains,
Mt. Fuji, and Mt. Tateyama in the Northern Japan Alps), we show that
permafrost potentially exists in nine domains in Japan (Daisetsu
Mountains, Mt. Fuji, Northern and Southern Japan Alps, Hidaka
Mountains, Mt. Shiretokodake, Sharidake, Akandake, and Yotei). In
the Daisetsu Mountains and Mt. Fuji, the environmental conditions
required for maintaining at least some permafrost are projected
to remain in the future if a decarbonized society is achieved
(RCP2.6 or RCP4.5). However, if greenhouse gas emissions continue
to increase (RCP8.5), the environmental conditions required for
sustaining permafrost are projected to disappear in the second half
of the twenty-first century. In other domains, the environmental
conditions required for maintaining permafrost are either projected
to disappear in the next ten years (Hidaka Mountains, Northern Japan
Alps) or they have almost disappeared already (Southern Japan Alps,
Mt. Shiretokodake, Sharidake, Akandake, and Yotei). Our projections
show that climate change has a tremendous impact on Japan's mountain
permafrost environment and suggests the importance of monitoring the
mountain environment and considering measures for adapting to future
climate change.
Title: Complex rupture process on the conjugate fault system of the
2014 Mw 6.2 Thailand earthquake
Authors: Tadapansawut, Tira; Yagi, Yuji; Okuwaki, Ryo; Yamashita,
Shinji; Shimizu, Kousuke
Bibcode: 2022PEPS....9...26T
Altcode:
A moment magnitude 6.2 crustal earthquake occurred in northern Thailand
on May 5, 2014, and its aftershocks exhibit several lineaments with
conjugate pattern, involving geometric complexity in a multi-segmented
fault system of the Phayao Fault Zone. However, a relationship between
those geometric complexities and the rupture evolution of the 2014
Thailand earthquake is still elusive, which is critical to understand
complex nature of the earthquake physics and to assess the hazard. Here,
we elaborated the newly developed potency density tensor inversion
method, used it to invert the globally observed teleseismic P waveforms,
and estimated the spatiotemporal distribution of both the slip and the
fault geometry. We found the complex rupture evolution consisting of
two rupture episodes along a conjugated strike-slip fault system that
comprises two distinct fault planes. The first episode originated at the
hypocenter and the rupture propagated south along the north-northeast
to south-southwest fault plane. The second episode was triggered
at around 5 km north from the epicenter, and the rupture propagated
along the east-northeast to west-southwest fault plane and terminated
at the west end of the source area at 5 s hypocentral time. Our work
demonstrates that our potency density tensor inversion can be applied
to the smaller-scale magnitude-6 class earthquakes, and it resolves
the complex rupture process controlled by the underlying geometric
complexity in the fault system.
Title: Depth profile of frictional properties in the inner Nankai
accretionary prism using cuttings from IODP Site C0002
Authors: Fujioka, Riho; Katayama, Ikuo; Kitamura, Manami; Okuda,
Hanaya; Hirose, Takehiro
Bibcode: 2022PEPS....9...31F
Altcode:
We conduct frictional experiments using cuttings collected at Nankai
Trough IODP Site C0002 over 980.5-3262.5 mbsf (meters below seafloor)
depth interval to better understand the frictional properties through
the accretionary prism. The experiments are conducted at the in situ
effective normal stresses (9-37 MPa) under brine-saturated conditions,
and the slip velocity is abruptly changed in a stepwise manner to either
of 0.3, 3, or 33 µm/s after the steady-state friction is reached. The
friction coefficient (μ) of the cuttings samples ranges from 0.45
to 0.60, with a slight increase in μ with increasing depth, related
to decreasing smectite content. The velocity dependence of friction
(a − b) is positive at all depths and ranges from 0.001 to 0.006,
which indicates a velocity-strengthening behavior; these values are
consistent with relatively homogeneous deformation microstructures. The
critical slip distance (Dc) ranges from 0.5 to 123 μm, with
relatively large values obtained for the smectite-rich samples. The
changes in both the friction coefficient and rate- and state-friction
parameters are likely associated with mineralogical change and
consolidation with increasing depth. Although all of the cuttings
samples collected from Site C0002 exhibit a velocity-strengthening
behavior, a slight decreasing trend in a − b with increasing depth
indicates either a nearly neutral velocity dependence or a possible
transition to velocity-weakening behavior at greater depths, which
may be attributed to the occurrence of slow earthquakes in the Nankai
accretionary prism.
Title: The swarm Langmuir probe ion drift, density and effective mass
(SLIDEM) product
Authors: Pakhotin, I. P.; Burchill, J. K.; Förster, M.; Lomidze, L.
Bibcode: 2022EP&S...74..109P
Altcode:
Current methods for estimating ion density on Swarm rely on the
assumption of 100% O + and no along-track ion velocity flows. These
assumptions are routinely violated, particularly on the nightside and
during high-latitude and polar cap traversals, compromising the accuracy
of the measurements. The use of faceplate current data along with the
Langmuir probe ion admittance measurements, and orbital-motion limited
(OML) theory, make it possible to relax some of the assumptions inherent
in current ESA Swarm density estimates. This further yields along-track
ion drift and effective ion mass estimates. This paper describes the
theoretical basis for estimating revised ion density, providing a
new estimate for effective ion mass, as well as an alternative way
of estimating along-track ion drift. The complete Swarm historical
data set has been generated and validated using empirical models
(International Reference Ionosphere, and an empirical electric field
model), as well as ground-spacecraft conjunctions. Case studies and
statistical results reveal clear geophysical signatures in the new
product of light ions at low- and mid-latitudes and along-track ion
drift at high latitudes, and their response to space weather.
Title: Millennial-scale oscillations in the Kuroshio-Oyashio boundary
during MIS 19 based on the radiolarian record from the Chiba composite
section, central Japan
Authors: Itaki, Takuya; Utsuki, Sakura; Haneda, Yuki; Izumi, Kentaro;
Kubota, Yoshimi; Suganuma, Yusuke; Okada, Makoto
Bibcode: 2022PEPS....9....5I
Altcode:
Marine isotope stage (MIS) 19 is considered to be the best orbital
analog for the present interglacial. Consequently, clarifying
the climatic features of this period can provide us with insights
regarding a natural baseline for assessing future climate changes. A
high-resolution radiolarian record from 800 to 750 ka (MIS 20 to MIS 18)
was examined from the Chiba composite section (CbCS) of the Kokumoto
Formation, including the Global Boundary Stratotype Section and Point
for the lower-middle Pleistocene boundary on the Boso Peninsula on
the Pacific side of central Japan. Millennial-scale oscillations
in the Kuroshio warm and Oyashio cold currents were revealed by
the Tr index, which is estimated using a simple equation based on
radiolarian assemblages. The estimated Tr values ranged between 0.1
and 0.8 for MIS 18 through MIS 19, with minimum and maximum values
corresponding to values observed off present day Aomori (41°N) and the
Boso Peninsula (35°N), respectively. The observed patterns tended to
be synchronous with the total radiolarian abundance associated with
their production. Multiple maxima in radiolarian abundance occurred
during periods of the Oyashio expanded mode before 785 ka and during
periods of Kuroshio extension after 785 ka in MIS 19. Such increases
in radiolarian abundance with the Kuroshio extension during MIS 19 are
likely related to improvements in nutrient and photic environments with
the development of a two-layer structure along the Kuroshio-Oyashio
boundary zone. A similar pattern of millennial-scale climatic changes
was also recognized in a precipitation record from the Sulmona Basin
in central Italy, suggesting a close relationship with the CbCS record
as a result of a large-scale climate system similar to the Arctic
Oscillation in the northern hemisphere.
Title: Evolution of the geological structure and mechanical properties
due to the collision of multiple basement topographic highs in a
forearc accretionary wedge: insights from numerical simulations
Authors: Miyakawa, Ayumu; Noda, Atsushi; Koge, Hiroaki
Bibcode: 2022PEPS....9....1M
Altcode:
We propose a conceptual geological model for the collision of multiple
basement topographic highs (BTHs; e.g., seamounts, ridges, and horsts)
with a forearc accretionary wedge. Even though there are many BTHs on
an oceanic plate, there are few examples of modeling the collision of
multiple BTHs. We conducted numerical simulations using the discrete
element method to examine the effects of three BTH collisions with
forearcs. The typical geological structure associated with a BTH
collision was reproduced during the collision of the first BTH, and
multiple BTH collisions create a cycle of formation of BTH collisional
structures. Each BTH forces the basal décollement to move up to the
roof décollement, and the roof décollement becomes inactive after the
passage of the BTH, and then the décollement moves down to the base. As
the active décollement position changes, the sequences of underthrust
sediments and uplifted imbricate thrusts are sandwiched between the
décollements and incorporated into the wedge. At a low horizontal
compressive stress, a "shadow zone" is formed behind (i.e., seaward
of) the BTH. When the next BTH collides, the horizontal compressive
stress increases and tectonic compaction progresses, which reduce
the porosity in the underthrust sediments. Heterogeneous evolution
of the geological and porosity structure can generate a distinctive
pore pressure pattern. The underthrust sediments retain fluid in the
"shadow" of the BTH. Under the strong horizontal compressive stresses
associated with the next BTH collision, pore pressure increases along
with a rapid reduction of porosity in the underthrust sediments. The
distinctive structural features observed in our model are comparable to
the large faults in the Kumano transect of the Nankai Trough, Japan,
where a splay fault branches from the plate boundary and there are
old and active décollements. A low-velocity and high-pore-pressure
zone is located at the bottom of the accretionary wedge and in front
(i.e., landward) of the subducting ridge in the Kumano transect. This
suggests that strong horizontal compressive stresses associated with
the current BTH collision has increased the pore pressure within the
underthrust sediments associated with previous BTHs.
Title: Capability of airline jets as an observation platform for
noctilucent clouds at middle latitudes
Authors: Suzuki, Hidehiko; Matsumoto, Ayako; Dalin, Peter; Nakamura,
Yuriko; Ishii, Satoshi; Sakanoi, Kazuyo; Sakaguchi, Kaori; Takada,
Taku; Tsuda, Takuo T.; Hozumi, Yuta
Bibcode: 2022PEPS....9...11S
Altcode:
The exact occurrence frequency of noctilucent clouds (NLCs) in middle
latitudes is significant information because it is thought to be
sensitive to long-term atmospheric change. We conducted NLC observation
from airline jets in the Northern Hemisphere during the summer
2019 to evaluate the effectiveness of NLC observation from airborne
platforms. By cooperating with the Japanese airline All Nippon Airways
(ANA), imaging observations of NLCs were conducted on 13 flights from
Jun 8 to Jul 12. As a result of careful analysis, 8 of these 13 flights
were found to successfully detect NLCs from middle latitudes (lower than
55° N) during their cruising phase. Based on the results of these test
observations, it is shown that an airline jet is a powerful tool to
continuously monitor the occurrence frequency of NLCs at midlatitudes
which is generally difficult with a polar orbiting satellite due to
sparse sampling in both temporal and spatial domain. The advantages
and merits of NLC observation from jets over satellite observation
from a point of view of imaging geometry are also presented.
Title: The response of the hydrological cycle to temperature changes
in recent and distant climatic history
Authors: Pratap, Shailendra; Markonis, Yannis
Bibcode: 2022PEPS....9...30P
Altcode:
The relationship between the hydrological cycle and the temperature
is rather complex and of great importance to human socioeconomic
activities. The prevailing theory suggests that as temperature increases
the hydrological cycle is intensified. Practically, this means more
and heavier precipitation. However, the exact magnitude of hydrological
cycle response and its spatio-temporal characteristics is still under
investigation. Looking back in Earth's hydroclimatic history, it is
easy to find some periods where global temperature was substantially
different than present. Here, we examine some of these periods to
present the current knowledge about past hydrological cycle variability
(specifically precipitation), and its relationship to temperature. The
periods under investigation are the Mid-Miocene Climate Optimum, the
Eemian Interglacial Stage, the Last Glacial Maximum, the Heinrich and
Dansgaard-Oeschger Events, the Bølling-Allerød, the Younger Dryas,
the 8.2 ka event, the Medieval Climate Anomaly, and the Little Ice
Age. We report that the hypothesis that a warmer climate is a wetter
climate could be an oversimplification, because the response of water
cycle appears to be spatio-temporally heterogeneous.
Title: Back-transformation processes in high-pressure minerals:
implications for planetary collisions and diamond transportation
from the deep Earth
Authors: Kubo, Tomoaki; Kamura, Ko; Imamura, Masahiro; Tange,
Yoshinori; Higo, Yuji; Miyahara, Masaaki
Bibcode: 2022PEPS....9...21K
Altcode:
We conducted back-transformation experiments in ringwoodite,
bridgmanite, and lingunite at 0.47-8.1 GPa and 310-920 °C by in
situ X-ray observation method. Ringwoodite back-transformed to
olivine by grain-boundary nucleation and growth mechanism. The site
saturation occurred at the early stage under the conditions far from
the equilibrium boundary, and we observed the growth-controlled
back-transformation kinetics in ringwoodite. The growth kinetics
determined in the present study is largely different from that in the
previous study (Reynard et al. in Am Min 81:585-594, 1996), which may be
due to the effects of water. Bridgmanite did not directly back-transform
to the stable phase orthoenstatite at ~ 1-4 GPa, but first becomes
amorphous with increasing temperatures. We observed kinetics of the
orthoenstatite crystallization from amorphous bridgmanite that was
controlled by both nucleation and growth processes. The temperature
range in the amorphous state became narrow with increasing pressures,
and the direct back-transformation to high-P clinoenstatite without
amorphization eventually occurred at 8 GPa. Amorphization was also
observed in lingunite when increasing temperature at ~ 1.5 GPa;
however, the plagioclase crystallization proceeded before the complete
amorphization. The back-transformation in ringwoodite variedly occurs
in shocked meteorites depending on the degree of the post-shock
annealing, which can be reasonably interpreted based on the growth
kinetics. On the other hand, the presence of hydrous ringwoodite in
diamond inclusions cannot be explained without the help of residual
stress. The present study also indicates that complete amorphization
or the back-transformation to enstatite is unavoidable in bridgmanite
during the post-shock annealing. This is inconsistent with the presence
of crystalline bridgmanite in shocked meteorites, still requiring
further investigations of kinetic behaviors in shorter timescales.
Title: Time difference between the 1854 CE Ansei-Tokai and
Ansei-Nankai earthquakes estimated from distant tsunami waveforms
on the west coast of North America
Authors: Kusumoto, Satoshi; Imai, Kentaro; Hori, Takane
Bibcode: 2022PEPS....9....2K
Altcode:
We estimated the time difference between the 1854 CE Ansei-Tokai and
Ansei-Nankai earthquakes from tidal records of two tide gauge stations
(San Francisco and San Diego) on the west coast of North America. The
first signals of the Ansei-Tokai tsunami were apparent, whereas those
of the Ansei-Nankai tsunami were obscured by the later waves of the
Ansei-Tokai tsunami. Waveforms of the Ansei-Nankai tsunami simulated
with nonlinear dispersive wave theory by assuming an origin time of
07:00 GMT on 24 December arrived earlier than in the observations. The
normalized root mean square and the misfit between the simulated and
observed waveforms of the Ansei-Nankai tsunami showed a time difference
between them of approximately 0.4 h. This finding suggests that the
actual origin time of the Ansei-Nankai tsunami was approximately 07:24
GMT on 24 December. A previous study estimated the origin time of the
Ansei-Tokai tsunami to be about 00:30 GMT on 23 December. Thus, we
concluded that the time difference between the 1854 CE Ansei-Tokai and
Ansei-Nankai tsunamis was 30.9 h. Despite the significant difference
in the time resolution between the seasonal timekeeping system used
in Japan in 1854 and waveform digitization, our result is roughly in
agreement with historical descriptions of the tsunamis, suggesting
that such information can be effectively used to determine the origin
times of historical earthquakes.
Title: Aeromagnetic Mapping and Radioelement Influence on
Mineralogical Composition of Mesothermal Gold Deposit in Part of
Ilesha Schist Belt, Southwestern Nigeria
Authors: Olomo, Kazeem Oladimeji; Bayode, Sunday; Alagbe, Olufemi
Adigun; Olayanju, Gbenga Moses; Olaleye, Oluwatoyin Khadijat
Bibcode: 2022JAsGe..11..177O
Altcode:
No abstract at ADS
Title: Amplitude enhancement of short period GPS-TEC oscillations
over rainfall area
Authors: Iyemori, Toshihiko; Yamada, Akiyasu; Aoyama, Tadashi; Hozumi,
Kornyanat; Yokoyama, Yoshihiro; Odagi, Yoko; Sano, Yasuharu; Pangsapa,
Vijak; Jarupongsakul, Thanawat; Saito, Akinori; Iguchi, Masato
Bibcode: 2022EP&S...74...45I
Altcode:
Correlation between rainfall and short period GPS-TEC (total electron
content) variations are investigated by using the precipitation
data obtained on the ground and estimated from satellite observations
(JAXA/GSMaP) as a proxy of lower atmospheric wave activity. The GPS-TEC
data obtained at a tropical station, PHIM, in Phimai, Thailand, for
2014-2020, and the data obtained at a mid-latitude station, NAKG,
in Tokara Nakanoshima Island, Japan, for 2017-2019, are examined. A
statistical analysis of MEM (maximum entropy method) power spectral
density (PSD) in the period range from 50 to 1200 s over PHIM clearly
shows an enhancement in the cases of rainfall from that in no-rainfall
cases, in particular, on the dusk side. The enhancement is observed
both acoustic wave periods less than 5-6 min and internal gravity
wave periods more than 10 min. The enhancement after sunset could be
an effect of strong rainfall more frequent on the dusk side than that
in other local time, or it could suggest the importance of ionospheric
electron density profile change for the TEC variation. On the other
hand, the PSD does not show such clear enhancement over NAKG on the
dusk side, although it shows a small enhancement on both dayside and
night-side. A clear PSD bulge near the main vertical acoustic resonance
periods, i.e., around 275 s, appears in the average PSD profile of
the TEC at PHIM, which suggests that the resonance effect contribute
to some extent the PSD enhancement under rainy condition. An event
analysis also suggests the contribution of acoustic resonance to the
enhancement of the short period TEC variation. A complicated spatial
distribution of TEC oscillation over a rainfall area around PHIM,
where the TEC oscillations with various periods co-exist, is presented.
Title: Influence of hydrothermal recharge on the evolution of eruption
styles and hazards during the 2018-2019 activity at Kuchinoerabujima
Volcano, Japan
Authors: Minami, Yusuke; Matsumoto, Keiko; Geshi, Nobuo; Shinohara,
Hiroshi
Bibcode: 2022EP&S...74...21M
Altcode:
The activity of the 2018-2019 eruption of Kuchinoerabujima Volcano in
Japan changed from continuous ejection of ash-laden plumes between
October 21 and the middle of December, to intermittent explosive
activity accompanied by several pyroclastic density currents until
January 2019. To understand the behaviors of magma and hydrothermal
fluid that controlled the eruptive sequence, we carried out component
analysis, X-ray diffractometry, and leachate analysis for ash
samples. The proportion of non-altered volcanic ash particles is ~
15% in the earlier phase, then it decreased to less than 10% in the
later explosive phase. Accordingly, the mineral assemblage of the
volcanic ash samples changed from plagioclase-dominant to sulfate
minerals-dominant. Concentration of SO42− and
Cl/SO4 values of the ash-leachates decreased toward the
later activity. These results indicate that the proportion of fresh
volcanic rocks decreased and sulfuric acid fluid-derived sulfate
minerals increased toward the later activities. Consequently, the
2018-2019 eruption at Kuchinoerabujima Volcano changed from magmatic
activity to phreatomagmatic activity. Weak glowing of the crater was
observed during the magmatic activity, indicating the volcanic conduit
was hot enough to dry up the sub-volcanic hydrothermal system. The
following phreatomagmatic activity indicates that the hydrothermal
fluid recharged after the magmatic eruption phase. Recharge of the
hydrothermal fluid likely caused the variation of the eruption style,
and is a process that may control the evolution of hazards during future
eruption scenarios at similar active volcanoes in Japan and worldwide.
Title: From desert to monsoon: irreversible climatic transition at
36 Ma in southeastern Tibetan Plateau
Authors: Zheng, Hongbo; Yang, Qing; Cao, Shuo; Clift, Peter D.;
He, Mengying; Kano, Akihiro; Sakuma, Aki; Xu, Huan; Tada, Ryuji;
Jourdan, Fred
Bibcode: 2022PEPS....9...12Z
Altcode:
Although there is increasing evidence for wet, monsoonal conditions
in Southeast Asia during the late Eocene, it has not been clear when
this environment became established. Cenozoic sedimentary sequences
constrained by radiometrically dated igneous rocks from the Jianchuan
Basin in the southeast flank of Tibetan Plateau now provide a section
whose facies and climatic proxies determine this evolution. Semi-arid
conditions had dominated the region since Paleocene controlled by the
northern sub-tropical high pressure system, culminating in mid Eocene
when desert dunes developed. From 36 Ma, the basin began to accumulate
swamp sediments with coals, together with synchronous braided river
deposits and diversified pollen assemblages, indicating significant
increase in precipitation. This remarkable transition from dry to
wet conditions precedes the Eocene/Oligocene boundary at 34 Ma, thus
excluding general global cooling as the prime driver. We propose that
uplift of Tibetan Plateau might have reached a threshold elevation
by that time, operating through thermal and dynamic forcing, causing
the inception or significant intensification of monsoonal rains to
penetrate into this downwind locality.
Title: BI-LSTM Based Encoding and GAN for Text-to-Image Synthesis
Authors: Talasila, Vamsidhar; Narasingarao, M. R.
Bibcode: 2022SenIm..23...23T
Altcode:
Synthesizing images from text is to produce images with reliable
content as specified text depiction that is an extremely demanding
task with the most important problems like: content consistency and
visual realism. Owing to considerable progression of GAN, it is now
possible to produce images with good visual certainty. The translation
of text descriptions to images with higher content reliability, on the
other hand, is still a work in progress. This paper intends to frame
a novel text-to-image synthesis approach, which includes two major
phases namely; (1) Text to image encoding and (2) GAN. Initially,
during text to image encoding, cross modal feature alignment takes
place including text and image features. Consequently, BI-LSTM is
deployed to transfer the text embedding to feature vector. At second
stage, the image is synthesized based on the encoding. Consequently,
text feature group are given as input to GAN, which offers the final
synthesized images. Finally, the supremacy of developed approach is
examined via evaluation over extant techniques.
Title: Efficiency of earthquake forecast models based on earth tidal
correlation with background seismicity along the Tonga-Kermadec trench
Authors: Hirose, Fuyuki; Maeda, Kenji; Kamigaichi, Osamu
Bibcode: 2022EP&S...74...10H
Altcode:
The correlation between Earth's tides and background seismicity has
been suggested to become stronger before great earthquakes and weaker
after. However, previous studies have only retrospectively analyzed this
correlation after individual large earthquakes; it thus remains vague
(i) whether such variations might be expected preceding future large
earthquakes, and (ii) the strength of the tidal correlation during
interseismic periods. Therefore, we retrospectively investigated
whether significant temporal variations of the tidal correlation
precede large interplate earthquakes along the Tonga-Kermadec trench,
where Mw 7-class earthquakes frequently occurred from
1977 to 31 December 2020. We evaluated a forecast model based on
the temporal variations of the tidal correlation via Molchan's error
diagram, using the tidal correlation value itself as well as its rate
of change as threshold values. For Mw ≥ 7.0 earthquakes,
this model was as ineffective as random guessing. For Mw
≥ 6.5, 6.0, or 5.5 earthquakes, the forecast model performed better
than random guessing in some cases, but even the best forecast only had
a probability gain of about 1.7. Therefore, the practicality of this
model alone is poor, at least in this region. These results suggest
that changes of the tidal correlation are not reliable indicators of
large earthquakes along the Tonga-Kermadec trench.
Title: Rapid and quantitative uncertainty estimation of coseismic
slip distribution for large interplate earthquakes using real-time
GNSS data and its application to tsunami inundation prediction
Authors: Ohno, Keitaro; Ohta, Yusaku; Hino, Ryota; Koshimura, Shunichi;
Musa, Akihiro; Abe, Takashi; Kobayashi, Hiroaki
Bibcode: 2022EP&S...74...24O
Altcode:
This study proposes a new method for the uncertainty estimation
of coseismic slip distribution on the plate interface deduced from
real-time global navigation satellite system (GNSS) data and explores
its application for tsunami inundation prediction. Jointly developed by
the Geospatial Information Authority of Japan and Tohoku University,
REGARD (REal-time GEONET Analysis system for Rapid Deformation
monitoring) estimates coseismic fault models (a single rectangular
fault model and slip distribution model) in real time to support
tsunami prediction. The estimated results are adopted as part of the
Disaster Information System, which is used by the Cabinet Office of the
Government of Japan to assess tsunami inundation and damage. However,
the REGARD system currently struggles to estimate the quantitative
uncertainty of the estimated result, although the obtained result
should contain both observation and modeling errors caused by
the model settings. Understanding such quantitative uncertainties
based on the input data is essential for utilizing this resource
for disaster response. We developed an algorithm that estimates the
coseismic slip distribution and its uncertainties using Markov chain
Monte Carlo methods. We focused on the Nankai Trough of southwest
Japan, where megathrust earthquakes have repeatedly occurred, and
used simulation data to assume a Hoei-type earthquake. We divided
the 2951 rectangular subfaults on the plate interface and designed a
multistage sampling flow with stepwise perturbation groups. As a result,
we successfully estimated the slip distribution and its uncertainty
at the 95% confidence interval of the posterior probability density
function. Furthermore, we developed a new visualization procedure that
shows the risk of tsunami inundation and the probability on a map. Under
the algorithm, we regarded the Markov chain Monte Carlo samples as
individual fault models and clustered them using the k-means approach
to obtain different tsunami source scenarios. We then calculated the
parallel tsunami inundations and integrated the results on the map. This
map, which expresses the uncertainties of tsunami inundation caused by
uncertainties in the coseismic fault estimation, offers quantitative
and real time insights into possible worst-case scenarios.
Title: Deformation source revealed from leveling survey in Jigokudani
valley, Tateyama volcano, Japan
Authors: Hotta, Kohei; Kusumoto, Shigekazu; Takahashi, Hidenori;
Hayakawa, Yuichi S.
Bibcode: 2022EP&S...74...32H
Altcode:
We modeled the vertical deformation detected from a leveling survey
in Jigokudani valley, Tateyama volcano, central Japan. In Jigokudani
valley, uplift of 4 cm/year was previously detected during the
period from 2007 to 2010 by interferometric synthetic aperture radar
(InSAR). To confirm whether this inflation has continued to present
day, we have conducted leveling surveys in Jigokudani valley since
2015. Most bench marks showed a subsidence of up to 5.6 cm during the
4-year period from October 2016 to September 2020, while a bench mark
located at the center of the leveling route uniquely showed an uplift of
1.6 cm. We applied a dislocation source model to the deformation using
a grid search method. A crack with a length of 650 m, a width of 425 m,
a strike of N18° E and a dip of 67° is located at a depth of 50 m near
the center of Jigokudani valley (Koya jigoku and the new fumarolic area)
where higher activity has been observed recently. Closing of the crack
of 59 cm yields a volume decrease of 163,000 m3. The closing
direction of the crack is parallel to the line of old explosion craters
(Mikurigaike and Midorigaike ponds) and corresponds to the current
maximum compressive stress field in the region of the Hida Mountains,
including Tateyama volcano. The deformation source of the previous
period from 2007 to 2010 detected from InSAR was estimated to be at
a depth of 50 m and a gas chamber was correspondingly found in an
audio-frequency magnetotelluric (AMT) survey. The AMT survey also
revealed that thermal fluid is accumulating from a magma chamber and
the location of our crack is similar to uppermost part of the thermal
fluid path. During the period from 2015 to 2016, the crack opened
and the inflation stopped during the next 1 year period from 2016 to
2017. During the period from 2017 to 2020, the crack began closing,
probably because of the increase in emissions of volcanic fluid or gas
with the formation of a new crater at the western side of Jigokudani
valley during the period from 2017 to 2018.
Title: Correction: Two pulse intrusive events of the Pliocene
Tanigawa-dake granites revealed from zircon U-Pb dating
Authors: Minami, Saki; Nagata, Mitsuhiro; Sueoka, Shigeru; Fukuda,
Shoma; Kajita, Yuya; Ogita, Yasuhiro; Kagami, Saya; Yokoyama,
Tatsunori; Tagami, Takahiro
Bibcode: 2022EP&S...74..129M
Altcode:
No abstract at ADS
Title: Global polygons for terrain classification divided into
uniform slopes and basins
Authors: Iwahashi, Junko; Yamazaki, Dai
Bibcode: 2022PEPS....9...33I
Altcode:
Global terrain classification data have been used for various issues
related to topography such as the estimation of soil types and of
ground vulnerability to earthquakes and the creation of seismic
hazard maps. However, due to the resolution of digital elevation
models (DEMs), the terrain classification data from previous studies
could not discriminate small landforms such as plains at the bottom of
narrow valleys and small rises in plains. Owing to the greater regional
variation of small landforms, there is trade-off between DEMs of higher
resolution and the creation of global geomorphological legends. To
address this problem, we first merged regions with similar topographic
characteristics using slope gradients and HAND (height above the nearest
drainage) calculated by the 90-m-spatial-resolution DEMs interpolated
from the multi-error-removed improved-terrain DEM (MERIT DEM), and
united the polygons with the unit catchments of the MERIT-Basins
dataset, so that the polygons contain calculated terrain measurements
(slope gradient, HAND, surface texture, local convexity, sinks)
and noise types as attributes, as well as the ID number of the unit
catchment. In addition, we performed k-means clustering on the dataset
using slope gradient, HAND, and surface texture, which can be combined
with the dataset as a simple terrain classification. The clustering
results were prepared in 15 and 40 global uniform clusters and 15 and
40 clusters for each basin to understand the global appearance of the
terrain and provide zoning data for regional problem-solving. The 15
clusters were prepared to observe the outline of the terrain without
any processing, whereas the 40 clusters were prepared to group and
reclassify the polygons to create zoning data for each region. This
dataset showed improvements in terms of capturing the small rises in
plains compared to the authors' previous global terrain classification
data. This dataset can be used as a proxy and is expected to contribute
to modeling and estimation in various applications that are known to
be related to topography. The datasets of this article are available at
[https://gisstar.gsi.go.jp/terrain2021/].
Title: Enhancement of equatorial OI(1D) emissions at midnight
Authors: Chiang, Chih-Yu; Chang, Tzu-Fang; Tam, Sunny W. Y.
Bibcode: 2022EP&S...74...39C
Altcode:
A number of recent studies have highlighted observational evidence
of midnight brightness of the 630.0 nm nightglow, which is usually
related to the midnight temperature maximum (MTM) effect. In this
report, MTM-related enhancements of the 630.0 nm airglow around
midnight are observed through images from the ISUAL/FORMOSAT-2
satellite. The data statistics are classified into three specific
types (no-peak, single-peaked, and double-peaked events) and separated
into the different seasons. In order to understand the influences of
geomagnetic conditions, the statistical analyses are also separated
into two regions. One is collected from the region whose geomagnetic
equator is north of the geographic equator, and the other is collected
from the region whose geomagnetic equator is south of the geographic
equator. The results show that the single-peaked brightness often
appears between the geographic equator and the geomagnetic equator. The
double-peaked brightness appears simultaneously on the two sides of the
region sandwiched by the two equators. Coupled with the summer-to-winter
neutral wind generated by seasonal effects, one side of brightness
could be enhanced or disappear due to the plasma moving along the
field line. The no-peak events mainly occur close to May-July, which
may be due to the effect of ionospheric annual anomalies. Overall,
the statistical results for the occurrence rate show strong seasonal
variations with different cycles at different longitudinal regions
for all three types of events.
Title: Preliminary study on hydrological angular momentum determined
from CMIP6 historical simulations
Authors: Nastula, Jolanta; Śliwińska, Justyna; Kur, Tomasz; Wińska,
Małgorzata; Partyka, Aleksander
Bibcode: 2022EP&S...74...84N
Altcode:
Polar motion (PM) is an essential parameter needed to transform
coordinates between celestial and terrestrial reference frames, thus
playing a crucial role in precise positioning and navigation. The role
of hydrological signals in PM excitation is not yet fully understood,
which is largely because of the lack of agreement between estimates
of hydrological angular momentum (HAM) computed from different data
sources. In this study, we used data obtained from the latest, sixth
phase of the Coupled Model Intercomparison Project (CMIP6) to assess
the impact of the continental hydrosphere on PM excitation. To do so,
we exploited soil moisture and snow water variables obtained from
historical simulations of CMIP6 to estimate climate-based HAM. The
HAM series were computed, then we analysed their variability in terms
of trends, seasonal and non-seasonal oscillations. An important part
of this study is the validation of HAM estimates based on comparison
with the hydrological signal in geodetically observed PM excitation
(geodetic residuals, GAO). In addition, HAM series based on climate
models were compared with those determined from global gravimetric data
provided by the Gravity Recovery and Climate Experiment (GRACE) mission,
and from the Land Surface Discharge Model (LSDM). This study also aimed
to identify the most appropriate CMIP6 models for interpretation of PM
variations. Overall, the correspondence between GAO and HAM received
from CMIP6 was lower than the previously obtained consistency with GRACE
results, and the level of agreement was dependent on the oscillation
considered and the model used. However, it may be possible to identify
several CMIP6 models from among the almost 100 available that provides
a HAM series more compatible with GAO than HAM from GRACE or LSDM,
especially in annual oscillations. The GISS-E2-1-G_historical_r10i1p1f1
model was found to provide the highest consistency with GAO for
annual prograde amplitudes, GFDL-CM4_historical_r1i1p1f1 for annual
retrograde amplitudes, BCC-ESM1_historical_r3i1p1f1 for the annual
prograde phase, and MIROC-ES2L_historical_r2i1p1f2 for the annual
retrograde phase. Because of their length, the CMIP6 data allow for
analysis of the past and future changes in HAM from 1850 to 2100,
which is of particular importance in the exploration of the impact of
climate change on PM excitation.
Title: Effect of heating-cooling imbalance on slow mode with
time-dependent background temperature
Authors: Kumar, Anil; Kumar, Nagendra
Bibcode: 2022JApA...43...40K
Altcode:
We study the effect of heating-cooling imbalance on slow
magnetohydrodynamic waves in solar coronal loops with time-varying
background temperature in the presence of thermal conduction, optically
thin radiation and heating. The MHD equations governing the plasma
motion are solved numerically to examine the effects of heating-cooling
imbalance on slow waves in the presence of thermal conduction and
radiation. It is found that the amplitude of perturbed velocity
decreases in the case of increasing background temperature, whereas
the perturbed velocity amplitude increases in the case of decaying
background temperature. The heating-cooling imbalance influences the
damping of slow waves. Damping of waves is stronger for characteristic
time τ =1000 s than the damping for τ =3000 s in both time-varying
background temperature plasmas.
Title: Comparison of the tidal signatures in sporadic E and vertical
ion convergence rate, using FORMOSAT-3/COSMIC radio occultation
observations and GAIA model
Authors: Sobhkhiz-Miandehi, Sahar; Yamazaki, Yosuke; Arras, Christina;
Miyoshi, Yasunobu; Shinagawa, Hiroyuki
Bibcode: 2022EP&S...74...88S
Altcode:
Sporadic E or Es is a transient phenomenon where thin layers of
enhanced electron density appear in the ionospheric E region (90-120
km altitude). The neutral wind shear caused by atmospheric tides can
lead ions to converge vertically at E-region heights and form the Es
layer. This research aims to determine the role of atmospheric solar
and lunar tides in Es occurrence. For this purpose, radio occultation
data of FORMOSAT-3/COSMIC have been used, which provide complete
global coverage of Es events. Moreover, GAIA model simulations have
been employed to evaluate the vertical ion convergence induced by
solar tides. The results show both migrating and non-migrating solar
tidal signatures and the semidiurnal migrating lunar tidal signature
mainly in low and mid-latitude Es occurrence. The seasonal variation
of the migrating solar tidal components of Es is in good agreement
with those in the vertical ion convergence derived from GAIA at higher
altitudes. Furthermore, some non-migrating components of solar tides,
including semidiurnal westward wavenumbers 1 and 3 and diurnal eastward
wavenumbers 2 and 3, also significantly affect the Es occurrence rate.
Title: Slow slip events following the afterslip of the 2002
Mw 7.1 Hualien offshore earthquake, Taiwan
Authors: Chen, Sean Kuanhsiang; Wu, Yih-Min; Chan, Yu-Chang
Bibcode: 2022EP&S...74...63C
Altcode:
Geodetic evidence for slow slip recurrence changed by stress
perturbations was rare, especially from afterslip following a
nearby large earthquake. The first observed slow slip events in the
southernmost Ryukyu subduction had occurred in 2005, 2009, and 2015
following the nearby 2002 March 31 Mw 7.1 Hualien offshore
earthquake. To investigate whether the Mw 7.1 earthquake
had influenced the occurrence times of the slow slip, we calculated
the coseismic slip distribution and afterslip distribution using the
surface displacements from onshore Global Navigation Satellite System
observations. The stress perturbation on the slow-slip regions caused by
the coseismic slip was quantified using the Coulomb failure criteria. We
also examined the aftershock distribution and the evolution with time
to clarify the stress perturbations from the afterslip offshore. Our
results show that the primary afterslip distribution may have overlapped
the 2009 and 2015 slow-slip patch at the downdip of the earthquake. The
coseismic stress perturbation may have influenced the SSEs area
directly by a Coulomb stress increase of probably 0.10 MPa. However,
the 2005 SSE patch in the updip depths had only a little coseismic
slip and afterslip with the Coulomb stress increase of approximately
0.06 MPa. We find that most of the aftershocks had occurred in the
2009 and 2015 slow-slip region that evolved into a typical aftershock
sequence at least 2.5 years after the earthquake. The surface geodetic
displacements reveal that the afterslip may have lasted longer than
4.5 years after the earthquake. The evidence for the afterslip proves
that the 2009 and 2015 slow-slip patch was influenced by the afterslip
directly for years. We suggest that the ongoing afterslip may have
modulated the coseismic stress perturbation. It may explain the delay
of the 2009 slow slip occurrence compared with the recurrence interval
between the 2009 and 2015 slow slip events.
Title: Global distribution of magnetic ripples and electron density
fluctuations as observed by the Swarm satellites on the dayside and
their relation to the rainfall estimated by the GSMaP
Authors: Iyemori, Toshihiko; Aoyama, Tadashi; Yokoyama, Yoshihiro
Bibcode: 2022EP&S...74...38I
Altcode:
In mid- and low-latitude ionospheric F-region on the dayside, magnetic
field and electron density (Ne) fluctuations with amplitude smaller than
a few nT and 1-2% of Ne, respectively, are commonly observed. Their
spatial scale along satellite orbit is around 70-250 km. It is
presumed that they are generated by the waves propagated from lower
atmosphere. However, the mode of waves (acoustic wave or internal
gravity wave) and their source are not yet clear. Among the possible
sources, cumulus convection and/or associated rainfall are considered
to be the strong candidates for the atmospheric wave generation. We
use the rainfall estimated by the hourly Global Satellite Mapping of
Precipitation (JAXA/GSMaP) as a proxy of lower atmospheric disturbance
as the wave source, and compare the rainfall with the amplitude
of magnetic fluctuations (magnetic ripples) and electron density
fluctuations observed by the Swarm satellites. The data from April 2014
to July 2020 are used. The global distribution of rainfall estimated by
the GSMaP and its seasonal variation have similarities with amplitude
distribution of magnetic ripples and electron density fluctuations on
the dayside. We calculate the ratio of their magnitude, i.e., amplitude
of magnetic ripples or electron density fluctuations in rainfall cases
to those in no-rainfall cases. Although the longitudinally averaged
ratio is not very large but around 1.1-1.2 in ± 10- ± 50° Apex
latitudes, it is clearly larger than 1.0. The ratio increases when the
intensity of rainfall (mm/h) increases. These results indicate that a
cumulous convection which causes rainfall is one of the main sources
of atmospheric waves that produce magnetic ripples and electron density
fluctuations commonly observed in the dayside ionosphere. Anticipating
acoustic waves as the driver of magnetic ripples and electron density
variations, a difference in the generation mechanism of electron density
fluctuations from that of magnetic ripples is suggested even if their
sources are common.
Title: Ocean-wave phenomenon around Japan due to the 2022 Tonga
eruption observed by the wide and dense ocean-bottom pressure gauge
networks
Authors: Kubo, Hisahiko; Kubota, Tatsuya; Suzuki, Wataru; Aoi, Shin;
Sandanbata, Osamu; Chikasada, Naotaka; Ueda, Hideki
Bibcode: 2022EP&S...74..104K
Altcode:
Ocean-bottom pressure gauges of wide and dense ocean-bottom observation
networks around Japan, S-net and DONET, observed ocean waves caused
by the Tonga eruption that started at approximately 13:00 JST (UTC +
0900) on January 15, 2022. We scrutinized the waveform records of the
arriving ocean waves to evaluate their nature and found two significant
disturbances between 20:00 and 21:00 and after 22:00. The first
disturbance with a positive-polarity pulse dominated by long-period
components (1000-3000 s) arrived at S-net and DONET stations between
20:00 and 21:00 from the southeast, corresponding to the direction
of the short great circle between Tonga and Japan. This arrival was
much earlier than expected for a direct tsunami from the volcano and
can be explained by assuming that the waves propagated along the short
great circle path at a velocity of approximately 300 m/s. After 22:00,
significant phases dominated by relatively shorter period components
(< 1000 s) arrived from the southeast direction in both observation
networks. In DONET, another phase arrived from the south-southeast
direction at approximately 23:30 with shorter period components
(approximately 500 s). Most of the near-trench S-net stations
recorded the peak amplitude during the first disturbance, whereas
the near-coast S-net stations and DONET stations observed their peak
after 22:00. The amplitudes of ocean-bottom pressure changes in both
networks increased as the water depth decreases. This amplification
behavior differed between the first and second disturbances, which is
attributed to the differences in the natures of the arriving ocean
and air waves. This study also found several arrivals of air-wave
disturbances to be correlated with the ocean-wave phases, which implies
that multiple disturbances of ocean-bottom pressures were generated
by the interactions of several disturbances of air waves following
the 2022 Tonga eruption with ocean waves.
Title: Inertial effects due to eruption-induced atmospheric
disturbances identified by superconducting gravimeter observations
at Matsushiro, Japan
Authors: Imanishi, Yuichi
Bibcode: 2022EP&S...74...54I
Altcode:
The violent eruption of Hunga Tonga-Hunga Ha'apai volcano on January
15, 2022 induced strong atmospheric disturbances, which traveled around
the world as atmospheric Lamb waves. When this wave passed through the
superconducting gravimeter station at Matsushiro, Japan, a large signal
of gravity changes was recorded. Also, barometers installed around
Matsushiro recorded wave trains of pressure changes. Analysis of the
barometer data revealed that the atmospheric disturbances traveled as
plane waves. Applying the theory of atmospheric loading for traveling
plane waves, the observed gravity changes were well reproduced by a
sum of three components of atmospheric loading, namely, Newtonian,
free-air and inertial effects. In particular, the inertial effect of
atmospheric loading, which is rarely observed, was clearly identified
in the gravity data. From the theoretical modeling, an estimate of
rigidity in the shallow region of the Earth was also obtained.
Title: On the use of ELF/VLF emissions triggered by HAARP to simulate
PLHR and to study associated MLR events
Authors: Parrot, Michel; Němec, Frantisěk; Cohen, Morris B.;
Gołkowski, Mark
Bibcode: 2022EP&S...74....4P
Altcode:
A spectrogram of Power Line Harmonic Radiation (PLHR) consists of a
set of lines with frequency spacing corresponding exactly to 50 or 60
Hz. It is distinct from a spectrogram of Magnetospheric Line Radiation
(MLR) where the lines are not equidistant and drift in frequency. PLHR
and MLR propagate in the ionosphere and the magnetosphere and are
recorded by ground experiments and satellites. If the source of PLHR
is evident, the origin of the MLR is still under debate and the purpose
of this paper is to understand how MLR lines are formed. The ELF waves
triggered by High-frequency Active Auroral Research Program (HAARP)
in the ionosphere are used to simulate lines (pulses of different
lengths and different frequencies). Several receivers are utilized
to survey the propagation of these pulses. The resulting waves are
simultaneously recorded by ground-based experiments close to HAARP in
Alaska, and by the low-altitude satellite DEMETER either above HAARP
or its magnetically conjugate point. Six cases are presented which show
that 2-hop echoes (pulses going back and forth in the magnetosphere) are
very often observed. The pulses emitted by HAARP return in the Northern
hemisphere with a time delay. A detailed spectral analysis shows that
sidebands can be triggered and create elements with superposed frequency
lines which drift in frequency during the propagation. These elements
acting like quasi-periodic emissions are subjected to equatorial
amplification and can trigger hooks and falling tones. At the end all
these known physical processes lead to the formation of the observed
MLR by HAARP pulses. It is shown that there is a tendency for the MLR
frequencies of occurrence to be around 2 kHz although the exciting
waves have been emitted at lower and higher frequencies.
Title: Upper and lower plane bed definitions revised
Authors: Ohata, Koji; Naruse, Hajime; Izumi, Norihiro
Bibcode: 2022PEPS....9...23O
Altcode:
Sedimentary structures in ancient deposits are clues to reconstruct
past geohazards. While parallel lamination formed by plane beds
is one of the most common sedimentary structures in event deposits
such as turbidites, the formative conditions for plane beds remain
unclear. In the literature, two types of plane beds (upper and lower
plane beds) exist and are supposed to develop under different shear
stresses, particle sizes, and flow regimes. Here, we present new phase
diagrams based on the compilation of existing data regarding formative
hydraulic conditions for plane beds to clarify the formation processes
associated with the two types of plane beds. The diagrams indicated
that the data form two separate populations and the gap between them
corresponds to the threshold condition of the particle entrainment
into suspension. Lower plane beds form when sediment particles move
only as bed load. This phase space can be discerned from fine sand to
gravel and differs from the conventional view in which the formation
of the lower plane bed is limited to grain sizes above 0.7 mm. In
addition, our phase diagrams suggest that upper plane beds appear under
conditions of the active suspended load. Our analyses demonstrate that
the suspended load contributes to the formation of plane beds, whereas
other mechanisms can also produce fine-grained plane beds in flows with
low bed shear stress. Thus, the results of this study suggest that the
existing interpretations on fine-grained parallel lamination such as
Bouma's Td division need to be reconsidered. The bedform
phase diagrams newly established in this study will be useful for
estimating the flow conditions from the geologic records of event beds.
Title: Effects of snow manipulation on larch trees in the taiga
forest ecosystem in northeastern Siberia
Authors: Shakhmatov, Ruslan; Hashiguchi, Shuhei; Maximov, Trofim C.;
Sugimoto, Atsuko
Bibcode: 2022PEPS....9....3S
Altcode:
Changes in winter precipitation (snow) may greatly affect vegetation
by altering hydrological and biochemical processes. To understand the
effects of changing snow cover depth and melt timing on the taiga forest
ecosystem, a snow manipulation experiment was conducted in December 2015
at the Spasskaya Pad experimental larch forest in Eastern Siberia, which
is characterized by a continental dry climate with extreme cold winters
and hot summers. Variables including soil temperature and moisture,
oxygen and hydrogen isotope ratios of soil moisture and stem water,
foliar nitrogen and carbon contents and their isotopes, phenology,
and soil inorganic nitrogen were observed at snow removal (SNOW−),
snow addition (SNOW+), and CONTROL plots. After snow manipulation, the
soil temperature at the SNOW− plot decreased significantly compared to
the CONTROL and SNOW+ plots. At SNOW− plot, snowmelt was earlier and
soil temperature was higher than at other plots during spring because
of low soil moisture caused by less snowmelt water. Despite the earlier
snowmelt and higher soil temperature in the SNOW− plot in the early
growing season, needle elongation was delayed. Leaf chemistry also
differed between the CONTROL and SNOW− plots. The needle nitrogen
content in the SNOW− plot was lower in the middle of July, whereas
no difference was observed among the three plots in August. The
soil inorganic nitrogen content of each plot corresponded to these
results. The amount of soil ammonium was lower in the SNOW− plot
than in the other plots at the end of July, however, once production
started in August, the amount of soil ammonium in the three plots was
comparable. Extremely low soil temperatures in winter and freeze-thaw
cycles in spring and dry soil condition in spring and early summer at
the SNOW− plot may have influenced the phenology and production of
soil inorganic nitrogen.
Title: Fabrication of dense albite aggregates by hot pressing
Authors: Shigematsu, Norio; Zhou, You; Hyuga, Hideki; Yoshizawa,
Yu-ichi; Kido, Masanori
Bibcode: 2022PEPS....9...34S
Altcode:
Synthetic rocks are used in laboratories to measure the physical
and chemical properties of Earth's constituent minerals in order
to understand Earth's interior. To understand the phenomena in the
middle and upper crust, dense aggregates of Na-rich plagioclase
are necessary. Therefore, we explored a method of fabricating dense
aggregates of albite with low porosities, homogeneous microstructures,
the absence of melt and sample sizes larger than a cubic centimetre
using hot pressing by solid-state sintering. We conducted multiple
experiments in which we varied the particle sizes, the agglomerations
of powder, the method of forming, the sintering temperature, and
the pressure and duration of the hot pressing. Two particle size
fractions of powder, less than two micrometres and less than a few
hundred nanometres, were prepared by pulverisation and decantation
of natural albite powder. Because fine-grained albite powder seems
to agglomerate easily, a technique to dry and disperse the powder
was also developed. Hot pressing was carried out at temperatures of
1000−1150 °C and pressures of 40−120 MPa. The following were
found to be important in obtaining dense aggregates of albite: (1)
powders with a particle size less than a few hundred nanometres; (2)
powders are adequately dispersed; and (3) preparation of green bodies
by slip casting, which makes hot pressing efficient. A dense albite
aggregate can then be fabricated using hot pressing at a temperature
of 1080 °C and pressure of 100 MPa by solid-state sintering.
Title: Derived precipitable water vapour from GNSS and radiosonde
data using time series and spatial least-square
Authors: Abdelfatah, M. A.; Elhaty, N. M.; Mousa, A. E.; El-Fiky, G. S.
Bibcode: 2022JAsGe..11..113A
Altcode:
No abstract at ADS
Title: Low-energy cosmic rays: regulators of the dense interstellar
medium
Authors: Gabici, Stefano
Bibcode: 2022A&ARv..30....4G
Altcode:
Low-energy cosmic rays (up to the GeV energy domain) play a crucial role
in the physics and chemistry of the densest phase of the interstellar
medium. Unlike interstellar ionising radiation, they can penetrate
large column densities of gas, and reach molecular cloud cores. By
maintaining there a small but not negligible gas ionisation fraction,
they dictate the coupling between the plasma and the magnetic field,
which in turn affects the dynamical evolution of clouds and impacts on
the process of star and planet formation. The cosmic-ray ionisation
of molecular hydrogen in interstellar clouds also drives the rich
interstellar chemistry revealed by observations of spectral lines
in a broad region of the electromagnetic spectrum, spanning from the
submillimetre to the visual band. Some recent developments in various
branches of astrophysics provide us with an unprecedented view on
low-energy cosmic rays. Accurate measurements and constraints on
the intensity of such particles are now available both for the very
local interstellar medium and for distant interstellar clouds. The
interpretation of these recent data is currently debated, and the
emerging picture calls for a reassessment of the scenario invoked to
describe the origin and/or the transport of low-energy cosmic rays in
the Galaxy.
Title: Quasi-stationary sequences of hyper-massive neutron stars
with exotic equations of state
Authors: Khadkikar, Sanika; Mangat, Chatrik Singh; Banik, Sarmistha
Bibcode: 2022JApA...43...57K
Altcode: 2022arXiv220401778K
In this work, we study the effect of differential rotation, finite
temperature and strangeness on the quasi-stationary sequences of
hyper-massive neutron stars. We generate constant rest-mass sequences
of differentially rotating and uniformly rotating stars. The nucleonic
matter relevant to the star interior is described within the framework
of relativistic mean field model with the DD2 parameter set. We also
consider the strange Λ hyperons using the BHBΛ ϕ equation of state
(EoS). Additionally, we probe the behaviour of neutron stars (NS)
with these compositions at different temperatures. We report that the
addition of hyperons to the EoS, produces a significant boost to the
spin-up phenomenon. Moreover, increasing the temperature can make the
spin-up more robust. We also study the impact of strangeness and thermal
effects on the T/W instability. Finally, we analyse the equilibrium
sequences of a NS following a stable transition from differential
rotation to uniform rotation. During this transition, the decrease in
frequency relative to angular momentum loss is significantly smaller
for EoS containing hyperons, compared to nucleonic EoS.
Title: Magnetohydrodynamic turbulence: Chandrasekhar's contributions
and beyond
Authors: Verma, Mahendra K.
Bibcode: 2022JApA...43...58V
Altcode: 2022arXiv220412799V
In the period of 1948-1955, Chandrasekhar wrote four papers on
magnetohydrodynamic (MHD) turbulence, which are the first set of papers
in that area. The field moved on after following these pioneering
efforts. In this paper, important works of MHD turbulence are briefly
described, starting from those by Chandrasekhar.
Title: Development of a detection method for short-term slow slip
events using GNSS data and its application to the Nankai subduction
zone
Authors: Okada, Yutaro; Nishimura, Takuya; Tabei, Takao; Matsushima,
Takeshi; Hirose, Hitoshi
Bibcode: 2022EP&S...74...18O
Altcode:
Using global navigation satellite system (GNSS) data to detect
millimeter-order signals of short-term slow slip events (S-SSEs) and to
estimate their source parameters, especially duration, is challenging
because of low signal-to-noise ratio. Although the duration of S-SSEs
in the Nankai subduction zone has been estimated using tiltmeters,
its regional variation has never been quantitatively studied. We
developed an S-SSE detection method to estimate both the fault model
and duration with their errors based on the detection methods developed
by previous studies and applied it to a 23-year period of GNSS data in
the Nankai subduction zone. We extracted S-SSE signals by calculating
correlation coefficients between the GNSS time series and a synthetic
template representing the time evolution of an S-SSE and by computing
the average of correlation coefficients weighted by the predicted S-SSE
signals. We enhanced the signals for duration estimation by stacking
GNSS time series weighted by displacements calculated from the estimated
fault model. By applying the developed method, we detected 284 S-SSEs
from 1997 to 2020 in the Nankai subduction zone from Tokai to Kyushu
and discussed their regional characteristics. The results include some
newly detected S-SSEs, including events accompanying very low-frequency
earthquakes and repeating earthquakes in offshore Kyushu. Our study
provides the first geodetic evidence for synchronization of S-SSEs
and other seismic phenomena in offshore Kyushu. We estimated the
cumulative slip and duration, and their error carefully. We also
estimated the average slip rate by dividing the cumulative slip by the
cumulative duration. This study clarified that the average slip rate in
western Shikoku was approximately twice as that in eastern Shikoku and
Kyushu. These regional differences were statistically significant at the
95% confidence interval. Multiple factors can influence the regional
characteristics of S-SSEs, and we speculate that the subducting plate
interface geometry is one of the dominant factors.
Title: Long-duration seismicity and their relation to Copahue
volcano unrest
Authors: Melchor, Ivan; Almendros, Javier; Hantusch, Marcia; Samsonov,
Sergey; Derauw, Dominique; Martínez, Enzo; Caselli, Alberto
Bibcode: 2022EP&S...74....3M
Altcode:
Understanding seismic tremor wavefields can shed light on the
complex functioning of a volcanic system and, thus, improve volcano
monitoring systems. Usually, several seismic stations are required
to detect, characterize, and locate volcanic tremors, which can be
difficult in remote areas or low-income countries. In these cases,
alternative techniques have to be used. Here, we apply a data-reduction
approach based on the analysis of three-component seismic data from
two co-located stations operating in different times to detect and
analyze long-duration tremors. We characterize the spectral content and
the polarization of 355 long-duration tremors recorded by a seismic
sensor located 9.5 km SE from the active vent of Copahue volcano in
the period 2012-2016 and 2018-2019. We classified them as narrow- (NB)
and broad-band (BB) tremors according to their spectral content. Several
parameters describe the characteristic peaks composing each NB episode:
polarization degree, rectilinearity, horizontal azimuth, vertical
incidence. Moreover, we propose two coefficients CP
and CL for describing to what extent the wavefield is
polarized. For BB episodes, we extend these attributes and express
them as a function of frequency. We compare the occurrence of NB and BB
episodes with the volcanic activity (including the level of the crater
lake, deformation, temperature, and explosive activity) to get insights
into their mechanisms. This comparison suggests that the wavefield of
NB tremors becomes more linearly polarized during eruptive episodes,
but does not provide any specific relationship between the tremor
frequency and volcanic activity. On the other hand, BB tremors show a
seasonal behavior that would be related to the activity of the shallow
hydrothermal system.
Title: Tsunami deposits associated with the 1983 Nihonkai-Chubu
earthquake tsunami in coastal forests near Happo Town, Akita
Prefecture, Japan
Authors: Chiba, Takashi; Nishimura, Yuichi
Bibcode: 2022EP&S...74..133C
Altcode:
On 26 May 1983 the Nihonkai-Chubu earthquake occurred off the western
coast of Noshiro City, Akita Prefecture, Japan. The tsunami associated
with this earthquake caused widespread damage to the northeastern
coastal region of the Sea of Japan, including Akita Prefecture, and left
behind sand and mud deposits. These deposits were first described in
the 1990s, but have not been studied further. During December 2019 and
January 2020, we conducted geological surveys to investigate post-1948
soil thinning in the pine-based coastal protective forests planted
near Happo Town. A sand layer that thinned inland was observed in the
soil at depths greater than 10 cm. Because the sand layer contained
well-preserved fossil brackish-marine diatoms and exhibited a high
bulk density, it is likely that the sand was transported inland from
the coast. The sand layer was distributed from the coast to 150-270
m inland, but only within the coastal protective forest. By reference
to historical records, we concluded that this sand layer was deposited
by the 1983 tsunami, because this region could not have been reached
by any event other than the tsunami produced by the Nihonkai-Chubu
earthquake. We also observed another sand layer above the tsunami
deposits, which may have been formed by Typhoon 9119 on 28 September
1991.
Title: Two-impulse transfer to multi-revolution halo orbits in the
Earth-Moon elliptic restricted three body problem framework
Authors: Neelakantan, Rithwik; Ramanan, R. V.
Bibcode: 2022JApA...43...50N
Altcode:
For the design of transfer trajectories in the Earth-Moon system, the
manifolds theory is popularly used in the existing literature. Because
the manifolds in the Earth-Moon system do not pass close to the Earth,
the transfers leveraging manifolds theory involves a bridge maneuver
that transfers the space vehicle from the trans-halo trajectory to the
stable manifold originating from the halo orbit. The transfer involves
two segments, and the bridge impulse makes the number of velocity
impulses three wherein, however, the third one is a very small one for
halo orbit insertion. Alternately, a direct technique that generates
two-impulse transfer trajectories to multi-revolution (MR) halo orbits
around Lagrangian point L1 in the Earth-Moon system under
elliptic restricted three body problem framework is proposed. Unlike
in the other direct transfer techniques, which divide the transfer
trajectory into multiple segments, the proposed technique designs the
transfer trajectory in a single segment. In the proposed technique,
the first maneuver injects the space vehicle directly into the single
segment transfer trajectory from an Earth parking orbit and the space
vehicle reaches the MR halo orbit. The second maneuver inserts the space
vehicle into the MR halo orbit. The location of insertion into the MR
halo orbit and the components of the insertion velocity are treated as
unknowns and obtained using differential evolution, an evolutionary
optimization technique. The optimal solutions indicate that there
exist trajectories with lower cost and for significantly lower time
of flight than those reported in the literature for similar problems.
Title: Dispersive features of electrostatic waves in bounded quantum
plasma under the effect of ionization
Authors: Ashish, Singh, Sukhmander
Bibcode: 2022JApA...43...59A
Altcode:
Bounded plasma occur in waveguide of nanodevices with dielectric
boundaries and the dimension of nanodevices control the frequency of
oscillation and particle acceleration. A system with cylindrical bounded
quantum plasma is used to study the electrostatic wave instability in
the presence of magnetic field. Bohm potential, exchange-correlation
potential and Fermi pressure significantly affect the characteristic
frequency of oscillation of particle in bounded plasma. Using quantum
hydrodynamic model, basic equations of cylindrical bounded quantum
plasma are constructed and linearized under the effect of ionization
rate. Dispersion relation for growing waves is obtained, which shows
dependence on ionization rate, magnetic field, number density, wave
vector and geometry of cylindrical waveguide. We investigated that
growth rate increases with magnetic field, ionization rate, number
density and poles of Bessel's function, whereas it decreases with wave
vector and radius of waveguide. The present investigation is performed
on the basis of numerical parameters of astrophysical plasma.
Title: Seismicity distribution in the Tonankai and Nankai seismogenic
zones and its spatiotemporal relationship with interplate coupling
and slow earthquakes
Authors: Yamamoto, Yojiro; Yada, Shuichiro; Ariyoshi, Keisuke; Hori,
Takane; Takahashi, Narumi
Bibcode: 2022PEPS....9...32Y
Altcode:
We conducted seismic tomography to estimate the seismic velocity
structure and to evaluate the spatiotemporal distribution of interplate
earthquakes of the Kii Peninsula, central Honshu, Japan, where the
Tonankai and Nankai megathrusts are located. Microearthquakes were
quantitatively detected by using the data from a cable-type seafloor
seismic observation network, completed in 2015. Our velocity model was
consistent with the previous 2-D active-source surveys, which reported
the areal extent of key structures: a high-velocity zone beneath Cape
Shionomisaki, a subducted seamount off Cape Muroto, and the subducted
Paleo-Zenith Ridge. The absence of any other subducted seamount with the
same or larger spatial scale, than the identified key structures, was
confirmed. Our velocity model also revealed that there was not a simple
relationship between areas of large coseismic slip or strong interplate
coupling and areas of high velocity in the overriding plate. Relocated
hypocenters widely ranged from the upper plate to within the slab,
while the most active region was attributed to the oceanic crust in
the aftershock region of 2004 off-Kii earthquake. Compared with the
results from the land-based observation network, the accuracy of the
focal depth estimation was substantially improved. Furthermore, we
identified the seismic activity in the vicinity of the plate boundary
and determined 14 locations for interplate seismicity areas. They were
primarily distributed in the range of seismogenic zone temperature
(150-350 °C) along the plate boundary and were located outside of the
strong interplate coupling zone. Several active areas of interplate
earthquakes exhibited clustered activity during the periods of slow-slip
events, observed and accompanied with shallow very-low-frequency
earthquakes. Thus, regular interplate microearthquakes became active
at the plate boundary in the conjunction with slow slip. In summary,
as regular earthquakes provide a more accurate source location than
slow earthquakes and can detect events of smaller magnitude, monitoring
such interplate earthquakes may reveal spatiotemporal variations in
the stick-slip conditions on the plate boundary.
Title: Impact of stratospheric ozone on the subseasonal prediction
in the southern hemisphere spring
Authors: Oh, Jiyoung; Son, Seok-Woo; Choi, Jung; Lim, Eun-Pa;
Garfinkel, Chaim; Hendon, Harry; Kim, Yoonjae; Kang, Hyun-Suk
Bibcode: 2022PEPS....9...25O
Altcode:
Antarctic ozone has been regarded as a major driver of the Southern
Hemisphere (SH) circulation change in the recent past. Here, we show
that Antarctic ozone can also affect the subseasonal-to-seasonal (S2S)
prediction during the SH spring. Its impact is quantified by conducting
two reforecast experiments with the Global Seasonal Forecasting System
5 (GloSea5). Both reforecasts are initialized on September 1st of
each year from 2004 to 2020 but with different stratospheric ozone:
one with climatological ozone and the other with year-to-year varying
ozone. The reforecast with climatological ozone, which is common in
the operational S2S prediction, shows the skill re-emergence in October
after a couple of weeks of no prediction skill in the troposphere. This
skill re-emergence, mostly due to the stratosphere-troposphere dynamical
coupling, becomes stronger in the reforecast with year-to-year varying
ozone. The surface prediction skill also increases over Australia. This
result suggests that a more realistic stratospheric ozone could lead
to improved S2S prediction in the SH spring.
Title: The GAs Extraction and Analyses system (GAEA) for immediate
extraction and measurements of volatiles in the Hayabusa2 sample
container
Authors: Miura, Yayoi N.; Okazaki, Ryuji; Takano, Yoshinori;
Sakamoto, Kanako; Tachibana, Shogo; Yamada, Keita; Sakai, Saburo;
Sawada, Hirotaka
Bibcode: 2022EP&S...74...76M
Altcode:
Hayabusa2 returned surface samples from the C-type near-Earth asteroid
(162173) Ryugu to Woomera, South Australia, in December 2020. The
samples returned from Ryugu are expected to contain not only volatile
components reflecting its primitive nature, but also solar wind
components due to exposure to space. Such volatiles may partly be
released inside the sealed sample container enclosing Ryugu samples
due to particle destruction or container heating in a contingency
case. In order to collect and analyze volatiles released in the
container prior to the container-opening, we set up a gas extraction
and analyses system (GAEA: GAs Extraction and Analyses system). The
system requires ultra-high vacuum conditions, small vacuum line volume
to minimize dead volume and simple configuration as well as having an
interface to connect the container. The system includes gas bottles
for passive collection of volatiles at room temperature and bottles
for active collection at liquid nitrogen temperature. A quadrupole
mass spectrometer is installed to analyze gases in the vacuum line,
and a non-evaporative getter pump is also used when noble gases are
analyzed. The rehearsal operation of the GAEA was made at ISAS/JAXA
as well as transportation tests in Japan. In November 2020, it was
transported safely to the Quick Look Facility (QLF) in Woomera. It was
set up at the QLF and worked as planned for collection and analysis of
gas components from the returned sample container. Here we report the
concept, design and calibration results for the GAEA and an outline
of analytical protocols applied in Woomera.
Title: Extreme solar events
Authors: Cliver, Edward W.; Schrijver, Carolus J.; Shibata, Kazunari;
Usoskin, Ilya G.
Bibcode: 2022LRSP...19....2C
Altcode: 2022arXiv220509265C
We trace the evolution of research on extreme solar and
solar-terrestrial events from the 1859 Carrington event to the rapid
development of the last twenty years. Our focus is on the largest
observed/inferred/theoretical cases of sunspot groups, flares on the
Sun and Sun-like stars, coronal mass ejections, solar proton events,
and geomagnetic storms. The reviewed studies are based on modern
observations, historical or long-term data including the auroral and
cosmogenic radionuclide record, and Kepler observations of Sun-like
stars. We compile a table of 100- and 1000-year events based on
occurrence frequency distributions for the space weather phenomena
listed above. Questions considered include the Sun-like nature of
superflare stars and the existence of impactful but unpredictable solar
"black swans" and extreme "dragon king" solar phenomena that can involve
different physics from that operating in events which are merely large.
Title: Special issue "Understanding phreatic eruptions - recent
observations of Kusatsu-Shirane volcano and equivalents -"
Authors: Ogawa, Yasuo; Ohba, Takeshi; Fischer, Tobias P.; Yamamoto,
Mare; Jolly, Art
Bibcode: 2022EP&S...74..100O
Altcode:
No abstract at ADS
Title: Earth-shaking J. LEAGUE supporters
Authors: Yabe, Suguru; Nishida, Kiwamu; Sakai, Shinichi
Bibcode: 2022EP&S...74..123Y
Altcode:
We conducted temporary seismic observations at the Hitachi-Kashiwa
Soccer Stadium on a J. LEAGUE game day to obtain unique seismic records
due to the collective action (i.e., jumping) of supporters, which
were also recorded in a permanent Metropolitan Seismic Observation
network (MeSO-net) station. This study investigated seismic wave
excitation as well as seismic wave propagation from the stadium to
its surroundings. The rhythms of the jumps of the supporters were
characterized by analyzing audio data recorded in the stadium, which
were compared with the characteristic frequencies observed in the
seismic records. The characteristic frequencies in the seismic records
are integer multiples of the jumping rhythms, which is consistent with
the loading model of jumping people proposed in earlier studies. This
implies that seismometers could be useful for monitoring collective
human activity. Travel times were studied using deconvolved waveforms
because seismic waves generated by the supporters are sinusoidal
with vague onset. Polarization analysis was performed to measure
the amplitude and polarization azimuths. The observed seismic wave
propagation was compared with synthetic waveforms calculated using
one-dimensional physical properties based on the Japan Seismic Hazard
Information Station (J-SHIS). The synthetic waveforms calculated with
the shallow and deep layer combined model are more consistent with
observations of travel times and amplitude decay than those calculated
with the only deep layer model, although a part of the observations
cannot be explained by both models. This result suggests that the
subsurface structure of J-SHIS is good in this region, although a more
detailed three-dimensional structure and topography must be considered
to fully explain the observations. As human-induced seismic signals
are expected to be generated in various situations, this study shows
that such unique seismic waves can be used as an artificial seismic
source for validating and improving local shallow subsurface structural
models in urban environments.
Title: Fast radio bursts at the dawn of the 2020s
Authors: Petroff, E.; Hessels, J. W. T.; Lorimer, D. R.
Bibcode: 2022A&ARv..30....2P
Altcode: 2021arXiv210710113P
Since the discovery of the first fast radio burst (FRB) in 2007, and
their confirmation as an abundant extragalactic population in 2013,
the study of these sources has expanded at an incredible rate. In
our 2019 review on the subject, we presented a growing, but still
mysterious, population of FRBs—60 unique sources, 2 repeating FRBs,
and only 1 identified host galaxy. However, in only a few short years,
new observations and discoveries have given us a wealth of information
about these sources. The total FRB population now stands at over 600
published sources, 24 repeaters, and 19 host galaxies. Higher time
resolution data, sustained monitoring, and precision localisations
have given us insight into repeaters, host galaxies, burst morphology,
source activity, progenitor models, and the use of FRBs as cosmological
probes. The recent detection of a bright FRB-like burst from the
Galactic magnetar SGR 1935 + 2154 provides an important link between
FRBs and magnetars. There also continue to be surprising discoveries,
like periodic modulation of activity from repeaters and the localisation
of one FRB source to a relatively nearby globular cluster associated
with the M81 galaxy. In this review, we summarise the exciting
observational results from the past few years. We also highlight
their impact on our understanding of the FRB population and proposed
progenitor models. We build on the introduction to FRBs in our earlier
review, update our readers on recent results, and discuss interesting
avenues for exploration as the field enters a new regime where hundreds
to thousands of new FRBs will be discovered and reported each year.
Title: Ram pressure stripping in high-density environments
Authors: Boselli, Alessandro; Fossati, Matteo; Sun, Ming
Bibcode: 2022A&ARv..30....3B
Altcode: 2021arXiv210913614B
Galaxies living in rich environments are suffering different
perturbations able to drastically affect their evolution. Among
these, ram pressure stripping, i.e. the pressure exerted by the
hot and dense intracluster medium (ICM) on galaxies moving at high
velocity within the cluster gravitational potential well, is a key
process able to remove their interstellar medium (ISM) and quench
their activity of star formation. This review is aimed at describing
this physical mechanism in different environments, from rich clusters
of galaxies to loose and compact groups. We summarise the effects of
this perturbing process on the baryonic components of galaxies, from
the different gas phases (cold atomic and molecular, ionised, hot)
to magnetic fields and cosmic rays, and describe their induced effects
on the different stellar populations, with a particular attention to
its role in the quenching episode generally observed in high-density
environments. We also discuss on the possible fate of the stripped
material once removed from the perturbed galaxies and mixed with the
ICM, and we try to estimate its contribution to the pollution of the
surrounding environment. Finally, combining the results of local and
high-redshift observations with the prediction of tuned models and
simulations, we try to quantify the importance of this process on
the evolution of galaxies of different mass, from dwarfs to giants,
in various environments and at different epochs.
Title: Large-scale dark matter simulations
Authors: Angulo, Raul E.; Hahn, Oliver
Bibcode: 2022LRCA....8....1A
Altcode: 2021arXiv211205165A
We review the field of collisionless numerical simulations for the
large-scale structure of the Universe. We start by providing the main
set of equations solved by these simulations and their connection with
General Relativity. We then recap the relevant numerical approaches:
discretization of the phase-space distribution (focusing on N-body
but including alternatives, e.g., Lagrangian submanifold and
Schrödinger-Poisson) and the respective techniques for their time
evolution and force calculation (direct summation, mesh techniques,
and hierarchical tree methods). We pay attention to the creation of
initial conditions and the connection with Lagrangian Perturbation
Theory. We then discuss the possible alternatives in terms of the
micro-physical properties of dark matter (e.g., neutralinos, warm
dark matter, QCD axions, Bose-Einstein condensates, and primordial
black holes), and extensions to account for multiple fluids (baryons
and neutrinos), primordial non-Gaussianity and modified gravity. We
continue by discussing challenges involved in achieving highly accurate
predictions. A key aspect of cosmological simulations is the connection
to cosmological observables, we discuss various techniques in this
regard: structure finding, galaxy formation and baryonic modelling,
the creation of emulators and light-cones, and the role of machine
learning. We finalise with a recount of state-of-the-art large-scale
simulations and conclude with an outlook for the next decade.
Title: Long-chain alkenones in the Shimosa Group reveal
palaeotemperatures of the Pleistocene interglacial Palaeo-Tokyo Bays
Authors: Kajita, Hiroto; Nakazawa, Tsutomu; Utsunomiya, Masayuki;
Ohkouchi, Naohiko; Sato, Miyako; Harada, Naomi; Kawahata, Hodaka
Bibcode: 2022PEPS....9...40K
Altcode:
The Shimosa Group, a Middle- to Late-Pleistocene sedimentary
succession, has been the focus of stratigraphic attention because it
lies beneath the Tokyo metropolitan area of central Japan. It is also of
palaeoclimatic significance because it contains important interglacial
marine strata of the past 450,000 years. Because the marine strata of
the Shimosa Group were formed in the shallow inner bay known as the
Palaeo-Tokyo Bay, rare occurrences of planktonic foraminifera make
it difficult to quantitatively reconstruct the palaeo-sea surface
temperatures (SSTs). Here, we extracted long-chain alkenones (LCAs)
from the core GS-UR-1 penetrating the Shimosa Group to Marine Isotope
Stage (MIS) 11. We found that the alkenone unsaturation ratio appears
to reflect the SST of the Palaeo-Tokyo Bay formed during the peaks of
MISs 5e, 7e, 9, and 11, which was consistent with the inflowing water
mass changes inferred from the benthic foraminiferal assemblages. The
palaeo-SSTs during each interglacial period were 2-3 °C higher than
the pre-industrial levels of Tokyo Bay and seemed to reach a level
similar to that of the Holocene thermal maximum. The findings of this
study demonstrate that the LCA-based proxy, which has not before been
utilised in studies on the Shimosa Group, has strong potential to
provide palaeoceanic and stratigraphic information.
Title: Geomorphological processes and their connectivity in hillslope,
fluvial, and coastal areas in Bangladesh: A review
Authors: Faisal, B. M. Refat; Hayakawa, Yuichi S.
Bibcode: 2022PEPS....9...41F
Altcode:
Geomorphological knowledge is critical in understanding watershed scale
surface processes, including steep mountainous areas and flat lowlands,
particularly if the mid- and downstream areas are densely populated
and hazard assessments are highly required. However, our knowledge
about such surface processes has relatively been limited in some
areas in South Asia due likely to the lack of comprehensive studies of
geomorphology and related fields. This article undertakes an overview of
the geomorphological processes of the disaster-prone deltaic landscape
of the Ganges-Brahmaputra-Meghna (GBM), particularly focusing on fluvial
processes. The area locates in the downstream of the watershed system
including Himalayan Mountains and highly connected with the upper
basin morphodynamics, hydrology, and sediment flux. The previous
studies are summarized at different geomorphic settings concerning
hillslopes, fluvial plains, and coastal areas to provide clarity about
the geomorphic processes linking erosion-prone upstream source areas to
deposition-dominated downstream areas. The review found that most of the
geomorphic researches in Bangladesh are exploring landslide inventory
and susceptibility mapping in hilly areas; river channel or riverbank
shifting, riverbank erosion and accretion in fluvial environments;
watershed morphometric analysis and geomorphic unit identification in
plain land; and coastline shifting or coastal erosion and accretion in
coastal environments at a small scale. Then, we discuss the fluvial
dynamics and sediment transport of the GBM river system to address
the knowledge gap in the context of deltaic plain land in Bangladesh,
where upstream fluvial sedimentation processes impact the geomorphic
connectivity from Himalayan to the Bay of Bengal. Although some studies
on the fluvial dynamics and sediment dispersal in the upstream GBM river
basin are present, the fluvial processes in the downstream domain of
Bangladesh are not fully understood with a limited number of research
with field-based approaches. Some future perspectives of geomorphic
research in Bangladesh are then mentioned to understand better the
complex geomorphological settings in the entire GBM watershed and
to strengthen the existing research capacity. This review will also
develop a holistic understanding of fluvial geomorphic processes of
the GBM River to the policymakers and may be helpful to improve the
transboundary river basin management policies or strategies.
Title: Electromagnetic counterparts to massive black-hole mergers
Authors: Bogdanović, Tamara; Miller, M. Coleman; Blecha, Laura
Bibcode: 2022LRR....25....3B
Altcode: 2021arXiv210903262B
The next two decades are expected to open the door to the first
coincident detections of electromagnetic (EM) and gravitational-wave
(GW) signatures associated with massive black-hole (MBH) binaries
heading for coalescence. These detections will launch a new era of
multimessenger astrophysics by expanding this growing field to the
low-frequency GW regime and will provide an unprecedented understanding
of the evolution of MBHs and galaxies. They will also constitute
fundamentally new probes of cosmology and would enable unique tests of
gravity. The aim of this Living Review is to provide an introduction to
this research topic by presenting a summary of key findings, physical
processes and ideas pertaining to EM counterparts to MBH mergers as they
are known at the time of this writing. We review current observational
evidence for close MBH binaries, discuss relevant physical processes
and timescales, and summarize the possible EM counterparts to GWs in
the precursor, coalescence, and afterglow stages of a MBH merger. We
also describe open questions and discuss future prospects in this
dynamic and quick-paced research area.
Title: Evidence of surface heterogeneity on active asteroid (3200)
Phaethon
Authors: MacLennan, Eric; Marshall, Sean; Granvik, Mikael
Bibcode: 2022Icar..38815226M
Altcode: 2022arXiv220308865M
Thermal infrared emission and thermophysical modeling techniques are
powerful tools in deciphering the surface properties of asteroids. The
near-Earth asteroid (3200) Phaethon is an active asteroid with a very
small perihelion distance and is likely the source of the Geminid
meteor shower. Using a thermophysical model with a non-convex shape
of Phaethon we interpret thermal infrared observations that span ten
distinct sightings. The results yield an effective diameter of 5 . 4 ±
0 . 1 km and independent thermal inertia estimates for each sighting. We
find that the thermal inertia varies across each of these sightings
in a way that is stronger than the theoretical temperature-dependent
expectation from radiative heat transfer within the regolith. Thus,
we test whether the variation in thermal inertia can be explained
by the presence of a regolith layer over bedrock, or by a spatially
heterogeneous scenario. We find that a model in which Phaethon's
hemispheres have distinctly different thermophysical properties
can sufficiently explain the thermal inertias determined herein. In
particular, we find that a boundary is located between latitudes -
30∘ and + 10∘ that separates two regions: a fine-grained southern
latitudes and a northern hemisphere that is dominated by coarse-grained
regolith and/or a high coverage of porous boulders. We discuss the
implications related to Phaethon's activity, potential association
with 2005 UD, and the upcoming DESTINY+ mission.
Title: Open clusters with proper motions fully separatedfrom the
field stars using Gaia DR2
Authors: Badawy, W. A.; Tadross, A. L.; Hendy, Y. H. M.; Hassan,
I. A.; Ismail, M. N.; Mouner, A.
Bibcode: 2022JAsGe..11..142B
Altcode: 2021arXiv210713350B
The study of open star clusters makes us understand a lot about the
composition and construction of the Milky Way Galaxy. Thanks to the
Gaia DR2 database that helps us to get the genetic members of star
clusters using their proper motions and parallaxes, estimating their
physical properties in a very accurate way. This study aims to detect
the reasons that make proper motions value of a cluster is completely
separated from the background field stars and not melted in. We studied
a large sample of open stellar clusters taken from Dias catalog and
drawing the vector point diagrams using the astrometric data of Gaia
DR2. Marking the separated clusters and melted ones and study their
mean parameters in each galactic quadrant.
Title: New horizons for fundamental physics with LISA
Authors: Arun, K. G.; Belgacem, Enis; Benkel, Robert; Bernard,
Laura; Berti, Emanuele; Bertone, Gianfranco; Besancon, Marc; Blas,
Diego; Böhmer, Christian G.; Brito, Richard; Calcagni, Gianluca;
Cardenas-Avendaño, Alejandro; Clough, Katy; Crisostomi, Marco;
De Luca, Valerio; Doneva, Daniela; Escoffier, Stephanie; Ezquiaga,
José María; Ferreira, Pedro G.; Fleury, Pierre; Foffa, Stefano;
Franciolini, Gabriele; Frusciante, Noemi; García-Bellido, Juan;
Herdeiro, Carlos; Hertog, Thomas; Hinderer, Tanja; Jetzer, Philippe;
Lombriser, Lucas; Maggio, Elisa; Maggiore, Michele; Mancarella,
Michele; Maselli, Andrea; Nampalliwar, Sourabh; Nichols, David;
Okounkova, Maria; Pani, Paolo; Paschalidis, Vasileios; Raccanelli,
Alvise; Randall, Lisa; Renaux-Petel, Sébastien; Riotto, Antonio;
Ruiz, Milton; Saffer, Alexander; Sakellariadou, Mairi; Saltas,
Ippocratis D.; Sathyaprakash, B. S.; Shao, Lijing; Sopuerta,
Carlos F.; Sotiriou, Thomas P.; Stergioulas, Nikolaos; Tamanini,
Nicola; Vernizzi, Filippo; Witek, Helvi; Wu, Kinwah; Yagi, Kent;
Yazadjiev, Stoytcho; Yunes, Nicolás; Zilhão, Miguel; Afshordi,
Niayesh; Angonin, Marie-Christine; Baibhav, Vishal; Barausse, Enrico;
Barreiro, Tiago; Bartolo, Nicola; Bellomo, Nicola; Ben-Dayan, Ido;
Bergshoeff, Eric A.; Bernuzzi, Sebastiano; Bertacca, Daniele; Bhagwat,
Swetha; Bonga, Béatrice; Burko, Lior M.; Compére, Geoffrey; Cusin,
Giulia; da Silva, Antonio; Das, Saurya; de Rham, Claudia; Destounis,
Kyriakos; Dimastrogiovanni, Ema; Duque, Francisco; Easther, Richard;
Farmer, Hontas; Fasiello, Matteo; Fisenko, Stanislav; Fransen, Kwinten;
Frauendiener, Jörg; Gair, Jonathan; Gergely, László Árpád; Gerosa,
Davide; Gualtieri, Leonardo; Han, Wen-Biao; Hees, Aurelien; Helfer,
Thomas; Hennig, Jörg; Jenkins, Alexander C.; Kajfasz, Eric; Kaloper,
Nemanja; Karas, Vladimír; Kavanagh, Bradley J.; Klioner, Sergei A.;
Koushiappas, Savvas M.; Lagos, Macarena; Le Poncin-Lafitte, Christophe;
Lobo, Francisco S. N.; Markakis, Charalampos; Martín-Moruno, Prado;
Martins, C. J. A. P.; Matarrese, Sabino; Mayerson, Daniel R.; Mimoso,
José P.; Noller, Johannes; Nunes, Nelson J.; Oliveri, Roberto;
Orlando, Giorgio; Pappas, George; Pikovski, Igor; Pilo, Luigi;
Podolský, Jiří; Pratten, Geraint; Prokopec, Tomislav; Qi, Hong;
Rastgoo, Saeed; Ricciardone, Angelo; Rollo, Rocco; Rubiera-Garcia,
Diego; Sergijenko, Olga; Shapiro, Stuart; Shoemaker, Deirdre;
Spallicci, Alessandro; Stashko, Oleksandr; Stein, Leo C.; Tasinato,
Gianmassimo; Tolley, Andrew J.; Vagenas, Elias C.; Vandoren, Stefan;
Vernieri, Daniele; Vicente, Rodrigo; Wiseman, Toby; Zhdanov, Valery
I.; Zumalacárregui, Miguel
Bibcode: 2022LRR....25....4A
Altcode: 2022arXiv220501597A
The Laser Interferometer Space Antenna (LISA) has the potential to
reveal wonders about the fundamental theory of nature at play in the
extreme gravity regime, where the gravitational interaction is both
strong and dynamical. In this white paper, the Fundamental Physics
Working Group of the LISA Consortium summarizes the current topics in
fundamental physics where LISA observations of gravitational waves can
be expected to provide key input. We provide the briefest of reviews to
then delineate avenues for future research directions and to discuss
connections between this working group, other working groups and the
consortium work package teams. These connections must be developed
for LISA to live up to its science potential in these areas.
Title: Effects of magma-generation and migration on the expansion
and contraction history of the Moon
Authors: U, Kenyo; Hasumi, Hiroki; Ogawa, Masaki
Bibcode: 2022EP&S...74...78U
Altcode:
Geological and geodetic observations of the Moon from spacecraft
revealed that it expanded by a few km for the first several hundred
million years and then contracted later. The period when the planet
expanded most coincides with that when the mare volcanism of the Moon
was active. Given the high initial temperature of the deep mantle
inferred from the giant impact and mantle overturn hypotheses of
the Moon, the observed early expansion is difficult to account for
by thermal expansion only. To understand the observed radial change
of the Moon, we numerically calculated the thermal evolution of a
one-dimensional spherically symmetric mantle caused by transport
of heat, mass, and incompatible heat-producing elements (HPEs)
by migration of magma that is generated by internal heating. The
mantle is assumed to be enriched in HPEs at its base in the initial
condition. The calculated mantle expands for the first several hundred
million years by melting of the deep mantle and upward migration
of the generated magma to the uppermost mantle; the top of the
partially molten region rises to the depth level of around 300 km,
which is shallow enough to generate mare basalts of the Moon. The
migrating magma, however, extracts HPEs from the deep interior, and
the planet then contracts gradually by cooling and solidification
of the partially molten mantle. We obtained a thermal history model
that is consistent with the observed history of radial change of the
Moon when the initial mid-mantle temperature TM≈1600 K
and the initial ratio of the concentration of HPEs in the crust to
that of the mantle Fcrst∗≤12 . This model
suggests that melting of the deep mantle and upward migration of the
generated magma strongly affect the thermal history of the Moon. The
model we developed here is a good starting point for constructing more
realistic models of the thermal history of the Moon where the effects
of heat and mass transport by mantle convection are also considered.
Title: Mapping of major tectonic lineaments across Cameroon using
potential field data
Authors: Cheunteu Fantah, Cyrille Armel; Mezoue, Cyrille Adiang;
Mouzong, Marcelin Pemi; Tokam Kamga, Alain Pierre; Nouayou, Robert;
Nguiya, Severin
Bibcode: 2022EP&S...74...59C
Altcode:
The cartography of lineaments across a territory can be optimized using
geophysical potential field data. In this study, land gravity and EMAG2
(Earth Magnetic Anomaly Grid) data were simultaneously used to identify
and characterize the major lineaments that spread across Cameroon. The
data were filtered using a multi-scale approach including horizontal and
vertical gradient analyses. The Euler Deconvolution method was later
applied to the filtered data to estimate the extension and depth of
the identified lineaments. Results show that the main lineaments across
Cameroon are laterally extended with a dominant N45°E orientation. Some
of these lineaments correlated well with the geographical location of
some known major tectonic structures found across the country. The depth
of these lineaments varies between 1 and 35 km. Some of the identified
faults are still active as their location correlated with the location
of some recent earthquakes that occurred in Cameroon. This work,
therefore, highlights some hidden tectonic features which knowledge
generally precedes exploration for subsurface resources.
Title: Special issue "International Geomagnetic Reference Field:
the thirteenth generation"
Authors: Alken, P.; Thébault, E.; Beggan, C. D.; Nosé, M.
Bibcode: 2022EP&S...74...11A
Altcode:
No abstract at ADS
Title: Determination of Seismic Site Class and Potential Geologic
Hazards using Multi-Channel Analysis of Surface Waves(MASW) at the
Industrial City of Abu Dhabi, UAE
Authors: Abdallatif, T. F.; Khozym, A. A.; Ghandour, A. A.
Bibcode: 2022JAsGe..11..193A
Altcode:
No abstract at ADS
Title: The assessment of rock drillability from elastic and
petrophysical parameters
Authors: Teama, Mostafa A.; Kassab, Mohamed A.; Gomaa, Moataz M.;
Moussa, Abdelrahman B.
Bibcode: 2022JAsGe..11...48A
Altcode:
No abstract at ADS
Title: Rapid, accurate computation of narrow-band sky radiance in
the 940 nm gas absorption region using the correlated k-distribution
method for sun-photometer observations
Authors: Momoi, Masahiro; Irie, Hitoshi; Sekiguchi, Miho; Nakajima,
Teruyuki; Takenaka, Hideaki; Miura, Kazuhiko; Aoki, Kazuma
Bibcode: 2022PEPS....9...10M
Altcode:
We developed lookup tables for the correlated k-distribution (CKD)
method in the 940 nm water vapor absorption region (WV-CKD), with the
aim of rapid and accurate computation of narrow-band radiation around
940 nm (10,000-10,900 cm-1) for ground-based angular-scanning
radiometer data analysis. Tables were constructed at three spectral
resolutions (2, 5, and 10 cm-1) with quadrature values
(point and weight) and numbers optimized using simulated sky radiances
at ground level, which had accuracies of ≤ 0.5% for sub-bands
of 10 cm-1 . Although high-resolution WV-CKD requires
numerous quadrature points, the number of executions of the radiative
transfer model is reduced to approximately 1/46 of the number used
in the line-by-line approach by our WV-CKD with a resolution of 2
cm-1. Furthermore, we confirmed through several simulations
that WV-CKD could be used to compute radiances with various vertical
profiles. The accuracy of convolved direct solar irradiance and diffuse
radiance at a full width at half maximum (FWHM) of 10 nm, computed
with the WV-CKD, is < 0.3%. In contrast, the accuracy of convolved
normalized radiance, which is the ratio of diffuse radiance to direct
solar irradiance, at an FWHM of 10 nm computed with the WV-CKD is <
0.11%. This accuracy is lower than the observational uncertainty of a
ground-based angular-scanning radiometer (approximately 0.5%). Finally,
we applied the SKYMAP and DSRAD algorithms (Momoi et al. in Atmos Meas
Tech 13:2635-2658, 2020. https://doi.org/10.5194/amt-13-2635-2020)
to SKYNET observations (Chiba, Japan) and compared the results with
microwave radiometer values. The precipitable water vapor (PWV) derived
with the WV-CKD showed better agreement (correlation coefficient
γ = 0.995, slope = 1.002) with observations than PWV derived with
the previous CKD table (correlation coefficient γ = 0.984, slope =
0.926) by Momoi et al. (Momoi et al., Atmos Meas Tech 13:2635-2658,
2020). Through application of the WV-CKD to actual data analysis,
we found that an accurate CKD table is essential for estimating PWV
from sky-radiometer observations.
Title: On the characterization of tidal ocean-dynamo signals in
coastal magnetic observatories
Authors: Petereit, Johannes; Saynisch-Wagner, Jan; Morschhauser,
Achim; Pick, Leonie; Thomas, Maik
Bibcode: 2022EP&S...74...67P
Altcode:
Periodic tidal ocean currents induce electric currents and, therefore,
magnetic field signals that are observable using spaceborne and
ground-based observation techniques. In theory, the signals can be used
to monitor oceanic temperature and salinity variations. Tidal magnetic
field amplitudes and phases have been extracted from magnetometer
measurements in the past. However, due to uncertainties caused by a
plentitude of influencing factors, the shape and temporal variation of
these signals are only known to a limited extent. This study uses past
extraction methods to characterize seasonal variations and long-term
trends in the ten year magnetometer time series of three coastal
island observatories. First, we assess data processing procedures used
to prepare ground-based magnetometer observations for tidal ocean
dynamo signal extraction to demonstrate that existing approaches,
i.e., subtraction of core field models or first-order differencing,
are unable to reliably remove low-frequency contributions. We hence
propose low-frequency filtering using smoothing splines and demonstrate
the advantages over the existing approaches. Second, we determine
signal and side peak magnitudes of the M2 tide induced magnetic field
signal by spectral analysis of the processed data. We find evidence
for seasonal magnetic field signal variations of up to 25 % from the
annual mean. Third, to characterize the long-term behavior of tidal
ocean dynamo signal amplitudes and phases, we apply different signal
extraction techniques to identify tidal ocean-dynamo signal amplitudes
and phases in sub-series of the ten-year time series with incrementally
increasing lengths. The analyses support three main findings: (1) trends
cause signal amplitude changes of up to ≈1 nT and phase changes are
in the order of O (10∘ ) within the observation period; (2)
at least four years of data are needed to obtain reliable amplitude and
phase values with the extraction methods used and (3) signal phases are
a less dependent on the chosen extraction method than signal amplitudes.
Title: A low-dispersion spectral video camera for observing lunar
impact flashes
Authors: Yanagisawa, Masahisa; Kakinuma, Fumihiro
Bibcode: 2022EP&S...74...62Y
Altcode:
An impact of a meteoroid on the lunar surface at speeds exceeding
several kilometers per second generates a light flash generally less
than 0.1 s in duration. We made a simple spectral video camera for
observing the lunar impact flashes and monitored the waxing crescent
Moon's non-sunlit surface from Oct. 2016 to May 2017. We detected
ten flash candidates though there was no report of simultaneous
detections by other observers. We obtained low-dispersion spectra
in visible wavelengths for nine of them. Six of them show spectra
similar to those of the flashes observed during the Geminids meteor
activity in Dec. 2018 by the same camera. The spectra are continuous
and red. Blackbody spectra fitted to them show temperatures around
3000 K. On the other hand, three of them show continuous blue
spectra. Blackbody spectra fitted to them show temperatures of more
than 6000 K. Specular reflection of sunlight by space debris might
lead to these flashes. However, the impact of a low-density meteoroid
not against the fine lunar regolith but solid lunar rocks could cause
blue flashes. In this paper, we give full details of the camera and the
analytical procedures of the videos. We also discuss recommendations
for future spectral observations.
Title: Climate, vegetation and fire history during the past 18,000
years, recorded in high altitude lacustrine sediments on the Sanetti
Plateau, Bale Mountains (Ethiopia)
Authors: Mekonnen, Betelhem; Glaser, Bruno; Zech, Roland; Zech,
Michael; Schlütz, Frank; Bussert, Robert; Addis, Agerie; Gil-Romera,
Graciela; Nemomissa, Sileshi; Bekele, Tamrat; Bittner, Lucas; Solomon,
Dawit; Manhart, Andreas; Zech, Wolfgang
Bibcode: 2022PEPS....9...14M
Altcode:
Low-altitude lakes in eastern Africa have long been investigated
and have provided valuable information about the Late Quaternary
paleohydrological evolution, such as the African Humid Period. However,
records often suffer from poor age control, resolution, and/or
ambiguous proxy interpretation, and only little focus has been
put on high-altitude regions despite their sensitivity to global,
regional, and local climate change phenomena. Here we report on Last
Glacial environmental fluctuations at about 4000 m asl on the Sanetti
Plateau in the Bale Mountains (SE Ethiopia), based on biogeochemical
and palynological analyses of laminated lacustrine sediments. After
deglaciation at about 18 cal kyr BP, a steppe-like herb-rich grassland
with maximum Chenopodiaceae/Amaranthaceae and Plantago existed. Between
16.6 and 15.7 cal kyr BP, conditions were dry with a desiccation
layer at ~ 16.3 cal kyr BP, documenting a temporary phase of maximum
aridity on the plateau. While that local event lasted for only a few
decades, concentrations of various elements (e.g. Zr, HF, Nb, Nd,
and Na) started to increase and reached a maximum at ~ 15.8-15.7 cal
kyr BP. We interpret those elements to reflect allochthonous, aeolian
dust input via dry northerly winds and increasingly arid conditions
in the lowlands. We suggest an abrupt versus delayed response at high
and low altitudes, respectively, in response to Northern Hemispheric
cooling events (the Heinrich Event 1). The delayed response at low
altitudes might be caused by slow negative vegetation and monsoon
feedbacks that make the ecosystem somewhat resilient. At ~ 15.7 cal
kyr BP, our record shows an abrupt onset of the African Humid Period,
almost 1000 years before the onset of the Bølling-Allerød warming
in the North-Atlantic region, and about 300 years earlier than in the
Lake Tana region. Erica pollen increased significantly between 14.4 and
13.6 cal kyr BP in agreement with periodically wet and regionally warm
conditions. Similarly, intense fire events, documented by increased
black carbon, correlate with wet and warm environmental conditions
that promote the growth of Erica shrubs. This allows to conclude that
biomass and thus fuel availability is one important factor controlling
fire events in the Bale Mountains.
Title: New interpretations of lunar mare basalt flow emplacement
from XCT analysis of Apollo samples
Authors: Gawronska, Aleksandra J.; McLeod, Claire L.; Blumenfeld,
Erika H.; Hanna, Romy D.; Zeigler, Ryan A.
Bibcode: 2022Icar..38815216G
Altcode:
The study of basaltic samples returned half a century ago through the
Apollo missions has provided unparalleled insights into the magmatic
processes associated with volcanism on planetary bodies. Traditional
study of these samples has been conducted in two dimensions (2D) via
interrogation of thin sections and subsequent in-situ chemical analyses,
yet returned samples are three-dimensional (3D) objects and therefore
preserve evidence of lunar volcanic processes in 3D. Here, X-ray
computed tomography (XCT) was used for the first time to evaluate lava
emplacement mechanisms on the lunar surface. A total of six samples from
the Apollo 11, 12, 15, and 17 missions were studied. From volumetric
mineralogies, textures, and petrofabrics, lunar lava cooling histories
were inferred. Collectively, these physical characteristics were then
correlated with pāhoehoe lava flow lobe stratigraphy. Samples 10057
and 15556 are inferred to have crystallized in the lobe crust of their
respective lava flow lobes. Samples 12038, 12043, and 70017 may mark
the transition between the vesiculated, fine-grained lobe crust, and
the dense, coarse-grained lobe core in their respective flows. Finally,
coarse-grained, and non-vesiculated sample 15085 is inferred to have
crystallized in a lobe core. No statistically significant petrofabric
is preserved in any of the samples, indicating that the basalt samples
studied here, and the lava flows they originated from, experienced
minimal strain during emplacement and solidification on the lunar
surface. This is consistent with the low viscosities attributed to
lunar mare lavas. Future in-situ sampling of extraterrestrial basaltic
products should focus on detailed documentation of, and collection from,
stratigraphically well-characterized lava flows to further evaluate
the interpretations presented here.
Title: Ambient noise tomography for a high-resolution 3D S-wave
velocity model of the Kinki Region, Southwestern Japan, using dense
seismic array data
Authors: Nthaba, Bokani; Ikeda, Tatsunori; Nimiya, Hiro; Tsuji,
Takeshi; Iio, Yoshihisa
Bibcode: 2022EP&S...74...96N
Altcode:
Research interest in the Kinki region, southwestern Japan, has been
aroused by the frequent occurrence of microearthquake activity that do
not always coincide with documented active fault locations. Previous
studies in the Kinki region focused mainly on deep, large-scale
structures and could not efficiently resolve fine-scale (~ 10 km)
shallow crustal structures. Hence, characterization of the upper
crustal structure of this region at an improved spatial resolution is
required. From the cross-correlation of the vertical components of the
ambient seismic noise data recorded by a densely distributed seismic
array, we estimated Rayleigh wave phase velocities using a frequency
domain method. Then, we applied a direct surface wave tomographic
method for the measured phase velocity dispersion data to obtain a
3D S-wave velocity model of the Kinki region. The estimated velocity
model reveals a NE-SW trending low-velocity structure coinciding with
the Niigata-Kobe Tectonic Zone (NKTZ) and the active Biwako-seigan
Fault Zone (BSFZ). Also, we identified fine-scale low-velocity
structures coinciding with known active faults on the eastern side
of the NKTZ, as well as sets of low-velocity structures across the
Tanba region. Furthermore, sedimentary basins manifest as low-velocity
zones extending to depths ranging from ~ 1.5 to 2 km, correlating with
those reported in previous studies. Our results therefore contribute
towards fundamental understanding of earthquake faulting as well
as tectonic boundary and will be useful for hazard assessment and
disaster mitigation.
Title: Episode 4 (2019-2020) Nishinoshima activity: abrupt transitions
in the eruptive style observed by image datasets from multiple
satellites
Authors: Kaneko, Takayuki; Maeno, Fukashi; Ichihara, Mie; Yasuda,
Atsushi; Ohminato, Takao; Nogami, Kenji; Nakada, Setsuya; Honda,
Yoshiaki; Murakami, Hiroshi
Bibcode: 2022EP&S...74...34K
Altcode:
In December 2019, a new activity started at Nishinoshima volcano in the
southern part of the Izu-Ogasawara arc, Japan. This is now referred to
as Episode 4 of a series of activities that began in 2013. We analyzed
the eruption sequence, including erupted volume and effusion rate,
based on combined observations of thermal anomalies by Himawari-8 and
topographic changes by ALOS-2. The total eruption volume during Episode
4 was ~ 132 × 106 m3, and the average effusion
rate over the entire period was 0.51 × 106 m3
day−1 (5.9 m3 s−1), which was
two to three times higher than that of Episode 1. Episode 4 had three
stages. In Stage 1, effusive activity was dominant, and most of the
lava erupted from a northeast vent at the foot of the pyroclastic cone
to cover the northern half of the island. The average effusion rate was
estimated to be 0.46 × 106 m3 day−1
(5.3 m3 s−1). In Stage 2, an intensive lava
fountain with a high discharge rate developed, and it increased the
size of the pyroclastic cone rapidly. The effusion rate temporarily
reached 2.6 × 106 m3 day−1 (30
m3 s−1). Pyroclastic rocks accounted for
45-88% of the total erupted volume in this stage. Lava flows with
rafted cone material were generated, and those possibly caused by
intensive spatter falls on the slope were also formed. These lavas
flowed down the southern half of the island. In Stage 3, continuous
phreatomagmatic eruptions released ash and spread it over a wide
area. The high effusion rate and the drastic change in the activity
style in Episode 4 can be explained by deep volatile-rich magma being
supplied to a shallower magma chamber prior to Episode 4. When the
volatile-rich magma reached a shallow part of the conduit in Stage 2,
fragmentation occurred due to rapid volume expansion to eject large
amounts of magma and form the intensive lava fountain. Observations
by satellite-borne ultraviolet-visible image sensors detected a rapid
increase in SO2 emissions in response to the intensive
lava-fountain activity. The less-differentiated nature of the ash
fragments collected during Stage 2 may reflect the composition of the
volatile-rich magma. Large-scale discolored-seawater areas appeared
during the late period of Stage 1, which may have been caused by ascent
of the volatile-rich magma.
Title: Spatio-temporal clustering of successive earthquakes as
inferred from analyses of global CMT and NIED F-net catalogs
Authors: Bantidi, Thystere Matondo; Nishimura, Takeshi
Bibcode: 2022EP&S...74..117B
Altcode:
Investigation of the characteristic behavior of successive earthquakes
that closely occur in space and time is important to understand the
generation mechanism of earthquakes and useful to assess a triggered
earthquake, especially around the area, where a first large earthquake
took place. Here, we analyzed the Global Centroid Moment Tensor
catalog from 1976 to 2016 for shallow earthquakes with a moment
magnitude, Mw, of at least 5.5, and the F-net catalog,
Japan, for 4 ≤Mw<5.5 , to clarify the spatio-temporal
characteristics of the successive earthquakes. We first sorted all of
the earthquakes in time and removed the aftershocks that occurred in
and around the faults of earthquakes with Mw larger than
the target magnitude range we investigated. Then, we selected source
events from the beginning and searched for earthquakes that occurred
within a horizontal distance (D) and a lapsed time (Ta)
from the source event to group them in clusters. Then, the source event
was selected from the catalog in order, and the same procedure was
repeated. We counted the number of clusters, each of which consisted of
successive earthquakes, for different D and Ta. To examine
whether successive earthquakes were explained by random occurrences,
we compared the results with simulations in which earthquakes occurred
randomly in time but at the same locations matching the centroids in
the real data. The comparison showed that the number of clusters for
the simulation rapidly increased with D and merged with that for real
data at a short distance, which is defined here as the triggering
distance. We find that triggering distance is proportional to about
1/5 to 1/4 of the seismic moment (M0) of the source event,
and exponentially decreases with increasing Ta. Relating
the derived empirical scaling relations between M0 and
triggering distance from the equations in the ETAS model, we show
that the observed exponents of 1/5 to 1/4 were well predicted from the
estimated ETAS parameters in various regions around the world. These
consistencies first show that successive occurrence of earthquakes is
well explained by the ETAS model.
Title: Evidence-based uncertainty estimates for the International
Geomagnetic Reference Field
Authors: Beggan, Ciarán D.
Bibcode: 2022EP&S...74...17B
Altcode:
The International Geomagnetic Reference Field (IGRF) is a
multi-institute model of the Earth's magnetic field, compactly described
by sets of up to 195 spherical harmonic (Gauss) coefficients to degree
and order 13, which allows the continuous evaluation of the field
at any location and time on or above the surface. It is developed
from satellite and ground-based magnetometer data and describes
the large-scale variation of the magnetic field in space and time
under quiet conditions. While much effort has been made on improving
the forecast of the secular variation of the field over the 5-year
intervals between release and renewal, less emphasis has been placed
on understanding the spatial errors from a user point of view. In this
study, we estimate the large-scale time-invariant spatial uncertainty
of the IGRF based on the globally averaged misfit of the model to
ground-based measurements at repeat stations and observatories between
1980 and 2021. As the ground measurements are reduced to quiet-time
values, the external field is minimized for the purposes of this
study. We find the 68.3% confidence interval is 87 nT in the North
(X) component, 73 nT in the East (Y) component and 114 nT in vertical
(Z) component. Due to the Laplacian distribution of the residuals,
the standard deviations are larger at 144, 136 and 293 nT, respectively.
Title: Surface and aloft NO2 pollution over the greater
Tokyo area observed by ground-based and MAX-DOAS measurements bridged
by kilometer-scale regional air quality modeling
Authors: Itahashi, Syuichi; Irie, Hitoshi
Bibcode: 2022PEPS....9...15I
Altcode:
To advance our understanding of surface and aloft nitrogen dioxide
(NO2) pollution, this study extensively evaluated
NO2 concentrations simulated by the regional air quality
modeling system with a 1.3 km horizontal grid resolution using the
Atmospheric Environmental Regional Observation System ground-based
observation network and aloft measurements by multi-axis differential
optical absorption spectroscopy (MAX-DOAS) over the greater Tokyo
area. Observations are usually limited to the surface level, and
gaps remain in our understanding of the behavior of air pollutants
above the near-surface layer, particularly within the planetary
boundary layer (PBL). Therefore, MAX-DOAS measurement was used,
which observes scattered sunlight in the ultraviolet/visible range at
several elevation angles between the horizon and zenith to determine
the aloft NO2 pollution averaged over 0-1 km. In total, four
MAX-DOAS measurement systems at Chiba University (35.63°N, 140.10°E)
systematically covered the north, east, west, and south directions
to capture the aloft NO2 pollution over the greater Tokyo
area. The target period was Chiba-Campaign 2015 conducted during 9-23
November 2015. The evaluations showed that the air quality modeling
system can generally capture the observed behavior of both surface
and aloft NO2 pollution in terms of spatial and temporal
coverage. The diurnal variation, which typically showed an increase
from evening to early morning without daylight and a decrease during
the daytime, was also captured by the model. During Chiba-Campaign
2015, two cases of episodic higher NO2 concentration were
identified: one during the nighttime and another during the daytime
as different diurnal patterns. These were related to a stagnant wind
field, with the latter also connected to a lower PBL height in cloudy
conditions. Comparison of the modeled daily-averaged surface and
aloft NO2 concentrations showed that aloft NO2
concentration exhibited a strong linear correlation with surface
NO2 concentration, with the aloft (0-1 km) value scaled to
0.4-0.5-fold the surface value, irrespective of whether the day was
clean or polluted. This scaling value was lower during the nighttime and
higher during the daytime. Based on this synergetic analysis of surface
and aloft observation bridged by a kilometer-scale fine-resolution
modeling simulation, this study contributes to fostering understanding
of aloft NO2 pollution.
Title: Reduced order and surrogate models for gravitational waves
Authors: Tiglio, Manuel; Villanueva, Aarón
Bibcode: 2022LRR....25....2T
Altcode: 2021arXiv210111608T
We present an introduction to some of the state of the art in
reduced order and surrogate modeling in gravitational-wave (GW)
science. Approaches that we cover include principal component analysis,
proper orthogonal (singular value) decompositions, the reduced basis
approach, the empirical interpolation method, reduced order quadratures,
and compressed likelihood evaluations. We divide the review into three
parts: representation/compression of known data, predictive models, and
data analysis. The targeted audience is practitioners in GW science, a
field in which building predictive models and data analysis tools that
are both accurate and fast to evaluate, especially when dealing with
large amounts of data and intensive computations, are necessary yet
can be challenging. As such, practical presentations and, sometimes,
heuristic approaches are here preferred over rigor when the latter is
not available. This review aims to be self-contained, within reasonable
page limits, with little previous knowledge (at the undergraduate
level) requirements in mathematics, scientific computing, and related
disciplines. Emphasis is placed on optimality, as well as the curse of
dimensionality and approaches that might have the promise of beating
it. We also review most of the state of the art of GW surrogates. Some
numerical algorithms, conditioning details, scalability, parallelization
and other practical points are discussed. The approaches presented
are to a large extent non-intrusive (in the sense that no differential
equations are invoked) and data-driven and can therefore be applicable
to other disciplines. We close with open challenges in high dimension
surrogates, which are not unique to GW science.
Title: Model of the mineralogy of the deep interior of Triton
Authors: Cioria, Camilla; Mitri, Giuseppe
Bibcode: 2022Icar..38815234C
Altcode:
Triton, the largest satellite of Neptune, is one of the most
fascinating icy moons in the outer Solar System, with an origin that
likely extends to the Kuiper Belt. Like other icy satellites, the
mineralogical composition of Triton's deep interior is a function of
its evolutionary path. In this work, we use the open- access Perple_X
software to model the evolutionary paths, anhydrous and hydrous,
describing three different mineralogical models to investigate the
possible mineral composition forming the rocky fraction of Triton's deep
interior. We modelled the phase assemblages adopting three carbonaceous
chondrites (Orgueil, Murchison, Allende) as precursor material of the
proto-Triton. We found that Triton's deep interior could have evolved
during its history into three possible mineral assemblages: an anhydrous
deep interior rich in olivine and pyroxenes, a hydrous deep interior
rich in hydrated silicates, and a dehydrated deep interior rich in
hydrated silicates (amphiboles and chlorite), olivine and pyroxenes. We
show that future measurement of the gravity field of Triton can be
used to determine the present mineral assemblages of its deep interior.
Title: Cometary ions detected by the Cassini spacecraft 6.5 au
downstream of Comet 153P/Ikeya-Zhang
Authors: Jones, G. H.; Elliott, H. A.; McComas, D. J.; Hill, M. E.;
Vandegriff, J.; Smith, E. J.; Crary, F. J.; Waite, J. H.
Bibcode: 2022Icar..38815199J
Altcode:
During March-April 2002, while between the orbits of Jupiter and
Saturn, the Cassini spacecraft detected a significant enhancement in
pickup proton flux. The most likely explanation for this enhancement
was the addition of protons to the solar wind by the ionization of
neutral hydrogen in the corona of comet 153P/Ikeya-Zhang. This comet
passed relatively close to the Sun-Cassini line during that period,
allowing pickup ions to be carried to Cassini by the solar wind. This
pickup proton flux could have been further modulated by the passage
of the interplanetary counterparts of coronal mass ejections past the
comet and spacecraft. The radial distance of 6.5 Astronomical Units
(au) traveled by the pickup protons, and the implied total tail length
of >7.5 au make this cometary ion tail the longest yet measured.
Title: Outgassing of selected possible cometary analogs: Laboratory
simulations
Authors: Kossacki, Konrad J.; Wesołowski, Marcin; Szutowicz,
Sławomira; Mikolajków, Tomasz
Bibcode: 2022Icar..38815209K
Altcode:
The paper presents experimental studies on the degassing of porous ice
and porous mixtures of ice and sand in a vacuum. The study aims to find
the relationship between the surface recession rate and the subsurface
temperature gradient as well as the granulation and composition of
the material. We propose an empirical equation tested on samples
with a mass fraction of non-volatile material to ice in the range of
0-3.65. Based on the proposed equation, calculations were carried out,
which indicate the possibility of landslides on the inclined areas on
the surface of comet 9P/Tempel 1.
Title: Studies of growing waves in Hall thruster beam plasma under
the influence of electron temperature
Authors: Bharti, Saty Prakash; Singh, Sukhmander
Bibcode: 2022JApA...43...47B
Altcode:
In this paper, the effect of electron temperature on the resistive
instability has been investigated in a Hall thruster beam plasma. The
dispersion relation for the axial-azimuthal propagating waves and
the instabilities has been derived using the first-order perturbation
technique under the effects of various parameters. The growth rate shows
Gaussian-type behaviour with the magnetic field, azimuthal wavenumber
and the electron temperature but it increases linearly with axial
wavenumber, beam density, beam velocity and collisional frequency. The
growth rate decreases with the drift velocity of electrons. The real
frequency almost increases with the axial-azimuthal wavenumbers,
electron drift velocity, electron temperature and the collisional
frequency.
Title: Probing a southern hemisphere VLBI Intensive baseline
configuration for UT1 determination
Authors: Böhm, Sigrid; Böhm, Johannes; Gruber, Jakob; Kern, Lisa;
McCallum, Jamie; McCallum, Lucia; McCarthy, Tiege; Quick, Jonathan;
Schartner, Matthias
Bibcode: 2022EP&S...74..118B
Altcode:
The deviation of Universal Time from atomic time, expressed as
UT1−UTC, reflects the irregularities of the Earth rotation speed
and is key to precise geodetic applications which depend on the
transformation between celestial and terrestrial reference frames. A
rapidly varying quantity such as UT1−UTC demands observation scenarios
enabling fast delivery of good results. These criteria are currently
met only by the Very Long Baseline Interferometry (VLBI) Intensive
sessions. Due to stringent requirements of a fast UT1−UTC turnaround,
the observations are limited to a few baselines and a duration of
one hour. Hence, the estimation of UT1−UTC from Intensives is
liable to constraints and prone to errors introduced by inaccurate a
priori information. One aspect in this context is that the regularly
operated Intensive VLBI sessions organised by the International
VLBI Service for Geodesy and Astrometry solely use stations in the
northern hemisphere. Any potential systematic errors due to this
northern hemisphere dominated geometry are so far unknown. Besides the
general need for stimulating global geodetic measurements with southern
observatories, this served as a powerful motivation to launch the SI
(Southern Intensive) program in 2020. The SI sessions are observed using
three VLBI antennas in the southern hemisphere: Ht (South Africa), Hb
(Tasmania) and Yg (Western Australia). On the basis of UT1−UTC results
from 53 sessions observed throughout 2020 and 2021, we demonstrate the
competitiveness of the SI with routinely operated Intensive sessions in
terms of operations and UT1−UTC accuracy. The UT1−UTC values of the
SI reach an average agreement of 32 µs in terms of weighted standard
deviation when compared with the conventional Intensives results of
five independent analysis centers and of 27 µs compared with the 14C04
series. The mean scatter of all solutions of the considered northern
hemisphere Intensives with respect to C04 is at a comparable level of
29 µs. The quality of the results is only slightly degraded if just
the baseline HtHb is evaluated. In combination with the e-transfer
capabilities from Ht to Hb, this facilitates continuation of the SI
by ensuring rapid service UT1−UTC provision.
Title: Gravitational waves and electromagnetic transients
Authors: Singhal, Akshat; Palit, Sourav; Bala, Suman; Waratkar,
Gaurav; Kumar, Harsh; Bhalerao, Varun
Bibcode: 2022JApA...43...53S
Altcode: 2022arXiv220405648S
The advanced gravitational wave (GW) detector network has started
routine detection of signals from merging compact binaries. Data
indicate that in a fair fraction of these sources, at least one
component was a neutron star, bringing with it the possibility of
electromagnetic (EM) radiation. So far, a confirmed link between EM and
GW radiation has been established for only one source, GW170817. Joint
analysis of broadband multi-wavelength data and the GW signal have
yielded rich information spanning fields as varied as jet physics,
cosmology and nucleosynthesis. Here, we discuss the importance of
such joint observations, as well as current and near-future efforts
to discover and study more EM counterparts to GW sources.
Title: GRB 210217A: a short or a long GRB?
Authors: Dimple, Misra, Kuntal; Ghosh, Ankur; Arun, K. G.; Gupta,
Rahul; Kumar, Amit; Resmi, L.; Pandey, S. B.; Yadav, Lallan
Bibcode: 2022JApA...43...39D
Altcode:
Gamma-ray bursts are traditionally classified as short and long bursts
based on their T90 value (the time interval during which an
instrument observes 5% to 95% of gamma-ray/hard X-ray fluence). However,
T90 is dependent on the detector sensitivity and the
energy range in which the instrument operates. As a result, different
instruments provide different values of T90 for a burst. GRB
210217A is detected with different duration by Swift and Fermi. It is
classified as a long/soft GRB by Swift-BAT with a T90 value
of 3.76 s. On the other hand, the sub-threshold detection by Fermi-GBM
classified GRB 210217A as a short/hard burst with a duration of 1.024
s. We present the multi-wavelength analysis of GRB 210217A (lying in the
overlapping regime of long and short GRBs) to identify its actual class
using multi-wavelength data. We utilized the T90-hardness
ratio, T90-Ep and T90-tmvts
distributions of the GRBs to find the probability of GRB 210217A being
a short GRB. Further, we estimated the photometric redshift of the
burst by fitting the joint XRT/UVOT SED and placed the burst in the
Amati plane. We found that GRB 210217A is an ambiguous burst showing
properties of both short and long class of GRBs.
Title: Intra-night optical variability monitoring of γ -ray emitting
blazars
Authors: Pandian, K. Subbu Ulaganatha; Natarajan, A.; Stalin, C. S.;
Pandey, Ashwani; Muneer, S.; Natarajan, B.
Bibcode: 2022JApA...43...48P
Altcode:
We present the results obtained from our campaign to characterize the
intra-night optical variability properties of blazars detected by the
Fermi large area telescope. This involves R-band monitoring observations
of a sample of 18 blazars, which includes five flat spectrum radio
quasars (FSRQs) and thirteen BL Lac objects (BL Lacs) covering the
redshift range z =0.085 -1.184 . Our observations carried out using the
1.3m J. C. Bhattacharya telescope cover a total of 40 nights (∼200
h) between the period December 2016 and March 2020. We characterized
variability using the power enhanced F-test. We found duty cycle (DC)
variability of about 11% for FSRQs and 12% for BL Lacs. Dividing
the sample into different sub-classes based on the position of the
synchrotron peak in their broadband spectral energy distribution (SED),
we found DC of ∼16%, ∼10% and ∼7% for low synchrotron peaked
(LSP), intermediate synchrotron peaked (ISP) and high synchrotron
peaked (HSP) blazars. Such high DC of variability in LSP blazars could
be understood in the context of the R-band tracing the falling part
(contributed by high energy electrons) of the synchrotron component of
the broadband SED. Also, the R-band tracing the rising synchrotron part
(produced by low energy electrons) in the case of ISP and HSP blazars,
could cause lesser variability in them. Thus, the observed high DC
of variability in LSP blazars relative to ISP and HSP blazars is in
accordance with the leptonic model of emission from blazar jets.
Title: The contribution of Galactic TeV pulsar wind nebulae to Fermi
large area telescope diffuse emission
Authors: Vecchiotti, Vittoria; Pagliaroli, Giulia; Villante,
Francesco Lorenzo
Bibcode: 2022CmPhy...5..161V
Altcode: 2021arXiv210703236V
The large-scale diffuse γ − ray flux observed by Fermi Large Area
Telescope (Fermi-LAT) in the 1-100 GeV energy range, parameterized as
∝ E−Γ, has a spectral index Γ that depends on the
distance from the Galactic center. This feature, if attributed to
the diffuse emission produced by cosmic rays interactions with the
interstellar gas, can be interpreted as the evidence of a progressive
cosmic ray spectral hardening towards the Galactic center. This
interpretation challenges the paradigm of uniform cosmic rays
diffusion throughout the Galaxy. We report on the implications of TeV
Pulsar Wind Nebulae observed by the High Energy Stereoscopic System
(H.E.S.S.) Galactic Plane Survey in the 1-100 TeV energy range for the
interpretation of Fermi-LAT data. We argue that a relevant fraction
of this population cannot be resolved by Fermi-LAT in the GeV domain
providing a relevant contribution to the large-scale diffuse emission,
ranging within ~4%-40% of the total diffuse γ-ray emission in the
inner Galaxy. This additional component may account for a large part
of the spectral index variation observed by Fermi-LAT, weakening the
evidence of cosmic ray spectral hardening in the inner Galaxy.
Title: Analyzing vertical dust distribution and associated
meteorological characteristics over Acidalia Planitia during a
regional and global dust event
Authors: Guha, Bijay Kumar; Panda, Jagabandhu
Bibcode: 2022Icar..38815230G
Altcode:
This study analyzed the vertical distribution of dust and associated
atmospheric structural changes over Acidalia Planitia during
one regional dust event (RDE) (MY 32, Ls = 220°) and one global
dust event (GDE) (MY 28, Ls = 260°), using Mars Climate Sounder
observations and Mars Weather Research and Forecasting (MarsWRF)
model simulations. Multilinear Regression Coefficient (MLRC) analysis
suggests that dustiness at 25-35 km and ~ 40-50 km altitudes contributed
significantly to the column integrated opacity during the RDE and
GDE, respectively. Both dust events reduced water ice opacity at
~40 km altitude. The atmosphere subsequently warmed ~10 K during the
RDE and ~ 30 K during the GDE because of dust radiative heating. An
inversion layer formed below ~20 km altitude during RDE due to the
combined effect of reduced surface temperature and the downwelling
radiation from suspended dust. However, the GDE's much larger opacity at
higher altitudes helped form a similar inversion layer at 40 km. This
atmospheric warming with the inversion layer below could be associated
with heating/cooling layers centered around 35-50 and 20-35 km heights,
influencing the variability of water ice within them. The MarsWRF
simulations showed downwelling over Acidalia Planitia at ~35-50 km
altitude, which supports the presence of the heating layer due to the
suspended atmospheric dust during the GDE. However, findings from the
heating rate analysis indicated a dominance of dust radiative heating
compared to adiabatic heating due to compression on the atmospheric
warming during the dust storm occurrences. The simulated boundary layer
height and surface radiation flux suggest weaker vertical mixing from
the surface and a surface energy budget dominated by downward radiation
from the suspended dust, which helped form heating/cooling layers
and drove variability in water ice clouds. The Empirical Orthogonal
Function analysis (carried out using MCS observations) suggests that
the seasonal cycle of the southern hemispheric dust storms, northern
hemispheric active storm track, and the cap-edge storms possibly
influenced the seasonality observed in the heating/cooling layer clouds.
Title: Altitude of pulsating arcs as inferred from tomographic
measurements
Authors: Safargaleev, Vladimir; Sergienko, Tima; Hosokawa, Keisuke;
Oyama, Shin-ichiro; Ogawa, Yasunobu; Miyoshi, Yoshizumi; Kurita,
Satoshi; Fujii, Ryochi
Bibcode: 2022EP&S...74...31S
Altcode:
Data from three all-sky cameras in Kiruna and Tjautjas (Sweden) were
used to estimate the altitude of pulsating arc-like forms using optical
tomography. The event under consideration occurred during the substorm
recovery phase and comprised both periodic luminosity variation of
the on/off type with repetition periods of 3-6 s (main pulsations)
and faster scintillation (approximately 2 Hz) during the "on" phase
of the main pulsations. It is found that (1) the altitudes of the
pulsating auroral arcs decrease during "on" intervals from ~ 95 km
to ~ 92 km and (2) for two closely spaced arcs, internal modulation
took place only in the lowest arc. The results may be interpreted in
the frame of the traditional mechanism assuming electron scattering
via VLF-wave/particle interaction in the equatorial magnetosphere,
while the internal modulation may also be alternatively interpreted
in the frame of the less-often inferred mechanism of field-aligned
acceleration somewhere between the equatorial plane and ionosphere.
Title: Evidence for presence of a global quasi-resonant mode of
oscillations during high-intensity long-duration continuous AE
activity (HILDCAA) events
Authors: Rout, Diptiranjan; Singh, Ram; Pandey, K.; Pant, T. K.;
Stolle, C.; Chakrabarty, D.; Thampi, S.; Bag, T.
Bibcode: 2022EP&S...74...91R
Altcode:
The responses of two High-Intensity Long-Duration Continuous AE Activity
(HILDCAA) events are investigated using solar wind observations at L1,
magnetospheric measurements at geosynchronous orbit, and changes in
the global ionosphere. This study provides evidence of the existence
of quasi-periodic oscillations (1.5-2 h) in the ionospheric electric
field over low latitudes, total electron content at high latitudes,
the magnetic field over the globe, energetic electron flux and magnetic
field at geosynchronous orbit, geomagnetic indices (SYM-H, AE, and PC)
and the Y-component of the interplanetary electric field (IEFy) during
the HILDCAA events at all local times. Based on detailed wavelet and
cross-spectrum analyses, it is shown that the quasi-periodic oscillation
of 1.5-2 h in IEFy is the most effective one that controls the solar
wind-magnetosphere-ionosphere coupling process during the HILDCAA events
for several days. Therefore, this investigation for the first time,
shows that the HILDCAA event affects the global magnetosphere-ionosphere
system with a "quasi-resonant" mode of oscillation.
Title: Measuring and deconvolving frequency response of SURA-4 as
a cosmic-ray radio-array experiment
Authors: Sabouhi, M.; Rastegarzadeh, G.; Meghdadi, H.
Bibcode: 2022JApA...43...56S
Altcode:
Semnan University Radio Array is a radio experiment aiming to detect
ultra-high-energy cosmic rays and investigate their properties using
radio-signal analyses. The first phase of this experiment is operational
on the roof of the physics faculty of Semnan University. Investigating
important cosmic-ray properties, including the primary particle's
energy scale, requires comparing experimental data and simulation-based
studies. This necessitates measuring and deconvolving the frequency
response of the experiment. In this study, we measure the frequency
response of the SURA-4 electronic chain and perform a computer
simulation of the Log-Periodic Dipole Antenna to obtain the system
frequency response of the SURA-4 setup. We describe the procedure of
deconvolving the measurements on the experimental data to reconstruct
the strength of the electric field trace. The result makes it possible
to investigate important cosmic-ray properties by comparing experimental
data with simulation-based studies.
Title: Spectral identification of pyroclastic deposits on Mercury
with MASCS/MESSENGER data
Authors: Galiano, A.; Capaccioni, F.; Filacchione, G.; Carli, C.
Bibcode: 2022Icar..38815233G
Altcode:
The pyroclastic deposits on Mercury are proof of explosive volcanism
that occurred on the innermost planet of the Solar System; pyroclastic
deposits are usually characterized by a central pit (vent) surrounded
by a spectrally bright and red deposit (facula). The pyroclastic
deposits on Mercury were mainly identified by analysing images
acquired from MDIS onboard the MESSENGER mission, which revealed about
200 deposits. In this work, we focus on the identification of
pyroclastic deposits on Mercury by applying spectral conditions on
radiometrically and photometrically corrected data acquired by the
MASCS spectrometer onboard the MESSENGER spacecraft. In addition, to
further optimize the quality of the used spectra, the spectral dataset
was limited by applying additional filters on observing conditions and
on detector temperature. We selected 8 pyroclastic deposits, out
of the 25 deposits recognized by the IAU, as a training field, and we
spectrally characterized the area of the deposits by using four spectral
parameters, i.e. reflectance and spectral slopes. We defined the range
of variability of the parameters able to distinguish the pyroclastic
deposits from the Average Mercury Terrain, and we filtered the MASCS
data set by applying the spectral conditions. As a result, 52 previously
recognized pyroclastic deposits and 16 new potential candidates were
revealed across the portion of Mercury's surface observed by MASCS. The
method also exposed extended areas such as the High-Reflectance Red
Plains (HRP) in Asparangi Planitia, Borealis Planitia, and the floor
of Rembrandt crater, in addition to Intermediate Terrains (IT) and
Intermediate Plains (IP). Nathair Facula, Agwo Facula, Abeeso
Facula and an unnamed facula that we termed "Facula 5" show a redder
UV slope than most of the recognized pyroclastic deposits, possibly
associated with fine regolith and/or a minor amount of Fe or C-phases
in the minerals composing the facula. Among the 16 new bright and
red areas, 6 potential candidates strongly suggest a nature connected
to explosive volcanism and could be considered as pyroclastic deposits.
Title: First-principles theory of the rate of magnetic reconnection
in magnetospheric and solar plasmas
Authors: Liu, Yi-Hsin; Cassak, Paul; Li, Xiaocan; Hesse, Michael;
Lin, Shan-Chang; Genestreti, Kevin
Bibcode: 2022CmPhy...5...97L
Altcode: 2022arXiv220314268L
The rate of magnetic reconnection is of the utmost importance in a
variety of processes because it controls, for example, the rate energy
is released in solar flares, the speed of the Dungey convection cycle
in Earth's magnetosphere, and the energy release rate in harmful
geomagnetic substorms. It is known from numerical simulations
and satellite observations that the rate is approximately 0.1 in
normalized units, but despite years of effort, a full theoretical
prediction has not been obtained. Here, we present a first-principles
theory for the reconnection rate in non-relativistic electron-ion
collisionless plasmas, and show that the same prediction explains why
Sweet-Parker reconnection is considerably slower. The key consideration
of this analysis is the pressure at the reconnection site (i.e., the
x-line). We show that the Hall electromagnetic fields in antiparallel
reconnection cause an energy void, equivalently a pressure depletion,
at the x-line, so the reconnection exhaust opens out, enabling the
fast rate of 0.1. If the energy can reach the x-line to replenish the
pressure, the exhaust does not open out. In addition to heliospheric
applications, these results are expected to impact reconnection studies
in planetary magnetospheres, magnetically confined fusion devices,
and astrophysical plasmas.
Title: Morphology of sporadic E layers derived from Fengyun-3C GPS
radio occultation measurements
Authors: Xu, Xiaohua; Luo, Jia; Wang, Han; Liu, Haifeng; Hu, Tianyang
Bibcode: 2022EP&S...74...55X
Altcode:
The Global Positioning System (GPS) radio occultation (RO) data provided
by the Fengyun-3C (FY-3C) mission during January 2015 to December
2019 are used to detect the existence of sporadic E (Es) layers over
the globe, based on which the spatial and temporal distributions of
the Es occurrence rates (ORs) are presented and analyzed. The results
are compared with the Es morphology obtained using the RO data from
the Constellation Observing System for the Meteorology, Ionosphere,
and Climate (COSMIC) mission. It is found that the seasonal variation
patterns of the spatial distributions of Es ORs derived from the FY-3C
RO data, which show clearly the effects of wind shear mechanism and the
Earth's magnetic field on the formation of Es layers, are basically
consistent with those derived from the COSMIC RO data. While the
limited local time distribution of the FY-3C RO-detected Es occurrences
makes it impossible to resolve the complete diurnal variations of Es
layers. Detailed comparisons of the Es morphologies derived from the two
different RO missions reveal that the magnitudes of the Es ORs derived
by FY-3C data are slightly smaller than those derived by COSMIC data
in the middle and low latitudes, which is due to that the top heights
of the 50 Hz RO data of FY-3C mission are generally lower than those
of the COSMIC mission. In the polar regions, the distinctly low ratio
of the FY-3C RO 50 Hz measurements which reach the height of 90 km
reduces the capability of these observations for Es-layer detections.
Title: Shared Data and Algorithms for Deep Learning in Fundamental
Physics
Authors: Benato, Lisa; Buhmann, Erik; Erdmann, Martin; Fackeldey,
Peter; Glombitza, Jonas; Hartmann, Nikolai; Kasieczka, Gregor;
Korcari, William; Kuhr, Thomas; Steinheimer, Jan; Stöcker, Horst;
Plehn, Tilman; Zhou, Kai
Bibcode: 2022CSBS....6....9B
Altcode: 2021arXiv210700656B
We introduce a PYTHON package that provides simple and unified access to
a collection of datasets from fundamental physics research—including
particle physics, astroparticle physics, and hadron- and nuclear
physics—for supervised machine learning studies. The datasets contain
hadronic top quarks, cosmic-ray-induced air showers, phase transitions
in hadronic matter, and generator-level histories. While public
datasets from multiple fundamental physics disciplines already exist,
the common interface and provided reference models simplify future
work on cross-disciplinary machine learning and transfer learning in
fundamental physics. We discuss the design and structure and line out
how additional datasets can be submitted for inclusion. As showcase
application, we present a simple yet flexible graph-based neural network
architecture that can easily be applied to a wide range of supervised
learning tasks. We show that our approach reaches performance close to
dedicated methods on all datasets. To simplify adaptation for various
problems, we provide easy-to-follow instructions on how graph-based
representations of data structures, relevant for fundamental physics,
can be constructed and provide code implementations for several of
them. Implementations are also provided for our proposed method and
all reference algorithms.
Title: Three-dimensional deformation and its uncertainty derived by
integrating multiple SAR data analysis methods
Authors: Morishita, Yu; Kobayashi, Tomokazu
Bibcode: 2022EP&S...74...16M
Altcode:
Three-dimensional (3D) surface deformation data with high accuracy
and resolution can help reveal the complex mechanisms and sources of
subsurface deformation, both tectonic and anthropogenic. Detailed 3D
deformation data are also beneficial for maintaining the position
coordinates of existing ground features, which is critical for
developing and advancing global positioning technologies and their
applications. In seismically active regions, large earthquakes have
repeatedly caused significant ground deformation and widespread damage
to human society. However, the delay in updating position coordinates
following deformation can hamper disaster recovery. Synthetic aperture
radar (SAR) data allow high-accuracy and high-resolution 3D deformation
measurements. Three analysis methods are currently available to measure
1D or 2D deformation: SAR interferometry (InSAR), split-bandwidth
interferometry (SBI), and the pixel offset method. In this paper, we
propose an approach to derive 3D deformation by integrating deformation
data from the three methods. The theoretical uncertainty of the
derived 3D deformations was also estimated using observed deformation
data for each of these methods and the weighted least square (WLS)
approach. Furthermore, we describe two case studies (the 2016 Kumamoto
earthquake sequence and the 2016 Central Tottori earthquake in Japan)
using L-band Advanced Land Observing Satellite 2 (ALOS-2) data. The
case studies demonstrate that the proposed approach successfully
retrieved 3D coseismic deformation with the standard error of ~ 1, ~
4, and ~ 1 cm in the east-west, north-south, and vertical components,
respectively, with sufficient InSAR data. SBI and the pixel offset
method filled the gaps of the InSAR data in large deformation areas in
the order of 10 cm accuracy. The derived standard errors for each pixel
are also useful for subsequent applications, such as updating position
coordinates and deformation source modeling. The proposed approach is
also applicable to other SAR datasets. In particular, next-generation
L-band SAR satellites, such as ALOS-4 and NASA-ISRO SAR (NISAR),
which have a wider swath width, more frequent observation capabilities
than the former L-band satellites, and exclusive main look directions
(i.e., right and left) will greatly enhance the applicability of 3D
deformation derivation and support the quick recovery from disasters
with significant deformation.
Title: Mass function of understudied open clusters NGC 2254 and
Mayer 2
Authors: Kowshik, Krishna Kumar; Komala, S.; Chandwani, Aahut;
Sujatha, S.
Bibcode: 2022JApA...43...54K
Altcode:
The results of the CCD photometric UBVRI observations of the open
clusters NGC 2254 and Mayer 2 are presented in this article. These
clusters were observed using the 2-metre Himalayan Chandra Telescope
at Hanle, India. NGC 2254 is located in the direction of Monoceros
constellation at a distance of 2.57 ± 0.2 kpc and Mayer 2 is located in
the direction of Camelopardalis constellation at a distance of 4.46 ±
0.3 kpc, obtained from their distance moduli in four CMDs. The cluster
radii of NGC 2254 and Mayer 2 are estimated as 3.5 ± 0.3 arc-min and
3.01 ± 0.2 arc-min, respectively. The interstellar reddening E (B -V )
along the line of sight of NGC 2254 is found to be 0.53 ± 0.03 mag,
whereas for Mayer 2 it is found to be 0.645 ± 0.08 mag. The log (ages)
of the clusters are found to be 8.2 ± 0.36 for NGC 2254 and 9 ± 0.44
for Mayer 2 using the theoretical isochrones of solar metallicity. They
were also used to obtain mass function from the apparent luminosity
function. The mass function slope of NGC 2254 is determined as 2.63
± 0.29 while Mayer 2 has a mass function slope of 2.9 ± 0.24.
Title: Dynamic deformation and fault locking of the Xianshuihe Fault
Zone, Southeastern Tibetan Plateau: implications for seismic hazards
Authors: Li, Layue; Wu, Yanqiang; Li, Yujiang; Zhan, Wei; Liu, Xinzhong
Bibcode: 2022EP&S...74...35L
Altcode:
The Xianshuihe Fault Zone is one of the most historically seismically
active regions in mainland China. However, the seismicity along
this fault zone has been quiescent for the past 40 years, since the
Daofu M6.9 earthquake in 1981. Understanding its current deformation
patterns and fault coupling characteristics is of great significance
to estimate the potential risk of strong earthquakes. In this study,
we analyzed the dynamic deformation and fault coupling characteristics
along the Xianshuihe Fault Zone using Global Navigation Satellite
System (GNSS) data for 1999-2007 and 2016-2020. The results show
that the deformation pattern of the Xianshuihe fault zone underwent
a dynamic adjustment after the 2008 Wenchuan Mw7.9
and 2013 Lushan Mw6.6 earthquakes, i.e., the maximum
shear strain accumulation rates of the Luhuo and Daofu sections
significantly decreased from 6.0 × 10-8/a to 3.2 ×
10-8/a, while that of the southeastern segment (i.e.,
Kangding and Moxi sections) increased from 4.5 × 10-8/a to
6.2 × 10-8/a. Additionally, the slip rate and deformation
width of the Xianshuihe Fault Zone also changed during these two
periods. Combined with the near-field cross-fault observation data,
we suggest that the surrounding strong earthquakes Wenchuan and Lushan
had evident differential impacts on the deformation pattern of the
Xianshuihe Fault Zone. The fault-coupling inversion results show that
the locking degree of the Xianshuihe Fault Zone continued to increase
after the Wenchuan and Lushan earthquakes, especially the Qianning
and Moxi sections increased significantly, with an average coupling
coefficient of greater than 0.9 and left-lateral slip-rate deficits of ~
5 mm/a and ~ 8 mm/a, respectively. In contrast, the locking degree of
the Kangding section decreased with almost no slip-rate deficit, which
is in a state of creeping status. The analysis of the recent rupture
history and strain accumulation characteristics of the Xianshuihe Fault
Zone indicates that both the Qianning and Moxi sections have a high
seismic potential for the next strong earthquake in the Xianshuihe
Fault Zone.
Title: Application of ERT and SSR for geotechnical site
characterization: A case study for resort assessment in New El
Alamein City, Egypt
Authors: Basheer, Alhussein Adham; Salama, Nouran S.
Bibcode: 2022JAsGe..11...58B
Altcode:
No abstract at ADS
Title: Characteristics of de Gerlache crater, site of girlands and
slope exposed ice in a lunar polar depression
Authors: Kereszturi, A.; Tomka, R.; Gläser, P. A.; Pal, B. D.;
Steinmann, V.; Warren, T.
Bibcode: 2022Icar..38815231K
Altcode:
The 31 km diameter and 7.5 km deep de Gerlache crater, located 30
km from the southern pole of the Moon was surveyed. At its bottom a
15 km diameter younger crater can be also found beside many smaller
overprinting craters. At moderately sloping terrains a few m high,
100-200 m wide, curving quasi-parallel, km long set of ridges
could be identified, which seem to be widespread on the surface,
and might cover the half or even more of the crater. We named these
"girland like features" in this work, which seem to be produced by
mass movements on slopes (however differ from most of the already
identified slope features, which show downslope elongated lineaments
or fallen/redeposited debris on the Moon). At all locations they are
superposed by recently formed 10-50 m diameter craters, thus might be
older than the equilibrium crater population shown age of about 100 Ma
old. This is the first identification of these features at the polar
terrains, where they might contribute both in the shielding or exposing
of subsurface ice. In de Gerlache crater ice occurrences have previously
been located on moderately steep slopes, indicating they might be
exposed by mass movement processes, where active movements might have
happened in the last some 10 Ma using crater statistics based age of
the shallow regolith layer. Only half of them were located at areas
with modelled surface temperatures below 110 K, where temperature might
be not enough to keep most of the deposited H2O there on Ga
time scale. However the real values are probably more diverse because
of the limited spatial resolution of available temperature data. Target
areas are indicated for possible future missions, where periodic solar
illumination, and subsurface ice at 0.5 m depth could be also present.
Title: Comment on "Soil salinity assessment by using near-infrared
channel and Vegetation Soil Salinity Index derived from Landsat
8 OLI data: a case study in the Tra Vinh Province, Mekong Delta,
Vietnam" by Kim-Anh Nguyen, Yuei-An Liou, Ha-Phuong Tran, Phi-Phung
Hoang and Thanh-Hung Nguyen
Authors: Silvestri, Sonia; Nguyen, Diep Ngoc; Chiapponi, Emilia
Bibcode: 2022PEPS....9...45S
Altcode:
Nguyen et al. (Prog Earth Planet Sci 7:1,
2020. https://doi.org/10.1186/s40645-019-0311-0) suggest that Landsat 8
OLI can be used to map and monitor soil salinity in the coastal zone of
the Mekong River Delta. The authors use empirical correlations between
the near-infrared (NIR) band, or vegetation indexes containing the
NIR band, and soil salinity. We show that within the coastal portion
of the Mekong Delta, extensively ponded due to widespread shrimp
farming, about 90% of Landsat 8 pixels are fully or partially covered
by water. We then find that, due to strong NIR radiation absorption,
NIR reflectance from ponded pixels decreases linearly with increasing
water percentage cover, while no significant correlation is found
between reflectance and soil salinity. Through detailed new analyses,
we conclude that NIR reflectance attenuation cannot be ascribed to
vegetation stress caused by soil salinity, but rather to the presence
of water ponds. We also show that a similar behavior exists in ponded
freshwater inland areas, confirming that the NIR absorption exerted
by water is independent of salinity.
Title: Right-lateral offset associated with the most recent earthquake
on the Ikeda fault of the Median Tectonic Line, southwest Japan,
revealed by ground-penetrating radar profiling
Authors: Patria, Adi; Kimura, Haruo; Kitade, Yoshihiro; Tsutsumi,
Hiroyuki
Bibcode: 2022PEPS....9....8P
Altcode:
The Median Tectonic Line (MTL) is an arc-parallel strike-slip fault
that accommodates much of the arc-parallel component of the oblique
convergence of the Philippine Sea and Eurasian plates at the Nankai
Trough. The MTL in Shikoku is one of the fastest-slipping faults in
Japan, with a late Quaternary right-lateral slip rate of 5-10 mm/yr. To
estimate the right-lateral slip amounts of the past faulting events on
the MTL, we acquired 2D and pseudo-3D ground-penetrating radar (GPR)
sections across the ENE-trending Ikeda fault of the MTL in eastern
Shikoku. We conducted the GPR surveys at the Higashi-Miyoshi site,
where two terrace riser offsets mark the active fault trace. The 2D
lines were about 28-64 m long, and the pseudo-3D data were sized 20 m
× 30 m with a 0.5-m inline spacing. We used 50 MHz GPR antennas and
conducted wide-angle measurements to estimate the electromagnetic wave
velocity. We identified three paleochannels on the final depth-converted
GPR sections, and two of them are deflected by the fault. A paleochannel
at 0.6-1.4 m depth is observed on all inline sections of the pseudo-3D
GPR data. We built a 3D model of this paleochannel and estimated
the right-lateral and vertical displacements of ~ 3.5 m and ~ 0.5 m,
respectively. This paleochannel offset is probably caused by the most
recent surface-rupturing earthquake on the Ikeda fault, which may be the
1596 Keicho-Fushimi earthquake. This study demonstrates the usefulness
of the GPR surveys to identify geological features displaced laterally
and vertically by the most recent surface-rupturing earthquake.
Title: Super-resolving star clusters with sheaves
Authors: Robinson, Michael; Capraro, Christopher T.
Bibcode: 2022EJASP2022...26R
Altcode: 2021arXiv210608123R
This article presents an optimization-based approach for counting
and localizing stars within a small cluster, based on photon counts
in a focal plane array. The array need not be arranged in any
particular way, and relatively small numbers of photons are required
to ensure convergence. The stars can be located close to one another,
as the location and magnitude errors were found to be low when the
separation was larger than 0.2 Rayleigh radii. To ensure generality
of our approach, it was constructed as a special case of a general
theory built upon topological signal processing using the mathematics
of sheaves that is applicable to general source decomposition problems.
Title: Precise aftershock distribution of the 2019 Yamagata-oki
earthquake using newly developed simple anchored-buoy ocean bottom
seismometers and land seismic stations
Authors: Shinohara, Masanao; Sakai, Shin'ichi; Okada, Tomomi; Sato,
Hiroshi; Yamashita, Yusuke; Hino, Ryota; Mochizuki, Kimihiro; Akuhara,
Takeshi
Bibcode: 2022EP&S...74....5S
Altcode:
An earthquake with a magnitude of 6.7 occurred in the Japan Sea off
Yamagata on June 18, 2019. The mainshock had a source mechanism of
reverse-fault type with a compression axis of WNW-ESE direction. Since
the source area is positioned in a marine area, seafloor seismic
observation is indispensable for obtaining the precise distribution
of the aftershocks. The source area has a water depth of less than
100 m, and fishing activity is high. It is difficult to perform
aftershock observation using ordinary free-fall pop-up type ocean
bottom seismometers (OBSs). We developed a simple anchored-buoy type
OBS for shallow water depths and performed the seafloor observation
using this. The seafloor seismic unit had three-component seismometers
and a hydrophone. Two orthogonal tiltmeters and an azimuth meter
monitored the attitude of the package. For seismic observation at
shallow water depth, we concluded that an anchored-buoy system would
have the advantage of avoiding accidents. Our anchored-buoy OBS was
based on a system used in fisheries. We deployed three anchored-buoy
OBSs in the source region where the water depth was approximately
80 m on July 5, 2019, and two of the OBSs were recovered on July 13,
2019. Temporary land seismic stations with a three-component seismometer
were also installed. The arrival times of P- and S-waves were read from
the records of the OBSs and land stations, and we located hypocenters
with correction for travel time. A preliminary location was performed
using absolute travel time and final hypocenters were obtained using
the double-difference method. The aftershocks were distributed at
a depth range of 2.5 km to 10 km and along a plane dipping to the
southeast. The plane formed by the aftershocks is consistent with the
focal mechanism of the mainshock. The activity region of the aftershocks
was positioned in the upper part of the upper crust. Focal mechanisms
were estimated using the polarity of the first arrivals. Although many
aftershocks had a reverse-fault focal mechanism similar to the focal
solution of the mainshock, normal-fault type and strike-slip fault
type focal mechanisms were also estimated.
Title: Peridotites with back-arc basin affinity exposed at the
southwestern tip of the Mariana forearc
Authors: Oya, Shoma; Michibayashi, Katsuyoshi; Ohara, Yasuhiko;
Martinez, Fernando; Kourim, Fatma; Lee, Hao-Yang; Nimura, Kohei
Bibcode: 2022PEPS....9...18O
Altcode:
Peridotites at water depths of 3430 to 5999 m have been discovered
using the submersible Shinkai6500 (dives 6K-1397 and 6K-1398) on the
southwestern slope of the 139°E Ridge (11°12'N, 139°15'E), a small
ridge at the southwesternmost tip of the Mariana forearc near the
junction with the Yap Trench and Parece Vela Basin. The peridotites
studied consist of 17 residual harzburgites and one dunite and show
various textures with respect to their depths. Peridotites with
coarse-grained (> 1 mm) textures were sampled from the shallowest
part (3705-4042 m) of the dive area, and peridotites with fine-grained
(< 0.5 mm) textures were sampled deeper (5996 m). Olivine
crystal-fabrics vary with grain size, with (010)[100] A-type patterns
for the coarse-grained peridotites, {0kl}[100] D-type patterns for the
fine-grained peridotites, and various indistinct patterns in samples
of variable grain sizes. Fine-grained peridotites with D-type olivine
crystal-fabrics could result from deformation under relatively higher
flow stresses, suggesting that a ductile shear zone in the lithospheric
mantle could occur in the deepest part of 139°E Ridge. Spinel Cr#
range from relatively low (0.36) to moderately high (up to 0.57), and
correlate with Ti contents (0.07-0.45 wt.%). The trace element patterns
of clinopyroxene similarly exhibit steepening slopes from the middle to
the light REEs regardless of textural variations. These mineralogical
and geochemical features would result from melt-rock interactions
under conditions of relatively shallow lithospheric mantle, which
are much more comparable with the Parece Vela Basin peridotites than
the Mariana forearc peridotites. Consequently, the Parece Vela Basin
mantle is more likely exposed on the inner slope of the westernmost
Mariana Trench, presumably due to the collision of the Caroline Ridge.
Title: Concurrent effects of Martian topography on the thermosphere
and ionosphere at high northern latitudes
Authors: Chen, Yiding; Liu, Libo; Le, Huijun; Zhang, Hui; Zhang,
Ruilong
Bibcode: 2022EP&S...74...26C
Altcode:
Martian topography modulated non-migrating tides play important roles in
the upper atmosphere and thus in the ionosphere through their coupling,
especially in their longitude variations. In this study, the neutral
scale height (Hn) and ionospheric peak electron density
(NmM2) and height (hmM2)
retrieved from the MGS radio occultation measurements were used
to investigate the coupling between the Martian thermosphere and
ionosphere under the forcing of topography modulated tides by
investigating their concurrent longitude variations. A segment of
the measurements with fixed local time was selected to analyze the
relationships between the longitude variations of the parameters in
detail. Longitude variations of the thermosphere and ionosphere are
significant though topographic fluctuations are not very prominent
at high northern latitudes. Longitude fluctuations of Hn
and NmM2 are nearly in anti-phase and percentage
fluctuation amplitudes of Hn are nearly twice as large as
those of NmM2, which indicate the non-migrating
tide forced coupling between the ionosphere and thermosphere
conforms to the Chapman theory, and suggests longitude variation of
NmM2 can be used as a quantitative indicator for
that of the thermal structure in the lower thermosphere. Longitude
variation phases of Hn and hmM2
are also discrepant. That is due to tide vertical propagation since
Hn and hmM2 depend on the atmospheric
thermal structures at different height levels. The thermosphere and
ionosphere show longitude variations due to the topography; however,
they are dominated by inconsistent longitude components. This implies
discrepant exciting and propagating efficiencies of various topography
modulated tides.
Title: On using a double-thin-shell approach and TEC perturbation
component to sound night-time mid-latitude E-F coupling
Authors: Fu, Weizheng; Yokoyama, Tatsuhiro; Ssessanga, Nicholas;
Yamamoto, Mamoru; Liu, Peng
Bibcode: 2022EP&S...74...83F
Altcode:
Observations and theoretical analysis on the night-time mid-latitude
ionospheric irregularities support the postulation of frequently
coupled E and F regions. In this paper, we attempt at asserting this
notion while using total electron content (TEC) measurements. The
TECs are from a dense GNSS receiver network over Japan with more than
1200 stations and a mean distance of ~ 25 km between receivers; thus,
ideal for analyzing small-scale perturbations in ionospheric electron
density. We take an ansatz that mid-latitude night-time plasma
instabilities concentrate at E and F layers. Then the integrated
three-dimensional density perturbations are parameterized with a
double-thin-shell model. At each shell, perturbation components are
assumed identical at any point within a given grid block. Two days with
events of night-time medium-scale traveling ionospheric disturbances
(MSTIDs), but with different amplitudes, were investigated. Results
show that the newly developed technique can infer several horizontal
characteristics on E-F coupled instabilities; the coexistence of
northwest-southeast (NW-SE) aligned irregular structures in E and F
regions is evident. Both E- and F-region irregularities share similar
propagation parameters, a shred of clear evidence of strong coupling.
Title: Lyman-alpha radiation escape caused by heating of atoms and
aberration in the era of recombination
Authors: Shepelev, A. V.
Bibcode: 2022JApA...43...55S
Altcode:
Determination of cosmological parameters from the results of the Planck
mission is based on the standard theory of primary recombination in
many respects. The recombination rate substantially depends on the
level of recombination radiation arising in this process. Considering
that into account the heating of hydrogen atoms by L yα
-radiation together with the aberration of radiation shows that the
level of L yα -radiation is lower than that predicted by
the standard theory. This results in an increase in the recombination
rate and a higher estimate of the redshift of last scattering, which
can lead to a correction of the values of some cosmological parameters
obtained from the results of Planck mission.
Title: Identification of marine magnetic anomalies based on the
sliding window curve similarity method
Authors: Wang, Mingming; Cao, Jing; Li, Jianlou; Liu, Xianghong
Bibcode: 2022EP&S...74...79W
Altcode:
Marine magnetic anomalies play an essential role in plate tectonics
and geodynamics. The conventional method to identify marine magnetic
anomalies is to visually compare synthetic and observed magnetic
anomaly profiles, and there is usually no quantitative evaluation for
the identification results. Therefore, we developed the sliding window
curve similarity (SWCS) method to objectively identify marine magnetic
anomalies and quantitatively evaluate the identification results. The
synthetic model tests and practical applications show that the SWCS
method is feasible and effective in identifying fast-spreading marine
magnetic anomalies. The applications of the SWCS method show that the
theoretical windows using combined polarity chrons can improve the
accuracy of identification.
Title: Comparison between the Hamiltonian Monte Carlo method and
the Metropolis-Hastings method for coseismic fault model estimation
Authors: Yamada, Taisuke; Ohno, Keitaro; Ohta, Yusaku
Bibcode: 2022EP&S...74...86Y
Altcode:
A rapid source fault estimation and quantitative assessment of the
uncertainty of the estimated model can elucidate the occurrence
mechanism of earthquakes and inform disaster damage mitigation. The
Bayesian statistical method that addresses the posterior distribution of
unknowns using the Markov chain Monte Carlo (MCMC) method is significant
for uncertainty assessment. The Metropolis-Hastings method, especially
the Random walk Metropolis-Hastings (RWMH), has many applications,
including coseismic fault estimation. However, RWMH exhibits a
trade-off between the transition distance and the acceptance ratio
of parameter transition candidates and requires a long mixing time,
particularly in solving high-dimensional problems. This necessitates
a more efficient Bayesian method. In this study, we developed a fault
estimation algorithm using the Hamiltonian Monte Carlo (HMC) method,
which is considered more efficient than the other MCMC method, but
its applicability has not been sufficiently validated to estimate
the coseismic fault for the first time. HMC can conduct sampling
more intelligently with the gradient information of the posterior
distribution. We applied our algorithm to the 2016 Kumamoto earthquake
(MJMA 7.3), and its sampling converged in 2 × 104
samples, including 1 × 103 burn-in samples. The estimated
models satisfactorily accounted for the input data; the variance
reduction was approximately 88%, and the estimated fault parameters
and event magnitude were consistent with those reported in previous
studies. HMC could acquire similar results using only 2% of the
RWMH chains. Moreover, the power spectral density (PSD) of each
model parameter's Markov chain showed this method exhibited a low
correlation with the subsequent sample and a long transition distance
between samples. These results indicate HMC has advantages in terms
of chain length than RWMH, expecting a more efficient estimation for a
high-dimensional problem that requires a long mixing time or a problem
using nonlinear Green's function, which has a large computational cost.
Title: Feasibility study on calculating the Q value of shallow media
by using a dense seismic array and a large-volume airgun source
Authors: Du, Shen; Yu, YanXiang; Xiao, Liang
Bibcode: 2022EP&S...74...68D
Altcode:
The feasibility of using a dense seismic array with an airgun source
to study the quality factors of shallow media is verified. Data
were obtained from 37 stations in the dense seismic array located
in Binchuan, Yunnan Province, China, and the amplitude-distance
attenuation method and the coda normalization method were applied to
calculate the S-wave quality factors in the area. The amplitude-distance
attenuation method yielded Qs-1=0.0260 ± 0.0103,
and the frequency-dependent Qs-1 calculated
by the coda normalization method can be expressed by the power law
Qs-1(f ) ≅0.0554 f-0.5643 . The
consistency between the results of these two methods shows that a dense
seismic array with an airgun source can be used to study the attenuation
characteristics of shallow media. The amplitudes at some points
deviate substantially from the fitted curve and thus have a certain
influence on the fitting results; hence, we must select high-precision
data for the calculation. Given the topography, we speculate that the
anomalous stations located on the edge of the Binchuan Basin and in
the western hilly area are due to the edge effect of the basin and
the weak attenuation of the hilly area and that the anomalous station
located in the northern Binchuan depocenter is attributable to local
site factors. Compared with the Qs-1 estimated by
previous studies, the Qs-1 in the Binchuan area
is found to lie between those of the hard soil and sedimentary rock and
is similar to the Qs-1 in the North China Basin,
corresponding to the shallow velocity structure in this area.
Title: The MMX rover: performing in situ surface investigations
on Phobos
Authors: Michel, Patrick; Ulamec, Stephan; Böttger, Ute; Grott,
Matthias; Murdoch, Naomi; Vernazza, Pierre; Sunday, Cecily; Zhang,
Yun; Valette, Rudy; Castellani, Romain; Biele, Jens; Tardivel, Simon;
Groussin, Olivier; Jorda, Laurent; Knollenberg, Jörg; Grundmann,
Jan Thimo; Arrat, Denis; Pont, Gabriel; Mary, Stephane; Grebenstein,
Markus; Miyamoto, Hirdy; Nakamura, Tomoki; Wada, Koji; Yoshikawa,
Kent; Kuramoto, Kiyoshi
Bibcode: 2022EP&S...74....2M
Altcode:
The Japanese MMX sample return mission to Phobos by JAXA will carry
a rover developed by CNES and DLR that will be deployed on Phobos to
perform in situ analysis of the Martian moon's surface properties. Past
images of the surface of Phobos show that it is covered by a layer
of regolith. However, the mechanical and compositional properties
of this regolith are poorly constrained. In particular, from current
remote images, very little is known regarding the particle sizes, their
chemical composition, the packing density of the regolith as well as
other parameters such as friction and cohesion that influence surface
dynamics. Understanding the properties and dynamics of the regolith
in the low-gravity environment of Phobos is important to trace back
its history and surface evolution. Moreover, this information is also
important to support the interpretation of data obtained by instruments
onboard the main MMX spacecraft, and to minimize the risks involved in
the spacecraft sampling operations. The instruments onboard the Rover
are a Raman spectrometer (RAX), an infrared radiometer (miniRad), two
forward-looking cameras for navigation and science purposes (NavCams),
and two cameras observing the interactions of regolith and the rover
wheels (WheelCams). The Rover will be deployed before the MMX spacecraft
samples Phobos' surface and will be the first rover to drive on the
surface of a Martian moon and in a very low gravity environment.
Title: The Mars system revealed by the Martian Moons eXploration
mission
Authors: Ogohara, Kazunori; Nakagawa, Hiromu; Aoki, Shohei;
Kouyama, Toru; Usui, Tomohiro; Terada, Naoki; Imamura, Takeshi;
Montmessin, Franck; Brain, David; Doressoundiram, Alain; Gautier,
Thomas; Hara, Takuya; Harada, Yuki; Ikeda, Hitoshi; Koike, Mizuho;
Leblanc, François; Ramirez, Ramses; Sawyer, Eric; Seki, Kanako;
Spiga, Aymeric; Vandaele, Ann Carine; Yokota, Shoichiro; Barucci,
Antonella; Kameda, Shingo
Bibcode: 2022EP&S...74....1O
Altcode:
Japan Aerospace Exploration Agency (JAXA) plans a Phobos sample return
mission (MMX: Martian Moons eXploration). In this study, we review
the related works on the past climate of Mars, its evolution, and
the present climate and weather to describe the scientific goals and
strategies of the MMX mission regarding the evolution of the Martian
surface environment. The MMX spacecraft will retrieve and return
a sample of Phobos regolith back to Earth in 2029. Mars ejecta are
expected to be accumulated on the surface of Phobos without being much
shocked. Samples from Phobos probably contain all types of Martian rock
from sedimentary to igneous covering all geological eras if ejecta
from Mars could be accumulated on the Phobos surface. Therefore,
the history of the surface environment of Mars can be restored
by analyzing the returned samples. Remote sensing of the Martian
atmosphere and monitoring ions escaping to space while the spacecraft
is orbiting Mars in the equatorial orbit are also planned. The camera
with multi-wavelength filters and the infrared spectrometer onboard
the spacecraft can monitor rapid transport processes of water vapor,
dust, ice clouds, and other species, which could not be traced by
the previous satellites on the sun-synchronous polar orbit. Such
time-resolved pictures of the atmospheric phenomena should be an
important clue to understand both the processes of water exchange
between the surface/underground reservoirs and the atmosphere and the
drivers of efficient material transport to the upper atmosphere. The
mass spectrometer with unprecedented mass resolution can observe ions
escaping to space and monitor the atmospheric escape which has made
the past Mars to evolve towards the cold and dry surface environment we
know today. Together with the above two instruments, it can potentially
reveal what kinds of atmospheric events can transport tracers (e.g.,
H2O) upward and enhance the atmospheric escape.
Title: Topside equatorial spread F-related field-aligned Poynting
flux: observations and simulations
Authors: Rodríguez-Zuluaga, J.; Stolle, C.; Hysell, D.; Knudsen, D. J.
Bibcode: 2022EP&S...74..119R
Altcode:
Electric and magnetic field data from the Swarm constellation
mission are used to report on the Poynting flux associated with
postsunset topside equatorial spread F. A three-dimensional numerical
simulation of plasma density irregularities in the F region ionosphere
leading to spread F is used to interpret and support the satellite
observations. Here, we focus on quasi-static magnetic and electric
fields nearby equatorial plasma depletions (EPDs). The observations
show a correlation of the Poynting flux with the plasma number density
when background densities are larger than 105cm-3
—typical of pre-midnight hours. In other words, the Poynting flux
increases as EPDs get more depleted. As time passes, both plasma
density and Poynting flux decay. For the latter, however, this temporal
dependence is evident in the pre-midnight sector only. Concerning
spatial variations, the Poynting flux is observed to enhance inside
EPDs as a function of magnetic latitude mainly due to the strengthening
of field-aligned currents as they flow away from the dip equator. The
Poynting flux follows the dynamo theory, wherein the winds in the F
region act as the generator at night and the E region conductivity
on shared magnetic field lines as the load. That said, the Poynting
flux is generally expected to flow along the field lines away from
a dynamo source at the dip equator. Nevertheless, observations
show unidirectional flows from one magnetic hemisphere to another,
suggesting a generator below the satellites' altitude. The numerical
simulations confirm these observations and show that such latitudinal
shifts of the generator are due almost entirely to the winds.
Title: Martian moons exploration MMX: sample return mission to Phobos
elucidating formation processes of habitable planets
Authors: Kuramoto, Kiyoshi; Kawakatsu, Yasuhiro; Fujimoto, Masaki;
Araya, Akito; Barucci, Maria Antonietta; Genda, Hidenori; Hirata, Naru;
Ikeda, Hitoshi; Imamura, Takeshi; Helbert, Jörn; Kameda, Shingo;
Kobayashi, Masanori; Kusano, Hiroki; Lawrence, David J.; Matsumoto,
Koji; Michel, Patrick; Miyamoto, Hideaki; Morota, Tomokatsu; Nakagawa,
Hiromu; Nakamura, Tomoki; Ogawa, Kazunori; Otake, Hisashi; Ozaki,
Masanobu; Russell, Sara; Sasaki, Sho; Sawada, Hirotaka; Senshu,
Hiroki; Tachibana, Shogo; Terada, Naoki; Ulamec, Stephan; Usui,
Tomohiro; Wada, Koji; Watanabe, Sei-ichiro; Yokota, Shoichiro
Bibcode: 2022EP&S...74...12K
Altcode:
Martian moons exploration, MMX, is the new sample return mission
planned by the Japan Aerospace Exploration Agency (JAXA) targeting
the two Martian moons with the scheduled launch in 2024 and return to
the Earth in 2029. The major scientific objectives of this mission are
to determine the origin of Phobos and Deimos, to elucidate the early
Solar System evolution in terms of volatile delivery across the snow
line to the terrestrial planets having habitable surface environments,
and to explore the evolutionary processes of both moons and Mars
surface environment. To achieve these objectives, during a stay in
circum-Martian space over about 3 years MMX will collect samples
from Phobos along with close-up observations of this inner moon and
carry out multiple flybys of Deimos to make comparative observations
of this outer moon. Simultaneously, successive observations of the
Martian atmosphere will also be made by utilizing the advantage of
quasi-equatorial spacecraft orbits along the moons' orbits.
Title: Array-size dependency of the upper limit wavelength normalized
by array radius for the standard spatial autocorrelation method
Authors: Cho, Ikuo
Bibcode: 2022EP&S...74...75C
Altcode:
This study has shown for the analysis of the standard spatial
autocorrelation (SPAC) method that the upper limit wavelength (ULW)
normalized by the array radius (normalized ULW, NULW) strongly depends
on the array size if we include small (radius r less than a few tens
of meters) and very small (r about 1 m or less) microtremor arrays in
addition to conventional larger arrays. First, field data of microtremor
arrays were analyzed to demonstrate the possible use of small/very
small arrays. Specifically, it was shown that, (i) even in the case of
a very small array, random errors in the analysis results for very long
wavelengths relative to the array radius are kept in an acceptable range
for practical use; (ii) the signal-to-noise ratio (SNR) is a crucial
factor determining the NULW; and (iii) an equation determining the
NULW applies, namely the relation (NULW ) ∝√{(SNR ) } holds through
very small to large arrays. The field data used are those distributed
for blind prediction (BP) experiments for an international symposium
(BP data), which consist of high-quality microtremor array data with
various radii from very small (r = 0.58 m) to large (r = 555 m). It
was then shown that SNRs of the BP data, and consequently the NULWs,
increase with a decrease of array radius. Statistical data obtained
from a few hundred arrays in our previous research also exhibit a
similar tendency. The BP data lie around the maximum values of these
distributions, showing the high quality of the BP data as well as
supporting the array-size dependency of the NULW. Finally, the BP
data were processed to identify the characteristics of the soil
attenuation. It was found that the array-size dependency of NULW,
as well as the large variations in NULW, can generally be explained
by soil attenuation. It is plausible that the SNR of small/very
small arrays are generally determined by the soil attenuation if the
self-noise of the recording system is excluded. A logical conclusion
drawn from these results, and also empirically supported, is that the
practicality of very small arrays increases as the soil gets softer.
Title: An electrodynamics model for Data Interpretation and Numerical
Analysis of ionospheric Missions and Observations (DINAMO)
Authors: Shidler, Samuel A.; Rodrigues, Fabiano S.
Bibcode: 2022PEPS....9....7S
Altcode:
We introduce a new numerical model developed to assist with Data
Interpretation and Numerical Analysis of ionospheric Missions and
Observations (DINAMO). DINAMO derives the ionospheric electrostatic
potential at low- and mid-latitudes from a two-dimensional dynamo
equation and user-specified inputs for the state of the ionosphere
and thermosphere (I-T) system. The potential is used to specify the
electric fields and associated F-region E × B plasma drifts. Most of
the model was written in Python to facilitate the setup of numerical
experiments and to engage students in numerical modeling applied to
space sciences. Here, we illustrate applications and results of DINAMO
in two different analyses. First, DINAMO is used to assess the ability
of widely used I-T climatological models (IRI-2016, NRLMSISE-00, and
HWM14), when used as drivers, to produce a realistic representation
of the low-latitude electrodynamics. In order to evaluate the results,
model E × B drifts are compared with observed climatology of the drifts
derived from long-term observations made by the Jicamarca incoherent
scatter radar. We found that the climatological I-T models are able to
drive many of the features of the plasma drifts including the diurnal,
seasonal, altitudinal and solar cycle variability. We also identified
discrepancies between modeled and observed drifts under certain
conditions. This is, in particular, the case of vertical equatorial
plasma drifts during low solar flux conditions, which were attributed
to a poor specification of the E-region neutral wind dynamo. DINAMO
is then used to quantify the impact of meridional currents on the
morphology of F-region zonal plasma drifts. Analytic representations of
the equatorial drifts are commonly used to interpret observations. These
representations, however, commonly ignore contributions from meridional
currents. Using DINAMO we show that that these currents can modify
zonal plasma drifts by up to ~ 16 m/s in the bottom-side post-sunset
F-region, and up to ~ 10 m/s between 0700 and 1000 LT for altitudes
above 500 km. Finally, DINAMO results show the relationship between the
pre-reversal enhancement (PRE) of the vertical drifts and the vertical
shear in the zonal plasma drifts with implications for equatorial
spread F.
Title: Viscous dissipative two-temperature accretion flows around
black holes
Authors: Sarkar, Shilpa; Chattopadhyay, Indranil
Bibcode: 2022JApA...43...34S
Altcode:
General relativistic, advective, viscous, two-temperature accretion
disc solutions are studied around a Schwarzschild black hole. The
thermodynamics of the flow is described by the relativistic equation
of state or Chattopadhyay and Ryu equation of state modified
for a two-temperature regime. The cooling processes considered are
bremsstrahlung, synchrotron and the Comptonization of these photons. The
degeneracy of accretion solutions in the two-temperature regime is
resolved using the so called `maximum entropy' methodology. Utilizing
this method, we analyzed the unique solutions and the corresponding
spectra for a broad range of parameter space. Interplay between heating
due to viscous dissipation and cooling due to different radiation
mechanisms plays a significant role in determining the solution and
spectrum obtained. In the end, we analyze the observation of a low
luminosity AGN, NGC 3998, fitted using our model.
Title: Influence of composition-dependent thermal conductivity on the
long-term evolution of primordial reservoirs in Earth's lower mantle
Authors: Li, Yang; Deschamps, Frédéric; Shi, Zhidong; Guerrero,
Joshua M.; Hsieh, Wen-Pin; Zhao, Liang; Tackley, Paul J.
Bibcode: 2022EP&S...74...46L
Altcode:
The influence of composition-dependent thermal conductivity and
heterogeneous internal heating of primordial dense material on the
long-term evolution of primordial reservoirs in the lower mantle of
the Earth is investigated utilizing thermochemical mantle convection
simulations in a 2-D spherical annulus geometry. Our results show
that a reduction in the thermal conductivity of primordial dense
material due to iron enrichment does not substantially alter mantle
dynamics nor the long-term stability of the reservoirs of this
dense material. If the primordial dense material is also enriched
in heat-producing elements, the average altitude of these reservoirs
slightly increases as the thermal conductivity is reduced, therefore,
covering smaller core-mantle boundary areas. Our study indicates that
the composition-dependent thermal conductivity of primordial material
plays a second order role in the long-term evolution of Earth's mantle.
Title: Improving estimates of the ionosphere during geomagnetic
storm conditions through assimilation of thermospheric mass density
Authors: Fernandez-Gomez, Isabel; Kodikara, Timothy; Borries, Claudia;
Forootan, Ehsan; Goss, Andreas; Schmidt, Michael; Codrescu, Mihail V.
Bibcode: 2022EP&S...74..121F
Altcode:
Dynamical changes in the ionosphere and thermosphere during geomagnetic
storm times can have a significant impact on our communication and
navigation applications, as well as satellite orbit determination and
prediction activities. Because of the complex electrodynamics coupling
processes during storms, which cannot be fully described with the
sparse set of thermosphere-ionosphere (TI) observations, it is crucial
to accurately model the state of the TI system. The approximation
closest to the true state can be obtained by assimilating relevant
measurements into physics-based models. Thermospheric mass density
(TMD) derived from satellite measurements is ideal to improve the
thermosphere through data assimilation. Given the coupled nature of
the TI system, the changes in the thermosphere will also influence
the ionosphere state. This study presents a quantification of the
changes and improvement of the model state produced by assimilating
TMD not only for the thermosphere density but also for the ionosphere
electron density under storm conditions. TMD estimates derived from
a single Swarm satellite and the Coupled Thermosphere Ionosphere
Plasmasphere electrodynamics (CTIPe) physics-based model are used
for the data assimilation. The results are presented for a case study
during the St. Patricks Day storm 2015. It is shown that the TMD data
assimilation generates an improvement of the model's thermosphere
density of up to 40% (measured along the orbit of the non-assimilated
Swarm satellites). The model's electron density during the course of
the storm has been improved by approximately 8 and 22% relative to
Swarm-A and GRACE, respectively. The comparison of the model's global
electron density against a high-quality 3D electron density model,
generated through assimilation of total electron content, shows that
TMD assimilation modifies the model's ionosphere state positively
and negatively during storm time. The major improvement areas are the
mid-low latitudes during the storm's recovery phase.
Title: Subgrade soil evaluation using integrated seismic refraction
tomography and geotechnical studies: A case of Ajaokuta-Anyigba
Federal highway, North-Central Nigeria
Authors: Daniel Opemipo, Obasaju; Moroof, Oloruntola; Sunday, Oladele;
Victor, Ojekunle; Christopher, Baiyegunhi
Bibcode: 2022JAsGe..11..293D
Altcode:
No abstract at ADS
Title: A new approach automatic separation of the Bouguer
gravity anomaly, using a new concept for 2D-semi-inversion of the
sphere-shaped model
Authors: Abdelfattah, M. Dahab
Bibcode: 2022JAsGe..11..257A
Altcode:
No abstract at ADS
Title: The production of actinides in neutron star mergers
Authors: Wu, Meng-Ru; Banerjee, Projjwal
Bibcode: 2022APPSB..32...19W
Altcode: 2022arXiv220511806W
Although the multimessenger detection of the neutron star merger
event GW170817 confirmed that mergers are promising sites producing
the majority of nature's heavy elements via the rapid neutron-capture
process (r-process), a number of issues related to the production
of translead nuclei—the actinides—remain to be answered. In this
short review paper, we summarize the general requirements for actinide
production in r-process and the impact of nuclear physics inputs. We
also discuss recent efforts addressing the actinide production in
neutron star mergers from different perspectives, including signatures
that may be probed by future kilonova and γ-ray observations, the
abundance scattering in metal-poor stars, and constraints put by the
presence of short-lived radioactive actinides in the Solar system.
Title: Outer trench slope extension to frontal wedge compression in
a subducting plate
Authors: Chang, Emmy T.; Mozziconacci, Laetitia
Bibcode: 2022EP&S...74..102C
Altcode:
The occurrence of faulting in subducting plates is a major process
that changes the mechanical properties of the subducting lithosphere
and carries surface materials into mantle wedges. Two ocean-bottom
seismometer networks deployed on the frontal accretionary wedge of
the northern Manila trench in 2005 and on the outer slope of the
trench in 2006 were used to detect earthquakes in the subducting
plate. All available P and S manually picked phases and the waveforms
of 16 short-period, three-component stations were used. Relocation was
performed using the double-difference method with differential times
derived from the phase-picked data. Two intraplate earthquake sequences
of small-to-moderate magnitudes in the northern Manila subduction
system were investigated in this study. The results revealed distinct
fault planes, but a contrasting seismogeny over the northern Manila
Trench. The seismicity in the frontal wedge (as measured in 2005)
was mainly contributed by a fluid overpressure sequence, whereas
that in the incoming plate (as measured in 2006) was contributed
by the aftershocks of an extensional faulting sequence. The obtained
seismic velocity models and Vp/Vs ratios revealed
that the overpressure was likely caused by high pore-fluid pressure
within the shallow subduction zone. By using the near-field waveform
inversion algorithm, we determined focal mechanism solutions for a
few relatively large earthquakes. Through the use of data obtained
from global seismic observations, we determined that stress transfer
may be responsible for the seismic activity in the study area during
the period of 2005-2006. In late 2005, the plate interface in the
frontal wedge area was unlocked by the overpressure effect due to
a thrusting-dominant sequence. This event changed the stress regime
across the Manila Trench and triggered a normal fault extension at
the outer trench slope in mid-2006. However, in the present study,
a hybrid focal mechanism solution indicating reverse and strike-slip
mechanisms was implemented, and it revealed that the plate interface
locked again in late 2006.
Title: Correction to: Anatomy of active volcanic edifice at the
Kusatsu-Shirane volcano, Japan, by magnetotellurics: hydrothermal
implications for volcanic unrests
Authors: Tseng, Kuo Hsuan; Ogawa, Yasuo; Nurhasan, Tank, Sabri Bülent;
Ujihara, Naoto; Honkura, Yoshimori; Terada, Akihiko; Usui, Yoshiya;
Kanda, Wataru
Bibcode: 2022EP&S...74...81T
Altcode:
No abstract at ADS
Title: Identifying tsunami traces beyond sandy tsunami deposits
using terrigenous biomarkers: a case study of the 2011 Tohoku-oki
tsunami in a coastal pine forest, northern Japan
Authors: Shinozaki, Tetsuya; Sawai, Yuki; Ikehara, Minoru; Matsumoto,
Dan; Shimada, Yumi; Tanigawa, Koichiro; Tamura, Toru
Bibcode: 2022PEPS....9...29S
Altcode:
The distributions of sandy tsunami deposits do not reflect the true
extents of tsunami inundation areas, leading to underestimates
of inundation by past tsunamis and thus the magnitudes of their
associated tsunamigenic earthquakes. To archive the sedimentological
and geochemical features of the 2011 Tohoku-oki tsunami deposit, we
performed visual observations and computed tomography, grain-size, water
content, and organic geochemical analyses of sediments from a coastal
forest at Oirase Town, northern Japan. Stratigraphic observations
revealed the 2011 tsunami deposit to be a landward-thinning interbedded
sand and soil layer that became ambiguous in landward locations. The
sediment samples from the inundated area did not contain marine-sourced
biomarkers; instead, peak concentrations of isolongifolene, an organic
compound derived from Pinus in the forest, were observed within or
just above the sandy tsunami deposits in sediment sections. Peak
isolongifolene concentrations were also detected in landward soils
inundated by the tsunami in which no sand layer was observable, but were
not observed beyond the inundation limit. Although this characteristic
biomarker is unique to this and similar depositional environments,
these results suggest that lateral changes of the concentrations of
environment-specific biological proxies in the sedimentary column may
record tsunami inundation.
Title: Exploration of spatial and temporal variability of rainfall
and their impact on rice production in Burma in 1901-1939 during
the colonial period
Authors: Shrestha, Badri Bhakta; Kawasaki, Akiyuki; Inoue, Tomoshige;
Matsumoto, Jun; Shiroyama, Tomoko
Bibcode: 2022PEPS....9...48S
Altcode:
Climate is one of the main factors for rice crop growth. Understanding
the relationship between climate variability and rice production during
the period from 1901 to 1939 in Burma can give a clear picture of the
impact of climate variability on rice yield since there were fewer
human interventions on the catchment and almost no use of chemical
fertilizer or high-yielding rice varieties at that time. However, the
quantitative analysis of climate variability and its impact on rice
production has not yet been paid sufficient scientific attention for the
historic period. First, the changing trends of rainfall and rice yield
between 1901 and 1939 were analyzed, including the effect of rainfall
variability on rice production from multiple perspectives regarding
rainfall characteristics, such as seasonal rainfall, various rainfall
indices, rainfall anomalies, and monthly rainfall variability. Then,
the relationship between rice yield and rainfall was investigated
using multiple regression analysis to show how rainfall spatial and
temporal variabilities have influenced rice yield and production,
including essential factors that affected rice yield in each Burma
district. The historical development of rice production in Burma during
the period was also explored. Our findings indicate that not only
the annual variability of rainfall, but also its monthly variability
within a particular year likely influenced rice production. Excessive
rainfall in the early or middle stage of crop growth or less during
the early-middle or latter half of crop growth possibly caused the rice
yield reduction in Burma during the colonial period. Furthermore, the
results indicated that although rainfall anomalies widely differed from
period to period, rice yield anomalies clearly showed the distinction of
periods with higher or lower rice yields than average rice yield. Mostly
higher than average rice yield was observed before 1910 in the Coastal
Zone and before 1918 in the Delta, Dry, and Hilly Zones. The results
of this study imply that selected rainfall indices could affect rice
yield, positively or negatively, including the varied magnitude of
their effects from one district to another, depending on climatic
zones and agricultural ecosystems.
Title: Precision and convergence speed of the ensemble Kalman
filter-based parameter estimation: setting parameter uncertainty
for reliable and efficient estimation
Authors: Sueki, Kenta; Nishizawa, Seiya; Yamaura, Tsuyoshi; Tomita,
Hirofumi
Bibcode: 2022PEPS....9...47S
Altcode:
Determining physical process parameters in atmospheric models is
critical to obtaining accurate weather and climate simulations;
estimating optimal parameters is essential for reducing model
error. Recently, automatic parameter estimation using the ensemble
Kalman filter (EnKF) has been tested instead of conventional manual
parameter tuning. To maintain uncertainty for the parameters to be
estimated and avoid filter divergence in EnKF-based methods, some
inflation techniques should be applied to parameter ensemble spread
(ES). When ES is kept constant through the estimation using an inflation
technique, the precision and convergence speed of the estimation
vary depending on the ES assigned to estimated parameters. However,
there is debate over how to determine an appropriate constant ES for
estimated parameters in terms of precision and convergence speed. This
study examined the dependence of precision and convergence speed of an
estimated parameter on the ES to establish a reliable and efficient
method for EnKF-based parameter estimation. This was carried out
by conducting idealized experiments targeting a parameter in a cloud
microphysics scheme. In the experiments, there was a threshold value for
ES where any smaller values did not result in any further improvements
to the estimation precision, which enabled the determination of the
optimal ES in terms of precision. On the other hand, the convergence
speed accelerates monotonically as ES increases. To generalize the
precision and convergence speed, we approximated the time series
of parameter estimation with a first-order autoregression (AR(1))
model. We demonstrated that the precision and convergence speed may be
quantified by two parameters from the AR(1) model: the autoregressive
parameter and the amplitude of random perturbation. As the ES increases,
the autoregressive parameter decreases, while the random perturbation
amplitude increases. The estimation precision was determined based on
the balance between the two values. The AR(1) approximation provides
quantitative guidelines to determine the optimal ES for the precision
and convergence speed of the EnKF-based parameter estimation.
Title: Extraordinary quasi-16-day wave activity from October 2013
to January 2014 with radar observations at mid-latitudes and MERRA2
reanalysis data
Authors: Huang, Xiansi; Huang, Kaiming; Zhang, Shaodong; Huang,
Chunming; Gong, Yun; Cheng, Hao
Bibcode: 2022EP&S...74...98H
Altcode:
Combining two meteor radar observations at mid-latitudes and MERRA2
reanalysis data, we report an extraordinary quasi-16-day wave (Q16DW)
activity in the mesosphere and lower thermosphere (MLT) from about
October 2013 to January 2014. The Q16DW is not only active for a long
period, but also unrelated to stratospheric sudden warming (SSW), while
7-year radar observations indicate that strong waves and oscillations
in the MLT at mid-latitudes occur generally in winter, and are almost
always associated with SSW and stratospheric final warming (SFW),
except the extraordinary Q16DW. Meanwhile, during the SSW and SFW in
February and March 2014, the observation and reanalysis data show that
an intense Q16DW arises in the stratosphere but is not present in the
MLT. The two Q16DWs are obviously distinguished from each other. The
exceptional Q16DW shows a slowly downward phase progression from the
MLT to the troposphere with predominant wavenumber 1, while the second
Q16DW has a steeper vertical phase in the stratosphere with predominant
wavenumber 2. Although the eastward winds prevail, these Q16DWs are
weakened and evanescent in the region with the westward wind and
negative refractive index. EP flux vector indicates that these waves
originate mainly from the lower atmosphere at mid- and high-latitudes,
and are intensified in the middle stratosphere. The first Q16DW may
make a little contribution to polar vortex intensification due to
small EP flux divergence. However, the Q16DW in the SSW has a strong
negative divergence almost in the whole polar stratosphere, implying
an important role in the stratospheric zonal wind reduction in the SSW.
Title: Experimental simulations of shock textures in BCC iron:
implications for iron meteorites
Authors: Ohtani, Eiji; Sakurabayashi, Toru; Kurosawa, Kosuke
Bibcode: 2022PEPS....9...24O
Altcode: 2022arXiv220409195O
Neumann band in iron meteorites, which is deformation twins in kamacite
(Fe-Ni alloy), has been known to be a characteristic texture indicating
ancient collisions on parent bodies of meteorites. We conducted a
series of shock recovery experiments on bcc iron with the projectile
velocity at 1.5 km/s at various initial temperatures, room temperature,
670 K, and 1100 K, and conducted an annealing experiment on the shocked
iron. We also conducted numerical simulations with the iSALE-2D code
to investigate peak pressure and temperature distributions in the
nontransparent targets. The effects of pressure and temperature on the
formation and disappearance of the twins (Neumann band) were explored
based on laboratory and numerical experiments. The twin was formed in
the run products of the experiments conducted at room temperature and
670 K, whereas it was not observed in the run product formed by the
impact at 1100 K. The present experiments combined with the numerical
simulations revealed that the twin was formed by impacts with various
shock pressures from 1.5-2 GPa to around 13 GPa. The twin in iron
almost disappeared by annealing at 1070 K. The iron meteorites with
Neumann bands were shocked at this pressure range and temperatures at
least up to 670 K, and were not heated to the temperatures above 1070
K after the Neumann band formation.
Title: Ancient and recent collisions revealed by phosphate minerals
in the Chelyabinsk meteorite
Authors: Walton, Craig R.; Shorttle, Oliver; Hu, Sen; Rae, Auriol
S. P.; Jianglong, Ji; Černok, Ana; Williams, Helen; Liu, Yu; Tang,
Guoqiang; Li, Qiuli; Anand, Mahesh
Bibcode: 2022ComEE...3...40W
Altcode: 2021arXiv211206038W
The collision history of asteroids is an important archive of inner
Solar System evolution. Evidence for these collisions is brought to
Earth by meteorites. However, as meteorites often preserve numerous
impact-reset mineral ages, interpretation of their collision histories
is controversial. Here, we combine analysis of phosphate U-Pb ages and
microtextures to interpret the collision history of Chelyabinsk—a
highly shocked meteorite. We show that phosphate U-Pb ages correlate
with phosphate microtextural state. Pristine phosphate domain U-Pb
compositions are generally concordant, whereas fracture-damaged
domains universally display discordance. Combining both populations
best constrains upper (4473 ± 11 Ma) and lower intercept (−9 ±
55 Ma, i.e., within error of present) U-Pb ages. All phosphate U-Pb
ages were completely reset during an ancient high energy collision,
whilst fracture-damaged domains experienced further Pb-loss during mild
and recent collisional re-heating. Targeting textural sub-populations
of phosphate grains permits more robust reconstruction of asteroidal
collision histories.
Title: A criterion for the stability of planets in chains of
resonances
Authors: Goldberg, Max; Batygin, Konstantin; Morbidelli, Alessandro
Bibcode: 2022Icar..38815206G
Altcode: 2022arXiv220713833G
Uncovering the formation process that reproduces the distinct properties
of compact super-Earth exoplanet systems is a major goal of planet
formation theory. The most successful model argues that non-resonant
systems begin as resonant chains of planets that later experience
a dynamical instability. However, both the boundary of stability in
resonant chains and the mechanism of the instability itself are poorly
understood. Previous work postulated that a secondary resonance between
the fastest libration frequency and a difference in synodic frequencies
destabilizes the system. Here, we use that hypothesis to produce a
simple and general criterion for resonant chain stability that depends
only on planet orbital periods and masses. We show that the criterion
accurately predicts the maximum mass of planets in synthetic resonant
chains up to six planets. More complicated resonant chains produced
in population synthesis simulations are found to be less stable than
expected, although our criterion remains useful and superior to machine
learning models.
Title: Non-planar magnetoactive GES-based solar plasma stability
Authors: Das, Souvik; Karmakar, Pralay Kumar
Bibcode: 2022JApA...43...44D
Altcode: 2022arXiv220714618D
A laboratory plasma-wall interaction-based astrophysical
gravito-electrostatic sheath (GES) model is methodologically applied
to study the dynamic stability of the magnetoactive bi-fluidic solar
plasma system in the presence of turbulence effect. The spherically
symmetric GES-model formalism couples the solar interior plasma (SIP,
internally self-gravitating, bounded) and the solar wind plasma (SWP,
externally point-gravitating, unbounded) through the diffused solar
surface boundary (SSB). A normal spherical mode ansatz results in a
generalized linear quadratic dispersion relation depicting the modal
fluctuations on both the SIP and SWP scales. A constructive numerical
platform reveals the evolution of both dispersive and non-dispersive
modal features of the modified-GES mode excitations. The reliability
of the derived non-planar dispersion laws is concretized with the
help of an exact analytic shape matching the previously reported
results founded on the plane-wave approximation. It is found that
the thermo-statistical GES stability depends mainly on the magnetic
field, equilibrium plasma density and plasma temperature . It is
speculated that the dispersive features are more pronounced in
the self-gravitational domains against the electrostatic ones. The
magneto-thermal interplay introduces decelerating (accelerating)
and destabilizing (stabilizing) influences on the SIP (SWP), and so
forth. At last, we briefly indicate the applicability of the proposed
analysis to understand diverse helioseismic activities from the
collective plasma dynamical viewpoint in accordance with the recent
astronomical observational scenarios reported in the literature.
Title: Acoustic modal instability in relativistic gyromagnetoactive
ultra-dense quantum fluids
Authors: Dasgupta, Sayanti; Karmakar, Pralay Kumar
Bibcode: 2022JApA...43...60D
Altcode:
The acoustic modal instability excitable in a relativistic
gyromagnetoactive quantum plasma model is methodologically
investigated. The proposed spherical model consists of fully degenerate
relativistic electronic species, governed by an appropriate barotropic
equation of state sourced in the gyrokinetic water-bag distribution. The
tiny degenerate electronic species is responsible for providing
the outward elastic force. The heavier relativistic singly charged
ionic species provides the required inertial force for sustaining the
acoustic instability mode excitation under consideration. It includes
the co-action of the quantum diffraction effects, Coriolis rotation,
electrostatic confinement pressure, Lorentz force fields, etc. A
standard normal spherical mode analysis yields a generalized quartic
linear dispersion relation dictated by a unique set of multiparametric
coefficients. A numerical illustrative platform is provided to analyze
the instability behaviours in two extreme regimes (ULF plus UHF). A
good number of new and interesting stability properties in response to
parametric variations are derived, discussed and established. It could
be useful to see the acoustic wave stability features naturalistically
excitable in the compact astrophysical class of bounded structures,
such as brown dwarfs, white dwarfs and neutron stars.
Title: Enstatite chondrites: condensation and metamorphism under
extremely reducing conditions and contributions to the Earth
Authors: Lin, Yangting
Bibcode: 2022PEPS....9...28L
Altcode:
Enstatite chondrites are a small clan of meteorites, only ~ 1% out
of all meteorite collection. However, they are the most reduced
meteorites and have almost identical isotopic compositions to
those of the Earth, suggestive of significant contributions to the
latter and other terrestrial planets. Enstatite chondrites contain a
unique mineral inventory of sulfides of typical lithophile elements,
Si-bearing metal, silicide and phosphide, which record the nebular
processes and the thermal metamorphism in asteroidal bodies under
extremely reducing environments. EH group is mainly characteristic of
the higher Si content of metallic Fe-Ni and the higher MnS contents
of sulfides than EL group, indicative of a more reducing condition
than the latter. However, the fugacity pH2S could be the
same in both EH and EL regions, because it was buffered by kamacite
and troilite. The majority of sulfides condensed from the nebula,
partially enclosing schreibersite micron-spherules formed probably by
early melting. Another part of troilite, sphalerite and djerfisherite,
intergrown with perryite, were produced via sulfidation of metallic
Fe-Ni. Minor exotic components were also found in enstatite chondrites,
including Ca-, Al-rich inclusions and FeO-rich silicate clasts. The Ca-,
Al-rich inclusions are identical to those in carbonaceous chondrites
except for the alteration under reducing environments, and the FeO-rich
silicate clasts show reduction reactions, both suggestive of migration
of dust in the protoplanetary disk. The highly reducing conditions
(as C/O ratios) might be established via repeating evaporation and
condensation of water ice and organic matter across the snow line
along the protoplanetary disk, but need to find evidence. Another
issue is the preservation of submicron-to-micron-sized presolar
grains during high-temperature condensation of the major constituent
minerals. After accretion, the parent bodies of EH and EL chondrites
probably experienced distinct thermal histories, indicated by their
distinct petrologic-type distributions and different correlations with
the closure temperatures determined by the FeS contents of sulfides
in contact with troilite.
Title: Imaging crustal features and Moho depths through enhancements
and inversion of gravity data from the Philippine island arc system
Authors: Casulla, Mel Anthony A.; Mizunaga, Hideki; Tanaka, Toshiaki;
Dimalanta, Carla B.
Bibcode: 2022PEPS....9...16C
Altcode:
The Philippine archipelago is a complex island arc system, where many
regions still lack geopotential field studies. The high-resolution
isostatic anomaly and free-air anomaly digital grids from the World
Gravity Map (WGM) were processed and analyzed to present a general
discussion of the Philippines' gravity signatures and contribute to
understanding its regional geology and tectonics. The isostatic anomaly
map was continued upward to investigate the high-density ophiolitic
basement rocks and low-gravity sedimentary basins at depth. The first
vertical derivative (1VD) filter was applied to the free-air anomaly
grid map to locate regional structures represented by density contrast
boundaries. The depth to the top of the Moho and basement rock over the
Sulu Sea was computed using the two-dimensional (2-D) radially averaged
power spectrum analysis. Three-dimensional (3-D) gravity inversion was
applied to some major sedimentary basins in the Philippines to present
3-D subsurface density contrast models. The interpreted gravity maps
highlighted prominent geologic features (e.g., trench manifestation,
ophiolite distribution, basin thickness). The negative isostatic
anomalies (< 0 mGal) represent the thick sedimentary basins, while
the moderate signatures (0 to 80 mGal) correspond to the metamorphic
belts. The distinct very high-gravity anomalies (> 80 mGal) typify
the ophiolitic basement rocks. The gravity data's upward continuation
revealed contrasting deep gravity signatures; the central Philippines
with continental affinity (with 20-35 mGal) was distinguished from the
regions with oceanic affinity (with 45-200 mGal). The 1VD map over the
Sulu Sea showed anomalies associated with shallow features dominantly
related to the Cagayan Ridge. The 2-D radially averaged power spectrum
analysis exposed gravity anomalies with tectonic significance (e.g.,
basement characterization, Moho depth estimation). The estimated average
Moho depth in the Sulu Sea is from 12 to 22 km, while the average
basement depth is within the range of 5 to 11 km. Lastly, the 3-D
subsurface density contrast models characterized the very low-density
zones representing the deep (> 7 km) sedimentary basins in the
northern Cagayan Valley and southern Central Luzon basins. Furthermore,
thin (~ 3.5 km) sedimentary formations are inferred for the low-density
areas in northern Agusan-Davao and eastern Cotabato basins.
Title: Utilization of a meteorological satellite as a space telescope:
the lunar mid-infrared spectrum as seen by Himawari-8
Authors: Nishiyama, Gaku; Namiki, Noriyuki; Sugita, Seiji; Uno,
Shinsuke
Bibcode: 2022EP&S...74..105N
Altcode:
The Japanese meteorological satellite Himawari-8 has captured the
Earth's atmosphere and stars, planets, and the Moon in its field of
view, enabling us to capture their spectroscopy with 16 bands from
visible to mid-infrared wavelengths. The nine infrared bands in
the Advanced Himawari Imager (AHI) onboard Himawari-8 are unique
in spaceborne observations and are potentially useful for lunar
science. In addition, infrared bands of AHI cover wavelengths similar
to those of other interplanetary instruments and thus are useful for
calibrations. However, infrared AHI data have not yet been investigated
in planetary science. To confirm the utility of AHI for planetary
science, we develop a procedure to retrieve the lunar infrared spectrum
and compare it with thermal conduction simulations. Our analysis shows
that lunar brightness temperature curves can be obtained in the morning,
evening, and nighttime for all nine bands. Particularly at 8.5 μm,
they show a good agreement with previous observations by the Diviner
radiometer onboard NASA's Lunar Reconnaissance Orbiter. As pointed
out previously, the brightness temperatures differ between the bands,
indicating temperature mixing within a pixel. Our simulation suggests
that surface roughness as steep as those measured at the Apollo landing
sites significantly contributes to the observed brightness temperature
differences in the morning and evening; however, nighttime brightness
temperatures are greatly affected by rocks with higher thermal inertia
than the regolith. The rock abundances are estimated to be 0.18-0.48%
and 6.1-10.3% at the equator and within Tycho crater, respectively. Our
estimations from AHI data are consistent with those of Diviner. These
results support the idea that AHI potentially serves as a space
telescope for future lunar and planetary sciences, for example, for
constraining water content on the lunar surface.
Title: Photometric and statistical comparisons of the old open
cluster M67 (NGC 2682) using KFISP and Gaia EDR3 astrometry
Authors: Hendy, Y. H. M.; Abdel Rahman, H. I.
Bibcode: 2022JAsGe..11..166H
Altcode:
No abstract at ADS
Title: Wave effects in double-plane lensing
Authors: Ramesh, Rahul; Meena, Ashish Kumar; Bagla, Jasjeet Singh
Bibcode: 2022JApA...43...38R
Altcode: 2021arXiv210909998R
We discuss the wave optical effects in gravitational lens systems with
two-point mass lenses in two different planes. We identify and vary
parameters (i.e., lens masses, related distances and alignments) related
to the lens system to investigate their effects on the amplification
factor. We find that due to many parameters, it is not possible to
make generalized statements regarding the amplification factor. The
best approach for two-plane and multi-plane lensing is to study various
possible lens systems case by case to explore the possibilities in the
parameter space instead of hoping to generalize the results of a few
test cases. We present a preliminary analysis of the parameter space
for a two-lens system here.
Title: Persistent mysteries of jet engines, formation, propagation,
and particle acceleration: Have they been addressed experimentally?
Authors: Blackman, Eric G.; Lebedev, Sergey V.
Bibcode: 2022NewAR..9501661B
Altcode: 2020arXiv200908057B
The physics of astrophysical jets can be divided into three regimes: (i)
engine and launch (ii) propagation and collimation, (iii) dissipation
and particle acceleration. Since astrophysical jets comprise a huge
range of scales and phenomena, practicality dictates that most studies
of jets intentionally or inadvertently focus on one of these regimes,
and even therein, one body of work may be simply boundary condition
for another. We first discuss long standing persistent mysteries that
pertain the physics of each of these regimes, independent of the method
used to study them. This discussion makes contact with frontiers of
plasma astrophysics more generally. While observations theory, and
simulations, and have long been the main tools of the trade, what
about laboratory experiments? Jet related experiments have offered
controlled studies of specific principles, physical processes, and
benchmarks for numerical and theoretical calculations. We discuss what
has been accomplished on these fronts. Although experiments have indeed
helped us to understand certain processes, proof of principle concepts,
and benchmarked codes, they have yet to solved an astrophysical jet
mystery on their own. A challenge is that experimental tools used for
jet-related experiments so far, are typically not machines originally
designed for that purpose, or designed with specific astrophysical
mysteries in mind. This presents an opportunity for a different way
of thinking about the development of future platforms: start with the
astrophysical mystery and build an experiment to address it.
Title: The Great Aurora of 4 February 1872 observed by Angelo Secchi
in Rome
Authors: Berrilli, Francesco; Giovannelli, Luca
Bibcode: 2022JSWSC..12....3B
Altcode: 2022arXiv220101171B
Observation of auroras at low latitudes is an extremely rare event
typically associated with major magnetic storms due to intense
Earth-directed Coronal Mass Ejections. Since these energetic events
represent one of the most important components of space weather,
their study is of paramount importance to understand the Sun-Earth
connection. Due to the rarity of these events, being able to access
all available information for the few cases studied is equally
important. Especially if we refer to historical periods in which
current accurate observations from ground-based instruments or space
were not available. Certainly, among these events, we must include the
great aurora of February 4, 1872. An event whose effects have been
observed in different regions of the Earth. What we could consider
today a global event, especially for its effects on the communication
systems of the time, such as the transatlantic cable that allowed a
connection between the United States and Europe since 1866. In this
paper, we describe the main results of the observations and studies
carried out by Angelo Secchi at the Observatory of the Roman College
and described in his Memoria sull'Aurora Elettrica del 4 Febbraio 1872
for the Notes of the Pontifical Academy of new Lincei. This note is
extremely modern both in its multi-instrumental approach to the study
of these phenomena and in its association between solar-terrestrial
connection and technological infrastructures on the Earth. The Secchi's
note definitely represents the first example of analysis and study of
an event on a global scale, such as the Atlantic cable, affecting the
Earth. What we nowadays call an extreme space weather event.
Title: Structured regularization based velocity structure estimation
in local earthquake tomography for the adaptation to velocity
discontinuities
Authors: Yamanaka, Yohta; Kurata, Sumito; Yano, Keisuke; Komaki,
Fumiyasu; Shiina, Takahiro; Kato, Aitaro
Bibcode: 2022EP&S...74...43Y
Altcode: 2021arXiv210409067Y
We propose a local earthquake tomography method that applies a
structured regularization technique to determine sharp changes in
Earth's seismic velocity structure using arrival time data of direct
waves. Our approach focuses on the ability to better image two common
features that are observed in Earth's seismic velocity structure: sharp
changes in velocities that correspond to material boundaries, such as
the Conrad and Moho discontinuities; and gradual changes in velocity
that are associated with pressure and temperature distributions in the
crust and mantle. We employ different penalty terms in the vertical
and horizontal directions to refine the earthquake tomography. We
utilize a vertical-direction (depth) penalty that takes the form of
the l1-sum of the l2-norms of the second-order
differences of the horizontal units in the vertical direction. This
penalty is intended to represent sharp velocity changes caused by
discontinuities by creating a piecewise linear depth profile of
seismic velocity. We set a horizontal-direction penalty term on
the basis of the l2-norm to express gradual velocity
tendencies in the horizontal direction, which has been often used
in conventional tomography methods. We use a synthetic data set to
demonstrate that our method provides significant improvements over
velocity structures estimated using conventional methods by obtaining
stable estimates of both steep and gradual changes in velocity. We
also demonstrate that our proposed method is robust to variations
in the amplitude of the velocity jump, the initial velocity model,
and the number of observed arrival times, compared with conventional
approaches, and verify the adaptability of the proposed method to
dipping discontinuities. Furthermore, we apply our proposed method
to real seismic data in central Japan and present the potential of
our method for detecting velocity discontinuities using the observed
arrival times from a small number of local earthquakes.
Title: The growing threat of light pollution to ground-based
observatories
Authors: Green, Richard F.; Luginbuhl, Christian B.; Wainscoat,
Richard J.; Duriscoe, Dan
Bibcode: 2022A&ARv..30....1G
Altcode:
Human activity is rapidly increasing the negative impact of
artificial skyglow at even the most remote professional observatory
sites. Assessment of the actual impact requires an understanding of the
propagation as a function of source spectral energy distribution. The
higher blue content of light-emitting diodes being widely used as
replacement for sodium discharge lamps has greater impact closer to the
source, and less impact for more distant mountain-top sites. All-sky
cameras with moderate angular resolution provide data and metrics
sufficient to model and remove celestial contributions and provide
measures of artificial light contribution. The natural skyglow is
significantly affected by solar activity, which must be accounted for
in determining secular trends in the artificial component. With the
availability of the New World Atlas of the Artificial Sky Brightness,
a direct comparison is made of the modeled artificial contribution to
the sites with the largest aperture telescopes, noting the possible
systematic errors in individual cases. Population growth of the nearest
urban centers allows a prediction of the change in that brightness over
a decade. All site protections are effected primarily by national or
regional regulation. A collection of worldwide regulations shows that
most are leveraged off environmental protection statutes, while in the
U.S., they are largely based on land-use zones. Particular examples
are presented in more detail for Flagstaff, Arizona, and the Island
of Hawai'i. The latest rapidly growing threat is that of reflected
sunlight from large constellations of satellites in low-earth orbit. A
snapshot is provided of that rapidly changing situation. In all cases,
astronomers must become very proactive in educating the public about the
cultural value of visual or naked eye astronomy as well as the science
and the need for access to a dark night sky for astronomical research.
Title: Reply to "Comment on `Soil salinity assessment by using
near-infrared channel and Vegetation Soil Salinity Index derived
from Landsat 8 OLI data: a case study in the Tra Vinh Province,
Mekong Delta, Vietnam' by Kim-Anh Nguyen, Yuei-An Liou, Ha-Phuong
Tran, Phi-Phung Hoang and Thanh-Hung Nguyen"
Authors: Nguyen, Kim-Anh; Liou, Yuei-An; Tran, Ha-Phuong; Hoang,
Phi-Phung; Nguyen, Thanh-Hung
Bibcode: 2022PEPS....9...46N
Altcode:
The Vietnamese Mekong Delta has been devastatingly impacted by
climate change coupled with sea level rise and natural hazards. As a
result, salinity intrusion has become a pressing issue in the coastal
provinces of the Mekong Delta in recent years. This environmental
problem has called a great attention from the global scientists as
demonstrated by the paper Nguyen et al. (Prog Earth Planet Sci 7:1,
2020. 10.1186/s40645-019-0311-0) "Soil salinity assessment by using
an indicator derived from Landsat 8 OLI data: A case study in the
Tra Vinh, Mekong Delta, Vietnam" (reached 27 k accesses as of July
31, 2022). Recently, Silvestri et al. (PEPS, 2022) have commented on
Nguyen et al. (2020) article with three main points highlighted: (1)
Within the coastal portion of the Mekong Delta, extensively ponded due
to widespread shrimp farming, about 90% of Landsat 8 pixels are fully
or partially covered by water so that Landsat 8 OLI spatial resolution
is not suitable to distinguish between ponded and non-ponded areas;
(2) The decreased near-infrared (NIR) reflectance ascribed to increased
soil salinity is instead due to the presence of water in Landsat 8
mixed pixels; and (3) NIR reflectance is equally reduced independently
of whether the water ponding area is salt or freshwater. We appreciate
Silvestri et al. (2022) for their correspondence regarding our 2020
article (Nguyen et al. 2020) where we showed the capacity of using
freely accessible Landsat 8 OLI image for the rapid soil salinity
detection at the top soil layer in the agricultural land that is
of valuable information for agricultural activities. We conducted
field survey and collected the soil samples during the dry season
at different agricultural soil types. Notably, the soil samples
were collected at the same time with the satellite passing over the
study area. The soil salinity derived from Landsat 8 is in line with
the analysis from in situ data and consistent with the findings of
previous studies. Importantly, two points are stressed in this reply:
(1) The goal of our study is to utilize the freely accessible data
source with rapid method of mapping soil salinity to investigate the
salinity in the agricultural land, but not in the water body. Therefore,
it has been a serious mistake to state that 90% of Landsat 8 pixels
are fully or partially covered by water as claimed in Silvestri et
al. (2022); and (2) The Tra Vinh Province has recorded the highest
salinity level normally in March or April every year when the rainfall
exhibits the lowest of the year, and at this time, most of the water in
the river/canal is affected by saline intrusion. Thus, it is advised
that Silvestri et al. (2022) should use the images acquired in March
or April rather than random months.
Title: Detection of Martian dust storms using mask regional
convolutional neural networks
Authors: Alshehhi, Rasha; Gebhardt, Claus
Bibcode: 2022PEPS....9....4A
Altcode:
Martian dust plays a crucial role in the meteorology and climate
of the Martian atmosphere. It heats the atmosphere, enhances the
atmospheric general circulation, and affects spacecraft instruments
and operations. Compliant with that, studying dust is also essential
for future human exploration. In this work, we present a method for
the deep-learning-based detection of the areal extent of dust storms
in Mars satellite imagery. We use a mask regional convolutional
neural network, consisting of a regional-proposal network and a mask
network. We apply the detection method to Mars daily global maps of the
Mars global surveyor, Mars orbiter camera. We use center coordinates
of dust storms from the eight-year Mars dust activity database as
ground-truth to train and validate the method. The performance of the
regional network is evaluated by the average precision score with 50 %
overlap (m A P50 ), which is around 62.1 %.
Title: A possible mechanism for spontaneous cyclic back-arc spreading
Authors: Ishii, Kazuhiko; Wallis, Simon R.
Bibcode: 2022PEPS....9...27I
Altcode:
Back-arc spreading is a non-steady-state process exemplified by the
repeated cycles of spreading of the South Fiji and the Lau Basins
behind the Tonga arc, and the Parece Vela Basin and the Mariana
Trough behind the Mariana arc. Spreading in these regions starts
with rifting within the volcanic arc before shifting to the back-arc
region where it develops into a phase of well-defined spreading. 2D
thermo-mechanical subduction modeling incorporating phase transitions at
depths of 410 km and 660 km suggests the presence of a low-viscosity and
low-density mantle wedge is an important condition for arc rifting to
occur. Back-arc spreading starts when a nearly vertical slab impinges
upon the 660 km discontinuity causing downdip compressive stress
that is transmitted up the slab resulting in extensional within-arc
stress. Trench retreat during a phase of back-arc spreading causes a
decrease in slab dip angle and buckling of the slab. Back-arc spreading
ceases during this buckling phase. Rifting starts once more when the
nearly vertically dipping `heel' of the buckled slab again impinges
upon the 660-km boundary. The second phase of rifting initially focuses
within the arc but subsequently shifts to the back-arc region leading
to renewed back-arc spreading. Our modeling predicts that subduction
of thick (old age) and weak (small yield stress) slabs, which have
intermediate resistance to slab bending, leads to cyclic back-arc
spreading. In contrast, continuous back-arc spreading is predicted
for thick and strong slabs with a large resistance to bending, and no
back-arc spreading is predicted for slabs with a small resistance to
bending (thin slabs). Geological processes such as toroidal mantle
flow around the lateral edges of a slab, collisions with buoyant
lithosphere and interactions with third plates may have important
roles in the development of cyclic back-arc spreading in specific
cases. However, the presence of a common timescale of ~ 20 Myr suggests
there a general underlying control on back-arc basin formation that is
common to many if not all subduction zones. The new model presented
here can account for the main features of cyclic back-arc spreading
seen in the Tonga-Kermadec and the Calabrian arcs.
Title: The message of oldhamites from enstatite chondrites
Authors: Hammouda, Tahar; Boyet, Maud; Frossard, Paul; Cartier, Camille
Bibcode: 2022PEPS....9...13H
Altcode:
We have determined rare-earth element (REE) abundances in oldhamites
(CaS) from 13 unequilibrated and equilibrated enstatite chondrites
(5 EH and 8 EL) and in a few enstatites by in situ, laser ablation
ICP-MS. In EH chondrites, oldhamite REE patterns vary from the most
primitive petrographic types (EH3) to the most metamorphosed types
(EH5). In EH3, CI-normalized REE patterns are convex downward with
strong positive Eu and Yb anomalies, whereas EH5 display flat patterns
with enrichments reaching about 80 times CI abundances. The positive
anomalies of Eu and Yb found in oldhamites of primitive EH chondrites
indicate that they represent the condensation of a residual gas
fraction, in a manner similar to fine-grained CAIs of carbonaceous
chondrites. The early condensate may have been preserved in the matrix
of unequilibrated EH. Equilibrated EH oldhamite patterns may result from
metamorphic evolution and REE redistribution on the EH parent body. On
the contrary, all the oldhamites from EL chondrites (EL3 to EL6) display
a single kind of patterns, which is convex upward and is about 100 times
enriched relative to CI, with a negative Eu anomaly. In addition, the
EL pattern is similar to that of oldhamites from aubrites (enstatite
achondrites). The latter observation suggests that oldhamites of all
EL metamorphic types (including primitive ones) bear the signature of a
magmatic event accompanied by FeS loss as vapor, prior to the assembly
of the EL parent body. Given the difficulty of obtaining precise ages
on enstatite chondrites, it is not possible to discuss the chronology
of the events recorded by the oldhamite REE patterns.
Title: Formation, preservation and extinction of high-pressure
minerals in meteorites: temperature effects in shock metamorphism
and shock classification
Authors: Hu, Jinping; Sharp, Thomas G.
Bibcode: 2022PEPS....9....6H
Altcode:
The goal of classifying shock metamorphic features in meteorites is
to estimate the corresponding shock pressure conditions. However, the
temperature variability of shock metamorphism is equally important
and can result in a diverse and heterogeneous set of shock features
in samples with a common overall shock pressure. In particular,
high-pressure (HP) minerals, which were previously used as a solid
indicator of high shock pressure in meteorites, require complex
pressure-temperature-time (P-T-t) histories to form and survive. First,
parts of the sample must be heated to melting temperatures, at high
pressure, to enable rapid formation of HP minerals before pressure
release. Second, the HP minerals must be rapidly cooled to below
a critical temperature, before the pressure returns to ambient
conditions, to avoid retrograde transformation to their low-pressure
polymorphs. These two constraints require the sample to contain large
temperature heterogeneities, e.g. melt veins in a cooler groundmass,
during shock. In this study, we calculated shock temperatures and
possible P-T paths of chondritic and differentiated mafic-ultramafic
rocks for various shock pressures. These P-T conditions and paths,
combined with observations from shocked meteorites, are used to
constrain shock conditions and P-T-t histories of HP-mineral bearing
samples. The need for rapid thermal quench of HP phases requires a
relatively low bulk-shock temperature and therefore moderate shock
pressures below ~ 30 GPa, which matches the stabilities of these HP
minerals. The low-temperature moderate-pressure host rock generally
shows moderate shock-deformation features consistent with S4 and,
less commonly, S5 shock stages. Shock pressures in excess of 50 GPa
in meteorites result in melt breccias with high overall post-shock
temperatures that anneal out HP-mineral signatures. The presence of
ringwoodite, which is commonly considered an indicator of the S6 shock
stage, is inconsistent with pressures in excess of 30 GPa and does not
represent shock conditions different from S4 shock conditions. Indeed,
ringwoodite and coexisting HP minerals should be considered as robust
evidence for moderate shock pressures (S4) rather than extreme shock
(S6) near whole-rock melting.
Title: A numerical study of the liquid motion in Titan's subsurface
ocean
Authors: Vincent, David; Lambrechts, Jonathan; Tyler, Robert H.;
Karatekin, Özgür; Dehant, Véronique; Deleersnijder, Éric
Bibcode: 2022Icar..38815219V
Altcode:
An ocean filled with liquid water lies beneath the icy surface of
several Jovian and Saturnian moons. In such an ocean, the currents
are driven by various phenomena such as the tidal forcing, the
deformation of the ice shell lying at its top, the temperature
gradient resulting from the surface and bottom heat fluxes…The flow
induced by the first two forcings can be modelled by means of a 2D
depth-averaged model, while the third one generates horizontal and
vertical density variations whose effects can only be captured by a
3D baroclinic model. We study the tides of Titan's subsurface
ocean and the impact of the ice shell on the liquid motion by means
of the Second-generation Louvain-la-Neuve Ice-ocean Model, SLIM
(https://www.climate.be/slim). The impact of the ice shell lying
at the top of the ocean is modelled by a surface friction term and
surface pressure terms. The latter are a function of the difference
between the ocean elevation and the vertical displacement of the
shell and the time derivative of this difference. Because of
Titan's appreciable obliquity (0.306°), the tidal motion expected
(and found) is similar to the Europa tidal scenario described by Tyler
(2008): the surface elevation consists of two bulges rotating around
Titan and the associated depth-averaged velocity field consists of two
gyres, separated by an area of high speed flow, whose centre follows a
sinusoidal path centred on the equator. The ice shell damps the surface
motion, thus slowing down the flow, without significantly modifying
the spatial patterns of these fields. The depth of the ocean and the
mechanical characteristics of the ice shell being poorly constrained,
a sensitivity analysis is conducted. The depth-averaged flow slows down
when the depth is increased and a lag appears in the tidal phase but the
tidal range remains similar. The ice shell mechanical characteristics
influences both the elevation and depth-averaged velocity fields in
terms of magnitude but does not modify the spatial patterns of these
fields. The influence of the surface heat flux is studied by
means of the 3D baroclinic version of SLIM. The heat flux derived from
Titan's topography by Kvorka et al. (2018) is used as surface boundary
condition for the temperature equation while a uniform bottom heat flux
is implemented. Its value is computed assuming that the heat budget of
the ocean is at equilibrium. These boundary conditions cause density
variations, which impact the hydrodynamics of the ocean. While the
flow velocity induced by these variations is two orders of magnitude
smaller than the tidal flow, its orientation is time-independent,
hence impacting the orientation of the velocity field. Although the
variations of ocean surface elevation and speed with respect to the
shell mechanical properties can be larger than those induced by the
surface heat flux, taking into account the latter results in large
variations of the velocity field global patterns, which was not observed
when modifying the shell mechanical properties. Future studies should
therefore focus on modelling the surface and bottom heat fluxes while
uncertainties about the mechanical characteristics of the shell can
be tolerated.
Title: Discriminating seismic events using 1D and 2D CNNs:
applications to volcanic and tectonic datasets
Authors: Nakano, Masaru; Sugiyama, Daisuke
Bibcode: 2022EP&S...74..134N
Altcode:
Detecting seismic events, discriminating between different event
types, and picking P- and S-wave arrival times are fundamental but
laborious tasks in seismology. In response to the ever-increasing
volume of seismic observational data, machine learning (ML) methods
have been applied to try to resolve these issues. Although it is
straightforward to input standard (time-domain) seismic waveforms into
ML models, many studies have used time-frequency-domain representations
because the frequency components may be effective for discriminating
events. However, detailed comparisons of the performances of these two
methods are lacking. In this study, we compared the performances of 1D
and 2D convolutional neural networks (CNNs) in discriminating events
in datasets from two different tectonic settings: tectonic tremor
and ordinary earthquakes observed at the Nankai trough, and eruption
signals and other volcanic earthquakes at Sakurajima volcano. We found
that the 1D and 2D CNNs performed similarly in these applications. Half
of the misclassified events were misassigned the same labels in both
CNNs, implying that the CNNs learned similar features inherent to
the input signals and thus misclassified them similarly. Because the
first convolutional layer of a 1D CNN applies a set of finite impulse
response (FIR) filters to the input seismograms, these filters are
thought to extract signals effective for discriminating events in the
first step. Therefore, because our application was the discrimination
of signals dominated by low- and high-frequency components, we tested
which frequency components were effective for signal discriminations
based on the filter responses alone. We found that the FIR filters
comprised high-pass and low-pass filters with cut-off frequencies
around 7-9 Hz, frequencies at which the magnitude relations of the
input signal classes change. This difference in the power of high-
and low-frequency components proved essential for correct signal
classifications in our dataset.
Title: Delineation of subsurface structures using gravity
interpretation around Nabaa Al Hammara area, Wadi El Natrun, Egypt
Authors: Awad, Mahmoud S.; El Kadi, Hassan H.; Abbas, Abbas M.;
Awad Sultan Araffa, Sultan
Bibcode: 2022JAsGe..11..282A
Altcode:
No abstract at ADS
Title: Ground-based VLF wave intensity variations investigated by
the principal component analysis
Authors: Bezděková, Barbora; Němec, František; Manninen, Jyrki
Bibcode: 2022EP&S...74...30B
Altcode:
Very low frequency wave intensity variations measured by the Kannuslehto
station, Finland in the frequency range 0-12 kHz between 2016 and
2020 are analyzed by the principal component analysis (PCA). As the
analyzed ground-based measurements are basically continuous, the
length of individual basis vectors entering into PCA is fundamentally
arbitrary. To better characterize both long- and short-period
variations, two PCAs with different lengths of the basis vectors
are eventually performed. Specifically, either daily frequency-time
spectrograms or individual frequency spectra are chosen as the PCA
basis vectors. Analysis of the first three principal components shows
substantial variations of the wave intensity due to seasonal and
local time effects. Intensity variations related to the geomagnetic
activity characterized by Kp and AE indices and standard deviation
of the magnetic field magnitude are less significant. Moreover, PCA
allows one to distinguish between nighttime and daytime Kannuslehto
variations and study them independently. Solar and geomagnetic activity
effects on the daytime and nighttime measurements are discussed. Wave
intensity variations related to substorm occurrence are also analyzed.
Title: Pattern in ejecta curtain generated by the impact into
granular targets of various sized particles and application to the
ejecta curtain observed in the Hayabusa2 impact experiment
Authors: Kadono, Toshihiko; Suzuki, Ayako I.; Suetsugu, Ryo; Shimaki,
Yuri; Hasegawa, Sunao
Bibcode: 2022EP&S...74..128K
Altcode:
We conducted impact experiments using targets composed of particles with
size distributions and projectiles with a size larger than or comparable
with the maximum size of particles in targets. The pattern and particle
concentration in the ejecta curtain were investigated. The results
show three types of ejecta curtain features: (i) filament pattern
extending throughout the entire curtain and high concentration, (ii)
filament pattern and low concentration, and (iii) mesh-like pattern
with a structure on smaller scales than the entire curtain and low
concentration. When the target consists of particles using a bimodal
size distribution with size differences of more than one order of
magnitude, the filament pattern appears, exhibiting case (i). If the
target consists of particles with various sizes with size differences
of more than one order of magnitude, the filament pattern appears, but
the concentration decreases, appearing the features of case (ii). Case
(iii) occurs when the target consists of particles with a single size
or when the mass of particles with a certain size is dominant. Thus,
the size distribution of the particles in the targets determines the
pattern and particle concentration in the ejecta curtain. Based on
these results, we confirm that the pattern in the ejecta curtain caused
by the impact of the Small Carry-on Impactor (SCI) in the Hayabusa2
mission showing case (i) is consistent with the evaluated sizes and
masses of grains and boulders in the ejecta curtain.
Title: Evaluation of near-surface conditions for engineering site
characterization using geophysical and geotechnical methods in Lagos,
Southwestern Nigeria
Authors: Ishola, K. S.; Amu, B. D.; Adeoti, L.
Bibcode: 2022JAsGe..11..237I
Altcode:
No abstract at ADS
Title: Updated absolute gravity rate of change associated with
glacial isostatic adjustment in Southeast Alaska and its utilization
for rheological parameter estimation
Authors: Naganawa, Kazuhiro; Kazama, Takahito; Fukuda, Yoichi; Miura,
Satoshi; Hayakawa, Hideaki; Ohta, Yusaku; Freymueller, Jeffrey T.
Bibcode: 2022EP&S...74..116N
Altcode:
In Southeast Alaska (SE-AK), rapid ground uplift of up to 3 cm/yr has
been observed associated with post-Little Ice Age glacial isostatic
adjustment (GIA). Geodetic techniques such as global navigation
satellite system (GNSS) and absolute gravimetry have been applied to
monitor GIA since the last 1990s. Rheological parameters for SE-AK were
determined from dense GNSS array data in earlier studies. However, the
absolute gravity rate of change observed in SE-AK was inconsistent with
the ground uplift rate, mainly because few gravity measurements from
2006 to 2008 resulted in imprecise gravity variation rates. Therefore,
we collected absolute gravity data at six gravity points in SE-AK
every June in 2012, 2013, and 2015, and updated the gravity variation
rate by reprocessing the absolute gravity data collected from 2006
to 2015. We found that the updated gravity variation rate at the
six gravity points ranged from −2.05 to −4.40 μ Gal/yr, and its
standard deviation was smaller than that reported in the earlier study
by up to 88 %. We also estimated the rheological parameters under
the assumption of the incompressible Earth to explain the updated
gravity variation rate, and their optimal values were determined to
be 55 km and 1.2 ×1019 Pa s for lithospheric thickness
and upper mantle viscosity, respectively. These optimal values are
consistent with those independently obtained from GNSS observations,
and this fact indicates that absolute gravimetry can be one of the most
effective methods in determining sub-surface structural parameters
associated with GIA accurately. Moreover, we utilized the gravity
variation rates for estimating the ratio of gravity variation to
vertical ground deformation at the six gravity points in SE-AK. The
viscous ratio values were obtained as −0.168 and −0.171 μ Gal/mm
from the observed data and the calculated result, respectively. These
ratios are greater (in absolute) than those for other GIA regions
(−0.15 to −0.16 μ Gal/mm in Antarctica and Fennoscandia), because
glaciers in SE-AK have melted more recently than in other regions.
Title: Correction to: Gravitational wave detection by interferometry
(ground and space)
Authors: Rowan, Sheila; Hough, Jim
Bibcode: 2022LRR....25....5R
Altcode:
No abstract at ADS
Title: Atmospheric resuspension of insoluble radioactive
cesium-bearing particles found in the difficult-to-return area
in Fukushima
Authors: Tang, Peng; Kita, Kazuyuki; Igarashi, Yasuhito; Satou,
Yukihiko; Hatanaka, Koutarou; Adachi, Kouji; Kinase, Takeshi; Ninomiya,
Kazuhiko; Shinohara, Atsushi
Bibcode: 2022PEPS....9...17T
Altcode:
The deposition of insoluble radiocesium-bearing microparticles
(CsMPs), which were released from the Fukushima Daiichi Nuclear Power
Plant (F1NPP) accident in March 2011, has resulted in the widespread
contamination of eastern Japan. Obviously, these deposited insoluble
CsMPs may become the secondary contamination sources by atmospheric
migration or other environmental transferring process; however, the
understanding of the transport mechanism remains non-elucidation,
and the relevant evidence has not been directly provided. This study,
for the first time, provides the direct evidence for the resuspension
of these insoluble CsMPs to the atmosphere from (1) proximity of
137Cs radioactivity and resemblance of the morphology and
the elemental compositions of CsMPs in the samples of soil and aerosol
derived from the same sampling site, (2) the special characteristics of
the resuspended CsMPs of which the ratios of Na/Si, K/Si and/or Cs/Si
were smaller than those from the initially released CsMPs collected at
either long distance or near F1NPP, which can be ascribed to the slowly
natural corrosion of CsMPs by the loss of the small amount of soluble
contents in CsMPs, and (3) high CsMPs concentration of 10 granules/g in
the surface soil of our sampling site and high resuspension frequency
of CsMPs in spring when predominant suspended particles were soil
dust. Specifically, 15 single CsMPs were successfully isolated from
the aerosol filters collected by unmanned high-volume air samplers at
a severely polluted area in Fukushima Prefecture, about 25 km away
from F1NPP, from January 2015 to September 2019. The mean diameter
of these CsMPs was 1.8 ± 0.5 μm, and the average 137Cs
radioactivity was 0.35 ± 0.23 Bq/granule. The contribution rate of
the resuspended CsMPs to the atmospheric radiocesium was estimated
from the ratio of 137Cs radioactivity of a single CsMP to
that of the aerosol filter to be of 23.9 ± 15.3%. There has been no
considerable decreasing trend in the annual CsMP resuspension frequency.
Title: Lightning evolution and VLF perturbations associated with
category 5 TC Yasa in the South Pacific Region
Authors: Redoblado, Paolo A. A. L.; Kumar, Sarwan; Kumar, Abhikesh;
Kumar, Sushil
Bibcode: 2022EP&S...74...65R
Altcode:
In this paper, we present the D-region ionospheric response during the
lifespan (10-19 December 2020) of a severe category 5 tropical cyclone
(TC) Yasa in the South Pacific by using the very low frequency (VLF,
3-30 kHz) signals from NPM, NLK, and JJI transmitters recorded at Suva,
Fiji. Results indicate enhanced lightning and convective activity in all
three regions (eyewall, inner rainbands, and outer rainbands) during
the TC Yasa that are also linked to the wave-sensitive zones of these
transmitter-receiver great circle paths. Of the three regions, the outer
rainbands showed the maximum lightning occurrence; hence convective
activity. Prominent eyewall lightning was observed just before the TC
started to weaken following its peak intensity. Analysis of VLF signals
amplitude showed both negative and positive perturbations (amplitudes
exceeding ± 3σ mark) lasting for more than 2 h with maximum change in
the daytime and nighttime signal amplitudes of − 4.9 dB (NPM) and −
19.8 dB (NLK), respectively. The signal perturbations were wave-like,
exhibiting periods of oscillations between ~ 2.2 and 5.5 h as revealed
by the Morlet wavelet analysis. Additionally, the LWPC modeling of the
signal perturbations indicated a 10 km increase in the daytime D-region
reference height, H', and a 12 km decrease in the nighttime D-region
H' during TC Yasa. The D-region density gradients (sharpness), β,
showed small perturbations of 0.01-0.14 km−1 from its
normal values. We suggest that the observed changes to the D-region
parameters are due to the enhanced convection during TC Yasa which
excites atmospheric gravity waves producing traveling ionospheric
disturbances to the D-region.
Title: Comparison of non-tidal loading data for application in a
secular terrestrial reference frame
Authors: Glomsda, Matthias; Bloßfeld, Mathis; Seitz, Manuela;
Angermann, Detlef; Seitz, Florian
Bibcode: 2022EP&S...74...87G
Altcode:
The Deutsches Geodätisches Forschungsinstitut der Technischen
Universität München (DGFI-TUM) is one of the three Combination
Centres of the International Earth Rotation and Reference Systems
Service for the International Terrestrial Reference System (ITRS). In
its upcoming realization of the ITRS, the DTRF2020, DGFI-TUM will
again correct for non-tidal loading (NTL) effects at the normal
equation level. Next to the dedicated NTL data set for the ITRS 2020
realization provided by the Global Geophysical Fluid Center (GGFC), we
also considered the data provided by the Earth System Modelling group
of the Deutsches GeoForschungsZentrum (ESMGFZ). Besides also comprising
all NTL components (atmospheric, oceanic, hydrological) and being mass
conserving, the ESMGFZ data has the advantage of daily availability and
is already in use at DGFI-TUM. The decision for one or the other data
set depends on their suitability for a secular terrestrial reference
frame like the DTRF2020, which will be assessed in this work. Although
we also compare the site displacements induced by NTL to the residuals
of station positions of the Global Navigation Satellite Systems, we
will not evaluate the quality of the underlying geophysical models
per se. The two data sets differ w.r.t. the underlying hydrological
models and the treatment of non-tidal oceanic loading, but the most
relevant difference is given in terms of trends in the displacement
time-series. After a close investigation of the latter, we finally
decided to apply the GGFC contribution to the ITRS 2020 realization
in the DTRF2020.
Title: Reservoir characterisations from bouguer gravity data,
Northern Western Desert, Egypt
Authors: Mohamed, Haby S.; Senosy, Mahmoud M.; Talat, Mahmoud
Bibcode: 2022JAsGe..11..224M
Altcode:
No abstract at ADS
Title: Characteristics of the deep sea tsunami excited offshore
Japan due to the air wave from the 2022 Tonga eruption
Authors: Tanioka, Yuichiro; Yamanaka, Yusuke; Nakagaki, Tatsuya
Bibcode: 2022EP&S...74...61T
Altcode:
A large eruption of the Hunga Tonga-Hunga Haʻapai volcano in Tonga
on January 15, 2022 generated air-sea coupled tsunamis observed at the
ocean-bottom pressure sensor network along the Japan Trench (S-net) in
Japan. Initial tsunamis from the 2022 Tonga eruption, detected by 106
ocean-bottom pressure sensors, were well modeled by an air-sea coupled
tsunami simulation, with a simple atmospheric pressure pulse as sine
function, having a half-wavelength of 300 km and a peak amplitude of
2 hPa. A one-dimensional air-sea coupled tsunami simulation having a
simple bathymetry shows that an input atmospheric pressure pulse with
a short half-wavelength of 50 km, which is shorter than the length of
the ocean bottom slopes, caused an amplitude increase via the Proudman
resonance effect near the deep trench. The wavefront distortion due to
the separation of the air-sea coupled wave propagating with a speed
of 312 m/s and tsunami propagating with that of √{gd }, where g is
gravity acceleration and d is the ocean depth, is also significant
near the shore. In contrast, these effects are not significant for
the half-wavelength of the input atmospheric pressure pulse of 300
km. These results indicate that the air-sea coupled tsunami propagating
through the trench is sensitive to the wavelength of an atmospheric
pressure pulse.
Title: On the formation of thrust fault-related landforms in Mercury's
Northern Smooth Plains: A new mechanical model of the lithosphere
Authors: Xie, Jingchun; Huang, Chengli; Zhang, Mian
Bibcode: 2022Icar..38815197X
Altcode:
There are numerous tectonic shortening structures distributed
across the planet, Mercury. As Mercury's largest single volcanic
deposit, the northern smooth plains (NSP) is dominated by thrust
fault-related landforms, showing particularity in their tectonic
patterns compared with their counterparts in other geological terrains
on Mercury. Geomorphic interpretations of these landforms assume
an internal layering lithosphere to account for the deformation
accommodating superficial units, implying the deformation in the
NSP is thin-rooted dominated. However, the commonly used lithospheric
mechanical model is an oversimplification that only allows for the sharp
transition from brittle to ductile deformation, failing to explain the
thin-rooted deformation well. In this work, we propose a new mechanical
model incorporating the semi-brittle deformation in the lithosphere to
account for an equivalent weak layer at shallow depth, filling the gap
between brittle and ductile deformation. In addition, we implement 2-D
numerical simulations to simulate the formation of thrust fault-related
landforms in the NSP of 3.8 billion years ago. As a result, we obtain
surface topographies roughly consistent with lobate scarps. Our results
also support that most thrust fault-related landforms were likely formed
over a period with a gradually decreased background compressive strain
rate, and these landforms can retain their basic geomorphic features on
this planet with little to no erosion. Although the physical properties
of semi-brittle deformation are not fully understood, considering
such a deformation model in planetary science is still promising,
especially when studying the thermodynamic processes of a planet.
Title: Shadow method retrievals of the atmospheric optical depth
above Gale crater on Mars using HRSC images
Authors: Shaheen, Farzana; Scariah, Nayama Valsa; Lala, Mili Ghosh Nee;
Krishna, A. P.; Jeganathan, C.; Hoekzema, N. M.
Bibcode: 2022Icar..38815229S
Altcode:
The 'Shadow Method' is a tool to estimate the Atmospheric Optical Depth
(AOD) on Mars from the brightness of shadows. This method is derived
from the equations of radiative transfer, but there are several
important simplifications that together invoke errors of several
tens of percent. Work by us and by others show that these errors
are largely systematic and can be minimized by adding an empirical
'Correction-Factor' to the equations. To quantify this factor, we
compared shadow method retrievals from orbiter images with in-situ
measurements by the Curiosity rover. We analysed a set of seven images
that was taken by DLR's High Resolution Stereo Camera (HRSC) on-board
ESA's orbiter Mars Express. The images were taken in seven channels:
NIR, red, green, blue, and in three panchromatic stereo channels S1,
Nadir, and S2. All these images show Gale crater and the exploration
site of the Curiosity rover therein. Comparing the rover measurement
of the AOD with shadow method retrievals from 5 close-by regions
yielded the following correction factors: 0.53 ± 0.03 for Nadir,
0.60 ± 0.04 for S1, 0.62 ± 0.03 for S2, 0.66 ± 0.03 for NIR,
0.64 ± 0.03 for Red, 0.55 ± 0.03 for Green, and 0.57 ± 0.03 for
Blue. We analysed 71 regions with varying altitudes between -4.6
km to +3.8 km and found that, on an average, the AOD decreases with
increasing altitude. The available channels yielded the following
averages of atmospheric optical depth before applying the correction
factor: Nadir: 0.47; S1: 0.46; S2: 0.52; Red: 0.49; Green: 0.53; Blue:
0.57 and NIR: 0.44 while after applying the correction factor we obtain
Nadir: 0.89; S1: 0.77; S2: 0.84; Red: 0.77; Green: 0.96; Blue: 1.0 and
NIR: 0.67. The Curiosity rover, at an altitude of -4.87 km, measured
a ground-truth AOD of 0.88. The shadowed and sunlit comparison
regions that were used for this work range in altitudes from -4.6 km
to +3.8 km. The AOD decreases with altitude and the decrease yields
the following scale heights: S1: 12.5 + 0.48/-0.35 km; nadir: 11.1 +
0.53/-0.33 km; S2: 14.3 + 0.48/-0.44 km; NIR: 11.1 + 0.56/-0.47 km;
red: 14.3 + 0.52/-0.49 km; green: 15.6 + 0.62/-0.59 km; blue: 14.3 +
0.44/-0.42 km. For this area and around that time of day, the Mars
Climate Database predicts a pressure scale height of 11.6-12.2 km,
which agrees well with the scale heights that we derived for Nadir, S1
and NIR. One region (number 42) contained a cloud with an optical depth
of up to 0.6-0.8; i.e., around one third of the total AOD of 1.9 ± 0.01
measured for this area. Region 29 showed the highest AOD of our sample.
Title: Synchrotron emission from neutralino dark matter annihilation
in dwarf spheroidal galaxies
Authors: Medhi, Jayashri; Nandy, Malay K.
Bibcode: 2022JApA...43...35M
Altcode:
The existence of non-baryonic cold dark matter has been established by
several astrophysical evidences. In the regions of high dark matter
density, the dark matter particles can undergo self-annihilation
yielding standard model particles. Such particles may have effects
on the observational properties of astronomical objects, which may
then be used to constrain the nature of dark matter. High-energy
electrons and positrons produced by dark matter annihilation in an
astrophysical system emit synchrotron radiation due to the presence
of the magnetic field. This synchrotron radiation can be detected by a
radio telescope. Dwarf spheroidal galaxies of the Milky Way are some of
the darkest matter-dominated objects in the Universe and thus provide
natural targets for indirect dark matter searches or to constrain the
synchrotron signal from the annihilation of dark matter. In this work,
we study the radio emission due to neutralino dark matter emission
in the nearby dwarf spheroidal galaxies - Ursa Minor, Willman I,
Sculptor and Ursa Major II. Assuming the Navarro-Frenk-White (NFW)
dark matter density profile within the halo of the dwarf galaxies, the
upper limit of synchrotron flux is found to be ~10−14
ergs cm−2 s−1 for neutralino mass
Mχ=1 TeV annihilating into μ+μ−
state and B0 = 4 μG. For B0 = 2 μG, the flux
is one order less. It is seen that as the electron energy approaches
the neutralino mass, electron number density decreases. Moreover,
the peak frequency is found to follow a power-law with the neutralino
mass with a universal exponent.
Title: Surface and interior meridional circulation in the Sun
Authors: Hanasoge, Shravan M.
Bibcode: 2022LRSP...19....3H
Altcode:
Solar meridional circulation is an axisymmetric flow system, extending
from the equator to the poles (∼20 m/s at the surface, ≈1% of the
mean solar rotation rate), plunging inwards and subsequently completing
the circuit in the interior through an equatorward return flow and a
radially outward flow back up to the surface. This article reviews
the profound role that meridional circulation plays in maintaining
global dynamics and regulating large-scale solar magnetism. Because
it is relatively weak in comparison to differential rotation (∼300
m/s, ≈7% of the mean solar rotation rate) and owing to numerous
systematical errors, accurate surface measurements were only first made
in 1978 and initial inferences of interior meridional circulation were
obtained using helioseismology two decades later. However, systematical
biases have made it very challenging to reliably recover flow in the
deep interior. Despite numerous advances that have served to improve
the accuracy of inferences, the location of the return flow and the full
extent of the circulation are still open problems. This article follows
the historical developments and summarises contemporary advances that
have led to modern inferences of surface and interior meridional flow.
Title: Magnetic reconnection: MHD theory and modelling
Authors: Pontin, David I.; Priest, Eric R.
Bibcode: 2022LRSP...19....1P
Altcode:
In this review we focus on the fundamental theory of magnetohydrodynamic
reconnection, together with applications to understanding a wide range
of dynamic processes in the solar corona, such as flares, jets, coronal
mass ejections, the solar wind and coronal heating. We summarise
only briefly the related topics of collisionless reconnection,
non-thermal particle acceleration, and reconnection in systems
other than the corona. We introduce several preliminary topics
that are necessary before the subtleties of reconnection can be
fully described: these include null points (Sects. 2.1-2.2), other
topological and geometrical features such as separatrices, separators
and quasi-separatrix layers (Sects. 2.3, 2.6), the conservation
of magnetic flux and field lines (Sect. 3), and magnetic helicity
(Sect. 4.6). Formation of current sheets in two- and three-dimensional
fields is reviewed in Sect. 5. These set the scene for a discussion of
the definition and properties of reconnection in three dimensions that
covers the conditions for reconnection, the failure of the concept of
a flux velocity, the nature of diffusion, and the differences between
two-dimensional and three-dimensional reconnection (Sect. 4). Classical
2D models are briefly presented, including magnetic annihilation
(Sect. 6), slow and fast regimes of steady reconnection (Sect. 7),
and non-steady reconnection such as the tearing mode (Sect. 8). Then
three routes to fast reconnection in a collisional or collisionless
medium are described (Sect. 9). The remainder of the review is
dedicated to our current understanding of how magnetic reconnection
operates in three dimensions and in complex magnetic fields such as
that of the Sun's corona. In Sects. 10-12, 14.1 the different regimes
of reconnection that are possible in three dimensions are summarised,
including at a null point, separator, quasi-separator or a braid. The
role of 3D reconnection in solar flares (Sect. 13) is reviewed, as
well as in coronal heating (Sect. 14), and the release of the solar
wind (Sect. 15.2). Extensions including the role of reconnection in the
magnetosphere (Sect. 15.3), the link between reconnection and turbulence
(Sect. 16), and the role of reconnection in particle acceleration
(Sect. 17) are briefly mentioned.
Title: Challenges for ΛCDM: An update
Authors: Perivolaropoulos, L.; Skara, F.
Bibcode: 2022NewAR..9501659P
Altcode: 2021arXiv210505208P
A number of challenges to the standard ΛCDM model have been emerging
during the past few years as the accuracy of cosmological observations
improves. In this review we discuss in a unified manner many existing
signals in cosmological and astrophysical data that appear to be in some
tension (2 σ or larger) with the standard ΛCDM model as specified
by the Cosmological Principle, General Relativity and the Planck18
parameter values. In addition to the well-studied 5 σ challenge
of ΛCDM (the Hubble H0 tension) and other well known
tensions (the growth tension, and the lensing amplitude AL
anomaly), we discuss a wide range of other less discussed less-standard
signals which appear at a lower statistical significance level than
the H0 tension some of them known as 'curiosities' in the
data) which may also constitute hints towards new physics. For example
such signals include cosmic dipoles (the fine structure constant α,
velocity and quasar dipoles), CMB asymmetries, BAO Ly α tension, age
of the Universe issues, the Lithium problem, small scale curiosities
like the core-cusp and missing satellite problems, quasars Hubble
diagram, oscillating short range gravity signals etc. The goal of this
pedagogical review is to collectively present the current status (2022
update) of these signals and their level of significance, with emphasis
on the Hubble tension and refer to recent resources where more details
can be found for each signal. We also briefly discuss theoretical
approaches that can potentially explain some of these signals.
Title: Feasibility study of observing γ -ray emission from high
redshift blazars using the MACE telescope
Authors: Tolamatti, A.; Singh, K. K.; Yadav, K. K.
Bibcode: 2022JApA...43...49T
Altcode:
Blazars are the most powerful class of persistent γ -ray sources
in the extragalactic Universe. Study of high redshift blazars is
important to understand their cosmological evolution and formation of
the supermassive black holes in the early phases of the Universe. The
distant blazars are expected to be faint in the γ -ray energy band
since the high-energy γ -ray photons traveling over cosmological
distances are absorbed by the low-energy extragalactic background
light photons via γ -γ pair production. Therefore, detection of
high-energy γ -ray emission from the blazars at high redshifts using
ground-based telescopes is a very challenging task. In this paper, we
report the feasibility of observing high redshift blazars with the MACE
gamma-ray telescope which has recently become operational at Hanle,
Ladakh. We have prepared a catalog of 94 high redshift blazars from
the Fourth Fermi-LAT catalog of γ -ray sources for their plausible
observation with the MACE telescope. We have calculated the integral
flux for these sources by extrapolating their Fermi-LAT spectra in
the energy range from 30 GeV to 5 TeV. Using the MACE sensitivity
information, we have estimated the total time required for the MACE
telescope to detect the high-energy γ -ray emission from these high
redshift blazars at 5σ statistical significance level.
Title: A global look into the world of interacting supernovae
Authors: Gangopadhyay, Anjasha; Misra, Kuntal; Kawabata, Koji;
Dastidar, Raya; Singh, Mridweeka
Bibcode: 2022JApA...43...51G
Altcode: 2022arXiv220306576G
Interacting supernovae (SNe) IIn and Ibn show narrow emission lines and
have always been a mysterious and unsolved genre in SNe physics. We
present a comprehensive analysis of the temporal and spectroscopic
behavior of a group of interacting SNe IIn and Ibn. We choose SNe
2012ab, 2020cui, 2020rc and 2019uo as representative members of these SN
sub-types to probe the nature of explosion. Our study reveals that SNe
IIn are heterogeneous, bright depicting multi-staged temporal evolution
while SNe Ibn are moreover homogeneous, comparatively fainter than SNe
IIn and short lived, but limited in a sample to firmly constrain the
homogeneity. The spectroscopic features display a great diversity in
Hα and He profiles for both SNe IIn and Ibn. The representative SN
Ibn also show flash ionization signatures of CIII and NIII. Modeling
of Hα reveals that SNe IIn have, in general, an asymmetric CSM which
interacts with SN ejecta resulting in diversity in Hα profiles.
Title: Numerical exploration of the motion of variable mass test
particle on the perturbed circular restricted three-body configuration
Authors: Ansari, Abdullah A.; Kellil, Rabah; Sahdev, Shiv Kumar
Bibcode: 2022NewA...9701885A
Altcode:
This paper represents analytical and numerical investigations of the
motion properties of a test particle having a variable mass according
to Jeans' law and subject to the influence of a heterogeneous primary
having N layers of different densities of a part and a second body
producing a modified Newton potential on the other hand. We also assume
that the whole system is perturbed by Coriolis force and centrifugal
force. The equations of motion that we derive, are used to determine
the locations of equilibrium points, Poincaré surfaces of section,
basins of attraction as well as to study questions related to the
stability of equilibrium points.
Title: Another one derives the dust: Ultraviolet dust aerosol
properties retrieved from MAVEN/IUVS data
Authors: Connour, Kyle; Wolff, Michael J.; Schneider, Nicholas M.;
Deighan, Justin; Lefèvre, Franck; Jain, Sonal K.
Bibcode: 2022Icar..38715177C
Altcode:
We derived the ultraviolet complex refractive indices of Martian
dust aerosols using data from the Mars year 34 global dust storm
(GDS). We used data taken by the Imaging Ultraviolet Spectrograph
(IUVS) instrument aboard the Mars Atmosphere and Volatile Evolution
spacecraft and surface-based derivations of the column-integrated
optical depth from the Mastcam instrument on Curiosity. We first
created an explicit microphysical representation of dust to compute
dust-scattering properties at wavelengths within IUVS' spectral range
for four dust particle-size distributions plausibly present during this
GDS. We then used radiative-transfer techniques to iteratively retrieve
the single-scattering albedo from IUVS data using the Mastcam-derived
column-integrated optical depth as a constraint. We converted the
dust single-scattering albedo into its refractive indices and report
the refractive indices at the four particle-size distributions. We
performed dust optical depth retrievals at another time period using
several of these refractive indices and show that our preferred
refractive indices produce optical depths which are consistent with
optical depths derived from Mastcam data at similar times. These
ultraviolet refractive indices will be particularly beneficial for
future observational and theoretical studies of Martian dust.
Title: Cellular patterns and dry convection in textured dust storms
at the edge of Mars North Polar Cap
Authors: Sánchez-Lavega, A.; Erkoreka, A.; Hernández-Bernal, J.;
del Río-Gaztelurrutia, T.; García-Morales, J.; Ordoñez-Etxeberría,
I.; Cardesín-Moinelo, A.; Titov, D.; Wood, S.; Tirsch, D.; Hauber,
E.; Matz, K. -D.
Bibcode: 2022Icar..38715183S
Altcode:
We present a study of textured local dust storms that develop at the
northern polar cap boundary on Mars springtime. We have used images
obtained with VMC and HRSC cameras onboard Mars Express and MARCI on MRO
to analyze dust storms captured from March to July 2019 (Ls = 350° in
MY 34-Ls = 54° in MY 35). The textured storms grow in the longitude
sector 150°E-210°E centered at latitude ~60°N and exhibit spiral,
filamentary and compact shapes that change and evolve rapidly in a daily
basis. The storms translate by prevailing east and southeast winds with
speeds 15-45 ms-1. In some areas of their interiors they show
organized clusters of cells formed typically by 100 elements with sizes
~5-30 km with a length/width ratio ~ 1.2-3 in the wind direction. The
cells have elongated downwind tails with lengths 4-8 times the cell
size. The cells top altitudes are ~6-11 km above their surroundings. We
propose that the spirals grow as baroclinic vortices within a vertically
sheared eastward jet present at this epoch in Mars due to the intense
meridional temperature gradient at the polar cap edge. We show using a
simple one-dimensional model that the cells can be produced by shallow
dry convection with dust acting as the heating source to generate the
updrafts. These patterns resemble those seen in laboratory experiments
and on clouds in Earth's atmosphere and can serve to comparatively
elucidate and discern the different mechanisms at work in each case.
Title: Frequency-dependent Ganymede's tidal Love number k2
detection by JUICE's 3GM experiment and implications for the
subsurface ocean thickness
Authors: De Marchi, Fabrizio; Cappuccio, Paolo; Mitri, Giuseppe;
Iess, Luciano
Bibcode: 2022Icar..38615150D
Altcode:
Ganymede will be the first icy satellite in the Solar System orbited
by a spacecraft, ESA's JUpiter ICy moons Explorer (JUICE). JUICE launch
is scheduled for April 2023 and the arrival at Ganymede is foreseen in
2035. Thanks to the advanced Ka-band radio tracking system, the
Geodesy and Geophysics of Jupiter and Galilean Moons (3GM) experiment
aboard the mission will provide range and range-rate measurements that
will be used to infer the static (up to degree 35-45) and time-varying
gravity field and the internal structure of the moon. Ganymede is
subject to tidal deformation, which periodically modifies its gravity
field. The larger contribution to the time-varying gravity is due
to the tidal interaction with Jupiter, modulated by the eccentricity
and the inclination of the moon's orbit. In addition, Ganymede also
experiences a lower amplitude time-varying tidal interaction with
Io, Europa and Callisto. To a good approximation, the corresponding
gravitational signals are periodic and they contain several harmonics
of the fundamental synodic frequencies. The elastic response of Ganymede
is expected to be frequency-dependent as well. In this work we describe
a procedure to estimate the Ganymede's tidal Love number k2
at different frequencies in the orbit determination process of the 3GM
experiment, supported by numerical simulations. Finally, we show that
3GM measurements can be used to characterize the interior structure
of Ganymede, providing a tight constraint on the subsurface ocean
thickness. The ocean density can be also constrained, but with a
lower precision.
Title: On the rhomboidal restricted five-body problem: Analysis of
the basins of convergence
Authors: Suraj, Md Sanam; Alhowaity, Sawsan; Aggarwal, Rajiv; Asique,
Md Chand; Alahmadi, Amani
Bibcode: 2022NewA...9701893S
Altcode:
This manuscript aims to investigate numerically the effect of
parameter λ on the basins of convergence (BoCs) associated with the
equilibrium points (EPs) of the restricted rhomboidal five-body problem
(RR5BP). Moreover, the parametric variation of EPs and zero velocity
curves (ZVCs) are also illustrated. Firstly, we have scanned the entire
interval for λ ∈(1/√{3},√{ 3 }) to evaluate the critical value
of λ where the number of EPs changes. It is observed that there exist
either eleven, thirteen or fifteen EPs in total, however the stability
analysis suggests that none of the EPs are linearly stable. The effect
of the parameter λ and Jacobian constant C on the regions of possible
motion are also illustrated. A systematic numerical investigation
is performed to unveil the fact that how the parameter λ affects
the geometry of the BoCs. Moreover, we have recorded the total
number of iterations needed for each of the initial condition (IC)
to converge a specific attractor and shown how the BoCs are related
to these iterations and the associated probability distributions. Our
numerical results strongly suggest that the parameter λ is indeed
very influential factor in this dynamical system. The evolution of
attracting regions in this dynamical system is very complicated yet
an issue of paramount importance.
Title: Mechanochemical generation of perchlorate
Authors: Edgar, J. O.; Gould, J. A.; Badreshany, K.; Telling, J.
Bibcode: 2022Icar..38715202E
Altcode:
Perchlorate (ClO4-) is widespread in the solar
system having been detected on Earth, on Mars, in chondrite meteorites
and in lunar samples. On Mars, perchlorates expand the potential for
habitable conditions by lowering the freezing point of liquid water
in the formation of brines. In future manned space exploration their
presence poses a hazard to human health, however, it also represents
opportunities as a source of oxygen and fuel. Despite their prevalence,
the mechanism(s) of perchlorate formation in different solar system
environments are poorly understood. Here we demonstrate that perchlorate
can be generated through the mechanical activation of silicates in
the presence of chloride.
Title: The magnetic susceptibility of Pleistocene paleosols as a
Martian paleoenvironment analog
Authors: Bradák, Balázs; Kereszturi, Ákos; Steinmann, Vilmos; Gomez,
Christopher; Csonka, Diána; Hyodo, Masayuki; Szeberényi, József;
Novothny, Ágnes; Végh, Tamás; Barta, Gabriella; Medveďová,
Alzbeta; Rostinsky, Pavel; Mihály, Enikő; Jó, Viviána; Horváth,
Erzsébet
Bibcode: 2022Icar..38715210B
Altcode:
This work aims to introduce and test various semiquantitative
field methods and environmental magnetic measurements to help
prepare future planetary missions on Mars. For analog observations,
paleosols of loess successions in various stages of soil development
were investigated and were used as models to infer environmental
change during environmental change on early Mars. Methods commonly
used in terrestrial soils and sediment environments, such as soil
development indices and low field and frequency-dependent magnetic
susceptibility, are introduced and evaluated as potential proxies to
constrain paleoenvironmental conditions and climate change on Mars
billions of years ago. These methods include the following: 1) low
field magnetic susceptibility, which may aid in the identification
of weathered horizons (e.g., palaeosols) and provide insight into
the degree of weathering intensity; 2) frequency-dependent magnetic
susceptibility can constrain nanoscale magnetic contributions,
including some with possible biogenic/bacterial origin, but its
applicability to indicate the degree of pedogenesis is limited; and 3)
the vertical distribution of low field magnetic susceptibility, i.e.,
the pattern of magnetic susceptibility curves, seems to work well in
the indication of the balance between the sedimentary and pedogenic
environment. Analysis of magnetic susceptibility curves may contribute
to the identification of Martian paleosols, the characterization of the
transition period between the soil-forming and subsequent sedimentary
periods (Noachian-Hesperian and Hesperian-Amazonian transitions)
and the identification of climate cycles; thus, these may be used
as a frame of reference for evaluating paleoclimatic changes on
Mars to e.g., the Noachian warm Mars and"Snowball Mars" periods. The results also suggest that the time dependence of the magnetic
enhancement of paleosols seems to be nonlinear compared to the length
of the pedogenic period itself, and magnetic susceptibility may work
as a relative chronometric parameter, which can help to constrain the
duration of pedogenic alteration and soil formation on Mars.
Title: Convective storms in closed cyclones in Jupiter: (II)
numerical modeling
Authors: Iñurrigarro, Peio; Hueso, Ricardo; Sánchez-Lavega, Agustín;
Legarreta, Jon
Bibcode: 2022Icar..38615169I
Altcode:
On May 31, 2020 a convective storm appeared in one small cyclone in the
South Temperate Belt (STB) of Jupiter. The storm, nicknamed as Clyde's
Spot, had an explosive start and quickly diminished in activity in a
few days. However, it left a highly turbulent cyclone as a remnant that
evolved to become a turbulent segment of the STB in a time-scale of
one year. A very similar storm erupted on August 7, 2021 in another
cyclone of the STB with a similar initial phenomenology. In both
cases, the outbreaks started in cyclones that were the result of the
merger of pre-existing vortices. In a previous paper we presented an
observational study of these storms compared with a similar cyclonic
convective system observed during the Voyager 2 flyby [Hueso et al.,
Convective storms in closed cyclones in Jupiter's South Temperate
Belt: (I) Observations, Icarus, 380, 2022]. Here we present numerical
simulations of these vortices and storms with the Explicit Planetary
Isentropic-Coordinate (EPIC) numerical model. We simulate mergers of
cyclones in Jupiter's STB and investigate the deep structure of the
resulting cyclone and its capability to uplift material from the water
condensation level. Convection is introduced in the model imposing
heating sources whose vertical extent, horizontal size and duration
are free parameters that we explore. Our simulations reproduce the
cloud field of both storms after short episodes of a few hours of
intense convection. The evolution of the morphology of the convective
cyclone after the convective pulse stopped shows a strong relation
between the convective energy released and the initial vorticity
in the cyclone. Similar results are obtained for the cyclonic storm
observed during the Voyager 2 flyby. We also compare our simulations
of these storms with numerical simulations of a storm that developed
in the STB in 2018 inside an elongated cyclone known as the South
Temperate Belt Ghost [Iñurrigarro et al., Observations and numerical
modelling of a convective disturbance in a large-scale cyclone in
Jupiter's South Temperate Belt, Icarus, 336, 2020]. In addition,
we also simulate one of the large-scale storms that develop in
the South Equatorial Belt comparing our simulations with Voyager
1 observations of one of those events. From these simulations, we
establish a relative scale of energies associated to these convective
storms. As coherent cyclones isolate the local atmosphere from their
surroundings, we propose that the availability of condensables inside
closed cyclones limits the duration of active convection, allowing
larger convective outbursts in larger cyclones. Our simulations of
the short and intense convective pulse associated to the 2020 and 2021
STB suggest a minimum local water abundance of 1.0-1.2 times solar at
the location of the storms. The lower number considers a significant
contribution of ammonia condensation, and the larger number considers
only water moist convection with a negligible role of ammonia.
Title: Trace element volatility and the conditions of liquid-vapor
separation in the proto-lunar disk
Authors: Ivanov, Dmitry; Fitoussi, Caroline; Bourdon, Bernard
Bibcode: 2022Icar..38615143I
Altcode:
The Moon is thought to have formed from material ejected by a giant
impact that took place at the end of Earth's accretion. The material
ejected to space generated a large hot structure where material beyond
the Roche limit accreted to form the Moon. It has long been known that
the Moon is characterized by abundances in moderately volatile elements
(MVE) lower than that of the Earth, while more recent studies have
established that the concentrations in refractory elements are similar
to the bulk Silicate Earth. The thermodynamic conditions that prevailed
after this impact are poorly known and understanding the origin of the
Moon-Earth differences in MVE requires a knowledge of the volatility
of elements under these conditions. In this study, we reexamine the
volatility of a large set of geochemically relevant elements and
attempt to determine the P-T conditions under which volatiles were
putatively separated from the liquid material. Our model predicts
very different condensation temperatures due to higher pressures,
compared with the conditions of the Solar Nebula and we extend the
values of these temperatures to a wide number of trace elements
(Se, Ag, Pt, Mo, W, Zn, Sn, Sb, Rb, Cs, U, Th, Cr, Ni, Co, Ga, Ge,
Cu, and P). Our modeling shows that the observed lunar compositions
cannot be explained by a single set of P and T conditions. Rather,
it is best explained by a mixture between high-temperature condensates
(~4000 K) and low temperature condensates (2000-2500 K). An important
constraint is that for the low temperature condensates, liquid metal
must have been stable and this is crucial for matching the abundance
of volatile siderophile elements in the bulk Moon.
Title: Characterization of groundwater chemistry beneath Gale Crater
on early Mars by hydrothermal experiments
Authors: Noda, Natsumi; Sekine, Yasuhito; Tan, Shuya; Kikuchi, Sakiko;
Shibuya, Takazo; Kurisu, Minako; Takahashi, Yoshio; Fukushi, Keisuke;
Rampe, Elizabeth B.
Bibcode: 2022Icar..38615149N
Altcode:
Hydrothermal groundwater may have played many roles in hydrogeochemical
cycles on early Mars, including being a source of cations and
reductants, a sink of CO2, and a causative fluid of
post-depositional diagenesis. However, few laboratory experiments
have been investigated hydrothermal reactions within the Martian
crust. Here we describe hydrothermal experiments simulating
water-rock reactions in the Martian subsurface, with the aim of
characterizing the fluid chemistry. Experiments at 120 °C and 200
°C show that the hydrothermal fluids have i) high Si concentrations
(~1-10 mmol kg-1), ii) low Fe and Mg concentrations
(<~10-3 mmol kg-1), iii) low H2
concentrations (<10-2 mmol kg-1), and iv)
alkaline pH (in-situ pH ~8). Effective drawdown of CO2
(4-5 mmol kg-1) occurs through the formation of
calcite. Concentrations of Si in the fluids are buffered by the
dissolution equilibrium of quartz at 200 °C and its metastable phase
(cristobalite) at 120 °C. These characteristics would not explain
the observed secondary mineral assemblages of Vera Rubin Ridge (VRR),
in particular high abundance of Fe (hydro)oxides and low levels of
silica and clay minerals, in the Murray formation of Gale Crater. This
implies that upwelling hydrothermal groundwater can be precluded as
a source of post-depositional diagenetic fluids. Our results under
reaction temperatures of ≤200 °C indicate that upwelling hydrothermal
groundwater provided only limited amounts of reductants and greenhouse
effect gases (Fe2+ and H2) to the surface of
early Mars.
Title: The impact of the large-scale circulation anomalies in the
northern hemisphere on air quality in Wuhan of China during the
Spring Festival in 2020
Authors: Tao, Niu; Jizhi, Wang; Yuanqin, Yang; Xiaofei, Jiang; Yiliang,
Jiang; Huizheng, Che
Bibcode: 2022JASTP.23805931T
Altcode:
During the 2020 Chinese Spring Festival extended holidays and
the COVID-19 period in Wuhan, the "quasi-zero emissions increase"
occurred due to the human activities have a considerably lower impact
on air quality. A new scientific question of concern: Why has high of
O3 and PM2.5 still been observed? The comparative
analysis of the influences of anomalous atmospheric circulation and
weather conditions during this special period in 2019-2020 with those
in the historical years can be useful. The results in the study were
as follows: (1) Even during this "quasi-zero emissions increase"
period, the concentrations of O3 and PM2.5 are
higher than normal, with O3 being significantly higher in
Wuhan. Which is associated with a anomaly large-scale humid/warm water
vapor transport in the Northern Hemisphere which is significantly
different from that of the same period with historical more-haze
years. (2) In this scenario, the large-scale humid/warm water vapor
transport brings sustained high-humidity water vapor lifting conditions
to north China. The daily cycling change of the sun's zenith angle to
support the high-humidity and high-condensation condition are conducive
to the elevation of high condensation (fc) and degree of
super-saturation (S) going up to the peak of S >10%. Under the
condition driven by high fc, it causes the power exponent
law to be followed converting NO2 to O3,
thereby resulting in an increase in O3 concentration. This
additional contribution to O3 concentration is as high as 37%
than those from pure chemical process. (3) An objective quantitative
reversal method for calculating the monthly threshold in fc
is given based on the power exponential conversion law by the observed
data. It can be prospectively applied to assess the feedback on the
impact of pollution on urban climate.
Title: Preparation and thermoelectric transport properties of BiSe
and Sb-doped BiSe single crystals
Authors: HE, ZiMin; WU, Rong; LAI, XiaoFang; JIAN, JiKang
Bibcode: 2022SSPMA..52k7311H
Altcode:
No abstract at ADS
Title: Crystal structure and electronic state in layered 3d(2)
system VI_3
Authors: Shu-Zong, Li; Bin-Guang, He; Hongxing, Li; Zhixiong, Yang;
Wei-Bing, Zhang
Bibcode: 2022SSPMA..52k6811S
Altcode:
No abstract at ADS
Title: Study of general relativistic shocks and their propagation
in neutron stars
Authors: Mallick, Ritam; Verma, Anshuman
Bibcode: 2022JHEAp..36...36M
Altcode:
Astrophysical shocks are very common and are interesting as they
are responsible for particle acceleration in supernovas, blazers,
and neutron stars. In this work, we study general relativistic shocks
in which the shock front is at rest. We derive the jump conditions
and the Taub adiabat equation for both the space-like and time-like
shocks. We solve these equations for a neutron star where the shock
wave is followed by a combustion front deconfining hadronic matter to
quark matter. We find that the maximum mass of the daughter quark star
(generated from the combustion of the parent neutron star) is consistent
with the maximum mass limit for the equation of state sequence. The
matter velocities under some conditions become super-luminous, which
although disputed may indicate a very fast combustion process. Also,
the matter velocities imply that for space-like shocks, the combustion
process is most probably a deflagration, and for time-like shocks,
it is a detonation and can even proceed with velocities that are
super-luminous.
Title: Thermal conductivity of planetary regoliths: The effects of
grain-size distribution
Authors: Mellon, Michael T.; McKay, Christopher P.; Grant, John A.
Bibcode: 2022Icar..38715211M
Altcode:
The thermal properties of a planet's regolith are of primary importance
in solar system exploration. Thermal conductivity and the related
parameter thermal inertia are often used to decipher the regolith's
structure, grain size, and areal distribution. In this work we utilize
a guarded-heat-flow apparatus to measure the thermal conductivity
of mono-dispersed and bimodal size populations of regolith analogs
(borosilicate-glass beads and terrestrial soils) under a range of
interstitial gas pressures from 10-5 to 103 mb,
at 20 °C. From these measurements we further develop a physically
based analytical model for use as a predictive tool for planetary
research. While our results for mono-dispersed grains agree well
with previous studies, our findings for bimodal grain-size mixtures
do not. Our results demonstrate that the functional dependence of
thermal conductivity on interstitial gas pressure closely follows that
of the fine-grained component of the mixture, but uniformly offset to
higher conductivity values depending only on the volume fraction of
the coarse component. The grain size of the coarse fraction plays no
role. The reason for the difference with previous studies appears to
be related to limitations with the transient-heated-wire method in
previous work. Our results suggest that, on Mars, large quantities
of coarse grain material, such as sand or cobbles, could be hidden
in regional dust deposits. Additionally, variations in the thermal
properties of aeolian dune fields may result from differences between
age-related dust infiltration and self-cleansing sand migration, rather
than any real differences in local grain size. On Earth, at high gas
pressures, grain size mixtures result in higher thermal conductivity
than any component alone, consistent with field observations.
Title: Holographic consistency and the sign of the Gauss-Bonnet
parameter
Authors: Ong, Yen Chin
Bibcode: 2022NuPhB.98415939O
Altcode: 2022arXiv220813360O
If Einstein-Gauss-Bonnet gravity is obtained as a low energy limit of
string theory, then the Gauss-Bonnet parameter α is essentially the
inverse string tension and thus necessarily positive. If one treats
Einstein-Gauss-Bonnet gravity as a modified theory of gravity in the
anti-de Sitter bulk in the bottom-up approach of holography, then
there is no obvious restriction on the sign of the parameter a priori,
though various studies involving boundary causality have restricted the
possible range of α. In this short note, we argue that if holographic
descriptions are to be consistent, then the Gauss-Bonnet parameter has
to be positive. This follows from a geometric consistency condition in
the Euclidean picture. From the Lorentzian signature perspective, black
holes with a negative α lead to uncontrolled brane nucleation in the
bulk and so the supposedly static geometry is untenable. In fact, even
the ground state without a black hole is problematic. In other words,
the bottom-up approach agrees with the top-down approach on the sign of
the parameter. Some possible loopholes of the conclusion are discussed.
Title: On the use of empirical models for high-latitude ionosphere
Authors: Shaikh, Muhammad Mubasshir
Bibcode: 2022JASTP.23805935S
Altcode:
Comparative analysis between a global ionospheric empirical model,
NeQuick2, with a regional empirical model for high-latitudes, E-CHAIM,
has been presented. Based on the calculation of F2-peak parameters
from both models and comparing them with one solar cycle data from
18 high-latitude ionosonde stations, it has been shown that E-CHAIM's
average improvement over NeQuick2 is less than 0.15-0.2 MHz in foF2 and
less than 15-20 km in hmF2. Data from 7 out of 18 stations showed less
than or equal to 0.1 MHz improvement in foF2 using E-CHAIM over NeQuick2
including 2 out of 3 stations located in the auroral latitudes. At
the other end, data from 13 out of 18 high latitude stations showed
less than or equal to 10 km improvement in hmF2 including all three
stations located in auroral latitudes, in using E-CHAIM over NeQuick2.
Title: A possible perchlorate-enabled mechanism for forming thick
near surface excess ice layers; in the Amazonian regolith of Mars
Authors: Fisher, David; Lacelle, Denis; Pollard, Wayne
Bibcode: 2022Icar..38715198F
Altcode:
We use the freezing point depressing magnesium and calcium perchlorates
in Martian regolith to redistribute ground ice by residual liquid water
migration following the initial emplacement of ground ice by vapour
deposition. This residual liquid water is moved by forces generated
by periodic surface temperatures that decay with depth in conjunction
with the geothermal vertical temperature gradient. We examine the period
means of the bulk water speeds with depth and the mean divergence of the
bulk water speeds, which relates to the rate of change in ice content
in the regolith. Silt and clay rich regoliths behave differently. In
silty regolith, for the short 1.88 a period and for longer 50 ka
(precession) and 120 ka (obliquity) temperature cycles, there is a
mean movement of liquid perchlorate aqueous solution that results in
formation of near surface excess ice layers. The excess ice formed by
the seasonal 1.88a period is confined at high latitudes to the upper
meter of regolith. For the longer periods, there is a well-defined
surface temperature region where near surface thick (≥40 m) excess
ice layers form; (from 192 K to 210 K). For mean surface temperatures
<192 K no near surface thick excess ice layers formed, but deeper
layers are predicted and followed. The formation of excess ice layers
in silt near the surface is controlled by the relationship between the
temperature cycles, geothermal gradient and the eutectic temperature of
the perchlorate (eg. ~198 K for Ca and ~ 205 K for Mg perchlorate). At
a given depth if the periodic temperature is below the eutectic then
there is nearly no liquid water left and what there is has much higher
viscosity. The sudden change in the liquid water amount and viscosity
with temperature generates net average water speeds in silts that are
two orders larger than in clays.
Title: Temperature-dependent kinetic analysis of cryogenic-specific
reddish coloration synthesized with cryoplasma
Authors: Phua, Yu Yu; Sakakibara, Noritaka; Ito, Tsuyohito; Terashima,
Kazuo
Bibcode: 2022Icar..38715152P
Altcode:
We recently reported on the reddish coloration of a
CH3OH/H2O ice irradiated by cryoplasma, which
is similar in appearance to the reddish surfaces seen on some icy
bodies in the outer Solar System, and is sustained only at cryogenic
temperatures. In this study, we analyzed the time evolution of
absorption spectra during irradiation of this ice at temperatures
of 70-90 K, and found that the nominal production rates of the
reddish materials decreased with increasing temperature. We conducted
kinetic analysis, which revealed that although the formation of the
materials that absorb at 500 nm showed no temperature dependence,
their disappearance under cryoplasma irradiation showed a positive
temperature dependence. This finding indicates that the interactions
of excited plasma species with the reddish materials, coupled with
thermally-driven processes, can increase the rates of disappearance
of the reddish materials and result in their destruction even at
temperatures below their thermal dissociation temperatures, which was
found to be 120-150 K in our previous study. These results suggest
that the effects of radiation-driven chemistry and thermally-driven
chemistry in concert can influence the formation and stability of
reddish materials such as those synthesized in this study.
Title: A reflectance calibration method for Multispectral Camera
(MSCam) on the Zhurong rover
Authors: Zhang, Qing; Liu, Dawei; Liu, Jianjun; Guo, Lin; Xue, Bin;
Yang, Jianfeng; Yang, Benyong; Wang, Xing; Huang, Hai; Liu, Bin;
Chen, Wangli; Ren, Xin
Bibcode: 2022Icar..38715208Z
Altcode:
The Multispectral Camera (MSCam) onboard the Zhurong rover, collecting
eight band images in the visible and near-infrared wavelengths, aims to
investigate the morphological characteristics and mineralogic properties
of the Martian surface. Due to the perturbation of Martian atmosphere,
accurate reflectance calibration for the MSCam data is crucial for
the further spectral interpretation. Here, we proposed a reflectance
calibration method to convert the MSCam radiance to reflectance
factor using the MSCam calibration target. This study begins with the
laboratory multi-angle measurements to characterize the photometric
properties of the MSCam calibration target. Based on these photometric
characteristics, a reflectance model consisting of a directional
reflection term and a specular reflection term is developed. The
constructed reflectance model achieves a high precision, the root mean
square errors (RMSEs) between the modeled and measured reflectance
factor are <1.5% and the determination coefficients (R2)
are >99.3% in all cases. We then applied this reflectance model to
the in-flight observations to derive the reflectance of the Martian
surface. The validations indicate that the in-flight derived reflectance
factors of the calibration target are consistent with the laboratory
measurements, and the derived reflectance spectra of the Martian
surface are comparable to the spectra captured by the other mission.
Title: Pre and post-landing atmospheric optical depths at the Zhurong
landing site on Mars retrieved using a single-image-based approach
Authors: Liu, Wai Chung; Wu, Bo; Li, Zhaojin; Dong, Jie; Rao, Wei
Bibcode: 2022Icar..38715223L
Altcode:
The atmosphere of Mars has complex photometric processes due to multiple
scattering and absorption by the suspended aerosols. The atmospheric
optical depth is an indicator of the aerosol concentrations and can
be used to model the contribution of atmospheric scattering, thereby
correcting surface spectra. The atmospheric optical depth is also
important in analysing the variations of atmospheric dust and evaluating
the risks facing landing and roving missions. Retrieving the atmospheric
optical depth from a single image is desirable as simultaneous stereo
observations of the Martian surface are not common. However, most of
the existing single-image-based methods rely on shadows in the image,
which can be challenging to identify when the site is smooth or when
the atmosphere becomes turbid. In this paper, we present a method of
retrieving the atmospheric optical depth from a single image based
solely on non-shadowed surfaces. This method was validated using HiRISE
images and measurements acquired by rovers on the Martian surface. The
method achieved an RMSE of 2%-7% in most cases, depending on the
different surface photometric models used. The results indicated that
aerosol scattering parameters have less impact on the retrievals than
the surface photometric properties, likely due to the fact that the
data is optically thin. The optical depths at the Zhurong landing site
before and after landing were estimated using the proposed method. The
results show that the optical depths first decreased and then increased,
with the turning point being around the landing date, indicating that
the Zhurong rover landed at an appropriate time. The proposed method
is of significance for the analysis of Martian atmospheric dust and
surface spectra with better spatio-temporal resolutions.
Title: Combination of swarm, Jason-3, and GNSS observations to
construct a new modeling of global ionospheric maps
Authors: Karimi, Sedigheh; Sharifi, Mohammad Ali; Farzaneh, Saeed;
Kosary, Mona
Bibcode: 2022JASTP.23805934K
Altcode:
By increasing various space geodetic observation techniques with
different orbital altitudes the capability for ionosphere layer
monitoring is enhanced. In this paper, in order to increase the accuracy
and reliability of Global Ionosphere Maps (GIMs) in regions with no or
sparse GNSS data coverage, the observational data derived from Swarm,
consisting of three Low Earth Orbiter (LEO) satellite constellation
missions and a satellite altimetry mission, was integrated with the
Global Positioning System (GPS) observations. The vertical total
electron content (VTEC) of GPS and Swarm LEO satellites was obtained
by employing the modified single-layer mapping function (MSLM) on
the slant total electron content (STEC) and then the VTECs derived
from three techniques were represented by the Spherical Harmonics (SH)
expansion function up to the degree and order 15 in a solar-geomagnetic
frame. In regard to the combination of different observation techniques,
the systematic biases between different data sources are required
to be considered. Here, the systematic biases of Swarm and Jason-3
satellites were expanded in terms of SH function and regarded as
unknown parameters for estimation. Moreover, in order to consider
different accuracy levels of ionospheric data groups, the Helmert
Variance Component Estimation (H-VCE) was used to determine appropriate
relative weights of observation groups. The two-dimensional combined
models were constructed during 10 days in the period of DOY 271-275,
2017 and DOY 003-007, 2018 by considering different high and low
Kp-indexes from 1 to 7 values. The obtained results showed that after
adding the Swarm and Jason-3 data to GPS observations, the reduction
of mean standard deviation (STD) maps was in the range of about 46-56%
in 10 days. The combined method improved the reliability and precision
of GIMs in oceanic regions significantly. However, the impact of VTECs
from Swarm satellites was higher than that of VTECs from satellite
altimetry due to the appropriate data sampling and coverage of Swarm
mission. The results are also validated against the VTECs derived from
5 IGS stations (that are not included in the modeling). Our results
indicate that the Combined method's mean Root Mean Square Error (RMSE)
compared to GNSS dual-frequency measurements were less than 1.6 TECU
with an improvement of about 9.56-25.80% respect to the mean RMSE of
GIMs constructed by only GPS measurements.
Title: Near-infrared spectroscopy of boulders with dust or patina
coatings on the Moon: A two-layer radiative transfer model
Authors: Sun, Lingzhi; Lucey, Paul G.
Bibcode: 2022Icar..38715204S
Altcode:
Previous remote sensing studies focus on lunar surface regolith, which
contains abundant mixtures of rock fragments and dust, making it hard to
track the petrologic origin. Igneous boulders exposed on lunar surface,
however, carry pristine mineralogy and chemistry since its formation,
therefore are direct evidence of lunar thermal evolution events. High
spatial-resolution remote sensing images and rover explorations of
the Moon allow us to study the spectroscopy of igneous boulders. We
modeled the optical scattering properties of rocks using the Legendre
and Double Henyey-Greenstein phase functions, porosity parameter
and grain size, and provided a modified radiative transfer model for
rocks rather than powdered minerals. Considering that space weathering
could generate a layer of dust or patina on the surface of boulders,
we introduced a two-layer radiative transfer modeling algorithm to
solve the spectroscopy of the substrate rock for dust- or patina-coated
boulder. The modeled substrate rock spectra show less reddening, larger
reflectance, and stronger absorption band depth compared to dust- or
patina-coated rock, consistent with the measurements of Apollo rock
samples. We applied this two-layer model on the dust-coated boulder
detected by Yutu-2 rover and derived the spectrum of the substrate
rock. Using Kaguya Multiband Imager data, we calculated the substrate
rock spectra for an anorthosite boulder, and our result shows good
consistency with laboratory measured anorthosite rock spectrum. This
work is a beginning of understanding lunar boulder spectroscopy for
a more precise interpretation of lunar thermal history.
Title: 2 D and 3 D axi-symmetric horseshoe periodic orbits about
Lagrangian points: A global grid search approach
Authors: Yousuf, Saleem; Kishor, Ram
Bibcode: 2022Icar..38715207Y
Altcode:
This paper presents the numerical exploration of planar as well
as spatial periodic horseshoe orbits about Lagrangian points in the
framework of restricted three-body problem with radiation pressure and
albedo as perturbations. The global grid search technique for obtaining
both types of periodic horseshoe orbits is described. Further, several
families of horseshoe orbits are obtained and then the orbital behaviour
of each periodic orbit is investigated. By global grid search method,
spatial axi-symmetric horseshoe orbits and their families are obtained
via pseudo-arclength continuation. Interestingly, new forms of spatial
horseshoe orbits are constructed and their orbital properties are
analysed. Moreover, it is found that stable horseshoe orbits exists
for different range of x0 in planar as well as in spatial
case. Using parameter continuation, the effect of radiation pressure
and albedo are discussed for the evolution of horseshoe orbits and
found that the radiation pressure affects the shape of horseshoe orbits
more then that of albedo. These results are helpful to analyse more
generalized problem with other perturbations.
Title: Martian gully activity and the gully sediment transport system
Authors: Dundas, Colin M.; Conway, Susan J.; Cushing, Glen E.
Bibcode: 2022Icar..38615133D
Altcode:
The formation process for Martian gullies is a critical unknown for
understanding recent climate conditions. Leading hypotheses include
formation by snowmelt in a past climate, or formation via currently
active CO2 frost processes. This paper presents an expanded
catalog of >300 recent flows in gullies. The results indicate that
sediment transport in current gully flows moves the full range of
materials needed for gully formation. New flows are more likely to
transport boulders in gullies that have pre-existing boulder-covered
aprons, indicating that current flows are transporting the same
materials required for gully formation overall. The distribution
of gully activity frequencies can be described by a power law and
indicates that the recurrence intervals for flows in individual gullies
are commonly tens to hundreds of Mars years. Over the last ~300 kyr,
climate variations have been modest but individual gullies have had
tens to thousands of flow events. This could be sufficient to account
for the entirety of gully formation in some cases, although the same
processes are likely to have occurred further in the past. For any
gullies that may have initiated under higher-obliquity conditions,
this level of recent activity indicates that the observable morphology
has been shaped by CO2-driven flows. These observations of
sediment transport and the tempo of gully activity are consistent with
gully formation entirely by CO2 frost processes, likely
with spatial and temporal variability, but with no role required for
liquid water.
Title: Matching resummed endpoint and continuum γ-ray spectra from
dark-matter annihilation
Authors: Beneke, M.; Urban, K.; Vollmann, M.
Bibcode: 2022PhLB..83437248B
Altcode: 2022arXiv220301692B
For the minimal wino and Higgsino benchmark models we provide accurate
energy spectra of high-energy photons from TeV scale dark-matter
annihilation χχ → γ + X by merging electroweak Sudakov resummation
near maximal energy with the electroweak parton-shower PPPC4DM,
and accounting for the Sommerfeld effect. Electroweak resummation
significantly changes the shape of the photon-energy spectrum in the
wide range Eγ ∼ (0.6 … 1)mχ and hence the
form of the so-called "line-signal".
Title: Gaussian and Lorentzian non-commutative wormhole solutions
in exponential gravity
Authors: Feng, Yihu
Bibcode: 2022NewA...9701858F
Altcode:
In this study, we explore the Lorentzian and Gaussian distributions. We
discuss the wormhole geometry in f(R) gravity with two different
exponential models. Both the models for f(R) gravity, i.e., f(R)
= R - αΥ(1 -e-Λ) and f(R) = R - αΥ ∗ tanh(Λ) ,
with the concept of non-commutative distribution. We fix the values of
unknowns parameters and provide the graphical behavior of the obtained
results. It is shown that obtained results fulfill all the necessary
conditions of shape function in both cases with both distributions. The
inquired wormhole solutions violate the null energy conditions in the
background of both models. It is concluded that our obtained results
are viable and stable.
Title: The synergy of the cosmic ray and high energy atmospheric
physics: Particle bursts observed by arrays of particle detectors
Authors: Chilingarian, A.; Hovsepyan, G.
Bibcode: 2022NewA...9701871C
Altcode:
Particle bursts detected on the earth's surface during thunderstorms
by various particle detectors originated from the relativistic runaway
electron avalanches (RREAs) initiated by free electrons accelerated
in the strong atmospheric electric fields. Two oppositely directed
dipoles in the thundercloud accelerate electrons in the direction
of the earth's surface, and to the open space. The particle bursts
observed by orbiting gamma ray observatories are called terrestrial
gamma ray flashes (TGFs, with energies of several MeV, only sometimes
reaching tens of MeV); ones registered by particle detectors located
on the ground - are called thunderstorm ground enhancements (TGEs,
with energies, usually reaching 40-50 MeV). Balloons and aircraft in
the troposphere register gamma ray glows (with energies of several
MeV). Recently, high-energy atmospheric physics includes also,
so-called, downward TGFs (DTGFs), intense particle bursts with a
duration of a few milliseconds. Well-known extensive air showers
(EASs) originate from the interactions of galactic protons and
fully-stripped nuclei with the atmosphere atoms. EAS particles have
very dense cores around the shower axes. However, high-energy particles
in the EAS cores comprise a very thin disc of (a few tens of ns),
and a particle detector traversed by an EAS core will not register a
particle burst, but only one very large pulse. Only neutron monitor, by
collecting delayed thermal neutrons from EAS core particle interactions
with soil, can register particle bursts. We discuss the relation between
short particle bursts available from the largest particle arrays with
EAS phenomena. We demonstrate that the neutron monitors can extend the
EAS "lifetime" up to a few milliseconds, a time comparable with DTGFs
duration. The possibility to use the network of neutron monitors for
high-energy cosmic ray research is also deliberated. Plain Language
Summary: Short and extended particle bursts are registered in space,
the troposphere, and the earth's surface. Coordinated monitoring of the
particle fluxes, near-surface electric fields, and lightning flashes
makes it possible to formulate a hypothesis on the origin of intense
bursts and their relation to extensive air showers and atmospheric
discharges. Analysis of the observational data and possible origination
scenarios of particle bursts allows us to conclude that the bursts can
be explained by the electron acceleration in the thunderous atmosphere
and by gigantic showers developed in the terrestrial atmosphere by
high-energy protons and fully-stripped nuclei accelerated in Galaxy.
Title: A new climatological electron density model for supporting
space weather services
Authors: Hoque, Mohammed Mainul; Jakowski, Norbert; Prol, Fabricio S.
Bibcode: 2022JSWSC..12....1H
Altcode:
The ionosphere is the ionized part of the Earth's atmosphere, ranging
from about 60 km up to several Earth radii, whereas the upper part
above about 1000 km height up to the plasmapause is usually called the
plasmasphere. We present a new three-dimensional electron density model
to support space weather services and mitigate propagation errors for
trans-ionospheric signals. The model is developed by superposing the
Neustrelitz Plasmasphere Model (NPSM) to an ionosphere model composed of
separate F and E-layer distributions. It uses the Neustrelitz TEC model
(NTCM), Neustrelitz Peak Density Model (NPDM), and the Neustrelitz
Peak Height Model (NPHM) for the total electron content (TEC), peak
ionization, and peak height information. These models describe the
spatial and temporal variability of the key parameters as a function
of local time, geographic/geomagnetic location, solar irradiation, and
activity. The model is developed to calculate the electron concentration
at any given location and time in the ionosphere for trans-ionospheric
applications and named the Neustrelitz Electron Density Model
(NEDM2020). A comprehensive validation study is conducted against
electron density in-situ data from DMSP and Swarm, Van Allen Probes and
ICON missions, and topside TEC data from COSMIC/FORMOSAT-3 mission,
bottom side TEC data from TOPEX/Poseidon mission, and ground-based
TEC data from International GNSS Service (IGS) covering both high and
low solar activity conditions. Additionally, the model performance is
compared with the 3D electron density model NeQuick2. Our investigation
shows that the NEDM2020 performs better than the NeQuick2 compared
with the in-situ data from Van Allen Probes and ICON satellites and TEC
data from COSMIC and TOPEX/Poseidon missions. When compared with DMSP
and IGS TEC data, both NEDM2020 and NeQuick2 perform very similarly.
Title: Photogravitational magnetic-binary problem with oblateness
and belt of material points
Authors: Arif, Mohd.; Ullah, M. Shahbaz; Kant, Laxmi
Bibcode: 2022NewA...9701877A
Altcode:
We study the motion of a charged particle in the framework of
magnetic-binary problem where the bigger primary is the source of
radiation and the smaller primary is the oblate body; and they are
enclosed by a homogeneous circular truss of material points centered at
the center of mass of the system. We have determined the equations of
motion that govern the motion of a charged particle. The coordinates
of collinear and non-collinear equilibrium points and their linear
stability have been calculated. Numerical results reveal that the ratio
of magnetic moment λ has a huge impact on the location, stability and
orbital dynamics of the problem. We observed that there exists eight,
eleven and thirteen equilibrium points for different values of mass
parameter μ and the ratio of magnetic moment λ. Further, we observed
that all non-collinear equilibrium points are unstable in the Lyapunov
sense. But the collinear points L4 and L6 show
a stable behavior for some values of μ and λ, while other collinear
equilibrium points are unstable. The geometric configuration of zero
velocity curves of the charged particle is numerically simulated and
addressed. Moreover, first order approximations to a Lyapunov and
Lissajous orbits are summarized near the collinear equilibrium points
under the effect of λ.
Title: Phonon damping in one-dimensional lattices with asymmetric
interactions
Authors: Feng, Sihan; Fu, Weicheng; Zhang, Yong; Zhao, Hong
Bibcode: 2022SCPMA..6517006F
Altcode:
The symmetry of interparticle interaction plays an important
role in determining the energy transport and diffusion behavior of
one-dimensional (1D) lattices, not only in the process of hydrodynamics
but also in the process of kinetics. In this paper, we study the
relaxation properties of phonons in 1D lattices with asymmetric
and symmetric interparticle interactions, exemplified by the famous
Fermi-Pasta-Ulam-Tsingou model. Asymmetric interparticle interactions
(AIIs) lead to larger damping rates of phonons as compared to symmetric
ones in the low-temperature limit, and the difference gradually
vanishes when the temperature increases. Moreover, in lattices
with AIIs, the dependence of the damping rate Γ of phonons still
follows a power-law on the wave number q, i.e., Γ ∼ qγ
for small q. In particular, at low temperatures, AIIs result in
γ ≈ 1, which is out of the predictions of 3/2 ≤ γ ≤ 2 from
various theories. Our results provide insights into understanding the
anomalous heat conduction observed in 1D chains and ultra-low phonon
heat conduction found in certain solids.
Title: The formation mechanisms for mid-latitude ice scarps on Mars
Authors: Williams, K. E.; Dundas, C. M.; Kahre, M. A.
Bibcode: 2022Icar..38615174W
Altcode:
Mid-latitude exposed ice scarps have recently been identified on Mars
(Dundas et al., 2018, 2021). The presence of such surface ice exposures
at relatively low latitudes was itself a mystery, and the evolutionary
dynamics of such scarps have also not been explained. In this work,
we model the ice ablation rates of several identified mid-latitude
scarps. We find that, given certain characteristics of their geographic
setting, the orientation and growth of the scarps can be explained by
energy balance models.
Title: Constraining the spectral behavior of the clay-bearing outcrops
in Oxia Planum, the landing site for ExoMars "Rosalind Franklin" rover
Authors: Brossier, Jeremy; Altieri, Francesca; De Sanctis, Maria
Cristina; Frigeri, Alessandro; Ferrari, Marco; De Angelis, Simone;
Apuzzo, Andrea; Costa, Nicole; Ma MISS Team
Bibcode: 2022Icar..38615114B
Altcode:
Oxia Planum (335.5°E, 18.2°N) is selected as the landing site
for ExoMars rover mission (ESA/Roscosmos), where the "Rosalind
Franklin" rover is scheduled to land in the decade. The region
reveals several extensive clay-bearing outcrops recently exhumed,
where biosignatures are possibly preserved. The objectives of the
mission are to search for organics and investigate traces of past
or extant life on Mars. Preliminary surveys of these outcrops show
infrared absorptions typical of Fe,Mg-rich clays in the 1.0-2.6 μm
range (1.4, 1.9, 2.3 and 2.4 μm) and an additional absorption at 2.5
μm implying a possible mixture with other mineral phase(s). Here we
provide a detailed description of absorptions of the clay-rich materials
detected in Oxia Planum, and map their strength and distribution
throughout the region using hyperspectral data gathered by the Compact
Reconnaissance Imaging Spectrometer for Mars (CRISM) onboard NASA's Mars
Reconnaissance Orbiter (MRO) mission. Our analysis suggests that the
Fe,Mg-rich clays identified in Oxia Planum mainly correspond to either
Fe-bearing saponites (e.g., Griffithite) or vermiculite ores (i.e.,
vermiculite associated with a hydrobiotite component). Conversely, large
clay-bearing outcrops found in the catchment area (337°E, 16.7°N) are
rather consistent with nontronites in association with Al-rich clays
and kaolins, in agreement with previous identification in the Mawrth
Vallis - west Arabia Terra province. Presence of Fe,Ca-rich carbonates
is recognized with the absorption near 2.53 μm and the observation
of a broad peak in the 3-4 μm range, supporting their co-occurrence
with the clays in Oxia Planum and its catchment area. Although we
favor a pedogenesis alteration for the clays found in the catchment
area, the origin of those studied in Oxia's basin remains enigmatic,
where alternative scenarios could be either lacustrine and deltaic
sedimentation, groundwater circulation, or even hydrothermal fluid
circulation. Future in-situ measurements by "Rosalind Franklin" rover
will indubitably provide new insights on the mineralogical diversity
seen in the region and their origins.
Title: Modeling the production of submicroscopic iron in the lunar
highlands
Authors: Jordan, A. P.; Shusterman, M. L.; Tai Udovicic, C. J.
Bibcode: 2022Icar..38715184J
Altcode:
Micrometeoroid impacts, solar wind bombardment, and dielectric breakdown
driven by solar energetic particles all potentially alter the optical
properties of the lunar regolith by creating submicroscopic metallic
iron (smFe0), which includes both nanophase (< 33 nm) and
microphase (> 33 nm) iron. We create a simple model that describes
the time-dependent accumulation of optically active smFe0
in the lunar highlands. Our model synthesizes recent analyses of how
space weathering processes form smFe0-bearing agglutinates
and rims on soil grains and how impact gardening controls the exposure
time of these grains. It successfully reproduces the results of a
prior analysis of the formation of smFe0 in the highlands,
particularly in regard to nanophase iron, showing that there is
consistency among diverse analyses of Apollo samples and of orbital
observations. We find that the results of our model are not consistent
with the solar wind directly forming smFe0 (although
the solar wind may play a role in optical maturation via hydrogen
implantation). Our model results are consistent with smFe0
in the lunar highlands being created mainly by micrometeoroid impacts,
with a possible contribution from dielectric breakdown weathering.
Title: High-energy and ultra-high-energy neutrinos: A Snowmass
white paper
Authors: Ackermann, Markus; Bustamante, Mauricio; Lu, Lu; Otte,
Nepomuk; Reno, Mary Hall; Wissel, Stephanie; Ackermann, Markus;
Agarwalla, Sanjib K.; Alvarez-Muñiz, Jaime; Alves Batista, Rafael;
Argüelles, Carlos A.; Bustamante, Mauricio; Clark, Brian A.; Cummings,
Austin; Das, Sudipta; Decoene, Valentin; Denton, Peter B.; Dornic,
Damien; Dzhilkibaev, Zhan-Arys; Farzan, Yasaman; Garcia, Alfonso;
Garzelli, Maria Vittoria; Glaser, Christian; Heijboer, Aart; Hörandel,
Jörg R.; Illuminati, Giulia; Seon Jeong, Yu; Kelley, John L.; Kelly,
Kevin J.; Kheirandish, Ali; Klein, Spencer R.; Krizmanic, John F.;
Larson, Michael J.; Lu, Lu; Murase, Kohta; Narang, Ashish; Otte,
Nepomuk; Prechelt, Remy L.; Prohira, Steven; Reno, Mary Hall; Resconi,
Elisa; Santander, Marcos; Valera, Victor B.; Vandenbroucke, Justin;
Vasil'evna Suvorova, Olga; Wiencke, Lawrence; Wissel, Stephanie;
Yoshida, Shigeru; Yuan, Tianlu; Zas, Enrique; Zhelnin, Pavel; Zhou,
Bei; Anchordoqui, Luis A.; Ashida, Yosuke; Bagheri, Mahdi; Balagopal,
Aswathi; Basu, Vedant; Beatty, James; Bechtol, Keith; Bell, Nicole;
Bishop, Abigail; Book, Julia; Brown, Anthony; Burgman, Alexander;
Campana, Michael; Chau, Nhan; Chen, Thomas Y.; Coleman, Alan; Connolly,
Amy; Conrad, Janet M.; Correa, Pablo; Creque-Sarbinowski, Cyril;
Cummings, Austin; Curtis-Ginsberg, Zachary; Dasgupta, Paramita; De
Kockere, Simon; de Vries, Krijn; Deaconu, Cosmin; Desai, Abhishek;
DeYoung, Tyce; di Matteo, Armando; Elsaesser, Dominik; Fürst,
Phillip; Fan, Kwok Lung; Fedynitch, Anatoli; Fox, Derek; Ganster,
Erik; Minh, Martin Ha; Haack, Christian; Hallman, Steffen; Halzen,
Francis; Haungs, Andreas; Ishihara, Aya; Judd, Eleanor; Karg, Timo;
Karle, Albrecht; Katori, Teppei; Kochocki, Alina; Kopper, Claudio;
Kowalski, Marek; Kravchenko, Ilya; Kurahashi, Naoko; Lamoureux,
Mathieu; León Vargas, Hermes; Lincetto, Massimiliano; Liu, Qinrui;
Madsen, Jim; Makino, Yuya; Mammo, Joseph; Marka, Zsuzsa; Mayotte,
Eric; Meagher, Kevin; Meier, Maximilian; Minh, Martin Ha; Miramonti,
Lino; Moulai, Marjon; Mulrey, Katharine; Muzio, Marco; Naab, Richard;
Nelles, Anna; Nichols, William; Nozdrina, Alisa; O'Sullivan, Erin;
OD́ell, Vivian; Osborne, Jesse; Pandey, Vishvas; Paudel, Ek Narayan;
Pizzuto, Alex; Plum, Mattias; Pobes Aranda, Carlos; Pyras, Lilly;
Raab, Christoph; Rechav, Zoe; Rojo, Juan; Romero Matamala, Oscar;
Santander, Marcos; Savina, Pierpaolo; Schroeder, Frank; Schumacher,
Lisa; Sciutto, Sergio; Sclafani, Stephen; Ful Hossain Seikh, Mohammad;
Silva, Manuel; Singh, Rajeev; Smith, Daniel; Spencer, Samuel Timothy;
Springer, Robert Wayne; Stachurska, Juliana; Suvorova, Olga; Taboada,
Ignacio; Toscano, Simona; Tueros, Matias; Twagirayezu, Jean Pierre;
van Eijndhoven, Nick; Veres, Péter; Vieregg, Abigail; Wang, Winnie;
Whitehorn, Nathan; Winter, Walter; Yildizci, Emre; Yu, Shiqi
Bibcode: 2022JHEAp..36...55A
Altcode:
Astrophysical neutrinos are excellent probes of astroparticle
physics and high-energy physics. With energies far beyond solar,
supernovae, atmospheric, and accelerator neutrinos, high-energy and
ultra-high-energy neutrinos probe fundamental physics from the TeV scale
to the EeV scale and beyond. They are sensitive to physics both within
and beyond the Standard Model through their production mechanisms and
in their propagation over cosmological distances. They carry unique
information about their extreme non-thermal sources by giving insight
into regions that are opaque to electromagnetic radiation. This white
paper describes the opportunities astrophysical neutrino observations
offer for astrophysics and high-energy physics, today and in coming
years.
Title: Breaking efficiency limit of thermal concentrators by
conductivity couplings
Authors: Zhuang, Pengfei; Xu, Liujun; Tan, Peng; Ouyang, Xiaoping;
Huang, Jiping
Bibcode: 2022SCPMA..6517007Z
Altcode:
The concentrating efficiency of a thermal concentrator can be reflected
in the ratio of its interior to exterior temperature gradients,
which, however, has an upper limit in existing schemes. Here, we
manage to break this upper limit by considering the couplings of
thermal conductivities and improve the concentrating efficiency
of thermal concentrators. For this purpose, we first discuss a
monolayer scheme with an isotropic thermal conductivity, which
can break the upper limit but is still restricted by its geometric
configuration. To go further, we explore another degree of freedom
by considering the monolayer scheme with an anisotropic thermal
conductivity or by adding the second shell with an isotropic thermal
conductivity, thereby making the concentrating efficiency completely
free from the geometric configuration. Nevertheless, apparent negative
thermal conductivities are required, and we resort to external heat
sources realizing the same effect without violating the second law of
thermodynamics. Finite-element simulations are performed to confirm the
theoretical predictions, and experimental suggestions are also provided
to improve feasibility. These results may have potential applications
for thermal camouflage and provide guidance to other diffusive systems
such as static magnetic fields and dc current fields for achieving
similar behaviors.
Title: pyFIT3D and pyPipe3D - The new version of the integral field
spectroscopy data analysis pipeline
Authors: Lacerda, Eduardo A. D.; Sánchez, S. F.; Mejía-Narváez,
A.; Camps-Fariña, A.; Espinosa-Ponce, C.; Barrera-Ballesteros, J. K.;
Ibarra-Medel, H.; Lugo-Aranda, A. Z.
Bibcode: 2022NewA...9701895L
Altcode: 2022arXiv220208027L
We present a new version of the FIT3D and Pipe3D codes, two packages to
derive properties of the stellar populations and the ionized emission
lines from optical spectroscopy and integral field spectroscopy data
respectively. The new codes have been fully transcribed to Python from
the original Perl and C versions, modifying the algorithms when needed
to make use of the unique capabilities of this language with the main
goals of (1) respecting as much as possible the original philosophy of
the algorithms, (2) maintaining a full compatibility with the original
version in terms of the format of the required input and produced output
files, and (3) improving the efficiency and accuracy of the algorithms,
and solving known (and newly discovered) bugs. The complete package
is freely distributed, with an available repository online. pyFIT3D
and pyPipe3D are fully tested with data of the most recent IFS data
surveys and compilations (e.g. CALIFA, MaNGA, SAMI and AMUSING++),
and confronted with simulations. We describe here the code, its new
implementation, its accuracy in recovering the parameters based on
simulations, and a showcase of its implementation on a particular
dataset.
Title: Catalog of spiral arm tangents (Galactic longitudes) in the
Milky Way, and the age gradient based on various arm tracers
Authors: Vallée, Jacques P.
Bibcode: 2022NewA...9701896V
Altcode: 2022arXiv220714220V
An updated catalog of 205 observed tangents to the spiral arms
(in Galactic longitudes) since 1980 is presented. This represents an
addition of 80 arm tangents in 6 years (since 2016). Most arm tangents
are observed at telescopes in the radio régime. In this study, the
separation of each arm tracer from the dust lane is analysed to obtain
the relative speed away from the dust lane (an age gradient). Each
arm tracer is observed to be separated from the dust lane, showing
an age gradient of about 11.3 ±2 Myr/kpc across the spiral arm -
a relative speed away from the dust lane of about 87 ±10 km/s.
Title: Paleosecular variation record from Pleistocene-Holocene lava
flows in southern Colombia
Authors: de Oliveira, Wellington P.; Hartmann, Gelvam A.; Savian,
Jairo F.; Nova, Giovanny; Parra, Mauricio; Biggin, Andrew J.; Trindade,
Ricardo I. F.
Bibcode: 2022PEPI..33206926D
Altcode:
Improvements in the spatial and temporal coverage of paleomagnetic
data are essential to better evaluate paleofield behaviour over the
past 10 Myr, especially due to data scarcity at low latitudes in the
South American region. Here, we provide new Pleistocene-Holocene (0-2
Ma age interval) paleodirectional data from three volcanic systems
(Doña Juana Volcanic Complex, Galeras Volcanic Complex and Morasurco
Volcano) in southwestern Colombia between latitudes 1.2 and 1.4°N. A
total of 38 paleodirectional sites were studied using progressive
alternating field and thermal demagnetization treatments. After
excluding transitional data, we obtain thirty site-mean directions for
analysis of paleosecular variation (PSV) and the time-averaged field
(TAF) in the study area. The mean direction (Dec = 351.2°, Inc =
-3.4°, α95 = 6.2°, k = 20.0) and the paleomagnetic pole
(Plat = 80.7°N, Plon = 173.1°E, A95 = 5.2°, K = 29.1)
of these sites are not statistically compatible with the expected
geocentric axial dipole (GAD) field direction and geographic
north pole, respectively. Virtual geomagnetic pole dispersion
(SB) for our filtered dataset (SB(2Ma)
= 15.212.017.6°) and the Brunhes chron
(SB(Bru) = 16.011.619.1°) are
consistent at the 95% confidence level with South American studies at
equatorial latitudes and recent PSV models for the 0-10 Ma and Brunhes
intervals. Likewise, the corresponding inclination anomaly (ΔI) for two
age groups ΔI2Ma = - 5.9-12.10.3° and
ΔIBru = - 5.3-13.73.1° suggests large
deviations relative to the GAD model, in accordance with predictions
from zonal TAF models. The high VGP dispersion could be linked to
strong longitudinal variability of the magnetic equator position
over South America. This feature reflects the presence of significant
non-dipole field components in this region that have been detected in
geomagnetic field models for the most recent centuries and millennia,
probably associated with the presence of the South Atlantic Magnetic
Anomaly in the South American region.
Title: A machine-generated catalogue of Charon's craters and
implications for the Kuiper belt
Authors: Ali-Dib, Mohamad
Bibcode: 2022Icar..38615142A
Altcode: 2022arXiv220608277A
In this paper we investigate Charon's craters size distribution using a
deep learning model. This is motivated by the recent results of Singer
et al. (2019) who, using manual cataloging, found a change in the
size distribution slope of craters smaller than 12 km in diameter,
translating into a paucity of small Kuiper Belt objects. These
results were corroborated by Robbins and Singer (2021), but opposed
by Morbidelli et al. (2021), necessitating an independent review. Our
MaskRCNN-based ensemble of models was trained on Lunar, Mercurian,
and Martian crater catalogues and both optical and digital elevation
images. We use a robust image augmentation scheme to force the model
to generalize and transfer-learn into icy objects. With no prior
bias or exposure to Charon, our model find best fit slopes of q =
-1.47 ± 0.33 for craters smaller than 10 km, and q = -2.91 ± 0.51
for craters larger than 15 km. These values indicate a clear change
in slope around 15 km as suggested by Singer et al. (2019) and thus
independently confirm their conclusions. Our slopes however are both
slightly flatter than those found more recently by Robbins and Singer
(2021). Our trained models and relevant codes are available online
on github.com/malidib/ACID.
Title: The meteor shower complex of comet 109P/Swift-Tuttle based
on its cloned orbits
Authors: Hajduková, M.; Neslušan, L.
Bibcode: 2022Icar..38715175H
Altcode:
Comet 109P/Swift-Tuttle is the well-known parent body of the Perseid
meteor shower, and, possibly, a few other showers, as we found in our
previous work (Paper I). In Paper I, we studied the meteoroid stream
of the comet using models derived from the comet's nominal orbit. In
respect to the uncertainty of its determination, the nominal orbit did
not appear to be the most probable orbit. Furthermore, our modeling
predicted the semi-major axes of Perseids typically larger than the
published mean semi-major axis of this shower by some authors. In
this paper, we repeat the modeling, in the same way as in Paper I,
except we derive the models of the stream from two cloned orbits of
the nominal orbit. The first clone attempts to fit the most probable
109P's orbits and the second clone had, in a certain period in the
past, the smallest semi-major axis among all constructed clones. We
confirmed the clear relationship of 109P with the Perseids, #7, and,
with regard to the stronger influence of non-gravitational forces,
its relationship with the 49 Andromedids, #549. Furthermore, we found
an indication that parts of the stream meteoroids of 109P, which have
long evolutionary periods, may correspond to the ζ-Cassiopeiids, #444,
u-Andromedids, #507, and UY Lyncids, #705. However, the modeling based
on the cloned orbits did not result, in general, in a better match of
our prediction with the real showers (mainly Perseids) than the modeling
described in Paper I, which was based on the nominal orbit of 109P.
Title: Impact craters and the observability of ancient martian
shorelines
Authors: Baum, Mark; Sholes, Steven; Hwang, Andrew
Bibcode: 2022Icar..38715178B
Altcode: 2022arXiv220609816B
The existence of possible early oceans in the northern hemisphere of
Mars has been researched and debated for decades. The nature of the
early martian climate is still somewhat mysterious, but evidence for one
or more early oceans implies long-lasting periods of habitability. The
primary evidence supporting early oceans is a set of proposed remnant
shorelines circling large fractions of the planet. The primary features
are thought to be older than 3.6 Ga and possibly as old as 4 Ga,
which would make them some of the oldest large-scale features still
identifiable on the surface of Mars. One question that has not been
thoroughly addressed, however, is whether shorelines this old could
survive modification and destruction processes like impact craters,
tectonics, volcanism, and hydrology in recognizable form. Here
we address one of these processes-impact cratering-in detail. We
use standard crater counting age models to generate synthetic,
global populations of craters and intersect them with hypothetical
shorelines, tracking portions of the hypothetical shoreline that are
directly impacted. The oldest shorelines (≥4 Ga) are at least 70
% destroyed by direct impacts. Shorelines of any age >3.6 Ga are
dissected into relatively short, discontinuous segments no larger than
about 40 km when including the effects of craters larger than 100 m
in radius. When craters smaller than 500 m in radius are excluded,
surviving segment lengths can be as large as ∼1000 km. The oldest
shorelines exhibit fractal structure after impacts, presenting as a
discontinuous collection of features over a range of scales. If the
features are truly shorelines, high-resolution studies should find
similar levels of destruction and discontinuity. However, our results
indicate that observing shorelines as old as 4 Ga, should they exist,
is a significant challenge and raises questions about prior mapping
efforts.
Title: Updated neutrino mass constraints from galaxy clustering and
CMB lensing-galaxy cross-correlation measurements
Authors: Tanseri, Isabelle; Hagstotz, Steffen; Vagnozzi, Sunny;
Giusarma, Elena; Freese, Katherine
Bibcode: 2022JHEAp..36....1T
Altcode: 2022arXiv220701913T
We revisit cosmological constraints on the sum of the neutrino masses
Σmν from a combination of full-shape BOSS galaxy clustering
[ P (k)] data and measurements of the cross-correlation between
Planck Cosmic Microwave Background (CMB) lensing convergence and
BOSS galaxy overdensity maps [Cℓκg ], using
a simple but theoretically motivated model for the scale-dependent
galaxy bias in auto- and cross-correlation measurements. We improve
upon earlier related work in several respects, particularly through a
more accurate treatment of the correlation and covariance between P (k)
and Cℓ/κg measurements. When combining
these measurements with Planck CMB data, we find a 95% confidence level
upper limit of Σmν < 0.14eV, while slightly weaker
limits are obtained when including small-scale ACTPol CMB data, in
agreement with our expectations. We confirm earlier findings that (once
combined with CMB data) the full-shape information content is comparable
to the geometrical information content in the reconstructed BAO peaks
given the precision of current galaxy clustering data, discuss the
physical significance of our inferred bias and shot noise parameters,
and perform a number of robustness tests on our underlying model. While
the inclusion of Cℓκg measurements does not
currently appear to lead to substantial improvements in the resulting
Σmν constraints, we expect the converse to be true for
near-future galaxy clustering measurements, whose shape information
content will eventually supersede the geometrical one.
Title: Zinc isotope anomalies in primitive meteorites identify
the outer solar system as an important source of Earth's volatile
inventory
Authors: Savage, Paul S.; Moynier, Frédéric; Boyet, Maud
Bibcode: 2022Icar..38615172S
Altcode:
The source of and timing of delivery of the volatile elements
to Earth is a question that is fundamental to understanding how
our planet evolved. Here, we show that primitive meteorites have
resolved mass-independent Zn isotope anomalies from the terrestrial
reservoir. Carbonaceous chondrites (CC), likely originating from
the outer Solar System are distinct from non-CC, and Earth is
intermediate between these two components. Modelling based on these
data indicates that around 30% of Earth's budget of Zn and other
moderately volatile material derives from the participation of 6%
of CC-like materials during Earth's accretion, with the remaining
coming from NC meteorites. This implies that, despite the relatively
minor mass of Earth thought to derive from CC-like material, the CC
component of Earth was relatively and significantly volatile-enriched;
this is in line with the observation that the terrestrial elemental
abundance pattern of moderately volatile elements could be explained
by a carbonaceous source, and with the carbonaceous chondrite-like
isotopic budget of more volatile-rich material accreted later in
Earth's accretion history (e.g. Hg, Se, N, noble gases).
Title: Vertical distribution of water vapour for Martian northern
hemisphere summer in Mars Year 28 from Mars Climate Sounder
Authors: Lolachi, R.; Irwin, P. G. J.; Teanby, N. A.
Bibcode: 2022Icar..38615141L
Altcode:
We present, for the first time, retrievals of the vertical
distribution of water vapour from Mars Climate Sounder (MCS) aboard
Mars Reconnaissance Orbiter (MRO), an original goal of the mission
compromised by channel filter performance issues. To work around this
problem a two-stage retrieval has been developed and was applied
to MCS observations for MY28 NH summer (Ls=111-173°,
26 September 2006 to 27 January 2007). Retrievals were consistent
with observations by other instruments for both column abundances
(e.g., peak NH summer column abundance of 70 pr. μm compared with 50
pr. μm in the literature) and vertical profiles. Other key results are
nightside vertical profiles of water vapour (retrieved for the first
time) and interaction of atmospheric water vapour with the aphelion
cloud belt. Seasonal changes in the hygropause (a proxy for condensation
level) are reflected in changes in the cloud belt. During late northern
summer, when the hygropause level is high at the equator and tropics,
the cloudbase is higher (increasing by ≈10 km from 25 to 35 km)
and the belt is weaker.
Title: Late Amazonian dike-fed distributed volcanism in the Tharsis
volcanic province on Mars
Authors: Pieterek, Bartosz; Ciazela, Jakub; Lagain, Anthony; Ciazela,
Marta
Bibcode: 2022Icar..38615151P
Altcode:
Tharsis is the largest volcanic province on Mars and in the solar
system. This region includes major volcanoes (Olympus Mons, Alba
Mons, Arsia Mons, Pavonis Mons, and Ascraeus Montes) and hundreds
of small volcanic cones and vents, whose origin is not yet fully
understood. Although the main Tharsis' edifices plumbing system has
been extensively studied, smaller volcanoes' origin remains unknown. The
formation of those minor volcanic landforms may be related to the large
volcanic edifices' evolution, and/or controlled by the fault systems
through which magma migrates towards the Martian surface. In this
study, we analyzed the central part of the Tharsis volcanic province
using satellite images with a resolution of ~6 m/px from the Context
Camera onboard the Mars Reconnaissance Orbiter (CTX/MRO). We identified
and mapped 659 volcanic edifices >1 km in diameter. We analyzed
(1) their spatial distribution, (2) alignment of summit craters,
and (3) surface model ages derived from crater counting. We found
that volcanic edifices are unevenly distributed across the Tharsis
province and proposed that their formation is controlled by at least
six individual magma-plumbing systems associated with major edifices:
Olympus Mons, Alba Mons, Arsia Mons, Pavonis Mons, Ascraeus Mons, and
Uranius Mons. Their summit alignment orientations indicate they were
controlled by radial and circumferential dikes originated from magma
sources beneath the six central volcanoes, either magma chambers in the
crust or other magmatic underplates at the base of the crust. Volcano
flanks of distributed volcanoes are of similar age or younger than
the summit calderas of the associated central volcano indicating a
common magmatic system. Magma migration and eruptions from distributed
volcanoes may thus extend beyond the magma waxing periods when magma
supply was high enough to sustain summit eruptions. The relatively
young age of documented volcanic activity within the Tharsis province
may imply recently active hydrothermal systems triggered by magma-water
interaction.
Title: Numerical simulations of radar echoes rule out basal
CO2 ice deposits at Ultimi Scopuli, Mars
Authors: Orosei, Roberto; Caprarelli, Graziella; Lauro, Sebastian;
Pettinelli, Elena; Cartacci, Marco; Cicchetti, Andrea; Cosciotti,
Barbara; De Lorenzis, Alessandro; De Nunzio, Giorgio; Mattei,
Elisabetta; Nenna, Carlo; Noschese, Raffaella; Soldovieri, Francesco
Bibcode: 2022Icar..38615163O
Altcode:
The principal objective of the radar sounder MARSIS experiment is
to look for ice and water in the Martian subsurface. One particular
focus of investigations, since 2005, has been the search for basal
liquid water in the south polar layered deposits (SPLD). Anomalously
strong basal echoes detected from four distinct areas at the base of
the deposits at Ultimi Scopuli have been interpreted to indicate the
presence of bodies of liquid water in this location, beneath a 1.5 km
thick cover of ice and dust. Other explanations for the bright basal
reflections have been proposed, however, including the possibility
of constructive interference in layered media. Here, we test this
mechanism through simulations of MARSIS radar signals propagating in
models of CO2-H2O ice sequences. We then compare
the results to real MARSIS data acquired over Ultimi Scopuli, finding
that no CO2-H2O ice model sequence reproduces
the set of real data. The results of our work have implications in
relation to the global CO2 inventory of Mars.
Title: Analysis of boulders population around a young crater using
very high resolution image of Orbiter High Resolution Camera (OHRC)
on board Chandrayaan-2 mission
Authors: Dagar, A. K.; Rajasekhar, R. P.; Nagori, R.
Bibcode: 2022Icar..38615168D
Altcode:
The Orbiter High Resolution Camera (OHRC) is a very high spatial
resolution panchromatic camera (0.45-0.70 μm) on-board Chandrayaan-2
orbiter. Its spatial resolution of 0.25 m from 100 km altitude
is highest among all lunar orbiter missions. A simple crater with
substantial boulder population was observed in an OHRC image of a region
near Boguslawsky E crater. Boulders are distinctly seen in this image
because of high spatial resolution of 0.28 m and low sun elevation
angle (6°) which enhanced the boulders' shadows. We have identified
and mapped >2000 boulders around this young un-named simple crater
(74.9216° S, 54.5148° E). It is observed that the OHRC is capable
of extending the lower limit of size for identifiable boulders below 1
m. The distributions of mapped boulders are studied and compared with
previous studies. It was found that the coefficient values estimated
by fitting power laws to various distributions, such as size-frequency,
size-range, etc., are well within the ranges reported in literature for
craters distributed on lunar surface around the landing sites. Weibull
distribution was also fit to the data, and the fitting coefficients were
compared with the values obtained in similar studies. The crater age was
estimated to be in the range of 50‑90 Ma using empirical relations,
and comparison with areal density of other craters near lunar landing
sites. This study also provides a glimpse of the low-light imaging
capability of the OHRC showing inside the shadow regions, which were
illuminated by reflected light from adjoining areas.
Title: Reflectance study of ice and Mars soil simulant
associations-II. CO2 and H2O ice
Authors: Yoldi, Zuriñe; Pommerol, Antoine; Poch, Olivier; Thomas,
Nicolas
Bibcode: 2022Icar..38615116Y
Altcode: 2022arXiv220713905Y
We measure the visible and near-infrared reflectance of icy analogues
of the Martian surface made of CO2 ice associated in
different ways with H2O ice and the regolith simulant
JSC Mars-1. Such experimental results obtained with well-controlled
samples in the laboratory are precious to interpret quantitatively
the imaging and spectral data collected by various Mars orbiters,
landers and rovers. Producing and maintaining well-characterised icy
samples while acquiring spectro-photometric measurements is however
challenging and we discuss some of the difficulties encountered in
preparing and measuring our samples. We present the results in the
form of photometric and spectral criteria computed from the spectra and
plotted as a function of the composition and physical properties of the
samples. Consistent with previous studies, we find that when intimately
mixed with other materials, including water ice, CO2
ice becomes rapidly undetectable due to its low absorptivity. As
low as 5 wt% of fine-grained H2O ice is enough to mask
entirely the signatures of CO2. Similarly, sublimation
experiments performed with ternary mixtures of CO2 ice,
H2O ice and JSC Mars-1 show that water, even when present
as a minor component (3 wt%), determines the texture and evolution of
the mixtures. We assess the ability of various combinations of spectral
parameters to identify samples with H2O, CO2, JSC
Mars-1, or various mixtures from their reflectance and orient our study
to helping interpret ice and soil reflectance spectra from the Martian
surface. From the laboratory spectra, we simulate the colour signal
generated by the CaSSIS instrument to allow for direct comparisons with
results from this instrument and provide to databases the necessary
spectral data to perform the same operations with other instruments.
Title: Nonlinear epsilon-near-zero material: Explanation with
time-varying thermal energy
Authors: YANG, YuanMu
Bibcode: 2022SSPMA..52k4231Y
Altcode:
No abstract at ADS
Title: Lightweight design of functionally graded hierarchical
stiffened cylindrical shells
Authors: LUO, XuanHe; ZHOU, HuanLin; MENG, Zeng
Bibcode: 2022SSPMA..52k4611L
Altcode:
No abstract at ADS
Title: Propagation and attenuation of pulses driven by low velocity
normal impacts in granular media
Authors: Quillen, A. C.; Neiderbach, Max; Suo, Bingcheng; South,
Juliana; Wright, Esteban; Skerrett, Nathan; Sánchez, Paul; Cúñez,
Fernando David; Miklavcic, Peter; Askari, Hesam
Bibcode: 2022Icar..38615139Q
Altcode: 2022arXiv220101225Q
We carry out experiments of low velocity normal impacts into
granular materials that fill an approximately cylindrical 42 liter
tub. Motions in the granular medium are tracked with an array of 7
embedded accelerometers. Longitudinal pulses excited by the impact
attenuate and their shapes broaden and become smoother as a function
of travel distance from the site of impact. Pulse propagation is
not spherically symmetric about the site of impact. Peak amplitudes
are about twice as large for the pulse propagating downward than at
45 degrees from vertical. An advection-diffusion model is used to
estimate the dependence of pulse properties as a function of travel
distance from the site of impact. The power law forms for pulse peak
pressure, velocity and seismic energy depend on distance from impact
to a power of -2.5 and this rapid decay is approximately consistent
with our experimental measurements. Our experiments support a seismic
jolt model, giving rapid attenuation of impact generated seismic
energy into rubble asteroids, rather than a reverberation model,
where seismic energy slowly decays. We apply our diffusive model to
estimate physical properties of the seismic pulse that will be excited
by the forthcoming DART mission impact onto the secondary, Dimorphos,
of the asteroid binary (65803) Didymos system. We estimate that the
pulse peak acceleration will exceed the surface gravity as it travels
through the asteroid.
Title: The impact of turbulent vertical mixing in the Venus clouds
on chemical tracers
Authors: Lefèvre, Maxence; Marcq, Emmanuel; Lefèvre, Franck
Bibcode: 2022Icar..38615148L
Altcode:
Venus' clouds host a convective layer between roughly 50 and 60 km
that mixes heat, momentum, and chemical species. Observations and
numerical modelling have helped to understand the complexity of this
region. However, the impact on chemistry is still not known. Here, we
use for the first time a three-dimensional convection-resolving model
with passive tracers to mimic SO2 and H2O for two
latitudinal cases. The tracers are relaxed towards a vertical profile in
agreement with measured values, with a timescale varying over several
orders of magnitude. The vertical mixing is quantified, it is strong
for a relaxation timescale high in front of the convective timescale,
around 4 h. The spatial and temporal variability of the tracer due to
the convective activity is estimated, with horizontal structures of
several kilometres. At the Equator, the model is resolving a convective
layer at the cloud top (70 km) suggested by some observations, the
impact of such turbulent activity on chemical species is accounted for
the first time. From the resolved convective plumes, a vertical eddy
diffusion is estimated, consistent with past estimations from in-situ
measurements, but several orders of magnitude higher than values used
in 1D chemistry modelling. The results are compared to observations,
with some spatial and temporal variability correlation, suggesting an
impact of the convective layer on the chemical species.
Title: Evolution of a dark vortex on Neptune with transient secondary
features
Authors: Wong, Michael H.; Sromovsky, Lawrence A.; Fry, Patrick M.;
Sánchez-Lavega, Agustín; Hueso, Ricardo; Legarreta, Jon; Simon,
Amy A.; Morales-Juberías, Raúl; Tollefson, Joshua; de Pater, Imke;
Irwin, Patrick G. J.
Bibcode: 2022Icar..38715123W
Altcode:
Dark spots on Neptune observed by Voyager and the Hubble Space Telescope
are thought to be anticyclones with lifetimes of a few years, in
contrast with very long-lived anticyclones in Jupiter and Saturn. The
full life cycle of any Neptune dark spot has not been captured due
to limited temporal coverage, but our Hubble observations of a recent
feature, NDS-2018, provide the most complete long-term observational
history of any dark vortex on Neptune. Past observations suggest some
dark spots meet their demise by fading and dissipating without migrating
meridionally. On the other hand, simulations predict a second pathway
with equatorward migration and disruption. We report HST observations
from 2018 to 2020 suggesting that NDS-2018 is following the second
pathway. Some of the HST observations reveal transient dark
features with widths of about 4000 to 9000 km, at latitudes between
NDS-2018 and the equator. The secondary dark features appeared before
changes in the meridional migration of NDS-2018 were seen. These
features have somewhat smaller size and much smaller contrast compared
to the main dark spot. Discrete secondary dark features of this scale
have never been seen near previous dark spots, but global-scale dark
bands are associated with several previous dark spots in addition to
NDS-2018. The absolute photometric contrast of NDS-2018 (as large as
19%) is greater than previous dark spots, including the Great Dark
Spot seen by Voyager. New simulations suggest that vortex internal
circulation is weak relative to the background vorticity, presenting a
clearly different case from stronger anticyclones observed on Jupiter
and Saturn.
Title: Early Noachian terrains: Vestiges of the early evolution
of Mars
Authors: Anderson, Robert C.; Dohm, James M.; Buczkowski, Debra;
Wyrick, Danielle Y.
Bibcode: 2022Icar..38715170A
Altcode:
NASA's main scientific reason for exploring Mars is to determine
the early evolution and the possibility of life on the red
planet. Scientists have adopted an approach for identifying habitable
environments on Mars that could be conducive to the early development
and preservation of life (e.g., robotically exploring hydrothermal and
lake deposits in impact basins). We believe the best approach in the
search for life on Mars is to investigate the ancient terrains that
exhibit sedimentological records comprising rock materials deposited
during a time when Mars was more geologically and hydrologically
active. A paradigm shift from investigating middle age (<3.7 Ga)
resurfaced Martian environments to exploring the extremely ancient
(>3.9 Ga) terrains is proposed here. Terra Cimmeria, Terra Sirenum,
and Arabia Terra are all distinctly older terrains that have not been
modified by the formation of the giant four impact basins (i.e.,
Hellas, Isidis, Argyre, and Chryse) and formed during a time when
Mars contained a thicker atmosphere and operating dynamo/magnetic
field. Exploring these ancient terrains will not only provide the
best opportunity to inform on the earliest stage of Mars' evolution
but also the early Earth and solar system.
Title: Atmospheric circulation and precipitation in Southwest Asia:
The role of the Arabian Anticyclone in precipitation of Iran
Authors: Karimi, Mostafa; Jafari, Mahnaz; Norouzi, Fahimeh;
Khoshakhlagh, Faramarz; Shamsipour, AliAkbar
Bibcode: 2022JASTP.23805933K
Altcode:
Arabian Anticyclone (AAC) is one of the components of atmospheric
circulation in Southwest Asia and is effective in the precipitation of
Iran. The study investigated the role of AAC position in October to May
precipitation in Iran. For this purpose, ERA-Interim gridded data were
used from 1981 to 2010. The relationship between AAC and precipitation
in Iran was conducted in three categories light (1-10 mm/day), moderate
(10-30 mm/day), and heavy (more than 30 mm/day) precipitation. The
geographical location of the AAC center was extracted by defining the
maximum geopotential elevation criterion for all of the above-mentioned
groups. The results indicated that AAC had an independent closed center
between 42 and 85% of the rainy days while it was branched or merged
with Siberian and Tibetan high pressures in other cases. The maximum
frequency of AAC centers was observed on rainy days at 41.62% on the
east coast of the Arabian Peninsula and northwest of the Arabian Sea
at the lower level. This position was mostly in the lower level of
the troposphere with light and moderate precipitation. In addition,
there was another frequency in the Gulf of Aden at the 700 and 500 hPa
levels. During heavy precipitations, the anticyclone at all three levels
was more active on the east coast of the Arabian Peninsula and west of
the Arabian Sea with east-west movements. In general, the AAC seems
to be related to the spatial patterns and intensity of precipitation
in Iran with the movement of the north, especially the east.
Title: Catastrophic rupture of lunar rocks: Implications for lunar
rock size-frequency distributions
Authors: Rüsch, Ottaviano; Marshal, Rachael M.; Iqbal, Wajiha;
Pasckert, Jan Hendrik; van der Bogert, Carolyn H.; Patzek, Markus
Bibcode: 2022Icar..38715200R
Altcode:
Like many airless planetary surfaces, the surface of the Moon is
scattered by populations of blocks and smaller boulders. These features
decrease in abundance with increasing exposure time due to comminution
by impact bombardment and produce regolith. Here we model the evolution
of block size-frequency distributions by updating the model of Hörz et
al. (1975) with new input functions: the size-frequency distributions of
cm-scale meteoroids observed over the last few tens of years and a rock
impact shattering function. The impact shattering function is calibrated
using measurements of a lunar block size-frequency distribution of known
age. We find that cumulative block size-frequency distributions change
with time from a power-law for young populations (<~50 Myr) to an
exponential distribution for older populations. The new destruction
rates are within the uncertainty of the original model, although,
for sizes >5 cm, they are two times faster than the original best
estimate. The faster rates are broadly consistent with observations
reported by other studies. Since the input functions are known for small
rock sizes, the rock abundance can be determined theoretically at sizes
below the current image spatial resolution (0.5 m). Surface exposure
age of block fields can be estimated together with the initial block
abundance from the measurement of block size-frequency distributions.
Title: Ma'adim Vallis, Mars: Insights into episodic and late-stage
water activity from an impact crater
Authors: Tuhi, S.; Harish; Kimi, K. B.; Vigneshwaran, K.; Sharini,
K. S.; Priya, R. K. S.; Vijayan, S.
Bibcode: 2022Icar..38715214T
Altcode:
Alluvial fans, a form of sedimentary deposit reported on Mars, offer
insight into the evolution and nature of fluvial activity on the
planet. Additionally, the region's preserved mineralogy can also be
used to study its hydrological history. In this context, we discuss
the diverse geomorphology and mineralogy of an unnamed crater that
formed on the eastern wall of Ma'adim Vallis, Mars. Ma'adim Vallis is
an irregular-shaped, flat-floored valley incised due to the outflow
of water from the Eridania basin. The rim of the unnamed crater is
breached at multiple locations and it hosts an alluvial fan of an
area ~ 50 km2. The CRISM spectral signatures show Mg-rich
olivine and Mg-rich smectite. Mg smectite was plausibly transported
through water or formed in situ while the underneath terrain was rich
in Mg olivine. The crater retention age on the ejecta of the unnamed
crater is 3.7 Ga which suggests that the crater likely formed during
the Noachian-Hesperian period boundary or earlier. This unnamed crater
probably witnessed the last episode of water activity in the Vallis,
which was most likely fed by water overflowing from a resurged early
Hesperian water activity in Eridania Basin. This study substantiates
episodic, late- stage water activity in Ma'adim Vallis, and the unnamed
crater formed on the floodplains of the Vallis providing an excellent
opportunity for future landing missions to explore astrobiological
significance of the region.
Title: Using machine learning to reduce observational biases when
detecting new impacts on Mars
Authors: Wagstaff, Kiri L.; Daubar, Ingrid J.; Doran, Gary; Munje,
Michael J.; Bickel, Valentin T.; Gao, Annabelle; Pate, Joe; Wexler,
Daniel
Bibcode: 2022Icar..38615146W
Altcode: 2022arXiv220705679W
The current inventory of recent (fresh) impacts on Mars shows a
strong bias towards areas of low thermal inertia. These areas are
generally visually bright, and impacts create dark scours and rays
that make them easier to detect. It is expected that impacts occur at a
similar rate in areas of higher thermal inertia, but those impacts are
under-detected. This study investigates the use of a trained machine
learning classifier to increase the detection of fresh impacts on
Mars using CTX data. This approach discovered 69 new fresh impacts
that have been confirmed with follow-up HiRISE images. We found that
examining candidates partitioned by thermal inertia (TI) values, which
is only possible due to the large number of machine learning candidates,
helps reduce the observational bias and increase the number of known
high-TI impacts.
Title: Photometric study and absolute parameters of four short period
W UMa binary stars of late spectral classes
Authors: Acerbi, Francesco; Barani, Carlo; Popov, Velimir
Bibcode: 2022NewA...9701873A
Altcode:
We present the first CCD complete light curves for the W Ursae
Majoris systems NSVS 870615, NSVS 0912043, NSVS 5049537 and LINEAR
3636597. The observations were performed at the IRIDA South dome of
the NAO Rozhen-Bulgaria and they confirm and revise the short-period
(0.22-0.25 days) for these objects. In particular two of them show
periods near to the cut-off limit. The modeling of the light curves
was done using the Wilson-Devinney code and the elements obtained
from this analysis are used to compute the physical parameters of the
system in order to study its evolutionary status. From a reasonable
synthetic fit of the original data we can derive that all components
of the systems are of K spectral types (T1 < 5000K),
one of the secondaries is of M spectral type. All targets are contact
binary systems of W-subtype, which is a common feature of K spectral
type contact binaries, and two of them, having 1/q > 0.72, belong
to the class of the high mass ratio binaries (H/W type). One, with a
total mass of about 0.73(M⊙) can be considered as Low Mass
Contact Binary system (LMCB). The degrees of contact (fill-out factors)
f are shallow for three of our targets, while for NSVS 0912043 the
analyzes return an important high value of f = 80.7%. The O'Connell
effect in the light curves is well explained by employing star spots
on the binary surface, which confirms that the systems are active at
present. The four systems are in good thermal contact with ΔT between
170K and 420K. The absolute elements of the systems are estimated and
the positions of the components is shown in the logarithmic diagrams.
Title: Venus boundary layer dynamics: Eolian transport and convective
vortex
Authors: Lefèvre, Maxence
Bibcode: 2022Icar..38715167L
Altcode:
Few spacecraft have studied the dynamics of Venus' deep atmosphere,
which is needed to understand the interactions between the surface and
atmosphere. Recent global simulations suggest a strong effect of the
diurnal cycle of surface winds on the depth of the planetary boundary
layer. We propose to use a turbulent-resolving model to characterize
the Venus boundary layer and the impact of surface winds for the first
time. Simulations were performed in the low plain and high terrain at
the Equator and noon and midnight. A strong diurnal cycle is resolved
in the high terrain, with a convective layer reaching 7 km above
the local surface and vertical wind of 1.3 m/s. The boundary layer
depth in the low plain is consistent with the observed wavelength
of the dune fields. At noon, the resolved surface wind field for
both locations is strong enough to lift dust particles and engender
micro-dunes. Convective vortices are resolved for the first time
on Venus.
Title: Cryolava Dome growth resulting from active eruptions on
Jupiter's moon Europa
Authors: Quick, Lynnae C.; Fagents, Sarah A.; Núñez, Karla A.; Wilk,
Kierra A.; Beyer, Ross A.; Beddingfield, Chloe B.; Martin, Emily S.;
Prockter, Louise M.; Hurford, Terry A.
Bibcode: 2022Icar..38715185Q
Altcode:
Europan domes are positive relief features that are typically circular
to elliptical in planform shape, and have characteristic diameters
<16 km. Although it cannot be ruled out that many of these domes may
have been formed from the intrusion of diapirs into Europa's crust,
a subset of domes have relatively smooth surfaces that do not mimic
the surrounding terrain. These domes appear to obscure the preexisting
terrain and have distinct margins which may be lobate or rounded. If
all domes on Europa's surface represented structures where the icy
crust had simply been "punched up" by diapiric intrusions, uplifts
with these distinct morphologies would not be expected to exist. In
this study, we revisit the hypothesis that a subset of europan domes
formed in a manner similar to lava domes on Earth and Venus. Previously,
we modeled dome formation as a consequence of the extrusion of viscous
cryolava. However, that approach only allowed for the investigation
of late-stage eruptive processes far from the vent and provided
little insight into how cryovolcanic fluids may have arrived at the
surface. Consideration of cryolava dome emplacement as fluids erupt
onto Europa's surface is therefore pertinent. A volume flux approach,
in which dome formation is modeled as fluid extrudes onto the surface at
a constant rate, has been successfully applied to the formation of lava
domes on Venus. That study showed that neglecting to consider changes in
fluid rheology while a constant flux of lava is actively extruded onto
the surface may result in overestimates, by several orders of magnitude,
of initial lava viscosities at the time of eruption. Obtaining accurate
viscosity estimates for Europa's cryovolcanic fluids is a critical
step in understanding the properties of near-surface fluids that
have participated in subsurface-surface exchange in the geologically
recent past. To place improved constraints on the rheology and
composition of europan cryolavas, and to better gauge the potential
for dome formation on Europa via effusive eruptions, we apply this
new volume flux approach to the formation of putative europan cryolava
domes. We present a perturbation solution to the generalized form of
the Boussinesq equation for fluid flow in a cylindrical geometry and
explore dome formation while fluid is continuously extruding onto the
surface. We find that at the time of eruption, dome-forming cryolavas
may have had viscosities of 101-103 Pa s. These
viscosity values suggest that cryolavas may be briny slurries composed
of a mixture of water, salts, and ice crystals, rather than pure water
(viscosity ~10-3 Pa s) or simple brines (viscosities
between 10-3 and 10-1 Pa s). Nevertheless,
the derived bulk viscosities indicate that dome-forming cryolavas
have a rheology more similar to basalt than typical higher-viscosity
andesite to rhyolitic dome-forming lavas on Earth. Several of the
domes in our study may be connected to liquid reservoirs in Europa's
crust, and subsurface-surface exchange may be ongoing today. As such,
these domes represent compelling targets for multispectral imaging,
radar sounding, and surface sampling by future missions to Europa.
Title: A method for digitization of archival astroplates of the
Fesenkov Astrophysical Institute
Authors: Shomshekova, S.; Izmailova, I.; Umirbayeva, A.; Omarov, Ch.
Bibcode: 2022NewA...9701881S
Altcode:
The paper presents work on the analysis of archival data on different
media, checking the preservation, quality of archival data, and
their sorting. Based on the analysis of the archival data of the
Fesenkov Astrophysical Institute, the "Digital Archive Data Log" was
developed. At the moment, the digital log contains information on ∼
10000 archived images. These are mainly spectra of planetary nebulae,
Seyfert galaxies, and photometric images of comets. For the digitization
of astroplates and frames, we have used two Epson Perfection V850 Pro
scanners with additional SilverFast8 software which allows choosing
the right parameters for each astroplate individually to get a reliable
result. Test scans of Astronegative samples and selection of necessary
parameters for scanning the entire data volume were performed. The test
scanning showed that the model with a spatial resolution of 1200 dpi is
the most optimal digitizing option. We have written program code in the
Python programming language to automate the header of each frame. The
data from the catalogs chosen to find the astrometric solutions are
given in the article. The paper shows that for the digitized data the
astrometric reduction can be correctly performed through astrometry.net
and in the APEX II systems.
Title: Dust storm 'hot spots' and Transport Pathways Affecting the
Arabian Peninsula
Authors: Al-Hemoud, Ali; Al-Dashti, Hassan; Al-Saleh, Abeer; Petrov,
Peter; Malek, Mariam; Elhamoud, Ebrahim; Al-Khafaji, Sarhan; Li,
Jing; Koutrakis, Petros; Doronzo, Domenico; Middleton, Nick
Bibcode: 2022JASTP.23805932A
Altcode:
The Arabian Peninsula (AP), the largest peninsula in the world,
contains 'hot spot' areas for intensive dust storms. Dust sources
outside the AP can also represent 'hot spots' that heavily impact
the AP. This study explores the source and transport pathways of
severe dust storm events over the AP over nine years (2010-2018)
using MODIS Aqua and Terra satellites (0.25-0.5 km/pxl resolution)
combined with the HYSPLIT model and synoptic meteorology. The study
identified ten dust source 'hot spots' that affect the AP; two are
local (within the AP) and eight are regional (outside the AP). The
identified local dust sources were (1) the Empty Quarter and (2)
the Mesopotamian flood plain in southern Iraq, while the regional
dust sources were (3) the Syria-Iraq border, (4) Hamun-e Jaz Murian,
(5) Coastal desert of Iran, (6) Seistan basin ephemeral lakes, (7)
Hamun-e Mashkel, (8) Thar desert of Rajasthan, (9) Nile River basin,
and (10) Wadi Langeb Tokar Delta. To the best of our knowledge, this
is the first study to investigate the emission and transport of dust
storms over the AP at the local and regional/subcontinental levels
using medium-high resolution remote sensing. This study has important
implications for the international community and the multilateral
environmental agreements related to desert dust.
Title: Stability analysis of first order resonant periodic orbit
Authors: Patel, Bhavika M.; Pathak, Niraj M.; Abouelmagd, Elbaz I.
Bibcode: 2022Icar..38715165P
Altcode:
In this work, the perturbed restricted three-body problem
is investigated numerically. The problem is applied to three real
systems: Saturn-Hyperion, Saturn-Titan, and Earth-Moon, for analyzing
the stability of first order resonant periodic orbits. In particular,
the nature of periodic orbits is studied for all three systems, where
their masses ratios represent small, moderate and large values. Using
different types of numerical techniques, we have identified how the
parameter of mass ratio, the Jacobi constant, and the oblateness
coefficient affect the geometrical properties, and the periodic
solutions of system.
Title: Multiple sites of recent wet-based glaciation identified from
eskers in western Tempe Terra, Mars
Authors: Woodley, Savana Z.; Butcher, Frances E. G.; Fawdon, Peter;
Clark, Chris D.; Ng, Felix S. L.; Davis, Joel M.; Gallagher, Colman
Bibcode: 2022Icar..38615147W
Altcode:
Precipitation in Mars' mid-latitudes formed Viscous Flow Features
(VFFs), landforms analogous to terrestrial debris-covered glaciers,
in the last 1 Gyr. Until recently, the prevailing view was that
the Amazonian environment was not conducive to basal melting of
VFFs. However, recent identification of VFF-linked eskers (sedimentary
ridges deposited by meltwater in sub-glacial tunnels) in Phlegra Montes
and Tempe Terra suggests localized basal melting has occurred. We
identify two VFF-linked sinuous ridges in western Tempe Terra, which
we propose are two additional eskers. To explore this hypothesis, we
produce a 1:300,000 map of the geomorphology of western Tempe Terra,
use impact crater counts to constrain the age of the sinuous ridges, and
analyze the morphology and morphometry of the sinuous ridges. Mapping
reveals a heavily deformed Noachian massif that was embayed by younger
volcanic material and subsequently glaciated. The sinuous ridges lie
3-7 km from the VFF-termini and are associated with mounds which we
interpret as ice-cored moraines. After considering multiple formation
hypotheses (including inverted paleochannels and volcanic features)
and comparing morphometries to Martian and terrestrial eskers, we
suggest that both the sinuous ridges are of glacial origin and most
likely eskers. This shows that basal melting of VFFs occurred at
more than one location in Tempe Terra, at least transiently. Thus,
our identification of two additional candidate eskers in Tempe Terra
suggests that the late Amazonian thermal environment may have been
more complex than previously thought and contributes to a better
characterization of the recent glacial history of the region.
Title: Dynamical classification of the asteroids in the Hungaria group
II: The objects affected by the exterior mean-motion resonances 3:4,
5:7, 7:10 and 8:11 with Mars
Authors: Correa-Otto, J. A.; Leiva, A. M.; Zoppetti, F. A.;
Cañada-Assandri, M.; García, R. S.; Trógolo, N. E.; Gil-Hutton, R.
Bibcode: 2022Icar..38615135C
Altcode:
In this work, we present a dynamical study of the Hungaria asteroids
close to the exterior 3:4, 5:7, 7:10 and 8:11 mean-motion resonances
with Mars. We aim to extend the classification of Hungaria asteroids
affected by mean-motion resonances initiated in our previous work with
the analysis of the 2:3 resonance. To do it, we use the semi-analytical
model developed in our previous study to identify the region of
candidates possibly affected for each particular resonance. Then,
we numerically integrate the temporal evolution of each candidate for
2 Myrs, considering the N-body problem where the asteroids are assumed
to be massless bodies affected by the gravitational perturbation of all
the planets in the Solar System. We find 38 asteroids captured inside
the considered mean-motion resonances and 582 whose dynamical evolution
is affected by these structures. Finally, we provide mean values for
the orbital elements that may be taken as first approximations of
proper elements, for those bodies that do not have these quantities
previously determined.
Title: The power of paired proximity science observations: Co-located
data from SHERLOC and PIXL on Mars
Authors: Razzell Hollis, Joseph; Moore, Kelsey R.; Sharma, Sunanda;
Beegle, Luther; Grotzinger, John P.; Allwood, Abigail; Abbey,
William; Bhartia, Rohit; Brown, Adrian J.; Clark, Benton; Cloutis,
Edward; Corpolongo, Andrea; Henneke, Jesper; Hickman-Lewis, Keyron;
Hurowitz, Joel A.; Jones, Michael W. M.; Liu, Yang; Martinez-Frías,
Jesús; Murphy, Ashley; Pedersen, David A. K.; Shkolyar, Svetlana;
Siljeström, Sandra; Steele, Andrew; Tice, Mike; Treiman, Alan;
Uckert, Kyle; VanBommel, Scott; Yanchilina, Anastasia
Bibcode: 2022Icar..38715179R
Altcode:
We present a synthesis of PIXL elemental data and SHERLOC Raman spectra
collected on two targets investigated by the Perseverance rover during
the first year of its exploration of Jezero Crater, Mars. The Bellegarde
target (in the Máaz formation) and Dourbes target (in the Séítah
formation) exhibit distinctive mineralogies that are an ideal case
study for in situ analysis by SHERLOC and PIXL. Each instrument alone
produces valuable data about the chemistry and spatial distribution of
mineral phases at the sub-millimeter scale. However, combining data from
both instruments provides a more robust interpretation that overcomes
the limitations of either instrument, for example: 1) Detection of
correlated calcium and sulfur in Bellegarde by PIXL is corroborated by
the co-located detection of calcium sulfate by SHERLOC. 2) Detection
of sodium and chlorine in Dourbes is consistent with either chloride
or oxychlorine salts, but SHERLOC does not detect perchlorate or
chlorate. 3) A Raman peak at 1120 cm-1 in Dourbes could
be sulfate or pyroxene, but elemental abundances from PIXL at that
location are a better match to pyroxene. This study emphasizes the
importance of analyzing co-located data from both instruments together,
to obtain a more complete picture of sub-millimeter-scale mineralogy
measured in situ in Jezero crater, Mars, by the Perseverance rover.
Title: Interstellar polarization and extinction toward the Recurrent
Nova T CrB
Authors: Nikolov, Yanko
Bibcode: 2022NewA...9701859N
Altcode: 2022arXiv220111521N
Spectropolarimetry is a powerful tool for diagnostic of interstellar
matter and gives information about the geometry of the ejected
material after the novae outbursts. In this paper are presented
spectropolarimetric observations of the recurrent nova T CrB at
quiescence obtained with FoReRo2 attached to the Cassegrain focus of
the 2.0 m RCC telescope of the Bulgarian Rozhen National Astronomical
Observatory. The interstellar polarization toward T CrB was estimated
using the field stars method. The spectropolarimetric observations were
obtained from February 2018 to August 2021. In the wavelength range from
4800 Å to 8200 Å the maximum of the degree of linear polarization
is Pmax(obs) (%) = 0 . 46 ± 0 . 01 at λ ≈ 5200 Å. The
position angle is P . A.obs = 100 ° . 8 ± 0 ° . 9 . During
the observations, there is no intrinsic polarization in T CrB, and the
derived values represent interstellar polarization. The polarization
toward T CrB is due to the foreground interstellar dust located at
the distance up to ≈ 400 pc. Based on the degree of polarization
the interstellar extinction toward T CrB is EB-V ≈ 0 . 07 .
Title: The general analytical expression for computation of
generalized relativistic Fermi-Dirac functions
Authors: Mamedov, Bahtiyar A.
Bibcode: 2022NewA...9701874M
Altcode:
In this paper, general sufficiently analytical formulae are developed
for the arbitrary order generalized relativistic Fermi-Dirac (FD)
functions. Analytical assessment of relativistic FD function is very
important for various fields of physics especially in the theory of
relativistic nondegenerate and degenerate electron gas systems. One
of the more appropriate and correct approximations is based on a
binomial expansion method and incomplete Gamma functions that have
been used in the calculations of the generalized relativistic FD
functions. Note that, the established expression in special cases of
specific values of parameters becomes the evaluation formulae of other
type FD functions. Calculation results of the generalized relativistic
FD functions are compared with the other approximations methods and
available numerical approaches and demonstrated satisfactory agreement.
Title: Stability analysis of Lagrangian points of geo-synchronous
satellite including the resistive force and earth's equatorial
ellipticity
Authors: Yadav, Sushil; Kumar, Mukesh; Kumar, Vinay; Behera,
Pravata Kumar
Bibcode: 2022NewA...9701887Y
Altcode:
In this paper, we have investigated the existence of the Lagrangian
points and their stability in the problem of geo-synchronous satellite
including the effect of resistive force and earth's equatorial
ellipticity parameter γ. Equations of motion of satellite are
expressed in spherical coordinates (r , θ , ϕ) including the terms
of earth's equatorial ellipticity parameter γ and the resistive
force. It is observed that there exists two collinear and two
non-collinear Lagrangian points for different values of γ. It is
found that the effect of γ on the position of the Lagrangian points
is very small. Zero velocity curves are also drawn at different values
of Jacobi constant for different values of γ. Finally, stability of
Lagrangian point is discussed. We have found that all the Lagrangian
points are unstable for different values of γ.
Title: Titan's haze at opposite seasons from HST-STIS spectroscopy
Authors: Karkoschka, Erich
Bibcode: 2022Icar..38715188K
Altcode:
We present an analysis of three new image cubes of Titan by the Space
Telescope Imaging Spectrograph taken in 2017, 2018, and 2019, half a
Titan year after previously analyzed image cubes. Both data sets probe
periods when Titan's seasonal north-south-asymmetry switched. The new
observations show that the new reversal came exactly half a Titan year
after the previous opposite reversal. On the other hand, the phase
lag of the reversals with respect to Titan's equinoxes was different
indicating that the seasonal variation is close to harmonic and does
not follow variations due to Saturn's orbital eccentricity. The reversal
had two components, a major one at altitudes below 80 km reversing two
years after a minor one above 150 km. The observations further revealed
small temporary deviations of <10% of the seasonal amplitude. The
new observations provide an improved seasonal model of Titan that
gives accurate constraints for future global circulation models.
Title: Effect of boulder size on ejecta velocity scaling law for
cratering and its implication for formation of tiny asteroids
Authors: Okawa, Hatsune; Arakawa, Masahiko; Yasui, Minami; Hasegawa,
Sunao; Toda, Mizuno; Shirai, Kei; Yamamoto, Yuya
Bibcode: 2022Icar..38715212O
Altcode:
Ejecta velocity distribution is an important property for controlling
asteroid surface evolution and for changing the size frequency
distribution of asteroids and planetary dusts. Recent asteroid
explorations revealed that boulders on an asteroid surface had a
wide size frequency distribution. On the other hand, many studies
on ejecta velocity distribution for cratering experiments used
fine-grained homogeneous targets. Thus, to study the ejection process
of various-sized boulders on rubble-pile asteroids, we conducted impact
experiments using gas guns at impact velocities of 100 m s-1
to 4 km s-1 on targets with various-sized glass beads,
and analyzed boulder trajectories in three dimensions to clarify the
effect of grain size on ejection velocity distribution. The results
showed that the ejection velocity, v0, decreased as the bead
size increased, and the ejecta velocity scaling law was improved to
v0√{/gR} =k2'(r0
+ a/R) - 1/μ' including the bead radius,
a; r0 is the initial position of the bead, g is
the gravitational acceleration, R is the crater radius, and
k2' and μ' are, respectively, 0.58 ±
0.02 and 0.62 ± 0.02 for the low-impact velocity range (<200 m
s-1) and 0.61 ± 0.07 and 0.57 ± 0.04 for the high-impact
velocity range (>1 km s-1). Using our improved ejecta
velocity scaling law, we calculated the landing points of ejected
boulders and concluded that boulders with radii >0.34R could not be
ejected outside the final crater. Moreover, when the Urashima crater
on asteroid 162173 Ryugu was formed on the surface, boulders up to
64 m in diameter may have been ejected beyond the escape velocity of
Ryugu to become tiny monolithic asteroids.
Title: Ghost instability in the teleparallel gravity model with
parity violations
Authors: Li, Mingzhe; Li, Zhihao; Rao, Haomin
Bibcode: 2022PhLB..83437395L
Altcode: 2022arXiv220102357L
In this paper we consider the parity violating gravity model within the
framework of teleparallel gravity. The parity violations are caused
by the couplings of a scalar field to the scalar invariants which
are parity-odd and quadratic in the torsion tensor. Totally there are
two such type independent invariants, and one of them is the Nieh-Yan
density. Through investigations on the cosmological perturbations of
this model, we find that in general it suffers from the difficulties of
ghost instability in the scalar and vector perturbations. But in the
special case only the coupling to the Nieh-Yan density exists, this
model is ghost free and reduces to the Nieh-Yan modified Teleparallel
Gravity model. We also analyze the severity of the ghost instability
by studying the perturbations around the Minkowski background.
Title: Meteoroid orbit determination from HPLA radar data
Authors: Blanchard, Jared T.; Lee, Nicolas; Elschot, Sigrid
Bibcode: 2022Icar..38615144B
Altcode:
High-power large-aperture radars have revolutionized meteor science
by allowing highly accurate position and velocity estimates to be
made from meteor head echoes. This paper describes a new open-source
software, MODA, for determining the heliocentric orbital parameters
of these meteoroids. We compare MODA with other current methods,
both analytical and numerical. We describe our modeling of third-body
perturbations and atmospheric drag, as well as solar radiation pressure,
which is not taken into account in other works. We verify MODA against
results from the literature and use it to compute the orbits for two
small particles observed by ALTAIR in 2008.
Title: On the reconstruction problem in quantum gravity
Authors: Fraaije, Mathijs; Platania, Alessia; Saueressig, Frank
Bibcode: 2022PhLB..83437399F
Altcode: 2022arXiv220610626F
Path integrals and the Wilsonian renormalization group provide two
complementary computational tools for investigating continuum approaches
to quantum gravity. The starting points of these constructions utilize
a bare action and a fixed point of the renormalization group flow,
respectively. While it is clear that there should be a connection
between these ingredients, their relation is far from trivial. This
results in the so-called reconstruction problem. In this work,
we demonstrate that the map between these two formulations does
not generate non-localities at quadratic order in the background
curvature. At this level, the bare action in the path integral and
the fixed-point action obtained from the Wilsonian renormalization
group differ by local terms only. This conclusion does not apply to
theories coming with a physical ultraviolet cutoff or a fundamental
non-locality scale.
Title: Reassessing the paleointensities of three Quaternary volcanic
structures of the -Michoacán-Guanajuato Volcanic Field (Mexico)
through a multimethodological analysis
Authors: Pérez-Rodríguez, Nayeli; Morales, Juan; Cejudo, Rubén;
Guilbaud, Marie-Noëlle; Goguitchaichvili, Avto
Bibcode: 2022PEPI..33206927P
Altcode:
An approach that has acquired popularity in the last decade to
ensure the quality of paleointensity determinations is the use of
multimethodological analysis, especially when comparing intensity
values obtained by methods with different physical bases such as
the conventional Thellier-type experiments against the Shaw-family
methods and the most recent multispecimen protocol. This research
presents the reevaluation of the intensities of three monogenetic
volcanic structures: the Rancho Seco and Jabalí cones and lavas,
and the Malpaís Prieto fissure lava flow, all located in the
Michoacán-Guanajuato volcanic field (central Mexico). This analysis
is accompanied by an exhaustive study of rock-magnetic properties to
obtain a complete characterization of the magnetization carriers and
a better understanding of the intensity results. The three volcanic
structures have previously published intensity data; one of them was
obtained with the original Shaw method that nowadays is considered
unreliable due to the absence of monitoring of thermal alteration
during the experiment. The quality of the previously published data is
discussed to be compared to our intensity values, which were obtained
employing Thellier-type methods and the multispecimen protocol
(MSP). A good concordance was found for the data obtained by more
than one methodology for samples from the Jabalí volcano and the
Malpaís Prieto lava flow, obtaining average intensity values of 43.7
± 5.1 μT and 47.8 ± 3.1 μT, respectively. However, a difference of
almost 30 μT was found between our MSP results (50.9 ± 2.8 μT) and
previously published data using the IZZI method (20.0 ± 1.4 μT) for
Rancho Seco volcano. An attempt was made to clarify this controversial
result with the support of stepwise susceptibility against temperature
curves analysis and the results obtained from a set of samples treated
with the Tsunakawa-Shaw paleointensity method. The results obtained
indicate that the low paleointensity values are associated with the
thermal alteration of the magnetic mineralogy of the samples.
Title: Formation age of lunar Lalande crater and its implications
for the source region of the KREEP-rich meteorite Sayh al Uhaymir 169
Authors: Xu, Luyuan; Qiao, Le; Xie, Minggang; Wu, Yunhua
Bibcode: 2022Icar..38615166X
Altcode:
As the most KREEP-rich lunar sample, the Sayh al Uhaymir (SaU) 169
meteorite would provide more valuable information concerning the
KREEP and early lunar evolution of the Moon if its source regions
can be pinpointed. Previous studies proposed Lalande crater as
the source region that corresponds to the impact event of ~2.8 Ga
recorded in SaU 169, whereas this linkage is highly dependent on
the age determination of the potential source crater. By counting
craters superposed on the ejecta blankets of Lalande and modelling
the burial process of these superposed craters by Lalande's ejecta,
we find that the crater statistics around Lalande are heavily
influenced by the existing of pre-Lalande craters larger than ~170
m in diameter, which could lead to a largely overestimated age of
Lalande crater. After taking this influence into consideration, we
obtain that Lalande crater is a Copernican crater with a formation age
of 410 ± 20 Ma, and the adjacent mare basalts unit has an Imbrian
age of 3.8-0.06+0.04 Ga. The formation age of
Lalande crater is inconsistent with any of the radio-isotopic ages
recorded in SaU 169, indicating that Lalande crater is unlikely to be
the source region of this lunar meteorite.
Title: Implications for the Hubble tension from the ages of the
oldest astrophysical objects
Authors: Vagnozzi, Sunny; Pacucci, Fabio; Loeb, Abraham
Bibcode: 2022JHEAp..36...27V
Altcode: 2021arXiv210510421V
We use the ages of old astrophysical objects (OAO) in the redshift range
0 ≲ z ≲ 8 as stringent tests of the late-time cosmic expansion
history. Since the age of the Universe at any redshift is inversely
proportional to H0, requiring that the Universe be older
than the oldest objects it contains at any redshift, provides an
upper limit on H0. Using a combination of galaxies imaged
from the CANDELS program and various high-z quasars, we construct an
age-redshift diagram of ≳100 OAO up to z ∼ 8. Assuming the ΛCDM
model at late times, we find the 95% confidence level upper limit
H0 < 73.2km / s / Mpc , in slight disagreement with a
host of local H0 measurements. Taken at face value, and
assuming that the OAO ages are reliable, this suggests that ultimately
a combination of pre- and post-recombination (z ≲ 10) new physics
might be required to reconcile cosmic ages with early-time and local
H0 measurements. In the context of the Hubble tension,
our results motivate the study of either a) combined global pre- and
post-recombination modifications to ΛCDM, or b) local new physics
which only affects the local H0 measurements.
Title: New practical discrete non-spherical N-body method: Validation
with the Brazil nut effect
Authors: Zeng, Xiangyuan; Wen, Tongge; Yu, Yang; Cheng, Bin; Qiao, Dong
Bibcode: 2022Icar..38715201Z
Altcode:
This paper presents an implementation of the contact dynamics method for
discrete non-spherical particles. The algorithm can handle particles
with a wide range of geometries as long as they are described in
triangular surface meshes. The contact detection between particles
is organized into two phases: coarse-grained and fine-grained contact
detection. Specifically, different hierarchies of grids are utilized to
perform fast contact detection: (a) A spatial sorting method is utilized
for coarse-grained contact detection, where each non-spherical particle
is represented with a corresponding bounding-sphere (b) The Polygonal
Contact Method is introduced into the fine-grained contact detection
phase to accurately determine the active contact areas between the
interacting particles. These techniques solve the difficulties of
determining the action point(s) of contact force and torque between
non-spherical particles. The smooth (force-based) method is employed to
calculate the contact force and torque, which is generally regarded as
conforming to the actual physical process. Particularly, the non-linear
Hertz and Mindlin-Deresiewicz theories are adopted to calculate the
normal and tangential forces. The non-spherical Brazil nut effect under
the shear vibration mode is simulated as validation by comparing with
the existing experimental results. The simulation results confirmed
that the convection and percolation mechanism mutually affect the nut
heap's behavior and finally drive the rise of the Brazil nut from the
bottom to the top layer.
Title: Calculation of dielectric constant, loss property and
scattering characteristics from the future martian GPR data
Authors: Zhang, Ling; Xu, Yi; Chen, Rui; Wong, Hon Kuan; Lai, Jialong;
Meng, Xindong; Chen, Ruonan; Zeng, Zhaofa; Feng, Xuan; Liu, Cai
Bibcode: 2022Icar..38615181Z
Altcode:
In 2021, the Perseverance rover and the Zhurong rover, both of which
carry GPRs (Ground-penetrating radars), commenced their operations on
martian soil to explore the shallow structure of the Jezero crater and
the Utopia Plain, respectively. These instruments are designed to reveal
the shallow structure of the landing zones and map the distribution
of subsurface water ice. How to recognize the target layer, especially
the water ice layer from the GPR data, is essential to the success of
the missions. Reliable data interpretation and target recognition rely
on the understanding of the properties and attributes of the measured
materials. This study has developed estimation methods for three key
material properties using martian GPR data: the dielectric constant,
loss property and scattering characteristics. The reliability of
the methods is validated by typical numerical and physical models
of martian terrains. The proposed methods will help with a correct
interpretation of future martian GPR data.
Title: Hunting for overlooked eccentric eclipsing binaries from
ASAS-3 survey
Authors: Khalikova, A. V.; Gaynullina, E. R.; Serebryanskiy, A. V.
Bibcode: 2022NewA...9701875K
Altcode:
We present the results of searching for new candidates of eclipsing
binaries with eccentric orbits in the ASAS Catalog of Variable Stars
(ACVS) using publicly available data from the All Sky Automated
Survey (ASAS) and the Transiting Exoplanet Survey Satellite
(TESS). Unsupervised machine learning techniques were applied to find
anomalies among the light curves of eclipsing binaries. The light
curves modeling were performed using JKTEBOP code. The pulsation
analysis was done with FAMIAS. We identified 19 new eclipsing binary
candidates with non-zero eccentricities in the ACVS, including 10
candidates with eccentricities e ≥ 0.1. Estimates of eccentricities
are given. We also report on possible presence of the small-amplitude
stellar pulsations at least in two of the reported systems.
Title: Ozone vertical distribution in Mars Years 27-30 from SPICAM/MEX
UV occultations
Authors: Määttänen, A.; Lefèvre, F.; Verdier, L.; Montmessin,
F.; Listowski, C.; Guilbon, S.; Fedorova, A.; Korablev, O.
Bibcode: 2022Icar..38715162M
Altcode:
The SPICAM/MEX ultraviolet spectrometer probed the Martian atmosphere
with the occultation method from 2004 until 2014. SPICAM/MEX performed
both stellar and solar occultations during in total four Martian
Years with good spatial and seasonal coverages. We have analyzed these
occultations and performed a rigorous quality check of the retrievals
to eliminate false detections. We present the observed features of the
vertical distribution of Martian ozone, a key chemical species. Stellar
occultations probe the nightside atmosphere, whereas solar occultations
are acquired at the terminator (sunrise or sunset), enabling the
study of the day-night transition of this photochemically active
species. Comparison of the observations with a global climate model
show a good overall agreement. However, quantitative differences are
found in certain regions, possibly related to difficulties in correct
modeling of the water cycle. Our dataset allows us to study certain
particular features of Martian ozone. The low- and midlatitude ozone
layer forming during northern spring is mapped in both hemispheres
and its night-terminator variations are probed with the combination
of stellar and solar occultations. The southern polar winter vortex
shows hints of the well-known mid-altitude ozone layer already detected
previously. During the northern polar spring, SPICAM observes the top
of the lower atmosphere ozone layer above 10 km, showing O3
concentrations that the model reproduces quite well. SPICAM observations
are in good agreement with previously published observations from
other instruments.
Title: Tale of GRB 171010A/SN 2017htp and GRB 171205A/SN 2017iuk:
Magnetar origin?
Authors: Kumar, Amit; Pandey, Shashi B.; Gupta, Rahul; Aryan, Amar;
Ror, Amit K.; Sharma, Saurabh; Brahme, Nameeta
Bibcode: 2022NewA...9701889K
Altcode: 2022arXiv220600950K
We present late-time optical follow-up observations of GRB 171010A/SN
2017htp (z = 0.33) and low-luminosity GRB 171205A/SN 2017iuk (z =
0.037) acquired using the 4K ×4K CCD Imager mounted at the 3.6
m Devasthal Optical Telescope (3.6 m DOT) along with the prompt
emission data analysis of these two interesting bursts. The prompt
characteristics (other than brightness) such as spectral hardness,
T90, and minimum variability time-scale are comparable
for both the bursts. The isotropic X-ray and kinetic energies of the
plateau phase of GRB 171205A are found to be less than the maximum
energy budget of magnetars, supporting magnetar as a central engine
powering source. The new optical data of SN 2017htp and SN 2017iuk
presented here, along with published ones, indicate that SN 2017htp
is one of the brightest and SN 21017iuk is among the faintest GRB
associated SNe (GRB-SNe). Semi-analytical light-curve modelling of
SN 2017htp, SN 2017iuk and only known GRB associated superluminous
supernova (SLSN 2011kl) are performed using the MINIM code. The model
with a spin-down millisecond magnetar as a central engine powering
source nicely reproduced the bolometric light curves of all three
GRB-SNe mentioned above. The magnetar central engines for SN 2017htp,
SN 2017iuk, and SLSN 2011kl exhibit values of initial spin periods
higher and magnetic fields closer to those observed for long GRBs and
H-deficient SLSNe. Detection of these rare events at such late epochs
also demonstrates the capabilities of the 3.6 m DOT for deep imaging
considering longitudinal advantage in the era of time-domain astronomy.
Title: Reproducing size distributions of swarms of barchan dunes on
Mars and Earth using a mean-field model
Authors: Robson, Dominic T.; Annibale, Alessia; Baas, Andreas C. W.
Bibcode: 2022PhyA..60628042R
Altcode: 2021arXiv211015850R
We apply a mean-field model of interactions between migrating
barchan dunes, the CAFE model, which includes spontaneous calving,
aggregation, fragmentation, and mass-exchange, yielding a steady-state
size distribution that can be resolved for different choices of
interaction parameters. The CAFE model is applied to empirically
measured distributions of dune sizes in two barchan swarms in the
north circumpolar region of Mars, three swarms in Morocco, and one
in Mauritania, each containing more than 1000 bedforms. When the
sizes of bedforms are rescaled by the mean size in each zone two
attractor states appear, with the Tarfaya zones all displaying a
common distribution and the Martian and Mauritanian zones sharing
a different distribution. Comparison of these attractor states
with the outputs of the CAFE model reveals that the Tarfaya-type
distribution results from a preference for aggregation and fragmentation
interactions whereas the Mars-Mauritania distribution is more likely
a result of exchange-dominated interactions. We observe that there
appears to be a greater number of collisions happening in Tarfaya
than in the other areas which is consistent with a greater rate of
aggregation-fragmentation processes as suggested by our model. Our
comparison with the CAFE model also predicts a universal rule for
the outputs of the different types of interactions with exchange
interactions favouring the production of two dunes roughly equal
in size. Fragmentation interactions often result in three bedforms
with volumes approximately in the ratio 1:1:2. Finally, we find that
spontaneous calving of dunes does not play an important role in shaping
the size distributions in barchan swarms.
Title: Quadratic-in-spin interactions at fifth post-Newtonian order
probe new physics
Authors: Kim, Jung-Wook; Levi, Michèle; Yin, Zhewei
Bibcode: 2022PhLB..83437410K
Altcode: 2021arXiv211201509K
We obtain for the first time all quadratic-in-spin interactions in
spinning binaries at the third subleading order in post-Newtonian
(PN) gravity, and provide their observable binding energies and their
gauge-invariant relations to the angular momentum. Our results are
valid for generic compact objects, orbits, and spin orientations,
and enter at the fifth PN order for maximally-rotating objects, thus
pushing the state of the art. This is accomplished through an extension
of the effective field theory of spinning gravitating objects, and of
its computational application. We also discover a new finite-size effect
which is unique to spinning objects, with a new "Spin Love number" as
its characteristic coefficient, that is a new probe for gravity and QCD.
Title: On the semi-analytical construction of halo orbits and halo
tubes in the elliptic restricted three-body problem
Authors: Paez, Rocío I.; Guzzo, Massimiliano
Bibcode: 2022PhyD..43933402P
Altcode: 2022arXiv220316315P
The halo orbits of the spatial circular restricted three-body problem
are largely considered in space-flight dynamics to design low-energy
transfers between celestial bodies. A very efficient analytical method
for the computation of halo orbits, and the related transfers, has been
obtained from the high-order resonant Birkhoff normal forms defined at
the Lagrangian points L1 -L2 . In this paper,
by implementing a non-linear Floquet-Birkhoff resonant normal form,
we provide the definition of orbits, as well as their manifold tubes,
which exist in a large order approximation of the elliptic three-body
problem and generalize the halo orbits of the circular problem. Since
the libration amplitude of such halo orbits is large (comparable to
the distance of L1 -L2 from the secondary body),
and the Birkhoff normal forms are obtained through series expansions
at the Lagrangian points, we provide also an error analysis of the
method with respect to the orbits of the genuine elliptic restricted
three-body problem.
Title: Rare events are nonperturbative: Primordial black holes from
heavy-tailed distributions
Authors: Hooshangi, Sina; Namjoo, Mohammad Hossein; Noorbala, Mahdiyar
Bibcode: 2022PhLB..83437400H
Altcode: 2021arXiv211204520H
In recent years it has been noted that the perturbative treatment of
the statistics of fluctuations may fail to make correct predictions for
the abundance of primordial black holes (PBHs). Moreover, it has been
shown in some explicit single-field examples that the nonperturbative
effects may lead to an exponential tail for the probability distribution
function (PDF) of fluctuations responsible for PBH formation-in contrast
to the PDF being Gaussian, as suggested by perturbation theory. In this
paper, we advocate that the so-called δN formalism can be considered
as a simple, yet effective, tool for the nonperturbative estimate of
the tail of the PDF. We discuss the criteria a model needs to satisfy
so that the results of the classical δN formalism can be trusted and
most possible complications due to the quantum nature of fluctuations
can be avoided. As a proof of concept, we then apply this method
to a simple example and show that the tail of the PDF can be even
heavier than exponential, leading to a significant enhancement of
the PBH formation probability, compared with the predictions of the
perturbation theory. Our results, along with other related findings,
motivate the invention of new, nonperturbative methods for the problem
and open up new ideas on generating PBHs with notable abundance.
Title: Investigation of wavelength-induced uncertainties in full-wave
radar tomography of high contrast domain: An application to small
solar system bodies
Authors: Yusuf, Yusuf Oluwatoki; Dufaure, Astrid; Sorsa, Liisa-Ida;
Eyraud, Christelle; Pursiainen, Sampsa
Bibcode: 2022Icar..38715173Y
Altcode:
This paper aims to reconstruct the internal structure of a
two-dimensional test object via numerically simulated full-wave time
domain radar tomography with the presence of wavelength-induced (WI)
uncertainties, following from a complex domain structure, and domain
diameters 21 or 64 times the wavelength of the signal propagating
inside the target. In particular, we consider an application
in planetary scientific studies of reconstructing the interior
structure of an arbitrary high contrast small Solar System Body
(SSSB), i.e., an asteroid, with a probing signal wavelength limited
by the instrument and mission payload requirements. Our uncertainty
reduction model finds the reconstruction via averaging multiple
inverse solutions assuming that the WI deviations in the solutions
correspond to random deviations, which we assume to be independent and
identically distributed (IID). It incorporates error marginalisation
via a randomised signal configuration, spatial-averaging of candidate
solutions, frequency-based error marginalisation, and the truncated
singular value decomposition (TSVD) filtering technique, based on our
assumptions of the phase discrepancy of the signal, domain parameters,
and the full-wave forward model. The numerical experiments are performed
for 20 and 60 MHz centre frequencies proposed for CubeSat-based radars,
the latter being the centre frequency of the Juventas Radar which will
be aboard Hera mission to investigate the interior structure of asteroid
Dimorphos. A benchmark reconstruction of the target was obtained with
the spatial averaging, sparse point density and frequency randomised
configuration for both 20 and 60 MHz frequency systems.
Title: Stellar models with generalized polytropic equation of state
Authors: Maharaj, S. D.; Kileba Matondo, D.
Bibcode: 2022NewA...9701852M
Altcode:
We find new classes of exact solutions to the Einstein field
equations where the matter distribution satisfies a generalized
polytropic equation of state. The matter distribution is uncharged
with anisotropic pressures. Equations of state for polytropes and quark
matter are contained as special cases. The matter variables and metric
potentials can be obtained explicitly. Known solutions, for the choice
of the gravitational potential made in this analysis, arise as special
cases for particular choice of the equation of state parameters. A
detailed physical analysis indicates that the model is well behaved.
Title: Three-dimensional structure of thermal waves in Venus'
mesosphere from ground-based observations
Authors: Giles, Rohini S.; Greathouse, Thomas K.; Irwin, Patrick G. J.;
Encrenaz, Thérèse; Brecht, Amanda S.
Bibcode: 2022Icar..38715187G
Altcode: 2022arXiv220711369G
High spectral resolution observations of Venus were obtained with
the TEXES instrument at NASA's Infrared Telescope Facility. These
observations focus on a CO2 absorption feature at 791.4
cm-1 as the shape of this absorption feature can be used
to retrieve the vertical temperature profile in Venus' mesosphere. By
scan-mapping the planet, we are able to build up three-dimensional
temperature maps of Venus' atmosphere, covering one Earth-facing
hemisphere and an altitude range of 60-83 km. A temperature map from
February 12, 2019 clearly shows the three-dimensional structure of
a planetary-scale thermal wave. This wave pattern appears strongest
in the mid-latitudes of Venus, has a zonal wavenumber of 2-4 and the
wave fronts tilt eastward with altitude at an angle of 8-15 degrees
per km. This is consistent with a thermal tide propagating upwards
from Venus' upper cloud decks. Ground-based observations provide the
opportunity to study Venus' temperature structure on an ongoing basis.
Title: A photometric study of V608 Cam: apparent period changes as
a result of surface activity
Authors: Šebek, F.; Walter, F.; Wolf, M.
Bibcode: 2022NewA...9701879S
Altcode:
The VRI light curves were measured for the low-mass eclipsing binary
V608 Cam as a part of our long-term observational project for studying
of eclipsing binaries with a short orbital period. The TESS light
curve solution in PHOEBE results to the detached configuration, where
the temperature of the primary component was fixed to T1 =
5300 K according to GAIA results, which gives us T2 = 4110
± 50 K for the secondary. The spectral type of the primary component
was derived to be K0 and the photometric mass ratio was estimated q =
0 . 92 ± 0 . 07 . Characteristics and temporal variation of the dark
region on the surface of the secondary component were estimated and
are attributed to apparent period changes of this eclipsing binary
with a cycle of about 2.4 yr.
Title: Neutrino signal from compact objects during their formation,
their mergers, or as a signature of electric-charge phase transition
Authors: Fraija, N.; Moreno-Méndez, E.; Morales, G.; Saracho, A.
Bibcode: 2022NewA...9701883F
Altcode:
We study neutrino creation, propagation, and oscillations within an
extremely magnetized background of finite-temperature nuclear matter
and strange-quark matter (SQM). We focus on three particularly
interesting cases and identify the astrophysical scenarios where
such a signal may be found. The first case involves nuclear matter
with electrons, and it is found during the central-engine stage of,
both, short and long gamma-ray bursts (GRBs). Thus, for the short
GRB case, it will also be associated with gravitational-wave events
where there exist electromagnetic counterparts (e.g., GW170817). The
second and third scenarios involve the presence of SQM. Accordingly,
the second scenario occurs if SQM can become negatively charged (SQM-;
which may only occur at high pressure) and, thus, it is embedded in a
positron plasma. The third case may be found at the interphase where
SQM transitions from positive (SQM+) to negative; here, positrons and
electrons may constantly annihilate and give a distinctive neutrino
signal. Therefore, this may also be a signature of the existence
of strange stars. Given the wide range of magnetic fields we find
in the literature, we also briefly discuss the maximum limit that a
stellar-mass compact object may possess.
Title: Absolute parameters of four W UMa stars with extreme low
mass ratios
Authors: Popov, Velimir A.; Petrov, Nikola I.
Bibcode: 2022NewA...9701862P
Altcode:
Photometric observations of four extreme low mass ratio W UMa
binaries with wide total eclipses, and their absolute parameters are
presented. The main results are as follows: (i) ASAS J015429+2042.8
is of A subtype while V755 Cep, VESPA V22 and GSC 02800-01387 are of W
subtype; (ii) The mass ratios are close to the lower mass-ratio limit
and can be classified as Extreme Low Mass Ratio Binaries (ELMRB). (iii)
The fill-out factors of ASAS J015429+2042.8 and VESPA V22 are 0.16 and
0.21 respectively, the one of GSC 02800-01387 is 0.63 while the one of
V755 Cep is 0.83; (iv) The smaller in size (and less massive) components
of all targets are located above the MS band of the evolutional diagrams
while the bigger (and more massive) components are located around ZAMS;
(v) Our ELMRB systems fall into the stability zone with Jspin
/Jorb lower than the Darwin's instability ∼ 1 / 3 .
Title: Nucleosynthetic zinc isotope anomalies reveal a dual origin
of terrestrial volatiles
Authors: Steller, Theodor; Burkhardt, Christoph; Yang, Chun; Kleine,
Thorsten
Bibcode: 2022Icar..38615171S
Altcode:
Determining the provenance of volatile elements in Earth is key for
understanding the processes that led to its formation as a habitable
planet. We show that the moderately volatile element zinc exhibits
an isotopic dichotomy between non‑carbonaceous and carbonaceous
meteorites, which presumably derive from the inner and outer Solar
System, respectively. Terrestrial zinc has an intermediate isotopic
composition, demonstrating that Earth accreted about 70% of its zinc
from inner Solar System bodies. Using literature data, we find the
same proportions for the more volatile elements hydrogen and nitrogen,
suggesting Earth's volatile elements predominantly derive from inner
Solar System objects and not, as often assumed, from the outer Solar
System. Thus, Earth may have evolved to a habitable planet even without
the contributions it received from the outer Solar System.
Title: Hyperbolic inflationary model with nonzero curvature
Authors: Paliathanasis, Andronikos; Leon, Genly
Bibcode: 2022PhLB..83437407P
Altcode: 2022arXiv220301598P
We consider a cosmological model consisting of two scalar fields
defined in the hyperbolic plane known as hyperbolic inflation. For the
background space, we consider a homogeneous and isotropic spacetime
with nonzero curvature. We study the asymptotic behaviour of solutions
and search for attractors in the expanding regime. We prove that two
hyperbolic inflationary stages are stable solutions that can solve the
flatness problem and describe acceleration for both open and closed
models, and additionally, we obtain a Milne-like attractor solution for
the open model. We also investigate the contracting branch obtaining
mirror solutions with the opposite dynamical behaviours.
Title: Sign-reversed anomalous Nernst effect in the ferromagnetic
Weyl-semimetal Fe3−δGeTe2: the role of
Fe vacancies
Authors: Yang, Haiyang; Wang, Qi; Huang, Junwu; Wang, Zhouliang; Xia,
Keqi; Cao, Chao; Tian, Mingliang; Xu, Zhuan; Dai, Jianhui; Li, Yuke
Bibcode: 2022SCPMA..6517411Y
Altcode: 2022arXiv220606545Y
Anomalous Nernst effect, as a thermal partner of anomalous Hall effect,
is particularly sensitive to the Berry curvature anomaly near the Fermi
level, and has been used to probe the topological nature of quantum
materials. In this work, we report the observation of both effects in
the ferromagnetic Weyl-semimetal Fe3−δGeTe2
with tunable Fe vacancies. With decreasing Fe vacancies, the
anomalous Hall conductivity evolves as a function of the longitudinal
conductivity from the hopping region to the region where the intrinsic
Berry curvature contribution dominates. Concomitant evolutions in the
anomalous Nernst signal and the anomalous off-diagonal thermoelectric
coefficient are observed below the Curie temperature, displaying a
unique sign change caused by the Fe vacancies. Combining these results
with first-principles calculations, we argue that the Fe-vacancy
concentration plays a unique role in simultaneously tuning the chemical
potential and ferromagnetism, which in turn controls the Berry curvature
contribution in this family of ferromagnetic topological semimetals.
Title: Gravitational waves with dark energy
Authors: Khodagholizadeh, Jafar
Bibcode: 2022JHEAp..36...48K
Altcode: 2022arXiv220806844K
In this article, we study the tensor mode equation of perturbation in
the presence of nonzero-Λ as dark energy, the dynamic nature of which
depends on the Hubble parameter H and/or its time derivative. Dark
energy, according to the total vacuum contribution, has a slight
effect during the radiation-dominated era, but it reduces the squared
amplitude of gravitational waves (GWs) up to 60% for the wavelengths
that enter the horizon during the matter-dominated era. Moreover,
the observations bound on dark energy models, such as running vacuum
model (RVM), generalized running vacuum model (GRVM) and generalized
running vacuum subcase (GRVS), are effective in reducing the GWs'
amplitude. Although this effect is less for the wavelengths that enter
the horizon at later times, this reduction is stable and permanent.
Title: DFT study of Interstellar PANH: Vibrational spectra of anionic
and cationic variants
Authors: Devi, Gauri; Pathak, Amit; Vats, Akant
Bibcode: 2022AdSpR..70.2133D
Altcode:
Polycyclic aromatic Hydrocarbons are present in the universe in varied
forms and are extensively studied over the years to account for the
complex natured Aromatic Infrared Bands (AIBs). As an abundant element
in the interstellar medium, nitrogen may substitute carbon atoms in the
aromatic rings of PAHs to form Polycyclic Aromatic Nitrogen Heterocyclic
(PANH) molecules. These PANH molecules can have new emission features
and may contribute to some of the AIBs. Extreme conditions of the
ISM may support PAH and/or PANH molecules in the formation of their
cationic or anionic forms to further explain the AIBs. The present
work reports DFT study of PANH molecules and their ionized variants
and discusses their IR spectroscopic features in the 6-10 μm region.
Title: Improved kinetics for mineral dissolution reactions in
pore-scale reactive transport modeling
Authors: Schabernack, Jonas; Fischer, Cornelius
Bibcode: 2022GeCoA.334...99S
Altcode:
Recent numerical investigations revealed that the heterogeneity of the
dissolution rate observed in numerous experiments cannot be explained by
fluid transport effects. This heterogeneity is attributed to intrinsic
surface reactivity. Therefore, reactive transport models (RTM) require
parameterization of the surface reactivity for accurate predictions. For
this purpose, a nanotopographic parametrization based on surface slope
has been recently suggested. In this study, we utilize and improve
this parametrization for RTMs of pore-scale systems, from the crystal
surface to the single crystal geometry, going beyond the previous
reactivity parametrization. 2D and 3D RTMs were developed using COMSOL
Multiphysics for calcite systems based on experimental measurements. We
compared the results between classically parameterized RTMs, RTMs with
new slope parameterization, and experimental data. The effect of flow
on dissolution under conditions far-from-equilibrium is found to be
negligible, highlighting the importance of surface reactivity in the
dissolution reaction. For the first time, the new slope factor was able
to accurately reproduce the experimental results on a crystal surface
with large field-of-view, large height variability of the topography,
and over a long-term reaction period. The new parameterization had
greatly improved sensitivity for intermediate reactivity ranges
compared to the previous parameterization. A 3D model is used to
present the general applicability of the parameterization for use
in realistic geometric data sets. Thus, we also show that neglecting
surface reactivity in an RTM leads to incorrect predictions regarding
the porosity, pore geometry, and surface topography of the system. Our
new slope factor can successfully serve as a first-order proxy for the
distribution of surface reactivity in 3D pore-scale rock systems. The
description of surface reactivity is crucial for accurate long-term
modeling of natural rock systems.
Title: Synchronous sequestration of cadmium and fulvic acid by
secondary minerals from Fe(II)-catalyzed ferrihydrite transformation
Authors: Hu, Shiwen; Zhen, Lirong; Liu, Shuhu; Liu, Chongxuan; Shi,
Zhenqing; Li, Fangbai; Liu, Tongxu
Bibcode: 2022GeCoA.334...83H
Altcode:
As consequence of the dual demands for pollution control and carbon
(C) fixation in soils, Fe(II)-catalyzed mineral transformation may be a
promising method to simultaneously immobilize heavy metals or organic
matter (OM), but the underlying mechanisms remain unclear. Here,
the synchronous sequestration mechanism of cadmium (Cd) and fulvic
acid (FA) during Fe(II)-catalyzed the transformation ferrihydrite
with C/Fe molar ratio of 0.21 were examined. Mineral phase analysis
revealed that increasing the Fe(II) concentration (1-5 mM) favored
the transformation of lepidocrocite and goethite to magnetite,
and ferrihydrite transformation rate increased with increasing
Fe(II) concentration. Color overlays and line profiles of elements
depicted that Cd was dominantly adsorbed on the lepidocrocite and
goethite surfaces. A positive correlation between the quantity of
nonextractable Cd and magnetite further indicated that Cd may be
sequestered by magnetite. Meanwhile, FA molecules were adsorbed on
goethite surfaces and magnetite aggregates, and incomplete structure of
lepidocrocite provide spaces for immobilizing C. Newly formed iron (Fe)
(oxyhydr)oxides may immobilize Cd through surface binding, structural
substitution, and physical encapsulation. The OM bound to the newly
formed Fe (oxyhydr)oxides was rich in aromatic and carboxyl functional
groups, which was beneficial for binding Cd, whereas the presence
of Cd promoted the generation of nano pore spaces or defects and
consequently enhanced FA sequestration. Therefore, Cd immobilization
and FA sequestration can be synchronously achieved during the phase
transformation. The findings provide a profound insight into various
nanoscale mechanisms accounting for the fate of Cd and FA coupled
with mineral transformation. The findings also are very helpful for
developing strategies for simultaneously immobilizing heavy metals
and C in soils.
Title: Mineral surface area accessibility and sensitivity constraints
on carbon mineralization in basaltic aquifers
Authors: Awolayo, Adedapo N.; Laureijs, Christiaan T.; Byng, John;
Luhmann, Andrew J.; Lauer, Rachel; Tutolo, Benjamin M.
Bibcode: 2022GeCoA.334..293A
Altcode:
Estimating mineral reactive surface areas in geologic media remains
one of the key challenges limiting the accuracy of reactive transport
modeling (RTM) predictions of subsurface processes, particularly those
controlling the fate of carbon dioxide (CO2) during geologic
storage. Although there have been numerous attempts to combine imaging
and experimental techniques to estimate mineral reactive surface area
for use in RTM predictions of geologic CO2 storage, these
techniques have yet to be adapted to basaltic reservoirs, which have
pore structure, mineralogy, and chemical composition that is unique
compared to their more often-studied sedimentary counterparts. Here,
we address this issue by quantifying fluid-accessible mineral
surface areas through image analysis of scanning electron microscope
(SEM) backscatter electron images (high-resolution 500 nm/pixel)
and Raman spectroscopic mapping of a basaltic rock sample from the
Eastern Snake River Plain, Idaho. To evaluate whether the determined
pore fluid-accessible mineral surface area accurately reflects
reactive surface area, a micro-continuum scale RTM was developed
and compared with a high-temperature, high-pressure flow-through
CO2 mineralization experiment conducted on the characterized
basalt. Importantly, simulations employing the image-derived pore
fluid-accessible mineral surface areas match the experimental effluent
chemistry well within uncertainties. These mineral surface areas were
then used to parametrize a field-scale model representative of the
Cascadia basin, Northeastern Pacific, to evaluate impacts of surface
area variations on mineral carbonation. Simulations were carried
out using variations in image-derived surface areas that cover one
to two orders of magnitude increase and decrease in surface area,
analogous to previously reported magnitudes of difference between
total and reactive surface areas. Carbonation efficiency in terms
of CO2 volume mineralized over the simulated period was
tracked and compared. Simulations with surface area increased and
decreased by two orders of magnitude show basalt carbonation efficiency
that is three times faster and six times slower, respectively, than
predictions with image-derived mineral surface area. These sensitivity
analyses demonstrate that accurate quantification of mineral surface
area is crucial for efforts to predict CO2 mineralization,
and that efforts such as those employed here can dramatically reduce
the uncertainty of field-scale predictions of basalt carbonation.
Title: Equilibrium fractionation of triple-oxygen and hydrogen
isotopes between ice and water
Authors: Galili, Nir; Sade, Ziv; Halevy, Itay
Bibcode: 2022E&PSL.59517753G
Altcode:
The triple-oxygen isotopic fractionation associated with freezing is
a fundamental property of water, knowledge of which is essential for
reconstructions of the hydrological cycle from the triple-oxygen
isotopic composition of natural materials. We constrained this
isotopic fractionation, in freshwater and seawater, in a series
of freezing experiments over a range of temperatures and freezing
rates. The freshwater freezing experiments with the lowest freezing
rates, which we consider closest to isotopic equilibrium, yield
18O/16O, 17O/16O and
2H/1H fractionations of 2.82 ± 0.12 ‰, 1.49
± 0.07‰ and 20.05 ± 0.72‰, respectively. The slowest-freezing
seawater experiments yield 18O/16O,
17O/16O and 2H/1H
fractionations of 2.92 ± 0.08‰, 1.55 ± 0.03‰ and 21.18
± 1.85‰, respectively. The 18O/16O and
2H/1H fractionation estimates in freshwater and
seawater are within error of each other and in broad agreement with
past estimates. Our newly determined 17O/16O
fractionations constrain the triple-oxygen mass dependence of water
freezing to be ≈0.528, but with large uncertainty. If this mass
dependence is accurate, then ice formation and melting processes in
the hydrological cycle are expected to generate variability that is
on the Global Meteoric Water Line.
Title: Asteroid regolith strength: Role of grain size and surface
properties
Authors: Brisset, Julie; Sánchez, Paul; Cox, Christopher; Corraliza,
Dennis; Hatchitt, John; Madison, Alexander; Miletich, Thomas
Bibcode: 2022P&SS..22005533B
Altcode:
Most of the small asteroids with sizes below a few km are believed
to be rubble piles. In order to study the strength of such bodies,
we have performed bulk measurements on simulant granular material,
varying the grain size and surface properties in ambient conditions. The
samples were prepared from a high-fidelity asteroid soil simulant
and subjected to compression and shear stresses. We measured the
material angle of repose, Young Modulus, its angle of internal
friction, bulk cohesion, and tensile strength. Grain sizes were
varied from 0.1 to 10 mm. Grain surface properties (friction and
cohesive forces) were modified by adding a surface frost layer. We
find that, in shear, larger grains increase the strength in confined
samples, representative of regolith subsurface layers on asteroids,
while they decrease strength in unconfined samples, representative of
surface regolith. In compression, confined samples become weaker with
increasing grain size, while unconfined samples are barely sensitive
to it. We also find that increasing surface friction and intergrain
cohesion increases the strength in all the samples. We measure bulk
cohesion values between ∼400 and 600 Pa, internal friction between 25
and 45°, and tensile strengths between 600 and 900 Pa. The measured
angles of repose varied between ∼25 and 45° in an opposite trend
to the internal friction. We compare these values to spacecraft data
and numerical simulations and discuss implications of our findings
for rubble-pile composition and disintegration behavior. We find that
grain size sorting with depth, depletion of fines at the surface, or
presence of water ice in the core can provide a mechanism for regular
surface shedding event on small asteroids.
Title: Bounding greybody and deflection angle of improved
Schwarzschild black hole
Authors: Javed, Wajiha; Aqib, Muhammad; Övgün, Ali
Bibcode: 2022NewA...9601827J
Altcode:
In this paper, we study the weak deflection angle in the spacetime of
improved Schwarzschild black hole using the method derived by Gibbons
and Werner. To do so, we derive the optical curvature from the optical
metric and calculate deflection angle in weak field limits by using
the Gauss-Bonnet theorem. Moreover, we study the effect of the plasma
medium on the weak gravitational lensing using the Gauss-Bonnet
theorem. Furthermore, we also study the graphical analysis of the
deflection angle in both the plasma and non-plasma mediums. Moreover,
we obtain the bound on greybody for improved Schwarzschild black hole.
Title: A billion or more years of possible periglacial/glacial
cycling in Protonilus Mensae, Mars
Authors: Soare, R. J.; Williams, J. -P.; Hepburn, A. J.; Butcher,
F. E. G.
Bibcode: 2022Icar..38515115S
Altcode:
The long-term cyclicity and temporal succession of glacial-periglacial
(or deglacial) periods or epochs are keynotes of Quaternary geology
on Earth. Relatively recent work has begun to explore the histories
of the mid- to higher-latitudinal terrain of Mars, especially in the
northern hemisphere, for evidence of similar cyclicity and succession
in the Mid to Late Amazonian Epoch. Here, we carry on with
this work by focusing on Protonilus Mensae [PM] (43-490
N, 37-590 E). More specifically, we discuss, describe
and evaluate an area within PM that straddles a geological contact
between two ancient units: [HNt], a Noachian-Hesperian Epoch transition
unit; and [eHT] an early Hesperian Epoch transition unit. Dark-toned
terrain within the eHt unit (HiRISE image ESP_028457_2255) shows
continuous coverage by structures akin to clastically-sorted circles
[CSCs]. The latter are observed in permafrost regions on Earth where the
freeze-thaw cycling of surface and/or near-surface water is commonplace
and cryoturbation is not exceptional. The crater-size frequency
distribution of the dark-toned terrain suggests a minimum age of ~100
Ma and a maximum age of ~1 Ga. The age estimates of the candidate
CSCs fall within this dispersion. Geochronologically, this places the
candidate CSCs among the oldest periglacial landforms identified on
Mars so far, by at least one and possibly two orders of magnitude. Unit HNt is adjacent to unit eHt and shows surface material that is
relatively light in tone. The coverage is topographically irregular
and, at some locations, discontinuous. Amidst the light-toned surface,
structures are observed that are akin to clastically non-sorted polygons
[NSPs] and polygonised thermokarst-depressions on Earth. Terrestrial
polygon/thermokarst assemblages occur in permafrost regions where the
freeze thaw cycling of surface and/or near-surface water is commonplace
and the permafrost is ice-rich. The crater-size frequency distribution
of the light-toned terrain suggests a minimum age of ~10 Ma and a
maximum age of ~100 Ma. The age estimates of the candidate ice-rich
assemblages fall within this dispersion. Geochronologically, this places
them well beyond the million-year ages associated with most of the
other candidate ice-rich assemblages reported in the literature. Stratigraphically intertwined with the two possible periglacial
terrains are landforms and landscape features (observed or unobserved
but modelled) that are indicative of relatively recent glaciation
(~10 Ma - 100 Ma) and glaciation long past (≥ ~ 1 Ga) to decametres
of depth: glacier-(cirque) like features; viscous-flow features,
lobate-debris aprons; moraine-like ridges at the fore, sides and
midst of the aprons; and, patches of irregularly shaped (and possibly
volatile-depleted) small-sized ridge/trough assemblages. Collectively,
this deeply-seated intertwining of glacial and periglacial cycles
suggests that the Mid to Late Amazonian Epochs might be more Earth-like
in their cold-climate geology than has been thought hitherto.
Title: On the impact of meridional wind circulation changes in the
electron density distribution over the Indian equatorial and low
latitude ionospheric region during a severe geomagnetic storm
Authors: Ambili, K. M.; Choudhary, R. K.
Bibcode: 2022AdSpR..70.2058A
Altcode:
Using a suite of instruments, which included a chain of ground-based
dual-frequency GPS receivers, and magnetometers, we have studied the
importance of thermospheric meridional wind circulation in controlling
the distribution of plasma over the Indian low latitude ionospheric
regions during the period of a severe geomagnetic storm. The storm on
15 May 2005, which had its onset coinciding with the local noon time
sector for the Indian ionospheric zone, was a severe geomagnetic storm
with symH ∼ - 305 nT. A steep increase in the Total Electron Content
(TEC) of the ionosphere over the entire Indian ionospheric region was
observed on May 15. The enhancement in the TEC was well correlated with
the increase in ΔH at the dip-equator due to the prompt penetration
of the convection electric field associated with the storm. However,
contrary to the previous studies on the storm impact over low latitude
regions, a clear signature of disturbance dynamo was absent on the
day after the storm. Enhancements in the TEC were observed on May 16,
a day after the storm, as well, though the ΔH at the dip-equator was
quite below the quite-time mean. The TEC remained well above its monthly
mean over the entire Indian ionospheric region during the storm recovery
period. We suggest that the TEC enhancement on May 16, even though it
looked like due to a prompt penetration effect, was directly related to
the compositional disturbances as given by the O/N2 ratio. We
conclude that the meridional wind circulation plays an important role
in the distribution of electron density over the equatorial and low
latitudinal region during the period of a geomagnetic storm.
Title: The Quadruple Image Configurations of Asymptotically Circular
Gravitational Lenses
Authors: Falor, Chirag; Schechter, Paul L.
Bibcode: 2022AJ....164..120F
Altcode: 2022arXiv220506269F
The quadruple image configurations of gravitational lenses
with vanishing ellipticity are examined. Even though such lenses
asymptotically approach circularity, the configurations are stable if
the position of the source relative to the vanishing diamond caustic
is held constant. The configurations are the solutions of a quartic
equation, an "asymptotically circular lens equation," parameterized
by a single complex quantity. Several alternative parameterizations
are examined. Relative magnifications of the images are derived. When
a nonvanishing quadrupole, in the form of an external shear (XS),
is added to the singular isothermal sphere (SIS), its configurations
emerge naturally as stretched and squeezed versions of the circular
configurations. And as the SIS+XS model is a good first approximation
for most quadruply lensed quasars, their configurations likewise
have only 2 + 1 salient dimensions. The asymptotically circular
configurations can easily be adapted to the problem of solar system
"occultation flashes."
Title: The VMC survey - XLIX. Discovery of a population of quasars
dominated by nuclear dust emission behind the Magellanic Clouds
Authors: Pennock, Clara M.; van Loon, Jacco Th; Anih, Joy O.; Maitra,
Chandreyee; Haberl, Frank; Sansom, Anne E.; Ivanov, Valentin D.;
Cowley, Michael J.; Afonso, José; Antón, Sonia; Cioni, Maria-Rosa
L.; Craig, Jessica E. M.; Filipović, Miroslav D.; Hopkins, Andrew M.;
Nanni, Ambra; Prandoni, Isabella; Vardoulaki, Eleni
Bibcode: 2022MNRAS.515.6046P
Altcode: 2022arXiv220712301P; 2022MNRAS.tmp.2008P
Following the discovery of SAGE0536AGN (z ~ 0.14), with the strongest
10-μm silicate emission ever observed for an active galactic nucleus
(AGN), we discovered SAGE0534AGN (z ~ 1.01), a similar AGN but with less
extreme silicate emission. Both were originally mistaken as evolved
stars in the Magellanic Clouds. Lack of far-infrared emission, and
therefore star formation, implies we are seeing the central engine of
the AGN without contribution from the host galaxy. They could be a key
link in galaxy evolution. We used a dimensionality reduction algorithm,
t-distributed stochastic neighbour embedding with multiwavelength
data from Gaia EDR3, VISTA survey of the Magellanic Clouds, AllWISE,
and the Australian Square Kilometre Array Pathfinder to find these two
unusual AGNs are grouped with 16 other objects separated from the rest,
suggesting a rare class. Our spectroscopy at South African Astronomical
Observatory/Southern African Large Telescope and literature data confirm
at least 14 of these objects are extragalactic (0.13 < z <
1.23), all hosting AGN. Using spectral energy distribution fitter C
IGALE we find that the majority of dust emission ($\gt 70 {{\ \rm per\
cent}}$) in these sources is due to the AGN. Host galaxies appear to
be either in or transitioning into the green valley. There is a trend
of a thinning torus, increasing X-ray luminosity, and decreasing
Eddington ratio as the AGN transition through the green valley,
implying that as the accretion supply depletes, the torus depletes
and the column density reduces. Also, the near-infrared variability
amplitude of these sources correlates with attenuation by the torus,
implying the torus plays a role in the variability.
Title: Long-term temperature and ozone response to natural drivers
in the mesospheric region using 16 years (2005-2020) of TIMED/SABER
observation data at 5-15°N
Authors: Bizuneh, Chalachew Lingerew; Jaya Prakash Raju, U.; Nigussie,
Melessew; Santos, Celso Augusto Guimarães
Bibcode: 2022AdSpR..70.2095B
Altcode:
The long-term mesospheric (60-100 km) temperature and ozone volume
mixing ratio variability during the period of January 2005 to December
2020 were analyzed to obtain trends and their response to natural
influences using the SABER, an instrument onboard the TIMED satellite
to obtain observation data in the latitude range of 5°N-15°N. A
wavelet analysis technique has been used to identify the dominant
periodic oscillations in mesospheric temperature and ozone. Using the
proxy data of F10.7, Nino 3.4, and zonal wind index (QBO at 30 hPa),
the mesospheric response to natural drivers was investigated using a
multiple linear regression technique. Among the three natural drivers,
solar radio flux (F10.7) is the dominant contributor to mesospheric
variability rather than ENSO and QBO. It influences negatively the
lower mesosphere (60-80 km), and above 80 km, it responds positively in
temperature (2.6 K), whereas ozone responds with a constant negative
value (0.12ppmv) up to 80 km, and after it influences by a maximum
positive value of 0.7 ppmv. At 80 km, the temperature and ozone
respond in phase to all natural influences (F10.7, ENSO, and QBO),
and are out of phase below and above 80 km. Both the temperature and
the ozone reveal cooling trends (-0.85 K/decade and -0.12 ppmv/decade)
of the the lower mesosphere (60-80 km) and are followed by the upper
mesospheric (85-100 km) warming trends (1.25 K/decade and 0.27 ppmv/
decade) over the low latitudes. In general, natural influences affected
the mesospheric temperature more strongly than the ozone volume
mixing ratio. Our results are expected to be an updated and reliable
estimation of the mesospheric temperature and ozone variability for
the equatorial mesosphere.
Title: Identifying Shocked Feldspar on Mars Using Perseverance
Spectroscopic Instruments: Implications for Geochronology Studies
on Returned Samples
Authors: Shkolyar, S.; Jaret, S. J.; Cohen, B. A.; Johnson, J. R.;
Beyssac, O.; Madariaga, J. M.; Wiens, R. C.; Ollila, A.; Holm-Alwmark,
S.; Liu, Y.
Bibcode: 2022EM&P..126....4S
Altcode:
The Perseverance rover (Mars 2020) mission, the first step in NASA's
Mars Sample Return (MSR) program, will select samples for caching based
on their potential to improve understanding Mars' astrobiological,
geological, geochemical, and climatic evolution. Geochronologic
analyses will be among the key measurements planned for returned
samples. Assessing a sample's shock history will be critical because
shock metamorphism could influence apparent sample age. Shock effects
in one Mars-relevant mineral class, plagioclase feldspar, have
been well-documented using various spectroscopy techniques (thermal
infrared reflectance, emission, and transmission spectroscopy, Raman,
and luminescence). A subset of these data will be obtained with the
SuperCam and SHERLOC (Scanning Habitable Environments with Raman
& Luminescence for Organics & Chemicals) instruments onboard
Perseverance to inform caching decisions for MSR. Here, we review shock
indicators in plagioclase feldspar as revealed in Raman, luminescence,
and IR spectroscopy lab data, with an emphasis on Raman spectroscopy. We
consider how this information may inform caching decisions for selecting
optimal samples for geochronology measurements. We then identify
challenges and make recommendations for both in situ measurements
performed with SuperCam and SHERLOC and for supporting lab studies to
enhance the success of geochronologic analyses after return to Earth.
Title: The ikaite to calcite transformation: Implications for
palaeoclimate studies
Authors: Vickers, Madeleine L.; Vickers, Martin; Rickaby, Rosalind
E. M.; Wu, Han; Bernasconi, Stefano M.; Ullmann, Clemens V.; Bohrmann,
Gerhard; Spielhagen, Robert F.; Kassens, Heidemarie; Pagh Schultz,
Bo; Alwmark, Carl; Thibault, Nicolas; Korte, Christoph
Bibcode: 2022GeCoA.334..201V
Altcode:
Marine sedimentary ikaite is the parent mineral to glendonite, stellate
pseudomorphs found throughout the geological record which are most
usually composed of calcite. Ikaite is known to be metastable at earth
surface temperatures and pressures, readily breaking down to more stable
carbonate polymorphs when exposed to warm (ambient) conditions. Yet
the process of transformation of ikaite to calcite is not well
understood, and there is an ongoing debate as to the palaeoclimatic
significance of glendonites in the geological record. This study uses a
combination of techniques to examine the breakdown of ikaite to calcite,
outside of the ikaite growth medium, and to assess the palaeoclimatic
and palaeoenvironmental significance of stable and clumped isotope
compositions of ikaite-derived calcite. Powder X-ray diffraction shows
that ikaite undergoes a quasi- solid-state transformation to calcite
during heating of samples in air, yet when ikaite transforms under a
high temperature differential, minor dissolution-recrystallisation
may also occur with the ikaite structural waters. No significant
isotopic equilibration to transformation temperature is observed in the
resulting calcite. Therefore, in cases of transformation of ikaite in
air, clumped and stable isotope thermometry can be used to reconstruct
ikaite growth temperatures. In the case of ancient glendonites, where
transformation of the ikaite occurred in contact with the interstitial
waters of the host sediments over unknown timescales, it is uncertain
whether the reconstructed clumped isotope temperatures reflect ikaite
crystallisation or its transformation temperatures. Yet clumped and
stable isotope thermometry may still be used conservatively to estimate
an upper limit for bottom water temperatures. Furthermore, stable
isotope along with element/Ca ratios shed light on the chemical
environment of ikaite growth. Our data indicate that a range of
(bio)geochemical processes may act to promote ikaite formation at
different marine sedimentary sites, including bacterial sulphate
reduction and anaerobic oxidation of methane. The colours of the
ikaites, from light brown to dark brown, indicate a high organic matter
content, favouring high rates of bacterial sulphate reduction as the
main driver of ikaite precipitation. Highest Mg/Ca ratios are found
in the most unstable ikaites, indicating that Mg acts to destabilise
ikaite structure.
Title: New constraints on the abundances of phosphorus and sulfur
in the lunar core: High-pressure and high-temperature experimental
study of the Fesbnd Ssbnd P ternary system
Authors: Zhai, Kuan; Yin, Yuan; Zhai, Shuangmeng
Bibcode: 2022GeCoA.334....1Z
Altcode:
High-pressure and high-temperature experiments for the Fesbnd Ssbnd
P ternary system were performed at 3-5 GPa and 1173-1873 K. We
systematically investigated the effect of pressure, temperature,
and bulk composition on the phase relationships, on the core
crystallization sequences, and on the presence of sulfur and
phosphorous in the lunar core. Our experimental results indicate that
while up to < 1 wt% phosphorus can be dissolved in solid iron in
the Fesbnd Ssbnd P ternary system at 3 and 5 GPa, S dissolution in
solid iron is near negligible. On the iron rich (S + P < 10 wt%)
side of the Fesbnd Ssbnd P phase diagram completely miscible Fesbnd
Ssbnd P liquids were observed. Combined with previous experimental
results, the relationship of the sulfur content in the liquid metal
(XSliquid) and the partitioning coefficient
of phosphorus (DP) between the solid and liquid metal
follows an equation of lgDP = - 1.8286 - 17.87 × lg(1 -
XSliquid). Tradeoff between the liquidus of the
Fesbnd Ssbnd P system and the (S + P) content of the lunar core well
constrain the upper limit of the (S + P) content in the liquid lunar
outer core to the concentrations between 8.7 and 13.1 wt%. Using the
result of the phosphorus coefficient and our partitioning model, we
further assessed the abundances of 6.08-7.15 wt% S, 0.54 ± 0.01 wt% P
in the lunar liquid outer core, and 0.05 ± 0.01 wt% S, 0.07 ± 0.01 wt%
P in the lunar solid inner core, respectively. Integrating the observed
lunar core adiabat and the pressure dependence of the Fesbnd Ssbnd P
liquidus temperature, we propose that the solidification regime in the
lunar core will switch from bottom-up to top-down once the abundance of
(S + P) in the liquid outer core exceeds 3.5 wt% as the core evolves.
Title: Nature of helicity injection in non-erupting solar active
regions
Authors: Vemareddy, P.
Bibcode: 2022MNRAS.516..158V
Altcode: 2022MNRAS.tmp.2169V; 2022arXiv220803228V
Using time-sequence vector magnetic field and coronal observations from
Solar Dynamics Observatory, we report the observations of the magnetic
field evolution and coronal activity in four emerging active regions
(ARs). The ARs emerge with leading polarity being the same as for the
majority of ARs in a hemisphere of solar cycle 24. After emergence,
the magnetic polarities separate each other without building a sheared
polarity inversion line. In all four ARs, the magnetic fields are
driven by foot point motions such that the sign of the helicity
injection (dH/dt) in the first half of the evolution is changed to
the opposite sign in the later part of the observation time. This
successive injection of opposite helicity is also consistent with the
sign of mean force-free twist parameter (αav). Further,
the EUV light curves off the ARs in 94 Å and GOES X-ray flux reveal
flaring activity below C-class magnitude. Importantly, the white-light
coronagraph images in conjunction with the AR images in Atmospheric
Imaging Assembly (AIA) 94 Å delineate the absence of associated
Coronal Mass ejections (CMEs) with the studied ARs. These observations
imply that the ARs with successive injection of opposite sign magnetic
helicity are not favourable to twisted flux rope formation with excess
coronal helicity, and therefore are unable to launch CMEs, according
to recent reports. This study provides the characteristics of helicity
flux evolution in the ARs referring to the conservative property of
magnetic helicity and more such studies would help to quantify the
eruptive capability of a given AR.
Title: Comment on "Orbital precession of the S2 star in
scalar-tensor-vector gravity"
Authors: Turimov, Bobur V.
Bibcode: 2022MNRAS.516..434T
Altcode: 2022MNRAS.tmp.2245T
The explicit derivation for the periastron precession of the S2-star
orbiting around the supermassive black hole located in the centre of
the Milky Way in the scalar-tensor-vector gravity has been discussed.
Title: Core-collapse supernovae in dense environments - particle
acceleration and non-thermal emission
Authors: Brose, R.; Sushch, I.; Mackey, J.
Bibcode: 2022MNRAS.516..492B
Altcode: 2022arXiv220804185B; 2022MNRAS.tmp.2160B
Supernova remnants (SNRs) are known to accelerate cosmic rays from
the detection of non-thermal emission in radio waves, X-rays, and
gamma-rays. However, the ability to accelerate cosmic rays up to
PeV energies has yet to be demonstrated. The presence of cut-offs in
the gamma-ray spectra of several young SNRs led to the idea that PeV
energies might only be achieved during the first years of a remnant's
evolution. We use our time-dependent acceleration-code RATPaC to study
the acceleration of cosmic rays in supernovae expanding into dense
environments around massive stars. We performed spherically symmetric
one-dimensional (1D) simulations in which we simultaneously solve
the transport equations for cosmic rays, magnetic turbulence, and the
hydrodynamical flow of the thermal plasma in the test-particle limit. We
investigated typical circumstellar-medium (CSM) parameters expected
around red supergiant (RSG) and luminous blue variable (LBV) stars for
freely expanding winds and accounted for the strong γγ absorption in
the first days after explosion. The maximum achievable particle energy
is limited to below $600\,$TeV even for the largest considered values
of the magnetic field and mass-loss rates. The maximum energy is not
expected to surpass $\approx 200\,$ and $\approx 70\,$TeV for LBVs and
RSGs that experience moderate mass-loss prior to the explosion. We find
gamma-ray peak-luminosities consistent with current upper limits and
evaluate that current-generation instruments are able to detect the
gamma-rays from Type-IIP explosions at distances up to $\approx 60\,$
kpc and Type-IIn explosions up to $\approx 1.0\,$ Mpc. We also find a
good agreement between the thermal X-ray and radio synchrotron emission
predicted by our models with a range of observations.
Title: V410 Puppis: A useful laboratory for early stellar evolution
Authors: Erdem, Ahmet; Sürgit, Derya; Özkardeş, Burcu; Hadrava,
Petr; Rhodes, Michael D.; Love, Tom; Blackford, Mark G.; Banks,
Timothy S.; Budding, Edwin
Bibcode: 2022MNRAS.515.6151E
Altcode: 2022arXiv220713768E; 2022MNRAS.tmp.2037E
New spectrometric (HERCULES) and ground-based multicolour photometric
data on the multiple star V410 Puppis are combined with satellite
photometry (HIPPARCOS and TESS), as well as historic astrometric
observations. Absolute parameters for V410 Pup Aab are derived:
MAa = 3.15 ± 0.10, MAb = 1.83 ± 0.08
(M⊙); RAa = 2.12 ± 0.10, RAb =
1.52 ± 0.08 (R⊙); a = 6.57 ± 0.04 R⊙;
TAa = 12500 ± 1000, TAb = 9070 ± 800(K),
and photometric distance 350 ± 10 (pc). We report the discovery of
a low-amplitude SPB variation in the light curve and also indications
of an accretion structure around V410 Pup B as well as emission cores
in V410 Pup C. We argue that V410 Pup is probably a young formation
connected with the Vela 2 OB Association. The combined evidence allows
an age in the range 7-25 Myr from comparisons with standard stellar
evolution modelling.
Title: Equivalence principle violation from large scale structure
Authors: Petruzziello, Luciano
Bibcode: 2022PhLB..83337293P
Altcode: 2022arXiv220510566P
We explore the interplay between the equivalence principle and a
generalization of the Heisenberg uncertainty relations known as extended
uncertainty principle, that comprises the effects of spacetime curvature
at large distances. Specifically, we observe that, when the modified
uncertainty relations hold, the weak formulation of the equivalence
principle is violated, since the inertial mass of quantum systems
becomes position-dependent whilst the gravitational mass is left
untouched. To obtain the above result, spinor and scalar fields are
separately analyzed by considering the non-relativistic limit of the
Dirac and the Klein-Gordon equations in the presence of the extended
uncertainty principle. In both scenarios, it is found that the ratio
between the inertial and the gravitational mass is the same.
Title: Instability of hairy black holes in regularized 4-dimensional
Einstein-Gauss-Bonnet gravity
Authors: Tsujikawa, Shinji
Bibcode: 2022PhLB..83337329T
Altcode: 2022arXiv220509932T
In regularized 4-dimensional Einstein-Gauss-Bonnet (EGB) gravity derived
from a Kaluza-Klein reduction of higher-dimensional EGB theory, we study
the existence and stability of black hole (BH) solutions on a static
and spherically symmetric background. We show that asymptotically-flat
hairy BH solutions realized for a spatially-flat maximally symmetric
internal space are unstable against linear perturbations for any
rescaled GB coupling constant. This instability is present for the
angular propagation of even-parity perturbations both in the vicinity
of an event horizon and at spatial infinity. There is also a strong
coupling problem associated with the kinetic term of even-parity
perturbations vanishing everywhere.
Title: The influence of crustal recycling on the molybdenum isotope
composition of the Earth's mantle
Authors: Hin, Remco C.; Hibbert, Kate E. J.; Chen, Shuo; Willbold,
Matthias; Andersen, Morten B.; Kiseeva, Ekaterina S.; Wood, Bernard
J.; Niu, Yaoling; Sims, Kenneth W. W.; Elliott, Tim
Bibcode: 2022E&PSL.59517760H
Altcode:
Several studies have suggested that the Earth's upper mantle is
slightly enriched in light molybdenum isotopes relative to bulk Earth,
defined by chondrites, but there is no consensus on the presence of
this subtle but potentially notable signature. To establish better
whether or not the 98Mo/95Mo of Earth's upper
mantle is indeed sub-chondritic, we have analysed hand-picked glasses of
depleted (i.e. chondrite normalised La/Sm<1) mid-ocean ridge basalts
(MORB) from the Pacific, Atlantic and Indian ocean basins. The mean
Mo isotope composition of our depleted MORB relative to reference
NIST SRM 3134 (δ 98 / 95MoNIST SRM 3134) is
-0.22±0.03‰ (95% confidence interval, c.i.) compared to a value of
-0.15±0.01‰ (95% c.i.) for bulk Earth. Our high precision analyses
of the 234U/238U activity ratios of these
samples are within uncertainty of unity, which rules out the effect
of possible secondary, sea-floor processes as the dominant cause of
their low δ 98 / 95MoNIST SRM 3134. We further
report experimental data showing that sulphide liquid has δ
98 / 95MoNIST SRM 3134 0.25±0.01‰ lower than
basaltic silicate liquid at 1400 °C. This fractionation is too small
to significantly alter the Mo isotope composition of basalts relative
to their sources during melting or differentiation. Our MORB data
show that resolvably sub-chondritic Mo isotope compositions are common
in the upper mantle. Moreover, an appropriately weighted average δ
98 / 95MoNIST SRM 3134 of depleted and enriched MORB,
taken from this study and the literature, yields an estimated mantle
value of -0.20±0.01‰, indicating that the upper mantle as a whole
is sub-chondritic. Since prior work demonstrates that core formation
will not create a residual silicate reservoir with a sub-chondritic
δ 98 / 95MoNIST SRM 3134, we propose that this
feature is a result of recycling oceanic crust with low δ 98 /
95MoNIST SRM 3134 because of Mo isotope fractionation
during subduction dehydration. Such an origin is in keeping with the
sub-chondritic Th/U and low Ce/Pb of the depleted mantle, features which
cannot be explained by simple melt extraction. We present mass balance
models of the plate tectonic cycle that quantitatively illustrate that
the δ 98 / 95MoNIST SRM 3134 of the Earth's
mantle can be suitably lowered by such oceanic crustal recycling. Our
Mo isotope study adds to the notion that the depleted mantle has been
substantially modified by geodynamic cycling of subduction-processed
oceanic crust.
Title: The effect of salinity on water 17O/16O
ratios in brines
Authors: Barkan, Eugeni; Fishman, Ekaterina; Affek, Hagit P.
Bibcode: 2022E&PSL.59517761B
Altcode:
Closed-basin lakes respond strongly to climate related changes in
their water balance. Lake water isotopic composition can thus serve
as a sensitive indicator of paleo-hydrological conditions. Such
lakes are often highly saline, so that the effect of salinity on
the isotopic composition of lake water has to be accounted for
in analyzing lake water evaporation and lake sediment isotopic
records. Whereas the effect of salinity on δ18O has been
well characterized, this has not been done for the emerging proxy
17Oexcess [O17excess
=106 [ ln (10-3δ17 O + 1) -
0.528 ln (10-3 δ18 O + 1)]. To this end,
we measured for the first time δ17O and δ18O
of water in NaCl, CaCl2, and MgCl2
solutions of a wide range of concentrations (1 to 4 molal), using
CO2-H2O isotope exchange at 25 °C. The results
show that although both δ18O and δ17O are
sensitive to salinity, 17Oexcess is independent
of salinity. Therefore, when analyzing lake water composition, the
effect of salinity on δ18O and δ17O has to
be accounted for, whereas 17Oexcess remains
unchanged. These findings have important implications when studying
evaporation in hypersaline lakes and for reconstructions of past water
balance in saline closed-basin lakes.
Title: Surface scattering model for dual-polarization planetary radars
Authors: Hickson, Dylan C.
Bibcode: 2022P&SS..22105560H
Altcode:
This work presents a surface scattering model to interpret radar
polarimetry derived from dual-polarization planetary radar systems,
such as Arecibo Observatory and the Goldstone Solar System Radar. This
model divides surface scattering contributions within a radar echo
into quasi-specular and diffuse components, and further divides the
quasi-specular component into single- and double-bounce scattering. In
particular, the increase in the degree of linear polarization resulting
from dihedral double-bounce scattering is emphasized, in addition to
the increase in the circular polarization ratio. This mechanism is
illustrated in radar observations of young craters on the Moon by the
Mini-RF radar on board the Lunar Reconnaissance Orbiter. Arecibo radar
observations of 8 near-Earth asteroids are compared to this model
and the implications for the physical properties of these objects
are discussed. This work provides new insight in interpreting radar
polarimetry from dual-polarization planetary radar systems and is
broadly applicable to all solar system targets.
Title: Revisiting the secondary eclipses of KELT-1b using TESS
observations
Authors: Eftekhar, Mohammad; Abedini, Yousefali
Bibcode: 2022NewA...9601837E
Altcode: 2022arXiv220414190E
We present the characterization of the transiting planet KELT-1b using
data from the Transiting Exoplanet Survey Satellite (TESS). Our light
curve model includes primary transit and secondary eclipse. Here, we
model the systematic noise using Gaussian processes (GPs) and fit it
to the data using the Markov Chain Monte Carlo (MCMC) method. Modeling
of the TESS light curve returns a planet-to-star radius ratio, p =
0.07652-0.00028+0.00029 and a relatively large
secondary eclipse depth of 388-13+12 ppm. The
transit ephemeris of KELT-1b is updated using the MCMC method. Finally,
we complement our work by searching for transit timing variations
(TTVs) for KELT-1b. We do not find significant variations from the
constant-period models in our transit time data.
Title: Seismic visibility of melt at the core-mantle boundary from
PKKP diffracted waves
Authors: Russell, Stuart; Irving, Jessica C. E.; Cottaar, Sanne
Bibcode: 2022E&PSL.59517768R
Altcode:
The core-mantle boundary (CMB) is a complex and poorly understood
region of the Earth. The existence of melt or partial melt at the CMB
is strongly debated with evidence coming from a range of sources. While
partial melt has been inferred in specific locations using seismology,
often as an explanation for ultra-low velocity zones (ULVZs), no global
layer of melt has been observed despite evidence that such melt should
accumulate at the CMB. Using high frequency synthetic seismograms
we have systematically examined the effect of a one-dimensional melt
layer at the CMB on the global seismic wavefield. We find that PKKP
diffracted waves are an extremely sensitive, robust and previously
underutilised seismic phase for studying the CMB and, in synthetic
testing, could resolve very thin melt layers. We have constructed a
global data set of PKKP diffracted observations to attempt to observe
or exclude melt at the CMB. We find that within the bounds of our data,
we are unable to robustly exclude or observe a melt layer at the CMB
on the order of single kilometres thick. The presence of a thin layer
of unobservable melt at the CMB would have profound impacts for the
internal dynamics of the Earth.
Title: Estimate of the source parameters of terrestrial gamma-ray
flashes observed at low-Earth-orbit satellites
Authors: Surkov, Vadim; Pilipenko, Vyacheslav
Bibcode: 2022JASTP.23705920S
Altcode:
A special attention has been paid in the past decades to studies
of terrestrial gamma-ray flashes (TGFs) observed above active
thunderstorms. The physical mechanism of the TGF generation and its
source location in the atmosphere have not been firmly established. A
numerical modelling, such as Monte Carlo simulation, is commonly
used to analyze the problem having regard to the complexity of basic
electrodynamic and transport equations. Here, in contrast to previous
numerical studies, we have constructed a suitably idealized analytical
model of a point source of gamma-rays in a vertically inhomogeneous
atmosphere. An energy-distribution of gamma photons is assumed to be
determined by the energy spectrum of electron bremsstrahlung resulted
from the relativistic runaway electron avalanche in a strong electric
field. The absorption of photon energy due to photoelectric effect,
Compton scattering and the electron-positron pair production have been
accounted for approximately with an effective coefficient of energy
absorption. A photon mean free path in the atmosphere is assumed to be
dependent on its energy and altitude. A spatiotemporal distribution of
gamma-ray flux density and photon fluence at a low-Earth orbit (LEO)
are estimated as functions of the TGF source altitude, total number of
photons emitted by the source, and other parameters. The model matches
the LEO observations indicating that the TGF source is located at
an altitude about 10 - 14 km. The same model can be applied for the
description of the recently found downward-directed TGF detected by
the large-area Telescope Array cosmic ray observatory.
Title: Potential energy sources for the deep continental biosphere
in isolated anoxic brines
Authors: Dowd, William S.; Schuler, Christopher J.; Santelli, Cara M.;
Toner, Brandy M.; Sheik, Cody S.; Pehr, Kelden; McDermott, Jill M.
Bibcode: 2022E&PSL.59517720D
Altcode:
In isolated fracture networks in the Precambrian Shield, long-term
water and rock interactions produce saline anoxic fluids that
host extant microbial communities deep within the continental
subsurface. Light and oxygen (O2) are absent in these
environments. Thus, chemotrophic organisms inhabiting these systems
rely on anaerobic reactions for energy. Viable electron donors
include short-chain alkanes, such as methane (CH4) and
C2+ alkanes, while alternative electron acceptors include
sulfate (SO24-), nitrate (NO3-),
and ferric iron (Fe3+). Here, we constrain the potential
sources of energy for microorganisms in Neoarchean bedrock on the 27th
level west drift of the Soudan Underground Mine State Park, MN, USA
(713.5 meters below the surface). The Gibbs Free Energy (ΔG) of 11
reactions are modeled and expressed as available chemical potential
energy per mass fluid (J/kgfluid). Metabolic reactions
involving CH4 oxidation by SO24-
would yield the highest potential energy of reactions modeled
in this study (-111 J/kgfluid). The free energy
for methanogenesis via the breakdown of dimethylamine (DMA;
∑(CH3)2NH(aq)) is exergonic but
with near-zero available energy per mass fluid, suggesting that
DMA may be cycled quickly to produce biological CH4 at
Soudan. We examine all the possible pathways by which CH4
and other short-chain alkanes may be formed. Conventional
δ13CCH4 values and C1/C2+
abundance ratios support a mixed biological and non-biological origin
of CH4. Doubly substituted 'clumped' CH4 isotope
13CH3D values are consistent with formation
temperatures of 84-89 °C that exceed current environmental conditions
of 11.5-12.1 °C. These estimated formation temperatures are too low
for CH4 to be formed solely through thermogenic degradation
of organic matter. Further, low or undetectable H2 rules out
active abiogenesis of CH4 from CO2 reduction. It
is more likely that the bulk CH4 pool reflects a mixture of
microbial CH4 with Δ13CH3D values
equilibrated at 11.5-12.1 °C and thermogenic CH4 formed
at temperatures >100 °C. Understanding the origin and cycling of
these electron donors contributes to a fundamental understanding of how
microbial activity may promote, maintain, or suppress the habitability
of these isolated systems over long timescales.
Title: Martian surface dating model refinement based on Chang'E-5
updated lunar chronology function
Authors: Yue, Zongyu; Di, Kaichang; Michael, Gregory; Gou, Sheng;
Lin, Yangting; Liu, Jianzhong
Bibcode: 2022E&PSL.59517765Y
Altcode:
Planetary surface ages are extremely important to geologic evolution
studies. For extraterrestrial bodies, the crater size-frequency
distribution dating method, including a crater production function and
a chronology function, was established based on the radiometric ages
of Apollo and Luna samples from the Moon. Recently, the radiometric
age of a sample from Chang'e-5 mission added a data point where
there was previously a gap in sample ages, and an updated lunar
chronology function was proposed. This research aims to recalculate the
Martian surface dating model from the newly updated lunar chronology
function. The calculation takes account of the differences in impact
rates, impact velocities, surface gravities, the threshold diameters of
craters' transition from the strength to gravity regime and from simple
to complex crater structures on the Moon and Mars. We use the Neukum
production function, although other production functions could also be
implemented with our method. A series of Martian isochrons is derived,
and an approximated analytical form production function is provided
for convenient applications in future studies. The Martian chronology
function is finally obtained through fitting crater frequencies
larger than 1.0 km in diameter with the corresponding ages of the
isochrons. The resultant Martian PF and CF in this research are largely
comparable with previous results. Based on the refined lunar chronology
function, our model will enhance the reliability of the estimating
Martian surface ages and we suggest it be used in future studies.
Title: SETI in 2021
Authors: Huston, Macy; Wright, Jason
Bibcode: 2022AcAau.199..166H
Altcode: 2022arXiv220311172H
In this second installment of SETI in 20xx, we very briefly and
subjectively review developments in SETI in 2021. Our primary focus is
98 papers and books published or made public in 2021, which we sort into
six broad categories: results from actual searches, new search methods
and instrumentation, target and frequency selection, the development
of technosignatures, theory of ETIs, and social aspects of SETI.
Title: The moving mirror model for fast radio bursts
Authors: Yalinewich, Almog; Pen, Ue-Li
Bibcode: 2022MNRAS.515.5682Y
Altcode: 2022MNRAS.tmp.1991Y; 2022arXiv220411663Y
Recent observations of coherent radiation from the Crab pulsar suggest
the emission is driven by an ultrarelativistic (γ ~ 104),
cold plasma flow. A relativistically expanding plasma shell can compress
the ambient magnetic field, like a moving mirror, and thus produce
coherent radiation whose wavelength is shorter than that of the ambient
medium by γ2. This mechanism has been previously studied
in the context of radio loud supernova explosions. In this work, we
propose that a similar mechanism drives the coherent emission in fast
radio bursts. The high Lorenz factors dramatically lower the implied
energy and magnetic field requirements, allowing the spin-down energy
of regular (or even recycled), fast spinning pulsars, rather than slow
spinning magnetars, to explain FRBs. We show that this model can explain
the frequency and the time evolution of observed FRBs, as well as their
duration, energetics, and absence of panchromatic counterparts. We also
predict that the peak frequency of subpulses decline with observation
time as $\omega _{\rm obs} \propto t_{\rm obs}^{-1/2}$. Unfortunately,
with current capabilities it is not possible to constrain the shape
of the curve ωobs(tobs). Finally, we find
that a variation of this model can explain weaker radio transients,
such as the one observed from a galactic magnetar. In this variant,
the shock wave produces low-frequency photons that are then Compton
scattered to the GHz range.
Title: Modeling and forecasting of ionosphere TEC using least squares
SVM in central Europe
Authors: Ghaffari-Razin, Seyyed Reza; Moradi, Amir Reza; Hooshangi,
Navid
Bibcode: 2022AdSpR..70.2035G
Altcode:
We propose a new method for spatio-temporal modeling of ionosphere
total electron content (TEC) using least squares support vector machine
(LS-SVM). In the SVM model, dual programming is used to solve the
system of equations. Therefore, large-scale problem solving with the
SVM greatly increases computation time and decreases accuracy. To
overcome these limitations, a LS-SVM method is proposed. This method
uses simple linear equations to solve the system of equations. As a
result, the complexity of the computational algorithm is reduced. In
addition, the convergence speed and accuracy of the results increase. To
evaluate the new method, observations of 30 GNSS stations in the
central Europe are used. The observations are for 80 days from 2014,
with different solar (F10.7) and geomagnetic activity (KP and DST)
indices. The results of the LS-SVM model at three control stations are
compared with the vertical TEC (VTEC) of the GPS and also with the
VTEC of the SVM, NeQuick and global ionosphere map (GIM) models. On
all days considered, the averaged RMSE of the LS-SVM, SVM, GIM and
NeQuick models at the control stations are calculated as 2.45, 3.13,
4.61 and 7.48 TECU, respectively. In precise point positioning (PPP)
analysis and at the high geomagnetic activity, the maximum RMSE of
LS-SVM, SVM, GIM and NeQuick models are computed 52.34, 63.22, 70.21
and 79.55 mm, respectively. During periods of low geomagnetic activity,
the RMSE of the LS-SVM model is lower than the other models. Seasonal
error analysis of all 4 models shows that the LS-SVM model has less
error in different seasons compared to the other models. The results
also show that the proposed model has a higher speed and accuracy than
the SVM, GIM and NeQuick. Therefore, it can be considered a regional
model of the ionosphere in the European region.
Title: Electron acoustic singular solitons interaction in the Earth's
magnetotail region
Authors: Ghosh, Uday Narayan
Bibcode: 2022AdSpR..70.2070G
Altcode:
Electron acoustic potential structures are generated in the presence
of a large-amplitude electric field in Earth's magnetotail region,
Earth's magnetosphere according to the numerous space observations by
satellites. In this article, we study the electron-acoustic solitary
waves (EASWs) in an unmagnetized electron-ion plasma consisting of cold
electrons and isothermal ions with two different temperatures. Nonlinear
evolution equations are derived from the hydrodynamic model of
collisionless, unmagnetized electron-ion plasma. Exact analytic
solutions are obtained from derived Korteweg-de Vries (KdV) equations
and modified Korteweg-de Vries (MKdV) equations separately with the
aid of the Hirota Bilinear method. Two singular soliton solutions of
both KdV and MKdV equations are obtained separately. The efficiency
and interactive approach of the heuristic Hirota Bilinear method
leads to multiple singular soliton solutions for its beautiful
algebraic technique which generates solitons solutions as well as
singular solitons explicitly. Then the significant multi singular
soliton interaction has been studied for KdV singular solitons and
MKdV singular solitons in the critical parameter set.
Title: External or internal companion exciting the spiral arms in
CQ Tau?
Authors: Hammond, Iain; Christiaens, Valentin; Price, Daniel J.;
Ubeira-Gabellini, Maria Giulia; Baird, Jennifer; Calcino, Josh;
Benisty, Myriam; Lodato, Giuseppe; Testi, Leonardo; Pinte, Christophe;
Toci, Claudia; Fedele, Davide
Bibcode: 2022MNRAS.515.6109H
Altcode: 2022MNRAS.tmp.2059H; 2022arXiv220708587H
We present new high-contrast images in near-infrared wavelengths
(λc = 1.04, 1.24, 1.62, 2.18, and 3.78 μm) of the young
variable star CQ Tau, aiming to constrain the presence of companions in
the protoplanetary disc. We reached a Ks-band contrast of 14 mag with
SPHERE/IRDIS at separations greater than 0${_{.}^{\prime\prime}}$4
from the star. Our mass sensitivity curve rules out giant planets
above 4 MJup immediately outside the spiral arms at ~60
au and above 2-3 MJup beyond 100 au to 5σ confidence
assuming hot-start models. We do, however, detect four spiral arms,
a double-arc and evidence for shadows in scattered light cast by a
misaligned inner disc. Our observations may be explained by an unseen
close-in companion on an inclined and eccentric orbit. Such a hypothesis
would also account for the disc CO cavity and disturbed kinematics.
Title: Mercury loss and isotope fractionation during high-pressure
and high-temperature processing of sediments: Implication for the
behaviors of mercury during metamorphism
Authors: Chen, Di; Ren, Dongsheng; Deng, Changzhou; Tian, Zhendong;
Yin, Runsheng
Bibcode: 2022GeCoA.334..231C
Altcode:
Metamorphic rocks show much lower mercury (Hg) levels than sedimentary
rocks, which may be due to the loss of Hg during high-pressure
and high-temperature conditions during metamorphism. To test this
hypothesis, we conduct high-pressure and high-temperature experiments
on ancient and modern sediments (WH black shale and GSS-4 soil). Under
0.3 GPa, the Hg concentrations decrease while the δ202Hg
values increase with rising temperatures (WH black shale: 333-89 ppb,
-1.34 to -0.79‰, 250-700 °C; GSS-4: 545-265 ppb, -1.39 to -1.01‰,
400-700 °C), suggesting the loss of isotopically light Hg isotopes
under high-temperature conditions. Under constant temperatures of both
200 °C and 500 °C, with increasing pressure (0.5-1.4 GPa), GSS-4
shows only a slight decrease in Hg concentration with no variation in
δ202Hg, suggesting that high-pressure conditions restrain
the loss of isotopically lighter isotopes. Consistent Δ199Hg
and Δ200Hg values were observed in both samples during
our experiment, implying no Hg isotope mass-independent fractionation
(Hg-MIF) under high-temperature and high-pressure conditions. While
results of this imply that metamorphism may lead to the emission
of isotopically lighter Hg from sedimentary rocks to the surface
environment, the lack of Hg-MIF during metamorphism provides important
support for the use of Hg isotopes for paleoenvironment reconstruction.
Title: The interplay between AGN feedback and precipitation of the
intracluster medium in simulations of galaxy groups and clusters
Authors: Nobels, Folkert S. J.; Schaye, Joop; Schaller, Matthieu;
Bahé, Yannick M.; Chaikin, Evgenii
Bibcode: 2022MNRAS.515.4838N
Altcode: 2022arXiv220402205N; 2022MNRAS.tmp.1955N
Using high-resolution hydrodynamical simulations of idealized galaxy
clusters, we study the interaction between the brightest cluster
galaxy, its supermassive black hole (BH), and the intracluster medium
(ICM). We create initial conditions for which the ICM is in hydrostatic
equilibrium within the gravitational potential from the galaxy and
an NFW dark matter halo. Two free parameters associated with the
thermodynamic profiles determine the cluster gas fraction and the
central temperature, where the latter can be used to create cool-core
or non-cool-core systems. Our simulations include radiative cooling,
star formation, BH accretion, and stellar and active galactic nucleus
(AGN) feedback. Even though the energy of AGN feedback is injected
thermally and isotropically, it leads to anisotropic outflows
and buoyantly rising bubbles. We find that the BH accretion rate
(BHAR) is highly variable and only correlates strongly with the star
formation rate (SFR) and the ICM when it is averaged over more than
$1~\rm Myr$. We generally find good agreement with the theoretical
precipitation framework. In $10^{13}~\rm M_\odot$ haloes, AGN feedback
quenches the central galaxy and converts cool-core systems into
non-cool-core systems. In contrast, higher mass, cool-core clusters
evolve cyclically. Episodes of high BHAR raise the entropy of the
ICM out to the radius, where the ratio of the cooling time and the
local dynamical time tcool/tdyn > 10, thus
suppressing condensation and, after a delay, the BHAR. The corresponding
reduction in AGN feedback allows the ICM to cool and become unstable
to precipitation, thus initiating a new episode of high SFR and BHAR.
Title: The Cenozoic Seawater Conundrum: New constraints from Mg
isotopes in island dolostones
Authors: Hu, Zhongya; Shi, Zhiqiang; Li, Gaojun; Xia, Zhiguang; Yi,
Liang; Liu, Chuan; Li, Weiqiang
Bibcode: 2022E&PSL.59517755H
Altcode:
The Mg/Ca ratio of seawater increased from ∼1.5 to its present value
of 5.4 over the Neogene, indicating a fundamental imbalance in the Mg-Ca
cycle during the late Cenozoic. The imbalance in Mg-Ca cycles since the
late Cenozoic, however, is contrasted by an arguable constancy in the
Mg isotope compositions of seawater (δ26Mgsw)
reconstructed from several low-resolution carbonate records. Addressing
such Cenozoic Seawater Conundrum requires reliable seawater Mg isotopic
records. The Xisha Islands in the South China Sea host large Cenozoic
dolostone sequences that record seawater chemistry over the past 23
Myr. This study reports the Mg isotopic and trace elemental compositions
of island dolostones in the well-studied Xike-1 drill core from the
Xisha Islands. Petrographic, C-O-Sr isotopic, and paleomagnetic data
from the drill core samples collectively support a "fluid-buffered",
syn-depositional origin for the dolostones. The dolostones from the
Xike-1 core have a narrow range of δ26Mg (- 2.83 ‰ ± 0.12
‰), confirming that δ26Mgsw have been stable
around the modern value (-0.83‰) since the late Cenozoic. This record
provides a new opportunity to better understand the Mg-Ca cycle during
the late Cenozoic. We ran numerical models of global seawater Mg-Ca
contents and δ26Mgsw with the most recently
published flux and isotope fractionation data. The results show that
the contrast between the constancy of δ26Mgsw
values and the dramatic increase in seawater Mg/Ca ratios cannot
be explained by a single mechanism (i.e., a decrease in the rate of
phyllosilicate formation on the seafloor alone). Instead, processes
involving different Mg fluxes need to be coupled to explain the observed
trends in Mg content and isotopic compositions of Cenozoic seawater. The
solution to the Cenozoic Seawater Conundrum includes simultaneous
decreases in the rates of both clay formation and dolomitization on
the seafloor, or an increase in the rate of both continental weathering
together with decreased seafloor clay formation. Our study underlines
the sensitivity of the Mg cycle to the interactions between climate,
continental weathering, and seafloor processes during the late Cenozoic.
Title: High-resolution crustal and upper mantle shear-wave velocity
structure beneath the central-southern Tanlu fault: Implications
for its initiation and evolution
Authors: Luo, Song; Yao, Huajian; Zhang, Zhiqi; Bem, Terbemba Shadrach
Bibcode: 2022E&PSL.59517763L
Altcode:
The Tanlu fault is a well-known lithosphere-cutting, strike-slip fault
in eastern China and it has played an important role in regional plate
tectonics since the middle Mesozoic. However, the initiation mechanisms
and tectonic evolution of the Tanlu fault remain controversial, in part
due to the absence of constraints from deep structures. In this study,
we inverted 5-150 s surface-wave dispersion data collected from 253
permanent stations and 111 temporary stations in the vicinity of the
central-southern Tanlu fault and obtained both isotropic and azimuthally
anisotropic shear-wave velocity (Vs) models in the crust and upper
mantle simultaneously. The new Vs models reveal unprecedented multiple
patterns of anomalies. There is, for example, an arc-shaped pattern of
fast directions found in the South China plate (SCP), providing direct
evidence of the sudden termination of the Tanlu fault at its southern
end; orogen-parallel fast directions and high-velocity anomalies were
detected beneath the Dabie and Sulu orogens, which are believed to
be the residue of the delaminated lithosphere. Based on the evidence
collected, we propose a four-stage tectonic model for the Tanlu
fault. The tectonic model suggests that the area has been subjected
to multiple geologic processes since the Early Mesozoic, including
oceanic-continental collision, continental-continental collision,
break-off of oceanic slabs, lithospheric delamination, and convective
erosion resulting from corner flow. As such, the proposed tectonic
model reconciles the newly discovered Vs anomalies as well as various
previous findings, providing profound insight into regional deformations
and the evolution of the Tanlu fault and its adjacent areas.
Title: Estimation of vertical land motion along the south and west
coast of Turkey from multi-sensor observations
Authors: Erkoç, Muharrem Hilmi; Doğan, Uğur; Yıldız, Hasan;
Sezen, Erdinç
Bibcode: 2022AdSpR..70.1761E
Altcode:
This study aims to estimate Vertical Land Motion (VLM) using
multi-sensor and in-situ data at the tide gauge stations (TG) located on
the western and southern coasts of Turkey. The analysis of tide gauge
data, used to determine sea level changes for centuries, was supported
by modern global geodetic observations, and the effect of VLM on the
sea level trend was determined. In this context, VLM was calculated
from the relative sea level trends of eight TG's between 1998 and 2018
and the absolute sea level trends obtained from the CTOH Along-Track
Sea Level Anomalies regional products (X-TRACK) and Copernicus Marine
Environment Monitoring Service (CMEMS) improved altimetry data covering
the same temporal period. GNSS (Global Navigation Satellite System)
measurements give a solution of the point-wise information about VLM
at TG's, whereas InSAR (Interferometric Synthetic Aperture Radar)
solutions give spatial information about VLM that were calculated from
Sentinel-1 data, which was put into service after 2014. The analyses
carried out on Turkey's south and west coasts revealed an uplift trend
at all TG's, whereas an insignificant subsidence trend was determined
at the MNTS tide gauge station. When focusing on the MNTS station,
in the period of 1998-2018 VLM from XTRACK minus TG and CMEMS minus TG
were estimated as -0.7 ± 0.9 mm/yr and -0.5 ± 0.8 mm/yr, respectively
and also during the period of 2014-2018 VLM from GNSS and InSAR were
estimated as -0.6 ± 0.2 mm/yr and -0.3 ± 0.1 mm/yr, respectively.
Title: Experimental demonstration of quantum transport enhancement
using time-reversal symmetry breaking on a silicon photonic chip
Authors: Wang, Yang; Yu, Xinyao; Xue, Shichuan; Wang, Yizhi; Zhan,
Junwei; Wu, Chao; Zhu, Pingyu; Zheng, Qilin; Yu, Miaomiao; Liu,
Yingwen; Qiang, Xiaogang; Wu, Junjie; Yang, Xuejun; Xu, Ping
Bibcode: 2022SCPMA..6500362W
Altcode:
The continuous-time quantum walk is a basic model for studying quantum
transport and developing quantum-enhanced algorithms. Recent studies
show that by introducing a phase into the standard continuous-time
quantum walk model, the time-reversal symmetry can be broken without
changing the Hermitian property of the Hamiltonian. The time-reversal
symmetry breaking quantum walk shows advantages in quantum transport,
such as perfect state transfer, directional control, transport speedup,
and quantum transport efficiency enhancement. In this work, we implement
the time-reversal symmetry breaking quantum walks on a reconfigurable
silicon photonic chip and demonstrate the enhancement introduced by
breaking time-reversal symmetry. Perfect state transfer on a three-site
ring, a quantum switch implemented on a six-site graph, and transport
speedup using a linear chain of triangles are demonstrated with high
fidelity. Time-reversal asymmetry has also been used in a simplified
light-harvesting model, implying the potential of time-reversal symmetry
breaking in photosynthesis investigations.
Title: Matched template analysis of continuous wave laser for space
debris ranging application
Authors: Raj, Shasidran; Francis, Samuel; Roberts, Lyle; Ward, Robert;
McClelland, David; Shaddock, Daniel
Bibcode: 2022AdSpR..70.1979R
Altcode:
The growth of human-made space debris, sharing the same Earth's
orbital space as active satellites, is a worrying environmental
condition. Precise tracking and orbital modelling of space debris
are vital to predict potential future collisions with active
satellites. This paper investigates a continuous-wave laser ranging
method where a bench-top experiment models the reflected amplitude
modulated optical signal from a space debris target. The optical signal
is digitised and stored to undergo post-digital signal processing
using a parameter estimation matched filter approach to estimate
the time-varying delay between the target debris and the observing
telescope. The experiment investigated two different detection methods,
the direct detection of the optical signal and the coherent detection
where the optical signal is amplified with a bright local oscillator
before signal detection. The experimental results show that the
coherent detection method can provide a more precise time-varying
delay estimate than the direct detection method due to the improved
signal-to-noise ratio. The experimental results also show improved
precision in the parameter estimation when using larger portions of the
acquired signal's time series. The experimental results were used to
model for a potential space debris application. For example, assuming
the received signal power from the target debris is approximately 3.5
fW , the time-varying delay of the target debris using the coherent
detection method can be estimated with a precision of 1 m / s using 2.5
s of the acquired signal time series. This is well within the expected
minimum time series that can be collected from a space debris target
from a single flyover at the telescope site.
Title: Low-budget CubeSat star tracker calibration using Earth's
rotation
Authors: Han, Hyogeun; Baeck, Kiwook; Wi, Junsung; Yoon, Hyosang
Bibcode: 2022AdSpR..70.1880H
Altcode:
A low-budget calibration method for a star tracker using Earth's
rotation is presented. The rotating Earth is one of the most accurate
turntables in nature, as its rotation rate and axis are known precisely,
thanks to astronomers. Using a precise model of the Earth's rotation
and time tags, it is possible to set the attitude of a star tracker
fixed on the ground so that all star measurements can be used in
a full-state estimation with only one attitude state. The proposed
method needs only a GPS receiver that outputs pulse-per second signals
for time synchronization, which is useful for low-budget star-tracker
development in university-level CubeSat projects. The simulation results
show that the proposed method outperforms the previous calibration
method, which does not use the Earth's rotation, in terms of estimate
covariance. An outdoor experiment demonstrated the accuracy of the
star tracker calibration with low-cost hardware.
Title: New unexpected soliton solutions to the generalized (2 + 1)
Schrödinger equation with its four-mixing waves
Authors: Zahran, Emad H. M.; Bekir, Ahmet
Bibcode: 2022IJMPB..3650166Z
Altcode:
The propagation of solitons in birefringent fiber is one of the
phenomena that has an important role in all modern technological
means of communication. The generalized (2 + 1) nonlinear Schrödinger
equation (GNLSE) with its four-mixing waves (FMW) is the famous model
that describes the propagation of solitons in birefringent fiber
perfectly. In fact, the FMW governed effectively the performance of
the resultant solitons amplitude. Hereby, we will study this model
to extract new unexpected optical soliton solutions to this model via
various three techniques. The three famous methods that are a candidate
for this purpose are the extended direct algebraic method (EDAM), the
extended simple equation method (ESEM) and the solitary wave ansatz
method (SWAM). The three techniques are implemented successively for
the suggested model to establish the optical solutions of the suggested
model successfully. The optical soliton solutions that are achieved
by these proposed techniques give surprise expectations that weren’t
achieved previously by any other authors who used other techniques.
Title: Planar black holes as a route to understanding the Weak
Gravity Conjecture
Authors: McInnes, Brett
Bibcode: 2022NuPhB.98315933M
Altcode: 2022arXiv220101939M
One version of the Weak Gravity Conjecture requires that it should
be possible for an extremal black hole to emit a smaller black hole:
that is, the original black hole bifurcates. For asymptotically flat
and asymptotically AdS Reissner-Nordström black holes with spherical
event horizons, such a bifurcation reduces the total classical entropy
of the system, and so it is apparently forbidden by the second law of
thermodynamics. It may well be possible to remedy this by taking other
(for example, quantum-gravitational) effects into account, but it is
difficult to understand this in a quantitative way. In the case of
asymptotically AdS Reissner-Nordström black holes with planar event
horizons, however, one can show that bifurcations are definitely
compatible with the second law. (Naked singularities, generated by
the bifurcation, may play an important role here.) Furthermore, in
this case one can exhibit a detailed mechanism explaining precisely
why planar black holes must indeed be unstable (through emission of
branes) when they are sufficiently close to extremality. Thus planar
black holes can improve our understanding of the WGC.
Title: Solar System evolution and terrestrial planet accretion
determined by Zr isotopic signatures of meteorites
Authors: Render, Jan; Brennecka, Gregory A.; Burkhardt, Christoph;
Kleine, Thorsten
Bibcode: 2022E&PSL.59517748R
Altcode:
Nucleosynthetic isotope signatures in meteorites provide key insights
into the structure and dynamics of the solar protoplanetary disk
and the accretion history of the planets. We present high-precision
Zr isotopic data of a comprehensive suite of non-carbonaceous (NC)
and carbonaceous (CC) meteorites, and find that various meteorite
groups, including enstatite chondrites, exhibit 96Zr
enrichments, whereas there is no resolved 91Zr and
92Zr variability. These new Zr isotope data reveal the
same fundamental NC-CC dichotomy observed for several other elements,
where CC meteorites are more anomalous compared to NC meteorites and
are shifted towards the isotopic composition of Ca-Al-rich inclusions
(CAIs). For Zr and other elements, the CC composition is reproduced as a
mixture of materials with CAI-like and NC-like isotopic compositions in
approximately constant proportions, despite these elements exhibiting
disparate nucleosynthetic origins or different cosmo- and geochemical
behaviors. These constant mixing proportions are inconsistent with an
origin of the dichotomy by thermal processing or selective dust-sorting
in the disk but indicate mixing of isotopically distinct materials
with broadly solar chemical compositions. This corroborates models
in which the NC-CC dichotomy reflects time-varied infall from an
isotopically heterogeneous molecular cloud. Among NC meteorites,
the isotope anomalies in Zr are linearly correlated with those of
other elements, which likewise reflects primordial mixing. Lastly,
the new Zr isotope data reinforce the notion that Earth incorporated
s-process enriched material from the innermost Solar System, which
is not represented by known meteorites. By contrast, contributions to
Earth and Mars from outer Solar System CC-like materials were limited,
indicating that these planets did not form by pebble accretion, which
would have led to high CC fractions.
Title: Basalt Mo isotope evidence for crustal recycling in continental
subduction zone
Authors: Fang, Wei; Dai, Li-Qun; Zheng, Yong-Fei; Zhao, Zi-Fu
Bibcode: 2022GeCoA.334..273F
Altcode:
Highly variable molybdenum (Mo) isotope compositions are common in
mafic arc magmas above oceanic subduction zones, but Mo isotopes
of mafic magmas related to continental deep subduction have not yet
been documented. Here, we report for the first time the Mo isotope
composition of mafic igneous rocks above a typical continental
subduction zone in east-central China, where the North China Block
was subducted by the South China Block in the Triassic. Continental
basalts of Early Cretaceous age show negative δ98Mo values
of -0.98 to -0.16 ‰, significantly lower than the normal mantle value
of -0.20 ± 0.01 ‰. These basalts also exhibit arc-like trace element
compositions, high (87Sr/86Sr)i ratios
of 0.7050 to 0.7058, negative εNd(t) values of -15.2 to
-10.4, and negative εHf(t) values of -18.7 to -7.9. The
light Mo isotope signatures are associated with enrichments in not
only radiogenic Sr-Nd-Hf isotopes but also melt-mobile incompatible
elements in the basalts. This indicates that the mantle source of
these basalts would be generated by metasomatic reaction of the mantle
wedge peridotite with felsic melts derived from partial melting of
the deeply subducted continental crust. Given that continental crust
usually exhibits heavy Mo isotope compositions, it would be dehydrated
during its subduction to subarc depths. While the dehydration would
have released isotopically heavy Mo fluids from the subducting crust,
it leaves isotopically light Mo in the residual crust. The dehydrated
continental crust underwent partial melting at subarc depths to produce
felsic melts with low δ98Mo values, transferring the light
Mo isotope signature into the mantle source of the basalts. Therefore,
Mo isotopes in mafic igneous rocks are a powerful means to decipher the
recycling of crustal components at convergent plate margins. Our study
provides the first insight into Mo isotope recycling in continental
subduction zones.
Title: Abundant presolar silicates of the CM chondrite Asuka 12169:
Implications for the thermal and aqueous alteration of the CM
parent body
Authors: Xu, Yuchen; Lin, Yangting; Hao, Jialong; Kimura, Makoto;
Hu, Sen; Yang, Wei; Liu, Yang; Zou, Yongliao
Bibcode: 2022GeCoA.334...45X
Altcode:
The solar system could be separated into two zones based on the
isotopic dichotomy between non-carbonaceous and carbonaceous groups,
with the latter likely accreted in the outer solar system. Among
carbonaceous groups, the CM chondrite contains high abundances of
organic carbon and water. They have undergone aqueous alteration,
thermal metamorphism and brecciation to different degrees (e.g.,
Rubin et al., 2007; Tonui et al., 2014; Zolensky et al., 1997), which
contributed to erasing most of the solar nebular records. Asuka 12169
was reported as the most primitive CM chondrite based on petrological
and geochemical results, with little aqueous alteration (Kimura et
al., 2020). In this paper, we report a survey of presolar grains
in the fine-grained matrix and the accretionary rims of chondrules
and CAIs in this meteorite, based on NanoSIMS mapping of C-, O-,
and Si-isotopes. A total of 158 presolar grains were identified,
including 119 silicates/oxides (208 ± 20 ppm), 38 SiC (73 ± 12 ppm)
and 1 carbonaceous grain (2-2+5 ppm). These
abundances are within the maximum abundance ranges of primitive
chondrites (80-280 ppm for O-rich grains and 10-180 ppm for C-rich
grains). In comparison with most CM chondrites (<40 ppm), Asuka
12169 is uniquely rich in presolar silicates (185 ± 18 ppm), with
a high presolar silicate/oxide ratio of ∼8, therefore providing
robust evidence for little aqueous alteration. The high abundances of
presolar SiC and silicates in Asuka 12169 clearly show its pristine
properties regarding both thermal and aqueous alteration. Group 1,
2, 3 and 4 subtypes of presolar O-rich grains account for 84%,
2.5%, 0.8% and 12.6%, respectively. One O-rich grain shows a
high enhancement in 17O/16O and a subsolar
18O/16O ratio (17O/16O =
6.45 ± 0.09 × 10-3 and 18O/16O = 1.90
± 0.02 × 10-3), indicating a stellar origin in binary star
systems or novae. Most identified presolar SiC are mainstream grains
of AGB origins. One with 28Si-excess is classified as an X
grain, suggesting a supernova origin. There are two SiC grains that have
12C/13C < 10 but close-to-solar Si isotopic
ratios, and are therefore classified as AB type. The pristine features
of Asuka 12169 suggest that it was probably located in the outermost
few kilometers of the CM asteroid, where temperature was high enough for
sublimation of water ice under vacuum, but where no aqueous alteration
occurred, and where the depth was enough for lithification. The high
abundances of various types of presolar grains, together with the
petrographic information of Asuka 12169, provide crucial constrains
on the original properties and subsequent evolution of the CM asteroids.
Title: Extremely weak early Cambrian dipole moment similar to
Ediacaran: Evidence for long-term trends in geomagnetic field
behaviour?
Authors: Lloyd, Simon J.; Biggin, Andrew J.; Paterson, Greig A.;
McCausland, Phil J. A.
Bibcode: 2022E&PSL.59517757L
Altcode:
Paleointensity data can yield insight on the state of the geodynamo,
providing constraints on deep Earth events and enabling analysis of
long-term trends in the paleomagnetic field. The Ediacaran (635 Ma-539
Ma) is a period of discrepant paleomagnetic behaviour that was recently
characterised by sustained, extremely weak, paleointensity. The interval
also coincides with some of the most recent estimates for Earth's
inner core nucleation (ICN) age, determined from numerical geodynamo
models and analysis of long-term paleointensity data. However, the
field strength during the subsequent Cambrian period (540 Ma-485 Ma) is
largely unknown with almost no data. Here, we provide high-quality
paleointensity results for the Cambrian. A Grenville dyke (∼590 Ma)
that was baked by the Chatham-Grenville stock (532 Ma), slowly cooled
at a rate controlled by the stock and recorded the paleointensity
averaged over this interval (up to several tens of thousands of
years). The characteristic paleomagnetic directions of the dyke are
well-defined and consistent with those previously obtained from the
Chatham-Grenville and Mont Riguad stocks. Paleointensity data
were obtained using multiple methods and indicate an extremely weak
field during a period coincidental with evidence for hyper-reversing
activity extending into the late Cambrian. The dipole strength is
similar to that of the 'ultra-weak' Ediacaran and may suggest that
this paleomagnetic behaviour persisted into the Cambrian. The cause
of this weak-field interval remains enigmatic but an approximate
200-million-year quasi-periodicity in dipole strength extending across
the entire Phanerozoic is not ruled out.
Title: Impact of estuaries on fluvial Cr input into the ocean:
Perspectives from the Mobile Bay Estuary, Northern Gulf of Mexico
Authors: Mallick, Debbrota; Wang, Xiangli; Beebe, Donald A.
Bibcode: 2022GeCoA.334..187M
Altcode:
The chromium (Cr) stable isotope system has been recently developed as
a promising redox proxy to study Earth's oxygenation history. However,
an incomplete understanding of the global marine Cr isotope mass balance
hinders its quantitative application. Specifically, whether estuary
environments can alter fluvial Cr flux into the global ocean, together
with its isotopic composition, is still debated. Here, we report the
first systematic redox-dependent stable Cr isotope data for an oxic
estuary (the Mobile Bay Estuary in the northern Gulf of Mexico). Our
data suggest that the Cr(VI) supplied by the Mobile River is completely
reduced to Cr(III) before salinity reaches 5. A Rayleigh distillation
model calculates an isotope fractionation factor of -0.1‰ to -0.3‰
(isotopically light Cr(VI) preferentially reduced). Approximately
15-30% of fluvial Cr(III) is removed from solution in the mixing zone,
and this process likely preferentially removes isotopically heavy
Cr(III). Therefore, if the face values of the Cr concentration and
δ53Cr of the Mobile River were used as input terms for the
Gulf of Mexico, Cr flux would have been overestimated by a factor of 5-7
and its δ53Cr overestimated by 0.3-0.7‰. A literature
survey suggests that seasonally variable fluvial Cr flux is lost
from solution in the majority of estuaries studied thus far. Estuary
loss of Cr and annual variation combined add an order of magnitude
uncertainty to the global fluvial Cr flux estimated previously. How
fluvial δ53Cr is affected in an estuary environment is
difficult to generalize because of the competition between partial
Cr(VI) reduction that removes light isotopes and Cr(III) scavenging
that likely removes heavy isotopes, and such competition likely varies
among estuaries.
Title: Design and analysis of emergency protection scheme for manned
spacecraft under leakage condition
Authors: Yang, Kaichun; Yang, Chunxin; Yang, Han
Bibcode: 2022AdSpR..70.1935Y
Altcode:
Spacecraft may encounter emergency pressure relief situations during
manned space exploration missions, such as when micrometeoroids break
through the bulkheads. The pressure emergency is one of the main
threats to the missions in low earth orbit or deep space explorations
to the Moon and Mars. It is critical to develop a pressure protection
scheme for emergency contingencies. In this study, in order to
improve the safety and reliability of spacecraft protection,
a periodic recompression recovery scheme (PRRS) is proposed for
cabin pressure protection. The PRRS adopts a combined mode of cabin
emergency recompression, cabin pressure maintenance, gas recovery,
and spacesuit protection, which can provide astronauts with a variety
of safety protection methods. A mathematical model of cabin pressure
control is established by using the lumped parameter method, and
the gas consumption of three types of pressure protection systems are
compared. The PRRS adopts the mature technologies and could provide the
reliable pressure emergency protection. Compared with the traditional
continuous gas supply scheme, the PRRS can reduce gas consumption by
more than 85%. In the case of limited spacecraft gas resources, the
PRRS promises a longer survival time for returning astronauts. This
study can provide a design idea for the overall design of manned
spacecraft in the future.
Title: Tungsten isotopic fractionation at the Mariana arc and
constraints on the redox conditions of subduction zone fluids
Authors: Stubbs, Daniel; Yang, Ruiyu; Coath, Christopher D.; John,
Timm; Elliott, Tim
Bibcode: 2022GeCoA.334..135S
Altcode:
Fluid release from subducting slabs during recycling of oceanic
lithosphere plays an important role in concentrating select elements
near the Earth's surface. Yet the extent to which these fluids are
oxidising or reducing (fO2), one of the key characteristics
that controls element mobility, remains poorly understood. Additionally,
it is unclear whether the fO2 signature of arc fluids is
generated deep within the slab during subduction or if it reflects
later, shallower subarc crustal processes. Previous experimental work
has shown that the extent to which highly incompatible W partitions
into aqueous fluids depends on the temperature and fO2
conditions of the fluids. In the subducting slab, W partitions
into rutile with a different coordination number to that which it
exhibits in fluids, a process which may generate stable W isotopic
fractionation. Therefore, if the competition between partitioning
into aqueous fluids versus rutile is controlled by the conditions
within the subducting slab, the elemental and stable W isotopic
systematics of arc lavas may provide a novel tool with which to
investigate subduction zones. We present isotopic compositions of
a well characterised suite of arc lavas from the central island
province of the Mariana arc (W. Pacific), and rutile separates from
exhumed fragments of subducted, depleted, mafic oceanic crust from
the Raspas Complex, Ecuador. Our data show that lavas from Guguan that
exhibit the strongest geochemical signature of subduction zone fluids
(e.g., high Ba/Th, Mo/Ce, Pb/Ce), contain the highest abundances of
W compared to similarly magmatically incompatible Th, in agreement
with anticipated fluid mobile behaviour. These Guguan lavas have
distinct, heavy stable W isotopic compositions (δ186/184W
= +0.134 to +0.156 ‰) compared to MORB (δ186/184W =
+0.078 to +0.099 ‰) and those from sediments-dominated islands
like Uracas and Agrigan (δ186/184W = +0.080 to +0.111
‰). The W isotopic compositions of sediments off-board the
Mariana arc are more variable, with the volcaniclastic sediments
having δ186/184W values closest to those of the sediment
dominated arc lavas. We show that rutile from representative subducting
mafic crust incorporates isotopically light W, consistent with a
coordination change from tetrahedral in fluids and melts to octahedral
in the structure of rutile. We suggest that isotopically heavy fluids,
complementary to the residual rutile in the mafic crust, account for
the high δ186/184W of the fluid-dominated Guguan lavas,
a process previously invoked to control Mo systematics in the same
samples. Combining our new elemental and isotopic W data with these
existing Mo data, we model the influence of oxygen fugacity on fluid
compositions in equilibrium with the mafic crust, and the fraction of
such fluids required to be added to the mantle wedge to reproduce the
Mo-W systematics of erupted arc lavas. Our models show that more fluid
is required (F = 6 %) than can be generated internally in the mafic
oceanic crust, and that this fluid must be oxidised, perhaps as high
as FMQ +5. We suggest that these requirements document the interaction
of subducted mafic crust with an external source of oxidising fluids
sourced from dehydration of underlying serpentinites.
Title: Neural-network-based adaptive quantized attitude takeover
control of spacecraft by using cellular satellites
Authors: Shi, Mingyue; Wu, Baolin; Wang, Danwei
Bibcode: 2022AdSpR..70.1965S
Altcode:
The problem of attitude takeover control of spacecraft by using cellular
satellites with the limited inter-satellite communication capacity,
the unknown inertia matrix and external disturbances is studied. A
hysteresis quantizer is employed to quantize the signal of control
torque generated by the controller cellular satellite. The signal
of quantized control torque is transmitted to the actuator cellular
satellites only when the quantization signal changes, which can greatly
reduce the communication burden between the controller cellular
satellite and the actuator cellular satellites. To approximate the
unknown attitude dynamics of the spacecraft, the radial basis function
neural network is introduced. Furthermore, a distributed control
allocation strategy is proposed to deal with the control allocation
problem for the actuator cellular satellites with faults. Lastly,
the effectiveness of the proposed scheme is validated by numerical
simulations.
Title: Characterizing the trend of channel braiding of a tropical
transboundary river using spatial growth component analysis and
ARIMA model
Authors: Deep Saha, Ujwal; Mannan Saheb, Abdul; Islam, Aznarul;
Deb Barman, Suman; Dutt, Sanjana; Reza Md. Towfiqul Islam, Abu
Bibcode: 2022AdSpR..70.1773D
Altcode:
Channel braiding is one of the fundamental fluvial processes in the
context of sediment-energy nexus. The present study intends to simulate
the channel braiding pattern of a tropical river (Jaldhaka River) on
the Himalayan foreland plains. The grain size of the bed material in
the Jaldhaka River decreases with distance from the mountain front,
as does the surface gradient from the piedmont plains to the northern
alluvial plains accompanied by the development of alluvial fans. Such
assemblage results in multiple facets of hydro-geomorphic controls
on channel planform dynamicity. This study is one of the pioneering
attempts to characterize the spatial and temporal trend of channel
braiding in any river running through the foreland region of the
Sikkim-Bhutan Himalayas. The type of channel braiding is determined by
the three indices - (1) Braiding Index (BI*), (2) Channel Count Index
(BI), and (3) Channel Length Index (Pt), in cases where
no gradual and uniform trend of development has been seen. The
spatial allometric growth of the channel braiding and time series
association using the ARIMA model was examined on the twenty stretches
of the river. The results depict nonuniformity in planform development
with distance downstream during a 30-year time span (1990-2020). The
nature of the planform value distribution concerning all three applied
indices has projected a polynomial trend where certain intermediate
channel segments break the general trend of the braiding intensity
with downstream distance. Since the downstream braiding intensity of
the Jaldhaka River hasn't decreased either linearly or exponentially,
we were unable to find any significant relationship of it with surface
gradient. The nature and association of the channel braiding of the
Jaldhaka River point towards the influence of local controls (e.g. river
terracing on the upper part and faultline controls in the middle part)
on channel planform dynamicity. The prediction of channel braiding
for 2030 and 2050 coupled with the model fitted with RMSE, and BIC
bears great significance in revealing the future bar growth which may
be useful for the different planners and stakeholders concerned with
the river basin development.
Title: Reconstructing the cosmic ray energy spectrum with HiSPARC
Authors: van Dam, K.; van Eijk, B.; Steijger, J. J. M.
Bibcode: 2022APh...14302747V
Altcode:
The high school project on astrophysics research with cosmics (HiSPARC)
employs a large number of small detection stations that sample the
footprint of extensive cosmic ray air showers. The cosmic ray energy
spectrum between 1016 - 1019 eV is reconstructed
by combining data from multiple four-detector stations located at the
Amsterdam Science Park. The obtained cosmic ray flux values agree
well with data from other experiments. Also the value of the slope
(- 3 . 08 ± 0 . 02) matches the literature value. Additionally,
a new method is presented in which a single two-detector station is
used to probe the cosmic ray energy spectrum at a complementary energy
regime between 1012 - 1016 eV. The flux values
and its slope value (- 2 . 71 ± 0 . 07) are in good agreement with
literature data. However, numerous simplifying assumptions bring about
large systematic uncertainties which are not well quantified. The
possibility to reconstruct the cosmic ray energy spectrum augments
HiSPARC's primary goal, which is to engage high school students with
modern physics and let them contribute to real scientific research.
Title: Search for variability in the spectra cosmic ray protons
Authors: Loznikov, V. M.
Bibcode: 2022APh...14302757L
Altcode:
Search for global time variability in the energy spectra of cosmic rays
protons was carried out using data 6 experiments: CALET [1], DAMPE [2],
NUCLEON [3], CREAM-III [37], AMS-02 [35] (3 years of observation) and
AMS-02 [60] (7 years of observation). Approximation of all spectra (in
the energy range of ∼ 6 GeV - 300 TeV) was produced by an empirical
model describing experimental data as the sum of three power components:
constant background and two variables of the power components with
various cuts off on high energies. It turned out that the "soft"
power component has slope index αH≈3 and the cutting
energy of ∼ 200 GeV, and the "hard" power component has slope
index αL≈2.4, the cutting energy of ∼ 100 TeV. To
find the variability of spectra of cosmic rays all experiments were
compared in pairs. Reliable changes in spectral curves of different
experiments were not found. The causes of lack of reliable variability
are discussed. Nevertheless, it was found that the cutoff parameter of
"hard" spectral components of some experiments may differ by more than
5σ. Since the global variability of the spectra is not detected,
it makes sense to see how well our model describes the combined
pairs of spectra. It turned out that the parameters of the fits of
the combined spectra coincide with the accuracy to errors with the
parameters of the fits of individual spectra. The significance of the
differences between the average values of the power indexes of slope
"soft" and "hard" component of more than 28σ. Consequently, the
"soft" and "hard" components of the spectra of protons of CR really
exist. The "hard" cutoff parameter EL_cut of the fit of
the pair of experiments "AMS_(3y)+DAMPE" is significantly different
by 8.6σ from the corresponding cutoff parameter of the pairs of
experiments "AMS_(3y)+NUCLEON". In the experiments "AMS_(7y)+DAMPE"
and "AMS_(3y)+NUCLEON" parameter EL_cut reliably differ by
8.3σ. Consequently, the variability of the cutoff parameter of the
"hard" component is real. In addition, our estimates show that the
global variability of CR spectra (that is, the variability of the whole
spectral curve) for nuclei of elements with large Z can be detected. The
explanation of the difference in the fluxes of nuclei (C, O, Fe)
of cosmic rays found in the AMS and CALET experiments is proposed.
Title: High-amplitude water-level fluctuations at the end of the
Mediterranean Messinian Salinity Crisis: Implications for gypsum
formation, connectivity and global climate
Authors: Andreetto, F.; Flecker, R.; Aloisi, G.; Mancini, A. M.;
Guibourdenche, L.; de Villiers, S.; Krijgsman, W.
Bibcode: 2022E&PSL.59517767A
Altcode:
The formation and dissolution of salt giants impacts ocean chemistry on
thousand-million year timescales. Gypsum precipitation and weathering
changes the oceanic calcium concentration with implications for the
carbon cycle and global temperatures. However, the connectivity
of salt giants with the global ocean is necessarily restricted,
making the timing of Ca2+ extraction and return more
uncertain. Here we reconstruct the final phase of gypsum precipitation
of the Late Miocene Mediterranean Salt Giant using micropaleontology,
sedimentology and 87Sr/86Sr analyses on the most
complete record preserved at Eraclea Minoa on Sicily and explore its
implications for global climate. Precessional gypsum-marl couplets
(Upper Gypsum) characterize the last 200 kyrs (Stage 3) of the
Messinian Salinity Crisis (MSC; 5.97-5.332 Ma) in both intermediate
(500-1000 m) and deep (>1000 m) Mediterranean basins. The interbedded
selenitic gypsum layers contain well-preserved calcareous nannofossil
assemblages dominated by Reticulofenestra minuta, a marine species
which tolerates stressful conditions. Marine water is also required
to explain the gypsum 87Sr/86Sr data, which
describe a small range of ratios (0.708704-0.708813) lower than
coeval ocean water. Mass-balance calculations indicate that during
gypsum precipitation, the Atlantic made up ≤20% of a Mediterranean
("Lago-Mare") water mass dominated by low salinity discharge from
large river systems and Eastern Paratethys. This suggests episodic
extraction of calcium and sulfate ions from the ocean throughout MSC
Stage 3. The marls commonly contain shallow (30-100 m) brackish-water
ostracods of Paratethyan (Black Sea) origin. Marls with Paratethyan
ostracods are also found in both marginal (<500 m) and deep
Mediterranean settings. This indicates that marl-deposition was not
synchronous across the basin, but that it occurred in intermediate
and deep basins during base-level lowstands at insolation minima and
on the shallow Mediterranean margins during insolation maxima-driven
highstands. These high-amplitude base-level fluctuations exposed the
evaporites to weathering, but ponded the products in the Mediterranean
basin until reconnection occurred at the beginning of the Pliocene.
Title: Selection of time-dependent worst-case thermal environmental
conditions for Low Earth Orbit spacecrafts
Authors: González-Bárcena, David; Bermejo-Ballesteros, Juan;
Pérez-Grande, Isabel; Sanz-Andrés, Ángel
Bibcode: 2022AdSpR..70.1847G
Altcode:
When facing the thermal analysis of a Low Earth Orbit satellite,
selecting the worst-case orbit where the minimum and maximum
temperatures are reached is essential for ensuring the success of the
mission. Typical orbits have a non-constant Solar Beta Angle throughout
the year providing a wide range of orbits with different heat loads
and eclipses. It is possible to focus the analysis on a single orbit
configuration by a rough analysis using a simple model. In order to
achieve this, every potential orbit with their corresponding thermal
environmental parameters must be analysed based on real data. The
direct solar radiation, the albedo and the Earth Outgoing Longwave
Radiation (OLR) characterize the thermal environment to be taken into
account. However, their values have a wide variability which depend
on many parameters. Based on the characteristics of the orbit and the
system thermo-optical properties and characteristic time, it is possible
to obtain particularized profiles of albedo and OLR that would lead
the system to its maximum and minimum temperatures. The conventional
criteria, which is studied here in depth, provides two constant values
of albedo and OLR as the hot and cold worst-cases. This is suitable
for massive system or cases in which the characteristics times of the
system are high. For lighter elements or low characteristic times,
temperatures throughout the orbit deviate considerably from the real
behaviour. In contrast, the methodology here proposed provides a
time-dependant profile that allows for the determination of a system
temperature response closer to the real one, together with the potential
minimum and maximum temperatures of the orbit, in order to optimize
the design and avoid the oversizing.
Title: Source mechanism of the 2020 Mw 6.3 Nima earthquake derived
from Bayesian inversions with InSAR observations: Insight into E-W
extensional activity in the central Tibet
Authors: Hu, Xiaoping; He, Ping; Zhang, Jue
Bibcode: 2022AdSpR..70.1721H
Altcode:
Normal faults and conjugate strike-slip faults have been considered
to play an important role in response to the extension deformation of
central Tibet. On 22 July 2020, a Mw 6.3 earthquake struck the Nima
county, central Tibet, in China, which provides a rare opportunity to
get insights into how the normal faults in central Tibet accommodates
the east-west extension caused by the Indian-Eurasian convergence. In
this study, the Sentinel-1 images are collected to measure the
coseismic deformation associated with this 2020 event and image its slip
distribution. To mitigate the atmospheric phase effects, the generic
atmospheric correction online service (GACOS) model is used to correct
the coseismic inteferograms. The final coseismic deformation results
show mainly negative displacement with a maximum value of ∼ 30 cm
in the line of sight (LOS) direction. After that, a Bayesian inversion
method is used to invert the fault model. Our results reveal the optimal
seismogenic fault of this event with a strike angle of 31.3°, a dip
angle of 51.6°, and show that its slip distribution is dominated by
normal slip with a maximum value of 2.55 m at a depth of 4.79-9.53 km,
which suggest it's a blind normal rupture with high east-trending dip
angle. The total released geodetic moment is, equivalent to Mw 6.3. In
addition, we analyze the Coulomb stress change due to the 2008 Gaize
and this 2020 Nima events, suggesting the 2020 event should not be
triggered by the 2008 event. Finally, we estimate an interseismic
slip rate of 4.7 ± 1.2 mm/yr on the Yibug Caka-RigainPun Co (YCRC)
fault with published global navigation satellite system (GNSS)
measurements. Given that these high frequent normal slip events but
a low crustal extension rate of 4.7 ± 1.2 mm/yr in this region, we
speculate that the asthenosphere material upwelling should be also a
possible reason for E-W extensional activities in central Tibet.
Title: Post-obduction listwaenite genesis in the Oman Mountains
inferred from structural analysis and U-Pb carbonate dating
Authors: Scharf, Andreas; Bailey, Christopher M.; Bolhar, Robert;
Mattern, Frank; Ring, Uwe
Bibcode: 2022E&PSL.59517756S
Altcode:
Listwaenite, a distinctive rock formed by carbonation of peridotite,
is important for understanding carbon fluxes and storage in the
deep Earth. In northern Oman, this lithology occurs near/at the
base of the Semail Ophiolite and has been proposed to have formed
in the mantle wedge during Late Cretaceous obduction and ophiolite
emplacement. Listwaenite occurs as tabular sheets associated with
post-obductional extensional faults. Specifically, listwaenite formed
in (1) extensional duplexes bound by shallowly-dipping normal faults,
(2) moderately- to steeply-dipping extensional faults, and (3) layers
that overlie rocks of the metamorphic sole and unmetamorphosed platform
carbonates. Two dolomite veins cutting listwaenite yield near-identical
LA-ICP-MS U-Pb ages of 60.3 ± 15.4 and 55.1 ± 4.7 Ma (2 standard
error). Thus, listwaenite formed prior to or is coeval with the ∼60-55
Ma veins. One carbonate listwaenite sample yields a LA-ICP-MS U-Pb age
of 64.31 ± 6.28 Ma. Further six listwaenite samples yield imprecise
ages of ∼33-3 Ma. Thus, listwaenite is interpreted to have formed
during at least two post-obductional deformational events in the Oman
Mountains. Hydrothermal circulation of carbon-rich fluids along upper
crustal extensional faults facilitated listwaenite formation. Our
results indicate that listwaenite formed during post-obductional
extension, challenging models of listwaenite genesis in the mantle
wedge during obduction.
Title: Optimal satellite formation reconfiguration based on the
uncertainty and disturbance estimator
Authors: Chen, Aijun; Ren, Jiadong; Wang, Zhenhua; Shen, Yi
Bibcode: 2022AdSpR..70.2013C
Altcode:
This paper investigates the energy-optimal path generating and robust
trajectory tracking of satellite formation reconfiguration. First,
to minimize the energy consumption during formation reconfiguration,
the problem of finding optimal path and control profile is studied. This
problem is solved based on the linear Hill-Clohessy-Wiltshire equations
and optimal control theory. Second, considering the nonlinearities and
disturbances in the dynamics of satellite relative motion, a robust
control law based on an uncertainty and disturbance estimator is
designed. The primary advantage of this estimator is the relaxation of
the assumption on disturbances, and only frequency range is needed. The
asymptotic stability of the closed-loop system formed by a robust
feedback controller is analyzed. Finally, numerical simulation
results are presented to validate the feasibility of the proposed
reconfiguration trajectory optimization approach and control strategy.
Title: Precise point positioning with BDS-2 and BDS-3 constellations:
ambiguity resolution and positioning comparison
Authors: Hu, Jiahuan; Li, Pan; Zhang, Xiaohong; Bisnath, Sunil;
Pan, Lin
Bibcode: 2022AdSpR..70.1830H
Altcode:
The full operational capability of the Chinese BeiDou Satellite
Navigation System (BDS) has injected additional energy into the GNSS
field. Along with the visibility of more BDS satellites, as well as
the precise products generated by analysis centers, ambguity float and
fixed Precise Point Positioning (PPP) performance with the complete BDS
constellation are evaluated in this study. Inter-system biases (ISBs)
between BDS-2 and BDS-3 are first evaluated, and Fractional Cycle Bias
(FCB) with and without consideration of ISBs are assessed. Results
show that when considering ISBs, the standard deviations of ambiguity
residuals are smaller, thus the ISB parameter should be taken into
consideration in BDS PPP. BDS-3 FCBs are more stable than those of
BDS-2, at the same time, the ambiguity residuals are smaller for BDS-3
satellites. In terms of PPP performance, BDS-3 outperforms BDS-2 in
positioning accuracy, convergence time and time to first fix. For the
test data, the convergence time of BDS-2 static solution is 48.8 min,
while for BDS-2 + 3 it is 19.7 min, representing an improvement of 59.6%
when BDS-3 satellites are included. The positioning accuracy of static
BDS-2, BDS-3 and BDS-2 + 3 PPP can reach the same millimeter-level after
a long time of convergence, while kinematic solution with BDS-2 + 3 has
the highest accuracy compared to BDS-2 and BDS-3, which could reach 1.7,
1.3 and 4.3 cm in East, North and Up components, respectively, in fixed
solution. The performance of BDS PPP with the whole constellation is
comparable with that of GPS and Galileo, and the PPP performance is
promising with receiver updates for MGEX stations in the near future.
Title: Simulation of anoxic lenses as exporters of reactivity in
alluvial aquifer sediments
Authors: Babey, Tristan; Boye, Kristin; Tolar, Bradley; Engel, Maya;
Noël, Vincent; Perzan, Zach; Kumar, Naresh; Francis, Christopher A.;
Bargar, John R.; Maher, Kate
Bibcode: 2022GeCoA.334..119B
Altcode:
Sedimentary interfaces between contrasting hydrogeological facies in
alluvial aquifers drive the development of biogeochemical interfaces
that influence subsurface and surface water quality. Here, we
calibrate a reactive transport model on a series of dual-domain
column experiments, where centimeter-scale, low-permeability,
organic-rich anoxic lenses are embedded in coarser-grained aquifer
material. Simulations explicitly account for C, Fe, and S cycling at
the interface between the lenses and the aquifer in water-saturated
conditions. Our results highlight the role of fine-grained, organic-rich
inclusions not only as sources or sinks for redox-sensitive species,
but also as exporters of nutrients that stimulate downgradient
biogeochemical cycling. By releasing large amounts of organic carbon
into the surrounding aquifer, such lenses drive the development of
proximal secondary reduction zones ("halos"), characterized by high
microbial activity (e.g., sulfate reduction) and accumulation of reduced
reaction products (e.g., iron sulfide). If similar secondary reduction
zones develop within the hydraulically conductive domain of an aquifer,
they would be highly susceptible to changes in hydrologic conditions,
for instance oxygen pulses associated with seasonal snowmelt. Our
results also emphasize the limitations of relying solely on aqueous
species measurements to inform reactivity in systems where fast redox
cycling and/or sizeable particulate transport may limit the signature
of reactivity in the dissolved phase.
Title: How strongly do plumes influence Pacific seamount distribution?
Authors: Zhao, Yanghui; Riel, Bryan; Foulger, Gillian; Ding, Weiwei
Bibcode: 2022E&PSL.59517786Z
Altcode:
Seamounts are submarine volcanoes postulated to be formed either by hot
mantle plumes rising from the deep mantle or by shallow, plate-related
processes. However, the relative importance of these two mechanisms
has not hitherto been quantified. In this study, applying Gaussian
Process regression to reconstruct irregular seamount topography above
and under the sedimentary layer, we calculate an accurate map of
volcanism distribution within the Pacific plate. We find that previous
erupted volumes have been underestimated by 75% on average. Our results
show that (1) the total erupted volume postulated to be plume-related
makes up only 18% of total Pacific intraplate volcanism, and (2) the
volume statistics for plume-related seamounts and those along the Large
Low-Shear-Velocity Province margins are nearly indistinguishable from
the rest of the intraplate seamounts. We conclude that proposed plumes
account for only a minority of the volume of intraplate volcanism in
the Pacific plate, implying that shallow rather than deep processes
are dominant.
Title: Validation and calibration of models to estimate
photosynthetically active radiation considering different time scales
and sky conditions
Authors: de Blas, Marian; García-Rodríguez, Ana; García, Ignacio;
Torres, José Luis
Bibcode: 2022AdSpR..70.1737D
Altcode:
Photosynthetically Active Radiation (PAR) is a fundamental parameter for
developing plant productivity models. Nevertheless, instrumentation for
measuring PAR and to record it is scarce at conventional meteorological
stations. Several procedures have therefore been proposed for PAR
estimation. In this work, 21 previously published analytical models
that correlate PAR with easily available meteorological parameters are
collected. Although longer time scales were considered in the original
publications, a minute range was applied in this work to calibrate
the PAR models. In total, more than 10 million input records were
gathered from the SURFRAD station network from a 10-year long time
series with data frequencies recorded every 1 min. The models were
calibrated both globally, using data from all stations and locally,
with data from each station. After calibration, the models were
validated for minute, hourly and daily data, obtaining low fitting
errors at the different stations in all cases, both when using the
globally calibrated models and with the models calibrated for each
location. Although the PAR results in general improved for locally
calibrated models, the use of local models is not justified, since the
global models presented offered very satisfactory PAR results for the
different climatic conditions where the meteorological stations are
located. Thus, PAR estimation model should then be selected, solely
considering the meteorological variables available at the specific
location. When applying the globally calibrated models to input data
classified according to sky conditions (from clear to overcast), the
PAR models continued to perform satisfactorily, although the error
statistics of some models for overcast skies worsened.
Title: Effect of the UV dose on the formation of complex organic
molecules in astrophysical ices: irradiation of methanol ices at 20
K and 80 K
Authors: Tenelanda-Osorio, Laura I.; Bouquet, Alexis; Javelle, Thomas;
Mousis, Olivier; Duvernay, Fabrice; Danger, Grégoire
Bibcode: 2022MNRAS.515.5009T
Altcode: 2022MNRAS.tmp.2087T
Methanol is a ubiquitous complex organic molecule (COM) in the
interstellar medium, thought to be a precursor of larger COMs when it is
submitted to different energetic processes, that can trigger chemical
reactions in solid and gas phases. Using laboratory experiments,
we report the characterization of the evolution of photoproducts
generated by the UV irradiation of methanol ice at different UV
doses and temperatures (20 and 80 K). We used gas chromatography
coupled to mass spectrometry (GC-MS) to analyse the volatile organic
compounds (VOCs) recovered during the warming of the photoprocessed
methanol ice. We identified 21 molecules (with up to five carbon
atoms, including alcohols, aldehydes, ketones, ester, and ethers)
and followed their abundance as a function of the UV fluence and ice
temperatures. With increasing UV fluence, an increase in the production
of heavier COMs is observed, while species with 1 or 2 carbon atoms
are depleted or do not increase. Species within a same chemical
family show the same pattern of evolution, with heavier molecules
present in smaller quantities. Ketones and esters are the chemical
families that lead to more complex molecules and start forming at the
earliest stages of irradiation. Their formation pathways are driven by
radical recombinations with CO as the main building blocks. Aldehydes
are formed before their alcohol counterparts, implying they do not
form through alcohol dehydrogenation, but via radical recombination
around HCO. Ethers seem to be the precursors of a large set of COMs,
and alcohols present a steady profile throughout irradiation.
Title: Reworking subducted sediments in arc magmas and the isotopic
diversity of the continental crust: The case of the Ordovician
Famatinian crustal section, Argentina
Authors: Cornet, J.; Laurent, O.; Wotzlaw, J. -F.; Antonelli, M. A.;
Otamendi, J.; Bergantz, G. W.; Bachmann, O.
Bibcode: 2022E&PSL.59517706C
Altcode:
Since the onset of plate tectonics, continents have evolved
through a balance between crustal growth, reworking, and recycling
at convergent plate margins. The term "reworking" involves the
re-insertion of crustal material into pre-existing crustal volumes,
while crustal growth and recycling respectively represent gains from
and losses to the mantle. Reworking that occurs in the mantle wedge
("source" contamination from slab material) or within the upper plate
("path" contamination), will have contrasting effects on crustal
evolution. However, due to limited access to deep crustal and
mantle rocks, quantifying source vs. path contamination remains
challenging. Based on the 4-dimensional record of the fossil
(Ordovician) Famatinian continental arc (Argentina), we demonstrate
that source contamination plays a dominant role in imprinting mafic
to granitic rocks with crustal oxygen-hafnium (O-Hf) isotopic
compositions. We argue that source contamination at convergent
plate margins significantly increased the diversity of O-Hf isotopic
signatures of continents over geologic time. Our interpretation implies
that crustal evolution models attributing this isotopic diversity
dominantly to intra-crustal reworking may be over-simplistic and may
underestimate continental growth in the last 2.5 billion years.
Title: Agile rest-to-rest attitude maneuvering of spacecraft
using pyramid-type SGCMG based on iteratively recalculated optimal
trajectory
Authors: Saito, Ryo; Shoji, Yasuhiro; Satoh, Satoshi; Yamada, Katsuhiko
Bibcode: 2022AdSpR..70.1988S
Altcode:
This paper is concerned with the agile rest-to-rest attitude maneuvering
of spacecraft using pyramid-type single-gimbal control moment gyroscopes
(SGCMGs). In this method, the gimbal rate command to the SGCMGs is
determined by calculating the pair of optimal trajectories of the
attitude and the gimbal angles without any "steering law". Thus, the
proposed method does not suffer from the singularity problem causing
the increase in control error and settling time. Before maneuvering, the
pair of the initial optimal trajectories of the attitude and the gimbal
angles is calculated by the minimum-time problem. Then, to compensate
for errors in maneuvering caused by disturbances and/or modeling errors,
the trajectories of the attitude and the gimbal angles are recalculated
and updated frequently during the control. In this paper, optimization
problems for generating and updating the trajectories are formulated,
and specific control algorithms are provided. Finally, numerical
simulations and ground experiments with an air floating table are
performed to verify the feasibility and effectiveness of the proposed
control method. For the rest-to-rest attitude maneuver, the proposed
method can be adapted not only to the presence of modeling error in
the inertia tensor, but also to the failure of one or two CMGs in the
SGCMG system, without changing the control algorithm. These demonstrate
the high robustness and practicality of the proposed method.
Title: Insights into the subsurface structure of wrinkle ridges
on Mars
Authors: Karagoz, Oguzcan; Kenkmann, Thomas; Wulf, Gerwin
Bibcode: 2022E&PSL.59517759K
Altcode:
Wrinkle ridges are important landforms on Mars and other planetary
bodies and result from horizontal tectonic shortening. This study
provides insights into the subsurface of selected wrinkle ridge sites,
based on exposures provided by steep escarpments and crater slopes that
crosscut wrinkle ridges. We mapped the complex fold and fault patterns
and measured fault dips, where faults appear planar. The fault pattern
underneath wrinkle ridges is diverse and is dominated by reverse faults
and thrusts. The predominance of one fault system leads to morphological
asymmetries of many wrinkle ridges. The upper tip of the dominant thrust
fault is commonly situated beneath the steeper wrinkle ridge slope and
may outcrop at its base. Polarity changes of wrinkle ridges along strike
go along with a change of the dominant thrust direction. Symmetric
wrinkle ridges are formed when a conjugate system of thrusts exists
in the subsurface. Several wrinkle ridges display a main thrust
fault whose dip angle bends over to a shallower dip at depth. The
measurements of average dip for primary thrust and backthrust faults
are 37° ± 2° and 28 ± 2°, respectively. In general, most of the
examined wrinkle ridges are characterized by a multitude of subsidiary
and backthrust faults. With the limitation that the uppermost 500-1000
m of the wrinkle ridges subsurface are accessible in this study and
despite the large morphological and structural variability of wrinkle
ridges, the kinematics of fault-propagation folds models seem to
show a large match to our observations and measurements. Likewise,
continuum mechanics models show a good fit to the obtained structural
data. Fault-bend fold models and simple buckle folding models seem
less compatible with observations.
Title: Transverse aeolian ridges in the landing area of the Tianwen-1
Zhurong rover on Utopia Planitia, Mars
Authors: Gou, Sheng; Yue, Zongyu; Di, Kaichang; Zhao, Chenxu;
Bugiolacchi, Roberto; Xiao, Jing; Cai, Zhanchuan; Jin, Shuanggen
Bibcode: 2022E&PSL.59517764G
Altcode:
The enigmatic transverse aeolian ridges (TARs), with distinct morphology
and albedo, are among the key geological features investigated by
China's Tianwen-1 Zhurong rover on southern Utopia Planitia, Mars. Their
morphologies and morphometrics are investigated through high-resolution
imaging science experiment (HiRISE) orthoimage and Digital Terrain Model
(DTM) products. A total of 5089 TARs are identified, with barchan
TARs being predominant (97.6%). Morphometric analysis shows these
TARs to be small and symmetrical aeolian landforms, with an average
crest-ridge lengths of 33.9 ± 20.5 m, profile widths of 9.4 ± 3.8
m, profile heights of 0.4 ± 0.4 m, profile-height-width ratios of
0.04 ± 0.02, and profile symmetry ratios of -0.01 ± 0.13. In-situ
observations from the Navigation and Terrain Camera (NaTeCam) show
the crests of the TARs to be dark and sharp, while the flanks are
interlaced by dark and bright materials. Close-up Multispectral Camera
(MSCam) images reveal the TARs to be coated by granules of ∼1.5 mm
in diameter. Given the morphometric characteristics and the presence of
coating granules, the TARs in the landing area could be categorized as
megaripples. Buffered crater counting (BCC) technique-derived absolute
model age (AMA) reveals the formation time, or the last active period
of the TARs, could be as recent as 1 Ma in the Late Amazonian. The
morphometrics and direction of the horns of the barchan TARs suggest
the winds for the formation of TARs blew mostly from the north. During
the spring-summer transition period (Ls: 50°-93°), the Mars Climate
Station (MCS) had recorded local bimodal winds in the landing area,
with the speed of the northerly wind in the afternoon being a little
stronger than the speed of the southerly wind in the morning. These
observations are consistent with the wind fields described in the Mars
Climate Database (MCD), which imply the northerly winds during the
northern winter season to be responsible for the net sediment transport
to the south. Two TARs observed in-situ with secondary NW-SE trending
crest-ridges indicate that forked TARs might form given sufficient time
(i.e., in the order of millions of years) under modern wind conditions,
i.e., the TARs may be currently reworked, if only extremely weakly.
Title: New 40Ar/39Ar age of the full vector
Upper Mammoth geomagnetic polarity transition recorded in the Pu'u
Kualakauila volcanic sequence, Hawaii
Authors: Herrero-Bervera, Emilio; Jicha, Brian R.
Bibcode: 2022PEPI..33106915H
Altcode:
Paleomagnetic measurements, coupled with 40Ar/39Ar
dating, are improving our understanding of the geodynamo by providing
detailed terrestrial lava records of the short-term behavior of the
Earth's magnetic field. As part of an investigation of the Wai'anae
Volcano, Oahu, and the short-term behavior of the geomagnetic
field, we sampled a long volcanic section located on the volcano's
collapsed flank at a locality known as Pu'u Kaulakauila. Prior
paleomagnetic investigations of the Kamaile'unu Volcanic Series
(i.e. Herrero-Bervera and Coe, 1999, Herrero-Bervera and Valet,
1999, 2005) revealed transitional directions. The fresh lava flows,
easy access, and close geographical proximity to Ksbnd Ar dated flows
made this ~215-m thick sequence of flows an excellent candidate for
detailed paleomagnetic analysis. At least eight samples, collected from
each of 47 successive flow sites, were stepwise demagnetized by both
alternating field and thermal methods. Magnetostratigraphic results
indicate the existence of four excursions or aborted reversals occurring
at approximately ~36, ~75, ~130, and ~ 151 m above flow#1. The mean
directions of magnetization of the entire section sampled indicate a
reversed polarity, with ∼10 m of the section characterized by truly
excursional/Cryptochron directions (~7 lava flows). Paleointensity
(P.I.) determinations indicate a steady decreasing of the PI values
from 75 μ-T to ~12.2 μ-T reaching a minimum of 7.1 μ-T. These
very low PI values are within the transitional/excursional part of
the record. The corresponding VGPs are located on the western part
of Australia. 40Ar/39Ar incremental heating
experiments on groundmass from transitional flow sites at different
stratigraphic levels yield a weighted mean plateau age of 3.201 ±
0.041 Ma, which, combined with the overall reversed polarity and two
older polarity reversals, strongly suggests that the transitional
lavas correspond to the Upper Mammoth polarity transition.
Title: The influence of variable oxygen fugacity on the source depths
of lunar high-titanium ultramafic glasses
Authors: Guenther, Megan E.; Brown Krein, Stephanie M.; Grove,
Timothy L.
Bibcode: 2022GeCoA.334..217G
Altcode:
We present the results of high pressure, high temperature
multiple saturation experiments at variable oxygen fugacity
(fO2) conditions (IW+1.5 and IW-2.1) on three
lunar high titanium ultramafic glasses: the Apollo 17 Orange glass
(A17O, 9.1 wt% TiO2), the Apollo 15 Red glass (A15R,
13.8 wt% TiO2), and the Apollo 14 Black glass (A14B,
16.4 wt% TiO2). We performed experiments in graphite
(fO2 = IW+1.5) and iron (fO2
= IW-2.1) capsules. The experimentally determined multiple saturation
points (MSPs) in graphite capsules are 2.5 GPa and ∼1530 °C (A17O),
1.3 GPa and ∼1350 °C (A15R), and 1.55 GPa and ∼1425 °C (A14B). In
iron, we found MSPs of 3.3 GPa and ∼1565 °C (A17O), 2.8 GPa and
∼1490 °C (A15R), and 4.0 GPa and ∼1540 °C (A14B). These results,
when combined with previous experiments on the lunar ultramafic glasses,
indicate that the increase in the pressure of multiple saturation
is linearly proportional to the TiO2 content of the melt
(ΔMSP(GPa) = 0.14 × TiO2 (wt %) - 0.15 ,R2 =
0.93 , RMSE = 0.2 GPa where RMSE = root mean square error. Equation (1)
indicates that melt TiO2 is the most important influence on
ΔMSP . While Brown and Grove (2015) previously suggested a regression
which includes other compositional characteristics (Fe-Ti #) to explain
the relationship between melt composition and ΔMSP , we have shown
that some of the critical data points used in their regression were
inaccurate. Our revised relationship reveals that Fe and Mg in the
melt play a minor role compared to Ti. Additionally, when we calculate
the uncertainties on the olivine-melt KDFe-Mg,
we find that the decrease proposed by Krawczynski and Grove (2012)
in olivine-melt KDFe-Mg with decreasing
fO2 is not resolvable. Thus, Reaction (2) in
Brown and Grove (2015), which was put forth to explain this effect,
is no longer needed.</ce:para>However, the oxidation reduction
melt reaction described by Reaction (1) in Brown and Grove (2015) is
still relevant as it explains the influence of TiO2 under
different oxidation conditions. Under lower fO2
conditions, Ti4+ is reduced to Ti3+ and a melt
reaction occurs that causes the melt to become more olivine-normative,
which explains the expansion of the olivine stability to higher
pressures. Therefore, under reducing conditions, such as those
experienced in iron capsules, the more titanium that is present in
the melt, the more olivine-normative the melt becomes and the greater
the ΔMSP.</ce:para>
Title: Quick-response attitude takeover control using multiple
servicing spacecraft based on inertia properties identification
Authors: Fan, Shaoyan; Xing, Fei; Liu, Xinyuan; Chen, Xuedi; You, Zheng
Bibcode: 2022AdSpR..70.1890F
Altcode:
Multi-spacecraft is essential to on-orbit servicing (OOS) which leads
to spacecraft life prolongation thus reducing space debris. However,
the abrupt change of inertia parameters caused by the attachment
of each servicing spacecraft is a critical obstacle to the stable
and high-accuracy attitude takeover control of a target spacecraft
during the entire servicing process using multiple servicing
spacecraft. Therefore, a quick-response attitude takeover control
method based on inertia properties identification is proposed in
this paper. Combining the Euler dynamical equations of combined
spacecraft with space environment moment model, a novel iterative
identification equation integrating inertia matrix is established
to eliminate ill-conditioned identification and realize the precise
identification of inertia parameters using only single sampling data
for each update. With the quickly and precisely estimated inertia
parameters, a Lyapunov-based attitude controller and an optimal torque
allocation method are designed to actualize the high-accuracy and
globally stable attitude takeover control with the minimum energy
consumption. The proposed method can actualize the quick-response
and stable attitude takeover control with low computational cost,
even at the moment of attachment of servicing spacecraft. Hence, it
is greatly appropriate for the OOS missions with multiple servicing
spacecraft. The ground experiments and numerical simulations were
conducted for demonstrating the feasibility and effectiveness of the
proposed method. The experiment result indicated that the trajectory
tracking error could converge to ± 0.02 ° and ± 0.02 ° / s and
the parameters identification error was less than 5.5%.
Title: Corrigendum to "Mid-infrared spectroscopy of crystalline
plagioclase feldspar samples with various Al,Si order and implications
for remote sensing of Mercury and other terrestrial Solar System
objects" [Earth Planet. Sci. Lett. 544 (2021) 116697]
Authors: Reitze, Maximilian P.
Bibcode: 2022E&PSL.59517766R
Altcode:
The numbers in Table 2 of the original version of the article were
overly rounded. The correct values are listed below:
Title: GJ 3236: An active red-dwarf eclipsing binary system
Authors: Zhang, B.; Qian, S. -B.; Zhi, Q. -J.; Dong, A. -J.; Zhu,
L. -Y.
Bibcode: 2022NewA...9601831Z
Altcode:
GJ 3236 is a low-mass red-dwarf eclipsing binary (EB) with two M4V
components. In this paper, new photometric light curves (LCs) of
GJ 3236 are presented and analyzed by using the 2013 version of the
Wilson-Devinney (W-D) code. Our photometric solutions suggest that GJ
3236 is an active detached EB system with strong magnetic field. Since
2009, we have monitored this target more than 10 years and obtained
22 mid-eclipse times with high precision. By using the O-C method, we
revised its period as 0.7712562 days. According to Applegate mechanism,
the O-C diagram of GJ 3236 should show a quasi-periodic variation,
however, it does not now. Based on these, we thought that it is possible
evolved through the accretion of circumstellar matter. Besides,
both of components of GJ 3236 present a similar radius inflation,
which could be explained by the strong magnetic activity.
Title: Running of the spectral index and inflationary dynamics of
F(R) gravity
Authors: Odintsov, S. D.; Oikonomou, V. K.
Bibcode: 2022PhLB..83337353O
Altcode: 2022arXiv220606024O
In this work we shall provide a model-independent general calculation
of the running of the spectral index for vacuum F (R) gravities. We
shall exploit the functional form of the spectral index and of the
tensor-to-scalar ratio in order to present a general ns
- r relation for vacuum F (R) gravity theories. As we show,
viable F (R) gravity theories can be classified to two classes
of models regarding their prediction for the running spectral
index. The R2-attractor models predict a running of the
spectral index in the range -10-3 <as <
-10-4, which classifies them in the same universality
class that most inflationary scalar field models belong to. We
provide three models of this sort, for which we verify our claims in
detail. However there exist viable F (R) gravity models with running
of spectral index outside the range -10-3 <as
< -10-4 and in some cases it can be positive. We also
present an R2-corrected scalar field model, which also
predicts a running of the spectral index in the range -10-3
<as < -10-4. For all the cases we studied,
we found no evidence for the most phenomenologically interesting
scenario of having r <10-4 and a running as
< -10-3, which in principle could be realized.
Title: Criteria for energy conditions
Authors: Maeda, Hideki; Harada, Tomohiro
Bibcode: 2022CQGra..39s5002M
Altcode: 2022arXiv220512993M
In model building studies, it is important to check the energy
conditions for the corresponding energy-momentum tensor determined by
the gravitational field equations in order to single out physically
reasonable models. In this process, one often encounters a situation
where the energy-momentum tensor has one off-diagonal 'space-time'
component in the frame with an orthonormal basis in a given
spacetime. We derive useful criteria of energy-momentum tensors
for their Hawking-Ellis types and the standard energy conditions in
such situations. As demonstrations, we apply those criteria to four
different systems.
Title: Explaining mercury via a single giant impact is highly unlikely
Authors: Franco, P.; Izidoro, A.; Winter, O. C.; Torres, K. S.;
Amarante, A.
Bibcode: 2022MNRAS.515.5576F
Altcode: 2022arXiv220714774F; 2022MNRAS.tmp.2082F
The classical scenario of terrestrial planet formation is characterized
by a phase of giant impacts among Moon-to-Mars mass planetary
embryos. While the classic model and its adaptations have produced
adequate analogues of the outer three terrestrial planets, Mercury's
origin remains elusive. Mercury's high-core mass fraction compared to
the Earth's is particularly outstanding. Among collisional hypotheses,
this feature has been long interpreted as the outcome of an energetic
giant impact among two massive protoplanets. Here, we revisit the
classical scenario of terrestrial planet formation with focus on the
outcome of giant impacts. We have performed a large number of N-body
simulations considering different initial distributions of planetary
embryos and planetesimals. Our simulations tested the effects of
different giant planet configurations, from virtually circular to
very eccentric configurations. We compare the giant impacts produced
in our simulations with those that are more likely to account for the
formation of Mercury and the Moon according to smoothed hydrodynamic
simulations. Impact events that could lead to Moon's formation are
observed in all our simulations with up to ~20 per cent of all giant
impacts, consistent with the range of the expected Moon-forming event
conditions. On the other hand, Mercury-forming events via a single giant
impact are extremely rare, accounting for less than ~1 per cent of all
giant impacts. Our results suggest that producing Mercury as a remnant
of a single giant impact that strips out the mantle of a differentiated
planetary object with Earth-like iron-silicate ratio is challenging
and alternative scenarios may be required (e.g. multiple collisions).
Title: Multi-instrument observations of low-latitude topside plumes
after sunrise during the recovery phase of the 27-29 May 2017
magnetic storm
Authors: Lyu, Huijuan; Fang, Hanxian; Meng, Xing
Bibcode: 2022AdSpR..70.2081L
Altcode:
Based on a variety of observation instruments, we have comprehensively
analysed the rare topside fossil plumes after sunrise during the
recovery phase of the 27-29 May 2017 magnetic storm over Sanya. The
results showed that the irregularities leading to these topside
plumes on Sanya Very High Frequency (VHF) radar maps were not freshly
generated after sunrise, but were able to survive at even ∼02:30UT
(∼09:48LT). Different from the fresh equatorial plasma bubbles (EPBs)
near sunrise, the |Vd| of these plumes was very small and
the zonal drift was also unnoticeable. Although a plasma depletion
could be observed by Swarm A satellite near Sanya, it was too small
and no ionospheric scintillation or TEC fast fluctuation was caused by
it. Since the simultaneous disturbances were found under the F peak
over Sanya and the corresponding plumes at Fuke appeared later than
those at Sanya by ∼40 min, it was inferred that the irregularities
leading to these topside plumes were generated somewhere to the south
of Sanya, and then grew and reached higher altitudes and extended to
higher latitudes along the geomagnetic field lines. Combining the
theory of disturbance electric field during storm, it was inferred
that the eastward overshielding penetration electric field as well as
the uplift of F layer supported the formation and sustainment of the
irregularities leading to the topside plumes.
Title: High P-T experimental perspective on Cr isotopic fractionation
during planetary core formation
Authors: Yang, Bing; Xia, Jiuxing; Guo, Xuan; Ni, Huaiwei; Shahar,
Anat; Fei, Yingwei; Carlson, Richard W.; Qin, Liping
Bibcode: 2022E&PSL.59517701Y
Altcode:
Core formation may modify the stable isotopic signatures for both the
mantles and cores of differentiated planetary bodies. We performed
high P-T experiments with a piston-cylinder apparatus at 1 GPa and
1873-2073 K to determine the Cr isotopic fractionation factor during
metal-silicate segregation. Experimental results consistently indicate
that the metal phase is isotopically heavier than the coexisting
silicate phase, with Δ53Crmetal-silicate
up to 0.3‰ at the investigated experimental conditions. Oxygen
fugacity, silicate composition, and S content in the metal phase
do not have significant effects on the Cr isotopic fractionation
factor. By contrast, increasing Ni content in the metal increases the
Δ53Crmetal-silicate value, implying that the Ni
content of the core could influence planetary isotopic signatures. We
conclude that heavier Cr isotopes enter the core preferentially during
planetary core formation. The δ53Cr value of the terrestrial
mantle could be lowered by up to ∼0.02‰ by core formation, despite
that this is within current analytical uncertainty of chondritic
Cr isotopic composition. For smaller bodies such as the Moon, Mars,
and Vesta, the lower core formation temperatures could potentially
generate a resolvable core-mantle Cr isotopic fractionation. However,
the Moon's small core size would limit the change in the Cr isotopic
composition of the lunar mantle compared to chondritic. For Vesta
and Mars, core formation could lower the δ53Cr values
of their mantles by ∼0.01-0.02‰, which is trivial relative to
the analytical uncertainty. On the other hand, core formation could
increase the δ53Cr values of the cores of the parent
bodies of iron meteorites by up to ∼0.2‰ at 1873 K. Therefore,
the significantly heavy Cr isotopic composition (up to 2.85‰)
of iron meteorites cannot be explained by equilibrium fractionation
between the core and the mantle of the parent bodies of iron meteorites.
Title: Searching for buried craters on Mars based on gravity potential
field separation method
Authors: Liang, Feng; Yan, Jianguo; Zhao, Jiannan; Meng, Zhiguo;
Barriot, Jean-Pierre
Bibcode: 2022P&SS..22005532L
Altcode:
There are many buried craters on Mars invisible in imaging or
topographic data; however, the residual gravity anomaly separated
from the Mars Bouguer gravity anomaly by minimum curvature separation
method can reveal these buried craters. In our research, gravity
separation results exposed 39 residual gravity anomaly highs (RGAHs),
which may represent deeply buried impact craters with 300-500 km
diameter. The RGAHs are widely distributed across the surface of Mars,
but are especially concentrated in volcanic areas like Tharsis and
Elysium, which indicates that there might be more craters buried in
these regions. Older craters in volcanic regions were likely buried
by subsequent volcanism coming from surrounding volcanoes, so the
retention age of craters in all areas where RGAHs are located will be
older than reported in the existing research based on topographic data
alone. This study will help improve the chronological model of Mars.
Title: Subsurface weathering signatures in stream chemistry during
an intense storm
Authors: Golla, Jon K.; Bouchez, Julien; Kuessner, Marie L.; Rempe,
Daniella M.; Druhan, Jennifer L.
Bibcode: 2022E&PSL.59517773G
Altcode:
Long-term relationships between stream chemistry and discharge are
regulated by watershed subsurface structure and biogeochemical
functioning. The extent to which these mechanisms are expressed
and may be explored in the geochemical response of streams
during storm events remains an open question. Here, we monitor
an intense storm as it infiltrated an upland hillslope draining
into a small steep canyon stream that is typified by chemostatic
concentration-discharge relationships in rock-derived solutes. Our
approach couples a high-frequency record of stable lithium isotope
ratios (δ7Li) in the stream with novel sampling of rock
moisture within the hillslope. At peak discharge, lithium-sodium
ratios (Li/Na) increased from 0.58 μM/mM to 0.82 μM/mM and
δ7Li decreased from + 28.9 ± 0.1‰ to + 26.4 ± 0.4‰ in
the stream. Hillslope hydrologic monitoring reveals that the rainwater
infiltrated the subsurface, yet attenuated breakthrough of the heavily
depleted δD signal of this storm (as low as -86‰) only reached
the upper 3-4 meters of the vadose zone. These δD data show that the
storm water mixed with previously stored rock moisture and displaced
stored fluid to deeper depths, causing an observable rise in the water
table. Groundwater 87Sr/86Sr and δ7Li
demonstrate consistency in the fluid-rock interactions that occur
below the water table prior to and during the storm. In total, these
observations indicate that the transfer of fluid and generation of
solutes through the interior of the hillslope produce the variability
of Li/Na and δ7Li within the stream during the storm, and
support application of a previously established 1-D reactive transport
model framework developed for the evolution of lithium within the
hillslope to this extreme hydrologic event. Based on the model, both
Li/Na and δ7Li versus discharge relationships reflect an
overall shorter transit time of fluid through the interior of the
hillslope. These model results are consistent with our hydrologic
observations and indicate that Li from further upslope (where the
vadose zone becomes thicker) contributes to stream solute chemistry
at the height of the storm. We conclude that in this system, stream
lithium isotope signatures record the routing of water and generation
of solutes within the hillslope even during intense storm events.
Title: Non-Gaussianity constraints with anisotropic μ distortion
measurements from Planck
Authors: Rotti, Aditya; Ravenni, Andrea; Chluba, Jens
Bibcode: 2022MNRAS.515.5847R
Altcode: 2022MNRAS.tmp.2000R
Primordial non-Gaussianity can source μ-distortion anisotropies that
are correlated with the large-scale temperature and polarization
signals of the cosmic microwave background (CMB). A measurement of
μT and μE correlations can therefore be used to constrain it on
wavelengths of perturbations not directly probed by the standard CMB
anisotropies. We carry out a first rigorous search for μ-distortion
anisotropies with Planck data, applying the well-tested constrained ILC
component-separation method combined with the needlet framework. We
correlate the reconstructed μ map with the CMB anisotropies to
derive constraints on the amplitude fNL of the local
form bispectrum, specifically on the squeezed configurations with
effective wavenumbers $k_s \simeq {740}\, \mathrm{Mpc^{-1}}$ and $k_L
\simeq {0.05}\, \mathrm{Mpc^{-1}}$, improving previously estimated
constraints by more than an order of magnitude. This enhancement
is owing to the fact that we are able to use the full multipole
information by carefully controlling biases and systematic effects in
the analysis. We also for the first time incorporate constraints from
measurements of μE correlations, which further tighten the limits. A
combination of the derived Planck μT and μE power spectra yields
|fNL| ≲ 6800 (95 per cent c.l.) on this highly squeezed
bispectrum. This is only ≃3 times weaker than the anticipated
constraint from Litebird. Furthermore we show that a combination of
Litebird with Planck can improve the expected future constraint by
${\simeq}20{{\%}}$. These limits can be used to constrain multifield
inflation models and primordial black hole formation scenarios, thus
providing a promising novel avenue forward in CMB cosmology.
Title: Design of a set of habitat units and the corresponding
surrounding cluster for long-term scientific missions in the
pre-terraforming era on Mars
Authors: Amini, Kasra; Moradi, Mojgan; Teymoori, Peyman Ebadi Belfeh;
Vossoughi, Bahareh; Janabadi, Ehsan Dehghani; Fayaz, Rima
Bibcode: 2022Icar..38515119A
Altcode:
We are living in a point in the history of science and technology,
where space travel for research and settlement is inevitable. As the
utmost crucial technology pieces for leaving Earth and travelling
into the cosmos is being established one after another, it is just
a matter of decades, until it all gets integrated together, solving
the engineering problems ahead of the way and being able to step on
the planets and moons of the solar system. In this quest, as has
been the case for most of the technological advancements so far,
there ought to be mind experiments, in which one skips one step,
assumes the availability of responses to the skipped-over step, and
searches for the solution to the questions of the next level. This way,
by getting passed the first, i.e. current step, the solution to the
next one is already available. The current manuscript is addressing
this very 'next step', on the long path to eventually colonize Mars
and inhabit it for long-term research-based missions; let it be for
terraforming, or other agenda to be defined by the research strategists,
then. And as mentioned earlier, the current step; being setting foot
on Mars, is well-deservedly taken for granted, as is to come forth
undoubtedly. Having that realized, we might find ourselves faced by
the engineering complexities of surviving and thriving on Mars, which
is the subject matter of the current research, from the aspect point
of space technological and architectural design. The design procedure
beginning from setting the philosophy of design upon the concerns
of sustaining in the hostile environment of Mars, to the stepwise
emergence of the final design of a cluster of Martian Habitat Units
(MHUs) considering the high-criteria of the case, is the subject matter
covered in this manuscript.
Title: An analytical initial orbit determination method using two
observations from a bistatic radar
Authors: Qu, Jinye; Fu, Tuo; Chen, Defeng; Cao, Huawei; Zhang, Shuo
Bibcode: 2022AdSpR..70.1949Q
Altcode:
An analytical initial orbit determination (IOD) method using two
observations from a bistatic radar is proposed. Each observation
contains bistatic range and the doppler frequency shift, azimuth
angle and elevation angle. This problem arises from the challenging
catalogue process for small space debris, which features sparse
radar observations. By incorporating doppler measurements into the
original Lambert's IOD problem which uses two position vectors and
can only be solved iteratively, we show that an analytical solution
can be obtained. The specific angular momentum conservation equation
and the specific mechanical energy equation are used as kinematic
constraints. An ad hoc coordinate system is proposed to derive the
solution. The geometric dilution of precision (GDOP) metric is analysed
to express the IOD accuracy using a linearization method. Simulations
are carried out to demonstrate the performance of the proposed method.
Title: Spectral unmixing analysis for the lunar surface mineralogy
using Chandrayaan-2 IIRS imagery
Authors: Ahmad, Touseef; Chakraborty, Tathagata; Lyngdoh, Rosly B.;
Bhattacharya, Satadru; Misra, Arundhati
Bibcode: 2022P&SS..22005537A
Altcode:
Hyperspectral imagery (HSI) in the visible to near-infrared
wavelength region has a high potential for deciphering mineral
compositions of terrestrial and planetary surfaces. Thus, ISRO's
Imaging Infrared Spectrometer (IIRS) sensor onboard Chandrayaan-2
(Ch-2) orbiter provides an opportunity to utilise the hyperspectral
observations to characterise the lunar surface minerals and composition
significantly. Hence, a sensitivity study of hyperspectral observations
of the IIRS sensor was carried out for the detection and mapping of
various lunar minerals using spectral unmixing analysis. A common
region within the hyperspectral image obtained from Chandrayaan-1's
(Ch-1) Moon Mineralogy Mapper (M3) sensor and Ch-2 IIRS sensor has
been identified in the South-East of the Taurus-Littrow valley nearby
Gardner crater for comparison and validation purposes. Ch-2 IIRS is
an advanced hyperspectral imaging spectrometer capable of collecting
spectra over a wider spectral range (800 nm - 5000 nm) with high
spatial (~80 m) and spectral resolution (20 nm - 25 nm). To examine
spectral unmixing analysis, an electromagnetic range (800 nm - 2500 nm)
in the near-infrared region was chosen for the Ch-2 IIRS sensor. An
L1 - norm based denoising algorithm is used for mixed noise
removal from both the IIRS and M3 reflectance datasets. Endmember
extraction and fractional abundance estimation are carried out using
the N-Findr algorithm and the fully-constrained least square method,
respectively. Our results reveal different minerals such as high-calcium
pyroxene (Clinopyroxene), low-calcium pyroxene (Orthopyroxene),
and regolith surface (matured and younger). The results obtained
from the IIRS and M3 observations are in strong agreement. Hence,
the hyperspectral observations made by the IIRS sensor are extremely
effective for describing the mineral and chemical compositions of the
lunar surface.
Title: Singlet extensions and W boson mass in light of the CDF
II result
Authors: Sakurai, Kodai; Takahashi, Fuminobu; Yin, Wen
Bibcode: 2022PhLB..83337324S
Altcode: 2022arXiv220404770S
Recently, the CDF collaboration has reported the precise measurement
of the W boson mass, MW = 80433.5 ± 9.4 MeV , based on
8.8 fb-1 of √{ s } = 1.96 TeV p p bar collision data
from the CDF II detector at the Fermilab Tevatron. This is about 7σ
away from the Standard Model prediction, MWSM
= 80357 ± 6 MeV . Such a large discrepancy may be partially due to
exotic particles that radiatively alter the relation between the W and
Z boson masses. In this Letter, we study singlet extensions of the
Standard Model focusing on the shift of the W boson mass since they
are accidentally flavor and CP safe without changing the Standard Model
structure. In the minimal extension with a real singlet field, using the
bounds from the electroweak oblique parameters, B meson decays, LEP,
and LHC, we find that the W boson mass shift is at most a few MeV,
and therefore it does not alleviate the tension between the CDF II
result and the SM prediction. We then examine how much various bounds
are relaxed when the singlet is allowed to decay invisibly, and find
that the increase of the W boson mass does not exceed 5 MeV due to the
bound from the Higgs signal strength. We also discuss phenomenological
and cosmological implications of the singlet extensions such as the muon
g - 2 anomaly, axion/hidden photon dark matter, and self-interacting
dark radiation as a possible alleviation of the Hubble tension.
Title: Fundamental physics with a state-of-the-art optical clock
in space
Authors: Derevianko, Andrei; Gibble, Kurt; Hollberg, Leo; Newbury,
Nathan R.; Oates, Chris; Safronova, Marianna S.; Sinclair, Laura C.;
Yu, Nan
Bibcode: 2022QS&T....7d4002D
Altcode: 2021arXiv211210817D
Recent advances in optical atomic clocks and optical time transfer
have enabled new possibilities in precision metrology for both tests
of fundamental physics and timing applications. Here we describe a
space mission concept that would place a state-of-the-art optical
atomic clock in an eccentric orbit around Earth. A high stability
laser link would connect the relative time, range, and velocity of the
orbiting spacecraft to earthbound stations. The primary goal for this
mission would be to test the gravitational redshift, a classical test
of general relativity, with a sensitivity 30 000 times beyond current
limits. Additional science objectives include other tests of relativity,
enhanced searches for dark matter and drifts in fundamental constants,
and establishing a high accuracy international time/geodesic reference.
Title: Lithospheric strength and stress revisited: Pruning the
Christmas tree
Authors: Ellis, Susan; Wang, Kelin
Bibcode: 2022E&PSL.59517771E
Altcode:
Whether lithospheric stress can reach the maximum level predicted by
the Christmas-tree strength envelope is a fundamental question but with
controversial answers. There is little controversy that a deforming
lithosphere in high heat flow regions is likely critically stressed,
i.e., at full yield at all depths, as described by the envelope. But
different conceptual frameworks offer opposite views for very cold
lithosphere, either at full yield or far below yield. Here, we
use simple numerical models to investigate stresses in end-member
cold cratonic lithosphere (e.g., Canadian Craton) in comparison
with end-member warm plate-boundary lithosphere (e.g., Canadian
Cordillera). The two key elements of our modelling are (1) that
lithospheric stress builds up elastically with horizontal tectonic
loading not only in the elastic-frictional brittle regime but also
in the viscoelastic ductile regime, and (2) that the stress level is
limited by the available tectonic force. In a cratonic lithosphere, the
limiting tectonic force is sustained by competent rock material over
a large depth range, represented by the competent thickness Tc that
exceeds 90 km. The lithosphere undergoes mostly elastic deformation
at a stress level of a few tens of MPa. While weakly stressed strong
lithosphere can still produce limited earthquakes at shallow depths
due to structural and stress heterogeneity, the lithospheric stress
under horizontal tectonic loading is theoretically predicted to
be orders of magnitude lower than predicted by the Christmas-tree
envelope. Stresses in a real lithosphere may substantially deviate
from this theoretical level because of spatiotemporal variations
in rheology and structure. For example, the stress memory of past
loading history in cold lithosphere may or may not be erased by more
recent tectonic stresses. Because much of previous scientific debates
on lithospheric stress levels and comparison with seismicity were
focused on topographically induced flexural stress, we also investigate
the effect of vertical loading. We show that the effective elastic
thickness Te derived from the flexural response is a reasonable proxy
for Tc derived from horizontal tectonic loading; a very large Te such
as > 80 km is generally associated with very low tectonic stress
far below yield. However, the flexure-induced bending stress is not
directly comparable with seismicity because it may either enhance or
suppress seismogenic stress in the crust.
Title: Towards an error-free 3-D memory for space applications
Authors: Garcia-Herrero, Francisco; Sánchez-Macián, Alfonso; Maestro,
Juan Antonio
Bibcode: 2022AdSpR..70.1917G
Altcode:
Three-dimensional memory devices solve the problem of limited storage
capacity on space missions, where the generation of data increases with
each launch. Unfortunately, with the actual state-of-the-art it is
necessary to protect these memory dies by applying specific designs
or ad hoc manufacturing techniques. Following these approaches,
it is not possible to use Commercial-Off-The-Shelf solutions based
on technology such as HBM2 or HMC, which increase excessively the
budget. This work defines an external solution compatible with legacy
and new technologies that exploits efficient Reed-Solomon architectures
and hardwired bits to reduce the failures-in-time rate to zero under
standard conditions (between five and two orders of magnitude compared
to the existing solutions) and increases the number of scenarios
in which the information can be recovered. All the features can be
achieved keeping the same throughput as the unprotected memory dices
and at a cost of 77% more area and an increase of 33% in parity.
Title: Characterising potential space suit textiles in proton beams
using radiotherapy-based dosimetry
Authors: Kuess, Peter; Sejkora, Nina; Klampfer, Anna; Madlener, Sarah;
Weiss, Peter; Schmied, Sibylle; Georg, Dietmar; Özdemir-Fritz, Seda;
Grömer, Gernot; Hirtl, Albert
Bibcode: 2022AdSpR..70.1925K
Altcode:
Four multi-layer textile samples for potential use in space suits,
developed within the Planetary Exploration Textiles project of the
European Space Agency, were exposed to a low energy proton beam,
to characterise their effect on dose deposition in astronauts. Each
textile stack contained all required layers for a potential space
suit component. The influence of the textiles on proton beams was
investigated using dosimetric equipment as utilised for medical
purposes. The experiments were conducted at the synchrotron-based
therapy and research centre MedAustron, Austria. To quantify the
radiation characteristics, the water equivalent thickness of the
fabrics was determined. A PEAKFINDER system (PTW, Freiburg, Germany)
was positioned downstream of the textiles and the positions of the Bragg
peaks were measured and compared to the range without any material in
front. As reference values aluminium and lead plates were used and the
results of the textiles were normalised to these materials. Furthermore,
proton threshold energies for stopping protons in the suit materials
were calculated. The position of the Bragg peak was shifted between
1.2mm to 2.6mm depending on the textile stacks. This corresponds
to a proton threshold energy for the investigated stacks between
10-15MeV. The study showed that methods used in particle therapy are
appropriate tools to quantify characteristics of space suit materials
in proton beams. However, the effect of the investigated textiles on
proton beams was comparable among the used fabrics.
Title: Electromagnetic vortex beam dynamics in degenerate
electron-positron astrophysical plasmas
Authors: Berezhiani, V. I.; Osmanov, Z. N.; Mikeladze, S. V.
Bibcode: 2022PhLA..44828323B
Altcode: 2021arXiv211100589B
For degenerate astrophysical electron-positron plasmas we have
considered dynamics of electromagnetic beams carrying angular
momentum. It is found for arbitrary level of degeneracy such a beam
having the power exceeding a certain critical value breaks up into
many filaments, eventually leading to the formation of stable spatial
solitons keeping zero field in the centre of the structure.
Title: Crustal anisotropy beneath southeastern Tibet inferred from
directional dependence of receiver functions
Authors: Tiwari, Ashwani Kant; Singh, Arun; Saikia, Dipankar; Singh,
Chandrani; Eken, Tuna
Bibcode: 2022PEPI..33106912T
Altcode:
The present study reveals depth-dependent crustal anisotropic signatures
beneath southeastern Tibet. It is used to characterize the rheology
of major faults and shear zones, which is important for understanding
crustal deformation and geodynamic processes beneath the study area. The
depth-dependent anisotropic orientations have been investigated based on
the directional dependence of radial and tangential receiver functions
(RFs). To achieve our objective, we first computed 3683 good-quality
P-RFs from 174 teleseismic earthquakes (M ≥ 5.5) recorded within
epicentral distance range of 30∘ to 90∘ at 70
seismic stations of the Eastern Syntaxis experiment (XE Network). After
that, we employed the harmonic decomposition technique at each seismic
station to retrieve the first (k = 0), second (k = 1) and third (k =
2) degree harmonics from the RF dataset. Our study characterizes the
type (horizontal or plunging) of the symmetry axis. The anisotropic
axes of the upper crust (0-20 km) appear to vary from approximately
N-S to NE-SW. They are usually orthogonal to orientations of
major faults and suture zones in the region, implying the effect of
structure-induced anisotropy. It can be explained by regularly oriented
cracks or macroscopic structure alignment along the major faults. The
anisotropic orientations of the middle crust (20-40 km) are NE-SW to
E-W direction, reflecting a different pattern than those estimated
in the upper crust. The lower crustal (40-70 km) anisotropic pattern
(E-W or ESE-WNW direction) exhibits distinct orientations than the
upper and middle crust. The crystal preferred orientations (CPO)
of the mica and amphibole minerals are likely to cause anisotropy
observed at mid-to-lower crustal depth ranges, emphasizing the role of
ductile deformation due to material movement towards the east underneath
southeastern Tibet. Our results, along with S(K)KS and direct S-waves
splitting signatures, suggest mid-to-lower crust and lithospheric
mantle material movement towards the east, while the discrepancies
in anisotropic symmetric axes directions may be indicative for the
partial coupling between the crust and upper mantle beneath the region.
Title: Shear Measurement with Poorly Resolved Images
Authors: Zhang, Jun; Liu, Cong; Vaquero, Pedro Alonso; Li, Hekun;
Wang, Haoran; Shen, Zhi; Dong, Fuyu
Bibcode: 2022AJ....164..128Z
Altcode: 2022arXiv220602434Z
Weak lensing studies typically require excellent seeing conditions for
the purpose of maximizing the number density of well-resolved galaxy
images. It is interesting to ask to what extent the seeing size limits
the usefulness of the astronomical images in weak lensing. In this
work, we study this issue with the data of the DECam Legacy Survey,
which is a part of the target selection program for the Dark Energy
Spectroscopic Instrument. Using the Fourier_Quad shear measurement
pipeline, we demonstrate that images with relatively poor seeing
conditions (~1.″5) can still yield accurate shear estimators. We
do not find any correlation between systematic shear error and the
image resolution.
Title: J-PLUS: a catalogue of globular cluster candidates around
the M 81/M 82/NGC 3077 triplet of galaxies
Authors: Chies-Santos, Ana L.; de Souza, Rafael S.; Caso, Juan P.;
Ennis, Ana I.; de Souza, Camila P. E.; Barbosa, Renan S.; Chen, Peng;
Javier Cenarro, A.; Ederoclite, Alessandro; Cristóbal-Hornillos,
David; Hernández-Monteagudo, Carlos; López-Sanjuan, Carlos;
Marín-Franch, Antonio; Moles, Mariano; Varela, Jesús; Vázquez
Ramió, Héctor; Dupke, Renato; Sodré, Laerte; Angulo, Raul E.
Bibcode: 2022MNRAS.516.1320C
Altcode: 2022arXiv220211472C
Globular clusters (GCs) are proxies of the formation assemblies of
their host galaxies. However, few studies exist targeting GC systems
of spiral galaxies up to several effective radii. Through 12-band
Javalambre Photometric Local Universe Survey (J-PLUS) imaging, we study
the point sources around the M 81/M 82/NGC 3077 triplet in search of new
GC candidates. We develop a tailored classification scheme to search for
GC candidates based on their similarity to known GCs via a principal
component analysis projection. Our method accounts for missing data
and photometric errors. We report 642 new GC candidates in a region
of 3.5 deg2 around the triplet, ranked according to their
Gaia astrometric proper motions when available. We find tantalizing
evidence for an overdensity of GC candidate sources forming a bridge
connecting M 81 and M 82. Finally, the spatial distribution of the GC
candidates (g - i) colours is consistent with halo/intra-cluster GCs,
i.e. it gets bluer as they get further from the closest galaxy in the
field. We further employ a regression-tree-based model to estimate the
metallicity distribution of the GC candidates based on their J-PLUS
bands. The metallicity distribution of the sample candidates is broad
and displays a bump towards the metal-rich end. Our list increases
the population of GC candidates around the triplet by threefold,
stresses the usefulness of multiband surveys in finding these objects,
and provides a testbed for further studies analysing their spatial
distribution around nearby (spirals) galaxies.
Title: A Novel Survey for Young Substellar Objects with the W-band
Filter. V. IC 348 and Barnard 5 in the Perseus Cloud
Authors: Lalchand, Bhavana; Chen, Wen-Ping; Biller, Beth A.; Albert,
Loïc; Allers, Katelyn; Dubber, Sophie; Zhang, Zhoujian; Liu, Michael
C.; Jose, Jessy; Damian, Belinda; Sharma, Tanvi; Bonnefoy, Mickaël;
Oasa, Yumiko
Bibcode: 2022AJ....164..125L
Altcode: 2022arXiv220808637L
We report the discovery of substellar objects in the young star cluster
IC 348 and the neighboring Barnard 5 dark cloud, both at the eastern
end of the Perseus star-forming complex. The substellar candidates
are selected using narrowband imaging, i.e., on and off photometric
technique with a filter centered around the water absorption feature at
1.45 μm, a technique proven to be efficient in detecting water-bearing
substellar objects. Our spectroscopic observations confirm three
brown dwarfs in IC 348. In addition, the source WBIS 03492858+3258064,
reported in this work, is the first confirmed brown dwarf discovered
toward Barnard 5. Together with the young stellar population selected
via near- and mid-infrared colors using the Two Micron All Sky Survey
and the Wide-field Infrared Survey Explorer, we diagnose the relation
between stellar versus substellar objects with the associated molecular
clouds. Analyzed by Gaia EDR3 parallaxes and kinematics of the cloud
members across the Perseus region, we propose the star formation
scenario of the complex under influence of the nearby OB association.
Title: White Dwarf Binaries across the H-R Diagram
Authors: Anguiano, Borja; Majewski, Steven R.; Stassun, Keivan G.;
Badenes, Carles; Daher, Christine Mazzola; Dixon, Don; Allende Prieto,
Carlos; Schneider, Donald P.; Price-Whelan, Adrian M.; Beaton,
Rachael L.
Bibcode: 2022AJ....164..126A
Altcode: 2022arXiv220713992A
We created the APOGEE-GALEX-Gaia catalog to study white dwarf (WD)
binaries. This database aims to create a minimally biased sample
of WD binary systems identified from a combination of GALEX, Gaia,
and APOGEE data to increase the number of WD binaries with orbital
parameters and chemical compositions. We identify 3414 sources as WD
binary candidates, with nondegenerate companions of spectral types
between F and M, including main-sequence stars, main-sequence binaries,
subgiants, sub-subgiants, red giants, and red clump stars. Among our
findings are (a) a total of 1806 systems having inferred WD radii R
< 25 R ⊕, which constitute a more reliable group of
WD binary candidates within the main sample; (b) a difference in the
metallicity distribution function between WD binary candidates and the
control sample of most luminous giants (M H < -3.0);
(c) the existence of a population of sub-subgiants with WD companions;
(d) evidence for shorter periods in binaries that contain WDs compared
to those that do not, as shown by the cumulative distributions of APOGEE
radial velocity shifts; (e) evidence for systemic orbital evolution in a
sample of 252 WD binaries with orbital periods, based on differences in
the period distribution between systems with red clump, main-sequence
binary, and sub-subgiant companions and systems with main-sequence or
red giant companions; and (f) evidence for chemical enrichment during
common envelope (CE) evolution, shown by lower metallicities in wide
WD binary candidates (P > 100 days) compared to post-CE (P <
100 days) WD binary candidates.
Title: Spectral and timing analysis of Be/X-ray binary EXO 2030+375
during its giant 2021 outburst
Authors: Tamang, Ruchi; Ghising, Manoj; Tobrej, Mohammed; Rai, Binay;
Paul, Bikash Chandra
Bibcode: 2022MNRAS.515.5407T
Altcode: 2022MNRAS.tmp.2081T
We report the X-ray spectral and timing analysis of the high mass
X-ray binary EXO 2030+375 during the 2021 type II outburst. We have
incorporated NuSTAR, NICER, Swift/BAT, and Fermi/GBM observations to
carry out a comprehensive analysis of the source. Pulse profiles in
different energy ranges and time intervals have been generated and
analysed. We have performed a brief comparison of the observations
amidst the peak outburst condition and also during the decaying state
of the outburst. Pulse profiles are found to evolve with time and
energy. An iron emission line at (6-7) keV is observed in the X-ray
continuum. Distinct absorption features were observed in the spectra
corresponding to the peak outburst state while such features were
not detected during the later decaying phase of the outburst. We have
estimated the characteristic spin-up time-scale to be ∽ 60 yr. The
continuum flux of the system and the varying luminosities covering the
entire outburst period have been used to interpret the characteristics
of the source. We have summarized the variability of various parameters
along with their underlying physical implications.
Title: Dynamics of dusty vortices - II. Stability of 2D dust-laden
vortices
Authors: Lovascio, Francesco; Paardekooper, Sijme-Jan; McNally, Colin
Bibcode: 2022MNRAS.516.1635L
Altcode: 2022MNRAS.tmp.2187L; 2022arXiv220903140L
Vortices have long been speculated to play a role in planet formation,
via the collection of dust in the pressure maxima that arise at the
cores of vortices in protoplanetary discs (PPDs). The question remains,
however: as dust collects in the core of a vortex, when does that
vortex remain stable and able to collect further dust, and when and
why does it break up? We study this question by running high-resolution
2D simulations of dust-laden vortices. By using the terminal velocity
approximation in a local shearing box, it was possible to efficiently
run simulations of back-reacting dust in a gas at high resolution. Our
results show how the stability of 2D dust-laden vortices in PPDs depends
on their size relative to the disc scale height, as well as the dust
coupling. We find small vortices with semiminor axis much smaller than
the scale height to be stable for the duration of the simulations
(t > 2000 orbits). Larger vortices, with semiminor axis smaller
than but of the order of scale height, exhibit a drag instability
after undergoing a long period of contraction where the core becomes
progressively more dust rich. The lifetime of these vortices depends
on the dust size, with larger dust grains causing the instability to
occur sooner. For the size ranges tested in this paper, micrometre-
to millimetre-sized grains, vortices survived for several hundreds of
orbits. The result implies that the stability of vortices formed by
vertical shear instability and zombie vortex instability, or the breakup
of larger vortices through hydrodynamic instabilities, is affected by
the presence of dust in the disc. The lifetimes observed in this paper,
while shortened by the presence of dust for larger vortices, were still
long enough to lead to considerable dust enrichment in the vortex cores.
Title: THE THREE HUNDRED: cluster dynamical states and relaxation
period
Authors: Zhang, Bowei; Cui, Weiguang; Wang, Yuhuan; Dave, Romeel;
De Petris, Marco
Bibcode: 2022MNRAS.516...26Z
Altcode: 2022MNRAS.tmp.2046Z; 2021arXiv211201909Z
We introduce a new parameter λDS to quantify the dynamical
state of galaxy clusters and test it using simulations from THE
THREE HUNDRED cluster zoom suite. λDS is a combination of
three previously used dynamical state measures, namely virial ratio,
centre of mass offset, and substructure mass fraction, crafted to
assume a double-Gaussian distribution, thereby yielding a natural
division between relaxed and unrelaxed clusters where the Gaussians
cross. Using dark matter-only simulations, we identify the optimal
separator to be λDS = 3.424. We test this same criterion on
two sets of fully hydrodynamical THE THREE HUNDRED runs (GADGET-X and
GIZMO-SIMBA), and find only a weak dependence on the input baryonic
physics. We correlate the evolution of λDS with the mass
accretion history and find that halo mass changes of $\frac{\Delta
M_{200}}{M_{200}} \lesssim 0.12$ do not typically alter the dynamical
state. We examine the relaxation period, defined as the time taken to
return to relaxation after becoming disturbed, and find a correlation
between this relaxation period and the strength of halo mass change
$\frac{\Delta M_{200}}{M_{200}}$. By fitting this correlation, we
show that the relaxation period can be estimated from $\frac{\Delta
M_{200}}{M_{200}}$ (even for multiple mass accretion events) with
good accuracy.
Title: Rapid source classification and distance estimation for
compact binary mergers with PyCBC live
Authors: Villa-Ortega, Verónica; Dent, Thomas; Curiel Barroso, Andrés
Bibcode: 2022MNRAS.515.5718V
Altcode: 2022MNRAS.tmp.2017V
During the third observing run (O3) of the advanced LIGO and advanced
virgo detectors, dozens of candidate gravitational-wave (GW) events
have been catalogued. A challenge of this observing run has been
the rapid identification and public dissemination of compact binary
coalescence (CBC) signals, a task carried out by low-latency searches
such as PyCBC Live. During the later part of O3, we developed a method
of classifying CBC sources via their probabilities of containing
neutron star or black hole components within PyCBC Live in order to
facilitate immediate follow-up observations by electromagnetic and
neutrino observatories. This fast classification uses the chirp mass
recovered by the search as input given the difficulty of measuring the
mass ratio with high accuracy for lower mass binaries. We also use a
distance estimate derived from the search output to correct for the
bias in chirp mass due to the cosmological redshift. We present results
for simulated signals, and for confirmed candidate events identified
in low latency over O3.
Title: Possible non-thermal origin of the hard X-ray emission in
the merging galaxy cluster SPT-CL J2031-4037
Authors: Mirakhor, M. S.; Walker, S. A.; Runge, J.; Diwanji, P.
Bibcode: 2022MNRAS.516.1855M
Altcode: 2022arXiv220809553M
Non-thermal emission from clusters of galaxies at the high-energy
X-ray regime has been searched with various instruments, but the
detection significance of this emission has yet been found to be
either marginal or controversial. Taking advantage of NuSTAR's
unique capability to focus X-rays in the hard energy band, we
present a detailed analysis of 238 ks NuSTAR observations of the
merging galaxy cluster SPT-CL J2031-4037, searching for non-thermal
inverse Compton emission. Our spectral analysis of SPT-CL J2031-4037
shows a possibility that the hard X-ray emission of the cluster can
be described by a non-thermal component, though we cannot completely
rule out a purely thermal origin for this hard emission. Including the
statistical and systematic uncertainties, our best model fit yields a
20-80 keV non-thermal flux of $3.93_{-1.10}^{+1.24} \times 10^{-12}$
erg s-1 cm-2. The estimated non-thermal flux
is comparable to those found in other galaxy clusters using NuSTAR
and other X-ray instruments. Using this non-thermal flux with the
existing radio data of the cluster, we estimate a volume-averaged
magnetic field strength in the range of around 0.1-0.2 µG.
Title: Combined full shape analysis of BOSS galaxies and eBOSS
quasars using an iterative emulator
Authors: Neveux, Richard; Burtin, Etienne; Ruhlmann-Kleider, Vanina; de
Mattia, Arnaud; Semenaite, Agne; Dawson, Kyle S.; de la Macorra, Axel;
Percival, Will J.; Rossi, Graziano; Schneider, Donald P.; Zhao, Gong-Bo
Bibcode: 2022MNRAS.516.1910N
Altcode: 2022arXiv220104679N; 2022MNRAS.tmp.2001N
Standard full-shape clustering analyses in Fourier space rely on a
fixed power spectrum template, defined at the fiducial cosmology used
to convert redshifts into distances, and compress the cosmological
information into the Alcock-Paczynski parameters and the linear growth
rate of structure. In this paper, we propose an analysis method that
operates directly in the cosmology parameter space and varies the
power spectrum template accordingly at each tested point. Predictions
for the power spectrum multipoles from the TNS model are computed at
different cosmologies in the framework of $\Lambda \rm {CDM}$. Applied
to the final eBOSS QSO and LRG samples together with the low-z DR12
BOSS galaxy sample, our analysis results in a set of constraints
on the cosmological parameters Ωcdm, H0,
σ8, Ωb, and ns. To reduce the
number of computed models, we construct an iterative process to sample
the likelihood surface, where each iteration consists of a Gaussian
process regression. This method is validated with mocks from N-body
simulations. From the combined analysis of the (e)BOSS data, we obtain
the following constraints: σ8 = 0.877 ± 0.049 and $\Omega
_{\rm m}=0.304^{+0.016}_{-0.010}$ without any external prior. The
eBOSS quasar sample alone shows a 3.1σ discrepancy compared to the
Planck prediction.
Title: Forecasting the cross-correlation of the CSST galaxy survey
with the FAST H I Intensity Map
Authors: Deng, Furen; Gong, Yan; Wang, Yougang; Dong, Shutong; Cao,
Ye; Chen, Xuelei
Bibcode: 2022MNRAS.515.5894D
Altcode: 2022arXiv220714566D; 2022MNRAS.tmp.2092D
The cross-correlation of optical galaxies with the neutral hydrogen
(H I) radiation intensity can enhance the signal-to-noise ratio (SNR)
of the H I intensity measurement. In this paper, we investigate the
cross-correlation of the galaxy samples obtained by the spectroscopic
survey of the China Space Station Telescope (CSST) with the H I
Intensity mapping (IM) survey of the Five-hundred-meter Aperture
Spherical Telescope (FAST). Using the IllusitrisTNG simulation result
at redshift 0.2 ~ 0.3, we generate mock data of the CSST survey and
a FAST L-band drift scan survey. The CSST spectroscopic survey can
yield a sample of galaxies with a high comoving number density of
$10^{-2}\, ({\ \rm Mpc}\,h^{ -1})^{-3}$ at z ~ 0.3. We cross-correlate
the foreground-removed radio intensity with the CSST galaxies,
including both the whole sample, and red and blue galaxy subsamples
separately. We find that in all cases the H I and optical galaxies
are well correlated. The total H I abundance can be measured with a
high precision from this correlation. A relative error of $\sim 0.6{{\
\rm per\ cent}}$ for $\Omega _{\rm H\, \small {I}}$ could be achieved
at z ~ 0.3 for an overlapping survey area of $10\,000\, {\ \rm deg}^2$.
Title: Reconstruction of the Virtual Geomagnetic Pole (VGP) path
at high latitude for the last 22 kyr: The role of radial field flux
patches as VGP attractor
Authors: Caricchi, Chiara; Campuzano, Saioa A.; Sagnotti, Leonardo;
Macrì, Patrizia; Lucchi, Renata G.
Bibcode: 2022E&PSL.59517762C
Altcode:
Reconstruction of geomagnetic field changes has a strong potential to
complement geodynamo modeling and improve the understanding of Earth's
core dynamics. Recent works based on geomagnetic measurements pointed
out that over the last two decades the position of the north magnetic
pole has been largely determined by the influence of two competing
flux lobes under Canada and Siberia. In order to understand if
the waxing and waning of magnetic flux lobes have driven the path of
geomagnetic paleopoles in the past, we present an augmented and updated
record of the chronology and paleosecular variation of geomagnetic field
for the last 22 kyr derived from sedimentary cores collected along the
north-western margin of Barents Sea and western margin of Spitsbergen
(Arctic). The path of the virtual geomagnetic pole (VGP) has been
reconstructed over this time period and compared with the maps of the
radial component of the geomagnetic field at the core-mantle boundary,
obtained from the most recent models. The VGP path includes centuries
during which the VGP position is stable and centuries during which its
motion accelerates. We recognize both clockwise and counterclockwise
VGP paths, mostly developing inside the surface projection of the
inner core tangent cylinder in the Arctic region. The VGP path seems
to follow the appearance of Br patches of normal magnetic
flux, especially those located under Siberia and Canada areas, but
also those that may cause peculiar paleomagnetic features such as the
Levantine Iron Age Anomaly.
Title: Stable sets mapping with Taylor differential algebra with
application to ballistic capture orbits around Mars
Authors: Caleb, T.; Merisio, G.; Lizia, P. Di; Topputo, F.
Bibcode: 2022CeMDA.134...39C
Altcode:
Ballistic capture orbits offer safer Mars injection at longer transfer
time. However, the search for such an extremely rare event is a
computationally intensive process. Indeed, it requires the propagation
of a grid sampling the whole search space. This work proposes a
novel ballistic capture search algorithm based on Taylor differential
algebra propagation. This algorithm provides a continuous description
of the search space compared to classical grid sampling research and
focuses on areas where the nonlinearities are the largest. Macroscopic
analyses have been carried out to obtain cartography of large sets of
solutions. Two criteria, named consistency and quality, are defined
to assess this new algorithm and to compare its performances with
classical grid sampling of the search space around Mars. Results
show that differential algebra mapping works on large search spaces,
and automatic domain splitting captures the dynamical variations on
the whole domain successfully. The consistency criterion shows that
more than 87% of the search space is guaranteed as accurate, with the
quality criterion kept over 80%.
Title: Aeolian disruption and reworking of TARs at the Zhurong rover
field site, southern Utopia Planitia, Mars
Authors: Lu, Yu; Edgett, Kenneth S.; Wu, Bo; Wang, Yiran; Li, Zhaojin;
Michael, Gregory G.; Yizhaq, Hezi; Jin, Qi; Wu, Yunzhao
Bibcode: 2022E&PSL.59517785L
Altcode:
Aeolian bedforms are the signatures of wind interaction with
unconsolidated, granular surface materials. Transverse aeolian ridges
(TARs) are widely distributed on Mars but their formation remains
enigmatic. China's Zhurong rover explored four crescent-shaped TARs,
with two horns generally facing south, during the first 107 sols
in southern Utopia Planitia, Mars. Rover images show that these
bedforms have distinct light and dark variations on their surfaces
that likely result from the combination of a bimodal distribution of
particle sizes and the crust formed by the accumulation of aeolian
dust. Two of these bedforms exhibit erosional forms on their west
sides, where megaripples facing in a direction different from that of
the crescentic bedforms they disrupt were created by more recent winds
from the northeast. Differing erosional configurations of each of these
bedforms in close proximity to each other are probably related to the
angle between the bedform crest and the wind direction, and may further
suggest that erosion of TARs starts from their two flanks. Secondary
ridges of TARs widely recognized on Mars could be megaripples formed
during this erosion process. At the Zhurong landing site, TARs degraded
into megaripples, suggesting that they might share similar formation
and evolution mechanisms there and elsewhere on Mars.
Title: Solidus melting of pyrolite and bridgmanite: Implication for
the thermochemical state of the Earth's interior
Authors: Pierru, Rémy; Pison, Laure; Mathieu, Antoine; Gardés,
Emmanuel; Garbarino, Gaston; Mezouar, Mohamed; Hennet, Louis;
Andrault, Denis
Bibcode: 2022E&PSL.59517770P
Altcode:
Melting properties of the deep mantle remain controversial due to
experimental difficulties; e.g., reports of solidus temperatures
of mantle-relevant compositions span over ∼700 K at 2000 km
depth. This situation limits our understanding of the thermochemical
state of the Earth's interior. Using the laser heated diamond
anvil cell (LH-DAC), we performed new experimental determination
of the solidus profile of ultra-dry pyrolite and the solidus
of two compositions of (Mg,Fe)(Si,Al)O3 bridgmanite
(Bg). Melting was detected (i) from -the correlation between laser
power and sample temperature, -changes of sample texture and -the
level of visible light absorption, for all samples, (ii) using X-ray
diffraction, for the MgSiO3 composition and (iii) after
scanning electron microscope observations, for selected Fe-bearing
samples. Special care was given to using ultra-dry experimental
chambers and to determination of sample temperature. In particular,
we discuss the wavelength-dependent thermal emission of silicate
samples, which lowers the solidus by 100 to 300 K, compared to the
grey-body assumption. The solidus of MgSiO3-Bg is in
good agreement with previous reports using ab initio calculations
and shock wave experiments. We observe a net decrease in the
solid-liquid Clapeyron slope at 60(3) GPa and 4400(200) K, which can be
related to rapid pressure-induced coordination change of Si in the melt.
(Mg0.955,Fe0.045)(Si0.993,Al0.007)O3
Bg melts 600-800 K lower than MgSiO3-Bg. Its solidus evolves
smoothly with pressure, suggesting progressive Si coordination change
in the melt. In the pressure range investigated (24-135 GPa) Clapeyron
slopes suggest rapid decrease of the volume of fusion, from 14 to 2%
for MgSiO3 and from 9 to 3% for (Fe,Al)-bearing Bg, assuming
congruent melting. By comparing the solidii of various silicates, it
appears that the higher the number of cations, the less pronounced
is the curvature of the solidus. This observation suggests that
the relatively ordered structure of simple liquid compositions with
a limited number of distinct network-modifying cations frustrates
the coexistence of tetrahedrally and octahedrally coordinated Si
polyhedral. The solidus of pyrolite presents a smooth evolution
from 2200(100) K to 3950(200) K in the same pressure interval. This
is very similar to our previous work on chondritic-type mantle. The
new solidus is 200-300 K lower than that of KLB-1 peridotite,
which can be related to more incompatible elements in pyrolite. It
remains problematic that our solidus plots several 100 K higher
than other recent measurements performed on pyrolite; we discuss
the possibility of a higher water content in previous samples,
compared to our experiments. Assuming a dry lowermost mantle, our
results imply a core-mantle boundary temperature lower than 3950(200)
K. Modeling the melting diagram at the core-mantle boundary suggests
a pseudo-eutectic melt significantly depleted in SiO2,
compared to the composition of the mean mantle.
Title: Trace elements in olivine fingerprint the source of 2018
magmas and shed light on explosive-effusive eruption cycles at
Kīlauea Volcano
Authors: Mourey, Adrien J.; Shea, Thomas; Lynn, Kendra J.; Lerner,
Allan H.; Lambart, Sarah; Costa, Fidel; Oalmann, Jeffrey; Lee,
R. Lopaka; Gansecki, Cheryl
Bibcode: 2022E&PSL.59517769M
Altcode:
Understanding magma genesis and the evolution of intensive parameters
(temperature, pressure, composition, degree of melting) in the mantle
source of highly active volcanic systems is crucial for interpreting
magma supply changes over time and recognizing cyclic behavior to
anticipate future volcanic behavior. Major and trace elements in
olivine are commonly used to study variations in mantle lithologies
and melting conditions (e.g., temperature, pressure, oxygen fugacity)
affecting the mantle over time. Here, we track the temporal evolution of
primary melts through the most recent cycle of explosive and effusive
eruptions at Kīlauea (Hawai'i), which spans the last ∼500 years. We
report major and trace elements in olivine from the last explosive
period (∼1500 - early 1820's Keanakāko'i Tephra) and the most recent
decade of the current effusive period (2018 LERZ, 2015-2018 Pu'u'ō'ō,
2008-2018 lava lake and 2020 eruption in Halema'uma'u). Scandium
concentrations in olivine allow characterizing changes in mantle source
between 1500 and 2018, and suggest that the recent (2015-2018) magma
feeding the Pu'u'ō'ō cone did not significantly interact with the
magma that erupted in the LERZ in 2018. The evolution of olivine and
melt compositions over the past 500 years is not easily reconcilable
with variations in mantle potential temperature, pressure of mantle
melt pooling and storage, or oxygen fugacity. Instead, Sc, Mn, and Co
concentrations and Ni/Mg ratio in high forsterite (Fo >87) olivine
advocate for an increase in the proportion of clinopyroxene in the
mantle source associated with a slightly higher degree of partial
melting from 1500 to 2018. Changes in primitive melt compositions and
degrees of mantle melting may well modulate magma supply to the crust
and formation-replenishment of steady or ephemeral summit reservoirs,
and thereby control transitions between explosive and effusive periods
at Kīlauea. Analyzing trace elements in olivine at Kīlauea and
elsewhere could therefore provide important clues on subtle changes
occurring at the mantle level that might herald changes in volcanic
behavior.
Title: A primordial atmospheric origin of hydrospheric deuterium
enrichment on Mars
Authors: Pahlevan, Kaveh; Schaefer, Laura; Elkins-Tanton, Linda T.;
Desch, Steven J.; Buseck, Peter R.
Bibcode: 2022E&PSL.59517772P
Altcode:
The deuterium-to-hydrogen (D/H or 2H/1H) ratio
of Martian atmospheric water (∼6× standard mean ocean water, SMOW)
is higher than that of known sources, requiring planetary enrichment. A
recent measurement by NASA's Mars Science Laboratory rover Curiosity
of Hesperian-era (>3 Ga) clays yields a D/H ratio ∼3×SMOW,
demonstrating that most of the enrichment occurs early in Mars's
history, reinforcing the conclusions of Martian meteorite studies. As on
Venus, Mars's D/H enrichment is widely thought to reflect preferential
loss to space of 1H (protium) relative to 2H
(deuterium), but both the cause and the global environmental context
of large and early hydrogen losses remain to be determined. Here, we
apply a recent model of primordial atmosphere evolution to Mars, link
the magma ocean of the accretion epoch with a subsequent water-ocean
epoch, and calculate the behavior of deuterium for comparison with the
observed record. In contrast to earlier works that consider Martian D/H
fractionation in atmospheres in which hydrogen reservoirs are present
exclusively as H2O or H2, here we consider
2-component (H2O-H2) outgassed atmospheres in
which both condensing (H2O) and escaping (H2)
components - and their interaction - are explicitly calculated. We
find that a ≈2-3× hydrospheric deuterium-enrichment is produced
rapidly if the Martian magma ocean is chemically reducing at last
equilibration with the primordial atmosphere, making H2
and CO the initially dominant species, with minor abundances of
H2O and CO2. Reducing gases - in particular
H2 - can cause substantial greenhouse warming and prevent a
water ocean from freezing immediately after the magma ocean epoch. We
find that greenhouse warming due to plausible H2 inventories
(pH2= 1 -102 bars) yields surface temperatures
high enough (Ts= 290 - 560 K) to stabilize a water ocean
and produce an early hydrological cycle through which surface water
can be circulated. Moreover, the pressure-temperature conditions are
high enough to produce ocean-atmosphere H2O-H2
isotopic equilibrium through gas-phase deuterium exchange such that
surface H2O strongly concentrates deuterium relative to
H2, which preferentially takes up protium and escapes
from the primordial atmosphere. The efficient physical separation of
deuterium-rich (H2O) and deuterium-poor (H2)
species via condensation permits equilibrium isotopic partitioning
and early atmospheric escape to be recorded in modern crustal
reservoirs. The proposed scenario of primordial H2-CO-rich
outgassing and escape suggests significant durations (>Myr) of
chemical conditions on the Martian surface conducive to prebiotic
chemistry immediately following magma ocean crystallization.
Title: Semiclassical Effects in Color Flavor Locked Strange Stars
Authors: Lorenzatto Volkmer, Guilherme; Hadjimichef, Dimiter
Bibcode: 2022BrJPh..52..179L
Altcode: 2021arXiv210706052L
Strange stars in the color flavor locked phase, as described by a
nonlinear generalization of the phenomenological MIT bag model proposed
in the context of color superconductivity, are studied through a
formalism motivated by the two semiclassical solutions for hydrostatic
equilibrium. The semiclassical effects in the model are represented
by a negative pressure fluid that might take place in the collapse
of ultradense matter. Results show that within this framework it is
possible to find ultracompact configurations situated between regular
compact stars and black holes.
Title: Stochastic approach to Markovian interrelationship assessment
of solar activity indices
Authors: Iqbal, A.; Siddiqi, T. A.
Bibcode: 2022A&C....4100637I
Altcode:
This paper employs a discrete-time Markov chain (DTMC) stochastic
process to investigate a state/event based Markovian interrelationship
between various solar activity indices (SAI) (including 10.7 cm
solar radio flux (SF10.7), coronal index (CI), solar
flare index (SFI) and total solar irradiance (TSI)) in relation to
sunspot number (SSN). First, we applied the first order DTMC model
as a first approximation to the total number of transitions between
different states of SAI in order to estimate the probability of
occurrence corresponding with each transition. Next, several DTMC
descriptors like persistency, state dependency, stationarity, mean
first passage time and entropy are derived from estimated transition
probability matrices. These descriptors are very useful as they related
to time series characteristics (like randomness, nature of cycles and
predictability) within a stochastic dynamical system as well as crucial
for checking the applicability of Markov chain method. Therefore, via
the DTMC analysis and derived descriptors, this study found remarkable
similarities in the formation of transition matrices and diagrams,
significant 2-dimensional correlation values, robust self-communication
behaviour among states, existence of dependent successive transitions
and stationary nature of data throughout the space. Further, the
resemblance in the average transit time from one state to another,
probabilistically disordered symmetrical time series and existence of
randomness in transition states has been observed. Therefore, results
obtained in this paper provide a new insight to increase the level of
knowledge of the possible linkage between underlying SAI that could
be helpful in enhanced understanding of the potential future climate
changes and other solar energy-related objectives.
Title: Nitrogen, helium, and argon reveal the magmatic signature of
fumarole gases and episodes of outgassing from upper-crustal magma
reservoirs: The case of the Nisyros caldera (Aegean Arc, Greece)
Authors: Bini, Giulio; Chiodini, Giovanni; Caliro, Stefano;
Tassi, Franco; Vaselli, Orlando; Rizzo, Andrea L.; Mollo, Silvio;
Vougioukalakis, Georgios E.; Bachmann, Olivier
Bibcode: 2022GeCoA.335...68B
Altcode:
The chemical composition of gases emitted by active volcanoes reflects
both magma degassing and shallower processes, such as fluid-rock
hydrothermal interaction and mixing with atmospheric-derived
fluids. Untangling the magmatic fluid endmember within surface gas
emission is therefore challenging, even with the use of well-known magma
degassing tracers such as noble gases. Here, we investigate the deep
magmatic fluid composition at the Nisyros caldera (Aegean Arc, Greece)
by measuring nitrogen and noble gas abundances and isotopes in naturally
degassing fumaroles. Gas samples were collected from 32 fumarolic vents
at water-boiling temperature between 2018 and 2021. These fumaroles are
admixtures of magmatic fluids typical of subduction zones, groundwater
(or air saturated water, ASW), and air. The N2, He, and Ar
composition of the magmatic endmember is calculated by reverse mixing
modeling and shows N2/He = 31.8 ± 4.5, N2/Ar =
281.6, δ15N = +7 ± 3 ‰, 3He/4He
= 6.2 Ra (where Ra is air 3He/4He),
and 40Ar/36Ar = 551.6 ± 19.8. Although
N2/He is significantly low with respect to typical values
for arc volcanoes (1,000-10,000), the contribution of subducted
sediments to the Aegean Arc magma generation is reflected by the
positive δ15N values of Nisyros fumaroles. The low
N2/He ratio indicates N2-depletion due to
solubility-controlled differential degassing of an upper-crustal silicic
(dacitic/rhyodacitic) melt in a high-crystallinity reservoir. We compare
our 2018-2021 data with N2, He, and Ar values collected
from the same fumaroles during a hydrothermal unrest following the
seismic crisis in 1996-1997. Results show additions of both magmatic
fluid and ASW during this unrest. In the same period, fumarolic vents
display an increase in magmatic species relative to hydrothermal gas,
such as CO2/CH4 and He/CH4 ratios, an
increase of ∼50 °C in the equilibrium temperature of the hydrothermal
system (up to 325 °C), and greater amounts of vapor separation. These
variations reflect an episode of magmatic fluid expulsion during the
seismic crisis. The excess of heat and mass supplied by the magmatic
fluid injection is then dissipated through boiling of deeper and
peripheral parts of the hydrothermal system. Reverse mixing modeling of
fumarolic N2-He-Ar has therefore important ramifications not
only to disentangle the magmatic signature from gases emitted during
periods of dormancy, but also to trace episodes of magmatic outgassing
and better understand the state of the upper crustal reservoir.
Title: PSI: Constructing ad-hoc simplices to interpolate
high-dimensional unstructured data
Authors: Lüders, Stefan; Dolag, Klaus
Bibcode: 2022JCoPh.46711476L
Altcode: 2021arXiv210913926L
Interpolating unstructured data using barycentric coordinates becomes
infeasible at high dimensions due to the prohibitive memory requirements
of building a Delaunay triangulation. We present a new algorithm to
construct ad-hoc simplices that are empirically guaranteed to contain
the target coordinates, based on a nearest neighbor heuristic and an
iterative dimensionality reduction through projection. We use these
simplices to interpolate the astrophysical cooling function Λ and show
that this new approach produces good results with just a fraction of
the previously required memory.
Title: The response of a red supergiant to a common envelope jets
supernova (CEJSN) impostor event
Authors: Ragoler, Nitzan; Bear, Ealeal; Schreier, Ron; Hillel, Shlomi;
Soker, Noam
Bibcode: 2022MNRAS.515.5473R
Altcode: 2022MNRAS.tmp.2045R; 2022arXiv220512056R
Using a 1D stellar evolution code, we simulate the response of a red
supergiant (RSG) star to injection of energy and to mass removal. We
take the values of the energy that we inject and the mass that we remove
according to our previous 3D hydrodynamical simulations of a neutron
star (NS) on a highly eccentric orbit that enters the envelope of an
RSG star for half a year and launches jets as it accretes mass via an
accretion disc. We find that for injected energies of $\simeq 10^{47}
{--} 10^{48} {~\rm erg}$ and removed mass of $\simeq 0.03{--}0.6\,
{\rm M}_\odot$ the RSG envelope expands to a large radius. Therefore,
we expect the NS to continue to orbit inside this massive inflated
envelope for several more months, up to about twice the initial RSG
radius, to continue to accrete mass and launch jets for a prolonged
period. Although these late jets are weaker than the jets that the
NS launches while inside the original RSG envelope, the late jets
might actually be more influential on the light curve, leading to a
long, several months to few years, and bright, about $\gtrsim10^8\,
{\rm L}_\odot$, transient event. The RSG returns to more or less a
relaxed structure after about 10 yr, and so another transient event
might occur in the next periastron passage of the NS. Our results add
to the already rich variety of jet-driven explosions/outbursts that
might account for many puzzling transient events.
Title: JLU-H: A novel lunar highland regolith simulant for use in
large-scale engineering experiments
Authors: Sun, Xumin; Zhang, Rui; Li, Xiujuan; Zou, Meng; Wang, Chu;
Chen, Lei
Bibcode: 2022P&SS..22105562S
Altcode:
High-fidelity lunar soil simulants are expensive and limited in
quantity, which is difficult to meet the needs of large-scale
engineering investigations about drilling, excavation or drop
tests of spacecraft. For large-scale engineering experiments, the
mechanical properties of simulants are more important because they
will affect the accuracy and credibility of results. To satisfy the
needs of large-scale engineering experiments, this study presents a
new lunar highland soil simulant (JLU-H) which was made entirely of
naturally available anorthosite complex without any added materials
or minerals. The geotechnical properties of JLU-H, such as chemical
composition, particle morphology, particle size distribution,
specific gravity, bulk density, maximum and minimum density, and
shear strength, were determined through a series of indoor tests, and
the results were compared with data from Apollo 16 lunar soil sample
parameters and other extant highland simulants. The results show that
JLU-H can be used as a mechanical substitute for lunar highland soil,
and its mechanical property parameters have good similarity with other
highland simulants. Although the simulant is not fully representative
of the Apollo 16 regolith samples in terms of chemical composition,
it is generally close in terms of mineralogical composition. Moreover,
compared with other highland simulants, JLU-H has the advantages of
low price and the possibility of mass production.
Title: The relation between optical and γ-ray emission in BL
Lac sources
Authors: La Mura, G.; Becerra Gonzalez, J.; Chiaro, G.; Ciroi, S.;
Otero-Santos, J.
Bibcode: 2022MNRAS.515.4810L
Altcode: 2022MNRAS.tmp.1874L; 2022arXiv220709764L
The relativistic jets produced by some Active Galactic Nuclei (AGNs) are
among the most efficient persistent sources of non-thermal radiation and
represent an ideal laboratory for studying high-energy interactions. In
particular, when the relativistic jet propagates along the observer's
line of sight, the beaming effect produces dominant signatures in the
observed spectral energy distribution (SED), from the radio domain up
to the highest energies, with the further possibility of resulting
in radiation-particle multimessenger associations. In this work,
we investigate the relationships between the emission of γ rays and
the optical spectra of a sample of AGN, selected from BL Lac sources
detected by the Fermi Large Area Telescope (Fermi-LAT). We find that
there is a close relationship between the optical and γ-ray spectral
indices. Despite all the limitations due to the non-simultaneity of
the data, this observation strongly supports a substantial role of
Synchrotron-Self Compton (SSC) radiation in a single zone leptonic
scenario for most sources. This result simplifies the application of
theoretical models to explore the physical parameters of the jets in
this type of sources.
Title: Comparison of the active galactic nuclei Baldwin effect with
the modified Baldwin effect of the ultraviolet-optical emission
lines in a single sample
Authors: Wang, Yongjiang; Liu, Wanqing; Shang, Zhaohui; Brotherton,
Michael S.
Bibcode: 2022MNRAS.515.5836W
Altcode: 2022MNRAS.tmp.1974W
The inverse relationship between equivalent width (EW) of broad
emission lines and the underlying continuum luminosity, known as the
Baldwin effect (BE), is an important and well-studied correlation in
active galactic nuclei (AGNs). However, the EW is also considered to be
anticorrelated with the Eddington ratio, referred to as the modified
Baldwin effect (MBE). Investigating whether the BE or MBE is the
stronger correlation is important for studying the ionization mechanism
and the broad-line region of AGN. Based on a sample of 85 bright quasars
with quasi-simultaneous ultraviolet (UV)-optical spectra and a redshift
range of 0.03-1.404 from Shang et al., we first present line fitting
and measurements of the O VI line that were not previously available and
the Si IV + O IV] line. We then investigate and compare the BE and MBE
of multiple UV and optical emission lines from this single sample. We
find that the BE of most of the broad emission lines is stronger than
the MBE. Furthermore, we confirm the previous result that the slope of
the BE steepens with the ionization energy of the line, and also find
that the MBE slope shows a similar trend. In addition, compared with
the C IV line, the O VI shows a broader line width and a larger peak
velocity blueshift with respect to the systemic redshift. These results
are also in agreement with previous studies and imply that, compared
to the C IV gas, the O VI line-emitting gas is closer to the accretion
disc and is more strongly influenced by the accretion disc wind.
Title: Resolved imaging of exoplanets with the solar gravitational
lens
Authors: Turyshev, Slava G.; Toth, Viktor T.
Bibcode: 2022MNRAS.515.6122T
Altcode: 2022MNRAS.tmp.2011T; 2022arXiv220404866T
We discuss the feasibility of direct multipixel imaging of exoplanets
with the solar gravitational lens (SGL) in the context of a realistic
deep space mission. For this, we consider an optical telescope, placed
in the image plane that forms in the strong interference region of
the SGL. We consider an Earth-like exoplanet located in our immediate
stellar neighbourhood and model its characteristics using our own
Earth. We estimate photon fluxes from such a compact, extended, resolved
exoplanet. This light appears in the form of an Einstein ring around
the Sun, seen through the solar corona. The solar corona background
contributes a significant amount of stochastic noise and represents
the main noise source for observations utilizing the SGL. We estimate
the magnitude of this noise. We compute the resulting signal-to-noise
ratios (SNRs) and related integration times that are needed to perform
imaging measurements under realistic conditions. It is known that
deconvolution, removing the blur due to the SGL's spherical aberration
substantially decreases the SNR. Our key finding is that this 'penalty'
is significantly mitigated when sampling locations in the image plane
(image pixels) remain widely spaced. Consequently, we conclude that an
imaging mission is challenging but feasible, using technologies that
are either already available or in active development. Under realistic
conditions, high-resolution imaging of Earth-like exoplanets in our
galactic neighbourhood requires only weeks or months of integration
time, not years as previously thought: a high quality 1000 × 1000 pixel
image of an Earth-like planet at Proxima Centauri could be obtained
with SNR > 10 using approximately 14 months of integration time.
Title: Development of a multispectral stereo-camera system comparable
to Hayabusa2 optical navigation camera (ONC-T) for observing samples
returned from asteroid (162173) Ryugu
Authors: Cho, Yuichiro; Yumoto, Koki; Yabe, Yuna; Mori, Shoki; Ogura,
Jo A.; Yada, Toru; Miyazaki, Akiko; Yogata, Kasumi; Hatakeda, Kentaro;
Nishimura, Masahiro; Abe, Masanao; Usui, Tomohiro; Sugita, Seiji
Bibcode: 2022P&SS..22105549C
Altcode: 2021arXiv210913480C
Hayabusa2 collected 5.4 g of samples from asteroid (162173) Ryugu
and brought them back to Earth. Obtaining multiband images of these
samples with spectral bands comparable to those used for remote-sensing
observations is important for characterizing the collected samples
and examining how representative they are compared with spacecraft
observations of Ryugu. In this study, we constructed a multiband
microscopic camera system that enables both visual multispectral
imaging at 390 (ul), 475 (b), 550 (v), 590 (Na), 700 (w), and 850 nm
(x), and three-dimensional (3D) shape reconstruction of individual
grain samples based on stereo imaging. The imaging system yields images
of 4096 × 2160 pixels with a pixel resolution of 1.93 μm/pix and
field of view of 7.9 mm × 4.2 mm. Our multispectral imaging system
observes the samples with spectral bands comparable to those on the
telescopic optical navigation camera (ONC-T) onboard Hayabusa2, and our
validation measurements yielded reflectance spectra and a 3D model with
a relative error of 3% and 5%, respectively. These results indicate that
the multiband imaging system with a 3D shape reconstruction capability
yields accurate spectral and shape data of the returned samples. Using
this instrument, we conducted multispectral measurements of two Ryugu
samples (grains in dishes A3 and C1) acquired from two locations on
the asteroid. The average spectra of the measured Ryugu samples were
flat and consistent with the global averaged spectrum of Ryugu. The
550-nm band (v-band) reflectance of the returned grains in the dishes
was 2.4% on average, higher than that of the global averaged spectrum
of Ryugu observed with ONC-T. This apparent difference could be because
the returned grains have greater specular reflectance. In this paper,
a hardware description, development, and experimental results are
presented.
Title: A new emulated Monte Carlo radiative transfer disc-wind model:
X-Ray Accretion Disc-wind Emulator - XRADE
Authors: Matzeu, G. A.; Lieu, M.; Costa, M. T.; Reeves, J. N.;
Braito, V.; Dadina, M.; Nardini, E.; Boorman, P. G.; Parker, M. L.;
Sim, S. A.; Barret, D.; Kammoun, E.; Middei, R.; Giustini, M.; Brusa,
M.; Cabrera, J. Pérez; Marchesi, S.
Bibcode: 2022MNRAS.515.6172M
Altcode: 2022arXiv220713731M; 2022MNRAS.tmp.2058M
We present a new X-Ray Accretion Disc-wind Emulator (XRADE) based on
the 2.5D Monte Carlo radiative transfer code that provides a physically
motivated, self-consistent treatment of both absorption and emission
from a disc wind by computing the local ionization state and velocity
field within the flow. XRADE is then implemented through a process
that combines X-ray tracing with supervised machine learning. We
develop a novel emulation method consisting in training, validating,
and testing the simulated disc-wind spectra into a purposely built
artificial neural network. The trained emulator can generate a single
synthetic spectrum for a particular parameter set in a fraction of
a second, in contrast to the few hours required by a standard Monte
Carlo radiative transfer pipeline. The emulator does not suffer from
interpolation issues with multidimensional spaces that are typically
faced by traditional X-ray fitting packages such as XSPEC. XRADE will
be suitable to a wide number of sources across the black hole mass,
ionizing luminosity, and accretion rate scales. As an example, we
demonstrate the applicability of XRADE to the physical interpretation
of the X-ray spectra of the bright quasar PDS 456, which hosts the
best-established accretion disc wind observed to date. We anticipate
that our emulation method will be an indispensable tool for the
development of high-resolution theoretical models, with the necessary
flexibility to be optimized for the next generation microcalorimeters
onboard future missions, like X-Ray Imaging and Spectroscopy Mission
(XRISM)/Resolve and Athena/X-ray Integral Field Unit (X-IFU). This
tool can also be implemented across a wide variety of X-ray spectral
models and beyond.
Title: Galaxy cluster aperture masses are more robust to baryonic
effects than 3D halo masses
Authors: Debackere, Stijn N. B.; Hoekstra, Henk; Schaye, Joop
Bibcode: 2022MNRAS.515.6023D
Altcode: 2022arXiv220508424D; 2022MNRAS.tmp.1981D
Systematic uncertainties in the mass measurement of galaxy clusters
limit the cosmological constraining power of future surveys that
will detect more than 105 clusters. Previously, we
argued that aperture masses can be inferred more accurately and
precisely than 3D masses without loss of cosmological constraining
power. Here, we use the Baryons and Haloes of Massive Systems (BAHAMAS)
cosmological, hydrodynamical simulations to show that aperture masses
are also less sensitive to changes in mass caused by galaxy formation
processes. For haloes with $m_\mathrm{200m,dmo} \gt 10^{14} \, h^{-1}
\, \mathrm{M_\odot }$, binned by their 3D halo mass, baryonic physics
affects aperture masses and 3D halo masses similarly when measured
within apertures similar to the halo virial radius, reaching a maximum
reduction of $\approx 3 \, \mathrm{per\, cent}$. For lower mass haloes,
$10^{13.5} \lt m_\mathrm{200m,dmo} / h^{-1} \, \mathrm{M_\odot }\lt
10^{14}$, and aperture sizes $\sim 1 \, h^{-1} \, \mathrm{cMpc}$,
representative of weak lensing observations, the aperture mass is
consistently reduced less ($\lesssim 5 \, \mathrm{per\, cent}$)
than the 3D halo mass ($\lesssim 10 \, \mathrm{per\, cent}$ for
m200m). The halo mass reduction evolves only slightly, by
up to 2 $\mathrm{per\, centage}$ points, between redshift 0.25 and 1
for both the aperture mass and m200m. Varying the simulated
feedback strength so the mean simulated hot gas fraction covers the
observed scatter inferred from X-ray observations, we find that the
aperture mass is consistently less biased than the 3D halo mass, by
up to $2 \,$$\mathrm{per\, centage}$ points at $m_\mathrm{200m,dmo}
= 10^{14} \, h^{-1} \, \mathrm{M_\odot }$. Therefore, aperture mass
calibrations provide a fruitful path to reduce the sensitivity of
future cluster surveys to systematic uncertainties.
Title: (3200) Phaethon polarimetry in the negative branch: new
evidence for the anhydrous nature of the DESTINY+
target asteroid
Authors: Geem, Jooyeon; Ishiguro, Masateru; Takahashi, Jun; Akitaya,
Hiroshi; Kawabata, Koji S.; Nakaoka, Tatsuya; Imazawa, Ryo; Mori,
Fumiki; Jin, Sunho; Bach, Yoonsoo P.; Jo, Hangbin; Kuroda, Daisuke;
Hasegawa, Sunao; Yoshida, Fumi; Ishibashi, Ko; Sekiguchi, Tomohiko;
Beniyama, Jin; Arai, Tomoko; Ikeda, Yuji; Shinnaka, Yoshiharu; Granvik,
Mikael; Siltala, Lauri; Djupvik, Anlaug A.; Kasikov, Anni; Pinter,
Viktoria; Knudstrup, Emil
Bibcode: 2022MNRAS.516L..53G
Altcode: 2022arXiv220811912G; 2022MNRAS.tmpL..69G
We report on the first polarimetric study of (3200) Phaethon, the target
of JAXA's DESTINY+ mission, in the negative branch to ensure
its anhydrous nature and to derive an accurate geometric albedo. We
conducted observations at low phase angles (Sun-target-observer
angle, α = 8.8-32.4°) from 2021 October to 2022 January and found
that Phaethon has a minimum polarization degree Pmin
= -1.3 ± 0.1 per cent, a polarimetric slope h = 0.22 ± 0.02 per
cent deg-1, and an inversion angle α0 = 19.9
± 0.3°. The derived geometric albedo is pV = 0.11 (in
the range of 0.08-0.13). These polarimetric properties are consistent
with anhydrous chondrites, contradict hydrous chondrites, and typical
cometary nuclei.
Title: Sterile neutrino production at small mixing in the early
universe
Authors: Alonso-Álvarez, Gonzalo; Cline, James M.
Bibcode: 2022PhLB..83337278A
Altcode: 2022arXiv220404224A
Sterile neutrinos can be produced in the early universe via interactions
with their active counterparts. For small active-sterile mixing angles,
thermal equilibrium with the standard model plasma is not reached
and sterile neutrinos are only produced via flavor oscillations. We
study in detail this regime, taking into account matter potentials and
decoherence effects caused by elastic scatterings with the plasma. We
find that resonant oscillations occurring at temperatures T ≲
10 GeV lead to a significant enhancement of the sterile neutrino
production rate. Taking this into account, we improve constraints on
the active-sterile mixing from Big Bang nucleosynthesis and the cosmic
microwave background, excluding mixing angles down to θs
∼10-10 -10-16 for sterile neutrino masses
in the 10 MeV to 10 GeV range. We observe that if sterile neutrinos
predominantly decay into metastable hidden sector particles, this
process provides a novel dark matter production mechanism, consistent
with the sterile neutrino origin of light neutrino masses via the
seesaw mechanism.
Title: A universal model for the evolution of tidally stripped systems
Authors: Drakos, Nicole E.; Taylor, James E.; Benson, Andrew J.
Bibcode: 2022MNRAS.516..106D
Altcode: 2022arXiv220714803D; 2022MNRAS.tmp.2095D
Accurate models of the structural evolution of dark matter subhaloes,
as they orbit within larger systems, are fundamental to understanding
the detailed distribution of dark matter at the present day. Numerical
simulations of subhalo evolution support the idea that the mass-loss
associated with tidal stripping is most naturally understood in
energy space, with the particles that are the least bound being
removed first. Starting from this premise, we recently proposed a
zero-parameter 'energy-truncation model' for subhalo evolution. We
tested this model with simulations of tidal stripping of satellites
with initial NFW profiles, and showed that the energy-truncation model
accurately predicts both the mass-loss and density profiles. In this
work, we apply the model to a variety of Hernquist, Einasto, and King
profiles. We show that it matches the simulation results quite closely
in all cases, indicating that it may serve as a universal model to
describe tidally stripped collision-less systems. A key prediction
of the energy-truncation model is that the central density of dark
matter subhaloes is conserved as they lose mass; this has important
implications for dark matter annihilation calculations, and for other
observational tests of dark matter.
Title: Implementation of dust particles in three-dimensional
magnetohydrodynamics simulation: dust dynamics in a collapsing
cloud core
Authors: Koga, Shunta; Kawasaki, Yoshihiro; Machida, Masahiro N.
Bibcode: 2022MNRAS.515.6073K
Altcode: 2022arXiv220712907K; 2022MNRAS.tmp.2043K
The aim of this study is to examine dust dynamics on a large scale and
investigate the coupling of dust with gas fluid in the star formation
process. We propose a method for calculating the dust trajectory in a
gravitationally collapsing cloud, where the dust grains are treated
as Lagrangian particles and are assumed to be neutral. We perform
the dust trajectory calculations in combination with non-ideal
magnetohydrodynamics simulation. Our simulation shows that dust
particles with a size of $\le 10\, {\rm \mu m}$ are coupled with gas
in a star-forming cloud core. We investigate the time evolution of the
dust-to-gas mass ratio and the Stokes number, which is defined as the
stopping time normalized by the freefall time-scale, and show that
large dust grains ($\gtrsim 100\, {\rm \mu m}$) have a large Stokes
number (close to unity) and tend to concentrate in the central region
(i.e. protostar and rotationally supported disc) faster than do small
grains ($\lesssim 10\, {\rm \mu m}$). Thus, large grains significantly
increase the dust-to-gas mass ratio around and inside the disc. We also
confirm that the dust trajectory calculations, which trace the physical
quantities of each dust particle, reproduce previously reported results
obtained using the Eulerian approach.
Title: Planetary systems with forces other than gravitational forces
Authors: Toxvaerd, Søren
Bibcode: 2022CeMDA.134...40T
Altcode: 2022arXiv220708084T
A discrete and exact algorithm for obtaining planetary systems is
derived in a recent article (Eur. Phys. J. Plus 2022, 137:99). Here,
the algorithm is used to obtain planetary systems with forces different
from the Newtonian inverse-square gravitational forces. A Newtonian
planetary system exhibits regular elliptical orbits, and here, it is
demonstrated that a planetary system with pure inverse forces also
is stable and with regular orbits, whereas a planetary system with
inverse cubic forces is unstable and without regular orbits. The
regular orbits in a planetary system with inverse forces deviate,
however, from the usual elliptical orbits by having revolving orbits
with tendency to orbits with three or eight loops. Newton's Proposition
45 in Principia for the Moon's revolving orbits caused by an additional
attraction to the gravitational attraction is confirmed, but whereas
the additional inverse forces stabilize the planetary system, the
additional inverse cubic forces can destabilize the planetary system
at a sufficient strength.
Title: Quasinormal modes and the correspondence with shadow in black
holes with a deficit solid angle and quintessence-like matter
Authors: Yu, Chengye; Chen, Deyou; Gao, Chuanhong
Bibcode: 2022NuPhB.98315925Y
Altcode: 2022arXiv220706796Y
In this paper, we investigate the photon sphere, shadow radius and
quasinormal modes of a 4-dimensional black hole with a deficit solid
angle and quintessence-like matter. We find that the radii of the
photon sphere and shadow decrease with the decreases of the deficit
solid angle and density of quintessence-like matter. The quasinormal
modes are gotten by the sixth order WKB approximation method and shadow
radius, respectively. The values of the real part and imaginary parts
of the quasinormal modes increase with the decrease of the values of
the deficit solid angle and density of quintessence-like matter when
the multipole number is fixed. The quasinormal modes gotten by these
two methods are in good agreement, especially when the multipole number
is large. It shows the correspondence between the quasinormal modes
in the eikonal limit and shadow.
Title: Efficient selection of SAR features using ML based algorithms
for accurate FVC estimation
Authors: Maurya, Ajay Kumar; Bhargava, Naman; Singh, Dharmendra
Bibcode: 2022AdSpR..70.1795M
Altcode:
Fractional vegetation cover (FVC) is a ratio of vertical projection
area of green vegetation to the total area under consideration. Crops
infested by pests, diseases or nutrient deficiency show their impact on
the crop coverage. Therefore, FVC is a good indicator of crop health
and arid soil. Recently, various models have been reported for FVC
estimation using optical data, but it is still limited to different
weather conditions. Therefore, it is not feasible to continue crop
monitoring using optical data. On the other hand, synthetic aperture
radar (SAR) data is weather independent, and has a good potential for
crop monitoring in all-weather conditions. SAR data has been used for
many crop parameters estimation, however has not been much explored for
FVC estimation. Plenty SAR features are available which are sensitive to
vegetation parameters. Some of the features are sensitive during early
crop stages (e.g., entropy, DpRVI-dual polarization radar vegetation
index), while others are sensitive during different stages of crops
(backscattering signal of VH and VV polarization). Therefore, there
is a need to critically assess all the features and find the optimum
combination that provides exemplary results during the entire crop
cycle. For this purpose, sixteen features are considered using the
different combinations of Sentinel-1 SLC data and their temporal
analysis is observed for their different phenology stages. Four machine
learning (ML) based models i.e., LightGBM, Xgboost, K-nearest neighbor
(KNN), and Random Forest have been explored on these features for
FVC estimation. The performance of each model is assessed with the
error metrics. Xgboost emerges as the best model with a minimum
RMSE value of 0.159. Xgboost model has the capability to recognize
the most important features. Due to the stochastic nature of the
algorithm, feature priority sequence may vary, therefore, algorithm
runs multiple times and the probability of each feature for every
position is calculated and on the basis of the highest probability,
feature importance sequences is decided. Xgboost model is developed by
increasing the input features in the order of their importance sequence
and the RMSE value is calculated for each input combination. It is
noted that initially, the RMSE value improved from 0.22 to 0.15 for
the top five input features. When additional features were included,
no further improvement in the RMSE was observed. Therefore; entropy,
alpha, VH, VH/VV, and VV are the top five features which are used in
the Xgboost model for FVC estimation instead of all sixteen features,
which delivers satisfactory results.
Title: Electromagnetic manifestations of Tonga eruption in Schumann
resonance band
Authors: Nickolaenko, Alexander P.; Schekotov, Alexander Yu; Hayakawa,
Masashi; Romero, Renato; Izutsu, Jun
Bibcode: 2022JASTP.23705897N
Altcode:
We present results of concurrent observations of anomalous Schumann
resonance (SR) signals during the major phase of eruption of Tonga
volcano on 15 January 2022. The experimental data were recorded at
French, Italian, Russian, and Japanese observatories that monitor
natural electromagnetic signals in the ELF and ULF bands. The major
phase of eruption ended by a huge blast, and all ELF/ULF observatories
concurrently detected anomalous SR signals for the first time in the ELF
observations, while the ULF records showed nothing unusual. The paper
presents anomalous dynamic SR spectra detected at four widely separated
observatories during the Tonga eruption on January 15, 2022. We show
that a fourfold increase in the SR intensity was caused by a compact
ELF source localized in the vicinity of Tonga volcano during the major
and concluding phase of eruption. Thus, the volcanic SR anomaly emerged
from the enormous amount of lightning strokes in the erupted cloud.
Title: Tailed radio galaxies from the TIFR GMRT sky survey
Authors: Bhukta, Netai; Mondal, Sushanta K.; Pal, Sabyasachi
Bibcode: 2022MNRAS.516..372B
Altcode: 2021arXiv211005484B
We present a list of tailed radio galaxies using the Tata Institute of
Fundamental Research (TIFR) Giant Metrewave Radio Telescope (GMRT) Sky
Survey Alternative Data Release 1 (TGSS ADR1) at 150 MHz. We visually
examined 5336 image fields and found 264 tailed radio galaxies. Tailed
radio galaxies are classified as wide-angle tailed (WAT) galaxies or
narrow-angle tailed (NAT) galaxies, based on the angle between the two
jets of the galaxy. Our sample of tailed radio galaxies included 203
WAT- and 61 NAT-type sources. These newly identified tailed sources are
significant additions to the list of known tailed radio galaxies. The
source morphology and luminosity features of the various galaxies and
their optical identifications are presented. Other radio properties
and general features of the sources are also discussed.
Title: Modelling the persistent low-state γ-ray emission of the
PKS 1510-089 blazar with electromagnetic cascades initiated in
hadronuclear interactions
Authors: Dzhatdoev, T. A.; Khalikov, E. V.; Latypova, V. S.; Podlesnyi,
E. I.; Vaiman, I. A.
Bibcode: 2022MNRAS.515.5242D
Altcode: 2021arXiv211107389D
Blazars may accelerate protons and/or nuclei as well as electrons. The
hadronic component of accelerated particles in blazars may constitute
the bulk of their high-energy budget; nevertheless, this component is
elusive because of the high value of the energy threshold of proton
interactions with photon fields inside the source. However, the
broad line regions (BLRs) of some flat spectrum radio quasars (FSRQs)
may contain a sufficient amount of matter to render primary protons
'visible' in γ-rays via hadronuclear interactions. In this paper,
we study the persistent γ-ray emission of the FSRQ PKS 1510-089 in
its low state, utilizing the publicly available Fermi-LAT data, as
well as using the spectrum measured with the Major Atmospheric Gamma
Imaging Cherenkov (MAGIC) telescopes. We find an indication that there
is an excess of γ-rays at the energy range ≳ 20 GeV with respect to
a simple baseline log-parabolic intrinsic spectral model. This excess
could be explained in a scenario invoking hadronuclear interactions
of primary protons on the BLR material with the subsequent development
of electromagnetic cascades in photon fields. We present a Monte Carlo
calculation of the spectrum of this cascade component, taking as input
the BLR photon field spectrum calculated with the CLOUDY code. To our
knowledge, this is the first calculation of an electromagnetic cascade
spectrum inside a blazar based on a direct calculation of the photon
field spectrum with a spectral synthesis code.
Title: Quasi-periodic Gaussian processes for stellar activity:
From physical to kernel parameters
Authors: Nicholson, B. A.; Aigrain, S.
Bibcode: 2022MNRAS.515.5251N
Altcode: 2022MNRAS.tmp.2007N; 2022arXiv220712164N
In recent years, Gaussian Process (GP) regression has become
widely used to analyse stellar and exoplanet time-series data
sets. For spotted stars, the most popular GP covariance function
is the quasi-periodic (QP) kernel, whose hyperparameters of the GP
have a plausible interpretation in terms of physical properties of
the star and spots. In this paper, we test the reliability of this
interpretation by modelling data simulated using a spot model using
a QP GP, and the recently proposed quasi-periodic plus cosine (QPC)
GP, comparing the posterior distributions of the GP hyperparameters
to the input parameters of the spot model. We find excellent agreement
between the input stellar rotation period and the QP and QPC GP period,
and very good agreement between the spot decay time-scale and the
length scale of the squared exponential term. We also compare the
hyperparameters derived from light and radial velocity (RV) curves
for a given star, finding that the period and evolution time-scales
are in good agreement. However, the harmonic complexity of the GP,
while displaying no clear correlation with the spot properties in
our simulations, is systematically higher for the RV than for the
light-curve data. Finally, for the QP kernel, we investigate the
impact of noise and time-sampling on the hyperparameters in the case
of RVs. Our results indicate that good coverage of rotation period and
spot evolution time-scales is more important than the total number of
points, and noise characteristics govern the harmonic complexity.
Title: Object classification on video data of meteors and meteor-like
phenomena: algorithm and data
Authors: Sennlaub, Rabea; Hofmann, Martin; Hankey, Mike; Ennes, Mario;
Müller, Thomas; Kroll, Peter; Mäder, Patrick
Bibcode: 2022MNRAS.516..811S
Altcode: 2022arXiv220814914S
Every moment, countless meteoroids enter our atmosphere unseen. The
detection and measurement of meteors offer the unique opportunity to
gain insights into the composition of our solar systems' celestial
bodies. Researchers therefore carry out a wide-area-sky-monitoring
to secure 360-degree video material, saving every single entry of
a meteor. Existing machine intelligence cannot accurately recognize
events of meteors intersecting the earth's atmosphere due to a lack
of high-quality training data publicly available. This work presents
four reusable open source solutions for researchers trained on data
we collected due to the lack of available labelled high-quality
training data. We refer to the proposed data set as the NightSkyUCP
data set, consisting of a balanced set of 10 000 meteor- and 10
000 non-meteor-events. Our solutions apply various machine-learning
techniques, namely classification, feature learning, anomaly detection,
and extrapolation. For the classification task, a mean accuracy of 99.1
per cent is achieved. The code and data are made public at figshare
with DOI 10.6084/m9.figshare.16451625.
Title: The intrinsic reddening of the Magellanic Clouds as traced
by background galaxies - III. The Large Magellanic Cloud
Authors: Bell, Cameron P. M.; Cioni, Maria-Rosa L.; Wright, Angus H.;
Nidever, David L.; Chiang, I. -Da; Choudhury, Samyaday; Groenewegen,
Martin A. T.; Pennock, Clara M.; Choi, Yumi; de Grijs, Richard; Ivanov,
Valentin D.; Massana, Pol; Nanni, Ambra; Noël, Noelia E. D.; Olsen,
Knut; van Loon, Jacco Th; Vivas, A. Katherina; Zaritsky, Dennis
Bibcode: 2022MNRAS.516..824B
Altcode: 2022arXiv220504406B; 2022MNRAS.tmp.1529B
We present a map of the total intrinsic reddening across ≃ 90
deg2 of the Large Magellanic Cloud (LMC) derived using
optical (ugriz) and near-infrared (IR; YJKs) spectral
energy distributions (SEDs) of background galaxies. The reddening
map is created from a sample of 222 752 early-type galaxies based on
the LEPHAREχ2 minimization SED-fitting routine. We find
excellent agreement between the regions of enhanced intrinsic reddening
across the central (4 × 4 deg2) region of the LMC and the
morphology of the low-level pervasive dust emission as traced by far-IR
emission. In addition, we are able to distinguish smaller, isolated
enhancements that are coincident with known star-forming regions and
the clustering of young stars observed in morphology maps. The level of
reddening associated with the molecular ridge south of 30 Doradus is,
however, smaller than in the literature reddening maps. The reduced
number of galaxies detected in this region, due to high extinction and
crowding, may bias our results towards lower reddening values. Our
map is consistent with maps derived from red clump stars and from
the analysis of the star formation history across the LMC. This study
represents one of the first large-scale categorizations of extragalactic
sources behind the LMC and as such we provide the LEPHARE outputs for
our full sample of ~ 2.5 million sources.
Title: Water-maser survey towards off-plane O-rich AGBs around the
orbital plane of the Sagittarius stellar stream
Authors: Wu, Yuanwei; Zhang, Bo; Li, Jingjing; Zheng, Xing-Wu
Bibcode: 2022MNRAS.516.1881W
Altcode: 2022arXiv220705914W
A 22 GHz water-maser survey was conducted towards 178 O-rich asymptotic
giant branch (AGB) stars with the aim of identifying maser emission
associated with the Sagittarius stellar stream. In this survey,
maser emissions were detected in 21 targets, 20 of which were new
detections. We studied the Galactic distributions of H2O-
and SiO-maser-traced AGBs towards the Sgr orbital plane, and found an
elongated structure towards the (l, b) ~ (340°, 40°) direction. In
order to verify its association with the Sagittarius tidal stream,
we further studied the 3D motion of these sources, but found that,
kinematically, these maser-traced AGBs are still Galactic disc sources
rather than stream debris. In addition, we found a remarkable outward
motion, ~50 km s-1 away from the Galactic Centre of these
maser-traced AGBs, but with no systermatic lag of rotational speed as
reported in 2000 for solar-neighbourhood Miras.
Title: Living on the Fermi edge: On baryon transport and Fermi
condensation
Authors: Trautner, Andreas
Bibcode: 2022PhLB..83337365T
Altcode: 2021arXiv210502900T
The transfer function of the baryon power spectrum from redshift z ≈
1100 to today has recently been, for the first time, determined from
data by Pardo and Spergel. We observe a remarkable coincidence between
this function and the transport function of a cold ideal Fermi gas
at different redshifts. Guided by this, we unveil an infinite set of
critical temperatures of the relativistic ideal Fermi gas which depend
on a very finely quantized long-distance cutoff. The sound horizon
scale of Baryon Acoustic Oscillations (BAO) seems to set such a cutoff,
which dials a critical temperature that is subsequently reached during
redshift. At the critical point the Fermi gas becomes scale invariant
and may condense to subsequently undergo gravitational collapse,
seeding small scale structure. We mention some profound implications
including the apparent quantization of Fermi momentum conjugate to
the cutoff and the corresponding "gapping" of temperature.
Title: A new candidate for central tidal disruption event in SDSS
J014124 + 010306 with broad Mg II line at z = 1.06
Authors: Zhang, Xue-Guang
Bibcode: 2022MNRAS.516L..66Z
Altcode: 2022MNRAS.tmpL..88Z
In the letter, a new candidate for central tidal disruption event (TDE)
is reported in SDSS J014124 + 010306 (= SDSS J0141) with broad Mg II
line at redshift $\mathit{ z}$ = 1.06. Based on long-term photometric
ugriz-band variabilities from SDSS Stripe82 Data base and PHOTOOBJALL
data base, a central TDE is preferred with a 1.3 M⊙
main-sequence star tidally disrupted by central black hole (BH) of
(14 ± 2) × 106 M⊙ in SDSS J0141. Moreover,
CAR process has been applied to confirm that the probability is only
about 0.4 per cent that the long-term variabilities in SDSS J0141
are not related to TDE but from intrinsic active galactic nucleus
(AGN) activities. Meanwhile, based on the apparent broad Mg II
emission lines, virial BH mass can be estimated as 245 × 106
M⊙, 18 times larger than the TDE model determined BH
mass, providing further clues to support a central TDE in SDSS J0141,
similar to the case in the TDE candidate SDSS J0159 with virial BH mass
two magnitudes larger than M-sigma relation expected BH mass. Among
the reported optical TDE candidates, SDSS J0141 is the candidate at
the highest redshift. The results in the letter indicate it should be
common to detect TDE candidates in high redshift galaxies with broad
Mg II lines.
Title: New highly precise weak gravitational lensing flexions
measurement method based on ERA method
Authors: Okura, Yuki; Futamase, Toshifumi
Bibcode: 2022MNRAS.516..668O
Altcode: 2022MNRAS.tmp.2126O; 2021arXiv210900155O
Weak gravitational lensing flexions are a kind of weak lensing
distortion that are defined as the spin 1 and spin 3 combinations of
the third order derivatives of gravitational lensing potential. Since
the shear has spin 2 combination of the second-order derivative,
the flexion signal gives partly independent information from shear
signal and is more sensitive to the local mass distribution than shear
signal. Thus its measurement is expected to play important roles in
observational cosmology. However, since the weakness of the flexion
signal, as well as the complicatedness of its intrinsic noise, made
its accurate observation very difficult. We propose a new method of
measuring the flexion signal using ERA method which is a method to
measure weak lensing shear without any approximation. We find two
particular combinations of the flexions which provide the quantities
with only lensing information and free of intrinsic noise when taken
average. It is confirmed by simple numerical simulation that the
statistical average of these combinations do not in fact depend on
the strength of the intrinsic distortion. Then, we introduce a method
which measures flexions with PSF correction. This method is developed by
applying the ERA method for flexion distortions and we call this method
the FIRE method. It uses the expansion technique with an assumption
of weak flexion, and we show by using typical examples of 1st and
2nd flexion images that the estimated errors become less than 1 per
cent in most cases with the lowest order of the expansion. Finally,
we apply the method for real data to measure flexion components in
real galaxy images.
Title: Optical spectroscopy of the extremely metal-deficient
star-forming galaxy HSC J1631+4426: a test of the strong-line method
Authors: Thuan, T. X.; Guseva, N. G.; Izotov, Y. I.
Bibcode: 2022MNRAS.516L..81T
Altcode: 2022arXiv220808766T; 2022MNRAS.tmpL..89T
Recently, Kojima and co-authors have reported a record low oxygen
abundance, 12 + logO/H = 6.90 ± 0.03, or 1.6 per cent of solar
metallicity, in the low-mass star-forming galaxy HSC J1631 +
4426. This exceptionally low oxygen abundance was obtained by the
direct method, using the [O III]λ4363Å emission line. However,
using the strong-line method by Izotov et al. (2019b), these authors
have derived a significantly higher metallicity 12 + logO/H = 7.175 ±
0.005. To clarify the situation, we have obtained new observations of
HSC J1631 + 4426 with the Large Binocular Telescope (LBT)/Multi-Object
Dual Spectrograph (MODS). We have derived a higher oxygen abundance,
12 + logO/H = 7.14 ± 0.03, using the direct method, a value similar
to the oxygen abundance obtained by the strong-line method. Thus,
HSC J1631 + 4426 has a metallicity close to that of the well known
blue compact dwarf galaxy I Zw 18.
Title: Milky Way mass with K giants and BHB stars using LAMOST,
SDSS/SEGUE, and Gaia: 3D spherical Jeans equation and tracer mass
estimator
Authors: Bird, Sarah A.; Xue, Xiang-Xiang; Liu, Chao; Flynn, Chris;
Shen, Juntai; Wang, Jie; Yang, Chengqun; Zhai, Meng; Zhu, Ling; Zhao,
Gang; Tian, Hai-Jun
Bibcode: 2022MNRAS.516..731B
Altcode: 2022MNRAS.tmp.1951B; 2022arXiv220708839B
We measure the enclosed Milky Way mass profile to Galactocentric
distances of ~70 and ~50 kpc using the smooth, diffuse stellar halo
samples of Bird et al. The samples are Large Sky Area Multi-Object Fiber
Spectroscopic Telescope (LAMOST) and Sloan Digital Sky Survey/Sloan
Extension for Galactic Understanding and Exploration (SDSS/SEGUE)
K giants (KG) and SDSS/SEGUE blue horizontal branch (BHB) stars
with accurate metallicities. The 3D kinematics are available through
LAMOST and SDSS/SEGUE distances and radial velocities and Gaia DR2
proper motions. Two methods are used to estimate the enclosed mass:
3D spherical Jeans equation and Evans et al. tracer mass estimator
(TME). We remove substructure via the Xue et al. method based on
integrals of motion. We evaluate the uncertainties on our estimates
due to random sampling noise, systematic distance errors, the adopted
density profile, and non-virialization and non-spherical effects of
the halo. The tracer density profile remains a limiting systematic in
our mass estimates, although within these limits we find reasonable
agreement across the different samples and the methods applied. Out
to ~70 and ~50 kpc, the Jeans method yields total enclosed masses
of 4.3 ± 0.95 (random) ±0.6 (systematic) × 1011
M⊙ and 4.1 ± 1.2 (random) ±0.6 (systematic)
× 1011 M⊙ for the KG and BHB stars,
respectively. For the KG and BHB samples, we find a dark matter virial
mass of $M_{200}=0.55^{+0.15}_{-0.11}$ (random) ±0.083 (systematic)
× 1012 M⊙ and $M_{200}=1.00^{+0.67}_{-0.33}$
(random) ±0.15 (systematic) × 1012 M⊙,
respectively.
Title: The pre-He white dwarfs in eclipsing binaries - IV. WASP
1814+48 with multiperiodic pulsations
Authors: Lee, Jae Woo; Hong, Kyeongsoo; Kim, Hye-Young; Park, Jang-Ho
Bibcode: 2022MNRAS.515.4702L
Altcode: 2022arXiv220711858L; 2022MNRAS.tmp.2110L
For the EL CVn candidate 1SWASPJ181417.43+481117.0 (WASP 1814+48),
we secured the first spectroscopic observations between 2015 April
and 2021 March. Using the echelle spectra, the radial velocities (RVs)
of the primary star were measured with its atmospheric parameters of
Teff, 1 = 7770 ± 130 K and $v$1sin i = 47 ± 6
km s-1. We fitted our single-lined RVs and the TESS light
curve simultaneously. From the binary modelling, we determined the
following fundamental parameters for each component: M1
= 1.659 ± 0.048 M⊙, R1 = 1.945 ± 0.027
R⊙, and L1 = 12.35 ± 0.90 L⊙ for
WASP 1814+48 A, and M2 = 0.172 ± 0.005 M⊙,
R2 = 0.194 ± 0.005 R⊙, and L2 =
0.69 ± 0.07 L⊙ for WASP 1814+48 B. The surface gravity
of log g2 = 5.098 ± 0.026 obtained from M2
and R2 is concurrent with 5.097 ± 0.025 computed directly
from the observable quantities. WASP 1814+48 B is well matched with
the 0.176-M⊙ white dwarf (WD) evolutionary model for Z =
0.01. The metallicity and our Galactic kinematics indicate that the
program target is a thin-disc star. The whole light residuals after the
removal of the binary trend were analysed and found to oscillate at
a total of 52 frequencies. Among these, most of the low frequencies
below 24 d-1 are aliases and orbital harmonics. The
five significant frequencies between 32 and 36 d-1 are
the pulsation modes of WASP 1814+48 A located in the δ Sct domain
on the zero-age main sequence, and the high frequencies of 128-288
d-1 arise from WASP 1814+48 B in the pre-He WD instability
strip. Our results reveal that WASP 1814+48 is the fifth EL CVn star
that is composed of a δ Sct-type primary and a pre-ELMV (extremely
low-mass pre-He WD variable).
Title: The very knotty lenser: Exploring the role of regularization in
source and potential reconstructions using Gaussian process regression
Authors: Vernardos, G.; Koopmans, L. V. E.
Bibcode: 2022MNRAS.516.1347V
Altcode: 2022MNRAS.tmp.1864V; 2022arXiv220209378V
Reconstructing lens potentials and lensed sources can easily become an
underconstrained problem, even when the degrees of freedom are low, due
to degeneracies, particularly when potential perturbations superimposed
on a smooth lens are included. Regularization has traditionally been
used to constrain the solutions where the data failed to do so, e.g. in
unlensed parts of the source. In this exploratory work, we go beyond
the usual choices of regularization and adopt observationally motivated
priors for the source brightness. We also perform a similar comparison
when reconstructing lens potential perturbations, which are assumed
to be stationary, i.e. permeate the entire field of view. We find that
physically motivated priors lead to lower residuals, avoid overfitting,
and are decisively preferred within a Bayesian quantitative framework in
all the examples considered. For the perturbations, choosing the wrong
regularization can have a detrimental effect that even high-quality
data cannot correct for, while using a purely smooth lens model can
absorb them to a very high degree and lead to biased solutions. Finally,
our new implementation of the semi-linear inversion technique provides
the first quantitative framework for measuring degeneracies between
the source and the potential perturbations.
Title: Spin-down induced quark-hadron phase transition in cold
isolated neutron stars
Authors: Prasad, R.; Mallick, Ritam
Bibcode: 2022MNRAS.516.1127P
Altcode: 2022MNRAS.tmp.2220P; 2022arXiv220703234P
We have studied the spin-down induced phase transition (PT) in cold,
isolated neutron stars in this work. After birth, as the star slows
down, its central density rises and crosses the critical density of
PT, and a quark core is seeded inside the star. Intermediate-mass
stars are more likely to have a quark seeding in their lifetime at
birth. Smaller neutron stars do not have a quark core and remain neutron
stars throughout their life, whereas in massive stars, a quark core
exists at their centre from birth. In intermediate and massive stars,
the quark core grows further as the star slows down. The appearance
of a quark core leads to a sudden change in the moment of inertia
of the star in its evolutionary history, and is also reflected in a
sudden discontinuity in the braking index of the star (at the frequency
where the quark core first seeds). The energy released during the PT
process as the quark core is seeded can excite the f-mode oscillation
in the star and is emitted in the form of the gravitational wave,
which is in the range of detection with present operating detectors;
however, future detectors will enable a more clean extraction of this
signals. Also, neutrinos and bursts of gamma-rays can originate from
PT events. The spin-down induced PT could be gradual or in the form of
subsequent leaps producing persistent or multiple transient emissions.
Title: Galaxy And Mass Assembly (GAMA): bulge-disc decomposition of
KiDS data in the nearby Universe
Authors: Casura, Sarah; Liske, Jochen; Robotham, Aaron S. G.; Brough,
Sarah; Driver, Simon P.; Graham, Alister W.; Häußler, Boris;
Holwerda, Benne W.; Hopkins, Andrew M.; Kelvin, Lee S.; Moffett,
Amanda J.; Taranu, Dan S.; Taylor, Edward N.
Bibcode: 2022MNRAS.516..942C
Altcode: 2022arXiv220807608C; 2022MNRAS.tmp.2205C
We derive single Sérsic fits and bulge-disc decompositions for 13
096 galaxies at redshifts z < 0.08 in the GAMA II equatorial survey
regions in the Kilo-Degree Survey (KiDS) g, r, and i bands. The surface
brightness fitting is performed using the Bayesian two-dimensional
profile fitting code PROFIT. We fit three models to each galaxy in
each band independently with a fully automated Markov chain Monte
Carlo analysis: a single Sérsic model, a Sérsic plus exponential
and a point source plus exponential. After fitting the galaxies, we
perform model selection and flag galaxies for which none of our models
are appropriate (mainly mergers/Irregular galaxies). The fit quality
is assessed by visual inspections, comparison to previous works,
comparison of independent fits of galaxies in the overlap regions
between KiDS tiles and bespoke simulations. The latter two are also
used for a detailed investigation of systematic error sources. We
find that our fit results are robust across various galaxy types
and image qualities with minimal biases. Errors given by the MCMC
underestimate the true errors typically by factors 2-3. Automated
model selection criteria are accurate to $\gt 90{{\ \rm per\ cent}}$
as calibrated by visual inspection of a subsample of galaxies. We also
present g-r component colours and the corresponding colour-magnitude
diagram, consistent with previous works despite our increased fit
flexibility. Such reliable structural parameters for the components of
a diverse sample of galaxies across multiple bands will be integral
to various studies of galaxy properties and evolution. All results
are integrated into the GAMA database.
Title: WR 63: a multiple system (O+O) + WR?
Authors: Chené, André-Nicolas; Mahy, Laurent; Gosset, Eric; St-Louis,
Nicole; Dsilva, Karan; Manick, Rajeev
Bibcode: 2022MNRAS.516.1022C
Altcode: 2022arXiv220802487C
The spectrum of the Wolf-Rayet (WR) star WR 63 contains spectral
lines of two different O stars that show regular radial velocity
(RV) variations with amplitudes of ~160 and ~225 km s-1
on a ~4.03 d period. The light curve shows two narrow eclipses that
are 0.2 mag deep on the same period as the RV changes. On the other
hand, our data show no significant RV variations for the WR spectral
lines. Those findings are compatible with WR 63 being a triple
system composed of two non-interacting late-O stars orbiting a WR
star on a period longer than 1000 d. The amplitude of the WR spectral
line-profile variability reaches 7-8 per cent of the line intensity
and seems related to a 0.04 mag periodic photometric variation. Large
wind density structures are a possible origin for this variability, but
our data are not sufficient to verify this. Our analysis shows that,
should the three stars be bound, they would be coeval with an age of
about 5.9 ± 1.4 Myr. The distance to the O stars is estimated to be
$3.4\, \pm \, 0.5$ kpc. Their dynamical masses are 14.3 ± 0.1 and
10.3 ± 0.1 M⊙. Using rotating single-star evolutionary
tracks, we estimate their initial masses to be 18 ± 2 and 16 ± 2
M⊙ for the primary and the secondary, respectively. Regular
spectral monitoring is required in the future to detect RV variations
of the WR star that would prove that it is gravitationally bound to
the close O+OB system and to determine its mass.
Title: The N2 production rate in comet C/2016 R2
(PanSTARRS)
Authors: Anderson, S. E.; Rousselot, P.; Noyelles, B.; Opitom, C.;
Jehin, E.; Hutsemékers, D.; Manfroid, J.
Bibcode: 2022MNRAS.515.5869A
Altcode: 2022MNRAS.tmp.2003A; 2022arXiv220814849A
Observations of comet C/2016 R2 (PanSTARRS) have revealed exceptionally
bright emission bands of N$_2^+$, the strongest ever observed in a comet
spectrum. Alternatively, it appears to be poor in CN compared to other
comets, and remarkably depleted in H2O. Here, we quantify
the N2 production rate from N$_2^+$ emission lines using the
Haser model. We derived effective parent and daughter scale lengths for
N2 producing N$_2^+$. This is the first direct measurement of
such parameters. Using a revised fluorescence efficiency for N$_2^+$,
the resulting production rate of molecular nitrogen is inferred to
be Q(N2) ~ 1 × 1028 molecules s-1
on average for 2018 February 11, 12, and 13, the highest for any known
comet. Based on a CO production rate of Q(CO) ~ 1.1 × 1029
molecules s-1, we find Q(N2)/Q(CO) ~ 0.09, which
is consistent with the N$_2^+$/CO+ ratio derived from the
observed intensities of N$_2^+$ and CO+ emission lines. We
also measure significant variations in this production rate between
our three observing nights, with Q(N2) varying by plus or
minus 20 per cent according to the average value.
Title: The Zwicky Transient Facility phase I sample of hydrogen-rich
superluminous supernovae without strong narrow emission lines
Authors: Kangas, T.; Yan, Lin; Schulze, S.; Fransson, C.; Sollerman,
J.; Lunnan, R.; Omand, C. M. B.; Andreoni, I.; Burruss, R.; Chen,
T. -W.; Drake, A. J.; Fremling, C.; Gal-Yam, A.; Graham, M. J.; Groom,
S. L.; Lezmy, J.; Mahabal, A. A.; Masci, F. J.; Perley, D.; Riddle,
R.; Tartaglia, L.; Yao, Y.
Bibcode: 2022MNRAS.516.1193K
Altcode: 2022arXiv220712059K; 2022MNRAS.tmp.2116K
We present a sample of 14 hydrogen-rich superluminous supernovae (SLSNe
II) from the Zwicky Transient Facility (ZTF) between 2018 and 2020. We
include all classified SLSNe with peaks Mg < -20 mag with
observed broad but not narrow Balmer emission, corresponding to roughly
20 per cent of all hydrogen-rich SLSNe in ZTF phase I. We examine
the light curves and spectra of SLSNe II and attempt to constrain
their power source using light-curve models. The brightest events are
photometrically and spectroscopically similar to the prototypical SN
2008es, while others are found spectroscopically more reminiscent
of non-superluminous SNe II, especially SNe II-L. 56Ni
decay as the primary power source is ruled out. Light-curve models
generally cannot distinguish between circumstellar interaction (CSI)
and a magnetar central engine, but an excess of ultraviolet (UV)
emission signifying CSI is seen in most of the SNe with UV data, at a
wide range of photometric properties. Simultaneously, the broad H α
profiles of the brightest SLSNe II can be explained through electron
scattering in a symmetric circumstellar medium (CSM). In other SLSNe
II without narrow lines, the CSM may be confined and wholly overrun
by the ejecta. CSI, possibly involving mass lost in recent eruptions,
is implied to be the dominant power source in most SLSNe II, and
the diversity in properties is likely the result of different mass
loss histories. Based on their radiated energy, an additional power
source may be required for the brightest SLSNe II, however - possibly
a central engine combined with CSI.
Title: AGN feedback duty cycle in Planck SZ selected clusters using
Chandra observations
Authors: Olivares, V.; Su, Y.; Nulsen, P.; Kraft, R.; Somboonpanyakul,
T.; Andrade-Santos, F.; Jones, C.; Forman, W.
Bibcode: 2022MNRAS.516L.101O
Altcode: 2022MNRAS.tmpL..91O; 2022arXiv220804888O
We present a systematic study of X-ray cavities using archival
Chandra observations of nearby galaxy clusters selected by their
Sunyaev-Zel'dovich (SZ) signature in the Planck survey, which provides a
nearly unbiased mass-selected sample to explore the entire AGN feedback
duty cycle. Based on X-ray image analysis, we report that 30 of the 164
clusters show X-ray cavities, which corresponds to a detection fraction
of 18 per cent. After correcting for spatial resolution to match the
high-$\mathit{ z}$ SPT-SZ sample, the detection fraction decreases to
9 per cent, consistent with the high-z sample, hinting that the AGN
feedback has not evolved across almost 8 Gyrs. Our finding agrees with
the lack of evolution of cool-core clusters fraction. We calculate
the cavity power, Pcav, and find that most systems of our
sample have enough AGN heating to offset the radiative losses of the
intracluster medium.
Title: Peculiar motion of Solar system from the Hubble diagram of
supernovae Ia and its implications for cosmology
Authors: Singal, Ashok K.
Bibcode: 2022MNRAS.515.5969S
Altcode: 2021arXiv210611968S; 2022MNRAS.tmp.1914S
Peculiar motion of the Solar system, determined from the dipole
anisotropy in the Cosmic Microwave Background Radiation (CMBR),
has given a velocity 370 km s-1 along RA = 168°, Dec. =
-7°. Subsequent peculiar motion determinations from the number counts,
sky brightness, or redshift dipoles observed in large samples of distant
radio galaxies and quasars yielded peculiar velocities 2 to 10 times
larger than CMBR, though in all cases the directions matched with the
CMBR dipole. Here, we introduce a novel technique for determining the
peculiar motion from the magnitude-redshift (mB-z) Hubble
diagram of Type Ia Supernovae (SN Ia), one of the best standard candles
available. We find a peculiar velocity 1.6 ± 0.5 × 103
km s-1, larger than the CMBR value roughly by a factor of
four, along RA = 173° ± 12°, Dec. = 10° ± 9°, the direction being
within $\stackrel{\lt }{_{\sim }}2\sigma$ of the CMBR dipole. Since a
genuine solar motion would not depend upon the method or the data set
employed, large discrepancies seen among various dipole amplitudes
could imply that these dipoles, including the CMBR one, might not
pertain to observer's peculiar motion. However, a common direction for
various dipoles might indicate a preferred direction in the Universe,
implying an intrinsic anisotropy, in violation of the cosmological
principle, a cornerstone of the modern cosmology.
Title: Arp 58 and Arp 68: two M 51-type systems
Authors: Zasov, Anatoly V.; Saburova, Anna S.; Egorov, Oleg V.;
Lander, Vsevolod Yu; Makarov, Dmitry I.
Bibcode: 2022MNRAS.516..656Z
Altcode: 2022arXiv220714214Z; 2022MNRAS.tmp.2064Z
We study two M 51-type systems Arp 68 and Arp 58, which strongly
differ by their stellar masses, gas content, and environment. Long-slit
spectral observations obtained at the Russian 6-m telescope were used
to trace the distributions of a line-of-sight (LOS) velocity and
a gas-phase oxygen abundance along the spectral cuts. Two systems
are compared by their observed properties. We found a very strong
large-scale non-circular motion of gas in both systems and a kpc-size
saw-edged velocity profile along the tidal spiral arm of Arp 68,
probably caused by the gas outflow due to the stellar feedback. A deep
decrease of LOS velocity is also found in the 'hinge' region in Arp
58, where the inner spiral arm transforms into the tidal spiral arm,
which was predicted earlier for M 51-type galaxies. Local sites of
star formation and the satellites are compared with the evolutionary
models at the colour-colour diagrams. Unlike the spiral galaxy Arp
58, the main galaxy in Arp 68 system is experiencing an ongoing burst
of star formation. Gas-phase metallicity estimates show that Arp 58
has a higher metal abundance and reveals a shallow negative radial
gradient of the gas-phase oxygen abundance. The emission gas in Arp
68 has noticeably lower metallicity than it is expected for a given
luminosity of this galaxy, which may be connected with its space
position in the local void.
Title: On the long-term stability of the Solar system in the presence
of weak perturbations from stellar flybys
Authors: Brown, Garett; Rein, Hanno
Bibcode: 2022MNRAS.515.5942B
Altcode: 2022arXiv220614240B; 2022MNRAS.tmp.1749B
The architecture and evolution of planetary systems are shaped in part
by stellar flybys. Within this context, we look at stellar encounters
that are too weak to immediately destabilize a planetary system but
are nevertheless strong enough to measurably perturb the system's
dynamical state. We estimate the strength of such perturbations
on secularly evolving systems using a simple analytic model and
confirm those estimates with direct N-body simulations. We then run
long-term integrations and show that even small perturbations from
stellar flybys can influence the stability of planetary systems over
their lifetime. We find that small perturbations to the outer planets'
orbits are transferred between planets, increasing the likelihood that
the inner planetary system will destabilize. Specifically, our results
for the Solar system show that relative perturbations to Neptune's
semimajor axis of order 0.1 per cent are strong enough to increase
the probability of destabilizing the Solar system within 5 Gyr by one
order of magnitude.
Title: KilonovaNet: Surrogate models of kilonova spectra with
conditional variational autoencoders
Authors: Lukošiute, K.; Raaijmakers, G.; Doctor, Z.; Soares-Santos,
M.; Nord, B.
Bibcode: 2022MNRAS.516.1137L
Altcode: 2022MNRAS.tmp.2265L; 2022arXiv220400285L
Detailed radiative transfer simulations of kilonova spectra play an
essential role in multimessenger astrophysics. Using the simulation
results in parameter inference studies requires building a surrogate
model from the simulation outputs to use in algorithms requiring
sampling. In this work, we present kilonovanet, an implementation of
conditional variational autoencoders (cVAEs) for the construction of
surrogate models of kilonova spectra. This method can be trained on
spectra directly, removing overhead time of pre-processing spectra,
and greatly speeds up parameter inference time. We build surrogate
models of three state-of-the-art kilonova simulation data sets and
present in-depth surrogate error evaluation methods, which can in
general be applied to any surrogate construction method. By creating
synthetic photometric observations from the spectral surrogate,
we perform parameter inference for the observed light-curve data of
GW170817 and compare the results with previous analyses. Given the
speed with which kilonovanet performs during parameter inference,
it will serve as a useful tool in future gravitational wave observing
runs to quickly analyse potential kilonova candidates.
Title: Feeding post-core collapse supernova explosion jets with an
inflated main sequence companion
Authors: Hober, Ofek; Bear, Ealeal; Soker, Noam
Bibcode: 2022MNRAS.516.1846H
Altcode: 2022arXiv220511059H; 2022MNRAS.tmp.2257H
We simulate the response of a main sequence star to the explosion of
a stripped-envelope (type Ib or Ic) core-collapse supernova (CCSN)
when the main sequence star orbits the core at a distance of $10 \,
\mathrm{R}_\odot$ or $20 \, \mathrm{R}_\odot$ at explosion. We use the
stellar evolution code MESA to follow the response of main sequence
stars of masses $3 \, \mathrm{M}_\odot$ and $7\, \mathrm{M}_\odot$
to energy deposition and mass removal. The collision of the CCSN
ejecta with the main sequence star deposits energy and inflate the
main sequence star. If the binary system stays bound after the CCSN
explosion, the inflated main sequence star might engulf the newly
born neutron star (NS). We assume that the NS accretes mass through
an accretion disc and launches jets. The jets remove mass from the
inflated main sequence star and collide with the CCSN ejecta. Although
this scenario is rare, it adds up to other rare scenarios to further
support the notion that many stripped envelope CCSNe are powered by
late jets. The late jets can power these CCSNe-I for a long time and
might power bumps in their light curve. The jets might also shape
the inner ejecta to a bipolar morphology. Our results further support
suggestions that there are several ways to feed an NS (or a black hole)
to launch the late jets in superluminous supernovae.
Title: SDSS-IV MaNGA: The MaNGA Dwarf Galaxy Sample Presentation
Authors: Cano-Díaz, M.; Hernández-Toledo, H. M.; Rodríguez-Puebla,
A.; Ibarra-Medel, H. J.; Ávila-Reese, V.; Valenzuela, O.;
Medellin-Hurtado, A. E.; Vázquez-Mata, J. A.; Weijmans, A.; González,
J. J.; Aquino-Ortiz, E.; Martínez-Vázquez, L. A.; Lane, Richard R.
Bibcode: 2022AJ....164..127C
Altcode: 2022arXiv220801664C
We present the MaNGA Dwarf galaxy (MaNDala) Value Added Catalog
(VAC), from the final release of the Sloan Digital Sky Survey-IV
program. MaNDala consists of 136 randomly selected bright dwarf
galaxies with M * < 109.1 M ⊙
and M g > -18.5, making it the largest integral
field spectroscopy homogeneous sample of dwarf galaxies. We release
a photometric analysis of the g, r, and z broadband imaging based on
the DESI Legacy Imaging Surveys, as well as a spectroscopic analysis
based on the Pipe3D SDSS-IV VAC. Our release includes the surface
brightness (SB), geometric parameters, and color profiles, Sérsic
fits as well as stellar population properties (such as stellar ages,
metallicities, and star formation histories), and emission lines'
fluxes within the FOV and the effective radii of the galaxies. We find
that the majority of the MaNDala galaxies are star-forming late-type
galaxies with <n Sersic,r> ~ 1.6 that are centrals
(central/satellite dichotomy). MaNDala covers a large range of SB values
(we find 11 candidate ultra-diffuse galaxies and three compact ones),
filling the gap between classical dwarfs and low-mass galaxies in
the Kormendy Diagram and in the size-mass/luminosity relation, which
seems to flatten at 108 < M */M ⊙
< 109 with <R e,r > ~ 2.7 kpc. A large
fraction of MaNDala galaxies formed from an early low-metallicity burst
of SF, but also from late SF events from more metal-enriched gas: half
of the MaNDala galaxies assembled 50% of their mass at <z> >
2, while the last 20% was at <z> < 0.3. Finally, a bending
of the sSFR-M * relation at M * ~ 109
M ⊙ for the main-sequence galaxies seems to be supported
by MaNDala.
Title: ULX pulsar Swift J0243.6+6124 observations with NuSTAR:
dominance of reflected emission in the super-Eddington state
Authors: Bykov, S. D.; Gilfanov, M. R.; Tsygankov, S. S.; Filippova,
E. V.
Bibcode: 2022MNRAS.516.1601B
Altcode: 2022arXiv220803126B; 2022MNRAS.tmp.2158B
We report the discovery of the bright reflected emission component
in the super-Eddington state of the ultraluminous X-ray pulsar Swift
J0243.6+6124, based on the NuSTAR observations of the source during its
2017 outburst. The flux of the reflected emission is weakly variable
over the pulsar phase while the direct emission shows significantly
larger pulsation amplitude. We propose that in this system the neutron
star finds itself in the centre of the well formed by the inner edge
of the geometrically thick super-Eddington accretion disc truncated by
the magnetic field of the pulsar. The aspect ratio of the well is H/R ~
1. The inner edge of the truncated disc is continuously illuminated
by the emission of the accretion column giving rise to the weakly
variable reflected emission. As the neutron star rotates, its emission
sweeps through the line of sight, giving rise to the pulsating direct
emission. From Doppler broadening of the iron line, we measure the
truncation radius of the accretion disc ~50 Rg. The inferred
dipole component of the magnetic field is consistent with previous
estimates favouring a not very strong field. The uniqueness of this
system is determined by its moderately super-Eddington accretion rate
and the moderate magnetic field so that the inner edge of the truncated
geometrically thick accretion disc is seen from the neutron star at
a large solid angle.
Title: Analytic models of dust temperature in high-redshift galaxies
Authors: Hirashita, Hiroyuki; Chiang, I. -Da
Bibcode: 2022MNRAS.516.1612H
Altcode: 2022arXiv220804546H; 2022MNRAS.tmp.2161H
We investigate physical reasons for high-dust temperatures
(Tdust ≳ 40K) observed in some high-redshift ($z$
> 5) galaxies using analytic models. We consider two models
that can be treated analytically: the radiative transfer (RT)
model, where a broad distribution of values for Tdust
is considered, and the one-tempearture (one-T) model, which assumes
uniform Tdust. These two extremes serve to bracket the most
realistic scenario. We adopt the Kennicutt-Schmidt (KS) law to relate
stellar radiation field to gas surface density, and vary the dust-to-gas
ratio. As a consequence, our model is capable of predicting the relation
between the surface density of star formation rate (ΣSFR)
or dust mass (Σdust) and Tdust. We show
that the high Tdust observed at $z$ ≳ 5 favour low
dust-to-gas ratios (≲ 10-3). An enhanced star formation
compared with the KS law gives an alternative explanation for the high
Tdust. The dust temperatures are similar between the two (RT
and one-T) models as long as we use ALMA Bands 6-8. We also examine the
relation among ΣSFR, Σdust, and Tdust
without assuming the KS law, and confirm the consistency with the actual
observational data at $z$ > 5. In the one-T model, we also examine a
clumpy dust distribution, which predicts lower Tdust because
of the leakage of stellar radiation. This enhances the requirement of
low-dust abundance or high-star formation efficiency to explain the
observed high Tdust.
Title: Saha equilibrium for metastable bound states and dark matter
freeze-out
Authors: Binder, Tobias; Filimonova, Anastasiia; Petraki, Kalliopi;
White, Graham
Bibcode: 2022PhLB..83337323B
Altcode: 2021arXiv211200042B
The formation and decay of metastable bound states can significantly
decrease the thermal-relic dark matter density, particularly for
dark matter masses around and above the TeV scale. Incorporating
bound-state effects in the dark matter thermal decoupling requires
in principle a set of coupled Boltzmann equations for the bound and
unbound species. However, decaying bound states attain and remain in a
quasi-steady state. Here we prove in generality that this reduces the
coupled system into a single Boltzmann equation of the standard form,
with an effective cross-section that describes the interplay among
bound-state formation, ionisation, transitions and decays. We derive a
closed-form expression for the effective cross-section for an arbitrary
number of bound states, and show that bound-to-bound transitions
can only increase it. Excited bound levels may thus decrease the dark
matter density more significantly than otherwise estimated. Our results
generalise the Saha ionisation equilibrium to metastable bound states,
potentially with applications beyond the dark matter thermal decoupling.
Title: Tracers of Dense Gas in the Outer Galaxy
Authors: Patra, Sudeshna; Evans, Neal J., II; Kim, Kee-Tae; Heyer,
Mark; Kauffmann, Jens; Jose, Jessy; Samal, Manash R.; Das, Swagat R.
Bibcode: 2022AJ....164..129P
Altcode: 2022arXiv220711613P
We have mapped $\mathrm{HCN}$ and HCO+ (J = 1 → 0)
line emission toward a sample of seven star-forming regions (with
$12+\mathrm{log}[{\rm{O}}/{\rm{H}}]$ ranging from 8.34 to 8.69) in
the outer Milky Way (Galactocentric distance >9.5 kpc), using the
14 m radio telescope of the Taeduk Radio Astronomy Observatory. We
compare these two molecular lines with other conventional tracers
of dense gas, millimeter-wave continuum emission from dust and
extinction thresholds (A V ≥ 8 mag), inferred from
the 13CO line data. $\mathrm{HCN}$ and HCO+
correlate better with the millimeter emission than with the extinction
criterion. A significant amount of luminosity comes from regions below
the extinction criterion and outside the millimeter clump for all
the clouds. The average fraction of $\mathrm{HCN}$ luminosity from
within the regions with A V ≥ 8 mag is 0.343 ± 0.225;
for the regions of millimeter emission, it is 0.478 ± 0.149. Based on
a comparison with column density maps from Herschel, $\mathrm{HCN}$
and HCO+ trace dense gas in high column density regions
better than does 13CO. HCO+ is less concentrated
than $\mathrm{HCN}$ for outer Galaxy targets, in contrast with the inner
Galaxy sample, suggesting that metallicity may affect the interpretation
of tracers of dense gas. The conversion factor between the dense gas
mass (M dense) and line luminosities of $\mathrm{HCN}$ and
HCO+, when integrated over the whole cloud, is comparable
to factors used in extragalactic studies.
Title: Impact of intrinsic alignments on clustering constraints of
the growth rate
Authors: Zwetsloot, Karel; Chisari, Nora Elisa
Bibcode: 2022MNRAS.516..787Z
Altcode: 2022arXiv220807062Z; 2022MNRAS.tmp.2249Z
Intrinsic alignments between galaxies and the large-scale structure
contaminate galaxy clustering analyses and impact constraints on
galaxy bias and the growth rate of structure in the Universe. This is
the result of alignments inducing a selection effect on spectroscopic
samples which is correlated with the large-scale structure. In this
work, we quantify the biases on galaxy bias and the growth rate
when alignments are neglected. We also examine different options for
the mitigation of alignments by considering external priors on the
effect and different probe combinations. We find that conservative
analyses that restrict to kmax = 0.1 Mpc-1
are not significantly affected. However, analyses that aim to go to
higher wave numbers could evidence a significant contamination from
alignments. In those cases, including a prior on alignment amplitude,
or combining clustering with the position-intrinsic shape correlation
of galaxies, can recover the same expected constraining power, or even
inform bias and growth rate measurements.
Title: Spectroscopic analysis of BPS CS 22940-0009: connecting
evolved helium stars
Authors: Snowdon, E. J.; Scott, L. J. A.; Jeffery, C. S.; Woolf, V. M.
Bibcode: 2022MNRAS.516..794S
Altcode: 2022MNRAS.tmp.2199S; 2022arXiv220807720S
BPS CS 22940-0009 is a helium-rich B-star that shares characteristics
with both helium-rich B subdwarfs and extreme helium stars. The
optical spectrum of BPS CS 22940-0009 has been analysed from SALT
observations. The atmospheric parameters were found to be $T_{\rm eff}
= 34\, 970 \pm 370$ K, $\log g/{\rm cm\, s^{-2}} = 4.79 \pm 0.17$,
nH/nHe ≃ 0.007, nC/nHe
≃ 0.007, nN/nHe ≃ 0.002, although further
improvement to the helium line fits would be desirable. This places the
star as a link between the He-sdB and EHe populations in g-T space. The
abundance profile shows enrichment of N from CNO-processing, and C from
3α burning. Depletion of Al, Si, S and a low upper limit for Fe show
the star to be intrinsically metal-poor. The results are consistent
with BPS CS 22940-0009 having formed from the merger of two helium
white dwarfs and currently evolving towards the helium main sequence.
Title: Probing the cosmological principle with the CSST photometric
survey
Authors: Xu, Yu-Tian; Dai, Ji-Ping; Zhao, Dong; Xia, Jun-Qing
Bibcode: 2022MNRAS.515.5587X
Altcode: 2022arXiv220810832X; 2022MNRAS.tmp.2104X
The cosmological principle states that our Universe is statistically
homogeneous and isotropic at large scales. However, due to the relative
motion of the Solar System, an additional kinematic dipole can be
detected in the distribution of galaxies, which should be consistent
with the dipole observed in the cosmic microwave background (CMB)
temperature. In this paper, we forecast the mock number count maps from
the China Space Station Telescope photometric survey to reconstruct
the kinematic dipole. Using the whole photometric mock data, we obtain
a positive evidence for the dipole signal detection at 3σ confidence
level, and the significance would be increased to 4σ when we only use
the high-redshift samples with z = 1.8 ~ 4. This result can provide
a good consistency check between the kinematic dipoles measured in
the CMB and that from the large-scale structure, which can help us to
verify the basic cosmological principle.
Title: The fall of CSS100217: a tidal disruption-induced low state
in an apparently hostless active galactic nucleus
Authors: Cannizzaro, G.; Levan, A. J.; van Velzen, S.; Brown, G.
Bibcode: 2022MNRAS.516..529C
Altcode: 2022arXiv220707402C; 2022MNRAS.tmp.1959C
CSS100217 was a nuclear, rapid, and luminous flare in a narrow-line
seyfert 1 galaxy, whose initial interpretation as a supernova is now
debated between variability of the active galactic nucleus (AGN) and a
tidal disruption event (TDE). In this paper, we present and discuss new
evidence in favour of a TDE or extreme flaring episode scenario. After
the decay of the flare, the galaxy entered a long-term low luminosity
state, 0.4 mag lower than the pre-outburst emission in the V band. We
attribute this to the creation of a cavity in the accretion disc after
the tidal disruption of a star in a retrograde orbit with respect to
the accretion disc rotation, making a TDE our favoured interpretation
of the flare. We also show how the host galaxy shows a point-like,
compact profile, no evidence for an extended component and a relatively
low mass, unlike what expected from an AGN host galaxy at z = 0.147. A
compact host galaxy may result in an increased TDE rate, strengthening
our interpretation of the event.
Title: Extreme mass ratio inspirals triggered by massive black hole
binaries: from relativistic dynamics to cosmological rates
Authors: Mazzolari, Giovanni; Bonetti, Matteo; Sesana, Alberto;
Colombo, Riccardo M.; Dotti, Massimo; Lodato, Giuseppe;
Izquierdo-Villalba, David
Bibcode: 2022MNRAS.516.1959M
Altcode: 2022MNRAS.tmp.2192M; 2022arXiv220405343M
Extreme mass ratio inspirals (EMRIs) are compact binary
systems characterized by a mass ratio q = m/M in the range
10-9-10-4 and represent primary gravitational
wave (GW) sources for the forthcoming Laser Interferometer Space
Antenna (LISA). While their standard formation channel involves
relaxation processes deflecting compact objects on very low angular
momentum orbits around the central massive black hole, a number of
alternative formation channels has been proposed, including binary
tidal break-up, migration in accretion discs and secular and chaotic
dynamics around a massive black hole binary (MBHB). In this work, we
take an extensive closer look at this latter scenario, investigating
how EMRIs can be triggered by MBHBs, formed in the aftermath of galaxy
mergers. By employing a suite of relativistic three-body simulations,
we evaluate the efficiency of EMRI formation for different parameters
of the MBHB, assessing the importance of both secular and chaotic
dynamics. By modelling the distribution of compact objects in galaxy
nuclei, we estimate the resulting EMRI formation rate, finding that
EMRI are produced in a sharp burst, with peak rates that are 10-100
times higher than the standard two-body relaxation channel, lasting
for 106-108 yr. By coupling our results with an
estimate of the cosmic MBHB merger rate, we finally forecast that LISA
could observe ${\cal O}(10)$ EMRIs per year formed by this channel.
Title: Searching for stellar flares from low-mass stars using ASKAP
and TESS
Authors: Rigney, Jeremy; Ramsay, Gavin; Carley, Eoin P.; Doyle,
J. Gerry; Gallagher, Peter T.; Wang, Yuanming; Pritchard, Joshua;
Murphy, Tara; Lenc, Emil; Kaplan, David L.
Bibcode: 2022MNRAS.516..540R
Altcode: 2022MNRAS.tmp.2052R; 2022arXiv220700405R
Solar radio emission at low frequencies (<1 GHz) can provide
valuable information on processes driving flares and coronal mass
ejections (CMEs). Radio emission has been detected from active M dwarf
stars, suggestive of much higher levels of activity than previously
thought. Observations of active M dwarfs at low frequencies can
provide information on the emission mechanism for high energy flares
and possible stellar CMEs. Here, we conducted two observations with
the Australian Square Kilometre Array Pathfinder Telescope totalling
26 h and scheduled to overlap with the Transiting Exoplanet Survey
Satellite Sector 36 field, utilizing the wide fields of view of both
telescopes to search for multiple M dwarfs. We detected variable
radio emission in Stokes I centred at 888 MHz from four known active
M dwarfs. Two of these sources were also detected with Stokes V
circular polarization. When examining the detected radio emission
characteristics, we were not able to distinguish between the models
for either electron cyclotron maser or gyrosynchrotron emission. These
detections add to the growing number of M dwarfs observed with variable
low-frequency emission.
Title: Potential utilization of air temperature, total electron
content, and air relative humidity as possible earthquake precursors:
A case study of Mexico M7.4 earthquake
Authors: Salh, Hemn; Muhammad, Ahmad; Ghafar, Marjan Mohammed;
Külahcı, Fatih
Bibcode: 2022JASTP.23705927S
Altcode:
This study examines ionospheric total electron content (TEC)
perturbations from six International Global Navigation Satellite
System stations (GNSS) including GUAT-Guatemala, SSIA-El Salvador,
INEG-Mexico, MANA-Nicaragua, MDO1-United States of America, and BOGT-
Colombia for several days around the occurrence of a major earthquake
(M 7.4 and depth 20.0 km) in Mexico, June 23, 2020 at 10:29 Local Time
(LT). The INEG station in the North-Northwest of the epicenter at a
distance of about 936 km indicated a positive TEC anomaly on June 18,
2020, which can be possibly viewed as an earthquake precursor due to
its occurrence during a quiet geomagnetic storm and inactive solar
activity. Study findings reveal that other TEC perturbations may not
be related to the earthquake, because they appeared during geomagnetic
activities. Moreover, the atmospheric parameters have significant
and synchronous deviations from the earthquake epicenter on June 13,
2020. The highest atmospheric chemical potential (ACP) is about 0.010
eV, atmospheric air temperature has positive deviation of 3.937 °C
at 15:00 LT, the lowest atmospheric relative humidity has negative
deviation of 25.387% at 13:00 LT and outgoing longwave radiation (OLR)
27.58 W m-2. Observations validate that in the earthquake
preparation zone, variations in atmospheric air temperature and relative
humidity reach at peak value during 10 days prior to the impending
earthquake event with the later perturbations in the ionosphere.
Title: Photon Frequency Diffusion Process
Authors: Oliveira, Guilherme Eduardo Freire; Maes, Christian; Meerts,
Kasper
Bibcode: 2022JSP...189....4O
Altcode: 2022arXiv220208660F
We introduce a stochastic multi-photon dynamics on reciprocal
space. Assuming isotropy, we derive the diffusion limit for a
tagged photon to be a nonlinear Markov process on frequency. The
nonlinearity stems from the stimulated emission. In the case of Compton
scattering with thermal electrons, the limiting process describes the
dynamical fluctuations around the Kompaneets equation. More generally,
we construct a photon frequency diffusion process which enables to
include nonequilibrium effects. Modifications of the Planck Law may
thus be explored, where we focus on the low-frequency regime.
Title: Dust grain size evolution in local galaxies: a comparison
between observations and simulations
Authors: Relaño, M.; De Looze, I.; Saintonge, A.; Hou, K. -C.;
Romano, L. E. C.; Nagamine, K.; Hirashita, H.; Aoyama, S.; Lamperti,
I.; Lisenfeld, U.; Smith, M. W. L.; Chastenet, J.; Xiao, T.; Gao,
Y.; Sargent, M.; van der Giessen, S. A.
Bibcode: 2022MNRAS.515.5306R
Altcode: 2022MNRAS.tmp.2024R; 2022arXiv220713196R
The evolution of the dust grain size distribution has been studied
in recent years with great detail in cosmological hydrodynamical
simulations taking into account all the channels under which dust
evolves in the interstellar medium. We present a systematic analysis
of the observed spectral energy distribution of a large sample of
galaxies in the local Universe in order to derive not only the total
dust masses but also the relative mass fraction between small and large
dust grains (DS/DL). Simulations reproduce fairly
well the observations except for the high-stellar mass regime where dust
masses tend to be overestimated. We find that ~45 per cent of galaxies
exhibit DS/DL consistent with the expectations of
simulations, while there is a subsample of massive galaxies presenting
high DS/DL (log (DS/DL) ~
-0.5), and deviating from the prediction in simulations. For these
galaxies which also have high-molecular gas mass fractions and
metallicities, coagulation is not an important mechanism affecting
the dust evolution. Including diffusion, transporting large grains
from dense regions to a more diffuse medium where they can be easily
shattered, would explain the observed high DS/DL
values in these galaxies. With this study, we reinforce the use of the
small-to-large grain mass ratio to study the relative importance of the
different mechanisms in the dust life cycle. Multiphase hydrodynamical
simulations with detailed feedback prescriptions and more realistic
subgrid models for the dense phase could help to reproduce the evolution
of the dust grain size distribution traced by observations.
Title: Developing a victorious strategy to the second strong
gravitational lensing data challenge
Authors: Bom, C. R.; Fraga, B. M. O.; Dias, L. O.; Schubert, P.;
Blanco Valentin, M.; Furlanetto, C.; Makler, M.; Teles, K.; Portes
de Albuquerque, M.; Metcalf, R. Benton
Bibcode: 2022MNRAS.515.5121B
Altcode: 2022arXiv220309536B; 2022MNRAS.tmp.1913B
Strong lensing is a powerful probe of the matter distribution in
galaxies and clusters and a relevant tool for cosmography. Analyses
of strong gravitational lenses with deep learning have become a
popular approach due to these astronomical objects' rarity and image
complexity. Next-generation surveys will provide more opportunities to
derive science from these objects and an increasing data volume to be
analysed. However, finding strong lenses is challenging, as their number
densities are orders of magnitude below those of galaxies. Therefore,
specific strong lensing search algorithms are required to discover
the highest number of systems possible with high purity and low
false alarm rate. The need for better algorithms has prompted the
development of an open community data science competition named strong
gravitational lensing challenge (SGLC). This work presents the deep
learning strategies and methodology used to design the highest scoring
algorithm in the second SGLC (II SGLC). We discuss the approach used
for this data set, the choice of a suitable architecture, particularly
the use of a network with two branches to work with images in different
resolutions, and its optimization. We also discuss the detectability
limit, the lessons learned, and prospects for defining a tailor-made
architecture in a survey in contrast to a general one. Finally, we
release the models and discuss the best choice to easily adapt the model
to a data set representing a survey with a different instrument. This
work helps to take a step towards efficient, adaptable, and accurate
analyses of strong lenses with deep learning frameworks.
Title: Measuring adhesion of microparticles in lunar regolith simulant
BHLD1000 by centrifugal technique
Authors: Sun, Hao; Li, Dong; Gao, Haiyang; Wu, Yao; Shen, Zhigang;
Liu, Zhaoyan; Li, Yi
Bibcode: 2022P&SS..22005535S
Altcode:
The adhesion of lunar material is strong and harmful to the functional
surfaces of spacecraft systems. Using lunar regolith simulant instead
of rare real one to understand the adhesive property of lunar regolith
is an economical approach. In this work, we firstly introduced a
theoretical model of the adhesive behavior between lunar regolith
simulant micro-particle and different aerospace materials. In this
model, total adhesion force is determined by Van der Waals force,
electrostatic force and capillary force. Surface energy, surface
potential, particle size and inertia force are the key factors affecting
adhesion. Then we designed an experimental method using centrifugal
technique and image processing to quantify and visualize the adhesion
effect. By using a newly developed lunar regolith simulant BHLD1000
and four types of aerospace functional surfaces, we found the size of
adhesive micro-particles are a few micrometers and the adhesion forces
on them are a few nN on average. This experimental value is three
orders of magnitude smaller than the theoretical one (several μN) due
to particle irregularity and surface roughness. The adhesion model,
the experimental approach and measurement results developed here are
useful in understanding the real adhesion of lunar regolith on the moon
as well as designing dust-proof tools for future lunar explorations.
Title: Impact of submarine groundwater discharge on biogeochemistry
and microbial communities in pockmarks
Authors: Purkamo, Lotta; von Ahn, Cátia Milene Ehlert; Jilbert, Tom;
Muniruzzaman, Muhammad; Bange, Hermann W.; Jenner, Anna-Kathrina;
Böttcher, Michael Ernst; Virtasalo, Joonas J.
Bibcode: 2022GeCoA.334...14P
Altcode:
The impact of submarine groundwater discharge (SGD) on coastal sea
biogeochemistry has been demonstrated in many recent studies. However,
only a few studies have integrated biogeochemical and microbiological
analyses, especially at sites with pockmarks of different degrees
of groundwater influence. This study investigated biogeochemical
processes and microbial community structure in sediment cores from
three pockmarks in Hanko, Finland, in the northern Baltic Sea. Pockmark
data were supplemented by groundwater and seawater measurements. Two
active pockmarks showed SGD rates of 0.02 cm d-1 and 0.31
cm d-1, respectively, based on porewater Cl-
profiles, while a third pockmark had no SGD influence. Reactive
transport modelling (RTM) established that the porewater systems
of these active pockmarks are dominated by advection, resulting
in the focusing of biogeochemical reactions and the microbial
community into a thin zone at the sediment surface. The advection
further reduces the accumulation of organic matter in the surface
sediments, resulting in the absence of a sulfate-methane transition
zone (SMTZ) at these pockmarks. Furthermore, the RTM estimated low
rates of consumption of SO42-, and low rates of
production of CH4, NH4+, DIC at the
active pockmarks. Archaeal communities in the active pockmarks were
dominated by ammonia-oxidizing archaea of predominantly groundwater
origin. In contrast, at the inactive pockmark, the lack of SGD
has permitted rapid deposition of organic-rich mud. The porewater
system in the inactive pockmark is dominated by diffusion, leading
to orders of magnitude higher metabolite concentrations at depth
compared to the active pockmarks. The biogeochemical environment in
the inactive pockmark resembles typical organic-rich mud seafloor
in the area, with sulphate reduction and methanogenesis dominating
organic matter remineralization. Accordingly, methanogens dominate the
archaeal community, whereas sulfate reducers dominate the bacterial
community. RTM results suggest that sulfate-mediated anaerobic oxidation
of methane (S-AOM) also occurs at this site. Although depth-integrated
fluxes of SO42-, CH4, NH4,
DIC at the inactive pockmark are orders of magnitude higher compared
to the active pockmarks, processes at the inactive pockmark represent
internal recycling in the coastal sea. Fluxes observed at the active
pockmarks, although comparatively small in magnitude, are partly
influenced by external inputs to the sea through SGD. Hence, effluxes
across the sediment-water interface at these sites partly represent
direct external fluxes to the marine environment, in addition to
diagenetic recycling at the benthic interface. The study highlights that
SGD can result in significant spatial heterogeneity of biogeochemical
processes and microbial community structure in the coastal zone, and
that the overall effects of SGD and associated solute fluxes at an
SGD site are a function of the number of pockmarks, the rate of SGD,
and the ratio of active to inactive pockmarks.
Title: The prevalence of galaxy overdensities around UV-luminous
Lyman 𝛼 emitters in the Epoch of Reionization
Authors: Leonova, E.; Oesch, P. A.; Qin, Y.; Naidu, R. P.; Wyithe,
J. S. B.; de Barros, S.; Bouwens, R. J.; Ellis, R. S.; Endsley, R. M.;
Hutter, A.; Illingworth, G. D.; Kerutt, J.; Labbé, I.; Laporte, N.;
Magee, D.; Mutch, S. J.; Roberts-Borsani, G. W.; Smit, R.; Stark,
D. P.; Stefanon, M.; Tacchella, S.; Zitrin, A.
Bibcode: 2022MNRAS.515.5790L
Altcode: 2022MNRAS.tmp.1931L; 2021arXiv211207675L
Before the end of the Epoch of Reionization, the Hydrogen in
the Universe was predominantly neutral. This leads to a strong
attenuation of Ly α lines of z ≳ 6 galaxies in the intergalactic
medium. Nevertheless, Ly α has been detected up to very high
redshifts (z ~ 9) for several especially UV luminous galaxies. Here,
we test to what extent the galaxy's local environment might impact
the Ly α transmission of such sources. We present an analysis of
dedicated Hubble Space Telescope (HST) imaging in the CANDELS/EGS
field to search for fainter neighbours around three of the most UV
luminous and most distant spectroscopically confirmed Ly α emitters:
EGS-zs8-1, EGS-zs8-2, and EGSY-z8p7 at zspec = 7.73, 7.48,
and 8.68, respectively. We combine the multiwavelength HST imaging with
Spitzer data to reliably select z ~ 7-9 galaxies around the central,
UV-luminous sources. In all cases, we find a clear enhancement of
neighbouring galaxies compared to the expected number in a blank
field (by a factor ~3-9×). Our analysis thus reveals ubiquitous
overdensities around luminous Ly α emitting sources in the heart of
the cosmic reionization epoch. We show that our results are in excellent
agreement with expectations from the DRAGONS simulation, confirming the
theoretical prediction that the first ionized bubbles preferentially
formed in overdense regions. While three UV luminous galaxies already
have spectroscopic redshifts, the majority of the remaining fainter,
surrounding sources are yet to be confirmed via spectroscopy. JWST
follow-up observations of the neighbouring galaxies identified here
will thus be needed to confirm their physical association and to map
out the ionized regions produced by these sources.
Title: A petrological and spectral characterisation of the NU-LHT-2M
lunar highlands regolith simulant in preparation for the PROSPECT
test campaign
Authors: Martin, Dayl J. P.; Donaldson Hanna, Kerri L.; Joy, Katherine
H.; Gillis-Davis, Jeffrey J.
Bibcode: 2022P&SS..22105561M
Altcode:
In preparation for the upcoming Luna 27 mission to the south polar
region of the Moon, the Package for Resource Observation and in-Situ
Prospecting for Exploration Commercial exploitation and Transportation
(PROSPECT) is undergoing a series of tests to ensure its suitability
for polar regolith and volatile analysis. A lunar regolith simulant,
NU-LHT-2M, was used for geotechnical validation and volatile extraction
testing. Therefore, the physical, chemical/mineralogical, and spectral
properties of separate batches of this simulant have been characterised
to better understand the results of the instrument laboratory testing
phase. Here we compare measurements from two different batches of the
simulant to Apollo bulk regolith samples in order to understand the
suitability and representativeness of the simulant to the properties of
surface highlands regolith. Based on our measurements, we recommend that
the physical, mineralogical, and spectral properties of simulants be
analysed both before and after space instrument testing campaigns. These
bookended measurements would allow for a more detailed understanding of
the test phase, including: how the simulants have been altered by the
test and, therefore, how the lunar surface may be affected by mission
extraction and sampling processes.
Title: The effect of neutrons on the background of HPGe detectors
operating deep underground
Authors: Baginova, M.; Vojtyla, P.; Povinec, P. P.
Bibcode: 2022APh...14302756B
Altcode:
The background of a High Purity Germanium (HPGe) detector measured
in a deep underground laboratory was investigated analytically and
by Monte Carlo simulations using the GEANT4 toolkit. Contributions of
different background sources to the experimental γ-ray background were
determined. Namely, contribution of radionuclides in materials of the
detector and around the detector, neutrons produced by (α, n) reactions
due to presence of radionuclides in rock and concrete and by spontaneous
fission of mainly 238U, and finally, cosmic rays with neutron
generation. The simulation, including radionuclides in the material,
was in a good agreement with the experiment. At the same time, neutron
and muon induced spectra were simulated. The radiation coming from the
presence of members of the 238U, and 232Th decay
series, and 40K in the detector parts and the laboratory
walls contribute to the continuum of the experimental spectrum at
the level of around 94%. According to simulations, the contribution
of muon events to the experimental energy spectrum was below 1% and
it was confirmed that muon induced spectra are about three orders of
magnitude lower than the experimental one. The comparison of integral
count rates of the experimental spectrum with the simulated spectrum
induced by neutrons showed that about 6% of the measured background
continuum originated from neutron reactions. Fast neutrons contributed
more to the background (at around 65%) than thermal neutrons. Despite
only a 6% share of neutron contributions in the total γ-ray background,
they contributed mainly to the lower continuum of the spectrum up to
250 keV, which is a region of interest for potential low mass weakly
interacting massive particle (WIMP) dark matter interactions. In
addition, they interact with the detector and the shield by inelastic
scattering and induce unwanted γ-rays. Neutron capture, elastic and
inelastic scattering were simulated separately as well. It was found
that inelastic scattering is the major contributor to the spectrum
induced by neutrons. The effect of neutrons on the background of the
HPGe detector operating underground, such as Obelix, is manifested
mainly by their contribution to the continuum up to 1 MeV, especially
in the lower part up to 500 keV. Thus, neutrons are an important
background component in deep underground laboratories, too. Possible
detector optimization is also discussed.
Title: Iron and manganese accumulation within the Eastern Tropical
North Pacific oxygen deficient zone
Authors: Bolster, Kenneth M.; Heller, Maija I.; Mulholland, Margaret
R.; Moffett, James W.
Bibcode: 2022GeCoA.334..259B
Altcode:
The Eastern Tropical North Pacific (ETNP) contains the largest oxygen
deficient zone (ODZ) in the modern ocean. We determined dissolved
concentrations of Fe, Fe(II), and Mn from three cruises in the
region. Similar to other reported ODZs, Fe(II) was highest in the
depth range associated with the secondary nitrite maximum. The main
source of this feature is likely lateral advection of water overlying
reducing shelf sediments within a narrow density range centered on the
potential density anomaly of 26.5 kg/m3. This density horizon
is similar to the Eastern Tropical South Pacific (ETSP) and reflects
the intersection of the same density range with a large fraction of the
continental shelf bottom waters. We also observed subsurface maxima
of dissolved Mn in this density range, in contrast to the ETSP. Deep
waters were enriched in Fe within the ETNP, analogous to other eastern
boundary upwelling systems as well as the Arabian Sea. We argue that
in these systems, reducing conditions on the shelf and overlying
water column facilitate a robust shelf to basin shuttle of Fe, moving
Fe from the coastal margin to deep plumes. Mn is also transported
offshore in the core of the ODZ, and the relationship between Fe(II),
Mn, and nitrite is remarkably similar between the ETNP, ETSP, and
Arabian Sea. The exception is that Mn supply from the Peruvian shelf
is less pronounced than in the other two ODZs, potentially reflecting
the absence of large rivers in the Peruvian system.
Title: Structural and biological analysis of faults in basalts in
Sheepshead Mountains, Oregon as an Earth analogue to Mars
Authors: Bohanon, Allison; Crane, Kelsey
Bibcode: 2022Icar..38515121B
Altcode:
Endoliths and chasmoendoliths, organisms that live in rock fractures,
rely on connected open spaces in rocks for fluid and nutrient
circulation on Earth and perhaps other planetary bodies. These
life forms are not visible from orbit or easily detectable by rover
cameras, but the fracture networks and scarp morphologies associated
with fracture networks are measurable. We conducted a field analogue
study of 92 normal fault scarps in the Sheepshead Mountains, Oregon
to examine the correlation between scarp morphology and vegetation
growth in the Steens Basalt of the Columbia River Flood Basalts. While
vegetation is not expected on Mars or other bodies, the fracture
networks that sustain vegetation are the same that would support
and protect endoliths. Structural variables measured in the field
are: percent of fault scarp that is fault surface and talus surface,
scale of columnar jointing, consistency in location of columns, talus
size and sorting, fault lengths, distance to hot springs and playa
lakes, and strike and dips of fault surfaces, talus surfaces, and flow
bedding. Infrared spectra of fault scarps were measured using a handheld
multispectral camera and Normalized Difference Vegetation Index (NDVI)
were calculated from these images in ArcGIS™. Statistical analysis
of the scarp morphologic parameters indicate that interconnectedness
of fractures is key for elevated NDVI and is represented by a range
of parameters including bedding strike, talus sorting, and proximity
to playas. Results support a model for ideal slopes to investigate
for preserved biological activity on Mars.
Title: Higher dimensional Reissner-Nordström black holes supporting
static scalar shells
Authors: Xie, Libo; Fang, Chaoxi; Jiang, Jie; Zhang, Ming
Bibcode: 2022PhLB..83337396X
Altcode: 2022arXiv220814224X
We analytically study scalarization of higher-dimensional charged
Reissner-Nordström (RN) black hole. It is shown that static massive
scalar field which is non-minimally coupled to Gauss-Bonnet invariant
can be supported by higher-dimensional black hole in super-critical
charge regime Q / M ≥Cbard with Q , M charge and
mass of the black hole and Cbard some unitless spacetime
dimension-dependent quantity. Moreover, we show that the static massive
scalar shell can be quite thin in the large mass regime μM
1/d-3 ≫ 1 with μ mass of the scalar field.
Title: Radial velocities from far-red spectra of Carina Arm O and
early B stars
Authors: Drew, J. E.; Blake-Parsons, F.; Mohr-Smith, M.
Bibcode: 2022MNRAS.515.5993D
Altcode: 2022MNRAS.tmp.1909D; 2022arXiv220709206D
Massive O and early B stars are important markers of recent star
formation and exert a significant influence on their environments
during their short lives via photoionization and winds and when they
explode as supernovae. In the Milky Way, they can be detected at great
distances but often lie behind large dust columns, making detection
at short wavelengths difficult. In this study, the use of the less
extinguished far-red spectrum (8400-8800 Å) for radial velocity
measurement is examined. Results are reported for a sample of 164
confirmed OB stars within a 2° field positioned on the Carina Arm. Most
stars are at distances between 3 and 6 kpc, and Westerlund 2 is at the
field edge. The measured radial velocities have errors concentrated in
the 3-10 km s-1 range, with a systematic uncertainty of 2-3
km s-1. These are combined with Gaia-mission astrometry to
allow full space motions to be constructed. Up to 22 stars are likely
to be runaways, although 8 of them are as likely to be interloping
(so far undetected) binaries. The mean azimuthal motion of the sample
fits in with recent measurements of Galactic disc rotation. In the
Galactocentric radial direction, the mean motion indicates modest
infall at a speed of ~10 km s-1. This experiment shows that
weak Paschen lines in the far-red can yield credible radial velocity
determination, offering the prospect of exploring OB-star kinematics
over much more of the Galactic disc than has hitherto been possible.
Title: Connecting radio emission to AGN wind properties with broad
absorption line quasars
Authors: Petley, J. W.; Morabito, L. K.; Alexander, D. M.; Rankine,
A. L.; Fawcett, V. A.; Rosario, D. J.; Matthews, J. H.; Shimwell,
T. M.; Drabent, A.
Bibcode: 2022MNRAS.515.5159P
Altcode: 2022arXiv220710102P; 2022MNRAS.tmp.1946P
Broad absorption line quasars (BALQSOs) show strong signatures
of powerful outflows, with the potential to alter the cosmic
history of their host galaxies. These signatures are only seen in
~10 per cent of optically selected quasars, although the fraction
significantly increases in IR and radio selected samples. A proven
physical explanation for this observed fraction has yet to be found,
along with a determination of why this fraction increases at radio
wavelengths. We present the largest sample of radio matched BALQSOs
using the LOFAR Two-metre Sky Survey Data Release 2 and employ it to
investigate radio properties of BALQSOs. Within the DR2 footprint, there
are 3537 BALQSOs from Sloan Digital Sky Survey DR12 with continuum
signal-to-noise ≥5. We find radio-detections for 1108 BALQSOs,
with an important subpopulation of 120 LoBALs, an unprecedented
sample size for radio matched BALQSOs given the sky coverage to
date. BALQSOs are a radio-quiet population that show an increase of
×1.50 radio-detection fraction compared to non-BALQSOs. LoBALs show
an increase of ×2.22 that of non-BALQSO quasars. We show that this
detection fraction correlates with wind-strength, reddening, and
C IV emission properties of BALQSOs and that these features may be
connected, although no single property can fully explain the enhanced
radio detection fraction. We create composite spectra for subclasses of
BALQSOs based on wind strength and colour, finding differences in the
absorption profiles of radio-detected and radio-undetected sources,
particularly for LoBALs. Overall, we favour a wind-ISM interaction
explanation for the increased radio-detection fraction of BALQSOs.
Title: A physical-constraint-preserving finite volume WENO method
for special relativistic hydrodynamics on unstructured meshes
Authors: Chen, Yaping; Wu, Kailiang
Bibcode: 2022JCoPh.46611398C
Altcode: 2022arXiv220709385C
This paper presents a highly robust third-order accurate
finite volume weighted essentially non-oscillatory (WENO)
method for special relativistic hydrodynamics on unstructured
triangular meshes. We rigorously prove that the proposed method is
physical-constraint-preserving (PCP), namely, always preserves the
positivity of the pressure and the rest-mass density as well as the
subluminal constraint on the fluid velocity. The method is built
on a highly efficient compact WENO reconstruction on unstructured
meshes, a simple PCP limiter, the provably PCP property of the
Harten-Lax-van Leer flux, and third-order strong-stability-preserving
time discretization. Due to the relativistic effects, the primitive
variables (namely, the rest-mass density, velocity, and pressure)
are highly nonlinear implicit functions in terms of the conservative
variables, making the design and analysis of our method nontrivial. To
address the difficulties arising from the strong nonlinearity, we adopt
a novel quasilinear technique for the theoretical proof of the PCP
property. Three provable convergence-guaranteed iterative algorithms
are also introduced for the robust recovery of primitive quantities from
admissible conservative variables. We also propose a slight modification
to an existing WENO reconstruction to ensure the scaling invariance of
the nonlinear weights and thus to accommodate the homogeneity of the
evolution operator, leading to the advantages of the modified WENO
reconstruction in resolving multi-scale wave structures. Extensive
numerical examples are presented to demonstrate the robustness,
expected accuracy, and high resolution of the proposed method.
Title: Forecasting the solar cycle 25 using a multistep Bayesian
neural network
Authors: Bizzarri, I.; Barghini, D.; Mancuso, S.; Alessio, S.;
Rubinetti, S.; Taricco, C.
Bibcode: 2022MNRAS.515.5062B
Altcode: 2022MNRAS.tmp.1902B
Predicting the solar activity of upcoming cycles is crucial nowadays
to anticipate potentially adverse space weather effects on the
Earth's environment produced by coronal transients and traveling
interplanetary disturbances. The latest advances in deep learning
techniques provide new paradigms to obtain effective prediction models
that allow to forecast in detail the evolution of cosmogeophysical
time series. Because of the underlying complexity of the dynamo
mechanism in the solar interior that is at the origin of the solar
cycle phenomenon, the predictions offered by state-of-the-art machine
learning algorithms represent valuable tools for our understanding
of the cycle progression. As a plus, Bayesian deep learning is
particularly compelling thanks to recent advances in the field that
provide improvements in both accuracy and uncertainty quantification
compared to classical techniques. In this work, a deep learning long
short-term memory model is employed to predict the complete profile
of Solar Cycle 25, thus forecasting also the advent of the next solar
minimum. A rigorous uncertainty estimation of the predicted sunspot
number is obtained by applying a Bayesian approach. Two different
model validation techniques, namely the Train-Test split and the time
series k-fold cross-validation, have been implemented and compared,
giving compatible results. The forecasted peak amplitude is lower than
that of the preceding cycle. Solar Cycle 25 will last 10.6 ± 0.7 yr,
reaching its maximum in the middle of the year 2024. The next solar
minimum is predicted in 2030 and will be as deep as the previous one.
Title: Testing a varying-Λ model for dark energy within co-varying
physical couplings framework
Authors: Cuzinatto, R. R.; Gupta, R. P.; Holanda, R. F. L.; Jesus,
J. F.; Pereira, S. H.
Bibcode: 2022MNRAS.515.5981C
Altcode: 2022MNRAS.tmp.1953C; 2022arXiv220410764C
The Co-varying Physical Couplings (CPC) framework is a modified gravity
set up assuming Einstein Field Equations wherein the quantities {G,
c, Λ} are promoted to space-time functions. Bianchi identity and
the requirement of stress-energy tensor conservation entangle the
possible variations of the couplings {G, c, Λ}, which are forced to
co-vary as dictated by the General Constraint (GC). In this paper,
we explore a cosmological model wherein G, c, and Λ are functions
of the redshift respecting the GC of the CPC framework. We assume a
linear parametrization of Λ in terms of the scale factor a. We use the
ansatz $\dot{G}/G = \sigma \left(\dot{c}/c \right)$ with σ = constant
to deduce the functional forms of c = c(z) and G = G(z). We show that
this varying-{G, c, Λ} model fits SNe Ia data and H(z) data with σ =
3. The model parameters can be constrained to describe dark energy at
the background level.
Title: Magnetic field measurement in TMC-1C using 22.3 GHz CCS
Zeeman splitting
Authors: Koley, Atanu; Roy, Nirupam; Momjian, Emmanuel; Sarma, Anuj
P.; Datta, Abhirup
Bibcode: 2022MNRAS.516L..48K
Altcode: 2022arXiv220712604K; 2022MNRAS.tmpL..81K
Measurement of magnetic fields in dense molecular clouds is
essential for understanding the fragmentation process prior to star
formation. Radio interferometric observations of CCS 22.3 GHz emission,
from the starless core TMC-1C, have been carried out with the Karl
G. Jansky Very Large Array to search for Zeeman splitting of the line in
order to constrain the magnetic field strength. Toward a region offset
from the dust peak, we report a detection of the Zeeman splitting of the
CCS 21-10 transition, with an inferred magnetic
field of ~2 mG. If we interpret the dust peak to be the core of TMC-1C,
and the region where we have made a detection of the magnetic field
to be the envelope, then our observed value for the magnetic field
is consistent with a subcritical mass-to-flux ratio envelope around
a core with supercritical mass-to-flux ratio. The ambipolar diffusion
time-scale for the formation of the core is consistent with the relevant
time-scale based on chemical modelling of the TMC-1C core. This work
demonstrates the potential of deep CCS observation to carry out future
measurements of magnetic field strengths in dense molecular clouds and,
in turn, understand the role of the magnetic field in star formation.
Title: A quantum mechanical calculation of the CN radiative
association
Authors: Zhang, Shuai; Qin, Zhi; Liu, Linhua
Bibcode: 2022MNRAS.515.6066Z
Altcode: 2022MNRAS.tmp.2012Z
Radiative association of CN is investigated through the quantum
mechanical method, including the cross sections and rate
coefficients. The ab initio potential energy curves, transition
dipole moments, and permanent dipole moments of CN are obtained by
the internally contracted multireference configuration interaction
method with Davidson correction and aug-cc-pwCV5Z-DK basis set. For
the collision of the ground state C (3Pg)
and N (4Su) atoms, except for the four
previously studied processes including the A2Π
→ X2Σ+, X2Σ+
→ A2Π, A2Π → A2Π, and
X2Σ+ → X2Σ+ transitions,
four other radiative association processes including b4Π
→ a4Σ+, a4Σ+
→ b4Π, b4Π → b4Π, and
a4Σ+ → a4Σ+ transitions
are considered. We also considered the collision of the excited C
(1Dg) and the ground N (4Su)
atoms including the 24Π → 14Σ-
process and the collision of the ground C (3Pg)
and the excited N (2Du) atoms including
22Π → B2Σ+, 32Π
→ B2Σ+, and 42Π
→ B2Σ+ transitions. The temperature
population factor is considered to describe the thermal population
of the three different dissociation asymptotic energies. The
results show that the contribution of the A2Π
→ X2Σ+ and b4Π →
a4Σ+ transitions to the total rate
coefficients is significant over the entire temperature range. While
considering the collision of C and N involving excited states, the
contribution of the 22Π → B2Σ+,
32Π → B2Σ+, and 42Π
→ B2Σ+ transitions to the total rate
coefficients cannot be ignored at the temperature range larger than
10 000 K. Finally, the rate coefficients are fitted to an analytical
function for astrochemical reaction modelling.
Title: Resonant enhancement of second harmonic generation in etchless
thin film lithium niobate heteronanostructure
Authors: Huang, Zhijin; Luo, Kaiwen; Feng, Ziwei; Zhang, Zhanyuan;
Li, Yang; Qiu, Wentao; Guan, Heyuan; Xu, Yi; Li, Xiangping; Lu, Huihui
Bibcode: 2022SCPMA..6504211H
Altcode:
Lithium niobate has received interest in nonlinear frequency
conversion due to its wide transparency window, from ultraviolet
to mid-infrared spectral regions, and large second-order nonlinear
susceptibility. However, its nanostructure is generally difficult
to etch, resulting in low-Q resonance and lossy nanostructures
for second harmonic generation. By applying the concept of bound
states in the continuum, we performed theoretical and experimental
investigations on high-Q resonant etchless thin-film lithium niobate
with SiO2 nanostructures on top for highly efficient
second harmonic generation. In the fabricated nanostructured devices,
a resonance with a Q factor of 980 leads to the strong enhancement
of second harmonic generation by over 1500 times compared with that
in unpatterned lithium niobate thin film. Although the pump slightly
deviates from central resonance, an absolute conversion efficiency
of 6.87×10−7 can be achieved with the fundamental
pump peak intensity of 44.65 MW/cm2, thus contributing
to the normalized conversion efficiency of 1.54×10−5
cm2/GW. Our work establishes an etchless lithium niobate
device for various applications, such as integrated nonlinear
nanophotonics, terahertz frequency generation, and quantum information
processing.
Title: A direct numerical verification of tidal locking mechanism
using the discrete element method
Authors: Wang, Yucang; Mora, Peter; Liang, Yunpei
Bibcode: 2022CeMDA.134...42W
Altcode:
We use a discrete element method to simulate the tidal evolution of
the spin of a viscoelastic circular body (a secondary body) moving in
a circular orbit under the attraction of a large point-mass (a primary
body) located at the centre, where the secondary body can have general
elasticity (e.g. variable Poisson's ratio). The model consists of a
group of rigid particles linked by elastic and dissipative springs and
allows for translational and bending degrees of freedom and rotation
of particles. The tidal deformation of the secondary body when it is
orbiting around the primary body under the gravitational attraction,
and a small lag angle between the direction of the bulge and a line
that connects the two bodies have been reproduced. We measure the
angular velocity evolution of the secondary body for different initial
angular velocities. It is found that if the initial angular velocity is
set as the special value (the locked angular velocity) such that the
spin period equals its orbital period, the angular velocity of this
body remains constant, indicating a stable "locked state". However,
if the initial angular velocity is smaller/larger than the locked
angular velocity, the body will spin up/down (i.e. its angular velocity
will increase/decrease) due to the effect of tidal torque. Therefore,
the spin velocity of an orbiting body (moon) will finally lock onto
the orbiting period. Parameters which determine how rapidly the tidal
locking occurs have been identified. These parameters include damping
coefficient, the gravitational constant, the mass of the primary body,
the distance between the primary and the secondary body, the rigidity
parameter and Poisson's ratio of the secondary body, the radius of
the secondary body and self-gravitation parameters. Tidal torques
obtained from our simulations are compared with the one from the
existing tidal theories and a good agreement is found. We demonstrate
that the discrete element method is capable of directly simulating
the deformation, spinning and tidal evolution of a viscoelastic object
under tidal stress.
Title: An optimized survey strategy for the ERIS/NIX imager: searching
for young giant exoplanets and very low mass brown dwarfs using the
K-peak custom photometric filter
Authors: Dubber, Sophie; Biller, Beth; Bonavita, Mariangela; Allers,
Katelyn; Fontanive, Clémence; Kenworthy, Matthew A.; Bonnefoy,
Mickaël; Taylor, William
Bibcode: 2022MNRAS.515.5629D
Altcode: 2022arXiv220614295D; 2022MNRAS.tmp.2013D
We present optimal survey strategies for the upcoming NIX imager,
part of the Enhanced Resolution Imager and Spectrograph instrument
to be installed on the Very Large Telescope. We will use a custom 2.2
µm K-peak filter to optimize the efficiency of a future large-scale
direct imaging survey, aiming to detect brown dwarfs and giant planets
around nearby stars. We use the results of previous large-scale imaging
surveys (primarily SPHERE SHINE and Gemini GPIES) to inform our choice
of targets, as well as improved planet population distributions. We
present four possible approaches to optimize survey target lists for
the highest yield of detections: (i) targeting objects with anomalous
proper motion trends, (ii) a follow-up survey of dense fields from
SPHERE SHINE and Gemini GPIES, (iii) surveying nearby star-forming
regions, and (iv) targeting newly discovered members of nearby young
moving groups. We also compare the predicted performance of NIX to
other state-of-the-art direct imaging instruments.
Title: Sulfur in apatite from the Nakhla meteorite record a late-stage
oxidation event
Authors: Brounce, Maryjo; Boyce, Jeremy W.; McCubbin, Francis M.
Bibcode: 2022E&PSL.59517784B
Altcode:
Estimates of the oxygen fugacity (fO2) recorded by the
Martian nakhlite meteorites from direct observations of the main igneous
phenocryst assemblages range from values similar to that recorded
by the quartz-fayalite-magnetite oxygen buffer to ∼two orders of
magnitude lower. Inferences of changes in fO2 during the
late stages of crystallization, volcanic degassing, and emplacement
of the nakhlite cumulate pile have been made based on variable sulfide
and apatite chemistry. We present S-XANES measurements of the oxidation
state of sulfur in apatite and associated mesostasis glass in Nakhla to
place direct constraints on the magnitude of changes in fO2
experienced by the Nakhla portion of the nakhlite cumulate pile
during apatite crystallization. Nakhla apatites range from containing
dominantly S2- to containing dominantly S6+. This,
together with correlations between S2-, Cl, and FeO in the
mesostasis glass near these apatites, suggest that our measurements
capture directly the oxidation of the interstitial late-stage Nakhla
magmas as the result of Cl-saturation and degassing. As the result of
this degassing, at least part of the nakhlite cumulate pile experienced
an increase in fO2 of ∼1.5-2.5 orders of magnitude
during apatite crystallization and final mesostasis cooling. Based on
these measurements, the sulfur oxidation states of apatites in the
other nakhlite meteorites are predicted to range from exclusively
S2--bearing to exclusively S6+-bearing.
Title: The PUMAS library
Authors: Niess, Valentin
Bibcode: 2022CoPhC.27908438N
Altcode: 2022arXiv220601457N
The PUMAS library is a transport engine for muon and tau leptons in
matter. It can operate with a configurable level of details, from a
fast deterministic CSDA mode to a detailed Monte Carlo simulation. A
peculiarity of PUMAS is that it is revertible, i.e. it can run in
forward or in backward mode. Thus, the PUMAS library is particularly
well suited for muography applications. In the present document,
we provide a detailed description of PUMAS, of its physics and of
its implementation.
Title: Constraining galaxy-halo connection with high-order statistics
Authors: Zhang, Hanyu; Samushia, Lado; Brooks, David; de la Macorra,
Axel; Doel, Peter; Gaztañaga, Enrique; Gontcho A Gontcho, Satya;
Honscheid, Klaus; Kehoe, Robert; Kisner, Theodore; Meisner, Aaron;
Poppett, Claire; Schubnell, Michael; Tarle, Gregory; Zhang, Kai;
Zou, Hu
Bibcode: 2022MNRAS.515.6133Z
Altcode: 2022MNRAS.tmp.2034Z; 2022arXiv220317214Z
We investigate using three-point statistics in constraining the
galaxy-halo connection. We show that for some galaxy samples,
the constraints on the halo occupation distribution parameters are
dominated by the three-point function signal (over its two-point
counterpart). We demonstrate this on mock catalogues corresponding to
the Luminous red galaxies (LRGs), Emission-line galaxies (ELGs), and
quasars (QSOs) targeted by the Dark Energy Spectroscopic Instrument
(DESI) Survey. The projected three-point function for triangle sides
less up to 20 h-1 Mpc measured from a cubic Gpc of data can
constrain the characteristic minimum mass of the LRGs with a preci
sion of 0.46 per cent. For comparison, similar constraints from the
projected two-point function are 1.55 per cent. The improvements for
the ELGs and QSOs targets are more modest. In the case of the QSOs,
it is caused by the high shot-noise of the sample, and in the case
of the ELGs, it is caused by the range of halo masses of the host
haloes. The most time-consuming part of our pipeline is the measurement
of the three-point functions. We adopt a tabulation method, proposed
in earlier works for the two-point function, to significantly reduce
the required compute time for the three-point analysis.
Title: A search for hot subdwarf binaries in data from the Transiting
Exoplanet Survey Satellite
Authors: Krzesinski, J.; Şener, H. T.; Zola, S.; Siwak, M.
Bibcode: 2022MNRAS.516.1509K
Altcode:
We present the results of a search for binary hot subdwarf stars
in photometric data from the Transiting Exoplanet Survey Satellite
(TESS). The sample of objects used in this work was a byproduct
of another search for pulsating hot subdwarfs, which resulted in
the discovery of nearly 400 non-pulsating variable candidates. The
periodogram for each object was calculated and a frequency signal with
one or more harmonics above the 4 σ detection threshold was used
to consider the candidate as a possible binary system. The type of
variability was subsequently confirmed by visual inspection. We present
a list of 46 binary system candidates that were not previously known
as binaries. We also analysed a few example light curves to demonstrate
the importance of double checking the variability of the source in the
TESS light curves corrected for instrumental signatures. Four objects,
TIC 55753808, TIC 118412596, TIC 4999380, and TIC 68834079, which
show variations in the TESS-calibrated fluxes, were actually found
to be constant. We also found that it might be more appropriate to
increase the commonly used 4σ detection threshold in order to avoid
the detection of multiple spurious peaks in the periodograms or Fourier
transform of the TESS light curves.
Title: Recent arrivals to the main asteroid belt
Authors: de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl
Bibcode: 2022CeMDA.134...38D
Altcode: 2022arXiv220707013D
The region where the main asteroid belt is now located may have started
empty, to become populated early in the history of the Solar system with
material scattered outward by the terrestrial planets and inward by the
giant planets. These dynamical pathways toward the main belt may still
be active today. Here, we present results from a data mining experiment
aimed at singling out present-day members of the main asteroid belt that
may have reached the belt during the last few hundred years. Probable
newcomers include 2003 BM1, 2007 RS62, 457175
(2008 GO98), 2010 BG18, 2010 JC58,
2010 JV52, 2010 KS6, 2010 LD74,
2010 OX38, 2011 QQ99, 2013 HT149,
2015 BH103, 2015 BU525, 2015 RO127,
2015 RS139, 2016 PC41, 2016 UU231,
2020 SA75, 2020 UO43, and 2021 UJ5,
all of them in the outer belt. Some of these candidates may have been
inserted in their current orbits after experiencing relatively recent
close encounters with Jupiter. We also investigated the likely source
regions of such new arrivals. Asteroid 2020 UO43, if real,
has a non-negligible probability of having an origin in the Oort cloud
or even interstellar space. Asteroid 2003 BM1 may have come
from the neighborhood of Uranus. However, most newcomers—including
457175, 2011 QQ99, and 2021 UJ5—might have had
an origin in Centaur orbital space. The reliability of these findings
is assessed within the context of the uncertainties of the available
orbit determinations.
Title: A high-order shock capturing discontinuous Galerkin-finite
difference hybrid method for GRMHD
Authors: Deppe, Nils; Hébert, François; Kidder, Lawrence E.;
Teukolsky, Saul A.
Bibcode: 2022CQGra..39s5001D
Altcode: 2021arXiv210911645D
We present a discontinuous Galerkin (DG)-finite difference (FD)
hybrid scheme that allows high-order shock capturing with the DG
method for general relativistic magnetohydrodynamics. The hybrid
method is conceptually quite simple. An unlimited DG candidate
solution is computed for the next time step. If the candidate
solution is inadmissible, the time step is retaken using robust
FD methods. Because of its a posteriori nature, the hybrid scheme
inherits the best properties of both methods. It is high-order with
exponential convergence in smooth regions, while robustly handling
discontinuities. We give a detailed description of how we transfer
the solution between the DG and FD solvers, and the troubled-cell
indicators necessary to robustly handle slow-moving discontinuities
and simulate magnetized neutron stars. We demonstrate the efficacy of
the proposed method using a suite of standard and very challenging
1D, 2D, and 3D relativistic magnetohydrodynamics test problems. The
hybrid scheme is designed from the ground up to efficiently simulate
astrophysical problems such as the inspiral, coalescence, and merger
of two neutron stars.
Title: Time-delay estimation in unresolved lensed quasars
Authors: Biggio, L.; Domi, A.; Tosi, S.; Vernardos, G.; Ricci, D.;
Paganin, L.; Bracco, G.
Bibcode: 2022MNRAS.515.5665B
Altcode: 2022MNRAS.tmp.1907B; 2021arXiv211001012B
Time-delay cosmography can be used to infer the Hubble parameter
H0 by measuring the relative time delays between multiple
images of gravitationally lensed quasars. A few of such systems have
already been used to measure H0: Their time delays were
determined from the light curves of the multiple images obtained by
regular, years long, monitoring campaigns. Such campaigns can hardly be
performed by any telescope: many facilities are often oversubscribed
with a large amount of observational requests to fulfill. While the
ideal systems for time-delay measurements are lensed quasars whose
images are well resolved by the instruments, several lensed quasars
have a small angular separation between the multiple images, and would
appear as a single, unresolved, image to a large number of telescopes
featuring poor angular resolutions or located in not privileged
geographical sites. Methods allowing to infer the time delay also from
unresolved light curves would boost the potential of such telescopes
and greatly increase the available statistics for H0
measurements. This work presents a study of unresolved lensed quasar
systems to estimate the time delay using a deep learning-based approach
that exploits the capabilities of one-dimensional convolutional neural
networks. Experiments on state-of-the-art simulations of unresolved
light curves show the potential of the proposed method and pave the
way for future applications in time-delay cosmography.
Title: The outer stellar mass of massive galaxies: a simple tracer of
halo mass with scatter comparable to richness and reduced projection
effects
Authors: Huang, Song; Leauthaud, Alexie; Bradshaw, Christopher;
Hearin, Andrew; Behroozi, Peter; Lange, Johannes; Greene, Jenny;
DeRose, Joseph; Speagle, Joshua S.; Xhakaj, Enia
Bibcode: 2022MNRAS.515.4722H
Altcode: 2022MNRAS.tmp.1843H; 2021arXiv210902646H
Using the weak gravitational lensing data from the Hyper Suprime-Cam
Subaru Strategic Program (HSC survey), we study the potential of
different stellar mass estimates in tracing halo mass. We consider
galaxies with log10(M⋆/M⊙)
> 11.5 at 0.2 < z < 0.5 with carefully measured light
profiles, and clusters from the redMaPPer and CAMIRA richness-based
algorithms. We devise a method (the 'Top-N test') to evaluate the
scatter in the halo mass-observable relation for different tracers,
and to inter-compare halo mass proxies in four number density bins
using stacked galaxy-galaxy lensing profiles. This test reveals three
key findings. Stellar masses based on CModel photometry and aperture
luminosity within R <30 kpc are poor proxies of halo mass. In
contrast, the stellar mass of the outer envelope is an excellent halo
mass proxy. The stellar mass within R = [50, 100] kpc, M⋆,
[50, 100], has performance comparable to the state-of-the-art
richness-based cluster finders at log10Mvir
≳ 14.0 and could be a better halo mass tracer at lower halo
masses. Finally, using N-body simulations, we find that the lensing
profiles of massive haloes selected by M⋆, [50, 100]
are consistent with the expectation for a sample without projection or
mis-centring effects. Richness-selected clusters, on the other hand,
display an excess at R ~ 1 Mpc in their lensing profiles, which may
suggest a more significant impact from selection biases. These results
suggest that M⋆-based tracers have distinct advantages in
identifying massive haloes, which could open up new avenues for cluster
cosmology. The codes and data used in this work can be found here:
Title: Reaching for the Edge I: probing the outskirts of massive
galaxies with HSC, DECaLS, SDSS, and Dragonfly
Authors: Li, Jiaxuan; Huang, Song; Leauthaud, Alexie; Moustakas,
John; Danieli, Shany; Greene, Jenny E.; Abraham, Roberto; Ardila,
Felipe; Kado-Fong, Erin; Lokhorst, Deborah; Lupton, Robert; Price, Paul
Bibcode: 2022MNRAS.515.5335L
Altcode: 2022MNRAS.tmp.2019L; 2021arXiv211103557L
The outer light (stellar haloes) of massive galaxies has recently
emerged as a possible low scatter tracer of dark matter halo mass. To
test the robustness of outer light measurements across different
data sets, we compare the 1D azimuthally averaged surface brightness
profiles of massive galaxies using four independent data sets: the
Hyper Suprime-Cam survey (HSC), the Dark Energy Camera Legacy Survey
(DECaLS), the Sloan Digital Sky Survey (SDSS), and the Dragonfly Wide
Field Survey (Dragonfly). We test the sky subtraction and proposed
corrections for HSC and DECaLS. For galaxies at z < 0.05, Dragonfly
has the best control of systematics, reaching surface brightness levels
of μr ≍ 30 mag arcsec-2. At 0.19 < z <
0.50, HSC can reliably recover individual surface brightness profiles
to μr ≍ 28.5 mag arcsec-2 (R = 100-150 kpc in
semimajor axis). In a statistical sense, DECaLS agrees with HSC to R
> 200 kpc. DECaLS and HSC measurements of the stellar mass contained
within 100 kpc agree within 0.05 dex. Finally, we use weak lensing to
show that measurements of outer light with DECaLS at 0.19 < z <
0.50 show a similar promise as HSC as a low scatter proxy of halo
mass. The tests and results from this paper represent an important
step forward for accurate measurements of the outer light of massive
galaxies and demonstrate that outer light measurements from DECam
imaging will be a promising method for finding galaxy clusters.
Title: Enhanced adsorption of inorganic arsenic by Mg-calcite under
circumneutral conditions
Authors: Gong, Peili; Li, Chengcheng; Yi, Qianqian; Gao, Xubo; Dai,
Chong; Du, Jiangkun; Liu, Juanjuan; Zhang, Xin; Duan, Yan; Tan, Ting;
Kong, Shuqiong
Bibcode: 2022GeCoA.335...85G
Altcode:
Calcite is an important reservoir for arsenic (As) and strongly
affects its mobility in various geological environments. However,
the method by which bulk As is taken up by calcite needs to be better
understood. To broaden our understanding, Mg-containing calcite
(Mg-calcite), which is a ubiquitous form of calcite in nature,
was investigated to determine its As adsorption capacity. Laboratory
experiments were conducted under aerobic and anaerobic conditions using
synthetic pure calcite (Ca10Mg0) and Mg-calcite
(Ca9Mg1, Ca8Mg2). As
speciation (determined using chromatography techniques, such as ion
chromatography-hydride generation-atomic fluorescence spectrometry
(IC-HG-AFS)) and microscopic characterization (field-emission scanning
electron microscopy coupled with energy-dispersive spectroscopy
(FE-SEM-EDS), X-ray diffraction (XRD), Fourier transform infrared
spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) analysis, and
X-ray photoelectron spectroscopy (XPS)) were coupled to investigate
the adsorption capacity and potential mechanisms of As adsorption
by Mg-calcite. The results showed that Mg-calcite exhibited an As
adsorption capacity that was several times higher than pure calcite,
especially for As(III). Based on microscopic characterizations, the
substitution of CO3/OH groups with As-O groups and the
formation of complexes on the Mg-calcite surface are the dominant
mechanisms of arsenate (As(V)) adsorption. The doping of Mg into
calcite results in a lattice contraction effect that provides
additional space for the substitution of larger As oxyanions for
carbonate ions. In parallel, as evidenced by the potentiometric
automatic titration results, the presence of Mg in calcite led to an
increased density of surface positive charges, which promotes greater
adsorption of negatively charged As. In addition to the substitution
of CO3 groups with As-O groups, the enhanced adsorption
of As(III) by Mg-calcite was also attributed to the larger amount of
H-bonding yielded by the addition of Mg. To the best of our knowledge,
this is the first experimental investigation to quantify the adsorption
of As by Mg-calcite, and it provides new insights into the fate and
transport of inorganic As by carbonates in aqueous environments.
Title: qrpca: A package for fast principal component analysis with
GPU acceleration
Authors: de Souza, R. S.; Quanfeng, X.; Shen, S.; Peng, C.; Mu, Z.
Bibcode: 2022A&C....4100633D
Altcode: 2022arXiv220606797D
We present qrpca, a fast and scalable QR-decomposition principal
component analysis package. The software, written in both R
and python languages, makes use of torch for internal matrix
computations, and enables GPU acceleration, when available. qrpca
provides similar functionalities to prcomp (R) and sklearn (python)
packages respectively. A benchmark test shows that qrpca can achieve
computational speeds 10-20 × faster for large dimensional matrices
than default implementations, and is at least twice as fast for a
standard decomposition of spectral data cubes. The qrpca source code
is made freely available to the community.
Title: Revealing the dynamics of equilibrium points in a binary
system with two radiating bodies
Authors: Alrebdi, H. I.; Smii, Boubaker; Zotos, Euaggelos E.
Bibcode: 2022AdSpR..70.2021A
Altcode:
The equilibrium dynamics of the post-Newtonian circular restricted
three-body problem (PNCRTBP), in the case of two massive stars or even
stellar remnants, are investigated. Numerical methods are deployed
for determining the points of equilibrium, as well as their linear
stability. Our systematic and rigorous analysis reveals the role and
influence of the transition parameter ∊ and the radiation pressure
factor q on the dynamics of the system. It is revealed that the amount
of equilibria increases with increasing value of the radiation pressure
factor. On the other hand, as the value of the transition parameter
tends to its maximum value the number of libration points is reduced,
implying that in the case of strong post-Newtonian gravity the system
degenerates.
Title: An ab initio study for the photodissociation of HCl and HF
Authors: Qin, Zhi; Bai, Tianrui; Liu, Linhua
Bibcode: 2022MNRAS.516..550Q
Altcode: 2022MNRAS.tmp.2124Q
Detailed studies of HCl and HF photodissociation are required for an
in-depth understanding the chlorine and fluorine chemistry in Venus and
exoplanets. Here, we present an ab initio study of photodissociation
of HCl and HF. Except for the widely studied A 1Π←X
1Σ+ photodissociation process, the ground-state
photodissociation processes for HCl and HF via higher excited states
are considered. State-resolved cross-sections are computed for
nine photodissociation processes of HCl from a total of 871 ground
rovibrational levels. For HF, seven photodissociation processes
are considered for the computation of state-resolved cross-sections
from all the rovibrational levels in the ground state. Subsequently,
temperature-dependent cross-sections for the considered transition
processes of HCl and HF are estimated from 0 to 10 000 K with a grid of
34 temperatures. Careful comparisons with the recent ExoMol study and
the Leiden Observatory database are made. The photodissociation rates
in the interstellar and blackbody radiation fields are also discussed.
Title: Detailed analysis of an eccentric TESS binary star with
solar-type components: TIC 284613090
Authors: Aliçavuş, Fahri
Bibcode: 2022NewA...9601860A
Altcode:
Eclipsing binary stars are significant objects for understanding stellar
evolution, stellar population synthesis, and galaxy dynamics. Thanks
to the increasing number of high-quality photometric data of space
observations, the sensitivity of the fundamental astrophysical
parameters (mass M, radius R) has risen and this situation has
highlighted the importance of eclipsing binary stars once again. There
are known relations between M and luminosity (L) for the eclipsing
binary systems, especially for the detached binaries. However, in
these M - L relations, some break-points appear and those points
need to be re-examined with accurate M and L parameters of stars
located at these areas. One of these break-points presents around the
Solar mass. Therefore, this study focuses on a TESS field object TIC
284613090 which is an eccentric binary system containing two solar-type
components. In the study, the fundamental parameters of the binary
component stars were precisely obtained by a simultaneous analysis of
the radial velocities and the TESS light curve. As a result, the masses
and radii of the primary and secondary binary components were found to
be M1 = 1.030 (8) M⊙, M2 = 1.019
(8) M⊙ and R1 = 1.611 (5)R⊙,
R2 = 1.485 (5) R⊙, respectively. When the
evolutionary status of the component stars was examined, it turned out
that they are approaching the end of their main sequence evolution
and the age of the system is 9.65 (20) Gyr. As a result of binary
evolutionary models, it was also found that TIC 284613090 started its
evolution with an orbital period of 11.83 days and an eccentric orbit
with a value of e = 0.227. The position of the binary components in
the M - L relation was examined as well and showed consistency with
the relation.
Title: A simulation of the joint estimation of the GM value and the
ephemeris of the asteroid 2016 HO3
Authors: Yan, Jianguo; Liu, Lu; Ye, Mao; Jin, Weitong; Qiu, Denggao;
Barriot, Jean-Pierre
Bibcode: 2022Icar..38515120Y
Altcode:
Asteroid 2016 HO3 is the first of the two small bodies in the Solar
System targeted by the Chinese Small Body Exploration Mission scheduled
to be launched in the next few years. In this paper, we perform a full
numerical simulation of a possible onboard radio science experiment
to obtain the GM value of this tiny asteroid with a relative accuracy
of ~10%. At such an accuracy, the GM value can be used to constrain
the internal structure of the asteroid. We demonstrate that such an
accuracy can be achieved through a joint estimation of the GM value
and the ephemeris of the asteroid by using ground-based and onboard
(spacecraft-asteroid) radiometric tracking data.
Title: Lightweight HI source finding for next generation radio surveys
Authors: Tolley, E.; Korber, D.; Galan, A.; Peel, A.; Sargent, M. T.;
Kneib, J. -P.; Courbin, F.; Starck, J. -L.
Bibcode: 2022A&C....4100631T
Altcode: 2022arXiv220409288T
Future deep HI surveys will be essential for understanding the nature
of galaxies and the content of the Universe. However, the large volume
of these data will require distributed and automated processing
techniques. We introduce LiSA, a set of python modules for the
denoising, detection and characterization of HI sources in 3D spectral
data. LiSA was developed and tested on the Square Kilometer Array
Science Data Challenge 2 dataset, and contains modules and pipelines
for easy domain decomposition and parallel execution. LiSA contains
algorithms for 2D-1D wavelet denoising using the starlet transform
and flexible source finding using null-hypothesis testing. These
algorithms are lightweight and portable, needing only a few user-defined
parameters reflecting the resolution of the data. LiSA also includes
two convolutional neural networks developed to analyze data cubes
which separate HI sources from artifacts and predict the HI source
properties. All of these components are designed to be as modular as
possible, allowing users to mix and match different components to create
their ideal pipeline. We demonstrate the performance of the different
components of LiSA on the SDC2 dataset, which is able to find 95%
of HI sources with SNR > 3 and accurately predict their properties.
Title: Extreme Mo isotope variations recorded in high-SiO2
granites: Insights into magmatic differentiation and melt-fluid
interaction
Authors: Fan, Jing-Jing; Wang, Qiang; Ma, Lin; Li, Jie; Zhang,
Xiu-Zheng; Zhang, Le; Wang, Zi-Long
Bibcode: 2022GeCoA.334..241F
Altcode:
The Mo stable isotope system has been used to trace material
recycling during subduction-related processes, but the behavior of Mo
isotopes during magmatic evolution (e.g., crystal-melt fractionation
and melt-fluid interaction) remains contentious, especially in
high-SiO2 granites. This study addresses the issue of
Mo isotope variation in high-SiO2 granites by measuring
bulk-rock and mineral Mo isotopes of biotite granites (BGs) and
garnet-bearing two-mica granites (GBGs) from the well-characterized
Zhengga granite pluton (southern Tibet, China). The GBGs have
similar Sr-Nd-O isotope compositions to those of the BGs but
show higher SiO2 and lower TiO2, MgO, total
Fe2O3, and CaO contents, and represent the
products of advanced fractionation of the BG magmas. The BGs have
lower Mo contents (0.02-0.07 ppm) and higher δ98/95Mo
values (-0.54‰ to 0.22‰) compared with the GBGs (0.029-2.121 ppm
and -0.97‰ to -0.41‰, respectively). Analysis of major silicate
minerals suggests that substantial segregation of biotite and feldspar
with high δ98/95Mo values of 0.00‰ to 0.38‰ and -1.06‰
to 0.57‰ (most within -0.58‰ to 0.13‰) could have driven the GBGs
and the late-stage crystalline phase of garnet (-1.22‰ to -0.98‰)
towards very low δ98/95Mo values. However, the trend of
decreasing δ98/95Mo with indices of magma differentiation is
not linear: one group of GBGs show increasing Mo contents and decreasing
δ98/95Mo values with decreasing Y, Ho, and Dy contents;
while the other group display increasing Mo contents and slightly
decreasing δ98/95Mo values with respect to the increasing
contents of Y, Ho, and Dy. These two contrasting behaviors can be
ascribed to further crystal fractionation and melt-fluid interaction
in a closed magmatic-hydrothermal system. This is also evidenced by
the formation of two types of garnets with different contents of Mo
and rare earth elements in these two groups of GBGs. Closed-system
fluid saturation is inferred to have driven the silicate melt to
be enriched in 98Mo, which limited the decrease in melt
δ98/95Mo caused by crystal fractionation. These observations
are supported by quantitative geochemical modeling. We conclude that
both fractional crystallization and melt-fluid interaction control
Mo isotope fractionation in high-SiO2 granites and that Mo
isotopes are useful for tracing the evolution of high-SiO2
igneous rocks.
Title: A transient ultraluminous X-ray source in NGC 55
Authors: Robba, A.; Pinto, C.; Pintore, F.; Rodriguez, G.; Ambrosi,
E.; Barra, F.; Cusumano, G.; D'Aì, A.; Del Santo, M.; Kosec, P.;
Marino, A.; Middleton, M.; Roberts, T.; Salvaggio, C.; Soria, R.;
Wolter, A.; Walton, D.
Bibcode: 2022MNRAS.515.4669R
Altcode: 2022MNRAS.tmp.1916R; 2022arXiv220709447R
Ultraluminous X-ray sources (ULXs) are a class of accreting
compact objects with X-ray luminosities above 1039 erg
s-1 . The average number of ULXs per galaxy is still not
well-constrained, especially given the uncertainty on the fraction of
ULX transients. Here, we report the identification of a new transient
ULX in the galaxy NGC 55 (which we label as ULX-2), thanks to recent
XMM-Newton and the Neil Gehrels Swift Observatory observations. This
object was previously classified as a transient X-ray source with a
luminosity around a few 1038 erg s-1 in a 2010
XMM-Newton observation. Thanks to new and deeper observations (~130
ks each), we show that the source reaches a luminosity peak >1.6
× 1039 erg s-1. The X-ray spectrum of ULX-2 is
much softer than in previous observations and fits in the class of
soft ULXs. It can be well-described using a model with two thermal
components, as often found in ULXs. The time-scales of the X-ray
variability are of the order of a month and are likely driven by small
changes in the accretion rate or due to super-orbital modulations,
attributed to precession of the accretion disc, which is similar to
other ULXs.
Title: Bridging the shocked monazite gap - Deformation microstructures
in natural and laser shock-loaded samples
Authors: Seydoux-Guillaume, A. -M.; de Resseguier, T.; Montagnac,
G.; Reynaud, S.; Leroux, H.; Reynard, B.; Cavosie, A. J.
Bibcode: 2022E&PSL.59517727S
Altcode:
Impact-related damage in minerals and rocks provides key evidence
to identify impact structures, and deformation of U-Th-minerals in
target rocks, such as monazite, makes possible precise dating and
determination of pressure-temperature conditions for impact events. Here
a laser-driven shock experiment using a high-energy laser pulse of
ns-order duration was carried out on a natural monazite crystal to
compare experimentally produced shock-deformation microstructures
with those observed in naturally shocked monazite. Deformation
microstructures from regions that may have experienced up to ∼50
GPa and 1000 °C were characterized using Raman spectroscopy and
transmission electron microscopy. Experimental results were compared
with nanoscale observations of deformation microstructures found
in naturally shocked monazite from the Vredefort impact structure
(South Africa). Raman-band broadening observed between unshocked and
shocked monazite, responsible for a variation of ∼3 cm-1
in the FWHM, is interpreted to result from the competition between
shock-induced distortion of the lattice, and post-shock annealing. At
nanoscale, three main plastic deformation structures were found in
both naturally and experimentally shocked monazite: deformation twins,
mosaïcism, and deformation bands. The element Ca is enriched along
host-twin boundaries, which further confirms that the laser shock
loading experiment produced both comparable styles of crystal-plastic
deformation, and also localized element mobility, as that found
in natural shock-deformed monazite. Deformation twins form in the
experiment were only along the (001) plane, an orientation which
is not considered diagnostic of shock deformation. However, both
mosaïcism and deformation, expressed in SAED patterns as streaking of
spots, and the presence of extra spots (more or less pronounced), are
interpreted as unambiguous nano-scale signatures of shock metamorphism
in monazite. Experimentally calibrated deformation features, such as
those documented here at TEM-scale, provide new tools for identifying
evidence of shock deformation in natural samples.
Title: Constraining the Planet Occurrence Rate around Halo Stars of
Potentially Extragalactic Origin
Authors: Yoshida, Stephanie; Grunblatt, Samuel; Price-Whelan, Adrian M.
Bibcode: 2022AJ....164..119Y
Altcode: 2022arXiv220613556Y
The search for planets orbiting other stars has recently expanded
to include stars from galaxies outside the Milky Way. With the
Transiting Exoplanet Survey Satellite (TESS) and Gaia surveys,
photometric and kinematic information can be combined to identify
transiting planet candidates of extragalactic origin. Here, 1080
low-luminosity red-giant branch stars observed by Gaia and TESS with
kinematics suggesting a high likelihood of extragalactic origin were
searched for planet transits. Transit injection-recovery tests were
performed to measure the sensitivity of the TESS data and completeness
of the transit search. Injected signals of planets larger than Jupiter
with orbital periods of 10 days or less were recovered in ≍44%
of cases. Although no planet transits were detected in this sample,
we find an upper limit on planet occurrence of 0.52% for hot Jupiters,
consistent with previous studies of planet occurrence around similar
host stars. As stars in the halo tend to be lower metallicity, and
short-period giant planet occurrence tends to be strongly correlated
with stellar metallicity, we predict that relative to the Galactic
disk population, a smaller fraction of halo stars will host planets
detectable by transit surveys. Thus, applying the known planet
occurrence trends to potential planet detection around halo stars,
we predict ≳13,000 stars must be searched with similar cadence and
precision as the stars studied here before a detection of a planet of
extragalactic origin is likely. This may be possible with future data
releases from the TESS and Gaia missions.
Title: Late-time acceleration in f(Q) gravity: Analysis and
constraints in an anisotropic background
Authors: Koussour, M.; El Bourakadi, K.; Shekh, S. H.; Pacif, S. K. J.;
Bennai, M.
Bibcode: 2022AnPhy.44569092K
Altcode: 2022arXiv220808877K
This paper is devoted to investigate the anisotropic locally
rotationally symmetric (LRS) Bianchi type-I space-time in the context
of the recently proposed f(Q) gravity in which Q is the non-metricity
scalar. For this purpose, we consider a linear form of f(Q) gravity
model, specifically, f(Q) = αQ + β , where α and β are free
parameters and then we analyze the exact solutions of LRS Bianchi type-I
space-time. The modified Friedmann equations are solved by presuming an
expansion scalar θ(t) is proportional to the shear scalar σ(t) which
leads to the relation between the metric potentials as A =Bn
where n is an arbitrary constant. Then we constrain our model parameters
with the observational Hubble datasets of 57 data points. Moreover,
we discuss the physical behavior of cosmological parameters such as
energy density, pressure, EoS parameter, and deceleration parameter. The
behavior of the deceleration parameter predicts a transition from
deceleration to accelerated phases in an expanding Universe. Finally,
the EoS parameter indicates that the anisotropic fluid behaves like
the standard ΛCDM model.
Title: KamLAND's search for correlated low-energy electron
antineutrinos with astrophysical neutrinos from IceCube
Authors: Abe, S.; Asami, S.; Eizuka, M.; Futagi, S.; Gando, A.;
Gando, Y.; Gima, T.; Goto, A.; Hachiya, T.; Hata, K.; Hosokawa, K.;
Ichimura, K.; Ieki, S.; Ikeda, H.; Inoue, K.; Ishidoshiro, K.; Kamei,
Y.; Kawada, N.; Kishimoto, Y.; Kinoshita, T.; Koga, M.; Kurasawa,
M.; Maemura, N.; Mitsui, T.; Miyake, H.; Nakahata, T.; Nakamura, K.;
Nakamura, R.; Ozaki, H.; Sakai, T.; Sambonsugi, H.; Shimizu, I.;
Shirai, J.; Shiraishi, K.; Suzuki, A.; Suzuki, Y.; Takeuchi, A.;
Tamae, K.; Watanabe, H.; Yoshida, Y.; Obara, S.; Ichikawa, A. K.;
Yoshida, S.; Umehara, S.; Fushimi, K.; Kotera, K.; Urano, Y.; Berger,
B. E.; Fujikawa, B. K.; Learned, J. G.; Maricic, J.; Axani, S. N.;
Smolsky, J.; Lertprasertpong, J.; Winslow, L. A.; Fu, Z.; Ouellet,
J.; Efremenko, Y.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Li,
A.; Detwiler, J. A.; Enomoto, S.; Decowski, M. P.; Grant, C.; Song,
H.; O'Donnell, T.; Dell'Oro, S.
Bibcode: 2022APh...14302758A
Altcode: 2022arXiv220207345A
We report the results of a search for MeV-scale astrophysical neutrinos
in KamLAND presented as an excess in the number of coincident neutrino
interactions associated with the publicly available high-energy
neutrino datasets from the IceCube Neutrino Observatory. We find no
statistically significant excess in the number of observed low-energy
electron antineutrinos in KamLAND, given a coincidence time window of
±500 s, ±1,000 s, ±3,600 s, and ±10,000 s around each of the IceCube
neutrinos. We use this observation to present limits from 1.8 MeV to
100 MeV on the electron antineutrino fluence, assuming a mono-energetic
flux. We then compare the results to several astrophysical measurements
performed by IceCube and place a limit at the 90% confidence level on
the electron antineutrino isotropic thermal luminosity from the TXS
0506+056 blazar.
Title: Study of scalar and tensor power spectra in the generalized
Starobinsky inflationary model using semiclassical methods
Authors: Rojas, Clara
Bibcode: 2022APh...14302745R
Altcode: 2022arXiv220300741R
In this work we solved the equation of scalar and tensor perturbations
for the generalized Starobinsky inflationary model using the improved
uniform approximation method and the phase-integral method up to
third-order in deviation. We compare our results with the numerical
integration. We have obtained that both semiclassical methods reproduce
the scalar power spectra PS,T, the scalar spectral index
nS, and the tensor-to-scalar ratio r. Also we present our
results in the (nS , r) plane.
Title: The global distribution and morphologic characteristics of
fan-shaped sedimentary landforms on Mars
Authors: Morgan, Alexander M.; Wilson, Sharon A.; Howard, Alan D.
Bibcode: 2022Icar..38515137M
Altcode:
Fan-shaped sedimentary landforms on Mars are important geomorphic
markers of past water flow and characterizing the distribution and
morphology of these features can yield insights into the planet's
climatic evolution. We present a new database of 1501 martian fan-shaped
sedimentary landforms that builds upon previous surveys and uses
Context Camera images. This comprehensive global survey includes
both alluvial fans and putative deltas, which we term scarp-fronted
fan deposits (SFDs), across the entire martian surface. We classified
each fan-shaped landforms based on their morphology as alluvial fans,
channelized SFDs, smooth SFDs, and terraced SFDs. Martian alluvial fans
are highly concentrated in the high southern tropical latitudes while
SFDs are more common near the equator. Both alluvial fans and SFDs are
found at lower elevations than Late Noachian to Early Hesperian valley
networks, suggesting a climatic change in the locations of stable liquid
water. Alluvial fans within impact craters are preferentially located
on north, south, and east facing slopes, and are concentrated near the
location of highest rim topographic relief; together these observations
support orographically-influenced precipitation and snowmelt as a runoff
source. For every fan in the database we collected morphologic data,
which we compare with terrestrial alluvial fans. Relationships between
alluvial fan catchment and fan morphology vary little across the martian
surface, suggesting relatively similar processes. Although stratigraphic
evidence of a deltaic deposition is lacking, previously conducted
experiments along with the depositional basins of the channelized
and terraced SFDs generally support deltaic formation. Crater counts
indicate that many alluvial fans are within Hesperian and Amazonian
impact craters, indicating that significant fluvial erosion occurred
during Mars' relatively recent history.
Title: Heterogeneous nature of the carbonaceous chondrite breccia
Aguas Zarcas - Cosmochemical characterization and origin of new
carbonaceous chondrite lithologies
Authors: Kerraouch, Imene; Kebukawa, Yoko; Bischoff, Addi; Zolensky,
Michael E.; Wölfer, Elias; Hellmann, Jan L.; Ito, Motoo; King,
Ashley; Trieloff, Mario; Barrat, Jean-Alix; Schmitt-Kopplin, Phillipe;
Pack, Andreas; Patzek, Markus; Hanna, Romy D.; Fockenberg, Thomas;
Marrocchi, Yves; Fries, Marc; Mathurin, Jérémie; Dartois, Emmanuel;
Duprat, Jean; Engrand, Cécile; Deniset, Ariane; Dazzi, Alexandre;
Kiryu, Kento; Igisu, Motoko; Shibuya, Takazo; Wakabayashi, Daisuke;
Yamashita, Shohei; Takeichi, Yasuo; Takahashi, Yoshio; Ohigashi,
Takuji; Kodama, Yu; Kondo, Masashi
Bibcode: 2022GeCoA.334..155K
Altcode:
On April 23rd, 2019, the Aguas Zarcas meteorite fall occurred in
Costa Rica. Because the meteorite was quickly recovered, it contains
valuable extraterrestrial materials that have not been contaminated
by terrestrial processes. Our X-ray computed tomography (XCT)
and scanning electron microscopy (SEM) results on various pre-rain
fragments from earlier work (Kerraouch et al., 2020; 2021) revealed
several distinct lithologies: Two distinct metal-rich lithologies
(Met-1 and Met-2), a CM1/2 lithology, a C1 lithology, and a brecciated
CM2 lithology consisting of different petrologic types. Here, we
further examined these lithologies in the brecciated Aguas Zarcas
meteorite and report new detailed mineralogical, chemical, isotopic,
and organic matter characteristics. In addition to petrographic
differences, the lithologies also display different chemical and
isotopic compositions. The variations in their bulk oxygen isotopic
compositions indicate that the various lithologies formed in different
environments and/or under diverse conditions (e.g., water/rock
ratios). Each lithology experienced a different hydration period during
its evolution. Together, this suggests that multiple precursor parent
bodies may have been involved in these processes of impact brecciation,
mixing, and re-assembly. The Cr and Ti isotopic data for both the CM1/2
and Met-1 lithology are consistent with those of other CM chondrites,
even though Met-1 displays a significantly lower ε50Ti
isotopic composition that may be attributable to sample heterogeneities
on the bulk meteorite scale and may reflect variable abundances of
refractory phases in the different lithologies of Aguas Zarcas. Finally,
examination of the organic matter of the various lithologies also
suggests no strong evidence of thermal events, but a short-term
heating cannot completely be excluded. Raman parameters indicate that
the peak temperature has been lower than that for Yamato-793321 (CM2,
∼400 °C). Considering the new information presented in this study,
we now better understand the origin and formation history of the Aguas
Zarcas daughter body.
Title: The refinement of reprocessed GNSS three-decade displacement
trajectory model with spectral analysis and hypothesis test
Authors: Wang, Hu; Ren, Yingying; Hou, Yangfei; Wang, Jiexian; Zhang,
Yize; Cheng, Yingyan; Xue, Shuqiang; Fang, Shushan
Bibcode: 2022AdSpR..70.1810W
Altcode:
Extensive data collection, unified and rigorous data processing,
and accurate construction of station motion model (especially the
correction of co-seismic/post-seismic effects of large earthquakes)
are three basic elements for the accuracy and reliability of Global
Navigation Satellite System (GNSS) velocity. Thus, we take advantage
of the sensitivity features of the spectral analysis and hypothesis
test to refine the site movement trajectory model, and apply it to
the reprocessed GNSS three-decade coordinate time series. Firstly, we
reprocess GNSS observations and seismic records based on the updated
convention and processing settings of International GNSS Service (IGS)
repro3. Secondly, we use the Improved Lomb-Scargle Periodogram (ILSP)
model to analyze the periodic characteristics of GNSS vertical time
series. The results represent that the primary period of about 35%
of sites is 365 days, and the secondary period of 20% of sites is 182
days. Thirdly, we evaluate the performance of different time series
model component combination of the time series (a: velocity only;
b: velocity + offset; c: velocity + offset + PSD; d: velocity +
offset + PSD + period) and Post-Seismic Deformation (PSD) modes
(PSD1: None; PSD 2: Exp; PSD 3: Log; PSD 4: Exp + Log). Fourthly,
we use the chi-square test to assess the overall correctness of the
trajectory model, followed by the t-test to test the significance
of each parameter further, and then use the optimized model to refit
and reanalyze GNSS time series. The analysis of the velocity results
illustrates that the fitting accuracy of GNSS time series is 3-6 mm in
the horizontal direction and 4-9 mm in the vertical direction. Lastly,
we obtain a refined global three-dimensional velocity field based
on GNSS three-decade time series, with the median velocity of Root
Mean Square Error (RMSE) as 0.17, 0.17, and 0.32 mm/a in N/E/U
direction. Compared with ITRF2014, the velocity difference is at 1-2
mm/a level due to differences in GNSS observations, trajectory model,
and geodetic technology.
Title: The EURONEAR Lightcurve Survey of Near Earth Asteroids
2017-2020
Authors: Vaduvescu, O.; Aznar Macias, A.; Wilson, T. G.; Zegmott,
T.; Pérez Toledo, F. M.; Predatu, M.; Gherase, R.; Pinter, V.;
Pozo Nunez, F.; Ulaczyk, K.; Soszyński, I.; Mróz, P.; Wrona,
M.; Iwanek, P.; Szymanski, M.; Udalski, A.; Char, F.; Salas Olave,
H.; Aravena-Rojas, G.; Vergara, A. C.; Saez, C.; Unda-Sanzana, E.;
Alcalde, B.; de Burgos, A.; Nespral, D.; Galera-Rosillo, R.; Amos,
N. J.; Hibbert, J.; López-Comazzi, A.; Oey, J.; Serra-Ricart, M.;
Licandro, J.; Popescu, M.
Bibcode: 2022EM&P..126....6V
Altcode:
This is the fourth data paper publishing lightcurve survey work
of 52 Near Earth Asteroids (NEAs) using 10 telescopes available to
the EURONEAR network between 2017 and 2020. Forty six targets were
not observed before our runs (88% of the sample) but some of these
were targeted during the same oppositions mainly by Brian Warner. We
propose new periods for 20 targets (38% of the sample), confirming
published data for 20 targets, while our results for 8 targets do not
match published data. We secured periods for 15 targets (29% of the
sample), candidate periods for 23 objects (44%), tentative periods for
11 asteroids (21%), and have derived basic information about 3 targets
(6% of the sample). We calculated the lower limit of the ellipsoid
shape ratios a/b for 46 NEAs (including 13 PHAs). We confirmed or
suggested 4 binary objects, recommending two of them for follow-up
during future dedicated campaigns.
Title: Erratum to "Understanding CYGNSS wind performance against
in-situ and satellite winds during low-to-moderate and cyclonic
conditions" [Adv. Space Res. 70 (2022) 587-600]
Authors: Shyam, Abhineet; Praveen Kumar, K.; Varma, Atul K.
Bibcode: 2022AdSpR..70.2142S
Altcode:
The publisher regrets there was an error with the layout of Fig. 2 in
the published article. Part (c) overlapped parts (a) and (b) of this
figure. Please find the full correct Fig. 2 below.
Title: Hydrothermal remobilization of subseafloor sulfide
mineralization along mid-ocean ridges contributes to the global
oceanic zinc isotopic mass balance
Authors: Liao, Shili; Tao, Chunhui; Wen, Hanjie; Yang, Weifang; Liu,
Jia; Jamieson, John W.; Dias, Ágata Alveirinho; Zhu, Chuanwei; Liang,
Jin; Li, Wei; Ding, Teng; Li, Xiaohu; Zhang, Huichao
Bibcode: 2022GeCoA.335...56L
Altcode:
Hydrothermal activity on mid-ocean ridges is an important mechanism for
the delivery of Zn from the mantle to the surface environment. Zinc
isotopic fractionation during hydrothermal activity is mainly
controlled by the precipitation of Zn-bearing sulfide minerals,
in which isotopically light Zn is preferentially retained in solid
phases rather than in solution during mineral precipitation. Thus,
seafloor hydrothermal activity is expected to supply isotopically
heavy Zn to the ocean. Here, we studied sulfide-rich samples from
the Duanqiao-1 hydrothermal field, located on the Southwest Indian
Ridge. We report that, at the hand-specimen scale, late-stage conduit
sulfide material has lower δ66Zn values (-0.05 ± 0.15
‰; n = 19) than early-stage material (+0.13 ± 0.15 ‰; n =
10). These lower values correlate with enrichments in Pb, As, Cd,
and Ag, and elevated δ34S values. We attribute the low
δ66Zn values to the remobilization of earlier sub-seafloor
Zn-rich mineralization. Based on endmember mass balance calculations,
and an assumption of a fractionation factor (αZnS-Sol.)
of about 0.9997 between sphalerite and its parent solution, the
remobilized Zn was found consist of about 1/3 to 2/3 of the total
Zn in the fluid that formed the conduit samples. Our study suggests
that late-stage subsurface hydrothermal remobilization may release
isotopically-light Zn to the ocean, and that this process may be common
along mid-ocean ridges, thus increasing the size of the previously
identified isotopically light Zn sink in the ocean.
Title: Investigating star-formation activity towards the southern
H II region RCW 42
Authors: Kumar, Vipin; Vig, S.; Veena, V. S.; Mohan, S.; Ghosh, S. K.;
Tej, A.; Ojha, D. K.
Bibcode: 2022MNRAS.515.5730K
Altcode: 2022arXiv220714040K; 2022MNRAS.tmp.2023K
The star-forming activity in the H II region RCW 42 is
investigated using multiple wavebands, from near-infrared to radio
wavelengths. Located at a distance of 5.8 kpc, this southern region has
a bolometric luminosity of 1.8 × 106 L⊙. The
ionized gas emission has been imaged at low radio frequencies of 610 and
1280 MHz using the Giant Metrewave Radio Telescope, India, and shows a
large expanse of the H II region, spanning 20 × 15 pc2. The
average electron number density in the region is estimated to be ~70
cm-3, which suggests an average ionization fraction of the
cloud to be 11 % . An extended green object EGO G274.0649-01.1460 and
several young stellar objects have been identified in the region using
data from the 2MASS and Spitzer surveys. The dust emission from the
associated molecular cloud is probed using Herschel Space Telescope,
which reveals the presence of five clumps, C1-C5, in this region. Two
millimetre emission cores of masses 380 and 390 M⊙ towards
the radio emission peak have been identified towards C1 from the ALMA
map at 1.4 mm. The clumps are investigated for their evolutionary
stages based on association with various star-formation tracers,
and we find that all the clumps are in active/evolved stage.
Title: Emerging material platforms for integrated microcavity
photonics
Authors: Liu, Jin; Bo, Fang; Chang, Lin; Dong, Chun-Hua; Ou, Xin;
Regan, Blake; Shen, Xiaoqin; Song, Qinghai; Yao, Baicheng; Zhang,
Wenfu; Zou, Chang-Ling; Xiao, Yun-Feng
Bibcode: 2022SCPMA..6504201L
Altcode:
Many breakthroughs in technologies are closely associated with the
deep understanding and development of new material platforms. As the
main material used in microelectronics, Si also plays a leading role
in the development of integrated photonics. The indirect bandgap,
absence of χ(2) nonlinearity and the parasitic nonlinear
absorptions at the telecom band of Si imposed technological bottlenecks
for further improving the performances and expanding the functionalities
of Si microcavities in which the circulating light intensity is
dramatically amplified. The past two decades have witnessed the
burgeoning of the novel material platforms that are compatible with the
complementary metal-oxide-semiconductor (COMS) process. In particular,
the unprecedented optical properties of the emerging materials in the
thin film form have resulted in revolutionary progress in microcavity
photonics. In this review article, we summarize the recently developed
material platforms for integrated photonics with the focus on chip-scale
microcavity devices. The material characteristics, fabrication processes
and device applications have been thoroughly discussed for the most
widely used new material platforms. We also discuss open challenges
and opportunities in microcavity photonics, such as heterogeneous
integrated devices, and provide an outlook for the future development
of integrated microcavities.
Title: Studying the chemical and kinematical structures of dense
cores TMC-1C, L1544, and TMC-1 in the Taurus molecular cloud using
CCS and NH3 observations
Authors: Koley, Atanu
Bibcode: 2022MNRAS.516..185K
Altcode: 2022arXiv220800968K
The measurement of chemical and kinematic structures in pre-stellar
cores is essential for better understanding of the star-formation
process. Here, we study three pre-stellar cores (TMC-1C, L1544, and
TMC-1) of the Taurus molecular cloud by means of the thioxoethenylidene
(CCS) radical and ammonia (NH3) molecule observed with
the Karl G. Jansky Very Large Array telescope in the D, C, and CNB
configurations. Our main results are based on the CCS observation of
the TMC-1C core, showing that complex structures are present. A spatial
offset relative to dust emission is observed in the CCS radical. Across
a wide region around the dust peak, inward motion is found through the
CCS radical. We have calculated the infall velocity and measured the
turbulence inside the core. The turbulence is found to be subsonic. We
obtain that the virial parameter α is < 1. Thus, thermal and
non-thermal motions cannot prevent the collapse. Spatial incoherence of
the CCS and NH3 is observed from the integrated intensity
maps in these cores, suggesting that these molecules trace different
environments in the cores. We compare the integrated flux densities
of CCS with previous single-dish data and find that a small amount of
flux is recovered in the interferometric observations, indicating the
presence of significant diffuse emission in favourable conditions for
producing CCS.
Title: Quintessence model of Tsallis holographic dark energy
Authors: Kumar, P. Suresh; Pankaj; Sharma, Umesh Kumar
Bibcode: 2022NewA...9601829K
Altcode:
In order to apply entropy relations and holography to the entire
universe, which is a gravitationally nonextensive framework, for
consistency one should apply the standard definition for the universe
horizon entropy, specifically Tsallis nonextensive entropy. The model
of Tsallis holographic dark energy quantified by a new dimensionless
parameter δ, which is a generalization of original holographic dark
energy is an endeavour for testing the idea of dark energy inside the
structure of holographic principle and entropy formalism. The Tsallis
parameter δ decides the principle property of the Tsallis holographic
dark energy. With the suitable choice of dimensionless parameter δ,
this article attempts to analyse the behaviour of Tsallis holographic
dark energy using the Tsallis entropy notion. The choice of δ < 1
describes completely the quintessence behaviour of Tsallis holographic
dark energy. The dynamics of the scalar field as well as potential of
the quintessence is reconstructed for the choices of δ < 1 .
Title: Identifying active galactic nuclei via brightness temperature
with sub-arcsecond international LOFAR telescope observations
Authors: Morabito, Leah K.; Sweijen, F.; Radcliffe, J. F.; Best,
P. N.; Kondapally, Rohit; Bondi, Marco; Bonato, Matteo; Duncan, K. J.;
Prandoni, Isabella; Shimwell, T. W.; Williams, W. L.; van Weeren,
R. J.; Conway, J. E.; Calistro Rivera, G.
Bibcode: 2022MNRAS.515.5758M
Altcode: 2022arXiv220713096M; 2022MNRAS.tmp.2025M
Identifying active galactic nuclei (AGNs) and isolating their
contribution to a galaxy's energy budget is crucial for studying the
co-evolution of AGNs and their host galaxies. Brightness temperature
(Tb) measurements from high-resolution radio observations at
GHz frequencies are widely used to identify AGNs. Here, we investigate
using new sub-arcsecond imaging at 144 MHz with the International LOFAR
Telescope to identify AGNs using Tb in the Lockman Hole
field. We use ancillary data to validate the 940 AGN identifications,
finding 83 percent of sources have AGN classifications from SED
fitting and/or photometric identifications, yielding 160 new AGN
identifications. Considering the multiwavelength classifications,
brightness temperature criteria select over half of radio-excess
sources, 32 percent of sources classified as radio-quiet AGNs, and
20 percent of sources classified as star-forming galaxies. Infrared
colour-colour plots and comparison with what we would expect to
detect based on peak brightness in 6 arcsec LOFAR maps imply that the
star-forming galaxies and sources at low flux densities have a mixture
of star-formation and AGN activity. We separate the radio emission
from star-formation and AGN in unresolved, Tb-identified
AGNs with no significant radio excess and find the AGN comprises
0.49 ± 0.16 of the radio luminosity. Overall, the non-radio excess
AGNs show evidence for having a variety of different radio emission
mechanisms, which can provide different pathways for AGNs and galaxy
co-evolution. This validation of AGN identification using brightness
temperature at low frequencies opens the possibility for securely
selecting AGN samples where ancillary data are inadequate.
Title: Is the remnant of GW190425 a strange quark star?
Authors: Sedaghat, J.; Zebarjad, S. M.; Bordbar, G. H.; Eslam Panah,
B.; Moradi, R.
Bibcode: 2022PhLB..83337388S
Altcode: 2021arXiv210400544S
This study investigates the effects of different QCD models on
the structure of strange quark stars (SQS). In these models, the
running coupling constant has a finite value in the infrared region of
energy. By imposing some constraints on the strange quark matter (SQM)
and exploiting the analytic and background perturbation theories, the
equations of states for the SQM are obtained. Then, the properties of
SQSs in general relativity are evaluated. By using component masses
of GW190425 [1] as well as some conversion relations between the
baryonic mass and the gravitational mass, the remnant mass of GW190425
is obtained. Our results for the maximum gravitational mass of SQS are
then compared with the remnant mass of GW190425. The results indicate
that the obtained maximum gravitational masses are comparable to the
remnant mass of GW190425. Therefore, it is proposed that the remnant
mass of GW190425 might be a SQS.
Title: AGN accretion and black hole growth across compact and extended
galaxy evolution phases
Authors: Aird, James; Coil, Alison L.; Kocevski, Dale D.
Bibcode: 2022MNRAS.515.4860A
Altcode: 2022MNRAS.tmp.2057A; 2022arXiv220111756A
The extent of black hole growth during different galaxy evolution phases
and the connection between galaxy compactness and active galactic
nucleus (AGN) activity remain poorly understood. We use Hubble Space
Telescope imaging of the CANDELS fields to identify star-forming and
quiescent galaxies at z = 0.5-3 in both compact and extended phases
and use Chandra X-ray imaging to measure the distribution of AGN
accretion rates and track black hole growth within these galaxies. We
show that accounting for the impact of AGN light changes ~20 per cent
of the X-ray sources from compact to extended galaxy classifications. We
find that ~10-25 per cent of compact star-forming galaxies host an AGN,
a mild enhancement (by a factor ~2) compared to extended star-forming
galaxies or compact quiescent galaxies of equivalent stellar mass and
redshift. However, AGNs are not ubiquitous in compact star-forming
galaxies and this is not the evolutionary phase, given its relatively
short time-scale, where the bulk of black hole mass growth takes
place. Conversely, we measure the highest AGN fractions (~10-30 per
cent) within the relatively rare population of extended quiescent
galaxies. For massive galaxies that quench at early cosmic epochs,
substantial black hole growth in this extended phase is crucial to
produce the elevated black hole mass-to-galaxy stellar mass scaling
relation observed for quiescent galaxies at z ~ 0. We also show that
AGN fraction increases with compactness in star-forming galaxies and
decreases in quiescent galaxies within both the compact and extended
subpopulations, demonstrating that AGN activity depends closely on
the structural properties of galaxies.
Title: Moon packing around an Earth-mass planet
Authors: Satyal, Suman; Quarles, Billy; Rosario-Franco, Marialis
Bibcode: 2022MNRAS.516...39S
Altcode: 2022MNRAS.tmp.2060S; 2022arXiv220803604S
All four giant planets in the Solar system host systems of multiple
moons, whereas the terrestrial planets only host up to two moons. The
Earth can capture small asteroids as temporary satellites, which begs
the question as to how many moons could stably orbit the Earth, or
an Earth-mass exoplanet. We perform a series of N-body simulations of
closely spaced equal-mass moons in nested orbits around an Earth-mass
planet orbiting a Sun-like star. The innermost moon begins near the host
planet's Roche radius, and the system is packed until the outermost moon
begins near the stability limit for single moons. The initial spacing
of the moons follows an iterative scheme commonly used for studies
of compact planetary systems around single stars. For the three-moon
system, we generate MEGNO maps to calculate periodic and chaotic
regions and to identify the destabilizing mean motion resonances. Our
calculations show that the maximum number of moons depends on the
assumed masses of the satellites (Ceres-, Pluto-, and Luna-mass) that
could maintain stable orbits in a tightly packed environment. Through
our N-body simulations, we find stable configurations for up to 7 ±
1 Ceres-mass, 4 ± 1 Pluto-mass, and 3 ± 1 Luna-mass moons. However,
outward tidal migration will likely play a substantial role in the
number of moons on stable orbits over the 10 Gyr stellar lifetime of
a Sun-like star.
Title: Hadrophilic light dark matter from the atmosphere
Authors: Arguëlles, Carlos A.; Muñoz, Víctor; Shoemaker, Ian M.;
Takhistov, Volodymyr
Bibcode: 2022PhLB..83337363A
Altcode: 2022arXiv220312630A
Light sub-GeV dark matter (DM) constitutes an underexplored target,
beyond the optimized sensitivity of typical direct DM detection
experiments. We comprehensively investigate hadrophilic light DM
produced from cosmic-ray collisions with the atmosphere. The resulting
relativistic DM, originating from meson decays, can be efficiently
observed in variety of experiments, such as XENON1T. We include for
the first time decays of η, η' and K+ mesons,
leading to improved limits for DM masses above few hundred MeV. We
incorporate an exact treatment of the DM attenuation in Earth and
demonstrate that nuclear form factor effects can significantly impact
the resulting testable DM parameter space. Further, we establish
projections for upcoming experiments, such as DARWIN, over a wide
range of DM masses below the GeV scale.
Title: Evolution of ice sheets on early Mars with subglacial river
systems
Authors: Kamada, A.; Kuroda, T.; Kodama, T.; Kasaba, Y.; Terada, N.
Bibcode: 2022Icar..38515117K
Altcode:
Geological observations have revealed that early Martian terrains were
carved with by numerous networks of valleys, which provides evidence
that prolonged water activity sculpted the ancient surface of Mars
during the late Noachian and the early Hesperian ages. Although
such geological records would in theory require a large volume of
liquid water under a long-term stable "warm and wet" climate, several
model studies have indicated a contrasting "cold and icy" climate
in early Mars, such that the formation of large-scale ice sheets on
highlands would provide a vast reservoir of meltwater. In this study,
we developed a global ice sheet model, named ALICE (Accumulation and
ablation of Large-scale ICE-sheets with dynamics and thermodynamics)
to perform the first simulation of the evolution of ice sheets coupled
with a paleo-Mars global climate model. We began our calculations of
glacial formation from the initial state with the ocean water amount
corresponding to a 500 m global equivalent layer (GEL) for "cool
and wet" atmospheric conditions with a surface pressure of 2 bar,
H2 mixing ratios of 0% and 3%, and obliquities of 20°,
40°, and 60°. Our results show that all the water of the ocean
and lakes were transferred to ice sheets within ~105 Mars
years, and extensive ice sheets (thousands of meters in thickness) were
formed in the southern low to middle latitudes. When geothermal heat
flux was suitably high and the atmosphere contained 3% of H2,
continuous subglacial melting supplied enough water due to widespread
temperate-based ice sheets, forming runoff systems in the southern
highlands where most valley networks are observed. With an obliquity of
40°, meltwater carved early Martian terrains within a relatively brief
geological timescale (~105 Mars years). We also revealed
that CO2 only atmosphere (H2 mixing ratio of 0%)
could not reproduce temperate-based ice sheets and subglacial erosions
even with assumed higher geothermal heat fluxes. There is still a
possibility that several valleys were produced by short-lived climatic
warming events, such as volcanism and meteorite impacts, which could
produce the vast amount of meltwater required to sculpt valley systems.
Title: Do tides destabilize Trojan exoplanets?
Authors: Dobrovolskis, Anthony R.; Lissauer, Jack J.
Bibcode: 2022Icar..38515087D
Altcode: 2022arXiv220607097D
One outstanding problem in extrasolar planet studies is why no
co-orbital exoplanets have been found, despite numerous searches among
the many known planetary systems, many of them in other mean-motion
resonances. Here we examine the hypothesis that dissipation of energy
by tides in Trojan planets is preventing their survival. The
Appendix of this paper generalizes the conventional theory of tides
to include tidal forces independent of dissipation, as well as the
effects of one body on tides raised by another. The main text applies
this theory to a model system consisting of a primary of stellar mass,
a secondary of sub-stellar mass in a circular orbit about the primary,
and a much lighter Trojan planet librating with small amplitude about an
equilateral point of the system. Next, we linearize the equations
of motion about the Trojan points, including the tidal forces, and solve
for the motion of the Trojan. The results indicate that tides damp out
the Trojan's motion perpendicular to the orbital plane of the primary
and secondary, as well as its epicycles due to its eccentricity; but
they pump up the amplitude of its tadpole librations exponentially. We
then verify our analytic solutions by integrating the non-linearized
equations of motion numerically for several sample cases. In each
case, we find that the librations grow until the Trojan escapes its
libration, which leads to a close encounter with either the primary
or the secondary.
Title: Water storage capacity of the martian mantle through time
Authors: Dong, Junjie; Fischer, Rebecca A.; Stixrude, Lars P.;
Lithgow-Bertelloni, Carolina R.; Eriksen, Zachary T.; Brennan,
Matthew C.
Bibcode: 2022Icar..38515113D
Altcode: 2022arXiv220515450D
Water has been stored in the Martian mantle since its formation,
primarily in nominally anhydrous minerals. The short-lived early
hydrosphere and intermittently flowing water on the Martian surface
may have been supplied and replenished by magmatic degassing of water
from the mantle. Estimating the water storage capacity of the solid
Martian mantle places important constraints on its water inventory and
helps elucidate the sources, sinks, and temporal variations of water
on Mars. In this study, we applied a bootstrap aggregation method to
investigate the effects of iron on water storage capacities in olivine,
wadsleyite, and ringwoodite, based on high-pressure experimental data
compiled from the literature, and we provided a quantitative estimate
of the upper bound of the bulk water storage capacity in the FeO-rich
solid Martian mantle. Along a series of areotherms at different mantle
potential temperatures (Tp), we estimated a water storage
capacity equal to 9.0-2.2+2.8 km Global Equivalent
Layer (GEL) for the present-day Martian mantle at Tp =
1600 K and 4.9-1.5+1.7 km GEL for the initial
Martian mantle at Tp = 1900 K. The water storage capacity
of the Martian mantle increases with secular cooling through time,
but due to the lack of an efficient water recycling mechanism on Mars,
its actual mantle water content may be significantly lower than its
water storage capacity today.
Title: Mechanism of field-like torque in spin-orbit torque switching
of perpendicular magnetic tunnel junction
Authors: Zhuo, Yudong; Cai, Wenlong; Zhu, Daoqian; Zhang, Hongchao; Du,
Ao; Cao, Kaihua; Yin, Jialiang; Huang, Yan; Shi, Kewen; Zhao, Weisheng
Bibcode: 2022SCPMA..6507511Z
Altcode:
The current-induced spin-orbit torque (SOT) is one of the most promising
ways for high speed and low power spintronics devices. However, the
mechanism of SOT driven magnetization reversal, especially the role
of the field-like torque (FLT), is still unclear. Here, we report the
observed promotion and suppression of switching by FLT, which depends on
the relative direction of FLT and spin polarization. Our results reveal
that the FLT could modulate the switching speed and power consumption
by affecting the work done by the damping-like torque, and leads two
different reversal dynamical paths during the switching. Furthermore,
the origin of incubation time in SOT induced switching is clarified
simultaneously.
Title: The effect of supercritical fluids on Nb-Ta fractionation
in subduction zones: Geochemical insights from a coesite-bearing
eclogite-vein system
Authors: Chen, Tie-Nan; Chen, Ren-Xu; Zheng, Yong-Fei; Zhou, Kun;
Yin, Zhuang-Zhuang; Wang, Zhi-Min; Gong, Bing; Zha, Xiang-Ping
Bibcode: 2022GeCoA.335...23C
Altcode:
Supercritical fluids are ideal media for mass transfer from the
subducting slab into the mantle wedge. However, little is known about
the role of natural supercritical fluids in subduction zones. A combined
study of petrology, geochemistry and zirconology was carried out for
a coesite-bearing eclogitic vein and its surrounding eclogites from
the Dabie orogen, one of the typical continental subduction zones on
Earth. The results are used to reveal the composition and source of
supercritical fluids, the P-T conditions and timing of their formation
and their geochemical effects in subduction zones. The eclogitic
vein is composed of garnet, omphacite, quartz, amphibole, rutile and
apatite, with minor amounts of epidote, plagioclase and zircon. Coesite
was identified in omphacite in the vein, demonstrating its formation
under ultrahigh-pressure (UHP) metamorphic conditions that correspond
to subarc depths in oceanic subduction zones. Zircons from the vein
give concordant U-Pb ages of 225 ± 5 Ma and flat HREE patterns for
newly grown rims, consistent with their crystallization at the UHP
eclogite facies. The vein shows similar Hf-O isotope compositions to
the host UHP eclogites, indicating that the UHP vein-forming fluid
is internally buffered within the UHP eclogites. Minerals in the vein
contain not only higher contents of Cr, Ni, Sr, REE and HFSE, but also
multiphase crystal inclusions (such as omphacite, quartz, epidote,
apatite, amphibole, plagioclase, mica, rutile, calcite, and anhydrite)
as well as liquid and gas phases of H2O. The calculated fluid
composition of major elements is 31 wt% SiO2, 20 wt% CaO, 10
wt% (SO4)2-, 8 wt% (CO3)2-,
8 wt% FeO, 7 wt% Al2O3, and 9 wt% H2O,
with traces of Na2O, K2O and TiO2. This
composition is responsible for the UHP veining from supercritical
silicate-rich fluids in equilibrium with peak UHP minerals. The
P-T-t path of the UHP eclogite-vein system indicates that the second
critical endpoint of the basalt-H2O system is located close
to 3.4 GPa and 770°C. The high contents of sulfate and carbonate in
the vein suggest that supercritical fluids were oxidized and likely a
predominant agent to transfer sulfur and carbon at subarc depths. High
Nb/Ta ratios of rutile crystals in the vein and quantitative modelling
indicate that dehydration of subducting eclogites at subarc depths can
produce supercritical fluids with suprachondritic Nb/Ta ratios. The UHP
eclogites and mantle wedge peridotites metasomatized by supercritical
fluids can acquire suprachondritic Nb/Ta ratios and thus provide a
complementary reservoir to balance the subchondritic reservoirs on
Earth. Based on a statistics of Nb-Ta data, two indices are proposed
to identify the existence of supercritical fluids in fossil subduction
zones: (1) rutile crystallized from supercritical fluids shows lower
Nb contents than that from aqueous solutions and hydrous melts;
(2) UHP eclogites associated with supercritical fluids exhibit a
distance >0.1 in their Nb-Ta compositions to the line defined by
basalts in the plot of log[Nb] vs log[Ta]. Therefore, the existence of
supercritical fluids during UHP metamorphism at subarc depths can be
recognized from their effect on the mobility of fluid-immobile trace
elements in UHP metamorphic rocks.
Title: Ferrocyanide survival under near ultraviolet (300-400 nm)
irradiation on early Earth
Authors: Todd, Zoe R.; Lozano, Gabriella G.; Kufner, Corinna L.;
Sasselov, Dimitar D.; Catling, David C.
Bibcode: 2022GeCoA.335....1T
Altcode:
Prebiotic lake environments containing ferrocyanide could have
fostered origins of life chemistry on early Earth. Ferrocyanide
can act to concentrate hydrogen cyanide (HCN), a prebiotically
important molecule. Additionally, ferrocyanide, coupled with sulfite,
can participate in an ultraviolet (UV)-driven photoredox cycle to
generate solvated electrons, which can reduce cyanide to form all
four major building blocks of life: sugars, amino acids, nucleotides,
and lipid precursors. However, longer wavelength UV light (∼300-400
nm) causes photoaquation of ferrocyanide into pentacyanoaquaferrate,
Fe(CN)5H2O. This species can either regain
cyanide to reform ferrocyanide or ultimately lose cyanide ligands,
which removes ferrocyanide from solution. Here, we investigate this near
ultraviolet (300-400 nm) UV-driven loss of ferrocyanide. In addition to
determining the wavelength dependence of the loss and the implications
from the UV environment on early Earth, we also study the effects of
pH, temperature, and concentration. We find that in dilute, slightly
alkaline solutions, ferrocyanide would degrade significantly on the
order of minutes under the near UV radiation expected on early Earth. We
further determine that the lifetime of ferrocyanide is extended at
more alkaline pH, lower temperatures, and higher concentrations. Under
a reasonable set of planetary conditions, we find that ferrocyanide
lifetimes in irradiated environments range from minutes to hours,
or longer. Our results can help to determine the constraints implied
by the UV-driven loss of ferrocyanide in prebiotic environments. We
assess the potential environmental limits and circumstances that would
allow for successful retention of significant amounts of ferrocyanide
in prebiotic lakes; we further evaluate how ferrocyanide photoaquation
may fit in to the larger network of reactions potentially occurring
throughout prebiotic chemistry. For example, our experiments show
that CN- can be released from ferrocyanide evaporite salts by aqueous
dissolution and UV light, making it potentially available for prebiotic
reactions. These results can aid in the construction of consistent
and plausible circumstances for prebiotic chemistry on early Earth.
Title: N = 2 resonant superalgebra for supergravity
Authors: Durka, Remigiusz; Graczyk, Krzysztof M.
Bibcode: 2022PhLB..83337366D
Altcode: 2022arXiv220505921D
We present new superalgebra for $\mathcal{N}=2$ $D=3,4$ supergravity
theory endowed with the $U(1)$ generator. The superalgebra is rooted in
the so-called Soroka-Soroka algebra and spanned by the Lorentz $J_{ab}$
and Lorentz-like $Z_{ab}$, translation $P_a$ and $T$ generators,
as well as two supercharges $Q^I_\alpha$. It is the only possible
realization for a given generator content. We construct a corresponding
3D Chern-Simons supergravity realization of the superalgebra and
discuss its relevance.
Title: Type II Dirac seesaw with observable ΔNeff in
the light of W-mass anomaly
Authors: Borah, Debasish; Mahapatra, Satyabrata; Nanda, Dibyendu;
Sahu, Narendra
Bibcode: 2022PhLB..83337297B
Altcode: 2022arXiv220408266B
We propose a type II seesaw model for light Dirac neutrinos to
provide an explanation for the recently reported anomaly in W boson
mass by the CDF collaboration with 7σ statistical significance. In
the minimal model, the required enhancement in W boson mass is
obtained at tree level due to the vacuum expectation value of a
real scalar triplet, which also plays a role in generating light
Dirac neutrino mass. Depending upon the couplings and masses of
newly introduced particles, we can have thermally or non-thermally
generated relativistic degrees of freedom ΔNeff in the form
of right handed neutrinos which can be observed at future cosmology
experiments. Extending the model to a radiative Dirac seesaw scenario
can also accommodate dark matter and lepton anomalous magnetic moment.
Title: Earth through the looking glass: how frequently are we detected
by other civilizations through photometric microlensing?
Authors: Suphapolthaworn, S.; Awiphan, S.; Chatchadanoraset, T.;
Kerins, E.; Specht, D.; Nakharutai, N.; Komonjinda, S.; Robin, A. C.
Bibcode: 2022MNRAS.515.5927S
Altcode: 2022MNRAS.tmp.1850S; 2022arXiv220609820S
Microlensing is proving to be one of the best techniques to detect
distant, low-mass planets around the most common stars in the Galaxy. In
principle, Earth's microlensing signal could offer the chance for
other technological civilizations to find the Earth across Galactic
distances. We consider the photometric microlensing signal of Earth
to other potential technological civilizations and dub the regions of
our Galaxy from which Earth's photometric microlensing signal is most
readily observable as the 'Earth microlensing zone' (EMZ). The EMZ can
be thought of as the microlensing analogue of the Earth Transit Zone
(ETZ) from where observers see Earth transit the Sun. Just as for
the ETZ, the EMZ could represent a game-theoretic Schelling point
for targeted searches for extra-terrestrial intelligence (SETI). To
compute the EMZ, we use the Gaia DR2 catalogue with magnitude G <
20 to generate Earth microlensing probability and detection rate maps
to other observers. While our Solar system is a multiplanet system, we
show that Earth's photometric microlensing signature is almost always
well approximated by a binary lens assumption. We then show that the
Earth is in fact well hidden to observers with technology comparable to
our own. Specifically, even if observers are located around every Gaia
DR2 star with G < 20, we expect photometric microlensing signatures
from the Earth to be observable on average only tens per year by any
of them. In addition, the EMZs overlap with the ETZ near the Galactic
Centres which could be the main areas for future SETI searches.
Title: On the optical properties of resonant drag instabilities:
variability of asymptotic giant branch and R Coronae Borealis stars
Authors: Steinwandel, Ulrich P.; Kaurov, Alexander A.; Hopkins,
Philip F.; Squire, Jonathan
Bibcode: 2022MNRAS.515.4797S
Altcode: 2021arXiv211109335S; 2022MNRAS.tmp.1962S
In dusty cool-star outflow or ejection events around asymptotic
giant branch (AGB) or R Coronae Borealis or RCB-like stars, dust is
accelerated by radiation from the star and coupled to the gas via
collisional drag forces. It has recently been shown that such dust-gas
mixtures are unstable to a super-class of instabilities called the
resonant drag instabilities (RDIs), which promote dust clustering. We
therefore consider idealized simulations of the RDIs operating on a
spectrum of dust grain sizes subject to radiative acceleration (allowing
for different grain optical properties), coupled to the gas with a
realistic drag law, including or excluding the effects of magnetic
fields and charged grains, and calculate for the first time how the
RDIs could contribute to observed variability. We show that the RDIs
naturally produce significant variations (spatially and temporally)
($\sim 10\!-\!20{{\ \rm per\ cent}}$ 1 σ-level) in the extinction,
corresponding to $\sim 0.1\!-\!1\,$mag level in the stellar types
above, on time-scales of order months to a year. The fluctuations
are surprisingly robust to the assumed size of the source as they are
dominated by large-scale modes, which also means their spatial structure
could be resolved in some nearby systems. We also quantify how this
produces variations in the line-of-sight grain size-distribution. All
of these variations are similar to those observed, suggesting that
the RDIs may play a key role driving observed spatial and temporal
variability in dust extinction within dusty outflow/ejection events
around cool stars. We further propose that the measured variations
in grain sizes could directly be used to identify the presence of the
RDIs in close by systems with observations.
Title: Serpentine-magnesite Association of Salem Ultramafic Complex,
Southern India: A Potential Analogue for Mars
Authors: Kakkassery, Asif Iqbal; Haritha, A.; Rajesh, V. J.
Bibcode: 2022P&SS..22105528K
Altcode:
The primary mineral olivine and its alteration products, serpentine
and magnesite, have been reported from several locales on Mars. The
mineralogical similarity of the altered ultramafic rocks on Earth
makes them a potential analogue that can provide significant insight
into the serpentinization and carbonation processes on Mars. This
serpentine-magnesite assemblage is significant in astrobiology
because serpentinization is known for the formation of simple organic
molecules like methane from inorganic precursors. An association
of olivine-serpentine-magnesite is widely distributed in the Salem
Ultramafic Complex (SUC) in Southern India. We used hyperspectral,
Laser Raman, and Fourier-transform infrared (FTIR) techniques to
characterize this mineral association in the SUC. The visible and
near-infrared (VNIR) spectra of all the serpentine samples show a narrow
and strong absorption feature at 1.4 μm and an in-depth feature at
2.35 μm. Magnesite samples have broad and strong features at 1.4 μm,
2.3 μm, and 2.5 μm. The obtained spectra were compared with their
Martian counterparts using the Mars Reconnaissance Orbiter-Compact
Reconnaissance Imaging Spectrometer for Mars (CRISM) type spectral
library. Raman spectroscopy is used to differentiate serpentine
polymorphs. The major polymorph in the area is antigorite, which shows
intense Raman peaks at 682 cm-1, 371 cm-1,
and 228 cm-1, and weak peaks at 635 cm-1
and 1040 cm-1. The Raman peaks at 1096 cm-1
and 326 cm-1 are typical of magnesite. FTIR spectra from
the serpentine samples are characterized by the absorption feature at
3680 cm-1 indicative of antigorite, formed due to hydroxyl
stretching. Diagnostic absorption features of magnesite are observed
at 748 cm-1, 877 cm-1, 1427 cm-1, 1826
cm-1, and 2358 cm-1. The results from this study
can be applied to future missions to validate orbital spectroscopic
data, instrument calibration purposes, and data interpretation.
Title: Galactic seismology: joint evolution of impact-triggered
stellar and gaseous disc corrugations
Authors: Tepper-García, Thor; Bland-Hawthorn, Joss; Freeman, Ken
Bibcode: 2022MNRAS.515.5951T
Altcode: 2022arXiv220412096T; 2022MNRAS.tmp.1859T
Evidence for wave-like corrugations are well established in the Milky
Way and in nearby disc galaxies. These were originally detected as a
displacement of the interstellar medium about the mid-plane, either in
terms of vertical distance or vertical velocity. Over the past decade,
similar patterns have emerged in the Milky Way's stellar disc. We
investigate how these vertical waves are triggered by a passing
satellite. Using high-resolution N-body/hydrodynamical simulations,
we systematically study how the corrugations set up and evolve jointly
in the stellar and gaseous discs. We find that the gas corrugations
follow the stellar corrugations, i.e. they are initially in phase
although, after a few rotation periods (500-700 Myr), the distinct
waves separate and thereafter evolve in different ways. The spatial
and kinematic amplitudes (and thus the energy) of the corrugations
dampen with time, with the gaseous corrugation settling at a faster rate
(~800 Myr versus ~1 Gyr). In contrast, the vertical energy of individual
disc stars is fairly constant throughout the galaxy's evolution. This
difference arises because corrugations are an emergent phenomenon
supported by the collective, ordered motions of co-spatial ensembles
of stars. We show that the damping of the stellar corrugations can
be understood as a consequence of incomplete phase mixing, while the
damping of the gaseous corrugations is a natural consequence of the
dissipative nature of the gas. We suggest that - in the absence of
further, strong perturbations - the degree of correlation between the
stellar and gaseous waves may help to age-date the phenomenon.
Title: A census of post-AGB stars in Gaia DR3: evidence for a
substantial population of Galactic post-RGB stars
Authors: Oudmaijer, René D.; Jones, Emma R. M.; Vioque, Miguel
Bibcode: 2022MNRAS.516L..61O
Altcode: 2022arXiv220802832O; 2022MNRAS.tmpL..83O
This paper presents the first census of Galactic post-asymptotic giant
branch (post-AGB) stars in the Hertzsprung-Russell (HR) diagram. We
combined Gaia DR3 parallax-based distances with extinction corrected
integrated fluxes and derived luminosities for a sample of 185 stars
that had been proposed to be post-AGB stars in the literature. The
luminosities allow us to create an HR diagram containing the largest
number of post-AGB candidate objects to date. A significant fraction
of the objects fall outside the typical luminosity range as covered
by theoretical evolutionary post-AGB tracks as well as observed
for planetary nebula central stars. These include massive evolved
supergiants and lower luminosity objects. Here, we highlight the fact
that one-third of the post-AGB candidates are underluminous and we
identify these with the recently recognized class of post-red giant
branch objects thought to be the result of binary evolution.
Title: Study on low gravity effect on bearing capacity and slope
stability of a new lunar highland soil simulant (LSS-ISAC-1) for
futuristic moon habitation
Authors: Prabu, Thannasi; Muthukkumaran, Kasinathan; Venugopal, Indaram
Bibcode: 2022AdSpR..70.1869P
Altcode:
The future lunar missions of the space research organizations (SRO)
such as the (US) National Aeronautics and Space Administration (NASA),
the China National Space Administration (CNSA), the European Space
Agency (ESA), the Indian Space Research Organisation (ISRO), the Japan
Aerospace Exploration Agency (JAXA), and the Russian Federal Space
Agency (RFSA or Roscosmos), etc., comprise extended stay on Moon,
making the lunar surface a launchpad for the interplanetary missions
and Moon habitation. These are the most challenging task for the
space research organizations (SRO) and the researchers, which needs
all engineering disciplines. Also, the distinct difference in the
environment between the lunar surface (lunar gravity, moonquakes, high
temperature, etc.) and the Earth forced the SROs and the researchers
to study the geotechnical properties such as specific gravity, particle
size distribution, density, shear strength, and bearing capacity of the
lunar soils. In this, the lunar gravity (1/6g) significantly influences
the bearing capacity of the lunar soil, which is the predominant
property for the design and analysis of foundation systems of the
lunar structures. Assessing the bearing capacity under the reduced
lunar gravity will enhance the evaluation of design criteria for
the lunar structures and their foundation systems. In this respect,
this paper explains the low gravity effect on the bearing capacity
of the new lunar highland soil simulant LSS-ISAC-1 developed to
represent the geotechnical properties of the highland soils of the
lunar surface. The bearing capacity of the simulant for both the lunar
and Earth gravity was evaluated and compared with the lunar soils and
lunar simulants. The plate load test and single wheel load tests were
performed to determine the sinkage property (compression/settlement)
of the LSS-ISAC-1. The slope stability and self-standing height of
the LSS-ISAC-1 were also determined for a better understanding of
stability. Overall, the comparison results state that the new simulant
LSS-ISAC-1 is more than sufficient to support virtually any conceivable
structures based on the results.
Title: A new estimate of galaxy mass-to-light ratios from flexion
lensing statistics
Authors: Fabritius, Joseph M.; Goldberg, David M.
Bibcode: 2022MNRAS.515.6191F
Altcode: 2022MNRAS.tmp.2142F; 2021arXiv210805453F
We perform a flexion-based weak gravitational analysis of the first two
Hubble Frontier Field clusters: Abell 2744 and MACS 0416. A parametric
method for using radially projected flexion signals as a probe of
cluster member mass is described in detail. The normalization and slope
of a L - θE (as a proxy for L - σ) scaling relation in
each cluster is determined using measured flexion signals. A parallel
field analysis is undertaken concurrently to provide a baseline measure
of method effectiveness. We find an agreement in the Faber-Jackson
slope ℓ associated with galaxy age and morphology for both clusters,
as well as a theoretical distinction in the cluster normalization mass.
Title: Raman spectroscopic documentation of Mars analog basalt
alteration by brines
Authors: Rodriguez, Andrew; Hunt, Lindsey; Phillips-Lander, Charity;
Mason, Daniel; Madden, Megan Elwood
Bibcode: 2022Icar..38515111R
Altcode:
Salts and basalt are widespread on the surface of Mars. Therefore,
basalt-brine interactions may have significant effects on
both the aqueous history of the planet, and near-surface
alteration assemblages. Raman spectra were collected
from McKinney Basalt samples that were immersed in eight
near-saturated brines composed of Na-Cl-H2O,
Na-SO4-H2O, Na-ClO4-H2O,
Mg-Cl-H2O, Mg-SO4-H2O,
and two salt mixtures (Mg-Cl-SO4-H2O and
Na-ClO4-SO4-H2O), as well as ultra-pure
water for up to one year. Secondary minerals were observed in the Raman
specta, including iron oxides, hydrated sulfates, amorphous silica,
phosphates, and carbonates. Detection of these secondary minerals
demonstrates the utility of Raman spectroscopy to identify basalt-brine
alteration assemblages on Mars. This work also demonstrates that major
classes of alteration phases can be distinguished using Raman spectra
with resolution similar to those expected from the Raman instruments
aboard the Perseverance and Rosalind Franklin Mars rovers. In addition,
observations of carbonate minerals within alteration assemblages suggest
CO2 from the atmosphere readily reacted with ions released
from the basalt during alteration in near-saturated brines.
Title: The interplanetary origins of geomagnetic storm with
Dstmin ≤ - 50 nT during solar cycle 24 (2009-2019)
Authors: Qiu, Shican; Zhang, Zhiyong; Yousof, Hamad; Soon, Willie;
Jia, Mingjiao; Tang, Weiwei; Dou, Xiankang
Bibcode: 2022AdSpR..70.2047Q
Altcode:
In this study, we analyzed 149 geomagnetic storms of moderate and
intensity (i.e., Dstmin ≤ - 50 nT) occurred during the
solar cycle 24 from 2009 to 2019, and identified their interplanetary
sources. Among them, there are 20 strong storms with - 200 nT
≤ Dst min ≤ - 100 nT , and 2 super-strong storms with
Dstmin ≤ - 200 nT . We have found that corotating
interaction regions (CIRs) account for 37% (55/149) of geomagnetic
storms, interplanetary coronal mass ejections (ICMEs) result in 30%
(45/149) of geomagnetic storms and sheath regions (SH) are responsible
for 15% (23/149) of geomagnetic storms. Meanwhile, 18/20 of the strong
storms are caused by the structures associated with interplanetary
coronal mass ejections (ICME, SH, and SH + ICME), while the CIR
constitutes only to 2/20 of the strong storms. It is found that the
two super-strong geomagnetic storms are caused by the SH + ICME. Our
findings also suggest that geomagnetic storms in different periods
of solar activity are caused by different interplanetary structures,
which is consistent with previous research. In comparison to solar
cycle 23, there is no substantial geomagnetic storm induced by CIR
during the dwindling and subsiding phases of solar cycle 24. In the
descending stage, the proportion of moderate events caused by ICME
decreases, and ICMEs cause no super-strong event. In ascending stage,
neither strong nor super strong events occur.
Title: Thin-shell wormholes in non-linear f(R) gravity with variable
scalar curvature
Authors: Godani, Nisha
Bibcode: 2022NewA...9601835G
Altcode:
The present paper explores a thin-shell wormhole (TSW) developed by
employing the cut and paste method to two copies of the black hole. It
develops TSW in modified f(R) theory of gravity with variable scalar
curvature. The effects of the model parameters on the wormhole solutions
are tested, the regions of linear stability are analyzed and stable
wormhole solutions have been obtained.
Title: Enigmatic super-heavy pyrite formation: Novel mechanistic
insights from the aftermath of the Sturtian Snowball Earth
Authors: Cai, Chunfang; Lyons, Timothy W.; Sun, Peng; Liu, Dawei; Wang,
Daowei; Tino, Christopher J.; Luo, Genming; Peng, Yanyan; Jiang, Lei
Bibcode: 2022GeCoA.334...65C
Altcode:
It is not well understood how, in the immediate aftermath of
the Sturtian Snowball Earth, marine sulfur cycling resulted in a
global distribution of sedimentary pyrite with δ34S
values higher than coeval seawater. Here, we analyze the quadruple
sulfur isotope systematics of organic-bound sulfur (OS) from
the lowermost post-Sturtian Datangpo Formation, South China,
and identify two generations of OS formation, each sampling an
isotopically distinct sulfate reservoir (δ34S ≈ 26‰
and 52-93‰) that differentially impacted its respective, co-occurring
pyrite. Combining several lines of geochemical evidence, we argue that
the first OS generation was the product of a sulfate-impoverished
meltwater-influenced setting, with OS preservation being the result
of resistance to acid hydrolysis. However, the second OS generation
was sourced from H2S produced in sediments during early
diagenesis via microbial reduction of a 34S-enriched sulfate
pool derived from overlying euxinic or ferruginous seawater. This is
the first ancient marine data set where all observed pyrite is more
enriched in 34S than its associated OS. Our proposed origin
may be applied to global superheavy pyrite (SHP) immediately after the
Sturtian and is comparable to processes linked to freshwater-to-marine
transitions during rising sea level in the wake of recent glaciation.
Title: Troposphere-to-mesosphere microphysics of carbon dioxide ice
clouds in a Mars Global Climate Model
Authors: Määttänen, A.; Mathé, C.; Audouard, J.; Listowski, C.;
Millour, E.; Forget, F.; González-Galindo, F.; Falletti, L.; Bardet,
D.; Teinturier, L.; Vals, M.; Spiga, A.; Montmessin, F.
Bibcode: 2022Icar..38515098M
Altcode:
We have implemented full CO2 ice cloud microphysics into the
LMD Mars Global Climate Model (MGCM) and we have conducted the first
global simulations. The microphysical model implementation follows
the modal scheme used for water ice cloud microphysics in the MGCM,
but includes specific aspects that need to be accounted for when
dealing with CO2 ice clouds. These include nucleation of
CO2 on water ice crystals and CO2 condensation
theory adapted for the Martian conditions. The model results are
compared to available observations globally, and separately for
polar regions and equatorial mesosphere. The observed seasonal
and latitudinal variability of the CO2 ice clouds is in
general reproduced. The polar regions are covered by CO2
ice clouds during the winter as observed. Instead of forming only in
the lowest 10-15 km of the atmosphere, they extend up to several tens
of kilometers above the surface in the model, dictated by the modeled
temperature structure. We have also quantified the contribution of the
cloud microphysics to the surface CO2 ice deposits. Snowfall
from these clouds contributes up to 10% of the atmosphere-surface ice
flux in the polar regions in our simulations, in the range that has
been indirectly deduced from observations. In the mesosphere, notable
amounts of CO2 ice clouds form only when water ice crystals
are used as condensation nuclei in addition to dust particles, and their
spatial distribution is in agreement with observations. The mesospheric
temperature structure, dominated by tides, dictates the longitudinal
and seasonal distribution of these clouds. The seasonal and local time
variations of the clouds are not fully reproduced by the model. There
is a long pause in CO2 ice cloud formation in the model
around the aphelion season, but clouds have been observed during this
period, although with a lower apparition frequency. Modeled mesospheric
clouds form mainly during the night and in the morning, whereas during
the daytime, when most of the cloud observations have been made, the
model rarely predicts clouds. These discrepancies could be explained
by the strong dependence of the cloud formation process on mesospheric
temperatures that are themselves challenging to reproduce and sensitive
to the MGCM processes and parameters. The rare possibilities for
nighttime observations might also bias the observational climatologies
towards daytime detections. Future developments of the model consist
in the inclusion of a possible exogenous condensation nucleus source
in the mesosphere and the radiative effect of CO2 ice clouds.
Title: SiC: An excellent platform for single-photon detection and
emission
Authors: Zhang, Feng
Bibcode: 2022SCPMA..6507331Z
Altcode:
No abstract at ADS
Title: BFS 10: a nascent bipolar H II region in a filamentary
molecular cloud
Authors: Larose, Nicholas; Kerton, C. R.
Bibcode: 2022MNRAS.515.6217L
Altcode: 2022MNRAS.tmp.2127L
We present a study of the compact blister H II region BFS 10 and
its highly filamentary molecular cloud. We utilize 12CO
observations from the Five College Radio Astronomy Observatory to
determine the distance, size, mass, and velocity structure of the
molecular cloud. Infrared observations obtained from the UKIRT Infrared
Deep Sky Survey and the Spitzer Infrared Array Camera, as well as radio
continuum observations from the Canadian Galactic Plane Survey, are used
to extract information about the central H II region. This includes
properties such as the ionizing photon rate and infrared luminosity,
as well as identifying a rich embedded star cluster associated with the
central O9 V star. Time-scales regarding the expansion rate of the H
II region and lifetime of the ionizing star reveal a high likelihood
that BFS 10 will develop into a bipolar H II region. Although the
region is expected to become bipolar, we conclude from the cloud's
velocity structure that there is no evidence to support the idea
that star formation at the location of BFS 10 was triggered by two
colliding clouds. A search for embedded young stellar objects (YSOs)
within the molecular cloud was performed. Two distinct regions of YSOs
were identified: one region associated with the rich embedded cluster
and another sparse group associated with an intermediate-mass YSO.
Title: Project Lyra: A mission to 1I/'Oumuamua without Solar Oberth
Manoeuvre
Authors: Hibberd, Adam; Hein, Andreas M.; Eubanks, T. Marshall;
Kennedy, Robert G.
Bibcode: 2022AcAau.199..161H
Altcode: 2022arXiv220104240H
To settle the question of the nature of the interstellar object
1I/'Oumuamua requires in-situ observations via a spacecraft, as the
object is already out of range of existing telescopes. Most previous
proposals for reaching 1I/'Oumuamua using near-term technologies are
based on the Solar Oberth Manoeuvre (SOM), as trajectories without
the SOM are generally significantly inferior in terms of lower mission
duration and higher total velocity requirement. While the SOM allows
huge velocity gains, it is also technically challenging and thereby
increases programmatic and mission-related risks. In this paper, we
identify an alternative route to the interstellar object 1I/'Oumuamua,
based on a launch in 2028, which does not require a SOM but has a
similar performance as missions with a SOM. It instead employs a Jupiter
Oberth Manoeuvre (JOM) with a total time of flight of around 26 years
or so. The efficacy of this trajectory is a result of it significantly
reducing the ΔV to Jupiter by exploiting the VEEGA sequence. The total
ΔV of the trajectory is 15.8 kms-1 and the corresponding
payload mass is 115 kg for a SLS Block 1B or 241 kg for a Block 2. A
further advantage of the JOM is that the arrival speed relative to
1I/'Oumuamua is approximately 18 kms-1 , much lower than
the equivalent for the SOM of around 30 kms-1 .
Title: Direct detection of spin-dependent sub-GeV dark matter via
Migdal effect
Authors: Wang, Wenyu; Wu, Ke-Yun; Wu, Lei; Zhu, Bin
Bibcode: 2022NuPhB.98315907W
Altcode: 2021arXiv211206492W
Motivated by the current strong constraints on the spin-independent
dark matter (DM)-nucleus scattering, we investigate the spin-dependent
(SD) interactions of the light Majorana DM with the nucleus mediated
by an axial-vector boson. Due to the small nucleus recoil energy,
the ionization signals have now been used to probe the light dark
matter particles in direct detection experiments. With the existing
ionization data, we derive the exclusion limits on the SD DM-nucleus
scattering through Migdal effect in the MeV-GeV DM mass range. It is
found that the lower limit of the DM mass can reach about several
MeVs. Due to the momentum transfer correction induced by the light
mediator, the bounds on the SD DM-nucleus scattering cross sections
can be weakened in comparison with the heavy mediator.
Title: Precession and Jitter in FRB 180916B
Authors: Katz, J. I.
Bibcode: 2022MNRAS.516L..58K
Altcode: 2022arXiv220515385K; 2022MNRAS.tmpL..76K
Recent CHIME/FRB observations of the periodic repeating fast radio
bursts (FRB) 180916B have produced a homogeneous sample of 44
bursts. These permit a redetermination of the modulation period and
phase window, in agreement with earlier results. If the periodicity
results from the precession of an accretion disc, in analogy with those
of Her X-1, SS 433, and many other superorbital periods, the width of
the observable phase window indicates that the disc axis jitters by
an angle of about 0.14 of the inclination angle, similar to the ratio
of 0.14 in the well-observed jittering jet source SS 433.
Title: The sources of apparently non-repeating FRB
Authors: Katz, J. I.
Bibcode: 2022MNRAS.516...53K
Altcode: 2022arXiv220303675K; 2022MNRAS.tmp.2097K
Repeating and apparently non-repeating fast radio bursts (FRBs)
differ qualitatively and are produced by distinct classes of
sources. Apparently non-repeating FRBs must actually repeat many
times in their lifetimes because there are insufficient catastrophic
events to explain their rate. Yet no such infrequent repetitions,
in contrast to the frequent activity of FRBs known to repeat, have
been observed, constraining their repetition rates. The large gap in
energy between FRB 200428 and its much weaker repetitions resembles
the large gap in energy between rare giant outbursts of soft gamma
repeaters (SGRs) and their lesser outbursts. This phenomenological
similarity suggests that the sources of apparently non-repeating FRBs
are related to SGRs. Apparently non-repeating FRBs are associated with
SGR outbursts more energetic than the 2020 April 28 outburst of SGR
1935+2154 associated with FRB 200428 but less energetic than the 2004
outburst of SGR 1806-20 that had no associated FRB. At 20-1000 times its
actual distance, FRB 200428 would have been an apparent non-repeater.
Title: Observable signatures of cosmic rays transport in Starburst
Galaxies on gamma-ray and neutrino observations
Authors: Ambrosone, Antonio; Chianese, Marco; Fiorillo, Damiano F. G.;
Marinelli, Antonio; Miele, Gennaro
Bibcode: 2022MNRAS.515.5389A
Altcode: 2022MNRAS.tmp.2040A; 2022arXiv220303642A
The gamma-ray emission from Starburst and Star-forming Galaxies (SBGs
and SFGs) strongly suggests a correlation between star-forming activity
and gamma-ray luminosity. However, the very nature of cosmic ray (CR)
transport and the degree of their confinement within SBG cores are still
open questions . We aim at probing the imprints left by CR transport
on gamma-ray and neutrino observations of point-like SFGs and SBGs,
looking into quantitative ways to discriminate among different transport
models. We analyse the 10-yr Fermi-LAT spectral energy distributions
of 13 nearby galaxies with two different CR transport models, taking
into account the corresponding IR and UV observations. We also generate
mock gamma-ray data to simulate the CTA performance in detecting these
sources. In this way, we propose a test to discriminate between the two
CR models, quantifying the statistical confidence at which one model
can be preferred over the other. We point out that the current data
already give a slight preference to CR models that are dominated by
advection. Moreover, we show that CTA will allow us to firmly disfavour
models dominated by diffusion over self-induced turbulence, compared
to advection-dominated models, with Bayes factors, which can be as
large as 107 for some of the SBGs. Finally, we estimate
the diffuse gamma-ray and neutrino fluxes of SFGs and SBGs, showing
that they can explain $25{{\,\rm per\ cent}}$ of the diffuse HESE data
while remaining consistent with gamma-ray limits on non-blazar sources.
Title: The annual cycle of water vapor above gale crater as retrieved
by CRISM and compared to ChemCam passive sky spectroscopy
Authors: Khayat, Alain S. J.; McConnochie, Timothy H.; Smith,
Michael D.
Bibcode: 2022Icar..38515136K
Altcode:
Using spectra returned from the Compact Reconnaissance Imaging
Spectrometer for Mars (CRISM) aboard the Mars Reconnaissance Orbiter
(MRO), we report atmospheric water vapor column abundances at a spatial
resolution of ~ 1 km from observations taken over Gale crater, the
landing site of the Mars Science Laboratory (MSL). The observations
span a little more than 3 Mars years (MY) from MY 28 at Ls =
116° (October 04, 2006) to MY 31 at Ls = 101° (April 24,
2012). The retrievals were performed using an improved algorithm to
correct for the changes in wavelength in the cross-track direction
of CRISM images, also known as the "spectral smile", allowing for a
larger fraction of area from each observation to be covered. The water
vapor column abundances are retrieved using the strong absorption band
of H2O centered at 2600 nm. The seasonal cycle of water
vapor above Gale is compared against that from reprocessed and new
MSL Curiosity rover ChemCam passive sky observations using updated
gas absorption parameters and covering the period between MY 31 at
Ls = 291° (March 30, 2013) and MY 35 at Ls =
42° (June 20, 2019). The retrieved annual variation of water vapor
from CRISM and ChemCam both display a similar trend with respect
to the timing of the maximum and minimum in water abundance, with
only minor differences caused by the interannual differences in water
vapor and the different retrieval approaches between both instruments,
addressing a previously existing discrepancy between ChemCam and CRISM
water vapor column abundances.
Title: A conservative finite element solver for the induction
equation of resistive MHD: Vector potential method and constraint
preconditioning
Authors: Li, Xujing; Li, Lingxiao
Bibcode: 2022JCoPh.46611416L
Altcode: 2021arXiv211111693L
A new conservative finite element solver for the three-dimensional
steady magnetohydrodynamic (MHD) kinematics equations is presented. The
solver utilizes magnetic vector potential and current density as
solution variables, which are discretized by H(curl)-conforming
edge-element and H(div)-conforming face element respectively. As a
result, the divergence-free constraints of discrete current density
and magnetic induction are both satisfied. Moreover the solutions
also preserve the total magnetic helicity. The generated linear
algebraic equation is a typical dual saddle-point problem that is
ill-conditioned and indefinite. To efficiently solve it, we develop a
block preconditioner based on constraint preconditioning framework and
devise a preconditioned FGMRES solver. Numerical experiments verify
the conservative properties, the convergence rate of the discrete
solutions and the robustness of the preconditioner. Simulation of
three-dimensional driven cavity flow problem using full MHD solver is
also conducted.
Title: The extended uncertainty principle effects on the phase
transitions of Reissner-Nordström and Schwarzschild black holes
Authors: Ökcü, Özgür; Aydiner, Ekrem
Bibcode: 2022NuPhB.98315934O
Altcode: 2022arXiv220810961O
In this paper, we investigate the phase transitions of
Reissner-Nordström (RN) and Schwarzschild black holes for the extended
uncertainty principle (EUP) framework. Considering temperature T,
charge Q and electric potential Φ as the state parameters, we show
the van der Waals (vdW) like phase transition of RN black hole in Q -
Φ diagrams and find the critical points depending on EUP parameter
α. Furthermore, we find Hawking-Page like phase transition for
Schwarzschild black hole. The results imply that the black holes in
asymptotically flat space have the similar phase structure with the
black holes in anti-de Sitter (AdS) space.
Title: Spectroscopic characterization of the Gefion Asteroid Family:
implications for L-chondrite Link
Authors: McGraw, Allison M.; Reddy, Vishnu; Sanchez, Juan A.
Bibcode: 2022MNRAS.515.5211M
Altcode: 2022MNRAS.tmp.2086M
Asteroid families are cosmic puzzles that help us understand the true
nature of their original parent body. Ordinary chondrites are the
most common types of meteorites that arrive to Earth and are composed
of three subtypes: H, L, and LL chondrites. The Gefion Asteroid
Family (GAF) has been proposed to be the source asteroids for the L
chondrites. In this work, we present the results of a spectroscopic
campaign of six dynamically defined members of the GAF to test the
hypothesis if L chondrites come from this family. Our compositional
analysis of these six asteroids shows a range of meteorite analogues
from L- to LL chondrites. Combining these results with our previous
work, we note that GAF asteroids span the entire ordinary chondrite
range of H-, L-, and LL. The observed compositional heterogeneity
in the GAF is likely due to largest members of the GAF consisting of
interlopers. A more detailed spectroscopic survey of a large subset
of asteroids in the GAF region is needed to further isolate true
family members.
Title: Forecast of neutrino cosmology from the CSST photometric
galaxy clustering and cosmic shear surveys
Authors: Lin, Hengjie; Gong, Yan; Chen, Xuelei; Chan, Kwan Chuen;
Fan, Zuhui; Zhan, Hu
Bibcode: 2022MNRAS.515.5743L
Altcode: 2022MNRAS.tmp.2028L; 2022arXiv220311429L
China Space Station Telescope (CSST) is a forthcoming powerful Stage IV
space-based optical survey equipment. It is expected to explore a number
of important cosmological problems in extremely high precision. In
this work, we focus on investigating the constraints on neutrino mass
and other cosmological parameters under the model of cold dark matter
with a constant equation of state of dark energy (wCDM), using the
mock data from the CSST photometric galaxy clustering and cosmic shear
surveys (i.e. 3 × 2 pt). The systematics from galaxy bias, photometric
redshift uncertainties, intrinsic alignment, shear calibration, baryonic
feedback, non-linear, and instrumental effects are also included in
the analysis. We generate the mock data based on the COSMOS catalogue
considering the instrumental and observational effects of the CSST,
and make use of the Markov chain Monte Carlo method to perform the
constraints. Comparing to the results from current similar measurements,
we find that CSST 3 × 2 pt surveys can improve the constraints on the
cosmological parameters by one order of magnitude at least. We can
obtain an upper limit for the sum of neutrino mass Σmν
≲ 0.36 (0.56) eV at 68 per cent (95 per cent) confidence level (CL),
and Σmν ≲ 0.23 (0.29) eV at 68 per cent (95 per cent)
CL if we ignore the baryonic effect, which is comparable to the Planck
results and much better than the current photometric surveys. This
indicates that the CSST photometric surveys can provide stringent
constraints on the neutrino mass and other cosmological parameters,
and the results also can be further improved by including data from
other kinds of CSST cosmological surveys.
Title: Sub-surface granular dynamics in the context of oblique,
low-velocity impacts into angular granular media
Authors: Miklavčič, Peter M.; Sánchez, Paul; Wright, Esteban;
Quillen, Alice C.; Askari, Hesam
Bibcode: 2022Icar..38515089M
Altcode: 2022arXiv220102585M
Oblique, low-velocity impacts onto non-terrestrial terrain are regular
occurrences during space exploration missions. These are not only
a necessary component of landing and sampling maneuvers, but can
also be used as impact experiments to reveal characteristics of the
interacting surfaces. We conduct two-dimensional discrete simulations
to model such impacts into a bed of triangular grains. Finite element
method provides the basis for simulation, enabling the angular grain
geometry. Our findings re-create the three classes of impact behavior
previously noted from experiments: full-stop, rollout, and ricochet
(Wright et al., 2020). An application of Set Voronoi tessellation
assesses packing fraction at a high resolution, revealing how grains
shift relative to each other during an impact event. We also assess how
packing fraction at the point of impact influences different impact
behavior types. Calculation of Von Mises strain distributions then
reveal how grains shift relative to the overall system, leading to the
notion of the 'skin zone'. Intuition would suggest that the region
of perturbed grains would grow deeper with higher velocity impacts,
results instead show that increasing velocity may evoke a change in
the grains' dissipative response that dispatches energy predominantly
laterally from the impact site instead of deeper into the bed. Finally,
we consider how sub-surface response could link with impactor dynamics
to deepen our understanding of oblique, low-velocity impact events,
one day helping to improve mission outcomes.
Title: Preface for special issue on the MASCOT lander exploring NEA
Ryugu - The mission and its outcome
Authors: Ho, Tra-Mi; Jaumann, Ralf; Bibring, Jean-Pierre; Moussi,
Aurelie
Bibcode: 2022P&SS..22005551H
Altcode:
On October 3, 2018 an important milestone in the exploration of the
surface of small bodies was reached when MASCOT landed on the C-type
near-Earth asteroid (162,173) Ryugu. MASCOT, a surface science package,
was a joint contribution of the German Aerospace Center (DLR) and the
Centre National d'Etudes Spatiales (CNES) for the Japanese Aerospace
Exploration Agency (JAXA) sample return mission Hayabusa2 (HY2). Its
main mission objective was to bring a suite of 4 scientific instruments
(MASCAM, MicrOMEGA, MARA and MASMAG) onto Ryugu enabling in-situ
investigation of the asteroid.
Title: Model BOSS and eBOSS luminous red galaxies at 0.2 < z <
1.0 using SubHalo Abundance Matching with three parameters
Authors: Yu, Jiaxi; Zhao, Cheng; Chuang, Chia-Hsun; Bautista, Julian
E.; Favole, Ginevra; Kneib, Jean-Paul; Mohammad, Faizan G.; Ross,
Ashley J.; Raichoor, Anand; Tao, Charling; Dawson, Kyle; Rossi,
Graziano
Bibcode: 2022MNRAS.516...57Y
Altcode: 2022MNRAS.tmp.2076Y; 2022arXiv220311069Y
SubHalo Abundance Matching (SHAM) is an empirical method for
constructing galaxy catalogues based on high-resolution N-body
simulations. We apply SHAM on the UNIT simulation to simulate SDSS
BOSS/eBOSS luminous red galaxies (LRGs) within a wide redshift range
of 0.2 < $z$ < 1.0. Besides the typical SHAM scatter parameter
σ, we include $v$smear and Vceil to take into
account the redshift uncertainty and the galaxy incompleteness,
respectively. These two additional parameters are critical for
reproducing the observed 2PCF multipoles on 5-25$\, h^{-1}\, {\rm
Mpc}$. The redshift uncertainties obtained from the best-fitting
$v$smear agree with those measured from repeat observations
for all SDSS LRGs except for the LOWZ sample. We explore several
potential systematics but none of them can explain the discrepancy
found in LOWZ. Our explanation is that the LOWZ galaxies might contain
another type of galaxies that needs to be treated differently. The
evolution of the measured σ and Vceil also reveals that
the incompleteness of eBOSS galaxies decreases with the redshift. This
is the consequence of the magnitude lower limit applied in eBOSS LRG
target selection. Our SHAM also set upper limits for the intrinsic
scatter of the galaxy-halo relation, given a complete galaxy sample:
σint < 0.31 for LOWZ at 0.2 < $z$ < 0.33,
σint < 0.36 for LOWZ at 0.33 < $z$ < 0.43, and
σint < 0.46 for CMASS at 0.43 < $z$ < 0.51. The
projected 2PCFs of our SHAM galaxies also agree with the observational
ones on the 2PCF fitting range.
Title: Two periods instead of one in a single 6.7 GHz methanol maser
feature in G9.62+0.20E
Authors: MacLeod, G. C.; Yonekura, Y.; Tanabe, Y.; Baan, W. A.; Brogan,
C. L.; Burns, R. A.; Chibueze, J. O.; Houde, M.; Hunter, T. R.; Kurtz,
S. E.; Rajabi, F.; Smits, D. P.; Stecklum, B.; Sugiyama, K.
Bibcode: 2022MNRAS.516L..96M
Altcode: 2022MNRAS.tmpL..82M
The source G9.62+0.20E surprises yet again! Analysis of the associated
methanol maser feature at vlsr = +8.8 km s-1
revealed a second period of P = 52.1 ± 0.3 d, along with the previously
reported period P = 243 d for this source. Various explanations,
harmonic flaring, Dicke's superradiance, a secondary pulsation,
or two different periodically varying radio sources in the field of
view with associated methanol masers are presented. The latter two
hypotheses appear more plausible but it is not clear which, if any,
best describe these observations.
Title: Structure of differentiated planetesimals: A chondritic fridge
on top of a magma ocean
Authors: Sturtz, Cyril; Limare, Angela; Chaussidon, Marc; Kaminski,
Édouard
Bibcode: 2022Icar..38515100S
Altcode:
Meteorites are interpreted as relics of early formed planetary bodies,
and they provide information about the processes that occurred in
the first few Myrs of our solar system. The ages measured for some
differentiated meteorites (achondrites), indicate that planetesimals
formed a differentiated silicate crust as early as ≈ 3 Myr after
the beginning of the solar system. The composition of the recently
discovered achondrite Erg Chech 002 (EC002), the oldest andesitic rock
known so far, betokens partial melting of a chondritic source taking
place as early as ≈ 1 Myr before all other known achondrites. However,
thermal models of early accreted planetesimals predict massive melting
of the planetesimal during core/mantle differentiation and cannot
account for the preservation of a substantial amount of chondritic
material. In this paper, we propose a way to interpret petrological
and geochemical constraints provided by differentiated meteorites by
introducing a refined thermal model of planetesimals formation and
evolution. We demonstrate that continuous, protracted accretion of
cold undifferentiated material upon a magma ocean over a timescale
2 times larger than the lifetime of the 26Al heat source
leads to the preservation of a few km thick chondritic crust. During
accretion, the heat released by radioactive decay further induces
episodes of partial melting at the base of the crust, which can led
to the formation of andesitic rocks such as EC002. Using the available
constraints on the age of EC002 and its cooling rate, the application
of our model constraints the terminal radius of its parent body between
70 and 130 km .
Title: New self-consistent effective one-body theory for spinless
binaries based on the post-Minkowskian approximation
Authors: Jing, Jiliang; Long, Sheng; Deng, Weike; Wang, Mengjie;
Wang, Jieci
Bibcode: 2022SCPMA..6500411J
Altcode: 2022arXiv220802420J
The effective one-body theories, introduced by Buonanno and Damour,
are novel approaches to constructing a gravitational waveform
template. By taking a gauge in which ψ1B and
ψ3B vanish, we find a decoupled equation with
separable variables for ψ4B in the effective
metric obtained in the post-Minkowskian approximation. Furthermore,
we set up a new self-consistent effective one-body theory for
spinless binaries, which can be applicable to any post-Minkowskian
orders. This theory not only releases the assumption that v/c should
be a small quantity but also resolves the contradiction that the
Hamiltonian, radiation-reaction force, and waveform are constructed
from different physical models in the effective one-body theory with
the post-Newtonian approximation. Compared with our previous theory
[Sci. China-Phys. Mech. Astron. 65, 260411 (2022)], the computational
effort for the radiation-reaction force and waveform in this new theory
will be tremendously reduced.
Title: SDSS-IV MaNGA: global properties of kinematically misaligned
galaxies
Authors: Zhou, Yuren; Chen, Yanmei; Shi, Yong; Bizyaev, Dmitry; Guo,
Hong; Bao, Min; Xu, Haitong; Yu, Xiaoling; Brownstein, Joel R.
Bibcode: 2022MNRAS.515.5081Z
Altcode: 2022MNRAS.tmp.1897Z; 2022arXiv220707487Z
We select 456 gas-star kinematically misaligned galaxies from
the internal Product Launch-10 of MaNGA survey, including 74
star-forming (SF), 136 green-valley (GV), and 206 quiescent (QS)
galaxies. We find that the distributions of difference between gas
and star position angles for galaxies have three local peaks at ~0°,
90°, and 180°. The fraction of misaligned galaxies peaks at log
(M*/M⊙) ~ 10.5 and declines to both low- and
high-mass end. This fraction decreases monotonically with increasing
star formation rate and specific star formation rate. We compare the
global parameters including gas kinematic asymmetry Vasym,
H I detection rate and mass fraction of molecular gas, effective radius
Re, Sérsic index n as well as spin parameter $\lambda
_{R_e}$ between misaligned galaxies and their control samples. We
find that the misaligned galaxies have lower H I detection rate and
molecular gas mass fraction, smaller size, higher Sérsic index,
and lower spin parameters than their control samples. The SF and GV
misaligned galaxies are more asymmetric in gas velocity fields than
their controls. These pieces of observational evidence point to the gas
accretion scenario followed by angular momentum redistribution from
gas-gas collision, leading to gas inflow and central star formation
for the SF and GV misaligned galaxies. We propose three possible
origins of the misaligned QS galaxies: (1) external gas accretion,
(2) merger, and (3) GV misaligned galaxies evolve into QS galaxies.
Title: Analysis of spatial distribution and evolution of terrestrial
precipitation
Authors: Gilarranz, Mónica; Pérez, Isidro A.; García, M. Ángeles;
Sánchez, M. Luisa; Pardo, Nuria; Fernández-Duque, Beatriz
Bibcode: 2022JASTP.23705930G
Altcode:
Monthly terrestrial precipitation was studied based on a dataset of
118 years covering the world. Different statistical indicators such as
the median, the interquartile range, the Yule-Kendall index and the
robust kurtosis were analysed taking into account time and latitudes
in order to reach conclusions about the evolution of precipitation
depending on its location around the world and also to observe its
yearly variation due to temperature increases on the planet. The study
enabled some of the effects of climate change to be seen, such as the
trend towards more extreme phenomena. Distribution of precipitation
depending on latitude, volume of water and rainfall frequency were
also determined. As a result, the heaviest precipitation occurrences
-with median values up to 2250 mm- were found over equatorial areas,
whereas middle latitudes were characterised by moderate rainfall
amounts, reaching 500 mm. Areas of the southern hemisphere at similar
latitudes presented precipitation regimes with values ranging from
250 to 1000 mm dependent upon by the orography and, particularly, by
weather events. The interquartile range showed a maximum at -40° due a
to higher variability of precipitation. In general, high values of the
Yule-Kendall index were found for deserts, whereas the equatorial area
presented low values. Robust kurtosis values mainly ranged between 0.2
and 0.3 following a Gaussian distribution. Latitudinal distribution
of the trend using the linear fit of the median of precipitation
revealed its decrease in the equatorial area and at high latitudes in
the southern hemisphere. However, an increase in the trend was found
between 60 and 80° latitude. Finally, the trend of the whole median
of precipitation in the long study period showed the combined effect
of extreme rainfall occurrences with only a slight variation.
Title: Statistical Thermodynamics of Surface-Bounded Exospheres
Authors: Schörghofer, Norbert
Bibcode: 2022EM&P..126....5S
Altcode:
Neutral exospheres of large airless bodies consist of atoms or
molecules on ballistic trajectories. An import example is the
lunar water exosphere, thought to transport water to cold traps. In
anticipation of future observational measurements, the theory of
thermalized surface-bounded gravitationally-bound exospheres is
further developed. The vertical density profile is calculated using
thermodynamic averages of an ensemble of ballistic trajectories. When
the launch velocities follow the Maxwell-Boltzmann Flux distribution,
the classical density profile results. For many other probability
distributions, including thermal desorption from a vertical wall,
the density diverges logarithmically near the surface. Hence, an
exosphere resulting from thermal desorption from a rough surface
includes a ground-hugging population that appears to be colder than the
surface. Another insight derived from the thermodynamic perspective
is that cold traps can be interpreted in terms of the frostpoint of
the water exosphere, if the long-term average of the pressure of the
exosphere is considered. Ice in lunar caves is long-lasting only if
the cave interior is below the cold trap temperature threshold.
Title: Electric fields calculation of lightning return-strokes in
the presence of an attachment point above the ground
Authors: Li, Quanxin; Gong, Zixuan; Wang, Jianguo; Cai, Li; Zhou,
Mi; Fan, Yadong
Bibcode: 2022JASTP.23705919L
Altcode:
The radiated electromagnetic fields and derivative waveforms from
lightning discharge were directly related with its inner physical
process. The return stroke initiated from ground (RSG) and the return
stroke initiated from an attachment point (RSAP) were analyzed. Two
types of current waveform from Gamerota et al. (2012) and Rachidi et
al. (2001), including both the first and subsequent return strokes,
were simulated in the presented paper. Both waveforms of the electric
field and electric field derivative were analyzed. The electric
fields were characterized by an obvious superimposed initial peak
on the rising edge, the electric field derivative was featured by a
bipolar waveshape with noticeably negative overshoot in the second
cycle. The downward return stroke current component is the main reason
for the superimposed initial peak in the electric field and the bipolar
waveshape with noticeably negative overshoot in the electric field
derivative. The subsequent return stroke with larger max steepness from
Gamerota et al. (2012) shows more noticeable superimposed initial peak
than that of Rachidi et al. (2001). The subsequent return stroke shows
more noticeable differences than that of the first return stroke. The
peak value enhancements at 100 km are similar to that at 15 km. The
changes were less than 0.5% for first return strokes, and 1.5% for
subsequent return strokes. Parameter sensitivity on the electric fields
and derivative waveforms were also presented.
Title: Mesoscopic energy ranking constraints in the IllustrisTNG
simulations
Authors: Dantas, Christine C.
Bibcode: 2022MNRAS.516..279D
Altcode: 2021arXiv211215385D; 2022MNRAS.tmp.2244D
We revisited the problem of mixing in a gravitational N-body system
from the point of view of the ordering of coarse-grained cells in the
one-particle energy space, here denoted energy ranking preservation
(ERP). This effect has been noted for some time in simulations,
although individual particle energies and their phase-space variables
mix considerably. The present investigation aimed to map ERP in terms
of parameters involving the collective range in which it is effective,
as well as in terms of global and historical characterizations of
gravitational systems evolving towards equilibrium. We examined a subset
of the IllustrisTNG cosmological magnetohydrodynamical simulations
(TNG50-4 and TNG100-3), considering both their full and dark-only
versions. For each simulation, we selected the 20 most massive haloes at
redshift z = 0, tracing their ERP fractions back at selected redshift
markers (z = {1.0, 5.0, 10 0}), and for a coarse-graining set ranging
from 5 to 30 energy bins. At the redshift marker z = 1, we found high
ERP fractions (above ${\sim}80\,\hbox{per cent}$) in both simulations,
regardless of the coarse-graining level. The decline in ERP fractions
with redshift was roughly a function of mass and fractional mass
increase in the analysed TNG50-4 haloes, but not in the TNG100-3 ones,
indicating a possible relative susceptibility of the ERP effect to mass
accretion for haloes less massive than ${\sim}10^{14} \, {\rm M}_{\odot
}$. We confirmed earlier indications in the literature concerning a
possible 'mesoscopic' constraint operative in a time span of at least
several Gyr.
Title: On the robustness of solitons crystals in the Skyrme model
Authors: Barriga, Gonzalo; Canfora, Fabrizio; Lagos, Marcela; Torres,
Matías; Vera, Aldo
Bibcode: 2022NuPhB.98315913B
Altcode: 2022arXiv220708712B
In this work we analize how the inclusion of extra mesonic degrees
of freedom affect the finite density solitons crystals of the Skyrme
model. In particular, the first analytic examples of hadronic crystals
at finite baryon density in both the Skyrme ω-mesons model as well as
for the Skyrme ρ-mesons theory are constructed. These configurations
have arbitrary topological charge and describe crystals of baryonic
tubes surrounded by a cloud of vector-mesons. In the ω-mesons case, it
is possible to reduce consistently the complete set of seven coupled
non-linear field equations to just two integrable differential
equations; one ODE for the Skyrmion profile and one PDE for the
ω-mesons field. This analytical construction allows to show explicitly
how the inclusion of ω-mesons in the Skyrme model reduces the repulsive
interaction energy between baryons. In the Skyrme ρ-mesons case, it is
possible to construct analytical solutions using a meron-type ansatz
and fixing one of the couplings of the ρ-mesons action in terms of
the others. We show that, quite remarkably, the values obtained for
the coupling constants by requiring the consistency of our ansatz
are very close to the values used in the literature to reduce nuclei
binding energies of the Skyrme model without vector-mesons. Moreover,
our analytical results are in qualitative agreement with the available
results on the nuclear spaghetti phase.
Title: Development of an electron impact ion source with high
ionization efficiency for future planetary missions
Authors: Kawashima, Oya; Yanase, Naho; Okitsu, Yoshihisa; Hirahara,
Masafumi; Saito, Yoshifumi; Karouji, Yuzuru; Yamamoto, Naoki; Yokota,
Shoichiro; Kasahara, Satoshi
Bibcode: 2022P&SS..22005547K
Altcode: 2022arXiv220500246K
Ion sources using electron impact ionization (EI) methods have been
widely accepted in mass spectrometry for planetary exploration missions
because of their simplicity. Previous space-borne mass spectrometers
were primarily designed with the EI method using rhenium tungsten alloy
filaments, enabling up to 100-200 μA emission in typical cases. The
emission level is desired to be enhanced because the sensitivity of
mass spectrometers is a critical requirement for the future in situ
mass spectrometry related to the measurement of trace components in
planetary samples. In this study, we developed a new high-emission EI
ion source using a Y2O3-coated iridium filament,
which has a lower work function than rhenium tungsten alloy. The size
of the ion source was 30 mm × 26 mm × 70 mm, and its weight was
∼70 g. We confirmed that when consuming ∼3.0 W power, the ion
source records 1-2 mA electrons, which is 10 times greater than the
conventional models' electron emission level. We verified the linearity
of ionization efficiency and the electron current in the range of
0.1-1 mA, which indicates our new model increased the ionization
efficiency. We conducted performance tests on the prototype with
the 3.0 W heating condition, confirming a high ionization efficiency
(∼104 nA/Pa). In addition, we conducted endurance tests
of the ion source and demonstrated the persistence of the ionization
efficiency for 30 min × 100 cycles.
Title: Epicyclic frequencies of spheroidal stars with non-uniform
density
Authors: Bollimpalli, D. A.
Bibcode: 2022MNRAS.515.6164B
Altcode: 2022arXiv220714170B; 2022MNRAS.tmp.2106B
We consider the gravitational potential of a rotating star with
non-uniform density to derive the orbital and epicyclic frequencies
of the particles orbiting the star. We assume that the star is
composed of concentric spheroids of constant density, with a global
power-law distribution of density inside the star. At the lowest
order approximation, we recover the known result for the Maclaurin
spheroid that the maximum in the radial epicyclic frequency occurs
at $r=\sqrt{2}ae$, for eccentricities ${\ge} 1/\sqrt{2}$. We find
that the nature of these characteristic frequencies differs based on
the geometry of the rotating star. For an oblate spheroid, the orbits
resemble retrograde Kerr orbits and the location of the radial epicyclic
maximum approaches the stellar surface as the density variation inside
the star becomes steeper. On the contrary, orbits around a prolate
spheroid resemble prograde Kerr orbits, but the marginally stable
orbit does not exist for prolate-shaped stars. The orbital frequency
is larger (smaller) than the Keplerian value for an oblate (prolate)
star with the equality attained as e → 0 or r → ∞. The radial
profiles of the angular velocity and the angular momentum allow for
a stable accreting disc around any nature of oblate/prolate spheroid.
Title: Understanding the spatial variation of Mg II and ionizing
photon escape in a local LyC leaker
Authors: Seive, Thomas; Chisholm, John; Leclercq, Floriane; Zeimann,
Gregory
Bibcode: 2022MNRAS.515.5556S
Altcode: 2022MNRAS.tmp.2100S; 2022arXiv220714328S
Ionizing photons must have escaped from high-redshift galaxies, but
the neutral high-redshift intergalactic medium makes it unlikely to
directly detect these photons during the Epoch of Reionization. Indirect
methods of studying ionizing photon escape fractions present a way to
infer how the first galaxies may have reionized the Universe. Here,
we use HET/LRS2 observations of J0919 + 4906, a confirmed z≍ 0.4
emitter of ionizing photons to achieve spatially resolved (12.5 kpc in
diameter) spectroscopy of Mg IIλ2796, Mg IIλ2803, [O II]λλ3727,
3729, [Ne III]λ3869, H γ, [O III]λ4363, H β, [O III]λ4959,
[O III]λ5007, and H α. From these data, we measure Mg II emission,
which is a promising indirect tracer of ionizing photons, along with
nebular ionization and dust attenuation in multiple spatially resolved
apertures. We find that J0919 + 4906 has significant spatial variation
in its Mg II escape and thus ionizing photon escape fraction. Combining
our observations with photoionization models, we find that the regions
with the largest relative Mg II emission and Mg II escape fractions have
the highest ionization and lowest dust attenuation. Some regions have
an escape fraction that matches that required by models to reionize
the early Universe, while other regions do not. We observe a factor
of 36 spatial variation in the inferred LyC escape fraction, which is
similar to recently observed statistical samples of indirect tracers
of ionizing photon escape fractions. These observations suggest that
spatial variations in neutral gas properties lead to large variations
in the measured LyC escape fractions. Our results suggest that single
sightline observations may not trace the volume-averaged escape fraction
of ionizing photons.
Title: Onset of common envelope evolution during a core helium flash
by rapid envelope expansion
Authors: Fainer, Stanislav; Bear, Ealeal; Soker, Noam
Bibcode: 2022MNRAS.515.5400F
Altcode: 2022MNRAS.tmp.2042F; 2022arXiv220412360F
We suggest that the vigorous core convection during core helium flash
on the tip of the red giant branch (RGB) of low-mass stars excites
waves that carry energy to the envelope and inflate it for few years
to increase the number of extreme horizontal branch (EHB; sdB and sdO)
stars with masses of $\simeq 0.47 \, \mathrm{M}_\odot$ with respect to
canonical binary evolution. Using the open-source MESA-BINARY, we follow
the evolution of a number of eccentric binary systems with an initial
primary stellar mass of $1.6 \, \mathrm{M}_\odot$. The energy that the
waves carry to the envelope leads to envelope expansion at the tip of
the RGB. The inflated RGB star engulfs many secondary stars to start
a CEE that otherwise would not occur. If the secondary star manages
to remove most of the RGB envelope the primary evolves to become an
EHB star with a mass of $\simeq 0.47 \, \mathrm{M}_\odot$. However,
we expect that in most cases the secondary star does not have time
to spiral-in to close orbits. It rather ends at a large orbit and
leaves a massive enough envelope for the primary star to later evolve
along the asymptotic giant branch and to engulf the secondary star,
therefore forming a non-spherical planetary nebula.
Title: Thermal state of earth's mantle during accretion
Authors: Arkani-Hamed, Jafar; Roberts, James H.
Bibcode: 2022PEPI..33106925A
Altcode:
We investigate the thermal evolution of the Earth's mantle during
accretion, assuming that the initial proto-Earth grows by accreting
25 Moon to Mars-sized planetary embryos in 100 Myr. The initial
proto-Earth is a differentiated planetary embryo with a liquid iron
core of 1670 km radius overlain by a silicate mantle of 3430 km
radius. Each embryo is assumed to impact vertically with a modified
escape velocity and completely merges to the proto-Earth. The impact
heating creates a large partially molten magma pond in the mantle
beneath the impact site that directly interacts with the core. The
iron content of the embryo sinks through the pond and merges to the
core, while the partially molten buoyant silicate with temperatures
higher than the stiff magma temperature pours out and spreads on
the proto-Earth, forming a superheated global magma ocean. The ocean
cools to the atmosphere by convection until it behaves like solid,
and then cools by thermal conduction. The successive embryo impacts
result in overlapping high temperature solidified magma oceans with
thicknesses of 70-135 km, which hamper the creation of global mantle
convection. We examine the effects of a few key physical parameters;
the kinetic viscosity of the magma ocean, the total accretion time,
the impact velocities of the embryos, the atmospheric temperature,
and the impact time intervals using 12 thermal evolution models. The
high temperature solid surface layers are the main characteristics of
all of the models. It takes about 150 Myr after the accretion for the
mantle to create a global convection.
Title: Scalable framework of intelligent RFI flagging for large-scale
HI survey data from FAST
Authors: Xiao, Jian; Zhang, Yajie; Zhang, Bo; Yang, Zhicheng; Yu,
Ce; Cui, Chenzhou
Bibcode: 2022NewA...9601825X
Altcode:
Radio frequency interference (RFI) identification is a key step
in radio data processing. In order to efficiently process huge
volumes of data produced by modern large radio telescopes, such as
the Five-hundred-meter Aperture Spherical radio Telescope (FAST),
exceptional balance between accuracy and performance (throughput)
is required for RFI flagging algorithms. RFI-Net is a single-process
RFI identification package based on deep learning technique, and has
achieved a higher flagging accuracy than the classical SumThreshold
method. In this paper, we present a scalable RFI flagging toolkit,
which can drive parallel workflows on multi-CPU and multi-GPU clusters,
with RFI-Net as its core detector. It can automatically schedule the
workload and aggregate itself after errors according to the running
environment. Moreover, its main components are all pluggable, and
can be easily customized according to requirements. The experiments
with real data of FAST showed that using eight parallel workflows,
the toolkit can process sky survey data at a speed of 66.79 GB/h,
which means quasi-real-time RFI flagging can be achieved considering
the data rate of FAST extragalactic spectral line observations.
Title: Primordial black holes as a probe of strongly first-order
electroweak phase transition
Authors: Hashino, Katsuya; Kanemura, Shinya; Takahashi, Tomo
Bibcode: 2022PhLB..83337261H
Altcode: 2021arXiv211113099H
Primordial black holes can be produced by density fluctuations generated
from delayed vacuum decays of first-order phase transition. The
primordial black holes generated at the electroweak phase transition
have masses of about 10-5 solar mass. Such primordial
black holes in the mass range can be tested by current and future
microlensing observations, such as Subaru HSC, OGLE, PRIME and
Roman telescope. Therefore, we may be able to explore new physics
models with strongly first-order electroweak phase transition via
primordial black holes. We examine this possibility by using models
with first-order electroweak phase transition in the standard model
effective field theory with dimension 6 and 8 operators. We find that
depending on parameters of the phase transition a sufficient number
of primordial black holes can be produced to be observed by above
mentioned experiments. Our results would suggest that primordial
black holes can be used as a new probe of models with strongly
first-order electroweak phase transition, which has complementarity
with measurements of the triple Higgs boson coupling at future
collider experiments and observations of gravitational waves at future
space-based interferometers.
Title: Three families of 5-body central configurations in the plane
Authors: Piña, Eduardo
Bibcode: 2022CeMDA.134...43P
Altcode:
We study the planar 5-body central configurations with different
masses in the plane, in the limit cases when one of the masses is very
large or very small with respect to the other four different positive
masses. The case of a very small mass reduces to find the planar
central configuration relative position of a satellite with respect to
a computed 4-body planar central configuration. We will numerically
find several examples of nine different positions of the satellite
allowed by each example of the 4-body central configuration. The case
of a large mass leads us to the co-orbital configuration with the
very large mass at the center and the other four different positive
masses on a circle. This case leads for a computed configuration to
a two-dimensional plane sector in the positive mass space compatible
with each geometrical configuration. The third studied case is a
kite configuration with three different positive masses on the axis of
symmetry and two equal masses located symmetrically with respect to that
axis on a perpendicular line; we give new cases where a two-dimensional
plane sector in the positive mass space is compatible with the geometric
configuration. Algorithms for computation are rather explicit.
Title: Geology and colour of Kupalo crater on Ceres
Authors: Hernandez, J.; Nathues, A.; Hiesinger, H.; Goetz, W.;
Hoffmann, M.; Schmedemann, N.; Thangjam, G.; Mengel, K.; Sarkar, R.
Bibcode: 2022P&SS..22005538H
Altcode:
Kupalo is a ∼4 Ma old, 26-km diameter impact crater on dwarf planet
Ceres, which exhibits extensive areas of bright bluish material. Here we
describe, for the first time, the geology of Kupalo on a regional and
local scale in detail, based on Dawn Framing Camera (FC) imagery. We
find the crater has a complex geology consistent with a brittle and
heterogeneous crust in this area. Through analyses of the FC colour
data, we identify a correlation between the geologic units and the
spectral variations, which can be explained by a mixture of subsurface
materials in response to the impact. The brightest sites of Kupalo,
located at the upper west wall and the central ridge, show similar FC
colour and spectral IR data, which suggest that the bright material in
these locations likely has the same origin. To explain the distribution
of the bright bluish material in the crater and its vicinity, we propose
two scenarios for the structure of the upper Cerean crust. Both require
deep-seated brine or salt reservoirs, possibly connected to a brine
ocean at the crust-mantle transition.
Title: Protostellar-disc fragmentation across all metallicities
Authors: Matsukoba, Ryoki; Tanaka, Kei E. I.; Omukai, Kazuyuki;
Vorobyov, Eduard I.; Hosokawa, Takashi
Bibcode: 2022MNRAS.515.5506M
Altcode: 2022MNRAS.tmp.2085M; 2022arXiv220603497M
Cosmic metallicity evolution possibly creates the diversity of star
formation modes at different epochs. Gravitational fragmentation
of circumstellar discs provides an important formation channel of
multiple star systems, including close binaries. We here study the
nature of disc fragmentation, systematically performing a suite of 2D
radiation-hydrodynamic simulations, in a broad range of metallicities,
from the primordial to the solar values. In particular, we follow
relatively long-term disc evolution over 15 kyr after the disc
formation, incorporating the effect of heating by the protostellar
irradiation. Our results show that the disc fragmentation occurs at
all metallicities 1-$0 \, \rm {Z}_{\odot }$, yielding self-gravitating
clumps. Physical properties of the clumps, such as their number and
mass distributions, change with the metallicity due to different gas
thermal evolution. For instance, the number of clumps is the largest
for the intermediate metallicity range of 10-2-$10^{-5} \,
\rm {Z}_{\odot }$, where the dust cooling is effective exclusively in
a dense part of the disc and causes the fragmentation of spiral arms,
although the disc might fragment at a similar rate, also at lower
metallicities 10-6-$0 \, \rm {Z}_{\odot }$ with higher
spatial resolution. The disc fragmentation is more modest for 1-$0.1
\, \rm {Z}_{\odot }$, thanks to the disc stabilization by the stellar
irradiation. Such metallicity dependence agrees with the observed trend
that the close binary fraction increases with decreasing metallicity
in the range of 1-$10^{-3} \, \rm {Z}_{\odot }$.
Title: A probabilistic method of background removal for high energy
astrophysics data
Authors: Ehlert, S.; Chen, C. T.; Swartz, D.; Hickox, R. C.; Lutovinov,
A.; Semena, A.; Krivonos, R.; Shtykovsky, A.; Tkachenko, A.
Bibcode: 2022MNRAS.515.5185E
Altcode: 2022arXiv220710165E; 2022MNRAS.tmp.1985E
We present a new statistical method for constructing background
subtracted measurements from event list data gathered by X-ray
and gamma-ray observatories. This method was initially developed
specifically to construct images that account for the high background
fraction and low overall count rates observed in survey data from the
Mikhail Pavlinsky ART-XC telescope aboard the Spektrum Röntgen Gamma
(SRG) mission, although the mathematical underpinnings are valid for
data taken with other imaging missions and analysis applications. This
method fully accounts for the expected Poisson fluctuations in both
the sky photon and non-X-ray background count rates in a manner that
does not result in unphysical negative counts. We derive the formulae
for arbitrary confidence intervals for the source counts and show
that our new measurement converges exactly to the standard background
subtraction calculation in the high signal limit. Utilizing these
results, we discuss several variants of images designed to optimize
different science goals for both pointed and slewing telescopes. Using
realistic simulated data of a galaxy cluster as observed by ART-XC,
we show that our method provides a more significant and robust
detection of the cluster emission as compared to a standard background
subtraction. We also demonstrate its advantages using real observations
of a point source from the ART-XC telescope. These calculations may
have widespread applications for a number of source classes observed
with high energy telescopes.
Title: Volume of a rotating black hole in 2+1 dimensions
Authors: Maurya, Suraj; Gutti, Sashideep; Nigam, Rahul
Bibcode: 2022PhLB..83337381M
Altcode: 2022arXiv220209543M
In this article we apply the technique for maximal volume estimation
of a black hole developed by Christodoulou and Rovelli [1] for
Schwarzschild black hole and by Zhang et al. [3] for non rotating BTZ
black hole, to the case of a rotating black hole in 2+1 dimensions. We
derive the equation of the maximal hyper-surface for the rotating
BTZ black hole using the Lagrangian formulation demonstrated in
[1]. Further we use maximization technique illustrated earlier by
Bengtsson et al. [4] for Kerr black hole to arrive at the similar
result for our case. We argue that the maximum contribution to
the volume of the hyper-surface comes from what we call the steady
state radius, which we show depends on mass M and the AdS length
scale. We demonstrate that this steady state radius can be derived
using independent considerations of vanishing extrinsic curvature. We
show that the volume of this segment of the maximal hyper-surface,
the CR volume, depends on mass, AdS length scale and angular momentum
J. We further compute the entropy of a scalar field living on the
maximal hyper-surface for a near extremal black hole and show that it
is proportional to the horizon entropy of the black hole.
Title: Photometric redshifts from SDSS images with an interpretable
deep capsule network
Authors: Dey, Biprateep; Andrews, Brett H.; Newman, Jeffrey A.; Mao,
Yao-Yuan; Rau, Markus Michael; Zhou, Rongpu
Bibcode: 2022MNRAS.515.5285D
Altcode: 2021arXiv211203939D; 2022MNRAS.tmp.2027D
Studies of cosmology, galaxy evolution, and astronomical transients
with current and next-generation wide-field imaging surveys like the
Rubin Observatory Legacy Survey of Space and Time are all critically
dependent on estimates of photometric redshifts. Capsule networks are
a new type of neural network architecture that is better suited for
identifying morphological features of the input images than traditional
convolutional neural networks. We use a deep capsule network trained on
ugriz images, spectroscopic redshifts, and Galaxy Zoo spiral/elliptical
classifications of ~400 000 Sloan Digital Sky Survey galaxies to do
photometric redshift estimation. We achieve a photometric redshift
prediction accuracy and a fraction of catastrophic outliers that are
comparable to or better than current methods for SDSS main galaxy
sample-like data sets (r ≤ 17.8 and zspec ≤ 0.4) while
requiring less data and fewer trainable parameters. Furthermore,
the decision-making of our capsule network is much more easily
interpretable as capsules act as a low-dimensional encoding of the
image. When the capsules are projected on a two-dimensional manifold,
they form a single redshift sequence with the fraction of spirals
in a region exhibiting a gradient roughly perpendicular to the
redshift sequence. We perturb encodings of real galaxy images in this
low-dimensional space to create synthetic galaxy images that demonstrate
the image properties (e.g. size, orientation, and surface brightness)
encoded by each dimension. We also measure correlations between galaxy
properties (e.g. magnitudes, colours, and stellar mass) and each
capsule dimension. We publicly release our code, estimated redshifts,
and additional catalogues at https://biprateep.github.io/encapZulate-1.
Title: Is (3599) Basov a large C-type super-fast rotator?
Authors: Pan, Kang-Shian; Ip, Wing-Huen; Lin, Chia-Lung; Huang,
Li-Ching; Cheng, Yu-Chi; Yeh, Ting-Shuo
Bibcode: 2022P&SS..22005520P
Altcode:
The rubble-pile model of asteroids deduced from the existence of
a spin cutoff is an important paradigm in the interior structure
of asteroids as a consequence of their collisional evolution. Many
objects with size less than 200 m have been found to be rotating with
a spin period less than 2.2 h but seldom so for bigger objects. Thus,
asteroids with rotation periods significantly less than this spin cutoff
limit are called super-fast rotators. Most often this picture of spin
cutoff and hence the rubble-pile model has been applied to the S-type
asteroids. In this study, we report the interesting case of (3599)
Basov which is a member of the Themis family of C-class composition. The
spin barrier of the Themis family asteroids has been shown to be P =
3 h. What is unusual about (3599) Basov is that its rotation period
has been confirmed to be P = 2.157 ± 0.037 h which is significantly
shorter than the critical value for centrifugal breakup. Furthermore,
its size of 18 km is much larger than those of the S-class super-fast
rotators. The physical property of (3599) Basov might therefore be
quite unique.
Title: A survey of deuterated ammonia in the Cepheus star-forming
region L1251
Authors: Galloway-Sprietsma, Maria; Shirley, Yancy L.; Di Francesco,
James; Keown, Jared; Scibelli, Samantha; Sipilä, Olli; Smullen, Rachel
Bibcode: 2022MNRAS.515.5219G
Altcode: 2022MNRAS.tmp.1989G; 2022arXiv220710718G
Understanding the chemical processes during starless core and
prestellar core evolution is an important step in understanding the
initial stages of star and disc formation. This project is a study of
deuterated ammonia, o-NH2D, in the L1251 star-forming region
towards Cepheus. Twenty-two dense cores (20 of which are starless or
prestellar, and two of which have a protostar), previously identified by
p-NH3 (1,1) observations, were targeted with the 12m Arizona
Radio Observatory telescope on Kitt Peak. o-NH2D J$_{\rm
{K_a} \rm {K_c}}^{\pm } =$$1_{11}^{+} \rightarrow 1_{01}^{-}$ was
detected in 13 (59 per cent) of the NH3-detected cores with
a median sensitivity of $\sigma _{T_{mb}} = 17$ mK. All cores detected
in o-NH2D at this sensitivity have p-NH3 column
densities >1014 cm-2. The o-NH2D
column densities were calculated using the constant excitation
temperature (CTEX) approximation while correcting for the filling
fraction of the NH3 source size. The median deuterium
fraction was found to be 0.11 (including 3σ upper limits). However,
there are no strong, discernible trends in plots of deuterium fraction
with any physical or evolutionary variables. If the cores in L1251 have
similar initial chemical conditions, then this result is evidence of
the cores physically evolving at different rates.
Title: Uncertainty maps for motion around binary asteroids
Authors: Fodde, Iosto; Feng, Jinglang; Vasile, Massimiliano
Bibcode: 2022CeMDA.134...41F
Altcode:
In this work, two novel dynamics indicators are introduced and used
to characterise the uncertain dynamics around a binary asteroid. These
indicators are derived from the propagated expansion of the states in
polynomial series of the uncertainty in initial conditions and dynamical
model parameters. Thus, each indicator encapsulates in a single scalar
the effect of the uncertainty in multiple model parameters. The first
indicator directly calculates the second statistical moment of the
propagated uncertainty set. This indicator gives a measure of the
rate of divergence of an ensemble of trajectories in phase space. The
second indicator estimates the approximation error of the polynomial
expansion. Hence, it captures the nonlinearity in the distribution
of the propagated states that is induced by the uncertainty. The
two indicators are then used to create a map in phase space, which
relates initial conditions to the sensitivity of the state over time
to multiple realisation of the uncertain parameters. The case of the a
spacecraft orbiting the binary asteroid system Didymos is considered
in this paper. The uncertainty maps proposed in this paper are shown
to reveal the characteristics of the motion around Didymos under
uncertainty in the masses of both bodies.
Title: Corrigendum to "Non-isostatic effects on crustal thickness:
A study using CRUST2. 0 in Fennoscandia" [Physics of the Earth and
Planetary Interiors, 2012, 200: 37-44]
Authors: Mohammad, Bagherbandi; Lars, Sjöberg
Bibcode: 2022PEPI..33106909M
Altcode:
The authors regret < that in the above paper an error has been
found in the equation, Eq. 19. It should read R/(γ(n - 1)). The error
does not affect the paper's main core. The unit of Fig. 2 should be
"km/(ms-2)">.
Title: Impacts of zonal winds on planetary oscillations and Saturn
ring seismology
Authors: Dewberry, Janosz W.; Mankovich, Christopher R.; Fuller, Jim
Bibcode: 2022MNRAS.516..358D
Altcode: 2022arXiv220704065D; 2022MNRAS.tmp.1881D
The excitation of density and bending waves in Saturn's C ring by
planetary oscillation modes presents a unique opportunity to learn about
gas giant interiors and rotation. However, theoretical complications
related to Saturn's rapid and differential rotation pose a barrier to
the full utilization of ring wave detections. We calculate oscillation
modes using a complete, non-perturbative treatment of differential
rotation modelled after Saturn's zonal winds in self-consistently
computed, polytropic equilibria. We find that previous, approximate
treatments of the effects of differential rotation in Saturn
overestimate shifts in the frequencies of fundamental modes (f modes)
thought to be responsible for the majority of the waves detected in
the C ring, due to an omitted modification of the equilibrium shape and
structure of the planet by differential rotation. The bias introduced
by these frequency overestimates is small, but significant relative to
the uncertainties afforded by Cassini data. We additionally consider
the non-perturbative effects of Saturn-like differential rotation on
the rotational mixing of f modes and internal gravity modes (g modes),
which is relevant to detections of multiple density waves with very
closely split pattern speeds. We find that higher-order rotational
effects can produce orders-of-magnitude enhancements in the surface
gravitational perturbations of g modes dominated by large spherical
harmonic degrees ℓ, regardless of frequency separation from the
sectoral f mode. Despite this enhancement, we find that the observed
fine splitting of density waves is unlikely to involve g modes dominated
by ℓ ≳ 10. This restriction may aid in the inference of possible
internal structures for Saturn.
Title: ExoMol line lists - XLVI. Empirical rovibronic spectra of
silicon mononitrate (SiN) covering the six lowest electronic states
and four isotopologues
Authors: Semenov, Mikhail; Clark, Nicholas; Yurchenko, Sergei N.;
Kim, Gap-Sue; Tennyson, Jonathan
Bibcode: 2022MNRAS.516.1158S
Altcode: 2022MNRAS.tmp.1942S
Silicon mononitride (28Si14N,
29Si14N, 30Si14N,
28Si15N) line lists covering infrared, visible,
and ultraviolet regions are presented. The SiNful line lists produced
by ExoMol include rovibronic transitions between six electronic states:
$X\, {}^{2}\Sigma ^{+}$, $A\, {}^{2}\Pi$, $B\, {}^{2}\Sigma ^{+}$,
$D\, {}^{2}\Delta$, $a\, {}^{4}\Sigma ^{+}$, $b\, {}^{4}\Pi$. The
ab initio potential energy and coupling curves, computed at the
multireference configuration interaction (MRCI/aug-cc-pVQZ) level of
theory, are refined for the observed states by fitting their analytical
representations to 1052 experimentally derived SiN energy levels
determined from rovibronic bands belonging to the X-X, A-X, and B-X
electronic systems through the MARVEL procedure. The SiNful line lists
are compared to previously observed spectra, recorded and calculated
lifetimes, and previously calculated partition functions. SiNful is
available via the www.exomol.com database.
Title: Thakurta metric does not describe a cosmological black hole
Authors: Harada, Tomohiro; Maeda, Hideki; Sato, Takuma
Bibcode: 2022PhLB..83337332H
Altcode: 2021arXiv210606651H
Recently, the Thakurta metric has been adopted as a model of primordial
black holes. We show that the spacetime described by this metric has
neither black-hole event horizon nor black-hole trapping horizon
and involves the violation of all the standard energy conditions
as a solution of the Einstein equation. Therefore, this metric does
not describe a cosmological black hole in the early universe. It is
pointed out that a contradictory claim by the other group stems from
an incorrect choice of sign.
Title: Double-lens scintillometry: the variable scintillation of
pulsar B1508 + 55
Authors: Sprenger, Tim; Main, Robert; Wucknitz, Olaf; Mall, Geetam;
Wu, Jason
Bibcode: 2022MNRAS.515.6198S
Altcode: 2022arXiv220413985S; 2022MNRAS.tmp.2061S
We report on observations of PSR B1508 + 55's scintillation at the
Effelsberg 100-m telescope spanning from early 2020 to early 2022. In
the autumn of 2020, close to the time the pulsar was predicted
to cross echoes in its pulse profile, a sudden transition in the
scintillation arcs from peculiar stripe-like features to parabolic
arclets was observed. To infer a geometric model of the scattering,
we measure the effects of the annual velocity curve of Earth, of
the relative movement of the line of sight, and of the projection
of points on a second scattering screen and develop novel methods
to do so. The latter phenomenon was discovered by this study and
strongly indicates a two-screen scattering geometry. We derive an
analytical two-screen model and demonstrate in a Markov chain Monte
Carlo analysis as well as simulations that it can be successfully
applied to explain the observations by interpreting the transition as
a change of relative amplitudes of images as well as a shift in the
orientation of anisotropy. The collection of methods, we demonstrate
here is transferable to other pulsars with the potential to strongly
improve constraints on scattering models.
Title: Terrestrial Martian analogues from the Indian subcontinent:
Implications for hydrological activity on Mars
Authors: Chavan, Anil; Bhore, Vivek; Bhandari, Subhash
Bibcode: 2022Icar..38515118C
Altcode:
Martian geology and surface geomorphic features are grouped under
Noachian, Hesperian, and Amazonian eras, based on the crater
retention ages and resurfacing ages by crater densities. Comparing
the similarities and differences between Martian landforms and
their terrestrial analogues promotes an understanding of how surface
processes operated on both planets. The study focusses on the processes
responsible for the evolution of fluvial valleys on the flanks of
volcanic craters and the fluvial terraces with an objective towards
ascertaining the role of changing climate, tectonic, and volcanic
conditions. We have studied the channels that developed on the flank
of volcanic crater Ceraunius Tholus and compared with the monogenetic
volcanic field of Dhinodhar Hill which have been significantly modified
by fluvial processes. Similarly, the fluvial basins developed on
the Hesperian volcanic units of Echus plateau were compared with the
Alaldari drainage of Upper Tapi river basin, showing the development
of theater-headed channels and valleys, and relative fluvial features
showing the strong influence of catastrophic climate and tectonic,
which is also supported by the morphometric analysis in modulating
the topography. The fluvial terraces developed in the Nubra and Shyok
rivers of Ladakh and Upper and Middle reaches of Satluj in Central
Himalayas are compared with Noctis fossae on Mars both developed due
to the interplay of tectonism and climate.
Title: Detecting undocumented trends in solar irradiance observations
Authors: Dudok de Wit, Thierry
Bibcode: 2022JSWSC..12...10D
Altcode:
Quantifying the long-term stability of solar irradiance observations is
crucial for determining how the Sun varies in time and detecting decadal
climate change signals. The stability of irradiance observations is
challenged by the degradation of instrumental sensitivity in space and
by the post-launch corrections needed to mitigate this degradation. We
propose a new framework for detecting instrumental trends based on
the existing idea of comparing the solar irradiance at pairs of dates
for which a proxy quantity reaches the same level. Using a parametric
model, we then reconstruct the trend and its confidence interval at all
times. While this method cannot formally prove the instrumental origin
of the trends, the observation of similar trends with different proxies
provides strong evidence for a non-solar origin. We illustrate the
method with spectral irradiance observations from the Solar Radiation
and Climate Experiment (SORCE) mission, using various solar proxies
such as sunspot number, MgII index, F10.7 index. The results support
the existence of non-solar trends that exceed the level of solar cycle
variability. After correcting the spectral irradiance for these trends,
we find the difference between the levels observed at solar maximum
and at solar minimum to be in good agreement with irradiance models.
Title: Patterns of martian glacial deformation: Implications for
glacio-geology, internal structure, and regional climate
Authors: Grau Galofre, Anna; Serla, Jayanth K.; Becerra, Patricio;
Noblet, Axel; Conway, Susan J.
Bibcode: 2022P&SS..22105548G
Altcode:
Viscous Flow Features (VFF) are widespread in the martian mid-latitudes
and indicative of near-surface ice deposits. Their distribution and
morphology hint at the regional history of ice deposition and ablation,
as well as changes in surface temperature. Here we interrogate the
deformation history of a type of VFF, a Lobate Debris Apron (LDA),
located in the eastern Hellas region, from its surface morphology,
discussing the implications it poses for its internal structure and
regional climate variability. Our observations integrate data from
the Colour and Stereo Surface Imaging System (CaSSIS), the SHAllow
RADar (SHARAD), the Context Camera (CTX), the High Resolution Imaging
Science Experiment (HiRISE), and the Mars Orbiter Laser Altimeter
(MOLA). Morphological observations, spectral analysis of characteristic
wavelengths, and ice deformation stability analysis place constraints
on the dynamics and deformation history of the deposit. We discuss
contrasting hypotheses for the origin of the different surface
structures, including the possibility of gelifluction in addition
to glacial creep. Our results provide a guide to interpret glacial
deformation patterns in martian VFFs in the light of internal structure,
regional climate history, and underlying topography.
Title: Detectability of satellites around directly imaged exoplanets
and brown dwarfs
Authors: Lazzoni, Cecilia; Desidera, Silvano; Gratton, Raffaele;
Zurlo, Alice; Mesa, Dino; Ray, Shrishmoy
Bibcode: 2022MNRAS.516..391L
Altcode: 2022arXiv220707569L; 2022MNRAS.tmp.2120L
Satellites around substellar companions are a heterogeneous class of
objects with a variety of different formation histories. Focusing
on potentially detectable satellites around exoplanets and brown
dwarfs (BDs), we might expect to find objects belonging to two main
populations: planet-like satellites similar to Titan or the Galileian
Satellites - likely formed within the scope of core accretion;
and binary-like objects, formed within different scenarios, such
as disc instability. The properties of these potential satellites
would be very different from each other. Additionally, we expect that
their characterization would provide insightful information about the
history of the system. This is particularly important for planets/BDs
discovered via direct imaging (DI) with ambiguous origins. In this
paper, we review different techniques, applied to DI planets/BDs,
that can be used to discover such satellites. This was achieved by
simulating a population of satellites around the exoplanet β Pic b,
which served as a test case. For each simulated satellite, the amplitude
of DI, radial velocity, transit and astrometric signals, with respect
to the planet, were retrieved and compared with the detection limits
of current and future instruments. Furthermore, we compiled a list
of 38 substellar companions discovered via DI to give a preliminary
estimate on the probability of finding satellites extracted from
the two populations mentioned above, with different techniques. This
simplified approach shows that detection of planet-like satellites,
though not strictly impossible, is very improbable. On the other hand,
the detection of binary-like satellites is within the capabilities of
current instrumentation.
Title: SDSS-IV MaNGA: a catalogue of spectroscopically detected
strong galaxy-galaxy lens candidates
Authors: Talbot, Michael S.; Brownstein, Joel R.; Neumann, Justus;
Thomas, Daniel; Maraston, Claudia; Drory, Niv
Bibcode: 2022MNRAS.515.4953T
Altcode: 2022MNRAS.tmp.1685T; 2022arXiv220609902T
We spectroscopically detected candidate emission-lines of 8 likely,
17 probable, and 69 possible strong galaxy-galaxy gravitational lens
candidates found within the spectra of $\approx 10\, 000$ galaxy
targets contained within the completed Mapping of Nearby Galaxies
at Apache Point Observatory survey. This search is based upon the
methodology of the Spectroscopic Identification of Lensing Objects
project, which extends the spectroscopic detection methods of the BOSS
Emission-Line Lensing Survey and the Sloan Lens ACS Survey. We scanned
the co-added residuals that we constructed from stacks of foreground
subtracted row-stacked-spectra so a sigma-clipping method can be
used to reject cosmic rays and other forms of transients that impact
only a small fraction of the combined exposures. We also constructed
narrow-band images from the signal to noise of the co-added residuals to
observe signs of lensed source images. We also use several methods to
compute the probable strong lensing regime for each candidate lens to
determine which candidate background galaxies may reside sufficiently
near the galaxy centre for strong lensing to occur. We present the
spectroscopic redshifts within a value-added catalogue (VAC) for data
release 17 (DR17) of SDSS-IV. We also present the lens candidates,
spectroscopic data, and narrow-band images within a VAC for DR17. High
resolution follow-up imaging of these lens candidates are expected to
yield a sample of confirmed grade-A lenses with sufficient angular
size to probe possible discrepancies between the mass derived from
a best-fitting lens model, and the dynamical mass derived from the
observed stellar velocities.
Title: Probing dark matter with strong gravitational lensing through
an effective density slope
Authors: Şengül, Atinç Çagan; Dvorkin, Cora
Bibcode: 2022MNRAS.516..336S
Altcode: 2022MNRAS.tmp.2150S
Many dark matter (DM) models that are consistent with current
cosmological data show differences in the predicted (sub)halo mass
function, especially at sub-galactic scales, where observations
are challenging due to the inefficiency of star formation. Strong
gravitational lensing has been shown to be a useful tool for detecting
dark low-mass (sub)haloes through perturbations in lensing arcs,
therefore allowing the testing of different DM scenarios. However,
measuring the total mass of a perturber from strong lensing data is
challenging. Overestimating or underestimating perturber masses can
lead to incorrect inferences about the nature of DM. In this paper,
we argue that inferring an effective slope of the DM density profile,
which is the power-law slope of perturbers at intermediate radii, where
we expect the perturber to have the largest observable effect, is a
promising way to circumvent these challenges. Using N-body simulations,
we show that (sub)halo populations under different DM scenarios differ
in their effective density slope distributions. Using realistic mocks
of Hubble Space Telescope observations of strong lensing images, we show
that the effective density slope of perturbers can be robustly measured
with high enough accuracy to discern between different models. We
also present our measurement of the effective density slope $\gamma
=1.96\substack{+0.12 \\ -0.12}$ for the perturber in JVAS B1938+666,
which is a 2σ outlier of the cold DM scenario. More measurements of
this kind are needed to draw robust conclusions about the nature of DM.
Title: Experimental serpentinization of iron-rich olivine
(hortonolite): Implications for hydrogen generation and secondary
mineralization on Mars and icy moons
Authors: McCollom, Thomas M.; Klein, Frieder; Moskowitz, Bruce;
Solheid, Peter
Bibcode: 2022GeCoA.335...98M
Altcode:
Serpentinization of olivine-rich ultramafic rocks is recognized to have
been widespread across the solar system throughout its history, with
substantial implications for the chemical and physical properties of
planetary lithospheres, atmospheric compositions, and astrobiology. One
especially significant product of serpentinization is molecular hydrogen
(H2), whose generation is closely linked to the oxidation of
Fe as serpentinization proceeds. While numerous experimental simulations
of serpentinization have been conducted over the years, these studies
have been performed almost exclusively using reactant minerals that
contain relatively high Mg and low Fe contents representative of
terrestrial mantle rocks. In contrast, very few studies have been
conducted with the more Fe-enriched mineral compositions that may
predominate on other solar system bodies. In this study, an experiment
was conducted to investigate mineral alteration and H2
generation during serpentinization of Fe-rich olivine (hortonolite;
Fo∼62) at 230 °C and 35 MPa. After 3500 h of reaction,
∼55 % of the hortonolite reacted to secondary minerals composed
of serpentine (chrysotile) and magnetite. Chrysotile contained
proportionally less Fe than the original hortonolite, reflecting
the partitioning of some Fe into magnetite; however, it contained
substantially more Fe than serpentine precipitated from alteration of
Mg-rich, Fe-poor terrestrial mantle olivine (Fo∼90) under
the same reaction conditions. Reaction of hortonolite also produced
more than four times as much magnetite as Mg-rich olivine. Generation
of H2 occurred steadily throughout the experiment, with more
than five times as much H2 generated per mole of hortonolite
reacted than observed for Fe-poor olivine at the same conditions. The
results suggest that serpentinization of Fe-rich ultramafic rocks
on Mars and other planetary bodies may have a substantially greater
capacity to generate H2 and to precipitate magnetite than
their Fe-poor terrestrial counterparts, which would enhance their
potential to support H2-based biological communities,
contribute to atmospheric warming, and augment local magnetic signatures
in planetary lithospheres.
Title: Investigation of Ag(Ga,In)Se2 as thin-film solar
cell absorbers: A first-principles study
Authors: Wang, Rong; Dou, Baoying; Zheng, Yifeng; Wei, Su-Huai
Bibcode: 2022SCPMA..6507311W
Altcode:
Using first-principles calculations, the structural, electronic,
and defect properties of AgInSe2 (AIS), AgGaSe2
(AGS), and their alloys (AIGS) are systematically studied and compared
with their Cu counterparts as potential candidates for thin-film
solar cell absorbers. The bandgap energies of AIS (1.24 eV) and AGS
(1.84 eV) are larger than their Cu counterparts, despite their larger
lattice parameters. According to the Shockley-Queisser theory, AIS
or AIGS could be more suitable for solar-cell-absorber materials
than their Cu counterparts. However, after investigating the band
structures and intrinsic defect properties of AIS and AGS, we find
that, (i) AIS and AGS have large negative crystal field splitting,
thus low density of states near the valence band maximum (VBM); (ii)
similar to the Cu counterparts, Ag vacancy (VAg) is the
main hole-carrier provider, while InAg (or GaAg)
serves as the hole-carrier killer in p-type AIS (or AGS). However,
because the positions of the VBM and conduction band minimum of
AIS (or AGS) are lower than those of CuInSe2 (CIS) [or
CuGaSe2 (CGS)], the compensation of the p-type doping in AIS
(or AGS) is more severe. Thus, the p-type doping of AIS (or AIGS) is
more difficult than that of CIS (or CIGS), which is consistent with
the doping limit rule. To improve the p-type doping of the AIS (or
AIGS) as the solar-cell absorber, thus, improve the power conversion
efficiency (PCE), the Ag-rich/(In,Ga)-poor/Se-rich growth condition is
preferred. Alloy engineering of AIS with AGS can enhance the PCE because
it can tune the bandgap energy of the absorber and band alignment at the
absorber/buffer interface. More importantly, we suggest that for AIS
(or AIGS) solar cell, the traditional buffer material of CdS is not
suitable anymore due to the large conduction band offset between AIS
and CdS. A new buffer layer material with a lower conduction band edge
is necessary for better electron transport in AIS (or AIGS) solar cell.
Title: Six-dimensional non-extremal Reissner-Nordstrom black hole,
charged massive scalar perturbation and black hole bomb
Authors: Zhao, Run-Dong; Huang, Jia-Hui
Bibcode: 2022PhLB..83337286Z
Altcode: 2022arXiv220507264Z
The superradiant stability of higher dimensional non-extremal
Reissner-Nordstrom black hole under charged massive scalar perturbation
is analytically studied. We extend our previous studies of four- and
five-dimensional non-extremal Reissner-Nordstrom black hole cases to
six-dimensional case. By analyzing the derivative of the effective
potential with an analytical method, we find that no potential well
exists outside the outer horizon of the black hole for the superradiant
scalar modes. This means that there is no black hole bomb for the system
consisting of six-dimensional Reissner-Nordstrom black hole and charged
massive scalar perturbation and the system is superradiantly stable.
Title: Impact ionization dust detection with compact, hollow and
fluffy dust analogs
Authors: Hunziker, S.; Moragas-Klostermeyer, G.; Hillier, J. K.;
Fielding, L. A.; Hornung, K.; Lovett, J. R.; Armes, S. P.; Fontanese,
J.; James, D.; Hsu, H. W.; Herrmann, I.; Fechler, N.; Poch, O.;
Pommerol, A.; Srama, R.; Malaspina, D.; Sterken, V. J.
Bibcode: 2022P&SS..22005536H
Altcode:
Impact ionization of high-velocity cosmic dust particles has been used
as a basic principle for dust detectors in space for many decades. It
has provided optimum means to gain insight into the dust environment
in the solar system. The Ulysses Dust Detector System provided for the
first time impact ionization-based detection of interstellar dust (ISD)
in the solar system and discovered surprisingly heavy ISD particles with
sizes up to a few microns. Studies based on astronomical observations
of the local interstellar medium, on the other hand, suggested a much
smaller upper limit of around 0.25 μm (silica) or 1 μm (graphite)
for the size distribution of ISD particles. Therefore, it has been
suggested that low-density fluffy dust particles may mimic the impact
signals of heavier compact particles. In this work, we discuss a series
of impact experiments that have been performed at the Heidelberg dust
accelerator facility with the Cosmic Dust Analyzer flight spare unit,
to compare the high-velocity impact ionization properties of compact
and hollow silicate particles, and carbon aerogel particles with each
other and with literature data. The experiments indicate differences
in the collected total amount of impact charges and how quickly the
charges are collected, between impacts from compact particles and their
non-compact counterparts. The results of this first study suggest that
fluffy particles generate less ions upon impact than their compact
counterparts, opposite to the suggested explanation for the heavy
ISD particles. Data from the performed impact experiments indicate
that a secondary process (e.g. secondary impacts from ejecta or more
target material ionization) could be the main cause for the observed
differences. These results imply that the previously detected heavy ISD
particles may be real. We identify the key problems with the performed
dust experiments and advise that future impact ionization instruments
should additionally be calibrated with improved low-density fluffy dust
particles that better represent the properties of cosmic dust particles.
Title: On the moment of inertia of PSR J0737-3039 A from LIGO/Virgo
and NICER
Authors: Miao, Zhiqiang; Li, Ang; Dai, Zi-Gao
Bibcode: 2022MNRAS.515.5071M
Altcode: 2021arXiv210707979M; 2022MNRAS.tmp.1912M
We perform a Bayesian analysis of neutrons star moment of inertia
by utilizing the available gravitational-wave data from LIGO/Virgo
(GW170817 and GW190425) and mass-radius measurements from the Neutron
Star Interior Composition Explorer (PSR J0030+0415 and PSR J0740 +
6620), incorporating the possible phase transition in the pulsar
inner core. We find that the moment of inertia of pulsar A in the
double pulsar binary J0737-3039 is $\sim 1.30\times 10^{45}\, {\rm g\,
cm^2}$, which only slightly depends on the employed hadronic equation of
states. We also demonstrate how a moment of inertia measurement would
improve our knowledge of the equation of state and the mass-radius
relation for neutron stars and discuss whether a quark deconfinement
phase transition is supported by the available data and forthcoming
data that could be consistent with this hypothesis. We find that if
pulsar A is a quark star, its moment of inertia is a large value of
$\sim 1.55\times 10^{45}\, {\rm g\, cm^2}$ suggesting the possibility
of distinguishing it from (hybrid-)neutron stars with measurements
of PSR J0737-3039A moment of inertia. We finally demonstrate the
moment-of-inertia-compactness universal relations and provide analytical
fits for both (hybrid-)neutron star and quark star results based on
our analysis.
Title: The environments of the radio galaxy population in SIMBA
Authors: Thomas, Nicole; Davé, Romeel
Bibcode: 2022MNRAS.515.5539T
Altcode: 2021arXiv210511484T; 2022MNRAS.tmp.2108T
We investigate the environmental properties of the z = 0 radio galaxy
population using the SIMBA cosmological hydrodynamic simulation. We
identify centrals and satellites from a population of high and low
excitation radio galaxies (HERGs and LERGs) in SIMBA, and study their
global properties. We find that $\sim 20{{\ \rm per\ cent}}$ of radio
galaxies are satellites, and that there are insignificant differences
in the global properties of LERGs based on their central/satellite
classification. HERG satellites display lower values of star formation,
1.4 GHz radio luminosity, and Eddington fractions than HERG centrals. We
further investigate the environments of radio galaxies and show that
HERGs typically live in less dense environments, similar to star-forming
galaxies. The environments of high-mass LERGs are similar to non-radio
galaxies, but low-mass LERGs live in underdense environments similar
to HERGs. LERGs with overmassive black holes reside in the most
dense environments, while HERGs with overmassive black holes reside in
underdense environments. The richness of a LERG's environment decreases
with increasing Eddington fraction, and the environments of all radio
galaxies do not depend on radio luminosity for $\, P_{\rm 1.4~GHz}\lt
10^{24} \rm {~W~Hz}^{-1}$. Complementing these results, we find that
LERGs cluster on the same scale as the total galaxy population, while
multiple HERGs are not found within the same dark matter halo. Finally,
we show that high density environments support the growth of HERGs
rather than LERGs at z = 2. SIMBA predicts that with more sensitive
surveys, we will find populations of radio galaxies in environments
much similar to the total galaxy population.
Title: Numerical simulations of a two-fluid jet at a magnetic null
point in a solar arcade
Authors: González-Avilés, J. J.; Murawski, K.; Zaqarashvili, T. V.
Bibcode: 2022MNRAS.515.5094G
Altcode: 2022arXiv220707610G
We study the formation and evolution of jets in the solar atmosphere
using numerical simulations of partially ionized plasma. The two-fluid
magnetohydrodynamic equations with ion+electron and neutral hydrogen
components are used in two-dimensional Cartesian geometry. Numerical
simulations show that a localized non-linear Gaussian pulse of ion and
neutral pressures initially launched from the magnetic null point of a
potential arcade located below the transition region quickly develops
into a shock due to the decrease of density with height. The shock
propagates upwards into the solar corona and lifts the cold and dense
chromospheric plasma behind in the form of a collimated jet with an
inverted-Y shape. The inverted-Y shape of jets is connected with the
topology of a magnetic null point. The pulse also excites a non-linear
wake in the chromosphere, which leads to quasi-periodic secondary
shocks. The secondary shocks lift the chromospheric plasma upwards and
create quasi-periodic jets in the lower corona. Ion and neutral fluids
show generally similar behaviour, but their relative velocity is higher
near the upper part of the jets, which leads to enhanced temperature
or heating due to ion-neutral collisions. Simulations of jets with an
inverted-Y shape and their heating may explain the properties of some
jets observed in the solar atmosphere.
Title: XMM-Newton observations of PSR J0554+3107: pulsing thermal
emission from a cooling high-mass neutron star
Authors: Tanashkin, A. S.; Karpova, A. V.; Potekhin, A. Y.; Shibanov,
Y. A.; Zyuzin, D. A.
Bibcode: 2022MNRAS.516...13T
Altcode: 2022arXiv220806160T; 2022MNRAS.tmp.2073T
XMM-Newton observations of the middle-aged radio-quiet γ-ray pulsar
J0554+3107 allowed us, for the first time, firmly identify it in
X-rays by detection of pulsations with the pulsar period. In the
0.2-2 keV band, the pulse profile shows two peaks separated by about
a half of the rotation phase with the pulsed fraction of 25 ± 6 per
cent. The profile and spectrum in this band can be mainly described by
thermal emission from the neutron star with the hydrogen atmosphere,
dipole magnetic field of ~1013 G, and non-uniform surface
temperature. Non-thermal emission from the pulsar magnetosphere is
marginally detected at higher photon energies. The spectral fit with the
atmosphere+power-law model implies that J0554+3107 is a rather heavy
and cool neutron star with the mass of 1.6-2.1 M⊙, the
radius of ≍13 km, and the redshifted effective temperature of ≍50
eV. The spectrum shows an absorption line of unknown nature at ≍350
eV. Given the extinction-distance relation, the pulsar is located at
≍2 kpc and has the redshifted bolometric thermal luminosity of ≍2
× 1032 erg s-1. We discuss cooling scenarios
for J0554+3107 considering plausible equations of state of superdense
matter inside the star, different compositions of the heat-blanketing
envelope, and various ages.
Title: Phobos and Deimos surface composition: search for spectroscopic
analogues
Authors: Poggiali, Giovanni; Matsuoka, M.; Barucci, M. A.; Brucato,
J. R.; Beck, P.; Fornasier, S.; Doressoundiram, A.; Merlin, F.;
Alberini, A.
Bibcode: 2022MNRAS.516..465P
Altcode: 2022MNRAS.tmp.2133P
Phobos and Deimos, the two satellites of Mars, were largely studied in
the past using ground-based telescope and spacecraft data, although
most of the data were obtained by opportunity observations performed
by Mars dedicated orbiters. Despite the data available so far, the
main composition of the two moons is not yet fully understood. The
possible presence of hydrated minerals along with mafic minerals olivine
and pyroxene seems to be the most plausible interpretation, but more
investigations are needed. MIRS spectrometer on-board the future JAXA
MMX sample return mission will help to unveil the open question on
the composition of Phobos and Deimos. In this work, we review past
spectroscopic observations of the Martian moons, both from ground
observatories and spacecraft data set, aiming at better understanding
the constraints in interpreting the Mars satellites composition and
at identifying the best spectroscopic analogues. We also present new
laboratory measurements on mineral mixing and meteorites to match
the satellites spectral behaviour. New measurements were acquired
at INAF-Astrophysical Observatory of Arcetri and IPAG laboratories
at room conditions exploring different geometries and the results
obtained set new constraints for future laboratory measurements. Our
preliminary results confirm that the surface of Phobos and Deimos
can be associated with samples characterized by a higher presence
of dark components (e.g. amorphous carbon) or minerals produced by
space weathering (e.g. Fe0 and FeS-bearing materials). Presence of
dark component could also be totally responsible for the reduced
hydrated band observed on the moons without invoking dehydration or
OH-implantation on anhydrous surface.
Title: The Pierre Auger exotic events and axion quark nuggets
Authors: Zhitnitsky, Ariel
Bibcode: 2022JPhG...49j5201Z
Altcode: 2022arXiv220308160Z
The Pierre Auger observatory have reported (Abreu et al 2021 PoS
ICRC2021 p 395; Colalillo 2019 EPJ Web Conf. 197 03003; Colalillo
2017 PoS ICRC2017 p 314) observation of several exotic cosmic ray
(CR)-like events which apparently related to thunderstorms. These
events are much larger in size than conventional CR events, and they
have very distinct timing features. A possible nature of the observed
phenomenon is still a matter of active research and debates as many
unusual features of these exotic events (EEs) are hard to explain. In
particular, the frequency of appearance of these EEs is very low (less
than 2 events yr-1), in huge contrast with a typical rate
of a conventional lightning strikes in the area. We propose that the
observed EEs can be explained within the so-called axion quark nugget
(AQN) dark matter model. The idea is that the AQNs may trigger and
initiate a special and unique class of lightning strikes during a
thunderstorm as a result of ionization of the atmospheric molecules
along its path. The corresponding AQN-induced lighting flashes may show
some specific features not shared by typical and much more frequent
conventional flashes. We support this proposal by demonstrating that
the observations (Abreu et al 2021 PoS ICRC2021 p 395; Colalillo 2019
EPJ Web Conf. 197 03003; Colalillo 2017 PoS ICRC2017 p 314), including
the frequency of appearance and time duration are consistent with
observations. We also comment on possible relation of AUGER EEs with
the Telescope Array bursts and the terrestrial gamma ray flashes. We
list a number of features of the AQN-induced EEs (such as specific radio
pulses synchronized with these events) which can be directly tested by
future experiments. We also suggest to use distributed acoustic sensing
instruments to detect the acoustic pulses which must be synchronized
with AUGER EEs.
Title: Fuzzy dark matter and the Dark Energy Survey Year 1 data
Authors: Dentler, Mona; Marsh, David J. E.; Hložek, Renée; Laguë,
Alex; Rogers, Keir K.; Grin, Daniel
Bibcode: 2022MNRAS.515.5646D
Altcode: 2021arXiv211101199D; 2022MNRAS.tmp.1977D
Gravitational weak lensing by dark matter haloes leads to a measurable
imprint in the shear correlation function of galaxies. Fuzzy dark
matter (FDM), composed of ultralight axion-like particles of mass m ~
10-22 eV, suppresses the matter power spectrum and shear
correlation with respect to standard cold dark matter. We model the
effect of FDM on cosmic shear using the optimized halo model HMCODE,
accounting for additional suppression of the mass function and halo
concentration in FDM as observed in N-body simulations. We combine Dark
Energy Survey Year 1 (DES-Y1) data with the Planck cosmic microwave
background anisotropies to search for shear correlation suppression
caused by FDM. We find no evidence of suppression compared to the
preferred cold dark matter model, and thus set a new lower limit to
the FDM particle mass. Using a log-flat prior and marginalizing over
uncertainties related to the non-linear model of FDM, we find a new,
independent 95 per cent C.L. lower limit log10m > -23
combining Planck and DES-Y1 shear, an improvement of almost two orders
of magnitude on the mass bound relative to CMB-only constraints. Our
analysis is largely independent of baryonic modelling, and of previous
limits to FDM covering this mass range. Our analysis highlights
the most important aspects of the FDM non-linear model for future
investigation. The limit to FDM from weak lensing could be improved
by up to three orders of magnitude with $\mathcal {O}(0.1)$ arcmin
cosmic shear angular resolution, if FDM and baryonic feedback can be
simultaneously modelled to high precision in the halo model.
Title: The infrared behavior of tame two-field cosmological models
Authors: Babalic, Elena Mirela; Lazaroiu, Calin Iuliu
Bibcode: 2022NuPhB.98315929B
Altcode: 2022arXiv220302297M
We study the first order infared behavior of tame hyperbolizable
two-field cosmological models, defined as those classical two-field
models whose scalar manifold is a connected, oriented and topologically
finite hyperbolizable Riemann surface (Σ , G) and whose scalar
potential Φ admits a positive and Morse extension to the end
compactification of Σ. We achieve this by determining the universal
forms of the asymptotic gradient flow of the classical effective
potential V with respect to the uniformizing metric G near all interior
critical points and ends of Σ, finding that some of the latter act
like fictitious but exotic stationary points of the gradient flow. We
also compare these results with numerical studies of cosmological
orbits. For critical cusp ends, we find that cosmological curves
have transient quasiperiodic behavior but are eventually attracted
or repelled by the cusp along principal geodesic orbits determined
by the extended effective potential. This behavior is approximated in
the infrared by that of gradient flow curves near the cusp.
Title: A large range of haziness conditions in hot-Jupiter atmospheres
Authors: Arfaux, Anthony; Lavvas, Panayotis
Bibcode: 2022MNRAS.515.4753A
Altcode: 2022MNRAS.tmp.1720A; 2022arXiv220613134A
We present a study of photochemical hazes of exoplanet atmospheres
based on a self-consistent model including haze microphysics,
disequilibrium chemistry, and radiative feedbacks. We derive
the haze properties required to match Hubble Space Telescope
observations of 10 hot-Jupiters. HAT-P-12b, HD-189733b, HD-209458b,
and WASP-6b require haze mass fluxes between 5 × 10-15
and 9 × 10-12 g cm-2 s-1 to match
the observations. WASP-12b and WASP-19b with equilibrium temperatures
above 2000 K are incompatible with the presence of haze and are better
fitted by heavy metals. HAT-P-1b and WASP-31b do not show clear evidence
for the presence of hazes with upper mass fluxes of 10-15
and 10-16 g cm-2 s-1, respectively,
while WASP-17b and WASP-39b present an upper mass flux limit of
10-16 g cm-2 s-1. We discuss the
implications of the self-consistent model and we derive upper limits for
the haze abundances based on photochemistry results. Our results suggest
HCN as the main haze precursor up to 1300 K effective temperatures
and CO above. Our derived haze mass fluxes based on the fit to the
observations are consistent with the photochemistry with formation
yields up to ~6.4 per cent. Disequilibrium chemistry has negligible
impact on the spectra considering the low-resolution observations used
but impacts the chemical composition and temperature profiles. We
find that hazes produce hotter upper atmosphere temperatures with
a detectable impact on the spectra. Clouds may have implications
for interpreting the transit spectra of HD-209458b, WASP-31b, and
WASP-39b. Nevertheless, the presence of silicate and iron clouds is
expected in all studied atmospheres except WASP-12b and WASP-19b.
Title: Acoustic neutrino detection in a Adriatic multidisciplinary
observatory (ANDIAMO)
Authors: Marinelli, Antonio; Migliozzi, Pasquale; Simonelli, Andreino
Bibcode: 2022APh...14302760M
Altcode: 2021arXiv210915199M
The existence of cosmic accelerators able to emit charged particles up
to ZeV energies has been confirmed by the observations made in the last
years by experiments such as Auger and Telescope Array. The interaction
of such energetic cosmic-rays with gas or low energy photons,
surrounding the astrophysical sources or present in the intergalactic
medium, guarantee an ultra-high-energy neutrino related emission. When
these energetic neutrinos interact in a medium produce a thermo-acoustic
process where the energy of generated particle cascades can be conveyed
in a pressure pulse propagating into the same medium. The kilometric
attenuation length as well as the well-defined shape of the expected
pulse suggest a large-area-undersea-array of acoustic sensors as an
ideal observatory. For this scope, we propose to exploit the existing
and no more operative offshore (oil rigs) powered platforms in the
Adriatic sea as the main infrastructure to build an acoustic submarine
array of dedicated hydrophones covering a surface area up to 10000
km2 and a volume up to 500 km3. In this work we
describe the advantages of this detector concept using a ray tracing
technique as well as the scientific goals linked to the challenging
purpose of observing for the first time ultra-high-energy cosmic
neutrinos. This observatory will be complementary to the dedicated
radio array detectors with the advantages of avoiding any possible
thermo-acoustic noise from the atmospheric muons.
Title: Composition and possible origins of dark crater ejecta
on Europa
Authors: Tomlinson, Tara C.; Hayne, Paul O.
Bibcode: 2022Icar..38515037T
Altcode:
The origins of low-albedo material on Europa's surface have been of
interest since Voyager first returned close-up images of the icy
moon. Material ejected from Io is known to contribute an exogenic
flux of dark material to Europa's trailing hemisphere, and hydrated
salt compounds concentrated within chaos terrain, ridges, and
pits may be endogenous to the subsurface ocean. Many of Europa's
impact craters also exhibit dark ejecta, the origins of which are
unknown. Our study examines the ejecta of several large impact craters
to determine possible origins for this dark material. We compared the
dark material found in crater ejecta to other surface materials using
Galileo Near-Infrared Mapping Spectrometer data to assess similarities
in composition between ejecta material and other dark materials on
Europa's surface. Our analysis shows that dark material found in crater
ejecta has similar composition to other dark features on Europa and may
be the result of comparable sources or alteration processes. We also
considered dark impactors as sources for the dark ejecta material. Using
crater scaling laws, we estimated the impactor size for each crater and
determined the impactor's potential contribution of dark material to
the ejecta. We then compared these quantities to those derived using a
radiative transfer model and the measured reflectance values of each
dark-ejecta crater. Our model results show that the lower albedo of
the ejecta of these craters cannot be solely attributed to an intimate
mixture of the impactor material with the target material. In contrast,
modeled impact heating and vaporization suggest sufficient amounts
of ice could be removed in order to explain the observed low-albedo
patterns, if preexisting or impactor-derived dark material is just
0.1% more resistant to vaporization than the ice. Given the lack of
spatial correlation, and the presence of similar-sized craters without
dark ejecta, these results point to either localized differences in
the concentration of dark non-ice materials in Europa's shell, or
variations in impact velocities and geometries leading to differences
in the amount of vaporized ejecta.
Title: Dissolved aluminium dynamics in response to dust storms,
wet deposition, and sediment resuspension in the Gulf of Aqaba,
northern Red Sea
Authors: Benaltabet, Tal; Lapid, Gil; Torfstein, Adi
Bibcode: 2022GeCoA.335..137B
Altcode:
Dissolved aluminium (Al) is a primary tracer of atmospheric deposition
to the open ocean. However, the impact of short-term environmental
perturbations such as dust storms, sediment resuspension and rainfall
events on the oceanic water column is poorly constrained due to the
typically low temporal resolution sampling in open ocean settings. The
Gulf of Aqaba (GoA), northern Red Sea, is a highly accessible deep
oligotrophic water body featuring exceptionally high atmospheric
deposition fluxes delivered by dust storms, which constitutes as
the main terrigenous input to the GoA surface water. Here, we
present a time series of dissolved Al and silicate (Si) concentration
profiles sampled during 2017 and 2018, with a particular focus on
daily time scale dust storms, episodes of sediment resuspension and
rain events. We evaluate the results in conjunction with high temporal
resolution measurements of airborne aerosols and sediment trap -based
water column sinking particulate fluxes. Dissolved Al and Si
concentrations ranged between 22 and 91 nmol kg-1 and 0.6 and
3.2 μmol kg-1, respectively. These two elements correlated
at depth but decoupled in the upper water column. Counter intuitively,
mixed layer Al (AlML) inventories decrease with increasing
aerosol loads, with dust storms promoting intense Al scavenging,
causing scavenging rates to surpass dissolution rates and abruptly
driving down AlML by up to 14 %. Concurrently, post dust
storm AlML change rates increase linearly with increasing
theoretical dissolution rates and thus net dissolution is predicted for
higher dust loads than observed in this study. However, low seawater
particle loads during low magnitude dust storms and deep mixing depths
will result in conditions that favor scavenging. Similarly, a sediment
resuspension event triggered a decrease of 34 % in the Al water column
inventory. By contrast, wet deposition may enhance the soluble Al
flux from mineral dust by a factor of 11. Atmospheric deposition
flux estimates (29.8 ± 4.4 g m-2 year-1)
calculated using long-term average AlML and mixed layer
depths agree with independent flux estimations. Conversely, fluxes
calculated using discrete profiles yielded a wide range of values
(8-93 g m-2 year-1). The combined results
demonstrate that atmospheric deposition in the oceans acts as a
long-term source for Al while concomitantly serving as a short-term
sink through scavenging. The in-situ rates and insights presented
here may be used to understand and quantify the true impact of abrupt
environmental events on water column chemical compositions.
Title: Mechanism of olivine and glass alteration under experimental
H2O-CO2 based supercritical gas: Application
to modern and ancient Venus
Authors: Esvan, Jérôme; Berger, Gilles; Fabre, Sébastien; Bêche,
Eric; Thébault, Yannick; Pages, Alain; Charvillat, Cédric
Bibcode: 2022GeCoA.335..124E
Altcode:
Extreme conditions encountered in some geological contexts (deep
serpentinization, interaction of Venus atmosphere with its basaltic
surface, volcanic degassing) activate mechanisms and rates of
silicate alteration that are poorly understood. In the present study,
we investigate the mechanisms of mineral reactions in a natural
geological system at high temperature, under conditions where the
low solvation of cations by fluids likely promotes surface reactions
such as surface diffusion and/or local recrystallization. We focus on
vitreous glasses and olivine, reputed to be the most alterable phases
in volcanic rocks, by reacting samples for one week in a Ni-based alloy
experimental vessel. For the framework of our experimental study, we
chose to apply the deep atmosphere conditions on Venus: 470 °C and 90
bar of reconstituted Venus-like gas. We also tested the effect of water
(Early Venus or wet volcanic degassing) by adding water vapor at up to
320 bar total pressure. The mineral reactions affecting the samples
were identified by a set of spectroscopic surface analyses of the
altered samples: Scanning Electron Microscopy, Energy Dispersive X-ray
Spectroscopy, X-ray Diffraction in grazing incidence mode, X-ray Photo
electron Spectroscopy and Raman spectroscopy. Samples of obsidian
and tholeiitic glasses are found to be sensitive to a threshold water
pressure, depending on glass composition, below which the reaction is
limited to some elemental mobility in the glass (alkali enrichment,
calcium loss) leading to a possibly more stable surface layer of tens
to hundreds of microns. Above this threshold water pressure (ca. 50
bar H2O for the obsidian but >250 bar H2O
for the tholeiitic glass), water promotes the depolymerization of the
glass and the crystallization of stable minerals. This crystalline rim
is less protective that the chemically modified layer. Olivine
samples react differently depending on whether the olivine is isolated
or included in a basaltic rock. In the latter case only, iron coatings
are formed, which are identified as hematite, suggesting that this
phase is not fed by olivine itself but rather by surface diffusion
from neighboring Fe-rich phases. This supports the conclusions
from experimental studies and orbital observations on the short-term
visibility of unaltered olivine in Venus lava flows: such a coating is
enhanced when Fe-bearing minerals are in the proximity of olivine. Under
high water vapor pressure, Fe-bearing talc (and not serpentine) forms
by a likely topotactic reaction that also incorporates silica from
the gas. This talc layer may form a protective layer, implying that
serpentinization of ultramafic rocks at high temperature may not be
as prevalent as one might think in a gas-dominated system like the
Early Venus surface.
Title: Effect of radiation drag on the line-force-driven winds
Authors: Wang, Bei-Chuan; Yang, Xiao-Hong; Bu, De-Fu; Huang, Shu-Su
Bibcode: 2022MNRAS.515.5594W
Altcode: 2022arXiv220801210W; 2022MNRAS.tmp.2119W
Ultra-fast outflows (UFOs) with mildly relativistic velocities are
measured using the X-ray spectra of radio-quiet and -loud active
galactic nuclei. In general, UFOs are believed to be generated from
the accretion disc around a black hole. A line-force driving model
is suggested to be the mechanism to drive UFOs from the accretion
disc. In this paper, we use the non-hydrodynamic approach to examine
the influences of radiation-drag effects on the line-force-driven
winds generated from the accretion disc. We find that the
radiation-drag effects can significantly weaken the line-force-driven
winds. Compared with the case without the radiation-drag effects,
when the radiation-drag effects are considered, the maximum speed of
winds is reduced by ~60 per cent-70 per cent, the mass outflow rate is
reduced by ~50 per cent-80 per cent, and the kinetic power is reduced
by about an order of magnitude. The radiation-drag effects narrow the
area where the winds are generated.
Title: On the relation between asymptotic charges, the failure of
peeling and late-time tails
Authors: Gajic, Dejan; Kehrberger, Leonhard M. A.
Bibcode: 2022CQGra..39s5006G
Altcode: 2022arXiv220204093G
The last few years have seen considerable mathematical progress
concerning the asymptotic structure of gravitational radiation in
dynamical, astrophysical spacetimes. In this paper, we distil some
of the key ideas from recent works and assemble them in a new way
in order to make them more accessible to the wider general relativity
community. In the process, we also discuss new physical findings. First,
we introduce the conserved f(r)-modified Newman-Penrose charges
on asymptotically flat spacetimes, and we show that these charges
provide a dictionary that relates asymptotics of massless, general spin
fields in different regions: asymptotic behaviour near i +
('late-time tails') can be read off from asymptotic behaviour towards
${\mathcal{I}}^{+}$ , and, similarly, asymptotic behaviour towards
${\mathcal{I}}^{+}$ can be read off from asymptotic behaviour near
i - or ${\mathcal{I}}^{-}$ . Using this dictionary, we
then explain how: (I) the quadrupole approximation for a system of
N infalling masses from i - causes the 'peeling property
towards ${\mathcal{I}}^{+}$ ' to be violated, and (II) this failure
of peeling results in deviations from the usual predictions for tails
in the late-time behaviour of gravitational radiation: instead of the
Price's law rate $r{{\Psi}}^{[4]}{\vert }_{{\mathcal{I}}^{+}}\sim
{u}^{-6}$ as u → ∞, we predict that $r{{\Psi}}^{[4]}{\vert
}_{{\mathcal{I}}^{+}}\sim {u}^{-4}$ , with the coefficient of this
latter decay rate being a multiple of the monopole and quadrupole
moments of the matter distribution in the infinite past.
Title: Enrichment and sources of REY in phosphate fractions:
Constraints from the leaching of REY-rich deep-sea sediments
Authors: Ren, Jiangbo; Jiang, Xuexiao; He, Gaowen; Wang, Fenlian;
Yang, Tianbang; Luo, Shuaijie; Deng, Yinan; Zhou, Jianhou; Deng,
Xiguang; Yao, Huiqiang; Yu, Hongxia
Bibcode: 2022GeCoA.335..155R
Altcode:
Rare earth elements and yttrium (REY)-rich deep-sea sediments, regarded
as a potential resource, have triggered extensive investigations over
the last decade. The conclusion that the REY enrichment is closely
related to the phosphate components contradicts the low REY content
(ΣREY) of marine phosphorites, leading to questions about the control
of deep-sea phosphate on the enrichment and cycling of REY. Herein,
we performed a series of chemical leaching experiments on a group of
REY-rich samples (up to 5983 ppm) from two sediment cores obtained from
the Pigafetta Basin in the western Pacific to investigate the phosphate
and non-phosphate fractions. We found that phosphate components in
deep-sea sediments, termed REY-rich phosphates, contain a mean ΣREY of
27,635 ppm and ΣREY/P2O5 of >0.75, which are
1-2 orders of magnitude higher than that of marine phosphorites. The
87Sr/86Sr (0.7083-0.7092) and εNd
(-6.41 to -5.15) of the phosphate fractions exhibited strong
terrigenous attributes and fell within the range of that of bottom
water since 25 Ma. Notably, the non-phosphate components, primarily
phillipsite and clay, exhibited stronger terrigenous attributes,
confirming extremely low sedimentation rate in the study area. The
development and accumulation of REY-rich phosphate, as a consequence of
low sedimentation rate in deep water together with erosion and sorting
by bottom current, control the content and patterns of REY in deep-sea
sediments. Fe-Mn oxides that migrated to the seafloor from the water
column were limited and consumed less REY, although their strong Ce
enrichment led to the loss of Ce in seawater. The phosphate components
in sediments inherited the primary REY pattern of seawater and became
the major REY budget on the seabed. In this study, we propose that the
mineralization during the sinking of biological particles not only
controls the REY distribution in the water column but also becomes
an important REY source migration to the seabed and rapidly releases
at the sediment-water interface. Consequently, REY can be effectively
concentrated by the phosphate components under low sedimentation rates,
yielding weak fractionated seawater REY patterns with lower Y/Ho ratios.
Title: Erratum: Circular polarimetry of suspect wind-accreting
magnetic pre-polars
Authors: Hakala, Pasi; Parsons, Steven G.; Marsh, Thomas R.; Gänsicke,
Boris T.; Ramsay, Gavin; Schwope, Axel; Hermes, J. J.
Bibcode: 2022MNRAS.516.1501H
Altcode:
No abstract at ADS
Title: Aging and rejuvenation during high-temperature deformation
in a metallic glass
Authors: Zhang, Langting; Wang, Yunjiang; Yang, Yong; Qiao, Jichao
Bibcode: 2022SCPMA..6506111Z
Altcode:
High-temperature deformation has been demonstrated as an effective
measure to rejuvenate and optimize the mechanical properties of
metallic glasses (MGs). Clarifying the competition between aging
and rejuvenation during high-temperature deformation is helpful in
rejuvenating MGs accurately. Signatures of aging and rejuvenation in a
La30Ce30Ni10Al20Co10
MG were investigated via high-temperature deformation and mechanical
relaxation. The coupling of thermal history, aging, and mechanical
disordering determines the transient deformation and the structural
state of MGs. The stress overshoot and anelastic deformation induce
structural rejuvenation, increasing the concentration of defects
and erasing thermal history. Therefore, the eventually steady-state
condition is dependent on ambient temperature and strain rate instead
of the initial structure. Furthermore, the one-to-one relationship
between defect concentration and strain rate clarifies the structural
nature of rejuvenation in amorphous materials. Such a relationship
also contributes toward a comprehensive understanding of the structural
rejuvenation behavior in amorphous materials.
Title: Revision of Faraday rotation measure constraints on the
primordial magnetic field using the IllustrisTNG simulation
Authors: Arámburo-García, Andrés; Bondarenko, Kyrylo; Boyarsky,
Alexey; Neronov, Andrii; Scaife, Anna; Sokolenko, Anastasia
Bibcode: 2022MNRAS.515.5673A
Altcode: 2022arXiv220405918A; 2022MNRAS.tmp.1970A
Previously derived Faraday rotation constraints on the volume-filling
intergalactic magnetic field (IGMF) have used analytical models that
made a range of simplifying assumptions about magnetic field evolution
in the intergalactic medium and did not consider the effect of baryonic
feedback on large-scale structures. In this work, we revise existing
Faraday rotation constraints on the IGMF using a numerical model of
the intergalactic medium from the IllustrisTNG cosmological simulation
that includes a sophisticated model of the baryonic feedback. We use
the IllustrisTNG model to calculate the rotation measure and compare
the resulting mean and median of the absolute value of the rotation
measure with data from the NRAO VLA Sky Survey (NVSS). The numerical
model of the intergalactic medium includes a full magnetohydrodynamic
model of the compressed primordial magnetic field as well as a
model of the regions where the magnetic field is not primordial, but
is rather produced by the process of baryonic feedback. Separating
these two types of regions, we are able to assess the influence of the
primordial magnetic field on the Faraday rotation signal. We find that
by correcting for regions of compressed primordial field and accounting
for the fact that part of the intergalactic medium is occupied by
magnetic fields spread by baryonic feedback processes rather than by
the primordial field relaxes the Faraday rotation bound by a factor
of ≃3. This results in B0 < 1.8 × 10-9
G for large correlation length IGMFs.
Title: The first photometric analysis study of the GW Psc binary
system
Authors: Tanrıver, Mehmet; Bulut, Ahmet
Bibcode: 2022NewA...9601848T
Altcode:
The first photometric solution in the B , V ,Rc and
Ic filters of the short period GW Psc eclipsing binary is
presented based on new ground-based CCD photometric observations. We
analysed the BVRI photometric light curves of the system, using
Phoebe0.31a, a binary star modelling program, with the Wilson and
Devinney (Wilson and Devinney (1971); Wilson (1979) method based on
Roche geometry to achieve the best accordance to the photometric
observations to estimate their absolute parameters from the light
curves. We updated the ephemeris of GW Psc using two new light curve
minima derived by our new observational data from those collected in the
literature and analysed the change of the system's orbital period. The
O-C plot suggests the presence of a companion. The distance of GW Psc
are 318 . 4 ± 19 . 4 pc . From the solutions, we find that GW Psc is
A-subtype W UMa over-contact binaries with q = 0 . 399 mass ratios
and f = 0 . 21 fill-out factor. The likely HR diagram positions of
the eclipsing binary system's components are discussed. The system's
estimated absolute dimensions were compared to those of similar binaries
in the logTeff - logL , logM - logL , logM - logR and logM -
logJ0 diagrams.
Title: The effect of external pressure & magnetic field in star
formation: The critical mass model
Authors: Kumssa, Gemechu M.; Tessema, S. B.
Bibcode: 2022NewA...9601854K
Altcode:
Theoretical work addressing the role of external pressure with magnetic
fields in collapsing molecular clouds is important in building
a comprehensive theory of star formation(SF). In many SF studies
turbulence, magnetic fields, and self-gravity are described as the
key dynamical processes involved in SF. However, the importance of
external pressure in collapsing strongly magnetized clouds has not yet
been particularly explained. Magnetic fields transport excess angular
momentum from the central core while external pressure compresses the
cloud. Thus the outflow of angular momentum, and on the other hand, the
compression made by external pressure are the cause for matter falling
onto the central core from the envelope. Therefore, external pressure
facilitates the collapse of gas and the inflow of matter. In this work,
we show theoretically how the strong magnetic field is dragged inward
by the external pressure during the core collapse and formulate the
critical mass of the core in the presence of external pressure.
Title: WISE-PS1-STRM: neural network source classification and
photometric redshifts for WISE×PS1
Authors: Beck, Róbert; Dodds, S. Curt; Szapudi, István
Bibcode: 2022MNRAS.515.4711B
Altcode: 2022MNRAS.tmp.1739B
We cross-match between the WISE All-Sky and PS1 3π DR2 source
catalogues. The resulting catalogue has 354 590 570 objects,
significantly fewer than the parent PS1 catalogue, but its combination
of optical and infrared colours facilitate both better source
classification and photometric redshift estimation. We perform a
neural network-based classification of the objects into galaxies,
quasars, and stars, then run neural network-based photometric redshift
estimation for the galaxies. The star sample purity and quasar sample
completeness measures improve substantially, and the resulting photo-z's
are significantly more accurate in terms of statistical scatter and
bias than those calculated from PS1 properties alone. The catalogue
will be a basis for future large-scale structure studies, and will
be made available as a high-level science product via the Mikulski
Archive for Space Telescopes.
Title: Broadband spectro-temporal study on blazar TXS 1700+685
Authors: Banerjee, Anuvab; Nandi, Prantik; Prince, Raj; Khatoon,
Rukaiya; Bose, Debanjan
Bibcode: 2022MNRAS.515.4675B
Altcode: 2022arXiv220302672B; 2022MNRAS.tmp.1948B
We attempt to present a multiwavelength variability and correlation
study as well as detailed multiwaveband spectral characteristics of
the May 2021 gamma-ray flare of the blazar source TXS 1700+685. The
multiwavelength observation from Fermi-LAT, Swift-XRT/UVOT as
well as radio archival data are used for our spectro-temporal
investigation. We estimate the variability time-scale of the source
from the flux doubling time in different flaring region detected in
Fermi-LAT observation and the shortest variability time is used to
put a constraint on the minimum Doppler factor and on the size of
the emission region. We have detected a statistically significant
quasi-periodic oscillation feature at ~17 d. The broad-band emission
is satisfactorily represented during its flaring state with a leptonic
synchrotron and inverse Compton component. From the broad-band spectral
modelling, we observe the external Comptonization of the seed photons
originating in the broad-line region to be dominant compared to the
dusty torus. The equipartition value implies the energy density of the
magnetic field in the jet comoving frame is weak. In order to produce
the high-energy hump, we need the injection of a large population of
high-energy electrons and/or the presence of strong magnetic field;
and we observe the later component to be subdominant in our case. The
gamma-ray spectral energy distribution shows the flat rising and steep
falling profile, as well as the break or spectral curvature at ~1 GeV,
which has been seen for other flat-spectrum radio quasar sources before.
Title: Photohadronic interpretations of the different incarnations
of 1ES 2344+514
Authors: Sahu, Sarira; Valadez Polanco, Isabel Abigail; Rajpoot,
Subhash
Bibcode: 2022MNRAS.515.5235S
Altcode: 2022arXiv220713932S
Since its discovery in 1995, the high-energy peaked blazar 1ES
2344+514 has undergone several episodes of GeV-TeV flaring and has been
observed in the multiwavelength by several telescopes. The observed
X-ray spectrum of 1996 and the flaring event of 2016 establish that
1ES 2344+514 has a temporary behaviour like that of an extremely
high-energy peaked BL Lacertae object (EHBL). Such behaviour has also
been observed in several nearby high-energy peaked blazars. We use the
photohadronic model to account for the GeV-TeV flaring observed events
of 1995 and 2007. Also, a recently proposed two-zone photohadronic
model, which is successful in explaining the multi-TeV flaring events
of many transient EHBL-like sources, is employed to explain the GeV-TeV
flaring spectra of MJD 57611 and MJD 57612. We find that the zone-2
parameters of the two-zone photohadronic model play a central role in
explaining these spectra. This is probably an indication of a new type
of transient EHBL-like source. We find that our fits to the observed
spectra are comparable or better than the other leptonic and hadronic
models employed in the literature to address the same issue.
Title: Complementary astrometry of Cassini Imaging Science Subsystem
images of phoebe
Authors: Zhang, Q. F.; Qin, W. H.; Ma, Y. L.; Lainey, V.; Cooper,
N. J.; Rambaux, N.; Li, Y.; Zhu, W. H.
Bibcode: 2022P&SS..22105553Z
Altcode: 2022arXiv220810345Z
Phoebe is the only major satellite of Saturn with a retrograde
orbit. The Cassini Imaging Science Subsystem (ISS) took a lot of
Phoebe images between 2004 and 2017, but only a selection of them has
been reduced. In this paper, we reduced the remaining ISS images of
Phoebe. In the reduction, the Gaia EDR3 catalogue was used to provide
the reference stars' positions, and the modified moment was used to
measure the centre of image stars and Phoebe. Finally, a total of
834 ISS images of Phoebe have been reduced successfully. Compared
with the JPL ephemeris SAT375, Phoebe's positions are consistent. The
average residuals in the right ascension and declination are 0.08″
and -0.05'', and the standard deviations of the residuals are about
0.2''. In terms of residuals in linear units, the means in the right
ascension and declination are about 5 km and -2 km, respectively; The
standard deviations are about 11 km. Compared with the JPL ephemeris
SAT427 and IMCCE ephemeris PH20, our measurements show a strong bias
and a large dispersion.
Title: Kasner metrics and very special geometry
Authors: Sabra, W. A.
Bibcode: 2022PhLB..83337380S
Altcode: 2022arXiv220600467S
We consider general charged Kasner-like solutions for the theory of
five-dimensional supergravity coupled to Abelian vector multiplets
in arbitrary space-time signature. These solutions, depending on
the choice of coordinates, can be thought of as generalisations of
Melvin/Rosen cosmologies, flux-branes and domain walls.
Title: Probing the z ≳ 6 quasars in a universe with IllustrisTNG
physics: impact of gas-based black hole seeding models
Authors: Bhowmick, Aklant K.; Blecha, Laura; Ni, Yueying; Matteo,
Tiziana Di; Torrey, Paul; Kelley, Luke Zoltan; Vogelsberger, Mark;
Weinberger, Rainer; Hernquist, Lars
Bibcode: 2022MNRAS.516..138B
Altcode: 2022arXiv220505717B; 2022MNRAS.tmp.2146B
We explore implications of a range of black hole (BH) seeding
prescriptions on the formation of the brightest $z$ ≳ 6 quasars in
cosmological hydrodynamic simulations. The underlying galaxy formation
model is the same as in the IllustrisTNG simulations. Using constrained
initial conditions, we study the growth of BHs in rare overdense regions
(forming $\gtrsim 10^{12}\, {\rm M}_{\odot }\,h^{-1}$ haloes by $z$
= 7) using a (9 Mpc h-1)3 simulated volume. BH
growth is maximal within haloes that are compact and have a low
tidal field. For these haloes, we consider an array of gas-based
seeding prescriptions wherein $M_{\mathrm{seed}}=10^4\!-\!10^6\,
{\rm M}_{\odot }\,h^{-1}$ seeds are inserted in haloes above
critical thresholds for halo mass and dense, metal-poor gas mass
(defined as $\tilde{M}_{\mathrm{h}}$ and $\tilde{M}_{\mathrm{sf,mp}}$,
respectively, in units of Mseed). We find that a seed model
with $\tilde{M}_{\mathrm{sf,mp}}=5$ and $\tilde{M}_{\mathrm{h}}=3000$
successfully produces a $z$ ~ 6 quasar with $\sim 10^9\, {\rm M}_{\odot
}$ mass and ~1047 erg s-1 luminosity. BH mergers
play a crucial role at $z$ ≳ 9, causing an early boost in BH mass
at a time when accretion-driven BH growth is negligible. With more
stringent seeding conditions (e.g. $\tilde{M}_{\mathrm{sf,mp}}=1000$),
the relative paucity of BH seeds results in a much lower merger
rate. In this case, $z$ ≳ 6 quasars can only be formed if we enhance
the maximum allowed BH accretion rates (by factors ≳10) compared
to the accretion model used in IllustrisTNG. This can be achieved
either by allowing for super-Eddington accretion, or by reducing the
radiative efficiency. Our results demonstrate that progenitors of $z$
~ 6 quasars have distinct BH merger histories for different seeding
models, which will be distinguishable with Laser Interferometer Space
Antenna observations.
Title: Low spin-axis variations of circumbinary planets
Authors: Chen, Renyi; Li, Gongjie; Tao, Molei
Bibcode: 2022MNRAS.515.5175C
Altcode: 2022arXiv220800018C; 2022MNRAS.tmp.1961C
Having a massive moon has been considered as a primary mechanism
for stabilized planetary obliquity, an example of which being our
Earth. This is, however, not always consistent with the exoplanetary
cases. This article details the discovery of an alternative mechanism,
namely that planets orbiting around binary stars tend to have low
spin-axis variations. This is because the large quadrupole potential of
the stellar binary could speed up the planetary orbital precession, and
detune the system out of secular spin-orbit resonances. Consequently,
habitable zone planets around the stellar binaries in low inclination
orbits hold higher potential for regular seasonal changes comparing
to their single star analogues.
Title: Force-free magnetic flux ropes: String confinement of
super-strong magnetic fields and flare energy release
Authors: Solov'ev, A. A.
Bibcode: 2022MNRAS.515.4981S
Altcode:
A new class of force-free solutions for a horizontal magnetic filament
with a circular cross-section is found, in which the magnetic field
strength on the axis significantly (up to 2-3 orders of magnitude and
more) exceeds the strength of the longitudinal external field that keeps
the rope from lateral expansion. A weak transverse field leads to a
small deviation from the force-free field structure and results in a
density deficit and an increase in temperature on the rope axis. The
possibility of a flare release of magnetic energy is shown when
critical values of the longitudinal electric current density in
the filament are reached at which 'anomalous resistance' occurs, caused
by the development of the current ion-sound plasma instability. It turns
out to be much larger than the usual Coulomb resistance. The following
values are determined: the scale of the current dissipation region,
the electric field strength in it, which significantly exceeds the
Dreicer value, and the possible energy of accelerated charged particles
(up to hundreds of MeV). The critical density of the longitudinal
current at which the plasma turbulence is excited does not depend
on the presence of a super-strong field on the flux-rope axis, so
that the current density depends only on the electron concentration,
temperature, and anomalous conductivity. However, super-strong magnetic
fields can manifest themselves in the fact that, in their presence,
the excitation of plasma instabilities can occur at sufficiently high
electron concentrations. This effect may explain the large number of
accelerated particles sometimes observed in solar flares.
Title: High-contrast imaging of HD 29992 and HD 196385 with the
Gemini Planet Imager
Authors: García, Luciano H.; Petrucci, R.; Jofré, E.; Gómez, M.
Bibcode: 2022MNRAS.515.4999G
Altcode:
Based on high-contrast images obtained with the Gemini Planet Imager
(GPI), we report the discovery of two point-like sources at angular
separations ρ ~ 0.18 and 0.80 arcsec from the stars HD 29992 and HD
196385. A combined analysis of the new GPI observations and images
from the literature indicates that the source close to HD 29992
could be a companion to the star. Concerning HD 196385, the small
number of contaminants (~0.5) suggests that the detected source may be
gravitationally bound to the star. For both systems, we discarded the
presence of other potential companions with m > 75 MJup at
ρ ~ 0.3-1.3 arcsec. From stellar model atmospheres and low-resolution
GPI spectra, we derive masses of ~0.2-0.3 M⊙ for these
sources. Using a Markov-chain Monte Carlo approach, we performed a joint
fit of the new astrometry measurements and published radial velocity
data to characterize the possible orbits. For HD 196385B, the median
dynamic mass is in agreement with that derived from model atmospheres,
whilst for HD 29992B the orbital fit favours masses close to the brown
dwarf regime (~0.08 M⊙). HD 29992 and HD 196385 might be
two new binary systems with M-type stellar companions. However, new high
angular resolution images would help to confirm definitively whether
the detected sources are gravitationally bound to their respective
stars, and permit tighter constraints on the orbital parameters of
both systems.
Title: Systematic light-curve modelling of TDEs: statistical
differences between the spectroscopic classes
Authors: Nicholl, Matt; Lanning, Daniel; Ramsden, Paige; Mockler,
Brenna; Lawrence, Andy; Short, Phil; Ridley, Evan J.
Bibcode: 2022MNRAS.515.5604N
Altcode: 2022arXiv220102649N; 2022MNRAS.tmp.2103N
With the sample of observed tidal disruption events (TDEs) now
reaching several tens, distinct spectroscopic classes have emerged:
TDEs with only hydrogen lines (TDE-H), only helium lines (TDE-He),
or hydrogen in combination with He II and often N III/O III (TDE-H +
He). Here, we model the light curves of 32 optically bright TDEs
using the Modular Open Source Fitter for Transients (MOSFIT) to
estimate physical and orbital properties, and look for statistical
differences between the spectroscopic classes. For all types, we find
a shallow distribution of star masses, compared to a typical initial
mass function, in the range ~0.1-1 M⊙, and no TDEs with
very deep encounters. Our main result is that TDE-H events appear to
come from less complete disruptions (and possibly lower SMBH masses)
than TDE-H+He, with TDE-He events fully disrupted. We also find that
TDE-H events have more extended photospheres, in agreement with recent
literature, and argue that this could be a consequence of differences
in the self-intersection radii of the debris streams. Finally, we
identify an approximately linear correlation between black hole mass
and radiative efficiency. We suggest that TDE-H may be powered by
collision-induced outflows at relatively large radii, while TDE-H +
He could result from prompt accretion discs, formed more efficiently
in closer encounters around more massive SMBHs.
Title: The effect of quasar redshift errors on Lyman-α forest
correlation functions
Authors: Youles, Samantha; Bautista, Julian E.; Font-Ribera, Andreu;
Bacon, David; Rich, James; Brooks, David; Davis, Tamara M.; Dawson,
Kyle; de la Macorra, Axel; Dhungana, Govinda; Doel, Peter; Fanning,
Kevin; Gaztañaga, Enrique; Gontcho A Gontcho, Satya; Gonzalez-Morales,
Alma X.; Guy, Julien; Honscheid, Klaus; Iršič, Vid; Kehoe, Robert;
Kirkby, David; Kisner, Theodore; Landriau, Martin; Le Guillou,
Laurent; Levi, Michael E.; Martini, Paul; Muñoz-Gutiérrez, Andrea;
Palanque-Delabrouille, Nathalie; Pérez-Ràfols, Ignasi; Poppett,
Claire; Ramírez-Pérez, César; Schubnell, Michael; Tarlé, Gregory;
Walther, Michael
Bibcode: 2022MNRAS.516..421Y
Altcode: 2022MNRAS.tmp.2031Y; 2022arXiv220506648Y
Using synthetic Lyman-α forests from the Dark Energy Spectroscopic
Instrument (DESI) survey, we present a study of the impact of errors
in the estimation of quasar redshift on the Lyman-α correlation
functions. Estimates of quasar redshift have large uncertainties of
a few hundred km s-1 due to the broadness of the emission
lines and the intrinsic shifts from other emission lines. We inject
Gaussian random redshift errors into the mock quasar catalogues, and
measure the auto-correlation and the Lyman-α-quasar cross-correlation
functions. We find a smearing of the BAO feature in the radial
direction, but changes in the peak position are negligible. However,
we see a significant unphysical correlation for small separations
transverse to the line of sight which increases with the amplitude
of the redshift errors. We interpret this contamination as a result
of the broadening of emission lines in the measured mean continuum,
caused by quasar redshift errors, combined with the unrealistically
strong clustering of the simulated quasars on small scales.
Title: Resolution of challenging problems in quantum cosmology with
electromagnetic radiation
Authors: Jalalzadeh, S.
Bibcode: 2022PhLB..83337285J
Altcode: 2022arXiv220700727J
We investigate the quantum cosmology of a closed spatially homogeneous
and isotropic Friedmann-Lemaître-Robertson-Walker (FLRW) minisuperspace
model with electromagnetic radiation as matter content. We solve the
corresponding Wheeler-DeWitt equation by utilizing Riemann's zeta
function regularization method. We demonstrate that the regularized
vacuum energy of the electromagnetic field can overcome factor ordering,
boundary conditions, and singularity problems.
Title: Propagation time delay and frame dragging effects of lightlike
geodesics in the timing of a pulsar orbiting SgrA*
Authors: Ben-Salem, Bilel; Hackmann, Eva
Bibcode: 2022MNRAS.516.1768B
Altcode: 2022MNRAS.tmp.2235B
Timing a pulsar in a close orbit around the supermassive black hole
SgrA* at the centre of the Milky Way would open the window for an
accurate determination of the black hole parameters and for new tests
of general relativity and alternative modified gravity theories. An
important relativistic effect which has to be taken into account in the
timing model is the propagation delay of the pulses in the gravitational
field of the black hole. Due to the extreme mass ratio of the pulsar
and the supermassive back hole we use the test particle limit to derive
an exact analytical formula for the propagation delay of lightlike
geodesics in a Kerr space-time, and deduce a relativistic formula for
the corresponding frame dragging effect on the arrival time. As an
illustration, we treat an edge-on orbit in which the frame dragging
effect on the emitted lightlike geodesics is expected to be maximal. We
compare our formula for the propagation time delay with Post-Newtonian
approaches, and in particular with the frame dragging terms derived
in previous works by Wex & Kopeikin and Rafikov & Lai. Our
approach correctly identifies the asymmetry of the frame dragging delay
with respect to superior conjunction, avoids singularities in the time
delay, and indicates that in the Post-Newtonian approach frame dragging
effects on the lightlike pulses are generally slightly overestimated.
Title: A dynamical evolution study of the open clusters: Berkeley 10,
Berkeley 81, Berkeley 89 and Ruprecht 135
Authors: Çakmak, Hikmet; Karataş, Yüksel
Bibcode: 2022NewA...9601833C
Altcode: 2022arXiv220407745C
By utilizing Gaia EDR3 photometric/astrometric data, we studied the
dynamical evolution from the obtained astrophysical, structural
and dynamical parameters of the open clusters (OCs), Berkeley 10
(Be 10), Berkeley 81 (Be 81), Berkeley 89 (Be 89), and Ruprecht 135
(Ru 135). The Gaia EDR3 photometric distances from the isochrone
fitting method are smaller than the ones of Gaia EDR2. The relaxation
times of four OCs are smaller than their ages, in this regard, they
are dynamically relaxed. Their steep overall mass function slopes
mean that their low mass stars outnumber their massive ones. Their
large τ/relatively small trlx values imply an advanced
mass segregation. Therefore, they seem to have lost their low-mass
stars much to the field. Be 89's outer parts indicate an expansion
with time. However, Be 10 and Be 81 show the relatively shrinkage
core/cluster radii due to dynamical evolution. Ru 135 (1.0 Gyr) may
have a primordial origin, instead of shrinking in size and mass with
time. Be 89's tidal radius is less than its cluster radius. This means
that its member stars lie within its tidal radius, in the sense it is
gravitationally bound to the cluster. For the rest OCs, the cluster
members beyond their tidal radii are gravitationally unbound to the
clusters, which are more influenced by the potential of the Galaxy.
Title: An approach to the quasi-equilibrium state of a
self-gravitating system
Authors: Azizi, Azizollah; Khodahami, Amir A.
Bibcode: 2022PhLB..83337334A
Altcode: 2021arXiv210705012A
We propose an approach to find out when a self-gravitating system is
in a quasi-equilibrium state. This approach is based on a comparison
between two quantities identifying behavior of the system: a measure
of interactions intensity and the area. Gravitational scattering cross
section of the system, defined by using the two-particle scattering
cross section formula, is considered as the measure of interactions
intensity here. A quasi-equilibrium state of such system is considered
as a state when there is a balance between these two quantities. As a
result, we obtain an equation which relates density and temperature for
such a system in the non-relativistic classical limit. This equation
is consistent with the TOV equation as expected.
Title: Multiwavelength analysis of short GRB 201221D and its
comparison with other high & low redshift short GRBs
Authors: Dimple; Misra, K.; Kann, D. A.; Arun, K. G.; Ghosh, A.;
Gupta, R.; Resmi, L.; Agüí Fernández, J. F.; Thöne, C. C.; de
Ugarte Postigo, A.; Pandey, S. B.; Yadav, L.
Bibcode: 2022MNRAS.516....1D
Altcode: 2022MNRAS.tmp.2096D; 2022arXiv220608947D
We present a detailed analysis of short GRB 201221D lying at redshift
$\mathit{ z}$ = 1.045. We analyse the high-energy data of the burst
and compare it with the sample of short gamma-ray bursts (SGRBs). The
prompt emission characteristics are typical of those seen in the case
of other SGRBs except for the peak energy (Ep), which lies
at the softer end (generally observed in the case of long bursts). We
estimate the host galaxy properties by utilizing the Python-based
software Prospector to fit the spectral energy distribution of the
host. The burst lies at a high redshift relative to the SGRB sample
with a median redshift of $\mathit{ z}$ = 0.47. We compare the burst
characteristics with other SGRBs with known redshifts along with GRB
200826A (SGRB originated from a collapsar). A careful examination of
the characteristics of SGRBs at different redshifts reveals that some
of the SGRBs lying at high redshifts have properties similar to long
GRBs indicating they might have originated from collapsars. Further
study of these GRBs can help to explore the broad picture of progenitor
systems of SGRBs.
Title: Gravitational wave of intermediate-mass black holes in
Population III star clusters
Authors: Wang, Long; Tanikawa, Ataru; Fujii, Michiko
Bibcode: 2022MNRAS.515.5106W
Altcode: 2022MNRAS.tmp.1966W; 2022arXiv220709621W
Previous theoretical studies suggest that the Population III
(Pop3) stars tend to form in extremely metal-poor gas clouds with
approximately $10^5 \ \mathrm{M}_\odot$ embedded in mini dark matter
haloes. Very massive stars can form via multiple collisions in Pop3
star clusters and eventually evolve to intermediate-mass black holes
(IMBHs). In this work, we conduct star-by-star N-body simulations
for modelling the long-term evolution of Pop3 star clusters. We find
that if the mini dark matter haloes can survive today, these star
clusters can avoid tidal disruption by the galactic environment
and can efficiently produce IMBH-black hole (BH) mergers among
a wide range of redshift from 0 to 20. The average gravitational
wave event rate is estimated to be $0.1\!-\!0.8\ \mathrm{yr}^{-1}
\,\mathrm{Gpc}^{-3}$, and approximately 40-80 per cent of the mergers
occur at high redshift (z > 6). The characteristic strain shows
that a part of low-redshift mergers can be detected by LISA, TianQin,
and Taiji, whereas most mergers can be covered by DECIGO and advanced
LIGO/Virgo/KAGRA. Mergers with pair-instability BHs have a rate of
approximately 0.01-0.15 yr-1 Gpc-3, which can
explain the GW190521-like events.
Title: Evaluating the prevalence of spurious correlations in pulsar
timing array data sets
Authors: Zic, Andrew; Hobbs, George; Shannon, R. M.; Reardon,
Daniel; Goncharov, Boris; Bhat, N. D. Ramesh; Cameron, Andrew; Dai,
Shi; Dawson, J. R.; Kerr, Matthew; Manchester, R. N.; Mandow, Rami;
Marshman, Tommy; Russell, Christopher J.; Thyagarajan, Nithyanandan;
Zhu, X. -J.
Bibcode: 2022MNRAS.516..410Z
Altcode: 2022MNRAS.tmp.2083Z; 2022arXiv220712237Z
Pulsar timing array collaborations have recently reported
evidence for a noise process with a common spectrum among the
millisecond pulsars in the arrays. The spectral properties of this
common-noise process are consistent with expectations for an isotropic
gravitational-wave background (GWB) from inspiralling supermassive
black hole binaries. However, recent simulation analyses based on
Parkes Pulsar Timing Array data indicate that such a detection may
arise spuriously. In this paper, we use simulated pulsar timing array
data sets to further test the robustness of the inference methods for
spectral and spatial correlations from a GWB. Expanding on our previous
results, we find strong support (Bayes factors exceeding 105)
for the presence of a common-spectrum noise process in data sets
where no common process is present, under a wide range of timing
noise prescriptions per pulsar. We show that these results are highly
sensitive to the choice of Bayesian priors on timing noise parameters,
with priors that more closely match the injected distributions of timing
noise parameters resulting in diminished support for a common-spectrum
noise process. These results emphasize shortcomings in current methods
for inferring the presence of a common-spectrum process, and imply
that the detection of a common process is not a reliable precursor
to detection of the GWB. Future searches for the nanohertz GWB should
remain focused on detecting spatial correlations, and make use of more
tailored specifications for a common-spectrum noise process.
Title: Nanobeacon: A time calibration device for the KM3NeT neutrino
telescope
Authors: Aiello, S.; Albert, A.; Alshamsi, M.; Garre, S. Alves; Aly,
Z.; Ambrosone, A.; Ameli, F.; Andre, M.; Androulakis, G.; Anghinolfi,
M.; Anguita, M.; Ardid, M.; Ardid, S.; Aublin, J.; Bagatelas, C.;
Baret, B.; du Pree, S. Basegmez; Bendahman, M.; Benfenati, F.; Berbee,
E.; van den Berg, A. M.; Bertin, V.; Biagi, S.; Boettcher, M.; Cabo,
M. Bou; Boumaaza, J.; Bouta, M.; Bouwhuis, M.; Bozza, C.; Brânzaş,
H.; Bruijn, R.; Brunner, J.; Bruno, R.; Buis, E.; Buompane, R.; Busto,
J.; Caiffi, B.; Calvo, D.; Campion, S.; Capone, A.; Carretero, V.;
Castaldi, P.; Celli, S.; Chabab, M.; Chau, N.; Chen, A.; Cherubini,
S.; Chiarella, V.; Chiarusi, T.; Circella, M.; Cocimano, R.; Coelho,
J. A. B.; Coleiro, A.; Molla, M. Colomer; Coniglione, R.; Coyle,
P.; Creusot, A.; Cruz, A.; Cuttone, G.; Dallier, R.; De Martino,
B.; Di Palma, I.; Díaz, A. F.; Diego-Tortosa, D.; Distefano, C.;
Domi, A.; Donzaud, C.; Dornic, D.; Dörr, M.; Drouhin, D.; Eberl,
T.; Eddyamoui, A.; van Eeden, T.; van Eijk, D.; El Bojaddaini, I.;
El Hedri, S.; Enzenhöfer, A.; Espinosa, V.; Fermani, P.; Ferrara,
G.; Filipović, M. D.; Filippini, F.; Fusco, L. A.; Gal, T.; Méndez,
J. García; Garufi, F.; Gatelet, Y.; Oliver, C. Gatius; Geißelbrecht,
N.; Gialanella, L.; Giorgio, E.; Gozzini, S. R.; Gracia, R.; Graf,
K.; Grella, G.; Guderian, D.; Guidi, C.; Guillon, B.; Gutiérrez, M.;
Haefner, J.; Hallmann, S.; Hamdaoui, H.; van Haren, H.; Heijboer, A.;
Hekalo, A.; Hennig, L.; Hernández-Rey, J. J.; Hofestädt, J.; Huang,
F.; Ibnsalih, W. Idrissi; Illuminati, G.; James, C. W.; Janezashvili,
D.; de Jong, M.; de Jong, P.; Jung, B. J.; Kalaczyński, P.; Kalekin,
O.; Katz, U. F.; Chowdhury, N. R. Khan; Kistauri, G.; van der Knaap,
F.; Kooijman, P.; Kouchner, A.; Kulikovskiy, V.; Labalme, M.; Lahmann,
R.; Lamoureux, M.; Larosa, G.; Lastoria, C.; Lazo, A.; Le Breton,
R.; Le Stum, S.; Lehaut, G.; Leonardi, O.; Leone, F.; Leonora, E.;
Lessing, N.; Levi, G.; Lincetto, M.; Clark, M. Lindsey; Lipreau, T.;
Alvarez, C. LLorens; Longhitano, F.; Lopez-Coto, D.; Maderer, L.;
Majumdar, J.; Mańczak, J.; Margiotta, A.; Marinelli, A.; Markou,
C.; Martin, L.; Martínez-Mora, J. A.; Martini, A.; Marzaioli, F.;
Mastroianni, S.; Melis, K. W.; Miele, G.; Migliozzi, P.; Migneco,
E.; Mijakowski, P.; Miranda, L. S.; Mollo, C. M.; Moser, M.; Moussa,
A.; Muller, R.; Musumeci, M.; Nauta, L.; Navas, S.; Nicolau, C. A.;
Nkosi, B.; Fearraigh, B. Ó.; O'Sullivan, M.; Organokov, M.; Orlando,
A.; González, J. Palacios; Papalashvili, G.; Papaleo, R.; Păun,
A. M.; Păvălaş, G. E.; Pellegrino, C.; Perrin-Terrin, M.; Pestel,
V.; Piattelli, P.; Pieterse, C.; Pisanti, O.; Poirè, C.; Popa, V.;
Pradier, T.; Probst, I.; Pulvirenti, S.; Quéméner, G.; Randazzo,
N.; Razzaque, S.; Real, D.; Reck, S.; Riccobene, G.; Romanov, A.;
Rovelli, A.; Greus, F. Salesa; Samtleben, D. F. E.; Losa, A. Sánchez;
Sanguineti, M.; Santonocito, D.; Sapienza, P.; Schnabel, J.; Schneider,
M. F.; Schumann, J.; Schutte, H. M.; Seneca, J.; Sgura, I.; Shanidze,
R.; Sharma, A.; Sinopoulou, A.; Spisso, B.; Spurio, M.; Stavropoulos,
D.; Stellacci, S. M.; Taiuti, M.; Tayalati, Y.; Thiersen, H.; Tingay,
S.; Tsagkli, S.; Tsourapis, V.; Tzamariudaki, E.; Tzanetatos, D.; Van
Elewyck, V.; Vasileiadis, G.; Versari, F.; Vivolo, D.; de Wasseige,
G.; Wilms, J.; Wojaczyński, R.; de Wolf, E.; Yousfi, T.; Zavatarelli,
S.; Zegarelli, A.; Zito, D.; Zornoza, J. D.; Zúñiga, J.; Zywucka, N.
Bibcode: 2022NIMPA104067132A
Altcode: 2021arXiv211100223A
The KM3NeT Collaboration is currently constructing a multi-site
high-energy neutrino telescope in the Mediterranean Sea consisting
of matrices of pressure-resistant glass spheres, each holding a set
of 31 small-area photomultipliers. The main goals of the telescope
are the observation of neutrino sources in the Universe and the
measurement of the neutrino oscillation parameters with atmospheric
neutrinos. A relative time synchronisation between photomultipliers
of the nanosecond order needed to guarantee the required angular
resolution of the detector. Due to the large detector volumes to be
instrumented by KM3NeT, a cost reduction of the different systems is
a priority. To this end, the inexpensive Nanobeacon has been designed
and developed by the KM3NeT Collaboration to be used for detector
time-calibration studies. At present, more than 600 Nanobeacons have
been already produced. The characterisation of the optical pulse and
the wavelength emission profile of the devices is critical for the
time calibration. The optical pulse rise time has been quantified
as less than 3 ns, while the Full Width Half Maximum is less than 6
ns. The wavelength drift, due to a variation of the supply voltage,
has also been qualified as lower than 10 nm for the full range of the
Nanobeacon. In this paper, more details about the main features of
the Nanobeacon design, production and operation, together with the
main properties of the light pulse generated are described.
Title: Three-body problem - From Newton to supercomputer plus
machine learning
Authors: Liao, Shijun; Li, Xiaoming; Yang, Yu
Bibcode: 2022NewA...9601850L
Altcode: 2021arXiv210611010L
The famous three-body problem can be traced back to Newton in 1687,
but quite few families of periodic orbits were found in 300 years
thereafter. In this paper, we propose an effective approach and roadmap
to numerically gain planar periodic orbits of three-body systems with
arbitrary masses by means of machine learning based on an artificial
neural network (ANN) model. Given any a known periodic orbit as a
starting point, this approach can provide more and more periodic orbits
(of the same family name) with variable masses, while the mass domain
having periodic orbits becomes larger and larger, and the ANN model
becomes wiser and wiser. Finally we have an ANN model trained by means
of all obtained periodic orbits of the same family, which provides a
convenient way to give accurate enough predictions of periodic orbits
with arbitrary masses for physicists and astronomers. It suggests that
the high-performance computer and artificial intelligence (including
machine learning) should be the key to gain periodic orbits of the
famous three-body problem.
Title: The evolution of protoplanetary disc radii and disc masses
in star-forming regions
Authors: Marchington, Bridget; Parker, Richard J.
Bibcode: 2022MNRAS.515.5449M
Altcode: 2022arXiv220804330M; 2022MNRAS.tmp.2049M
Protoplanetary discs are crucial to understanding how planets form
and evolve, but these objects are subject to the vagaries of the birth
environments of their host stars. In particular, photoionizing radiation
from massive stars has been shown to be an effective agent in disrupting
protoplanetary discs. External photoevaporation leads to the inward
evolution of the radii of discs, whereas the internal viscous evolution
of the disc causes the radii to evolve outwards. We couple N-body
simulations of star-forming regions with a post-processing analysis
of disc evolution to determine how the radius and mass distributions
of protoplanetary discs evolve in young star-forming regions. To be
consistent with observations, we find that the initial disc radii must
be of the order of 100 au, even though these discs are readily destroyed
by photoevaporation from massive stars. Furthermore, the observed
disc radius distribution in the Orion Nebula Cluster (ONC) is more
consistent with moderate initial stellar densities (100 M⊙
pc-3), in tension with dynamical models that posit much
higher initial densities for the ONC. Furthermore, we cannot reproduce
the observed disc radius distribution in the Lupus star-forming region
if its discs are subject to external photoevaporation. A more detailed
comparison is not possible due to the well-documented uncertainties
in determining the ages of pre-main-sequence (disc-hosting) stars.
Title: Biermann battery powered by resistive heating induced by
cosmic ray streaming
Authors: Yokoyama, Shota L.; Ohira, Yutaka
Bibcode: 2022MNRAS.515.5467Y
Altcode: 2022MNRAS.tmp.2051Y; 2022arXiv220405787Y
It is recently proposed that cosmic rays generate a seed magnetic field
in the early Universe. In this paper, we propose another generation
mechanism of magnetic fields by cosmic rays, which is the Biermann
battery driven by resistive heating induced by the streaming of cosmic
rays. This mechanism is dominant in small-scale, low-temperature,
and strongly ionized regions, compared with other previously proposed
mechanisms. Because cosmic rays are expected to be accelerated after
the death of the first stars, this mechanism can work during structure
formation in the early Universe. We show that it makes the seed magnetic
field with sufficient strength for the subsequent dynamo to amplify
it to the micro Gauss level in the current galaxies.
Title: The heliospheric ambipolar potential inferred from
sunward-propagating halo electrons
Authors: Horaites, Konstantinos; Boldyrev, Stanislav
Bibcode: 2022MNRAS.515.5135H
Altcode: 2022MNRAS.tmp.1920H; 2022arXiv220406532H
We provide evidence that the sunward-propagating half of the solar
wind electron halo distribution evolves without scattering in the
inner heliosphere. We assume the particles conserve their total energy
and magnetic moment, and perform a 'Liouville mapping' on electron
pitch angle distributions measured by the Parker Solar Probe SPAN-E
instrument. Namely, we show that the distributions are consistent
with Liouville's theorem if an appropriate interplanetary potential is
chosen. This potential, an outcome of our fitting method, is compared
against the radial profiles of proton bulk flow energy. We find that the
inferred potential is responsible for nearly 100 per cent of the proton
acceleration in the solar wind at heliocentric distances 0.18-0.79
AU. These observations combine to form a coherent physical picture:
the same interplanetary potential accounts for the acceleration of the
solar wind protons as well as the evolution of the electron halo. In
this picture the halo is formed from a sunward-propagating population
that originates somewhere in the outer heliosphere by a yet-unknown
mechanism.
Title: Antarctica ice-mass variations on interannual timescale:
Coastal Dipole and propagating transports
Authors: Li, Zhen; Chao, Benjamin F.; Wang, H. S.; Zhang, Z. Z.
Bibcode: 2022E&PSL.59517789L
Altcode:
The target is the non-secular, non-seasonal, interannual ice-mass
redistribution over the Antarctica continent, as observed by the
satellite mission GRACE (Gravity Recovery and Climate Experiment)
for the period from 2002 to 2016. We employ the empirical orthogonal
function (EOF) and complex EOF (CEOF) methods on the GRACE monthly
time-variable gravity in the form of the mascon data. We find three
separate phenomena on different timescales that are hitherto unreported:
(i) EOF Mode 1 represents an interannual standing "seesaw" pattern
largely concentrates along the coast, which we refer to as the
Antarctica Coastal Dipole (ACD), with turnarounds coincident with
ENSO events, relative to precipitation anomalies, whereas Mode 2-3
both correlate with the Antarctica Oscillation (AAO); (ii) the leading
CEOF Mode shows two different propagating waves, one is the Eastward
Propagation (EP) with the periodicity of ∼4.7 years most evident in
the East Antarctica, may be induced by the Antarctica Circumpolar Wave;
(iii) another is a Westward Propagation (WP) with ∼2 years periodicity
in the West Antarctica that mainly travels from the Ronnie Ice Shelf
to the Ross Ice Shelf, may relate to AAO.
Title: Fingerprints of modified gravity on galaxies in voids
Authors: Cataldi, Pedro; Pedrosa, Susana; Padilla, Nelson; Landau,
Susana; Arnold, Christian; Li, Baojiu
Bibcode: 2022MNRAS.515.5358C
Altcode: 2022arXiv220712917C; 2022MNRAS.tmp.2021C
We search for detectable signatures of f(R) gravity and its chameleon
screening mechanism in the baryonic and dark matter (DM) properties
of simulated void galaxies. The enhancement of the gravitational
acceleration can have a meaningful impact on the scaling relations as
well as on the halo morphology. The galaxy rotational velocity field
(calculated with the velocity of the gas disc and the acceleration
fields) deviates from the typical values of the Tully-Fisher Relation in
General Relativity (GR). For a given stellar mass, f(R) gravity tends
to produce greater maximum velocities. On the other hand, the mass in
haloes in f(R) gravity is more concentrated than their counterparts in
GR. This trend changes when the concentration is calculated with the
dynamical density profile, which takes into account the unscreened
outer regions of the halo. Stellar discs interact with the overall
potential well in the central regions, modifying the morphology of the
screening regions and reshaping them. We find a trend for galaxies with
a more dominant stellar disc to deviate further from round screening
regions. We find that small haloes are less triaxial and more round in
f(R) than their GR counterparts. The difference between halo morphology
becomes smaller in f(R) haloes whose inner regions are screened. These
results suggest possible observables that could unveil modified gravity
effects on galaxies in voids in future cosmological tests of gravity.
Title: CMB spectral distortions from continuous large energy release
Authors: Acharya, Sandeep Kumar; Chluba, Jens
Bibcode: 2022MNRAS.515.5775A
Altcode: 2022MNRAS.tmp.2072A; 2021arXiv211206699A
Accurate computations of spectral distortions of the cosmic microwave
background (CMB) are required for constraining energy release scenarios
at redshifts z ≳ 103. The existing literature focuses on
distortions that are small perturbations to the background blackbody
spectrum. At high redshifts (z ≳ 106), this assumption
can be violated, and the CMB spectrum can be significantly distorted
at least during part of its cosmic evolution. In this paper, we carry
out accurate thermalization computations, evolving the distorted CMB
spectrum in a general, fully non-linear way, consistently accounting
for the time-dependence of the injection process, modifications to the
Hubble expansion rate and relativistic Compton scattering. Specifically,
we study single energy injection and decaying particle scenarios,
discussing constraints on these cases. We solve the thermalization
problem using two independent numerical approaches that are now
available in CosmoTherm as dedicated setups for computing CMB spectral
distortions in the large distortion regime. New non-linear effects at
low frequencies are furthermore highlighted, showing that these warrant
a more rigorous study. This work eliminates one of the long-standing
simplifications in CMB spectral distortion computations, which also
opens the way to more rigorous treatments of distortions induced
by high-energy particle cascade, soft photon injection, and in the
vicinity of primordial black holes.
Title: Iron isotope evidence in ocean island basalts for plume-
and plate-controlled melting, São Miguel, Azores
Authors: Ruttor, Saskia; Nebel, Oliver; Williams, Helen; Beier,
Christoph; Richter, Marianne; Nebel-Jacobsen, Yona; Romer, René H. W.;
Turner, Simon P.; Soderman, Caroline R.
Bibcode: 2022GeCoA.335..111R
Altcode:
Primitive ocean island basalts (OIB) display a large variability in
stable iron (Fe) isotopes, beyond what can plausibly be explained by
partial melting and crystal fractionation processes. This Fe isotopic
heterogeneity is widely ascribed to inheritance from various exotic
mantle components of enriched crustal origin, i.e., subducted and
resurfacing oceanic or continental crust, its underlying lithosphere or
overlying sediments. These enriched mantle components are characterised
by variations in radiogenic Sr-Nd-Pb-Hf isotopes. The extent to
which the inherited Fe isotopic signature of subducted and recycled
material influences the Fe isotopic composition of OIB and which role
secondary processes accompanied with partial melting play is, however,
not well understood. The eastern Azores island of São Miguel displays
a systematic change from a mantle source less radiogenic in Sr-Nd-Hf-Pb
isotopes in the West to a highly enriched source in the East. These
variations are among the largest reported in an OIB, indicating
variable source component additions to the melt that offer a natural
laboratory to elucidate sub-oceanic island processes. Among these,
the eastern São Miguel component is unique amongst global OIB in that
it has both, extremely radiogenic 206Pb/204Pb
and 87Sr/86Sr isotopic ratios. The spatial
distribution, complexity and uniqueness of these isotopic source
characteristics are ideally suited to gain insights into the spatial
distribution of mantle components and their potential controls on
Fe isotope systematics. Comparing δ57Feprim,
which is the isotopic composition calculated to primitive lavas
along a liquid line of descent, with 87Sr/86Sr,
143Nd/144Nd, 206Pb/204Pb
and 208Pb/204Pb reveals that the depleted
component of western São Miguel shows a heavy Fe isotopic composition
ranging from δ57Feprim = +0.09 to +0.18‰
(excluding one outlier at -0.02‰ δ57Feprim),
whereas the enriched component of eastern São Miguel shows lighter
δ57Feprim = +0.05 to +0.12‰. Both suites show a
continuum of isotopic compositions between two apparent endmembers. The
light Fe isotopic signature of eastern São Miguel lavas, coupled with
elevated Rb/Sr and K2O, indicate K-rich mantle metasomatism
in their source. The Fe isotopic composition of western São Miguel's
lavas are likely related to a similar source, but have been overprinted
by the active Terceira Rift. The latter adds low-degree mid-ocean ridge
basalt (MORB)-type melts to the original OIB, likely in the form of a
re-fertilised depleted mantle component that underpins the ultraslow
spreading region. The two-component mix that contributes to western São
Miguel lavas highlights that both enriched mantle components and shallow
crustal features can add to the Fe isotopic signatures of erupting
OIB, with spatial separation within single volcanic islands. This
suggests that a careful evaluation of local geologic features, such
as rifting, is required when OIB are probed for their mantle sources,
and that heavy Fe isotopic signatures in OIB may not reflect deep,
plume-source lithologies. In summary, São Miguel lavas are sourced by
a mantle plume, but within a spatially controlled region accompanied by
a plate-controlled melt associated with a rifting zone. This dichotomy
adds another complication to the genesis of OIB, which however maybe
elucidated through combined radiogenic-stable isotope systematics.
Title: The initial magnetic criticality of pre-stellar cores
Authors: Priestley, Felix D.; Yin, Charles; Wurster, James
Bibcode: 2022MNRAS.515.5689P
Altcode: 2022arXiv220712441P; 2022MNRAS.tmp.1995P
Direct observational measurements of the magnetic field strength
in pre-stellar cores typically find supercritical mass-to-flux
ratios, suggesting that the magnetic field is insufficient to
prevent gravitational collapse. These measurements suffer from
significant uncertainties; an alternative approach is to utilize the
sensitivity of pre-stellar chemistry to the evolutionary history,
and indirectly constrain the degree of magnetic support. We combine
non-ideal magnetohydrodynamic simulations of pre-stellar cores with
time-dependent chemistry and radiative transfer modelling, producing
synthetic observations of the model cores in several commonly observed
molecular lines. We find that molecules strongly affected by freeze-out,
such as CS and HCN, typically have much lower line intensities in
magnetically subcritical models compared to supercritical ones, due
to the longer collapse time-scales. Subcritical models also produce
much narrower lines for all species investigated. Accounting for a
range of core properties, ages, and viewing angles, we find that
supercritical models are unable to reproduce the distribution of
CS and N2H+ line strengths and widths seen
in an observational sample, whereas subcritical models are in good
agreement with the available data. This suggests that despite presently
having supercritical mass-to-flux ratios, pre-stellar cores form as
magnetically subcritical objects.
Title: An X-ray view of the ambiguous nuclear transient AT2019pev
Authors: Yu, Zhefu; Kochanek, C. S.; Mathur, S.; Auchettl, K.; Grupe,
D.; Holoien, T. W. -S.
Bibcode: 2022MNRAS.515.5198Y
Altcode: 2022MNRAS.tmp.1984Y; 2022arXiv220505097Y
AT2019pev is a nuclear transient in a narrow-line Seyfert 1 galaxy at
z = 0.096. The archival ultraviolet, optical, and infrared data showed
features of both tidal disruption events and active galactic nuclei
(AGNs), and its nature is not fully understood. We present detailed
X-ray observations of AT2019pev taken with Swift, Chandra, and NICER
over 173 d of its evolution since the first Swift XRT epoch. The X-ray
luminosity increases by a factor of 5 in 5 d from the first Swift
XRT epoch to the light-curve peak. The light curve decays by a factor
of 10 over ~75 d and then flattens with a weak re-brightening trend
at late times. The X-ray spectra show a 'harder-when-brighter' trend
before peak and a 'harder-when-fainter' trend after peak, which may
indicate a transition of accretion states. The archival ground-based
optical observations show similar time evolution as the X-ray light
curves. Beyond the seasonal limit of the ground-based observations,
the Gaia light curve is rising towards an equally bright or brighter
peak 223 d after the optical discovery. Combining our X-ray analysis
and archival multiwavelength data, AT2019pev more closely resembles
an AGN transient.
Title: Application of scaling geology in magnetic basement mapping
around the Middle Benue Trough in Northcentral Nigeria
Authors: Ejiga, Eko Gerald; Yusoff, Ismail; Ismail, Noer El Hidayah;
Lawal, Mutari; Yelwa, Nura Abdulmumini
Bibcode: 2022PEPI..33106914E
Altcode:
Using the scaling spectral method applied on high resolution
aeromagnetic data, we mapped the magnetic basement and estimated the
scaling exponents across various lithologies within the Middle Benue
Trough of Northcentral Nigeria. We estimated a depth range of 1.8-6.3
km, with an average of 3.7 km to the basement beneath the Cretaceous
sediments of the trough. Shallow basement depths of <3 km are mostly
found on the trough's northern and southeastern margins. These are
uplifted Precambrian Basement Complex regions made up of older granite,
gneiss, and migmatite. Deeper basement depths of >4 km predominate in
the southwestern, central, and northeastern portions of the study area,
trending along the trough's axis. These deep zones are filled with
Cretaceous sediments that must have accumulated after the Mesozoic
development of the Benue Trough's subsided graben structure. Our
study estimated scaling exponent ranging from 0 to 2. There were some
correlations with the geology of the area, particularly around the
crystalline basement complex in the northern portion. Within the central
portion of the Middle Benue Trough, however, the source distributions
are less correlated, uneven, and not always consistent with the geology
of the area. This could be due to the region's dynamic and unstable
tectonics, as numerous magmatic intrusions have been emplaced into
the Cretaceous sediments at various depths, potentially influencing
the scaling exponent values.
Title: Evidence for C and Mg variations in the GD-1 stellar stream
Authors: Balbinot, Eduardo; Cabrera-Ziri, Ivan; Lardo, Carmela
Bibcode: 2022MNRAS.515.5802B
Altcode: 2021arXiv211112626B; 2022MNRAS.tmp.1837B
Dynamically cold stellar streams are the relics left over from globular
cluster dissolution. These relics offer a unique insight into a now
fully disrupted population of ancient clusters in our Galaxy. Using a
combination of Gaia eDR3 proper motions, optical and near-UV colours,
we select a sample of likely Red Giant Branch stars from the GD-1 stream
for medium-low resolution spectroscopic follow-up. Based on radial
velocity and metallicity, we are able to find 14 new members of GD-1,
5 of which are associated with the spur and blob/cocoon off-stream
features. We measured C-abundances to probe for abundance variations
known to exist in globular clusters. These variations are expected
to manifest in a subtle way in globular clusters with such low masses
($\sim 10^4\,{\rm ~\textrm {M}_\odot }$) and metallicities ([Fe/H] ~
-2.1 dex). We find that the C-abundances of the stars in our sample
display a small but significant (3σ level) spread. Furthermore, we
find ~3σ variation in Mg-abundances among the stars in our sample
that have been observed by APOGEE. These abundance patterns match the
ones found in Galactic globular clusters of similar metallicity. Our
results suggest that GD-1 represents another fully disrupted low-mass
globular cluster where light-element abundance spreads have been found.
Title: Energy balance and Alfvén Mach numbers in compressible
magnetohydrodynamic turbulence with a large-scale magnetic field
Authors: Beattie, James R.; Krumholz, Mark R.; Skalidis, Raphael;
Federrath, Christoph; Seta, Amit; Crocker, Roland M.; Mocz, Philip;
Kriel, Neco
Bibcode: 2022MNRAS.515.5267B
Altcode: 2022MNRAS.tmp.2006B; 2022arXiv220213020B
Energy equipartition is a powerful theoretical tool for understanding
astrophysical plasmas. It is invoked, for example, to measure magnetic
fields in the interstellar medium (ISM), as evidence for small-scale
turbulent dynamo action, and, in general, to estimate the energy
budget of star-forming molecular clouds. In this study, we motivate
and explore the role of the volume-averaged root-mean-squared (rms)
magnetic coupling term between the turbulent, $\delta {\boldsymbol{B}}$
, and large-scale, ${\boldsymbol{B}}_0$, fields, ${\left\langle (\delta
\mathrm{{\boldsymbol {\mathit {B}}}}\cdot {\mathrm{{\boldsymbol {\mathit
{B}}}}_0})^{2} \right\rangle ^{1/2}_{\mathcal {V}}}$. By considering
the second moments of the energy balance equations we show that the
rms coupling term is in energy equipartition with the volume-averaged
turbulent kinetic energy for turbulence with a sub-Alfvénic large-scale
field. Under the assumption of exact energy equipartition between
these terms, we derive relations for the magnetic and coupling term
fluctuations, which provide excellent, parameter-free agreement with
time-averaged data from 280 numerical simulations of compressible
magnetohydrodynamic (MHD) turbulence. Furthermore, we explore the
relation between the turbulent mean field and total Alfvén Mach
numbers, and demonstrate that sub-Alfvénic turbulence can only be
developed through a strong, large-scale magnetic field, which supports
an extremely super-Alfvénic turbulent magnetic field. This means
that the magnetic field fluctuations are significantly subdominant
to the velocity fluctuations in the sub-Alfvénic large-scale field
regime. Throughout our study, we broadly discuss the implications for
observations of magnetic fields and understanding the dynamics in the
magnetized ISM.
Title: Charged black-bounce spacetimes: Photon rings, shadows and
observational appearances
Authors: Guo, Yang; Miao, Yan-Gang
Bibcode: 2022NuPhB.98315938G
Altcode: 2021arXiv211201747G
The photon ring, shadow and observational appearance of the emission
originating near a charged black-bounce are investigated. Based on
the geodesic analysis, we determine the upper and lower limits of
critical impact parameters of a charged black-bounce. In particular,
we find that the charged black-bounce shares the same critical impact
parameter with the Reissner-Nordström black hole. In addition,
we classify the light trajectories coming from the region near
the charged black-bounce by utilizing the rays tracing procedure,
and then investigate the observational appearance of the emissions
from a thin disk accretion and a spherically symmetric infalling
accretion. We reveal that a large charge increases the observed
intensity but decreases the apparent size of shadows, and that the
photon ring presents the intrinsic property of a spacetime geometry,
which is independent of the types of the two accretions. Our results
are in good agreement with the recent observations.
Title: Gravitationally lensed orphan afterglows of gamma-ray bursts
Authors: Gao, Hao-Xuan; Geng, Jin-Jun; Hu, Lei; Hu, Mao-Kai; Lan,
Guang-Xuan; Chang, Chen-Ming; Zhang, Song-Bo; Zhang, Xiao-Li; Huang,
Yong-Feng; Wu, Xue-Feng
Bibcode: 2022MNRAS.516..453G
Altcode: 2022arXiv220403823G; 2022MNRAS.tmp.2112G
The cosmological nature of gamma-ray bursts (GRBs) implies that a
small portion of them could be gravitationally lensed by foreground
objects during their propagation. The gravitational lensing effect
on the GRB prompt emission and on-axis afterglows has been discussed,
and some candidates have been found in the literature. In this work,
considering the high detection rate of GRB orphan afterglows in future
wide-field survey era, we investigate the gravitationally lensed
orphan afterglows in view of three lens models, i.e. the point-mass
model, the singular isothermal sphere model, and the Chang-Refsdal
model. The structure of the GRB jet itself is also incorporated
in calculating the lensed afterglow light curves. It is found that
lensed optical/X-ray orphan afterglows in principle could be diagnosed
through their temporal characteristics, and the optical band is the
best band to observe the galaxy-lensed orphan afterglows. Moreover,
the event rate for galaxy-lensed orphan afterglows is estimated to be
≲ 1.8 yr-1 for the whole sky. If most orphan afterglows
could be identified (from other transients in the survey data), the
optimistic detection rates of the 2.5 m Wide Field Survey Telescope
of China and 8.4 m Vera Rubin Observatory Legacy Survey of Space and
Time for galaxy-lensed orphan afterglows in the optical band are ≲
0.01-0.02 and ≲ 0.04-0.08 yr-1, respectively.
Title: AutoEnRichness: A hybrid empirical and analytical approach
for estimating the richness of galaxy clusters
Authors: Chan, Matthew C.; Stott, John P.
Bibcode: 2022MNRAS.516..316C
Altcode: 2022arXiv220811944C; 2022MNRAS.tmp.2109C
We introduce AutoEnRichness, a hybrid approach that combines empirical
and analytical strategies to determine the richness of galaxy clusters
(in the redshift range of 0.1 ≤ z ≤ 0.35) using photometry data from
the Sloan Digital Sky Survey Data Release 16, where cluster richness
can be used as a proxy for cluster mass. In order to reliably estimate
cluster richness, it is vital that the background subtraction is as
accurate as possible when distinguishing cluster and field galaxies
to mitigate severe contamination. AutoEnRichness is comprised of
a multistage machine learning algorithm that performs background
subtraction of interloping field galaxies along the cluster line of
sight and a conventional luminosity distribution fitting approach that
estimates cluster richness based only on the number of galaxies within
a magnitude range and search area. In this proof-of-concept study, we
obtain a balanced accuracy of 83.20 per cent when distinguishing between
cluster and field galaxies as well as a median absolute percentage error
of 33.50 per cent between our estimated cluster richnesses and known
cluster richnesses within r200. In the future, we aim for
AutoEnRichness to be applied on upcoming large-scale optical surveys,
such as the Legacy Survey of Space and Time and Euclid, to estimate the
richness of a large sample of galaxy groups and clusters from across
the halo mass function. This would advance our overall understanding
of galaxy evolution within overdense environments as well as enable
cosmological parameters to be further constrained.
Title: Chaos bound and its violation in charged Kiselev black hole
Authors: Gao, Chuanhong; Chen, Deyou; Yu, Chengye; Wang, Peng
Bibcode: 2022PhLB..83337343G
Altcode: 2022arXiv220407983G
The chaos bound in the near-horizon regions has been studied through
the expansions of the metric functions on the horizon. In this paper,
we investigate the chaos bound in the near-horizon region and at a
certain distance from the horizon of a charged Kiselev black hole. The
value of the Lyapunov exponent is accurately calculated by a Jacobian
matrix. The angular momentum of a charged particle around the black hole
affects not only the exponent, but also the position of the equilibrium
orbit. This position gradually moves away from the horizon with the
increase of the angular momentum. We find that the bound is violated
at a certain distance from the horizon and there is no violation in
the near-horizon region when the charge mass ratio of the particle is
fixed. The small value of the normalization factor is more likely to
cause the violation.
Title: Forecasting cosmological parameter constraints using multiple
sparsity measurements as tracers of the mass profiles of dark
matter haloes
Authors: Corasaniti, P. S.; Le Brun, A. M. C.; Richardson, T. R. G.;
Rasera, Y.; Ettori, S.; Arnaud, M.; Pratt, G. W.
Bibcode: 2022MNRAS.516..437C
Altcode: 2022arXiv220406582C; 2022MNRAS.tmp.2091C
The dark matter halo sparsity, i.e. the ratio between spherical halo
masses enclosing two different overdensities, provides a non-parametric
proxy of the halo mass distribution that has been shown to be a
sensitive probe of the cosmological imprint encoded in the mass
profile of haloes hosting galaxy clusters. Mass estimations at several
overdensities would allow for multiple sparsity measurements, which
can potentially retrieve the entirety of the cosmological information
imprinted on the halo profile. Here, we investigate the impact of
multiple sparsity measurements on the cosmological model parameter
inference. For this purpose, we analyse N-body halo catalogues from the
Raygal and M2Csims simulations and evaluate the correlations among six
different sparsities from spherical overdensity halo masses at Δ = 200,
500, 1000, and 2500 (in units of the critical density). Remarkably,
sparsities associated to distinct halo mass shells are not highly
correlated. This is not the case for sparsities obtained using halo
masses estimated from the Navarro-Frenk-White (NFW) best-fitting
profile, which artificially correlates different sparsities to order
one. This implies that there is additional information in the mass
profile beyond the NFW parametrization and that it can be exploited
with multiple sparsities. In particular, from a likelihood analysis of
synthetic average sparsity data, we show that cosmological parameter
constraints significantly improve when increasing the number of sparsity
combinations, though the constraints saturate beyond four sparsity
estimates. We forecast constraints for the CHEX-MATE cluster sample
and find that systematic mass bias errors mildly impact the parameter
inference, though more studies are needed in this direction.
Title: The theory of symmetric tensor field: From fractons to
gravitons and back
Authors: Blasi, Alberto; Maggiore, Nicola
Bibcode: 2022PhLB..83337304B
Altcode: 2022arXiv220705956B
We consider the theory of a symmetric tensor field in 4D, invariant
under a subclass of infinitesimal diffeomorphism transformations,
where the vector diff parameter is the 4-divergence of a scalar
parameter. The resulting gauge symmetry characterizes the "fracton"
quasiparticles and identifies a theory which depends on a dimensionless
parameter, which cannot be reabsorbed by a redefinition of the tensor
field, despite the fact that the theory is free of interactions. This
kind of "electromagnetic gauge symmetry" is weaker that the original
diffeomorphism invariance, in the sense that the most general action
contains, but is not limited to, linearized gravity, and we show how it
is possible to switch continuously from linearized gravity to a mixed
phase where both gravitons and fractons are present, without changing
the degrees of freedom of the theory. The gauge fixing procedure is
particularly rich and rather peculiar, and leads to the computation
of propagators which in the massive case we ask to be tachyonic-free,
thus constraining the domain of the parameter of the theory. Finally,
a closer contact to fractons is made by the introduction of a parameter
related to the "rate of propagation". For a particular value of this
parameter the theory does not propagate at all, and we guess that,
for this reason, the resulting theory should be tightly related to
the fracton excitations.
Title: Demonstrating quantum transport enhancement in time-reversal
asymmetric quantum walks
Authors: Long, Gui-Lu
Bibcode: 2022SCPMA..6500361L
Altcode:
No abstract at ADS
Title: Propagating torsional Alfvén waves in thermally active
solar plasma
Authors: Belov, S. A.; Vasheghani Farahani, S.; Molevich, N. E.
Bibcode: 2022MNRAS.515.5151B
Altcode:
The aim of this study is to shed light on the effects connected with
thermal misbalance due to non-equal cooling and heating rates induced
by density and temperature perturbations in solar active regions
hosting either propagating torsional or shear Alfvén waves. A
description for the non-linear forces connected with Alfvén waves
in non-ideal conditions is provided, based on the second-order thin
flux tube approximation. This provides insight into the effects of
Alfvén-induced motions on the boundary of thin magnetic structures
in thermally active plasmas. The equations describing the process of
generating longitudinal velocity perturbations, together with density
perturbations by non-linear torsional Alfvén waves, are obtained and
solved analytically. It is shown that the phase shift (compared with
the ideal case) and the amplitude of the induced longitudinal plasma
motions against the period of the mother Alfvén wave are greater for
shear Alfvén waves compared with torsional Alfvén waves, although
following the same pattern. The difference in the influence of thermal
misbalance on the induced velocity perturbations is governed by the
plasma-β although its effect is stronger for shear waves. It is deduced
that for a harmonic Alfvén driver the induced density perturbations
are left uninfluenced by the thermal misbalance.
Title: Traveling wave solutions of conformable Duffing model in
shallow water waves
Authors: Cevikel, Adem C.
Bibcode: 2022IJMPB..3650164C
Altcode:
The Duffing equation is a nonlinear second-order differential
equation. The equation describes the motion of a damped oscillator
with a more complicated potential than in simple harmonic motion; in
physical terms, it models, for example, a spring pendulum whose spring
stiffness does not exactly obey Hooke’s law. It is also an example of
a dynamical system that exhibits chaotic behavior. Nonlinear equations,
such as Duffing model, exhibit significant spectral energy transfer
for finite amplitude waves in shallow areas above the flat seafloor. In
this paper, a method is proposed to solve nonlinear conformable Duffing
model. The solutions found are hyperbolic function solutions. These
solutions are new solutions.
Title: SNAD transient miner: Finding missed transient events in ZTF
DR4 using k-D trees
Authors: Aleo, P. D.; Malanchev, K. L.; Pruzhinskaya, M. V.; Ishida,
E. E. O.; Russeil, E.; Kornilov, M. V.; Korolev, V. S.; Sreejith,
S.; Volnova, A. A.; Narayan, G. S.
Bibcode: 2022NewA...9601846A
Altcode: 2021arXiv211111555A
We report the automatic detection of 11 transients (7 possible
supernovae and 4 active galactic nuclei candidates) within the
Zwicky Transient Facility fourth data release (ZTF DR4), all of them
observed in 2018 and absent from public catalogs. Among these, three
were not part of the ZTF alert stream. Our transient mining strategy
employs 41 physically motivated features extracted from both real
light curves and four simulated light curve models (SN Ia, SN II,
TDE, SLSN-I). These features are input to a k-D tree algorithm, from
which we calculate the 15 nearest neighbors. After pre-processing and
selection cuts, our dataset contained approximately a million objects
among which we visually inspected the 105 closest neighbors from seven
of our brightest, most well-sampled simulations, comprising 89 unique
ZTF DR4 sources. Our result illustrates the potential of coherently
incorporating domain knowledge and automatic learning algorithms,
which is one of the guiding principles directing the SNAD team. It
also demonstrates that the ZTF DR is a suitable testing ground for
data mining algorithms aiming to prepare for the next generation of
astronomical data.
Title: Constraining H0 via extragalactic parallax
Authors: Ferree, Nicolas C.; Bunn, Emory F.
Bibcode: 2022MNRAS.515.4990F
Altcode: 2021arXiv210907529F; 2022MNRAS.tmp.1801F
We examine the prospects for measurement of the Hubble parameter
H0 via observation of the secular parallax of other galaxies
due to our own motion relative to the cosmic microwave background rest
frame. Peculiar velocities make distance measurements to individual
galaxies highly uncertain, but a survey sampling many galaxies
can still yield a precise H0 measurement. We use both
a Fisher information formalism and simulations to forecast errors
in H0 from such surveys, marginalizing over the unknown
peculiar velocities. The optimum survey observes ~102
galaxies within a redshift zmax = 0.06. The required errors
on proper motion are comparable to those that can be achieved by Gaia
and future astrometric instruments. A measurement of H0
via parallax has the potential to shed light on the tension between
different measurements of H0.
Title: New ab initio calculations and collisional properties of
closed-shell NCCP (1Σ+) by collisions with He
(1S)
Authors: Ritika; Dhilip Kumar, T. J.
Bibcode: 2022MNRAS.515.5145R
Altcode:
NCCP, a phosphorous species, is believed to have been discovered in
the carbon-rich star IRC+10216. Understanding collisional properties,
such as cross-sections ($\sigma _{j\rightarrow j^{\prime }}$) and
rate coefficients ($k_{j\rightarrow j^{\prime }}$), is important for
the reliable determination of molecular abundance. The non-reactive
collisions between NCCP and He species at low temperatures are the
subject of this study. Calculations are based on new ab initio potential
energy surface (PES) of NCCP-He. The PES calculations are carried out at
the CCSD(T)-F12a in conjunction with the aug-cc-pVTZ basis set. The PES
is found to have a global minimum towards the N end with a well depth
of -46.40 cm-1. The ab initio points are analytically fitted
on to the Legendre polynomial relevant for quantum scattering. From
this fitted PES, the integral inelastic rotational cross-sections
of NCCP with He collisions are computed for total energies up to
550 cm-1, using the accurate close coupling approach of
quantum mechanics. The resonances are observed at low total energies
due to quasi-bound states of the NCCP-He complex. Rate coefficients are
determined among the 19 lowest rotational levels of NCCP by thermally
averaging the cross-sections at low temperatures. The de-excitation
rate coefficients increase with decreasing Δj.
Title: Cosmological perturbations in the spatially covariant gravity
with a dynamical lapse function
Authors: Zhu, Xue-Zheng; Yu, Yang; Gao, Xian
Bibcode: 2022PhLB..83337356Z
Altcode: 2022arXiv220803629Z
We investigate the scalar perturbations in a class of spatially
covariant gravity theory with a dynamical lapse function. Generally,
there are two scalar degrees of freedom due to the presence of the
velocity of the lapse function. We treat the scalar perturbations as
analogues of those in a two-field inflationary mode, in which one is
light mode and the other is the heavy mode. This is justified by the
fact that the scalar mode due to the dynamical lapse function becomes
infinitely heavy in the limit when the lapse function reduces to
be an auxiliary variable. The standard approaches of multiple filed
perturbations can be applied to deal with our model. By integrating
out the heavy mode and derive the effective theory for the single
light field, we find the solution to the single mode in the form of
plane waves. Then we calculate the corrections to the power spectrum
of the light mode from the heavy mode, by making use of the standard
perturbative method of field theory. At last, when the two fields are
not weakly coupled, we find a power law mode for the coupled system
in large scales.
Title: Noble gases, cosmic ray exposure and radiogenic ages in
selected ordinary chondrites
Authors: Mahajan, Ramakant R.
Bibcode: 2022AdSpR..70.2112M
Altcode:
Noble gas isotopic ratios and concentrations provide powerful
constrains on the nature of trapped component presence in the
meteorites. Concentrations and isotopic composition of the noble
gases (He, Ne, Ar, Kr and Xe) in eleven bulk ordinary chondrites
(OCs), Mahadevpur (H4/5), Didwana-Rajod (H5), Monahans (1998) (H5),
Portales Valley (H6), Itawa Bhopji (L3-5), Jodiya (L5), Jalangi (L5/6),
Kaprada (L5/6), Devri-Khera (L6), Katol (L6) and Bruderheim (L6) are
presented. The aim of the study is to examine the exposure history and
radiogenic ages of the recent meteoritic falls. The results of stepwise
heating analyses indicate that noble gases are mixture of trapped and
cosmic ray produced. Neon isotopes are enriched from galactic cosmic ray
(GCR) produce gas, but many samples show a Q-type contribution. Argon
isotopes show 40Ar excesses (40Ar/36Ar
up to (42.6 ± 0.2) × 104), which is the decay product of
40K. Measured Kr and Xe isotopes in all the studied OCs
predominantly shows Q component. Minor contribution from primordial
noble gases of HL component is also observed in stepwise heating
extractions in few cases. Solar gases are absent in the specimens
studied here. The cosmic-ray exposure (CRE) ages of the OCs range
from 5.2 ± 0.9 Ma to 36.3 ± 6.7 Ma. These ages are within the range
typically observed for the respective meteorite types of OCs. However,
the CRE ages of many meteorites are inconsistent with peaks in the
exposure age histogram for respective sub classes of OCs, H and L
types. The nominal radiogenic age obtained from 40Ar ranges
between 0.87 ± 0.09 Ga to 4.57 ± 0.46 Ga in the meteorites with
exception of two meteorites. The 4He gas retention ages for
the OCs are in the range 0.27 ± 0.03 Ga to 4.40 ± 0.50 Ga, showing
different degree of degassing either at a thermal event on the parent
body. Radiogenic 129Xe from the decay of 129I
was observed in all the studied samples of OCs.
Title: Simulating Spectral Kurtosis Mitigation against Realistic
Radio Frequency Interference Signals
Authors: Smith, E.; Lynch, Ryan S.; Pisano, D. J.
Bibcode: 2022AJ....164..123S
Altcode: 2022arXiv220707642S
We investigate the effectiveness of the statistical radio
frequency interference (RFI) mitigation technique spectral
kurtosis ( $\widehat{{SK}}$ ) in the face of simulated realistic RFI
signals. $\widehat{{SK}}\,$ estimates the kurtosis of a collection of M
power values in a single channel and provides a detection metric that
is able to discern between human-made RFI and incoherent astronomical
signals of interest. We test the ability of $\widehat{{SK}}\,$ to flag
signals with various representative modulation types, data rates, duty
cycles, and carrier frequencies. We flag with various accumulation
lengths M and implement multiscale $\widehat{{SK}}$ , which combines
information from adjacent time-frequency bins to mitigate weaknesses in
single-scale $\widehat{{SK}}$ . We find that signals with significant
sidelobe emission from high data rates are harder to flag, as well
as signals with a 50% effective duty cycle and weak signal-to-noise
ratios. Multiscale $\widehat{{SK}}$ with at least one extra channel
can detect both the center channel and sideband interference, flagging
greater than 90% as long as the bin channel width is wider in frequency
than the RFI.
Title: Fast nodal precession of the disc around Pleione requires a
broken disc
Authors: Martin, Rebecca G.; Lepp, Stephen
Bibcode: 2022MNRAS.516L..86M
Altcode: 2022MNRAS.tmpL..87M; 2022arXiv220804063M
Pleione is a Be star that is in a 218-d orbit with a low-mass binary
companion. Recent numerical simulations have shown that a Be star disc
can be subject to breaking when material is actively being fed into
the inner parts of the disc. After breaking, the disc is composed of
two rings: an inner ring that is anchored to the stellar equator and
an outer ring that is free to nodally precess. A double ring disc may
explain some of the observed variability in Pleione. We model the nodal
precession of the outer disc ring that is driven by the companion on an
observed time-scale of $80.5\, \rm yr$. We find that the outer ring of
a broken disc in a binary with an eccentricity of eb = 0.6
can precess on the observed time-scale and have an outer radius that is
in rough agreement with the observed disc size. An unbroken disc model
cannot fit both the observed precession rate and disc size. Suppression
of Kozai-Lidov driven disc eccentricity is more likely for a high
binary eccentricity if the disc extends to the tidal truncation radius.
Title: On the thermal structure of the proto-super star cluster 13
in NGC 253
Authors: Rico-Villas, F.; González-Alfonso, E.; Martín-Pintado,
J.; Rivilla, V. M.; Martín, S.
Bibcode: 2022MNRAS.516.1094R
Altcode: 2022MNRAS.tmp.2149R; 2022arXiv220801941R
Using high angular resolution ALMA observations (0.02 arcsec ≍ 0.34
pc), we study the thermal structure and kinematics of the proto-super
star cluster 13 in the central region of NGC 253 through their continuum
and vibrationally excited HC3N emission from J = 24-23 and
J = 26-25 lines arising from vibrational states up to v4 =
1. We have carried 2D-LTE and non-local radiative transfer modelling
of the radial profile of the HC3N and continuum emission
in concentric rings of 0.1 pc width. From the 2D-LTE analysis, we
found a Super Hot Core (SHC) of 1.5 pc with very high vibrational
temperatures (>500 K), and a jump in the radial velocity (21 km
s-1) in the SE-NW direction. From the non-local models,
we derive the HC3N column density, H2 density,
and dust temperature (Tdust) profiles. Our results show that
the thermal structure of the SHC is dominated by the greenhouse effect
due to the high dust opacity in the IR, leading to an overestimation
of the LTE Tdust and its derived luminosity. The kinematics
and Tdust profile of the SHC suggest that star formation was
likely triggered by a cloud-cloud collision. We compare proto-SSC 13
to other deeply embedded star-forming regions, and discuss the origin
of the $L_\text{IR}/M_{\text{H}_2}$ excess above ~100 L⊙
M$_\odot ^{-1}$ observed in (U)LIRGs.
Title: OGLE-2019-BLG-1470LABc: Another microlensing giant planet in
a binary system?
Authors: Kuang, Renkun; Zang, Weicheng; Jung, Youn Kil; Udalski,
Andrzej; Yang, Hongjing; Mao, Shude; Albrow, Michael D.; Chung,
Sun-Ju; Gould, Andrew; Han, Cheongho; Hwang, Kyu-Ha; Ryu, Yoon-Hyun;
Shin, In-Gu; Shvartzvald, Yossi; Yee, Jennifer C.; Cha, Sang-Mok;
Kim, Dong-Jin; Kim, Hyoun-Woo; Kim, Seung-Lee; Lee, Chung-Uk; Lee,
Dong-Joo; Lee, Yongseok; Park, Byeong-Gon; Pogge, Richard W.; Mróz,
Przemek; Skowron, Jan; Poleski, Radoslaw; Szymański, Michał K.;
Soszyński, Igor; Pietrukowicz, Paweł; Kozłowski, Szymon; Ulaczyk,
Krzysztof; Rybicki, Krzysztof A.; Iwanek, Patryk; Wrona, Marcin;
Gromadzki, Mariusz; Wang, Hanyue; Huang, Shuo; Zhu, Wei
Bibcode: 2022MNRAS.516.1704K
Altcode: 2022arXiv220405606K; 2022MNRAS.tmp.2206K
We report the discovery and analysis of a candidate triple-lens
single-source (3L1S) microlensing event, OGLE-2019-BLG-1470. This event
was first classified as a normal binary-lens single-source (2L1S) event,
but a careful 2L1S modelling showed that it needs an additional lens
or source to fit the observed data. It is found that the 3L1S model
provides the best fit, but the binary-lens binary-source (2L2S) model
is only disfavoured by Δχ2 ≃ 18. All of the feasible
models include a planet with planet-to-host mass-ratios 10-3
≲ q ≲ 10-2. A Bayesian analysis based on a Galactic model
indicates that the planet is super-Jovian, and the projected host-planet
separation is about 3 au. Specifically, for the best-fitting 3L1S
model, the two stars have masses of $M_1=0.57^{+0.43}_{-0.32}{\rm
M}_{\odot}$, and $M_2=0.18^{+0.15}_{-0.10}\mathrm{M}_{\odot}$
with projected separation of $1.3^{+0.5}_{-0.5}$ au, and the
planetary mass is $M_3=2.2^{+1.8}_{-1.3}M_{\rm {Jupiter}}$. For
the 2L2S model, the masses of the host star and the planet are
$0.55^{+0.44}_{-0.31}\mathrm{M}_{\odot }$ and $4.6^{+3.7}_{-2.6}M_{\rm
{Jupiter}}$, respectively. By investigating the properties of
all known microlensing planets in binary systems, we find that all
planets in binary systems published by the KMTNet survey are located
inside the resonant caustics range with q ≳ 2 × 10-3,
indicating the incompleteness of the KMTNet sample for planets in
binary systems. Thus, planets in binary systems cannot be included in
the current study of the KMTNet mass-ratio function, and a systematic
search for planetary anomalies in KMTNet microlensing light curves of
binary systems is needed.
Title: High resolution X-ray spectroscopy of V4641 Sgr during its
2020 outburst
Authors: Shaw, A. W.; Miller, J. M.; Grinberg, V.; Buisson, D. J. K.;
Heinke, C. O.; Plotkin, R. M.; Tomsick, J. A.; Bahramian, A.; Gandhi,
P.; Sivakoff, G. R.
Bibcode: 2022MNRAS.516..124S
Altcode: 2022arXiv220801732S; 2022MNRAS.tmp.2123S
We observed the Galactic black hole X-ray binary V4641 Sgr with the
high resolution transmission gratings on Chandra during the source's
2020 outburst. Over two epochs of Chandra gratings observations,
we see numerous highly ionized metal lines, superimposed on a hot,
disc-dominated X-ray continuum. The measured inner disc temperatures
and luminosities imply an unfeasibly small inner disc radius, such
that we suggest that the central engine of V4641 Sgr is obscured,
and we are viewing scattered X-rays. We find that the emission lines
in the Chandra spectra cannot be constrained by a single photoionized
model, instead finding that two separate photoionized model components
are required, one to reproduce the iron lines and a second for the
other metals. We compare the observed X-ray spectra of V4641 Sgr to
optical studies during previous outbursts of the source, suggesting
that the lines originate in an accretion disc wind, potentially with
a spherical geometry.
Title: Standardizing reverberation-measured C IV time-lag quasars, and
using them with standardized Mg II quasars to constrain cosmological
parameters
Authors: Cao, Shulei; Zajaček, Michal; Panda, Swayamtrupta;
Martínez-Aldama, Mary Loli; Czerny, Bożena; Ratra, Bharat
Bibcode: 2022MNRAS.516.1721C
Altcode: 2022arXiv220515552C; 2022MNRAS.tmp.2223C
We use 38 C IV quasar (QSO) reverberation-mapped observations, which
span eight orders of magnitude in luminosity and the redshift range
0.001064 ≤ z ≤ 3.368, to simultaneously constrain cosmological-model
and QSO radius-luminosity (R-L) relation parameters in six cosmological
models, using an improved technique that more correctly accounts for
the asymmetric errors bars of the time-lag measurements. We find that
R-L relation parameters are independent of the cosmological models used
in the analysis and so the R-L relation can be used to standardize the
C IV QSOs. The C IV QSO cosmological constraints are consistent with
those from Mg II QSOs, allowing us to derive joint C IV + Mg II QSO
cosmological constraints which are consistent with currently accelerated
cosmological expansion, as well as consistent with cosmological
constraints derived using better-established baryon acoustic oscillation
(BAO) and Hubble parameter [H(z)] measurements. When jointly analysed
with H(z) + BAO data, current C IV + Mg II QSO data mildly tighten
current H(z) + BAO data cosmological constraints.
Title: The importance of black hole repositioning for galaxy formation
simulations
Authors: Bahé, Yannick M.; Schaye, Joop; Schaller, Matthieu; Bower,
Richard G.; Borrow, Josh; Chaikin, Evgenii; Kugel, Roi; Nobels,
Folkert; Ploeckinger, Sylvia
Bibcode: 2022MNRAS.516..167B
Altcode: 2021arXiv210901489B; 2022MNRAS.tmp.1324B
Active galactic nucleus (AGN) feedback from accreting supermassive
black holes (SMBHs) is an essential ingredient of galaxy formation
simulations. The orbital evolution of SMBHs is affected by dynamical
friction that cannot be predicted self-consistently by contemporary
simulations of galaxy formation in representative volumes. Instead,
such simulations typically use a simple 'repositioning' of SMBHs,
but the effects of this approach on SMBH and galaxy properties
have not yet been investigated systematically. Based on a suite of
smoothed particle hydrodynamics simulations with the SWIFT code and
a Bondi-Hoyle-Lyttleton sub-grid gas accretion model, we investigate
the impact of repositioning on SMBH growth and on other baryonic
components through AGN feedback. Across at least a factor ~1000 in
mass resolution, SMBH repositioning (or an equivalent approach) is
a necessary prerequisite for AGN feedback; without it, black hole
growth is negligible. Limiting the effective repositioning speed to
≲10 km s-1 delays the onset of AGN feedback and severely
limits its impact on stellar mass growth in the centre of massive
galaxies. Repositioning has three direct physical consequences. It
promotes SMBH mergers and thus accelerates their initial growth. In
addition, it raises the peak density of the ambient gas and reduces
the SMBH velocity relative to it, giving a combined boost to the
accretion rate that can reach many orders of magnitude. Our results
suggest that a more sophisticated and/or better calibrated treatment
of SMBH repositioning is a critical step towards more predictive galaxy
formation simulations.
Title: H I properties of satellite galaxies around local volume hosts
Authors: Karunakaran, Ananthan; Spekkens, Kristine; Carroll, Rhys;
Sand, David J.; Bennet, Paul; Crnojević, Denija; Jones, Michael G.;
Mutlu-Pakdıl, Burçın
Bibcode: 2022MNRAS.516.1741K
Altcode: 2022arXiv220611907K; 2022MNRAS.tmp.2236K
We present neutral atomic hydrogen (H I) observations using the Robert
C. Byrd Green Bank Telescope along the lines of sight to 49 confirmed
or possible dwarf satellite galaxies around eight Local Volume systems
(M104, M51, NGC 1023, NGC 1156, NGC 2903, NGC 4258, NGC 4565, and NGC
4631). We detect the H I reservoirs of two candidates (dw0934+2204 and
dw1238-1122) and find them to be background sources relative to their
nearest foreground host systems. The remaining 47 satellite candidates
are not detected in H I, and we place stringent 5σ upper limits on
their H I mass. We note that some (15/47) of our non-detections stem
from satellites being occluded by their putative host's H I emission. In
addition to these new observations, we compile literature estimates
on the H I mass for an additional 17 satellites. We compare the H I
properties of these satellites to those within the Local Group, finding
broad agreement between them. Crucially, these observations probe a
'transition' region between -10 ≳ MV ≳ -14 where we
see a mixture of gas-rich and gas-poor satellites. While there are
many gas-poor satellites within this region, some are gas-rich and
this suggests that the transition towards predominantly gas-rich
satellites occurs at LV ~ 107L⊙,
in line with simulations. The observations presented here are a key
step toward characterizing the properties of dwarf satellite galaxies
around Local Volume systems and future wide-field radio surveys with
higher angular resolution (e.g. WALLABY) will vastly improve upon the
study of such systems.
Title: Milky Way-like galaxies: stellar population properties of
dynamically defined discs, bulges and stellar haloes
Authors: Ortega-Martinez, Sara; Obreja, Aura; Dominguez-Tenreiro,
Rosa; Pedrosa, Susana E.; Rosas-Guevara, Yetli; Tissera, Patricia B.
Bibcode: 2022MNRAS.516..197O
Altcode: 2022arXiv220708776O; 2022MNRAS.tmp.1950O
The formation of galaxies can be understood in terms of the assembly
patterns of each type of galactic component. To perform this kind of
analysis, it is necessary to define some criteria to separate those
components. Decomposition methods based on dynamical properties are
more physically motivated than photometry-based ones. We use the
unsupervised Gaussian Mixture model of galactic structure finder to
extract the components of a sub-sample of galaxies with Milky Way-like
masses from the EAGLE simulations. A clustering in the space of first-
and second-order dynamical moments of all identified substructures
reveals five types of galaxy components: thin and thick discs, stellar
haloes, bulges and spheroids. We analyse the dynamical, morphological
and stellar population (SP) properties of these five component types,
exploring to what extent these properties correlate with each other,
and how much they depend on the total galaxy stellar and dark matter
halo masses. All galaxies contain a bulge, a stellar halo and a disc. In
total, 60 per cent of objects host two discs (thin and thick), and 68
per cent host also a spheroid. The dynamical disc-to-total ratio does
not depend on stellar mass, but the median rotational velocities of the
two discs do. Thin discs are well separated in stellar ages, [Fe/H]
and α-enhancement from the three dispersion-dominated components,
while thick discs are in between. Except for thin discs, all components
show correlations among their SP properties: older ages mean lower
metallicities and larger α-enhancement. Finally, we quantify the weak
dependence of SP properties on each component's dynamics.
Title: Magnetic support for neutrino-driven explosion of 3D
non-rotating core-collapse supernova models
Authors: Matsumoto, J.; Asahina, Y.; Takiwaki, T.; Kotake, K.;
Takahashi, H. R.
Bibcode: 2022MNRAS.516.1752M
Altcode: 2022MNRAS.tmp.2214M; 2022arXiv220207967M
The impact of the magnetic field on post-bounce supernova
dynamics of non-rotating stellar cores is studied by performing 3D
magnetohydrodynamics simulations with spectral neutrino transport. The
explodability of strongly and weakly magnetized models of 20 and 27
M⊙ pre-supernova progenitors are compared. We find that
although the efficiency for the conversion of the neutrino heating
into turbulent energy including magnetic fields in the gain region is
not significantly different between the strong and weak field models,
the amplified magnetic field due to the neutrino-driven convection
on large hot bubbles just behind stalled shock results in a faster
and more energetic explosion in the strongly magnetized models. In
addition, by comparing the difference between the 2nd- and 5th-order
spatial accuracy of the simulation in the strong field model for
27 M⊙ progenitor, we also find that the higher order
accuracy in space is beneficial to the explosion because it enhances
the growth of neutrino-driven convection in the gain region. Based on
our results of core-collapse supernova simulations for the non-rotating
model, a new possibility for the origin of the magnetic field of the
protoneutron star (PNS) is proposed. The magnetic field is accumulated
and amplified to magnetar level, that is, $\mathcal {O}(10^{14})$ G,
in the convectively stable shell near the PNS surface.
Title: HIPASS study of southern ultradiffuse galaxies and low surface
brightness galaxies
Authors: Zhou, Yun-Fan; Sengupta, Chandreyee; Chandola, Yogesh; Wong,
O. Ivy; Scott, Tom C.; Ma, Yin-Zhe; Chen, Hao
Bibcode: 2022MNRAS.516.1781Z
Altcode: 2022MNRAS.tmp.2230Z; 2022arXiv220808640Z
We present results from an H I counterpart search using the HI Parkes
All Sky Survey (HIPASS) for a sample of low surface brightness galaxies
(LSBGs) and ultradiffuse galaxies (UDGs) identified from the Dark Energy
Survey (DES). We aimed to establish the redshifts of the DES LSBGs
to determine the UDG fraction and understand their properties. Out
of 409 galaxies investigated, none were unambiguously detected in H
I. Our study was significantly hampered by the high spectral rms of
HIPASS and thus in this paper we do not make any strong conclusive
claims but discuss the main trends and possible scenarios our results
reflect. The overwhelming number of non-detections suggest that
(a) Either all the LSBGs in the groups, blue or red, have undergone
environment aided pre-processing and are H I deficient or the majority
of them are distant galaxies, beyond the HIPASS detection threshold. (b)
The sample investigated is most likely dominated by galaxies with H I
masses typical of dwarf galaxies. Had there been Milky Way (MW) size
(Re) galaxies in our sample, with proportionate H I content,
they would have been detected, even with the limitations imposed by
the HIPASS spectral quality. This leads us to infer that if some of the
LSBGs have MW-size optical diameters, their H I content is possibly in
the dwarf range. More sensitive observations using the SKA precursors
in future may resolve these questions.
Title: Revisiting the evidences for spectral anomalies in distant
blazars: New data on the photon-ALP mixing
Authors: Cenedese, Francesco; Franceschini, Alberto; Galanti, Giorgio
Bibcode: 2022MNRAS.516..216C
Altcode: 2022arXiv220408865C; 2022MNRAS.tmp.2090C
We re-examine possible dependencies on redshift of the spectral
parameters of blazars observed at very-high energies (VHEs) with Imaging
Atmospheric Cherenkov telescopes. This is relevant to assess potential
effects with the source distance of the photon to axion-like particle
mixing that would deeply affect the propagation of VHE photons across
the Universe. We focus our spectral analysis on 38 BL Lac objects
(32 high-peaked and 6 intermediate-peaked) up to redshift z ≃ 0.5,
and a small sample of 5 Flat Spectrum Radio Quasars up to z = 1 treated
independently to increase the redshift baseline. The 78 independent
spectra of these sources are first of all carefully corrected for the
gamma-gamma interaction with photons of the Extragalactic Background
Light that are responsible for the major redshift-dependent opacity
effect. Then, the corrected spectra are fitted with simple power laws
to infer the intrinsic spectral indices Γem at VHE, to
test the assumption that such spectral properties are set by the local
rather than the global cosmological environment. We find some systematic
anticorrelations with redshift of Γem that might indicate,
although with low-significance, a spectral anomaly potentially requiring
a revision of the photon propagation process. More conclusive tests
with higher statistical significance will require the observational
improvements offered by the forthcoming new generation of Cherenkov
arrays (CTA, ASTRI, LHAASO).
Title: Red Dragon: a redshift-evolving Gaussian mixture model for
galaxies
Authors: Black, William K.; Evrard, August
Bibcode: 2022MNRAS.516.1170B
Altcode: 2022MNRAS.tmp.1923B; 2022arXiv220410141B
Precision-era optical cluster cosmology calls for a precise definition
of the red sequence (RS), consistent across redshift. To this end,
we present the Red Dragon algorithm: an error-corrected multivariate
Gaussian mixture model (GMM). Simultaneous use of multiple colours
and smooth evolution of GMM parameters result in a continuous RS
and blue cloud (BC) characterization across redshift, avoiding the
discontinuities of red fraction inherent in swapping RS selection
colours. Based on a mid-redshift spectroscopic sample of SDSS galaxies,
an RS defined by Red Dragon selects quiescent galaxies (low specific
star formation rate) with a balanced accuracy of over $90{{\ \rm per\
cent}}$. This approach to galaxy population assignment gives more
natural separations between RS and BC galaxies than hard cuts in
colour-magnitude or colour-colour spaces. The Red Dragon algorithm is
publicly available at bitbucket.org/wkblack/red-dragon-gamma/.
Title: Characterization of the eclipsing post-common-envelope binary
TIC 60040774
Authors: Priyatikanto, R.; Knigge, C.; Scaringi, S.; Brink, J.;
Buckley, D. A. H.
Bibcode: 2022MNRAS.516.1183P
Altcode: 2022arXiv220802986P; 2022MNRAS.tmp.2093P
Binaries with a white dwarf primary and a main sequence secondary
can be used to test our understanding of both single and binary
star evolution. A small fraction of such systems experienced a
common-envelope phase from which they emerged with a relatively short
orbital period. Here, we present the characterization of an eclipsing
post-common-envelope binary of this kind, TIC 60040774, based on the
light curve provided by the Transiting Exoplanet Survey Satellite
(TESS), multiband photometry collated from the virtual observatory,
and spectroscopic data obtained the Southern African Large Telescope
(SALT). With an orbital period of 0.404807 ± 0.000149 d this system
consists of a young white dwarf paired with an M6.5 dwarf companion. We
estimate the masses of the primary and secondary to be 0.598 ± 0.029
M⊙ and 0.107 ± 0.020 M⊙, while the effective
temperatures are 14050 ± 360 K and 2759 ± 50 K, respectively. The
eclipse ingress and egress profile is shallower than expected from a
simple geometric model such that more precise high-cadence photometry is
required to understand the nature of this system. Given the similarity
of TIC 60040774 to systems like GK Vir and NN Ser, it will be worth
tracking its eclipse times to check for the presence of one or more
circumbinary planets.
Title: Solving small-scale clustering problems in approximate
light-cone mocks
Authors: Smith, Alex; Cole, Shaun; Grove, Cameron; Norberg, Peder;
Zarrouk, Pauline
Bibcode: 2022MNRAS.516.1062S
Altcode: 2022arXiv220608763S
Realistic light-cone mocks are important in the clustering analyses
of large galaxy surveys. For simulations where only the snapshots are
available, it is common to create approximate light-cones by joining
together the snapshots in spherical shells. We assess the two-point
clustering measurements of central galaxies in approximate light-cones
built from the Millennium-XXL simulation, which are constructed using
different numbers of snapshots. The monopole and quadrupole of the
real-space correlation function is strongly boosted on small scales
below 1 h-1 Mpc, due to some galaxies being duplicated at
the boundaries between snapshots in the light-cone. When more snapshots
are used, the total number of duplicated galaxies is approximately
constant, but they are pushed to smaller separations. The effect of
this in redshift space is small, as long as the snapshots are cut into
shells in real space. Randomly removing duplicated galaxies is able
to reduce the excess clustering signal. Including satellite galaxies
will reduce the impact of the duplicates, since many small-scale pairs
come from satellites in the same halo. Galaxies that are missing from
the light-cone at the boundaries can be added to the light-cone by
having a small overlap between each shell. This effect will impact
analyses that use very small-scale clustering measurements, and when
using mocks to test the impact of fibre collisions.
Title: Secular variation of magnetic declination for the past 500
years from Empire to Republic in Anatolia
Authors: Maden, Nafiz; Yıldız, Burak
Bibcode: 2022PEPI..33106913M
Altcode:
Seydi Ali Reis first mentioned the declination angle in his
book titled Kitab-ı Muhit in 1554. Kitab-ı Cihannüma (1654),
Füyuzat-i Mıknatisiye (1731), and Mârifetname (1757) gave the
magnetic declination angle values in Anatolia. We have compiled
magnetic declination data from 1500 to the present day in Anatolia
and Istanbul. The plot of the magnetic declination angle was drawn
for the first time using historical data between 1500 and 1947 for
Istanbul. Three new magnetic declination maps for the periods of
1909-1910, 1970 and 2009 were produced for Turkey. The annual change map
based on the data of 1970 and 2009 is also given for whole Turkey. The
agonic line extending in NW-SE direction between Sinop and Antep divides
Anatolia into two regions in 1910. The mean declination values obtained
from qibla direction measurements made by the Presidency of Religious
Affairs in all mosques give 3.11° E for 1970 and 4.74° E for 2009
in Turkey.
Title: A TESS search for donor-star pulsations in high-mass X-ray
binaries
Authors: Ramsay, Gavin; Hakala, Pasi; Charles, Philip A.
Bibcode: 2022MNRAS.516.1219R
Altcode: 2022arXiv220802064R; 2022MNRAS.tmp.2128R
Ground-based optical photometry of the counterparts of high-mass X-ray
binaries (HMXBs) has revealed the presence of periodic modulations on
time-scales of ~0.3-0.5 d. More recent space-based observations (CoRoT
and TESS) of OB and Be stars have shown that pulsations caused by p and
g modes are common in early-type stars. We have therefore undertaken
a systematic search for variability in the optical counterparts of 23
HMXBs (mostly neutron star systems, but including one black hole, Cyg
X-1) using TESS data primarily in 2 min cadence mode. After removing the
orbital period modulation in four systems, we find that all 23 sources
show evidence for quasi-periodic variability on periods shorter than
~1 d. We compare their power spectra with those from observations of
other OB- and Be-type stars. In two systems, V725 Tau and HD 249179
(which may not be an HMXB), we find evidence for an outburst, the
former being simultaneous with an X-ray flare. We search for changes
in the power spectra over the outburst duration and compare them with
outbursts seen in other Be systems.
Title: BD+47 378: An Eclipsing Binary Containing a δ Sct Pulsating
Star
Authors: Hong, Kyeongsoo; Woo Lee, Jae; Rittipruk, Pakakaew; Park,
Jang-Ho; Kim, Hye-Young; Han, Cheongho
Bibcode: 2022AJ....164..121H
Altcode:
New high-resolution spectra of the eclipsing binary BD+47 378 were
obtained on five nights between 2020 and 2021 with the Bohyunsan
Observatory Echelle Spectrograph in Korea. We collected the TESS light
curve of the system obtained from Sectors 17 to 18, which shows a flat
bottom at the secondary eclipse, an O'Connell effect, and oscillation
features. From the spectral analysis, the radial velocities (RVs) of the
primary and secondary stars were obtained, and the temperature of the
brighter and more massive primary component was determined to be 7140
± 100 K. According to a simultaneous analysis of the double-lined RVs
and TESS light curves, the masses and radii of both components are M
1 = 1.69 ± 0.03 M ⊙, M 2 = 0.80 ±
0.02 M ⊙, R 1 = 2.01 ± 0.01 R ⊙,
and R 2 = 0.79 ± 0.01 R ⊙, respectively. The
primary component of the system is located on the δ Sct and γ Dor
instability strips. After subtracting the theoretical light curve
from the TESS data, a total of four independent frequencies (5.7235
day-1, 6.2577 day-1, 6.9588 day-1, and
14.7675 day-1) were detected using the multiple frequency
analysis. These frequencies are typical of a δ Sct pulsator. The
results reveal that BD+47 378 is a detached system consisting of two
main-sequence stars with a δ Sct type primary component.
Title: Kiloparsec-scale Radio Structure in z 0.25 Radio-quiet QSOs
Authors: McCaffrey, Trevor V.; Kimball, Amy E.; Momjian, Emmanuel;
Richards, Gordon T.
Bibcode: 2022AJ....164..122M
Altcode: 2022arXiv220713792M
We present analysis of a homogeneous, optically selected, volume-limited
(0.2 < z < 0.3) sample of 128 radio-quiet quasi-stellar objects
(QSOs) recently observed at 6 GHz with the Very Large Array (VLA) in
A configuration (~0.″33 resolution). We compare these new results to
earlier (2010-2011) 6 GHz observations with the VLA in C configuration
(~3.″5). While all of these radio-quiet QSOs (RQQs) were unresolved
on a 3.″5 scale (~14 kpc at z = 0.25), we resolve notable complex
subgalactic structures in about half of the RQQs at 0.″33 resolution
(~1.3 kpc at z = 0.25). By comparison of flux density measurements
between the two sets of observations, we demonstrate that significant
sub-galactic-scale radio structure is present in at least 70% of the
RQQ population and that the central component accounts for an average
of ≍65% of the total detected radio power. One RQQ, J0935+4819,
shows striking symmetric, double-lobed morphology and appears to
be the first identified example of a radio-quiet QSO with FR II type
morphology on ~arcsec scale (projected size of ≳6 kpc). In addition to
revealing RQQ subgalactic morphology, we employ counterparts from legacy
(FIRST at 1.4 GHz) and recent (VLA Sky Survey at 3 GHz) VLA surveys
to investigate radio spectral indices and potential variability over
decades-long timescales for a subset of the RQQs and for the cores of
radio-intermediate and radio-loud sources in the parent sample of 178
QSOs. These results support the growing notion that the RQQ population
is not a monolithic phenomenon but instead consists of a mixture of
mainly starburst-powered and jet-powered galaxies.
Title: The effect of magnetic field on the inner Galactic rotation
curve
Authors: Chan, Man Ho; Del Popolo, Antonino
Bibcode: 2022MNRAS.516L..72C
Altcode: 2022MNRAS.tmpL..84C; 2022arXiv220806098C
In the past few decades, some studies pointed out that magnetic field
might affect the rotation curves in galaxies. However, the impact
is relatively small compared with the effects of dark matter and
the baryonic components. In this letter, we revisit the impact of
magnetic field on the rotation curve of our Galaxy. We show that the
inner Galactic rotation curve could be affected significantly by the
magnetic field. The addition of the inner bulge component, which has
been proposed previously to account for the inner rotation curve data,
is not necessary. The magnetic field contribution can fully account
for the excess of the inner rotation velocity between 5 to 50 pc from
the Galactic Centre. Our analysis can also constrain the azimuthal
component of the central regular magnetic field strength to $B_0 \sim
50-60\, \mu$G, which is consistent with the observed range.
Title: Colour evolution of Betelgeuse and Antares over two millennia,
derived from historical records, as a new constraint on mass and age
Authors: Neuhäuser, R.; Torres, G.; Mugrauer, M.; Neuhäuser, D. L.;
Chapman, J.; Luge, D.; Cosci, M.
Bibcode: 2022MNRAS.516..693N
Altcode: 2022arXiv220704702N; 2022MNRAS.tmp.2009N
After core hydrogen burning, massive stars evolve from blue-white
dwarfs to red supergiants by expanding, brightening, and cooling within
few millennia. We discuss a previously neglected constraint on mass,
age, and evolutionary state of Betelgeuse and Antares, namely their
observed colour evolution over historical times: We place all 236
stars bright enough for their colour to be discerned by the unaided
eye (V ≤ 3.3 mag) on the colour-magnitude-diagram (CMD), and focus
on those in the Hertzsprung gap. We study pre-telescopic records on
star colour with historically critical methods to find stars that have
evolved noticeably in colour within the last millennia. Our main result
is that Betelgeuse was recorded with a colour significantly different
(non-red) than today (red, B - V = 1.78 ± 0.05 mag). Hyginus (Rome)
and Sima Qian (China) independently report it two millennia ago as
appearing like Saturn (B - V = 1.09 ± 0.16 mag) in colour and 'yellow'
(quantifiable as B - V = 0.95 ± 0.35 mag), respectively (together,
5.1σ different from today). The colour change of Betelgeuse is a new,
tight constraint for single-star theoretical evolutionary models (or
merger models). It is most likely located less than one millennium
past the bottom of the red giant branch, before which rapid colour
evolution is expected. Evolutionary tracks from MIST consistent with
both its colour evolution and its location on the CMD suggest a mass
of ~14 M⊙ at ~14 Myr. The (roughly) constant colour of
Antares for the last three millennia also constrains its mass and
age. Wezen was reported white historically, but is now yellow.
Title: A Chandra survey of milky way globular clusters -
III. Searching for X-ray signature of intermediate-mass black holes
Authors: Su, Zhao; Li, Zhiyuan; Hou, Meicun; Zhang, Mengfei; Cheng,
Zhongqun
Bibcode: 2022MNRAS.516.1788S
Altcode: 2022MNRAS.tmp.2218S; 2022arXiv220600284S
Globular clusters (GCs) are thought to harbor the long-sought population
of intermediate-mass black holes (IMBHs). We present a systematic
search for a putative IMBH in 81 Milky Way GCs, based on archival
Chandra X-ray observations. We find in only six GCs a significant X-ray
source positionally coincident with the cluster centre, which have
0.5-8 keV luminosities between ~1 × 1030 erg s-1
and ~4 × 1033 erg s-1. However, the spectral and
temporal properties of these six sources can also be explained in terms
of binary stars. The remaining 75 GCs do not have a detectable central
source, most with 3σ upper limits ranging between 1029-32
erg s-1 over 0.5-8 keV, which are significantly lower than
predicted for canonical Bondi accretion. To help understand the feeble
X-ray signature, we perform hydrodynamic simulations of stellar wind
accretion on to a 1000 M⊙ IMBH from the most-bound orbiting
star, for stellar wind properties consistent with either a main-sequence
(MS) star or an asymptotic giant branch (AGB) star. We find that the
synthetic X-ray luminosity for the MS case ($\sim 10^{19}\rm ~erg \,
s^{-1}$) is far below the current X-ray limits. The predicted X-ray
luminosity for the AGB case ($\sim 10^{34}\rm ~erg \, s^{-1}$), on the
other hand, is compatible with the detected central X-ray sources, in
particular the ones in Terzan 5 and NGC 6652. However, the probability
of having an AGB star as the most-bound star around the putative IMBH
is very low. Our study strongly suggests that it is very challenging
to detect the accretion-induced X-ray emission from IMBHs, even if
they were prevalent in present-day GCs.
Title: Tracing the environmental history of observed galaxies via
extended fast action minimization method
Authors: Sarpa, E.; Longobardi, A.; Kraljic, K.; Veropalumbo, A.;
Schimd, C.
Bibcode: 2022MNRAS.516..231S
Altcode: 2022arXiv220409709S; 2022MNRAS.tmp.2026S
We present a novel application of the extended Fast Action Minimization
method (eFAM) aimed at assessing the role of the environment in shaping
galaxy evolution and validate our approach against the Magneticum
hydrodynamical simulation. We consider the z ≃ 0 snapshot as our
observed catalogue and use the reconstructed trajectories of galaxies to
model the evolution of cosmic structures. At the statistical level, the
fraction of volume occupied by voids, sheets, filaments, and clusters
in the reconstructed and simulated high-redshift snapshots agree within
1σ. Locally, we estimate the accuracy of eFAM structures by computing
their purity with respect to simulated structures, P, at the cells of
a regular grid. Up to z = 1.2, clusters have 0.58 < P < 0.93,
filaments vary in 0.90 < P < 0.99, sheets show 0.78 < P <
0.92, and voids have 0.90 < P < 0.92. As redshift increases,
comparing reconstructed and simulated tracers becomes more difficult and
the purity decreases to P ~ 0.6. We retrieve the environmental history
of individual galaxies by tracing their trajectories through the cosmic
web and relate their observed gas fraction, fgas, with
the time spent within different structures. For galaxies in clusters
and filaments, eFAM reproduces the dependence of fgas on
the redshift of accretion/infall as traced by the simulations with a
1.5σ statistical agreement (which decreases to 2.5σ for low-mass
galaxies in filaments). These results support the application of
eFAM to observational data to study the environmental dependence of
galaxy properties, offering a complementary approach to that based on
light-cone observations.
Title: Observability of forming planets and their circumplanetary
discs - IV. With JWST and ELT
Authors: Chen, Xueqing; Szulágyi, Judit
Bibcode: 2022MNRAS.516..506C
Altcode: 2022MNRAS.tmp.1928C; 2021arXiv211212821C
To understand the potential for observing forming planets and their
circumplanetary discs (CPDs) with James Webb Space Telescope (JWST)
and Extremely Large Telescope (ELT), we created mock observations from
three-dimensional radiative hydrodynamic simulations and radiative
transfer post-processing for planets with 10, 5, and 1 Jupiter
and 1 Saturn masses with orbital separation of 50 and 30 au in 0,
30, and 60○ inclinations. Instrumental effects were
then simulated with Mirage for JWST/NIRCam and NIRISS, MIRISim for
JWST/MIRI, and SimCADO and SimMETIS for ELT/MICADO and METIS. We found
that the longer wavelengths (mid-infrared and beyond) are the best to
detect CPDs, since they allow CPD of planet with smaller mass to be
detected. MIRI on JWST and METIS on ELT offer the best possibility
on these telescopes. Specifically, below 3 $\mu{\rm m}$, only 10
MJup planets with their CPDs are detectable with NIRCam
and MICADO. 5 MJup planets are only detectable if at 30 au
(i.e. closer) orbital separation. Planets above 5 MJup
with their CPDs are detectable between 3 and 5 $\mu{\rm m}$ with
NIRCam and METIS L/M band, or above 10 $\mu{\rm m}$ with MIRI and
METIS N band. For ≤1 MJup planets >15 $\mu{\rm m}$
are needed, where MIRI uniquely offers imaging capability. We present
magnitudes and spectral energy distributions for separate components of
the planet + CPD + circumstellar disc (CSD) system, to differentiate
the extinction rates of CPDs and CSDs and to provide predictions for
observational proposals. Because the CPD turns out to be the main
absorber of the planet's emission, especially <10 $\mu{\rm m}$,
this makes the detection of forming planets quite challenging.
Title: Solar and stellar activity cycles - no synchronization with
exoplanets
Authors: Obridko, V. N.; Katsova, M. M.; Sokoloff, D. D.
Bibcode: 2022MNRAS.516.1251O
Altcode: 2022arXiv220806190O; 2022MNRAS.tmp.2179O
Cyclic activity on the Sun and stars is primarily explained by
the generation of the magnetic field by a dynamo mechanism, which
converts the energy of the poloidal field into the energy of the
toroidal component due to differential rotation . There is, however,
an alternative point of view, which explains the field generation
by the gravitational influence of the planetary system and, first
of all, Jupiter. This hypothesis can be verified by comparing the
characteristics of exoplanets with the activity variations on their
associated stars. We have performed such a comparison and have drawn
a negative conclusion. No relationship between the gravitational
influence of the exoplanets and cycle of the host star could be found
in any of the cases considered. Moreover, there are reasons to believe
that a strong gravitational influence may completely eliminate cyclic
variation in stellar activity.
Title: The physical origin for spatially large scatter of IGM
opacity at the end of reionization: The IGM Lyα opacity-galaxy
density relation
Authors: Ishimoto, Rikako; Kashikawa, Nobunari; Kashino, Daichi; Ito,
Kei; Liang, Yongming; Cai, Zheng; Yoshioka, Takehiro; Okoshi, Katsuya;
Misawa, Toru; Onoue, Masafusa; Takeda, Yoshihiro; Uchiyama, Hisakazu
Bibcode: 2022MNRAS.515.5914I
Altcode: 2022arXiv220705098I
The large opacity fluctuations in the z > 5.5 Lyα forest may
indicate inhomogeneous progress of reionization. To explain the observed
large scatter of the effective Lyα optical depth (τeff)
of the intergalactic medium (IGM), fluctuation of UV background
(Γ model), or the IGM gas temperature (T model) have been proposed,
which predict opposite correlations between τeff and galaxy
density. In order to address which model can explain the large scatter
of τeff, we search for Lyα emitters (LAEs) around two
(J1137+3549 and J1602+4228) quasar sightlines with τeff
~ 3 and J1630+4012 sightline with τeff ~ 5.5. Using
a narrow-band imaging with Subaru/Hyper Suprime-Cam, we draw LAE
density maps to explore their spatial distributions. Overdensities
are found within 20 h-1 Mpc of the quasar sightlines in the
low-τeff regions, while a deficit of LAEs is found in the
high τeff region. Although the τeff of the
three quasar sightlines are neither high nor low enough to clearly
distinguish the two models, these observed τeff-galaxy
density relations all consistently support the Γ model rather than
the T model in the three fields, along with the previous studies. The
observed overdensities near the low-τeff sightlines
may suggest that the relic temperature fluctuation does not affect
reionization that much. Otherwise, these overdensities could be
attributed to other factors besides the reionization process, such as
the nature of LAEs as poor tracers of underlying large-scale structures.
Title: Accelerating astronomical and cosmological inference with
preconditioned Monte Carlo
Authors: Karamanis, Minas; Beutler, Florian; Peacock, John A.;
Nabergoj, David; Seljak, Uroš
Bibcode: 2022MNRAS.516.1644K
Altcode: 2022arXiv220705652K; 2022MNRAS.tmp.2186K
We introduce preconditioned Monte Carlo (PMC), a novel Monte Carlo
method for Bayesian inference that facilitates efficient sampling of
probability distributions with non-trivial geometry. PMC utilizes a
Normalizing Flow (NF) in order to decorrelate the parameters of the
distribution and then proceeds by sampling from the preconditioned
target distribution using an adaptive Sequential Monte Carlo (SMC)
scheme. The results produced by PMC include samples from the posterior
distribution and an estimate of the model evidence that can be used
for parameter inference and model comparison, respectively. The
aforementioned framework has been thoroughly tested in a variety
of challenging target distributions achieving state-of-the-art
sampling performance. In the cases of primordial feature analysis
and gravitational wave inference, PMC is approximately 50 and 25 times
faster, respectively, than nested sampling (NS). We found that in higher
dimensional applications, the acceleration is even greater. Finally,
PMC is directly parallelisable, manifesting linear scaling up to
thousands of CPUs.
Title: On the asymptotic behaviour of cosmic density-fluctuation
power spectra of cold dark matter
Authors: Konrad, Sara; Ginat, Yonadav Barry; Bartelmann, Matthias
Bibcode: 2022MNRAS.515.5823K
Altcode: 2022arXiv220208059K; 2022MNRAS.tmp.1958K
We study the small-scale asymptotic behaviour of the cold dark matter
density fluctuation power spectrum in the Zel'dovich approximation,
without introducing an ultraviolet cut-off. Assuming an initially
correlated Gaussian random field and spectral index 0 < ns
< 1, we derive the small-scale asymptotic behaviour of the initial
momentum-momentum correlations. This result is then used to derive the
asymptotics of the power spectrum in the Zel'dovich approximation. Our
main result is an asymptotic series, dominated by a k-3
tail at large wave-numbers, containing higher-order terms that
differ by integer powers of $k^{n_\mathrm{ s}-1}$ and logarithms
of k. Furthermore, we show that dark matter power spectra with an
ultraviolet cut-off develop an intermediate range of scales where the
power spectrum is accurately described by the asymptotics of dark
matter without a cut-off. These results reveal information about
the mathematical structure that underlies the perturbative terms in
kinetic field theory and thus the non-linear power spectrum. We also
discuss the sensitivity of the small-scale asymptotics to the spectral
index ns.
Title: KMT-2021-BLG-0171Lb and KMT-2021-BLG-1689Lb: two microlensing
planets in the KMTNet high-cadence fields with followup observations
Authors: Yang, Hongjing; Zang, Weicheng; Gould, Andrew; Yee, Jennifer
C.; Hwang, Kyu-Ha; Christie, Grant; Sumi, Takahiro; Zhang, Jiyuan;
Mao, Shude; Albrow, Michael D.; Chung, Sun-Ju; Han, Cheongho;
Jung, Youn Kil; Ryu, Yoon-Hyun; Shin, In-Gu; Shvartzvald, Yossi;
Cha, Sang-Mok; Kim, Dong-Jin; Kim, Hyoun-Woo; Kim, Seung-Lee; Lee,
Chung-Uk; Lee, Dong-Joo; Lee, Yongseok; Park, Byeong-Gon; Pogge,
Richard W.; Drummond, John; Maoz, Dan; McCormick, Jennie; Natusch,
Tim; Penny, Matthew T.; Zhu, Wei; Bond, Ian A.; Abe, Fumio; Barry,
Richard; Bennett, David P.; Bhattacharya, Aparna; Donachie, Martin;
Fujii, Hirosane; Fukui, Akihiko; Hirao, Yuki; Itow, Yoshitaka;
Kirikawa, Rintaro; Kondo, Iona; Koshimoto, Naoki; Li, Man Cheung Alex;
Matsubara, Yutaka; Muraki, Yasushi; Miyazaki, Shota; Olmschenk, Greg;
Ranc, Clément; Rattenbury, Nicholas J.; Satoh, Yuki; Shoji, Hikaru;
Silva, Stela Ishitani; Suzuki, Daisuke; Tanaka, Yuzuru; Tristram,
Paul J.; Yamawaki, Tsubasa; Yonehara, Atsunori; MOA Collaboration
Bibcode: 2022MNRAS.516.1894Y
Altcode: 2022arXiv220512584Y; 2022MNRAS.tmp.1872Y
Follow-up observations of high-magnification gravitational
microlensing events can fully exploit their intrinsic sensitivity
to detect extrasolar planets, especially those with small mass
ratios. To make followup observations more uniform and efficient,
we develop a system, HighMagFinder, to automatically alert possible
ongoing high-magnification events based on the real-time data from
the Korea Microlensing Telescope Network (KMTNet). We started a new
phase of follow-up observations with the help of HighMagFinder in
2021. Here we report the discovery of two planets in high-magnification
microlensing events, KMT-2021-BLG-0171 and KMT-2021-BLG-1689, which
were identified by the HighMagFinder. We find that both events
suffer the 'central-resonant' caustic degeneracy. The planet-host
mass-ratio is q ~ 4.7 × 10-5 or q ~ 2.2 × 10-5
for KMT-2021-BLG-0171, and q ~ 2.5 × 10-4 or q ~ 1.8 ×
10-4 for KMT-2021-BLG-1689. Together with two other events,
four cases that suffer such degeneracy have been discovered in the 2021
season alone, indicating that the degenerate solutions may have been
missed in some previous studies. We also propose a quantitative factor
to weight the probability of each solution from the phase space. The
resonant interpretations for the two events are disfavoured under
this consideration. This factor can be included in future statistical
studies to weight degenerate solutions.
Title: Cosmological simulations with rare and frequent dark matter
self-interactions
Authors: Fischer, Moritz S.; Brüggen, Marcus; Schmidt-Hoberg, Kai;
Dolag, Klaus; Kahlhoefer, Felix; Ragagnin, Antonio; Robertson, Andrew
Bibcode: 2022MNRAS.516.1923F
Altcode: 2022arXiv220502243F; 2022MNRAS.tmp.2105F
Dark matter (DM) with self-interactions is a promising solution for the
small-scale problems of the standard cosmological model. Here we perform
the first cosmological simulation of frequent DM self-interactions,
corresponding to small-angle DM scatterings. The focus of our analysis
lies in finding and understanding differences to the traditionally
assumed rare DM (large-angle) self-scatterings. For this purpose, we
compute the distribution of DM densities, the matter power spectrum,
the two-point correlation function, and the halo and subhalo mass
functions. Furthermore, we investigate the density profiles of
the DM haloes and their shapes. We find that overall large-angle
and small-angle scatterings behave fairly similarly with a few
exceptions. In particular, the number of satellites is considerably
suppressed for frequent compared to rare self-interactions with the
same cross-section. Overall, we observe that while differences between
the two cases may be difficult to establish using a single measure, the
degeneracy may be broken through a combination of multiple ones. For
instance, the combination of satellite counts with halo density or
shape profiles could allow discriminating between rare and frequent
self-interactions. As a by-product of our analysis, we provide -
for the first time - upper limits on the cross-section for frequent
self-interactions.
Title: Photometric IGM tomography: Efficiently mapping quasar light
echoes with deep narrow-band imaging
Authors: Kakiichi, Koki; Schmidt, Tobias; Hennawi, Joseph
Bibcode: 2022MNRAS.516..582K
Altcode: 2022arXiv220708202K; 2022MNRAS.tmp.2252K
In the standard picture, episodes of luminous quasar activity are
directly related to supermassive black hole (SMBH) growth. The ionizing
radiation emitted over a quasar's lifetime alters the ionization state
of the surrounding intergalactic medium (IGM), enhancing the Lyα forest
transmission - so-called proximity effect - which can be observed in
absorption spectra of background sources. Owing to the finite speed of
light, the transverse direction of the proximity effect is sensitive
to the quasar's radiative history, resulting in 'light echoes' that
encode the growth history of the SMBH on Myr time-scales. In this paper,
we introduce a new technique to photometrically map this quasar light
echoes using Lyα forest tomography by using a carefully selected pair
of narrow-band filters. A foreground narrow-band filter is used to
measure Lyα forest transmission along background galaxies selected as
Lyα emitters by a background narrow-band filter. This novel double
narrow-band tomographic technique utilizes the higher throughput
and wider field of view of imaging over spectroscopy to efficiently
reconstruct a two-dimensional map of Lyα forest transmission around a
quasar. We present a fully Bayesian framework to measure the luminous
quasar lifetime of a SMBH from photometric IGM tomography, and examine
the observational requirements. This new technique provides an efficient
strategy to map a large area of the sky with a modest observing time
and to identify interesting regions to be examined by further deep 3D
follow-up spectroscopic Lyα forest tomography.
Title: Performance of the X-Calibur hard X-ray polarimetry mission
during its 2018/19 long-duration balloon flight
Authors: Abarr, Q.; Beheshtipour, B.; Beilicke, M.; Bose, R.;
Braun, D.; de Geronimo, G.; Dowkontt, P.; Errando, M.; Gadson, T.;
Guarino, V.; Heatwole, S.; Hossen, M.; Iyer, N.; Kislat, F.; Kiss,
M.; Kitaguchi, T.; Krawczynski, H.; Lanzi, J.; Li, S.; Lisalda, L.;
Okajima, T.; Pearce, M.; Peterson, Z.; Press, L.; Rauch, B.; Simburger,
G.; Stuchlik, D.; Takahashi, H.; Tang, J.; Uchida, N.; West, A.
Bibcode: 2022APh...14302749A
Altcode: 2022arXiv220409761A
X-Calibur is a balloon-borne telescope that measures the polarization of
high-energy X-rays in the 15-50 keV energy range. The instrument makes
use of the fact that X-rays scatter preferentially perpendicular to the
polarization direction. A beryllium scattering element surrounded by
pixellated CZT detectors is located at the focal point of the InFOCμS
hard X-ray mirror. The instrument was launched for a long-duration
balloon (LDB) flight from McMurdo (Antarctica) on December 29, 2018,
and obtained the first constraints of the hard X-ray polarization of
an accretion-powered pulsar. Here, we describe the characterization
and calibration of the instrument on the ground and its performance
during the flight, as well as simulations of particle backgrounds and
a comparison to measured rates. The pointing system and polarimeter
achieved the excellent projected performance. The energy detection
threshold for the anticoincidence system was found to be higher than
expected and it exhibited unanticipated dead time. Both issues will
be remedied for future flights. Overall, the mission performance was
nominal, and results will inform the design of the follow-up mission
XL-Calibur, which is scheduled to be launched in summer 2022.
Title: System Architecture and Planetary Obliquity: Implications
for Long-term Habitability
Authors: Vervoort, Pam; Horner, Jonathan; Kane, Stephen R.; Kirtland
Turner, Sandra; Gilmore, James B.
Bibcode: 2022AJ....164..130V
Altcode: 2022arXiv220804439V
In the search for life beyond our solar system, attention should
be focused on those planets that have the potential to maintain
habitable conditions over the prolonged periods of time needed for the
emergence and expansion of life as we know it. The observable planetary
architecture is one of the determinants for long-term habitability as
it controls the orbital evolution and ultimately the stellar fluxes
received by the planet. With an ensemble of n-body simulations and
obliquity models of hypothetical planetary systems, we demonstrate
that the amplitude and period of the eccentricity, obliquity, and
precession cycles of an Earth-like planet are sensitive to the orbital
characteristics of a giant companion planet. A series of transient,
ocean-coupled climate simulations show how these characteristics of
astronomical cycles are decisive for the evolving surface conditions
and long-term fractional habitability relative to the modern Earth. The
habitability of Earth-like planets increases with the eccentricity
of a Jupiter-like companion, provided that the mean obliquity is
sufficiently low to maintain temperate temperatures over large parts
of its surface throughout the orbital year. A giant companion closer
in results in shorter eccentricity cycles of an Earth-like planet but
longer, high-amplitude, obliquity cycles. The period and amplitude
of obliquity cycles can be estimated to first order from the orbital
pathways calculated by the n-body simulations. In the majority of
simulations, the obliquity amplitude relates directly to the orbital
inclination whereas the period of the obliquity cycle is a function
of the nodal precession and the proximity of the giant companion.
Title: Photometric and dynamic characterization of active asteroid
(248370) 2005QN173
Authors: Novaković, Bojan; Pavela, Debora; Hsieh, Henry H.; Marčeta,
Dušan
Bibcode: 2022MNRAS.516..757N
Altcode: 2022arXiv220900971N; 2022MNRAS.tmp.2147N
We present the physical and dynamical properties of the recently
discovered active asteroid (248370) 2005QN173 (aka
433P). From our observations, we derived two possible rotation period
solutions of 2.7 ± 0.1 and 4.1 ± 0.1 h. The corresponding light-curve
amplitudes computed after correcting for the effect of coma are 0.28
and 0.58 mag, respectively. Both period solutions are shorter than
the critical rotation limit computed for a strengthless triaxial
ellipsoid, suggesting that rotation mass shedding should at least
partly be responsible for the observed activity. We confirm that the
activity level is fading further, but at a very modest rate of only
0.006 mag d-1, still also compatible with sublimation-driven
activity. We found that 248370 likely belongs to the Themis asteroid
family, making it a fourth main-belt comet associated with this
group. Orbital characteristics of 248370 are also consistent with its
origin in the young 288P cluster of asteroids. The 288P cluster is
associated with its namesake main-belt comet, providing an exciting
possibility for a comparative analysis of intriguing main-belt comets
248370 and 288P.
Title: Deprojection of X-ray data in galaxy clusters: confronting
simulations with observations
Authors: Sarkar, Kartick C.; Dey, Arjun; Sharma, Prateek
Bibcode: 2022MNRAS.516..992S
Altcode: 2021arXiv211012447S; 2022MNRAS.tmp.2189S
Numerical simulations with varying realism indicate an emergent
principle-multiphase condensation and large cavity power
occur when the ratio of the cooling time to the free-fall time
(tcool/tff) falls below a threshold value
close to 10. Observations indeed show cool-core signatures when
this ratio falls below 20-30, but the prevalence of cores with
tcool/tff ratio below 10 is rare as compared
to simulations. In X-ray observations, we obtain projected spectra
from which we have to infer radial gas density and temperature
profiles. Using idealized models of X-ray cavities and multiphase gas
in the core and 3D hydro jet-ICM simulations, we quantify the biases
introduced by deprojection based on the assumption of spherical symmetry
in determining tcool/tff. We show that while the
used methods are able to recover the tcool/tff
ratio for relaxed clusters, they have an uncertainty of a factor of 2-3
in systems containing large cavities (≳ 20 kpc). We also show that
the mass estimates from these methods, in the absence of X-ray spectra
close to the virial radius, suffer from a degeneracy between the virial
mass (M200) and the concentration parameter (c) in the form
of M200c2 ≍ constant. Additionally, the lack
of soft-X-ray (≲ 0.5 keV) coverage and poor spatial resolution
makes us overestimate min(tcool/tff) by a
factor of few in clusters with min(tcool/tff)
≲ 5. This bias can largely explain the lack of cool-core clusters
with min(tcool/tff) ≲ 5.
Title: Cosmic filament spin from dark matter vortices
Authors: Alexander, Stephon; Capanelli, Christian; G. M. Ferreira,
Elisa; McDonough, Evan
Bibcode: 2022PhLB..83337298A
Altcode: 2021arXiv211103061A
The recent observational evidence for cosmic filament spin on megaparsec
scales Wang et al. (2021) [41] demands an explanation in the physics
of dark matter. Conventional collisionless cold particle dark matter
is conjectured to generate cosmic filament spin through tidal torquing,
but this explanation requires extrapolating from the quasi-linear regime
to the non-linear regime. Meanwhile no alternative explanation exists
in the context of ultra-light (e.g., axion) dark matter, and indeed
these models would naively predict zero spin for cosmic filaments. In
this Letter we study cosmic filament spin in theories of ultra-light
dark matter, such as ultra-light axions, and bosonic and fermionic
condensates, such as superfluids and superconductors. These models
are distinguished from conventional particle dark matter models by the
possibility of dark matter vortices. We take a model agnostic approach,
and demonstrate that a collection of dark vortices can explain the
data reported in Wang et al. Modeling a collection of vortices with a
simple two-parameter analytic model, corresponding to an averaging of
the velocity field, we find an excellent fit to the data. We perform a
Markov Chain Monte Carlo analysis and find constraints on the number
of vortices, the dark matter mass, and the radius of the inner core
region where the vortices are distributed, in order for ultra-light
dark matter to explain spinning cosmic filaments.
Title: Molecular flows in contemporary active galaxies and the
efficacy of radio-mechanical feedback
Authors: Tamhane, Prathamesh D.; McNamara, Brian R.; Russell, Helen
R.; Edge, Alastair C.; Fabian, Andrew C.; Nulsen, Paul E. J.; Babyk,
Iurii V.
Bibcode: 2022MNRAS.516..861T
Altcode: 2022MNRAS.tmp.2053T; 2022arXiv220714326T
Molecular gas flows are analysed in 14 cluster galaxies (BCGs) centred
in cooling hot atmospheres. The BCGs contain $10^{9}\!-\!10^{11}~\rm
M_\odot$ of molecular gas, much of which is being moved by radio jets
and lobes. The molecular flows and radio jet powers are compared to
molecular outflows in 45 active galaxies within z < 0.2. We seek
to understand the relative efficacy of radio, quasar, and starburst
feedback over a range of active galaxy types. Molecular flows powered
by radio feedback in BCGs are ~10-1000 times larger in extent compared
to contemporary galaxies hosting quasar nuclei and starbursts. Radio
feedback yields lower flow velocities but higher momenta compared to
quasar nuclei, as the molecular gas flows in BCGs are usually ~10-100
times more massive. The product of the molecular gas mass and lifting
altitude divided by the AGN or starburst power - a parameter referred
to as the lifting factor - exceeds starbursts and quasar nuclei by
2-3 orders of magnitude, respectively. When active, radio feedback
is generally more effective at lifting gas in galaxies compared to
quasars and starburst winds. The kinetic energy flux of molecular
clouds generally lies below and often substantially below a few per
cent of the driving power. We find tentatively that star formation is
suppressed in BCGs relative to other active galaxies, perhaps because
these systems rarely form molecular discs that are more impervious to
feedback and are better able to promote star formation.
Title: Ensemble-based unsupervised machine learning method for
membership determination of open clusters using Mahalanobis distance
Authors: Deb, Sukanta; Baruah, Amiya; Kumar, Subhash
Bibcode: 2022MNRAS.515.4685D
Altcode: 2022MNRAS.tmp.2062D
We present an improved method for the determination of membership of
an open cluster using ensemble-based unsupervised machine learning
techniques. The working principle of this method relies on two stages:
(i) choosing a suitable range of three astrometric parameters (π,
μαcos δ, μδ) using k-nearest neighbour (kNN)
algorithm on the data downloaded for the cluster within a smaller
search radius; (ii) application of two component Gaussian mixture
modelling (GMM) on the resulting one dimensional Gaussian distribution
of Mahalanobis distance (MD) of stars using the range of parameters
obtained from the earlier step, but with the data downloaded within
a bigger search radius. MD is calculated from the mean of each of the
parameters in three dimensions. Thus the use of MD reduces the input of
the GMM from the 3D parameter space into a 1D parameter space for the
cluster membership determination. The method has been tested on a few
clusters including those which have overlaps in some/all the parameters
using the data obtained from the Gaia DR3 data base. It is found that
the approach can easily separate the cluster members from the field
stars. The clean colour-magnitude diagrams and similar direction of
proper motions of the member stars obtained for the clusters shows that
this method is very efficient and robust in segregating the cluster
members from the field stars.
Title: The GOGREEN survey: constraining the satellite quenching
time-scale in massive clusters at z ≳ 1
Authors: Baxter, Devontae C.; Cooper, M. C.; Balogh, Michael L.;
Carleton, Timothy; Cerulo, Pierluigi; De Lucia, Gabriella; Demarco,
Ricardo; McGee, Sean; Muzzin, Adam; Nantais, Julie; Pintos-Castro,
Irene; Reeves, Andrew M. M.; Rudnick, Gregory H.; Sarron, Florian;
van der Burg, Remco F. J.; Vulcani, Benedetta; Wilson, Gillian;
Zaritsky, Dennis
Bibcode: 2022MNRAS.515.5479B
Altcode: 2022arXiv220714302B; 2022MNRAS.tmp.2054B
We model satellite quenching at z ~ 1 by combining 14 massive
(1013.8 < Mhalo/M⊙ <
1015) clusters at 0.8 < z < 1.3 from the GOGREEN
and GCLASS surveys with accretion histories of 56 redshift-matched
analogues from the IllustrisTNG simulation. Our fiducial model,
which is parametrized by the satellite quenching time-scale
(τquench), accounts for quenching in our simulated satellite
population both at the time of infall by using the observed coeval
field quenched fraction and after infall by tuning τquench
to reproduce the observed satellite quenched fraction versus stellar
mass trend. This model successfully reproduces the observed satellite
quenched fraction as a function of stellar mass (by construction),
projected cluster-centric radius, and redshift and is consistent with
the observed field and cluster stellar mass functions at z ~ 1. We find
that the satellite quenching time-scale is mass dependent, in conflict
with some previous studies at low and intermediate redshift. Over
the stellar mass range probed (M⋆ > 1010
M⊙), we find that the satellite quenching time-scale
decreases with increasing satellite stellar mass from ~1.6 Gyr at
1010 M⊙ to ~0.6-1 Gyr at 1011
M⊙ and is roughly consistent with the total cold gas (HI
+ H2) depletion time-scales at intermediate z, suggesting
that starvation may be the dominant driver of environmental quenching
at z < 2. Finally, while environmental mechanisms are relatively
efficient at quenching massive satellites, we find that the majority
($\sim 65{\!-\!}80{{\ \rm per\ cent}}$) of ultra-massive satellites
(M⋆ > 1011 M⊙) are quenched
prior to infall.
Title: Formation of black holes in the pair-instability mass gap:
Evolution of a post-collision star
Authors: Costa, Guglielmo; Ballone, Alessandro; Mapelli, Michela;
Bressan, Alessandro
Bibcode: 2022MNRAS.516.1072C
Altcode: 2022arXiv220403492C; 2022MNRAS.tmp.2125C
The detection of GW190521 by the LIGO-Virgo collaboration has revealed
the existence of black holes (BHs) in the pair-instability (PI)
mass gap. Here, we investigate the formation of BHs in the PI mass
gap via star-star collisions in young stellar clusters. To avoid PI,
the stellar-collision product must have a relatively small core and a
massive envelope. We generate our initial conditions from the outputs
of a hydrodynamical simulation of the collision between a core helium
burning star (~58 M⊙) and a main-sequence star (~42
M⊙). The hydrodynamical simulation allows us to take into
account the mass lost during the collision (~12 M⊙) and to
build the chemical composition profile of the post-collision star. We
then evolve the collision product with the stellar evolution codes
PARSEC and MESA. We find that the post-collision star evolves through
all the stellar burning phases until core collapse, avoiding PI. At the
onset of core collapse, the post-collision product is a blue supergiant
star. We estimate a total mass-loss of about 1 M⊙ during
the post-collision evolution, due to stellar winds and shocks induced
by neutrino emission in a failed supernova. The final BH mass is ≍87
M⊙. Therefore, we confirm that the collision scenario is
a suitable formation channel to populate the PI mass gap.
Title: The formation of early-type galaxies through monolithic
collapse of gas clouds in Milgromian gravity
Authors: Eappen, Robin; Kroupa, Pavel; Wittenburg, Nils; Haslbauer,
Moritz; Famaey, Benoit
Bibcode: 2022MNRAS.516.1081E
Altcode: 2022arXiv220900024E; 2022MNRAS.tmp.2144E
Studies of stellar populations in early-type galaxies (ETGs) show
that the more massive galaxies form earlier and have a shorter
star formation history. In this study, we investigate the initial
conditions of ETG formation. The study begins with the collapse
of non-rotating post-Big-Bang gas clouds in Milgromian (MOND)
gravitation. These produce ETGs with star-forming time-scales (SFT)
comparable to those observed in the real Universe. Comparing these
collapse models with observations, we set constraints on the initial
size and density of the post-Big-Bang gas clouds in order to form
ETGs. The effective-radius-mass relation of the model galaxies falls
short of the observed relation. Possible mechanisms for later radius
expansion are discussed. Using hydrodynamic MOND simulations, this work
thus for the first time shows that the SFTs observed for ETGs may be a
natural occurrence in the MOND paradigm. We show that different feedback
algorithms change the evolution of the galaxies only to a very minor
degree in MOND. The first stars have, however, formed more rapidly in
the real Universe than possible just from the here studied gravitational
collapse mechanism. Dark-matter-based cosmological structure formation
simulations disagree with the observed SFTs at more than 5σ confidence.
Title: Three-dimensional structure of the central molecular zone
Authors: Sofue, Yoshiaki
Bibcode: 2022MNRAS.516..907S
Altcode: 2022arXiv220802451S; 2022MNRAS.tmp.2166S
A detailed comparison of H I and CO line cube data of the Galactic
Centre (GC) region from the archives is obtained. The central molecular
zone (CMZ) is shown to be embedded in the H I disc (central H I zone,
CHZ) of radius ~320 pc and vertical scale height ~70 pc. A radio
continuum belt is shown to run parallel to molecular Arms I and II. The
belt draws a double infinity (∞∞) on the sky, connecting Sgr E (l ~
-1${_{.}^{\circ}}$2), C, B1, B2, and Sgr D (+1${_{.}^{\circ}}$2), and
is interpreted as a warping star-forming ring. The molecular Arms are
closely associated with the H I arms on the longitude-velocity diagram
(LVD), showing coherent rigid-body ridges. Due to the close relationship
between H I and CO, the H I line absorption can be used to determine
the Arms' position relative to Sgr A, B1, B2, and C. Combining the
trigonometric data of proper motions of Sgr A* and maser sources of
Sgr B2 as well as radial velocities, the 3D velocity vector of Sgr B2
is determined. From these analyses, the molecular Arm I with Sgr B2 is
shown to be located in the near side of Sgr A*, and Arm II with Sgr C
in the other side, both composing a pair of symmetrical Arms around
the GC. We present a possible 3D view of Sgr A through E and Arms I
and II along with a parameter list.
Title: A fresh look at AGN spectral energy distribution fitting with
the XMM-SERVS AGN sample
Authors: Marshall, Adam; Auger-Williams, Matthew W.; Banerji, Manda;
Maiolino, Roberto; Bowler, Rebecca
Bibcode: 2022MNRAS.515.5617M
Altcode: 2022arXiv220605055M; 2022MNRAS.tmp.1862M
We perform spectral energy distribution (SED) fitting to 711 luminous
X-ray AGN at 0.7 < z < 4.5 using 10-bands of optical and
infra-red photometric data for objects within XMM-SERVS. This fitting
provided 510 reliable (reduced χ2 < 3) inferences
on AGN and host galaxy properties. The AGN optical (3000 Å)
luminosity inferred from SED-fitting is found to correlate with the
measured X-ray (2-10 keV) luminosity, in good agreement with previous
work. Using X-ray hardness as a proxy for AGN obscuration, we also
study the differences in the host galaxy properties of obscured and
unobscured AGNs. Both populations have consistent stellar masses
(log10(M*/M⊙) = 10.88 $\pm 0.09\,
{\rm M}_\odot$ and log10(M*/M⊙)
= 10.8 $\pm 0.1\, {\rm M}_\odot$ for unobscured and obscured AGNs,
respectively). We also find evidence for varying AGN emission line
properties from a standard AGN template in 18.8 per cent of the
sample with a reduced χ2 < 3 where the inclusion of an
additional emission line strength free parameter was found to improve
the quality of the fit. Comparison of these fits to SDSS spectra showed
that emission line properties inferred from broad-band photometry
were consistent with the results from spectroscopy for 91 per cent of
objects. We find that the presence of weaker, more blueshifted emission
lines as inferred from the SED fits are associated with more negative
values of αox. While the correlation between the hardness
of the ionizing SED and the emission line properties has been known
for some time, we are able to derive this correlation purely from
broad-band photometry.
Title: Morphology, colour-magnitude, and scaling relations of galaxies
in Abell 426
Authors: Khanday, Sheeraz A.; Saha, Kanak; Iqbal, Nasser; Dhiwar,
Suraj; Pahwa, Isha
Bibcode: 2022MNRAS.515.5043K
Altcode: 2022MNRAS.tmp.1901K; 2022arXiv220708729K
We present photometric properties of 183 member galaxies in the
Abell 426 cluster using the Sloan Digital Sky Survey (SDSS) imaging
and spectroscopic observation. Detailed morphology based on visual
classification followed by multicomponent image decomposition of 179
galaxies is presented in the SDSS g, r, i bands. More than 80 per cent
of the members are early-type galaxies (ETGs), with elliptical, dwarf
elliptical (dE), and lenticular morphology and follow the red-sequence
in the colour-magnitude diagram (CMD). With a few dEs and spirals in
the blue cloud, the cluster CMD is nearly unimodal. The dEs are ~2-mag
fainter and follow a different Sersic index and central velocity
dispersion distribution than their bright counterparts. Further,
we establish the Kormendy relation (KR) and the fundamental plane
relation (FPR) for five different samples of ETGs constructed based
on derived physical parameters such as Sersic index, concentration,
central velocity dispersion in g, r, i bands. The mean r-band slope
and zero-point of the KR are 3.02 ± 0.1 and 18.65 ± 0.03 in close
agreement to other cluster ellipticals in the local and higher
redshift. Kinematics-based ETG sample produces the least scatter in
KR with zero-point getting brighter by ~1.3 mag from g to i band. The
dEs and other low-mass ETGs follow the KR with a similar slope but
with ~1.3 mag fainter zero-point and form a parallel KR. The bright
ellipticals follow an FPR with a = 1.37 ± 0.003, b = 0.35 ± 0.05,
and c = -9.37 ± 0.02 in the r band; galaxies tend to deviate from
this relation at the low-mass end. A catalogue with morphology and 2D
structural analysis is available online.
Title: Exploring metallicity-dependent rates of Type Ia supernovae
and their impact on galaxy formation
Authors: Gandhi, Pratik J.; Wetzel, Andrew; Hopkins, Philip F.;
Shappee, Benjamin J.; Wheeler, Coral; Faucher-Giguère, Claude-André
Bibcode: 2022MNRAS.516.1941G
Altcode: 2022arXiv220210477G; 2022MNRAS.tmp.2137G
Type Ia supernovae are critical for feedback and elemental enrichment
in galaxies. Recent surveys like the All-Sky Automated Survey for
Supernova (ASAS-SN) and the Dark Energy Survey (DES) find that the
specific supernova Ia rate at z ~ 0 may be ≲20-50× higher in lower
mass galaxies than at Milky Way-mass. Independently, observations
show that the close-binary fraction of solar-type Milky Way stars
is higher at lower metallicity. Motivated by these observations,
we use the FIRE-2 cosmological zoom-in simulations to explore the
impact of metallicity-dependent rate models on galaxies of $M_* \sim
10^7\!-\!10^{11}\, \rm {M}_{\odot }$. First, we benchmark our simulated
star formation histories against observations, and show that the assumed
stellar mass functions play a major role in determining the degree of
tension between observations and metallicity-independent rate models,
potentially causing ASAS-SN and DES observations to agree more than
might appear. Models in which the supernova Ia rate increases with
decreasing metallicity ($\propto Z^{-0.5 \,\, \rm {to} \,\, -1}$)
provide significantly better agreement with observations. Encouragingly,
these rate increases (≳10× in low-mass galaxies) do not significantly
impact galaxy masses and morphologies, which remain largely unaffected
except for our most extreme models. We explore implications for both
[Fe/H] and [$\alpha /\rm {Fe}$] enrichment; metallicity-dependent rate
models can improve agreement with the observed stellar mass-metallicity
relations in low-mass galaxies. Our results demonstrate that a range
of metallicity-dependent rate models are viable for galaxy formation
and motivate future work.
Title: On the response of a star cluster to a tidal perturbation
Authors: Martinez-Medina, Luis A.; Gieles, Mark; Gnedin, Oleg Y.;
Li, Hui
Bibcode: 2022MNRAS.516.1237M
Altcode: 2020arXiv200906643M; 2022MNRAS.tmp.2131M
We study the response of star clusters to individual tidal perturbations
using controlled N-body simulations. We consider perturbations
by a moving point mass and by a disc, and vary the duration of
the perturbation as well as the cluster density profile. For fast
perturbations (i.e. 'shocks'), the cluster gains energy in agreement
with theoretical predictions in the impulsive limit. For slow disc
perturbations, the energy gain is lower, and this has previously been
attributed to adiabatic damping. However, the energy gain due to slow
perturbations by a point-mass is similar to, or larger than that due
to fast shocks, which is not expected because adiabatic damping should
be almost independent of the nature of the tides. We show that the
geometric distortion of the cluster during slow perturbations is of
comparable importance for the energy gain as adiabatic damping, and
that the combined effect can qualitatively explain the results. The
half-mass radius of the bound stars after a shock increases up to ~7
per cent for low-concentration clusters, and decreases ~3 per cent for
the most concentrated ones. The fractional mass loss is a non-linear
function of the energy gain, and depends on the nature of the tides
and most strongly on the cluster density profile, making semi-analytic
model predictions for cluster lifetimes extremely sensitive to the
adopted density profile.
Title: Sub-stellar companions of intermediate-mass stars with CoRoT:
CoRoT-34b, CoRoT-35b, and CoRoT-36b
Authors: Sebastian, D.; Guenther, E. W.; Deleuil, M.; Dorsch, M.;
Heber, U.; Heuser, C.; Gandolfi, D.; Grziwa, S.; Deeg, H. J.; Alonso,
R.; Bouchy, F.; Csizmadia, Sz; Cusano, F.; Fridlund, M.; Geier, S.;
Irrgang, A.; Korth, J.; Nespral, D.; Rauer, H.; Tal-Or, L.; CoRoT-team
Bibcode: 2022MNRAS.516..636S
Altcode: 2022MNRAS.tmp.2069S; 2022arXiv220708742S
Theories of planet formation give contradicting results of how
frequent close-in giant planets of intermediate mass stars (IMSs;
$1.3\le M_{\star }\le 3.2\, \mathrm{M}_{\odot }$) are. Some theories
predict a high rate of IMSs with close-in gas giants, while others
predict a very low rate. Thus, determining the frequency of close-in
giant planets of IMSs is an important test for theories of planet
formation. We use the CoRoT survey to determine the absolute frequency
of IMSs that harbour at least one close-in giant planet and compare
it to that of solar-like stars. The CoRoT transit survey is ideal for
this purpose, because of its completeness for gas-giant planets with
orbital periods of less than 10 d and its large sample of main-sequence
IMSs. We present a high precision radial velocity follow-up programme
and conclude on 17 promising transit candidates of IMSs, observed with
CoRoT. We report the detection of CoRoT-34b, a brown dwarf close to
the hydrogen burning limit, orbiting a 1.1 Gyr A-type main-sequence
star. We also confirm two inflated giant planets, CoRoT-35b, part of a
possible planetary system around a metal-poor star, and CoRoT-36b on a
misaligned orbit. We find that $0.12 \pm 0.10\, {{\ \rm per\ cent}}$
of IMSs between $1.3\le M_{\star }\le 1.6\, \mathrm{M}_{\odot }$
observed by CoRoT do harbour at least one close-in giant planet. This
is significantly lower than the frequency ($0.70 \pm 0.16\, {{\ \rm
per\ cent}}$) for solar-mass stars, as well as the frequency of IMSs
harbouring long-period planets ($\sim 8\, {{\ \rm per\ cent}}$).
Title: MAXI J1957+032: a new accreting millisecond X-ray pulsar in
an ultra-compact binary
Authors: Sanna, A.; Bult, P.; Ng, M.; Ray, P. S.; Jaisawal, G. K.;
Burderi, L.; Di Salvo, T.; Riggio, A.; Altamirano, D.; Strohmayer,
T. E.; Manca, A.; Gendreau, K. C.; Chakrabarty, D.; Iwakiri, W.;
Iaria, R.
Bibcode: 2022MNRAS.516L..76S
Altcode: 2022arXiv220805807S; 2022MNRAS.tmpL..86S
The detection of coherent X-ray pulsations at ~314 Hz (3.2 ms)
classifies MAXI J1957+032 as a fast-rotating, accreting neutron
star. We present the temporal and spectral analysis performed
using NICER observations collected during the latest outburst of
the source. Doppler modulation of the X-ray pulsation revealed
the ultra-compact nature of the binary system characterized by an
orbital period of ~1 h and a projected semimajor axis of 14 lt-ms. The
neutron star binary mass function suggests a minimum donor mass of
1.7 × 10-2 M⊙, assuming a neutron star mass
of 1.4 M⊙ and a binary inclination angle lower than 60
deg. This assumption is supported by the lack of eclipses or dips in
the X-ray light curve of the source. We characterized the 0.5-10 keV
energy spectrum of the source in outburst as the superposition of a
relatively cold black-body-like thermal emission compatible with the
emission from the neutron star surface and a Comptonization component
with photon index consistent with a typical hard state. We did not
find evidence for iron K α lines or reflection components.
Title: Four new deeply eclipsing white dwarfs in Zwicky Transient
Facility
Authors: Kosakowski, A.; Kilic, M.; Brown, W. R.; Bergeron, P.;
Kupfer, T.
Bibcode: 2022MNRAS.516..720K
Altcode: 2022MNRAS.tmp.1151K; 2022arXiv220503431K
We present the results of a search for deeply eclipsing white dwarfs
in the Zwicky Transient Facility (ZTF) Data Release 4 (DR4). We
identify nine deeply eclipsing white dwarf candidates, four of which
we followed up with high-cadence photometry and spectroscopy. Three of
these systems show total eclipses in the ZTF data and our follow-up
Apache Point Observatory 3.5 m telescope observations. Even though
the eclipse duration is consistent with sub-stellar companions, our
analysis shows that all four systems contain a white dwarf with low-mass
stellar companions of ~0.1 M⊙. We provide mass and radius
constraints for both stars in each system based on our photometric
and spectroscopic fitting. Finally, we present a list of 41 additional
eclipsing WD+M candidates identified in a preliminary search of ZTF DR7,
including 12 previously studied systems. We identify two new candidate
short-period, eclipsing, white dwarf-brown dwarf binaries within our
sample of 41 WD+M candidates based on Pan-STARRS colours.
Title: Modelling observable signatures of jet-ISM interaction:
thermal emission and gas kinematics
Authors: Meenakshi, Moun; Mukherjee, Dipanjan; Wagner, Alexander Y.;
Nesvadba, Nicole P. H.; Bicknell, Geoffrey V.; Morganti, Raffaella;
Janssen, Reinier M. J.; Sutherland, Ralph S.; Mandal, Ankush
Bibcode: 2022MNRAS.516..766M
Altcode: 2022MNRAS.tmp.2138M; 2022arXiv220310251M
Relativistic jets are believed to have a substantial impact on
the gas dynamics and evolution of the interstellar medium (ISM) of
their host galaxies. In this paper, we aim to draw a link between the
simulations and the observable signatures of jet-ISM interactions by
analyzing the emission morphology and gas kinematics resulting from
jet-induced shocks in simulated disc and spherical systems. We find
that the jet-induced laterally expanding forward shock of the energy
bubble sweeping through the ISM causes large-scale outflows, creating
shocked emission and high-velocity dispersion in the entire nuclear
regions (~2 kpcs) of their hosts. The jetted systems exhibit larger
velocity widths (>800 km s-1), broader Position-Velocity
maps and distorted symmetry in the disc's projected velocities than
systems without a jet. We also investigate the above quantities at
different inclination angles of the observer with respect to the
galaxy. Jets inclined to the gas disc of its host are found to be
confined for longer times, and consequently couple more strongly
with the disc gas. This results in prominent shocked emission and
high-velocity widths, not only along the jet's path, but also in the
regions perpendicular to them. Strong interaction of the jet with
a gas disc can also distort its morphology. However, after the jets
escape their initial confinement, the jet-disc coupling is weakened,
thereby lowering the shocked emission and velocity widths.
Title: Tentative Evidence for Water Vapor in the Atmosphere of the
Neptune-sized Exoplanet HD 106315c
Authors: Kreidberg, Laura; Mollière, Paul; Crossfield, Ian J. M.;
Thorngren, Daniel P.; Kawashima, Yui; Morley, Caroline V.; Benneke,
Björn; Mikal-Evans, Thomas; Berardo, David; Kosiarek, Molly R.;
Gorjian, Varoujan; Ciardi, David R.; Christiansen, Jessie L.; Dragomir,
Diana; Dressing, Courtney D.; Fortney, Jonathan J.; Fulton, Benjamin
J.; Greene, Thomas P.; Hardegree-Ullman, Kevin K.; Howard, Andrew W.;
Howell, Steve B.; Isaacson, Howard; Krick, Jessica E.; Livingston,
John H.; Lothringer, Joshua D.; Morales, Farisa Y.; Petigura, Erik A.;
Rodriguez, Joseph E.; Schlieder, Joshua E.; Weiss, Lauren M.
Bibcode: 2022AJ....164..124K
Altcode:
We present a transmission spectrum for the Neptune-sized exoplanet
HD 106315c from optical to infrared wavelengths based on transit
observations from the Hubble Space Telescope/Wide Field Camera 3,
K2, and Spitzer. The spectrum shows tentative evidence for a water
absorption feature in the 1.1-1.7 μm wavelength range with a small
amplitude of 30 ppm (corresponding to just 0.8 ± 0.04 atmospheric scale
heights). Based on an atmospheric retrieval analysis, the presence
of water vapor is tentatively favored with a Bayes factor of 1.7-2.6
(depending on prior assumptions). The spectrum is most consistent
with either an enhanced metallicity or high-altitude condensates,
or both. Cloud-free solar composition atmospheres are ruled out at
>5σ confidence. We compare the spectrum to grids of cloudy and hazy
forward models and find that the spectrum is fit well by models with
moderate cloud lofting or haze formation efficiency over a wide range
of metallicities (1-100× solar). We combine the constraints on the
envelope composition with an interior structure model and estimate that
the core mass fraction is ≳0.3. With a bulk composition reminiscent
of that of Neptune and an orbital distance of 0.15 au, HD 106315c hints
that planets may form out of broadly similar material and arrive at
vastly different orbits later in their evolution.
Title: The redshift dependence of black hole mass distribution:
is it reliable for standard sirens cosmology?
Authors: Mukherjee, Suvodip
Bibcode: 2022MNRAS.515.5495M
Altcode: 2022MNRAS.tmp.2056M; 2021arXiv211210256M
An upper limit on the mass of a black hole set by the pair-instability
supernovae (PISN) process can be useful in inferring the redshift
of the gravitational wave (GW) sources by lifting the degeneracy
between mass and redshift. However, for this technique to work,
it is essential that the PISN mass scale is redshift independent
or at least has a predictable redshift dependence. We show that the
observed PISN mass scale can get smeared and the position of the PISN
mass scale is likely to exhibit a strong redshift dependence due to
a combined effect from the non-zero value of the delay time between
the formation of a star and the merging of two black holes and the
metallicity dependence of PISN mass scale. Due to the unknown form of
the delay-time distribution, the redshift dependence of the PISN mass
cutoff of the binary black holes (BBHs) cannot be well characterized
and will exhibit a large variation with the change in redshift. As a
result, the use of a fixed PISN mass scale to infer the redshift of
the BBHs from the observed masses will be systematically biased. Though
this uncertainty is not severe for the third observation run conducted
by the LIGO-Virgo-KAGRA collaboration, in the future this uncertainty
will cause a systematic error in the redshift inferred from the PISN
mass scale. The corresponding systematic error will be a bottleneck
in achieving a few per cent precision measurements of the cosmological
parameters using this method in the future.
Title: Galaxy pairs in THE THREE HUNDRED simulations: a study on
the performance of observational pair-finding techniques
Authors: Contreras-Santos, Ana; Knebe, Alexander; Cui, Weiguang;
Haggar, Roan; Pearce, Frazer; Gray, Meghan; De Petris, Marco; Yepes,
Gustavo
Bibcode: 2022MNRAS.515.5375C
Altcode: 2022arXiv220713451C; 2022MNRAS.tmp.2014C
Close pairs of galaxies have been broadly studied in the literature as
a way to understand galaxy interactions and mergers. In observations,
they are usually defined by setting a maximum separation in the sky
and in velocity along the line of sight, and finding galaxies within
these ranges. However, when observing the sky, projection effects can
affect the results, by creating spurious pairs that are not close
in physical distance. In this work, we mimic these observational
techniques to find pairs in THE THREE HUNDRED simulations of clusters
of galaxies. The galaxies' 3D coordinates are projected into 2D,
with Hubble flow included for their line-of-sight velocities. The
pairs found are classified into 'good' or 'bad' depending on whether
their 3D separations are within the 2D spatial limit or not. We find
that the fraction of good pairs can be between 30 and 60 per cent
depending on the thresholds used in observations. Studying the ratios
of observable properties between the pair member galaxies, we find that
the likelihood of a pair being 'good' can be increased by around 40, 20,
and 30 per cent if the given pair has, respectively, a mass ratio below
0.2, metallicity ratio above 0.8, or colour ratio below 0.8. Moreover,
shape and stellar-to-halo mass ratios, respectively, below 0.4 and 0.2
can increase the likelihood by 50 to 100 per cent. These results suggest
that these properties can be used to increase the chance of finding
good pairs in observations of galaxy clusters and their environment.
Title: Chaotic diffusion of asteroids in the exterior 1:2 mean motion
resonance with Mars
Authors: Christou, Apostolos A.; Dermott, Stanley F.; Li, Dan
Bibcode: 2022MNRAS.516.1428C
Altcode: 2022MNRAS.tmp.2118C; 2022arXiv220714047C
The inner asteroid belt between 2.1 and 2.5 au is of particular
dynamical significance because it is the dominant source of both
chondritic meteorites and near-Earth asteroids. This inner belt is
bounded by an eccentricity-type secular resonance and by the 1:3
mean motion resonance with Jupiter. Unless asteroid perihelia are low
enough to allow scattering by Mars, escape requires transport to one
of the bounding resonances. In addition Yarkovsky forces are generally
ineffective in changing either the eccentricity and/or inclination for
asteroids with diameter ≳30 km. Thus, large asteroids with pericentres
far from Mars may only escape from the inner belt through large changes
in their eccentricities. In this paper, we study chaotic diffusion of
orbits near the 1:2 mean motion resonance with Mars in a systematic
way. We show that, while chaotic orbital evolution in both resonant
and non-resonant orbits increase the dispersion of the inclinations and
eccentricities, it does not significantly change their mean values. We
show further that, while the dispersive growth is greatest for resonant
orbits, at high e the resonance acts to mitigate asteroid scattering
by Mars - making the asteroid lifetime in the belt longer than it would
have been for a non-resonant orbit. For asteroids of all sizes in both
resonant and non-resonant orbits, the changes in eccentricity needed
to account for the observations cannot be achieved by gravitational
forces alone. The role of resonant trapping in protecting asteroids
from encounters with Mars is also analysed.
Title: Maximal X-ray feedback in the pre-reionization Universe
Authors: Jeon, Junehyoung; Bromm, Volker; Finkelstein, Steven L.
Bibcode: 2022MNRAS.515.5568J
Altcode: 2022arXiv220709527J; 2022MNRAS.tmp.2080J
X-ray feedback in the pre-reionization Universe provided one of the
major energy sources for reionization and the thermal evolution of the
early intergalactic medium. However, X-ray sources at high redshift
have remained largely inaccessible to observations. One alternative
approach to study the overall effects of X-ray feedback in the early
Universe is a full cosmological simulation. Towards this goal, in this
paper we create an analytic model of X-ray feedback from accretion on
to supermassive black holes (SMBHs), to be used as a sub-grid model
in future cosmological simulations. Our analytic model provides a
relation between the mass of a dark matter halo and the SMBH it hosts,
where the efficiency is governed by an energy balance argument between
thermal feedback and the confining gravitational potential of the
halo. To calibrate the model, we couple the halo-level recipe with
the Press-Schechter halo mass function and derive global mass and
energy densities. We then compare our model to various observational
constraints, such as the resulting soft X-ray and IR cosmic radiation
backgrounds, to test our choice of model parameters. We in particular
derive model parameters that do not violate any constraints, while
providing maximal X-ray feedback prior to reionization. In addition,
we consider the contribution of SMBH X-ray sources to reionization
and the global 21 cm absorption signal.
Title: The ALMA REBELS Survey: specific star formation rates in the
reionization era
Authors: Topping, Michael W.; Stark, Daniel P.; Endsley, Ryan; Bouwens,
Rychard J.; Schouws, Sander; Smit, Renske; Stefanon, Mauro; Inami,
Hanae; Bowler, Rebecca A. A.; Oesch, Pascal; Gonzalez, Valentino;
Dayal, Pratika; da Cunha, Elisabete; Algera, Hiddo; van der Werf,
Paul; Pallottini, Andrea; Barrufet, Laia; Schneider, Raffaella;
De Looze, Ilse; Sommovigo, Laura; Whitler, Lily; Graziani, Luca;
Fudamoto, Yoshinobu; Ferrara, Andrea
Bibcode: 2022MNRAS.516..975T
Altcode: 2022arXiv220307392T; 2022MNRAS.tmp.2188T
We present specific star formation rates (sSFRs) for 40
ultraviolet (UV)-bright galaxies at z ~ 7-8 observed as part of the
Reionization Era Bright Emission Line Survey (REBELS) Atacama Large
Millimeter/submillimeter Array (ALMA) large programme. The sSFRs
are derived using improved star formation rate (SFR) calibrations
and spectral energy distribution (SED)-based stellar masses, made
possible by measurements of far-infrared (FIR) continuum emission
and [C II]-based spectroscopic redshifts. The median sSFR of the
sample is $18_{-5}^{+7}$ Gyr-1, significantly larger than
literature measurements lacking constraints in the FIR, reflecting the
larger obscured SFRs derived from the dust continuum relative to that
implied by the UV+optical SED. We suggest that such differences may
reflect spatial variations in dust across these luminous galaxies,
with the component dominating the FIR distinct from that dominating
the UV. We demonstrate that the inferred stellar masses (and hence
sSFRs) are strongly dependent on the assumed star formation history in
reionization-era galaxies. When large sSFR galaxies (a population that
is common at z > 6) are modelled with non-parametric star formation
histories, the derived stellar masses can increase by an order of
magnitude relative to constant star formation models, owing to the
presence of a significant old stellar population that is outshined by
the recent burst. The [C II] line widths in the largest sSFR systems are
often very broad, suggesting dynamical masses capable of accommodating
an old stellar population suggested by non-parametric models. Regardless
of these systematic uncertainties among derived parameters, we find that
sSFRs increase rapidly toward higher redshifts for massive galaxies
(9.6 < log (M*/M⊙) < 9.8), evolving as
(1 + z)1.7 ± 0.3, broadly consistent with expectations
from the evolving baryon accretion rates.
Title: A multiwavelength study of nearby star-forming spiral galaxies
and the clustering of star formation in M63
Authors: Smith, Madison V.; van Zee, L.; Dale, D. A.; Staudaher, S.;
Wrock, T.
Bibcode: 2022MNRAS.516..477S
Altcode: 2022MNRAS.tmp.2143S
This multiwavelength study of the star formation and star formation
history (SFH) trends in the nearby universe looks at nine nearby
late-type spirals. Spectral energy distributions fitted with
measurements from the far-ultraviolet (FUV) to the mid-infrared are used
to estimate parameters in a double-exponential SFH. Azimuthally averaged
radial trends in the SFHs are shown and discussed for each galaxy. In
addition to the radial analysis, catalogues of UV-selected sources
are identified for each galaxy. An analysis of the clustering of the
UV sources in M63 (NGC 5055) is done using a two-point correlation
function. There is evidence for hierarchical star formation and
clustering out to scales of several kpc. We then discuss the level of
clustering in M63's sources with differing FUV - NUV colours, and how
spiral arms may play a role in the organization of star formation even
in the low surface brightness regions of a galaxy.
Title: The completed SDSS-IV extended Baryon Oscillation Spectroscopic
Survey: measurement of the growth rate of structure from the
small-scale clustering of the luminous red galaxy sample
Authors: Chapman, Michael J.; Mohammad, Faizan G.; Zhai, Zhongxu;
Percival, Will J.; Tinker, Jeremy L.; Bautista, Julian E.; Brownstein,
Joel R.; Burtin, Etienne; Dawson, Kyle S.; Gil-Marín, Héctor;
de la Macorra, Axel; Ross, Ashley J.; Rossi, Graziano; Schneider,
Donald P.; Zhao, Gong-Bo
Bibcode: 2022MNRAS.516..617C
Altcode: 2021arXiv210614961C; 2022MNRAS.tmp.1973C
We measure the small-scale clustering of the Data Release 16 extended
Baryon Oscillation Spectroscopic Survey Luminous Red Galaxy sample,
corrected for fibre-collisions using Pairwise Inverse Probability
weights, which give unbiased clustering measurements on all scales. We
fit to the monopole and quadrupole moments and to the projected
correlation function over the separation range $7-60\, h^{-1}{\rm Mpc}$
with a model based on the AEMULUS cosmological emulator to measure the
growth rate of cosmic structure, parametrized by fσ8. We
obtain a measurement of fσ8(z = 0.737) = 0.408 ± 0.038,
which is 1.4σ lower than the value expected from 2018 Planck data for
a flat ΛCDM model, and is more consistent with recent weak-lensing
measurements. The level of precision achieved is 1.7 times better
than more standard measurements made using only the large-scale modes
of the same sample. We also fit to the data using the full range of
scales $0.1\text{--}60\, h^{-1}{\rm Mpc}$ modelled by the AEMULUS
cosmological emulator and find a 4.5σ tension in the amplitude of the
halo velocity field with the Planck + ΛCDM model, driven by a mismatch
on the non-linear scales. This may not be cosmological in origin, and
could be due to a breakdown in the Halo Occupation Distribution model
used in the emulator. Finally, we perform a robust analysis of possible
sources of systematics, including the effects of redshift uncertainty
and incompleteness due to target selection that were not included in
previous analyses fitting to clustering measurements on small scales.
Title: Impact of the primordial stellar initial mass function on
the 21-cm signal
Authors: Gessey-Jones, T.; Sartorio, N. S.; Fialkov, A.; Mirouh, G. M.;
Magg, M.; Izzard, R. G.; de Lera Acedo, E.; Handley, W. J.; Barkana, R.
Bibcode: 2022MNRAS.516..841G
Altcode: 2022arXiv220202099G; 2022MNRAS.tmp.1919G
Properties of the first generation of stars [referred to as the
Population III (Pop III) stars], such as their initial mass function
(IMF), are poorly constrained by observations and have yet to converge
between simulations. The cosmological 21-cm signal of neutral hydrogen
is predicted to be sensitive to Lyman-band photons produced by
these stars, thus providing a unique way to probe the first stellar
population. In this paper, we investigate the impacts of the Pop
III IMF on the cosmic-dawn 21-cm signal via the Wouthuysen-Field
effect, Lyman-Werner feedback, Ly α heating, and cosmic microwave
background heating. We calculate the emission spectra of star-forming
haloes for different IMFs by integrating over individual metal-free
stellar spectra, computed from a set of stellar evolution histories and
stellar atmospheres, and taking into account variability of the spectra
with stellar age. Through this study, we therefore relax two common
assumptions: that the zero-age main-sequence emission rate of a Pop III
star is representative of its lifetime mean emission rate, and that Pop
III emission can be treated as instantaneous. Exploring bottom-heavy,
top-heavy, and intermediate IMFs, we show that variations in the 21-cm
signal are driven by stars lighter than 20 M⊙. For the
explored models, we find maximum relative differences of 59 per cent
in the cosmic-dawn global 21-cm signal, and 131 per cent between power
spectra. Although this impact is modest, precise modelling of the
first stars and their evolution is necessary for accurate prediction
and interpretation of the 21-cm signal.
Title: Prospects of strongly lensed fast radio bursts: simultaneous
measurement of post-Newtonian parameter and Hubble constant
Authors: Gao, Ran; Li, Zhengxiang; Gao, He
Bibcode: 2022MNRAS.516.1977G
Altcode: 2022arXiv220810175G; 2022MNRAS.tmp.2191G
Strong gravitational lensing effect is a powerful tool to probe
cosmological models and gravity theories. Recently, the time-delay
cosmography from strong lensing and the stellar kinematics of the
deflector, which encode the Hubble constant and the post-Newtonian
parameter via two distance ratios reflecting the lensing mass and
dynamical mass, respectively, have been proposed to investigate these
two parameters simultaneously. Among strong-lensing systems with
different sources, strongly lensed fast radio bursts (FRBs) have been
proposed as precision probes of the universe since the time-delay ~
10 d between images could be measured extremely precisely because of
their short duration of a few milliseconds. In this work, we investigate
the ability of strongly lensed FRBs on simultaneously estimating these
two parameters via simulations. Take the expected FRB detection rate
of upcoming facilities and lensing probability into consideration,
it is likely to accumulate 10 lensed FRBs in several years and we
find that H0 could be determined to an $\sim 1.5{{\,\rm
per\,cent}}$ precision and γPPN could be constrained to an
$\sim 8.7{{\,\rm per\,cent}}$ precision simultaneously from them. These
simultaneous estimations will be helpful for properly reflecting the
possible correlation between these two fundamental parameters.
Title: Detailed study of extended γ-ray morphology in the vicinity
of the Coma cluster with Fermi Large Area Telescope
Authors: Baghmanyan, Vardan; Zargaryan, Davit; Aharonian, Felix;
Yang, Ruizhi; Casanova, Sabrina; Mackey, Jonathan
Bibcode: 2022MNRAS.516..562B
Altcode: 2021arXiv211000309B; 2022MNRAS.tmp.2159B
Galaxy clusters can be sources of high-energy (HE) γ-ray radiation due
to the efficient acceleration of particles exceeding EeV energies. At
present, though, the only candidate for emitting HE γ-rays is the Coma
cluster, towards which an excess of γ-ray emission has been detected by
the Fermi Large Area Telescope (Fermi-LAT). Using ~12.3 yr of Fermi-LAT
data, we explored the region of the Coma cluster between energies 100
MeV and 1 TeV by detailed spectral and morphological analysis. In the
region of the Coma cluster, we detected diffuse γ-ray emission of
energies between 100 MeV and 1 TeV with a 5.4σ extension significance
and a 68 per cent containment radius of $0.82^{+0.10}_{-0.05}$ degrees
derived with a two-dimensional homogeneous disc model. The corresponding
γ-ray spectrum extends up to ~50 GeV, with a power-law index of Γ =
2.23 ± 0.11 and flux of $\mathrm{(3.84\pm 0.67)\times 10^{-12}\, erg\,
cm^{-2}\, s^{-1}}$. Using energy arguments we show that point-like
sources such as radiogalaxies and star-forming galaxies are unlikely to
explain the emission, and more likely, the emission is produced in the
Coma cluster. Besides, we also identified three point-like sources in
the region. However, because of limited statistics, we could neither
exclude nor confirm the contribution of three point-like sources to
the total emissions.
Title: The effect of ionizing background fluctuations on the spatial
correlations of high redshift Lyα-emitting galaxies
Authors: Meiksin, Avery; Suarez, Teresita
Bibcode: 2022MNRAS.516..572M
Altcode: 2022MNRAS.tmp.2168M; 2022arXiv220804203M
We investigate the possible influence of fluctuations in the
metagalactic photoionizing ultraviolet background (UVBG) on the
clustering of Lyα-emitting galaxies through the modulation of the
ionization level of the gas surrounding the systems. At redshift z >
5, even when assuming the reionization of the intergalactic medium
has completed, the fluctuations are sufficiently large that they
may non-negligibly enhance, and possibly even dominate, the angular
correlation function on scales up to a few hundred arcsecs. Whilst a
comparison with observations at z ≃ 5.7 is statistically consistent
with no influence of UVBG fluctuations, allowing for the fluctuations
opens up the range of acceptable models to include those with relatively
low bias factors for the Lyα-emitting galaxies. In this case, the
evolution in the bias factor of Lyα-emitters over the approximate
redshift range 3 < z < 7 corresponds to a nearly constant halo
mass for Lyα-emitting galaxies of ~1010.5 M⊙.
Title: ATOMS: ALMA three-millimeter observations of massive
star-forming regions - XII: Fragmentation and multiscale gas
kinematics in protoclusters G12.42+0.50 and G19.88-0.53
Authors: Saha, Anindya; Tej, Anandmayee; Liu, Hong-Li; Liu, Tie;
Issac, Namitha; Lee, Chang Won; Garay, Guido; Goldsmith, Paul F.;
Juvela, Mika; Qin, Sheng-Li; Stutz, Amelia; Li, Shanghuo; Wang,
Ke; Baug, Tapas; Bronfman, Leonardo; Xu, Feng-Wei; Zhang, Yong;
Eswaraiah, Chakali
Bibcode: 2022MNRAS.516.1983S
Altcode: 2022arXiv220809877S
We present new continuum and molecular line data from the ALMA
Three-millimeter Observations of Massive Star-forming regions (ATOMS)
survey for the two protoclusters, G12.42+0.50 and G19.88-0.53. The
3 mm continuum maps reveal seven cores in each of the two globally
contracting protoclusters. These cores satisfy the radius-mass
relation and the surface mass density criteria for high-mass star
formation. Similar to their natal clumps, the virial analysis of the
cores suggests that they are undergoing gravitational collapse ($\rm
\alpha _{vir} \lt \lt 2$). The clump to core scale fragmentation is
investigated and the derived core masses and separations are found to
be consistent with thermal Jeans fragmentation. We detect large-scale
filamentary structures with velocity gradients and multiple outflows in
both regions. Dendrogram analysis of the H13CO+
map identifies several branch and leaf structures with sizes ~ 0.1 and
0.03 pc, respectively. The supersonic gas motion displayed by the branch
structures is in agreement with the Larson power law indicating that
the gas kinematics at this spatial scale is driven by turbulence. The
transition to transonic/subsonic gas motion is seen to occur at spatial
scales of ~0.1 pc indicating the dissipation of turbulence. In agreement
with this, the leaf structures reveal gas motions that deviate from the
slope of Larson's law. From the large-scale converging filaments to the
collapsing cores, the gas dynamics in G12.42+0.50 and G19.88-0.53 show
scale-dependent dominance of turbulence and gravity and the combination
of these two driving mechanisms needs to be invoked to explain massive
star formation in the protoclusters.
Title: Gamma-ray burst data strongly favour the three-parameter
fundamental plane (Dainotti) correlation over the two-parameter one
Authors: Cao, Shulei; Dainotti, Maria; Ratra, Bharat
Bibcode: 2022MNRAS.516.1386C
Altcode: 2022arXiv220408710C; 2022MNRAS.tmp.2047C
Gamma-ray bursts (GRBs), observed to redshift z = 9.4, are potential
probes of the largely unexplored z ~ 2.7-9.4 part of the early
Universe. Thus, finding relevant relations among GRB physical properties
is crucial. We find that the Platinum GRB data compilation, with 50
long GRBs (with relatively flat plateaus and no flares) in the redshift
range 0.553 ≤ z ≤ 5.0, and the LGRB95 data compilation, with 95 long
GRBs in 0.297 ≤ z ≤ 9.4, as well as the 145 GRB combination of the
two, strongly favour the 3D Fundamental Plane (Dainotti) correlation
(between the peak prompt luminosity, the luminosity at the end of the
plateau emission, and its rest-frame duration) over the 2D one (between
the luminosity at the end of the plateau emission and its duration). The
3D Dainotti correlations in the three data sets are standardizable. We
find that while LGRB95 data have ~50 per cent larger intrinsic scatter
parameter values than the better-quality Platinum data, they provide
somewhat tighter constraints on cosmological-model and GRB-correlation
parameters, perhaps solely due to the larger number of data points,
95 versus 50. This suggests that when compiling GRB data for the
purpose of constraining cosmological parameters, given the quality
of current GRB data, intrinsic scatter parameter reduction must be
balanced against reduced sample size.
Title: Radial oscillations and gravitational wave echoes of strange
stars with nonvanishing lambda
Authors: Bora, Jyatsnasree; Dev Goswami, Umananda
Bibcode: 2022APh...14302744B
Altcode: 2021arXiv210504145B
We study the effect of the cosmological constant on radial oscillations
and gravitational wave echoes (GWEs) of non-rotating strange stars. To
depict strange star configurations we used two forms of equations
of state (EoSs), viz., the MIT Bag model EoS and the linear EoS. By
taking a range of positive and negative values of cosmological
constant, the corresponding mass-radius relationships for these
stars have been calculated. For this purpose, first we solved the
Tolman-Oppenheimer-Volkoff (TOV) equations with a non-zero cosmological
constant and then we solved the pressure and radial perturbation
equations arising due to radial oscillations. The eigenfrequencies of
the fundamental f-mode and first 22 pressure p-modes are calculated
for each of these EoSs. Again considering the remnant of the GW170817
event as a strange star, the echo frequencies emitted by such stars in
presence of the cosmological constant are computed. From these numerical
calculations, we have inferred relations between cosmological constant
and mode frequency, structural parameters, GWE frequencies of strange
stars. Our results show that for strange stars, the effective range
of cosmological constant is 10-15cm-2 ≤ Λ
≤ 3 × 10-13cm-2 .
Title: Anaerobic ammonium oxidation coupled to arsenate reduction,
a novel biogeochemical process observed in arsenic-contaminated
paddy soil
Authors: Zhang, Miaomiao; Kolton, Max; Häggblom, Max M.; Sun, Xiaoxu;
Yu, Ke; He, Bin; Yuan, Zaijian; Dong, Yiran; Su, Xianfa; Chen, Zhenyu;
Li, Hui; Xiao, Tangfu; Xiao, Enzong; Sun, Weimin
Bibcode: 2022GeCoA.335...11Z
Altcode:
Anaerobic ammonium oxidation represents an important pathway of N
loss, which can be coupled with reduction of nitrite and metal(loid)s
(e.g., Fe(III) and Mn(IV)). Similar to Fe(III) and Mn(IV), As(V) is
also an active metal(loid) and ammonium oxidation coupled with As(V)
reduction is thermodynamically feasible. However, little is known
about this potential process. In this study, anaerobic ammonium
oxidation coupled with As(V) reduction, designated as Asammox, was
observed in cultures inoculated from As-contaminated paddy soil
using 15N isotope tracer analysis. Compared with the
treatment amended with 15N-urea only, the production of
15N-labeled N2 (i.e., 30N2
and 29N2) was significantly greater in the
treatment amended with As(V) and 15N-urea. Furthermore,
the abundances of the genes encoding for arsenate reductase (arrA)
and hydrazine synthase (hzsB) were significantly higher in the
treatment amended with As(V) and 15N-urea than those in
the treatment amended with 15N-urea only. In addition,
putative Asammox bacteria affiliated with Halomonas, Pelagibacterium,
and Chelativorans were identified by DNA-stable isotope probing. Members
of Ca. Brocadia were the most dominant Anammox bacteria in the soil
cultures and may interact with Asammox bacteria in ammonium oxidation,
suggesting that the N loss may be attributed to the contribution of
Asammox and Anammox in the As-contaminated soil. The observation of
Asammox, a novel biogeochemical process, and identification of bacteria
responsible for this biogeochemical process expands the fundamental
understanding of both N and As biogeochemical cycling. In addition,
this study provides a proof-of-concept for investigating anaerobic
ammonium oxidation coupled with metal(loid)s reduction by combining
stable isotope probing and isotope tracer microcosm incubations.
Title: Presolar O- and C-anomalous grains in unequilibrated ordinary
chondrite matrices
Authors: Barosch, Jens; Nittler, Larry R.; Wang, Jianhua; Dobrică,
Elena; Brearley, Adrian J.; Hezel, Dominik C.; Alexander, Conel M. O'D.
Bibcode: 2022GeCoA.335..169B
Altcode: 2022arXiv220902632B
Presolar grains are trace components in chondrite matrices. Their
abundances and compositions have been systematically studied
in carbonaceous chondrites but rarely in situ in other major
chondrite classes. We have conducted a NanoSIMS isotopic search for
presolar grains with O- and C-anomalous isotopic compositions in
the matrices of the unequilibrated ordinary chondrites Semarkona
(LL3.00), Meteorite Hills 00526 (L/LL3.05), and Northwest Africa
8276 (L3.00). The matrices of even the most primitive ordinary
chondrites have been aqueously altered and/or thermally metamorphosed,
destroying their presolar grain populations to varying extents. In
addition to randomly placed isotope maps, we specifically targeted
recently reported, relatively pristine Semarkona matrix areas to
better explore the original inventory of presolar grains in this
meteorite. In all samples, we found a total of 122 O-anomalous
grains (silicates + oxides), 79 SiC grains, and 22 C-anomalous
carbonaceous grains (organics, graphites). Average matrix-normalized
abundances with 1σ uncertainties are 151-46+
50 ppm O-anomalous grains, 53-12+ 14 ppm
SiC grains and 56-14+ 19 ppm carbonaceous
grains in Semarkona, 55-10+ 11 ppm (O-anom.),
22-4+ 5 ppm (SiC) and 3-1+2
ppm (carb.) in MET 00526 and 12-3+6 ppm (O-anom.),
15-5+7 ppm (SiC) and 1-1+3
ppm (carb.) in NWA 8276. In relatively pristine ordinary chondrites
and in primitive carbonaceous and C-ungrouped chondrites, the O and C
isotopic composition of presolar grains and their matrix-normalized
abundances are similar, despite the likely differences in
chondrite-formation time and nebular location. These results suggest
a relatively homogenous distribution of presolar dust across major
chondrite-forming reservoirs in the solar nebula. Secondary asteroidal
processes are mainly responsible for differences in presolar grain
abundances between and within chondrites, highlighting the need to
identify and target the most pristine chondrite matrices for such
studies.
Title: Formation of dust rings and gaps in non-ideal MHD discs
through meridional gas flows
Authors: Hu, Xiao; Li, Zhi-Yun; Zhu, Zhaohuan; Yang, Chao-Chin
Bibcode: 2022MNRAS.516.2006H
Altcode: 2022arXiv220305629H; 2022MNRAS.tmp.1814H
Rings and gaps are commonly observed in the dust continuum emission of
young stellar discs. Previous studies have shown that substructures
naturally develop in the weakly ionized gas of magnetized, non-ideal
MHD discs. The gas rings are expected to trap large mm/cm-sized grains
through pressure gradient-induced radial dust-gas drift. Using 2D
(axisymmetric) MHD simulations that include ambipolar diffusion and
dust grains of three representative sizes (1 mm, 3.3 mm, and 1 cm),
we show that the grains indeed tend to drift radially relative to
the gas towards the centres of the gas rings, at speeds much higher
than in a smooth disc because of steeper pressure gradients. However,
their spatial distribution is primarily controlled by meridional gas
motions, which are typically much faster than the dust-gas drift. In
particular, the grains that have settled near the mid-plane are carried
rapidly inwards by a fast accretion stream to the inner edges of the
gas rings, where they are lifted up by the gas flows diverted away from
the mid-plane by a strong poloidal magnetic field. The flow pattern in
our simulation provides an attractive explanation for the meridional
flows recently inferred in HD 163296 and other discs, including both
'collapsing' regions where the gas near the disc surface converges
towards the mid-plane and a disc wind. Our study highlights the
prevalence of the potentially observable meridional flows associated
with the gas substructure formation in non-ideal MHD discs and their
crucial role in generating rings and gaps in dust.
Title: The BLUETIDES mock image catalogue: simulated observations
of high-redshift galaxies and predictions for JWST imaging surveys
Authors: Marshall, Madeline A.; Watts, Katelyn; Wilkins, Stephen;
Matteo, Tiziana Di; Kuusisto, Jussi K.; Roper, William J.; Vijayan,
Aswin P.; Ni, Yueying; Feng, Yu; Croft, Rupert A. C.
Bibcode: 2022MNRAS.516.1047M
Altcode: 2022arXiv220608941M; 2022MNRAS.tmp.1999M
We present a mock image catalogue of ~100 000 MUV ≃ -22.5
to -19.6 mag galaxies at z = 7-12 from the BLUETIDES cosmological
simulation. We create mock images of each galaxy with the James Webb
Space Telescope (JWST), Hubble, Roman, and Euclid Space Telescopes,
as well as Subaru, and VISTA, with a range of near- and mid-infrared
filters. We perform photometry on the mock images to estimate the
success of these instruments for detecting high-z galaxies. We predict
that JWST will have unprecedented power in detecting high-z galaxies,
with a 95 per cent completeness limit at least 2.5 mag fainter than
VISTA and Subaru, 1.1 mag fainter than Hubble, and 0.9 mag fainter than
Roman, for the same wavelength and exposure time. Focusing on JWST, we
consider a range of exposure times and filters, and find that the NIRCam
F356W and F277W filters will detect the faintest galaxies, with 95 per
cent completeness at m ≃ 27.4 mag in 10-ks exposures. We also predict
the number of high-z galaxies that will be discovered by upcoming JWST
imaging surveys. We predict that the COSMOS-Web survey will detect ~1000
M1500 Å < -20.1 mag galaxies at 6.5 < z < 7.5,
by virtue of its large survey area. JADES-Medium will detect almost
$100{{\ \rm per\ cent}}$ of M1500 Å ≲ -20 mag galaxies
at z < 8.5 due to its significant depth, however, with its smaller
survey area it will detect only ~100 of these galaxies at 6.5 <
z < 7.5. Cosmic variance results in a large range in the number of
predicted galaxies each survey will detect, which is more evident in
smaller surveys such as CEERS and the PEARLS NEP and GOODS-S fields.
Title: The distribution of dust in edge-on galaxies: I. The global
structure
Authors: Mosenkov, Aleksandr V.; Usachev, Pavel A.; Shakespear,
Zacory; Guerrette, Jacob; Baes, Maarten; Bianchi, Simone; Xilouris,
Emmanuel M.; Gontcharov, George A.; Il'in, Vladimir B.; Marchuk,
Alexander A.; Savchenko, Sergey S.; Smirnov, Anton A.
Bibcode: 2022MNRAS.515.5698M
Altcode: 2022MNRAS.tmp.2039M; 2022arXiv220711589M
In this first paper in a series we present a study of the global
dust emission distribution in nearby edge-on spiral galaxies. Our
sample consists of 16 angularly large and 13 less spatially resolved
galaxies selected from the DustPedia sample. To explore the dust
emission distribution, we exploit the Herschel photometry in the
range 100-500 $\mu $m. We employ Sérsic and 3D disc models to fit
the observed 2D profiles of the galaxies. Both approaches give similar
results. Our analysis unequivocally states the case for the presence
of extraplanar dust in between 6 and 10 large galaxies. The results
reveal that both the disc scale length and height increase as a function
of wavelength between 100 and 500 $\mu $m. The dust disc scale height
positively correlates with the dust disc scale length, similar to what
is observed for the stellar discs. We also find correlations between
the scale lengths and scale heights in the near- and far-infrared
which suggest that the stellar discs and their dust counterparts
are tightly connected. Furthermore, the intrinsic flattening of the
dust disc is inversely proportional to the maximum rotation velocity
and the dust mass of the galaxy: more massive spiral galaxies host,
on average, relatively thinner dust discs. Also, there is a tendency
for the dust-to-stellar scale height ratio to decrease with the dust
mass and rotation velocity. We conclude that low-mass spiral galaxies
host a diffuse, puffed-up dust disc with a thickness similar to that
of the stellar disc.
Title: The cold gas and dust properties of red star-forming galaxies
Authors: Chown, Ryan; Parker, Laura; Wilson, Christine D.; Brown, Toby;
Evans, Fraser; Gao, Yang; Hwang, Ho Seong; Lin, Lihwai; Saintonge,
Amelie; Sargent, Mark; Smith, Matthew; Xiao, Ting
Bibcode: 2022MNRAS.516...84C
Altcode: 2022arXiv220803842C; 2022MNRAS.tmp.2151C
We study the cold gas and dust properties for a sample of red
star-forming galaxies called 'red misfits.' We collect single-dish
CO observations and H I observations from representative samples
of low-redshift galaxies, as well as our own James Clerk Maxwell
Telescope CO observations of red misfits. We also obtain SCUBA-2
850 $\mu$m observations for a subset of these galaxies. With
these data we compare the molecular gas, total cold gas, and dust
properties of red misfits against those of their blue counterparts
('blue actives') taking non-detections into account using a survival
analysis technique. We compare these properties at fixed position
in the log SFR-log M⋆ plane, as well as versus offset
from the star-forming main sequence. Compared to blue actives, red
misfits have slightly longer molecular gas depletion times, similar
total gas depletion times, significantly lower molecular- and total-gas
mass fractions, lower dust-to-stellar mass ratios, similar dust-to-gas
ratios, and a significantly flatter slope in the log Mmol-log
M⋆ plane. Our results suggest that red misfits as a
population are likely quenching due to a shortage in gas supply.
Title: Active galactic nuclei signatures in Red Geyser galaxies from
Gemini GMOS-IFU observations
Authors: Ilha, Gabriele S.; Riffel, Rogemar A.; Ricci, Tiago V.;
Rembold, Sandro B.; Storchi-Bergmann, Thaisa; Riffel, Rogério;
Roy, Namrata; Bundy, Kevin; Nemmen, Rodrigo; Schimoia, Jáderson S.;
da Costa, Luiz N.
Bibcode: 2022MNRAS.516.1442I
Altcode: 2022MNRAS.tmp.2164I; 2022arXiv220803383I
Red Geysers are quiescent galaxies with galactic scale ionized
outflows, likely due to low-luminosity active galactic nuclei
(AGN). We used Gemini GMOS-IFU observations of the inner ~1-3 kpc
of nine Red Geysers selected from the MaNGA survey to study the
gas ionization and kinematics. The emission-line ratios suggest the
presence of Seyfert/LINER (Low Ionization Nuclear Emission Region)
nuclei in all sources. Two galaxies show Hα equivalent width ( Hα EW)
larger than 3 Å (indicative of AGN ionization) within an aperture 2
${_{.}^{\prime\prime}}$5 of diameter (1.3-3.7 kpc at the distance of
galaxies) for MaNGA data, while with the higher resolution GMOS data,
four galaxies present Hα EW>3 Å within an aperture equal to the
angular resolution (0.3-0.9 kpc). For two objects with GMOS-IFU data,
the Hα EW is lower than 3 Å but larger than 1.5 Å, most probably due
to a faint AGN. The spatially resolved electron density maps show values
between 100 and 3000 cm -3 and are consistent with those
determined in other studies. The large (MaNGA) and the nuclear scale
(GMOS-IFU) gas velocity fields are misaligned, with a kinematic position
angle difference between 12° and 60°. The [N II] λ6583 emission-line
profiles are asymmetrical, with blue wings on the redshifted side of
the velocity field and red wings on the blueshifted side. Our results
support previous indications that the gas in Red Geysers is ionized by
an AGN, at least in their central region, with the presence of outflows,
likely originating in a precessing accretion disc.
Title: The ALMaQUEST Survey X: what powers merger induced star
formation?
Authors: Thorp, Mallory D.; Ellison, Sara L.; Pan, Hsi-An; Lin, Lihwai;
Patton, David R.; Bluck, Asa F. L.; Walters, Dan; Scudder, Jillian M.
Bibcode: 2022MNRAS.516.1462T
Altcode: 2022MNRAS.tmp.2181T; 2022arXiv220806426T
Galaxy mergers are known to trigger both extended and central star
formation. However, what remains to be understood is whether this
triggered star formation is facilitated by enhanced star formation
efficiencies (SFEs), or an abundance of molecular gas fuel. This work
presents spatially resolved measurements of CO emission collected
with the Atacama Large Millimetre Array (ALMA) for 20 merging galaxies
(either pairs or post-mergers) selected from the Mapping Nearby Galaxies
at Apache Point Observatory (MaNGA) survey. Eleven additional merging
galaxies are selected from the ALMA MaNGA QUEnching and STar formation
(ALMaQUEST) survey, resulting in a set of 31 mergers at various
stages of interaction and covering a broad range of star formation
rates (SFRs). We investigate galaxy-to-galaxy variations in the
resolved Kennicutt-Schmidt relation, (rKS: $\Sigma _{\textrm {H}_2}$
versus ΣSFR), the resolved molecular gas main sequence
(rMGMS: Σ⋆ versus $\Sigma _{\textrm {H}_2}$), and the
resolved star-forming main sequence (rSFMS: Σ⋆ versus
ΣSFR). We quantify offsets from these resolved relations to
determine if SFR, molecular gas fraction, or/and SFE is/are enhanced
in different regions of an individual galaxy. By comparing offsets
in all three parameters, we can discern whether gas fraction or SFE
powers an enhanced ΣSFR. We find that merger-induced star
formation can be driven by a variety of mechanisms, both within a
galaxy and between different mergers, regardless of interaction stage.
Title: A Giant Arc on the Sky
Authors: Lopez, Alexia M.; Clowes, Roger G.; Williger, Gerard M.
Bibcode: 2022MNRAS.516.1557L
Altcode: 2022arXiv220106875L; 2022MNRAS.tmp.2122L
We present the serendipitous discovery of a 'Giant Arc on the Sky' at
$z$ ~ 0.8. The Giant Arc (GA) spans ~1 Gpc (proper size, present epoch)
and appears to be almost symmetrical on the sky. It was discovered
via intervening Mg II absorbers in the spectra of background quasars,
using the catalogues of Zhu & Ménard. The use of Mg II absorbers
represents a new approach to the investigation of large-scale structures
(LSSs) at redshifts $0.45 \la z \la 2.25$. We present the observational
properties of the GA, and we assess it statistically using methods
based on (i) single-linkage hierarchical clustering (~4.5σ); (ii)
the Cuzick-Edwards test (~3.0σ); and (iii) power-spectrum analysis
(~4.8σ). Each of these methods has distinctive attributes and
powers, and we advise considering the evidence from the ensemble. We
discuss our approaches to mitigating any post hoc aspects of analysing
significance after discovery. The overdensity of the GA is δρ/ρ ~
1.3 ± 0.3. The GA is the newest and one of the largest of a steadily
accumulating set of very large LSSs that may (cautiously) challenge the
Cosmological Principle, upon which the 'standard model' of cosmology
is founded. Conceivably, the GA is the precursor of a structure like
the Sloan Great Wall (but the GA is about twice the size), seen when
the Universe was about half its present age.
Title: Impact of the turnover in the high-z galaxy luminosity function
on the 21-cm signal during Cosmic Dawn and Epoch of Reionization
Authors: Zhang, Zekang; Shan, Huanyuan; Gu, Junhua; Zheng, Qian; Xu,
Yidong; Yue, Bin; Liu, Yuchen; Zhu, Zhenghao; Guo, Quan
Bibcode: 2022MNRAS.516.1573Z
Altcode: 2022arXiv220801492Z
The shape of the faint-end of the high-z galaxy luminosity function
(LF) informs early star formation and reionization physics during the
Cosmic Dawn and Epoch of Reionization. Until recently, based on the
strong gravitational lensing cluster deep surveys, the Hubble Frontier
Fields (HFF) has found a potential turnover in the ultraviolet (UV)
LF at $\mathit{ z}$ ~ 6. In this paper, we analyse the contribution of
extremely faint galaxies with the magnitude larger than the turnover
magnitude in LF to cosmic reionization. We apply the measurement
from HFF to our suppressed star formation efficiency model, including
three free parameters: halo mass threshold Mt, curvature
parameter β, and a UV conversion factor lUV. According
to our fit of 68 per cent confidence level, the high-redshift star
formation in haloes smaller than $M_t=1.82^{+2.86}_{-1.08}\times
10^{10} \, \rm M_{\odot }$ is found to be dampened. The turnover
magnitude $\rm \gtrsim -13.99-2.45$, correspondingly the halo mass
$\lesssim (4.57+20.03)\times 10^{9} \, \rm M_{\odot }$. We find
that the absorption trough in the global 21-cm signal is sensitive
to our SFE model parameters. Together with (β, lUV) =
($2.17^{+2.42}_{-1.72}$, $9.33^{+0.43}_{-0.42} \, \rm ~erg~yr ~s^{-1}\,
M_{\odot }^{-1})$, the trough locates at ~$134^{+10}_{-17}$$\rm MHz$
with an amplitude of ~$-237^{-6}_{+7}$$\rm mK$, compared to (106 MHz,
-212 mK) in the absence of turnover. Besides, we find that the star
formation of faint galaxies has also an impact on the 21-cm power
spectra. The best-fitting peak power decreases by$\sim 4{{\ \rm
per\ cent}}$ and shifts towards smaller scales from $0.88 \, h\, \rm
Mpc^{-1}$ to $0.91 \, h\, \rm Mpc^{-1}$. According to our calculation,
such impact is distinguishable with the forthcoming Square Kilometre
Array.
Title: DeWitt boundary condition is consistent in Hořava-Lifshitz
quantum gravity
Authors: Matsui, Hiroki; Mukohyama, Shinji; Naruko, Atsushi
Bibcode: 2022PhLB..83337340M
Altcode: 2021arXiv211100665M
In quantum cosmology the DeWitt boundary condition is a proposal to set
the wave function of the universe to vanish at the classical big-bang
singularity. In this Letter, we show that in many gravitational theories
including general relativity, the DeWitt wave function does not take
a desired form once tensor perturbations around a homogeneous and
isotropic closed universe are taken into account: anisotropies and
inhomogeneities due to the perturbations are not suppressed near the
classical singularity. We then show that Hořava-Lifshitz gravity
provides a satisfactory DeWitt wave function. In particular, in the
limit of z = 3 anisotropic scaling, we find an exact analytic expression
for the DeWitt wave function of the universe with scale-invariant
perturbations. In general cases with relevant deformations, we show
that the DeWitt wave function can be systematically expanded around
the classical big-bang singularity with perturbations under control.
Title: A new probe of relic neutrino clustering using cosmogenic
neutrinos
Authors: Brdar, Vedran; Bhupal Dev, P. S.; Plestid, Ryan; Soni, Amarjit
Bibcode: 2022PhLB..83337358B
Altcode: 2022arXiv220702860B
We propose a new probe of cosmic relic neutrinos (CνB) using their
resonant scattering against cosmogenic neutrinos. Depending on the
lightest neutrino mass and the energy spectrum of the cosmogenic
neutrino flux, a Standard Model vector meson (such as a hadronic ρ)
resonance can be produced via ν ν bar annihilation. This leads
to a distinct absorption feature in the cosmogenic neutrino flux
at an energy solely determined by the meson mass and the neutrino
mass, apart from redshift. By numerical coincidence, the position of
the ρ-resonance overlaps with the originally predicted peak of the
Greisen-Zatsepin-Kuzmin (GZK) neutrino flux, which offers an enhanced
effect at higher redshifts. We show that this absorption feature in
the GZK neutrino flux may be observable in future radio-based neutrino
observatories, such as IceCube-Gen2 radio, provided there exists a
large overdensity in the CνB distribution. This therefore provides
a new probe of CνB clustering at large redshifts, complementary to
the laboratory probes (such as KATRIN) at zero redshift.
Title: The winking eye of a very massive star: WR 21a revealed as
an eclipsing binary by TESS
Authors: Barbá, Rodolfo H.; Gamen, Roberto C.; Martín-Ravelo, Pablo;
Arias, Julia I.; Morrell, Nidia I.
Bibcode: 2022MNRAS.516.1149B
Altcode: 2021arXiv210906311B
WR 21a was known as a massive spectroscopic binary composed of an O2.5
If*/WN6ha primary and an O3 V((f*))z secondary. Although a minimum
value, the mass estimated for the primary placed it as one of the
most massive stars found in our Galaxy. We report the discovery of
photometric variations in the time series observations carried out
by the Transiting Exoplanet Survey Satellite (TESS). These light
variations are interpreted as formed by two main components: a sharp
partial eclipse of the O3 secondary by the O2.5/WN6 star, and tidally
excited oscillations. Based on the light minima, a new ephemeris for
the system is calculated. The system configuration is detached and
the observed eclipse corresponds to the periastron passage. During the
eclipse, the light curve shape suggests the presence of the heartbeat
effect. The frequencies derived for the tidally excited oscillations
are harmonics of the orbital period. Combining new and previously
published radial velocity measurements, a new spectroscopic orbital
solution is also obtained. Using the PHOEBE code we model the TESS
light curve and determine stellar radii of RO2.5/WN6 =
23.4 R⊙ and RO3 = 14.3 R⊙ and an
orbital inclination i = 62${_{.}^{\circ}}$2 ± 0${_{.}^{\circ}}$9. The
latter combined with the spectroscopic minimum masses lead to absolute
masses of MO2.5/WN6 = 93.2 M⊙ and MO3
= 52.9 M⊙, which establishes WR 21a as belonging to the
rare group of the very massive stars.
Title: Evidence of hard power-law spectral cutoff and disc reflection
features from the X-ray transient XTE J1739-285
Authors: Mondal, Aditya S.; Raychaudhuri, B.; Dewangan, G. C.;
Beri, Aru
Bibcode: 2022MNRAS.516.1256M
Altcode: 2022MNRAS.tmp.2229M; 2022arXiv220316198M
We report on the nearly simultaneous NICER and NuSTAR observations of
the known X-ray transient XTE J1739-285. These observations provide
the first sensitive hard X-ray spectrum of this neutron star X-ray
transient. The source was observed on 2020 February 19 in the hard
spectral state with a luminosity of 0.007 of the Eddington limit. The
broadband 1-70 keV NICER and NuSTAR observation clearly detects a cutoff
of the hard spectral component around 34-40 keV when the continuum is
fitted by a soft thermal component and a hard power-law component. This
feature has been detected for the first time in this source. Moreover,
the spectrum shows evidence for disc reflection - a relativistically
broadened Fe K α line around 5-8 keV and a Compton hump in the 10-20
keV energy band. The accretion disc reflection features have not been
identified before from this source. Through accretion disc reflection
modelling, we constrain the radius of the inner disc to be $R_{\rm
in}=3.1_{-0.5}^{+1.8}R_{\rm ISCO}$ for the first time. In addition,
we find a low inclination, i ~ 33°. Assuming the magnetosphere is
responsible for such truncation of the inner accretion disc above the
stellar surface, we establish an upper limit of 6.2 × 108
G on the magnetic field at the poles.
Title: Photometric variability in star-forming galaxies as evidence
for low-mass AGN and a precursor to quenching
Authors: Cleland, Cressida; McGee, Sean L.
Bibcode: 2022MNRAS.515.5905C
Altcode: 2022arXiv220800831C; 2022MNRAS.tmp.2135C
We measure the optical variability in ~16 500 low-redshift (z ~ 0.1)
galaxies to map the relations between active galactic nucleus (AGN)
activity and galaxy stellar mass, specific star formation rate,
half-light radius, and bulge-to-total ratio. To do this, we use a
reduced χ2 variability measure on >10 epoch light curves
from the Zwicky Transient Facility and combine with spectroscopic data
and derive galaxy parameters from the Sloan Digital Sky Survey. We find
that below the stellar mass of 1011 M⊙, galaxies
classed as star-forming via the Baldwin-Phillips-Terlevich diagram have
higher mean variabilities than AGN or composite galaxies. Revealingly,
the highest mean variabilities occur in star-forming galaxies
in a narrow range of specific star formation rate: -11 <
log(sSFR/yr-1) < -10. In very actively star-forming
galaxies [log(sSFR/yr-1) > -10], the reduced variability
implies a lack of instantaneous correlation with star formation
rate. Our results may indicate that a high level of variability, and
thus black hole growth, acts as a precursor for reduced star formation,
bulge growth, and revealed AGN-like emission lines. These results add
to the mounting evidence that optical variability can act as a viable
tracer for low-mass AGNs and that such AGNs can strongly affect their
host galaxy.
Title: A correlation between H α trough depth and inclination in
quiescent X-ray transients: evidence for a low-mass black hole in
GRO J0422+32
Authors: Casares, J.; Muñoz-Darias, T.; Torres, M. A. P.; Mata
Sánchez, D.; Britt, C. T.; Armas Padilla, M.; Álvarez-Hernández,
A.; Cúneo, V. A.; González Hernández, J. I.; Jiménez-Ibarra, F.;
Jonker, P. G.; Panizo-Espinar, G.; Sánchez-Sierras, J.; Yanes-Rizo,
I. V.
Bibcode: 2022MNRAS.516.2023C
Altcode: 2022arXiv220701628C
We present a new method to derive binary inclinations in quiescent black
hole (BH) X-ray transients (XRTs), based on the depth of the trough (T)
from double-peaked H α emission profiles arising in accretion discs. We
find that the inclination angle (i) is linearly correlated with T in
phase-averaged spectra with sufficient orbital coverage (≳50 per cent)
and spectral resolution, following i(deg) = 93.5 × T + 23.7. The
correlation is caused by a combination of line opacity and local
broadening, where a leading (excess broadening) component scales with
the deprojected velocity of the outer disc. Interestingly, such scaling
allows to estimate the fundamental ratio M1/Porb
by simply resolving the intrinsic width of the double-peak profile. We
apply the T-i correlation to derive binary inclinations for GRO
J0422+32 and Swift J1357-0933, two BH XRTs where strong flickering
activity has hindered determining their values through ellipsoidal
fits to photometric light curves. Remarkably, the inclination derived
for GRO J0422+32 (i = 55.6 ± 4.1○) implies a BH mass
of $2.7^{+0.7}_{-0.5}$ M⊙ thus placing it within the
gap that separates BHs from neutron stars. This result proves that
low-mass BHs exist in nature and strongly suggests that the so-called
'mass gap' is mainly produced by low number statistics and possibly
observational biases. On the other hand, we find that Swift J1357-0933
contains a $10.9^{+1.7}_{-1.6}$ M⊙ BH, seen nearly edge
on ($i=87.4^{+2.6}_{-5.6}$ deg). Such extreme inclination, however,
should be treated with caution since it relies on extrapolating the
T-i correlation beyond i ≳ 75○, where it has not yet
been tested.
Title: Turbulent magnetic helicity fluxes in solar convective zone
Authors: Kleeorin, N.; Rogachevskii, I.
Bibcode: 2022MNRAS.515.5437K
Altcode: 2022MNRAS.tmp.2102K; 2022arXiv220614152K
Combined action of helical motions of plasma (the kinetic α effect)
and non-uniform (differential) rotation is a key dynamo mechanism of
solar and galactic large-scale magnetic fields. Dynamics of magnetic
helicity of small-scale fields is a crucial mechanism in a non-linear
dynamo saturation where turbulent magnetic helicity fluxes allow to
avoid catastrophic quenching of the α effect. The convective zone
of the Sun and solar-like stars, as well as galactic discs, are the
source for production of turbulent magnetic helicity fluxes. In the
framework of the mean-field approach and the spectral τ approximation,
we derive turbulent magnetic helicity fluxes using the Coulomb gauge in
a density-stratified turbulence. The turbulent magnetic helicity fluxes
include non-gradient and gradient contributions. The non-gradient
magnetic helicity flux is proportional to a non-linear effective
velocity (which vanishes in the absence of the density stratification)
multiplied by small-scale magnetic helicity, while the gradient
contributions describe turbulent magnetic diffusion of the small-scale
magnetic helicity. In addition, the turbulent magnetic helicity
fluxes contain source terms proportional to the kinetic α effect or
its gradients, and also contributions caused by the large-scale shear
(solar differential rotation). We have demonstrated that the turbulent
magnetic helicity fluxes due to the kinetic α effect and its radial
derivative in combination with the non-linear magnetic diffusion of the
small-scale magnetic helicity are dominant in the solar convective zone.
Title: A global test of jet structure and delay time distribution
of short-duration gamma-ray bursts
Authors: Luo, Jia-Wei; Li, Ye; Ai, Shunke; Gao, He; Zhang, Bing
Bibcode: 2022MNRAS.516.1654L
Altcode: 2022MNRAS.tmp.2171L; 2022arXiv220607865L
The multimessenger joint observations of GW170817 and GRB170817A shed
new light on the study of short-duration gamma-ray bursts (SGRBs). Not
only did it substantiate the assumption that SGRBs originate from binary
neutron star (BNS) mergers, but it also confirms that the jet generated
by this type of merger must be structured, hence the observed energy
of an SGRB depends on the viewing angle from the observer. However,
the precise structure of the jet is still subject to debate. Moreover,
whether a single unified jet model can be applied to all SGRBs is not
known. Another uncertainty is the delay time-scale of BNS mergers with
respect to star-formation history of the Universe. In this paper, we
conduct a global test of both delay and jet models of BNS mergers across
a wide parameter space with simulated SGRBs. We compare the simulated
peak flux, redshift, and luminosity distributions with the observed
ones and test the goodness-of-fit for a set of models and parameter
combinations. Our simulations suggest that GW170817/GRB 170817A and all
SGRBs can be understood within the framework of a universal structured
jet viewed at different viewing angles. Furthermore, model invoking
a jet plus cocoon structure with a lognormal delay time-scale is
most favoured. Some other combinations (e.g. a Gaussian delay with a
power-law jet model) are also acceptable. However, the Gaussian delay
with Gaussian jet model and the entire set of power-law delay models
are disfavoured.
Title: Exploring the dependence of hot Jupiter occurrence rates on
stellar mass with TESS
Authors: Beleznay, Maya; Kunimoto, M.
Bibcode: 2022MNRAS.516...75B
Altcode: 2022MNRAS.tmp.2078B; 2022arXiv220712522B
We present estimates for the occurrence rates of hot Jupiters around
dwarf stars based on data from the Transiting Exoplanet Survey
Satellite (TESS) Prime Mission. We take 97 hot Jupiters orbiting 198
721 AFG dwarf stars (ranging in mass from 0.8 to $2.3\, {\rm M}_{\odot
}$) from an independent search for hot Jupiters using TESS Prime
Mission data. We estimate our planet sample's false positive rates
(FPRs) as $14\pm 7{{\,\rm per\,cent}}$ for A stars, $16\pm 6{{\,\rm
per\,cent}}$ for F stars, and 0 per cent for G stars. We find hot
Jupiter occurrence rates of $0.29 \pm 0.05{{\,\rm per\,cent}}$ for A
stars, $0.36 \pm 0.06{{\,\rm per\,cent}}$ for F stars and $0.55 \pm
0.14{{\,\rm per\,cent}}$ for G stars, with a weighted average across
AFG stars of $0.33\pm 0.04{{\,\rm per\,cent}}$. Our results show a
correlation between higher hot Jupiter abundance and lower stellar mass
and are in good agreement with occurrence rates found by Kepler. After
correcting for the presence of binaries in the TESS stellar sample,
we estimate a single-star hot Jupiter occurrence rate of $0.98\pm
0.36{{\,\rm per\,cent}}$ for G stars. This is in agreement with
results from radial velocity (RV) surveys, indicating that stellar
multiplicity correction is able to resolve the discrepancy between
hot Jupiter occurrence rates based on transits and RVs.
Title: Searching for giant planets in the outer Solar system with
far-infrared all-sky surveys
Authors: Sedgwick, Chris; Serjeant, Stephen
Bibcode: 2022MNRAS.515.4828S
Altcode: 2022MNRAS.tmp.2022S; 2022arXiv220709985S
We have explored a method for finding giant planets in the outer Solar
system by detecting their thermal emission and proper motion between
two far-infrared all-sky surveys separated by 23.4 yr, taken with the
InfraRed Astronomical Satellite (IRAS) and the AKARI Space Telescope. An
upper distance limit of about 8000 AU is given by both the sensitivities
of these surveys and the distance at which proper motion becomes too
small to be detected. This paper covers the region from 8000 AU to
700 AU. We have used a series of filtering and SED-fitting algorithms
to find candidate pairs, whose IRAS and AKARI flux measurements could
together plausibly be fitted by a Planck thermal distribution for a
likely planetary temperature. Theoretical studies have placed various
constraints on the likely existence of unknown planets in the outer
Solar system. The main observational constraint to date comes from a
WISE study: an upper limit on an unknown planet's mass out into the
Oort cloud. Our work confirms this result for our distance range,
and provides additional observational constraints for lower distances
and planetary masses, subject to the proviso that the planet is not
confused with Galactic cirrus. We found 535 potential candidates with
reasonable spectral energy distribution (SED) fits. Most would have
masses close to or below that of Neptune (~0.05 Jupiter mass), and
be located below 1000 AU. However, examination of the infrared images
of these candidates suggests that none is sufficiently compelling to
warrant follow-up, since all are located inside or close to cirrus
clouds, which are most likely the source of the far-infrared flux.
Title: A double-peaked Lyman-α emitter with a stronger blue peak
multiply imaged by the galaxy cluster RXC J0018.5+1626
Authors: Furtak, Lukas J.; Plat, Adèle; Zitrin, Adi; Topping,
Micheal W.; Stark, Daniel P.; Strait, Victoria; Charlot, Stéphane;
Coe, Dan; Andrade-Santos, Felipe; Bradač, Maruša; Bradley, Larry;
Lemaux, Brian C.; Sharon, Keren
Bibcode: 2022MNRAS.516.1373F
Altcode: 2022arXiv220409668F; 2022MNRAS.tmp.2066F
We report the discovery of a double-peaked Lyman-α (Ly α) emitter
(LAE) at z = 3.2177 ± 0.0001 in VLT/MUSE data. The galaxy is strongly
lensed by the galaxy cluster RXC J0018.5+1626 recently observed in
the RELICS survey, and the double-peaked Ly α emission is clearly
detected in the two counter images in the MUSE field of view. We
measure a relatively high Ly α rest-frame equivalent width (EW) of
EWLy α, 0 = (63 ± 2) Å. Additional spectroscopy with
Gemini/GNIRS in the near-infrared (NIR) allows us to measure the H β,
[O III] λ4959 Å, and [O III] λ5007 Å emission lines, which show
moderate rest-frame EWs of the order of a few ~10-100 Å, an [O III]
λ5007 Å/H β ratio of 4.8 ± 0.7, and a lower limit on the [O III]/[O
II] ratio of >9.3. The galaxy has very blue UV-continuum slopes of
βFUV = -2.23 ± 0.06 and βNUV = -3.0 ± 0.2,
and is magnified by factors μ ~ 7-10 in each of the two images,
thus enabling a view into a low-mass ($M_{\star }\simeq 10^{7.5}\,
\mathrm{M}_{\odot }$) high-redshift galaxy analogue. Notably, the blue
peak of the Ly α profile is significantly stronger than the red peak,
which suggests an inflow of matter and possibly very low H I column
densities in its circumgalactic gas. To the best of our knowledge,
this is the first detection of such a Ly α profile. Combined with the
high lensing magnification and image multiplicity, these properties
make this galaxy a prime candidate for follow-up observations to search
for LyC emission and constrain the LyC photon escape fraction.
Title: A spectroscopic study of 14 structures behind Holm15A:
detecting a galaxy group candidate at z = 0.58
Authors: Ibarra-Medel, H.
Bibcode: 2022MNRAS.515.6032I
Altcode: 2022MNRAS.tmp.2070I; 2022arXiv220711287I
Holm15A hosts one of the most massive back holes ever known. Hence,
it is important to characterize any structure within its core to avoid
any wrong association with its central black hole and therefore bias
any future study. In this work, we present the first identification
and characterization of 14 structures hidden behind the surface
brightness of Holm15A. We model and subtract the spectral contribution
of Holm15A to obtain the spectral information of these structures. We
spectroscopically confirm that the 14 objects found are not associated
with Holm15A. 10 objects have a well-defined galaxy spectrum from
which we implement a fossil record analysis to reconstruct their
past evolution. Nine objects are candidates members to be part
of a compact galaxy group at redshift 0.5814. We find past mutual
interaction among the group candidates that support the scenario of
mutual crossings. Furthermore, the fossil reconstruction of the group
candidates brings evidence that at least three different merger trees
could assemble the galaxy group. We characterize the properties of the
galaxy group from which we estimate a lower limit of the scale and mass
of this group. We obtain a scale of >146 ± 3 kpc with a dispersion
velocity of 622 ± 300 km s-1. These estimations consider
the lensing effects of the gravitational potential of Holm15A. The
other five objects were studied individually. We use public archive
data of integral field spectroscopic observations from the Multi-Unit
Spectroscopic Explorer instrument.
Title: Evolution of massive stellar triples and implications for
compact object binary formation
Authors: Stegmann, Jakob; Antonini, Fabio; Moe, Maxwell
Bibcode: 2022MNRAS.516.1406S
Altcode: 2021arXiv211210786S
Most back hole and neutron star progenitors are found in triples or
higher multiplicity systems. Here, we present a new triple stellar
evolution code, ${\tt TSE}$, which simultaneously takes into account
the physics of the stars and their gravitational interaction. ${\tt
TSE}$ is used to simulate the evolution of massive stellar triples
in the galactic field from the zero-age main sequence until they
form compact objects. To this end, we implement initial conditions
that incorporate the observed high correlation between the orbital
parameters of early-type stars. We show that the interaction with a
tertiary companion can significantly impact the evolution of the inner
binary. High eccentricities can be induced by the third-body dynamical
effects, leading to a Roche lobe overflow or even to a stellar merger
from initial binary separations 103-$10^5\, \rm R_\odot$. In
$\sim 5\, {{\ \rm per\ cent}}$ of the systems, the tertiary companion
itself fills its Roche lobe, while $\sim 10\, {{\ \rm per\ cent}}$ of
all systems become dynamically unstable. We find that between $0.3{{\
\rm per\ cent}}$ and $5{{\ \rm per\ cent}}$ of systems form a stable
triple with an inner compact object binary, where the exact fraction
depends on metallicity and the natal kick prescription. Most of these
triples are binary black holes with black hole companions. We find no
binary neutron star in any surviving triple, unless zero natal kicks are
assumed. About half of all black hole binaries formed in our models are
in triples, where in the majority, the tertiary black hole can perturb
their long-term evolution. Our results show that triple interactions
are key to a full understanding of massive star evolution and compact
object binary formation.
Title: Chemical abundance of LINER galaxies - metallicity calibrations
based on SDSS-IV MaNGA
Authors: Oliveira, C. B.; Krabbe, A. C.; Hernandez-Jimenez, J. A.;
Dors, O. L.; Zinchenko, I. A.; Hägele, G. F.; Cardaci, M. V.;
Monteiro, A. F.
Bibcode: 2022MNRAS.515.6093O
Altcode: 2022arXiv220710260O
The ionizing source of low-ionization nuclear emission-line
regions (LINERs) is uncertain. Because of this, an empirical
relation to determine the chemical abundances of these objects has
not been proposed. In this work, for the first time, we derived
two semi-empirical calibrations based on photoionization models to
estimate the oxygen abundance of LINERS as a function of the N2 and O3N2
emission-line intensity ratios. These relations were calibrated using
oxygen abundance estimations obtained by comparing the observational
emission-line ratios of 43 LINER galaxies (taken from the MaNGA survey)
and grids of photoionization models built with the CLOUDY code assuming
post-asymptotic giant branch stars with different temperatures. We
found that the oxygen abundance of LINERs in our sample is in the
$\rm 8.48 \: \lesssim \: 12+log(O/H) \: \lesssim 8.84$ range, with
a mean value of $\rm 12+\log (O/H)=8.65$. We recommend the use of
the N2 index to estimate the oxygen abundances of LINERs, since the
calibration with this index presented a much smaller dispersion than
the O3N2 index. In addition, the estimated metallicities are in good
agreement with those derived by extrapolating the disc oxygen abundance
gradients to the centre of the galaxies showing that the assumptions
of the models are suitable for LINERs. We also obtained a calibration
between the logarithm of the ionization parameter and the [O III]/[O
II] emission-line ratio.
Title: Discovery and origin of the radio emission from the multiple
stellar system KQ Vel
Authors: Leto, P.; Oskinova, L. M.; Buemi, C. S.; Shultz, M. E.;
Cavallaro, F.; Trigilio, C.; Umana, G.; Fossati, L.; Pillitteri,
I.; Krtička, J.; Ignace, R.; Bordiu, C.; Bufano, F.; Catanzaro,
G.; Cerrigone, L.; Giarrusso, M.; Ingallinera, A.; Loru, S.; Owocki,
S. P.; Postnov, K. A.; Riggi, S.; Robrade, J.; Leone, F.
Bibcode: 2022MNRAS.515.5523L
Altcode: 2022MNRAS.tmp.2067L; 2022arXiv220714075L
KQ Vel is a binary system composed of a slowly rotating magnetic Ap
star with a companion of unknown nature. In this paper, we report the
detection of its radio emission. We conducted a multifrequency radio
campaign using the ATCA interferometer (band-names: 16 cm, 4 cm,
and 15 mm). The target was detected in all bands. The most obvious
explanation for the radio emission is that it originates in the
magnetosphere of the Ap star, but this is shown unfeasible. The known
stellar parameters of the Ap star enable us to exploit the scaling
relationship for non-thermal gyro-synchrotron emission from early-type
magnetic stars. This is a general relation demonstrating how radio
emission from stars with centrifugal magnetospheres is supported by
rotation. Using KQ Vel's parameters the predicted radio luminosity is
more than five orders of magnitudes lower than the measured one. The
extremely long rotation period rules out the Ap star as the source
of the observed radio emission. Other possible explanations for the
radio emission from KQ Vel, involving its unknown companion, have been
explored. A scenario that matches the observed features (i.e. radio
luminosity and spectrum, correlation to X-rays) is a hierarchical
stellar system, where the possible companion of the magnetic star is a
close binary (possibly of RS CVn type) with at least one magnetically
active late-type star. To be compatible with the total mass of the
system, the last scenario places strong constraints on the orbital
inclination of the KQ Vel stellar system.
Title: A lensed radio jet at milliarcsecond resolution I: Bayesian
comparison of parametric lens models
Authors: Powell, Devon M.; Vegetti, Simona; McKean, J. P.; Spingola,
Cristiana; Stacey, Hannah R.; Fassnacht, Christopher D.
Bibcode: 2022MNRAS.516.1808P
Altcode: 2022arXiv220703375P
We investigate the mass structure of a strong gravitational lens
galaxy at z = 0.350, taking advantage of the milliarcsecond (mas)
angular resolution of very long baseline interferometric (VLBI)
observations. In the first analysis of its kind at this resolution,
we jointly infer the lens model parameters and pixellated radio
source surface brightness. We consider several lens models of
increasing complexity, starting from an elliptical power-law density
profile. We extend this model to include angular multipole structures,
a separate stellar mass component, additional nearby field galaxies,
and/or a generic external potential. We compare these models using
their relative Bayesian log-evidence (Bayes factor). We find strong
evidence for angular structure in the lens; our best model is comprised
of a power-law profile plus multipole perturbations and external
potential, with a Bayes factor of +14984 relative to the elliptical
power-law model. It is noteworthy that the elliptical power-law mass
distribution is a remarkably good fit on its own, with additional
model complexity correcting the deflection angles only at the ~5
mas level. We also consider the effects of added complexity in the
lens model on time-delay cosmography and flux-ratio analyses. We
find that an overly simplistic power-law ellipsoid lens model can
bias the measurement of H0 by ~3 per cent and mimic flux
ratio anomalies of ~8 per cent. Our results demonstrate the power of
high-resolution VLBI observations to provide strong constraints on
the inner density profiles of lens galaxies.
Title: Photometric characterization and trajectory accuracy of
Starlink satellites: implications for ground-based astronomical
surveys
Authors: Halferty, Grace; Reddy, Vishnu; Campbell, Tanner; Battle,
Adam; Furfaro, Roberto
Bibcode: 2022MNRAS.516.1502H
Altcode: 2022MNRAS.tmp.2035H; 2022arXiv220803226H
Starlink is a low-Earth orbit (LEO) satellite constellation
operated by Space Exploration Technologies Corp. (SpaceX) which
aims to provide global satellite internet access. Thus far, most
photometric observations of Starlink satellites have primarily been
from citizen scientists' visual observations without using quantitative
detectors. This paper aims to characterize Starlink satellites and
investigate the impact of mega constellations on ground-based astronomy,
considering both the observed magnitude and two-line element (TLE)
residuals. We collected 353 observations of 61 different Starlink
satellites over a 16-month period and we found an average GAIA G
magnitude of 5.5 ± 0.13 with a standard deviation of 1.12. The
average magnitude of V1.0 (pre-VisorSat) Starlinks was 5.1 ± 0.13
with a standard deviation of 1.13. SpaceX briefly used a low-albedo
coating on a Starlink satellite called DarkSat to test light pollution
mitigation technologies. The brightness of DarkSat was found to be 7.3
± 0.13 with a standard deviation of 0.78, or 7.6 times fainter than
V1.0 Starlinks. This concept was later abandoned due to thermal control
issues and sun visors were used in future models called VisorSats. The
brightness of VisorSats was found to be 6.0 ± 0.13 with a standard
deviation of 0.79, or 2.3 times fainter than V1.0 Starlinks. Over
the span of the observations, we found that TLEs were accurate to
within an average of 0.12 deg in right ascension and -0.08 deg in
declination. The error is predominantly along-track, corresponding
to a 0.3 s time error between the observed and TLE trajectories. Our
observations show that a time difference of 0.3 ± 0.28 s is viable
for a proposed 10 s shutter closure time to avoid Starlinks in images.
Title: Bulirsh-Stoer algorithm in the planar restricted three-body
problem
Authors: Demidova, T.
Bibcode: 2022A&C....4100635D
Altcode:
The applicability of the Bulirsh-Stoer algorithm for solving the planar
restricted three-body problem is investigated. Variations in the value
of the Jacobi integral are considered as the main parameter. Massive
calculations were carried out with a small step in the parameter
characterizing the ratio of the masses of a planet and star (the mass
parameter). It is shown that violations of the Jacobi integral occur
inside the planetary chaotic region. This fact can be used to determine
chaotic region boundaries, as well as the boundaries of a stable
structure which coorbital with the planet. The average dependences
of the value of the Jacobi integral on the mass parameter, which
determine the boundaries of the chaotic zone and the coorbital ring,
are derived. Estimates were obtained for the maximum relative change in
the Jacobi integral for different values of the accretion radius. It
is shown that the value of the accretion radius corresponding to the
average radius of known exoplanets does not cause significant changes
in the value of the Jacobi integral. The dependences of the clearing
time of the chaotic zone for different accretion radii are also given
with and without taking into account the coorbital structure.
Title: The impact of a massive Sagittarius dSph on GD-1-like streams
Authors: Dillamore, Adam M.; Belokurov, Vasily; Evans, N. Wyn;
Price-Whelan, Adrian M.
Bibcode: 2022MNRAS.516.1685D
Altcode: 2022arXiv220513547D; 2022MNRAS.tmp.2193D
We investigate the effects of a massive ($\gtrsim 4\times 10^{10}\,
\mathrm{M}_\odot$) Sagittarius dwarf spheroidal galaxy (Sgr) on
stellar streams using test particle simulations in a realistic
Milky Way potential. We find that Sgr can easily disrupt streams
formed more than ~3 Gyr ago, while stars stripped more recently
are generally unaffected. In certain realizations, Sgr is able to
produce asymmetry between the leading and trailing tails of Pal 5,
qualitatively similar to observations. Using data from the Gaia space
telescope and elsewhere, we fit models to the GD-1 stream in the
presence of a Sgr with various initial masses. While the best-fitting
models do show perturbations resulting from interactions with Sgr,
we find that the level of disruption is not significantly greater than
in the observed stream. To investigate the general effects of Sgr on
a population of streams, we generate 1000 mock streams on GD-1-like
orbits with randomized orientations. Some streams show clear evidence
of disruption, becoming folded on the sky or developing asymmetry
between their two tails. However, many survive unaffected and the
peak surface brightness of stars is decreased by no more than ~0.3
mag arcsec-2 on average. We conclude that Sgr
having an initial mass of $\gtrsim 4\times 10^{10}\, \mathrm{M}_\odot$
is compatible with the survival and detection of streams formed more
than 3 Gyr ago.
Title: VLT/UVES observation of the outflow in quasar SDSS J1439-0106
Authors: Byun, Doyee; Arav, Nahum; Walker, Andrew
Bibcode: 2022MNRAS.516..100B
Altcode: 2022MNRAS.tmp.2154B; 2022arXiv220807405B
We analyse the VLT/UVES spectrum of the quasar SDSS J143907.5-010616.7,
retrieved from the UVES Spectral Quasar Absorption Database. We
identify two outflow systems in the spectrum: a mini broad absorption
line (mini-BAL) system and a narrow absorption line (NAL) system. We
measure the ionic column densities of the mini-BAL ($v$ = -1550 km
s-1) outflow, which has excited state absorption troughs
of ${\rm Fe\, \rm {\small {ii}}}$. We determine that the electron
number density $\log {n_e}=3.4^{+0.1}_{-0.1}$, based on the ratios
between the excited and ground state abundances of ${\rm Fe\, \rm
{\small {ii}}}$, and find the kinetic luminosity of the outflow to be
${\lesssim}0.1\,\hbox{per cent}$ of the quasar's Eddington luminosity,
making it insufficient to contribute to AGN feedback.
Title: Gamma-ray light curves and spectra of classical novae
Authors: Leung, Shing-Chi; Siegert, Thomas
Bibcode: 2022MNRAS.516.1008L
Altcode: 2022MNRAS.tmp.1647L; 2021arXiv211206893L
The nucleosynthesis in classical novae, in particular that
of radioactive isotopes, is directly measurable by its γ-ray
signature. Despite decades of observations, MeV γ-rays from novae have
never been detected - neither individually at the time of the explosion,
nor as a result of radioactive decay, nor the diffuse Galactic emission
from the nova population. Thanks to recent developments in modelling
of instrumental background for MeV telescopes such as INTEGRAL/SPI and
Fermi/GBM, the prospects to finally detect these elusive transients are
greatly enhanced. This demands for updated and refined models of γ-ray
spectra and light curves of classical novae. In this work, we develop
numerical models of nova explosions using sub- and near-Chandrasekhar
CO white dwarfs as the progenitor. We study the parameter dependence
of the explosions, their thermodynamics and energetics, as well as
their chemical abundance patterns. We use a Monte Carlo radiative
transfer code to compute γ-ray light curves and spectra, with a
focus on the early time evolution. We compare our results to previous
studies and find that the expected 511-keV-line flash at the time
of the explosion is heavily suppressed, showing a maximum flux of
only $10^{-9}\, \mathrm{ph\, cm^{-2}\, s^{-1}}$ and thus making
it at least one million times fainter than estimated before. This
finding would render it impossible for current MeV instruments to
detect novae within the first day after the outburst. Nevertheless,
our time-resolved spectra can be used for retrospective analyses of
archival data, thereby improving the sensitivity of the instruments.
Title: A new method to correct for host star variability in multiepoch
observations of exoplanet transmission spectra
Authors: Panwar, Vatsal; Désert, Jean-Michel; Todorov, Kamen O.; Bean,
Jacob L.; Stevenson, Kevin B.; Huitson, C. M.; Fortney, Jonathan J.;
Bergmann, Marcel
Bibcode: 2022MNRAS.515.5018P
Altcode: 2022MNRAS.tmp.1858P; 2022arXiv220701606P
Transmission spectra of exoplanets orbiting active stars suffer
from wavelength-dependent effects due to stellar photospheric
heterogeneity. WASP-19b, an ultra-hot Jupiter (Teq
~ 2100 K), is one such strongly irradiated gas-giant orbiting an
active solar-type star. We present optical (520-900 nm) transmission
spectra of WASP-19b obtained across eight epochs, using the Gemini
Multi-Object Spectrograph (GMOS) on the Gemini-South telescope. We apply
our recently developed Gaussian Processes regression based method to
model the transit light-curve systematics and extract the transmission
spectrum at each epoch. We find that WASP-19b's transmission spectrum
is affected by stellar variability at individual epochs. We report an
observed anticorrelation between the relative slopes and offsets of
the spectra across all epochs. This anticorrelation is consistent with
the predictions from the forward transmission models, which account for
the effect of unocculted stellar spots and faculae measured previously
for WASP-19. We introduce a new method to correct for this stellar
variability effect at each epoch by using the observed correlation
between the transmission spectral slopes and offsets. We compare our
stellar variability corrected GMOS transmission spectrum with previous
contradicting MOS measurements for WASP-19b and attempt to reconcile
them. We also measure the amplitude and timescale of broad-band
stellar variability of WASP-19 from TESS photometry, which we find
to be consistent with the effect observed in GMOS spectroscopy and
ground-based broad-band photometric long-term monitoring. Our results
ultimately caution against combining multiepoch optical transmission
spectra of exoplanets orbiting active stars before correcting each
epoch for stellar variability.
Title: The fifth-order post-Newtonian Hamiltonian dynamics of two-body
systems from an effective field theory approach
Authors: Blümlein, J.; Maier, A.; Marquard, P.; Schäfer, G.
Bibcode: 2022NuPhB.98315900B
Altcode: 2021arXiv211013822B
Within an effective field theory method to general relativity, we
calculate the fifth-order post-Newtonian (5PN) Hamiltonian dynamics
also for the tail terms, extending earlier work on the potential
contributions, working in harmonic coordinates. Here we calculate
independently all (local) 5PN far-zone contributions using the in-in
formalism, on which we give a detailed account. The five expansion
terms of the Hamiltonian in the effective one body (EOB) approach,
q82 ,q63 ,q44 ,d5 bar
and an, can all be determined from the local contributions to the
periastron advance K loc , h (E ˆ , j), without further
assumptions on the structure of the symmetric mass ratio, ν, of the
expansion coefficients of the scattering angle χk. The O
(ν2) contributions to the 5PN EOB parameters have been
unknown in part before. We perform comparisons of our analytic
results with the literature and also present numerical results on
some observables.
Title: Molecular tracers of planet formation in the atmospheres of
hot Jupiters
Authors: Hobbs, Richard; Shorttle, Oliver; Madhusudhan, Nikku
Bibcode: 2022MNRAS.516.1032H
Altcode: 2022MNRAS.tmp.2036H; 2021arXiv211204930H
The atmospheric chemical composition of a hot Jupiter can lead to
insights into where in its natal protoplanetary disc it formed and its
subsequent migration pathway. We use a 1D chemical kinetics code to
compute a suite of models across a range of elemental abundances to
investigate the resultant abundances of key molecules in hot Jupiter
atmospheres. Our parameter sweep spans metallicities between 0.1x and
10x solar values for the C/H, O/H, and N/H ratios, and equilibrium
temperatures of 1000 and 2000 K. We link this parameter sweep to
the formation and migration models from previous works to predict
connections between the atmospheric molecular abundances and formation
pathways, for the molecules H2O, CO, CH4,
CO2, HCN, and NH3. We investigate atmospheric
H2O abundances in eight hot Jupiters reported in the
literature. All eight planets fall within our predicted ranges for
various formation models; however, six of them are degenerate between
multiple models and hence require additional molecular detections
for constraining their formation histories. The other two planets,
HD 189733 b and HD 209458 b, have water abundances that fall within
ranges expected from planets that formed beyond the CO2
snowline. Finally, we investigate the detections of H2O,
CO, CH4, CO2, HCN, and NH3 in the
atmosphere of HD 209458 b and find that, within the framework of our
model, the abundances of these molecules best match with a planet that
formed between the CO2 and CO snowlines and then underwent
disc-free migration to reach its current location.
Title: The Hot Neptune WASP-166 b with ESPRESSO - I. Refining the
planetary architecture and stellar variability
Authors: Doyle, L.; Cegla, H. M.; Bryant, E.; Bayliss, D.; Lafarga, M.;
Anderson, D. R.; Allart, R.; Bourrier, V.; Brogi, M.; Buchschacher,
N.; Kunovac, V.; Lendl, M.; Lovis, C.; Moyano, M.; Roguet-Kern,
N.; Seidel, J. V.; Sosnowska, D.; Wheatley, P. J.; Acton, J. S.;
Burleigh, M. R.; Casewell, S. L.; Gill, S.; Goad, M. R.; Henderson,
B. A.; Jenkins, J. S.; Tilbrook, R. H.; West, R. G.
Bibcode: 2022MNRAS.516..298D
Altcode: 2022MNRAS.tmp.2101D; 2022arXiv220710127D
In this paper, we present high-resolution spectroscopic transit
observations from ESPRESSO of the super-Neptune WASP-166 b. In addition
to spectroscopic ESPRESSO data, we analyse photometric data from TESS
of six WASP-166 b transits along with simultaneous NGTS observations
of the ESPRESSO runs. These observations were used to fit for the
planetary parameters as well as assessing the level of stellar
activity (e.g. spot crossings, flares) present during the ESPRESSO
observations. We utilize the reloaded Rossiter McLaughlin (RRM)
technique to spatially resolve the stellar surface, characterizing
the centre-to-limb convection-induced variations, and to refine the
star-planet obliquity. We find WASP-166 b has a projected obliquity
of $\lambda = -15.52^{+2.85}_{-2.76}\, ^{\circ }$ and vsin (i) = 4.97
± 0.09 km s-1 which is consistent with the literature. We
were able to characterize centre-to-limb convective variations as a
result of granulation on the surface of the star on the order of a few
km s-1 for the first time. We modelled the centre-to-limb
convective variations using a linear, quadratic, and cubic model with
the cubic being preferred. In addition, by modelling the differential
rotation and centre-to-limb convective variations simultaneously, we
were able to retrieve a potential antisolar differential rotational
shear (α ~ -0.5) and stellar inclination (i* either
42.03$^{+9.13}_{-9.60}\, ^{\circ }$ or 133.64$^{+8.42}_{-7.98}\,
^{\circ }$ if the star is pointing towards or away from us). Finally, we
investigate how the shape of the cross-correlation functions change as
a function of limb angle and compare our results to magnetohydrodynamic
simulations.
Title: Statistical properties of cataclysmic variables in the local
galactic disc: a joint analysis of Gaia and XMM-Newton data
Authors: Xu, Xiao-jie; Wang, Q. Daniel; Li, Xiangdong
Bibcode: 2022MNRAS.516.1263X
Altcode:
Cataclysmic variables (CVs) represent a key evolutionary phase of
many low-mass stellar binaries and appear to collectively dominate the
galactic X-ray background above ~1 keV. Statistical properties of CVs,
however, remain poorly understood, even in the solar neighbourhood. We
aim to obtain an X-ray luminosity-complete sample of local CVs whose
distances put them within three volumes. Here we present a pilot
investigation on the X-ray and optical properties of local CVs or
their candidates, mainly by cross-correlating the 3XMM DR8 and Gaia
DR2 source catalogues. We first examine a nearly complete sample of CVs
within 150 pc by characterizing their X-ray luminosity, X-ray to Gaia
G-band flux ratio, and X-ray hardness ratio distributions, as well as
their locations in the Gaia colour-magnitude diagram. We show that these
distributions of this very local sample are consistent with those of a
CV sample obtained at distances between 150 and 300 pc. We also present
a catalogue of 15 new CV candidates within 500 pc based primarily on
their X-ray to Gaia G-band flux ratios. The X-ray luminosities of these
candidates are between 1029 to several 1031 erg
s-1, and their stacked X-ray spectrum can be well described
by a multitemperature optically thin thermal plasma model with a maximum
temperature $T_{\rm max}=7.5^{+6.3}_{-2.4}$ keV. These properties
are consistent with those of the very local CVs. In particular, one
of the CV candidates is within 150 pc, indicating that a considerable
number of local CVs are yet detected. These results provide a base for
a more complete statistical understanding of CVs and their quantitative
contribution to the galactic X-ray background.
Title: Interstellar extinction correction in ionized regions using
He I lines
Authors: Zamora, S.; Díaz, Ángeles I.; Terlevich, Elena; Fernández,
Vital
Bibcode: 2022MNRAS.516..749Z
Altcode: 2022MNRAS.tmp.2136Z; 2022arXiv220800669Z
The logarithmic extinction coefficient, c(H β), is usually derived
using the H α/H β ratio for case B recombination and assuming standard
values of electron density and temperature. However, the use of strong
Balmer lines can lead us to selection biases when studying regions
with different surface brightness, such as extended nebulae, with the
use of single integral field spectroscopy observations, since, in some
cases, the H α line can be saturated in moderate to long exposures. In
this work, we present a method to derive extinction corrections based
only on the weaker lines of He I, taking into account the presence
of triplet states in these atoms and its influence on recombination
lines. We have applied this procedure to calculate the extinction of
different regions of the 30 Doradus nebula from MUSE integral-field
spectroscopy data. The comparison between helium and hydrogen c(H β)
determinations has been found to yield results fully compatible within
the errors and the use of both sets of lines simultaneously reduces
considerably the error in the derivation.
Title: Polarimetry and photometry of gamma-ray bursts afterglows
with RINGO3
Authors: Shrestha, M.; Steele, I. A.; Kobayashi, S.; Smith, R. J.;
Guidorzi, C.; Jordana-Mitjans, N.; Jermak, H.; Arnold, D.; Mundell,
C. G.; Gomboc, A.
Bibcode: 2022MNRAS.516.1584S
Altcode: 2022MNRAS.tmp.2180S; 2022arXiv220801729S
We present photometric and polarimetric measurements of gamma-ray burst
(GRB) optical afterglows observed by the RINGO3 imaging polarimeter
over its ~7 yr lifetime mounted on the Liverpool Telescope. During
this time, RINGO3 responded to 67 GRB alerts. Of these, 28 had optical
afterglows and a further ten were sufficiently bright for photometric
and polarimetric analysis (R ⪅ 17). We present high quality
multicolour light curves of ten sources: GRB 130606A, GRB 130610A,
GRB 130612A, GRB 140430A, GRB 141220A, GRB 151215A, GRB 180325A, GRB
180618A, GRB 190114C, and GRB 191016A and polarimetry for seven of
these (excluding GRB 130606A, GRB 130610A, and GRB 130612A, which were
observed before the polarimetry mode was fully commissioned). Eight
of these ten GRBs are classical long GRBs, one sits at the short-long
duration interface with a T90 ~ 4 s and one is a classical
short, hard burst with extended emission. We detect polarization for
GRB 190114C and GRB 191016A. While detailed analyses of several of
these GRBs have been published previously, here we present a uniform
re-reduction and analysis of the whole sample and investigation of the
population in a broad context relative to the current literature. We
use survival analysis to fully include the polarization upper limits
in comparison with other GRB properties, such as temporal decay rate,
isotropic energy, and redshift. We find no clear correlation between
polarization properties and wider sample properties and conclude that
larger samples of early time polarimetry of GRB afterglows are required
to fully understand GRB magnetic fields.
Title: Quantifying the role of ram-pressure stripping of galaxies
within galaxy groups
Authors: Kolcu, Tutku; Crossett, Jacob P.; Bellhouse, Callum;
McGee, Sean
Bibcode: 2022MNRAS.515.5877K
Altcode: 2022MNRAS.tmp.2074K; 2022arXiv220801666K
It is often stated that the removal of gas by ram-pressure stripping of
a galaxy disc is not a common process in galaxy groups. In this study,
with the aid of an observational classification of galaxies and a simple
physical model, we show that this may not be true. We examined and
identified 45 ram-pressure-stripped galaxy candidates from a sample
of 1311 galaxy group members within 125 spectroscopically selected
galaxy groups. Of these, 13 galaxies are the most secure candidates
with multiple distinct features. These candidate ram-pressure-stripped
galaxies have similar properties to those found in clusters - they occur
at a range of stellar masses, are largely blue and star-forming, and
have phase-space distributions consistent with being first infallers
into their groups. The only stand-out feature of these candidates
is they exist not in clusters, but in groups, with a median halo
mass of 1013.5 M⊙. Although this may seem
surprising, we employ an analytic model of the expected ram-pressure
stripping force in groups and find that reasonable estimates of the
relevant infall speeds and intragroup medium content would result in
ram-pressure-stripped galaxies at these halo masses. Finally, given the
considerable uncertainty on the lifetime of the ram-pressure phase,
this physical mechanism could be the dominant quenching mechanism in
galaxy groups, if our ram-pressure-stripped candidates can be confirmed.
Title: The first seven months of the 2020 X-ray outburst of the
magnetar SGR J1935+2154
Authors: Borghese, A.; Coti Zelati, F.; Israel, G. L.; Pilia, M.;
Burgay, M.; Trudu, M.; Zane, S.; Turolla, R.; Rea, N.; Esposito, P.;
Mereghetti, S.; Tiengo, A.; Possenti, A.
Bibcode: 2022MNRAS.516..602B
Altcode: 2022MNRAS.tmp.1279B; 2022arXiv220504983B
The magnetar SGR J1935+2154 underwent a new active episode on 2020 April
27-28, when a forest of hundreds of X-ray bursts and a large enhancement
of the persistent flux were detected. For the first time, a radio burst
with properties similar to those of fast radio bursts and with a X-ray
counterpart was observed from this source, showing that magnetars can
power at least a group of fast radio bursts. In this paper, we report
on the X-ray spectral and timing properties of SGR J1935+2154 based
on a long-term monitoring campaign with Chandra, XMM-Newton, NuSTAR,
Swift, and NICER covering a time-span of ~7 months since the outburst
onset. The broad-band spectrum exhibited a non-thermal power-law
component (Γ ~ 1.2) extending up to ~20-25 keV throughout the campaign
and a blackbody component with temperature decreasing from ~1.5 keV at
the outburst peak to ~0.45 keV in the following months. We found that
the luminosity decay is well described by the sum of two exponential
functions, reflecting the fast decay (~1 d) at the early stage of the
outburst followed by a slower decrease (~30 d). The source reached
quiescence about ~80 d after the outburst onset, releasing an energy
of ~6 × 1040 erg during the outburst. We detected X-ray
pulsations in the XMM-Newton data sets and derived an average spin-down
rate of ~3.5 × 10-11 s s-1 using the spin period
measurements derived in this work and three values reported previously
during the same active period. Moreover, we report on simultaneous
radio observations performed with the Sardinia Radio Telescope. No
evidence for periodic or single-pulse radio emission was found.
Title: Signatures of Light Massive Relics on non-linear structure
formation
Authors: Banerjee, Arka; Das, Subinoy; Maharana, Anshuman; Sharma,
Ravi Kumar
Bibcode: 2022MNRAS.516.2038B
Altcode: 2022MNRAS.tmp.2084B; 2022arXiv220209840B
Cosmologies with Light Massive Relics (LiMRs) as a subdominant
component of the dark sector are well-motivated from a particle physics
perspective, and can also have implications for the σ8
tension between early and late time probes of clustering. The effects of
LiMRs on the cosmic microwave background (CMB) and structure formation
on large (linear) scales have been investigated extensively. In this
paper, we initiate a systematic study of the effects of LiMRs on
smaller, non-linear scales using cosmological N-body simulations;
focusing on quantities relevant for photometric galaxy surveys. For
most of our study, we use a particular model of non-thermal LiMRs but
the methods developed generalizing to a large class of LiMR models -
we explicitly demonstrate this by considering the Dodelson-Widrow
velocity distribution. We find that, in general, the effects of LiMR
on small scales are distinct from those of a ΛCDM universe, even when
the value of σ8 is matched between the models. We show
that weak lensing measurements around massive clusters, between ~0.1
h-1Mpc and ~10 h-1Mpc, should have sufficient
signal-to-noise in future surveys to distinguish between ΛCDM and
LiMR models that are tuned to fit both CMB data and linear scale
clustering data at late times. Furthermore, we find that different
LiMR cosmologies indistinguishable by conventional linear probes can
be distinguished by non-linear probes if their velocity distributions
are sufficiently different. LiMR models can, therefore, be best tested
by jointly analyzing the CMB and late-time structure formation on both
large and small scales.
Title: A deep survey of short GRB host galaxies over z 0-2:
implications for offsets, redshifts, and environments
Authors: O'Connor, B.; Troja, E.; Dichiara, S.; Beniamini, P.; Cenko,
S. B.; Kouveliotou, C.; González, J. B.; Durbak, J.; Gatkine, P.;
Kutyrev, A.; Sakamoto, T.; Sánchez-Ramírez, R.; Veilleux, S.
Bibcode: 2022MNRAS.515.4890O
Altcode: 2022MNRAS.tmp.1924O; 2022arXiv220409059O
A significant fraction (30 per cent) of well-localized short
gamma-ray bursts (sGRBs) lack a coincident host galaxy. This leads
to two main scenarios: (i) that the progenitor system merged outside
of the visible light of its host, or (ii) that the sGRB resided
within a faint and distant galaxy that was not detected by follow-up
observations. Discriminating between these scenarios has important
implications for constraining the formation channels of neutron star
mergers, the rate and environments of gravitational wave sources,
and the production of heavy elements in the Universe. In this work, we
present the results of our observing campaign targeted at 31 sGRBs that
lack a putative host galaxy. Our study effectively doubles the sample
of well-studied sGRB host galaxies, now totaling 72 events of which
$28{{\ \rm per\ cent}}$ lack a coincident host to deep limits (r ≳
26 or F110W ≳ 27 AB mag), and represents the largest homogeneously
selected catalogue of sGRB offsets to date. We find that 70 per cent
of sub-arcsecond localized sGRBs occur within 10 kpc of their host's
nucleus, with a median projected physical offset of 5.6 kpc. Using
this larger population, we discover an apparent redshift evolution in
their locations: bursts at low-z occur at 2 × larger offsets compared
to those at z > 0.5. This evolution could be due to a physical
evolution of the host galaxies themselves or a bias against faint high-z
galaxies. Furthermore, we discover a sample of hostless sGRBs at z ≳
1 that are indicative of a larger high-z population, constraining the
redshift distribution and disfavoring lognormal delay time models.
Title: Supermassive stars with random transverse magnetic fields
Authors: Lou, Yu-Qing; Ma, Jing-Ze
Bibcode: 2022MNRAS.516.1481L
Altcode: 2021MNRAS.tmp.2369L
Gravitational dynamic collapses of supermassive stars (SMSs)
triggered at certain critical stages may give rise to black holes
(BHs) in a broad mass range that populate the Universe including the
early Universe. SMSs have been speculated as the progenitors or seeds
of supermassive BHs that power quasars and active galactic nuclei. We
study quasi-spherical magnetostatic equilibria and magnetohydrodynamic
(MHD) radial pulsational (in)stability properties of non-rotating SMSs
involving random transverse magnetic fields (RTMFs) using the general
relativity (GR). With RTMFs, the maxima of the gravitational binding
energy mark the GR MHD transition from stability to instability and
the RTMF does not modify the GR stability criterion significantly when
the ratio ${\cal M}/\left|\Omega \right|\lesssim0.1$, where $\cal M$ is
the total magnetic energy and Ω is the total gravitational potential
energy. When $0.1\lesssim{\cal M}/\left|\Omega \right|\lesssim1$,
nevertheless, the critical GR magnetostatic equilibria on the verge of
GR MHD collapses or explosions may change drastically, raising the upper
mass limit at the onset of GR MHD instability from ~105
to ~106 M⊙ and even higher. For ${\cal
M}/\left|\Omega \right|\sim 1$, the evolution track of magnetized SMS
is shifted towards the redder part of the Hertzsprung-Russell diagram,
featuring a sort of 'magnetic reddening' associated with the stellar
'magnetized envelope inflation'. By estimates, the RTMF energy stored
in an SMS can be as large as ~1057 erg, enough to power
gamma-ray bursts, fast radio bursts, or other forms of powerful
electromagnetic wave bursts. It is possible for magnetized massive
stars to dynamically form BHs in the mass range from several tens to
thousands of solar masses without necessarily triggering the central
electron-positron e± instability inside such stars - this
fact is highly pertinent to the reports of LIGO-Virgo gravitational
wave event scenario of binary BH mergers.
Title: Emission from hadronic and leptonic processes in galactic
jet-driven bubbles
Authors: Owen, Ellis R.; Yang, H. -Y. Karen
Bibcode: 2022MNRAS.516.1539O
Altcode: 2022MNRAS.tmp.2170O; 2021arXiv211101402O
We investigate the multiwavelength emission from hadronic and
leptonic cosmic rays (CRs) in bubbles around galaxies, analogous to
the Fermi bubbles of the Milky Way. The bubbles are modelled using 3D
magnetohydrodynamical simulations, and are driven by a 0.3 Myr intense
explosive outburst from the nucleus of Milky Way-like galaxies. We
compute their non-thermal emission properties at different stages
throughout their evolution, up to 7 Myr, by post-processing the
simulations. We compare the spectral and spatial signatures of
bubbles with hadronic, leptonic, and hybrid hadro-leptonic CR
compositions. These each show broadly similar emission spectra,
comprised of radio synchrotron, inverse Compton, and non-thermal
bremsstrahlung components. However, hadronic and hybrid bubbles were
found to be brighter than leptonic bubbles in X-rays, and marginally
less bright at radio frequencies, and in γ-rays between ~0.1 and a
few 10s of GeV, with a large part of their emission being driven by
secondary electrons formed in hadronic interactions. Hadronic systems
were also found to be slightly brighter in high-energy γ-rays than
their leptonic counterparts, owing to the π0 decay emission
that dominates their emission between energies of 100s of GeV and a
few TeV.
Title: Kinematics of the H α and H β broad-line region in an SDSS
sample of type-1 AGNs
Authors: Rakić, N.
Bibcode: 2022MNRAS.516.1624R
Altcode: 2022arXiv220804359R; 2022MNRAS.tmp.2153R
Here, we investigate the kinematics of the part of the broad-line region
(BLR) in active galactic nuclei (AGNs) emitting H β and H α emission
lines. We explore the widths and asymmetries of the broad H β and H α
emission lines in a sample of high-quality (i.e. high signal-to-noise
ratio) spectra of type-1 AGN taken from the Data Release 16 of the
Sloan Digital Sky Survey in order to explore possible deviation from
the gravitationally bound motion. To find only the broad component
of H β and H α, we use the FANTASY (Fully Automated pythoN Tool
for AGN Spectra analYsis) code for the multicomponent modelling of
the AGN spectra and for careful extraction of the broad emission-line
parameters. We show that based on the broad-line profiles widths and
asymmetries, the BLR gas emitting H β and H α lines follows similar
kinematics, and seems to be virialized in our sample of type-1 AGN.
Title: Emergence of a new H I 21-cm absorption component at z 1.1726
towards the γ-ray blazar PKS 2355-106
Authors: Srianand, Raghunathan; Gupta, Neeraj; Petitjean, Patrick;
Momjian, Emmanuel; Balashev, Sergei A.; Combes, Françoise; Chen,
Hsiao-Wen; Krogager, Jens-Kristian; Noterdaeme, Pasquier; Rahmani,
Hadi; Baker, Andrew J.; Emig, Kimberly L.; Józsa, Gyula I. G.;
Kloeckner, Hans-Rainer; Moodley, Kavilan
Bibcode: 2022MNRAS.516.1339S
Altcode: 2022MNRAS.tmp.1884S; 2022arXiv220701807S
We report the emergence of a new H I 21-cm absorption at zabs
= 1.172 635 in the damped Lyα absorber (DLA) towards the γ-ray
blazar PKS 2355-106 (zem~1.639) using science verification
observations (2020 June) from the MeerKAT Absorption Line Survey
(MALS). Since 2006, this DLA is known to show a narrow H I 21-cm
absorption at zabs = 1.173019 coinciding with a distinct
metal absorption-line component. We do not detect significant H
I 21-cm optical depth variations from this known H I component. A
high-resolution optical spectrum (2010 August) shows a distinct Mg I
absorption at the redshift of the new H I 21-cm absorber. However, this
component is not evident in the profiles of singly ionized species. We
measure the metallicity ([Zn/H] = -(0.77 ± 0.11) and [Si/H]= -(0.96
± 0.11)) and depletion ([Fe/Zn] = -(0.63 ± 0.16)) for the full
system. Using the apparent column density profiles of Si II, Fe II,
and Mg I, we show that the depletion and the N(Mg I)/N(Si II) column
density ratio systematically vary across the velocity range. The region
with high depletion tends to have a slightly larger N(Mg I)/N(Si II)
ratio. The two H I 21-cm absorbers belong to this velocity range. The
emergence of zabs = 1.172 635 can be understood if there is a
large optical depth gradient over a length-scale of ~0.35 pc. However,
the gas producing the zabs = 1.173 019 component must
be nearly uniform over the same scale. Systematic uncertainties
introduced by the absorption-line variability has to be accounted for
in experiments measuring the variations of fundamental constants and
cosmic acceleration even when the radio emission is apparently compact
as in PKS 2355-106.
Title: GRANDMA observations of ZTF/Fink transients during summer 2021
Authors: Aivazyan, V.; Almualla, M.; Antier, S.; Baransky, A.;
Barynova, K.; Basa, S.; Bayard, F.; Beradze, S.; Berezin, D.; Blazek,
M.; Boutigny, D.; Boust, D.; Broens, E.; Burkhonov, O.; Cailleau,
A.; Christensen, N.; Cejudo, D.; Coleiro, A.; Coughlin, M. W.;
Datashvili, D.; Dietrich, T.; Dolon, F.; Ducoin, J. -G.; Duverne,
P. -A.; Marchal-Duval, G.; Galdies, C.; Granier, L.; Godunova, V.;
Gokuldass, P.; Eggenstein, H. B.; Freeberg, M.; Hello, P.; Inasaridze,
R.; Ishida, E. E. O.; Jaquiery, P.; Kann, D. A.; Kapanadze, G.;
Karpov, S.; Kiendrebeogo, R. W.; Klotz, A.; Kneip, R.; Kochiashvili,
N.; Kou, W.; Kugel, F.; Lachaud, C.; Leonini, S.; Leroy, A.; Leroy, N.;
Van Su, A. Le; Marchais, D.; Mašek, M.; Midavaine, T.; Möller, A.;
Morris, D.; Natsvlishvili, R.; Navarete, F.; Noysena, K.; Nissanke,
S.; Noonan, K.; Orange, N. B.; Peloton, J.; Popowicz, A.; Pradier,
T.; Prouza, M.; Raaijmakers, G.; Rajabov, Y.; Richmond, M.; Romanyuk,
Ya; Rousselot, L.; Sadibekova, T.; Serrau, M.; Sokoliuk, O.; Song,
X.; Simon, A.; Stachie, C.; Taylor, A.; Tillayev, Y.; Turpin, D.;
Vardosanidze, M.; Vlieghe, J.; Melo, I. Tosta e.; Wang, X. F.; Zhu, J.
Bibcode: 2022MNRAS.515.6007A
Altcode: 2022arXiv220209766A; 2022MNRAS.tmp.1968A
We present our follow-up observations with GRANDMA of transient sources
revealed by the Zwicky Transient Facility (ZTF). Over a period of
six months, all ZTF alerts were examined in real time by a dedicated
science module implemented in the Fink broker, which will be used in
filtering of transients discovered by the Vera C. Rubin Observatory. In
this article, we present three selection methods to identify kilonova
candidates. Out of more than 35 million alerts, a hundred sources have
passed our selection criteria. Six were then followed-up by GRANDMA
(by both professional and amateur astronomers). The majority were
finally classified either as asteroids or as supernovae events. We
mobilized 37 telescopes, bringing together a large sample of images,
taken under various conditions and quality. To complement the orphan
kilonova candidates, we included three additional supernovae alerts
to conduct further observations during summer 2021. We demonstrate
the importance of the amateur astronomer community that contributed
images for scientific analyses of new sources discovered in a magnitude
range r' = 17 - 19 mag. We based our rapid kilonova classification
on the decay rate of the optical source that should exceed 0.3 mag
d-1. GRANDMA's follow-up determined the fading rate within
1.5 ± 1.2 d post-discovery, without waiting for further observations
from ZTF. No confirmed kilonovae were discovered during our observing
campaign. This work will be continued in the coming months in the
view of preparing for kilonova searches in the next gravitational-wave
observing run O4.
Title: The feasibility of constraining DM interactions with
high-redshift observations by JWST
Authors: Kurmus, Ali; Bose, Sownak; Lovell, Mark; Cyr-Racine,
Francis-Yan; Vogelsberger, Mark; Pfrommer, Christoph; Zavala, Jesús
Bibcode: 2022MNRAS.516.1524K
Altcode: 2022MNRAS.tmp.2089K; 2022arXiv220304985K
Observations of the high redshift universe provide a promising avenue
for constraining the nature of the dark matter (DM). This will be
even more true with the advent of the James Webb Space Telescope
(JWST). We run cosmological simulations of galaxy formation as part of
the Effective Theory of Structure Formation (ETHOS) project to compare
high redshift galaxies in cold dark matter (CDM) and alternative DM
models which have varying relativistic coupling and self-interaction
strengths. The interacting DM scenarios produce a cutoff in the
linear power spectrum on small-scales, followed by a series of
'dark acoustic oscillations'. We find that DM interactions suppress
the abundance of galaxies below $M_\star \sim 10^8\, {\rm M}_\odot$
for the models considered. The cutoff in the power spectrum delays
structure formation relative to CDM. Objects in ETHOS that end up at
the same final masses as their CDM counterparts are characterized by
a more vigorous phase of early star formation. While galaxies with
$M_\star \lesssim 10^6\, {\rm M_\odot }$ make up more than 60 per cent
of star formation in CDM at z ≍ 10, they contribute only about half
the star formation density in ETHOS. These differences diminish with
decreasing redshift. We find that the effects of DM self-interactions
are negligible compared to effects of relativistic coupling (i.e. the
effective initial conditions for galaxy formation) in all properties of
the galaxy population we examine. Finally, we show that the clustering
strength of galaxies at high redshifts depends sensitively on DM
physics, although these differences are manifest on scales that may
be too small to be measurable by JWST.
Title: Three-point intrinsic alignments of dark matter haloes in
the IllustrisTNG simulation
Authors: Pyne, Susan; Tenneti, Ananth; Joachimi, Benjamin
Bibcode: 2022MNRAS.516.1829P
Altcode: 2022MNRAS.tmp.2227P; 2022arXiv220410342P
We use the IllustrisTNG suite of cosmological simulations to measure
intrinsic alignment (IA) bispectra of dark matter subhaloes between
redshifts 0 and 1. We decompose the intrinsic shear field into
E- and B- modes and find that the bispectra BδδE
and BδEE, between the matter overdensity field, δ,
and the E-mode field, are detected with high significance. We also
model the IA bispectra analytically using a method consistent with
the two-point non-linear alignment model. We use this model and the
simulation measurements to infer the IA amplitude AIA and
find that values of AIA obtained from IA power spectra
and bispectra agree well at scales up to $k_\mathrm{max}= 2 \, h
\mathrm{Mpc}^{-1}$. For example at z = 1, AIA = 2.13 ± 0.02
from the cross power spectrum between the matter overdensity and E-mode
fields and AIA = 2.11 ± 0.03 from BδδE. This
demonstrates that a single physically motivated model can jointly
model two-point and three-point statistics of IAs, thus enabling a
cleaner separation between IAs and cosmological weak lensing signals.
Title: Making BEASTies: dynamical formation of planetary systems
around massive stars
Authors: Parker, Richard J.; Daffern-Powell, Emma C.
Bibcode: 2022MNRAS.516L..91P
Altcode: 2022arXiv220903365P
Exoplanets display incredible diversity, from planetary system
architectures around Sun-like stars that are very different from our
Solar system, to planets orbiting post-main-sequence stars or stellar
remnants. Recently, the B-star Exoplanet Abundance STudy (BEAST)
reported the discovery of at least two super-Jovian planets orbiting
massive stars in the Sco Cen OB association. Whilst such massive stars
do have Keplerian discs, it is hard to envisage gas giant planets being
able to form in such hostile environments. We use N-body simulations of
star-forming regions to show that these systems can instead form from
the capture of a free-floating planet or the direct theft of a planet
from one star to another, more massive star. We find that this occurs
on average once in the first 10 Myr of an association's evolution,
and that the semimajor axes of the hitherto confirmed BEAST planets
(290 and 556 au) are more consistent with capture than theft. Our
results lend further credence to the notion that planets on more distant
(>100 au) orbits may not be orbiting their parent star.
Title: SDSS-IV MaNGA: the chemical co-evolution of gas and stars in
spiral galaxies
Authors: Greener, Michael J.; Aragón-Salamanca, Alfonso; Merrifield,
Michael; Peterken, Thomas; Sazonova, Elizaveta; Haggar, Roan; Bizyaev,
Dmitry; Brownstein, Joel R.; Lane, Richard R.; Pan, Kaike
Bibcode: 2022MNRAS.516.1275G
Altcode: 2022MNRAS.tmp.2233G; 2022arXiv220809008G
We investigate archaeologically how the metallicity in both stellar
and gaseous components of spiral galaxies of differing masses evolve
with time, using data from the SDSS-IV MaNGA survey. For the stellar
component, we can measure this evolution directly by decomposing the
galaxy absorption-line spectra into populations of different ages
and determining their metallicities. For the gaseous component, we
can only measure the present-day metallicity directly from emission
lines. However, there is a well-established relationship between gas
metallicity, stellar mass, and star formation rate which does not
evolve significantly with redshift; since the latter two quantities
can be determined directly for any epoch from the decomposition
of the absorption-line spectra, we can use this relationship to
infer the variation in gas metallicity over cosmic time. Comparison
of present-day values derived in this way with those obtained directly
from the emission lines confirms the validity of the method. Application
of this approach to a sample of 1619 spiral galaxies reveals how the
metallicity of these systems has changed over the last 10 billion yr
since cosmic noon. For lower-mass galaxies, both stellar and gaseous
metallicity increase together, as one might expect in well-mixed
fairly isolated systems. In higher-mass systems, the average stellar
metallicity has not increased in step with the inferred gas metallicity,
and actually decreases with time. Such disjoint behaviour is what one
might expect if these more massive systems have accreted significant
amounts of largely pristine gas over their lifetimes, and this material
has not been well mixed into the galaxies.
Title: Grain growth during protostellar disc formation
Authors: Tu, Yisheng; Li, Zhi-Yun; Lam, Ka Ho
Bibcode: 2022MNRAS.515.4780T
Altcode: 2022MNRAS.tmp.1903T; 2022arXiv220714151T
Recent observations indicate that mm/cm-sized grains may exist in
the embedded protostellar discs. How such large grains grow from the
micron size (or less) in the earliest phase of star formation remains
relatively unexplored. In this study, we take a first step to model the
grain growth in the protostellar environment, using 2D (axisymmetric)
radiation hydrodynamic and grain growth simulations. We show that the
grain growth calculations can be greatly simplified by the 'terminal
velocity approximation', where the dust drift velocity relative to the
gas is proportional to its stopping time, which is proportional to the
grain size. We find that the grain-grain collision from size-dependent
terminal velocity alone is too slow to convert a significant fraction
of the initially micron-sized grains into mm/cm sizes during the deeply
embedded Class 0 phase. Substantial grain growth is achieved when the
grain-grain collision speed is enhanced by a factor of 4. The dust
growth above and below the disc midplane enables the grains to settle
faster towards the midplane, which increases the local dust-to-gas
ratio, which, in turn, speeds up further growth there. How this needed
enhancement can be achieved is unclear, although turbulence is a strong
possibility that deserves further exploration.
Title: Sub-percentage measure of distances to redshift of 0.1 by a
new cosmic ruler
Authors: Shi, Yong; Chen, Yanmei; Mao, Shude; Gu, Qiusheng; Wang,
Tao; Xia, Xiaoyang; Zhang., Zhi-Yu
Bibcode: 2022MNRAS.516.1662S
Altcode: 2022arXiv220900761S; 2022MNRAS.tmp.2211S
Distance-redshift diagrams probe expansion history of the Universe. We
show that the stellar mass-binding energy (massE) relation of
galaxies proposed in our previous study offers a new distance ruler
at cosmic scales. By using elliptical galaxies in the main galaxy
sample of the Sloan Digital Sky Survey Data Release 7, we construct
a distance-redshift diagram over the redshift range from 0.05 to 0.2
with the massE ruler. The best-fit dark energy density is 0.675 ±
0.079 for flat Λ-cold dark matter (ΛCDM) model, consistent with those
by other probes. At the median redshift of 0.11, the median distance
is estimated to have a fractional error of 0.34 per cent, much lower
than those by supernova (SN) Ia and baryonic acoustic oscillation (BAO)
and even exceeding their future capability at this redshift. The above
low-$\mathit{ z}$ measurement is useful for probing dark energy that
dominates at the late Universe. For a flat dark energy equation of
state model (flat wCDM), the massE alone constrains w to an error that
is only a factor of 2.2, 1.7, and 1.3 times larger than those by BAO,
SN Ia, and cosmic microwave background (CMB), respectively.
Title: How baryons affect haloes and large-scale structure: a unified
picture from the SIMBA simulation
Authors: Sorini, Daniele; Davé, Romeel; Cui, Weiguang; Appleby, Sarah
Bibcode: 2022MNRAS.516..883S
Altcode: 2021arXiv211113708S; 2022MNRAS.tmp.2132S
Using the state-of-the-art suite of hydrodynamic simulations SIMBA,
as well as its dark-matter-only counterpart, we study the impact of the
presence of baryons and of different stellar/AGN feedback mechanisms on
large-scale structure, halo density profiles, and on the abundance of
different baryonic phases within haloes and in the intergalactic medium
(IGM). The unified picture that emerges from our analysis is that the
main physical drivers shaping the distribution of matter at all scales
are star formation-driven galactic outflows at z > 2 for lower
mass haloes and AGN jets at z < 2 in higher mass haloes. Feedback
suppresses the baryon mass function with time relative to the halo
mass function, and it even impacts the halo mass function itself at the
~20 per cent level, particularly evacuating the centres and enhancing
dark matter just outside haloes. At early epochs baryons pile up in
the centres of haloes, but by late epochs and particularly in massive
systems gas has mostly been evacuated from within the inner halo. AGN
jets are so efficient at such evacuation that at low redshifts the
baryon fraction within ~1012-1013 M⊙
haloes is only 25 per cent of the cosmic baryon fraction, mostly in
stars. The baryon fraction enclosed in a sphere around such haloes
approaches the cosmic value Ωb/Ωm only at
10-20 virial radii. As a result, 87 per cent of the baryonic mass in
the Universe lies in the IGM at z = 0, with 67 per cent being in the
form of warm-hot IGM (T > 105K).
Title: The H0 Olympics: A fair ranking of proposed models
Authors: Schöneberg, Nils; Abellán, Guillermo Franco; Sánchez,
Andrea Pérez; Witte, Samuel J.; Poulin, Vivian; Lesgourgues, Julien
Bibcode: 2022PhR...984....1S
Altcode: 2021arXiv210710291S
Despite the remarkable success of the Λ Cold Dark Matter (ΛCDM)
cosmological model, a growing discrepancy has emerged (currently
measured at the level of ∼ 4 - 6 σ) between the value of the Hubble
constant H0 measured using the local distance ladder and
the value inferred using the cosmic microwave background and galaxy
surveys. While a vast array of ΛCDM extensions have been proposed to
explain these discordant observations, understanding the (relative)
success of these models in resolving the tension has proven difficult
- this is a direct consequence of the fact that each model has been
subjected to differing, and typically incomplete, compilations of
cosmological data. In this review, we attempt to make a systematic
comparison of seventeen different models which have been proposed
to resolve the H0 tension (spanning both early- and
late-Universe solutions), and quantify the relative success of each
using a series of metrics and a vast array of data combinations. Owing
to the timely appearance of this article, we refer to this contest as
the "H0 Olympics"; the goal being to identify which of the
proposed solutions, and more broadly which underlying mechanisms, are
most likely to be responsible for explaining the observed discrepancy
(should unaccounted for systematics not be the culprit). This work
also establishes a foundation of tests which will allow the success
of novel proposals to be meaningfully "benchmarked".
Title: Intensity mapping from the sky: synergizing the joint potential
of [O III] and [C II] surveys at reionization
Authors: Padmanabhan, Hamsa; Breysse, Patrick; Lidz, Adam; Switzer,
Eric R.
Bibcode: 2022MNRAS.515.5813P
Altcode: 2022MNRAS.tmp.1983P; 2021arXiv210512148P
We forecast the ability of future-generation experiments to detect
the fine-structure lines of the carbon and oxygen ions, [C II] and
[O III] in intensity mapping (IM) from the Epoch of Reionization (z ~
6-8). Combining the latest empirically derived constraints relating
the luminosity of the [O III] line to the ambient star formation rate,
and using them in conjunction with previously derived estimates for the
abundance of [C II] in haloes, we predict the expected autocorrelation
IM signal to be observed using new experiments based on the Fred
Young Submillimetre Telescope (FYST) and the balloon-borne facility,
Experiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM)
over z ~ 5.3-7. We describe how improvements to both the ground-based
and balloon-based surveys in the future will enable a cross-correlation
signal to be detected at ~10-30σ over z ~ 5.3-7. Finally, we propose
a space-based mission targeting the [O III] 88 and 52 $\mu$m lines
along with the [C II] 158 $\mu$m line, configured to enhance the
signal-to-noise ratio of cross-correlation measurements. We find
that such a configuration can achieve a high-significance detection
(hundreds of σ) in both auto and cross-correlation modes.
Title: Characterizing the daytime sextantids meteor shower and
unveiling the nature of the phaethon-geminid stream complex
Authors: Kipreos, Y.; Campbell-Brown, Margaret; Brown, P.; Vida, D.
Bibcode: 2022MNRAS.516..924K
Altcode: 2022arXiv220803521K; 2022MNRAS.tmp.2167K
The Daytime Sextantids meteor shower, part of the Phaethon-Geminid
Stream Complex (PGC), is closely related to the Geminids, currently the
strongest meteor shower visible at the Earth. The Daytime Sextantids
(DSX) share a similar orbit to asteroid 2005 UD, but the nature of the
association remains unclear. From optical data we find that DSX meteors
ablate similarly to Geminids, suggesting that they are also high density
and consistent with a common origin. From radar data we have isolated
19 007 DSX orbits through application of a novel convex hull approach
to determine stream membership. We find at the peak the mean semimajor
axis is near 1 au, eccentricity is 0.86 and that both decrease as a
function of solar longitude. The inclination averages 25 deg at the
peak but increases over time. Noticeable DSX activity extends from solar
longitude 173-196° with a flux plateau between 186 and 189°. The peak
flux is 2 ± 0.05 × 10-3 km-2 hr-1,
equivalent to a ZHR of 20. We estimate a true differential mass index
for the shower of s = 1.64 ± 0.06 at the time of peak and an average
of 1.70 ± 0.07 for days surrounding the peak. The mass of the DSX
stream is estimated to be 1016 g, the same order as 2005 UD,
suggesting the stream is too massive to have been created by recent
meteoroid production from 2005 UD. We propose that the DSX and 2005
UD were created in the same break-up event that created 3200 Phaethon.
Title: Effects of the environment and feedback physics on the initial
mass function of stars in the STARFORGE simulations
Authors: Guszejnov, Dávid; Grudić, Michael Y.; Offner, Stella S. R.;
Faucher-Giguère, Claude-André; Hopkins, Philip F.; Rosen, Anna L.
Bibcode: 2022MNRAS.515.4929G
Altcode: 2022MNRAS.tmp.1982G; 2022arXiv220510413G
One of the key mysteries of star formation is the origin of the stellar
initial mass function (IMF). The IMF is observed to be nearly universal
in the Milky Way and its satellites, and significant variations are
only inferred in extreme environments, such as the cores of massive
elliptical galaxies and the Central Molecular Zone. In this work,
we present simulations from the STARFORGE project that are the first
cloud-scale radiation-magnetohydrodynamic simulations that follow
individual stars and include all relevant physical processes. The
simulations include detailed gas thermodynamics, as well as stellar
feedback in the form of protostellar jets, stellar radiation, winds, and
supernovae. In this work, we focus on how stellar radiation, winds, and
supernovae impact star-forming clouds. Radiative feedback plays a major
role in quenching star formation and disrupting the cloud; however,
the IMF peak is predominantly set by protostellar jet physics. We find
that the effect of stellar winds is minor, and supernovae 'occur too
late' to affect the IMF or quench star formation. We also investigate
the effects of initial conditions on the IMF. We find that the IMF is
insensitive to the initial turbulence, cloud mass, and cloud surface
density, even though these parameters significantly shape the star
formation history of the cloud, including the final star formation
efficiency. Meanwhile, the characteristic stellar mass depends weakly on
metallicity and the interstellar radiation field, which essentially set
the average gas temperature. Finally, while turbulent driving and the
level of magnetization strongly influence the star formation history,
they only influence the high-mass slope of the IMF.
Title: The sensitivity of the redshift distribution to galaxy
demographics
Authors: Sudek, Philipp; de la Bella, Lucia F.; Amara, Adam; Hartley,
William G.
Bibcode: 2022MNRAS.516.1670S
Altcode: 2022MNRAS.tmp.2247S; 2021arXiv211211345S
Photometric redshifts are commonly used to measure the distribution
of galaxies in large surveys. However, the demands of ongoing and
future large-scale cosmology surveys place very stringent limits on
the redshift performance that are difficult to meet. A new approach to
meet this precision need is forward modelling, which is underpinned by
realistic simulations. In the work presented here, we use simulations to
study the sensitivity of redshift distributions to the underlying galaxy
population demographics. We do this by varying the redshift evolving
parameters of the Schechter function for two galaxy populations:
star-forming and quenched galaxies. Each population is characterized by
eight parameters. We find that the redshift distribution of shallow
surveys, such as the Sloan Digital Sky Survey (SDSS), is mainly
sensitive to the parameters for quenched galaxies. However, for deeper
surveys such as the Dark Energy Survey (DES) and the Hyper Suprime-Cam
(HSC), the star-forming parameters have a stronger impact on the
redshift distribution. Specifically, the slope of the characteristic
magnitude, aM, for star-forming galaxies has overall the
strongest impact on the redshift distribution. Decreasing aM
by 148 per cent (its given uncertainty) shifts the mean redshift by
~45 per cent. We explore which combination of colour and magnitude
measurements is most sensitive to aM and we find that each
colour-magnitude pair studied is similarly affected by a modification
of aM.
Title: Excitation of vertical breathing motion in disc galaxies by
tidally-induced spirals in fly-by interactions
Authors: Kumar, Ankit; Ghosh, Soumavo; Kataria, Sandeep Kumar; Das,
Mousumi; Debattista, Victor P.
Bibcode: 2022MNRAS.516.1114K
Altcode: 2022arXiv220807096K; 2022MNRAS.tmp.2194K
It is now clear that the stars in the Solar neighbourhood display
large-scale coherent vertical breathing motions. At the same
time, Milky Way-like galaxies experience tidal interactions with
satellites/companions during their evolution. While these tidal
interactions can excite vertical oscillations, it is still not
clear whether vertical breathing motions are excited directly by the
tidal encounters or are driven by the tidally-induced spirals. We
test whether excitation of breathing motions are directly linked to
tidal interactions by constructing a set of N-body models (with mass
ratio 5:1) of unbound single fly-by interactions with varying orbital
configurations. We first reproduce the well-known result that such
fly-by interactions can excite strong transient spirals (lasting for
${\sim}2.9{-}4.2\,{\rm Gyr}$) in the outer disc of the host galaxy. The
generation and strength of the spirals are shown to vary with the
orbital parameters (the angle of interaction, and the orbital spin
vector). Furthermore, we demonstrate that our fly-by models exhibit
coherent breathing motions whose amplitude increases with height. The
amplitudes of breathing motions show characteristic modulation along
the azimuthal direction with compressing breathing motions coinciding
with the peaks of the spirals and expanding breathing motions falling
in the inter-arm regions - a signature of a spiral-driven breathing
motion. These breathing motions in our models end when the strong
tidally-induced spiral arms fade away. Thus, it is the tidally-induced
spirals which drive the large-scale breathing motions in our fly-by
models, and the dynamical role of the tidal interaction in this context
is indirect.
Title: A photometry pipeline for SDSS images based on convolutional
neural networks
Authors: Shi, Jing-Hang; Qiu, Bo; Luo, A. -Li; He, Zhen-Dong; Kong,
Xiao; Jiang, Xia
Bibcode: 2022MNRAS.516..264S
Altcode: 2022MNRAS.tmp.2055S
In this paper, we propose a convolutional neural network (CNN)-based
photometric pipeline for the Sloan Digital Sky Survey (SDSS)
images. The pipeline includes three main parts: the target source
detection, the target source classification, and the photometric
parameter measurement. The last part is completed using traditional
methods. The paper mainly focuses on the first two parts and does
not present the last. In the 1st part, a network named TSD-YOLOv4 is
proposed to detect new sources missed by the SDSS photometric pipeline
according to the PhotoObjAll catalogue of SDSS. In the second part,
a target source classification network named TSCNet is constructed
to classify sources into galaxies, quasars, and stars directly from
photometric images. Experiments show that TSD-YOLOv4 outperforms other
networks (Faster-RCNN, YOLOv4, YOLOX, etc.) in all metrics, with an
accuracy of 0.988, a recall of 0.997, and an F1-score of 0.992, and
TSCNet has good performance with a classification accuracy of 0.944
on the test set with 23 265 sources, and precision rates of 0.98,
0.908, and 0.918 for galaxies, quasars, and stars, respectively. On the
other hand, the recall rates are 0.982, 0.903, and 0.921 for galaxies,
quasars, and stars, respectively. The TSCNet has higher accuracy, fewer
parameters, and faster inference speed than the leading astronomical
photometric source classification network, the APSCNet model. In
addition, the effect of magnitude distribution on the classification
results is discussed in the experiments. The experiments prove that
the proposed pipeline can be used as a powerful tool to supplement
the SDSS photometric catalogue.
Title: X-ray morphology of cluster-mass haloes in self-interacting
dark matter
Authors: Shen, Xuejian; Brinckmann, Thejs; Rapetti, David;
Vogelsberger, Mark; Mantz, Adam; Zavala, Jesús; Allen, Steven W.
Bibcode: 2022MNRAS.516.1302S
Altcode: 2022arXiv220200038S
We perform cosmological zoom-in simulations of 19 relaxed cluster-mass
haloes with the inclusion of adiabatic gas in the cold dark matter
(CDM) and self-interacting dark matter (SIDM) models. These clusters
are selected as dynamically relaxed clusters from a parent simulation
with $M_{\rm 200} \simeq (1\!-\!3)\times 10^{15}{\, \rm M_\odot
}$. Both the dark matter and the intracluster gas distributions in
SIDM appear more spherical than their CDM counterparts. Mock X-ray
images are generated based on the simulations and are compared to
the real X-ray images of 84 relaxed clusters selected from the
Chandra and ROSAT archives. We perform ellipse fitting for the
isophotes of mock and real X-ray images and obtain the ellipticities
at cluster-centric radii of $r\simeq 0.1\!-\!0.2R_{\rm 200}$. The
X-ray isophotes in SIDM models with increasing cross-sections are
rounder than their CDM counterparts, which manifests as a systematic
shift in the distribution function of ellipticities. Unexpectedly,
the X-ray morphology of the observed non-cool-core clusters agrees
better with SIDM models with cross-section $(\sigma /m)= 0.5\!-\!1\,
{\rm cm}^2\, {\rm g}^{-1}$ than CDM and SIDM with $(\sigma /m)=0.1\,
{\rm cm}^2\, {\rm g}^{-1}$. Our statistical analysis indicates that
the latter two models are disfavoured at the $68{{\ \rm per\ cent}}$
confidence level (as conservative estimates). This conclusion is not
altered by shifting the radial range of measurements or applying a
temperature selection criterion. However, the primary uncertainty
originates from the lack of baryonic physics in the adiabatic model,
such as cooling, star formation and feedback effects, which still have
the potential to reconcile CDM simulations with observations.
Title: Semi-analytic forecasts for JWST - VI. Simulated light-cones
and galaxy clustering predictions
Authors: Yung, L. Y. Aaron; Somerville, Rachel S.; Ferguson, Henry C.;
Finkelstein, Steven L.; Gardner, Jonathan P.; Davé, Romeel; Bagley,
Micaela B.; Popping, Gergö; Behroozi, Peter
Bibcode: 2022MNRAS.515.5416Y
Altcode: 2022arXiv220613521Y; 2022MNRAS.tmp.2032Y
In anticipation of the new era of high-redshift exploration marked
by the commissioning of the James Webb Space Telescope (JWST), we
present two sets of galaxy catalogues that are designed to aid the
planning and interpretation of observing programs. We provide a set of
40 wide-field light-cones with footprints spanning approximately ~1000
arcmin2 containing galaxies up to z = 10, and a new set of
eight ultradeep light-cones with 132 arcmin2 footprints,
containing galaxies up to z ~ 12 down to the magnitudes expected
to be reached in the deepest JWST surveys. These mock light-cones
are extracted from dissipationless N-body simulations and populated
with galaxies using the well-established, computationally efficient
Santa Cruz semi-analytic model for galaxy formation. We provide a wide
range of predicted physical properties, and simulated photometry from
Near-Infrared Camera (NIRCam) and many other instruments. We explore
the predicted counts and luminosity functions and angular two-point
correlation functions for galaxies in these simulated light-cones. We
also explore the predicted field-to-field variance using multiple
light-cone realizations. We find that these light-cones reproduce
the available measurements of observed clustering from 0.2 ≲ z ≲
7.5 very well. We provide predictions for galaxy clustering at high
redshift that may be obtained from future JWST observations. All of
the light-cones presented here are made available through a web-based
interactive data release portal.
Title: MIGHTEE: the nature of the radio-loud AGN population
Authors: Whittam, I. H.; Jarvis, M. J.; Hale, C. L.; Prescott, M.;
Morabito, L. K.; Heywood, I.; Adams, N. J.; Afonso, J.; An, Fangxia;
Ao, Y.; Bowler, R. A. A.; Collier, J. D.; Deane, R. P.; Delhaize, J.;
Frank, B.; Glowacki, M.; Hatfield, P. W.; Maddox, N.; Marchetti, L.;
Matthews, A. M.; Prandoni, I.; Randriamampandry, S.; Randriamanakoto,
Z.; Smith, D. J. B.; Taylor, A. R.; Thomas, N. L.; Vaccari, M.
Bibcode: 2022MNRAS.516..245W
Altcode: 2022arXiv220712379W; 2022MNRAS.tmp.2068W
We study the nature of the faint radio source population detected
in the MeerKAT International GHz Tiered Extragalactic Exploration
(MIGHTEE) Early Science data in the COSMOS field, focusing on the
properties of the radio-loud active galactic nuclei (AGNs). Using the
extensive multiwavelength data available in the field, we are able
to classify 88 per cent of the 5223 radio sources in the field with
host galaxy identifications as AGNs (35 per cent) or star-forming
galaxies (54 per cent). We select a sample of radio-loud AGNs with
redshifts out to z ~ 6 and radio luminosities 1020 <
L1.4 GHz/W Hz-1 < 1027 and
classify them as high-excitation and low-excitation radio galaxies
(HERGs and LERGs). The classification catalogue is released with this
work. We find no significant difference in the host galaxy properties
of the HERGs and LERGs in our sample. In contrast to previous work,
we find that the HERGs and LERGs have very similar Eddington-scaled
accretion rates; in particular we identify a population of very slowly
accreting AGNs that are formally classified as HERGs at these low radio
luminosities, where separating into HERGs and LERGs possibly becomes
redundant. We investigate how black hole mass affects jet power,
and find that a black hole mass ≳ 107.8 M⊙
is required to power a jet with mechanical power greater than the
radiative luminosity of the AGN (Lmech/Lbol >
1). We discuss that both a high black hole mass and black hole spin
may be necessary to launch and sustain a dominant radio jet.
Title: ctkelley/NotebookSIAMFANL: NotebookSIAMFANL version 1.0:
Publication release
Authors: Kelley, C. T. "Tim"; Pasquier, Benoit
Bibcode: 2022zndo...4284687K
Altcode:
This is the final publication version suite of notebooks for my book
project Solving Nonlinear Equations with Iterative Methods: Solvers and
Examples in Julia The project includes the print book, this suite of
Jupyter notebooks that are a very good approximation of the print book,
and a Julia package. The package is SIAMFANLEquations.jl, now at version
1.0. You install it like any other registered Julia package. The github
repos are Package: https://github.com/ctkelley/SIAMFANLEquations.jl
Notebooks: https://github.com/ctkelley/NotebookSIAMFANL The package and
notebooks are open source. License data are on the repos. Enjoy, -- Tim
Title: ctkelley/SIAMFANLEquations.jl: Final publication release
Authors: Kelley, C. T. "Tim"
Bibcode: 2022zndo...4284807K
Altcode:
This is the final publication release of the package. This package
supports my shiny new orange book Solving Nonlinear Equations with
Iterative Methods: Solvers and Examples in Julia. @book{ctk:fajulia,
author="C. T. Kelley", title="{Solving Nonlinear Equations with
Iterative Methods: Solvers and Examples in Julia}", year=2022,
publisher="SIAM", address="Philadelphia", series="Fundamentals of
Algorithms", number=20 } The solvers are documented with Documenter.jl
on the package repo and with a collection of IJulia notebooks. The
notebooks are a pretty faithful version of the print book. The
final manuscript went to the printer on Sept 6. The target date for
publication is October 2022.
Title: Generalizations of the Pfaffian to non-antisymmetric matrices
Authors: Varjas, Daniel
Bibcode: 2022zndo...7050920V
Altcode:
We provide algorithms implemented in Python to compute the Wigner normal
form and generalized Pfaffian of conjugate-normal matrices that are not
necessarily antisymmetric. Requirements: numpy, scipy, pfapack, kwant
Running the file performs a series of tests to validate the algorithms.
Title: Initial algebra semantics for de Bruijn monads in HOL Light
Authors: Maggesi, Marco
Bibcode: 2022zndo...7053686M
Altcode:
Formalisation in HOL Light of the theory of De Bruijn monads with
application to the initial semantics for the lambda calculus.
Title: A Formal Theory of Choreographic Programming in Coq
Authors: Cruz-Filipe, Luís; Montesi, Fabrizio; Peressotti, Marco
Bibcode: 2022zndo...7050062C
Altcode:
A formalisation in Coq of: a choreographic programming language (CC.v)
a calculus of stateful processes (SP.v) a certified compiler for the
choreographic language to the process calculus (EPP.v, EPPTheorem.v)
Title: Layer-Resolved Resonance Intensity of Evanescent Polariton
Modes in Anisotropic Multilayers (Matlab Files)
Authors: Passler, Nikolai Christian; Carini, Giulia; Paarmann,
Alexander
Bibcode: 2022zndo...7034721P
Altcode:
The attached Matlab files allow the calculation of layer-resolved mode
intensity after evanescent excitation for any number of arbitrarily
anisotropic or isotropic, absorbing and non-absorbing multilayer
systems. The formalism builds on the electric field distributions
obtained from our 4x4 transfer matrix formalism (Passler and Paarmann,
JOSA B 34, 2128 (2017)) in its corrected form (Passler & Paarmann,
Erratum, JOSA B 36, 3246 (2019)) with the respective Matlab (zenodo
link) and Python (zenodo link) implementations. The code further
extends a previous implementation of layer-resolved absorption,(Passler
et al., PRB B 101, 165425 (2020), Zenodo code: matlab, python). Here,
now also evanescent exciation is treated.The code provided here includes
the transfer matrix implementation. The respective publication was
recently submitted, with its preprint available on the arXiv. We
also note a small improvement of the TMM formalism over the previous
versions(TMM, Layer resolved absorption). We noticed that in the case
of birefringent layers, in some very special cases the mode ordering
and eigenmode calculations according to Xu et al Phys. Rev. B 61,
1740–1743 (2000) used in our previous code produced faulty results,
likely linked to the ambuigity of mode sorting in the case of
birefringence. Therefore, we now instead directly use the Berreman
eigenmodes for birefringent layers, which removes the necessity of
mode sorting and thereby also circumvents the rare issues encountered
with the previous implementations. All calculations preformed with
this new implementation did not show any problems. Apart from the
core code file (passler_layer_resolved_absorption_core.m) and an
auxilliary function for generation of the dielectric tensors for all
layers (passler_epsTarray_generator.m), we also provide two example
scripts which demonstrate the capabilities of the formalism. These
sample scripts also generate the figures shown in the associated
publication (arXiv). For any questions please contact Alex Paarmann,
Title: A large dataset of software mentions in the biomedical
literature (the code)
Authors: Istrate, Ana-Maria; Li, Donghui; Taraborelli, Dario; Torkar,
Michaela; Veytsman, Boris; Williams, Ivana
Bibcode: 2022zndo...7041594I
Altcode:
The code accompanying our new dataset of software mentions in biomedical
papers (dataset, preprint). Plain-text software mentions are extracted
with a trained SciBERT model from several sources: the NIH PubMed
Central collection and from papers provided by various publishers to
the Chan Zuckerberg Initiative. The dataset provides sources, context
and metadata, and, for a number of mentions, the disambiguated software
entities and links.
Title: The influence of sediment diagenesis and aluminium on oxygen
isotope exchange of diatom frustules
Authors: Akse, Shaun P.; Polerecky, Lubos; Kienhuis, Michiel V. M.;
Middelburg, Jack J.
Bibcode: 2022GeCoA.333..362A
Altcode:
The oxygen isotope composition of diatom frustules,
δ18Odiatom, is thought to reflect the
isotopic composition of the ambient seawater at the time of
biomineralization. However, the δ18Odiatom can be
overprinted due to the susceptibility of silanol groups (both external
and internal) to isotope exchange. Here, using high-resolution imaging,
we investigate what factors may influence this post-mortem isotopic
alteration during the initial stages of diagenesis in the sediment. A
diatomaceous clay was incubated with 18O-enriched seawater
with fresh diatom detritus placed at the sediment-water interface
(SWI) and at depth in the sediment. NanoSIMS analysis showed that the
fresh diatom detritus as well as fossil frustules became significantly
enriched in 18O, and that a relationship between Al-content
and 18O-exchange could be observed. To further study the
potential role of Al as an inhibitor of oxygen exchange, we measured Al
on the surface of fossil frustules and performed additional incubations
of diatom detritus in seawater with various concentrations of dissolved
Al. The presence of Al-rich material bound to the surface of fossil
frustules did not reduce the extent of 18O-enrichment in the
underlying silica. However, exposure of diatoms detritus to dissolved
Al, which led to a significant increase in frustule Al/Si ratio and
a homogenously distributed Al in the frustule valve, significantly
lowered the amount of 18O-enrichment. We hypothesize that
Al incorporated into the silica structure can slow down 18O
exchange while Al present as surface contaminants (clays or other
aluminosilicates) has no inhibitory role.
Title: Machine-guided exploration and calibration of astrophysical
simulations
Authors: Oh, Boon Kiat; An, Hongjun; Shin, Eun-jin; Kim, Ji-hoon;
Hong (홍 성 욱), Sungwook E.
Bibcode: 2022MNRAS.515..693O
Altcode: 2022MNRAS.tmp.1562O
We apply a novel method with machine learning to calibrate sub-grid
models within numerical simulation codes to achieve convergence with
observations and between different codes. It utilizes active learning
and neural density estimators. The hyper parameters of the machine are
calibrated with a well-defined projectile motion problem. Then, using
a set of 22 cosmological zoom simulations, we tune the parameters
of a popular star formation and feedback model within Enzo to
match observations. The parameters that are adjusted include the
star formation efficiency, coupling of thermal energy from stellar
feedback, and volume into which the energy is deposited. This number
translates to a factor of more than three improvements over manual
calibration. Despite using fewer simulations, we obtain a better
agreement to the observed baryon makeup of a Milky Way (MW)-sized
halo. Switching to a different strategy, we improve the consistency of
the recommended parameters from the machine. Given the success of the
calibration, we then apply the technique to reconcile metal transport
between grid-based and particle-based simulation codes using an isolated
galaxy. It is an improvement over manual exploration while hinting
at a less-known relation between the diffusion coefficient and the
metal mass in the halo region. The exploration and calibration of the
parameters of the sub-grid models with a machine learning approach is
concluded to be versatile and directly applicable to different problems.
Title: Characterizing the aerosol atmosphere above the Observatorio
del Roque de los Muchachos by analysing seven years of data taken
with an GaAsP HPD-readout, absolutely calibrated elastic LIDAR
Authors: Fruck, Christian; Gaug, Markus; Hahn, Alexander; Acciari,
Victor; Besenrieder, Jürgen; Dominis Prester, Dijana; Dorner, Daniela;
Fink, David; Font, Lluís; Mićanović, Saša; Mirzoyan, Razmik;
Müller, Dominik; Pavletić, Lovro; Schmuckermaier, Felix; Will, Martin
Bibcode: 2022MNRAS.515.4520F
Altcode: 2022arXiv220209561F; 2022MNRAS.tmp.1591F
We present a new elastic LIDAR concept, based on a bi-axially mounted
Nd:YAG laser and a telescope with HPD readout, combined with fast FADC
signal digitization and offline pulse analysis. The LIDAR return signals
have been extensively quality checked and absolutely calibrated. We
analyse seven years of quasi-continuous LIDAR data taken during those
nights when the MAGIC telescopes were operating. Characterization of
the nocturnal ground layer yields zenith and azimuth angle dependent
aerosol extinction scaleheights for clear nights. We derive aerosol
transmission statistics for light emitted from various altitudes
throughout the year and separated by seasons. We find further
seasonal dependencies of cloud base and top altitudes, but none for
the LIDAR ratios of clouds. Finally, the night sky background light
is characterized using the LIDAR photon backgrounds.
Title: Seismic imaging of subsurface structural variations along
the Japan trench south of the 2011 Tohoku earthquake rupture zone
Authors: Qin, Yanfang; Nakamura, Yasuyuki; Kodaira, Shuichi; Fujie, Gou
Bibcode: 2022E&PSL.59417707Q
Altcode:
The coseismic slip during the 2011 Tohoku earthquake has been
revealed to reach the Japan trench axis, but the detailed slip
behaviors in different zones along the trench remain an unsolved
problem. To investigate the along-trench structures that directly
affect the coseismic activities, we collected densely distributed
seismic reflection data south of the major coseismic slip zone in
the region of 36-37.5°N. Our seismic data document numerous local
structural variations along different segments of the study zone:
varying thicknesses of incoming sediments; chaotic structures in the
north and fold-and-thrust belts in the south at the wedge front;
different morphologies of the subducting plate, correlating with
the physical properties above the plate interface and influencing,
in turn, shallow megathrust slip and tsunami genesis. The southern
limit of the 2011 event large coseismic rupture zone at ∼37°N works
as a transition zone, which appears to correlate with the landward
extension of a subducting channel in the deep places, and the shallower
detachment fault structures in the graben beneath the trench axis that
are less developed than those in the large slip zone further north. It
also appears to correlate with the different elastic properties along
the basal layer of the overriding plate caused by regionally various
thickness and lithologies.
Title: Semi-analytical investigations on the dynamics of BeiDou
inclined geosynchronous satellite orbit
Authors: Tan, Pan; Tang, Jing-Shi; Hou, Xi-Yun
Bibcode: 2022AdSpR..70.1234T
Altcode:
A semi-analytical investigation on the dynamics of BeiDou IGSO
is conducted in this paper. First, a semi-analytical propagator is
constructed based on the mean element method. The comparison of results
of semi-analytical propagation with reference orbits shows that all
orbital elements except the semi-major axis agree well within six
centuries. For some example orbits, the semi-analytical propagation
of the semi-major axis is accurate only within several decades,
which is related to the chaotic motion of the one-to-one tesseral
resonance. Compared with the numerical ephemeris of Moon, an improvement
of accuracy in the semi-analytical propagation is observed when a simple
analytical ephemeris of Moon is adopted. This phenomenon agrees with
the doubly averaging process of the third-body perturbation. Second,
the dynamics of BeiDou IGSO are investigated using the Hamiltonian
approach with simplified models. The transition between different
resonance regions of one-to-one tesseral resonance is investigated
by the computation of one-dimensional maximal Lyapunov characteristic
exponent (1-mLCE). The secular resonance from the lunisolar perturbation
modeled by a 2-DOF system is systematically investigated using the
surface of section. The secondary resonance related to the precession
of lunar node is identified by the computation of 1-mLCE. In the end,
the reentry disposal for BeiDou IGSO is investigated as an optimization
problem. With IGSO3 as an example of reentry orbit, the sensitivity
analysis is conducted to study its stability and predictability.
Title: Whole-rock geochemistry and zircon O-Hf isotope compositions
of ca. 2.35 Ga strongly peraluminous granites: Implications for
increase in zircon δ18O values during the Paleoproterozoic
Authors: Xie, Shi-Wen; Wang, Fang; Bucholz, Claire E.; Liu, Fu-Lai;
Wang, Pei-Zhi; Bao, Ze-Min; Liu, Dun-Yi
Bibcode: 2022GeCoA.332..186X
Altcode:
Zircon oxygen isotope ratios have been used to trace the incorporation
of sedimentary rocks into magmas. The dramatic increase in maximum
zircon δ18O values in the Paleoproterozoic observed in
global databases coincides with changes in surface environments
(e.g., the rise of subaerial and oxidative weathering), implying
a connection between elevated zircon δ18O and these
changes. Zircon δ18O between 2.5 and 2.2 Ga, however,
is relatively under-constrained owing to limited available data in
this age range. To augment data from this critical time period and
understand potential causes for the elevated zircon δ18O
values, we report U-Pb zircon ages and δ18O values of
zircon, as well as, whole-rock major and trace element geochemistry
of Paleoproterozoic strongly peraluminous granites (SPGs) from the
southwestern margin of the Yangtze Block (China). Our geochronological
data demonstrate that these SPGs crystallized at ∼2.35 Ga and
that inherited zircon with ages of 2428-2721 Ma are present in these
granites, indicating the source rocks of these granites were deposited,
subsequently metamorphosed, and partially melted between 2.43 and
2.35 Ga. Synmagmatic zircon from samples dated in this study have
εHf(t) values of -6.4 to -0.9 and high δ18O
values of 7.6-9.9‰, elevated above the maximum value observed in
Archean zircon (∼7‰). These granites can be divided into two
groups based on whole-rock geochemistry. Both Group 1 and Group
2 granites were derived from a similar high δ18O,
metapelitic source, but were generated by dehydration melting and
hydrous melting, respectively. Our results demonstrate that the
fine-grained sedimentary rocks from which the SPGs were derived had
relatively high δ18O (as compared to older sedimentary
rocks) by 2.43-2.35 Ga. The depositional time interval of the
high-δ18O sedimentary sources for SPGs studied here
coincides with the emergence of continental crust above sea level
and the Great Oxidation Event. Supporting the findings of previous
studies, the contemporaneity of our dataset with these changes in
Earth's surface environments suggests that subaerial and potentially
oxidative weathering contributed (at least partially) to the elevation
of δ18O of fine-grained sedimentary rocks. Recycling of
these high-δ18O sedimentary rocks into magmas contributed
to the dramatic change in δ18O of magmatic zircon in
the earliest Paleoproterozoic. In addition, although this study is
focused on a single locality, our results suggest that the abrupt shift
observed in global zircon δ18O data sets likely occurred
by 2.35 Ga. Last, a literature compilation of zircon δ18O
data from SPGs suggested that zircon δ18O values may
have also experienced a stepwise increase in the Neoproterozoic to
Phanerozoic from 12 to 14‰. The coincidence of these increases in
zircon δ18O values with global oxygenation events suggests
that atmospheric oxygenation may have contributed to the increase in
δ18O of sedimentary rocks.
Title: Shallow magma dynamics at open-vent volcanoes tracked by
coupled thermal and SO2 observations
Authors: Laiolo, Marco; Delle Donne, Dario; Coppola, Diego; Bitetto,
Marcello; Cigolini, Corrado; Della Schiava, Massimo; Innocenti,
Lorenzo; Lacanna, Giorgio; La Monica, Francesco Paolo; Massimetti,
Francesco; Pistolesi, Marco; Silengo, Maria Cristina; Aiuppa,
Alessandro; Ripepe, Maurizio
Bibcode: 2022E&PSL.59417726L
Altcode:
Open-vent volcanic activity is typically sustained by ascent and
degassing of shallow magma, in which the rate of magma supply to the
upper feeding system largely exceeds the rate of magma eruption. Such
unbalance between supplied (input) and erupted (output) magma rates
is thought to result from steady, degassing-driven, convective magma
overturning in a shallow conduit/feeding dyke. Here, we characterize
shallow magma circulation at Stromboli volcano by combining independent
observations of heat (Volcanic Radiative Power; via satellite images)
and gas (SO2, via UV camera) output in a temporal interval
(from August 1, 2018 to April 30, 2020) encompassing the summer 2019
effusive eruption and two paroxysmal explosions (on July 3 and August
28, 2019). We show that, during the phase of ordinary strombolian
explosive activity that preceded the 2019 effusive eruption, the
average magma input rate (0.1-0.2 m3/s) exceeds the
magma eruption rate (0.001-0.01 m3/s) by ∼2 orders
of magnitude. Conversely, magma input and output rates converge to
an average of ∼0.4 m3/s during the summer 2019 summit
effusion, implying an overall suppression of magma recycling back
into the feeding system, and hence of excess degassing. We find that,
during the effusive eruption, the peak in SO2 emissions lags
behind the thermal emission peak by ∼27 days, suggesting that magma
output, feeding the lava flow field, initially dominates over magma
input in the conduit. We propose that this conduit mass unloading,
produced by this initial phase of the effusive eruption, leads to an
overall decompression (of up to 30 Pa/s) of the shallow plumbing system,
ultimately causing ascent of less-dense, volatile-rich magma batch(es)
from depth, enhanced explosive activity, and elevated SO2
fluxes culminating into a paroxysmal explosion on August 28. Our results
demonstrate that combined analysis of thermal and SO2
flux time-series paves the way to improved understanding of shallow
magmatic system dynamics at open-vent volcanoes, and of the transition
from explosive to effusive activity regimes.
Title: MaNGA 8313-1901: gas accretion observed in a blue compact
dwarf galaxy?
Authors: Ju, Mengting; Yin, Jun; Liu, Rongrong; Hao, Lei; Shao,
Zhengyi; Feng, Shuai; Riffel, Rogério; Liu, Chenxu; Stark, David V.;
Shen, Shiyin; Telles, Eduardo; Fernández-Trincado, José G.; Wang,
Junfeng; Xu, Haiguang; Bizyaev, Dmitry; Rong, Yu
Bibcode: 2022arXiv220903298J
Altcode:
Gas accretion is an important process in the evolution of galaxies,
but it has limited direct observational evidences. In this paper, we
report the detection of a possible ongoing gas accretion event in a Blue
Compact Dwarf (BCD) galaxy, MaNGA 8313-1901, observed by the Mapping
Nearby Galaxies and Apache Point Observatory (MaNGA) program. This
galaxy has a distinct off-centered blue clump to the northeast (the
NE clump) that shows low metallicity and enhanced star-formation. The
kinematics of the gas in the NE clump also seems to be detached from the
host BCD galaxy. Together with the metallicity drop of the NE clump,
it suggests that the NE clump likely has an external origin, such as
the gas accretion or galaxy interaction, rather than an internal origin,
such as an \hii~complex in the disk. After removing the underlying host
component, we find that the spectrum of the "pure" clump can match
very well with a modeled spectrum containing a stellar population of
the young stars ($\le 7$ Myr) only. This may imply that the galaxy
is experiencing an accretion of cold gas, instead of a merger event
involving galaxies with significant pre-existing old stars. We also
find signs of another clump (the SW clump) at the south-west corner
of the host galaxy, and the two clumps may share the same origin of
gas accretion.
Title: A simple analytical model of magnetic jets
Authors: Zdziarski, Andrzej A.; Stawarz, Łukasz; Sikora, Marek;
Nalewajko, Krzysztof
Bibcode: 2022MNRAS.515L..17Z
Altcode: 2022MNRAS.tmpL..59Z; 2022arXiv220411637Z
We propose a simple analytical jet model of magnetic jets, in which
radially averaged profiles of main physical quantities are obtained
based on conservation laws and some results of published general
relativistic magnetohydrodynamic jet simulations. We take into account
conversion of the magnetic energy flux to bulk acceleration in jets
formed around rotating black holes assuming the mass continuity equation
and constant jet power, which leads to the Bernoulli equation. For
assumed profiles of the bulk Lorentz factor and the radius, this gives
us the profile of the toroidal magnetic field component along the
jet. We then consider the case where the poloidal field component
is connected to a rotating black hole surrounded by an accretion
disc. Our formalism then recovers the standard formula for the power
extracted from a rotating black hole. We find that the poloidal field
strength dominates over the toroidal one in the comoving frame up
to large distances, which means that jets should be more stable to
current-driven kink modes. The resulting magnetic field profiles can
then be used to calculate the jet synchrotron emission.
Title: Multi-stage evolution of the Lost City hydrothermal vent fluids
Authors: Aquino, Karmina A.; Früh-Green, Gretchen L.; Rickli, Jörg;
Bernasconi, Stefano M.; Lang, Susan Q.; Lilley, Marvin D.; Butterfield,
David A.
Bibcode: 2022GeCoA.332..239A
Altcode:
Serpentinization-influenced hydrothermal systems, such as the Lost City
Hydrothermal Field (LCHF), are considered as potential sites for the
origin of life. Despite an abundance of reducing power in this system
(H2 and CH4), microbial habitability may be
limited by high pH, elevated temperatures, and/or low concentrations of
bioavailable carbon. At the LCHF, the relative contribution of biotic
and abiotic processes to the vent fluid composition, especially in
the lower temperature vents, remain poorly constrained. We present
fluid chemistry and isotope data that suggest that all LCHF fluids
are derived from a single endmember produced in the hotter, deeper
subsurface essentially in the absence of microbial activity. The
strontium isotope composition (87Sr/86Sr) of
this fluid records the influence of underlying mantle and/or gabbroic
rocks, whereas sulfur isotope composition indicates closed-system
thermochemical sulfate reduction. Conductive cooling and transport
is accompanied by continued sulfate reduction, likely microbial,
and mixing with unaltered seawater, which produce second-order vents
characterized by higher δ34Ssulfide and lower
δ34Ssulfate values. Third-order vent fluids are
produced by varying degrees of subsurface mixing between the first-
and second-order fluids and a seawater-dominated fluid. Additional
biotic and abiotic processes along different flow paths are needed to
explain the spatial variability among the vents. Relationships between
sulfur geochemistry and hydrogen concentrations dominantly reflect
variations in temperature and/or distance from the primary outflow
path. Methane concentrations are constant across the field which point
to an origin independent of flow path and venting temperature. At Lost
City, not all vent fluids appear to have zero Mg concentrations. Thus,
we propose an extrapolation to a Sr isotope-endmember composition
as an alternative method to estimate endmember fluid compositions at
least in similar systems where a two-component mixing with respect to
Sr isotopes between seawater and endmember fluids can be established.
Title: AO-24 LETG/ACIS-S Calibration Observations of RXJ 1856
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6433C
Altcode:
We continue to monitor the build-up of contamination on ACIS with
LETG/ACIS-S observations RXJ1856.
Title: Differential mobilization and sequestration of sedimentary
black carbon in the East China Sea
Authors: Liu, Jingyu; Wang, Nan; Xia, Cuimei; Wu, Weifeng; Zhang,
Yang; Li, Guangxue; Zhou, Yang; Zhong, Guangcai; Zhang, Gan; Bao, Rui
Bibcode: 2022E&PSL.59417739L
Altcode:
Black carbon (BC) derived from incomplete combustion of biomass
and fossil fuels on land can be mobilized and transported to the
ocean. Burial of BC in the ocean sequesters atmospheric CO2
into a long-term carbon sink, likely exerting a positive influence on
mitigating global warming. However, the abundances, sources, and burial
of sedimentary BC in marine sediments remain poorly constrained,
hindering us from accurately understanding the mobilization and
sequestration of BC and its roles in the ocean carbon cycle. Here,
we investigate concentrations and isotopes (13C and
14C) of BC among grain size-fractionated surface sediments
along a across-shelf transect from the Yangtze River prodelta to
the Okinawa Trough to decipher the fate of BC in the East China Sea
(ECS). Our results show that the bulk BC concentrations decrease firstly
from the Yangtze River prodelta to the outer shelf and then increase to
the Okinawa Trough. Grain size-fractionated BC concentrations vary along
the transect, which we mainly attribute to the differential mobilization
of BC driven by hydrodynamic processes. We argue that BC is aged during
the mobilization, which results in an older 14C ages of
BC found seaward. After considering biomass- and fossil-derived BC
apportionments based on 14C balance calculation, we think
that BC aging may be verified by more fossil-derived BC burial in
the Okinawa Trough. We estimate that BC may account for ∼15% of
sedimentary organic carbon (SOC), and up to ∼30% of terrestrial SOC
buried in the ECS. BC burial fluxes decrease along the transect, and
are heterogeneous in different size fractions, indicating differential
sequestration of BC in the shelf and trough. We further estimate that
685 Gg/yr of BC is sequestered in the ECS, and 491 Gg/yr in the prodelta
area, with ∼30% being continental biomass-derived BC. We suggest
that increasing biomass-derived BC production on land and burying it in
the ocean may serve as a powerful means for sequestrating atmospheric
CO2, potentially contributing to carbon neutrality.
Title: Hydrothermal activity and associated subsurface processes
at Niuatahi rear-arc volcano, North East Lau Basin, SW Pacific:
Implications from trace elements and stable isotope systematics in
vent fluids
Authors: Klose, Lukas; Kleint, Charlotte; Bach, Wolfgang; Diehl,
Alexander; Wilckens, Frederike; Peters, Christian; Strauss, Harald;
Haase, Karsten; Koschinsky, Andrea
Bibcode: 2022GeCoA.332..103K
Altcode:
Hydrothermal activity is abundant in the area between the North
Eastern Lau Spreading Center and the Tofua intra-oceanic island arc
with multiple active sites in the rear-arc at the Mata and Niuatahi
volcanoes. We report geochemical data for high-temperature vent fluids
sampled from within the caldera of Niuatahi volcano. Hydrothermal
fluids were sampled from three vent sites: South Central, Southwestern
Cone and Northern Cone located in water depths between 1607 and 1699
m. Maximum temperatures of 334 °C were measured and pH values were
as low as 2.8. The vent fluids were characterized by depletions in
Mg, SO4 and U as well as an enrichment of (trace) metals
(e.g., Fe, Mn, K, Li) and dissolved gases (e.g., H2S,
CO2, H2) relative to seawater. Water-rock
ratios calculated based on concentrations (K, Li, Rb, Cs,
REE) and isotope ratios (δ7Li, δ11B,
87Sr/86Sr) suggest fluid-rock interactions
under rock-dominated conditions at all three vent sites. The
South Central vents lie closest to the site of most recent volcanic
activity in the Niuatahi caldera. Vent fluids are characterized by
relatively low Cl concentrations (as low as 292 mmol/kg) that are
indicative of sub-critical phase separation. These fluids also had
the lowest pH values (2.8-3.1), highest H2S and lowest
H2, CH4 and CO2 concentrations of
the three sites. The δD and δ18O values suggest that
H2O and CO2 were added in small amounts by
subduction-related volcanic vapors. However, there was no evidence
for magmatic SO2 input in the vent fluids at the time of
sampling in 2018. Vent fluids from the Northern and Southwestern Cone
sites on the caldera ring fault had a similar chemical composition,
despite being situated at opposite sides of the caldera. Fluids
from these sites had lower Fe/Mn ratios (<1) and H2S
concentrations than those from South Central suggesting that they were
affected by subsurface cooling and sulfide precipitation. This study
indicates variations of the Niuatahi hydrothermal vent sites depending
on the location within the caldera with variable effects of fluid-rock
interaction and magmatic input on fluid compositions in agreement with
previous work on fluid S isotopes and sulfides.
Title: The XXL survey. XLIX. Linking the members star formation
histories to the cluster mass assembly in the z = 1.98 galaxy cluster
XLSSC 122
Authors: Trudeau, A.; Willis, J. P.; Rennehan, D.; Canning, R. E. A.;
Carnall, A. C.; Poggianti, B.; Noordeh, E.; Pierre, M.
Bibcode: 2022MNRAS.515.2529T
Altcode: 2022MNRAS.tmp.1705T; 2022arXiv220610063T
The most massive protoclusters virialize to become clusters at
z ~ 2, which is also a critical epoch for the evolution of their
member galaxies. XLSSC 122 is a z = 1.98 galaxy cluster with 37
spectroscopically confirmed members. We aim to characterize their star
formation histories in the context of the cluster accretion history. We
measure their photometry in 12 bands and create a PSF-matched catalogue
of the cluster members. We employ BAGPIPES to fit star formation
histories characterized by exponentially decreasing star-forming
rates. Stellar masses, metal, and dust contents are treated as free
parameters. The oldest stars in the red-sequence galaxies display
a range of ages, from 0.5 Gyr to ~3 Gyr. Characteristic times are
between ~0.1 and ~0.3 Gyr, and the oldest members present the longest
times. Using MultiDark Planck 2 dark matter simulations, we calculate
the assembly of XLSSC 122-like haloes, weighted by the age posteriors
of the oldest members. We found that 74 per cent of these haloes were
<10 per cent assembled at the onset of star formation, declining to
67 per cent of haloes when such galaxies had formed half of their z =
1.98 stellar masses. When 90 per cent of their stellar masses were
formed, 75 per cent of the haloes were <30 per cent assembled. The
star formation histories of the red-sequence galaxies seem consistent
with episodes of star formation with short characteristic times. Onset
and cessation of star formation in the oldest galaxies are likely to
precede XLSSC 122 virialization.
Title: A Region Selection Method for Real-time Local Correlation
Tracking of Solar Full-disk Magnetographs
Authors: Bai, Yang; Lin, Jia-Ben; Bai, Xian-Yong; Yang, Xiao; Wang,
Dong-Guang; Deng, Yuan-Yong; Zhu, Xiao-Ming; Hu, Xing; Huang, Wei;
Tong, Li-Yue
Bibcode: 2022RAA....22i5010B
Altcode:
Hundreds of images with the same polarization state are first registered
to compensate for the jitters during an observation and then integrated
to realize the needed spatial resolution and sensitivity for solar
magnetic field measurement. Due to the feature dependent properties
of the correlation tracker technique, an effective method to select
the feature region is critical for low-resolution full-disk solar
filtergrams, especially those with less significant features when the
Sun is quiet. In this paper, we propose a region extraction method
based on a Hessian matrix and information entropy constraints for
local correlation tracking (CT) to get linear displacement between
different images. The method is composed of three steps: (1) extract
feature points with the Hessian matrix, (2) select good feature points
with scale spaces and thresholds, and (3) locate the feature region
with the two-dimensional information entropy constraints. Both the
simulated and observational experiments demonstrated that our region
selection method can efficiently detect the linear displacement and
improve the quality of a ground-based full-disk solar magnetogram. The
local CT with the selected regions can obtain displacement detection
results as good as the global CT and at the same time significantly
reduce the average calculation time.
Title: Improving the line of sight for the anisotropic 3-point
correlation function of galaxies: Centroid and Unit-Vector-Average
methods scaling as 𝒪 (N2)
Authors: Garcia, Karolina; Slepian, Zachary
Bibcode: 2022MNRAS.515.1199G
Altcode: 2022MNRAS.tmp.1509G
The 3-point correlation function (3PCF) is a powerful tool for the
current era of high-data volume, high-precision cosmology. It goes
beyond the Gaussian cosmological perturbations probed by the 2-point
correlation function, including late-time non-Gaussianities, and encodes
information about peculiar velocities, which distort observed positions
of galaxies along the line of sight away from their true positions. To
access this information, we must track the 3PCF's dependence not only on
each triangle's shape, but also on its orientation with respect to the
line of sight. Consequently, different choices for the line of sight
will affect the measured 3PCF. Up to now, the line of sight has been
taken as the direction to a single triplet member, but which triplet
member is used impacts the 3PCF by ~20 per cent of the statistical error
for a BOSS-like survey. For DESI (5× more precise) this would translate
to ~100 per cent of the statistical error. We propose a new method that
is fully symmetric between the triplet members, and uses either the
average of the three galaxy position vectors, or the average of their
unit vectors. We prove that these methods are equivalent to $\mathcal
{O}(\theta ^2)$, where θ is the angle subtended at the observer by
any triangle side. By harnessing the solid harmonic shift theorem,
we show how these methods can be evaluated scaling as N2,
with N the number of objects. We expect that they can be used to make
a robust, systematics-free measurement of the anisotropic 3PCF of
upcoming redshift surveys such as DESI.
Title: Characterization of acetonitrile ice irradiated by X-rays
employing the PROCODA code - I. Effective rate constants and
abundances at chemical equilibrium
Authors: Carvalho, Geanderson A.; Pilling, Sérgio; Galvão, Breno
R. L.
Bibcode: 2022MNRAS.515.3760C
Altcode: 2022MNRAS.tmp.1861C
In this work, the chemical evolution of pure acetonitrile ice at
13 K irradiated with broad-band soft X-rays (from 6 eV to 2 keV)
is determined by using a computational methodology (PROCODA code)
to best fit the experimental data. To simulate the chemical evolution
of the acetonitrile ice under an astrophysical analogous situation,
the code employs 273 reaction rates involving 33 molecular species (5
species observed in the experiment and 28 non-observed or unknown). The
considered reaction network describes 240 chemical reactions (including
dissociation, bimolecular, and termolecular rates) and 33 individual
desorption rates. The summed desorption yield was determined to be 0.23
molecules per photon, in agreement with previous estimates. Average
values for dissociation, bimolecular, and termolecular effective rate
constants were determined as 2.3 × 10-3 s-1, 9.7
× 10-26 cm3 molecule-1 s-1,
and 3.2 × 10-47 cm6 molecule-2
s-1, respectively. Some branching ratios within reaction
groups were also determined. Molecular abundances at chemical
equilibrium were obtained, such as CH3CN (67.5 per cent),
H (10.6 per cent), CN (6.7 per cent), CH2 (6.4 per cent),
CH (2.5 per cent), CH3 (1.2 per cent), CH4
(1.1 per cent), C2N2 (0.8 per cent), HCN (0.8
per cent), and CH3NC (0.6 per cent). The results of this
work can be employed in future astrochemical models to map chemical
evolution embedded species in astrophysical regions in the presence
of an ionizing radiation field.
Title: Magnetic fields and outflows in the large Bok globule CB 54
Authors: Pattle, Kate; Lai, Shih-Ping; Sadavoy, Sarah; Coudé,
Simon; Wolf, Sebastian; Furuya, Ray; Kwon, Woojin; Lee, Chang Won;
Zielinski, Niko
Bibcode: 2022MNRAS.515.1026P
Altcode: 2022MNRAS.tmp.1680P; 2022arXiv220506055P
We have observed the large Bok globule CB 54 in 850-$\mu$m polarized
light using the POL-2 polarimeter on the James Clerk Maxwell Telescope
(JCMT). We find that the magnetic field in the periphery of the globule
shows a significant, ordered deviation from the mean-field direction
in the globule centre. This deviation appears to correspond with the
extended but relatively weak 12CO outflow emanating from
the Class 0 sources at the centre of the globule. Energetics analysis
suggests that if the outflow is reshaping the magnetic field in the
globule's periphery, then we can place an upper limit of $\lt 27\, \mu$G
on the magnetic field strength in the globule's periphery. Comparison
with archival Planck and CARMA measurements shows that the field in the
centre of the globule is consistent over several orders of magnitude
in size scale, and oriented parallel to the density structure in the
region in projection. We thus hypothesize that while non-thermal motions
in the region may be sub-Alfvénic, the magnetic field is subdominant
to gravity over a wide range of size scales. Our results suggest that
even a relatively weak outflow may be able to significantly reshape
magnetic fields in star-forming regions on scales >0.1 pc.
Title: Reshuffled strongly interacting massive particle dark matter
Authors: Ho, Shu-Yu; Ko, Pyungwon; Lu, Chih-Ting
Bibcode: 2022PDU....3701061H
Altcode: 2021arXiv210704375H
In this work, we reanalyze the multi-component strongly interacting
massive particle (mSIMP) scenario using an effective operator
approach. As in the single-component SIMP case, the total relic
abundance of mSIMP dark matter (DM) is determined by the coupling
strengths of 3 → 2 processes achieved by a five-point effective
operator. Intriguingly, we notice that there is an irreducible 2 →
2 process induced by the corresponding five-point interaction in the
dark sector, which would reshuffle the mass densities of SIMP DM after
the chemical freeze-out. We dub this DM scenario as reshuffled SIMP
(rSIMP). Given this observation, we then numerically solve the coupled
Boltzmann equations including the 3 → 2 and 2 → 2 processes to get
the correct yields of rSIMP DM. It turns out that the masses of rSIMP DM
must be nearly degenerate for them to contribute sizeable abundances. On
the other hand, we also introduce effective operators to bridge the
dark sector and visible sector via a vector portal coupling. Notably,
we find that the reshuffled mechanism in the rSIMP scenario is sensitive
to the size of the DM self-interacting cross section.
Title: Recursion operators and bi-Hamiltonian representations of
cubic evolutionary (2+1)-dimensional systems
Authors: Sheftel, M. B.; Yazıcı, D.
Bibcode: 2022CNSNS.11206527S
Altcode: 2021arXiv210904111S
We construct all (2+1)-dimensional PDEs depending only on 2nd-order
derivatives of unknown which have the Euler-Lagrange form and determine
the corresponding Lagrangians. We convert these equations and their
Lagrangians to two-component forms and find Hamiltonian representations
of all these systems using Dirac's theory of constraints. We consider
three-parameter integrable equations that are cubic in partial
derivatives of the unknown applying our method of skew factorization of
the symmetry condition. Lax pairs and recursion relations for symmetries
are determined both for one-component and two-component forms. For cubic
three-parameter equations in the two-component form we obtain recursion
operators in 2 × 2 matrix form and bi-Hamiltonian representations,
thus discovering three new bi-Hamiltonian (2+1) systems.
Title: Global SN Project Transient Classification Report for
2022-09-01
Authors: Hiramatsu, D.; Hosseinzadeh, G.
Bibcode: 2022TNSCR2548....1H
Altcode:
No abstract at ADS
Title: Exomoons as Sources of White Dwarf Pollution
Authors: Trierweiler, Isabella L.; Doyle, Alexandra E.; Melis, Carl;
Walsh, Kevin J.; Young, Edward D.
Bibcode: 2022ApJ...936...30T
Altcode: 2022arXiv220507935T
Polluted white dwarfs (WDs) offer a unique way to study the bulk
compositions of exoplanetary material, but it is not always clear if
this material originates from comets, asteroids, moons, or planets. We
combine N-body simulations with an analytical model to assess the
prevalence of extrasolar moons as WD polluters. Using a sample of
observed polluted WDs, we find that the extrapolated parent body
masses of the polluters are often more consistent with those of many
solar system moons, rather than solar-like asteroids. We provide
a framework for estimating the fraction of WDs currently undergoing
observable moon accretion based on results from simulated WD planetary
and moon systems. Focusing on a three-planet WD system of super-Earth
to Neptune-mass bodies, we find that we could expect about one percent
of such systems to be currently undergoing moon accretions as opposed
to asteroid accretion.
Title: Dual constraints with ALMA: new [O III] 88-μm and
dust-continuum observations reveal the ISM conditions of luminous
LBGs at z 7
Authors: Witstok, Joris; Smit, Renske; Maiolino, Roberto; Kumari,
Nimisha; Aravena, Manuel; Boogaard, Leindert; Bouwens, Rychard;
Carniani, Stefano; Hodge, Jacqueline A.; Jones, Gareth C.; Stefanon,
Mauro; van der Werf, Paul; Schouws, Sander
Bibcode: 2022MNRAS.515.1751W
Altcode: 2022MNRAS.tmp.1838W; 2022arXiv220700022W
We present new [${\rm O\, {\small III}}$] 88-$\mu \mathrm{{m}}$
observations of five bright z ~ 7 Lyman-break galaxies spectroscopically
confirmed by ALMA through [${\rm C\, {\small II}}$] 158 $\mu
\mathrm{{m}}$, unlike recent [${\rm O\, {\small III}}$] detections
where Lyman α was used. This nearly doubles the sample of Epoch of
Reionization galaxies with robust (5σ) [${\rm C\, {\small II}}$] and
[${\rm O\, {\small III}}$] detections. We perform a multiwavelength
comparison with new deep HST images of the rest-frame UV, whose compact
morphology aligns well with [${\rm O\, {\small III}}$] tracing ionized
gas. In contrast, we find more spatially extended [${\rm C\, {\small
II}}$] emission likely produced in neutral gas, as indicated by an
[${\rm N\, {\small II}}$] 205-$\mu \mathrm{{m}}$ non-detection in one
source. We find a correlation between the optical ${[{\rm O\, {\small
III}}]}+ {\mathrm{H\,\beta }}$ equivalent width and [${\rm O\, {\small
III}}$]/[${\rm C\, {\small II}}$], as seen in local metal-poor dwarf
galaxies. CLOUDY models of a nebula of typical density harbouring a
young stellar population with a high-ionization parameter adequately
reproduce the observed lines. Surprisingly, however, our models
fail to reproduce the strength of [${\rm O\, {\small III}}$] 88-$\mu
\mathrm{{m}}$, unless we assume an α/Fe enhancement and near-solar
nebular oxygen abundance. On spatially resolved scales, we find
[${\rm O\, {\small III}}$]/[${\rm C\, {\small II}}$] shows a tentative
anticorrelation with infrared excess, LIR/LUV,
also seen on global scales in the local Universe. Finally, we introduce
the far-infrared spectral energy distribution fitting code MERCURIUS to
show that dust-continuum measurements of one source appear to favour a
low dust temperature and correspondingly high dust mass. This implies
a high stellar metallicity yield and may point towards the need of
dust production or grain-growth mechanisms beyond supernovae.
Title: Enthalpy-based modeling of tomographically reconstructed
quiet-Sun coronal loops
Authors: Mac Cormack, C.; López Fuentes, M.; Mandrini, C. H.;
Lloveras, D.; Vásquez, A. M.
Bibcode: 2022AdSpR..70.1570M
Altcode: 2022arXiv220609896M
The structure of the solar corona is made of magnetic flux tubes or
loops. Due to the lack of contrast with their environment, observing
and studying coronal loops in the quiet Sun is extremely difficult. In
this work we use a differential emission measure tomographic (DEMT)
technique to reconstruct, from a series of EUV images covering an entire
solar rotation, the average 3D distribution of the thermal properties of
the coronal plasma. By combining the DEMT products with extrapolations
of the global coronal magnetic field, we reconstruct coronal loops
and obtain the energy input required to keep them at the typical
million-degree temperatures of the corona. We statistically study a
large number of reconstructed loops for Carrington rotation (CR) 2082
obtaining a series of typical average loops of different lengths. We
look for relations between the thermal properties and the lengths of
the constructed typical loops and find similar results to those found
in a previous work (Mac Cormack et al., 2020).. We also analyze the
typical loop properties by comparing them with the zero-dimensional (0D)
hydrodynamic model Enthalpy-Based Thermal Evolution of Loops (EBTEL,
Klimchuk et al., 2008). We explore two heating scenarios. In the first
one, we apply a constant heating rate assuming that typical loops are in
quasi-static equilibrium. In the second scenario we heat the plasma in
the loops using short impulsive events. We find that the reconstructed
typical loops are overdense with respect to quasi-static equilibrium
solutions of the hydrodynamic model. Impulsive heating, on the other
hand, reproduces better the observed densities and temperatures for the
shorter and approximately semicircular loops. The thermal properties of
longer loops cannot be correctly reproduced with the EBTEL model. We
suggest that to properly assess the physical characteristics of the
analyzed loops in future works, it would be necessary to use a more
sophisticated 1D model, with which to study the loop temperature and
density profiles and test localized heating at different locations
along the loops.
Title: Neural Network Reconstruction of $H'(z)$ and its application
in Teleparallel Gravity
Authors: Mukherjee, Purba; Levi Said, Jackson; Mifsud, Jurgen
Bibcode: 2022arXiv220901113M
Altcode:
In this work, we explore the possibility of using artificial neural
networks to impose constraints on teleparallel gravity and its $f(T)$
extensions. We use the available Hubble parameter observations from
cosmic chronometers and baryon acoustic oscillations from different
galaxy surveys. We discuss the procedure for training a network
model to reconstruct the Hubble diagram. Further, we describe the
procedure to obtain $H'(z)$, the first order derivative of $H(z)$,
in a novel way. These analyses are complemented with two presently
debated values of $H_0$, namely, the local measurements by the SH0ES
team ($H_0^{\text{R20}} = 73.2 \pm 1.3$~km~Mpc$^{-1}$~s$^{-1}$) and
the updated TRGB calibration from the Carnegie Supernova Project
($H_0^{\text{TRGB}} = 69.8 \pm 1.9$~km~Mpc$^{-1}$~s$^{-1}$),
respectively. Additionally, we investigate the validity of the
concordance model, through some cosmological null tests with these
reconstructed data sets. Finally, we reconstruct the allowed $f(T)$
functions for different combinations of the observational Hubble data
sets. Results show that the $\Lambda$CDM model lies comfortably included
at the 1$\sigma$ confidence level for all the examined cases.
Title: Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy
(HEARTS) VII. Detection of sodium on the long-transiting inflated
sub-Saturn KELT-11 b
Authors: Mounzer, Dany; Lovis, Christophe; Seidel, Julia V.; Attia,
Omar; Allart, Romain; Bourrier, Vincent; Ehrenreich, David; Wyttenbach,
Aurélien; Astudillo-Defru, Nicola; Beatty, Thomas G.; Cegla, Heather;
Heng, Kevin; Lavie, Baptiste; Lendl, Monika; Melo, Claudio; Pepe,
Francesco; Pepper, Joshua; Rodriguez, Joseph E.; Ségransan, Damien;
Udry, Stéphane; Linder, Esther; Sousa, Sergio
Bibcode: 2022arXiv220900597M
Altcode:
KELT-11b is an inflated sub-Saturn with a hot atmosphere and that
orbits a bright evolved subgiant star, making it a prime choice for
atmospheric characterization, but that transits its host star for
more than seven hours. We observed this system in series of three
consecutive nights with the HARPS spectrograph and report on the
analysis of the transmission spectrum obtained from this dataset. Our
results highlight the potential for independent observations of a
long-transiting planet over consecutive nights. Our study reveals a
sodium excess absorption of $0.28 \pm 0.05 \%$ and $0.50 \pm 0.06 \%$
in the Na D1 and D2 lines, respectively. This corresponds to 1.44 and
1.69 times the white-light planet radius in the line cores. Wind pattern
modeling tends to prefer day-to-night side winds with no vertical
winds, which is surprising considering the planet bloatedness. The
modeling of the Rossiter-Mclaughlin effect yields a significantly
misaligned orbit, with a projected spin-orbit angle of ${\lambda} =
-77.86^{+2.36}_{-2.26}{}^\circ$. The characteristics of KELT-11 b,
notably its extreme scale height and long transit, make it an ideal
and unique target for next-generation telescopes. Our results as well
as recent findings from HST, TESS, and CHEOPS observations could make
KELT-11 b a benchmark exoplanet in atmospheric characterization.
Title: GJMS-like operators on symmetric 2-tensors and their
gravitational duals
Authors: Aros, Rodrigo; Bugini, Fabrizzio; Diaz, Danilo E.
Bibcode: 2022arXiv220900582A
Altcode:
We study a family of higher-derivative conformal operators
$P^{(2)}_{2k}$ acting on transverse-traceless symmetric 2-tensors
on generic Einstein spaces. They are a natural generalization of the
well-known construction for scalars. We first provide the alternative
description in terms of a bulk Poincaré-Einstein metric by making
use of the AdS/CFT dictionary and argue that their holographic dual
generically consists of bulk massive gravitons. For special values
of the mass, the bulk fields acquire an additional gauge invariance
with vector and scalar gauge parameters in the cases of massless
and partially massless gravitons, respectively. Having clarified
the correspondence at the tree level, we move on to the one-loop
quantum level and put forward a holographic formula for the functional
determinant of the higher-derivative conformal operators $P^{(2)}_{2k}$
in terms of the functional determinant for massive gravitons with
standard and alternate boundary conditions. In the process, the
analogous construction for vectors $P^{(1)}_{2k}$ is worked out as well,
and we end up with an interesting recursive structure. The holographic
formula also provides the necessary building blocks to address the
special cases of massless and partially massless bulk gravitons where
gauge invariance turns up. In four and six dimensions we are able to
provide evidence for the correctness of the holographic formula by
computing the partition functions and the Weyl anomaly coefficients,
verifying for the latter full agreement between bulk and boundary
computations and with results available in the literature.
Title: Fluid nature constrains Horndeski gravity
Authors: Miranda, Marcello; Vernieri, Daniele; Capozziello, Salvatore;
Faraoni, Valerio
Bibcode: 2022arXiv220902727M
Altcode:
The elusive physical nature of Horndeski gravity is elucidated in
a new approach depicting this class of theories as a dissipative
effective fluid. Requiring the constitutive equations of the latter
to be those of a Newtonian fluid restricts the theory to only two
disconnected subclasses of "viable" Horndeski gravity. Therefore, a
stress-energy tensor of Horndeski effective fluid, linear in the first
derivatives of the fluid's 4-velocity, is a sufficient condition for
gravitational waves to propagate at light speed. All other Horndeski
theories correspond to exotic non-Newtonian effective fluids.
Title: On the equivalence of the adiabatic expansion and Hadamard
renormalization for a charged scalar field
Authors: Pla, Silvia; Winstanley, Elizabeth
Bibcode: 2022arXiv220901079P
Altcode:
We examine the relationship between three approaches (Hadamard,
DeWitt-Schwinger and adiabatic) to the renormalization of expectation
values of field operators acting on a charged quantum scalar
field. First, we demonstrate that the DeWitt-Schwinger representation
of the Feynman Green's function is a particular case of the Hadamard
representation. Next, we restrict attention to a spatially flat
Friedmann-Lemaitre-Robertson-Walker universe with time-dependent,
purely electric, background electromagnetic field, considering two,
three and four-dimensional space-times. Working to the order required
for the renormalization of the stress-energy tensor (SET), we find
the adiabatic and DeWitt-Schwinger expansions of the Green's function
when the space-time points are spatially separated. In two and four
dimensions, the resulting DeWitt-Schwinger and adiabatic expansions
are identical. In three dimensions, the DeWitt-Schwinger expansion
contains terms of adiabatic order four which are not necessary for
the renormalization of the SET and hence absent in the adiabatic
expansion. The equivalence of the DeWitt-Schwinger and adiabatic
approaches to renormalization in the scenario considered is thereby
demonstrated up to well-known renormalization ambiguities in three
space-time dimensions.
Title: On Graviton non-Gaussianities in the Effective Field Theory
of Inflation
Authors: Cabass, Giovanni; Stefanyszyn, David; Supeł, Jakub;
Thavanesan, Ayngaran
Bibcode: 2022arXiv220900677C
Altcode:
We derive parity-even graviton bispectra in the Effective Field
Theory of Inflation (EFToI) to all orders in derivatives. Working
in perturbation theory, we construct all cubic interactions that
can contribute to tree-level graviton bispectra, showing that they
all come from EFToI operators containing two or three powers of the
extrinsic curvature and its covariant derivatives: all other operators
can be removed by field redefinitions or start at higher-order
in perturbations. For operators cubic in the extrinsic curvature,
where the single-clock consistency relations are satisfied without a
correction to the graviton two-point function, we use the Manifestly
Local Test (MLT) to efficiently extract the effects of evolving graviton
fluctuations to the end of inflation. Despite the somewhat complicated
nature of the bulk interactions, the final boundary correlators take a
very compact form. For operators quadratic in the extrinsic curvature,
the leading order bispectra are a sum of contact and single exchange
diagrams, which are tied together by spatial diffeomorphisms, and to
all orders in derivatives we derive these bispectra by computing the
necessary bulk time integrals. For single exchange diagrams we exploit
factorisation properties of the bulk-bulk propagator for massless
gravitons and write the result as a finite sum over residues. Perhaps
surprisingly, we show these single exchange contributions have only
total-energy poles and also satisfy the MLT.
Title: Discovering Axions with X-Ray Searches Towards Magnetic
White Dwarfs
Authors: Safdi, Benjamin
Bibcode: 2022cxo..prop.6279S
Altcode:
Axions, which are hypothetical ultra-light particles, are
a well-motivated extension to the Standard Model of particle
physics. White dwarf (WD) stars may radiate keV-energy axions produced
in their stellar cores. This has been studied as a channel by which WDs
may cool, with some analyses suggesting that axions can help explain
the WD luminosity function. The radiated axions may convert into X-rays
in the magnetic fields surrounding magnetic WDs (MWDs). We propose
two 40 ks observations of the MWDs WD 1859+148 and PG 0945+246. In
the absence of axions we will set the strongest limits to-date on the
axion coupling strength and disfavor nearly all of the parameter space
for axions predicted by string theory.
Title: Climate-driven stress changes and normal fault behavior in
the Lake Malawi (Nyasa) Rift, East Africa
Authors: Xue, Liang; Moucha, Robert; Scholz, Christopher A.
Bibcode: 2022E&PSL.59317693X
Altcode:
Climate-triggered fluctuations of surface masses, including ice
and water, can cause transient stress in the Earth's crust, further
affecting the slip behavior of faults over different temporal and length
scales. In particular, lakes developed within active continental rifts
may modulate the stress states and slip rates of rift border faults
and intrarift faults. Here, we utilize a numerical model in a case
study of the Malawi (Nyasa) Rift to understand the response of faults
to mass fluctuations on the Earth's surface. The water level of Lake
Malawi rose 600 m over the last 150 kyr, and significantly influenced
the stress state of faults in rift valley. We find that such water load
fluctuations can exert 4.6 MPa normal stress on fault planes and produce
a negative Coulomb stress (down to -2.0 MPa) on fault planes as well
as a pronounced reduction of slip (∼2 m) on fault planes within the
rift. Moreover, along-strike differences in fault geometries and their
position relative to the center of the water column load resulted in
variable along-strike stress and slip changes. These results suggest
that lakes that develop within continental rifts play an important role
in the evolution of extensional faulting. Our case study provides a
basis for evaluating the relationship between climate-driven surface
mass variations and the subsurface stress state of fault planes and
associated seismic potentials.
Title: Calibration at elevation of the WEAVE fibre positioner
Authors: Hughes, Sarah; Dalton, Gavin; Dee, Kevin; Abrams, Don Carlos;
Middleton, Kevin; Lewis, Ian; Terrett, David; Aguerri, Alfonso L.;
Balcells, Marc; Bishop, Georgia; Bonifacio, Piercarlo; Carrasco,
Esperanza; Trager, Scott; Vallenari, Antonella
Bibcode: 2022arXiv220901166H
Altcode:
WEAVE is the new wide-field spectroscopy facility for the prime focus of
the William Herschel Telescope in La Palma, Spain. Its fibre positioner
is essential for the accurate placement of the spectrograph's 960
fibre multiplex. We provide an overview of the recent maintenance,
flexure modifications, and calibration measurements conducted at the
observatory prior to the final top-end assembly. This work ensures
that we have a complete understanding of the positioner's behaviour
as it changes orientation during observations. All fibre systems have
been inspected and repaired, and the tumbler structure contains new
clamps to stiffen both the internal beam and the retractor support disk
onto which the field plates attach. We present the updated metrology
procedures and results that will be verified on-sky.
Title: The 3-D X-ray Ejecta Structure of Tycho's Supernova Remnant
Authors: Millard, Matthew J.; Park, Sangwook; Sato, Toshiki; Hughes,
John P.; Slane, Patrick; Patnaude, Daniel; Burrows, David; Badenes,
Carles
Bibcode: 2022arXiv220901632M
Altcode:
We present our velocity measurements of 59 clumpy, metal-rich ejecta
knots in the supernova remnant (SNR) of SN 1572 (Tycho). We use our 450
ks Chandra High Energy Transmission Grating Spectrometer observation
to measure the Doppler shift of the He-like Si K$\alpha$ line-center
wavelength emitted from these knots to find their line-of-sight (radial)
velocities ($v_r$). We find $v_r$ up to $\sim$ 5500 km s$^{-1}$,
with roughly consistent speeds between blueshifted and redshifted
ejecta knots. We also measure the proper motions (PMs) for our sample
based on archival Chandra Advanced CCD Imaging Spectrometer data taken
from 2003, 2009, and 2015. We estimate PMs up to 0$"$.35 yr$^{-1}$,
which corresponds to a transverse velocity of about 5800 km s$^{-1}$
for the distance of 3.5 kpc to Tycho. Our $v_r$ and transverse velocity
measurements imply space velocities of $\sim$ 1900 - 6000 km s$^{-1}$
for the ejecta knots in Tycho. We estimate a new expansion center of
R.A.(J2000) = 00$^h$25$^m$18$^s$.725 $\pm$ 1$^s$.157 and decl.(J2000)
= +64$^{\circ}$08$'$02$"$.5 $\pm$ 11$"$.2 from our PM measurements,
consistent to within $\sim$ 13$"$ of the geometric center. The
distribution of space velocities throughout the remnant suggests
that the southeast quadrant generally expands faster than the rest
of the SNR. We find that blueshifted knots are projected more in
the northern shell, while redshifted knots are more in the southern
shell. The previously estimated reverse shock position is consistent
with most of our estimated ejecta distribution, however some ejecta
show deviations from the 1-D picture of the reverse shock.
Title: Controlling petals using fringes: discontinuous wavefront
sensing through sparse aperture interferometry at Subaru/SCExAO
Authors: Deo, Vincent; Vievard, Sébastien; Cvetojevic, Nick; Ahn,
Kyohoon; Huby, Elsa; Guyon, Olivier; Lacour, Sylvestre; Lozi, Julien;
Martinache, Frantz; Norris, Barnaby; Skaf, Nour; Tuthill, Peter
Bibcode: 2022arXiv220902898D
Altcode:
Low wind and petaling effects, caused by the discontinuous apertures
of telescopes, are poorly corrected -- if at all -- by commonly used
workhorse wavefront sensors (WFSs). Wavefront petaling breaks the
coherence of the point spread function core, splitting it into several
side lobes, dramatically shutting off scientific throughput. We
demonstrate the re-purposing of non-redundant sparse aperture
masking (SAM) interferometers into low-order WFSs complementing the
high-order pyramid WFS, on the SCExAO experimental platform at Subaru
Telescope. The SAM far-field interferograms formed from a 7-hole mask
are used for direct retrieval of petaling aberrations, which are almost
invisible to the main AO loop. We implement a visible light dual-band
SAM mode, using two disjoint 25 nm wide channels, that we recombine to
overcome the one-lambda ambiguity of fringe-tracking techniques. This
enables a control over petaling with sufficient capture range yet
without conflicting with coronagraphic modes in the near-infrared. We
present on-sky engineering results demonstrating that the design is
able to measure petaling well beyond the range of a single-wavelength
equivalent design.
Title: Shadow and quasinormal modes of the
Kerr-Newman-Kiselev-Letelier black hole
Authors: Atamurotov, Farruh; Hussain, Ibrar; Mustafa, G.; Jusufi, Kimet
Bibcode: 2022arXiv220901652A
Altcode:
We investigate the null geodesics and the shadow cast by the
Kerr-Newman-Kiselev-Letelier (KNKL) black hole for the equation
of state parameter $\omega_q=-2/3$ and for different values of the
spacetime parameters, including the quintessence parameter $\gamma$,
the cloud of string (CS) parameter $b$, the spin parameter $a$ and the
charge $Q$ of the black hole. We notice that for the increasing values
of the parameters $\gamma$ and $b$ the size of the shadow of the KNKL
black hole increases and consequently the strength of the gravitational
field of the black hole increases. On the other hand with increase in
the charge $Q$ of the black hole the size of the shadow of the black
hole decreases. Further with the increase in the values of the spin
parameter $a$ of the KNKL black hole, we see that the distortion of the
shadow of the black hole becomes more prominent. Moreover we use the
data released by the Event Horizon Telescope (EHT) collaboration, to
restrict the parameters $b$ and $\gamma$ for the KNKL black hole, using
the shadow cast by the KNKL black hole. To this end, we also explore
the relation between the typical shadow radius and the equatorial and
polar quasinormal mods (QNMs) for the KNKL black hole and extend this
correspondence to non-asymptotically flat spacetimes. We also study the
emission energy rate from the KNKL black hole for the various spacetime
parameters, and observe that it increases for the increasing values
of both the parameters $\gamma$ and $b$ for fixed charge-to-mass and
spin-to-mass ratios of the KNKL black hole. Finally, we investigate
the effects of plasma on the photon motion, size and shape of the
shadow cast by the KNKL black hole...
Title: Searching for Winds and Jets in Black Hole State Transitions
Authors: Neilsen, Joey
Bibcode: 2022cxo..prop.6298N
Altcode:
We propose a large multiwavelength campaign (120 ks Chandra HETGS,
NuSTAR, JVLA/ATCA, NICER, Swift, Gemini) on a black hole transient
to study the influence of ionized winds on relativistic jets and
state transitions. With a new observing strategy based on integrating
radio/X-ray monitoring and timing studies, we will search for winds
during and after the state transition to test their influence on and
track their coevolution with the disk and the jet over the next 2-3
months. Our spectral and timing constraints will provide precise probes
of the accretion geometry and accretion/ejection physics.
Title: High Velocity Stars in SDSS/APOGEE DR17
Authors: Quispe-Huaynasi, Fredi; Roig, Fernando; McDonald, Devin J.;
Loaiza-Tacuri, Veronica; Majewski, Steven R.; Wanderley, Fabio C.;
Cunha, Katia; Pereira, Claudio B.; Hasselquist, Sten; Daflon, Simone
Bibcode: 2022arXiv220903560Q
Altcode:
We report 23 stars having Galactocentric velocities larger than
$450~\mathrm{km\,s}^{-1}$ in the final data release of the APOGEE
survey. This sample was generated using space velocities derived by
complementing the high quality radial velocities from the APOGEE project
in Sloan Digital Sky Survey's Data Release 17 (DR17) with distances and
proper motions from Gaia early Data Release 3 (eDR3). We analyze the
observed kinematics and derived dynamics of these stars, considering
different potential models for the Galaxy. We find that three stars
could be unbound depending on the adopted potential, but in general
all of the stars show typical kinematics of halo stars. The APOGEE DR17
spectroscopic results and Gaia eDR3 photometry are used to assess the
stellar parameters and chemical properties of the stars. All of the
stars belong to the red giant branch, and, in general, they follow the
abundance pattern of typical halo stars. There are a few exceptions that
would deserve further analysis through high-resolution spectroscopy. In
particular, we identify a high velocity Carbon-Enhanced Metal-Poor
(CEMP) star, with Galactocentric velocity of 482 km\,s$^{-1}$. We do
not confirm any hypervelocity star in the sample, but this result is
very sensitive to the adopted distances, and less sensitive to the
Galactic potential.
Title: Searching for X-ray Emission from Two Type Ia SNe with Halpha
Emission Lines in their Optical Spectrum
Authors: Dwarkadas, Vikram
Bibcode: 2022cxo..prop.6313D
Altcode:
We propose 50 ks observations of Type Ia SNe 2016jae and 2018cqj. These
sub-luminous and fast-declining SNe are distinguished by the presence
of an Halpha line, previously seen in the Type Ia-CSM SNe, and in the
subluminous SN 2018fhw. These SNe have a lower Halpha flux compared
to the Ia-CSM, and occur in an early type galaxy. The presence of the
Halpha line indicates interaction with a H-rich high density surrounding
medium. Investigating various mechanisms that could produce the Halpha
line suggests that the density could be as high as 1.e8 particles/cc,
and the X-ray luminosity could be greater than 1.e39 erg/s. A 50 ks
observation would give rise to detectable emission. The only other
Type Ia detected in X-rays so far has been the Type Ia-CSM SN 2012ca.
Title: Detecting non-Gaussian gravitational wave backgrounds:
a unified framework
Authors: Buscicchio, Riccardo; Ain, Anirban; Ballelli, Matteo; Cella,
Giancarlo; Patricelli, Barbara
Bibcode: 2022arXiv220901400B
Altcode:
We describe a novel approach to the detection and parameter estimation
of a non-Gaussian stochastic background of gravitational waves. The
method is based on the determination of relevant statistical parameters
using importance sampling. We show that it is possible to improve
the Gaussian detection statistics, by simulating realizations of the
expected signal for a given model. While computationally expensive,
our method improves the detection performance leveraging the prior
knowledge on the expected signal, and can be used in a natural way to
extract physical information about the background. We present the basic
principles of our approach, characterize the detector performances in
a simplified context and discuss possible applications to the detection
of some astrophysical foregrounds. We argue that the proposed approach,
complementarily to the ones available in literature, might be used to
detect suitable astrophysical foregrounds by currently operating and
future gravitational wave detectors.
Title: Nano-arcsecond Tomography of the Central Regions of the Quasar
in SDSS J0924+0219
Authors: Pooley, David
Bibcode: 2022cxo..prop.6367P
Altcode:
SDSS J0924+0219 is the most anomalous quadruply lensed quasar
known. Its close pair of images should have nearly equal brightness
but differ by a factor of 14 in the optical and by over a factor
of 30 in the X-rays. The source of the anomaly is unquestionably
due to microlensing by stars in the intervening galaxy since the
close pair of images has nearly the same brightness in the radio. Its
other saddle point image is also anomalously demagnified, again due to
microlensing. The reappearance of either image, which will occur at some
point, will provide a once-in-Chandra's-lifetime opportunity to perform
nano-arcsecond scale tomography of the central regions of a quasar.
Title: Light Echoes from X-ray Transients as Probes of Interstellar
Dust and Galactic Structure
Authors: Heinz, Sebastian
Bibcode: 2022cxo..prop.6342H
Altcode:
When an X-ray Transient exhibits a bright flare, scattering by
interstellar dust clouds can give rise to a light echo in the
form of concentric rings. Several such echoes have been detected,
leading to significant discoveries and press attention. We propose a
Target-of-Opportunity campaign to observe a cycle 23 echo with the aim
of following the temporal evolution of the echo in order to (a) map the
3D distribution of interstellar dust along the line of sight to parsec
accuracy, (b) constrain the composition and grain size distribution
of ISM dust in each of the clouds towards the source, (c) measure the
distance to the X-ray source, (d) constrain the velocity dispersion of
molecular clouds, and (e) search for evidence of streaming velocities
by combining X-ray and CO data.
Title: A Galactic SNR and its Quiescent Black Hole
Authors: Reynolds, Mark
Bibcode: 2022cxo..prop.6309R
Altcode:
Radio and X-ray imaging of a newly discovered, transient X-ray binary
reveals a coincident supernova remnant (SNR). High extinction inhibits
determination of mass function for the binary at the current time, but
every available diagnostic signals that the primary is a black hole. The
structure of the SNR is particularly clear in radio, and similar to
Cas A. However, the X-ray structure is not clearly revealed in a prior
XMM-Newton snapshot observation. We request a 60~ks ACIS-I observation
to reveal the X-ray morphology of the SNR, obtain basic age constraints
from spectral modeling, and to detect the quiescent black hole.
Title: Dark Matter: DAMA/LIBRA and its perspectives
Authors: Bernabei, R.; Belli, P.; Cappella, F.; Caracciolo, V.;
Cerulli, R.; Dai, C. J.; d'Angelo, A.; Incicchitti, A.; Leoncini,
A.; Ma, X. H.; Merlo, V.; Montecchia, F.; Sheng, X. D.; Ye, Z. P.
Bibcode: 2022arXiv220900882B
Altcode:
The long-standing model-independent annual modulation effect measured
by DAMA deep underground at Gran Sasso Laboratory with different
experimental configurations is summarized and perspectives will
be highlighted. DAMA/LIBRA-phase2 set-up, $\simeq$ 250 kg highly
radio-pure NaI(Tl) confirms the evidence of a signal that meets all
the requirements of the model independent Dark Matter annual modulation
signature at high C.L.; the full exposure is 2.86 ton $\times$ yr over
22 annual cycles. The experiment is currently collecting data in the
DAMA/LIBRA-phase2 empowered configuration with an even lower software
energy threshold. Other recent claims are shortly commented.
Title: Rotational spectroscopy of mono-deuterated oxirane
($c$-C$_2$H$_3$DO) and its detection towards IRAS 16293$-$2422 B
Authors: Müller, Holger S. P.; Jørgensen, Jes K.; Guillemin,
Jean-Claude; Lewen, Frank; Schlemmer, Stephan
Bibcode: 2022arXiv220901414M
Altcode:
We prepared a sample of mono-deuterated oxirane and studied its
rotational spectrum in the laboratory between 490 GHz and 1060 GHz
in order to improve its spectroscopic parameters and consequently
the calculated rest frequencies of its rotational transitions. The
updated rest frequencies were employed to detect $c$-C$_2$H$_3$DO
for the first time in the interstellar medium in the Atacama Large
Millimetre/submillimetre Array (ALMA) Protostellar Interferometric Line
Survey (PILS) of the Class 0 protostellar system IRAS 16293$-$2422. Fits
of the detected lines using the rotation diagrams yield a temperature
of $T_{\rm rot} = 103 \pm 19$ K, which in turn agrees well with 125
K derived for the $c$-C$_2$H$_4$O main isotopologue previously. The
$c$-C$_2$H$_3$DO to $c$-C$_2$H$_4$O ratio is found to be $\sim$0.15
corresponding to a D-to-H ratio of $\sim$0.036 per H atom which is
slightly higher than the D-to-H ratio of species such as methanol,
formaldehyde, ketene and but lower than those of the larger complex
organic species such as ethanol, methylformate and glycolaldehyde. This
may reflect that oxirane is formed fairly early in the evolution of
the prestellar cores. The identification of doubly deuterated oxirane
isotopomers in the PILS data may be possible judged by the amount of
mono-deuterated oxirane and the observed trend that multiply deuterated
isotopologues have higher deuteration rates than their mono-deuterated
variants.
Title: Comprehensive Chandra, Gemini, JVLA and HST observations of
a fast blue optical transient
Authors: Chrimes, Ashley
Bibcode: 2022cxo..prop.6318C
Altcode:
Fast blue optical transients (FBOTs) are a poorly understood class of
extragalactic transient. They are at odds with being radioactively
powered due to their rapid rise and fall timescales, and are very
blue, indicating a high photospheric temperature. Faint FBOTs are now
routinely detected, but bright, local events are rare. Only four were
followed up with X-ray, optical spectroscopic, and radio observations in
the last four years, of which only two had early time multi-wavelength
observations. We propose a ToO joint programme (with Chandra, Gemini,
JVLA and HST) to follow-up a single bright FBOT in detail. Our proposal
will help to discern which features all FBOTs have in common, and
will put strong constraints on the nature of the central engine and
emission mechanisms.
Title: Unveiling the Nature of Fossil Groups Through Progenitors
Authors: dupke, renato
Bibcode: 2022cxo..prop.6404D
Altcode:
Even though the first fossil group (FG) was discovered almost three
decades ago their nature still remains unclear. The initial hypothesis
that they are the remains of groups that lost energy through dynamical
friction and have been undisturbed is not fully consistent with their
typically lack the expected large cool cores. Recently developed
techniques to measure the ICL coupled with good quality X-ray data
suggest that FGs are systems that are indeed very old, probably having
achieved the end of their merging tree. To corroborate this scenario we
need to observe the phases prior to FG formation, or FG progenitors,
of which extremely few systems exist with high quality X-ray and HST
data for the analysis. We propose to observe the hottest, most suitable
for Chandra FG progenitor, CSWA28.
Title: Like black holes Buchdahl stars cannot be extremalized
Authors: Shaymatov, Sanjar; Dadhich, Naresh
Bibcode: 2022arXiv220902560S
Altcode:
It was shown long back in \cite{Dadhich97} that a non-extremal
black hole cannot be converted into an extremal one by test particle
adiabatic accretion. The Buchdahl star is the most compact object
without horizon and is defined by the gravitational potential, $\Phi(R)
= 4/9$, while a black hole by $\Phi(R) = 1/2$. In this letter we examine
the question of extremalization for the Buchdhal stars and show that the
same result holds good as for the black holes. That is, a non-extremal
Buchdahl star cannot be extremalized by test particle accretion.
Title: Searching for X-rays from a z > 12 Source with Chandra
Authors: Pacucci, Fabio
Bibcode: 2022cxo..prop.6372P
Altcode:
Recently, the discovery of two candidate z~13 sources, HD1 and HD2,
was reported. These would be, by far, the highest-redshift sources
ever detected, and are scheduled for an upcoming JWST observation. Two
physical interpretations for these UV-bright sources were proposed:
either an extreme starburst (producing ~100 solar masses per year),
or a quasar of ~10^8 solar masses, accreting close to the Eddington
rate. We propose a 250 ks observation of HD2, the brightest of the
two sources, to conclusively test the quasar hypothesis, predicting
a detection at >4 sigma. A non-detection would strongly favor
the starburst hypothesis, which could require star formation with a
top-heavy initial mass function, indicative of a galaxy dominated by
metal-free stars, also a first in the field.
Title: Investigating an extreme ULX detected in eRASS1
Authors: Roberts, Timothy
Bibcode: 2022cxo..prop.6338R
Altcode:
Many of our key breakthroughs in understanding ultraluminous X-ray
sources (ULXs) have come from observations of the more luminous 'extreme
ULXs' (Lx = 10^40 - 10^41 erg/s). One means of better understanding
ULXs is therefore to find new examples of this class that are located
close enough for detailed observation. Here we propose a short (10
ks) Chandra observation of one such new eULX (d=9 Mpc) detected in
eRASS1, which will provide two key diagnostics only obtainable with
Chandra: a sub-arcsecond position that permits the identification of
multi-wavelength counterparts, and the best determination of whether
this is a single point source at the highest spatial resolution.
Title: Neural Networks Optimized by Genetic Algorithms in Cosmology
Authors: Gómez-Vargas, Isidro; Briones Andrade, Joshua; Vázquez,
J. Alberto
Bibcode: 2022arXiv220902685G
Altcode:
The applications of artificial neural networks in the cosmological
field have shone successfully during the past decade, this is due to
their great ability of modeling large amounts of datasets and complex
nonlinear functions. However, in some cases, their use still remains
controversial becasue their ease of producing inaccurate results
when the hyperparameters are not carefully selected. In this paper,
to find the optimal combination of hyperparameters that describe
the artificial neural networks, we propose to take advantage of the
genetic algorithms. As a proof of the concept, we analyze three
different cosmological cases to test the performance of the new
architecture achieved with the genetic algorithms and compare the
output with the standard process, consisting of a grid with all possible
configurations. First, we carry out a model-independent reconstruction
of the distance modulus using a Type Ia Supernovae compilation. Second,
the neural networks learn to solve dynamical system of the Universe's
content, and finally with the latest Sloan Digital Sky Survey data
release we train the networks for the classification of astronomical
objects. We found that the genetic algorithms improve considerably
the generation of the architecture, which can ensure more confidence
in their physical results because of the better performance in the
metrics with respect to the grid method.
Title: GUP Corrected Casimir Wormholes in $f(Q)$ Gravity
Authors: Hassan, Zinnat; Ghosh, Sayantan; Sahoo, P. K.; Rao,
V. Sree Hari
Bibcode: 2022arXiv220902704H
Altcode:
We have presented systematically the effect of the Generalized
Uncertainty Principle (GUP) in Casimir wormholes space-time in
the recently proposed modified gravity, the so-called symmetric
teleparallel gravity or $f(Q)$ gravity. Here $Q$ is the non-metricity
scalar that drives the gravitation interaction. We consider two famous
GUP relations, such as the Kempf, Mangano, and Mann (KMM) model and the
Detournay, Gabriel, and Spindel (DGS) model, in our study. Besides this,
we investigate with three different redshift functions under anisotropic
fluid located at the throat. Further, we analyzed the obtained wormhole
solutions with energy conditions, especially null energy conditions
(NEC) at the throat of the wormhole, and encountered that some arbitrary
quantity disrespects the classical energy conditions at the wormhole
throat of radius $r_0$. Later, the ADM mass and the volume integral
quantifier are also discussed to calculate the amount of exotic matter
required near the wormhole throat. Additionally, we show the behavior
of the equation of state parameters under the effect of GUP.
Title: The unusual active galaxy H1821+643 and the elusive nature
of FRI quasars
Authors: Garofalo, David; Singh, Chandra B.
Bibcode: 2022arXiv220901964G
Altcode:
The moderate spin estimate for the black hole at the center of the cool
core cluster H1821+643 motivates the completion of a story about this
object's origin and evolution that was in the making since the work
by Blundell and Rawlings over two decades ago as the first example
of a massive black hole accreting at near Eddington rates with an FRI
jet. This elusive combination of properties was explained in our 2010
model where we showed it to be part of a small parameter space that
includes X shaped radio galaxies. As an accreting black hole that
never experienced a counterrotating phase, H1821+643 is constrained
by theory to produce a jet for spin values between 0.1 and about 0.7
and an FRI jet for a slightly smaller range. The feedback from such
a black hole is not subject to a tilted jet and is why star formation
rates remain high in this cluster environment. The prediction is that
H1821+643 is within millions of years of becoming jetless.
Title: A Deep Resolved Study of CGCG341-006, a 1.5 kpc Nearby Dual AGN
Authors: Koss, Michael
Bibcode: 2022cxo..prop.6384K
Altcode:
The coalescence of binary supermassive black holes in galaxy mergers
is thought to constitute the strongest source of gravitational waves,
however, crucial information about the population of inpsiraling SMBH
pairs at the few hundred pc to few kpc scale that are observable
as dual AGN is only possible in nearby AGN. The Seyfert galaxy
CGCG341-006 has recently been found to host a hidden nuclear merger
in NIR AO separated by 1.6'' (1.5 kpc) at redshift z=0.046. A 23 ks
Chandra observation found a dual X-ray nuclei, but with only 9 counts
in the secondary; insufficient to resolve the intrinsic luminosity
and obscuration. We request a longer 156 ks observation, to resolve
the intrinsic luminosity and obscuration and further study the high
variability changing-look nature.
Title: Reshaping and ejection processes on rubble-pile asteroids
by impacts
Authors: Raducan, S. D.; Jutzi, M.; Zhang, Y.; Ormö, J.; Michel, P.
Bibcode: 2022arXiv220902677R
Altcode:
Context. Most small asteroids (<50 km in diameter) are the result
of the breakup of a larger parent body and are often considered to be
rubble-pile objects. Similar structures are expected for the secondaries
of small asteroid binaries, including Dimorphos, the smaller component
of the 65803 Didymos binary system and the target of NASA's Double
Asteroid Redirection Test (DART) and ESA's Hera mission. The DART impact
occurs on September 26th, 2022 and it will alter the orbital period of
Dimorphos around Didymos. Aims. In this work we assume Dimorphos-like
bodies with a rubble-pile structure, and quantify the effects of
boulder packing in its interior on the post-impact morphology, degree
of shape change and material ejection processes. Methods. We used
the Bern SPH shock physics code to numerically model hypervelocity
impacts into small, 160 m in diameter rubble-pile asteroids, with a
variety of boulder distributions. Results. We find that the post-impact
target morphology is most sensitive to the mass-fraction of boulders
in the target, while the asteroid deflection efficiency depends on
both the mass-fraction of boulders in the target and on the boulder
size-distribution close to the impact point. Our results may also have
important implications for the structure of small asteroids.
Title: Inflationary magnetogenesis of primordial magnetic fields
with multiple vector fields
Authors: Li, Yu; Zhang, Le-Yao
Bibcode: 2022arXiv220903545L
Altcode:
In this paper, we discussed the multiple vector fields during the
inflation era and the inflationary magnetogenesis with multiple vector
fields. Instead of a single coupling function in single vector field
models, the coupling matrix between vector fields and scalar field
which drive the inflation is introduced. The dynamical equations for
multiple vector fields are obtained and applied to the inflation era. We
discussed three cases for the double-field model. In no mutual-coupling
case, one can find that both electric and magnetic spectrum can be
scale-invariant at the end of inflation, meanwhile, the strong coupling
problem can be avoided. The effect of mutual-coupling between different
vector fields is also discussed. We found that weak mutual-coupling
can lead to the slightly blue spectrum of the magnetic field. On the
other hand, in the strong mutual-coupling case, the scale-invariant
magnetic spectrum can also be obtained but the energy density of
electromagnetic fields either lead to the backreaction problem or is
diluted by inflation.
Title: Attitude tracking control for fractionated spacecraft with
actuator failures under adaptive event-triggered strategy
Authors: Di, Fuqiang; Li, Aijun; Guo, Yong; Wang, Changqing; Wang,
Lihao
Bibcode: 2022AdSpR..70.1209D
Altcode:
In this paper, two event-triggered algorithms are investigated to
reduce the consumption and occupation of system resources for attitude
tracking control of spacecraft system under external disturbances,
model uncertainties, actuator failures, and limited communication. The
first robust controller is designed with the triggering condition
based on a time-based exponential function that has a dynamically
decreasing trigger threshold. To improve the first controller, the
second controller with the adaptive triggering condition based on
a time-based exponential function is established to facilitate the
realization of a comprehensive combination of feedback compensation
mechanism and event-triggered control theory. It follows from the
theoretical analysis that asymptotic convergence and Zeno-free are
achieved under the proposed controller. Simulation results are provided
to verify the effectiveness of the developed adaptive event-triggered
fault-tolerant control laws.
Title: Pulsars as candidates of LHAASO sources J2226+6057, J1908+0621
and J1825-1326
Authors: Chang, Zhe; Zhang, Xukun; Zhou, Jing-Zhi
Bibcode: 2022arXiv220902917C
Altcode:
The LHAASO Collaboration has observed ultrahigh-energy photons up to
$1.4$PeV from $12$ $\gamma$-ray Galactic sources. In particular, the
$\gamma$-ray spectra of the sources J2226+6057, J1908+0621, J1825-1326
have been published. We investigate the possibility of suggested origin
pulsars near the sources as the PeVatrons. The pulsar is described by a
rotating magnetic dipole. Assuming protons are uniform distributed out
of the light cylinders, we obtain the Lorentz distribution of proton
energy spectrum. It is found that the protons around pulsar could be
accelerated to PeV at short times. The hadronic $\gamma$-ray spectra
of the suggested origin pulsars are in good agreement with the LHAASO
observed $\gamma$-ray spectra of the sources J2226+6057, J1908+0621,
J1825-1326.
Title: Measuring Neutron Star Proper Motions with Chandra
Authors: Holland-Ashford, Tyler
Bibcode: 2022cxo..prop.6328H
Altcode:
We propose Chandra ACIS observations of 4 Galactic supernova remnants
(SNRs) - G11.2-0.3, G18.9-1.1, MSH 11-62, and RCW 103 - to measure the
proper motions of their neutron stars (NSs). The origin of NS kick
velocities is debated, and constraints on the relationship between
NS kicks and SNR ejecta can help inform SN explosion models. All of
these SNRs have been observed years ago by Chandra; the proposed Cycle
24 observations would create ~22-year (14 for G18.9-1.1) baselines
and enable the measurement of these NSs' transverse velocities with
<100-150 km/s 1-sigma uncertainties. Only Chandra has the spatial
resolution and past observations necessary for this work. Any subset
of the 4 targets would also provide valuable science.
Title: Spacetime and Spectra: Joint Chandra/EHT Observations of Sgr A*
and M87
Authors: Neilsen, Joey
Bibcode: 2022cxo..prop.6363N
Altcode:
In April 2019, the Event Horizon Telescope released the first image
of a black hole's silhouette. This M87* discovery image offered a
glimpse of one of only two sources, M87* and Sgr A*, for which the
EHT can achieve imaging quality sufficient to resolve their black
hole shadows and provide a close-up view of accretion and jets at the
horizon. Coordinated Chandra/EHT data placed crucial constraints on
M87*'s energy budget, jet power, and spin. Sgr A* and M87 are both X-ray
variable and new Chandra/EHT observations offer a chance to observe
structures near the event horizon while tracking their high-energy
variability. We propose Chandra/EHT obs of Sgr A* (4x25 ks) and M87
(2x5 ks) to enable searches for flares, hotspots, the bases of jets,
and to aide priors for EHT image reconstruction.
Title: Fluctuating Dark Energy and the Luminosity Distance
Authors: Vedder, C. J. G.; Belgacem, E.; Chisari, N. E.; Prokopec, T.
Bibcode: 2022arXiv220900440V
Altcode:
The origin of dark energy driving the accelerated expansion of
the universe is still mysterious. We explore the possibility that
dark energy fluctuates, resulting in spatial correlations. Due to
these fluctuations, the Hubble rate itself becomes a fluctuating
quantity. We discuss the effect this has on measurements of type Ia
supernovae, which are used to constrain the luminosity distance. We
show that the luminosity distance is affected by spatial correlations
in several ways. First, the luminosity distance becomes dressed by the
fluctuations, thereby differing from standard $\Lambda$CDM. Second,
angular correlations become visible in the two-point correlation
function of the luminosity distance. To investigate the latter
we construct the angular power spectrum of luminosity distance
fluctuations. We then perform a forecast for two supernova surveys,
the ongoing Dark Energy Survey (DES) and the upcoming Legacy Survey
of Space and Time (LSST), and compare this effect with relativistic
lensing effects from perturbed $\Lambda$CDM. We find that the signal
can rise above the lensing effects and that LSST could test this
effect for a large part of the parameter space. As an example, a
specific realisation of such a scenario is that quantum fluctuations
of some field in the early universe imprint spatial correlations with
a predictable form in the dark energy density today. In this case,
the Hubble rate fluctuates due to the intrinsic quantum nature of the
dark energy density field. We study whether the signal of this specific
model would be measurable, and conclude that testing this model with
LSST would be challenging. However, taking into account a speed of sound
$c_s<1$ of the dark energy fluid can make this model observable.
Title: Neutrino transport in general relativistic neutron star
merger simulations
Authors: Foucart, Francois
Bibcode: 2022arXiv220902538F
Altcode:
Numerical simulations of neutron star-neutron star and neutron
star-black hole binaries play an important role in our ability to
model gravitational wave and electromagnetic signals powered by these
systems. These simulations have to take into account a wide range of
physical processes including general relativity, magnetohydrodynamics,
and neutrino radiation transport. The latter is particularly important
in order to understand the properties of the matter ejected by many
mergers, the optical/infrared signals powered by nuclear reactions
in the ejecta, and the contribution of that ejecta to astrophysical
nucleosynthesis. However, accurate evolutions of the neutrino transport
equations that include all relevant physical processes remain beyond
our current reach. In this review, I will discuss the current state of
neutrino modeling in general relativistic simulations of neutron star
mergers and of their post-merger remnants, focusing in particular on
the three main types of algorithms used in simulations so far: leakage,
moments, and Monte-Carlo scheme. I will discuss the advantages and
limitations of each scheme, as well as the various neutrino-matter
interactions that should be included in simulations. We will see that
the quality of the treatment of neutrinos in merger simulations has
greatly increased over the last decade, but also that many potentially
important interactions remain difficult to take into account in
simulations (pair annihilation, oscillations, inelastic scattering).
Title: X-ray Properties of two new z>6 Jetted Quasars
Authors: Ighina, Luca
Bibcode: 2022cxo..prop.6350I
Altcode:
We propose the observation of two new radio-bright z>6 jetted
QSOs. The primary aim of the observation is to characterise their X-ray
emission for the first time. Thanks to their very high redshift, these
sources are the ideal candidates to study the evolution of jetted
QSOs by providing constraints on the role played by relativistic
jets in the still poorly explored primordial Universe. The angular
resolution of Chandra and the requested time of 60 and 90ksec for the
two targets will allow us to: (1) firmly determine the X-ray flux and
spectral features of the core; (2) detect the possible presence of an
extended X-ray emission produced by their jets. These points will be
instrumental to test the IC/CMB mechanism for X-ray jets in QSOs at
the end of the re-ionisation epoch.
Title: An intermediate polar candidate toward the Galactic plane
Authors: Mondal, Samaresh; Ponti, Gabriele; Haberl, Frank;
Anastasopoulou, Konstantina; Campana, Sergio; Mori, Kaya; Hailey,
Charles J.; Rea, Nanda
Bibcode: 2022arXiv220900970M
Altcode:
For the past decade, it has been suggested that intermediate polars
(IPs), a subclass of magnetic cataclysmic variables (CVs), are
one of the main contributors to the hard diffuse X-ray emission
from the Galactic center (GC) and Galactic ridge. In our ongoing
\emph{XMM-Newton} survey of the central region of the Galactic disk
($20^\circ\times2^\circ$), we detected a persistent IP candidate,
$1.7^\circ$ away from the GC. In this work, we better characterize
the behavior of this source by looking at the new and archival
XMM-Newton data. We performed a detailed X-ray spectral modeling of
the source. Furthermore, we searched for X-ray pulsations in the light
curve as well as its counterpart at other wavelengths. The XMM-Newton
spectrum (0.8--10 keV) of the source is described by a partial
covering collisionally ionized diffuse gas with plasma temperature
$kT=15.7^{+20.9}_{-3.6}$ keV. In addition, the spectrum shows the
presence of iron lines at $E=6.44$, 6.65, and 6.92 keV with equivalent
widths of $194^{+89}_{-70}$, $115^{+79}_{-75}$, and $98^{+93}_{-74}$ eV,
respectively. The X-ray light curve shows a coherent modulation with a
period of $P=432.44\pm0.36$ s, which we infer is the spin period of the
white dwarf. The white dwarf mass estimated from fitting a physical
model to the spectrum results in $M_{\rm WD}=1.05^{+0.16}_{-0.21}\
M_{\odot}$. We were able to find a likely optical counterpart in the
Gaia catalog with a G magnitude of 19.26, and the distance to the
source derived from the measured Gaia parallax is $\sim$4.3 kpc. We
provide an improved source localization with subarcsec accuracy. The
spectral modeling of the source indicates the presence of intervening
circumstellar gas, which absorbs the soft X-ray photons. The measured
equivalent width of the iron lines and the detection of the spin period
in the light curve are consistent with those from IPs.
Title: Global HI Properties of Galaxies via Super-profile Analysis
Authors: Kim, Minsu; Oh, Se-Heon
Bibcode: 2022arXiv220900390K
Altcode:
We present a new method which constructs an HI super-profile of
a galaxy which is based on profile decomposition analysis. The
decomposed velocity profiles of an HI data cube with an optimal number
of Gaussian components are co-added after being aligned in velocity
with respect to their centroid velocities. This is compared to the
previous approach where no prior profile decomposition is made for
the velocity profiles being stacked. The S/N improved super-profile
is useful for deriving the galaxy's global HI properties like velocity
dispersion and mass from observations which do not provide sufficient
surface brightness sensitivity for the galaxy. As a practical test,
we apply our new method to 64 high-resolution HI data cubes of nearby
galaxies in the local Universe which are taken from THINGS and LITTLE
THINGS. In addition, we also construct two additional HI super-profiles
of the sample galaxies using symmetric and all velocity profiles of
the cubes whose centroid velocities are determined from Hermite $h_3$
polynomial fitting, respectively. We find that the HI super-profiles
constructed using the new method have narrower cores and broader
wings in shape than the other two super-profiles. This is mainly
due to the effect of either asymmetric velocity profiles' central
velocity bias or the removal of asymmetric velocity profiles in the
previous methods on the resulting HI super-profiles. We discuss how
the shapes ($\sigma_{\rm{n}}/\sigma_{\rm{b}}$, $A_{\rm{n}}/A_{\rm{b}}$,
and $A_{\rm{n}}/A_{\rm{tot}}$) of the new HI super-profiles which are
measured from a double Gaussian fit are correlated with star formation
rates of the sample galaxies and are compared with those of the other
two super-profiles.
Title: A transitional millisecond pulsar candidate in Terzan 6
Authors: Homan, Jeroen
Bibcode: 2022cxo..prop.6288H
Altcode:
Chandra observations of Terzan 6 in 2021 have confirmed a second
bursting, eclipsing neutron-star LMXB in the cluster. Based on its
X-ray luminosity and spectrum, variable optical counterpart, likely
association with a nearby (~0.2 arcsec) variable radio source, and a
tentative detection of 2.2 ms pulsations in RXTE data, the source is
a strong candidate transitional millisecond pulsar (tMSP). Only three
such systems are known--adding a fourth would be of tremendous value,
as the phenomenology of tMSPs is still in its infancy. We request three
strictly simultaneous Chandra (20 ks) and VLA (4 hr) observations
of the source, to study the behavior of its X-ray/radio-luminosity
correlation in comparison to other accretion-powered MSPs, and to put
its classification as tMSP on firmer footing.
Title: Magnetic-induced Spontaneous Scalarization in Dynamcial
Chern-Simons Gravity
Authors: Zhang, Shao-Jun; Wang, Bin; Papantonopoulos, Eleftherios;
Wang, Anzhong
Bibcode: 2022arXiv220902268Z
Altcode:
In the framework of the dynamical Chern-Simons gravity, we study
the scalar field perturbations of the Reissner-Nordström-Melvin
spacetime, which describes a charged black hole permeated by a
uniform magnetic field. In the presence of the magnetic field, the
scalar field acquires an effective mass whose square takes negative
value in the half domain of the angular direction. This inevitably
introduces the tachyonic instability and associated spontaneous
scalarization as long as the coupling constant between the scalar
field and the Chern-Simons invariant exceeds a threshold value. We
study the object pictures of the time evolutions of the scalar field
perturbations at the linear level, and find that the presence of the
magnetic field will dramatically change the waveforms and associated
ringdown modes. Nonlinear evolutions for the unstable perturbations are
also performed in the decoupling limit, which demonstrate the scalar
cloud as the final fate. Influences of the coupling constant and the
black hole charge on the wave dynamics are also studied.
Title: Chandra and XMM-Newton Observations of the Most Extreme z >
1.25 ACTPol Survey Clusters
Authors: Flores, Anthony
Bibcode: 2022cxo..prop.6397F
Altcode:
Sunyaev-Zel'dovich (SZ) surveys are currently the most powerful and
consistent method of detecting high mass, high redshift galaxy clusters,
whose dynamic, thermodynamic, and chemical properties serve as unique
probes of the composition and growth of structure in our Universe. The
Atacama Cosmology Telescope (ACT) has surveyed >13000 sq. deg of
sky, and the resulting ACTPol survey has detected thousands of clusters
(hundreds at z>1) based on their SZ signal. This proposal targets the
most massive high-z ACTPol clusters without X-ray follow-up, allowing
us to obtain detailed measurements of cluster masses, morphologies,
and thermodynamic properties, while nearly doubling the number of X-ray
observed clusters in this redshift range for which these measurement
are possible.
Title: Highlights from the Telescope Array Experiments
Authors: Sagawa, Hiroyuki
Bibcode: 2022arXiv220903591S
Altcode:
The Telescope Array (TA) is the largest hybrid cosmic ray detector
in the Northern Hemisphere, which observes primary particles in the
energy range from 2 PeV to 100 EeV. The main TA detector consists of
507 plastic scintillation counters on a 1.2-km spacing square grid
and fluorescence detectors at three stations overlooking the sky
above the surface detector array. The TA Low energy Extension (TALE)
hybrid detectors, which consists of ten fluorescence telescopes, and 80
infill surface detectors with 400-m and 600-m spacing, has continued
to provide stable observations since its construction completion in
2018. The TAx4, a plan to quadruple the detection area of TA is also
ongoing. About half of the planned detectors have been deployed, and
the current TAx4 continues to operate stably as a hybrid detector. I
review the present status of the TA experiment and the recent results
on the cosmic-ray anisotropy, mass composition and energy spectrum.
Title: Quantum current dissipation in superconducting strings
and vortons
Authors: Abe, Yoshihiko; Hamada, Yu; Saji, Kota; Yoshioka, Koichi
Bibcode: 2022arXiv220903223A
Altcode:
In this work, the current stability is discussed for cosmic strings with
the bosonic superconductivity. A non-vanishing curvature of string
generally induce the quantum instability of the current-carrying
particle. Its decay rates are explored for various types of model
parameters, curved string shapes, and decay processes. As a cosmological
application, the stability is examined for superconducting strings
in the string network and also for cosmic vortons by evaluating
their cosmological evolution. The zero mode and hence the vorton
cannot be stable in various cases, e.g., with a hierarchy between the
current-carrying particle mass off the string and the string tension
or with sizable couplings of the current-carrying particle to light
species such as the Standard Model particles.
Title: Recovering the conformal limit of color superconducting quark
matter within a confining density functional approach
Authors: Ivanytskyi, Oleksii; Blaschke, David
Bibcode: 2022arXiv220902050I
Altcode:
We generalize a recently proposed confining relativistic
density-functional approach to the case of density dependent vector
and diquark couplings. The particular behavior of these couplings is
motivated by the non-perturbative gluon exchange in dense quark matter
and provides the conformal limit at asymptotically high densities. We
demonstrate that this feature of the quark matter EoS is consistent
with a significant stiffness in the density range typical for the
interiors of neutron stars. In order to model these astrophysical
objects we construct a family of hybrid quark-hadron EoSs of cold
stellar matter. We also confront our approach with the observational
constraints on the mass-radius relation of neutron stars and their
tidal deformabilities and argue in favor of a quark matter onset at
masses below ${1.0 ~\rm M}_\odot$.
Title: A spherically symmetric gravitational solution of nearly
conformally flat metric measure space
Authors: Oghbaiee, Samaneh; Rahmanpour, Nafiseh; Shojaie, Hossein
Bibcode: 2022arXiv220900719O
Altcode:
In this manuscript, we study the nearly flat approximation of a
conformally invariant gravitational theory in metric measure space
(MMS). In addition, we investigate the vacuum solution of MMS and
obtain its weak field limit in the spherically symmetric coordinates. We
show that while it is already a vacuum solution, it can simulate dark
matter when restricted to the framework of general relativity, i.e.,
a symmetry broken conformal frame. This is done by means of a density
function which is an essential part of MMS. We derive an equation for
the density function for a general profile of a rotation curve obtained
from observations. Specifically, the density function corresponding
to two well-known profiles PSS and NFW are provided.
Title: X-rays in the Prime of Life: Measuring the High Energy Dose
to Exo-Earths
Authors: Wolk, Scott
Bibcode: 2022cxo..prop.6276W
Altcode:
We propose HRC observations of 5 nearby star-planet systems: TRAPPIST-1,
GJ 1061, TOI-700. Wolf 359 and GJ 887 to measure the soft X-ray/EUV
fluence on the surrounding planets. Together, the stars host over
a dozen earth-mass planets, with 10 planets located in the presumed
habitable zones (HZs). The targets are all M-stars. While a star's
bolometric luminosity is important, the high energy EUV/X-ray stellar
irradiation is a major driver of photochemistry, upper atmospheric
heating, and atmospheric mass loss in exoplanets. We will observe
using HRC-S using both the thin and thick filters. The thick filter
data measure the broad-band X-ray flux, while the ratio of the count
rates allow us to estimate the EUV fluence.
Title: X-ray AGN in post-merger galaxies
Authors: Li, Wenhao
Bibcode: 2022cxo..prop.6424L
Altcode:
Post mergers are disturbed, coalesced mergers with shells and tidal
tails, which are expected to host AGN. We have confirmed a high
X-ray AGN fraction of 62% in 79 high-mass (10.5<logM<12) post
mergers. This is three times higher than that in control non-merger
galaxies, confirming mergers trigger AGN with 5? significance. We
also find the high X-ray AGN fraction in post mergers is independent
of stellar mass above logM>10. Here we propose to extend our
analysis to 33 post mergers and 604 control galaxies in the Chandra
archive with 9<logM<10.5 to (1) determine the X-ray AGN fraction
to place statistical constraints on whether mergers trigger AGN at
9<logM<10.5, and (2) investigate the mass dependence of X-ray AGN
fraction to place constraints on supermassive black hole seed models.
Title: Second-order stochastic theory for self-interacting scalar
fields in de Sitter spacetime
Authors: Cable, Archie; Rajantie, Arttu
Bibcode: 2022arXiv220902545C
Altcode:
We introduce a second-order stochastic effective theory for light
scalar fields in de Sitter spacetime, extending the validity of
the stochastic approach beyond the massless limit and demonstrating
how it can be used to compute long-distance correlation functions
non-perturbatively. The parameters of the second-order stochastic
theory are determined from quantum field theory through a perturbative
calculation, which is valid if the self-interaction parameter $\lambda$
satisfies $\lambda\ll m^2/H^2$, where $m$ is the scalar and $H$ is
the Hubble rate. Therefore it allows stronger self-interactions than
conventional perturbation theory, which is limited to $\lambda\ll
m^4/H^4$ by infrared divergences. We demonstrate the applicability
of the second-order stochastic theory by comparing its results
with perturbative quantum field theory and overdamped stochastic
calculations, and discuss the prospects of improving its accuracy with
a full one-loop calculation of its parameters.
Title: Energy functionals from Conformal Gravity
Authors: Anastasiou, Giorgos; Araya, Ignacio J.; Olea, Rodrigo
Bibcode: 2022arXiv220902006A
Altcode:
We provide a new derivation of the Hawking mass and Willmore
energy functionals for asymptotically AdS spacetimes, by embedding
Einstein-AdS gravity in Conformal Gravity. By construction, the
evaluation of the four-dimensional Conformal Gravity action in a
manifold with a conical defect produces a codimension-2 conformal
invariant functional $L_{\Sigma}$. The energy functionals are then
particular cases of $L_{\Sigma}$ for Einstein-AdS and pure AdS ambient
spaces, respectively. The bulk action is finite for AdS asymptotics
and both Hawking mass and Willmore energy are finite as well. The
result suggests a generic relation between conformal invariance and
renormalization, where the codimension-2 properties are inherited from
the bulk gravity action.
Title: Rapid Galaxy Evolution in the Compact Group IC 2431
Authors: Soria, Roberto
Bibcode: 2022cxo..prop.6394S
Altcode:
IC 2431 is a compact galaxy group displaying a thermally-dominated X-ray
emission far in excess of expectations based on its star formation
rate. We request a 100-ks ACIS-S3 imaging observation of this iconic
merger system in order to: (a) resolve the luminous point source
population, including potential AGN components; (b) map the diffuse
hot gas, distinguishing between the thermal emission from star-forming
structures, potential intergalactic shocks, outflows and intragroup
hot medium. Combining X-ray, optical/IR and radio maps will enable
us to model the collisions and the evolution of this system towards
a fossil group stage.
Title: ZAMS X-rays and Primordial Planetary Atmospheres
Authors: Getman, Konstantin
Bibcode: 2022cxo..prop.6280G
Altcode:
X-ray emission from young stars has a significant impact on
the loss of early planetary atmospheres and conditions promoting
habitability. Tracking the temporal decline of X-ray radiation during
the first ~100 Myr needs to consider both quasi-continuous and powerful
flare emission with dependencies on stellar age and mass. We propose
a Chandra Large Project GO/GTO study, complemented by Gaia DR3 data,
for four [40-70] Myr old open clusters to obtain X-ray properties
of 1500-2000 stars. Together with existing studies of [0.5-25] Myr
old star clusters, we will derive mass-stratified X-ray luminosity
distributions, including both X-ray detections and nondetections,
to allow improved calculations of planetary atmospheric survival,
chemistry and habitability.
Title: A jet-driven bow-shock near the black hole binary GRS 1915+105
Authors: Motta, Sara Elisa
Bibcode: 2022cxo..prop.6292M
Altcode:
We propose a 90 ksec ACIS-I observation of a candidate jet-driven
bow-shock associated with black hole binary GRS 1915+105, observed
in radio 17 arcmin away from the system's position, and aligned with
the resolved radio jets observed previously. If detected, this would
be the second confirmed X-ray bow shock associated with a Galactic
X-ray binary. Such a detection will allow us to estimate the kinetic
power transferred by the jet to the ambient medium, and ultimately to
improve our understanding of the overall matter and energy input/output
balance around accreting black holes.
Title: A Complex Window-Based Joint Chirp Rate Time Frequency
Transform for BBH Merger Gravitational Wave Signal Detection
Authors: Li, Xiyuan; Houde, Martin; Valluri, S. R.
Bibcode: 2022arXiv220902673L
Altcode:
With the development of Machine Learning algorithms, many attempts have
been made to use Artificial Neural Networks (ANN) for complicated
tasks related to data classification, pattern recognition, and
predictive modeling. Among such applications include Binary Black
Hole (BBH) and Binary Neutron Star (BNS) merger Gravitational Wave
(GW) signal detection and merger forecasting. Despite the surge
of interest in all types of ANN, image neural networks that take
time-frequency spectrograms as input remain one of the most prominent
methods due to their relevance to some highly efficient and robust
ANN architectures. BBH and BNS merger GW signals are chirp signals
whose frequencies vary continuously in time. Earlier studies used
traditional Fourier transform-based time-frequency decomposition
methods for spectrogram generation, which in some cases have had
difficulties identifying rapid frequency changes in merger signals. In
this paper, we introduce a signal decomposition method called the
Joint-Chirp-rate-Time-Frequency Transform (JCTFT), where complex-valued
window functions are used to modulate the amplitude, frequency, and
phase of the input signal. In addition, we outline general techniques
for generating chirp rate enhanced time-frequency spectrograms from
the results of a JCTFT and compare the signal localization performance
to the short-time-Fourier-transform.
Title: Deep forest: neural network reconstruction of intergalactic
medium temperature
Authors: Wang, Runxuan; Croft, Rupert A. C.; Shaw, Patrick
Bibcode: 2022MNRAS.515.1568W
Altcode: 2022MNRAS.tmp.1729W; 2021arXiv211205721W
We explore the use of deep learning to infer the temperature of the
intergalactic medium from the transmitted flux in the high-redshift Ly
α forest. We train neural networks on sets of simulated spectra from
redshift z = 2-3 outputs of cosmological hydrodynamic simulations,
including high-temperature regions added in post-processing to
approximate bubbles heated by He II reionization. We evaluate how
well the trained networks are able to reconstruct the temperature from
the effect of Doppler broadening in the simulated input Ly α forest
absorption spectra. We find that for spectra with high resolution
(10 $\, {\rm km}\, {\rm s}^{-1}$ pixel) and moderate signal-to-noise
ratio (20-50), the neural network is able to reconstruct the
intergalactic medium temperature smoothed on scales of $\sim 6 \,
h^{-1}\, {\rm Mpc}$ quite well. Concentrating on discontinuities,
we find that high-temperature regions of width $25 \, h^{-1}\, {\rm
Mpc}$ and temperature $20\, 000$ K can be fairly easily detected
and characterized. We show an example where multiple sightlines are
combined to yield tomographic images of hot bubbles. Deep learning
techniques may be useful in this way to help us understand the complex
temperature structure of the intergalactic medium around the time of
helium reionization.
Title: Mineralogy and regolith maturity at the Chang'E-5 landing
site inferred from the Lunar Mineralogical Spectrometer
Authors: Wu, Xing; Liu, Yang; Yang, Yazhou; Guo, Dijun; Du, Jun; Li,
Shuai; Lin, Honglei; Fu, Xiaohui; Xiao, Zhiyong; Xu, Yuchen; Xu, Rui;
He, Zhiping; Zhang, Feng; Lin, Yangting; Zou, Yongliao
Bibcode: 2022E&PSL.59417747W
Altcode:
Chang'E-5 (CE-5) landed in the northeast of the Oceanus Procellarum and
successfully returned ∼1.73 kg lunar samples from a distinctively
young mare basalt unit. The reflectance spectra between 0.45 μm
to 3.20 μm at the landing site were acquired by the onboard Lunar
Mineralogical Spectrometer before and after the sampling. The results
from the spectral parameter analysis show the regolith is dominated
by clinopyroxene, consistent with both orbital observations and
laboratory analyses of the returned CE-5 samples. Optical maturity
(OMAT) of regolith in the landing region of CE-5, Chang'E-4 (CE-4),
and Chang'E-3 (CE-3) was analyzed, and the results show that the
regoliths at CE-5 and CE-3 sites sitting on the ejecta blanket
of the relatively young impact craters are both less mature than
that at the CE-4 landing site. The OMAT and estimated content of
submicroscopic metallic iron (SMFe) in the regolith show no obvious
variations between the rock-shielded and unshielded regolith during
the CE-5 descent, indicating the disturbance from rocket exhaust did
not affect regolith maturity. Similar results on the effects of rocket
exhaust were obtained from analyzing the regolith maturity along the
CE-4 rover's traverse. Additionally, the surficial regolith and the
scooped underlying layer in the centimeter-depth at CE-5 landing area
exhibit similar maturities, suggestive of rapid gardening despite the
geologically young age of the region. The results presented in this
work shed light on the regolith evolution on the Moon and provide
vital geological context for the analysis of the returned CE-5 samples.
Title: Swarm seismicity illuminates stress transfer prior to the
2021 Fagradalsfjall eruption in Iceland
Authors: Fischer, T.; Hrubcová, P.; Salama, A.; Doubravová, J.;
Ágústsdóttir, T.; Gudnason, E. Á.; Horálek, J.; Hersir, G. P.
Bibcode: 2022E&PSL.59417685F
Altcode:
The 2021 Fagradalsfjall volcanic eruption in the Reykjanes Peninsula,
Iceland, was followed by effusive lava outflow lasting six months. It
was preceded by an intensive earthquake swarm lasting one month with
the largest earthquake exceeding ML 5. We analyze seismic
data recorded by the Reykjanet local seismic network to trace the
processes leading to the eruption to understand the relation between
seismic activity and magma accumulation. Precise relocations
show two hypocenter clusters of the 2021 swarm in the depth range of
1-6 km; a NE-SW trending cluster that maps the dyke propagation, and
a WSW-ENE trending cluster that follows the axis of the oblique plate
boundary. Additionally, we relocated the preceding earthquake swarms
of 2017, 2019 and 2020 and found that they form two branches along
the oblique plate boundary, which coincide with the WSW-ENE trending
cluster of the 2021 swarm. These branches form a stepover of ∼1 km
offset, forming a pull-apart basin structure at the intersection with
the dyke. This is the place where the eruption occurred, suggesting
that magma erupted at the place of crustal weakening. The strong
seismic activity started with a ML 5.3 earthquake of 24
February 2021, which triggered the aftershocks on the oblique plate
boundary and in the area of magmatic dyke, both in an area of elevated
Coulomb stress. The seismicity shows a complex propagation of the
dyke, which started at its northern end, migrated southwestward and
then jumped back to the central part where the effusive eruption took
place. The observed N-S striking focal mechanisms are interpreted as
right-lateral antithetic Riedel shears that accommodate the left lateral
slip along the oblique plate boundary. The co-existence of seismic and
magmatic activity suggests that the past seismic activity weakened
the crust in the eruption site area, where magma accumulated. The
following ML 5.3 earthquake of 24 February 2021 triggered
the seismic swarm and likely perturbed the magma pocket which led to
the six-months lasting eruption that started on 19 March.
Title: Sequences of seismic and aseismic slip on bimaterial faults
show dominant rupture asymmetry and potential for elevated seismic
hazard
Authors: Abdelmeguid, Mohamed; Elbanna, Ahmed
Bibcode: 2022E&PSL.59317648A
Altcode:
We perform numerical simulations of sequences of earthquake and aseismic
slip on planar rate and state faults separating dissimilar material
within the 2-D plane strain approximation. We resolve all stages of the
earthquake cycle from aseismic slip to fast ruptures while incorporating
full inertia effects during seismic event propagation. We show that
bimaterial coupling results in favorable nucleation site and subsequent
asymmetric rupture propagation. We demonstrate that increasing the
material contrast enhances this asymmetry leading to higher slip
rates and normal stress drops in the preferred rupture propagation
direction. The normal stress drop, induced by the bimaterial effect,
leads to strong dynamic weakening of the fault and may destabilize the
creeping region on a heterogeneous rate and state fault, resulting in
extended rupture propagation. Such rupture penetration into creeping
patches may lead to more frequent opening of earthquake gates, causing
increased seismic hazard. Furthermore, bimaterial coupling may lead to
irregular seismicity pattern in terms of event length, peak slip rates,
and hypocenter location, depending on the properties of the creeping
patches bordering the seismogenically active part of the fault. Our
results highlight robust characteristics of bimaterial interfaces that
persist over long sequence of events and suggest the need for further
exploration of the role of material contrast in earthquake physics
and models of seismic hazard.
Title: The factors controlling equilibrium inter-mineral Ca isotope
fractionation: Insights from first-principles calculations
Authors: Xiao, Zi-Cong; Zhou, Chen; Kang, Jin-Ting; Wu, Zhong-Qing;
Huang, Fang
Bibcode: 2022GeCoA.333..373X
Altcode:
Equilibrium isotope fractionation factors are crucial to quantitatively
interpreting Ca isotope data of natural samples. Recent studies have
revealed significant equilibrium Ca isotope fractionation between
minerals, but the controlling factors remain poorly understood. Using
density functional theory, this study calculates the reduced partition
function ratios (RPFRs) among amphiboles (richterite and tremolite),
sorosilicates (akermanite and gehlenite), K-bearing carbonates
(butschliite), Na-bearing diopside (jadeite), and other Ca-bearing
minerals (fluorapatite, anhydrite, CaTiO3 perovskite,
and fluorite) at 0 GPa. The RPFRs of diopside and anorthite over
a pressure range from 0 to 5 GPa are calculated to investigate the
pressure effect. The effect of force constant, bond length, coordination
number, anion type, solid solution composition, and pressure on RPFRs
are discussed by compiling the literature data. The RPFRs show good
correlations with the force constant and bond length but have no
clear correlation with the coordination number. This suggests that
the bond length is more reliable than the coordination number for
roughly predicting the signs and magnitudes of inter-mineral isotope
fractionation. Na-bearing clinopyroxene (e.g., jadeite) has similar
RPFR with Na-free clinopyroxene, suggesting that the jadeite effect
should be insignificant in natural samples. The RPFR of anorthite
is lower than that of diopside at low pressure, and the two minerals
both show a positive correlation between RPFR and pressure. Notably,
the heavy Ca isotope enrichment between these two minerals can be
reversed at high pressure (>3 GPa at 1000 K) because anorthite's
RPFR changes more sharply with increasing pressure than that of
diopside. However, such a reverse may not occur in Earth's modern
crust due to the stability of anorthite at lower pressures. Combining
the theoretical predictions of amphibole and plagioclase and natural
sample observation on granitoids, we infer that the RPFR of granitic
magma may be lower than that of basaltic magma.
Title: Heavy δ26Mg values in carbonate indicate a
magmatic-hydrothermal origin of Carlin-type Au deposit
Authors: Xie, Zhuojun; Huang, Kang-Jun; Xia, Yong; Cline, Jean; Tan,
Qinping; Liu, Jianzhong; Xiao, Jingdan; Yan, Bing
Bibcode: 2022GeCoA.333..166X
Altcode:
The Carlin-type Au deposits in Youjiang Basin, SW China, (referred to
as Guizhou Carlin-type Au deposits) are the second largest Carlin-type
Au province in the world after Nevada, USA. To date, the source of ore
fluids that formed the Guizhou deposits remains controversial, hampering
the formulation of a genetic model. Compared to Nevada Carlin-type Au
deposits, a significant difference is that the Guizhou Carlin-type
Au deposits contain abundant ore-stage dolomite in the ore. Herein,
we present carbonate Mg isotopes combined with C-O isotopes from the
giant Shuiyindong deposit to provide new insights into the source of
ore fluids and to constrain the ore genesis of the Guizhou Carlin-type
Au deposits. Petrographic observation shows that from least
altered bioclastic limestone to high-grade ore, dolomite increased
significantly, suggesting that dolomite formed as part of the Au
mineralization process. Chemical analyses reflect a small amount of Mg
in the ore fluids was variably added to ore during Au mineralization,
and this added Mg was fixed in the dolomite. Although most ore-stage
dolomite formed from the sulfidation of Fe in Fe-dolomite, some
ore-stage dolomite formed by the combination of host rock calcite with
Mg from ore fluids. The δ26Mg values of carbonate,
primarily dolomite, range from -3.49‰ to -0.07‰, with a median
value of -1.01‰. The δ18O values range from 21.7‰ to
27.6‰, with a median value of 23.2‰. The δ13C values
vary from -14.6‰ to 1.2‰, with a median value of -0.7‰. The
δ26Mg values exhibit a positive correlation trend with MgO,
S, SiO2, and Carlin-suite elements (Au, As, Hg, Sb, Tl,
and Cu), and a negative correlation trend with CaO. Comparison of Mg
isotopes data from this study with the major Mg reservoirs indicates
that the Shuiyindong samples contain heavier Mg isotopes that drifts
towards the heavy Mg reservoirs (magmatic and metamorphic rocks)
compared with normal carbonate rocks. Two mechanisms, namely heavy Mg
addition from ore fluids and isotopic exchange reaction with heavy
Mg-rich ore fluids, could have attributed to heavy Mg in carbonates
in the Shuiyindong deposit. The Mg isotopes results, combined
with other isotopes (e.g., S, Hg, and He-Ar) and geologic evidence,
support a magmatic-hydrothermal origin for the ore fluids. The
thick Devonian-Triassic sedimentary sequence and weak extension
following sedimentation prevented igneous activity from reaching the
surface. However, buoyant ore fluids released from the deep-seated
intrusions are interpreted to have ascended along basement-penetrating
faults and eventually produced the Guizhou Carlin-type Au deposits at
shallow levels. This study implies that Mg isotopes are a novel proxy
to infer ore fluids source and evolution, and that they can provide
significant constraints on the genesis of hydrothermal deposit.
Title: Two-Spacecraft Detection of Short-period Decayless Kink
Oscillations of Solar Coronal Loops
Authors: Zhong, Sihui; Nakariakov, Valery M.; Kolotkov, Dmitrii Y.;
Verbeeck, Cis; Berghmans, David
Bibcode: 2022arXiv220901917Z
Altcode:
Decayless kink oscillations of an ensemble of loops are captured
simultaneously by the High Resolution Imager (HRI) of the Extreme
Ultraviolet Imager (EUI) and the Atmospheric Imaging Assembly (AIA)
from 22:58 UT on 5 November to 00:27 UT on 6 November 2021. Oscillations
are analysed by processing image sequences taken by the two instruments
with a motion magnification technique. The analysed loops are around 51
Mm in length, and oscillate with short periods of 1-3 min (1.6 min in
average) and displacement amplitudes of 27-83 km. The signals recorded
by AIA are delayed by 66 s as compared to HRI, which coincides with
the light travel time difference from the Sun to each instrument. After
correction of this time difference, the cross-correlation coefficient
between the signals from the two data varies from 0.82 to 0.97,
indicating that they are well consistent. This work confirms that HRI
sees the same oscillations as AIA, which is the necessary first step
before proceeding to the detection of shorter time scales by EUI. In
addition, our results indicate the robustness of the de-jittering
procedure in the study of kink oscillations with HRI.
Title: Machine Learning Post-Minkowskian Integrals
Authors: Jinno, Ryusuke; Kälin, Gregor; Liu, Zhengwen; Rubira,
Henrique
Bibcode: 2022arXiv220901091J
Altcode:
We study a neural network framework for the numerical evaluation
of Feynman loop integrals that are fundamental building blocks for
perturbative computations of physical observables in gauge and gravity
theories. We show that such a machine learning approach improves
the convergence of the Monte Carlo algorithm for high-precision
evaluation of multi-dimensional integrals compared to traditional
algorithms. In particular, we use a neural network to improve the
importance sampling. For a set of representative integrals appearing
in the computation of the conservative dynamics for a compact binary
system in General Relativity, we perform a quantitative comparison
between the Monte Carlo integrators VEGAS and i-flow, an integrator
based on neural network sampling.
Title: An Unusual X-ray Flare Near the Center of a Galactic Globular
Cluster
Authors: Irwin, Jimmy
Bibcode: 2022cxo..prop.6337I
Altcode:
An abrupt factor of >40 X-ray flare was previously observed within
7 arcsec of the center of the Milky Way globular cluster NGC6540. The
quiescent and flare luminosities and symmetric rise/fall temporal
shape of the flare are inconsistent with known classes of X-ray
variable objects in globular clusters such as X-ray binaries or stellar
flares. The shape of the flare resembles a scaled-down version of Sgr A*
flares and could represent an accretion event onto an intermediate-mass
black hole in the cluster. The orbit of the cluster in the disk of
the Milky way might give it access to gas to accrete to power the
flare event. We propose a 65 ksec ACIS-S observation to detect its
non-flare emission to determine the correct optical counterpart within
the crowded inner regions of the cluster.
Title: Quantum precision limits of displacement noise free
interferometers
Authors: Gefen, Tuvia; Tarafder, Rajashik; Adhikari, Rana X.; Chen,
Yanbei
Bibcode: 2022arXiv220902998G
Altcode:
Current laser-interferometric gravitational wave detectors suffer from
a fundamental limit to their precision due to the displacement noise
of optical elements contributed by various sources. Several schemes
for Displacement-Noise Free Interferometers (DFI) have been proposed
to mitigate their effects. The idea behind these schemes is similar
to decoherence-free subspaces in quantum sensing i.e. certain modes
contain information about the gravitational waves but are insensitive
to the displacement noise. In this paper we derive quantum precision
limits for general DFI schemes, including optimal measurement basis
and optimal squeezing schemes. We introduce a triangular cavity DFI
scheme and apply our general bounds to it. Precision analysis of this
scheme with different noise models shows that the DFI property leads to
interesting sensitivity profiles and improved precision due to noise
mitigation and larger gain from squeezing. Further extensions of this
scheme are presented.
Title: Cooling process of white dwarf stars in Palatini $f(R)$ gravity
Authors: Kalita, Surajit; Sarmah, Lupamudra; Wojnar, Aneta
Bibcode: 2022arXiv220902095K
Altcode:
A simple cooling model of white dwarf stars is re-analyzed in Palatini
$f(R)$ gravity. Modified gravity affects the white dwarf structures and
consequently their ages. We find that the resulting super-Chandrasekhar
white dwarfs need more time to cool down than sub-Chandrasekhar ones,
or when compared to the Newtonian models.
Title: Scale-invariant enhancement of gravitational waves during
inflation
Authors: Ota, Atsuhisa; Sasaki, Misao; Wang, Yi
Bibcode: 2022arXiv220902272O
Altcode:
The inflationary 1-loop tensor power spectrum from an excited
spectator scalar field is calculated. Recent studies on primordial
black holes suggest that the inflationary curvature perturbation
may be huge on small scales. An enhanced curvature perturbation
may arise from a drastic enhancement of spectator scalar field
fluctuations. In this letter, using the in-in formalism, we calculate
1-loop quantum corrections to primordial gravitational waves by such
an excited spectator field with a sharp peak in momentum space. We
find scale-invariant loop corrections in this full quantum setup,
in contrast to the sharply peaked corrections in the previously
calculated scalar-induced tensor modes. Especially, on super Hubble
scales, the primordial gravitational waves are also amplified, which
can be understood as a Bogolyubov transformation of the vacuum due
to the excited scalar field. This mechanism allows us to probe the
scalar field properties on extremely short-distance scales with the
current and future cosmic microwave background and gravitational wave
experiments, opening a novel window for inflationary cosmology.
Title: Pre-subduction mantle noble gas elemental pattern reveals
larger missing xenon in the deep interior compared to the atmosphere
Authors: Péron, Sandrine; Mukhopadhyay, Sujoy
Bibcode: 2022E&PSL.59317655P
Altcode:
Understanding volatile evolution on Earth provides critical
information on the processes that shape the Earth, and hence the
solar system. The noble gas elemental and isotopic composition of
the Earth's mantle traces the sources of Earth's volatiles as well
as evolution processes, such as mantle degassing and regassing via
subduction. However, ubiquitous shallow-level atmospheric contamination
of mantle-derived samples has hampered determining the deep mantle
heavy noble gas (Kr, Xe) isotopic and elemental composition. Moreover,
the present-day elemental composition of the mantle reflects mixing
of initial volatiles with atmospheric noble gases recycled through
subduction that makes understanding the elemental signatures acquired
during accretion difficult. Using a recently-developed protocol,
we previously measured the krypton and xenon isotopic and elemental
compositions of the Galápagos and Iceland plume sources, which have
among the most primitive helium and neon isotopic signatures, sampling
one of the least degassed, most primordial mantle reservoirs. Based
on these measurements, here we introduce a new approach to correct
for recycling and hence determine the initial noble gas elemental
ratios of the deep mantle. Our study leaves room for a substantial
proportion of 36Ar in the mantle to be primordial in
origin. Most importantly, we show that the deep mantle, prior to the
injection of any atmospheric volatiles, was depleted in Xe relative
to Kr by about two orders of magnitude when compared to chondritic
compositions, and the Xe depletion was larger in the mantle than in
the modern-day atmosphere. Unlike the atmosphere that has protracted
history of Xe depletion through the Archean, the deep mantle xenon
depletion was acquired very early in Earth's history, most likely
during accretion. Hence, missing xenon in the Earth's interior and
in the atmosphere appears to be two distinct problems. Three possible
scenarios, potentially acting in sync, may have led to the mantle xenon
depletion: Xe partitioning into the core, magma ocean outgassing and
a xenon deficit in the Earth's parent bodies, such as comets.
Title: Determining the High-Energy Emission Mechanism in Extragalactic
Jets with HST
Authors: Meyer, Eileen T.
Bibcode: 2022cxo..prop.6448M
Altcode:
No abstract at ADS
Title: Multi-scalar Gauss-Bonnet gravity: scalarized black holes
beyond spontaneous scalarization
Authors: Staykov, Kalin V.; Doneva, Daniela D.
Bibcode: 2022arXiv220901038S
Altcode:
Recently, a new nonlinear mechanism for black hole scalarization,
different from the standard spontaneous scalarization, was demonstrated
to exist for scalar Gauss-Bonnet theories in which no tachyonic
instabilities can occur. Thus Schwarzschild black hole is linearly
stable but instead nonlinear instability can kick-in. In the present
paper we extend on this idea in the case of multi-scalar Gauss-Bonnet
gravity with exponential coupling functions of third and fourth leading
order in the scalar field. The main motivation comes from the fact that
these theories admit hairy compact objects with zero scalar charge,
thus zero scalar-dipole radiation, that automatically evades the binary
pulsar constraints on the theory parameters. We demonstrate numerically
the existence of scalarized black holes for both coupling functions and
for all possible maximally symmetric scalar field target spaces. The
thermodynamics and the stability of the obtained solution branches is
also discussed.
Title: Tolerance Analysis of Octave Bandwidth Millimeter-Wave Planar
Orthomode Transducer
Authors: Hubmayr, Johannes; Austermann, Jason E.; Beall, James A.;
Connors, Jake A.; Duff, Shannon M.; McMahon, Jeffrey J.
Bibcode: 2022arXiv220900603H
Altcode:
Planar Orthomode Transducers (OMTs) are commonly used for polarization
measurements at millimeter wavelengths. We present an optical coupling
study of an octave bandwidth planar OMT in circular waveguide based on
3D electromagnetic simulations. We quantify results through metrics such
as co- and cross- polar coupling, reflection, and waveguide leakage as
a function of the OMT construction geometry. We evaluate the tolerance
of these metrics to the waveguide backshort distance, probe impedance,
waveguide gap size, and waveguide-to-probe misalignment. Two probe
geometries are studied: the `classic' shape used in several previous
experiments, and a new `wineglass' geometry. The bandwidth ratio of
both optimized OMTs is 2.0:1, defined where co-polar coupling exceeds
80%. The average co-polar coupling, cross-polar coupling, reflection,
and waveguide leakage of the classic probe is approximately 93%,
$<$-50 dB, 5% and 2%, respectively and depends slightly on the
exact frequency range. The wineglass probe co-polar coupling is $\sim$
2% larger. Radial waveguide misalignment at the level of 4% of the
waveguide radius can result in up to a 10% reduction in co-polar
coupling and -20 dB cross-polar coupling in one polarization. These
results may be used to guide the detector module designs of future
Cosmic Microwave Background experiments and beyond
Title: Rosetta: a container-centric science platform for
resource-intensive, interactive data analysis
Authors: Russo, Stefano Alberto; Bertocco, Sara; Gheller, Claudio;
Taffoni, Giuliano
Bibcode: 2022arXiv220902003R
Altcode:
Rosetta is a science platform for resource-intensive, interactive
data analysis which runs user tasks as software containers. It is
built on top of a novel architecture based on framing user tasks
as microservices - independent and self-contained units - which
allows to fully support custom and user-defined software packages,
libraries and environments. These include complete remote desktop and
GUI applications, besides common analysis environments as the Jupyter
Notebooks. Rosetta relies on Open Container Initiative containers,
which allow for safe, effective and reproducible code execution; can use
a number of container engines and runtimes; and seamlessly supports
several workload management systems, thus enabling containerized
workloads on a wide range of computing resources. Although developed
in the astronomy and astrophysics space, Rosetta can virtually support
any science and technology domain where resource-intensive, interactive
data analysis is required.
Title: An X-ray Census of YSOs in an IRDC interacting with a SNR
Authors: Cheng, Yu
Bibcode: 2022cxo..prop.6282C
Altcode:
Supernova remnants (SNRs) contribute to regulate the star formation
efficiency and time evolution of galaxies. However, observationally
there are currently few constraints on the detailed star formation
properties of molecular cloud that is affected by the interaction with
SNRs. To address this issue we propose to perform an X-ray census with
Chandra/ACIS, towards the young stellar population in G34.77. G34.77
is a massive infrared dark cloud (IRDC), i.e., cold and dense cloud in
the earliest stage of star cluster formation, and also among the best
known sites of SNR-cloud interaction. The proposed study will give
constraints on the star formation timescale, efficiency, and shape of
initial mass function in this SNR-IRDC interaction environment.
Title: A Chandra view of massive Post-Starburst Galaxies
Authors: Goulding, Andy
Bibcode: 2022cxo..prop.6354G
Altcode:
Post-starburst galaxies, the direct product of the quenching process,
may hold the key to understanding the physics of quenching and the
role of active galactic nuclei (AGN). We propose to observe a sample of
WISE-luminous massive (M*~10^11Msun) post-starburst galaxies at z~0.7,
whose spectra indicate an abrupt end to a massive starburst. We do
not know if the WISE luminosity arises from an AGN, in which case our
census of AGN in these galaxies is very incomplete, or from buried
star formation, in which case the galaxies are not quenched. Only
Chandra can definitively distinguish between these two options.
Title: Magnetosphere-PWN-Velocity Connection: Resolving the X-ray
PWN in CTA 1
Authors: Kargaltsev, Oleg
Bibcode: 2022cxo..prop.6332K
Altcode:
CXO observations often reveal pulsar wind nebulae (PWNe) with jets
and/or tori allowing one to measure the angle between the pulsar's
spin axis and the line-of-sight. If a pulsar's GeV lightcurve is
available, then by fitting the magnetospheric emission model one can
also determine the magnetic inclination angle for a known viewing
angle. If the pulsar is nearby and moving fast enough, one can measure
the transverse velocity. However, if the jets are resolved, then the
estimation of the kick angle between the pulsar velocity and spin axis
becomes possible by modeling the jet bending. The PWN in the nearby
CTA 1 SNR is one of such rare cases. Deep CXO observations of such PWNe
shed light on the connection between the pulsar magnetosphere geometry,
PWN morphologies, and supernova kicks.
Title: Thermodynamics of Schwarzschild black hole surrounded by
quintessence in gravity's rainbow
Authors: Hamil, B.; Lütfüoğlu, B. C.
Bibcode: 2022arXiv220900960H
Altcode:
According to some quantum gravity models, Lorentz invariance can be
violated in the Planck energy scale. With this motivation, we analyze
the thermal quantities and the stability of Schwarzschild black hole
surrounded by quintessence in gravity's rainbow formalism. To do that,
we consider the rainbow functions which are motivated by loop quantum
gravity and gamma-ray bursts, and we derive Hawking temperature,
specific heat, entropy and the equation of state function. We observe
that the presence the quintessence matter field and rainbow gravity
affect the stability of the black hole.
Title: Tidal disruption events unveiled: understanding their long-term
accretion with Chandra and HST
Authors: Nicholl, Matt
Bibcode: 2022cxo..prop.6371N
Altcode:
Tidal disruption events (TDEs) provide a unique laboratory for studying
supermassive black holes. Shortly after disruption, most TDEs are
'veiled': emitting mainly UV/optical while X-ray signs of accretion
are obscured. However by >~3 years, the stellar debris should settle
into a thin, unobscured disk, brightest in X-rays and UV. We propose to
observe 3 very nearby and well-studied TDEs at late phases using Chandra
and HST. Only previous 1 TDE (and no veiled TDEs) have high S/N X-ray
data at late times. Covering the SED peak with X-ray+UV reveals (1)
the evolution of the accretion rate, and whether embedded accretion
powered the optical flare; (2) the dominant energy release mechanism
in the disk; and (3) fundamental disk parameters such as masses and
possibly spin.
Title: Magnetic field spectral evolution in the inner heliosphere
Authors: Sioulas, Nikos; Huang, Zesen; Shi, Chen; Velli, Marco;
Tenerani, Anna; Vlahos, Loukas; Bowen, Trevor A.; Bale, Stuart D.;
Bonnell, J. W.; Harvey, P. R.; Larson, Davin; Pulupa, arc; Livi,
Roberto; Woodham, L. D.; Horbury, T. S.; Stevens, Michael L.; Dudok
de Wit, T.; MacDowall, R. J.; Malaspina, David M.; Goetz, K.; Huang,
Jia; Kasper, Justin; Owen, Christopher J.; Maksimović, Milan; Louarn,
P.; Fedorov, A.
Bibcode: 2022arXiv220902451S
Altcode:
The radial evolution of the magnetic field fluctuations spectral
index and its dependence on plasma parameters is investigated using
a merged Parker Solar Probe ($PSP$) and Solar Orbiter ($SO$) dataset
covering heliocentric distances between $0.06 ~ \lesssim R ~\lesssim
1$ au. The spectrum is studied as a function of scale, normalized to
the radially dependent ion inertial scale $d_{i}$. In the vicinity of
the Sun, the magnetic spectrum inertial range is limited with a power
law exponent $\alpha_{B}$ consistent with the Iroshnikov-Kraichman
phenomenology of Alfvénic turbulence, $\alpha_{B} = -3/2$, independent
of plasma parameters. The inertial range of turbulence grows with
distance from the Sun, progressively extending to larger spatial
scales, while at the same time steepening towards a Kolomogorov
scaling, with a mean value of $\alpha_{B} =-5/3$. Highly alfvénic
intervals seem to retain their near-Sun scaling and only show a minor
steepening with distance. In contrast, intervals, where turbulence
is characterized by large magnetic energy excess and no dominance of
outwardly propagating Alfvénic fluctuations, appear to have spectra
that steepen significantly with distance from the Sun, resulting in
slightly anomalously steep inertial range slopes at $1~au$. Though
generically slower solar wind streams exhibit steeper spectra, the
correlation can be attributed to the underlying positive correlation
between solar wind speed and alfvénicity, i.e. to the relatively rare
occurrence of highly Alfvénic slow wind.
Title: Properties of dust along the line of sight of Cygnus X-1
Authors: Zeegers, Sascha
Bibcode: 2022cxo..prop.6343Z
Altcode:
We propose to observe the high mass X-ray binary Cygnus X-1 with
ACIS-S HETG with an observing time of 80 ks. Our observational
goals are to determine the properties of the silicate dust along
this sightline. Cygnus X-1 is especially suitable for such a study
since it allows - for the first time - to study the Si, O, Mg and Fe
edges simultaneously, i.e. the main constituents of silicates. The
XAFS features in the edges give information about the composition,
crystallinity and grain size. Cyg X-1 is also the only known X-ray
source with a corresponding infrared observation of the silicate
features by the Spitzer space telescope, allowing for the first time
a direct comparison of the silicate dust features. Our feasibility
study shows that our proposed observation serves our objectives well.
Title: Velocity distribution of elliptical galaxies in the framework
of Non-local Gravity model
Authors: Borka, D.; Borka Jovanović, V.; Capozziello, Salvatore;
Jovanović, P.
Bibcode: 2022arXiv220901696B
Altcode:
We investigate the velocity distribution of elliptical galaxies in
the framework of Non-local Gravity. According to this approach,
it is possible to recover the fundamental plane of elliptical
galaxies without the dark matter hypothesis. Specifically, we compare
theoretical predictions for circular velocity in Non-local Gravity
context with the corresponding values coming from a large sample
of observed elliptical galaxies. We adopt the surface brightness,
effective radius and velocity dispersion as structural parameters
for the fundamental plane. As final result, it is possible to show
that non-local gravity effects can reproduce the stellar dynamics in
elliptical galaxies and fit consistently observational data.
Title: The Beat Goes On
Authors: Ayres, Thomas
Bibcode: 2022cxo..prop.6408A
Altcode:
Chandra has been following magnetic heartbeats of late-type stars
via high-contrast coronal X-rays. Goal is to provide fundamental
observational constraints for contemporary and future studies of the
underlying magnetic dynamo, whose internal workings remain elusive. The
Sun's high-energy modulations play an important space weather role in
our heliosphere, as do stellar counterparts for their exoplanets. A
3-year continuation (joint with HST) is proposed for current cycles
targets Xi Boo (G8V+K4) and 70 Oph (K0V+K5V). Key questions: (1)
origin of diverging branches in rotational period vs. cycle duration,
where Sun sits isolated in the middle, possibly in a transitional
state; (2) extent of high-energy variability bias, which can affect
interpretations of large surveys.
Title: Assembling the most massive galaxy clusters: AGN and
environment in HS1549+19 at z=2.9
Authors: chapman, scott
Bibcode: 2022cxo..prop.6405C
Altcode:
The HS1549+19 proto-cluster at z=2.9 represents potentially the most
massive structure known at this epoch, traced spectroscopically over a
degree scale, showing an extreme phase of star formation in a centrally
concentrated region. This is one of the best examples of the precursor
to today's massive galaxy clusters and has been studied to unprecedented
depth with Subaru, ALMA, and Keck, and is now a legacy survey field,
in which we are working to observe and characterize the galaxy star
formation properties. Chandra is the missing piece of the puzzle in
understanding this structure is the role of SMBHs in the excitation of
the ALMA and optical sources. We request 210 ks Chandra exposure with
ACIS-I (a total resource usage of 281ks) to probe AGN luminosities
of ~1e44.
Title: Where is the Dragonfly going? Measuring the Proper Motion of
the PSR J2021+3651
Authors: Jin, Ruolan
Bibcode: 2022cxo..prop.6329J
Altcode:
We propose an ACIS observation of PSR J2021+3651 for measuring its
proper motion. Previous studies assumed that the pulsar is moving from
the location of its associated TeV source, which is believed to be the
pulsar?s birth site. The inferred pulsar moving velocity based on this
agrees with the observed bow-shock structures caused by a supersonically
moving pulsar. However, the undisturbed torus and the jets of the pulsar
wind nebula suggest a mildly moving pulsar, which contradicts with
the fast-moving assumption. Only a direct measurement of the pulsar?s
velocity can confirm this. By adopting ?Figure of Merit? method, it
will become feasible for measuring proper motion of PSR J2021+3651
between the archival data and a new cycle 24 Chandra observation. 1
Title: Tracing the evolution of X-ray and radio bright supernova,
AT 2020ywx
Authors: Chandra, Poonam
Bibcode: 2022cxo..prop.6331C
Altcode:
Type IIn supernovae (SNe IIn) are a heterogeneous class of supernovae
believed to be powered by vigorous circumstellar (CS) interaction. Their
evolutionary status remains an open question. X-ray emission along
with radio emission are the result of CS interaction and hence offer
unique constraints on the progenitor star. SN 2020ywx is a Type IIn
SN with an absolute magnitude of M=-18.4. The previous Chandra X-ray
observations in May2021 and Dec2021 witnessed evolution of the column
density (by a factor of 2) pointing towards a variable CSM. In addition,
the SN has been detected with the VLA and GMRT radio bands covering
frequency range 0.3-30 GHz. In this joint Chandra-VLA proposal we
request for 80ks Chandra time during cycle 24 and 8 hrs of VLA time
during semester 2023A.
Title: MeV-GeV Polarimetry with $\gamma \to e^+e^-$: Asserting the
Performance of Silicon Strip Detectors-Based Telescopes
Authors: Bernard, Denis
Bibcode: 2022arXiv220900684B
Altcode:
The polarimetry of gamma rays converting to an $e^+e^-$ pair would
open a new window on the high-energy gamma-ray sky by, among other
things, providing insight into the radiation mechanism in pulsars
(curvature or synchrotron) or deciphering the composition of the
gamma-ray emitting jets in blazars (leptonic or lepto-hadronic). The
performance of polarimeters based on homogeneous active targets (gas
detectors (MeV, HARPO) or emulsions (GeV, GRAINE) has been studied both
with simulation and by the analysis of data collected with telescope
prototypes on linearly-polarised gamma-ray beams, and found to be
excellent. The present (Fermi LAT), AGILE and future project (AMEGO,
ASTROGAM) gamma-ray missions, though, are using active targets based on
silicon strip detectors (SSD). No demonstration of a non-zero effective
polarisation asymmetry with SSDs has been published to date, be it only
with simulated data, and sensitivity estimations were obtained from
an assumed value of the effective polarisation asymmetry. I present
a characterisation of the potential of SSD-based active targets for
polarimetry with gamma-ray conversions to pairs and the development
of various methods to improve on the sensitivity. This work could
pave the way to providing the polarimetry of the brightest gamma-ray
sources of the sky from the decade of data collected by the Fermi LAT
and by AGILE, and to guiding the design of future missions.
Title: Correlated 1-1000 Hz magnetic field fluctuations from lightning
over earth-scale distances and their impact on gravitational wave
searches
Authors: Janssens, Kamiel; Ball, Matthew; Schofield, Robert M. S.;
Christensen, Nelson; Frey, Raymond; van Remortel, Nick; Banagiri,
Sharan; Coughlin, Michael W.; Effler, Anamaria; Gołkowski, Mark;
Kubisz, Jerzy; Ostrowski, Michał
Bibcode: 2022arXiv220900284J
Altcode:
We report Earth-scale distance magnetic correlations from lightning
strokes in the frequency range 1-1000 Hz at several distances ranging
from 1100 to 9000 km. Noise sources which are correlated on Earth-scale
distances can affect future searches for gravitational-wave signals
with ground-based gravitational-wave interferometric detectors. We
consider the impact of correlations from magnetic field fluctuations on
gravitational-wave searches due to Schumann resonances ($<$50 Hz)
as well as higher frequencies ($>$100 Hz). We demonstrate that
individual lightning strokes are a likely source for the observed
correlations in the magnetic field fluctuations at gravitational-wave
observatories and discuss some of their characteristics. Furthermore,
we predict their impact on searches for an isotropic gravitational-wave
background, as well as for searches looking for short-duration transient
gravitational waves, both unmodeled signals (bursts) as well as modeled
signals (compact binary coalescence). Whereas the recent third observing
run by LIGO and Virgo was free of an impact from correlated magnetic
field fluctuations, future runs could be affected. For example,
at current magnetic coupling levels, neutron star inspirals in
third generation detectors are likely to be contaminated by multiple
correlated lightning glitches. We suggest that future detector design
should consider reducing lightning coupling by, for example, reducing
the lightning-induced beam tube currents that pass through sensitive
magnetic coupling regions in current detectors. We also suggest that
the diurnal and seasonal variation in lightning activity may be useful
in discriminating between detector correlations that are produced by
gravitational waves and those produced by lightning.
Title: On the cosmological constant in the deformed Einstein-Cartan
gauge gravity in De Donder-Weyl Hamiltonian formulation
Authors: Vasak, D.; Kirsch, J.; Struckmeier, J.; Stoecker, H.
Bibcode: 2022arXiv220900501V
Altcode:
A modification of the Einstein-Hilbert theory, the Covariant
Canonical Gauge Gravity (CCGG), leads to a cosmological constant that
represents the energy of the space-time continuum when deformed
from its (A)dS ground state to a flat geometry. CCGG is based
on the canonical transformation theory in the De Donder-Weyl (DW)
Hamiltonian formulation. That framework modifies the Einstein-Hilbert
Lagrangian of the free gravitational field by a quadratic Riemann-Cartan
concomitant. The theory predicts a total energy-momentum of the system
of space-time and matter to vanish, in line with the conjecture of a
"Zero-Energy-Universe" going back to Lorentz (1916) and Levi-Civita
(1917). Consequently a flat geometry can only exist in presence of
matter where the bulk vacuum energy of matter, regardless of its value,
is eliminated by the vacuum energy of space-time.% $\lambda_0$. The
observed cosmological constant $\Lambda_{\mathrm{obs}}$ is found to
be merely a small correction %of the order $10^{-120} \,\lambda_0$
attributable to deviations from a flat geometry and effects of
complex dynamical geometry of space-time, namely torsion and possibly
also vacuum fluctuations of matter and space-time. That quadratic
extension of General Relativity, anticipated already in 1918 by Einstein
\cite{einstein18}, thus provides a significant and natural contribution
to resolving the %$120$ orders of magnitude miss-estimate called the
"cosmological constant problem".
Title: Ostrogradsky mode in scalar-tensor theories with higher-order
derivative couplings to matter
Authors: Naruko, Atsushi; Saito, Ryo; Tanahashi, Norihiro; Yamauchi,
Daisuke
Bibcode: 2022arXiv220902252N
Altcode:
A metric transformation is a tool to find a new theory of gravity beyond
general relativity. The gravity action is guaranteed to be free from
a dangerous Ostrogradsky mode as long as the metric transformation is
regular and invertible. Various degenerate higher-order scalar-tensor
theories (DHOST) without extra degrees of freedom have been found
through the metric transformation with a scalar field and its
derivatives. In this work, we examine how a matter coupling changes
the degeneracy for a theory generated from the Horndeski theory through
the metric transformation with the second derivative of a scalar field,
taking a minimally-coupled free scalar field as the matter field. When
the transformation is invertible, this theory is equivalent to the
Horndeski theory with a higher-order derivative coupling to the matter
scalar field. Working in this Horndeski frame and the unitary gauge,
we find that the degeneracy conditions are solvable and the matter
metric must have a certain structure to remove the Ostrogradsky mode.
Title: The crossed-sine wavefront sensor: first tests and results
Authors: Schreiber, Laura; Feng, Yan; Spang, Alain; Henault, Francois;
Correia, Jean-Jacques; Stadler, Eric; Mouillet, David
Bibcode: 2022arXiv220900829S
Altcode:
The crossed-sine wavefront sensor (WFS) is a pupil plane wavefront
sensor that measures the first derivatives of the wavefront. It
is made by three main components: a gradient transmission filter
(GTF) built from a product of sine functions rotated by 45 degrees
around the optical axis, a 2x2 mini-lens array (MLA) at the focus of
the tested optical system and a detector array located on a plane
conjugated to the pupil. The basic principle consists in acquiring
four pupil images simultaneously, each image being observed from
different points located behind the GTF. After the simulation work
which demonstrated the wavefront reconstruction capability, we are
now in the phase of implementation of the prototype in the lab. The
crossed-sine WFS could achieve a simultaneous high spatial resolution
at the pupil of the tested optics and absolute measurement accuracy
comparable to that attained by laser-interferometers. In this paper
we introduce seven customized phase masks and make measurements of
them.First tests and resultsare demonstrated, based on which we explore
the performance of our crossed-sine WFS and make comparisons with that
of the laser-interferomete
Title: Systematic study of ionospheric scintillation over the indian
low-latitudes during low solar activity conditions
Authors: Ayyagari, Deepthi; Datta, Abhirup; Chakraborty, Sumanjit
Bibcode: 2022arXiv220900708A
Altcode:
A systematic study of ionospheric scintillation at the low-latitudes,
especially around the Equatorial Ionization Anomaly (EIA) and the
magnetic equator, is essential in understanding the dynamics of
ionospheric variation and related physical processes. Our study involves
NavIC $S_{4_C}$ observations over Indore and Hyderabad. Additionally,
GPS $S_{4_C}$ observations over Indore were analyzed, under disturbed
as well as quiet time ionospheric conditions from September 2017
through 2019, falling in the declining phase of the solar cycle 24. The
$S_{4_C}$ observations were further analyzed using proxy parameters:
ROT and ROTI. These results have been obtained from three satellites
of the NavIC constellation (PRNs 2, 5, and 6). The onset times of
scintillations \textbf{were} observed to be around 19:30 LT (h) and
20:30 LT (h) for Hyderabad and Indore respectively, while the $S_{4_C}$
peak values occurred between 22:00 LT (h) and 23:00 LT (h). The
reliability of NavIC was evaluated using scattering coefficients that
revealed a good correlation across the pair of signals during quiet
time ionospheric conditions. The observations clearly show that the
amplitude scintillation of the NavIC signal follows the Nakagami-m
distribution along with the $\alpha-\mu$ distribution as a depiction
of the deep power fades caused by scintillation on these signals. This
paper shows the impact of such systematic studies near these locations
for the first time, in improving the understanding of the dynamic
nature of low-latitude ionosphere under low solar activity conditions.
Title: Solar Observing with the Atacama Large Millimeter-Submillimeter
Array
Authors: Bastian, Timothy; Shimojo, Masumi; Barta, Miroslav; White,
Stephen; Iwai, Kazumasa
Bibcode: 2022arXiv220901659B
Altcode:
The Atacama Large Millimeter-submillimeter Array (ALMA), sited on the
high desert plains of Chajnantor in Chile, has opened a new window onto
solar physics in 2016 by providing continuum observations at millimeter
and sub-millimeter wavelengths with an angular resolution comparable
to that available at optical (O), ultraviolet (UV), extreme ultraviolet
(EUV), and X-ray wavelengths, and with superior time resolution. In the
intervening years, progress has been made testing and commissioning
new observing modes and capabilities, in developing data calibration
strategies, and in data imaging and restoration techniques. Here we
review ALMA current solar observing capabilities, the process by which
a user may propose to use the instrument, and summarize the observing
process and work flow. We then discuss some of the challenges users
may encounter in imaging and analyzing their data. We conclude with a
discussion of additional solar observing capabilities and modes under
consideration that are intended to further exploit the unique spectral
coverage provided by ALMA.
Title: Schwarzschild black holes in Starobinsky-Bel-Robinson gravity
Authors: Campos Delgado, Ruben; Ketov, Sergey V.
Bibcode: 2022arXiv220901574C
Altcode:
We study physical properties of a Schwarzschild black hole in the
framework of the recently proposed Starobinsky-Bel-Robinson (SBR)
modified theory of gravity, working perturbatively in the coupling
constant. In particular, we compute the temperature, entropy, pressure
and lifetime of a Schwarzschild black hole.
Title: General Formulation of Topos Many-Node Theory
Authors: Simchi, Hamidreza
Bibcode: 2022arXiv220902701S
Altcode:
We consider the created entities (events) in the first moments of
universe creation. It is assumed that there exists a causal energetic
relationship between all events (nodes) such that all nodes are placed
on a world line and each node occupies a region (instead of a point)
in space-time, called locale, in mathematical terms. The set of locale
nodes form a topos many-node system. Using some basic assumptions, we
introduce two kinds of Hamiltonians. By attributing a general structural
Hamiltonian to the system, it is shown that the system has an optimized
critical dimension with a probable Raman and infrared spectrums. Also,
we consider a general nonstructural Hamiltonian which includes a set
of commutative self-adjoint operators and an interaction terms due
to the spin, charge, or other kinds of probable degrees of freedoms
for each $n^{th}$-optimized graph. For finding the state-space, truth
values and quantity valued objects of the many-node system, a general
procedure is introduced. The set of these values is a classical snapshot
of the $n^{th}$-optimized graph which forms its kinematic. We show that
the dynamic of the system can be explained by defining a combined map
between the $n^{th}$- state-space belongs to the $n^{th}$-graph and
the $({n+1)}^{th}$-state-space belong to $({n+1)}^{th}$-graph. Finally,
by providing an interpretation of the general formulation of many-node
theory, we discuss and explain how one can use the data of the cosmic
background radiations and cosmic rays for finding a detailed model of
both general structural and nonstructural introduced Hamiltonian. Here,
time is no more than the change in truth value during comparison
between $n^{th}$ and $({n+1)}^{th}$-graph.
Title: Morphokinematic modelling of the point-symmetric Cat's Eye,
NGC 6543: Ring-like remnants of a precessing jet
Authors: Clairmont, Ryan; Steffen, Wolfgang; Koning, Nico
Bibcode: 2022arXiv220901313C
Altcode:
The planetary nebula known as the Cat's Eye Nebula (NGC 6543)
has a complex, point-symmetric morphology that cannot be fully
explained by the current theory of planetary nebula formation,
the Interacting Stellar Winds Model. In order to reveal the three
dimensional (3D) structure of the Cat's Eye Nebula, we created a
detailed 3D morpho-kinematic model of this nebula using a [NII] image
from the Hubble Space Telescope and five different position-velocity
diagrams using the SHAPE code. This modeling approach has revealed
point-symmetric partial rings, which were likely formed by a precessing
jet.
Title: Constraining the time-dependent accretion rate of a novel
class of X-ray source
Authors: Cunningham, Tim
Bibcode: 2022cxo..prop.6283C
Altcode:
White dwarfs accreting the remnants of evolved planetary systems
have recently been confirmed as a new class of X-ray source using
Chandra. This is the first direct evidence that these degenerate stars
are actively accreting the remains of the planetary systems that orbit
them. This discovery of accreting planetary debris marks the beginning
of a new field within X-ray astronomy. We propose to exploit Chandra
to search for variations in the accretion rate of the only system
detected to date, G29-38.
Title: Chandra Sub-Arcsecond Localization of Swift Short GRBS
Authors: Dichiara, Simone
Bibcode: 2022cxo..prop.6320D
Altcode:
We propose a Chandra ToO program to observe short GRBs detected by
Swift in order to localize their X-ray afterglow with sub-arcsecond
accuracy. Our ToO program will increase the number of short GRBs having
an unambiguous host galaxy identification, and provide a less biased
sample of GRB host galaxies. We request a maximum of 2 ToOs for 20
ksec each. Our trigger criteria are 1) Swift short GRBs localized by
Swift/XRT and 2) no afterglow confirmation in optical within 24 hours
after the burst. We request <2 days response to our ToO, so that
the afterglow can be observed while still bright.
Title: Generalized non-local $R^2$-like inflation
Authors: Koshelev, Alexey S.; Sravan Kumar, K.; Starobinsky, Alexei A.
Bibcode: 2022arXiv220902515K
Altcode:
The $R^2$ inflation which is an extension of general relativity (GR)
by quadratic scalar curvature introduces a quasi-de Sitter expansion
of the early Universe governed by Ricci scalar being an eigenmode
of d'Alembertian operator. In this paper, we derive a most general
theory of gravity admitting $R^2$ inflationary solution which turned
out to be higher curvature non-local extension of GR. We study in
detail inflationary perturbations in this theory and analyse the
structure of form factors that leads to a massive scalar (scalaron)
and massless tensor degrees of freedom. We argue that the theory
contains only finite number of free parameters which can be fixed by
cosmological observations. We derive predictions of our generalized
non-local $R^2$-like inflation and obtain the scalar spectral index
$n_s\approx 1-\frac{2}{N}$ and any value of the tensor-to-scalar ratio
$r<0.036$. In this theory, tensor spectral index can be either
positive or negative $n_t\lessgtr 0$ and the well-known consistency
relation $r = -8n_t$ is violated in a non-trivial way. We also
compute running of the tensor spectral index and discuss observational
implications to distinguish this model from several classes of scalar
field models of inflation. These predictions allow us to probe the
nature of quantum gravity in the scope of future CMB and gravitational
wave observations. Finally we comment on how the features of generalized
non-local $R^2$-like inflation cannot be captured by established notions
of the so-called effective field theory of single field inflation and
how we must redefine the way we pursue inflationary cosmology.
Title: Proton radiation damage tolerance of wide dynamic range SOI
pixel detectors
Authors: Tsunomachi, Shun; Kohmura, Takayoshi; Hagino, Kouichi;
Kitajima, Masatoshi; Doi, Toshiki; Aoki, Daiki; Ohira, Asuka; Shimizu,
Yasuyuki; Fujisawa, Kaito; Yamazaki, Shizusa; Uchida, Yuusuke; Shimizu,
Makoto; Itoh, Naoki; Arai, Yasuo; Miyoshi, Toshinobu; Nishimura,
Ryutaro; Tsuru, Takeshi Go; Kurachi, Ikuo
Bibcode: 2022arXiv220903636T
Altcode:
We have been developing the SOI pixel detector ``INTPIX'' for space
use and general purpose applications such as the residual stress
measurement of a rail and high energy physics experiments. INTPIX is
a monolithic pixel detector composed of a high-resistivity Si sensor,
a SiO2 insulator, and CMOS pixel circuits utilizing Silicon-On-Insulator
(SOI) technology. We have considered the possibility of using INTPIX to
observe X-ray polarization in space. When the semiconductor detector
is used in space, it is subject to radiation damage resulting from
high-energy protons. Therefore, it is necessary to investigate whether
INTPIX has high radiation tolerance for use in space. The INTPIX8
was irradiated with 6 MeV protons up to a total dose of 2 krad at
HIMAC, National Institute of Quantum Science in Japan, and evaluated
the degradation of the performance, such as energy resolution and
non-uniformity of gain and readout noise between pixels. After 500
rad irradiation, which is the typical lifetime of an X-ray astronomy
satellite, the degradation of energy resolution at 14.4 keV is less
than 10%, and the non-uniformity of readout noise and gain between
pixels is constant within 0.1%.
Title: Isotopic evidence for two chondrule generations in CR
chondrites and their relationships to other carbonaceous chondrites
Authors: Marrocchi, Yves; Piralla, Maxime; Regnault, Maxence; Batanova,
Valentina; Villeneuve, Johan; Jacquet, Emmanuel
Bibcode: 2022E&PSL.59317683M
Altcode:
Among primitive meteorites, CR chondrites have peculiar isotopic
compositions, the origin of which is uncertain and may have
involved contributions from primordial molecular cloud material
or the chondrites' formation and agglomeration late during the
evolution of the protoplanetary disk. Here, we report a comprehensive
textural and isotopic characterization of type I CR chondrules and
provide new insights on their formation conditions. We find that two
chondrule populations characterized by different sizes and oxygen
isotopic compositions co-exist in CR chondrites. The typically larger,
16O-poor (Δ17 O >-4‰) chondrules (type I-CR
chondrules) appear to have formed late out of a CR reservoir already
populated by typically smaller, 16O-rich (Δ17
O <-4‰) chondrules (type I-CO chondrules). Before formation of type
I-CR chondrules, the CR reservoir was likely dominated by CI-like dust,
in line with the proximity of CR with CI chondrites for many isotopic
ratios. The CR reservoir thus may have largely belonged to the continuum
shown by other carbonaceous chondrites, although some isotopic ratios
maintain some originality and suggest isotopic variation of CI-like
dust in the outer disk. Combined with literature data, our data (i)
demonstrates that recycling processes are responsible for the singular
compositions of CR chondrites and their chondrules for isotopic systems
with drastically different geochemical behaviors (O, Cr, Te) and (ii)
support the homogeneous distribution of 26Al throughout
the protoplanetary disk.
Title: Path integral suppression of badly behaved causal sets
Authors: Carlip, P.; Carlip, S.; Surya, S.
Bibcode: 2022arXiv220900327C
Altcode:
Causal set theory is a discrete model of spacetime that retains a
notion of causal structure. We understand how to construct causal sets
that approximate a given spacetime, but most causal sets are not at
all manifold-like, and must be dynamically excluded if something like
our universe is to emerge from the theory. Here we show that the most
common of these "bad" causal sets, the Kleitman-Rothschild orders, are
strongly suppressed in the gravitational path integral, and we provide
evidence that a large class of other "bad" causal sets are similarly
suppressed. It thus becomes plausible that continuum behavior could
emerge naturally from causal set quantum theory.
Title: LBT SOUL data as a science test bench for MICADO PSF-R tool
Authors: Simioni, Matteo; Arcidiacono, Carmelo; Wagner, Roland;
Grazian, Andrea; Gullieuszik, Marco; Portaluri, Elisa; Vulcani,
Benedetta; Zanella, Anita; Agapito, Guido; Davies, Richard; Helin,
Tapio; Pedichini, Fernando; Piazzesi, Roberto; Pinna, Enrico; Ramlau,
Ronny; Rossi, Fabio; Salo, Aleksi
Bibcode: 2022arXiv220903212S
Altcode:
Current state-of-the-art adaptive optics (AO) provides ground-based,
diffraction-limited observations with high Strehl ratios (SR). However,
a detailed knowledge of the point spread function (PSF) is required
to fully exploit the scientific potential of these data. This is even
more crucial for the next generation AO instruments that will equip
30-meter class telescopes, as the characterization of the PSF will
be mandatory to fulfill the planned scientific requirements. For
this reason, there is a growing interest in developing tools that
accurately reconstruct the observed PSF of AO systems, the so-called
PSF reconstruction. In this context, a PSF-R service is a planned
deliverable for the MICADO@ELT instrument and our group is in charge of
its development. In the case of MICADO, a blind PSF-R approach is being
pursued to have the widest applicability to science cases. This means
that the PSF is reconstructed without extracting information from the
science data, relying only on telemetry and calibrations. While our
PSF-R algorithm is currently being developed, its implementation is
mature enough to test performances with actual observations. In this
presentation we will discuss the reliability of our reconstructed PSFs
and the uncertainties introduced in the measurements of scientific
quantities for bright, on-axis observations taken with the SOUL+LUCI
instrument of the LBT. This is the first application of our algorithm
to real data. It demonstrates its readiness level and paves the way
to further testing. Our PSF-R algorithm is able to reconstruct the
SR and full-width at half maximum of the observed PSFs with errors
smaller than 2% and 4.5%, respectively. We carried out the scientific
evaluation of the obtained reconstructed PSFs thanks to a dedicated
set of simulated observations of an ideal science case.
Title: Exploring the Early Universe with Chandra and JWST
Authors: Cappelluti, Nico
Bibcode: 2022cxo..prop.6423C
Altcode:
With this proposal we aim to study z>5 X-ray sources using data
from the Cycle 1 JWST COSMOS-Webb treasury program and the ERS program
JWST-TDF in the NEP field in conjunction with Deep Chandra archival
data to probe the early Universe by means of stacking analysis. Our
goal is to determine a) the abundance of AGN-like X-ray sources at
z>5 in order to shed new light on early SMBH growth; b) constrain
the high-z Star Formation Rate (SFR)-L_X efficiency by deriving Chandra
X-ray luminosities and SFRs obtained by JWST and c) compute the space
density and X-ray throughput of early AGN candidates and compare them
with predictions of SMBH seeding models.
Title: On the saturation of late-time growth of complexity in
supersymmetric JT gravity
Authors: Alishahiha, Mohsen; Banerjee, Souvik
Bibcode: 2022arXiv220902441A
Altcode:
In this work we use the modified replica trick, proposed in
arXiv:2205.01150, to compute the late time behaviour of complexity for
JT gravity with ${\cal N} = 1$ and ${\cal N} = 2$ supersymmetries. For
the ${\cal N} = 1$ theory, we compute the late time behaviour of
complexity defined by the ``quenched geodesic length" and obtain
the expected saturation of complexity at time $t \sim e^{S_0}$,
to a constant value with time-independent variance. For the ${\cal
N} = 2$ theory, we explicitly compute complexity at the disk level
which yields the late-time linear growth of complexity. However, we
comment on the expectation of the late-time saturation by speculating
the trumpet partition function and the non-perturbative corrections
to the spectral correlation, relevant for the late-time behaviour of
complexity. Furthermore, we compute the matter correlation functions
for both the theories.
Title: Unsupervised machine learning correlations in EoS of neutron
stars
Authors: Lobato, R.; Chimanski, E.; Bertulani, C.
Bibcode: 2022iwhp.confE..62L
Altcode: 2022arXiv220213940L; 2022PoS...408E..62L
Neutron stars are compact objects of large interest in the nuclear
astrophysics community. The extreme conditions present in such
systems impose big challenges to our current microscopic models of
nuclear structure. Equation of states (EoS) are frequently derived
from sophisticated quantum mechanical models, such as: relativistic,
non-relativistic and many mean-field approaches. Every single model, in
general, contains many parameters such as the NN interaction strength,
particle compositions, etc. These are particular features of each model
and can be represented by numbers and categories in a machine learning
context. Different choices of features will affect EoS properties
leading to different macroscopic properties of the star. In this work
we analyze a selection of EoS containing a variety of different physics
models. One of our objectives is to develop tools that enable a better
understanding of the correlations among the different model features
and the outcome produced by them when employed to model neutron stars.
Title: AO-24 Cross-Calibration Observations of 3C273
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6434C
Altcode:
This observation of 3C273 is used for cross-calibration with XMM-Newton
and NuStar.
Title: BRUTE, PSF Reconstruction for the SOUL pyramid-based Single
Conjugate Adaptive Optics facility of the LBT
Authors: Arcidiacono, Carmelo; Grazian, Andrea; Zanella, Anita;
Vulcani, Benedetta; Portaluri, Elisa; Pedichini, Fernando; Gullieuszik,
Marco; Simioni, Matteo; Piazzesi, Roberto; Wagner, Roland; Pinna,
Enrico; Agapito, Guido; Rossi, Fabio; Plantet, Cedric
Bibcode: 2022arXiv220903278A
Altcode:
The astronomical applications greatly benefit from the knowledge of the
instrument PSF. We describe the PSF Reconstruction algorithm developed
for the LBT LUCI instrument assisted by the SOUL SCAO module. The
reconstruction procedure considers only synchronous wavefront sensor
telemetry data and a few asynchronous calibrations. We do not compute
the Optical Transfer Function and corresponding filters. We compute
instead a temporal series of wavefront maps and for each of these
the corresponding instantaneous PSF. We tested the algorithm both
in laboratory arrangement and in the nighttime for different SOUL
configurations, adapting it to the guide star magnitudes and seeing
conditions. We nick-named it "BRUTE", Blind Reconstruction Using
TElemetry, also recalling the one-to-one approach, one slope-to one
instantaneous PSF the algorithm applies.
Title: Blazar constraints on neutrino-dark matter scattering
Authors: Cline, James M.; Gao, Shan; Guo, Fangyi; Lin, Zhongan; Liu,
Shiyan; Puel, Matteo; Todd, Phillip; Xiao, Tianzhuo
Bibcode: 2022arXiv220902713C
Altcode:
Neutrino emission in coincidence with gamma rays has been observed
from the blazar TXS 0506+056 by the IceCube telescope. Neutrinos
from the blazar had to pass through a dense spike of dark matter (DM)
surrounding the central black hole. The observation of such a neutrino
implies new upper bounds on the neutrino-DM scattering cross section
as a function of DM mass. The constraint is stronger than existing
ones for a range of DM masses, if the cross section rises linearly
with energy. For constant cross sections, competitive bounds are also
possible, depending on details of the DM spike.
Title: Extracting the Heliographic Coordinates of Coronal Rays using
Images from WISPR/Parker Solar Probe
Authors: Liewer, P. C.; Qiu, J.; Ark, F.; Penteado, P.; Stenborg,
G.; Vourlidas, A.; Hall, J. R.; Riley, P.
Bibcode: 2022arXiv220902779L
Altcode:
The Wide-field Imager for Solar Probe (WISPR) onboard Parker Solar
Probe (PSP), observing in white light, has a fixed angular field
of view, extending from 13.5 degree to 108 degree from the Sun and
approximately 50 degree in the transverse direction. In January 2021,
on its seventh orbit, PSP crossed the heliospheric current sheet (HCS)
near perihelion at a distance of 20 solar radii. At this time, WISPR
observed a broad band of highly variable solar wind and multiple coronal
rays. For six days around perihelion, PSP was moving with an angular
velocity exceeding that of the Sun. During this period, WISPR was able
to image coronal rays as PSP approached and then passed under or over
them. We have developed a technique for using the multiple viewpoints
of the coronal rays to determine their location (longitude and latitude)
in a heliocentric coordinate system and used the technique to determine
the coordinates of three coronal rays. The technique was validated by
comparing the results to observations of the coronal rays from Solar
and Heliophysics Observatory (SOHO) / Large Angle and Spectrometric
COronagraph (LASCO)/C3 and Solar Terrestrial Relations Observatory
(STEREO)-A/COR2. Comparison of the rays' locations were also made with
the HCS predicted by a 3D MHD model. In the future, results from this
technique can be used to validate dynamic models of the corona.
Title: Reconstruction of spectra and an algorithm based on the
theorems of Darboux and Puiseux
Authors: Grozdanov, Sašo; Lemut, Timotej
Bibcode: 2022arXiv220902788G
Altcode:
Assuming only a known dispersion relation of a single mode in the
spectrum of a two-point function in some quantum field theory, we
investigate when and how the reconstruction of the complete spectrum
of physical excitations is possible. In particular, we develop a
constructive algorithm based on the theorems of Darboux and Puiseux
that allows for such a reconstruction of all modes connected by
level-crossings. For concreteness, we focus on theories in which
the known mode is a gapless excitation described by the hydrodynamic
gradient expansion, known at least to some (preferably high) order. We
first apply the algorithm to a simple algebraic example and then to
the transverse momentum excitations in the holographic theory that
describes a stack of M2 branes and includes momentum diffusion as its
gapless excitation.
Title: Completing Observations of the Highest-Redshift Planck
SZ Clusters
Authors: Mantz, Adam
Bibcode: 2022cxo..prop.6388M
Altcode:
Measurements of the growth of cosmic structure, based on the number
density and mass distribution of galaxy clusters as a function of
redshift, place powerful constraints on cosmological models. As the
only all-sky Sunyaev-Zel'dovich (SZ) selected cluster sample, Planck's
PSZ2 sample has a uniquely powerful role. Despite this, follow-up
X-ray observations of the z>0.4 PSZ2 sample are incomplete, with
archival coverage biased towards the X-ray brightest systems, which
is problematic for most cosmological studies. Completing the X-ray
follow-up coverage, and thus providing low-scatter X-ray mass proxies
for every cluster at z>0.4, will enable significantly improved,
more robust cosmological constraints to be obtained.
Title: Constraining primordial tensor features with the anisotropies
of the Cosmic Microwave Background
Authors: Hamann, Jan; Malhotra, Ameek
Bibcode: 2022arXiv220900827H
Altcode:
It is commonly assumed that the stochastic background of gravitational
waves on cosmological scales follows an almost scale-independent
power spectrum, as generically predicted by the inflationary
paradigm. However, it is not inconceivable that the spectrum could
have strongly scale-dependent features, generated, e.g., via transient
dynamics of spectator axion-gauge fields during inflation. Using
the temperature and polarisation maps from the \textit{Planck} and
BICEP/Keck datasets, we search for such features, taking the example of
a log-normal bump in the primordial tensor spectrum at CMB scales. We do
not find any evidence for the existence of bump-like tensor features at
present, but demonstrate that future CMB experiments such as LiteBIRD
and CMB-S4 will greatly improve our prospects of determining the
amplitude, location and width of such a bump. We also highlight the
role of delensing in constraining these features at angular scales
$\ell\gtrsim 100$.
Title: Unveiling the Nature of a Dust Reddened Quasar Hosting a
Ten-Billion Solar Mass Black Hole at z=7.1
Authors: Yang, Jinyi
Bibcode: 2022cxo..prop.6376Y
Altcode:
Recently, a unique luminous quasar at z=7.1 has been discovered,
hosting a super-massive black hole (SMBH) with at least 10 billion
solar masses. It is the only known quasar at z>6.5 with 10 billion
solar mass BH and also the most distant dust-reddened quasar known. Its
rest-frame UV continuum shows evidence of strong dust reddening, which
is highly unusual, suggestive of extinction due to supernova produced
dust. This new quasar provides a unique opportunity to study the SMBH
growth and early quasar evolution. The proposed Chandra observations
will, for the first time, directly probe BH accretion properties of a
ten billion solar mass BH at z>7 and measure the column density to
explore its obscuration in the early growing phase of a quasar during
the epoch of reionization.
Title: Spectral variability in NGC 1042 ULX1
Authors: Ghosh, Tanuman; Rana, Vikram
Bibcode: 2022arXiv220902458G
Altcode:
We report X-ray spectral variability in an ultraluminous X-ray
source NGC 1042 ULX1, using archival XMM-NEWTON and recent NuSTAR
observations. In long-term evolution, the source has shown a trend
of variation in spectral hardness. The variability in different
XMM-NEWTON observations is prominent above $\sim 1$ keV. Cool thermal
disk component with a characteristic temperature of $\sim 0.2$ keV
manifests that the spectral state of NGC 1042 ULX1 in all epochs
is similar to that of the ultraluminous state sources. An apparent
anti-correlation between luminosity and powerlaw index demonstrates
that the source becomes spectrally harder when it is in a brighter
state. That is conceivably related to stronger Comptonization when
the accretion rate is higher or due to a change in the occultation of
the disk geometry. Typical hard ultraluminous type spectra indicate
that NGC 1042 ULX1 is a low inclination system in general. Spectral
properties suggest that, like many other ULXs which show spectral
curvature around $\sim 6-10$ keV, NGC 1042 ULX1 could be another
stellar-mass super-Eddington accretor.
Title: Extended planetary chaotic zones
Authors: Shevchenko, Ivan I.
Bibcode: 2022MNRAS.515.3996S
Altcode: 2022arXiv220712747S; 2022MNRAS.tmp.1893S
We consider the chaotic motion of low-mass bodies in two-body high-order
mean-motion resonances with planets in model planetary systems,
and analytically estimate the Lyapunov and diffusion time-scales of
the motion in multiplets of interacting subresonances corresponding
to the mean-motion resonances. We show that the densely distributed
(though not overlapping) high-order mean-motion resonances, when certain
conditions on the planetary system parameters are satisfied, may produce
extended planetary chaotic zones - 'zones of weak chaotization,' -
much broader than the well-known planetary connected chaotic zone,
the Wisdom gap. This extended planetary chaotic zone covers the orbital
range between the 2/1 and 1/1 resonances with the planet. On the other
hand, the orbital space inner (closer to the host star) with respect
to the 2/1 resonance location is essentially long-term stable. This
difference arises because the adiabaticity parameter of subresonance
multiplets specifically depends on the particle's orbit size. The
revealed effect may control the structure of planetesimal discs in
planetary systems: the orbital zone between the 2/1 and 1/1 resonances
with a planet should be normally free from low-mass material (only that
occasionally captured in the first-order 3/2 or 4/3 resonances may
survive); whereas any low-mass population inner to the 2/1 resonance
location should be normally long-lived (if not perturbed by secular
resonances, which we do not consider in this study).
Title: Stellar Population Astrophysics (SPA) with the
TNG. alpha-elements, lithium, sodium and aluminum in 16 open clusters
Authors: Zhang, R.; Lucatello, S.; Bragaglia, A.; Alonso-Santiago,
J.; Andreuzzi, G.; Casali, G.; Carrera, R.; Carretta, E.; Orazi,
V. D; Frasca, A.; Fu, X.; Magrini, L.; Minchev, I.; Origlia, L.;
Spina, L.; Vallenari, A.
Bibcode: 2022arXiv220901738Z
Altcode:
Exploring the Galactic chemical evolution and enrichment scenarios
with open clusters allows us to understand the history of the Milky
Way disk. High-resolution spectra of OCs are a crucial tool, as they
provide precise chemical information, to combine with precise distances
and ages. The aim of the Stellar Population Astrophysics project is to
derive homogeneous and accurate comprehensive chemical characterization
of a number of poorly studied OCs.Using the HARPS-N echelle spectrograph
at the Telescopio Nazionale Galileo, we obtained high-resolution spectra
of giant stars in 18 OCs, 16 of which are chemically characterized for
the first time, and two of which are well studied for comparison. The
OCs in this sample have ages from a few tens of Myr to 4 Gyr, with a
prevalence of young clusters. We already presented the radial velocities
and atmospheric parameters for them in a previous SPA paper. Here,
we present results for the alpha-elements O, and the light elements,
all determined by the equivalent width method. We also measured Li
abundance through the synthesis method.We discuss the behaviors of
lithium, sodium and aluminum in the context of stellar evolution. We
study the radial, vertical, and age trends for the measured abundance
ratios in a sample that combines our results and recent literature
for OCs, finding significant gradients only for [Mg/Fe] and [Ca/Fe]
in all cases. Finally,we compare O and Mg in the combined sample with
chemo-dynamical models, finding a good agreement for intermediate-age
and old clusters. There is a sharp increase in the abundance ratios
measured among very young clusters, accompanied by a poorer fit
with the models for O and Mg, likely related to the inadequacy
of traditional model atmospheres and methods in the derivation of
atmospheric parameters and abundance ratios for stars of such young ages
Title: Catching a Relativistic Jet Shut Off in the Tidal Disruption
Event AT2022cmc
Authors: Eftekhari, Tarraneh
Bibcode: 2022cxo..prop.6373E
Altcode:
Transient accretion onto a supermassive black hole through the
tidal disruption of a stray star offers a unique opportunity to
map the complete lifecycle of relativistic jets and outflows. In
2011, X-ray observations of the tidal disruption event (TDE) Swift
J1644+57 revealed that these events can power luminous relativistic
jets. Nevertheless, observations have revealed that powerful jets in
TDEs are extremely rare; despite over a decade of searching, there
are only two well-studied jetted TDEs to date. In this proposal we
request Chandra X-ray observations of the recently discovered transient
AT2022cmc, the first TDE observed to launch a powerful relativistic
jet in 11 years, to track the longterm X-ray evolution and map the
transition to sub-Eddington accretion as the jet turns off.
Title: Compact Binary Foreground Subtraction in Next-Generation
Ground-Based Observatories
Authors: Zhou, Bei; Reali, Luca; Berti, Emanuele; Çalışkan, Mesut;
Creque-Sarbinowski, Cyril; Kamionkowski, Marc; Sathyaprakash, B. S.
Bibcode: 2022arXiv220901221Z
Altcode:
The stochastic gravitational-wave backgrounds (SGWBs) for current
detectors are dominated by binary black-hole (BBH) and binary
neutron-star (BNS) coalescences. The sensitivity of current networks of
gravitational-wave (GW) detectors allows only a small fraction of BBHs
and BNSs to be resolved and subtracted, but previous work indicated
that the situation should significantly improve with next-generation
(XG) observatories. We revisit these conclusions by taking into account
waveform-modeling uncertainties, updated astrophysical models, and
(crucially) the full set of parameters that must be estimated to remove
the resolved sources. Compared to previous studies, we find that the
residual background from BBHs and BNSs is large even with XG detector
networks. New data analysis methods will thus be required to observe
the SGWB from cosmic supernovae or contributions from early-Universe
phenomena like cosmic strings, stiff post-inflation fluids, or axion
inflation.
Title: After a Mega-Flare: Surface Magnetic Fields, Particle Ejection
and Disk Ionization
Authors: Getman, Konstantin
Bibcode: 2022cxo..prop.6409G
Altcode:
The most powerful magnetic reconnection flares in normal stars
occur during the pre-main sequence phase, and the greatest number of
flares accessible to a single pointing of Chandra is the Orion Nebula
Cluster. In this multi-telescope project, Chandra will repeatedly
observe the ONC to identify mega-flares with enormous energies. These
flares will trigger ground-based observations over the following
days to: detect extended radio emission from mega-flare coronal mass
ejections with the VLBA; test predictions of elevated surface magnetic
field strengths by Zeeman infrared spectroscopy; and study the rise
and fall of ionization in a protoplanetary disk following a stellar
mega-flare with H13CO+ emission using ALMA.
Title: How the super-Eddington regime affects black hole spin
evolution in high-redshift galaxies
Authors: Massonneau, Warren; Dubois, Yohan; Volonteri, Marta; Beckmann,
Ricarda S.
Bibcode: 2022arXiv220901369M
Altcode:
By performing three-dimensional hydrodynamical simulations of a galaxy
in an isolated dark matter halo, we follow the evolution of the spin
parameter $a$ of a black hole (BH) undergoing super-Eddington phases
throughout its growth. This regime, suspected to be accompanied by
powerful jet outflows, is expected to decrease the BH spin magnitude. We
combine super-Eddington accretion with sub-Eddington phases (quasar
and radio modes) and follow the BH spin evolution. Due to the low
frequency of super-Eddington episodes, relativistic jets in this
regime are not able to decrease the magnitude of the spin effectively,
as thin disc accretion in the quasar mode inevitably increases the BH
spin. The combination of super- and sub-Eddington accretion does not
lead to a simple explicit expression for the spin evolution because
of feedback from super-Eddington events. An analytical expression can
be used to calculate the evolution for $a\lesssim0.3$, assuming the
super-Eddington feedback is consistently weak. Finally, BHs starting
with low spin magnitude are able to grow to the highest mass, and if
they initially start misaligned with the galactic disc, they get a
small boost of accretion through retrograde accretion.
Title: A Census of Pulsar Wind Nebulae and Their Pulsars
Authors: Kargaltsev, Oleg
Bibcode: 2022cxo..prop.6418K
Altcode:
The CXO's sub-arcsecond resolution and low background makes it uniquely
suited for PWN studies. In fact, ~80% of PWNe were discovered in X-rays
with CXO. Earlier populations studies of PWNe revealed some intriguing
trends and correlations, but there has not been a comprehensive PWN
census since 2012 although many new PWNe have been found. In the past
decade Fermi LAT has discovered and characterized the properties of many
gamma-ray pulsars associated with the CXO-resolved PWNe. Evidence is
emerging that the PWN morphological and spectral properties are linked
to the pulsar's magnetospheric geometry, which also shapes the GeV
pulse profiles and spectra. We propose to study this connection while
performing an overdue census of PWNe and pulsars observed with CXO.
Title: A first look at two newly discovered MeerKAT minihalos
Authors: O'Sullivan, Ewan
Bibcode: 2022cxo..prop.6390O
Altcode:
Radio minihalos are diffuse synchrotron sources of unknown origin
which occupy the cool cores of massive clusters, often confined
within sloshing fronts. To date only about 25 minihalos are known
but additional examples are beginning to be identified by the new
generation of radio observatories. We propose snapshot observations
of two newly-identified minihalos from the MeerKAT Galaxy Cluster
Legacy Survey for which no modern X-ray data is available. With 45ks
of ACIS-I time we will determine the basic properties of the host
clusters, confirm their cool core status, examine them for signs of
sloshing and recent interactions, and characterize the intra-cluster
medium in their minihalos, allowing comparison with minihalo formation
models and the wider cluster population.
Title: Core orientations and magnetic fields in isolated molecular
clouds
Authors: Sharma, Ekta; Gopinathan, Maheswar; Soam, Archana; Lee,
Chang Won; Seshadri, T. R.
Bibcode: 2022arXiv220901509S
Altcode:
Molecular clouds are sites of star formation. Magnetic fields are
believed to play an important role in their dynamics and shaping
morphology. We aim to study any possible correlation that might exist
between the magnetic fields orientation inside the clouds and the
magnetic fields at envelope scales and their connection with respect to
the observed morphology of the selected clouds. We examine the magnetic
field orientation towards the clouds L1512, L1523, L1333, L1521E, L1544,
L1517, L1780, and L183 using optical and \textit{Planck} polarization
observations. We also found the correlation between the ambient magnetic
field and core orientations derived using \textit{Astrodendrogram} on
the \textit{Herschel} 250 $\mu$m data. We find that the magnetic fields
derived from optical and \textit{Planck} agree with each other. The
derived magnetic fields are aligned along the observed emission of
each cloud as seen in \textit{Herschel} 250 $\mu$m data. We also
find that the relative orientation between the cores and the magnetic
fields is random. This lack of correlation may arise due to the fact
that the core orientation could also be influenced by the different
magnetization within individual clouds at higher densities or the
feedback effects which may vary from cloud to cloud. The estimated
magnetic field strength and the mass-to-flux ratio suggest that all
the clouds are in a magnetically critical state except L1333, L1521E,
and L183 where the cloud envelope could be strongly supported by the
magnetic field lines.
Title: ToO Observations of the Microquasar GRS 1915+105 in Quiescence
Authors: Casella, Piergiorgio
Bibcode: 2022cxo..prop.6284C
Altcode:
In July 2018 the black hole binary GRS 1915+105 underwent a transition
to unprecedented low-flux state, which might precede the end of
a 30-years-long outburst of this source. We propose to observe this
system with three Chandra observations, each 30-ks long (plus four Swift
observations, 0.5-ks each), should its outburst end during the 24th
observing cycle. GRS 1915+105 has never been observed in quiescence:
observations in this state will allow us to measure the spectrum and
test the proposed models for quiescent emission in black-hole binaries.
Title: On observational signatures of multi-fractional theory
Authors: Asghari, Mahnaz; Sheykhi, Ahmad
Bibcode: 2022arXiv220903055A
Altcode:
We study the multi-fractional theory with $q$-derivatives, where the
multi-fractional measure is considered to be in the time direction. The
evolution of power spectra and also the expansion history of the
universe are investigated in the $q$-derivatives theory. According to
the matter power spectra diagrams, the structure growth would increase
in the multi-fractional model, expressing incompatibility with low
redshift measurements of large scale structures. Furthermore, concerning
the diagrams of Hubble parameter evolution, there is a reduction in
the value of Hubble constant which conflicts with local cosmological
constraints. We also explore the multi-fractional model with current
observational data, principally Planck 2018, weak lensing, supernovae,
baryon acoustic oscillations (BAO), and redshift-space distortions
(RSD) measurements. Numerical analysis reveals that the degeneracy
between multi-fractional parameters makes them remain unconstrained
under observations.
Title: Propagation of scalar and tensor gravitational waves in
Horndeski theory
Authors: Kubota, Kei-ichiro; Arai, Shun; Mukohyama, Shinji
Bibcode: 2022arXiv220900795K
Altcode:
Gravitational waves travel through the distributions of matter and
dark energy during propagation. For this reason, gravitational waves
emitted from binary compact objects serve as a useful tool especially to
probe the nature of dark energy. The geometrical optics approximation
is a conventional way of investigating wave propagation. However,
the approximation becomes less accurate as the wavelength approaches
the curvature radius of the background, which can occur in generic
situations. In this paper, we suggest a formulation for higher-order
corrections of the geometrical optics expansion, applied to Horndeski
theory which accommodates many dark energy models. At the level of
the background, assuming that the derivative of the scalar field is
non-vanishing and timelike, we choose the time slices to coincide with
the contours of the scalar field. This choice of the background time
slices is advantageous as the sound cones of both scalar and tensor
gravitational waves are upright with respect to the background time
slices whenever the scalar field behaves as a perfect fluid. We then
analyze the equations of motion for scalar and tensor components
of gravitational waves at the leading and next-to-leading order in
the geometrical optics expansion, deriving the evolution equations
for their amplitudes under certain conditions. In particular, for
Generalized Brans-Dicke theories, we find a simple description of
equations for gravitational waves in terms of an effective metric.
Title: Light propagation in (2+1)-dimensional electrodynamics:
the case of linear constitutive laws
Authors: Goulart, Érico; Bittencourt, Eduardo; Brandão, Elliton O. S.
Bibcode: 2022arXiv220900770G
Altcode:
In this paper, we turn our attention to light propagation in
three-dimensional electrodynamics. More specifically, we investigate
the behavior of light rays in a continuous bi-dimensional hypothetical
medium living in a three-dimensional ambient spacetime. Relying on
a fully covariant approach, we assume that the medium is endowed
with a local and linear response tensor which maps field strengths
into excitations. In the geometric optics limit, we then obtain the
corresponding Fresnel equation and, using well-known results from
algebraic geometry, we derive the effective optical metric.
Title: Changing-Look Quasars: How/Does Accretion Variability Scale?
Authors: Green, Paul
Bibcode: 2022cxo..prop.6380G
Altcode:
Virtually unknown a decade ago, dozens of 'changing look quasars' (CLQs)
have recently been found, where UV continuum and broad emission lines
drop (or rise) dramatically. CLQ transitions have been attributed to
tidal disruption events, significant changes in intrinsic absorption
or in accretion rate, but all these hypotheses suffer theoretical or
empirical challenges. We propose Chandra ToOs for CLQs with existing
X-ray observations, triggered only after confirmation via optical
imaging and spectroscopy. For both dim and bright states we thereby
characterize CLQ changes in nuclear X-ray luminosity, intrinsic
absorption, and accretion rate, testing several contending models,
including - together with joint VLA imaging - promising analogies to
the accretion states of X-ray binaries.
Title: Smaller Sensitivity of Precipitation to Surface Temperature
under Massive Atmospheres
Authors: Xiong, Junyan; Yang, Jun; Liu, Jiachen
Bibcode: 2022arXiv220902294X
Altcode:
Precipitation and its response to forcings is an important aspect of
planetary climate system. In this study, we examine the strength of
precipitation in the experiments with different atmospheric masses
and their response to surface warming, using three global atmospheric
general circulation models (GCMs) and one regional cloud-resolving model
(CRM). We find that precipitation is weaker when atmospheric mass is
larger for a given surface temperature. Furthermore, the increasing
rate of precipitation with increasing surface temperature under a
larger atmospheric mass is smaller than that under a smaller atmospheric
mass. These behaviors can be understood based on atmospheric or surface
energy balance. Atmospheric mass influences Rayleigh scattering,
multiple scattering in the atmosphere, pressure broadening, lapse
rate, and thereby precipitation strength. These results have important
implications on the climate and habitability of early Earth, early Mars,
and exoplanets with oceans.
Title: A Mechanism for Dark Matter and Dark Energy in the Theory of
Causal Fermion Systems
Authors: Finster, Felix; Isidro, J. M.
Bibcode: 2022arXiv220902234F
Altcode:
It is shown that the theory of causal fermion systems gives rise to a
novel mechanism for dark matter and dark energy. This mechanism is first
worked out for cubical subsets of Minkowski space with periodic boundary
conditions. Then it is studied in Friedmann-Lemaître-Roberson-Walker
spacetimes. The magnitude of the effect scales like one over the
lifetime of the universe squared. In contrast to most models of
dark matter and dark energy, our mechanism does not postulate any
new particles. Instead, it is a result of the collective behavior of
all the wave functions which form the Dirac sea, needed in order to
arrange correlated initial and end quantum states of the universe.
Title: Turbulence in outer protoplanetary disks: MRI or VSI?
Authors: Cui, Can; Bai, Xue-Ning
Bibcode: 2022arXiv220902897C
Altcode:
The outer protoplanetary disks (PPDs) can be subject to the
magnetorotational instability (MRI) and the vertical shear instability
(VSI). While both processes can drive turbulence in the disk, existing
numerical simulations have studied them separately. In this paper,
we conduct global 3D non-ideal magnetohydrodynamic (MHD) simulations
for outer PPDs with ambipolar diffusion and instantaneous cooling, and
hence conductive to both instabilities. Given the range of ambipolar
Elsässer numbers ($Am$) explored, it is found that the VSI turbulence
dominates over the MRI when ambipolar diffusion is strong ($Am=0.1$);
the VSI and MRI can co-exist for $Am=1$; and the VSI is overwhelmed by
the MRI when ambipolar diffusion is weak ($Am=10$). Angular momentum
transport process is primarily driven by MHD winds, while viscous
accretion due to MRI and/or VSI turbulence makes a moderate contribution
in most cases. Spontaneous magnetic flux concentration and formation
of annular substructures remain robust in strong ambipolar diffusion
dominated disks ($Am\leq1$) with the presence of the VSI. Ambipolar
diffusion is the major contributor to the magnetic flux concentration
phenomenon rather than advection.
Title: The quest for the energy source powering Superluminous
Supernovae (SLSNe)
Authors: Chornock, Ryan
Bibcode: 2022cxo..prop.6323C
Altcode:
We propose an in-depth study of 1 SLSN. SLSNe are >10-100 times more
luminous than ordinary SN and represent the deaths of the most massive
stars. Their extreme luminosity requires exotic explosion mechanisms
and sources of energy whose nature is unclear. Building on the recent
detections of SLSNe 2018bsz and 2020tcw, we propose a focused Chandra
program to map the SLSN X-ray emission down to unprecedented limits
as part of a multi-wavelength effort (UV, optical/NIR, radio, hard
X-rays). The final goal is to: (i) Pin down the energy source; (ii) Map
the diversity of the pre-explosion evolution of their progenitors. (iii)
Constrain their possible association with GRBs. This study opens
a new window of investigation on the physics of the most powerful
stellar explosions.
Title: Studying a Co-Evolving Cluster Population over 9 Gyr with
Chandra
Authors: McDonald, Michael
Bibcode: 2022cxo..prop.6403M
Altcode:
The study of galaxy cluster evolution has exploded in recent years with
the advent of Sunyaev Zel'dovich surveys. However, these surveys, which
are redshift-independent but strongly mass dependent, are sensitive
to increasingly rare clusters as a function of redshift. This may
be biasing evolutionary studies which compare z>1 clusters to z~0
clusters despite the fact that these samples are not evolutionarily
connected. We propose here the extension of a sample of 200 clusters
spanning 9 Gyr in cosmic time that all lie along the same evolutionary
track. This sample will provide new, strong constraints on the
evolution of the cool core fraction, the evolution of the merger rate
and relaxation time, and the evolution of AGN in clusters, along with
a variety of other exciting topics.
Title: Black Hole Candidate in an Extreme SMC Heartbeat Star
Authors: Oey, Sally
Bibcode: 2022cxo..prop.6289O
Altcode:
The extreme, 50 M_sun Oe star, AzV 493 in the SMC is most likely a
heartbeat-like star with an unseen companion of orbital eccentricity
~0.99. We propose to confirm its nature with a 20 ks ACIS observation
near periastron to identify this system as a transient HMXB. This
would be the earliest, highest eccentricity OBeXRB known. The putative
progenitor of the unseen compact companion likely had initial mass
> 30 M_sun, implying a high likelihood that it could be a black
hole. Confirmation of a compact companion would make this metal-poor,
extreme system a key empirical prototype for understanding massive
binary evolution, supernova kicks, OBe stars, binary compact objects,
and their descendant phenomena including gravitational waves.
Title: Skylight: a new code for general-relativistic ray-tracing
and radiative transfer in arbitrary space-times
Authors: Pelle, Joaquin; Reula, Oscar; Carrasco, Federico; Bederian,
Carlos
Bibcode: 2022MNRAS.515.1316P
Altcode: 2022arXiv220606429P; 2022MNRAS.tmp.1785P
To reproduce the observed spectra and light curves originated in
the neighbourhood of compact objects requires accurate relativistic
ray-tracing codes. In this work, we present Skylight, a new numerical
code for general-relativistic ray-tracing and radiative transfer
in arbitrary space-time geometries and coordinate systems. The
code is capable of producing images, spectra, and light curves
from astrophysical models of compact objects as seen by distant
observers. We incorporate two different schemes, namely Monte Carlo
radiative transfer integrating geodesics from the astrophysical region
to distant observers, and camera techniques with backwards integration
from the observer to the emission region. The code is validated by
successfully passing several test cases, among them: thin accretion
discs and neutron stars hotspot emission.
Title: Kinetic and equilibrium reactions on natural and laboratory
generation of thermogenic gases from Type II marine shale
Authors: Li, Xiaoqiang; Horita, Juske
Bibcode: 2022GeCoA.333..263L
Altcode:
The phenomenon that laboratory pyrolysis experiments produce much wetter
gases than those in natural reservoirs is a long-recognized and debated
problem in the investigation of natural gases in sedimentary basins. In
this study, we explore the discrepancy by pyrolyzing a type II kerogen
from the Woodford Shale in Oklahoma, compared with the previous results
on the produced natural gases from the Arkoma Basin generated from the
same source rock (Liu et al., 2019) with the discussion of gas and
isotopic compositions at bulk and position-specific (PS) levels. An
improved GC-pyrolysis-GC IRMS method is applied for the determination
of PS δ13C of propane produced in the pyrolysis of the
Woodford Shale at Easy %Ro from 0.76 to 3.27. Kinetic
and thermodynamic considerations of the chemical and isotopic
compositions of the natural and laboratory pyrolysis gases suggest
that the generation of light hydrocarbons involves uni-directional
cracking reactions, exchange reactions with water, and likely
reversible reactions among light hydrocarbons and other H-containing
volatiles. After the gas generation in the unconventional Woodford
Shale reservoirs, the C1-C4 gases might have
approached close to chemical equilibrium of C1-C3
and isotope equilibrium of C2-C1 and
C3-C1 pairs at their peak temperatures. The
capping H for the generation of C1-C4 in the
Woodford Shale gases appears to have experienced at least partial
exchange with the water, while that in the pyrolysis gases is only
originated from organic-bound compounds with large kinetic isotope
effects (KIE). Our findings indicate that elevated compound-specific
and PS δ13C values of propane in the wet-gas cracking stage
are significantly influenced by the breakdown of the thermally stable
compounds (e.g., remaining kerogen, residues). A first synthesis of PS
δ13C and δ2H isotopic compositions of propane
from this study and the literature data suggests relatively similar
isotopic structures of propane precursors in kerogens. This study
demonstrates that PS isotope analysis of propane can contribute to
identifying various geological (e.g., maturation, wet-gas cracking,
H exchange, diffusion) and biodegradation processes.
Title: Reduction of $^{222}$Rn-induced Backgrounds in a Hermetic
Dual-Phase Xenon Time Projection Chamber
Authors: Dierle, Julia; Brown, Adam; Fischer, Horst; Glade-Beucke,
Robin; Grigat, Jaron; Kuger, Fabian; Lindemann, Sebastian; Rajado
Silva, Mariana; Schumann, Marc
Bibcode: 2022arXiv220900362D
Altcode:
The continuous emanation of $^{222}$Rn from detector surfaces causes the
dominant background in current liquid xenon time projection chambers
(TPCs) searching for dark matter. A significant reduction is required
for the next generation of detectors which are aiming to reach the
neutrino floor, such as DARWIN. $^{222}$Rn-induced back\-grounds can
be reduced using a hermetic TPC, in which the sensitive target volume
is mechanically separated from the rest of the detector containing
the majority of Rn-emanating surfaces. We present a hermetic TPC that
mainly follows the well-established design of leading xenon TPCs and
has been operated successfully over a period of several weeks. By
scaling up the results achieved to the DARWIN-scale, we show that the
hermetic TPC concept can reduce the $^{222}$Rn concentration to the
required level, even with imperfect separation of the volumes.
Title: Stellar activity with TESS and Chandra
Authors: Guenther, Hans
Bibcode: 2022cxo..prop.6412G
Altcode:
Stellar activity is the signature of magnetic fields powered by
a convective dynamo. By studying X-ray activity, we work towards
understanding stellar structure and stellar evolution. Also, X-ray
and FUV radiation can evaporate exoplanet atmospheres and sterilize
planetary surfaces. On the other hand, it also drives a rich
photochemistry, possibly enabling the building blocks of life. In
this proposal, we request funding to study, as a homogeneous set,
a number of Chandra Cool Attitude Target (CAT) observations taken in
the Stellar activity with TESS and Chandra program.
Title: Joule-Thomson expansion of charged dilatonic black holes
Authors: Zhang, Meng-Yao; Chen, Hao; Hassanabadi, Hassan; Long,
Zheng-Wen; Yang, Hui
Bibcode: 2022arXiv220900868Z
Altcode:
Based on the Einstein-Maxwell theory, the Joule-Thomson (J-T)
expansion of charged dilatonic black holes(neither flat nor AdS) for
high-dimensional spacetime is studied. To this end, we analyze effects
of dimensions $n$ and dilaton field $\alpha$ on the J-T expansion in
terms of the J-T coefficient, inversion curves and the isenthalpic
curves. This shows that the divergence point of the J-T coefficient
coincides exactly with the zero point of Hawking temperature. We also
reveal the more fine structure with the increase of dimension in the
$T-P$ plane. In contrast to the effect of dimension, the inversion
curve decreases with electric charge $Q$ at low pressure and the
opposite is observed at high pressure. Then, we plot the isonthalpic
curve in the $T-P$ plane, it show that there are intersecting points
between the inversion curves and the maximum extremum of isonthalpic
curves. Furthermore, concerning the ratio $T_{min}/T_{c}$, we analyse
it numerically and find that the ratio has a fixed value which is
independent of the dilaton parameter $\alpha$ for a given fixed charge.
Title: Hadamard states on spherically symmetric characteristic
surfaces, the semi-classical Einstein equations and the Hawking effect
Authors: Janssen, Daan W.; Verch, Rainer
Bibcode: 2022arXiv220900577J
Altcode:
We investigate quasi-free Hadamard states defined via characteristic
initial data on nullcones centred at the axis of symmetry in spherically
symmetric space-times. We characterize the necessary singular behaviour
of null-boundary two-point functions such that one can define non-linear
observables at this null-boundary and give formulas for the calculation
of these observables. These results extend earlier characterizations
of null-boundary states defining Hadamard states in the bulk of the
null-cone. As an application of our derived formulas, we consider its
implications for the semi-classical Einstein equations and calculate
a Wick square associated with Hawking radiation near a collapsing body.
Title: Quantifying the redshift space distortion of the bispectrum
III : Detection prospects of the multipole moments
Authors: Mazumdar, Arindam; Sarkar, Debanjan; Bharadwaj, Somnath
Bibcode: 2022arXiv220903233M
Altcode:
The redshift space anisotropy of the bispectrum is generally quantified
using multipole moments. The possibility of measuring these multipoles
in any survey depends on the level of statistical fluctuations. We
present a formalism to compute the statistical fluctuations in the
measurement of bispectrum multipoles for galaxy surveys. We consider
specifications of a {\it Euclid} like galaxy survey and present
two quantities: the signal-to-noise ratio (SNR) which quantifies the
detectability of a multipole, and the rank correlation which quantifies
the correlation in measurement errors between any two multipoles. Based
on SNR values, we find that {\it Euclid} can potentially measure the
bispectrum multipoles up to $\ell=4$ across various triangle shapes,
formed by the three {\bf k} vectors in Fourier space. In general,
SNR is maximum for the linear triangles. SNR values also depend on the
scales and redshifts of observation. While, $\ell \leq 2$ multipoles
can be measured with ${\rm SNR}>5$ even at linear/quasi-linear ($k
\lesssim 0.1 \,{\rm Mpc}^{-1}$) scales, for $\ell>2$ multipoles,
we require to go to small scales or need to increase bin sizes. For
most multipole pairs, the errors are only weakly correlated across much
of the triangle shapes barring a few in the vicinity of squeezed and
stretched triangles. This makes it possible to combine the measurements
of different multipoles to increase the effective SNR.
Title: WD Periastron Passage in the R Aqr System: Zooming on the
New Ejecta and Jet
Authors: Karovska, Margarita
Bibcode: 2022cxo..prop.6447K
Altcode:
We propose HST observations of the R Aqr symbiotic binary system,
jointly with Chandra and VLA, as a follow up on the 2020 and 2021
archival observations which show dramatic changes within 1 from
the central binary resulting from the enhanced accretion during the
recent periastron passage of the white dwarf (WD) accretor. These
phenomena are observable in R Aqr only about twice a century, with the
next periastron expected in about 40 years. Our goal is to carry out a
timely high-angular resolution multi-wavelength study of this event by
zooming in on the central 3 radius circumbinary region. This will allow
us to determine the spatial/spectral evolution of the distribution and
the characteristics of the new ejecta and jet, and to gain a unique
insight into jet formation and early pr
Title: Dinamic of Atlas
Authors: Tadeu Ceccatto, Demetrio; Callegari, Nelson; Rodrigues, Adrian
Bibcode: 2022arXiv220901213T
Altcode:
The current orbit of Atlas was analyzed using frequency phase space
mapping. Finding that the Corotation and Lindblad resonances are
separated by about 4 kilometers, the latter is related to Atlas
eccentricity greater than 0.0095. Extending the Dynamic Maps concept
we find, in addition to the 53:52 resonance (Cooper et al. 2015), the
55:54 resonance. Finally, we demonstrate how gravitational perturbations
by Pandora contribute to additional oscillations of the critical angle
for the 54:53 resonance
Title: The Quadrupole Moment of Compact Binaries to the Fourth
post-Newtonian Order: Relating the Harmonic and Radiative Metrics
Authors: Trestini, David; Larrouturou, François; Blanchet, Luc
Bibcode: 2022arXiv220902719T
Altcode:
Motivated by the completion of the fourth post-Newtonian (4PN)
gravitational-wave generation from compact binary systems, we analyze
and contrast different constructions of the metric outside an isolated
system, using post-Minkowskian expansions. The metric in "harmonic"
coordinates has been investigated previously, in particular to compute
tails and memory effects. However, it is plagued by powers of the
logarithm of the radial distance $r$ when $r\to\infty$ (with $t-r/c=$
const). As a result, the tedious computation of the "tail-of-memory"
effect, which enters the gravitational-wave flux at 4PN order, is more
efficiently performed in the so-called "radiative" coordinates, which
admit a (Bondi-type) expansion at infinity in simple powers of $r^{-1}$,
without any logarithms. Here we consider a particular construction,
performed order by order in the post-Minkowskian expansion, which
directly yields a metric in radiative coordinates. We relate both
constructions, and prove that they are physically equivalent as soon
as a relation between the "canonical" moments which parametrize the
radiative metric, and those parametrizing the harmonic metric, is
verified. We provide the appropriate relation for the mass quadrupole
moment at 4PN order, which will be crucial when deriving the
"tail-of-memory" contribution to the gravitational flux.
Title: Non-perturbative production of fermionic dark matter from
fast preheating
Authors: Klaric, Juraj; Shkerin, Andrey; Vacalis, Georgios
Bibcode: 2022arXiv220902668K
Altcode:
We investigate non-perturbative production of fermionic dark matter in
the early universe. We study analytically the gravitational production
mechanism accompanied by the coupling of fermions to the background
inflaton field. The latter leads to the variation of effective fermion
mass during preheating and makes the resulting spectrum and abundance
sensitive to its parameters. Assuming fast preheating that completes
in less than the inflationary Hubble time and no oscillations of the
inflaton field after inflation, we find an abundant production of
particles with energies ranging from the inflationary Hubble rate to
the inverse duration of preheating. The produced fermions can account
for all observed dark matter in a broad range of parameters. As an
application of our analysis, we study non-perturbative production of
heavy Majorana neutrino in the model of Palatini Higgs inflation.
Title: An X-ray Study of a Tidal Disruption Event in an AGN Host
Galaxy
Authors: Blanchard, Peter
Bibcode: 2022cxo..prop.6369B
Altcode:
The latest generation of wide-field time-domain surveys have discovered
new rare types of transients including luminous transients coincident
with the nuclei of AGN galaxies that could be due to superluminous
supernovae, tidal disruption events, or extreme AGN activity. We propose
to obtain a Chandra observation of PS16dtm, one of the first members
of this class of luminous nuclear transients in galaxies with AGN. The
disappearance of X-ray emission relative to an archival detection of
the AGN suggests that PS16dtm is a tidal disruption event in which
the accretion of the stellar debris obscures the X-ray emission from
the AGN. Chandra observations of PS16dtm will allow us to determine if
and when the X-rays reappear, providing a crucial test of this scenario.
Title: Point spread function reconstruction for SOUL+LUCI LBT data
Authors: Simioni, Matteo; Arcidiacono, Carmelo; Wagner, Roland;
Grazian, Andrea; Gullieuszik, Marco; Portaluri, Elisa; Vulcani,
Benedetta; Zanella, Anita; Agapito, Guido; Davies, Richard; Helin,
Tapio; Pedichini, Fernando; Piazzesi, Roberto; Pinna, Enrico; Ramlau,
Ronny; Rossi, Fabio; Salo, Aleksi
Bibcode: 2022arXiv220901563S
Altcode:
This paper presents the status of an ongoing project aimed at developing
a PSF reconstruction software for adaptive optics (AO) observations. In
particular, we test for the first time the implementation of pyramid
wave-front sensor data on our algorithms. As a first step in assessing
its reliability, we applied the software to bright, on-axis, point-like
sources using two independent sets of observations, acquired with the
single-conjugated AO upgrade for the Large Binocular Telescope. Using
only telemetry data, we reconstructed the PSF by carefully calibrating
the instrument response. The accuracy of the results has been first
evaluated using the classical metric: specifically, the reconstructed
PSFs differ from the observed ones by less than 2% in Strehl ratio and
4.5% in full-width at half maximum. Moreover, the recovered encircled
energy associated with the PSF core is accurate at 4% level in the worst
case. The accuracy of the reconstructed PSFs has then been evaluated
by considering an idealized scientific test-case consisting in the
measurements of the morphological parameters of a compact galaxy. In
the future, our project will include the analysis of anisoplanatism, low
SNR regimes, and the application to multi-conjugated AO observations.
Title: A Search for Pulsar Filaments
Authors: Romani, Roger
Bibcode: 2022cxo..prop.6314R
Altcode:
The rare misaligned pulsar filaments (e.g. the Guitar nebula filament)
represent an important channel for the escape of multi-TeV e+/e- to the
ISM, likely enabled by a small bow shock stand-off distance. From the
ATNF catalog, we select pulsars expected to have small stand-off and
find that almost none have had sensitive X-ray observations. From the
best such candidates, we identify a set with small CXO resource cost. We
also develop a new statistic capable of identifying filaments comparable
to the faintest long filament known, using modest ACIS exposures. Our
survey could double the number of known pulsar filaments, helping
test their physical nature and importance for the Galactic cosmic
ray positrons.
Title: Gravity theories with local energy-momentum exchange: a closer
look at Rastall's theory
Authors: Vanzella, Daniel A. T.
Bibcode: 2022arXiv220901186V
Altcode:
The famous Einstein's equivalence principle is certainly one of
the most striking features of the gravitational interaction. In a
strict reading, it states that the effects of gravity can be made to
disappear $locally$ by a convenient choice of reference frame. As a
consequence, no covariantly-defined gravitational force should exist
and energy-momentum of all matter and interaction fields combined,
with gravity $excluded$, should be locally conserved. Although elegant,
this separate conservation law represents a strong constraint on the
dynamics of a gravitating system and it is only logical to question
its naturality and observational basis. This is the purpose of the
present work. For concreteness sake, we analyze, in the context
of metric theories of gravity, the simplest phenomenological model
which allows for energy-momentum exchange between the spacetime and
matter/interaction fields, revisiting, with a new look, the socalled
Rastall's theory. We show that by imposing compatibility with Newtonian
gravity in the proper regime, this issue of "nonconservative gravity" is
inevitably tied to the existence of "dark" ingredients -- a connection
which seems to have been overlooked thus far. We conclude by exploring
consequences of Rastall's theory, with the correct Newtonian limit,
on standard gravitational (astrophysical and cosmological) scenarios.
Title: Multi-kink braneworld configurations in the scalar-tensor
representation of $f(R,T)$ gravity
Authors: Bazeia, D.; Lobão, A. S., Jr.; Luís Rosa, João
Bibcode: 2022arXiv220901928B
Altcode:
In this work we investigate the $f(R,T)$ brane in the scalar-tensor
representation, where the solutions of the equations of motions for the
source field engender topological defects with two-kink profiles. We use
the first-order formalism to obtain analytical solutions for the source
field of the brane and analyze how these solutions modify the structure
of the auxiliary fields arising from the scalar-tensor representation of
the theory. We found that when the model engenders two-kink solutions,
the auxiliary fields are modified in order to allow for the appearance
of an internal structure. In addition, the stability potential and zero
mode also have their internal structure modified by two-kink solution.
Title: Characterizing the Energetics and Dynamics of V750 Ara,
a gamma Cas-type Star
Authors: Huenemoerder, David
Bibcode: 2022cxo..prop.6277H
Altcode:
We propose to obtain high resolution spectra with HETG of the gamma
Cas-type star, V750 ara. These stars, of which about 25 are known,
are Oe/Be stars which have very hard and strong X-ray emission. Their
nature is enigmatic with several proposed explanations, one of which is
that they have an He-star companion with a strong wind. With a 200 ks
HETGS spectrum, we will characterize plasma temperatures from emission
lines of Fe, Si, Mg, and S, and determine dynamical parameters from
line widths and centroids. We also request a NuSTAR observation of
100 ks which is necessary to constrain the high temperature plasma,
via the spectral energy distribution between 10 and 30 keV.
Title: Background independence and the Adler-Bardeen theorem
Authors: Zahn, Jochen
Bibcode: 2022arXiv220902393Z
Altcode:
We prove that for renormalizable Yang-Mills gauge theory with
arbitrary compact gauge group (of at most a single abelian factor)
and matter coupling, the absence of gauge anomalies can be established
at the one-loop level. This proceeds by relating the gauge anomaly to
perturbative agreement, which formalizes background independence.
Title: KMTNet Nearby Galaxy Survey: Overview and a Survey Description
Authors: Byun, Woowon; Sheen, Yun-Kyeong; Seon, Kwang-Il; Ho, Luis C.;
Lee, Joon Hyeop; Jeong, Hyunjin; Kim, Sang Chul; Park, Byeong-Gon;
Lee, Yongseok; Cha, Sang-Mok; Kim, Minjin
Bibcode: 2022arXiv220900902B
Altcode:
Recently, there has been an increasing demand for deep imaging
surveys to investigate the history of the mass assembly of galaxies
in detail by examining the remnants of mergers and accretions,
both of which have very low surface brightness (LSB). In addition,
the nature of star formation in LSB regions, such as galaxy outer
disks, is also an intriguing topic in terms of understanding the
physical mechanisms of disk evolution. To address these issues,
this study conducts a survey project, called the Korea Microlensing
Telescope Network (KMTNet) Nearby Galaxy Survey to construct a deep
imaging data set of nearby galaxies in the southern hemisphere using
KMTNet. It provides deep and wide-field images with a field-of-view of
$\sim$12 deg$^2$ for 13 nearby galaxies drawn from the Carnegie-Irvine
Galaxy Survey catalog, in optical broadbands ($BRI$) and an H$\alpha$
narrowband. Through a dedicated data reduction, the surface brightness
limit in 10$^{\prime\prime}\times10^{\prime\prime}$ boxes was found
to reach as deep as $\mu_{1\sigma}\sim29$-31 mag arcsec$^{-2}$ in
the optical broadbands and $f_{1\sigma}\sim1$-$2\times 10^{-18}$
erg s$^{-1}$ cm$^{-2}$ arcsec$^{-2}$ in the H$\alpha$ narrowband. To
conclude the paper, several possible scientific applications for this
data set are described.
Title: Exponential Fluctuations in the Modes of Orthogonal
Polarization in Pulsar Radio Emission
Authors: McKinnon, M. M.
Bibcode: 2022arXiv220900743M
Altcode:
A statistical model for the polarization of pulsar radio emission
is enhanced to account for the heavy modulation of the emission,
the possible covariance of the Stokes parameters, and the observed
asymmetries in the distributions of total intensity, polarization, and
fractional polarization by treating the intensities of the orthogonal
polarization modes as exponential random variables. The model is used to
derive theoretical distributions to compare with what is observed. The
resulting distributions are unimodal and generally asymmetric. The
unimodality arises from the model's fundamental assumption that the
orthogonal modes are superposed. The asymmetry originates primarily
from different fluctuations in mode intensities. The distributions
of fractional polarization are truncated at the degree of linear and
circular polarization intrinsic to the modes. A number of observable
parameters that quantify the statistical properties of the emission
and its polarization are derived and are shown to be functions only
of the ratio of the modes' mean intensities, M, suggesting their
spectra coevolve according to the frequency dependence of M. This
particular implementation of the model requires the modes to fluctuate
differently in order to replicate the observations. Since a single
underlying emission mechanism seems unlikely to selectively modulate
the mode intensities, the different fluctuations are attributed either
to different emission mechanisms for the modes or to mode-dependent
propagation or scattering effects in the pulsar magnetosphere.
Title: Navigating low-metallicity galaxies: clearing X-ray binary
channels and mapping feedback currents in NGC3109.
Authors: Oskinova, Lidia
Bibcode: 2022cxo..prop.6339O
Altcode:
We propose a joint, 100 ks Chandra and 30 ks XMM-Newton study of the
low-metallicity galaxy NGC3109. By combining unprecedented spatial
resolution of Chandra with the soft XMM-Newton response, we will obtain
a census of X-ray binaries, probe the nature of accreting sources, and
find hot bubbles in this template low-metallicity galaxy. New Chandra
observations will complement the HST observations of massive stars
in NGC3109. Obtaining first robust measurements of X-ray sources in
NGC3109 is a necessary next step to progress in our understanding of
massive binary star evolution and feedback at low-metallicities and,
by proxy, in early cosmic times.
Title: Tip-tilt anisoplanatism in MCAO-assisted astrometric
observations
Authors: Carlà, Giulia; Busoni, Lorenzo; Plantet, Cédric; Agapito,
Guido; Arcidiacono, Carmelo; Ciliegi, Paolo
Bibcode: 2022arXiv220900912C
Altcode:
A new era of ground-based observations, either in the infrared with
the next-generation of 25-40m extremely large telescopes or in the
visible with the 8m Very Large Telescope, is going to be assisted by
multi-conjugate adaptive optics (MCAO) to restore the unprecedented
resolutions potentially available for these systems in absence of
atmospheric turbulence. Astrometry is one of the main science drivers,
as MCAO can provide good quality and uniform correction over wide
field of views ($\sim$ 1 arcmin) and offer a large number of reference
sources with high image quality. The requirements have been set to
very high precisions on the differential astrometry (e.g. 50$\mu$as
for MICADO/MORFEO - formerly known as MAORY - at the Extremely Large
Telescope) and an accurate analysis of the astrometric error budget is
needed. In this context, we present an analysis of the impact of MCAO
atmospheric tip-tilt residuals on relative astrometry. We focus on
the effects of the scientific integration time on tip-tilt residuals,
that we model through the temporal transfer function of the exposure. We
define intra- and inter-exposure tip-tilt residuals that we use in the
estimation of the centroiding error and the differential tilt jitter
error within the astrometric error budget. As a case study, we apply
our results in the context of the MORFEO astrometric error budget.
Title: Thermal luminosity degeneracy of magnetized neutron stars
with and without hyperon cores
Authors: Anzuini, F.; Melatos, A.; Dehman, C.; Viganò, D.; Pons, J. A.
Bibcode: 2022MNRAS.515.3014A
Altcode: 2022MNRAS.tmp.2010A
The dissipation of intense crustal electric currents produces high Joule
heating rates in cooling neutron stars. Here, it is shown that Joule
heating can counterbalance fast cooling, making it difficult to infer
the presence of hyperons (which accelerate cooling) from measurements
of the observed thermal luminosity Lγ. Models with and
without hyperon cores match Lγ of young magnetars (with
poloidal-dipolar field Bdip ≳ 1014 G at the
polar surface and Lγ ≳ 1034 erg s-1
at t ≲ 105 yr) as well as mature, moderately magnetized
stars (with Bdip ≲ 1014 G and 1031
erg s-1 ≲ Lγ ≲ 1032 erg
s-1 at t ≳ 105 yr). In magnetars, the crustal
temperature is almost independent of hyperon direct Urca cooling in the
core, regardless of whether the latter is suppressed or not by hyperon
superfluidity. The thermal luminosities of light magnetars without
hyperons and heavy magnetars with hyperons have Lγ in the
same range and are almost indistinguishable. Likewise, Lγ
data of neutron stars with Bdip ≲ 1014 G but
with strong internal fields are not suitable to extract information
about the equation of state as long as hyperons are superfluid, with
maximum amplitude of the energy gaps of the order ≍1 MeV.
Title: Mass loss and the Eddington parameter
Authors: Bestenlehner, Joachim M.
Bibcode: 2022arXiv220901007B
Altcode:
Mass loss through stellar winds plays a dominant role in the
evolution of massive stars. Very massive stars (VMSs, $> 100
M_{\odot}$) display Wolf-Rayet spectral morphologies (WNh) whilst
on the main-sequence. Bestenlehner (2020) extended the elegant and
widely used stellar wind theory by Castor, Abbott & Klein (1975)
from the optically thin (O star) to the optically thick main-sequence
(WNh) wind regime. The new mass-loss description is able to explain
the empirical mass-loss dependence on the Eddington parameter and is
suitable for incorporation into stellar evolution models for massive
and very massive stars. The prescription can be calibrated with the
transition mass-loss rate defined in Vink & Gräfener (2012). Based
on the stellar sample presented in Bestenlehner et al. (2014) we
derive a mass-loss recipe for the Large Magellanic Cloud using the
new theoretical mass-loss prescription of Bestenlehner (2020).
Title: Cloud-scale Radio Surveys of Star Formation and Feedback in
Triangulum Galaxy M 33: VLA Observations
Authors: Tabatabaei, F. S.; Cotton, W.; Schinnerer, E.; Beck, R.;
Brunthaler, A.; Menten, K. M.; Braine, J.; Corbelli, E.; Kramer, C.;
Beckman, J. E.; Knapen, J. H.; Paladino, R.; Koch, E.; Camps Farina, A.
Bibcode: 2022arXiv220901389T
Altcode:
Studying the interplay between massive star formation and the
interstellar medium (ISM) is paramount to understand the evolution of
galaxies. Radio continuum (RC) emission serves as an extinction-free
tracer of both massive star formation and the energetic components
of the interstellar medium. We present a multi-band radio continuum
survey of the local group galaxy M 33 down to ~30 pc linear
resolution observed with the Karl G. Jansky Very Large Array
(VLA). We calibrate the star-formation rate surface density and
investigate the impact of diffuse emission on this calibration using
a structural decomposition. Separating the thermal and nonthermal
emission components, the correlation between different phases of the
interstellar medium and the impact of massive star formation are also
investigated. Radio sources with sizes <~ 200 pc constitute about 36%
(46%) of the total RC emission at 1.5 GHz (6.3 GHz) in the inner 18' x
18' (or 4kpc x 4kpc) disk of M 33. The nonthermal spectral index becomes
flatter with increasing star-formation rate surface density, indicating
the escape of cosmic ray electrons {from their birth places}. The
magnetic field strength also increases with star-formation rate
following a bi-modal relation, indicating that the small-scale turbulent
dynamo acts more efficiently at higher luminosities and star-formation
rates. Although the correlations are tighter in star-forming regions,
the nonthermal emission is correlated also with the more quiescent
molecular gas in the ISM. An almost linear molecular star-formation law
exists in M 33 when excluding diffuse structures. Massive star formation
amplifies the magnetic field and increases the number of high-energy
cosmic ray electrons, which can help the onset of winds and outflows.
Title: Deducing the Composition of Venus Cloud Particles with the
Autofluorescence Nephelometer (AFN)
Authors: Baumgardner, Darrel; Fisher, Ted; Newton, Roy; Roden, Chris;
Zmarzly, Pat; Seager, Sara; Petkowski, Janusz J.; Carr, Christopher
E.; Špaček, Jan; Benner, Steven A.; Tolbert, Margaret A.; Jansen,
Kevin; Grinspoon, David H.; Mandy, Christophe
Bibcode: 2022arXiv220902054B
Altcode:
The composition, sizes and shapes of particles in the clouds of Venus
have previously been studied with a variety of in situ and remote sensor
measurements. A number of major questions remain unresolved, however,
motivating the development of an exploratory mission that will drop
a small probe, instrumented with a single-particle autofluorescence
nephelometer (AFN), into Venus' atmosphere. The AFN is specifically
designed to address uncertainties associated with the asphericity
and complex refractive indices of cloud particles. The AFN projects
a collimated, focused, linearly polarized, 440 nm wavelength laser
beam through a window of the capsule into the airstream and measures
the polarized components of some of the light that is scattered by
individual particles that pass through the laser beam. The AFN also
measures fluorescence from those particles that contain material that
fluoresce when excited at a wavelength of 440 nm and emit at 470-520
nm. Fluorescence is expected from some organic molecules if present
in the particles. AFN measurements during probe passage through the
Venus clouds are intended to provide constraints on particle number
concentration, size, shape, and composition. Hypothesized organics,
if present in Venus aerosols, may be detected by the AFN as a precursor
to precise identification via future missions. The AFN has been chosen
as the primary science instrument for the upcoming Rocket Lab mission
to Venus, to search for organic molecules in the cloud particles and
constrain the particle composition.
Title: Field theory capable of guaranteeing the initial conditions
needed for inflation
Authors: Kaganovich, Alexander
Bibcode: 2022arXiv220900378K
Altcode:
Inflatonary model of a single scalar field with primordial potential
V(\phi)=\frac{1}{2}m^2\phi^2+\frac{\lambda}{4}\phi^4 (m^2 >0)
non-minimally coupled to gravity is studied in two-measures theory
(TMT) in the Palatini formalism. In the equations of motion presented
in the Einstein frame and rewritten in terms of the canonically
normalized scalar field \varphi, there arises a TMT effective
potential, which differs from the potential of the T-model in that it
has a plateau of finite length: for \varphi greater a certain value
varphi_0 the TMT effective potential becomes exponentially steep. The
length of the plateau, and hence the duration of a quasi-de Sitter
inflation, is controlled by a model parameter. The appearance of
this parameter, as well as the form of the TMT effective potential,
are a direct consequence of the features inherent only in TMT. A
detailed analysis shows that there is a rather narrow interval
of initial values of \varphi, bounded from above by \varphi_0, in
which the initial kinetic \rho_{kin,in} and gradient \rho_{grad,in}
energy densities turn out to be less than the potential energy
density; this requires the only additional condition, which is that
\rho_{kin,in}>\rho_{grad,in}. Therefore, in the space-time domain
where these restrictions are satisfied, the initial conditions necessary
for inflation are guaranteed.
Title: X-raying dual AGN candidates at sub-arcsec separation
identified by Gaia
Authors: Nardini, Emanuele
Bibcode: 2022cxo..prop.6375N
Altcode:
Dual AGNs are expected to be ubiquitous by all cosmological models,
yet their identification still represents a major observational
challenge. This limitation prevents us from testing the predictions
of a wide range of theories, from AGN triggering to galaxy evolution,
structure formation, and gravitational wave background. Chandra remains
the ultimate facility to discover elusive AGNs, hence also dual AGNs
down to separations of ~0.5. We propose to observe with Chandra four
dual AGN candidates selected from Gaia EDR3 with separation of ~0.5-0.8
(2.5-5.6 kpc). These observations will not only confirm the AGN nature
of both components and measure their X-ray luminosity, spectral shape,
and possible obscuration but they will also serve as a key step towards
a desirable population study.
Title: Quasi-local stress-tensor formalism and the Casimir effect
Authors: Nazari, Borzoo
Bibcode: 2022arXiv220902122N
Altcode:
We apply the quasi-local stress-energy tensor formalism to the Casimir
effect of a scalar field confined between conducting planes located in
a static spacetime. We show that the surface energy vanishes for both
Neumann and Dirichlet boundary conditions and consequently the volume
Casimir energy reduces to the famous zero point energy of the quantum
field, i.e. $E^{vol.}=\sum\frac{\hbar \omega}{2}$. This enables us to
reinforce previous results in the literature and extend the calculations
to the case of massive and arbitrarily coupled scalar field. We found
that there exists a first order perturbation correction to the Casimir
energy contrary to previous claims which state that it vanishes. This
shows many orders of magnitude greater than previous estimations for the
energy corrections and makes it detectable by near future experiments.
Title: Early dark energy by dark Higgs, and axion-induced non-thermal
trapping
Authors: Nakagawa, Shota; Takahashi, Fuminobu; Yin, Wen
Bibcode: 2022arXiv220901107N
Altcode:
We propose a new scenario of early dark energy (EDE) with a dark
Higgs trapped at the origin. To keep this dark Higgs trapped until
around the matter-radiation equality, we use dark photons produced
non-thermally by coherent oscillations of axions, which have a much
stronger trapping effect than thermal mass. When the trapping ends, the
dark Higgs quickly decays into dark photons, which are then red-shifted
as radiation. The dark Higgs EDE scenario works well for an ordinary
Mexican-hat potential, and the dark Higgs naturally sits at the origin
from the beginning, since it is the symmetry-enhanced point. Thus,
unlike the axion EDE, there is no need for elaborate potentials or
fine-tuning with respect to the initial condition. Interestingly,
the axion not only produces dark photons, but also explains dark
matter. We find the viable parameter region of the axion decay constant
and the axion mass where dark matter and the $H_0$ tension can be
simultaneously explained. We also discuss the detectability of the
axion in the presence of axion-photon coupling, and show that the
axion can be the QCD axion.
Title: Rapid parameter estimation for an all-sky continuous
gravitational wave search using conditional varitational auto-encoders
Authors: Bayley, Joseph; Messenger, Chris; Woan, Graham
Bibcode: 2022arXiv220902031B
Altcode:
All-sky searches for continuous gravitational waves are generally model
dependent and computationally costly to run. By contrast, SOAP is a
model-agnostic search that rapidly returns candidate signal tracks
in the time-frequency plane. In this work we extend the SOAP search
to return broad Bayesian posteriors on the astrophysical parameters
of a specific signal model. These constraints drastically reduce the
volume of parameter space that any follow-up search needs to explore,
so increasing the speed at which candidates can be identified and
confirmed. Our method uses a machine learning technique, specifically a
conditional variational auto-encoder, and delivers a rapid estimation
of the posterior distribution of the four Doppler parameters of a
continuous wave signal. It does so without requiring a clear definition
of a likelihood function, or being shown any true Bayesian posteriors
in training. We demonstrate how the Doppler parameter space volume can
be reduced by a factor of $\mathcal{O}(10^{-7})$ for signals of SNR 100.
Title: The thermal-orbital evolution of the Earth-Moon system with
a subsurface magma ocean and fossil figure
Authors: Downey, Brynna G.; Nimmo, Francis; Matsuyama, Isamu
Bibcode: 2022arXiv220900935D
Altcode:
Various theories have been proposed to explain the Moon's
current inclined orbit. We test the viability of these theories by
reconstructing the thermal-orbital history of the Moon. We build on past
thermal-orbital models and incorporate the evolution of the lunar figure
including a fossil figure component. Obliquity tidal heating in the
lunar magma ocean would have produced rapid inclination damping, making
it difficult for an early inclination to survive to the present-day. An
early inclination is preserved only if the solid-body of the early Moon
were less dissipative than at present. If instabilities at the Laplace
plane transition were the source of the inclination, then the Moon had
to recede slowly, which is consistent with previous findings of a weakly
dissipative early Earth. If collisionless encounters with planetesimals
up to 140 Myr after Moon formation excited the inclination, then the
Moon had to migrate quickly to pass through the Cassini state transition
at 33 Earth radii and reach a period of limited inclination damping. The
fossil figure was likely established before 16 Earth radii to match
the present-day degree-2 gravity field observations.
Title: X-ray confirmation of optically selected IMBH-powered AGN
and high-resolution imaging of their host galaxies
Authors: Chilingarian, Igor
Bibcode: 2022cxo..prop.6378C
Altcode:
A population of intermediate black holes (IMBH) will allow us to solve
one of the long-standing problems in modern astrophysics, the origin
of supermassive black holes. We explore the published sample of 305
optically selected IMBH candidates (3e4<M_BH<2e5 M_Sun), which
reside in galaxy centers and appear as weak type-I AGN. As of now, 24
of them were confirmed in X-ray using archival data. Here we propose
to observe 23 objects from that list with Chandra and 5 most compact
host galaxies with the HST to double the number of X-ray confirmed IMBHs
and get the first insight on structural properties of compact IMBH host
galaxies. This will enable detailed studies of the IMBH population and
help to constrain the masses of seed black holes in the early Universe.
Title: The C/M Ratio of AGB Stars in the Local Group Galaxies
Authors: Ren, Tongtian; Jiang, Biwei; Ren, Yi; Yang, Ming
Bibcode: 2022arXiv220902506R
Altcode:
The number ratio of carbon-rich to oxygen-rich asymptotic giant
branch (AGB) stars (the so-called C/M ratio) is closely related
to the evolution environment of the host galaxy. This work studies
the C/M ratio in 14 galaxies within the Local Group with the most
complete and clean sample of member stars identified in our previous
works. The borderlines between carbon-rich AGB and oxygen-rich AGB
stars as well as red supergiants are defined by Gaussian mixture
model fitting to the number density in the $(J - K)/K$ diagram for
the member stars of the LMC and M33, and then applied to the other
galaxies by shifting the difference in the position of tip red
giant branch (TRGB). The C/M ratios are obtained after precise and
consistent categorization. Although for galaxies with larger distance
modulo there is greater uncertainty, the C/M ratio is clearly found to
decrease with the color index $(J - K)_0$ of TRGB as the indicator of
metallicity, which agrees with previous studies and can be explained
by the fact that carbon stars are more easily formed in a metal-poor
environment. Furthermore, the C/M ratio within M33 is found to increase
with galactocentric distance, which coincides with this scenario and
the galactic chemical evolution model. On the other hand, the C/M
ratio within M31 is found to decrease with galactocentric radius,
which deserves further study.
Title: Formation of the massive bedded chert and coupled Silicon
and Iron cycles during the Ediacaran-Cambrian transition
Authors: Li, Chenqing; Dong, Lin; Ma, Haoran; Liu, Hui; Li, Chao;
Pei, Haoxiang; Shen, Bing
Bibcode: 2022E&PSL.59417721L
Altcode:
Direct inorganic silica precipitation was a major silicon sink
in the Paleoproterozoic oceans, whereas the diagenetic silica
replacement of peritidal carbonate rocks became an increasingly
important sink for silica in Mesoproterozoic and Neoproterozoic. The
unique widespread bedded chert documenting transition from platform
margin to basinal environments in the Yangtze Block, South China,
during the Ediacaran-Cambrian transition (ECT, 550-521 Ma), however,
remains enigmatic. Here, we report consistently low Germanium/Silicon
(Ge/Si) ratios (0.2-0.5 μmol/mol) of the ECT Liuchapo cherts. The
low (Ge/Si) ratios, combined with rare earth elements (REE) analysis,
point to normal seawater source for the Liuchapo cherts. The primary
nature of the chert was verified by Oxygen isotopes (δ18O)
of silica and thus the measured Ge/Si ratios of the cherts could
represent the maximum estimate of seawater Ge/Si ratios during
ECT. Seawater during ECT has a significantly lower Ge/Si ratio than
that of the modern marine. Low Ge/Si requires a high fraction of
seawater germanium to be buried by a non-SiO2 sink. We
speculate that germanium removal may be associated with a very active
iron cycle driven by oscillating redox during ECT. The iron redox
cycle may also effectively shuttle seawater silicon to sediments,
causing bedded cherts precipitation. This study suggests that silica
precipitation may be directly linked to the redox cycling of iron,
and that this linkage favors silica precipitation regardless of its
saturation state in the ocean.
Title: Cosmological inflation in f(Q , T) gravity
Authors: Shiravand, Maryam; Fakhry, Saeed; Farhoudi, Mehrdad
Bibcode: 2022PDU....3701106S
Altcode: 2022arXiv220400906S
We study the cosmological inflation within the context of f(Q , T)
gravity, wherein Q is the nonmetricity scalar and T is the trace of
the matter energy-momentum tensor. By choosing a linear combination of
Q and T, we first analyze the realization of an inflationary scenario
driven via the geometrical effects of the linear f(Q , T) gravity and
then, we obtain the modified slow-roll parameters, the scalar and the
tensor spectral indices, and the tensor-to-scalar ratio for the proposed
model. In addition, by choosing three inflationary potentials, i.e. the
power-law, hyperbolic and natural potentials, and by applying the
slow-roll approximations, we calculate these inflationary observables
in the presence of an inflaton scalar field. The results indicate that
by properly restricting the free parameters, the proposed model provides
appropriate predictions that are consistent with the observational data
obtained from the Planck 2018. Also, we specify that the contribution
of linear model of f(Q , T) gravity with the hyperbolic and natural
potentials can impose different restrictions on the parameters of these
potentials. Furthermore, the predictions of natural inflation in this
model are in good agreement with the joint Planck, BK15 and BAO data,
justifying the use of the f(Q , T) gravity.
Title: Erratum: Grid of pseudo-2D chemistry models for tidally locked
exoplanets - I. The role of vertical and horizontal mixing
Authors: Baeyens, Robin; Decin, Leen; Carone, Ludmila; Venot, Olivia;
Agúndez, Marcelino; Mollière, Paul
Bibcode: 2022MNRAS.515.1839B
Altcode:
No abstract at ADS
Title: Holographic cold dense matter constrained by neutron stars
Authors: Zhang, Lin; Huang, Mei
Bibcode: 2022arXiv220900766Z
Altcode:
The equation of state (EoS) for cold dense matter inside neutron
stars is investigated by using holographic QCD models in the
framework of the Einstein-Maxwell-dilaton (EMD) system and the
improved Karch-Katz-Son-Stephanov (KKSS) action for matter part. This
method of describing holographic nuclear matter in the EMD$+$KKSS
framework is different from that by using the Dirac-Born-Infeld
(DBI) action and the Chern-Simons (CS) terms. Combining with the
Hebeler-Lattimer-Pethick-Schwenk (HLPS) intermediate equation of state
(EoS), the hybrid EoS inside the neutron stars is constructed. The
obtained hybrid EoS is located in the range that is defined by the
low-density chiral effective theory, the high-density perturbative QCD,
and the polytropic interpolations between them, and is constrained
by the astrophysics observations. The square of the sound velocity
reaches a maximum value larger than $0.8$ in the region of $2-5$ times
the saturation baryon number density and approaches the conformal
limit at the high baryon density range. The mass-radius relation and
the tidal deformability of the neutron stars are in agreement with
astrophysical measurements. The possible maximum mass for the neutron
star is about $2.5 M_{\odot}$ and the radius is about $12 \mathrm{km}$
then. It is noticed that the holographic quark matter branch in the
mass-radius relation is always unstable and the holographic nuclear
matter can produce a stable branch. These results indicate that even
in the core of the NS, the matter is still in the confinement phase
and the quark matter is not favored.
Title: Probing Plasmas in the Colliding Wind Binary WR 25
Authors: Huenemoerder, David
Bibcode: 2022cxo..prop.6407H
Altcode:
WR 25 is a colliding wind binary with a 208-day period. These very
massive stars have strong winds, and with an orbital eccentricity of
0.5, they present us with a wind-collision-shocks whose conditions
change with stellar separation, and which can be viewed at different
geometrical aspects and changing lines-of-sight through the O-star
or WR-star winds. This aids exploration of wind structure in ways
not easy or possible for single stars. Here we propose to obtain
high-resolution X-ray spectra at conjunction, viewing the shock cone
face-on, to complement the observation near periastron. Emission line
centroids, widths, and fluxes will provide unique constraits on the
winds' and shock cone's structures, and ultimately the wind properties
of each star.
Title: Mineralogy of interstellar dust towards GX339-4
Authors: Psaradaki, Ioanna
Bibcode: 2022cxo..prop.6345P
Altcode:
We propose joint TOO category Chandra/HETGS (120 ks) and XMM-Newton/RGS
(40 ks) observations of the galactic black hole binary GX 339-4 during
an outburst. We aim to obtain high-quality spectra in order to study the
imprints of interstellar gas and dust towards the source. The proposed
observations will enable, for the first time, a simultaneous study of
the OK, FeL, MgK, SiK, using the newest laboratory measurements of
astrophysical dust templates and gas phase absorption models. This
source provides the ideal laboratory to appropriately identify the
absorption features from interstellar solids and determine their
chemical composition and lattice structure, which is one of the major,
unsolved problems in the astrophysics of the interstellar medium.
Title: Mapping extreme mass loss from evolved massive stars with
coordinated Chandra-NuSTAR observations
Authors: Brethauer, Daniel
Bibcode: 2022cxo..prop.6321B
Altcode:
Contrary to expectations from stellar evolutionary models, recent
observations uncovered the ejection of shells of material massive
stars in the years before the supernova (SN) explosion. The physical
mechanism behind the impulsive mass ejection synchronized with the
stellar core-collapse is unclear. Here we propose a continuation
of our coordinated Chandra-NuSTAR effort to map the evolution of the
broad-band X-ray spectrum of 1 nearby (d<50 Mpc) strongly interacting
SN and enable progress. Our program is designed to characterize the
medium around strongly interacting SN, which originate from stellar
progenitors with the most extreme mass loss before explosion. The
overarching goal is to constrain the nature of the physical process
responsible for mass loss in evolved massive stars.
Title: Evolution of Galaxy Types and HI Gas in Hickson Compact Groups
Authors: Liu, Yao; Zhu, Ming
Bibcode: 2022arXiv220903490L
Altcode:
Compact groups have high galaxy densities and low velocity dispersions,
and their group members have experienced numerous and frequent
interactions during their lifetimes. They provide a unique environment
to study the evolution of galaxies. We examined the galaxies types
and HI contents in groups to make a study on the galaxy evolution in
compact groups. We used the group crossing time as an age indicator
for galaxy groups. Our sample is derived from the Hickson Compact Group
catalog. We obtained group morphology data from the Hyper-Leda database
and the IR classification based on Wide-Field Infrared Survey Explorer
(WISE) fluxes from Zucker et al. (2016). By cross-matching the latest
released ALFALFA 100% HI source catalog and supplemented by data found
in literature, we obtained 40 galaxy groups with HI data available. We
confirmed that the weak correlation between HI mass fraction and group
crossing time found by Ai & Zhu (2018) in SDSS groups also exists in
compact groups. We also found that the group spiral galaxy fraction is
correlated with the group crossing time, but the actively star-forming
galaxy fraction is not correlated with the group crossing time. These
results seem to fit with the hypothesis that the sequential acquisition
of neighbors from surrounding larger-scale structures has affected the
morphology transition and star formation efficiency in compact groups.
Title: Nonequilibrium Hanbury-Brown-Twiss experiment: Theory and
application to binary stars
Authors: Rubio Lopez, Adrian E.; Boddeti, Ashwin K.; Bao, Fanglin;
Choi, Hyunsoo; Jacob, Zubin
Bibcode: 2022arXiv220902571R
Altcode:
Intensity-interferometry based on Hanbury-Brown and Twiss's seminal
experiment for determining the radius of the star Sirius formed
the basis for developing the quantum theory of light. To date, the
principle of this experiment is used in various forms across different
fields of quantum optics, imaging and astronomy. Though, the technique
is powerful, it has not been generalized for objects at different
temperatures. Here, we address this problem using a generating
functional formalism by employing the P-function representation
of quantum-thermal light. Specifically, we investigate the photon
coincidences of a system of two extended objects at different
temperature using this theoretical framework. We show two unique
aspects in the second-order quantum coherence function - interference
oscillations and a long-baseline asymptotic value that depends on the
observation frequency, temperatures and size of both objects. We apply
our approach to the case of binary stars and discuss the advantages
of measuring these two features in an experiment. In addition to the
estimation of the radii of each star and the distance between them,
we also show that the present approach is suitable for the estimation
of temperatures as well. To this end, we apply it to the practical
case of binary stars Luhman 16 and Spica $\alpha$ Vir. We find that
for currently available telescopes, an experimental demonstration is
feasible in the near term. Our work contributes to the fundamental
understanding of intensity interferometry of quantum-thermal light
and can be used as a tool for studying two-body thermal emitters -
from binary stars to extended objects.
Title: Performance of the upgraded VERITAS Stellar Intensity
Interferometer (VSII)
Authors: Kieda, David B.; VERITAS Collaboration
Bibcode: 2022arXiv220903453K
Altcode:
The VERITAS Imaging Atmospheric Cherenkov Telescope array (IACT)
was augmented in 2019 with high-speed focal plane electronics to
create a new Stellar Intensity Interferometry (SII) observational
capability (VERITAS-SII, or VSII). VSII operates during bright moon
periods, providing high angular resolution observations ( < 1 mas)
in the B photometric band using idle telescope time. VSII has already
demonstrated the ability to measure the diameters of two B stars at 416
nm (Bet CMa and Eps Ori) with < 5% accuracy using relatively short
(5 hours) exposures. The VSII instrumentation was recently improved to
increase instrumental sensitivity and observational efficiency. This
paper describes the upgraded VSII instrumentation and documents the
ongoing improvements in VSII sensitivity. The report describes VSII's
progress in extending SII measurements to dimmer magnitude stars and
improving the VSII angular diameter measurement resolution to better
than 1%.
Title: X-ray Observations of an Outbursting Class 0 Protostar in Orion
Authors: Megeath, Tom
Bibcode: 2022cxo..prop.6281M
Altcode:
Class 0 protostars are the earliest observed stage of stellar
evolution, where a hydrostatically supported protostar is rapidly
accreting mass from a massive infalling envelope. This accretion is
thought to be mediated by a disk, potentially via the magnetic field
of the central protostar. Evidence for stellar magnetic fields around
Class 0 protostars, however, is limited. Searches for X-ray emission
from Class 0 protostars have produced only one reliable detection: the
post-outburst protostar HOPS 383. We propose observations of HOPS 124,
the most luminous of the three known currently or recently outbursting
Class 0 protostars. Since the outburst may subside in the near future,
this object provides a rare opportunity. These data will complement
JWST searches for magnetospheric accretion.
Title: Δ13CH3 D and
Δ12CH2D2 signatures of methane
aerobically oxidized by Methylosinus trichosporium with implications
for deciphering the provenance of methane gases
Authors: Krause, Sebastian J. E.; Liu, Jiarui; Young, Edward D.;
Treude, Tina
Bibcode: 2022E&PSL.59317681K
Altcode:
Aerobic oxidation of methane (MOx) is an important biologically mediated
process that consumes methane in a wide range of environments. Here we
report results of culture experiments with the aerobic methane-oxidizing
bacterium Methylosinus trichosporium (OB3b) that are used to
characterize the mass-18 isotopologue (Δ13CH3D
and Δ12CH2D2) signatures of MOx in
residual methane gases. MOx activity was confirmed by simultaneous
decrease of methane and oxygen in the bulk gas headspace. Bulk carbon
(13C/12C) and hydrogen (D/H) isotope ratios of
the methane gas increased while both Δ13CH3D
and Δ12CH2D2 decreased as the
oxidation proceeded. The corresponding fractionation factors (α)
calculated from our experimental results are 0.98485 ± 0.00006 for
13C/12C, 0.7265 ± 0.0010 for D/H, 0.7141 ±
0.0011 for 13CH3D/12CH4,
and 0.4757 ± 0.0023 for
12CH2D2/12CH4.
Deviations of the mass-18 fractionation factors from the Rule of the
Geometric Mean (RGM) expressed as γ values are 0.9981 ± 0.0017 for
13CH3D/12CH4
and 0.9013 ± 0.0045 for
12CH2D2/12CH4.
Our α and γ values suggest that while MOx
fractionates 13CH3D within
error of the RGM, the Δ13CH3D
and Δ12CH2D2
trajectories are very sensitive to even small deviations in
13CH3D/12CH4 from the
RGM. Fractionation of 12CH2D2 deviates
considerably from RGM, and this causes dramatic and robust effects on
the trajectories of residual methane in Δ13CH3D
vs. Δ12CH2D2 space. Our
models suggest that Δ13CH3D and
Δ12CH2D2 could potentially mimic
microbial methanogenesis signatures in an environment that exhibits a
strong Rayleigh Distillation process with little to no replenishment
of methane during oxidation. However, in closed or open systems
where oxidation is attended by simultaneous methane production, we
find that modest increases in Δ13CH3D and
dramatic increases in Δ12CH2D2
are to be expected, thus resulting in isotopologue signatures
distinct from microbial methanogenesis. The overall trend in these
conditions suggest that methane altered by MOx is distinguishable
from other methane sources in Δ13CH3D and
Δ12CH2D2 space.
Title: Thunderstorm Ground Enhancements: Multivariate analysis of
12 years of observations
Authors: Chilingarian, A.; Hovsepyan, G.; Aslanyan, D.; Karapetyan,
T.; Khanikyanc, Y.; Kozliner, L.; Pokhsraryan, D.; Sargsyan, B.;
Soghomonyan, S.; Chilingaryan, S.; Zazyan, M.
Bibcode: 2022arXiv220901385C
Altcode:
We present a survey of more than half a thousand thunderstorm
ground enhancements, fluxes of electrons, and gamma rays associated
with thunderstorms registered from 2008 to 2022 at Aragats space
environmental center. We analyze correlations between various measured
parameters characterizing TGEs measured on Aragats. Two special cases of
TGE events are considered: one, terminated by nearby lightning flashes,
and another one with a sufficiently large ratio of electrons to gamma
rays. On the basis of the analysis, we summarize the most important
results obtained during 12 years of TGE study, which include: We show
the operation of the electron accelerators in the thunderous atmosphere
by directly measuring the electron flux during thunderstorms; Quite
frequently, TGEs occur prior to lightning flashes and are terminated
by them. The energy spectra of avalanche electrons observed on Aragats
indicate that the strong electric field region can extend very low
above the ground covering a large area on the ground. TGEs originated
from multiple relativistic runaway electron avalanches (RREAs) starting
with seed electrons from the ambient population of cosmic rays, which
enter an extended region of the electric field with strength exceeding
the critical value.
Title: Recognizing the constitution of small bodies in
extreme-mass-ratio inspirals by gravitational waves
Authors: Yang, Shu-Cheng; Tang, Run-Dong; Zhong, Xing-Yu; Zhang,
Yuan-Hao; Han, Wen-Biao
Bibcode: 2022arXiv220901110Y
Altcode:
The extreme mass ratio inspirals(EMRIs) are promising gravitational
wave(GW) sources for space-borne GW detectors. The signals of EMRIs
usually have long timescales, ranging from several months to several
years, and their detection requires accurate GW signal templates. In
most waveform models, the compact objects in EMRIs are considered
test particles, which do not consider the small bodies' spin, mass
distribution, and tidal deformation. In this work, we simulate the GW
signals of EMRIs by considering the compact objects' spin and mass
quadrupole. We find that a compact object's spin can significantly
influence the GW signals, and the tidal-induced and spin-induced
quadrupoles matter only if the compact objects are white dwarfs,
especially EMRIs of a higher symmetric mass ratio. We can distinguish
white dwarfs from other compact objects in this case. The structures of
black holes and neutron stars in EMRIs do not have detectable effects
on GW signals. Furthermore, compared with the GW signals that use
test particle approximation, the signal-to-noise ratios(SNRs) of GW
signals that consider extended bodies decrease slightly, which hints
that we can omit the spin and quadrupole of the compact object in the
detection of EMRIs.
Title: Search for high redshift dual, binary, and offset AGN, using
gravitational lensing for milli-arcsec X-ray astrometry.
Authors: Schwartz, Daniel
Bibcode: 2022cxo..prop.6422S
Altcode:
We propose to use rich archival Chandra observations of eight highly
magnified lensed quasars to elucidate the location of the X-ray emission
relative to the radio and optical origins. This is a pioneering
project, which can enable us to use Chandra observations in a novel
way that can provide an unprecedented X-ray astrometric accuracy of a
milliarcsecond, <10 pc for sources at cosmological distances. The
technique can improve X-ray astrometry and resolution by even 3 orders
of magnitude, which in turn will allow us to probe the inner regions
of selected quasars for dual, binary, or offset active galactic nuclei
(AGN). These sources were originally observed with very different
objectives, and the analysis we propose has never been applied.
Title: Comparing Instrument Spectral Sensitivity of Dissimilar
Electromagnetic Haloscopes to Axion Dark Matter and High Frequency
Gravitational Waves
Authors: Tobar, Michael E.; Thomson, Catriona A.; Campbell, William
M.; Quiskamp, Aaron; Bourhill, Jeremy F.; McAllister, Benjamin T.;
Ivanov, Eugene N.; Goryachev, Maxim
Bibcode: 2022arXiv220903004T
Altcode:
It is known that axion haloscopes that operate to search for dark matter
axions via the 2-photon anomaly are also sensitive to gravitational
waves (GWs) through the inverse Gertsenshtein effect. Recently
this way of searching for high frequency GWs has gained momentum
as it has been shown that the strain sensitivity of such detectors,
h_g, are of the same order of sensitivity as the axion-photon theta
angle, \theta_a, which is related to the axion 2-photon coupling,
g_{a\gamma\gamma}, by, \theta_a = g_{a\gamma\gamma}a, where, a, is
the axion scalar field. This means after calculating the sensitivity
of a haloscope to an axion signal, we also have calculated the order
of magnitude sensitivity to a GW signal of the same spectral and
temporal form. However, it is unlikely that a GW and an axion signal
will be of the same form since physically the way the signals are
generated are completely different. For GW detection, the spectral
strain sensitivity in units strain per square root Hz, and is the
natural way to compare the sensitivity of GW detectors due to its
independence on the GW signal. Likewise, one can define a spectral
axion-photon theta angle sensitivity in units of theta angle per
square root Hz for axion detectors, which is independent of the axion
signal. In this work we introduce a systematic way to calculate the
spectral sensitivity of an axion haloscope so instrument comparison
may be achieved independent of signal assumptions and only depends
on the axion to signal transduction sensitivity and noise in the
instrument. Thus, the calculation of the spectral sensitivity not
only allows the comparison of dissimilar axion detectors independent
of signal, but also allows comparison of the GW sensitivity in terms
of spectral strain sensitivity, allowing comparisons to standard GW
detectors based on optical interferometers and resonant-mass technology.
Title: Study of correlation between optical flux and polarization
variations in BL Lac objects
Authors: Rajput, Bhoomika; Pandey, Ashwani; Stalin, C. S.; Mathew,
Blesson
Bibcode: 2022arXiv220902444R
Altcode:
Polarized radiation from blazars is one key piece of evidence for
synchrotron radiation at low energy, which also shows variations. We
present here our results on the correlation analysis between optical
flux and polarization degree (PD) variations in a sample of 11 BL Lac
objects using $\sim$ 10 years of data from the Steward Observatory. We
carried out the analysis on long-term ($\sim$ several months) as well as
on short-term timescales ($\sim$ several days). On long-term timescales,
for about 85% of the observing cycles, we found no correlation between
optical flux and PD. On short-term timescales, we found a total of
58 epochs with a significant correlation between optical flux and
PD, where both positive and negative correlation were observed. In
addition, we also found a significant correlation between optical flux
and $\gamma$-ray flux variations on long-term timescales in 11% of the
observing cycles. The observed PD variations in our study cannot be
explained by changes in the power-law spectral index of the relativistic
electrons in the jets. The shock-in-jet scenario is favoured for the
correlation between optical flux and PD, whereas the anti-correlation
can be explained by the presence of multi-zone emission regions. The
varying correlated behaviour can also be explained by the enhanced
optical flux caused by the newly developed radio knots in the jets and
their magnetic field alignment with the large scale jet magnetic field.
Title: Optimisation of the WEAVE target assignment algorithm
Authors: Hughes, Sarah; Dalton, Gavin; Smith, Daniel; Duncan, Kenneth;
Terrett, David; Abrams, Don Carlos; Aguerri, J. Alfonso; Balcells,
Marc; Bishop, Georgia; Bonifacio, Piercarlo; Carrasco, Esperansa;
Jin, Shoko; Lewis, Ian; Trager, Scott; Vallenari, Antonella
Bibcode: 2022arXiv220901145H
Altcode:
WEAVE is the new wide-field spectroscopic facility for the prime
focus of the William Herschel Telescope in La Palma, Spain. Its fibre
positioner is essential for the accurate placement of the spectrograph's
~960-fibre multiplex. To maximise the assignment of its optical
fibres, WEAVE uses a simulated annealing algorithm called Configure,
which allocates the fibres to targets in the field of view. We have
conducted an analysis of the algorithm's behaviour using a subset of
mid-tier WEAVE-LOFAR fields, and adjusted the priority assignment
algorithm to optimise the total fibres assigned per field, and the
assignment of fibres to the higher priority science targets. The output
distributions have been examined, to investigate the implications for
the WEAVE science teams.
Title: A Survey of New Fermi Millisecond Pulsar Binaries
Authors: Swihart, Sam
Bibcode: 2022cxo..prop.6291S
Altcode:
Millisecond pulsar spiders are binary systems in which the wind of a
millisecond pulsar ablates a non-degenerate, Hydrogen-rich companion. As
part of an ongoing multiwavelength survey of unidentified Fermi-LAT
gamma-ray sources, we have identified 7 new candidate millisecond
pulsars that have been carefully selected based on their measured
gamma-ray properties and a current lack of deep X-ray observations. Here
we request Chandra/ACIS observations of these candidates. Our goals
are to search for X-ray counterparts to the gamma-ray sources,
helping to confirm their associations with optical variable stars,
measure the X-ray fluxes and spectra, and to search for variability
that can reveal the origin of the high-energy emission.
Title: Azimuthal anisotropy of the westernmost Mediterranean: New
constraints on lithospheric deformation and geodynamical evolution
Authors: Feng, Lili; Díaz, Jordi
Bibcode: 2022E&PSL.59317689F
Altcode:
A new high-resolution azimuthally anisotropic Vs model beneath the
westernmost Mediterranean is constructed based on Rayleigh wave
dispersions obtained from 1186 broadband seismic stations. The model
reveals several prominent features, including: (1) Anisotropy beneath
Iberia inferred from surface waves is generally consistent with the
results independently deduced from the analysis of SKS splitting,
with fast velocity directions aligned close to E-W in most of the
investigated area. (2) Vertically coherent mantle deformation is
found across the vast majority part of the westernmost Mediterranean,
namely, lithospheric deformation is coupled with the underlying
asthenosphere. (3) Two anisotropic mantle layers are required to
fit the data in a region in central Iberia, including part of the
Duero and Tagus basins and the Central System. This is interpreted as
denoting deformation in the mantle lithosphere related to the Alpine
compressional regime. (4) The anisotropy in the Alboran Basin is
complex and can be related to a deflected mantle flow pattern around
the Alboran slab.
Title: Shear wave velocities across the olivine - wadsleyite -
ringwoodite transitions and sharpness of the 410 km seismic
discontinuity
Authors: Perrillat, Jean-Philippe; Tauzin, Benoît; Chantel, Julien;
Jonfal, Julie; Daniel, Isabelle; Jing, Zhicheng; Wang, Yanbin
Bibcode: 2022E&PSL.59317690P
Altcode:
The seismic signature of the 410-km seismic discontinuity is
generally attributed to the olivine to wadsleyite polymorphic
transformation. However, apparent discrepancies exist between seismic
and experimental observations. Among those, the sharpness of the
discontinuity as inferred from the reflectivity of seismic waves
is difficult to reconcile with the gradual nature of the olivine to
wadsleyite transformation predicted by phase equilibria. In this study,
we explore the contribution of the phase transition kinetics to the
sharpness of the discontinuity by performing X-ray diffraction and
sound velocity measurements on (Mg,Fe)2SiO4
with an unprecedented time resolution as a function of the
reaction progress. Our data document for the first time a transient
velocity softening phenomenon and attenuation which we relate to the
formation of a metastable spineloid phase. In the Earth's mantle this
transformation mechanism would affect the elastic gradient within the
olivine-wadsleyite two-phase loop, potentially creating a low-velocity
layer; hence explaining the unique sharpness and reflectivity of the
discontinuity.
Title: Precipitation of arsenic-bearing solids as a secondary control
on arsenic speciation in groundwater: Evidence from field study and
geochemical analysis
Authors: Nilling, Jacklin Jeke; Verma, Akshat; Singh, Abhas
Bibcode: 2022GeCoA.333..308N
Altcode:
Among the mechanisms controlling elevated arsenic (As) speciation in
groundwater, dissolution-precipitation of As-bearing solids, possibly
as colloids, has not been systematically evaluated even though reported
groundwater saturation states often indicate super- or near-saturation
with respect to multiple solids. In this contribution, a detailed
geochemical analysis was performed on well-constrained groundwater
quality data collected through (a) sustained sampling (n = 84) over
2.5 y at a newly-identified site in the middle Gangetic plain of
India; and (b) metadata analysis on studies conducted worldwide (n =
414). Groundwater saturation indices, speciation (EH-pH),
and mineral solubilities (logC-pH) were calculated, consistent with a
carefully-selected and updated thermodynamic database. Results suggest
that under oxidizing conditions, secondary precipitation of solids
similar to scorodite [FeAsO4·2H2O(s)]
and pharmacolite [CaHAsO4·2H2O(s)]
influences the As(V) concentrations in groundwater. In addition,
groundwater at the investigated site was saturated with calcite
[CaCO3(s)] and rhodochrosite [MnCO3(s)]. Evidence
of colloidal forms of As-containing and As-free solids was found
from SEM-EDS characterization of solids collected on 0.2 μm filter
membranes used to sample groundwater. XPS analysis showed that the
relative As(V) and As(III) signatures in these solids were consistent
with the prevalence of dissolved As(V) and As(III) in groundwater,
independently quantified using IC-ICP-MS. HR-TEM-SAED characterization
of these solids indicated the possible presence of poorly crystalline
scorodite- and pharmacolite-like phases along with calcite and
lepidocrocite [γ-FeOOH(s)] in a predominantly amorphous
matrix. Also, a possible role of Mn in inducing As immobilization
in calcite was suggested with the identification of ∼ 1:1 Mn:As
atomic ratios in these solids, consistent with significant (p <
0.05) correlation of dissolved total As and total Mn. These findings
imply that solubility-driven secondary processes may exert additional
controls on the eventual fate and transport of arsenic in mixed-redox
state shallow groundwaters, apart from the known primary mobilization
mechanisms. To the best of our knowledge, this is the first study that
has characterized colloidal arsenic in groundwater and related it to
prevailing mechanisms.
Title: Probing Self-Interacting Dark Matter in Strong Lensing Clusters
Authors: Jeltema, Tesla
Bibcode: 2022cxo..prop.6389J
Altcode:
The nature of dark matter remains unknown, despite efforts spanning
decades including comprehensive searches for cold dark matter
candidates. An especially compelling possibility, and one that might
resolve small-scale tensions of cold dark matter, is a class of models
where the dark matter possesses non-trivial interactions with itself,
self-interacting dark matter (SIDM). SIDM models give measurable
predictions for the structure of dark matter halos in particular
producing cored central density profiles. We propose to constrain SIDM
on cluster scales with follow up of new cluster strong lensing systems
selected from the over 200 in the Dark Energy Survey Y3 sample. We
will use the combination of strong lensing, X-ray, and dynamical data
to model the dark matter density profiles.
Title: Calibration Observations to Measure the Intrinsic Linewidths
in Cas A
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6446C
Altcode:
These observations will be used to measure the intrinsic line widths
in the Cas A supernova remnant.
Title: The SAMI Galaxy Survey: Using concentrated star-formation
and stellar population ages to understand environmental quenching
Authors: Wang, Di; Croom, Scott M.; Bryant, Julia J.; Vaughan, Sam
P.; Schaefer, Adam L.; D'Eugenio, Francesco; Barsanti, Stefania;
Brough, Sarah; Lagos, Claudia del P.; Medling, Anne M.; Oh, Sree;
van de Sande, Jesse; Santucci, Giulia; Bland-Hawthorn, Joss; Goodwin,
Michael; Groves, Brent; Lawrence, Jon; Owers, Matt S.; Richards, Samuel
Bibcode: 2022arXiv220900290W
Altcode:
We study environmental quenching using the spatial distribution of
current star-formation and stellar population ages with the full
SAMI Galaxy Survey. By using a star-formation concentration index
[C-index, defined as log10(r_{50,Halpha}/r_{50,cont})], we separate
our sample into regular galaxies (C-index>-0.2) and galaxies
with centrally concentrated star-formation (SF-concentrated;
C-index<-0.2). Concentrated star-formation is a potential
indicator of galaxies currently undergoing `outside-in' quenching. Our
environments cover ungrouped galaxies, low-mass groups (M_200<10^12.5
M_sun), high-mass groups (M_200 in the range 10^{12.5-14} M_sun) and
clusters (M_200>10^14 M_sun). We find the fraction of SF-concentrated
galaxies increases as halo mass increases with 9\pm2 per cent, 8\pm3
per cent, 19\pm4 per cent and 29\pm4 per cent for ungrouped galaxies,
low-mass groups, high-mass groups and clusters, respectively. We
interpret these results as evidence for `outside-in' quenching in groups
and clusters. To investigate the quenching time-scale in SF-concentrated
galaxies, we calculate light-weighted age (Age_L) and mass-weighted age
(Age_M) using full spectral fitting, as well as the Dn4000 and Hdelta_A
indices. We assume that the average galaxy age radial profile before
entering a group or cluster is similar to ungrouped regular galaxies. At
large radius (1-2 R_e), SF-concentrated galaxies in high-mass groups
have older ages than ungrouped regular galaxies with an age difference
of 1.83\pm0.38 Gyr for Age_L and 1.34\pm0.56 Gyr for Age_M. This
suggests that while `outside-in' quenching can be effective in groups,
the process will not quickly quench the entire galaxy. In contrast,
the ages at 1-2 R_e of cluster SF-concentrated galaxies and ungrouped
regular galaxies are consistent (0.19\pm0.21 Gyr for Age_L, 0.40\pm0.61
Gyr for Age_M), suggesting the quenching process must be rapid.
Title: X-Ray Jets in Microquasars
Authors: Corbel, StÃÂ. ©phane
Bibcode: 2022cxo..prop.6305C
Altcode:
We propose Target of Opportunity (ToO) observations for detailed studies
of X-ray jets from microquasars. Following the discovery by Chandra of
radio/X-ray jets in four microquasars, it becomes clear that X-ray jets
are probably much more common than previously thought, and they offer an
exciting new way to probe the physics of relativistic jets from black
holes and their feedback on the ISM. The proposed ToO observations
are optimized to discover and study (flux evolution, morphology, SED,
proper motion, ...) new X-ray jets from microquasars, triggered by
their detection as radio lobes. This will have implications not only
for the study of jets from Galactic X-ray binaries, but also for our
understanding of relativistic jets from active galactic nuclei (AGN).
Title: Catching the Changing-Look AGN Mrk 1018 as it undergoes
another Significant Change in Accretion Rate
Authors: Brogan, Roisin
Bibcode: 2022cxo..prop.6365B
Altcode:
One joint Chandra/HST ToO observation (70 ks/3 orbits each) is proposed
of the changing-look AGN Mrk 1018. This is to be triggered if the
optical flux increases by at least a factor of two compared to the
highest optical flux seen over the period 06/2017- 03/2020. The major
outburst in summer 2020 indicates that Mrk 1018 is still dynamic and
unpredictable. Chandra data will be used to study how the X-ray emitting
corona responds to another change in the accretion rate, whereas
joint UV data are needed to study the X-ray corona/UV accretion disk
connection during a major reconfiguration of the system. In addition,
the HST data will check whether the UV outflow discovered in 2016 is
directly linked to Mrk 1018's significant drop in luminosity.
Title: Probing hadronic interaction models with the hybrid data of
the Pierre Auger Observatory
Authors: Vícha, Jakub
Bibcode: 2022arXiv220900744V
Altcode:
Presently large systematic uncertainties remain in the description of
hadronic interactions at ultra-high energies and a fully consistent
description of air-shower experimental data is yet to be reached. The
amount of data collected by the Pierre Auger Observatory using
simultaneously the fluorescence and surface detectors in the energy
range $10^{18.5}-10^{19.0}$ eV has provided opportunity to perform a
multi-parameter test of model predictions. We apply a global method to
simultaneously fit the mass composition of cosmic rays and adjustments
to the simulated depth of shower maximum ($X_\text{max}$), and hadronic
signals at ground level ($R_\text{Had}$). The best description of
hybrid data is obtained for a deeper scale of simulated $X_\text{max}$
than predicted by hadronic interaction models tuned to the LHC
data. Consequently, the deficit of the simulated hadronic signal at
ground level, dominated by muons, is alleviated with respect to the
unmodified hadronic interaction models. Because of the size of the
adjustments $\Delta X_\text{max}$ and $R_\text{Had}$ and the large
number of events in the sample, the statistical significance of these
assumed adjustments is large, greater than 5$\sigma_\text{stat}$,
even for the combination of the systematic experimental shifts within
1$\sigma_\text{sys}$ that are the most favorable for the models.
Title: Giant Radio Galaxies: Testing the Extremes of AGN Feedback
Authors: O'Sullivan, Ewan
Bibcode: 2022cxo..prop.6386O
Altcode:
Giant radio galaxies (GRGs), whose lobes can extend to Mpc scales, tend
to avoid rich environments. It is rare to find them in the centers of
galaxy clusters, but in this environment they raise important questions
for AGN feedback models. With most of the energy of the jets dissipated
in lobes far outside the cool core, do such systems represent a failure
mode of feedback? If not, how do these sources maintain the thermal
balance of the ICM? We propose to observe two nearby cluster-central
GRGs, using Chandra's exquisite spatial resolution to characterize
their halos, examine conditions in their cool cores and search for
evidence of interactions between the intra-cluster medium and the jets
of these exceptionally powerful, long-lived radio galaxies.
Title: Barrow holographic dark energy models in $f\left( Q\right)$
symmetric teleparallel gravity with Lambert function distribution
Authors: Koussour, M.; Shekh, S. H.; Filali, H.; Bennai, M.
Bibcode: 2022arXiv220900341K
Altcode:
The paper presents Barrow holographic dark energy (infrared cut-off
is the Hubble horizon) suggested by Barrow recently (Physics Letters
B 808 (2020): 135643) in an anisotropic Bianchi type-I Universe within
the framework of $% f\left( Q\right) $ symmetric teleparallel gravity,
where the non-metricity scalar $Q$ is responsible for the gravitational
interaction. We consider two cases: Interacting and non-interacting
models of pressureless dark matter and Barrow holographic dark energy by
solving $f\left( Q\right) $ symmetric teleparallel field equations. To
find the exact solutions of the field equations, we assume that the
time-redshift relation follows a Lambert function distribution as
$t\left( z\right) =\frac{mt_{0}}{l}g\left( z\right) $, where $g\left(
z\right) =LambertW\left[ \frac{l}{m}e^{\frac{l-\ln \left( 1+z\right)
}{m}}\right] $, $m$ and $l$ are non-negative constants and $t_{0}$
represents the age of the Universe. Moreover, we discuss several
cosmological parameters such as energy density, equation of state
(EoS) and skewness parameters, squared sound speed, and $(\omega
_{B}-\omega _{B}^{^{\prime }})$ plane. Finally, we found the values of
the deceleration parameter (DP) for the Lambert function distribution
as $q_{(z=0)}=-0.45$ and $q_{(z=-1)}=-1$ which are consistent with
recent observational data, i.e. DP evolves with cosmic time from
initial deceleration to late-time acceleration.
Title: The cosmic censor of shock-wave singularities
Authors: Fischer, Uwe R.; Datta, Satadal
Bibcode: 2022arXiv220902763F
Altcode:
A dispersionless shock wave in a fluid without friction develops a sonic
spacetime singularity which is naked (not hidden by a horizon). We argue
that an analogue of the cosmic censorship hypothesis of Penrose can be
realized by dressing these naked singularities with trans-Planckian
dispersion. We find that including quantum pressure in Bose-Einstein
condensates provides such a censor: When one approaches the instant of
shock $t_s$, rapid spatial oscillations of density and velocity develop,
which, remarkably, begin to emerge already slightly before $t_s$. The
oscillations make the spacetime structure completely regular, and
therefore lead to a removal of the spacetime singularity. The dressing
mechanism of the naked singularity by the microscopic structure of the
underlying "${\rm a}\!{\rm e}$ther" and the resulting trans-Planckian
dispersion can therefore be regarded as an analogue fluid-dynamical
cosmic censor.
Title: Dynamical systems analysis in $f(T,\phi)$ gravity
Authors: Duchaniya, L. K.; Kadam, S. A.; Levi Said, Jackson; Mishra, B.
Bibcode: 2022arXiv220903414D
Altcode:
Teleparallel based cosmological models provide a description of gravity
in which torsion is the mediator of gravitation. Several extensions
have been made within the so-called Teleparallel equivalent of general
relativity which is equivalent to general relativity at the level of
the equations of motion where attempts are made to study the extensions
of this form of gravity and to describe more general functions of the
torsion scalar $T$. One of these extensions is $f(T,\phi)$ gravity;
$T$ and $\phi$ respectively denote the torsion scalar and scalar
field. In this work, the dynamical system analysis has been performed
for this class of theories to obtain the cosmological behaviour of a
number of models. Two models are presented here with some functional
form of the torsion scalar and the critical points are obtained. For
each critical point, the stability behaviour and the corresponding
cosmology are shown. Through the graphical representation the equation
of state parameter and the density parameters for matter-dominated,
radiation-dominated and dark energy phase are also presented for both
the models.
Title: Global halogen flux of subducting oceanic crust
Authors: Beaudoin, Grace M.; Barnes, Jaime D.; John, Timm; Hoffmann,
J. Elis; Chatterjee, Rudra; Stockli, Daniel F.
Bibcode: 2022E&PSL.59417750B
Altcode:
In order to constrain the geochemical cycling of halogens (F, Cl, Br,
I) during subduction of altered ocean crust (AOC), this study compares
bulk halogen concentrations from seven seafloor AOC drill cores (n =
21) and exhumed eclogites (n = 22) from three paleo-subduction settings
(Raspas Complex, Ecuador; Zambezi Belt, Zambia; Cabo Ortegal, Spain). As
ocean crust undergoes hydrothermal alteration, basalts and gabbros
preferentially incorporate different halogens. Fluorine is predominantly
hosted in basalts (averaging 155 μg/g); Cl and Br are enriched in
gabbros (averaging 241 μg/g and 225 ng/g, respectively). During
prograde metamorphism of AOC, F behaves compatibly and is decoupled
from the heavy halogens (Cl, Br, I). Eclogite samples retain F in
concentrations (30-160 μg/g) similar to seafloor values (20-190
μg/g). Chlorine and Br are strongly coupled and effectively mobilized
during prograde metamorphism, with high-pressure (HP) samples containing
between 5-15 μg/g Cl and 17-69 ng/g Br. Elevated F/Cl, Br/Cl, and I/Cl
in eclogites relative to MORB and AOC ratios support the decoupling of
halogens during metamorphism as Cl is most efficiently expelled from
the slab; the mobility of halogens in subducting AOC is as follows:
Cl ≈ Br > I ≫ F. In conjunction with published values of
halogen abundances in seafloor serpentinites, marine sediments, and
HP metaserpentinites and metasediments, the results of this study
are used to estimate global halogen fluxes. Mass balance estimates
indicate that up to 2% of the initial F, 50% of the initial Cl, 93%
of the initial Br, and 97% of initial I entering subduction zones is
lost between the trench and eclogite facies. Subducted AOC represents
a substantial halogen reservoir to arc magma depths and may represent
the most significant carrier of halogens to the deep mantle.
Title: Experimental verification of off-axis polarimetry with Cadmium
Zinc Telluride detectors of AstroSat-CZT Imager
Authors: Vaishnava, C. S.; Mithun, N. P. S.; Vadawale, Santosh V.;
Aarthy, Esakkiappan; Patel, Arpit R.; Adalja, Hiteshkumar L.; Tiwari,
Neeraj Kumar; Ladiya, Tinkal; Navale, Nilam; Chattopadhyay, Tanmoy;
Rao, A. R.; Bhalerao, Varun; Bhattacharya, Dipankar
Bibcode: 2022arXiv220900222V
Altcode:
The Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat consists of an
array of a large number of pixellated CZT detectors capable of measuring
the polarization of incident hard X-rays. The polarization measurement
capability of CZTI for on-axis sources was experimentally confirmed
before the launch. CZTI has yielded tantalizing results on the X-ray
polarization of the Crab nebula and pulsar in the energy range of 100 -
380 keV. CZTI has also contributed to the measurement of prompt emission
polarization for several Gamma-Ray Bursts (GRBs). However, polarization
measurements of off-axis sources like GRBs are challenging. It is
vital to experimentally calibrate the CZTI sensitivity to off-axis
sources to enhance the credence of the measurements. In this context,
we report the verification of the off-axis polarimetric capability of
pixellated CZT detectors through the controlled experiments carried
out with a CZT detector similar to that used in CZTI and extensive
Geant4 simulations of the experimental set-up. Our current results
show that the CZT detectors can be used to measure the polarization of
bright GRBs up to off-axis angles of ~60 degrees. However, at incidence
angles between 45-60 degrees, there might be some systematic effects
which needs to be taken into account while interpreting the measured
polarisation fraction.
Title: GOTCHA! Gravitational wave counterparts Observed wiTh CHAndra
Authors: Troja, Eleonora
Bibcode: 2022cxo..prop.6334T
Altcode:
During the next science run (O4), planned to start in late 2022, the GW
detectors will operate with an increased sensitivity, leading to routine
detections of GW sources and their electromagnetic counterparts. We
propose to exploit the unique capabilities of Chandra in conjunction
with HST and the VLA to map out the diversity of these sources, probe
their surrounding environment, and constrain the structure of their
outflows. The next few detections of electromagnetic counterparts will
shape our knowledge of GW sources for years to come, and the proposed
observations will lead to seminal results in the nascent field of
multi-messenger astronomy.
Title: Discovery of an Ultra Lithium-rich Metal-Poor Red Giant star
Authors: Kowkabany, Jeremy; Ezzeddine, Rana; Charbonnel, Corinne;
Roederer, Ian U.; Li, Yangyang; Hackshaw, Zoe; Beers, Timothy C.;
Frebel, Anna; Hansen, Terese T.; Holmbeck, Erika; Placco, Vinicius M.;
Sakari, Charli M.
Bibcode: 2022arXiv220902184K
Altcode:
We present the discovery of 2MASS J05241392-0336543 (hereafter
J0524-0336), a very metal-poor ([Fe/H]=-2.43 \pm 0.16), highly
r-process-enhanced ([Eu/Fe]=+1.34 \pm 0.10) Milky Way halo field red
giant star, with an ultra high Li abundance of A(Li)(3D,NLTE)=5.62 \pm
0.25 and [Li/Fe]=+7.00 \pm 0.25, respectively. This makes J0524-0336
the most lithium-enhanced giant star discovered to date. We present
a detailed analysis of the star's atmospheric stellar parameters and
chemical-abundance determinations. Additionally, we detect infrared
excess and variable emission in the wings of the H$_\alpha$ absorption
line across multiple epochs, indicative of a potential enhanced
mass-loss event with possible outflows. Our analysis reveals that
J0524-0336 lies either between the bump and the tip of the Red Giant
Branch (RGB), or on the early-Asymptotic Giant Branch (e-AGB). We
investigate the possible sources of lithium enrichment in J0524-0336,
including both internal and external sources. Based on current models
and on the observational evidence we have collected, our study shows
that J0524-0336 may be undergoing the so-called lithium flash that
is expected to occur in low-mass stars when they reach the RGB bump
and/or the early-AGB.
Title: Using Chandra's superior imaging resolution to get the most
out of XRISM scattering halo science
Authors: Corrales, Lia
Bibcode: 2022cxo..prop.6347C
Altcode:
The dust scattering halo around LMXB GX 13+1 is slated for Performance
Verification (PV) phase observations by the X-ray Imaging Spectroscopy
Mission (XRISM). XRISM will measure a high resolution spectrum of the
dust scattering halo to directly calculate the scattering opacity of
interstellar silicates in high resolution, revealing X-ray scattering
fine structure (XSFS) and providing the most direct identification of
its mineral composition yet. We propose a coordinated Chandra-HETG
observation with the XRISM PV phase. HETG is the only instrument
capable of separating the point source from diffuse scattering halo
emission with a spectral resolution suitable for constraining the
XRISM observations. This will vastly reduce the complexity of the data
analysis and reduce uncertainty to <10%.
Title: Noncommutative hamiltonian for $\star$-gravity, and
$\star$-Noether theorems
Authors: Castellani, Leonardo
Bibcode: 2022arXiv220902716C
Altcode:
We present a covariant canonical formalism for noncommutative gravity,
and in general for noncommutative geometric theories defined via a
twisted $\star$-wedge product between forms. Noether theorems are
generalized to the noncommutative setting, and gauge generators are
constructed in a twisted phase space with $\star$-deformed Poisson
bracket. This formalism is applied to noncommutative $D=4$ vierbein
gravity, and allows to find the canonical generators of the tangent
space $\star$-gauge group.
Title: Pros and cons of gaussian filters versus step filters for
light pollution monitoring
Authors: Sánchez de Miguel, Alejandro
Bibcode: 2022arXiv220902100S
Altcode:
There is debate about which indicators should currently be used to
monitor levels of artificial light pollution. To be most valuable,
methods need to be sensitive to variation in the spectral composition
of light emissions (which are changing rapidly, particularly through
increasing use of light-emitting diode [LED] lamps), to be readily
available, to be capable of being used on a large spatial scale and of
being deployed rapidly. Two sets of photometric systems are the most
spread in the world currently, the RGB colors from DSLR cameras that
are based on typical gaussian filters and RGB step filters. The first
set of filters are optimum for human perception and calculation of
most of the most popular environmental impacts although, some of these
environmental impacts are better characterized by the step filters.
Title: Identifying the fingerprints of r-process heavy metals in a
short GRB
Authors: Troja, Eleonora
Bibcode: 2022cxo..prop.6333T
Altcode:
The afterglow of some short GRBs displays a late-time rebrightening,
visible in the near-infrared a few days after the burst. This late-time
bump could be explained as kilonova emission, providing a direct link
to neutron star mergers, and a compelling proof for the synthesis of
heavy nuclei through the rapid neutron capture process (r-process). We
propose a multi-wavelength follow-up campaign of a nearby (z<0.4)
short GRB in order to detect the expected kilonova bump and constrain
its properties. Multi-band observations, and in particular X-rays,
are critical to pin down the nature of the observed rebrightening,
and to distinguish it from the standard afterglow emission.
Title: Capture of dark matter particles by a galaxy in the case of
a bimodal distribution of their velocities
Authors: Durrer, Ruth; Parnovsky, Serge; Parnowski, Aleksei
Bibcode: 2022arXiv220901819D
Altcode:
We have analyzed the rate of capture of dark matter (DM) particles by
the galaxy in the case of the existence of two different types of DM or
a bimodal velocity distribution function for DM. It is shown that, in
addition to the scenario considered in our previous work which is based
on the assumption of an unimodal distribution, more complex scenarios
are possible in which the transition to the state of intense capture
and/or exit from it can occur in two stages. A detailed description
is given of the change in the curve describing the rate of capture
of dark matter particles as a function of the rate of increase in the
baryon mass of the galaxy for various values of the rate of decrease
of the DM density.
Title: Next generation spectroscopic analysis for large samples of
massive stars
Authors: Bestenlehner, Joachim M.
Bibcode: 2022arXiv220900998B
Altcode:
Upcoming large-scale spectroscopic surveys such as WEAVE and 4MOST will
provide thousands of spectra of massive stars, which need to be analysed
in an efficient and homogeneous way. Studies on massive stars are
usually based on samples of a few hundred objects which pushes current
spectroscopic analysis tools to their limits because visual inspection
is necessary to verify the spectroscopic fit. The novel spectroscopic
analysis pipeline takes advantage of the statistics that large samples
provide, and determines the model error to account for imperfections
in stellar atmosphere codes due to simplified, wrong or missing
physics. Considering observational plus model uncertainties improve
spectroscopic fits. The pipeline utilises the entire spectrum rather
than selected diagnostic lines allowing a wider range of temperature
from B to early O stars to be analysed. A small fraction of stars
like peculiar, contaminated or spectroscopic binaries require visual
inspection, which are identified through their larger uncertainties.
Title: SolTrack: a free, fast and accurate routine to compute the
position of the Sun
Authors: van der Sluys, Marc; van Kan, Paul
Bibcode: 2022arXiv220901557V
Altcode:
We present a simple, free, fast and accurate C/C++ and Python
routine called SolTrack, which can compute the position of the Sun
at any instant and any location on Earth. The code allows tracking
of the Sun using a low-specs embedded processor, such as a PLC or
a microcontroller, and can be used for applications in the field of
(highly) concentrated (photovoltaic) solar power ((H)CPV and CSP), such
as tracking control and yield modelling. SolTrack is accurate, fast
and open in its use, and compares favourably with similar algorithms
that are currently available for solar tracking and modelling. SolTrack
computes $1.5 \times 10^6$ positions per second on a single 2.67GHz CPU
core. For the period between the years 2017 and 2116 the uncertainty in
position is $0.0036 \pm 0.0042^\circ$, that in solar distance 0.0017
$\pm$ 0.0029%. In addition, SolTrack computes rise, transit and set
times to an accuracy better than 1 second. The code is freely available
online (http://soltrack.sf.net, https://pypi.org/project/soltrack/).
Title: The quiet Sun at mm Wavelengths as Seen by ALMA
Authors: Alissandrakis, Costas; Bastian, Timothy; Brajša, Roman
Bibcode: 2022arXiv220902569A
Altcode:
Solar observations at sub-mm, mm and cm wavelengths offer a
straightforward diagnostic of physical conditions in the solar
atmosphere because they yield measurement of brightness temperature
which, for optically thick features, equals intrinsic temperature -
much unlike solar diagnostics in other spectral ranges. The Atacama
Large Millimeter and sub-millimeter Array (ALMA) has therefore opened a
new, hitherto underexplored, spectral window for studying the enigmatic
solar chromosphere. In this review we discuss initial ALMA studies of
the quiet chromosphere that used both single-dish and compact-array
interferometric observing modes. We present results on the temperature
structure of the chromosphere, comparison with classic empirical models
of the chromosphere, and observations of the chromospheric network and
spicules. Furthermore, we discuss what may be expected in the future,
since the ALMA capabilities continuously expand and improve towards
higher angular resolution, wavelength coverage, and polarization
measurement for magnetometry.
Title: Radiative processes as diagnostics of cometary atmospheres
Authors: Bodewits, D.; Bonev, B. P.; Cordiner, M. A.; Villanueva, G. L.
Bibcode: 2022arXiv220902616B
Altcode:
In this chapter, we provide a review of radiative processes in cometary
atmospheres spanning a broad range of wavelengths, from radio to
X-rays. We focus on spectral modeling, observational opportunities,
and anticipated challenges in the interpretation of new observations,
based on our current understanding of the atomic and molecular
processes occurring in the atmospheres of small, icy bodies. Close
to the surface, comets possess a thermalized atmosphere that traces
the irregular shape of the nucleus. Gravity is too low to retain
the gas, which flows out to form a large, collisionless exosphere
(coma) that interacts with the heliospheric radiation environment. As
such, cometary comae represent conditions that are familiar in the
context of planetary atmosphere studies. However, the outer comae are
tenuous, with densities lower than those found in vacuum chambers on
Earth. Comets, therefore, provide us with unique natural laboratories
that can be understood using state-of-the-art theoretical treatments
of the relevant microphysical processes. Radiative processes offer
direct diagnostics of the local physical conditions, as well as
the macroscopic coma properties.These can be used to improve our
understanding of comets and other astrophysical environments such as
icy moons and the interstellar medium.
Title: AstroPix: Novel monolithic active pixel silicon sensors for
future gamma-ray telescopes
Authors: Steinhebel, Amanda L.; Fleischhack, Henrike; Striebig,
Nicolas; Jadhav, Manoj; Suda, Yusuke; Luz, Ricardo; Kierans, Carolyn;
Caputo, Regina; Tajima, Hiroyasu; Leys, Richard; Peric, Ivan; Metcalfe,
Jessica; Perkins, Jeremy S.
Bibcode: 2022arXiv220902631S
Altcode:
Space-based gamma-ray telescopes such as the Fermi Large Area
Telescope have used single sided silicon strip detectors to track
secondary charged particles produced by primary gamma-rays with high
resolution. At the lower energies targeted by keV-MeV telescopes, two
dimensional position information within a single detector is required
for event reconstruction - especially in the Compton regime. This
work describes the development of monolithic CMOS active pixel silicon
sensors - AstroPix - as a novel technology for use in future gamma-ray
telescopes. Based upon sensors (ATLASPix) designed for use in the ATLAS
detector at the Large Hadron Collider, AstroPix has the potential
to maintain high performance while reducing noise with low power
consumption. This is achieved with the dual detection and readout
capabilities in each CMOS pixel. The status of AstroPix development
and testing, as well as outlook for future testing and application,
will be presented.
Title: Quasinormal modes of anyons
Authors: C, Vishnulal; Das, Saurya; Basak, Soumen
Bibcode: 2022arXiv220901798C
Altcode:
We derive the quasinormal modes of anyons from (2+1)-dimensional
Banados, Teitelboim, and Zanelli(BTZ) and analogue black holes, and
discuss potential experiments to measure these quasinormal modes.
Title: Comparing NED and SIMBAD classifications across the contents
of nearby galaxies
Authors: Kuhn, L.; Shubat, M.; Barmby, P.
Bibcode: 2022MNRAS.515..807K
Altcode: 2022arXiv220613311K; 2022MNRAS.tmp.1750K
Cataloguing and classifying celestial objects is one of the fundamental
activities of observational astrophysics. In this work, we compare
the contents of two comprehensive data bases, the NASA Extragalactic
Database (NED) and Set of Identifications, Measurements and Bibliography
for Astronomical Data (SIMBAD) in the vicinity of nearby galaxies. These
two data bases employ different classification schemes - one flat and
one hierarchical - and our goal was to determine the compatibility of
classifications for objects in common. Searching both data bases for
objects within the respective isophotal radius of each of the ~1300
individual galaxies in the Local Volume Galaxy sample, we found that,
on average, NED contains about 10 times as many entries as SIMBAD
and about two-thirds of SIMBAD objects are matched by position to
a NED object, at 5 arcsec tolerance. These quantities do not depend
strongly on the properties of the parent galaxies. We developed an
algorithm to compare individual object classifications between the two
data bases and found that 88 per cent of the classifications agree;
we conclude that NED and SIMBAD contain consistent information for
sources in common in the vicinity of nearby galaxies. Because many
galaxies have numerous sources contained only in one of NED or SIMBAD,
researchers seeking the most complete picture of an individual galaxy's
contents are best served by using both data bases.
Title: AlH lines in the blue spectrum of Proxima Centauri
Authors: Pavlenko, Yakiv V.; Tennyson, Jonathan; Yurchenko, Sergei
N.; Schmidt, Mirek R.; Jones, Hugh R. A.; Lyubchik, Yuri; Suárez
Mascareño, A.
Bibcode: 2022arXiv220903037P
Altcode:
The recently-computed ExoMol line lists for isotopologues of AlH
are used to analyse the blue spectrum (4000-4500 Å) of Proxima Cen
(M5.5 V). Comparison of the observed and computed spectra enables
the identification of a large number of 27AlH lines of the A1{\Pi}
- X1{\Sigma}+ band system: the spectral range covering 1-0, 0-0 and
1-1 bands is dominated by clearly resolved AlH lines. We reveal the
diffuse nature of transitions close to the dissociation limit which
appears in the form of increasingly wider(up to 5 Å) and shallower
(up to the continuum confusion limit) AlH line profiles. The predicted
wavelengths of AlH diffuse lines are systematically displaced. The
effect broadening by pre-dissociation states on the line profiles is
included by increasing the radiative damping rate by up to 5 orders
of magnitude. We determine empirical values of damping rates for a
number of the clean 0-0 Q-branch transitions by comparing the observed
and synthetic stellar spectra. We find excellent agreement between our
damping rates and lifetimes available in the literature. A comparison
of 27Al1H ExoMol and REALH spectra shows that the observed spectrum is
better described by the ExoMol line list. A search for 26Al1H lines
in the Proxima Cen spectrum does not reveal any notable features;
giving an upper limit of 27Al1H/26Al1H {>} 100.
Title: Asymptotically Hyperbolic Einstein Constraint Equations with
Apparent Horizon Boundary and the Penrose Inequality for Perturbations
of Schwarzschild-AdS
Authors: Khuri, Marcus; Kopiński, Jarosław
Bibcode: 2022arXiv220901234K
Altcode:
We prove the existence of asymptotically hyperbolic solutions to the
vacuum Einstein constraint equations with a marginally outer trapped
boundary of positive mean curvature, using the constant mean curvature
conformal method. As an application of this result, we verify the
Penrose inequality for certain perturbations of Schwarzschild Anti-de
Sitter black hole initial data.
Title: Flux reconstruction for the NIR camera CAGIRE at the focus
of the Colibrí telescope
Authors: Nouvel de la Flèche, Alix; Atteia, Jean-Luc; Valentin,
Hervé; Larrieu, Marie; Boy, Jérémie; Gravrand, Olivier; Boulade,
Olivier; Clemens, Jean-Claude; Secroun, Aurélia; Kajfasz, Eric;
Llido, Olivier; Basa, Stéphane; Dolon, François; Floriot, Johan;
Lombardo, Simona; Lamoure, Adrien; Rubaldo, Laurent; Fieque, Bruno;
Roumegoux, Julien; Geoffray, Hervé; Watson, Alan M.; Lee, William H.;
Butler, Nathaniel
Bibcode: 2022arXiv220900386N
Altcode:
CAGIRE is the near infrared camera of the Colibrí robotic telescope,
designed for the follow-up of SVOM alerts. It is based on the ALFA
2k x 2k detector, from the LYNRED French Company, operating in "Up
the Ramp" mode. An observation consists in a series of short (1-2
minutes) exposures during which the pixels are read out every 1.3
second, while continuously accumulating charges proportionally to the
received flux. We discuss here the preprocessing of CAGIRE data and
a method that can be used to recover the flux received by each pixel
from the slope of the ramp.
Title: Axial and equatorial shocks in merging galaxy clusters:
the case of MCXC J0928.6+3747
Authors: Hoang, Duy
Bibcode: 2022cxo..prop.6385H
Altcode:
We propose a 126 ks Chandra observation on the low-mass merging galaxy
cluster MCXC J0928.6+3747, hosting two relics and a halo. Our main aim
is to search for merger shocks at the relic locations. Observations
indicate that the relics in the cluster likely originate from axial
and equatorial shocks during cluster merger. Although predicted by
simulations, equatorial shocks have only been reported in one case and
their properties are largely unknown. The SW relic in MCXC J0928.6+3747
is an ideal case to study this type of shocks. In addition, the Chandra
data allows us to study thermal and non-thermal correlation of the
halo that provide crucial insights into the mechanisms responsible
for the generation of relativistic electron and the amplification of
magnetic field in the halo.
Title: Investigation of Dust Ion Acoustic Shock and Solitary Waves
in a Viscous Dusty Plasma
Authors: Goswami, J.; Kausik, S. S.
Bibcode: 2022arXiv220902070G
Altcode:
A viscous dusty plasma containing Kappa distributed electrons, positive
warm viscous ions and constant negatively charged dust grains with
viscosity have been considered to study the modes of dust ion acoustic
waves (DIAWs) theoretically and numerically. The derivations and basic
features of shock and solitary waves with different plasma parameters
like Mach number, finite temperature coefficient, unperturbed dust
streaming velocity, kinematic viscosity of dust etc. of this DIAWs mode
have been performed. Considering the dynamical equation from Korteweg de
Vries(KdV) equation, a phase portrait has been drawn and the position
of saddle point or col. and center have also been discussed. This
type of dusty plasma can be found in celestial bodies. The results of
this research work can be applied to study the properties of DIAWs in
various astrophysical situations where Kappa distributive electrons
are present and careful modification of the same model can help us to
understand the nature of the DIAWs of laboratory plasma as well.
Title: Validation & Testing of the CROBAR 3D Coronal
Reconstruction Method with a MURaM simulation
Authors: Plowman, Joseph
Bibcode: 2022arXiv220901753P
Altcode:
I report on validation and testing of a novel 3D reconstruction method
than can obtain coronal plasma properties from a single snapshot
perspective. I first reported on the method in 2021, and I have since
named it the Coronal Reconstruction Onto B-Aligned Regions, or 'CROBAR',
method. The testing was carried out with a cube from a MURaM 3D MHD
simulation, which affords a coronal-like 'ground truth' against which
the reconstruction method can be applied and compared. I find that the
method does quite well, recovering the 'coronal veil'-like features
recently reported from the MURaM simulations, and allaying concerns that
these features would thwart recovery of valid 3D coronal structure from
a limited number of perspectives. I also find that a second perspective
at between $\sim 45$ and 90 degrees, does significantly improve the
reconstructions. Two distinct channels with Soft X-Ray like temperature
response (peaking above 5 MK) would suffice for CROBAR's optically
thin observables; barring that, a suite of AIA-like EUV passbands,
with good coverage of the 3-8 MK temperature range.
Title: Lofting of low speed ejecta produced in the DART experiment
and production of a dust cloud
Authors: Tancredi, Gonzalo; Liu, Po-Yen; Campo-Bagatin, Adriano;
Moreno, Fernando; Domínguez, Bruno
Bibcode: 2022arXiv220902805T
Altcode:
NASA sent the DART (Double Asteroid Redirection Test) mission
to impact Dimorphos, the satellite of the asteroid binary system
(65803) Didymos. DART will release LICIACube prior to impact to obtain
high-resolution post-impact images. The impact will produce a crater and
a large amount of material ejected at high speed (several tens of m/s),
producing an ejecta cone that will quickly disperse. We analyzed an
additional effect: the lofting of material at low velocity due to the
generation of seismic waves that propagate inside Dimorphos, producing
surface shaking far from the impact point. We divide the process
into different stages: from the generation of impact-induced waves,
the interaction of them with surface particles, the ejection of dust
particles at velocities, and the prediction of the observability of the
dust coma and trail. We anticipate the following observable effects:
i) generation of a dust cloud that will produce a hazy appearance of
Dimorphos' surface, detectable by LICIACube; ii) brightness increase
of the binary system due to enhancement of the cross section produced
by the dust cloud; iii) generation of a dust trail, similar to those
observed in some Active Asteroids, which can last for several weeks
after impact. Numerical prediction of the detectability of these effects
depends on the amount and size distribution of ejected particles, which
are largely unknown. In case these effects are observable, an inversion
method can be applied to compute the amount of ejected material and its
velocity distribution, and discuss the relevance of the shaking process.
Title: Spatial and orbital planes of the Milky Way satellites:
unusual but consistent with $\Lambda$CDM
Authors: Pham, Khanh; Kravtsov, Andrey; Manwadkar, Viraj
Bibcode: 2022arXiv220902714P
Altcode:
We examine the spatial distribution and orbital pole correlations
of satellites in a suite of zoom-in high-resolution dissipationless
simulations of Miky Way (MW) sized haloes. We use the measured
distribution to estimate the incidence of satellite configurations
as flattened and as correlated in their orbital pole distribution as
satellite system of the Milky Way. We confirm that this incidence is
sensitive to the radial distribution of subhaloes and thereby to the
processes that affect it, such as artificial disruption due to numerical
effects and disruption due to the central disk. Controlling for the
resolution effects and bracketing the effects of the disk, we find that
the MW satellite system is somewhat unusual (at the $\approx 2-3\sigma$
level) but is statistically consistent with the $\Lambda$CDM model, in
general agreement with results and conclusions of other recent studies.
Title: Experimental evidence for type-1.5 superconductivity in
ZrB12 single crystal
Authors: Zhang, An-Lei; Gao, Li-Xin; He, Jing-Yu; Filipov, Volodimir
B.; Cao, Shixun; Xiao, Qi-Ling; Ge, Jun-Yi
Bibcode: 2022SCPMA..6597412Z
Altcode:
Recent studies proposed the two-band effect and the related type-1.5
superconductivity in ZrB12 single crystal. Here, by combining
both macroscopic and microscopic measurements, the superconducting
properties and the intricate vortex matter of ZrB12
are studied in detail. The vortex phase diagram is constructed,
where the temperature dependence of the upper critical field can
be well reproduced using a two-band Werthamer-Helfand-Hohenberg
(WHH) model. A pronounced surface superconductivity is also found
in the same temperature range, where the semi-Meissner state is
observed. Both phenomena are attributed to the weakly coupled two-band
effect. The direct visualization of the semi-Meissner state exhibits an
inhomogeneous distribution of vortex clusters, vortex chains and large
Meissner areas. With the increase of magnetic field, a transition from
the semi-Meissner state to the mixed state is revealed and further
supported by statistical analysis of the vortex pattern. Our results
provide direct experimental evidence for the type-1.5 superconductivity
in ZrB12.
Title: Beyond anoxia: Exploring sedimentary thallium isotopes in
paleo-redox reconstructions from a new core top collection
Authors: Wang, Yi; Lu, Wanyi; Costa, Kassandra M.; Nielsen, Sune G.
Bibcode: 2022GeCoA.333..347W
Altcode:
The thallium isotopic composition (ε205Tl) of seawater
has been identified as a promising proxy for global oceanic redox
conditions due to its close association with Mn oxide burial. Currently
the preferred archives for past seawater Tl isotope reconstructions are
from anoxic (no oxygen detected) and/or sulfidic (no oxygen detected
and free sulfide present) environments that may suffer from basin
restriction. Here we conduct a comprehensive modern calibration of
authigenic sedimentary ε205Tl with core tops covering a
wide range of bottom water oxygenation and sediment compositions. We
show that quantitative Tl removal in the reducing porewaters (e.g.,
Mn reduction) at/near the sediment-water interface could allow the
sediments to track the water column ε205Tl. Even if the
bottom water is not anoxic, a shallow oxygen penetration depth under
high export productivity and/or high sedimentation rates may still
allow rapid oxygen consumption and buildup of reducing porewaters
conducive for complete Tl removal. Thus, applications of the Tl
isotope redox proxy can be greatly expanded beyond the anoxic
conditions into places with open-ocean connections and high mass
accumulation rates for high-resolution temporal reconstructions. We
present a decision tree using the sediment enrichment factors of Mn,
Ba, and U to determine whether sediment archives are likely to record
the seawater ε205Tl. We additionally provide an estimate
of authigenic Tl burial fluxes in environments with quantitative Tl
removal, which is roughly double the size of the 'euxinic/anoxic'
sink in previously published global marine Tl mass balance estimates.
Title: COCONUT, a Novel Fast-converging MHD Model for Solar Corona
Simulations: I. Benchmarking and Optimization of Polytropic Solutions
Authors: Perri, Barbara; Leitner, Peter; Brchnelova, Michaela;
Baratashvili, Tinatin; Kuźma, Błażej; Zhang, Fan; Lani, Andrea;
Poedts, Stefaan
Bibcode: 2022ApJ...936...19P
Altcode: 2022arXiv220503341P
We present a novel global 3D coronal MHD model called COCONUT,
polytropic in its first stage and based on a time-implicit backward
Euler scheme. Our model boosts run-time performance in comparison
with contemporary MHD-solvers based on explicit schemes, which is
particularly important when later employed in an operational setting
for space-weather forecasting. It is data-driven in the sense that
we use synoptic maps as inner boundary inputs for our potential-field
initialization as well as an inner boundary condition in the further MHD
time evolution. The coronal model is developed as part of the EUropean
Heliospheric FORecasting Information Asset (EUHFORIA) and will replace
the currently employed, more simplistic, empirical Wang-Sheeley-Arge
(WSA) model. At 21.5 R ⊙ where the solar wind is already
supersonic, it is coupled to EUHFORIA's heliospheric model. We validate
and benchmark our coronal simulation results with the explicit-scheme
Wind-Predict model and find good agreement for idealized limit cases
as well as real magnetograms, while obtaining a computational time
reduction of up to a factor 3 for simple idealized cases, and up to 35
for realistic configurations, and we demonstrate that the time gained
increases with the spatial resolution of the input synoptic map. We
also use observations to constrain the model and show that it recovers
relevant features such as the position and shape of the streamers
(by comparison with eclipse white-light images), the coronal holes
(by comparison with EUV images), and the current sheet (by comparison
with WSA model at 0.1 au).
Title: No Self-shadowing Instability in 2D Radiation Hydrodynamical
Models of Irradiated Protoplanetary Disks
Authors: David Melon Fuksman, Julio; Klahr, Hubert
Bibcode: 2022ApJ...936...16D
Altcode:
Theoretical models of protoplanetary disks including stellar irradiation
often show a spontaneous amplification of scale height perturbations,
produced by the enhanced absorption of starlight in enlarged regions. In
turn, such regions cast shadows on adjacent zones that consequently
cool down and shrink, eventually leading to an alternating pattern of
overheated and shadowed regions. Previous investigations have proposed
this to be a real self-sustained process, the so-called self-shadowing
or thermal wave instability, which could naturally form frequently
observed disk structures such as rings and gaps, and even potentially
enhance the formation of planetesimals. All of these, however, have
assumed in one way or another vertical hydrostatic equilibrium and
instantaneous radiative diffusion throughout the disk. In this work
we present the first study of the stability of accretion disks to
self-shadowing that relaxes these assumptions, relying instead on
radiation hydrodynamical simulations. We first construct hydrostatic
disk configurations by means of an iterative procedure and show that
the formation of a pattern of enlarged and shadowed regions is a direct
consequence of assuming instantaneous radiative diffusion. We then let
these solutions evolve in time, which leads to a fast damping of the
initial shadowing features in layers close to the disk surface. These
thermally relaxed layers grow toward the midplane until all temperature
extrema in the radial direction are erased in the entire disk. Our
results suggest that radiative cooling and gas advection at the disk
surface prevent a self-shadowing instability from forming, by damping
temperature perturbations before these reach lower, optically thick
regions.
Title: The Ratio of Perpendicular and Parallel Diffusion Coefficients
of Low-energy Particles in Turbulent Space Plasmas
Authors: Shalchi, A.
Bibcode: 2022ApJ...936....1S
Altcode:
Recently an improved nonlinear theory for the transport of energetic
particles across a mean magnetic field has been developed. The
latter theory is called the field line-particle decorrelation theory
and is the first analytical theory that agrees with test-particle
simulations without the need of a correction parameter, nor does
the theory contain any other free parameter. In the current paper we
derive analytical forms for the ratio of perpendicular and parallel
spatial diffusion coefficients κ ⊥/κ ∥
of low-energy particles. In the considered limit the latter ratio
is constant meaning that it does not depend on particle energy or
rigidity. It is shown that the ratio always has the form ${\kappa
}_{\perp }/{\kappa }_{\parallel }={a}^{2}\delta {B}_{x}^{2}/{B}_{0}^{2}$
if a two-dimensional turbulence model is employed. Furthermore, the
parameter a 2 depends only on the shape of the turbulence
spectrum but not on the magnetic fields. The obtained results can
be important for a variety of applications such as studies of solar
modulation and diffusive shock acceleration.
Title: Effects of galactic magnetic field on the UHECR correlation
studies with starburst galaxies
Authors: Higuchi, Ryo; Sako, Takashi; Fujii, Toshihiro; Kawata,
Kazumasa; Kido, Eiji
Bibcode: 2022arXiv220900305H
Altcode:
We estimate the biases caused by the coherent deflection due to the
galactic magnetic field (GMF) in the previous maximum-likelihood
analysis for searching the UHECR sources. We simulate the mock event
datasets with a set of assumptions for the starburst galaxy (SBG)
source model, coherent deflection by a GMF model, and the mixed-mass
composition, then conducted a maximum-likelihood analysis with
ignorance of the GMF in the same manner as previous studies. We find
that the anisotropic fraction $f_{\rm ani}$ is estimated systematically
lower than the true value. We estimate the true parameters which are
compatible with the best-fit parameters with the observation. We find
that except for a narrow region with a large anisotropic fraction and
small separation angular scale wide parameter space is still compatible
with the experimental results. We also develop the maximum-likelihood
method with consideration of the GMF model and confirm that the
estimated parameters would be improved.
Title: Presence of clay minerals can obscure spectral evidence of
Mg sulfates: implications for orbital observations of Mars
Authors: Sheppard, Rachel Y.; Milliken, Ralph E.; Robertson, Kevin M.
Bibcode: 2022Icar..38315083S
Altcode:
The martian crust is often viewed through the lens of its dominant
secondary minerals, Noachian phyllosilicates and Hesperian sulfates,
based on orbital spectral observations. However, the effects of
surface exposure on the spectra of these hydrous minerals are not
fully understood. We use an environmental chamber to measure changes in
near-infrared (NIR) spectral absorptions related to H2O in
smectite (montmorillonite) and Mg-sulfate under different temperature,
pressure, and relative humidity conditions with relevance to the
surface of Mars. Observed spectral differences are attributed to
changes in water content (hydration state), mineral phase, and degree
of crystallinity. It is observed that even minor changes in hydration
state and phase (for Mg sulfate) cause perceptible changes in NIR
H2O absorption features when measured in a controlled
laboratory setting under dry Mars-like conditions. Based on these
results and the known ability of smectite to rehydrate under increased
RH, smectites exposed at the surface of Mars are expected to exchange
water with the martian atmosphere under specific conditions, making them
active participants in the present-day hydrological cycle of Mars, and
in theory these hydration-dehydration processes should be detectable
using NIR reflectance spectroscopy. However, some of the spectral
changes associated with these hydration changes are subtle and may not
be detectable with orbital or landed VNIR spectrometers. Furthermore,
we find that the presence of clay minerals can spectrally mask the
presence of Mg sulfates under a range of hydration states if the clay
minerals are above ∼10 wt% abundance. Random noise was added to the
laboratory spectral data to simulate orbital-quality reflectance data,
and it is observed that expected changes related to hydration state
and crystallinity are likely difficult to detect in current orbital
VNIR data such as CRISM and OMEGA. This highlights the importance of
future in situ NIR reflectance observations to accurately determine
the extent to which hydrous minerals exposed as the surface cycle water
with the martian atmosphere under present-day environmental conditions
and to properly assess the role of hydrous minerals in the martian
water budget.
Title: The sensitivity of the WRF-4DVar data assimilation system to
the control variables: A study on heavy rainfall events over India
Authors: Gopalakrishnan, Deepak; Chandrasekar, A.
Bibcode: 2022DyAtO..9901304G
Altcode:
The impact of different formulations of background error covariances
(BECs) is examined for three heavy rainfall episodes over north India
with a regional 4-dimensional variational (4DVar) data assimilation
(DA) system. Three BEC formulations are analyzed, in which two
of them employ stream function and velocity potential (ψ and χ)
and the third one uses zonal and meridional velocity components (v
and v) as momentum control variables. The uv -based formulation is
completely univariate whereas, the correlations among the control
variables are taken into account in the ψχ -based formulations
through linear regression relations. Among the two ψχ -based BECs,
one uses univariate relation and the other one uses multivariate
relations for the moisture field. The multivariate relationship
allows for impacting the moisture analysis through the assimilation
of temperature or wind observations. Three experiments are carried
out for each case with cyclic 4DVar assimilation. The conventional
surface and upper-air observations are assimilated in combination
with atmospheric motion vectors (AMVs) and ocean surface winds. Free
forecast for 48 h is performed from respective final analysis fields for
all the experiments. The results indicate that the uv -based analysis
fields are closer to the observations. A comparative analysis of the
4DVar experiments with the 3DVar DA system provided a critical insight
on the role of the 4DVar DA system on implicitly accounting for the
multivariate correlations. The precipitation forecasts confirm the
improved performance of the ψχ -based experiment, when multivariate
nature of the humidity is incorporated. The time evolution of the
intense rainfall episodes over the location of maximum rainfall are
relatively well reproduced in the uv -based experiment. The results
indicate that the inclusion of multivariate humidity variable in the
BEC formulation does have a significant impact on suppressing the
excessive overestimation in rainfall intensity.
Title: Potassium isotope fractionation during chemical weathering
in humid and arid Hawaiian regoliths
Authors: Li, Wenshuai; Liu, Xiao-Ming; Hu, Yan; Teng, Fang-Zhen;
Chadwick, Oliver A.
Bibcode: 2022GeCoA.333...39L
Altcode:
The controls on potassium (K) isotope fractionation during chemical
weathering are evaluated using two regolith profiles developed over
∼350 kyr on the humid and arid sides of Kohala Mountain, Hawai'i. The
humid regolith shows 145% K enrichment relative to the basaltic parent
in shallow (≤1 m) horizons, but losses of up to 90% in the deeper
horizons. By contrast, the arid regolith has lost between 60 and 90%
K from the top 1 m of the soil with the least depletion in the deeper
horizons due to limited chemical weathering. This apparent contradiction
can be explained by enhanced accumulation of K-bearing mineral aerosols
in the humid regolith. Bulk δ41K varies from -0.76 ± 0.08
to -0.31 ± 0.06‰ in the humid regolith compared with -0.48‰ for the
underlying basalt. In contrast, the arid regolith shows δ41K
values ranging from -0.39 ± 0.10 to -0.02 ± 0.05‰, heavier than
that of their basaltic parent. Exchangeable (NH4Ac extracts)
δ41K of the humid and arid regoliths ranges from -0.63
± 0.07 to 0.11 ± 0.07‰ and -0.01 ± 0.05 to 0.04 ± 0.08‰,
respectively. Exchangeable K has δ41K higher than (or
similar to) the bulk values in most samples, reflecting a potential
contribution of marine aerosols to the labile (plant available)
K pool. In the shallow regolith, K derived from mineral aerosols is
significant, especially for the humid site, and this idea is supported
by enriched quartz, radiogenic Nd-Sr isotope values towards the surface,
and increasing δ41K close to the upper crustal composition
(an analogue of the dust). The enrichment of K in humid surface soils,
an upward decrease in exchangeable δ41K in the humid
regolith and plant-like δ41K in the topmost, organic-rich
soils may reveal the contribution of plant cycling. Low δ41K
in deep, humid regolith relative to δ41KBasalt
appears to be driven by clay incorporation of isotopically light
K. In comparison, higher δ41K in the arid regolith than
δ41KBasalt likely reflects an interplay between
preferential clay 41K sorption in alkaline environments and
preservation of seawater-derived K in forms of clay adsorbed complex
and carbonate phases (via adsorption and/or incorporation). Our results
reveal that the K isotope composition in Hawaiian regoliths depends on
climate, while it is complicated by the interaction among weathering,
plant cycling and addition of marine and mineral aerosols.
Title: On the nature of oxygen-isotope heterogeneity of igneous
calcium-aluminum-rich inclusions in cv carbonaceous chondrites
Authors: Krot, Alexander N.; Nagashima, Kazuhide; MacPherson, Glenn
J.; Ulyanov, Alexander A.
Bibcode: 2022GeCoA.332..327K
Altcode:
Coarse-grained igneous Ca,Al-rich inclusions (CAIs) in CV (Vigarano
group) carbonaceous chondrites have typically heterogeneous
O-isotope compositions with melilite, anorthite, and high-Ti
(>10 wt% TiO2) fassaite being 16O-depleted
(Δ17O up to ∼ - 3 ± 2‰) compared to hibonite,
spinel, low-Ti (<10 wt% TiO2) fassaite, Al-diopside,
and forsterite, all having close-to-solar Δ17O ∼ - 24 ±
2‰. To test a hypothesis that this heterogeneity was established,
at least partly, during aqueous fluid-rock interaction, we studied
the mineralogy, petrology, and O-isotope compositions of igneous
CAIs CG-11 (Type B), TS-2F-1, TS-68, and 818-G (Compact Type A), and
818-G-UR (davisite-rich) from Allende (CV > 3.6), and E38 (Type B)
from Efremovka (CV3.1-3.4). Some of these CAIs contain (i) eutectic
mineral assemblages of melilite, Al,Ti-diopside, and ± spinel which
co-crystallized and therefore must have recorded O-isotope composition
of the eutectic melt; (ii) isolated inclusions of Ti-rich fassaite
inside spinel grains which could have preserved their initial O-isotope
compositions, and/or (iii) pyroxenes of variable chemical compositions
which could have recorded gas-melt O-isotope exchange during melt
crystallization and/or postcrystallization exchange controlled by
O-isotope diffusivity. If these CAIs experienced isotopic exchange
with an aqueous fluid, O-isotope compositions of some of their primary
minerals are expected to approach that of the fluid. We find that
in the eutectic melt regions composed of highly-åkermanitic melilite
(Åk65-71), anorthite, low-Ti fassaite, and spinel of E38,
spinel, fassaite, and anorthite are similarly 16O-rich
(Δ17O ∼ - 24‰), whereas melilite is 16O-poor
(Δ17O ∼ - 1‰). In the eutectic melt regions of CG-11,
spinel and low-Ti fassaite are 16O-rich (Δ17O
∼ - 24‰), whereas melilite and anorthite are 16O-poor
(Δ17O ∼ - 3‰). In TS-2F-1, TS-68, and 818-G, melilite
and high-Ti fassaite grains outside spinel have 16O-poor
compositions (Δ17O range from - 12 to - 3‰); spinel
is 16O-rich (Δ17O ∼ - 24‰); perovskite
grains show large variations in Δ17O, from - 24 to
- 1‰. Some coarse perovskites are isotopically zoned with a
16O-rich core and a 16O-poor edge. Isolated
high-Ti fassaite inclusions inside spinel grains are 16O-rich
(Δ17O ∼ - 24‰), whereas high-Ti fassaite inclusions
inside fractured spinel grains are 16O-depleted:
Δ17O range from - 12 to - 3‰. In 818-G-UR, davisite
is 16O-poor (Δ17O ∼ - 2‰), whereas
Al-diopside of the Wark-Lovering rim is 16O-enriched
(Δ17O < - 16‰). On a three-isotope oxygen diagram,
the 16O-poor melilite, anorthite, high-Ti fassaite,
and davisite in the Allende CAIs studied plot close to O-isotope
composition of an aqueous fluid (Δ17O ∼ - 3 ± 2‰)
inferred from O-isotope compositions of secondary minerals resulted from
metasomatic alteration of the Allende CAIs. We conclude that CV
igneous CAIs experienced post-crystallization O-isotope exchange that
most likely resulted from an aqueous fluid-rock interaction on the CV
asteroid. It affected melilite, anorthite, high-Ti fassaite, perovskite,
and davisite, whereas hibonite, spinel, low-Ti fassaite, Al-diopside,
and forsterite retained their original O-isotope compositions
established during igneous crystallization of CV CAIs. However, we
cannot exclude some gas-melt O-isotope exchange occurred in the solar
nebula. This apparently "mineralogically-controlled" exchange process
was possibly controlled by variations in oxygen self-diffusivity of CAI
minerals. Experimentally measured oxygen self-diffusion coefficients in
CAI-like minerals are required to constrain relative roles of O-isotope
exchange during aqueous fluid-solid and nebular gas-melt interaction.
Title: Chemical diffusion of fluorine in phlogopite
Authors: Zhang, Kai; Liu, Hanyong; Ingrin, Jannick; Zhang, Baohua;
Yang, Xiaozhi
Bibcode: 2022GeCoA.333...95Z
Altcode:
Fluorine is a minor yet important component of volatiles in silicate
minerals, and affects greatly the physicochemical properties of the host
materials. The diffusivity of fluorine provides critical information for
quantitatively understanding its many effects, but very few studies have
been documented. Here we evaluated the orientation-related chemical
diffusion of fluorine in phlogopite, by conducting experiments on
single crystal samples. Runs were carried out by the diffusion couple
technique at 1 GPa and 700-800 °C, and durations were typically
25-264 h. Concentration profiles of fluorine in recovered samples and
chemical compositions of minerals were analyzed by electron microprobe,
and sample water content was determined by Fourier-transform infrared
spectroscopy. The results show that, under the experimental conditions,
the fluorine diffusivity is on the order of 10-19 to
10-17 m2/s and is slightly anisotropic. The
diffusion is fast along the direction ⊥(1 1 0) and slow along the
direction ⊥(0 0 1), with the direction ⊥(0 1 0) falling between
them, and the activation energy is 176 to 246 kJ/mol along the three
directions. The comparison of the diffusivity data of fluorine with
those reported for other species in phlogopite and fluorine in other
minerals suggests a strong enhancement of the ionic diffusion along the
interlayer direction, thus the diffusivity anisotropy, by the presence
of molecular H2O in the system. The theoretically calculated
electrical conductivity of phlogopite, by applying the Nernst-Einstein
relation and our determined diffusion data, is remarkably lower than
that experimentally measured for the phlogopite with the same fluorine
content and with conduction dominated by fluorine. This indicates that
the self diffusion of fluorine in phlogopite is much faster than its
chemical diffusion, and/or that the mobility of fluorine is largely
different between the diffusion and the conductivity experiments. The
diffusivity data provide crucial constraints on the closure temperature
of fluorine in phlogopite, which is critical for the kinetic analyses
of preserved fluorine zonation in natural phlogopites.
Title: Light Zn and Cu isotope compositions recorded in ferromanganese
crusts during the Cenozoic as evidence for hydrothermal inputs in
South Pacific deep seawater
Authors: Gueguen, Bleuenn; Rouxel, Olivier; Fouquet, Yves
Bibcode: 2022GeCoA.333..136G
Altcode:
This study presents a high-resolution record of Cu and Zn isotopes
in four Fe-Mn crusts from the North and South Pacific oceans. North
Pacific crusts were collected on the Apuupuu seamount south of the
Hawaiian archipelago and South Pacific crusts were recovered near Rurutu
Island in the Tahiti archipelago. Major and trace element compositions
suggest that Cu and Zn in these crusts is of hydrogenous origin, i.e.,
precipitated from seawater, and they may therefore mirror deep seawater
metal isotope. We show that Cu and Zn display different isotopic
patterns between the North and the South Pacific Oceans but show
similar temporal evolution within each geographical area. Copper and
Zn isotope composition of both North Pacific crusts vary between 0.57
‰ to 0.73 ‰ for δ65/63CuNIST976 and 0.97 ‰
to 1.25 ‰ for δ66/64ZnJMC-Lyon. In contrast,
South Pacific crusts show resolvable temporal variations, with Cu and Zn
isotopic ratios increasing sharply over the last ∼ 6 Ma from 0.16 ‰
to 0.51 ‰ and 0.67 ‰ to 1.09 ‰ respectively. Notably, we observed
a positive correlation between δ65/63CuNIST976
and δ66/64ZnJMC-Lyon values in Fe-Mn
crusts from the South Pacific. The correlation suggests mixing
between two components in Fe-Mn crusts, a hydrothermal component
with δ65/63CuNIST976 ∼ 0.2 ‰ and
δ66/64ZnJMC-Lyon ∼ 0.7 ‰, and a Pacific
deep seawater component with δ65/63CuNIST976 ∼
0.7 ‰ and δ66/64ZnJMC-Lyon ∼ 1.2 ‰. These
values are fractionated from modern dissolved Cu and Zn by a factor of
-0.3 ‰ and 0.5 ‰ respectively. We suggest that the deep Southern
Pacific Ocean received sustained hydrothermal input during the last
6 Ma, which was recorded in the Cu and Zn isotope composition of
Fe-Mn crusts precipitated thousands of kilometers away. Our study
highlights that hydrothermal venting may be a significant source of
Cu and Zn in the deep oceans despite their extensive precipitation
within hydrothermal vent fields. We show that this source could be
persistent through time, and thus, it could have a significant impact
on the biogeochemical cycling of Cu and Zn in seawater which would
ultimately be recorded by Fe-Mn crusts.
Title: Probing Super-Eddington Outflows via Accreting Galactic BeXRBs
Authors: Reynolds, Mark
Bibcode: 2022cxo..prop.6308R
Altcode:
Observations of the population of ultra luminous X-ray sources has
revealed that at least a subset of this group contains a neutron
star primary. Thus, dramatically demonstrating the viability of
super-Eddington accretion for this source class. However, the physics
of these super-Eddington accretion flows are poorly understood with the
sources typically lying at Mpc distances. The population of Galactic
Be/X-ray binaries (BeXRBs) are known to have giant outbursts that enter
the super-Eddington regime and promise the opportunity to learn much
about this mode of accretion. Herein, we propose to obtain simultaneous
high resolution X-ray, UV and radio spectroscopy of the next bright
Galactic BeXRB to enter a giant outburst when the neutron star will
be accreting in the super-Eddington regime.
Title: Variability of Ionospheric Plasma: Results from the ESA
Swarm Mission
Authors: Wood, Alan G.; Alfonsi, Lucilla; Clausen, Lasse B. N.; Jin,
Yaqi; Spogli, Luca; Urbář, Jaroslav; Rawlings, James T.; Whittaker,
Ian C.; Dorrian, Gareth D.; Høeg, Per; Kotova, Daria; Cesaroni,
Claudio; Cicone, Antonio; Miedzik, Jan; Gierlach, Ewa; Kochańska,
Paula; Wojtkiewicz, Pawel; Shahtahmassebi, Golnaz; Miloch, Wojciech J.
Bibcode: 2022SSRv..218...52W
Altcode:
Swarm is the first European Space Agency (ESA) constellation mission
for Earth Observation. Three identical Swarm satellites were launched
into near-polar orbits on 22 November 2013. Each satellite hosts a
range of instruments, including a Langmuir probe, GPS receivers, and
magnetometers, from which the ionospheric plasma can be sampled and
current systems inferred. In March 2018, the CASSIOPE/e-POP mission was
formally integrated into the Swarm mission through ESA's Earthnet Third
Party Mission Programme. Collectively the instruments on the Swarm
satellites enable detailed studies of ionospheric plasma, together
with the variability of this plasma in space and in time. This allows
the driving processes to be determined and understood. The purpose
of this paper is to review ionospheric results from the first seven
years of the Swarm mission and to discuss scientific challenges for
future work in this field.
Title: Lithium isotope fractionation during magmatic differentiation
and hydrothermal processes in post-collisional adakitic rocks
Authors: Tian, Heng-Ci; Tian, Shi-Hong; Hou, Zeng-Qian; Yang, Zhi-Ming;
Zheng, Yuanchuan
Bibcode: 2022GeCoA.332...19T
Altcode:
To investigate the behavior of Li isotopes during magmatic
differentiation and the petrogenesis of Cu-bearing ore deposits, a
suite of post-collisional adakitic rocks from Qulong region, southern
Tibet, was studied. Their lithologies range from diorite through
granodiorite to granite porphyry with the latter containing giant
Cu deposits. Detailed evidence of field observation and geochemical
signature suggest that these three sets of rocks were most likely formed
by various degrees of partial melting and fractional crystallization
from the same source. The dioritic enclave, granodiorite and granite
porphyry have δ7Li values ranging from 0.2 to 8.2‰, 3.1
to 6.8‰, and 3.9 to 7.4‰, respectively. Most of these samples are
overlapping in Li isotope composition, comparable to other granitoids
worldwide, indicating insignificant Li isotope fractionation during
partial melting and magma differentiation in adakite-like rocks. By
contrast, their Li concentrations are mainly controlled by fractional
crystallization as suggested from different modal mineralogy. This
process does not lead to further enrichment of Cu although they have
initial high concentrations (an average of ∼ 104 ppm). In comparison,
granite porphyry has extremely high Cu contents (up to 2000 ppm)
and their δ7Li values are positively correlated with Cu
content, suggesting the involvement of magmatic fluids that most likely
exsolved from deep magma chamber. Such fluids not only modified the Li
isotopic compositions of granite porphyries, but also extracted metal
elements from the highly evolved magma, eventually resulting in the Cu
mineralization. Our work here provides new insight into the formation
and evolution of the porphyry Cu-bearing deposit.
Title: Pressure-induced structural evolution in boron-bearing model
rhyolitic glasses under compression: Implications for boron isotope
compositions and properties of deep melts in Earth's interior
Authors: Lee, A. Chim; Kim, Eun Jeong; Lee, Sung Keun
Bibcode: 2022GeCoA.332..220L
Altcode:
The pressure-induced structural evolutions of boron-bearing model
rhyolitic melts under high pressures enable to infer the detailed
geochemical processes (melting and fluid-rock-melt interactions)
occurring in Earth interiors and to control the melt properties
(viscosity and the boron isotope composition, δ11B)
of complex magmatic melts, providing insights into the boron cycle
toward the deeper part of the upper mantle (∼10 GPa). Despite the
importance, the structures of multicomponent boron-bearing silicate
melts above 3 GPa are currently unavailable. Here, we explore the
structures, particularly, coordination transformation of constituent
elements in boron-bearing nepheline and albite glasses - a model
rhyolitic melts - upon compression to a depth of ∼270 km (∼9.2
GPa) in the mantle using multi-nuclear solid-state nuclear magnetic
resonance (NMR) spectroscopy. The results showed that the conversion
of [3]B into [4]B is prominent upon compression
up to 6 GPa. In contrast, the formation of [5,6]Al is
accompanied by the formation of oxygen tricluster above 6 GPa, where
all the nonbridging oxygens are consumed. We quantify how the melt
composition affects tendency to form highly coordinated B, Al, and Si
upon compression. Particularly, the increase in the [4]B
population tends to be larger for the glasses with low Si content
as pressure increases to 9.2 GPa. We reveal the relationship between
such structural adaptations of the compressed melts at high pressure
and the melt properties, including viscosity and element partition
coefficient in boron-bearing melts. The current NMR results also
unravel the structural origins of 11B/10B ratios
in rhyolitic melts at high pressure. Considering a preferential
partitioning of 10B to [4]B, an increase in
[4]B population in the melts leads to an pressure-induced
enrichment of 10B. As the increase in Si/B ratio in the
melts tends to decrease the pressure-induced increase in [4]B
fraction, the contribution of boron coordination transformation on the
11B/10B ratios in silicate melt would be somewhat
minor in deep mantle melts with increasing Si content. The detailed
boron environments in rhyolitic melts at high pressure yield useful
constraints for the isotope composition (11B/10B)
of dense mantle melts, thereby enabling quantification of deep boron
cycle.
Title: Simulating nearly edge-on sloshing in the galaxy cluster
Abell 2199
Authors: Machado, R. E. G.; Laganá, T. F.; Souza, G. S.; Caproni,
A.; Antas, A. S. R.; Mello-Terencio, E. A.
Bibcode: 2022MNRAS.515..581M
Altcode: 2022arXiv220614127M; 2022MNRAS.tmp.1756M
Off-axis collisions between galaxy clusters may induce the phenomenon
of sloshing, causing dense gas to be dragged from the cool core of
a cluster, resulting in a spiral of enhanced X-ray emission. Abell
2199 displays signatures of sloshing in its core and it is possible
that the orbital plane of the collision is seen nearly edge-on. We aim
to evaluate whether the features of Abell 2199 can be explained by a
sloshing spiral seen under a large inclination angle. To address this,
we perform tailored hydrodynamical N-body simulations of a non-frontal
collision with a galaxy group of $M_{200}=1.6\times 10^{13}\, {\rm
M_{\odot }}$. We obtain a suitable scenario in which the group passed
by the main cluster core 0.8 Gyr ago, with a pericentric separation
of 292 kpc. A good agreement is obtained from the temperature maps
as well as the residuals from a β-model fit to the simulated X-ray
emission. We find that under an inclination of i = 70° the simulation
results remain consistent with the observations.
Title: Novel quantum circuit implementation of Advanced Encryption
Standard with low costs
Authors: Li, ZhenQiang; Cai, BinBin; Sun, HongWei; Liu, HaiLing; Wan,
LinChun; Qin, SuJuan; Wen, QiaoYan; Gao, Fei
Bibcode: 2022SCPMA..6590311L
Altcode:
In this study, we examine how the quantum circuit of the Advanced
Encryption Standard (AES) can be optimized from two aspects, i.e.,
number of qubits and T-depth. To reduce the number of qubits, we
present three kinds of improved quantum circuits of S-box for different
phases in the AES. We found that the number of qubits in the round
function can be decreased by introducing the circuit sending |a» to |S
(a)». As a result, compared with the previous quantum circuits where
400/640/768 qubits are required, our circuits of AES-128/-192/-256 only
require 270/334/398 qubits. To reduce the T-depth, we propose a new
circuit of AES's S-box with a T-depth of 4. Accordingly, the T-depth
of our AES-128/-192/-256 quantum circuits become 80/80/84 instead of
120/120/126 in a previous study.
Title: First few overtones probe the event horizon geometry
Authors: Konoplya, R. A.; Zhidenko, A.
Bibcode: 2022arXiv220900679K
Altcode:
It is broadly believed that quasinormal modes (QNMs) cannot tell the
black-hole near-horizon geometry, because usually the low-lying modes
are determined by the scattering of perturbations around the peak of the
effective potential. Using the general parametrization of the black-hole
spacetimes respecting the generic post-Newtonian asymptotic, we will
show that tiny modifications of the Schwarzschild/Kerr geometry
in a small region near the event horizon lead to almost the same
Schwarzschild/Kerr fundamental mode, but totally different first few
overtones. Having in mind that the first several overtones affect
the quasinormal (QN) ringing at its early and intermediate stage
[M. Giesler, M. Isi, M. Scheel, and S. Teukolsky, Phys. Rev. X 9,
041060 (2019)], we argue that the near-horizon geometry could in
principle be studied via the first few overtones of the QN spectrum,
which is important because corrections to the Einstein theory must
modify precisely the near-horizon geometry, keeping the known weak
field regime. We discuss the connection of this observation with the
so called ``overtones' instability'' recently studied in [J. Jaramillo
et. al. Phys. Rev. Lett. 128, 211102 (2022)].
Title: Emission of gravitational waves by superconducting cosmic
strings
Authors: Rybak, I. Yu.; Sousa, L.
Bibcode: 2022arXiv220901068R
Altcode:
We study the gravitational radiation emission efficiency $\Gamma$ of
superconducting cosmic strings. We demonstrate, by using a solvable
model of transonic strings, that the presence of a current leads to a
suppression of the gravitational emission of cusps, kinks and different
types of loops. We also show that, when a current is present, the
spectrum of emission of loops with cusps is exponentially suppressed
as the harmonic mode increases, thus being significantly different
from the power law spectrum of currentless loops. Furthermore,
we establish a phenomenological relationship between $\Gamma$ and
the value of the current on cosmic strings. We conjecture that this
relation should be valid for an arbitrary type of current-carrying
string. We use this result to study the potential impact of current
on the stochastic gravitational wave background generated by cosmic
strings with additional degrees of freedom and show that both the
amplitude and shape of the spectrum may be significantly affected.
Title: The Unmixed Debris of Gaia-Sausage/Enceladus in the Form of
a Pair of Halo Stellar Overdensities
Authors: Perottoni, Hélio D.; Limberg, Guilherme; Amarante, João
A. S.; Rossi, Silvia; Queiroz, Anna B. A.; Santucci, Rafael M.;
Pérez-Villegas, Angeles; Chiappini, Cristina
Bibcode: 2022ApJ...936L...2P
Altcode: 2022arXiv220711869P
In the first billion years after its formation, the Galaxy underwent
several mergers with dwarf satellites of various masses. The debris
of Gaia-Sausage/Enceladus (GSE), the galaxy responsible for the last
significant merger of the Milky Way, dominates the inner halo and has
been suggested to be the progenitor of both the Hercules-Aquila Cloud
(HAC) and Virgo Overdensity (VOD). We combine SEGUE, APOGEE, Gaia, and
StarHorse distances to characterize the chemodynamical properties and
verify the link between HAC, VOD, and GSE. We find that the orbital
eccentricity distributions of the stellar overdensities and GSE are
comparable. We also find that they have similar, strongly peaked,
metallicity distribution functions, reinforcing the hypothesis of common
origin. Furthermore, we show that HAC and VOD are indistinguishable from
the prototypical GSE population within all chemical-abundance spaces
analyzed. All these evidences combined provide a clear demonstration
that the GSE merger is the main progenitor of the stellar populations
found within these halo overdensities.
Title: Research on the On-orbit Background of the Hard X-Ray Imager
Onboard ASO-S
Authors: Liu, Wei; Chen, Deng-Yi; Jiang, Xian-Kai; Wu, Jian; Zhang,
Zhe; Hu, Yi-Ming; Su, Yang; Chen, Wei; Ma, Tao
Bibcode: 2022RAA....22i5011L
Altcode:
The space environment background of various particle fluxes of
the Hard X-ray Imager (HXI), one of the payloads of the Advanced
Space-based Solar Observatory (ASO-S) spacecraft, is investigated
and presented. Different approaches are used to obtain the input
information on various space environment particles (protons, alpha
particles, electrons, positrons, neutrons, and photons). Some special
regions (SAA and radiation belt) are also taken into account. The
findings indicate that electrons are the primary background source
in the radiation belt. Due to the large background flux generated by
electrons, HXI cannot effectively observe solar flares in the radiation
belt. Outside the radiation belt, primary protons and albedo photons
are the main sources of background at low and high magnetic latitudes
respectively. The statistical analysis of the flare and background
spectra shows that the errors of the flare energy spectrum observation
are mainly concentrated in the high energy band, and the detector still
has a certain spectrum observation capability for flares of C-class and
below in the low energy band of the non-radiation belt. The imaging
observation of flares of C-class and below is significantly affected
by the accuracy of background subtraction. The energy band with the
best signal-to-noise ratio is from 10 to 50 keV, which can be used to
monitor the formation and class of flares.
Title: Machine learning for galactic archaeology: a chemistry-based
neural network method for identification of accreted disc stars
Authors: Tronrud, Thorold; Tissera, Patricia B.; Gómez, Facundo A.;
Grand, Robert J. J.; Pakmor, Ruediger; Marinacci, Federico; Simpson,
Christine M.
Bibcode: 2022MNRAS.515.3818T
Altcode: 2022MNRAS.tmp.1900T; 2022arXiv220706586T
We develop a method ('Galactic Archaeology Neural Network', GANN)
based on neural network models (NNMs) to identify accreted stars in
galactic discs by only their chemical fingerprint and age, using a
suite of simulated galaxies from the Auriga Project. We train the
network on the target galaxy's own local environment defined by the
stellar halo and the surviving satellites. We demonstrate that this
approach allows the detection of accreted stars that are spatially
mixed into the disc. Two performance measures are defined - recovery
fraction of accreted stars, frecov and the probability that
a star with a positive (accreted) classification is a true-positive
result, P(TP). As the NNM output is akin to an assigned probability
(Pa), we are able to determine positivity based on flexible
threshold values that can be adjusted easily to refine the selection
of presumed-accreted stars. We find that GANN identifies accreted
disc stars within simulated galaxies, with high frecov
and/or high P(TP). We also find that stars in Gaia-Enceladus-Sausage
(GES) mass systems are over 50 per cent recovered by our NNMs in
the majority (18/24) of cases. Additionally, nearly every individual
source of accreted stars is detected at 10 per cent or more of its peak
stellar mass in the disc. We also demonstrate that a conglomerated
NNM, trained on the halo and satellite stars from all of the Auriga
galaxies provides the most consistent results, and could prove to be
an intriguing future approach as our observational capabilities expand.
Title: Spatial correlations of dark energy from quantum fluctuations
in inflation
Authors: Belgacem, Enis; Prokopec, Tomislav
Bibcode: 2022arXiv220901601B
Altcode:
This paper contains a detailed study of the properties of a simple
model attempting to explain dark energy as originated from quantum
fluctuations of a light spectator scalar field in inflation. In [1] we
recently outlined how Starobinsky's stochastic formalism can be used to
study the spatial correlations imprinted on dark energy by its quantum
origin in this model and we studied their possible role in relieving
the Hubble tension. Here we provide a more comprehensive derivation of
the results in [1] and we refine some of our estimates, comparing to
the approximate results obtained previously. Among the main results,
we analyze the non-coincident correlators predicted by a full field
theoretical treatment and their relation with those computed within
the stochastic formalism. We find that in the region where stochastic
theory predicts significant sub-Hubble correlators it is in disagreement
with field theoretical predictions. However, agreement can be restored
by introducing a reduced speed of sound for the scalar field. We also
discuss an alternative approach to the problem of studying correlators
within the stochastic formalism based directly on the evolution of
probability distributions. Remarkably we find that the two approaches
give the same answer for 2-point functions of the field, but not for
4-point functions relevant to density correlators and we discuss the
behaviour of the two methods with respect to Wick's theorem.
Title: The study of thermonuclear X-ray bursts in accreting
millisecond pulsar MAXI J1816-195 with NuSTAR and NICER
Authors: Mandal, Manoj; Pal, Sabyasachi; Chauhan, Jaiverdhan; Lohfink,
Anne; Bharali, Priya
Bibcode: 2022arXiv220900911M
Altcode:
The millisecond pulsar MAXI J1816--195 was recently discovered by
MAXI in 2022 May. We have studied different properties of the pulsar
using data from NuSTAR and NICER observations. The position of the
source is measured by NuSTAR as RA = $18^h 16^m 52^s.40$, Dec =
$-19^o37^{'} 58^{''}.35$. The unstable burning of accreted material
on the surface of neutron stars induces thermonuclear (Type-I)
bursts. Several thermonuclear bursts have been detected from the
source during the outburst. We study the evolution of burst profile
with flux and energy using NuSTAR and NICER observations. During the
NuSTAR observation, a total of four bursts were detected from the
source. The duration of each burst was around $\sim$ 30 s and the
ratio of peak to persistent count rate is $\sim$ 26 as seen from the
NuSTAR data. The thermonuclear bursts are modeled to determine the
burst timing parameters using a sharp linear rise and exponential
decay function. The burst profiles show a relatively long tail in
lower energies. The hardness ratio during the thermonuclear bursts
shows significant variation as observed by NuSTAR. We successfully
model the broadband burst-resolved spectra with a combination of an
absorbed blackbody along with a non-thermal component to account for
the persistent emission. The burst-resolved spectral parameters show
significant evolution during the burst. During the peak of the burst,
the Eddington luminosity is found to be $\sim 3.7 \times 10^{38}$
erg s$^{-1}$. The burst-resolved spectral parameters provide a source
distance of $8.5\pm1.2$ kpc for isotropic burst emission.
Title: Instability of spherically-symmetric black holes in Quadratic
Gravity
Authors: Held, Aaron; Zhang, Jun
Bibcode: 2022arXiv220901867H
Altcode:
We investigate the linear stability of the two known branches of
spherically-symmetric black holes in Quadratic Gravity. We extend
previous work on the long-wavelength (Gregory-Laflamme) instability of
the Schwarzschild branch to a corresponding long-wavelength instability
in the non-Schwarzschild branch. In both cases, the instability sets in
below a critical horizon radius at which the two black-hole branches
intersect. This suggests that classical perturbations enforce a lower
bound on the horizon radius of spherically-symmetric black holes in
Quadratic Gravity.
Title: GRB 080928 afterglow imaging and spectro-polarimetry
Authors: Brivio, R.; Covino, S.; D'Avanzo, P.; Wiersema, K.; Maund,
J. R.; Bernardini, M. G.; Campana, S.; Melandri, A.
Bibcode: 2022arXiv220902557B
Altcode:
Among the large variety of astrophysical sources that we can
observe, gamma-ray bursts (GRBs) are the most energetic of the whole
Universe. The definition of a general picture describing the physics
behind GRBs has always been a compelling task, but the results obtained
so far from observations have revealed a puzzling landscape. The lack of
a clear, unique paradigm calls for further observations and additional,
independent techniques for this purpose. Polarimetry constitutes a
very useful example as it allows us to investigate some features of
the source such as the geometry of the emitting region and the magnetic
field configuration. To date, only a handful of bursts detected by space
telescopes have been accompanied by ground-based spectro-polarimetric
follow-up, and therefore such an analysis of more GRBs is of crucial
importance in order to increase the sample of bursts with multi-epoch
polarisation analysis. In this work, we present the analysis of the
GRB 080928 optical afterglow, with observations performed with the
ESO-VLT FORS1 instrument. We find that the GRB optical afterglow
was not significantly polarised on the first observing night. The
polarisation degree ($P$) grew on the following night to a level of
$P \sim$ 4.5%, giving evidence of polarised radiation at a 4 $\sigma$
confidence level. The GRB 080928 light curve is not fully consistent
with standard afterglow models, making any comparison with polarimetric
models partly inconclusive. The most conservative interpretation is
that the GRB emission was characterised by a homogeneous jet and was
observed at an angle of 0.6 $< \theta_{obs}/\theta_{jet} <$
0.8. Moreover, the non-zero polarisation degree on the second night
suggests the presence of a dominant locally ordered magnetic field in
the emitting region.
Title: Nonlinear mechanisms in Al and Ti superconducting
travelling-wave parametric amplifiers
Authors: Zhao, Songyuan; Withington, S.; Thomas, C. N.
Bibcode: 2022JPhD...55J5301Z
Altcode: 2022arXiv220211656Z
The underlying nonlinear mechanisms behind the operation of
travelling-wave parametric amplifiers (TWPAs) are important in
determining their performance in terms of added noise, maximum
gain, and bandwidth. We describe a method of characterising the
underlying nonlinearity of a superconducting material in terms of
its dissipative-reactive ratio and the response time of the underlying
microscopic processes. We describe and calculate the different behaviour
arising from the equilibrium supercurrent nonlinearity, which has low
dissipation and fast response time, and the non-equilibrium heating
nonlinearity, which has high dissipation and slow response time. We
have fabricated TWPAs based on Al and Ti, and characterised their
nonlinearities using our analysis. For both Al and Ti, the measured
dissipative-reactive ratios and response times are quantitatively
similar to predictions for the non-equilibrium heating nonlinearity. We
were able to obtain more than $20\,\mathrm{dB}$ of peak power gain,
although only over a narrow bandwidth of a few kilohertz. Our method
of characterising the underlying nonlinearities could also be useful
in the understanding and design of other superconducting nonlinear
devices such as parametric up-converters, kinetic inductance Fourier
transform spectrometers, and resonator parametric amplifiers.
Title: Observables from spherically symmetric modified dispersion
relations
Authors: Läänemets, Dagmar; Hohmann, Manuel; Pfeifer, Christian
Bibcode: 2022IJGMM..1950155L
Altcode: 2022arXiv220104694L
In this work, we continue the systematic study of observable effects
emerging from modified dispersion relations. We study the motion of
test particles subject to a general first-order modification of the
general relativistic dispersion relation as well as subject to the
κ-Poincaré dispersion relation in spherical symmetry. We derive
the corrections to the photon sphere, the black hole shadow, the
and the light deflection and identify the additional dependence of
these observables on the photons’ four momentum, which leads to
measurable effects that can be compared to experimental data. The
results presented here can be interpreted in two ways, depending on
the origin of the modified dispersion relation: on the one hand as
prediction for traces of quantum gravity, when the modified dispersion
relation is induced by phenomenological approaches to quantum gravity,
on the other hand as predictions of observables due to the presence
of a medium, like a plasma, which modifies the dispersion relation of
light on curved spacetimes.
Title: Effects of nuclear matter and composition in core-collapse
supernovae and long-term proto-neutron star cooling
Authors: Sumiyoshi, Kohsuke; Furusawa, Shun; Nagakura, Hiroki; Harada,
Akira; Togashi, Hajime; Nakazato, Ken'ichiro; Suzuki, Hideyuki
Bibcode: 2022arXiv220902474S
Altcode:
We study the influence of hot and dense matter in core-collapse
supernovae by adopting up-to-date nuclear equation of state (EOS)
based on the microscopic nuclear many-body frameworks. We explore
effects of EOS based on the Dirac Brueckner Hartree-Fock theory through
comparisons with those based on the variational method. We also examine
effects of the differences in the composition of nuclei and nucleons
by using the same EOS by the variational method but employing two
different treatments in computations of nuclear abundances. We perform
numerical simulations of core-collapse supernovae adopting the three
EOSs. We also perform numerical simulations of the long-term evolution
over 70 s of the proto-neutron star cooling. We show that impacts
by different modeling of composition are remarkable as in those by
different treatments of uniform matter in the gravitational collapse,
bounce, and shock propagation. The cooling of proto-neutron star and
the resulting neutrino emission are also affected by the compositional
difference even if the same treatment in computing uniform matter
of EOS.
Title: On the transit spectroscopy features of warm Neptunes in the
TOI-421 system, revealed with their 3D aeronomy simulations
Authors: Berezutsky, A. G.; Shaikhislamov, I. F.; Rumenskikh, M. S.;
Khodachenko, M. L.; Lammer, H.; Miroshnichenko, I. B.
Bibcode: 2022MNRAS.515..706B
Altcode: 2022MNRAS.tmp.1706B
We simulate with a global 3D aeronomy code two warm Neptunes in the
TOI-421 system and show that both planets experience significant escape
of their upper atmospheres. The double shock structures, generated
around the planets in course of their interaction with the stellar wind
(SW) plasma flow are revealed. The calculations of stellar Ly α transit
absorption by the planets reveal that it reaches a detectable level only
for a moderate or strong SW, with a sufficiently high density. In this
case, the energetic neutral atoms provide significant absorption at the
high velocity blue wing of the Ly α line, whereas the corresponding
transit light curves exhibit an early ingress and extended egress
features. With the same code, we also modelled the absorption at the
position of the 10 830 Å line of the metastable helium, showing that
it can be detected only for the farthest planet of the considered two,
if the helium abundance is comparable to the solar value.
Title: Signature of a chemical spread in the open cluster M37
Authors: Griggio, M.; Salaris, M.; Cassisi, S.; Pietrinferni, A.;
Bedin, L. R.
Bibcode: 2022arXiv220900487G
Altcode:
Recent Gaia photometry of the open cluster M37 have disclosed the
existence of an extended main-sequence turn off -- like in Magellanic
clusters younger than about 2 Gyr -- and a main sequence that is
broadened in colour beyond what is expected from the photometric
errors, at magnitudes well below the region of the extended turn off,
where neither age differences nor rotation rates (the candidates
to explain the extended turn off phenomenon) are expected to play a
role. Moreover, not even the contribution of unresolved binaries can
fully explain the observed broadening. We investigated the reasons
behind this broadening by making use of synthetic stellar populations
and differential colour-colour diagrams using a combination of Gaia and
Sloan filters. From our analysis we have concluded that the observed
colour spread in the Gaia colour-magnitude diagram can be reproduced
by a combination of either a metallicity spread Delta[Fe/H] ~ 0.15
plus a differential reddening across the face of the cluster spanning
a total range DeltaE (B - V) ~ 0.06, or a spread of the initial helium
mass fraction DeltaY ~ 0.10 plus a smaller range of reddening DeltaE
(B - V) ~ 0.03. High-resolution differential abundance determinations
of a sizeable sample of cluster stars are necessary to confirm or
exclude the presence of a metal abundance spread. Our results raise
the possibility that also individual open clusters, like globular
clusters and massive star clusters, host stars born with different
initial chemical compositions.
Title: Giant dikes and dike-induced seismicity in a weak crust
underneath Cerberus Fossae, Mars
Authors: Rivas-Dorado, Sam; Ruíz, Javier; Romeo, Ignacio
Bibcode: 2022E&PSL.59417692R
Altcode:
Cerberus Fossae is a long and narrow graben system located approximately
1000 km southeast of Elysium Mons, Mars. These structures have
long been thought to be dike-induced, and are the focus of renewed
attention due to the detection of seismic activity in this area by
InSight. Here we report that structural modeling and linear elastic
fracture mechanics provide strong evidence that the Cerberus Fossae
grabens are dike-related structures, and that their intrusion may
have released significant amounts of seismic energy. The modeled
dike apertures are between ∼175 and 750 m, and their aspect ratios
are consistent with fluid-induced fractures formed in a weakened host
rock. We observe densely fractured terrains in high-resolution images of
the graben walls, confirming the presence of a weakened crust underneath
Cerberus. We used dike geometry and plausible mechanical properties to
calculate the source moment released by dike opening and inflation in
two scenarios; using the present-day dike dimensions (Md)
and in dikes with downscaled sizes to represent smaller intrusions
(md). These yielded values between 2.7⋅1016
and 1.3 1021 Nm. From these we estimate that the Cerberus
diking events may have expressed seismically through a marsquake
series with cumulative moment magnitudes (Mw) between 4.6
and 7.8. InSight has so far detected seismic events with Mw
magnitudes as low as 1. Therefore, these results suggest that if the
emplacement of even smaller dikes than those inferred below Cerberus is
currently taking place, intrusion-induced seismicity could be detected
by InSight.
Title: Multi-instrument observations of microseisms generated by
typhoon Kalmaegi (2014) over the Northwestern Pacific
Authors: Lin, Jianmin; Fang, Sunke; Xu, Wen; Ni, Sidao; Zhang, Han;
Yang, Ting
Bibcode: 2022E&PSL.59417746L
Altcode:
The typhoon-generated microseisms, originating from the complex energy
coupling and transferring among the Atmosphere-Ocean-Solid Earth
spheres, can be detected remotely by seismometers as the strongest
ambient seismic noise. The lack of in situ observations during the
passage of typhoons has hampered numerical modeling of wind fields
and ocean waves, and limited our understanding of the generation
mechanisms of microseisms associated with typhoons. Here we present
a comprehensive investigation of microseisms generated by typhoon
Kalmaegi (September 2014) based on multiple-instrument constraints from
observations including terrestrial and ocean-bottom seismic stations
as well as ocean buoys. To understand the generation mechanisms, we
apply an improved frequency-domain beamforming method to seismic array
data leading to successful location of double-frequency (DF) microseism
source regions. For comparison, we calculate the typhoon-induced ocean
waves and theoretical source regions of the DF microseisms using the
coupled ocean-atmosphere-wave-sediment transport modeling system
with validation by ocean buoy observations. Both observations and
numerical modeling results reveal two different generation mechanisms
for typhoon-induced DF microseisms during the lifespan of Kalmaegi. When
over the Philippine Sea, the DF microseisms were generated mainly by
opposing ocean waves from two distinct storms. After Kalmaegi entered
the South China Sea, the DF microseisms were generated mainly by
the fast-moving typhoon with source regions just trailing behind,
with the minimum frequencies determined by the typhoon translation
speed. DF microseisms generated in coastal source regions were not
detected by ocean bottom seismometers, suggesting that DF microseisms
might not effectively propagate across the ocean-basin seafloor covered
by thick sediments, owing to severe seismic attenuation and spreading
losses. This information is crucial for the use of DF microseisms for
future tracking and monitoring of typhoons.
Title: Crustal structure and subsidence mechanisms of the Williston
Basin: New constraints from receiver function imaging
Authors: Song, Jianguo; Gao, Stephen S.; Liu, Kelly H.; Sun, Muchen;
Yu, Youqiang; Kong, Fansheng; Mickus, Kevin
Bibcode: 2022E&PSL.59317686S
Altcode:
Mechanisms responsible for the long-term subsidence of intracontinental
basins such as the Williston Basin in North America remain enigmatic,
partly due to the thick sedimentary layer commonly found in the basins
that prevents reliably imaging the deep crustal and upper mantle
structures using some of the most-commonly employed seismic methods
such as receiver function analysis. In this study, we used receiver
functions recorded by 274 USArray and other stations in the Williston
Basin and adjacent areas to investigate the layered structure of the
crust in the hydrocarbon-rich intracontinental basin. After the removal
of strong reverberations on the receiver functions associated with a
low-velocity sedimentary layer using a recently developed time-domain
deconvolution approach, two positive arrivals representing downward
increases of seismic velocities are imaged beneath the basin and the
area to the west. The top interface has a depth of about 40 km at the
depocenter of the basin, and gradually shallows eastward to about 30 km
beneath the Superior Craton, and the deeper interface has a mean depth
of about 65 km beneath the Williston Basin. The layer between the two
interfaces may represent an eclogitized or garnet-rich lower crustal
layer. The results are consistent with the hypothesis that continuous
retrograde metamorphic reactions in the previously-thickened lower
crust during the Paleoproterozoic Trans-Hudson Orogeny resulted in
the subsidence of the intracontinental Williston Basin.
Title: Narrow Lines from a Slowly Rotating Neutron Star
Authors: Chakrabarty, Deepto
Bibcode: 2022cxo..prop.6306C
Altcode:
The detection of photospheric absorption lines from a neutron star
surface would enable measurement of it gravitational redshift and hence
the neutron star compactness. The line shape yields mass and radius
separately. This is one of the cleanest methods for measuring a neutron
star radius, but such lines are not yet detected. X-ray bursters are the
best targets for this search, but most spin so rapidly that any lines
are too broadened to detect. However, the burster Terzan 5 X-2 spins
at only 11 Hz, 20 times slower than the next slowest rotator. It is a
rare transient, last seen in 2010. We propose an HETGS observation to
search for narrow lines if this transient becomes active (10 percent
likely). This is the best known chance to detect a narrow atomic line
from a neutron star.
Title: Testing the M_BH-M_Bulge Relation with Radio-Selected Low
Surface Brightness Galaxies
Authors: Roberts, Hayley
Bibcode: 2022cxo..prop.6377R
Altcode:
The relationship between a galaxy's black hole (BH) mass and its bulge
mass are considered a result of their coevolution - a test that has not
been considered for low surface brightness (LSB) galaxies. LSB galaxies
are diffuse, faint galaxies that are dominated by dark matter. Previous
studies suggest that LSB galaxies are poorly evolved and do not follow
typical coevolution trends. In order to constrain the BH mass-bulge
mass relation for LSB galaxies, we propose a search to measure BH
masses in 7 LSB galaxies. The proposed targets were selected after
being detected in a neutral hydrogen (HI) survey and have coincident
radio emission. Understanding how these dark matter rich galaxies
differ from typical galaxies is imperative for understanding the role
of dark matter in galaxy evolution.
Title: Winds, disks, streams and spots: deciphering Cen X-3 during
a rare low state
Authors: Torrejon, Jose
Bibcode: 2022cxo..prop.6287T
Altcode:
Cen X-3 is among the brightest disk-fed high mass X-ray binaries with
evolved donors and represents, thus, a prime benchmark to study the
close binaries structure and evolution. It also shows marked long term
variability. We plan to use the unique characteristics of Chandra to
perform phase resolved spectroscopy of this outstanding system during
egress, at low luminosity, when the lightcurve has shown the existence
of large emitting structures (stream, disk) emerging from eclipse. We
want to cover, for the first time, orbital phases up to 0.6, at low
luminosity, to constrain the plasma emission sites, study the physics
of accretion and to test several predictions.
Title: Low-energy nuclear physics and global neutron star properties
Authors: Carlson, Brett V.; Dutra, Mariana; Lourenço, Odilon;
Margueron, Jérôme
Bibcode: 2022arXiv220903257C
Altcode:
We address the question of the role of low-energy nuclear physics data
in constraining neutron star global properties, e.g., masses, radii,
angular momentum, and tidal deformability, in the absence of a phase
transition in dense matter. To do so, we assess the capacity of 415
relativistic mean field and non-relativistic Skyrme-type interactions
to reproduce the ground state binding energies, the charge radii
and the giant monopole resonances of a set of spherical nuclei. The
interactions are classified according to their ability to describe
these characteristics and we show that a tight correlation between the
symmetry energy and its slope is obtained providing $N=Z$ and $N\ne Z$
nuclei are described with the same accuracy (mainly driven by the charge
radius data). By additionally imposing the constraints from isobaric
analog states and neutron skin radius in $^{208}$Pb, we obtain the
following estimates: $E_{sym,2}=31.8\pm 0.7$ MeV and $L_{sym,2}=58.1\pm
9.0$ MeV. We then analyze predictions of neutron star properties and we
find that the 1.4$M_\odot$ neutron star (NS) radius lies between 12 and
14 km for the "better" nuclear interactions. We show that i) the better
reproduction of low-energy nuclear physics data by the nuclear models
only weakly impacts the global properties of canonical mass neutron
stars and ii) the experimental constraint on the symmetry energy is the
most effective one for reducing the uncertainties in NS matter. However,
since the density region where constraints are required are well above
densities in finite nuclei, the largest uncertainty originates from
the density dependence of the EDF, which remains largely unknown.
Title: Late X-ray Emission from Compact Binary Mergers
Authors: Gompertz, Benjamin
Bibcode: 2022cxo..prop.6296G
Altcode:
The coincident detection of gravitational waves and a kilonova
alongside short gamma-ray burst (sGRB) 170817A established sGRBs as
signposts for key sites of universal heavy element production. However,
multiple events have shown unexplained late X-ray activity that may
bias efforts to accurately derive the r-process yield. We propose deep
Chandra observations of a nearby (z < 0.35) sGRB spanning days to
weeks after trigger. Our observations will measure the magnitude of
any flares and excesses, determine the lifetime of the central engine
(and possibly the remnant), and measure the jet opening angle to
improve our understanding of the merger rate.
Title: Role of magma differentiation depth in controlling the Au
grade of giant porphyry deposits
Authors: Hao, Hongda; Park, Jung-Woo; Campbell, Ian H.
Bibcode: 2022E&PSL.59317640H
Altcode:
Porphyry deposits are the world's most important source of Cu and a
major source of Au. It has been recognized that low Au grades generally
characterize porphyry deposits in thick continental arcs, like the
Andes, where the magmas are likely to differentiate at depth. In
contrast, Au-rich porphyries are mainly found in thin island arcs,
for example, those of the southwest Pacific, or associated with
short extensional periods in continental arcs, where the magmas are
likely to experience relatively shallow differentiation. However,
the key factors that control this difference remain debated. This
study shows that the Au grade of giant porphyry deposits and La/Yb
ratios of the ore-associated suites are negatively correlated (r =
∼ 0.7, p =10-7). We attribute the negative correlation
to be mainly due to varying sulfide saturation histories, modulated
by the depth of magma differentiation. Magmas differentiating
in deep crustal reservoirs are likely to reach sulfide saturation
early due to high pressure and early depletion of FeO (calc-alkaline
trend). Early sulfide saturation causes most Au to be held in cumulus
sulfides, making it unavailable to enter ore-forming fluid released in
the upper crust, resulting in Au-poor porphyry systems. In contrast,
magmas evolving in shallow reservoirs are likely to experience late
sulfide saturation because of the high sulfur solubility induced by low
pressure and the high FeO content of the melts (tholeiitic trend). Late
sulfide saturation enhances the potential of a magmatic system to form
Au-rich porphyry deposits due to the high Au content of the magma at
voluminous fluid saturation and efficient Au transfer from melt to the
ore-forming fluids via sulfide-fluid interaction. The link between
average magma differentiation depth and Au content is supported by
platinum-group element geochemistry of the porphyry ore-forming suites,
which shows that the magmas differentiating at shallower depths (lower
La/Yb) reach sulfide saturation later and therefore have higher Au
concentrations than those that differentiate at deeper levels (higher
La/Yb). Numerical models for ore-associated magmas with different
sulfide saturation histories indicate that variations in the Au grades
of giant porphyry deposits can be explained by the variations in the
timing of sulfide saturation. Based on the results, we propose that Au
concentration in the magma, modulated by average magma differentiation
depth and sulfide saturation history, is one of the critical factors
controlling the Au grade of giant porphyry Cu deposits.
Title: The stability of a liquid-water body below the south polar
cap of Mars
Authors: Egea-González, Isabel; Lois, Paula C.; Jiménez-Díaz,
Alberto; Bramson, Ali M.; Sori, Michael M.; Tendero-Ventanas,
Juan-Ángel; Ruiz, Javier
Bibcode: 2022Icar..38315073E
Altcode:
Radar data from the Mars Express spacecraft show bright subsurface
reflections in the Planum Australe area that could be due to liquid
water located at a depth of 1.5 km (Orosei et al., 2018). If this
interpretation of the data is correct, the presence of such water
would have important implications for the present-day thermal state
of the region. In this article, we recalculate the depth of the liquid
water and we analyze the influence of the regional thermal properties
in the surface heat flow and the subsurface temperatures. We have
obtained a new depth to the bright reflector between 1.3 and 1.5 km
by using a temperature dependent relative permittivity for the water
ice and taking into account the dust content in the area. We show that
regional properties in the SPLD moderately influence the thermal state
of the area where the liquid water is located. A better knowledge of
the porosity profile in the studied area is necessary to constrain
surface heat flow and subsurface temperatures accurately. Our findings
are in agreement with previous work that shows anomalously high local
heat flows would be required to sustain liquid water at this location.
Title: CHANG-ES XXIX: the sub-kpc nuclear bubble of NGC 4438
Authors: Li, Jiang-Tao; Wang, Q. Daniel; Wiegert, Theresa; Bregman,
Joel N.; Beck, Rainer; Damas-Segovia, Ancor; Irwin, Judith A.; Ji,
Li; Stein, Yelena; Sun, Wei; Yang, Yang
Bibcode: 2022MNRAS.515.2483L
Altcode: 2022arXiv220512343L
Active galactic nucleus (AGN) bubbles could play an important role in
accelerating high-energy cosmic rays (CRs) and galactic feedback. Only
in nearby galaxies could we have high enough angular resolution in
multiwavelengths to study the sub-kpc environment of the AGN, where
the bubbles are produced and strongly interact with the surrounding
interstellar medium. In this paper, we present the latest Chandra
observations of the Virgo cluster galaxy NGC 4438, which hosts
multiscale bubbles detected in various bands. The galaxy also has
low current star formation activity, so these bubbles are evidently
produced by the AGN rather than a starburst. We present spatially
resolved spectral analysis of the Chandra data of the ~3 arcsec × 5
arcsec (${\sim} 200{\rm ~pc}\times 350\rm ~pc$) nuclear bubble of NGC
4438. The power-law tail in the X-ray spectra can be most naturally
explained as synchrotron emission from high-energy CR leptons. The
hot gas temperature increases, while the overall contribution of the
non-thermal X-ray emission decreases with the vertical distance from
the galactic plane. We calculate the synchrotron cooling time-scale of
the CR leptons responsible for the non-thermal hard X-ray emission to
be only a few tens to a few hundreds of years. The thermal pressure
of the hot gas is about three times the magnetic pressure, but the
current data cannot rule out the possibility that they are still in
pressure balance. The spatially resolved spectroscopy presented in this
paper may have important constraints on how the AGN accelerates CRs
and drives outflows. We also discover a transient X-ray source only
~5 arcsec from the nucleus of NGC 4438. The source was not detected
in 2002 and 2008, but became quite X-ray bright in 2020 March, with
an average 0.5-7 keV luminosity of ${\sim} 10^{39}\rm ~erg~s^{-1}$.
Title: Surveying for Jets in the First Radio-Loud Quasars
Authors: Connor, Thomas
Bibcode: 2022cxo..prop.6353C
Altcode:
We propose a Large Program to survey all known radio-loud quasars at
z>6. The supermassive black holes powering these quasars have grown
to tremendous size in a short time, and explaining this growth remains
a challenge. One potential explanation -- jets -- should produce
a characteristic X-ray signature as relativistic particles inverse
Compton scatter off the CMB. This effect would be maximized at high
redshift due to the (1+z)^4 scaling of the CMB's energy density. Our
proposed program will conduct a thorough census of all known radio-loud
quasars at z>6 to search for signs of X-ray emission from jets,
a tell-tale signature of rapid growth
Title: Multi-Probe Studies of Merging Galaxy Clusters
Authors: Sayers, Jack
Bibcode: 2022cxo..prop.6387S
Altcode:
Projection effects can make it difficult to study cluster mergers by
diluting morphological features and producing degeneracies between
merger parameters and viewing angle. As a result, much of our knowledge
comes from the handful of systems with mergers occurring in the plane of
the sky (POS). We have assembled a unique set of multi-probe data for
a sample of eight galaxy clusters. For each system we have kinematic
Sunyaev-Zel'dovich effect maps and approximately 200 member redshifts
to probe the LOS velocity of the gas and dark matter, and Chandra
X-ray maps and HST lensing models and to probe the POS distributions
of the gas and dark matter. One cluster, MACS J2129.4, lacks sufficient
Chandra X-ray counts, and we are proposing 170 ksec of new observations
of this system.
Title: Revisiting subglacial hydrology as an origin for Mars'
valley networks
Authors: Buffo, J. J.; Ojha, L.; Meyer, C. R.; Ferrier, K. L.; Palucis,
M. C.
Bibcode: 2022E&PSL.59417699B
Altcode:
Although the nature of the early Martian climate is a matter
of considerable debate, the presence of valley networks (VN)
provides unambiguous evidence for the presence of liquid water on
Mars' surface. A subaerial fluvial origin of VN is at odds with the
expected phase instability of near-surface water in the cold, dry Late
Noachian climate. Furthermore, many geomorphic properties of VN (e.g.,
deep U-shaped valleys with constant widths; longitudinal profile
reversals) are inconsistent with surface water flow. Conversely,
subglacial channels exhibit many of these characteristics and could
have persisted beneath ice sheets even in a cold climate. Here
we model basal melting beneath a Late Noachian Icy Highlands ice
sheet and map subglacial hydrological flow paths to investigate
the distribution and geomorphometry of subglacial channels. We
show that subglacial processes produce enough melt water to carve
Mars' VN; that predicted channel distribution is consistent with
observations; and corroborate reversed channel gradient measurements
of VN consistent with subglacial formation mechanisms. We suggest
that, given a sufficient historical global water inventory and Late
Noachian geothermal heat flux, subglacial hydrology may have played
a significant role in the surface modification of Mars. Plain
language summary. Thousands of valley networks on Mars appear to have
been carved by flowing water, and exhibit branching characteristics akin
to river networks on Earth. Their origins, however, remain enigmatic
for two primary reasons. First, ancient Mars was potentially cold,
dry, and unable to support liquid water on its surface. Second, many
physical characteristics of the valleys are inconsistent with features
formed by precipitation and runoff. On Earth, water flowing beneath ice
sheets produces channels with similar characteristics to Mars' valley
networks. Here we model the deposition and evolution of Martian ice
sheets and show that melting at the ice sheet base is likely even under
cold and dry surface conditions. The volume, regional distribution,
and flow patterns of melt are consistent with the volume and dynamics
needed to carve the observed valley networks. A subglacial origin
for Mars' valley networks accounts for their formation in a cold,
dry climate and produces valley characteristics that match observations.
Title: Seafloor overthrusting causes ductile fault deformation and
fault sealing along the Northern Hikurangi Margin
Authors: Morgan, Julia K.; Solomon, Evan A.; Fagereng, Ake; Savage,
Heather M.; Wang, Maomao; Meneghini, Francesca; Barnes, Philip M.;
Bell, Rebecca E.; French, Melodie E.; Bangs, Nathan L.; Kitajima,
Hiroko; Saffer, Demian M.; Wallace, Laura M.
Bibcode: 2022E&PSL.59317651M
Altcode:
IODP Site U1518, drilled during IODP Expeditions 372 and 375,
penetrated a large-offset (∼6 km) thrust, the Pāpaku fault,
rising from a megathrust that hosts recurring slow slip events along
the Hikurangi margin. Although drilling intersected the fault zone
at only ∼300 m below the seafloor within porous silty mudstone, it
exhibits intense tectonic ductile deformation, including finely banded
mudstones contorted into decimeter-scale folds; elongate mudstone
clasts with grain tail complexes; stacked and truncated silt beds in
distorted mudstones; and soft sediment injections. Locally, these
ductile features are overprinted by brittle deformation, including
normal faults, fracture arrays, and breccias. The more consolidated
hanging wall is dominated by brittle structures, whereas the footwall
exhibits ductile and brittle deformation that decreases in intensity
with depth. The intense tectonic ductile deformation and asymmetric
distribution of structures across the fault zone at Site U1518 can be
explained by seafloor overthrusting. The emplacement of the hanging
wall upon the footwall flat overrode high-porosity, undeformed, and
previously unburied sediments, localizing shear deformation within
these weak sediments. In contrast, the overconsolidated hanging
wall preferentially experienced brittle deformation during folding
and displacement. Interstitial pore water geochemical profiles at
Site U1518 show a repetition of near-seafloor diagenetic sequences
below the fault, consistent with overthrusting of previously unburied
strata. The preserved diagenetic profiles in the footwall suggest that
overthrusting occurred within the last 50-100 kyr, and indicate little
along- or across-fault fluid flow at the location of Site U1518. Thus
the Pāpaku fault appears to define a low-permeability seal that
restricts footwall consolidation, maintaining locally high pore fluid
pressures and low fault strength. If similar low permeability structures
occur elsewhere along the margin, they could support regionally high
pore pressure conditions favorable to the occurrence of SSEs on the
Hikurangi megathrust fault.
Title: Calibration Observations of ACIS-S2 and S3 with Cas A at a
Non-Standard Focal Plane Temperature of -105C
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6445C
Altcode:
These observations will be used to calibrate ACIS at a focal plane
temperature of -105C.
Title: 2023 Fall Semester - Calibration Observations of Cas A
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6432C
Altcode:
Due to the continued fading of the ECS, the calibration team is
transferring the ACIS gain calibration to Cas A.
Title: Chandra Investigation of New INTEGRAL Sources
Authors: Nowak, Michael
Bibcode: 2022cxo..prop.6304N
Altcode:
We propose to trigger a 20 ks Chandra-HETG} fast (5--20 days) ToO
observation of a new source discovered by INTEGRAL. The aims are: 1)
to determine the source position with the unique Chandra sub-arcsecond
accuracy which will allow for source identification and multi-wavelength
follow-up observations, crucial in the crowded Galactic plane and center
regions; and 2) to obtain a high resolution HETG X-ray spectrum, free
from pile-up distortions, which will be essential to determine the
nature of the new source. We aim to contribute to the rich Chandra
history of identifying and characterizing new transient X-ray sources.
Title: Recalculated Orbits Of Binaries and New Linear Solutions
Authors: Cvetković, Z.; Pavlović, R.
Bibcode: 2022AJ....164...98C
Altcode:
In this paper we present recalculated orbital elements for nine
binaries: EGG 2Aa, Ab, COU 1085, COU 1897, COU 1006, A 578Aa, Ab, A
1400, A 606, BU 984, and BU 992. Seven binaries have orbital periods
longer than 100 yr, and two binaries have shorter orbital periods,
38 and 76 yr. Also, we present linear solutions determined for three
double stars: COU 966, J838, and A 1247. In addition to the orbital
elements for nine binaries, we give absolute magnitudes, spectral types,
estimates of the masses, dynamical parallaxes, and for all 12 pairs the
(O - C) residuals in θ and ρ.
Title: Chandra's Crucial Role in Identifying a Robust and Practical
Accretion-Rate Indicator for Quasars
Authors: Shemmer, Ohad
Bibcode: 2022cxo..prop.6374S
Altcode:
Understanding the rapid growth of supermassive black holes and the
assembly of their host galaxies is severely limited by the lack of
reliable estimates of black-hole mass and accretion rate in distant
quasars. We propose Chandra observations of 54 luminous, high-redshift
quasars to boost our ability to identify the most reliable and practical
Eddington-ratio indicator. In conjunction with archival data, we
will investigate diagnostics of quasar accretion power in the X-ray
and UV-optical spectral bands of a carefully selected sample of ~80
sources. We will ``stress test'' these diagnostics, relying critically
on the X-ray observable properties, and deliver a prescription for the
most robust Eddington-ratio estimate that can be utilized economically
at the highest accessible redshifts.
Title: Structure of the X-Ray Continuum Source in the Heavily
Microlensed Quasar SDSS 1339+1310
Authors: Morgan, Christopher
Bibcode: 2022cxo..prop.6351M
Altcode:
We propose to observe the doubly-imaged lensed quasar SDSS J1339+1310
using ACIS at four epochs with the primary goal of measuring the size
of this quasar's continuum emission region at X-ray energies. Imagery
of this heavily microlensed system taken at intervals corresponding to
the time delay will yield three measurements of the contemporaneous
ratio between the fluxes of the two images, variability in which
must be due to extrinsic factors such as microlensing by stars in
the lens galaxy. Applying a Monte Carlo analysis technique to the new
X-ray measurements and the existing optical light curves will yield
a measurement of the size of the X-ray continuum emission region.
Title: Verifying the cooling of the Cas A neutron star with HRC-S
Authors: Heinke, Craig
Bibcode: 2022cxo..prop.6319H
Altcode:
The central neutron star in Cassiopeia A (Cas A NS) has evidence from
Chandra ACIS data for a rapid temperature decline (2-3% per decade). If
this is correct, it is a crucial constraint on understanding the cooling
of young NSs, and particularly on superfluidity in their cores. However,
systematic uncertainties in ACIS data suggest the importance of a
verification observation using another detector. A new HRC-S observation
of Cas A in 2023 would provide this crucial cross-check.
Title: A new Monte Carlo radiative transfer simulation of cyclotron
resonant scattering features
Authors: Kumar, Sandeep; Bala, Suman; Bhattacharya, Dipankar
Bibcode: 2022MNRAS.515..914K
Altcode: 2022arXiv220700657K; 2022MNRAS.tmp.1806K
We present a new Monte Carlo radiative transfer code, which we have used
to model the cyclotron line features in the environment of a variable
magnetic field and plasma density. The code accepts an input continuum
and performs only the line transfer by including the three cyclotron
resonant processes (cyclotron absorption, cyclotron emission, cyclotron
scattering). Subsequently, the effects of gravitational redshift and
light bending on the emergent spectra are computed. We have applied our
code to predict the observable spectra from three different emission
geometries; (1) an optically thin slab near the stellar surface, (2)
an accretion mound formed by the accumulation of the accreted matter,
(3) an accretion column representing the zone of a settling flow on to
the star. Our results show that the locally emergent spectra from the
emission volume are significantly anisotropic. However, in the presence
of strong light bending the anisotropy reduces considerably. This
averaging also drastically reduces the strength of harmonics higher
than second in the observable cyclotron spectra. We find that uniform
field slabs produce line features that are too narrow, and mounds with
large magnetic distortions produce features that are too wide compared
to the average widths of the spectral features observed from various
sources. The column with a gently varying (dipole) field produces
widths in the intermediate range, similar to those observed.
Title: Resolving an orphan cloud as a signpost of ICM clumping
Authors: Sun, Ming
Bibcode: 2022cxo..prop.6401S
Altcode:
A first and only known isolated (or galaxy-less) cloud detected
in Ha, CO and X-rays was discovered in the nearby galaxy cluster
A1367. This discovery provides a firm connection between the clumps
in the intracluster medium (ICM) and the stripped gas from infall
galaxies. This case suggests that at least some ICM clumps are
multi-phase in nature. The cloud presents a great laboratory to
study the evolution of the stripped ISM far away from the parent
galaxy and ICM clumps in details. We request joint Chandra, HST and
VLA observations to 1) look for a sharp edge in X-rays; 2) study the
central orphan X-ray cool core; 3) resolve X-ray point sources; 4) study
SF history and conditions; and 5) search for HI gas around the cloud.
Title: Slow cooling during crystallisation of barred olivine
chondrules
Authors: Faure, François; Auxerre, Marion; Casola, Valentin
Bibcode: 2022E&PSL.59317649F
Altcode:
Barred olivine (BO) chondrules are small ferromagnesian silicate
igneous droplets with unique dendritic textures that are considered
to have formed in the early solar system during one or more brief
high-temperature episodes, followed by rapid cooling in a gas. Rapid
cooling rates of 100-7200 °C/h during chondrule formation have been
proposed based on experiments attempting to reproduce BO crystal
textures. However, the BO texture has never truly been reproduced
under such rapid cooling conditions. Here, we experimentally show
that true BO textures can be produced either after rapid cooling
(>50 °C/h) following by reheating step or by cooling rates slower
than 10 °C/h. Regardless of the thermal history considered, the
chemical compositions of glass inclusions trapped within olivines
of BO chondrules imply a final slow cooling rate one to two orders
of magnitude below previous estimates. Such slow cooling rates are
consistent with those estimated for plagioclase-bearing porphyritic
chondrules and magmatic type-B Ca-Al-rich inclusions, suggesting that
slow cooling rates are common to all similar chondritic objects.
Title: Numerical behaviour of the Keplerian Integrals methods for
initial orbit determination
Authors: Rodríguez, Óscar; Gronchi, Giovanni F.; Baù, Giulio;
Jedicke, Robert
Bibcode: 2022Icar..38415080R
Altcode:
We investigate the behaviour of two recent methods for the computation
of preliminary orbits. These methods are based on the conservation
laws of Kepler's problem, and enable the linkage of very short arcs
of optical observations even when they are separated in time by a
few years. Our analysis is performed using both synthetic and real
data of 822 main belt asteroids. The differences between computed
and true orbital elements have been analysed for the true linkages,
as well as the occurrence of alternative solutions. Some metrics have
been introduced to quantify the results, with the aim of discarding as
many of the false linkages as possible and keeping the vast majority
of true ones. These numerical experiments provide thresholds for the
metrics which take advantage of the knowledge of the ground truth:
the values of these thresholds can be used in normal operation mode,
when we do not know the correct values of the orbital elements and
whether the linkages are true or false.
Title: A detailed view of the rare and colossal 800kpc sloshing cold
front in the outskirts of Abell 399
Authors: Walker, Stephen
Bibcode: 2022cxo..prop.6393W
Altcode:
Large scale sloshing cold fronts reaching out to nearly a megaparsec are
extremely rare, and have been observed in only a handful of clusters. We
propose a 175ks observation of the 800kpc cold front in Abell 399. The
existing XMM-Newton observation shows tantalizing suggestions of complex
structure, including a feature which may be a giant Kelvin-Helmholtz
roll, which only deeper Chandra observations can resolve. These rare
systems provide a unique way to test our understanding of how cold
fronts are supported against instabilities as they expand outwards,
and provide powerful tests of simulations of magnetic draping.
Title: Probing Radiatively Inefficient Accretion Flow in the Neutron
Star X-ray Binary System Aquila X-1
Authors: Maitra, Dipankar
Bibcode: 2022cxo..prop.6295M
Altcode:
The nature of radiatively inefficient accretion flows (RIAF) near
neutron stars and black holes remains largely enshrouded in mystery,
primarily due to their low luminosity. Long term monitoring of Aql
X-1 has revealed that during certain outbursts, the system goes into a
relatively bright RIAF state for periods lasting several weeks. These
low-intensity states offer a unique opportunity to probe radiatively
inefficient flows. We request an 80 ksec Chandra/HETGS ToO observation
of Aql X-1 during a low-intensity state. Emission line diagnostics of
the observed spectrum will be used to test different RIAF models and
constrain flow properties such as the radial temperature and density
profile, existence of an outflowing wind, spatial extent of the RIAF,
and gas dynamics within the flow.
Title: The tadpole galaxy Kiso 5639: a laboratory for high-energy
astrophysics of metal-poor starburst
Authors: Wang, Q. Daniel
Bibcode: 2022cxo..prop.6336W
Altcode:
The nearby tadpole galaxy Kiso 5639 contains a starburst head of a 0.1
solar metallicity -- a manifestation of metal-poor gas accretion. We
propose a joint Chandra/VLA observing program to study high-energy
activity in and around this remarkable dwarf galaxy. We will 1)
examine the nature of an ultra-luminous X-ray source; 2) determine
the hidden X-ray source population; and 3) quantify the mechanical and
chemical feedback of the starburst and its impact on the surrounding
medium, as evidenced by an extended X-ray/radio-emitting feature,
which most likely represents an energetic blowout from the starburst
into the galactic halo. This program will thus provide insights into
the end-products of massive stars in low metallicity galaxies, which
are common in early universe.
Title: The collimation and energetics of short GRBs: searching for
jet-breaks with Chandra
Authors: O'Connor, Brendan
Bibcode: 2022cxo..prop.6294O
Altcode:
At the dawn of gravitational wave astronomy, the degree of collimation
of short GRBs is a key issue, bearing critical information on the true
energy release and event rate of neutron star mergers. The geometry of
the GRB outflow can be constrained through afterglow observations,
and, in particular, through the measurement of the so-called
jet-breaks''. The intrinsic faintness of short GRB afterglows prevents
jet-breaks to be detected with Swift/XRT observations. We propose to
overcome this limit by triggering deep Chandra ToOs observations of
short GRB afterglows.
Title: Completing the Chandra survey of extended hard X-ray emission
in heavily obscured AGN
Authors: Ma, Jingzhe
Bibcode: 2022cxo..prop.6348M
Altcode:
We propose a Chandra/ACIS-S survey (122 ks total) of 6 nearby heavily
obscured (logNh>23) Active Galactic Nuclei (AGN) to find or set
limits at the 10% level on their extended hard (2-7 keV) continuum
and Fe-K emission. The Chandra discovery that 10-30% of the 2-7 keV
continuum from high Nh AGN can be extended on scales from ~100 pc up
to ~2 kpc affects the structure of the obscuring torus determined
from NuSTAR spectra and demonstrates the AGN impact on the host
galaxy, i.e. AGN feedback. This proposal aims to produce a complete,
well-defined statistical sample of heavily obscured AGN, which will
be large enough to look for trends between hard extent and other
AGN properties.
Title: Pan-STARRS Transient Discovery Report for 2022-09-01
Authors: Chambers, K. C.; Boer, T. D.; Bulger, J.; Fairlamb, J.; Huber,
M.; Lin, C. C.; Lowe, T.; Magnier, E.; Schultz, A.; Wainscoat, R. J.;
Willman, M.; Smith, K. W.; Young, D. R.; McBrien, O.; Gillanders,
J.; Srivastav, S.; Fulton, M.; Smartt, S. J.; O'Neill, D.; Clark,
P.; Sim, S.; Wright, D. E.
Bibcode: 2022TNSTR2544....1C
Altcode:
No abstract at ADS
Title: Out of sequence faulting in the backbone range, Taiwan:
Implications for thickening and exhumation processes
Authors: Lee, Yuan-Hsi; Byrne, Timothy B.; Lo, Wei; Wang, Shao-Jyun;
Tsao, Shuh-Jong; Chen, Cheng-Hong; Yu, Han-Cheng; Tan, Xinbin; van
Soest, Matthijs; Hodges, Kip; Mesalles, Lucas; Robinson, Holden;
Fosdick, Julie C.
Bibcode: 2022E&PSL.59417711L
Altcode:
The Taiwan orogenic belt results from convergence between the Philippine
Sea plate and Eurasia plate since the late Cenozoic. An extremely high
exhumation rate has been observed in the Backbone Range, which has
motivated interpretive models that show underplating as the primary
process in driving uplift and thickening. Here we integrate new
(U-Th)/He and fission-track dates of detrital zircons with previously
published thermochronology to document a significant out-of-sequence
thrust in the core of Taiwan orogen. The thrust, informally named the
Tayulin fault system, is identified by structural kinematics and offset
metamorphic temperature trends, low-temperature thermochronometric
dates, and seismic tomography. The OOST appears to be composed of
three segments that crop out along the western flank of the Backbone
Range. The apparent age-elevation profiles suggest a relatively slow
exhumation rate, <1.0 mm/yr, in the early stages from 8 Ma to 2 Ma
followed by a stage of significantly higher exhumation rates, ranging
from 2.3 to 6.5 mm/yr after 2 Ma. The early slow exhumation stage is
related to regional folding and foliation development. In contrast,
we suggest the younger rapid exhumation stage is related to slip on
the out-of-sequence thrust.
Title: Kinetic isotope effects in H2O2
self-decomposition: Implications for triple oxygen isotope systematics
of secondary minerals in the solar system
Authors: Guo, Hao; Yu, Xiaoxiao; Lin, Mang
Bibcode: 2022E&PSL.59417722G
Altcode:
Hydrogen peroxide (H2O2) is a ubiquitous molecule
in nature that shapes the redox state of planetary surfaces. Given
that H2O2 is a major oxidant, isotope effects
associated with H2O2 chemistry play a key role
in determining triple oxygen isotopic compositions (δ17O
and δ18O) of secondary aerosols and minerals, which are
powerful proxies for understanding terrestrial/Martian atmospheric
chemistry, and chemical evolution in the solar nebular. However, isotope
effects in H2O2 self-decomposition processes,
which actively occur in nature due to the thermal instability of
H2O2, remains poorly understood. Here, we report
a hitherto overlooked large and mass-dependent isotope fractionation
in aqueous H2O2 self-decomposition processes
quantified in a series of kinetic experiments. δ18O in
remaining H2O2 is several tens of per mil
(‰) with respective to initial H2O2. By
synthesizing triple oxygen isotope measurements of natural
H2O2, ozone, various oxyanions formed in
the atmosphere (sulfate, nitrate, perchlorate, and carbonate),
and oxygen-bearing secondary minerals in meteorites, we find that
a decoupled Δ17O-δ18O pattern in natural
H2O2 is attributed in part to the high degree of
mass-dependent δ18O variation in H2O2
decomposition, and further argue that this unique signature may play a
crucial role in triple oxygen isotope systematics in a board spectrum of
secondary minerals in our solar system including aerosols, sediments,
and meteorites. Our results shed fresh insights into recent debates
on the role of H2O2 in the formation of these
secondary minerals in the modern Earth, geological past, and other
planets. The isotope effect experimentally quantified in this study
are needed for future improvements of planetary atmosphere and solar
nebular evolution models. We highlight the importance of further
experimental and theoretical efforts to quantify isotope effects
in H2O2 chemistry that are representative of
natural systems.
Title: Observation of Cas A During FP Heating Test
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6261C
Altcode:
Cas A will be observed during the ACIS FP Heating Test to monitor the
detector gain, spectral resolution, and QE.
Title: Brane inflation: Swampland criteria, TCC, and reheating
predictions
Authors: Mohammadi, Abolhassan; Golanbari, Tayeb; Nasri, Salah;
Saaidi, Khaled
Bibcode: 2022APh...14202734M
Altcode:
We consider inflation in a five -dimensional space time with the
inflaton field confined to live on a brane world. In this scenario,
we study different types of potentials for the inflaton, discuss
their observational consequences, and compare with data. We find that
some class of potentials are in good agreement with observation and
that the value of the inflaton field can be sub-Planckian. Moreover,
we investigate the swampland criteria in this scenario and determine
the consistency of the model with the conjectures. Doing so, we could
determine models that simultaneously satisfy both observational data
and swampland criteria. More constraints are applied by studying
the reheating phase where the acceptable range for the reheating
temperature imposes some bounds on the models. As the last step,
the result of trans-Planckian censorship conjecture for the model is
considered where it is shown the constraint of TCC will be very strong
and it could be used to apply limits on the brane tension.
Title: Rendez-vous after 20 years with a z 4 X-ray jet
Authors: Siemiginowska, Aneta
Bibcode: 2022cxo..prop.6356S
Altcode:
We propose ACIS-S observation of a high redshift resolved X-ray jet to
study emission processes responsible for the observed X-rays. Chandra
will probe hard X-ray (2.5-30 keV) rest frame energies critical for
studies of jet and particle acceleration physics. The source was
observed in Cycle 4. Our new observation ~20 years (rest frame ~4.4
years) later will provide a baseline for the variability test of the
X-ray emission process. This jet is propagating in a high-z environment
and our studies will have potential insights on feedback.
Title: Paleogene buried landscapes and climatic aberrations triggered
by mantle plume activity
Authors: Conway-Jones, Benedict W.; White, Nicky
Bibcode: 2022E&PSL.59317644C
Altcode:
The Icelandic plume, a major mantle upwelling located beneath the North
Atlantic Ocean, plays a dominant role in controlling periodic uplift
of continental margins and of oceanographic gateways during Cenozoic
times. Independent evidence shows that plume activity fluctuates on
timescales of ≤1 Myr. Here, we describe and analyze a spectacular
sequence of Paleogene buried landscapes imaged on seismic reflection
surveys from the continental margin of northwest Europe. These transient
landscapes recur on intervals of 2-3 Myrs, coincide with volcanic
activity, and exhibit topographic relief of hundreds of meters. They
probably represent the surficial expression of thermal fluctuations
that spread radially away from the plume conduit. Five landscapes
are coeval with global hyperthermal aberrations characterized by
negative excursions of δ13C and by positive excursions of
Fe intensity, which is a proxy for carbonate dissolution. We propose
a causal relationship whereby thermal fluctuations of the mantle plume
generate transient uplift and volcanic activity, which act to release
significant quantities of greenhouse gases and thus trigger hyperthermal
aberrations. A longer period oscillation of δ13C values
is superimposed upon these aberrations that is attributable to a
combination of silicate weathering and volcanic degassing caused by
the interaction of plume activity and plate spreading.
Title: Calibration Observations of ACIS-I3 with Cas A at a
Non-Standard Focal Plane Temperature of -105C
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6441C
Altcode:
These observations will be used to calibrate ACIS at a focal plane
temperature of -105C.
Title: Mining the Transient Sky: Chandra-NuSTAR Observations of the
Fastest Explosions
Authors: Matthews, David
Bibcode: 2022cxo..prop.6324M
Altcode:
We propose an in-depth X-ray study of fast blue optical transients
(FBOTs), a new class of transients with luminosities and time scales
that challenge traditional SN models. Alternative scenarios include
a failed SN of a stripped star, He-shell detonation on a white dwarf,
and a SN shock breaking through a dense medium. FBOTs have mostly been
studied in the optical/UV regime, which is of thermal origin and it is
not sensitive to the nature of the underlying energy source. Here we
propose to capitalize on the recent discovery of X-rays from the FBOT
AT2018cow with unprecedented properties, and start the first broad-band
X-ray monitoring campaign of FBOTs. The primary goal is to test for the
presence of engines driving the explosions and constrain their nature.
Title: Recurring AGN feedback in the galaxy group NEST 200047
Authors: Simionescu, Aurora
Bibcode: 2022cxo..prop.6402S
Altcode:
We propose a 150 ks observation of the galaxy group Nest 200047. LOFAR
and GMRT images revealed a unique morphology of this system, with
the AGN in the central galaxy hosting four pairs of radio lobes
spanning sizes from 10 to ~200 kpc, showing intriguing edges and
filamentary structures. Shallow XMM-Newton data show a limb-brightened
cavity surrounded by a shocked rim corresponding to one of the older
radio lobes. Deep Chandra images are required to detect substructures
associated with the younger outbursts that have smaller angular extents,
and determine the energetics of and interaction between each generation
of feedback events. This has important implications for understanding
the multi-scale impact and time evolution of kinetic-mode feedback.
Title: Role of seafloor production versus continental
basalt weathering in Middle to Late Ordovician seawater
87Sr/86Sr and climate
Authors: Avila, Teresa D.; Saltzman, Matthew R.; Adiatma, Y. Datu;
Joachimski, Michael M.; Griffith, Elizabeth M.; Olesik, John W.
Bibcode: 2022E&PSL.59317641A
Altcode:
The global climate of the Ordovician Period (486.9 to 443.1 Ma)
is characterized by cooling that culminated in the Hirnantian
glaciation. Chemical weathering of Ca- and Mg-bearing silicate
minerals and the subsequent trapping of carbon in marine carbonates
act as a sink for atmospheric CO2 on multi-million-year
time scales, with basaltic rocks consuming CO2 at a greater
rate than rocks of granitic composition. The oceanic Sr isotope ratio
(87Sr/86Sr) can act as a geochemical proxy for
the relative proportion of basaltic versus granitic weathering. Oxygen
isotopes (δ18O) act as a proxy for paleotemperature and ice
volume, providing a useful complement to 87Sr/86Sr
in studies of ancient climate. Previous studies have reported
stepwise cooling (increasing δ18O) during the Middle to
Late Ordovician. Combined with Sr and C cycle models, this has led to
the hypothesis that continental silicate weathering of mafic material
drove Ordovician cooling (e.g., the Taconic Orogeny). However, Sr and
C cycle models have not accounted for an apparent rise in sea level and
seafloor production in the Middle Ordovician (Darriwilian), which would
increase the hydrothermal Sr flux as well as degassing along continental
volcanic arcs. Furthermore, some Ordovician studies contain temporal
uncertainty between 87Sr/86Sr and δ18O
curves if they are not based on paired analyses, which can obscure the
relationship between silicate weathering and cooling. Here, we present
new paired 87Sr/86Sr and δ18O data
from conodont apatite and integrate this with both a deterministic
(forward) and stochastic (reverse) modeling approach to argue that
increased hydrothermal weathering played a role in driving marine
87Sr/86Sr, specifically an inflection occurring
in the Pygoda serra conodont zone of the mid-Darriwilian Stage (∼
460.9 Ma ± 1 My). This 87Sr/86Sr inflection
is accompanied by an increase in δ18O, consistent with
climate cooling. Clarifying the role of seafloor production for marine
87Sr/86Sr and the implications for Ordovician
cooling allows for a more nuanced understanding of the factors that
drive multi-million-year shifts in climate.
Title: Preliminary approach to assess the seismic hazard on a
lunar site
Authors: Ruiz, Santiago; Cruz, Alejandro; Gomez, Daniel; Dyke,
Shirley J.; Ramirez, Julio
Bibcode: 2022Icar..38315056R
Altcode:
The passive seismic network deployed on the Moon during the Apollo
missions operated for eight years and allowed the observation of seismic
activity. More than 12500 seismic events were registered, where 28
were classified as shallow moonquakes with moment magnitudes up to
4.1. Seismic events of this nature pose a significant risk to future
long-term lunar habitats; thus, these events must be carefully studied
and considered in the seismic design of these structures. This paper
proposes a preliminary seismic hazard assessment imposed by shallow
moonquakes. The hazard assessment is performed using the Probabilistic
Seismic Hazard Analysis (PSHA) methodology, considering previous
studies and theories regarding the seismic environment of the Moon. The
study zone covers ∼ 860 km2 of the Taurus-Littrow Valley,
containing the Apollo 17 landing site and the Lee-Lincoln lobate scarp
as the considered seismic source. The seismic hazard is quantified
in terms of peak ground acceleration (PGA) and spectral acceleration
(5% damped pseudo-acceleration, PSA). Seismic hazard deaggregation
scenarios, Uniform Hazard Spectra (UHS) for different hazard levels,
and a Conditional Mean Spectrum (CMS) for a target period of 0.2 s
are obtained to quantify the seismic hazard on a specific site on the
Moon. The developed seismic hazard assessment provides a preliminary
approach for realistic scenarios to conduct structural designs that
ensure the seismic performance of fully operational long-term lunar
structures.
Title: Decals J0542-2125: the Dynamical State of AN Extraordinary
Cluster Merger at Z=0.61
Authors: Napier, Kate
Bibcode: 2022cxo..prop.6391N
Altcode:
Merging galaxy clusters are rare laboratories to test the nature of
dark matter and hierarchical assembly. We propose Chandra observation
of DECALS J0542-2125, a candidate cluster merger at z=0.61. Two galaxy
clusters of comparable mass are separated by < 500 km/s and 1 Mpc in
projection. Additionally, one cluster gravitationally lenses a z=1.84
quasar, the largest-separation lensed quasar known. The proposed
Chandra data will provide the necessary resolution to determine the
morphology of the X-ray emitting gas and definitely determine the
system?s dynamical state. Joint Hubble Space Telescope observations
will provide the necessary constraints for a robust lens model. Taken
together, this program will map the distribution of dark matter,
X-ray gas, and stars in DECALS J0542-2125.
Title: Constraining the Nature of the Super-virial Temperature Phase
of the Milky-Way CGM
Authors: Gupta, Anjali
Bibcode: 2022cxo..prop.6346G
Altcode:
Recently, there have been reports of the detection of a super-virial
temperature phase in the MW CGM. But nature of this hot phase
largely remains unknown; is it diffuse or clumpy, truly extended or
extraplanar? A recent Suzaku survey provided an opportunity to explore
the nature of the hot component, but the results were inconclusive due
to the uncertainty in the point source contamination. We propose here
to use the unprecedented angular resolution of Chandra to identify
the point sources in two Suzaku fields where there is evidence of
large variation in the X-ray emission. We will determine whether the
unusually large variation in the X-ray emission is truly from the CGM
emission, suggesting that the hot component is clumpy, or it is due
to the variation in point source number density.
Title: Evidence for crustal seismic anisotropy at the InSight
lander site
Authors: Li, Jiaqi; Beghein, Caroline; Wookey, James; Davis, Paul;
Lognonné, Philippe; Schimmel, Martin; Stutzmann, Eleonore; Golombek,
Matthew; Montagner, Jean-Paul; Banerdt, William Bruce
Bibcode: 2022E&PSL.59317654L
Altcode:
We analyzed broadband and low-frequency events recorded on Mars and made
the first detection of horizontally polarized shear wave reflections,
which help constrain the crustal structure at NASA's InSight lander
site. Coherent signals from five well-recorded marsquakes appear to
be independent of the focal depth and are consistent with SH-wave
reflections off the topmost crustal interface (8 ± 2 km). This phase
confirms the existence of the ∼8 km interface in the crust and
the large wave speed (or impedance) contrast across it. The range of
acceptable parameters determined from the detected SH-wave reflections
differs from the majority of the vertically polarized shear wave models
resulting from a previous receiver function study, indicating that
the velocity of the vertically polarized waves is larger than that of
horizontally polarized waves. We propose that this inconsistency results
from the presence of seismic anisotropy within the top crustal layer
at the lander site. Modeling results show that dry- or liquid-filled
cracks/fractures and igneous intrusions can reproduce the observed
radial anisotropy.
Title: Deep learning reveals one of Earth's largest landslide terrain
in Patagonia
Authors: Schönfeldt, Elisabeth; Winocur, Diego; Pánek, Tomáš;
Korup, Oliver
Bibcode: 2022E&PSL.59317642S
Altcode:
Hundreds of basaltic plateau margins east of the Patagonian Cordillera
are undermined by numerous giant slope failures. However, the overall
extent of this widespread type of plateau collapse remains unknown and
incompletely captured in local maps. To detect giant slope failures
consistently throughout the region, we train two convolutional
neural networks (CNNs), AlexNet and U-Net, with Sentinel-2 optical
data and TanDEM-X topographic data on elevation, surface roughness,
and curvature. We validated the performance of these CNNs with
independent testing data and found that AlexNet performed better
when learned on topographic data, and UNet when learned on optical
data. AlexNet predicts a total landslide area of 12,000 km2
in a study area of 450,000 km2, and thus one of Earth's
largest clusters of giant landslides. These are mostly lateral spreads
and rotational failures in effusive rocks, particularly eroding the
margins of basaltic plateaus; some giant landslides occurred along
shores of former glacial lakes, but are least prevalent in Quaternary
sedimentary rocks. Given the roughly comparable topographic, climatic,
and seismic conditions in our study area, we infer that basalts topping
weak sedimentary rocks may have elevated potential for large-scale
slope failure. Judging from the many newly detected and previously
unknown landslides, we conclude that CNNs can be a valuable tool to
detect large-scale slope instability at the regional scale. However,
visual inspection is still necessary to validate results and correctly
outline individual landslide source and deposit areas.
Title: Average VNIR reflectance: A rapid, sample-free method to
estimate glass content and crystallinity of fresh basaltic lava
Authors: Rader, E.; Ackiss, S.; Sehlke, A.; Bishop, J.; Orrill, B.;
Odegaard, K.; Meier, M.; Doloughan, A.
Bibcode: 2022Icar..38315084R
Altcode:
The microcrystalline texture in basaltic lava, scoria, and spatter can
vary widely from pure glass to holocrystalline due to complex cooling
histories after eruption. How quickly a molten rock cools is a function
of the environmental surroundings, including water, ice, sustained heat
source, and atmospheric conditions. Thus, petrologic texture serves as
an indicator of cooling history captured in the rock record. As basalt
is a common component of terrestrial bodies across the solar system,
relating the abundance of crystalline components to spectral character
would allow for a more thorough understanding of the cooling history
and emplacement conditions on planetary surfaces. Visible/near-infrared
(VNIR) reflectance spectroscopy has been used to examine the absorptions
associated with volcanic glass, however, the non-linearity of absorption
features in this spectral region requires complex spectral unmixing
modeling to achieve modal percentages of minerals. Here we present
evidence that average reflectance from 500 to 1000 nm (referred
to as R500-1000) of solid surface
samples is indicative of the crystal texture and degree of glassiness
of basaltic rocks. Several factors, such as sample surface roughness,
lichen cover, coatings, weathering, and chemical composition can affect
the R500-1000 of a sample. However, our
data indicate that these factors can be sufficiently controlled during
sample selection to attribute relative glassiness values to basaltic
surfaces. This quick and straightforward method requires no sample
preparation or modeling and is demonstrated with training data from
sixteen rocks from five basaltic flow fields with differing mineralogy,
surface qualities, and geochemistry across Idaho and Oregon, USA. We
further test our relationship with two published datasets of synthetic
and natural basalts, as well as a subset of our own data collected with
our methods to examine the sensitivities of the correlation. This method
has the potential to broadly identify glassier basaltic lavas across
planetary surfaces. This could be applied toward understanding lava
eruption temperatures, cooling rates, magma petrogenesis, paleoclimate
reconstruction, and astrobiology due to the involvement of water in
quenching of lava.
Title: Possible particle ejection contributions to the shape and
spin stability of small near-Earth asteroids
Authors: Vance, Leonard D.; Thangavelautham, Jekan; Asphaug, Erik;
Cotto-Figueroa, Desireé
Bibcode: 2022Icar..38415078V
Altcode:
Top Shaped Asteroids (TSAs) have proven to be common amongst the
near-Earth rubble pile population, with multiple examples confirmed
via groundbased radar and spaceborne optical sensors through the past
20 years. A substantial body of literature has developed, exploring
the formation of these unique shapes either through rotation-induced
landslides and creep, or collisional reaccumulation. Models of
such mass movements can provide good explanations for mid and low
latitude material redistribution, but Bennu also shows a significant
increase in radius in the high polar regions, which is harder to
explain with these processes. The discovery of repeated and probably
ongoing particle ejections around the 500 m diameter asteroid Bennu
by the OSIRIS-REx mission suggests that we need to consider an
alternate or additional mechanism which, we show, can anticipate the
detailed variety of TSA shapes. This paper explores asteroid shape
evolution as the result of particle ejections, modeled as being
simply correlated with latitude via diurnal heating (or meteorite
impacts), and re-accumulation using simulations including gravity
and solar radiation pressure. Asteroid outlines are evolved with time
as a function of particle ejection velocities and asteroid rotation
rates. Bennu's shape can be anticipated by our model with RMS surface
errors of less than 1.1% (2.7 m) although some southern latitudes have
errors up to 10 m. Straightforward variation in conditions can produce
shapes matching other TSAs. However, the observed particle fluxes on
Bennu are approximately 3 orders of magnitude too low for this to be
the only shaping mechanism on Bennu. The time necessary to form these
shapes by our mechanism alone is far longer than the lifetimes of
near-Earth asteroids, unless fluxes were once much greater, or there
was an underlying oblate shape.
Title: Tractor Geometry of Asymptotically Flat Spacetimes
Authors: Herfray, Yannick
Bibcode: 2022AnHP...23.3265H
Altcode: 2021arXiv210310405H
In a recent work it was shown that conformal Carroll geometries are
canonically equipped with a null-tractor bundle generalizing the
tractor bundle of conformal geometry. We here show that in the case
of the conformal boundary of an asymptotically flat spacetime of any
dimension d>=3, this null-tractor bundle over null infinity can
be canonically derived from the interior spacetime geometry. As was
previously discussed, compatible normal connections on the null-tractor
bundle are not unique: We prove that they are in fact in one-to-one
correspondence with the germ of the asymptotically flat spacetimes to
leading order. In dimension d=3 the tractor connection invariantly
encodes a choice of mass and angular momentum aspect, in dimension
d>=4 a choice of asymptotic shear. In dimension d=4 the presence of
tractor curvature correspond to gravitational radiation. Even thought
these results are by construction geometrical and coordinate invariant,
we give explicit expressions in BMS coordinates for concreteness.
Title: Fluvial evolution in a growing thrust-fold range of the Yumu
Shan, NE Tibetan Plateau
Authors: Hu, Xiaofei; Wu, Jiakun; Wen, Zhenling; Zhang, Jiaxin; Zhao,
Qiming; Pan, Baotian
Bibcode: 2022E&PSL.59417704H
Altcode:
In an active thrust-fold belt, the drainage evolution, such as the
alternation between transverse and longitudinal rivers, will influence
the surface erosion within the range and the sedimentary sequence in
the foreland basin. However, knowledge of the controls of changes in
transverse or longitudinal drainage patterns in an uplifting range
is limited. The Yumu Shan, on the northeastern margin of the Tibetan
Plateau, is an example for a young and active thrust-fold range that
shows evidence for drainage reversals since ∼3 Ma. The materials
we used are the late Cenozoic depositional sequences around the Yumu
Shan. Analyses of the lithology, grain size, roundness, and clast
orientation of gravel deposits on the northern and southern flanks,
combined with the results of cosmogenic nuclide burial dating, reveal
that a transverse river, the Liyuan River, crossed the Yumu Shan range
during 3.0-1.8 Ma by eroding weak Cenozoic sedimentary rocks. After 1.8
Ma, however, this transverse river was deflected and flowed along the
edge of the range, and a longitudinal river developed along the back
flank of the range. This process was synchronous with the exposure of
resistant Paleozoic rocks by the continuous uplift of the range. After
comparison with other potential controlling factors for drainage
reversals, such as variations in rock uplift, climate or upstream
aggradation, we find that the change in bedrock resistance was the
most likely control on the change from a transverse to a longitudinal
drainage pattern in this relatively young thrust-fold belt. Furthermore,
through comparison with a series of active fold-thrust belts worldwide,
we propose a simple conceptual model for the drainage evolution
of active fold-thrust belts. In the earlier stage of the uplift,
the exposed soft sedimentary rocks will cause transverse (antecedent)
rivers to cross the range. After the continuous uplift of the range,
resistant rocks cause the deflection of a transverse river and its
change to a longitudinal river along the back flank of the range. In the
final stage, after the several million years to around ten million years
of uplift, with the development of a mature range, the local base level
of the foreland will greatly fall, promoting a return to a transverse
drainage pattern by headward erosion and capture of longitudinal rivers.
Title: Calcium isotope constraints on OIB and MORB petrogenesis:
The importance of melt mixing
Authors: Eriksen, Z. T.; Jacobsen, S. B.
Bibcode: 2022E&PSL.59317665E
Altcode:
Lithological and isotopic heterogeneity in the mantle archive the
mantle's melting history and fingerprint crustal recycling processes
coupling the deep Earth with the terrestrial biosphere. Oceanic
basalts, consisting of ocean island basalts (OIBs) and mid-ocean
ridge basalts (MORBs), are invaluable tools for studying the chemical
evolution of the mantle because they sample mantle heterogeneity
at a variety of depths and length scales. In this study, we probe
mantle heterogeneity by exploring the systematics of stable Ca
isotopes in OIBs and MORBs. We find that OIBs from Iceland have
δ44/40Ca values (∼0.85‰) that are indistinguishable
from MORBs, while OIBs from Mangaia, the Azores, the Canary Islands
and Hawaii have an average δ44/40Ca value ∼0.08‰
lower than the MORB-Iceland group. Moreover, MORB and Iceland
δ44/40Ca values are relatively invariable, while OIBs
range from 0.70‰ to 0.85‰ and correlate negatively with La/Lu
and Nb/Y. The Ca isotope signature of the MORB-Iceland group is
consistent with equilibrium fractionation during high-degree melting
of average spinel/garnet peridotite with bulk silicate Earth (BSE)
δ44/40Ca. Calcium-isotope variability in OIBs requires
two-component mixing of melts with distinct δ44/40Ca values,
one of which is a high-degree melt consistent with derivation from
average peridotite with BSE δ44/40Ca. The melt-mixing
endmember with isotopically light Ca (≤0.70‰) must be a deep,
low-degree melt. This low-degree melt cannot be derived from
a peridotite source with BSE δ44/40Ca, but instead
requires either a source with lower-than-BSE δ44/40Ca or
a different source mineralogy. The isotopically light, low-degree melt
is consistent with derivation from a pyroxene- and garnet-rich source,
but the effects of mineralogical heterogeneity in the source regions
of OIBs cannot be easily distinguished from the possible influence of
Ca isotope heterogeneity in the mantle. Regardless, mixing of melts
from a shallow peridotite source and a deep source appears to be a
ubiquitous part of OIB petrogenesis.
Title: Investigation of atmospheric turbulence and scale lengths using
radiosonde measurements of GVAX-campaign over central Himalayan region
Authors: Rajput, Akanksha; Singh, Narendra; Singh, Jaydeep; Rastogi,
Shantanu
Bibcode: 2022JASTP.23505895R
Altcode:
The atmospheric turbulence characteristics such as energy dissipation
rate (ε), eddy diffusivity (K), and refractive index structure
parameter (Cn2), which are inevitable to
understand the vertical mixing and transport of pollutants, momentum,
and energy, are least explored over the Himalayan region owing to the
unavailability of observations. Here, we investigate the characteristics
of turbulence in the troposphere (TS) and lower stratosphere (LS) using
Thorpe's method for intense radiosonde measurements made during July
2011 to March 2012, from a central Himalayan site Manora Peak (79.5°E,
29.4°N, and 1936 m AMSL). Findings reveal that the energy dissipation
rate (log ε), and eddy diffusivity (log K), are right-skewed with
central mean values about -3.90 (-3.30) m2s-3
and -0.19 (-0.24) m2s-1, in the TS (LS)
region. However, Cn2 follows the right
(left) -skewed distribution with the mean value of -16.9 (-19)
m-2/3, in the TS (LS). The mean values of inner scale
(lo) and buoyancy scale (LB) are 0.051 (0.104)
m and 84.62 (8.34) m in the TS (LS). The monthly and seasonal
variations of these parameters were also examined and presented. The
mean profiles of log ε show the lowest dissipation rate (-4.5
m2s-3) during the post-monsoon season and constant
dissipation rate (∼-4 m2s-3) below 5 km in
winter, however, mixing coefficient log K shows a constant variation
(∼-0.01 m2s-1) above 8 km. Larger buoyancy
scales (>100 m) are observed in the altitude range of 8-14 km during
moist and lighter monsoon circulations. This study extricates the
effect of orography-induced local circulations that controls turbulence
intensity in the lower troposphere, especially in the weak mean flow
conditions. This study essentially provides the quantified vertical
distribution of the atmospheric parameters associated with turbulence
and to be utilized for understanding the related physical processes.
Title: Was there an upward atmospheric discharge in the Tunguska
catastrophe?
Authors: Gladysheva, Olga G.
Bibcode: 2022JASTP.23605909G
Altcode:
This work deals with the issue of the light emission that took place
during the Tunguska catastrophe of 1908. According to eyewitnesses,
after the disappearance of the flying object over the horizon, a column
of light rose above the place of its fall. This pillar was visible on
a sunny morning from a distance of ∼500 km and reached a height of
∼80 km above the ground. The duration of the existence of this column
of light was estimated at 6-7 s. The thermal effect of radiation from
this column was great: at a distance of ∼30 km from the epicenter,
live needles caught fire, and at a distance of 65 km, the effect was
close to a burn of human skin. The model of the radiation source is most
consistent with the level of thermal impact on the environment if this
source was located at an altitude of 30 km above the ground. According
to estimates, the energy of this radiation exceeded 5·1022
erg. This work discusses the assumption that during the Tunguska
catastrophe there was a powerful upward atmospheric discharge, which
was a consequence of the formation of numerous relativistic runaway
electron avalanches.
Title: Negative polarization of light at backscattering from a
numerical analog of planetary regoliths
Authors: Grynko, Yevgen; Shkuratov, Yuriy; Alhaddad, Samer; Förstner,
Jens
Bibcode: 2022Icar..38415099G
Altcode:
We model negative polarization, which is observed for planetary
regoliths at backscattering, solving a full wave problem of light
scattering with a numerically exact Discontinuous Galerkin Time
Domain (DGTD) method. Pieces of layers with the bulk packing density
of particles close to 0.5 are used. The model particles are highly
absorbing and have irregular shapes and sizes larger than the wavelength
of light. This represents a realistic analog of low-albedo planetary
regoliths. Our simulations confirm coherent backscattering mechanism
of the origin of negative polarization. We show that angular profiles
of polarization are stabilized if the number of particles in a layer
piece becomes larger than ten. This allows application of our approach
to the negative polarization modeling for planetary regoliths.
Title: Clay sediments derived from fluvial activity in and around
Ladon basin, Mars
Authors: Weitz, Catherine M.; Bishop, Janice L.; Grant, John A.;
Wilson, Sharon A.; Irwin, Rossman P.; Saranathan, Arun M.; Itoh,
Yuki; Parente, Mario
Bibcode: 2022Icar..38415090W
Altcode:
The morphology and mineralogy of light-toned layered sedimentary
deposits were investigated using multiple orbital datasets across the
Ladon basin region, including within northern Ladon Valles, southern
Ladon basin, and the southwestern highlands of Ladon basin. Light-toned
layered deposits are particularly widespread in Ladon Valles and Ladon
basin, ranging laterally for distances over 200 km, with the thickest
exposure (54 m) located at the mouth of Ladon Valles. The restriction
of layered sediments below a common elevation (-1850 m) in Ladon
Valles and Ladon basin and their broad conformable distribution with
bedding dips between 1 and 4° favor a lacustrine environment within
this region during the Late Noachian to Early Hesperian. The Ladon
layered deposits have spectral signatures consistent with Mg-smectites,
even when the morphology of the layering varies considerably in color
and brightness. These phyllosilicates were most likely eroded from the
highlands upstream to the south, but the lacustrine environment may have
also been favorable for in situ alteration and formation of clays. The
southwestern highlands also display light-toned layered deposits
within valleys and small basins. These sediments predominantly have
signatures of Mg-smectites, although we also identified Fe/Mg-smectites
and additional hydrated phases in some deposits. One of these altered
deposits was found within a younger Holden crater secondary chain,
possessing a Late Hesperian to Early Amazonian age for valleys and
sediments that postdate the deposits within Ladon Valles and Ladon
basin. Phyllosilicate signatures were also detected in the ejecta from
two fresh craters that exposed highland materials upstream of Arda
Valles, revealing that the highlands are clay-bearing and may be the
most plausible source of the clay-bearing fluvial-derived sediments
found within the valleys and basins downstream. Some of the highland
deposits are likely coeval to similar clay-bearing sediments found
to the south within Holden and Eberswalde craters, indicating late,
widespread fluvial activity and deposition of allochthonous clays
within the broader Margaritifer Terra region when Mars was thought to
be colder and drier.
Title: Detailed petrogenesis of the unsampled Oceanus Procellarum:
The case of the Chang'e-5 mare basalts
Authors: He, Qi; Li, Yiheng; Baziotis, Ioannis; Qian, Yuqi; Xiao,
Long; Wang, Zaicong; Zhang, Wen; Luo, Biji; Neal, Clive R.; Day,
James M. D.; Pan, Fabin; She, Zhenbing; Wu, Xiang; Hu, Zhaochu; Zong,
Keqing; Wang, Lu
Bibcode: 2022Icar..38315082H
Altcode:
Lunar mare basalts provide a probe to study the magmatic and thermal
evolution of the Moon. The Chang'e-5 (CE-5) mission returned samples
from a young and hitherto unsampled mare terrain, providing fresh
opportunities to understand lunar volcanic history. A detailed
petrologic survey was conducted in this study on basalt fragments and
glasses from the returned CE-5 soil samples. Relatively large-sized
(100-400 μm) basaltic fragments were hand-picked and examined for
texture, mineral assemblage and mineral chemistries. Basaltic fragments
exhibit dominantly subophitic textures and are phenocryst-free,
with low to intermediate-Ti (2.1-5.5 wt%) and low Mg# (Mg/(Mg + Fe)
× 100, 19-47, with an average whole-rock Mg# of 33) consistent
with olivine-melt equilibrium calculation (Mg# = 34). A range of
highly evolved basaltic materials have been identified, in which
abundant fayalitic olivine, symplectitic intergrowths, and Si +
K-rich mesostasis co-exist were found resulting from late-stage
silicate liquid immiscibility. Basaltic glass compositions largely
overlap with basaltic fragment compositions suggesting they are
locally derived. The CE-5 basalts have a relatively limited range of
eruption temperatures of 1150-1230 °C. Based on their petrographic
and geochemical characteristics, some CE-5 mare basalts are highly
evolved and some of the resultant basaltic melt products underwent
high crystallization. Thermodynamic modeling using MELTS suggests
highly evolved basaltic magma was produced by a low-pressure and
simple fractional crystallization under reduced conditions. This
may have occurred at the surface in the inflated Em4/P58 flow with a
thickness of ~50 m. The low degree of partial melting mantle source
of the parental melts is the late-stage lunar magma ocean cumulates
in a similar manner to some evolved low-Ti mare basalt meteorites,
although the source of CE-5 basalts may have been slightly more Ti-rich.
Title: Probable ice-rich deposits on north-facing slopes in Alba
Patera, Mars
Authors: Schiff, Nicholas L. G.; Gregg, Tracy K. P.
Bibcode: 2022Icar..38315063S
Altcode:
We examine unconformable lobate deposits along the north-facing
slopes of Alba Patera (40°N, 250°E with an elevation of ~6 km),
Mars, using data from the Mars Reconnaissance Orbiter Context Camera,
High-Resolution Imaging Science Experiment, and the Mars Orbiter
Laser Altimeter. We interpret the lobate north-facing slope deposits
(NSFDs) to be small (<3 km from source to toe) lobate debris
aprons (LDAs), making them the highest-elevation LDAs yet identified
on Mars. The total volume of the deposits along the caldera walls is
~5-11 km3. Deposits filling impact craters around the Alba
Mons summit appear to be similar to the NFSDs. These NFSDs bear two
distinct textures either singly or together: a hummocky surface of
decameter-scale hills and a smooth surface. Smooth-textured NFSDs have
lobate margins and convex-up topographic profiles, and show evidence
of having flowed; hummocky NSFDs have concave or linear topographic
profiles and are generally found on steep slopes. These deposits
likely formed due to reduced insolation on north-facing slopes, which
allowed for the preferential accumulation or preservation of water
ice. The presence of small LDAs restricted to north-facing slopes
could indicate that Alba Patera was only a marginal environment for
glaciation, possibly because little water vapor was available at such a
high elevation. The hummocky material is interpreted to be the eroded
remnants of a mantle of ice-cemented dust that was superposed on the
NFSDs. This mantle has been almost completely removed in smooth-textured
areas. This difference in rates of ice removal was the result of either
lower insolation on steep north-facing slopes than on shallow slopes or
the greater mobility of the thicker, lobate portions of NFSDs producing
a more densely fractured mantle.
Title: Absorption of methane broadened by carbon dioxide in the 3.3
μm spectral region: From line centers to the far wings
Authors: Tran, H.; Auwera, J. Vander; Bertin, T.; Fakhardji, W.;
Pirali, O.; Hartmann, J. -M.
Bibcode: 2022Icar..38415093T
Altcode:
This work studied the infrared absorption of methane broadened by
carbon dioxide, which can contribute to the radiative budget of
CO2-dominated atmospheres. Fourier transform absorption
spectra of CH4 perturbed by CO2 were recorded in
the 3.3 μm spectral region, at room temperature and total pressures
ranging from 3 to 25 bars. These experimental data were modeled
using a theoretical approach taking collision-induced line mixing into
account. Comparisons between measured and calculated spectra demonstrate
that the proposed model is capable of accurately representing the
absorption of methane broadened by collisions with CO2,
from line centers to the far wings. For practical applications, this
rigorous spectral modeling was used to derive a simple χ-factor
model to represent the spectral shape of CO2-broadened
CH4 line wings. Comparisons with experimental values show
that, at room temperature, the proposed χ-factor reproduces the
measured spectra to within 10% in the band wings where the absorption
is mainly due to the far line wings, while the usual Lorentzian profile
leads to relative differences several orders of magnitude larger. This
line-shape correction was successfully validated through comparisons
with heavily saturated spectra of the ν3 band of methane
recorded at sub-atmospheric pressures.
Title: Iron isotope fractionation in anoxygenic phototrophic Fe(II)
oxidation by Rhodobacter ferrooxidans SW2
Authors: Han, Xiaohua; He, Yongsheng; Li, Jinhua; Kappler, Andreas;
Pan, Yongxin
Bibcode: 2022GeCoA.332..355H
Altcode:
Microbially mediated Fe(II) oxidation is one of the most important
pathways of Fe redox cycling on both present and early Earth. It was
proposed to participate in iron formations (IFs) deposition under
oxygen-depleted oceanic conditions before the Great Oxidation Event
(GOE). Fe isotopic records in IFs provide important archives for the
redox state of iron pool in paleo oceans. There have been a number
of iron-oxidizing experiments which used bacteria with different
metabolic pathways. However, it still needs further research on how
and to what extent Fe isotopes are fractionated during Fe(II) oxidation
mediated by the anoxygenic phototrophic Fe(II)-oxidizer, as well as its
implications for the redox state of iron pool in paleo oceans. Here,
we report Fe isotope fractionation between Fe(II)aq
and Fe(III) (oxyhydr)oxides precipitates produced by the anoxygenic
phototrophic Fe(II)-oxidizer Rhodobacter ferrooxidans SW2 at ambient
temperature (20 °C). Mössbauer spectroscopy analyses indicated
that the final mineral product was ferrihydrite. The corrected Fe
isotope fractionation between Fe(II)aq and precipitates
(Δ56Feprecipitate-Fe(II)aq) ranged from
ca. -0.37 ± 0.04‰ (2se, N = 2) after 1 day of cultivation to 2.96
± 0.17‰ (2se, N = 2) after 22 days of cultivation. The observed
fractionation cannot be explained by neither a simple Rayleigh nor
equilibrium process, but likely recorded a process from an isotopic
disequilibrium reaching complete or near-complete equilibrium during 22
days of cultivation. The lower precipitation rate after 7 days, small
size of oxidation products and dissolution-oxidation-reprecipitation
processes probably promoted isotope exchange overwhelming the kinetic
effect, resulting in a final isotope equilibrium between precipitates
and Fe(II)aq. It revealed that the ferrihydrite produced
by Fe(II) oxidation by anoxygenic photoferrotrophy could reach Fe
isotope equilibrium relatively easily, thus IFs may record Fe isotope
equilibrium with the fluids from which they precipitated, i.e. in some
cases solely from seawater in Archean oceans.
Title: Gravitational Deformation Measurement Method for the Main
Reflector and Sub-reflector of the 70 m Antenna by Laser Scanner
Authors: Fu, Lian-Bo; Liu, Jian-Jun; Yan, Wei; Kong, De-Qing; Ren,
Xin; Liu, Chen-Di; Zhang, Hong-Bo
Bibcode: 2022RAA....22i5001F
Altcode:
Large antennas play an important role in deep space exploration and
astronomical research. However, their performances are inevitably
affected by the main reflector surface deformation and sub-reflector
displacement resulting from the factors of wind, temperature, and
gravity, among which the effect of gravity is especially pronounced. In
this work, a three-dimensional laser scanner was employed to measure
the main reflector and sub-reflector gravitational deformation of the
Tianjin 70 m antenna at different elevation angles. Here, we solved
the antenna main reflector deformation and sub-reflector displacement,
and analyzed the deformation law of the antenna under the action of
gravity. A new measurement method of antenna main reflector deformation
and sub-reflector displacement is realized by mutual verification of
the measured results and theoretical simulations. This method will
help to improve the antenna performance and provide a reference to
optimize the design of large-aperture antennas.
Title: The SHERLOC Calibration Target on the Mars 2020 Perseverance
Rover: Design, Operations, Outreach, and Future Human Exploration
Functions
Authors: Fries, Marc D.; Lee, Carina; Bhartia, Rohit; Razzell Hollis,
Joseph; Beegle, Luther W.; Uckert, Kyle; Graff, Trevor G.; Abbey,
William; Bailey, Zachary; Berger, Eve L.; Burton, Aaron S.; Callaway,
Michael J.; Cardarelli, Emily L.; Davis, Kristine N.; DeFlores, Lauren;
Edgett, Kenneth S.; Fox, Allison C.; Garrison, Daniel H.; Haney,
Nikole C.; Harrington, Roger S.; Jakubek, Ryan S.; Kennedy, Megan R.;
Hickman-Lewis, Keyron; McCubbin, Francis M.; Miller, Ed; Monacelli,
Brian; Pollock, Randy; Rhodes, Richard; Siljeström, Sandra; Sharma,
Sunanda; Smith, Caroline L.; Steele, Andrew; Sylvia, Margarite; Tran,
Vinh D.; Weiner, Ryan H.; Yanchilina, Anastasia G.; Aileen Yingst, R.
Bibcode: 2022SSRv..218...46F
Altcode:
The Scanning Habitable Environments with Raman and Luminescence for
Organics and Chemicals (SHERLOC) is a robotic arm-mounted instrument
onboard NASA's Perseverance rover. SHERLOC combines imaging via two
cameras with both Raman and fluorescence spectroscopy to investigate
geological materials at the rover's Jezero crater field site. SHERLOC
requires in situ calibration to monitor the health and performance of
the instrument. These calibration data are critically important to
ensure the veracity of data interpretation, especially considering
the extreme martian environmental conditions where the instrument
operates. The SHERLOC Calibration Target (SCT) is located at
the front of the rover and is exposed to the same atmospheric
conditions as the instrument. The SCT includes 10 individual
targets designed to meet all instrument calibration requirements. An
additional calibration target is mounted inside the instrument's
dust cover. The targets include polymers, rock, synthetic material,
and optical pattern targets. Their primary function is calibration
of parameters within the SHERLOC instrument so that the data can be
interpreted correctly. The SCT was also designed to take advantage
of opportunities for supplemental science investigations and includes
targets intended for public engagement. The exposure of materials to
martian atmospheric conditions allows for opportunistic science on
extravehicular suit (i.e., "spacesuit") materials. These samples will
be used in an extended study to produce direct measurements of the
expected service lifetimes of these materials on the martian surface,
thus helping NASA facilitate human exploration of the planet. Other
targets include a martian meteorite and the first geocache target
to reside on another planet, both of which increase the outreach and
potential of the mission to foster interest in, and enthusiasm for,
planetary exploration. During the first 200 sols (martian days) of
operation on Mars, the SCT has been analyzed three times and has proven
to be vital in the calibration of the instrument and in assisting the
SHERLOC team with interpretation of in situ data.
Title: Intrinsic tension in the supernova sector of the local Hubble
constant measurement and its implications
Authors: Wojtak, Radosław; Hjorth, Jens
Bibcode: 2022MNRAS.515.2790W
Altcode: 2022arXiv220608160W; 2022MNRAS.tmp.1832W
We reanalyse observations of Type Ia supernovae (SNe) and Cepheids
used in the local determination of the Hubble constant and find
strong evidence that SN standardization in the calibration sample
(galaxies with observed Cepheids) requires a steeper slope of the
colour correction than in the cosmological sample (galaxies in the
Hubble flow). The colour correction in the calibration sample is
consistent with being entirely due to an extinction correction
due to dust with properties similar to those of the Milky Way
(RB ≍ 4.6 ± 0.4) and there is no evidence for intrinsic
scatter in the SN peak magnitudes. An immediate consequence of this
finding is that the local measurement of the Hubble constant becomes
dependent on the choice of SN reference colour, i.e. the colour of an
unreddened SN. Specifically, the Hubble constant inferred from the same
observations decreases gradually with the reference colour assumed in
the SN standardization. We recover the Hubble constant measured by SH0ES
for the standard choice of reference colour (SALT2 colour parameter c =
0), while for a reference colour that coincides with the blue end of
the observed SN colour distribution (c ≍ -0.13), the Hubble constant
from Planck observations of the cosmic microwave background (CMB)
[assuming a flat Lambda cold dark matter (ΛCDM) cosmological model]
is recovered. These results are intriguing in that they may provide
an avenue for resolving the Hubble tension. However, since there is
no obvious physical basis for the differences in colour corrections in
the two SN samples, the origin of these requires further investigation.
Title: Spectropolarimetry of magnetic Chemically Peculiar stars in
the Orion OB1 association
Authors: Semenko, Eugene; Romanyuk, Iosif; Yakunin, Ilya; Kudryavtsev,
Dmitry; Moiseeva, Anastasiya
Bibcode: 2022MNRAS.515..998S
Altcode: 2022arXiv220700337S; 2022MNRAS.tmp.1791S
We summarize the results of a spectropolarimetric survey of 56
chemically peculiar (CP) stars in the association of Orion OB1. We
uniformly collected the observational material with the 6-m telescope
BTA of the Special Astrophysical Observatory in 2013-2021. We identify
14 new magnetic CP stars with a longitudinal magnetic field exceeding
approximately 500 G. The studied sample contains 31 magnetic stars or
55 per cent of the whole CP population in Orion OB1. We show that the
percentage of the magnetic CP stars and the field strength drop sharply
with age. The mean longitudinal magnetic field in the young subgroup
OB1b (log t = 6.23) is confidently almost three times stronger than in
the older subgroups OB1a (log t = 7.05) and OB1c (log t = 6.66). In
the Orion Nebula, a place with the youngest stellar population (log
t < 6.0), we detect the magnetic field only in 20 per cent of CP
stars. Such an occurrence drastically differs from 83 per cent of
magnetic CP stars in the nearby subgroup OB1c. We consider this effect
an observational bias caused by a significant portion of a very young
population with the signatures of Herbig Ae/Be stars. The technique
we used for magnetic measurements and the quality of available data do
not allow us to detect weak fields in the case of stars with a limited
number of lines and emissions in spectra.
Title: C-O-H-S fluids released by oceanic serpentinite in subduction
zones: Implications for arc-magma oxidation
Authors: Duan, Wen-Yong; Li, Xu-Ping; Schertl, Hans-Peter; Willner,
Arne P.
Bibcode: 2022E&PSL.59417709D
Altcode:
Subducted oceanic serpentinite carries H2O, ferric iron,
carbon and sulfur into the subduction zone, where they are stepwise
released during dehydration. These C-O-H-S fluids are intimately linked
to magma oxidation and ore formation within magmatic arcs. However,
the mechanism of transfer of carbon, sulfur and ferric iron into
fluids is poorly known. It is also controversial whether the C-O-H-S
fluids can oxidize arc magmas. We present new thermodynamic models for
serpentinite to predict the species produced in C-O-H-S fluids during
subduction. Closed system modeling provides molar concentrations of
species at different P-T conditions, and shows that reducing species
generally have high solubilities at low P-T conditions. Oxidizing
species mainly partition into the fluid at higher P-T conditions. The
concentration of iron in fluids is much lower than that of other
major elements. Open-system fluid fractionation shows that only 5-14%
of the carbon is lost to the mantle wedge, while the loss of sulfur is
as high as 55-100% at sub-arc depths. Almost all carbon and sulfur lost
are released as oxidizing species. The redox properties of the fluids
are controlled by sulfur, resulting in an oxygen fugacity of the fluids
that is 0.6-0.95 log units higher than the HM buffer. Sulfur loss is
a function of the whole-rock composition (e.g., Mg/Si, Al, Ca, and
especially Fe3+/Fetot ratio) and the geothermal
gradient of the subduction zone, with elevated sulfur fluxes predicted
for serpentinite in cold subduction zones. The maximum amount of sulfur
released in a cold subduction regime is 5.5 times higher than in a warm
subduction regime. Our modeling results are consistent with petrological
observations and global-arc-basalt oxygen fugacity calculations and
highlight that the C-O-H-S fluids released from the subducted slab
may contribute considerably to the composition of arc magmas.
Title: Anisotropic decoupled spheres in f(G,T) gravity
Authors: Sharif, M.; Hassan, K.
Bibcode: 2022IJGMM..1950150S
Altcode:
This paper aims to determine the anisotropic solutions for static
spherically symmetric spacetime via gravitational decoupling technique
in the context of f(G,T) gravity, where G indicates the Gauss-Bonnet
term and T represents trace of the energy-momentum tensor. The
additional source, present alongside the isotropic seed source in the
sphere, induces anisotropy in the system. In order to decouple the two
sources, we impose a minimal geometric deformation on the radial metric
component which gives rise to two sets. The first array represents the
isotropic system while the second set corresponds to the anisotropic
structure. In order to determine the solution of first set, we use
the metric potentials of the Tolman V spacetime while two solutions of
the second set are extracted with the help of two constraints on the
components of the additional source. These solutions are combined with
the solution of the first set to formulate two extensions of Tolman V
spacetime. The matching between the interior and exterior geometries
yields the values of unknown constants. Furthermore, the viability and
stability of the obtained solutions are checked for different values
of the parameters. It is concluded that both solutions are viable and
the first solution is stable as well, while the second solution shows
unstable behavior.
Title: Can the violent merger of white dwarfs explain the slowest
declining Type Ia supernova SN 2011aa?
Authors: Dutta, Anirban; Anupama, G C; Chakradhari, N K; Sahu, D K
Bibcode: 2022arXiv220900569D
Altcode:
We present optical observations and Monte Carlo radiative transfer
modeling of the Type Ia supernova SN 2011aa. With a $\Delta m_{15} (B)$
of $0.59 \pm 0.07$ mag and a peak magnitude $M_{\rm B}$ of $-19.30 \pm
0.27$ mag, SN 2011aa has the slowest decline rate among SNe Ia. The
secondary maximum in the $I$-band is absent or equally bright as the
primary maximum. The velocity of C II is lower than the velocity of Si
II. This indicates either presence of C at lower velocities than Si or a
line of sight effect. Application of Arnett's radiation diffusion model
to the bolometric light curve indicates a massive ejecta $M_{\rm{ej}}
~ 1.8 - 2.6~M_{\odot}$. The slow decline rate and large ejecta mass,
with a normal peak magnitude, are well explained by double degenerate,
violent merger explosion model. The synthetic spectra and light curves
generated with SEDONA considering a violent merger density profile
match the observations.
Title: Robustness of BSISO and air-sea interactions in the CMIP
(Phase-6) models over the North Indian Ocean
Authors: Konda, Gopinadh; Vissa, Naresh Krishna
Bibcode: 2022DyAtO..9901316K
Altcode:
Historical runs of 30 Coupled Model Intercomparison Project
Phase-6 (CMIP6) General circulation models (GCMs) are evaluated
for the representation of Boreal Summer Intraseasonal Oscillations
(BSISO). Several statistical metrics were developed to evaluate the
characteristic features of BSISO, such as propagation, phase speed,
and exchange of air-sea fluxes at the air-sea interface over the
major regions of the Indian Summer Monsoon (ISM). The mean state of
the monsoon precipitation in the CMIP6 models is evaluated by using
seasonal mean bias, pattern correlation, and root mean square error. The
majority of CMIP6 models underestimate the precipitation over central
India and overestimate the precipitation over the eastern equatorial
region. Multi-model mean (MME) of the models shows good agreement
of precipitation pattern with the observations. In the observations,
the precipitation anomalies propagate northward from the equatorial
latitudes to the northern latitudes over the ISM region (60°E-100°E
longitudes). However, the initiation of northward propagating convection
shows a significant variation with time in the CMIP6 models. Most of the
models well simulated the BSISO propagation over the Bay of Bengal (BoB)
and the Indian subcontinent. The majority of the models underestimate
the phase speed of BSISO over the Arabian Sea (AS), and easterlies
from the western north Pacific, which led to the failure of models
in representing the northwest-southeast tilt of convection. Surface
turbulent fluxes and zonal winds lag the deep convection over
the North Indian Ocean on intraseasonal timescales. However,
misrepresentation of air-sea fluxes in the CMIP6 models leads to the
significant biases of intraseasonal variances. This study examines
the simulation characteristic features of BSISO by CMIP6 models
and is mainly attributes them to the atmospheric internal dynamics
and air-sea interactions. The present study further suggests that
improving atmospheric-oceanic feedback mechanisms, specific humidity,
and low-level winds in the CMIP6 models is necessary to accurately
predict the ISM intraseasonal variability.
Title: Combined dynamical and morphological characterisation of
geodynamo simulations
Authors: Nakagawa, Takashi; Davies, Christopher J.
Bibcode: 2022E&PSL.59417752N
Altcode:
Numerical dynamo simulations cannot operate at the physical
conditions of Earth's core, yet they often produce fields that appear
morphologically similar to the present geomagnetic field. A key
issue is therefore to decipher under what conditions "Earth-like"
simulations can be achieved. Recent work has shown that a set of
simulations undertaken along a specific path in parameter space smoothly
approach the QG-MAC dynamics that are expected in Earth's core, whereby
the leading order force balance is Quasi-Geostrophic with Magnetic,
Archimedean and Coriolis forces equilibrating at first order. However,
a systematic link between QG-MAC balance and morphological features
of the simulated fields has yet to be established. Here we assess a
suite of 67 simulations using established compliance criteria for the
field morphology and scale-dependent force balances to quantify the
internal dynamics. Morphological compliance with the modern geomagnetic
field does not imply a single underlying force balance or vice versa;
however, the majority of compliant simulations, including all those
approaching a realistic value of the magnetic Reynolds number Rm, are
in QG-MAC balance. Simulations that simultaneously achieve excellent
morphological compliance with Earth's modern field, QG-MAC balance,
and high Rm, are confined to an intermediate range of dipolarity (the
ratio of energy in the dipole field to the energy truncated at degree
12 at the outer boundary). Reversing simulations in this dipolarity
range maintain dominant QG-MAC balance during polarity transition,
though inertia makes a non-negligible contribution to the force balance.
Title: The luminosity of cluster galaxies in the Cluster-EAGLE
simulations
Authors: Negri, Andrea; Dalla Vecchia, Claudio; Aguerri, J. Alfonso
L.; Bahé, Yannick
Bibcode: 2022MNRAS.515.2121N
Altcode: 2022MNRAS.tmp.1447N; 2022arXiv220513553N
We computed the luminosity of simulated galaxies of the C-EAGLE
project, a suite of 30 high-resolution zoom-in simulations of
galaxy clusters based on the EAGLE simulation. The AB magnitudes are
derived for different spectral bands, from ultraviolet to infrared,
using the simple stellar population modelling based on the E-MILES
stellar spectra library. We take into account obscuration due to
dust in star forming regions and diffuse interstellar medium. The
g - r colour-stellar mass diagram, at z = 0.1, presents a defined
red sequence, reaching g - r ≃ 0.8, 0.05 dex redder than EAGLE at
high masses, and a well populated blue cloud, when field galaxies are
included. The clusters' inner regions are dominated by red-sequence
galaxies at all masses, although a non-negligible amount of blue
galaxies are still present. We adopt Bayesian inference to compute
the clusters LFs, testing for statistical significance of both single
and double Schechter functions. The multicolour LFs at z = 0 show
a knee luminosity that peaks in the infrared and increases with the
cluster's mass. The faint-end is weakly dependent on colour and mass
and shows an upturn in the optical, bounded between -1.25 and -1.39,
just moderately steeper than the field. The simulations reproduce,
within the observational errors, the spectroscopic LFs of the Hercules
and Abell 85 clusters, including their faint end upturn. C-EAGLE LFs are
in broad agreement with observed LFs taken from SDSS and XXL surveys,
up to z = 0.67, showing a rather flat faint end when the observational
constrains are taken into account.
Title: Seasonal variations of Mg and Ca in the exosphere of Mercury
Authors: Chaufray, J. -Y.; Leblanc, F.; Werner, A. I. E.; Modolo,
R.; Aizawa, S.
Bibcode: 2022Icar..38415081C
Altcode:
We simulate the seasonal variations of the Mg 285.3 nm and Ca 422.7 nm
brightness and compared our results to the MESSENGER/MASCS observations
at dawn. Our results are consistent with the previous studies of
Ca while for Mg we used another seasonal variation for the g -value
(excitation frequency) at 285.3 nm. We find that both emissions are well
reproduced from micrometeoroid impacts when the true anomaly angle (TAA)
of Mercury is larger than 80°. For true anomaly angle lower than 80°,
an additional source is needed to reproduce the Ca observations in
agreement with previous studies, and possibly the Mg observations. We
compare several solar spectra (observed or modeled) to study the Mg
g-value and found that the seasonal variation of the g-value peaking
near TAA = 60° used by previous studies to analyse the MESSENGER
observations of Mg may be due to an artefact not present in the solar
spectrum. The observed seasonal variations of the Mg brightness are
better reproduced without this artefact. However, observations of the
solar spectrum near 285.3 nm at a spectral resolution of ~20 mA would be
needed to better estimate the seasonal variations of the Mg excitation
frequencies and then to better understand the possible differences in
the source of these two species in the exosphere of Mercury.
Title: Widespread magmatic provinces at the onset of the Sturtian
snowball Earth
Authors: Lu, Kai; Mitchell, Ross N.; Yang, Chuan; Zhou, Jiu-Long;
Wu, Li-Guang; Wang, Xuan-Ce; Li, Xian-Hua
Bibcode: 2022E&PSL.59417736L
Altcode:
The striking coincidence of the Franklin large igneous province
(LIP) and the Sturtian glaciation onset ca. 717 million years ago
(Ma) has inspired the hypothesis that either basaltic weathering or
stratospheric sulfate aerosol injection of the Franklin LIP plunged
Earth into global glaciation. The cool background climate just
before the Sturtian has been commonly invoked by such initiation
models. Difficulty in definitively linking these concepts with
geological evidence has precluded complete demonstration of a snowball
trigger mechanism. Here, we report that Franklin-aged magmatism was
not only present in Laurentia and Siberia, but also in South China,
where the Hubei-Shaanxi Magmatic Province formed at 720 Ma, revealing
widespread magmatic provinces immediately preceding the onset of
the Sturtian snowball Earth. Geochronological and geochemical data
suggest that the geographically widespread magmatic provinces were
emplaced over a short duration (ca. 720-717 Ma) and likely related to
a mantle superplume beneath supercontinent Rodinia. We propose that
low-to-mid-latitude volcanism prior to the Sturtian by a few million
years enhanced global weatherability and created the background cool
climate for the superimposed shock of stratospheric sulfate aerosol
injection of the terminal Franklin eruption. Such widespread 720-717
Ma volcanism on different continents may have driven the Sturtian
snowball initiation.
Title: Deciphering aseismic deformation along submarine fault branches
below the eastern Sea of Marmara (Turkey): Insights from seismicity,
strainmeter, and GNSS data
Authors: Durand, V.; Gualandi, A.; Ergintav, S.; Kwiatek, G.;
Haghshenas, M.; Motagh, M.; Dresen, G.; Martínez-Garzón, P.
Bibcode: 2022E&PSL.59417702D
Altcode:
The recently observed slow transients in the Sea of Marmara are
important to quantify the seismic hazard and risk for the greater
Istanbul metropolitan region. In this study, we analyze and characterize
a slow slip event that occurred in the Eastern Sea of Marmara in
2016. To characterize the temporal history and the location of this
event, we combine for the first time in this region different types
of geodetic data (strainmeters and GNSS stations) and seismicity. We
propose two interpretations to explain the observations: either the
slow event initiated on the western part of the Armutlu fault and then
propagated approximately 40 km eastward, or it initiated on the western
section of the Armutlu fault, and then jumped onto a perpendicular
fault after propagating ca. 15 km. We deduce these interpretations
from forward modeling of the strain and displacement data. In addition,
our results also suggest that this slow event triggered seismicity on
a neighboring perpendicular fault.
Title: Analysis of local geomagnetic index under the influence of
equatorial electrojet (EEJ) at the equatorial Phuket geomagnetic
station in Thailand
Authors: Myint, Lin M. M.; Hozumi, Kornyanat; Saito, Susumu; Supnithi,
Pornchai
Bibcode: 2022AdSpR..70.1429M
Altcode:
The local K-index is an important proxy to monitor geomagnetic
disturbances due to the solar wind in space weather study. The
diurnal variation of geomagnetic fields observed in the magnetic
equatorial region is dominated by the equatorial electrojet (EEJ),
and the variation of EEJ is directly related to the local ionospheric
dynamics; therefore, in this work, the local K-index is generated
by based on the geomagnetic field measurement at an equatorial
geomagnetic station in Phuket, Thailand and the effects of EEJ on the
computed local K-indices are analyzed. At each station, an L9 (the
lower limit for K = 9) value is set to develop a conversion table
between the magnetic range scales and K-indices, and that L9 value
must be assigned based on the characterization of the geomagnetic
variations at that station. In this work, suitable L9 values are
determined by analyzing the distributions of the local K-index and
the planetary geomagnetic index, Kp-index. According to the results in
the present study, the L9 value of 500 nT can provide local K-indices
that can classify the geomagnetic disturbances more correctly. The
results show that 40% of the local K-index is consistent with the
Kp-index, and about 45% of the local K indices are ±1 deviated from
Kp-indices. It is found that using the suitable L9 value can partially
control the EEJ's dominance on K-index. Moreover, we investigated the
seasonal and day-to-day variability of the diurnal variation of the
geomagnetic fields from the Phuket station. Upon reviewing the data,
the equatorial geomagnetic field variations were consistent with the
planetary geomagnetic activity levels, and the day-to-day changes of
the daytime field amplitudes were relatively high in the high solar
activity year and moderate in the low solar activity year.
Title: The First Detection of a Protostellar CO Outflow in the Small
Magellanic Cloud with ALMA
Authors: Tokuda, Kazuki; Zahorecz, Sarolta; Kunitoshi, Yuri; Higashino,
Kosuke; Tanaka, Kei E. I.; Konishi, Ayu; Suzuki, Taisei; Kitano, Naoya;
Harada, Naoto; Shimonishi, Takashi; Neelamkodan, Naslim; Fukui, Yasuo;
Kawamura, Akiko; Onishi, Toshikazu; Machida, Masahiro N.
Bibcode: 2022ApJ...936L...6T
Altcode: 2022arXiv220708396T
Protostellar outflows are one of the most outstanding features of star
formation. Observational studies over the last several decades have
successfully demonstrated that outflows are ubiquitously associated
with low- and high-mass protostars in solar-metallicity Galactic
conditions. However, the environmental dependence of protostellar
outflow properties is still poorly understood, particularly in
the low-metallicity regime. Here we report the first detection
of a molecular outflow in the Small Magellanic Cloud with 0.2
Z ⊙, using Atacama Large Millimeter/submillimeter
Array observations at a spatial resolution of 0.1 pc toward the
massive protostar Y246. The bipolar outflow is nicely illustrated by
high-velocity wings of CO(3-2) emission at ≳15 km s-1. The
evaluated properties of the outflow (momentum, mechanical force,
etc.) are consistent with those of the Galactic counterparts. Our
results suggest that the molecular outflows, i.e., the guidepost of
the disk accretion at the small scale, might be universally associated
with protostars across the metallicity range of ~0.2-1 Z ⊙.
Title: A proposal to extend the spectrographic global survey method
Authors: Kovalev, I. I.; Olemskoy, S. V.; Sdobnov, V. E.
Bibcode: 2022JASTP.23505887K
Altcode:
We present a modified spectrographic global survey method to split
the cosmic ray variations into components of the interplanetary,
geomagnetospheric, and atmospheric origin from ground-based observations
of the cosmic ray intensity. We show a possibility to use all the
available suite of ground-based instrumentation recording cosmic rays
(global network of the neutron monitors located at different locations
and altitudes, ground- and underground-based muon telescopes, etc.) for
such studies without involving the data from aerologic atmospheric
sounding. As a demonstration of the method functionality, we provide
the calculation results for the variations in the isotropic flux, pitch
angle anisotropy of primary cosmic rays in the interplanetary space,
changes in the planetary system of geomagnetic cutoff rigidities for
every observational hour, as well as the atmosphere temperature above
the point of observation of cosmic ray charged components for selected
time intervals.
Title: Topographic and orbital forcing of Titan's hydroclimate
Authors: Lora, Juan M.; Battalio, J. Michael; Yap, Mary; Baciocco,
Colin
Bibcode: 2022Icar..38415095L
Altcode:
The cause of the hemispheric asymmetry of Titan's methane lakes and
seas is the subject of ongoing debate. A leading hypothesis posits
that seasonal insolation asymmetries caused by Saturn's eccentric
orbit lead to differences in net precipitation over the two poles,
perhaps mediated by asymmetric atmospheric transport of moisture. But
topographic variations have also been proposed to contribute, albeit
without considering the importance of surface hydrology. Here we present
general circulation model simulations including a synchronously coupled
surface and ground hydrology scheme, testing the separate and combined
influences of topography and orbital forcing on Titan's hydroclimate. We
find that, while topography leads to warmer polar regions relative to a
flat surface which in turn enhance methane loss to the atmosphere, the
overall effect on the global distribution of surface methane liquid is
minor. In particular, topography does not force any notable asymmetry
in the meridional circulation, nor does it affect the seasonality of
the methane cycle, though it does increase the regional heterogeneity
of average precipitation at mid-latitudes. We also find that Titan's
atmospheric methane transport robustly responds to orbital forcing, in
agreement with previous results, but this is insufficient to overcome
the distribution of surface liquids dictated by surface hydrology. We
conclude that Croll-Milankovitch cycles are plausible on Titan, but
potentially not the dominant driver of the current distribution of
liquids; relatedly, our results suggest that the volume of the large
seas and lakes has not varied substantially on millennial timescales.
Title: Forbush decreases associated with coronal mass ejections from
active and non-active regions: statistical comparison
Authors: Melkumyan, A. A.; Belov, A. V.; Abunina, M. A.; Abunin,
A. A.; Shlyk, N. S.; Oleneva, V. A.; Yanke, V. G.
Bibcode: 2022MNRAS.515.4430M
Altcode: 2022MNRAS.tmp.1875M
In this paper, Forbush decreases (FDs) from 1997 to 2020 associated
with coronal mass ejections from active and non-active regions are
compared between themselves and to FDs caused by high-speed streams
from coronal holes. The two types of sporadic FDs are also compared when
corresponding solar wind (SW) disturbances contain, or do not contain,
magnetic clouds (MCs) near Earth. Cosmic ray density and anisotropy
variations, SW speed, interplanetary magnetic field (IMF) strength, and
geomagnetic indices have been examined using statistical methods. The
results reveal that these parameters are larger for FDs associated with
active region (AR) ejections and have highly skewed distributions for
both types of sporadic events. In the same ranges of SW parameters,
FD magnitude is larger for flare-associated events; more efficient
modulation occurs in FDs associated with AR ejections. Differences
between FDs associated with AR and non-AR ejections are more pronounced
when an MC is registered. For IMF strength and geomagnetic indices,
differences between the distributions depend more upon MC presence or
absence than on the type of solar source. Correlation of IMF strength
and SW speed differs slightly between FDs caused by AR and non-AR
ejections regardless of the presence or absence of an MC, akin to the
partial correlation between FD magnitude and IMF strength. Difference
between the speeds of disturbed and background SW is larger for FDs
associated with AR ejections especially when an MC is registered;
the interaction region of different-speed SW streams occurs more
frequently in interplanetary disturbances induced by AR ejections.
Title: New Metrics for Probing the Dynamical State of Galaxy Clusters
Authors: Cerini, Giulia
Bibcode: 2022cxo..prop.6429C
Altcode:
We propose a new metric to study the cross-correlation of fluctuations
between non-baryonic dark matter and hot gas in a sample of galaxy
clusters. Clusters are assumed to be in hydrostatic equilibrium
with gas and member galaxies tracing the underlying gravitational
potential. Studies of merging clusters reveals that these assumptions
are suspect. Using empirically derived HST lensing mass maps in
combination with X-ray images from archival Chandra data of a sample
of galaxy clusters that span a wide range of masses, redshifts and
differing dynamical states, we will spatially resolve mass and gas
fluctuations and study their coherence. Fluctuation analysis of the
lensing and X-ray surface brightness maps will permit evaluating how
well the gas traces the underlying dark matter potential.
Title: The morphometry of small impact craters on Bennu: Relationships
to geologic units, boulders, and impact armoring
Authors: Daly, R. Terik; Barnouin, Olivier S.; Bierhaus, Edward B.;
Daly, Michael G.; Seabrook, Jeffrey A.; Ballouz, Ronald L.; Nair, Hari;
Espiritu, Raymond C.; Jawin, Erica R.; Trang, David; DellaGuistina,
Daniella N.; Burke, Keara N.; Brodbeck, Juliette I.; Walsh, Kevin J.
Bibcode: 2022Icar..38415058D
Altcode:
The Origins, Spectral Interpretation, Resource Identification, and
Security-Regolith Explorer (OSIRIS-REx) mission revealed that the
asteroid Bennu has ~1500 impact craters (Bierhaus et al., 2022). Here
we use data from the OSIRIS-REx laser altimeter (OLA) to measure the
depths, d, and diameters, D, of a sample of small (D ≤ 10 m) impact
craters that span a broad range of latitudes and longitudes. d/D in this
sample ranges from 0.04 to 0.27, with a mean of 0.13 ± 0.04. Compared
to larger (D ≥ 10 m) craters on Bennu, those studied here have a
greater average d/D. The mean d/D of craters on Bennu's younger, Rugged
Unit is statistically larger than the mean d/D of those on the older,
Smooth Unit. One of the studied craters contains an interior mound
that may indicate the presence of stronger material at depth. A large
fraction of craters studied here are located near large boulders whose
lengths are >50% the diameter of the crater. Some of these large
boulders cross the crater rim crest, protruding into and perched above
the crater interior. In the most extreme cases, the boulder length is
~2.5 times the crater diameter. The d/D of craters near large boulders
is bimodal, which could be a consequence of how boulders affect crater
formation. Laboratory experiments and results from Hayabusa2's Small
Carry-On Impactor experiment indicate that preexisting boulders and
heterogeneities affect crater formation and d/D. The abundance of small
craters on Bennu makes the asteroid a rich resource for understanding
impact processes.
Title: Stochastic models of tropical cyclone genesis in the
Philippine Sea
Authors: Hong, Dang Thi Bich; Vinh, Tran Quang
Bibcode: 2022DyAtO..9901318H
Altcode:
Climate change has influenced the anomalies of extreme weather events,
including tropical cyclones (TCs), strong wind, flood and landslide. The
investigation of TC genesis is of great significance in evaluating
TC activity in order to mitigate TC - induced risks. This study
focuses on developing the stochastic models to simulate TC geneses
over the Philippine Sea, considering seasonal effects. The historical
TC data, including TC number and genesis positions, were obtained
from the Japanese Meteorology Agency (JMA) over the period 1951 -
2020. To select the optimal probability distributions to fit the
observed TC data, the good-of-fit tests were performed throughout
three metrics, namely Mean Absolute Error; Normalized Mean Squared
Error and Correlation Distance. Moreover, the Chi-square test and the
Kolmogorov - Smirnov test were utilized to evaluate the homogeneity of
the selected probability distributions to the observed TC data. The
statistical analysis on TC characteristics presented that most TC
geneses occurred in the latitudinal belt 8°N - 30°N from July to
October, called the active season (AS). Meanwhile, there was a low
TC genesis frequency distributed in the region south of 15°N from
November to June, called the inactive TC season (IAS). The stochastic
models showed the distributions of the observed TC number followed
Negative binomial (NB) distribution for the two seasons. Generalized
extreme value (Gev) distribution fitted TC genesis longitude well for
the inactive season and fitted TC genesis latitude well for the active
season. In the active season, the kernel distribution was appropriate
for genesis longitude, whereas in the inactive season, it was suitable
for genesis latitude. Monte Carlo simulations for 1000 years indicated
the similarities in the geographical distributions of the simulated
TC geneses and the historical ones for the inactive and active seasons.
Title: Massive central galaxies of galaxy groups in the ROMULUS
simulations: an overview of galaxy properties at z = 0
Authors: Jung, S. Lyla; Rennehan, Douglas; Saeedzadeh, Vida;
Babul, Arif; Tremmel, Michael; Quinn, Thomas R.; Loubser, S. Ilani;
O'Sullivan, E.; Yi, Sukyoung K.
Bibcode: 2022MNRAS.515...22J
Altcode: 2022arXiv220300016J; 2022MNRAS.tmp.1576J
Contrary to many stereotypes about massive galaxies, observed brightest
group galaxies (BGGs) are diverse in their star formation rates,
kinematic properties, and morphologies. Studying how they evolve into
and express such diverse characteristics is an important piece of
the galaxy formation puzzle. We use a high-resolution cosmological
suite of simulations ROMULUS and compare simulated central galaxies
in group-scale haloes at z = 0 to observed BGGs. The comparison
encompasses the stellar mass-halo mass relation, various kinematic
properties and scaling relations, morphologies, and the star formation
rates. Generally, we find that ROMULUS reproduces the full spectrum
of diversity in the properties of the BGGs very well, albeit with a
tendency toward lower than the observed fraction of quenched BGGs. We
find both early-type S0 and elliptical galaxies as well as late-type
disc galaxies; we find ROMULUS galaxies that are fast-rotators as well
as slow-rotators; and we observe galaxies transforming from late-type to
early-type following strong dynamical interactions with satellites. We
also carry out case studies of selected ROMULUS galaxies to explore
the link between their properties, and the recent evolution of the
stellar system as well as the surrounding intragroup/circumgalactic
medium. In general, mergers/strong interactions quench star-forming
activity and disrupt the stellar disc structure. Sometimes, however,
such interactions can also trigger star formation and galaxy
rejuvenation. Black hole feedback can also lead to a decline of the
star formation rate but by itself, it does not typically lead to
complete quenching of the star formation activity in the BGGs.
Title: Precise Proper Motion of the Unusual Pulsar Calvera
Authors: Halpern, Jules
Bibcode: 2022cxo..prop.6317H
Altcode:
Calvera is a 59 ms pulsar at high Galactic latitude that is detected
only in X-rays. Two previous Chandra observations measured a proper
motion of 69+/-26 mas/yr away from the Galactic plane. Analysis of
its surface thermal spectrum and pulse profiles using NICER indicate a
model-dependent distance of 3.3 kpc. The implied projected velocity of
1100 km/s is greater than that of any well-measured pulsar. Possible
explanations are all problematic, except perhaps for one in which a
runaway massive star from the Galactic plane exploded in the Galactic
halo. We propose to confront these scenarios with a third observation,
which will refine the proper motion and test for association with a
possible SNR detected as a diffuse, radio emitting ring surrounding
Calvera.
Title: The Details of Limb Brightening Reveal the Structure of the
Base of the Jet in M87 for the First Time
Authors: Punsly, Brian
Bibcode: 2022ApJ...936...79P
Altcode: 2022arXiv220710059P
It has become commonplace in astronomy to describe the transverse coarse
structure of jets in loosely defined terms such as "sheath" and "spine"
based on discussions of parsec scale properties. But, the applicability,
dimension, and prominence of these features on sub-light-year scales has
previously been unconstrained by observation. The first direct evidence
of jet structure near the source in M87 is extreme limb brightening (a
double-rail morphology), 0.3-0.6 mas from the source, which is prominent
in observations with high resolution and sensitivity. Intensity
crosscuts of these images provide three strong, interdependent
constraints on the geometry responsible for the double-rail morphology:
the rail to rail separation, the peak to trough intensity ratio, and the
rail widths. Analyzing these constraints indicates that half or more of
the jet volume resides in a thick-walled, tubular, mildly relativistic,
protonic jet only ~0.25 lt-yr (or ~300 M, where M is the central black
hole mass in geometrized units) from the source. By contrast, the Event
Horizon Telescope Collaboration interprets their observations with
the aid of general relativistic magnetohydrodynamic simulations that
produce an invisible (by construction) jet with a surrounding luminous,
thin sheath. Yet, it is shown that synthetic images of simulated
jets are center brightened 0.3-0.6 mas from the source. This serious
disconnection with observation occurs in a region previously claimed
in the literature to be well represented by the simulations. The limb
brightening analysis motivates a discussion of possible simulation
modifications to improve conformance with observations.
Title: Spontaneous symmetry breaking in the BFSS model: Analytical
results using the Gaussian expansion method
Authors: Brahma, Suddhasattwa; Brandenberger, Robert; Laliberte, Samuel
Bibcode: 2022arXiv220901255B
Altcode:
We apply the Gaussian expansion method to the BFSS matrix model in the
high temperature limit. When the (Euclidean) BFSS action is expanded
about a Gaussian ansatz, it is shown that the SO(9) symmetry is
spontaneously broken, analogous to what happens in the IKKT model. The
analysis of the free energy, using the set of gap equations which
determines the width of the Gaussian terms, is sufficient to show
that this symmetry breaking happens only when the fermionic terms are
included and is absent in the bosonic case.
Title: Synchrotron Pair Production Equilibrium in Relativistic
Magnetic Reconnection
Authors: Chen, Alexander Y.; Uzdensky, Dmitri; Dexter, Jason
Bibcode: 2022arXiv220903249C
Altcode:
Magnetic reconnection is ubiquitous in astrophysical systems, and in
many such systems, the plasma suffers from significant cooling due to
synchrotron radiation. We study relativistic magnetic reconnection
in the presence of strong synchrotron cooling, where the ambient
magnetization $\sigma$ is high and the magnetic compactness $\ell_{B}$
of the system is of order unity. In this regime, $e^{\pm}$ pair
production from synchrotron photons is inevitable, and this process
can regulate the magnetization $\sigma$ surrounding the current
sheet. We investigate this self-regulation analytically and find
a self-consistent steady state for a given magnetic compactness of
the system and initial magnetization. This result helps estimate the
self-consistent upstream magnetization in systems where plasma density
is poorly constrained, and can be useful for a variety of astrophysical
systems. As illustrative examples, we apply it to study the properties
of reconnecting current sheets near the supermassive black hole of M87,
as well as the equatorial current sheet outside the light cylinder of
the Crab pulsar.
Title: The origin of Weyl gauging in metric-affine theories
Authors: Sauro, Dario; Zanusso, Omar
Bibcode: 2022CQGra..39r5001S
Altcode: 2022arXiv220308692S
In the first part, we discuss the interplay between local scale
invariance and metric-affine degrees of freedom from few distinct
points of view. We argue, rather generally, that the gauging of Weyl
symmetry is a natural byproduct of requiring that scale invariance
is a symmetry of a gravitational theory that is based on a metric and
on an independent affine structure degrees of freedom. In the second
part, we compute the Nöther identities associated with all the gauge
symmetries, including Weyl, Lorentz and diffeomorphisms invariances,
for general actions with matter degrees of freedom, exploiting a gauge
covariant generalization of the Lie derivative. We find two equivalent
ways to approach the problem, based on how we regard the spin-connection
degrees of freedom, either as an independent object or as the sum of
two Weyl invariant terms. The latter approach, which rests upon the
use of a Weyl-covariant connection with desirable properties, denoted
$\hat{\nabla }$ , is particularly convenient and constitutes one of
our main results.
Title: Searching the SETI Ellipsoid with Gaia
Authors: Davenport, James R. A.; Cabrales, Bárbara; Sheikh, Sofia;
Croft, Steve; Siemion, Andrew P. V.; Giles, Daniel; Cody, Ann Marie
Bibcode: 2022AJ....164..117D
Altcode: 2022arXiv220604092D
The search for extraterrestrial intelligence (SETI) Ellipsoid is a
geometric method for prioritizing technosignature observations based
on the strategy of receiving signals synchronized to conspicuous
astronomical events. Precise distances to nearby stars from Gaia makes
constraining Ellipsoid crossing times possible. Here we explore the
utility of using the Gaia Catalog of Nearby Stars to select targets
on the SN 1987A SETI Ellipsoid, as well as the Ellipsoids defined by
278 classical novae. Less than 8% of stars within the 100 pc sample
are inside the SN 1987A SETI Ellipsoid, meaning the vast majority of
nearby stars are still viable targets for monitoring over time. We
find an average of 734 stars per year within the 100 pc volume will
intersect the Ellipsoid from SN 1987A, with ~10% of those having
distance uncertainties from Gaia better than 0.1 lyr.
Title: High-resolution topography from planetary images and laser
altimetry
Authors: Fernandes, Iris; Mosegaard, Klaus
Bibcode: 2022P&SS..21805514F
Altcode:
Mapping landforms on the Moon is of great interest and importance
for future human settlements and resources exploration. One
of the first steps is to map the topography in great detail and
resolution. However, data from the Lunar Orbiter Laser Altimeter (LOLA)
provide low-resolution elevation maps in comparison to the size of
detailed geological features. To improve resolution, we developed a
new method to upscale topographic maps to a higher resolution using
images from the Lunar Reconnaissance Orbiter Camera (LROC). Our method
exploits the relation between topographic gradients and degrees of
shading of incoming sunlight. In contrast to earlier published methods,
our approach is based on probabilistic, linear inverse theory, and its
computational efficiency is very high due to its formulation through
the Sylvester Equation. The method operates on multiple images and
incorporates albedo variations. A further advantage of the method is
that we avoid/reduce the use of arbitrary tuning parameters through
a probabilistic formulation where all weighting of data and model
parameters is based on prior information about data uncertainties and
reasonable bounds on the model. Our results increase the resolution of
the topography from ∼60 m per pixel to 0.9 m per pixel, bringing it
to the same pixel resolution as the optical images from LROC, allowing
in some cases detection of craters as small as ∼3 m of diameter. We
estimate uncertainties of the topographic model due to noise in the
images, and in the low-resolution (LOLA) model.
Title: Consistent mass formulae for higher even-dimensional Taub-NUT
spacetimes and their AdS counterparts
Authors: Wu, Di; Wu, Shuang-Qing
Bibcode: 2022arXiv220901757W
Altcode:
Currently, there is a great deal of interest in seeking of consistent
thermodynamics of the Lorentzian Taub-NUT spacetimes. Despite a lot of
"satisfactory" efforts have been made, all of these activities have been
confined to the four-dimensional cases, with the higher even-dimensional
cases remaining unexplored. The aim of this article is to fill the
gap for the first time. To the end of this subject, we first adopt
our own idea that "The NUT charge is a thermodynamical multi-hair" to
investigate the consistent thermodynamics of $D = 6, 8, 10$ Lorentzian
Taub-NUT spacetimes without a cosmological constant. Similarly to the
$D = 4$ cases as did in our previous works, we find that the first
law and Bekenstein-Smarr mass formulas are perfectly satisfied if we
still assign the secondary hair: $J_n = Mn$ as a conserved charge in
both mass formulae. Turning to the cases with a nonzero cosmological
constant, our treatment continues to work very well and all the results
can be fairly generalized to the corresponding Taub-NUT AdS spacetimes
in higher even-dimensions, although we do not know how to define and
introduce a similar higher-dimensional version of the dual (magnetic)
mass that is well known in four dimensions.
Title: Interaction of a Relativistic Magnetized Collisionless Shock
with a Dense Clump
Authors: Tomita, Sara; Ohira, Yutaka; Kimura, Shigeo S.; Tomida,
Kengo; Toma, Kenji
Bibcode: 2022ApJ...936L...9T
Altcode: 2022arXiv220408222T
The interactions between a relativistic magnetized collisionless shock
and dense clumps have been expected to play a crucial role in magnetic
field amplification and cosmic-ray acceleration. We investigate this
process using two-dimensional Particle-In-Cell (PIC) simulations,
for the first time, where the clump size is much larger than the
gyroradius of the downstream particles. We also perform relativistic
magnetohydrodynamic (MHD) simulations for the same condition, to see the
kinetic effects. We find that particles escape from the shocked clump
along magnetic field lines in the PIC simulations, so that the vorticity
is lower than that in the MHD simulations. Moreover, in both the PIC
and MHD simulations, the shocked clump quickly decelerates because
of relativistic effects. Owing to the escape and the deceleration,
the shocked clump cannot amplify the downstream magnetic field in
relativistic collisionless shocks. This large-scale PIC simulation opens
a new window to understanding large-scale behaviors in collisionless
plasma systems.
Title: Similarity solutions for a magnetized supercritical accretion
disc around a rotating object
Authors: Habibi, Fahimeh
Bibcode: 2022MNRAS.515.3867H
Altcode: 2022MNRAS.tmp.1972H
The effect of toroidal magnetic fields on a supercritical accretion
disc (slim disc) around a rotating object is examined. In this
research, it is supposed that angular momentum transport is due to
viscous turbulence and the α-prescription is used for the kinematic
coefficient of viscosity. Moreover, the general relativistic effects
are neglected. The degree of advection that demonstrates the fraction
of energy that accretes by matter on to the central object is considered
by f parameter. For the steady-state structure of such accretion flows,
a set of self-similar solution is presented. Our solutions will include
two important non-dimensional parameters β and a. β is the ratio of
the magnetic pressure to the gas pressure, the so-called friction of
magnetic pressure, which shows the magnetic field strength. The ratio
of the angular velocities of the central body and the accretion flow is
indicated by the rotating parameter a. The possible combined effects
of magnetic field, spin of central object, and degree of advection
are investigated. We also show the effect of rotating parameter a
on the physical quantities of disc is different for co-rotating and
counter-rotating flows. Moreover, by increasing the degree of advection
and strength of magnetic field, the behaviour of the radial and angular
velocities becomes reversed with respect to a. The model implies that
the surface temperature, thickness, and luminosity of disc strongly
depend on rotation parameter and strength of magnetic field.
Title: Experimental study of the removal of excited state phosphorus
atoms by H2O and H2: implications for the
formation of PO in stellar winds
Authors: Douglas, Kevin M.; Gobrecht, David; Plane, John M. C.
Bibcode: 2022MNRAS.515...99D
Altcode: 2022MNRAS.tmp.1662D; 2022arXiv220608193D
The reactions of the low-lying metastable states of atomic phosphorus,
P(2D) and P(2P), with H2O and
H2 were studied by the pulsed laser photolysis at 248 nm of
PCl3, combined with laser-induced fluorescence detection of
P(2D), P(2P), and PO. Rate coefficients between
291 and 740 K were measured, along with a yield for the production
of PO from P(2D or 2P) + H2O of (35
± 15) %. H2 reacts with both excited P states relatively
efficiently; physical (i.e. collisional) quenching, rather than chemical
reaction to produced PH + H, is shown to be the more likely pathway. A
comprehensive phosphorus chemistry network is then developed using a
combination of electronic structure theory calculations and a Master
Equation treatment of reactions taking place over complex potential
energy surfaces. The resulting model shows that at the high temperatures
within two stellar radii of a MIRA variable AGB star in oxygen-rich
conditions, collisional excitation of ground-state P(4S)
to P(2D), followed by reaction with H2O, is
a significant pathway for producing PO (in addition to the reaction
between P(4S) and OH). The model also demonstrates that
the PN fractional abundance in a steady (non-pulsating) outflow is
underpredicted by about 2 orders of magnitude. However, under shocked
conditions where sufficient thermal dissociation of N2
occurs at temperatures above 4000 K, the resulting N atoms convert a
substantial fraction of PO into PN.
Title: Non-minimally coupled Natural Inflation: Palatini and Metric
formalism with the recent BICEP/Keck
Authors: Bostan, Nilay
Bibcode: 2022arXiv220902434B
Altcode:
In this work, we show the effect of the non-minimal coupling
$\xi \phi^2 R$ on the inflationary parameters by considering the
single-field inflation and present the inflationary predictions
of the appealing potential for the particle physics viewpoint:
Natural Inflation, an axion-like inflaton which has a cosine-type
periodic potential and the inflaton naturally emerges as a
pseudo-Nambu-Goldstone boson with a spontaneously broken global
symmetry. We present the inflationary predictions for this potential,
$n_s$, $r$, and $\alpha=\mathrm{d}n_s/\mathrm{d}\ln k$. In addition,
we assume standard thermal history after inflation, and using this,
for considered potential, we show compatible regions for the $n_s$,
$r$ within the recent BICEP/Keck results.
Title: Big Bang Nucleosynthesis constraints on $f(T,T_G)$ gravity
Authors: Asimakis, Petros; Saridakis, Emmanuel N.; Basilakos, Spyros;
Yesmakhanova, Kuralay
Bibcode: 2022arXiv220901595A
Altcode:
We confront $f(T,T_G)$ gravity, with Big Bang Nucleosynthesis (BBN)
requirements. The former is obtained using both the torsion scalar,
as well as the teleparallel equivalent of the Gauss-Bonnet term, in
the Lagrangian, resulting to modified Friedmann equations in which the
extra torsional terms constitute an effective dark energy sector. We
calculate the deviations of the freeze-out temperature $T_f$, caused by
the extra torsion terms in comparison to $\Lambda$CDM paradigm. Then we
impose five specific $f(T,T_G)$ models and we extract the constraints
on the model parameters in order for the ratio $|\Delta T_f/ T_f|$
to satisfy the observational BBN bound. As we find, in most of the
models the involved parameters are bounded in a narrow window around
their General Relativity values as expected, as in the power-law model
where the exponent $n$ needs to be $n\lesssim 0.5$. Nevertheless the
logarithmic model can easily satisfy the BBN constraints for large
regions of the model parameters. This feature should be taken into
account in future model building.
Title: Is Mk 34 the most massive binary star system? A dynamic
modeling effort afforded by Chandra
Authors: Russell, Christopher
Bibcode: 2022cxo..prop.6413R
Altcode:
Mk 34 is a WNh+WNh system that is potentially the most massive binary
known. Chandra has spent 2 Ms observing the system throughout its
orbital phase, which shows phase-varying X-ray emission consistent
with other long-period binaries. Unknown about the system is its
inclination, which thus prevents a definitive mass measurement from
being made. However, the phase-dependent absorption of the thermal
X-ray emission is subject to the system inclination, thereby making an
independent measurement of the system inclination possible. We aim for a
series of hydrodynamic simulations and radiative transfer calculations
that leverage the Chandra observations to determine the inclination
of the system, thereby determining the fundamental parameter of the
masses in Mk 34.
Title: X-ray and radio observations of a kilonova identified in a
wide field survey
Authors: Levan, Andrew
Bibcode: 2022cxo..prop.6322L
Altcode:
Kilonovae (KN) are transients created in the mergers of compact
objects, with the best example the counterpart of the neutron star
merger GW170817. While the upcoming O4 gravitational wave run may find
more events, an alternative is that they can be found in the many high
cadence wide-field optical/IR surveys. Here we request observations
of one such event. These observations will search for non-thermal
emission, ascertaining if all mergers create relativistic ejecta and
gamma-ray bursts to a suitably oriented observer. Further, our data
will provide a route of measuring the jet properties, searching for
the KN outflow interacting with the ISM, and comparing optical KN and
X-ray properties. This can inform both heavy element nucleosynthesis
and future KN searches in GW error boxes.
Title: CaSSIS-based stereo products for Mars after three years
in orbit
Authors: Re, Cristina; Fennema, Audrie; Simioni, Emanuele; Sutton,
Sarah; Mège, Daniel; Gwinner, Klaus; Józefowicz, Mateusz; Munaretto,
Giovanni; Pajola, Maurizio; Petrella, Amedeo; Pommerol, Antoine;
Cremonese, Gabriele; Thomas, Nicolas
Bibcode: 2022P&SS..21905515R
Altcode:
The Colour and Stereo Surface Imaging System (CaSSIS) on board the
ExoMars Trace Gas Orbiter (TGO), operating in push-frame mode, provides
multiband images at four different wavelengths thanks to a Filter Strip
Assembly with a panchromatic filter and three broadband filters within
the visible and near infrared range. The camera acquires stereo pairs
fundamental for the initialization of the photogrammetric process
to perform three-dimensional reconstruction of the Martian surface
at the best resolution of 4.6 m per pixel for regions up to ∼400
km2 in one imaging sequence. The 3D points derived
from the stereo processing are used to generate Digital Terrain Models
(DTMs) with height accuracy on the order of one image pixel on ground
allowing high-resolution morphometric studies and in general improving
the understanding of the geology and geomorphology of the surface of
Mars. This work provides a review of the CaSSIS stereo products
supported by a description of the applied methods and examines some
specific approaches directed to science analysis. Furthermore, our
development of methods is herein focused on the proof of concept and
the performance of our dedicated pipeline. The DTM generation procedure
has been implemented in a stereo photogrammetric pipeline by the team
of the National Institute for Astrophysics-Astronomical Observatory
of Padova (INAF-OAPd). The workflow is based on area-based image
matching integrated in a multi-resolution approach where the quality
of the image matching largely determines the quality of the output
DTM. For this reason, the influence of the parameters involved in the
matching process (i.e. number of tie-points, template sizes and shape
models in matching) has been studied. CaSSIS stereo products
have been generated for approximately 0.1% of the surface of Mars
and 16.3% of the total stereo images acquired so far. In this work,
some scientifically interesting targets have been considered in the
investigation to provide an overview of the quality of the stereo
results. The experimental studies related to stereo analysis
frequently led to comparison tests since they represent the best
approach for contributing to the methodological consolidation of
the photogrammetric data processing. The quality assessment based
on comparison with reference terrain data is very promising also in
considering areas with different surface type and morphologies.
Title: Orbital parameters and activity of ZZ Tau - a low-mass young
binary with circumbinary disc
Authors: Belinski, A.; Burlak, M.; Dodin, A.; Emelyanov, N.;
Ikonnikova, N.; Lamzin, S.; Safonov, B.; Tatarnikov, A.
Bibcode: 2022MNRAS.515..796B
Altcode: 2022MNRAS.tmp.1732B; 2022arXiv220614154B
We present the results of our new observations of the young binary ZZ
Tau with a circumbinary disc. The system was found to consist of two
coeval (age < 2 Myr) classical T Tauri stars with the total mass 0.86
± 0.09 M⊙, orbital period 46.8 ± 0.8 yr, semimajor axis
88.2 ± 2.1 mas, eccentricity 0.58 ± 0.02, and the orbital inclination
123${_{.}^{\circ}}$8 ± 1${_{.}^{\circ}}$0. The accretion rate of ZZ
Tau A and ZZ Tau B is approximately 7 × 10-10 and 2 ×
10-10 M⊙ yr-1, respectively. No
correlation was found between the long-term photometric variability
of ZZ Tau and orbital position of its components. The periodic light
variations with P = 4.171 ± 0.002 d were observed in the BVRI bands
presumably connected with an accretion (hot) spot on the surface of
the primary (ZZ Tau A). At the same time, no periodicity was observed
in the U band nor in the emission line profile variations probably,
due to the significant contribution of ZZ Tau B's emission, which
dominates shortward of λ ≍ 0.4 $\mu$m. We argue that the extinction
in the direction to the primary is noticeably larger than that to
the secondary. It appeared that the rotation axis of the primary is
inclined to the line of sight by ≍31° ± 4°. We also concluded
that ZZ Tau is the source of a CO molecular outflow; however, ZZ Tau
IRS rather than ZZ Tau is the source of the Herbig-Haro object HH393.
Title: Transit least-squares survey. IV. Earth-like transiting
planets expected from the PLATO mission
Authors: Heller, René; Harre, Jan-Vincent; Samadi, Réza
Bibcode: 2022A&A...665A..11H
Altcode: 2022arXiv220602071H
In its long-duration observation phase, the PLATO satellite (scheduled
for launch in 2026) will observe two independent, non-overlapping
fields, nominally one in the northern hemisphere and one in the
southern hemisphere, for a total of four years. The exact duration
of each pointing will be determined two years before launch. Previous
estimates of PLATO's yield of Earth-sized planets in the habitable zones
(HZs) around solar-type stars ranged between 6 and 280. We use the
PLATO Solar-like Light curve Simulator (PSLS) to simulate light curves
with transiting planets around bright (mV ≤ 11) Sun-like
stars at a cadence of 25 s, roughly representative of the >15 000
targets in PLATO's high-priority P1 sample (mostly F5-K7 dwarfs and
subdwarfs). Our study includes light curves generated from synchronous
observations of 6, 12, 18, and 24 of PLATO's 12 cm aperture cameras
over both 2 and 3yr of continuous observations. Automated detrending
is done with the Wotan software, and post-detrending transit detection
is performed with the transit least-squares (TLS) algorithm. Light
curves combined from 24 cameras yield true positive rates (TPRs) near
unity for planets ≥1.2 R⊕ with two transits. If a third
transit is in the light curve, planets as small as 1 R⊕
are recovered with TPR ~ 100%. We scale the TPRs with the expected
number of stars in the P1 sample and with modern estimates of the
exoplanet occurrence rates and predict the detection of planets with
0.5 R⊕ ≤ Rp ≤ 1.5 R⊕ in the HZs
around F5-K7 dwarf stars. For the long-duration observation phase (2yr
+ 2yr) strategy we predict 11-34 detections, and for the (3 yr + 1 yr)
strategy we predict 8-25 discoveries. These estimates neglect exoplanets
with monotransits, serendipitous detections in stellar samples P2-P5,
a dedicated removal of systematic effects, and a possible bias of
the P1 sample toward brighter stars and high camera coverage due to
noise requirements. As an opposite effect, Earth-sized planets might
typically exhibit transits around P1 sample stars shallower than we
have assumed since the P1 sample will be skewed toward spectral types
earlier than the Sun-like stars assumed in our simulations. Moreover,
our study of the effects of stellar variability on shallow transits
of Earth-like planets illustrates that our estimates of PLATO's planet
yield, which we derive using a photometrically quiet star similar to the
Sun, must be seen as upper limits. In conclusion, PLATO's detection of
about a dozen Earth-sized planets in the HZs around solar-type stars
will mean a major contribution to this as yet poorly sampled part of
the exoplanet parameter space with Earth-like planets.
Title: Anisotropic Maxwell ultracompact star in modified gravity
Authors: Azmat, Hina; Zubair, M.
Bibcode: 2022PDU....3701049A
Altcode:
In this article, we have developed an analytical version of
charged gravastar model with non-uniform anisotropic feature in the
framework of f(R , T) theory. In order to introduce anisotropy in the
system, we considered gravitational decoupling by means of Minimal
Geometric Deformation (MGD). In the interior region, we obtained
a family of interior solutions which smoothly joins a conformally
deformed Reissner-Nordström exterior solution as well as standard
Reissner-Nordström solution at the stellar boundary R = a(τ) , being
τ as proper time. In both cases, we have different ranges of λ for
the smooth joint at the stellar boundary. The ultracompact interior
solution representing a family of charged stellar models satisfies some
of the fundamental properties of a stable configuration, which includes
regularity at the center, positive energy density with monotonically
decreasing behavior from the center outwards, and non-uniform pressure
with monotonic profile. All the energy bounds except the strong one are
satisfied inside the ultracompact interior for all the values of λ,
compatible with regularity condition.
Title: The Stability of Fiber Spectrographs in the Faint-source Regime
Authors: Bundy, Kevin; Law, David; MacDonald, Nick; Westfall, Kyle
B.; Sivarani, T.; Divakar, Devika; Bershady, Matthew; Gu, Meng; Yan,
Renbin; Roy, Namrata; Poppett, Claire; Drory, Niv
Bibcode: 2022AJ....164...94B
Altcode:
The use of optical fibers in astronomical instrumentation offers
high-multiplex and light-gathering flexibility. However, with most
previous fiber spectrographs optimized for large fields of view on
modest-aperture telescopes, the performance of fibers in the context
of faint targets on large telescopes remains largely untested. In
this paper, we evaluate aspects of fiber stability, especially as they
apply in the context of precision sky subtraction of faint sources at
modest spectral resolution (R ~ 3000). After introducing a framework
for describing potential systematic errors, we use publicly available
data from existing instruments, including instrumentation used by the
fourth-generation Sloan Digital Sky Survey's MaNGA project (MaNGA:
Mapping Nearby Galaxies at Apache Point Observatory) and the Very Large
Telescope's FLAMES: Fiber Large Array Multi Element Spectrograph. We
isolate sources of fiber systematics and estimate the observed amplitude
of persistent residuals as well as stochastic noise contributions
resulting from changing fiber stresses. Comparing these levels against
their impact on various sky subtraction schemes demonstrates that 0.1%
precision sky subtraction with fiber instruments is possible. As a
demonstration, we show that the MaNGA instrument can deliver 0.2%
residuals on bright near-IR sky lines with nonlocal sky subtraction,
if pseudo-slit limitations are addressed by allocating 50% of its
fibers to sky. We further highlight recently published deep exposures
that achieved a 1σ background level of 27.6 AB per square arc second,
equivalent to a precision of 0.2% of the sky background continuum.
Title: HRC checkout observation of ar Lac
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6438C
Altcode:
As part of continued activities to develop a new HRC operations concept,
we will observe ar Lac for 10ks, during a real time contact on August
25, 2022.
Title: Screening models and neutrino oscillations
Authors: Ahmadabadi, H. Yazdani; Mohseni Sadjadi, H.
Bibcode: 2022PDU....3701067A
Altcode:
In screening models with scalar-matter conformal coupling, we
study the flavor transition of neutrinos. We employ an analytical
method for studying the oscillation phase in a spherically symmetric
spacetime filled by a scalar field. Since the ambient matter density
determines the scalar field's behavior, an indirect environmental
effect contributes to the flavor conversion inside matter. We evaluate
the survival probabilities and show that the existence of the scalar
field affects the oscillations of neutrinos. We discuss the results
in the framework of screening mechanisms and the end, confront our
results with observational data.
Title: Awakening the beast: How are X-ray binary outbursts triggered?
Authors: Russell, David
Bibcode: 2022cxo..prop.6300R
Altcode:
Disk instability models predict that for X-ray binaries in quiescence,
there should be a brightening of the optical flux prior to an X-ray
outburst. With regular optical monitoring, it is possible to detect
the optical rise of new outbursts before they are detected by X-ray
all-sky monitors. Using a real-time data analysis pipeline, it is
possible to detect new outbursts in real-time from their optical flux
rise. Here, we propose to catch the early stages of a new outburst in
X-rays with Chandra, using an optical trigger. We will be able to test
the theory that the X-ray flux starts to rise after the optical flux,
a key prediction of the disk instability model.
Title: Probing the Role of X-ray Emission-Line Gas in Large Scale
Outflows in QSO2s
Authors: kraemer, steve
Bibcode: 2022cxo..prop.6370K
Altcode:
Feedback, in the form of AGN winds, has been proposed as the process
which sets the relationship between the masses of central black
holes and galactic bulges. Although optical studies have detected
NLR winds, consistent with feedback, the wind dynamics are not well
understood. A recent HST/ACS/STIS study of QSO2s revealed outflows
often terminating close to the AGN, but disturbed gas further than ~
kpc. One possibility is that the disturbed gas is entrained by an X-ray
wind. In this case, the distribution of the X-ray gas will correlate
with the extent of the NLR. To test this scenario, we request 90 ksec
Chandra ACIS images of the two QSO2s in the HST study with the largest
NLRs: FIRST J120041.4+314745, which shows large-scale disturbance,
and 2MASX J13003807+5454367, which does not.
Title: Following a black hole X-ray transient into quiescence
Authors: Plotkin, Richard
Bibcode: 2022cxo..prop.6301P
Altcode:
There is increasing evidence that the quiescent state of black hole
X-ray binaries (BHXBs) is different from the canonical hard state at
higher luminosities. Quiescent BHXB X-ray spectra are generally softer,
and not every system takes the same path through the radio:X-ray
luminosity plane during the decay into quiescence. We request TOO
observations for six coordinated X-ray and radio epochs to monitor a
BHXB during an outburst decay between 3e-7 and 1e-4 L_Edd, a crucial
luminosity range that represents the transition into quiescence for many
systems, but still has sparse data coverage. From these coordinated
observations we will place new constraints on jet-dominated and
radiatively inefficient accretion flow models.
Title: Parker Solar Probe Observations of Near-f Ce
Harmonic Emissions in the Near-Sun Solar Wind and Their Dependence
on the Magnetic Field Direction
Authors: Tigik, Sabrina F.; Vaivads, Andris; Malaspina, David M.;
Bale, Stuart D.
Bibcode: 2022ApJ...936....7T
Altcode: 2022arXiv220511356T
Wave emissions at frequencies near electron gyrofrequency harmonics are
observed at small heliocentric distances below about 40 R ⊙
and are known to occur in regions with quiescent magnetic fields. We
show the close connection of these waves to the large-scale properties
of the magnetic field. Near electron gyrofrequency harmonic emissions
occur only when the ambient magnetic field points to a narrow range
of directions bounded by polar and azimuthal angular ranges in the
RTN coordinate system of correspondingly 80° ≲ θ B
≲ 100° and 10° ≲ ϕ B ≲ 30°. We show that the
amplitudes of wave emissions are highest when both angles are close
to the center of their respective angular interval favorable to wave
emissions. The intensity of wave emissions correlates with the magnetic
field angular changes at both large and small timescales. Wave emissions
intervals correlate with intervals of decreases in the amplitudes of
broadband magnetic fluctuations at low frequencies of 10-100 Hz. We
discuss possible generation mechanisms of the waves.
Title: Unveiling the connection between AGN and massive gas reservoirs
in protoclusters
Authors: Vito, Fabio
Bibcode: 2022cxo..prop.6355V
Altcode:
Gas-rich galaxy protoclusters at z>2 are excellent laboratories
to study the effect of environment on SMBH growth, the physics of
inflowing gas, and the on-set of AGN feedback in overdense regions. We
propose to observe with ACIS-I (710 ks in total) three protoclusters
at z=2.3-3.2 that, due to their properties, will provide us with
the best insights into such scientific issues. These structures
were discovered as overdensities of sub-mm galaxies, Lya emitters,
and confirmed AGN around bright QSOs. Moreover, enormous Lya nebulae
(>200 kpc) have been detected in their central regions, pinpointing
the presence of massive gas inflows. We aim at obtaining a complete
census of AGN in the protoclusters, measuring the AGN contribution to
Lya nebula powering, and detecting extended X-ray emission.
Title: Prediction of thermal conductivity of diamond film by neural
network based on first principles
Authors: WANG, Biao; REN, Hai-Jie; CAO, Wen-Xin; HU, Yan-Wei; HE,
Yu-Rong; HAN, Jie-Cai; ZHU, Jia-Qi
Bibcode: 2022SSPMA..52C7306W
Altcode:
No abstract at ADS
Title: ANTARES/ZTF Transient Discovery Report for 2022-09-01
Authors: Aleo, P.; Lee, C.; Malanchev, K.; Matheson, T.; Narayan,
G.; Saha, A.; Scheidegger, C.; Scott, A.; Soraisam, M.; Stubens, C.;
Wolf, N.
Bibcode: 2022TNSTR2541....1A
Altcode:
No abstract at ADS
Title: Diffusional isotope fractionation of singly and doubly
substituted isotopologues of H2, N2 and
O2 during air-water gas transfer
Authors: Cao, Xiaobin
Bibcode: 2022GeCoA.332...78C
Altcode:
Air-water gas transfer largely influences the geochemical
and biogeochemical cycles of essential atmospheric components
(e.g. O2 and CO2), in which gas molecular
diffusion in water is recognized as the rate limiting step. Isotope
compositions in these gas molecules are useful tools to quantify
this mass transfer process, in which diffusional isotope fractionation
factors (i.e. αdiff) are the key intrinsic parameters. These
αdiffs are often determined by gas transfer experiments
with large uncertainties because the roughness of water surface can
affect the interpretation of experimental data. In this study,
molecular dynamic simulations were employed to investigate
directly the diffusional isotope fractionation for singly and
doubly substituted isotopologues of H2, N2,
and O2. The results show that diffusional isotope
fractionation factors are dependent on both the molecular mass
and moment of inertia, which is consistent with previous findings
for polyatomic molecules rather than for monoatomic ones. When
comparing with the kinetic isotope fractionation (i.e. αk)
determined by gas transfer experiments, I found that αk
is likely close to (αdiff)1/2 within errors
(i.e. αk = (αdiff)1/2), rather than
to (αdiff)2/3 that has often been employed
to calculate αdiff using αk in literature
(i.e. αk = (αdiff)2/3). If this
is the case, the results further indicate that the nuclear quantum
effect is not significant when αdiff is of interest. With
these findings, I determined the isotope fractionation relationship
θ for different O2 isotopologues to be 0.5100 ± 0.0002
and 1.9535 ± 0.0013 respectively for 17θdiff
(≡ln17αdiff/ln18αdiff)
and 36θdiff
(≡ln36αdiff/ln18αdiff)
as an example.
Title: The Impact of Inelastic Collisions with Hydrogen on NLTE
Copper Abundances in Metal-poor Stars
Authors: Xu, Xiaodong; Shi, Jianrong; Wang, Xiaofeng
Bibcode: 2022ApJ...936....4X
Altcode: 2022arXiv220811812X
We investigate the non-local thermodynamic equilibrium (non-LTE,
hereafter NLTE) analysis for Cu I lines with the updated model
atom that includes quantum-mechanical rate coefficients of Cu +
H and Cu+ + H- inelastic collisions from the
recent study of Belyaev et al. The influence of these data on NLTE
abundance determinations has been performed for six metal-poor stars
in a metallicity range of -2.59 dex ≤ [Fe/H] ≤ -0.95 dex. For Cu
I lines, the application of accurate atomic data leads to a decrease
in the departure from LTE and lower copper abundances compared to that
obtained with Drawin's theoretical approximation. To verify our adopted
copper atomic model, we also derived the LTE copper abundances of Cu II
lines for the sample stars. A consistent copper abundance from the Cu
I (NLTE) and Cu II (LTE) lines has been obtained, which indicates the
reliability of our copper atomic model. It is noted that the [Cu/Fe]
ratios increase with increasing metallicity when ~-2.0 dex <
[Fe/H] < ~-1.0 dex, favoring a secondary (metallicity-dependent)
copper production.
Title: Carrollian hydrodynamics from symmetries
Authors: Freidel, Laurent; Jai-akson, Puttarak
Bibcode: 2022arXiv220903328F
Altcode:
In this work, we revisit Carrollian hydrodynamics, a type of
non-Lorentzian hydrodynamics which has recently gained increasing
attentions due to its underlying connection with dynamics of spacetime
near null boundaries, and we aim at exploring symmetries associated with
conservation laws of Carrollian fluids. With an elaborate construction
of Carroll geometries, we generalize the Randers-Papapetrou metric by
incorporating the fluid velocity field and the sub-leading components
of the metric into our considerations and we argue that these two
additional fields are compulsory phase space variables in the derivation
of Carrollian hydrodynamics from symmetries. We then present a new
notion of symmetry, called the near-Carrollian diffeomorphism, and
demonstrate that this symmetry consistently yields a complete set of
Carrollian hydrodynamic equations. Furthermore, due to the presence of
the new phase space fields, our results thus generalize those already
presented in the previous literatures. Lastly, the Noether charges
associated with the near-Carrollian diffeomorphism and their time
evolutions are also discussed.
Title: Review of the results from the NUCLEON space mission
Authors: Podorozhny, D.; Grebenyuk, V.; Karmanov, D.; Kovalev, I.;
Kudryashov, I.; Kurganov, A.; Merkin, M.; Panov, A.; Tkachev, L.;
Turundaevskiy, A.; Vasiliev, O.; Voronin, A.
Bibcode: 2022AdSpR..70.1529P
Altcode:
The NUCLEON space observatory was developed to measure the spectra of
cosmic ray nuclei with individual charge resolution in the energy range
of several TeV to 1 PeV per particle. This work is a brief review of
the results from the NUCLEON observatory over three years of operation
in orbit. The spectra of the main primary abundant nuclei and secondary
nuclei of cosmic rays (CRs) are presented. Some new interesting features
of the CR spectra found in the NUCLEON data are discussed.
Title: Proper motion of central compact object in SNR RCW 103
Authors: Pazhayath Ravi, Aravind
Bibcode: 2022cxo..prop.6315P
Altcode:
We propose a ~65 ks ACIS-I observation in Cycle 24 to measure the
proper motion of the central compact object (CCO), 1E 161348-5055.1,
in RCW 103. A follow-up observation of the CCO in RCW 103 in Cycle 24
increases the time baseline from ~16 years (in the archival Chandra
data) to ~24 years, ensuring a compelling 5 - 7 sigma detection of the
proper motion. We will compare the measurement of the projected motion
of the CCO with the ejecta distribution in RCW 103 to provide crucial
observational constraints on the origin of the natal kick imparted
to the CCO at birth. Constraining the direction of the motion of the
CCO with the proposed new observation provides a unique opportunity
to reveal the true nature of RCW 103's explosion asymmetry.
Title: ZTF Transient Classification Report for 2022-09-01
Authors: Fremling, C.; Neill, D.; Sharma, Y.
Bibcode: 2022TNSCR2549....1F
Altcode:
No abstract at ADS
Title: Mining the GW+EM sky: a community program of CXO/VLA
observations of compact binary mergers
Authors: Xray, GW
Bibcode: 2022cxo..prop.6411X
Altcode:
Chandra was the first facility to detect X-ray light from a neutron
star (NS) merger. In this ToO program we propose to continue Chandra's
legacy in the nascent field of GW astronomy to identify, monitor,
and characterize X-ray emission from compact-object mergers detected
during LIGO/Virgo Observing Run 4 (O4). Our goals are three-fold: (i)
to characterize the diversity of emission from NS-NS mergers; (ii) to
enable breakthroughs, such as the discovery of emission from a neutron
star-black hole (NS-BH) merger and (iii) to model panchromatic jet
emission to constrain system parameters, particularly inclination. We
will support these Chandra observations via coordinated radio follow-up
with the VLA.
Title: Study on self heating effect of enhancement-mode
Ga2O3 vertical MOSFET
Authors: Guo, Liangliang; Luan, Suzhen; Zhang, Hongpeng; Qiao, Rundi;
Yu, Jiangang; Zhang, Yuming; Jia, Renxu
Bibcode: 2022SSPMA..52C7307G
Altcode:
No abstract at ADS
Title: Unveiling obscured quasars in dual systems with Subaru/HSC
and Chandra
Authors: Silverman, John
Bibcode: 2022cxo..prop.6359S
Altcode:
We propose to use Chandra to confirm the nature of luminous dual
quasar candidates having a projected separation <14 kpc, a rare
population. With the Hyper Suprime-Cam Subaru Strategic Program,
we have identified a population of luminous quasars as having two
distinct components. Optical spectroscopy has confirmed ten dual quasar
systems to date. There are additional cases for which the companion
may be an obscured quasar. The spatial resolution and sensitivity of
Chandra will allow us to confirm their nature as dual quasars. Here,
we aim to solidify the dual nature of one such case previously targeted
with Chandra and observe two new cases. With the full sample, we will
measure their frequency and evolution of such systems and compare to
cosmological simulations of galaxy mergers.
Title: Chaotic shadows of black holes: a short review
Authors: Wang, Mingzhi; Chen, Songbai; Jing, Jiliang
Bibcode: 2022CoTPh..74i7401W
Altcode: 2022arXiv220505855W
We give a brief review on the formation and the calculation of black
hole shadows. Firstly, we introduce the concept of a black hole shadow
and the current works on a variety of black hole shadows. Secondly,
we present the main methods of calculating photon sphere radius and
shadow radius, and then explain how the photon sphere affects the
boundary of black hole shadows. We review the analytical calculation
for black hole shadows which have analytic expressions for shadow
boundary due to the integrable photon motion system. And we introduce
the fundamental photon orbits which can explain the patterns of black
hole shadow shape. Finally, we review the numerical calculation of black
hole shadows with the backward ray-tracing method and introduce some
chaotic black hole shadows with self-similar fractal structures. Since
the gravitational waves from the merger of binary black holes have
been detected, we introduce a couple of shadows of binary black holes,
which all have eyebrowlike shadows around the main shadows with the
fractal structures. We discuss the invariant phase space structures
of the photon motion system in black hole space-time, and explain the
formation of black hole shadow is dominated by the invariant manifolds
of certain Lyapunov orbits near the fixed points.
Title: The impact of primordial black holes on the 21-cm angular-power
spectrum in the dark ages
Authors: Yang, Yupeng
Bibcode: 2022arXiv220900851Y
Altcode:
We investigate the impact of radiation from primordial black
holes (PBHs), in the mass range of $10^{15} \lesssim M_{\rm PBH}
\lesssim 10^{17}~\rm g$ and $10^{2} \lesssim M_{\rm PBH} \lesssim
10^{4}~M_{\odot}$, on the 21-cm angular-power spectrum in the dark
ages. PBHs in the former mass range effect the 21-cm angular-power
spectrum through the evaporation known as Hawking radiation, while the
radiation from the accretion process in the latter mass range. In the
dark ages, radiation from PBHs can increase the ionization fraction
and temperature of the intergalactic medium, change the global
21-cm differential brightness temperature and then effect the 21-cm
angular-power spectrum. Taking into account the effects of PBHs, we find
that in the dark ages, $30 \lesssim z \lesssim 100$, the amplitude of
the 21-cm angular-power spectrum is decreased depending on the mass and
mass fraction of PBHs. We also investigate the potential constraints
on the mass fraction of PBHs in the form of dark matter for the future
radio telescope in lunar obit or on the farside surface of the Moon.
Title: Hard X-Ray Nebulae in Star-Forming Galaxies
Authors: Yukita, Mihoko
Bibcode: 2022cxo..prop.6419Y
Altcode:
Superheated gas is thought to drive galactic outflows from regions of
intense star formation, and this gas has been detected in the nuclei
of several starburst galaxies. However, a major unsolved problem is
how (or whether) this gas connects to the kpc-scale winds seen from
radio through the X-rays. Recently, diffuse, hard X-ray, kpc-scale
nebulae have been reported in several galaxies, and they may provide
the missing link between the nucleus and the larger wind. We propose
an archival survey to quantify the frequency and properties of diffuse,
hard emission in star-forming galaxies, search for superheated nuclear
gas via Fe XXV emission, and construct thermodynamic maps of the soft
X-ray nebulae to connect them to the harder emission.
Title: Glueing CSC to Gaia to probe stellar activity evolution
Authors: Kashyap, Vinay
Bibcode: 2022cxo..prop.6414K
Altcode:
X-ray stellar surveys show there are problems in our understanding of
the evolution of stellar magnetic activity and star formation history
in our neighbourhood. Matching sources from the Chandra Source Catalog
(CSC) with Gaia will provide a major improvement in our understanding
by allowing comparisons with predictions from state-of-the-art models
of stellar activity. We will build the first detailed picture of the
evolution of magnetic dynamos and coronal heating for stars with ages
1-10 Gyr, probe the disk star formation history, and test conclusions of
population surveys that find an excess of young yellow stars. We will
use ML methods to remove ambiguity in multiple matches. Our work will
add value to the CSC by building one of the cleanest stellar matched
samples possible.
Title: Soil potassium isotope composition during four million years
of ecosystem development in Hawai'i
Authors: Li, Wenshuai; Liu, Xiao-Ming; Wang, Kun; Takahashi, Yoshio;
Hu, Yongfeng; Chadwick, Oliver A.
Bibcode: 2022GeCoA.332...57L
Altcode:
We combine spectroscopic and geochemical approaches to interpret
the fate of potassium (K) during forest soil development along a
4-million-year chronosequence sampled from relatively undisturbed
rainforests in Hawai'i. Potassium derived from weathering of lava is
dominant in the youngest site (0.3 ky), but its contribution to the
soil K budget declines as weathering progresses. Sites older than 0.3
ky are characterized by substantial K depletion (τK,Nb
∼-1), with soil isotopic composition (41K/39K,
δ41K) varying from -1.91 ± 0.08‰ to -0.09 ± 0.08‰,
relative to the homogeneous basaltic substrate (-0.48‰). Exchangeable
and interlayered K show δ41K values ranging from -1.32
± 0.06‰ to 0.06 ± 0.08‰, higher than their corresponding
bulk δ41K values. The δ41K patterns of
soils and exchangeable components are vertically similar, implying
similar environmental controls. The variability in K phase and
isotope composition reflects the accumulative effect of different
processes. Chemical weathering and plant cycling retain isotopically
light K in soils, in particular for 20-150 ky sites. In contrast,
atmospheric inputs of marine aerosols (0.14‰) and mineral aerosols
(-0.44‰) add heavier K (than native basalts) and crust-like K (similar
to basaltic δ41K) in soils, respectively. In sites older
than 150 ky, nearly complete depletion of basaltic K and reduced plant
K imprints result in the dominance of atmospheric inputs in soils. In
sum, this study emphasizes the sensitivity of δ41K to
terrestrial biotic and abiotic K cycles.
Title: Mapping the aliphatic hydrocarbon content of interstellar
dust in the Galactic plane
Authors: Günay, B.; Burton, M. G.; Afşar, M.; Schmidt, T. W.
Bibcode: 2022MNRAS.515.4201G
Altcode: 2022arXiv220801058G; 2022MNRAS.tmp.1531G
We implement a new observational method for mapping the aliphatic
hydrocarbon content in the solid phase in our Galaxy, based on
spectrophotometric imaging of the 3.4 $\mu$m absorption feature from
interstellar dust. We previously demonstrated this method in a field
including the Galactic Centre cluster. We applied the method to a new
field in the Galactic Centre where the 3.4 $\mu$m absorption feature
has not been previously measured and we extended the measurements to a
field in the Galactic plane to sample the diffuse local interstellar
medium, where the 3.4 $\mu$m absorption feature has been previously
measured. We have analysed 3.4 $\mu$m optical depth and aliphatic
hydrocarbon column density maps for these fields. Optical depths
are found to be reasonably uniform in each field, without large
source-to-source variations. There is, however, a weak trend towards
increasing optical depth in a direction towards b = 0° in the Galactic
Centre. The mean value of column densities and abundances for aliphatic
hydrocarbon were found to be about several $\rm \times 10^{18} \,
cm^{-2}$ and several tens × 10-6, respectively for the new
sightlines in the Galactic plane. We conclude that at least 10-20 per
cent of the carbon in the Galactic plane lies in aliphatic form.
Title: Velocity-based detumbling strategy for a post-capture tethered
net system
Authors: Shan, Minghe; Shi, Lingling
Bibcode: 2022AdSpR..70.1336S
Altcode:
Tether-net is known as a popular method to actively remove space
debris. After successfully capturing a space debris object by a net,
a tethered system consisting of a chaser satellite, a main tether and
a target is formed. Since the most urgent and important task after
capture is to avoid collision between the chaser and the tumbling
target, detumbling of the target via the force by the main tether
has to be performed. In this paper, we propose a novel and simple
detumbling strategy to effectively stabilize the tethered system by
controlling the motion of the chaser. Comparing to a previously proposed
tension-based detumbling strategy, this newly proposed velocity-based
method is simpler and more practical. Moreover, the fuel consumption
of the proposed method is only 1% that of the tension-based method
for investigated scenarios. With the proposed detumbling strategy,
we not only analyze the influence of the system configuration on the
detumbling effectiveness, but also analyze the detumbling capability
of the method, concluding that the velocity-based detumbling strategy
is able to detumble a spinning target up to 1.5 rad/s under a specific
configuration. In addition, the proposed method is found to be suitable
for both light and massive target detumbling.
Title: Titanite links rare-element (meta-)pegmatite mineralization
to Caledonian metamorphism
Authors: Zhou, Haoyang; Müller, Axel; Augland, Lars Eivind;
Kristoffersen, Magnus; Erambert, Muriel
Bibcode: 2022GeCoA.332..285Z
Altcode:
The metamorphic reworking of mineralized pegmatites during orogenesis
remains unclear, making the genesis and the tectonomagmatic significance
of pegmatite mineralization obscure. This study demonstrates the
multiple utilities of titanite geochemistry in establishing the
Caledonian metamorphic evolution of the world's largest intra-plutonic
Nb-Y-F pegmatites in the Paleoproterozoic host rocks in Tysfjord,
Northern Norway. A combination of titanite-specific barometry,
Zr-in-titanite thermobarometry, and titanite U-Pb geochronology yields
peak metamorphism of ∼12 kbar and 730-750 °C at ∼410 Ma for the
host rocks and the largest metamorphosed Paleoproterozoic pegmatite
(meta-pegmatite) in the region. In relation to published U-Pb
ages of 410-400 Ma for other regional meta-pegmatites, interpreted
as Caledonian overprinting here, we argue that the Paleoproterozoic
pegmatite protoliths have undergone metamorphism analogous to the host
rocks, which was caused by allochthonous nappe stacking late in the
Caledonian collisional orogeny (∼440-400 Ma). Published formation
ages of ∼400-380 Ma for the regional undeformed pegmatites are 10-30
Ma younger than the peak metamorphism, supporting an anatectic link to
the Caledonian post-collisional extension. The Caledonian orogeny led
to strong shearing of preexisting pegmatite bodies and resetting of
trace elements and U-Pb isotopic systems of the constituent minerals
via mineral re-crystallization, inheritance of Pb isotopic components,
and element diffusion. This cautions against the interpretation
of meta-pegmatite-derived ages and geochemical information in
tectonomagmatic terranes without detailed textural investigation.
Title: The soft X-ray background with Suzaku: I. Milky Way halo
Authors: Ueda, Masaki; Sugiyama, Hayato; Kobayashi, Shogo B.;
Fukushima, Kotaro; Yamasaki, Noriko Y.; Sato, Kosuke; Matsushita, Kyoko
Bibcode: 2022arXiv220901698U
Altcode:
We present measurements of the soft X-ray background emission
for 130 Suzaku observations at $75^\circ<l < 285^\circ$ and
$|b|>15^\circ$ obtained from 2005 to 2015, covering nearly one
solar cycle. In addition to the standard soft X-ray background model
consisting of the local hot bubble and the Milky Way Halo (MWH),
we include a hot collisional-ionization-equilibrium component
with a temperature of $\sim 0.8$ keV to reproduce spectra of a
significant fraction of the lines of sight. Then, the scatter in
the relation between the emission measure vs. temperature of the
MWH component is reduced. Here, we exclude time ranges with high
count rates to minimize the effect of the solar wind charge exchange
(SWCX). However, the spectra of almost the same lines of sight are
inconsistent. The heliospheric SWCX emissions likely contaminate
and gives a bias in measurements of temperature and the emission
measure of the MWH. Excluding the data around the solar maximum and
using the data taken before the end of 2009, at $|b|>35^\circ$
and $105^\circ<l<255^\circ$, the temperature (0.22 keV)
and emission measure ($2\times 10^{-3}~\rm{cm^{-6}pc}$) of the MWH
are fairly uniform. The increase of the emission measure toward the
lower Galactic latitude at $|b|<35^\circ$ indicates a presence of
a disk-like morphology component. A composite model which consists
of disk-like and spherical-morphology components also reproduces
the observed emission measure distribution of MWH. In this case,
the hydrostatic mass at a few tens of kpc from the Galactic center
agrees with the gravitational mass of the Milky Way. The plasma with
the virial temperature likely fills the Milky Way halo in nearly
hydrostatic equilibrium. Assuming the gas metallicity of 0.3 solar,
the upper limit of the gas mass of the spherical component out to 250
kpc, or the virial radius, is $\sim$ a few $\times 10^{10}~ M_\odot$.
Title: Observational signatures of black hole accretion: rotating
versus spherical flows with tilted magnetic fields
Authors: Jia, He; White, Christopher J.; Quataert, Eliot; Ressler,
Sean M.
Bibcode: 2022MNRAS.515.1392J
Altcode: 2022arXiv220108431J; 2022MNRAS.tmp.1526J
We study the observational signatures of magnetically arrested black
hole accretion with non-rotating inflow on to a rotating black hole;
we consider a range of angles between the black hole spin and the
initial magnetic field orientation. We compare the results of our
general relativistic magneto-hydrodynamic simulations to more commonly
used rotating initial conditions and to the Event Horizon Telescope
(EHT) observations of M87. We find that the mm intensity images,
polarization images, and synchrotron emission spectra are very
similar among the different simulations when post-processed with the
same electron temperature model; observational differences due to
different electron temperature models are significantly larger than
those due to the different realizations of magnetically arrested
accretion. The orientation of the mm synchrotron polarization is
particularly insensitive to the initial magnetic field orientation,
the electron temperature model, and the rotation of the inflowing
plasma. The largest difference among the simulations with different
initial rotation and magnetic tilt is in the strength and stability of
the jet; spherical inflow leads to kink-unstable jets. We discuss the
implications of our results for current and future EHT observations
and for theoretical models of event-horizon-scale black hole accretion.
Title: Molybdenum isotopic constraint from Java on slab inputs to
subduction zone magmatism
Authors: Yu, Yang; Huang, Xiao-Long; Chung, Sun-Lin; Li, Jie; Lai,
Yu-Ming; Setiawan, Iwan; Sun, Min
Bibcode: 2022GeCoA.332....1Y
Altcode:
Molybdenum isotope is a diagnostic tracer for crustal and mantle
components in arc magmatism. However, the mechanism of Mo isotopic
variation in arc magmas is still debated, e.g., input of different
subduction components into the mantle wedge versus isotopic
fractionation during dehydration of subducted slab. Here we present
whole-rock Mo-Sr-Nd-Hf-Pb isotopic data for the Continental Arc Basalt
(CAB) and Back Arc Basalt (BAB) from Java, Indonesia, to investigate
the role of slab inputs in Mo isotopic variation of the Sunda arc
magmatism. The CAB samples have variable K2O contents
(0.44-2.49 wt%) and are mainly classified as calc-alkaline series,
while the BAB samples are shoshonitic with markedly high K2O
contents (2.12-6.90 wt%) relative to the CABs. The Java CABs and BABs
have similar Mo isotopic compositions (δ98/95Mo = -0.65
to -0.07‰ and -0.66 to -0.07‰, respectively, relative to NIST
SRM3134), suggesting that such a significant Mo isotopic variation
should not be caused solely by the isotopic fractionation during the
subduction. Instead, δ98/95Mo values of the Java basalts
positively correlate with Pb isotopic ratios. This implies that the
Mo isotopic variations in the Java arc rocks should result from the
metasomatism in the mantle wedge by hybrid agents, including varying
proportions of melts from subducted sediments (with heavy Mo isotope)
and melts from the subducted altered upper oceanic crust (SAOC) (with
light Mo isotope). The light Mo isotope of the Java arc rocks, compared
with the Mariana arc basalts, suggests that melts from the SAOC have
much lighter Mo isotopic compositions than the components from the lower
oceanic crust. Thus, Mo isotope has great potential to distinguish the
components from the subducted upper and lower oceanic crust. The Java
CABs show along-arc variations in Mo-Sr-Nd-Hf-Pb isotopes, which is
related closely with the thermal status of the subducted slab. Upwelling
of the asthenosphere due to the slab tearing beneath the Java arc
might have enhanced the partial melting of subducted sediments nearby
the slab window. The complicated subduction system in the Sunda arc
has strongly controlled the geochemical composition of arc magmas,
which changes with input of different subduction components into the
mantle wedge along arc.
Title: The dynamic formation process of the CB chondrite Gujba
Authors: Koefoed, Piers; Pravdivtseva, Olga; Ogliore, Ryan; Jiang,
Yun; Lodders, Katharina; Neuman, Mason; Wang, Kun
Bibcode: 2022GeCoA.332...33K
Altcode:
The many unique characteristics of CB chondrites have resulted in the
impact hypothesis becoming the favoured model for their formation. Here,
we further investigate the formation mechanisms of CB chondrites by
analysing the elemental and K isotope compositions of chondrules and
bulk fractions from the CBa chondrite Gujba. Similar to
previous work, the refractory element ratios in the Gujba chondrules
show evidence of a differentiated precursor, with the Nb/Ta, Zr/Hf,
Sc/Th and Zr/Th ratios showing fractionation relative to other
chondrites. In addition, the bulk fractions, and to a lesser extent
the chondrules with attached matrix and metals, display significantly
more refractory element fractionation and a large enrichment in
light REEs. Based on EDS elemental mapping and comparisons with
previous studies, the most likely source of this highly fractionated
material appears to be the small amount of heterogeneously distributed
interstitial fine-grained material within Gujba. These large refractory
element fractionations (i.e., Nb/Ta, Zr/Hf, Sc/Th Zr/Th, and LREE/HREE)
are best explained by a significant partial melting process such as
crustal formation. Nevertheless, the mechanism of patrial melting
cannot be conclusively determined with the data available here. The K
isotopic compositions of the Gujba chondrules analyzed here range from
-2.24‰ to -0.41‰ in δ41K, whereas the bulk analyses
show δ41K values of -0.81‰ to -0.72‰. This range of
chondrule K isotope compositions is significantly larger, and extends to
much lighter compositions, compared to all other chondrites measured so
far by bulk ICP-MS. In addition, the Gujba chondrules display a clear
negative correlation of K isotopic composition with K concentration,
with the chondrules showing the lightest K isotope compositions having
the highest K concentrations. This distinctive correlation indicates
that evaporation was likely the dominant process affecting the K
isotopic variation observed in the Gujba chondrules. Nevertheless,
the extremely light δ41K values seen in the most K-rich
chondrules (which are lighter than any other early solar system
material so far measured) indicate that incomplete condensation
likely took place before evaporation. As such, we propose a two-stage
model to explain the formation of chondrules in Gujba, with Stage 1
characterized by incomplete condensation of vaporized material with
an average isotopic fractionation factor (α) of 0.9984 (when using
the most K enriched chondrule to constrain the model), and Stage 2
representing partial evaporation in a vapor plume with an average
α range of 0.9976 to 0.9990. Using these α values we calculate an
approximate vapor saturation index value of 0.935 for condensation
and between 0.903 and 0.960 for evaporation. This formation process
requiring both condensation and evaporation for CB chondrules is
consistent with an impact generated vapor plume and further expands
our understanding of CB chondrite formation.
Title: Thermodynamics and phase transition of BTZ black hole in
a cavity
Authors: Huang, Yuchen; Tao, Jun
Bibcode: 2022NuPhB.98215881H
Altcode: 2021arXiv211213249H
In this paper, we study the thermodynamics and phase transition of a
BTZ black hole in a finite space region, namely a cavity. By imposing
a temperature-fixed boundary condition on the wall of the cavity and
evaluating the Euclidean action, we derive the thermodynamic quantities
and then construct the first law of thermodynamics for a static and
neutral BTZ black hole, a rotating BTZ black hole and a charged BTZ
black hole, respectively. We prove that heat capacities of these three
types of black holes are always non-negative. Considering a grand
canonical ensemble, we find that the non-extreme rotating black hole
and the charged black hole are locally thermodynamically stable by
calculating the Hessian matrix of their internal energy. At the phase
transition level, it shows that for the static and neutral BTZ black
hole, the phase transition only exists between thermal AdS3
spacetime and the black hole. The temperature where the phase transition
occurs is only determined by the cavity radius. For rotating and
charged cases, there may exist an extra second-order phase transition
between the black hole and the black hole-cavity merger state. The phase
structure of a BTZ black hole in a cavity shows strong dissimilarities
from that without the cavity.
Title: Thermodynamic modelling of perchlorate/chloride and
perchlorate/chlorate deliquescence at Mars-relevant temperatures
Authors: Chevrier, Vincent F.; Fitting, Alec; Elsenousy, Amira;
Rivera-Valentín, Edgard G.
Bibcode: 2022GeCoA.333...56C
Altcode:
Perchlorate (ClO4-) salts were discovered on Mars
and are known to absorb water vapor from the atmosphere and deliquesce
into the aqueous phase. Other species such as chlorides (Cl-)
and chlorates (ClO3-) were also identified;
these species can affect the deliquescence of perchlorates. Here we
generate phase diagrams of perchlorate/chloride and perchlorate/chlorate
binary mixtures for K, Na, Mg and Ca in the temperature range 223-273
K. Using a new approach based on thermodynamic modelling of evaporation,
we determined the deliquescence relative humidity (the minimum relative
humidity at which a salt converts into a liquid by absorbing atmospheric
water vapor) and the eutonic relative humidity (the minimum relative
humidity at which two salts are in equilibrium with liquid) for binary
salt mixtures. Our modelling results show that the deliquescence
relative humidity values of all salt mixtures is always lower than that
of each individual end-member salt at a fixed temperature, typically a
few percent lower. The closer the eutonic is to one of the end-member,
the smaller the decrease in relative humidity compared to the pure
pole. Thus, only eutonics which are far from both poles exhibit a
significant drop in relative humidity. Moreover, the eutonic relative
humidity always increases with decreasing temperature, which does
not favor liquids in the dry and cold Martian environment. Finally,
the increased stability of water ice at the lowest temperatures always
reduces or even eliminates the stability of liquids. Therefore, the
favorable temperature and relative humidity conditions under which
binary salt liquid mixtures exist are generally not significantly
improved compared to single salts.
Title: Dense mantle flows periodically spaced below ocean basins
Authors: Panet, Isabelle; Greff-Lefftz, Marianne; Romanowicz, Barbara
Bibcode: 2022E&PSL.59417745P
Altcode:
Understanding mantle flow is key to elucidate how deep Earth dynamics
relate to tectonics at the global scale. The convective mass transport
is reflected in lateral variations of the gravity field, seismic
velocities, as well as deformations of the Earth's surface. Yet,
upper to mid-mantle dynamics have been difficult to constrain at the
medium scales of thousands of km. Here, we analyze the second-order
horizontal derivatives of seafloor topography and of the gravity
potential over the Pacific and Northern Indian ocean basins, and provide
evidence for periodic undulations of 1600-2000 km wavelength in both
signals, elongated along the direction of absolute plate motion. We
investigate potential crustal and lithospheric sources and show that
at least part of this signal must originate below the lithosphere,
with alignments of sub-lithospheric upper mantle mass excess below
seafloor lows. Furthermore, we find that these alignments coincide
geographically over wide areas with similarly periodic slow seismic
velocity fingers located at upper mantle depths. These two fields
may thus record an intermediate scale of mantle convection below
ocean basins, which cannot be explained by purely thermal convection
and requires instead lateral variations in composition in the upper
mantle. Elucidating the nature of the detected mass excess sources
coincident with the slow seismic velocities calls for a joint dynamical
modeling of all observations in a thermo-chemical context.
Title: High-energy γ-ray detection of supernova remnants in the
Large Magellanic Cloud
Authors: Campana, R.; Massaro, E.; Bocchino, F.; Miceli, M.; Orlando,
S.; Tramacere, A.
Bibcode: 2022MNRAS.515.1676C
Altcode: 2022MNRAS.tmp.1798C; 2022arXiv220701272C
We present the results of a cluster search in the γ-ray sky images of
the Large Magellanic Cloud (LMC) region by means of the Minimum Spanning
Tree (MST) and DBSCAN algorithms, at energies higher than 6 and 10
GeV, using 12 yr of Fermi-LAT data. Several significant clusters were
found, the majority of which associated with previously known γ-ray
sources. We confirm our previous detection of the supernova remnants N
49B and N 63A and found new significant clusters associated with the
SNRs N 49, N 186D, and N 44. These sources are among the brightest
X-ray remnants in the LMC and corresponds to core-collapse supernovae
interacting with dense H II regions, indicating that a hadronic origin
of high-energy photons is the most likely process.
Title: Calcium diffusion in enstatite, with application to closure
temperature of the Ca-in-opx thermometer
Authors: Cherniak, D. J.; Liang, Y.
Bibcode: 2022GeCoA.332..124C
Altcode:
Chemical diffusion of Ca has been characterized in natural enstatite
under buffered conditions (IW, NNO) and in air. Experiments were
conducted using synthesized powder sources, with Ca diffusion profiles
measured with Rutherford Backscattering Spectrometry. A variety
of sources of diffusant were used to investigate the effects of
silica activity and Ca concentration on diffusion. Calcium diffusion
appears relatively insensitive to crystallographic orientation and
oxygen fugacity under the range of investigated conditions, and
also appears little influenced by differences in silica activity
and Ca concentration in the diffusant source. For Ca diffusion in
a natural enstatite, we obtain the following Arrhenius relation
for diffusion over the temperature range 750-1150 °C, D =
1.17 × 10-10exp(-240 ± 10 kJ mol-1/RT)
m2sec-1. Calcium diffusion is slower
than Mg, Cr and Fe in enstatite, but faster than larger divalent
cations Pb and Eu that also are likely to preferentially occupy the M2
site. Calcium diffusion is also faster than that for trivalent REE and
tetravalent Ti in enstatite. Calcium diffusivities in enstatite are
intermediate between Ca diffusivities in clinopyroxene and olivine,
with Ca diffusion in enstatite about 2 orders of magnitude faster
than Ca self-diffusion in diopside and 2 orders of magnitude slower
than Ca diffusion in olivine. Diffusion parameters obtained from
this study were used to develop a simple model for closure temperature
of the Ca-in-opx thermometer of Brey and Köhler (1990). By coupling
closure temperature and the Ca-in-opx thermometer, it is possible to
constrain cooling rates of peridotites and pyroxenites. Applications to
peridotites from the Lanzo Massif and the Oman ophiolite are presented.
Title: Investigating a predicted metallicity [Fe/H] variation in
the Type II Globular Cluster NGC 362
Authors: Vargas, C.; Villanova, S.; Geisler, D.; Muñoz, C.; Monaco,
L.; O'Connell, J.; Sarajedini, Ata
Bibcode: 2022MNRAS.515.1903V
Altcode: 2022MNRAS.tmp.1704V; 2022arXiv220705693V
NGC 362 is a non-common Type II Galactic globular cluster, showing
a complex pseudo two-colour diagram or 'chromosome map'. The clear
separation of its stellar populations in the colour-magnitude diagram
and the distribution of the giant stars in the chromosome map strongly
suggests that NGC 362 could host stars with both cluster-nominal, as
well as enhanced heavy-element abundances, and one of them could be
iron. However, despite previous spectroscopic observations of NGC 362,
no such iron variation has been detected. Our main goal is to confirm
or disprove this result by searching for any internal variation of
[Fe/H], which would give us insight into the formation and evolution
of this interesting globular cluster. In this paper, we present the
abundance analysis for a sample of 11 red giant branch members based
on high-resolution and high S/N spectra obtained with the MIKE echelle
spectrograph mounted at the Magellan-Clay telescope. HST and GAIA
photometry and astrometry has been used to determine atmospheric
parameters and membership. We obtained Teff, log(g),
and vt for our target stars and measured the mean iron
content of the sample and its dispersion with three different methods,
which lead to [Fe/H]1 = -1.10 ± 0.02, [Fe/H]2
= -1.09 ± 0.01, and [Fe/H]3 = -1.10 ± 0.01, while the
internal dispersion turned out to be $\sigma _{[\text{Fe/H}]_1}$ =
0.06 ± 0.01, $\sigma _{[\text{Fe/H}]_2}$ = 0.03 ± 0.01, and $\sigma
_{[\text{Fe/H}]_3}$ = 0.05 ± 0.01, respectively. The error analysis
gives an internal dispersion due to observational error of 0.05
dex. Comparing the observed dispersion with the internal errors,
we conclude that NGC 362 does not show any trace of an internal
iron spread.
Title: Adaptive finite-time control for six-degree-of-freedom
leader-following spacecraft formation using twistors
Authors: Zhang, Bo; Li, Fei
Bibcode: 2022AdSpR..70.1297Z
Altcode:
An adaptive finite-time attitude and position coupled tracking
controller for six-degree-of-freedom (6-DOF) leader-following spacecraft
formation is proposed in this paper. The relative motion of the
follower with respect to its desired pose is represented by twistors in
a unified way without state redundancy. A fast terminal sliding surface
is proposed for the twistor-based dynamic system to achieve finite-time
convergence. Then an adaptive finite-time controller is developed with
the unknown inertial parameters of the follower spacecraft and the upper
bounds of the disturbances estimated by elaborately designed adaptive
laws. The finite-time convergence of the closed-loop system is proven
via Lyapunov analysis. In addition, an simple but effective strategy is
proposed to eliminate the attitude unwinding phenomenon. The proposed
adaptive finite-time control scheme possesses faster convergence, higher
control accuracy, and more preferable control inputs. In addition,
the possible numerical difficulties caused by logarithmic function of
dual quaternions is avoided. Finally, simulation results demonstrate
the effectiveness of the proposed algorithm.
Title: Nickel isotopic composition of the upper continental crust
Authors: Wu, Guangliang; Zhu, Jian-Ming; Wang, Xiangli; Johnson,
Thomas M.; He, Yongsheng; Huang, Fang; Wang, Lian-Xun; Lai, Shao-Cong
Bibcode: 2022GeCoA.332..263W
Altcode:
Establishing the nickel (Ni) isotopic composition of the upper
continental crust (UCC) is crucial for using the Ni isotope system
to trace biogeochemical processes and understand crust-mantle
interactions. This study reports the Ni isotopic composition of
eighty-four well-characterized upper crustal samples, including
granites, granodiorites, tonalite-trondhjemite-granodiorite (TTG),
loess, river sediments and glacial diamictites, to constrain
the Ni isotopic composition of the UCC. Significant variations
in δ60Ni are revealed for I-type (0.02-0.26‰),
A-type (-0.05-0.08‰) and S-type (0.08-0.36‰) granites for the
first time. These Ni isotopic variations are attributed to magmatic
differentiation for I- and A- type granites and source heterogeneity for
S-type granites. The δ60Ni values of fine-grained clastic
sediments (including loess, river sediments and glacial diamictites)
range from -0.01‰ to 0.23‰. Such δ60Ni variations cannot
be explained by Ni isotopic fractionation during chemical weathering
because there are no clear correlations between δ60Ni and
Ni/Al2O3, or the chemical index of alteration
(CIA). Instead, the δ60Ni variations in fine-grained clastic
sediments are likely inherited from source rocks. The δ60Ni
values of our samples for 3.2-3.5 Ga TTGs (0.00-0.13‰), 2.4-2.5
Ga TTGs (0.04-0.13‰) and < 0.4 Ga granites (excluding S-type
granites) are statistically indistinguishable (P < 0.05, student's
t-test), implying limited variation of δ60Ni in the felsic
igneous UCC since 3.5 Ga. Similarly, the δ60Ni values of
glacial diamictites suggest insignificant temporal variation in the
weathered UCC since 2.4 Ga. The data gathered in this study combined
with literature data yields an arithmetic mean δ60Ni
value of 0.12 ± 0.15‰ (2SD) for the UCC (ranging from -0.07‰ to
0.36‰). And the weighted average δ60Ni is estimated to be
0.07 ± 0.10‰ (2SD) or 0.11 ± 0.09‰ (2SD) depending on the assumed
δ60Ni of the metamorphic rocks. Thus, a lithology-weighted
average δ60Ni needs to be further determined by future
studies when the δ60Ni values of metamorphosed sedimentary
rocks in the UCC are constrained.
Title: Using neutrino oscillations to measure H0
Authors: Khalifeh, Ali Rida; Jimenez, Raul
Bibcode: 2022PDU....3701063K
Altcode:
The tension between late and early universe probes of today's expansion
rate, the Hubble parameter H0, remains a challenge for the
standard model of cosmology ΛCDM. There are many theoretical proposals
to remove the tension, with work still needed on that front. However,
by looking at new probes of the H0 parameter one can get
new insights that might ease the tension. Here, we argue that neutrino
oscillations could be such a probe. We expand on previous work and
study the full three-flavor neutrino oscillations within the ΛCDM
paradigm. We show how the oscillation probabilities evolve differently
with redshift for different values of H0 and neutrino mass
hierarchies. We also point out how this affects neutrino fluxes which,
from their measurements at neutrino telescopes, would determine which
value of H0 is probed by this technique, thus establishing
the aforementioned aim.
Title: Explaining prolonged fluctuations in light curves of classical
novae via modelling
Authors: Hillman, Yael
Bibcode: 2022MNRAS.515.1404H
Altcode: 2022MNRAS.tmp.1636H; 2022arXiv220514708H
Fluctuations during a prolonged maximum have been observed in several
nova eruptions, although it is not clear, and cannot be deduced directly
from observations, whether the phenomenon is an actual physical reaction
to some mechanism originating in the erupting white dwarf, whether it
is occurring in the expanding ejected shell, or whether it is a form
of interaction with the red dwarf companion. A handful of erupting nova
models are investigated in this work, in order to assess the possibility
of this sort of feature being an actual part of the eruption itself. The
results explain that the mechanism that may produce these fluctuations
is the repeated approach and recession of the convective front from the
surface. The efficiency of this mechanism, being dependent on the mass
of the WD (white dwarf) envelope and the time-scale of the nova cycle,
favours low-mass WDs and long accretion phases.
Title: Scanning dual-microcomb spectroscopy
Authors: Wang, Yang; Wang, Zhichuang; Wang, Xinyu; Shao, Wen; Huang,
Long; Liang, Bo; Little, Brent E.; Chu, Sai T.; Zhao, Wei; Wang,
Weiqiang; Zhang, Wenfu
Bibcode: 2022SCPMA..6594211W
Altcode:
Dual-comb spectroscopy (DCS) is a powerful tool in molecular
spectroscopy benefiting from the advantages of high resolution and
short measurement time. The recently developed soliton microcomb (SMC)
can potentially transfer the dual-comb method to an on-chip platform. In
this paper, we demonstrate DCS using two frequency scanning SMCs, termed
scanning dual-microcomb spectroscopy (SDMCS). The two SMCs are generated
by an auxiliary-assisted thermal balance scheme, and the pump laser
frequency sweeps over one free spectral range of the microresonator
(∼49 GHz) using a feedback control system. The proposed SDMCS has
a spectral resolution of 12.5 MHz, which is determined by the minimum
sweeping step of the pump laser. Using this SDMCS system, we perform
three types of gas molecule absorption spectroscopy recognition and
gas concentration detection. This study paves the way for integrated
DCS with a high signal-to-noise ratio, high spectral resolution,
and fast acquisition rate.
Title: Slab-driven flow at the base of the mantle beneath the
northeastern Pacific Ocean
Authors: Wolf, Jonathan; Long, Maureen D.
Bibcode: 2022E&PSL.59417758W
Altcode:
Flow in the mantle's bottom boundary layer plays an important role in
shaping structures and processes in the deep mantle; however, knowledge
of lowermost mantle flow patterns remains elusive. In particular,
the influence of remnant slabs on lowermost mantle flow is poorly
known, although it is likely that slabs play an important role in
driving flow and thus in controlling key aspects of lowermost mantle
behavior. Measurements of seismic anisotropy can yield relatively
direct constraints on slab-induced lowermost mantle flow; however,
such observations are challenging to make. We take advantage of the
excellent raypath coverage beneath the northeastern Pacific Ocean
provided by the USArray deployment in North America to provide
detailed sampling of a region that has a long subduction history,
with remnant slabs likely impinging on the core-mantle boundary. We
present observations of coherent, strong shear wave splitting of SKKS
and Sdiff phases across USArray stations and show through
global wavefield modeling that the splitting is due to lowermost mantle
anisotropy. A stacking approach enables us to make robust estimates of
lowermost mantle splitting parameters, which we model by considering
realistic mineral physics scenarios. Under the assumption of simple
horizontal shear deformation, our observations are consistent with
generally north-south flow directions for either a post-perovskite or a
bridgmanite mineralogy; ferropericlase cannot explain observations. We
speculate that this flow is driven by subducting slab remnants impinging
on the core-mantle boundary.
Title: Low-pressure and low-temperature phase equilibria applied to
Pluto's lower atmosphere
Authors: Tan, Sugata P.
Bibcode: 2022MNRAS.515.1690T
Altcode: 2022MNRAS.tmp.1851T
While phase equilibria at conditions on Pluto's surface have been
studied, the fate of the equilibria in the lower atmosphere as the
altitude increases has not. In this study, the gravitational effect is
included in the thermodynamic modelling so that not only the deposition
point can be located, but also the vertical pressure and density
profiles below the deposition point can be determined, along with the
corresponding compositional profiles in the equilibrium phases. The
non-ideality of vapour-solid phase equilibria at low pressures and
temperatures is also discussed for Pluto's applications to allow for
more accurate calculations if a conventional method, such as modified
Raoult's law, is used.
Title: Orbital distances and options for small body satellites in
Non-Keplerian orbits dominated by solar radiation pressure
Authors: Damme, Friedrich; Oberst, Jürgen
Bibcode: 2022P&SS..21905518D
Altcode:
We offer a comprehensive description for the dynamics of a
spacecraft affected by solar radiation pressure (SRP) orbiting
a small body. Constrains are given for regions, in which stable
motion is possible. For short and long time scales two different
analytical frameworks are summarized and applied. (1) For time scales
well below one heliocentric revolution we examine the "static" case,
involving SRP fixed in both magnitude and direction. We demonstrate
a closed-form solution for quasi terminator orbits using parabolic
coordinates. (2) Next, we study the "dynamic" case where the asteroid
is in an eccentric orbit about the Sun, involving changing solar aspect
angle and distance. To solve this Augmented Hill Three-Body Problem
(AH3BP), SRP effects are averaged over the anomaly of the orbiter. From
this approximation we derive constrains for Sun-synchronous orbits in
size and eccentricity. The findings of the analysis (1) and (2) are
then applied to small- and medium-sized spacecraft orbiting specific
asteroids, comets, dwarf planets and (for comparison) planets. We
consider ranges of orbiter mass and surface area exposed to the
Sun, as well as small body parameters, including mass and orbit. We
show the resulting constrains on orbit size as well as parameters
of Sun-synchronous orbits and frozen orbits in tables. While
terminator orbits may only vary in size, quasi terminator orbits can
cover wide regions best described in the parabolic coordinates of case
(1). This region has four parameters for our orbit options. As
alternative application for orbit stability we calculate constraints
on orbit and particle sizes for dust particles. Numerical integration
is used to validate the resilience of these solutions to further
perturbation by third bodies or the small body's non-spherical shape.
Title: On the enigmatic mid-Proterozoic: Single-lid versus plate
tectonics
Authors: Roberts, Nick M. W.; Salminen, Johanna; Johansson, Åke;
Mitchell, Ross N.; Palin, Richard M.; Condie, Kent C.; Spencer,
Christopher J.
Bibcode: 2022E&PSL.59417749R
Altcode:
The mid-Proterozoic (ca. 1850-850 Ma) is a peculiar period of
Earth history in many respects: ophiolites and passive margins of
this age are rare, whereas anorthosite and A-type granite suites
are abundant; metamorphic rocks typically record high thermobaric
(temperature/pressure) ratios, whereas ultrahigh pressure (UHP) rocks
are rare; and the abundance of economic mineral deposits features
rare porphyry Cu-Au and abundant Ni-Cu and Fe-oxide Cu-Ag (IOCG)
deposit types. These collective observations have been used to propose
that a stagnant-lid, or single-lid, tectonic regime operated at this
time, between periods of plate tectonics in the Paleoproterozoic and
Neoproterozoic. In our reappraisal of the mid-Proterozoic geological
record, we not only assess the viability of the single-lid hypothesis
for each line of evidence, but also that of the plate tectonic
alternative. We find that evidence for the single-lid hypothesis is
equivocal in all cases, whereas for plate tectonics the evidence is
equivocal or supporting. We therefore find no reason to abandon a
plate tectonic model for the mid-Proterozoic time period. Instead,
we propose that the peculiarities of this enigmatic interval can be
reconciled through the combination of two processes working in tandem:
secular mantle cooling and the exceptionally long tenure and incomplete
breakup of Earth's first supercontinent, where both of these phenomena
had a dramatic effect on lithospheric behaviour and its resulting
imprint in the geological record.
Title: Anisotropic effect on barrow holographic dark energy
Authors: Sharma, Umesh Kumar; Varshney, Gunjan; Dubey, Vipin Chandra;
Kumar, Mukesh
Bibcode: 2022IJGMM..1950146S
Altcode:
In this paper, we investigate a non-interacting model considering
a spatially anisotropic and homogeneous Bianchi type-I Universe,
filled with Barrow holographic dark energy (BHDE) and pressureless
dark matter. We examine some important cosmological parameters for the
evolutionary report and to witness adequate nature in BHDE model as
including deceleration parameter, the jerk parameter, equation of state
parameter and density parameter. To study more briefly, we diagnose
statefinder parameters, ωD − ωD′ analysis and explain that the
model parameter significantly modifies the evolutionary trajectories
in these planes.
Title: Oxidative dissolution of orpiment and realgar induced by
dissolved and solid Mn(III) species
Authors: Wang, Xingxing; Wang, Jiajia; Lu, Xiaohan; Zhou, Ming; Wang,
Qihuang; Pan, Zezhen; Kumar, Naresh; Zhu, Mengqiang; Wang, Zimeng
Bibcode: 2022GeCoA.332..307W
Altcode:
A thorough understanding of the complex redox coupling among
manganese, arsenic, sulfur and oxygen in subsurface environments
is still obscured by their metastable intermediate valances and
speciation. Arsenic sulfide minerals may be disturbed by natural or
anthropogenic activities, and encounter oxidants such as oxygen and
reactive trivalent Mn species, and how these abiotic interactions
impact the mineral dissolution and transformation of arsenic and
sulfur species, remains unknown. In this study, we investigated the
effects of dissolved Mn(III) and manganite (γ-MnIIIOOH)
on the dissolution behaviors of orpiment (As2S3)
and realgar (AsS) under anoxic and oxic conditions. Complementary
control experiments were also performed with dissolved arsenite without
reduced sulfur. Oxygen, dissolved Mn(III) or manganite did not induce
the oxidation of dissolved arsenite within several weeks. Orpiment's
initial dissolution is a non-redox process releasing of arsenite and
sulfide, and the three above oxidants promoted the dissolution of
orpiment by rapid oxidation of dissolved sulfide. However, only when
both dissolved Mn(III) and dissolved oxygen were present, substantial
accumulation of arsenate and sulfate were observed. These results
suggested the critical role of sulfur species in abiotic arsenic
transformation and a synergetic effect of Mn and oxygen on sulfur
oxidation. In contrast to orpiment, the dissolution of realgar was a
redox reaction that involved the oxidation of As(II) to As(III) and the
direct releasing of sulfide, which could be promoted by both dissolved
oxygen and manganite. The effect of dissolved Mn(III) and oxygen on
the formation of arsenate and sulfate was also clearly observed during
the dissolution of realgar. Despite of the slow abiotic oxidation of
dissolved arsenite to arsenate in the presence dissolved Mn(III) and
oxygen, the coexistence of sulfide could enable rapid accumulation of
arsenate, accompanied by substantial transformation to sulfate. The
evidence of thioarsenic species in these experiments provided a
plausible explanation as an alternative pathway for the oxidation
of the two elements by dissolved Mn(III). These results provide new
insights for the Mn-As-S cycling in redox transition environments.
Title: Intracontinental and arc-related hydrothermal systems display
distinct δ202Hg and Δ199Hg features:
Implication for large-scale mercury recycling and isotopic
fractionation in different tectonic settings
Authors: Deng, Changzhou; Lehmann, Bernd; Xiao, Tingting; Tan, Qinping;
Chen, Di; Tian, Zhendong; Wang, Xueyun; Sun, Guangyi; Yin, Runsheng
Bibcode: 2022E&PSL.59317646D
Altcode:
Mercury isotopes display both mass-dependent and mass-independent
fractionation and allow the tracing of pathways and storage of
surface-derived Hg in the lithosphere. While the subduction-related
orogenic recycling of Hg from marine reservoirs into hydrothermal
systems in continental arc settings has been documented recently,
the source of Hg in intracontinental hydrothermal systems
remains unclear. We measured Hg isotopes in two intracontinental
anorogenic/postorogenic Late Mesozoic hydrothermal gold deposits in
the South China craton and the Central Asian orogenic belt of northern
China, respectively. The ore and sulfide samples from the studied
systems have positive δ202Hg (0.70 ± 0.39‰, 1SD, n =
49) and negative Δ199Hg values (-0.12 ± 0.05‰, 1SD, n =
49). These values are different from their country rocks and regional
geological environment (volcanic arc granites, marine sedimentary rocks)
which have positive Δ199Hg values, but similar to that of
their Precambrian supracrustal basement rocks of largely non-marine
continental materials. We conclude that Hg in the intracontinental
hydrothermal systems was leached from basement rocks by upper crustal
basinal fluid circulation driven by regional heat flow, likely due
to lithospheric thinning and upwelling of the asthenosphere in the
Late Mesozoic. The intracontinental hydrothermal systems and their
continental sources with positive δ202Hg and negative
Δ199Hg values are complementary to volcanic-arc and marine
sedimentary rocks with opposite δ202Hg - Δ199Hg
compositions. The distinct Hg isotopic features of hydrothermal
systems in different tectonic settings, in particular the indelible
Δ199Hg signature, allow the tracing of large-scale material
cycling in the Earth.
Title: Density wakes driving dynamical friction in cored potentials
Authors: Kaur, Karamveer; Stone, Nicholas C.
Bibcode: 2022MNRAS.515..407K
Altcode: 2022MNRAS.tmp.1689K; 2021arXiv211210801K
Dynamical friction is often modelled with reasonable accuracy by the
widely used Chandrasekhar formula. However, in some circumstances,
Chandrasekhar's local and uniform approximations can break down
severely. An astrophysically important example is the 'core stalling'
phenomenon seen in N-body simulations of massive perturber inspiralling
into the near-harmonic potential of a stellar system's constant-density
core (and possibly also in direct observations of dwarf galaxies with
globular clusters). In this paper, we use the linearized collisionless
Boltzmann equation to calculate the global response of a cored galaxy
to the presence of a massive perturber. We evaluate the density
deformation, or wake, due to the perturber and study its geometrical
structure to better understand the phenomenon of core stalling. We also
evaluate the dynamical friction torque acting on perturber from the
Lynden-Bell-Kalnajs (LBK) formula. In agreement with past work, we find
that the dynamical friction force arising from corotating resonances
is greatly weakened, relative to the Chandrasekhar formula, inside
a constant-density core. In contrast to past work, however, we find
that a population of previously neglected high-order and non-corotating
resonances sustain a minimum level of frictional torque at $\sim 10{{\
\rm per\ cent}}$ of the torque from Chandrasekhar formula. This suggests
that complete core stalling likely requires phenomena beyond the LBK
approach; we discuss several possible explanations. Additionally, to
study core stalling for multiple perturbers, we investigate approximate
secular dynamical interactions (akin to Lidov-Kozai dynamics) between
two perturbers orbiting a cored stellar system and derive a criterion
for instability arising due to their close encounters.
Title: A MeerKAT, e-MERLIN, H.E.S.S., and Swift search for persistent
and transient emission associated with three localized FRBs
Authors: Chibueze, J. O.; Caleb, M.; Spitler, L.; Ashkar, H.;
Schüssler, F.; Stappers, B. W.; Venter, C.; Heywood, I.; Richards,
A. M. S.; Williams, D. R. A.; Kramer, M.; Beswick, R.; Bezuidenhout,
M. C.; Breton, R. P.; Driessen, L. N.; Jankowski, F.; Keane, E. F.;
Malenta, M.; Mickaliger, M.; Morello, V.; Qiu, H.; Rajwade, K.;
Sanidas, S.; Surnis, M.; Scragg, T. W.; Walker, C. R. H.; Wrigley,
N.; Aharonian, H E S S Collaboration: F; Ait Benkhali, F.; Angüner,
E. O.; Backes, M.; Baghmanyan, V.; Barbosa Martins, V.; Batzofin, R.;
Becherini, Y.; Berge, D.; Böttcher, M.; Boisson, C.; Bolmont, J.;
de Bony de Lavergne, M.; Breuhaus, M.; Brose, R.; Brun, F.; Bulik,
T.; Cangemi, F.; Caroff, S.; Casanova, S.; Catalano, J.; Cerruti,
M.; Chand, T.; Chen, A.; Chibueze, O. U.; Cotter, G.; Cristofari,
P.; Damascene Mbarubucyeye, J.; Devin, J.; Djannati-Ataï, A.;
Dmytriiev, A.; Egberts, K.; Ernenwein, J. -P.; Fiasson, A.; Fichet de
Clairfontaine, G.; Fontaine, G.; Funk, S.; Gabici, S.; Ghafourizadeh,
S.; Giavitto, G.; Glawion, D.; Grondin, M. -H.; Hörbe, M.; Hoischen,
C.; Holch, T. L.; Huang, Zhiqiu; Jamrozy, M.; Jankowsky, F.; Joshi,
V.; Jung-Richardt, I.; Kasai, E.; Katarzyński, K.; Katz, U.; Khélifi,
B.; Kluźniak, W.; Komin, Nu; Kosack, K.; Kostunin, D.; Lemière, A.;
Lenain, J. -P.; Leuschner, F.; Lohse, T.; Luashvili, A.; Lypova, I.;
Mackey, J.; Malyshev, D.; Marandon, V.; Marchegiani, P.; Marcowith, A.;
Martí-Devesa, G.; Marx, R.; Mitchell, A.; Moderski, R.; Mohrmann, L.;
Moulin, E.; Muller, J.; Nakashima, K.; de Naurois, M.; Nayerhoda, A.;
Niemiec, J.; Priyana Noel, A.; O'Brien, P.; Ohm, S.; Olivera-Nieto,
L.; de Ona Wilhelmi, E.; Ostrowski, M.; Panny, S.; Parsons, R. D.;
Pita, S.; Poireau, V.; Prokhorov, D. A.; Prokoph, H.; Pühlhofer, G.;
Quirrenbach, A.; Reichherzer, P.; Reimer, A.; Reimer, O.; Rowell, G.;
Rudak, B.; Ruiz-Velasco, E.; Sahakian, V.; Sailer, S.; Salzmann, H.;
Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schutte, H. M.; Schwanke,
U.; Shapopi, J. N. S.; Specovius, A.; Spencer, S.; Steenkamp, R.;
Steinmassl, S.; Takahashi, T.; Tanaka, T.; Thorpe-Morgan, C.; Tsuji,
N.; van Eldik, C.; Veh, J.; Vink, J.; Wagner, S. J.; Wierzcholska, A.;
Wong, Yu Wun; Yusafzai, A.; Zacharias, M.; Zargaryan, D.; Zdziarski,
A. A.; Zech, A.; Zhu, S. J.; Zouari, S.; Żywucka, N.
Bibcode: 2022MNRAS.515.1365C
Altcode: 2022arXiv220100069C; 2022MNRAS.tmp.1614C
We report on a search for persistent radio emission from the one-off
fast radio burst (FRB) 20190714A, as well as from two repeating FRBs,
20190711A and 20171019A, using the MeerKAT radio telescope. For
FRB 20171019A, we also conducted simultaneous observations with the
High-Energy Stereoscopic System (H.E.S.S.) in very high-energy gamma
rays and searched for signals in the ultraviolet, optical, and X-ray
bands. For this FRB, we obtain a UV flux upper limit of $1.39 \times
10^{-16}~{\rm erg\, cm^{-2}\, s^{-1}}$Å-1, X-ray limit
of $\sim 6.6 \times 10^{-14}~{\rm erg\, cm^{-2}\, s^{-1}}$ and a
limit on the very high energy gamma-ray flux $\Phi (E\gt 120\, {\rm
GeV}) \lt 1.7\times 10^{-12}\, \mathrm{erg\, cm^{-2}\, s^{-1}}$. We
obtain a radio upper limit of ~15 $\mu$Jy beam-1 for
persistent emission at the locations of both FRBs 20190711A and
20171019A with MeerKAT. However, we detected an almost unresolved
(ratio of integrated flux to peak flux is ~1.7 beam) radio emission,
where the synthesized beam size was ~ 8 arcsec size with a peak
brightness of $\sim 53\, \mu$Jy beam-1 at MeerKAT and
$\sim 86\, \mu$Jy beam-1 at e-MERLIN, possibly associated
with FRB 20190714A at z = 0.2365. This represents the first detection
of persistent continuum radio emission potentially associated with a
(as-yet) non-repeating FRB. If the association is confirmed, one of the
strongest remaining distinction between repeaters and non-repeaters
would no longer be applicable. A parallel search for repeat bursts
from these FRBs revealed no new detections down to a fluence of 0.08
Jy ms for a 1 ms duration burst.
Title: Bias on tensor-to-scalar ratio inference with estimated
covariance matrices
Authors: Beck, Dominic; Cukierman, Ari; Wu, W. L. Kimmy
Bibcode: 2022MNRAS.515..229B
Altcode: 2022arXiv220205949B; 2022MNRAS.tmp.1721B
We investigate simulation-based bandpower covariance matrices commonly
used in cosmological parameter inferences such as the estimation of
the tensor-to-scalar ratio r. We find that upper limits on r can be
biased low by tens of per cent. The underestimation of the upper limit
is most severe when the number of simulation realizations is similar
to the number of observables. Convergence of the covariance-matrix
estimation can require a number of simulations an order of magnitude
larger than the number of observables, which could mean $\mathcal
{O}(10\ 000)$ simulations. This is found to be caused by an additional
scatter in the posterior probability of r due to Monte Carlo noise in
the estimated bandpower covariance matrix, in particular, by spurious
non-zero off-diagonal elements. We show that matrix conditioning can
be a viable mitigation strategy in the case that legitimate covariance
assumptions can be made.
Title: Weathering of chlorite from grain to watershed: The role and
distribution of oxidation reactions in the subsurface
Authors: Liao, Ruxue; Gu, Xin; Brantley, Susan L.
Bibcode: 2022GeCoA.333..284L
Altcode:
The reaction mechanism of weathering of chlorite, an important
rock-forming phyllosilicate, is not well understood in natural
settings. In this work we investigated the weathering of Fe-rich
chlorite from deep protolith to saprock to soil across a small
shale-underlain watershed in the Appalachian Mountains, USA (Shale
Hills). We found that oxidation of Fe(II) in chlorite always occurs
prior to dissolution of the interlayers of the mineral. The oxidation
of pyrite and chlorite commence near the water table across narrow
depth intervals under the upper-catchment ridges, but well below
the water table across wide depth intervals under the valley. We
hypothesize that these patterns can be explained by hydrological and
geochemical differences between the ridge and the valley: oxygenated
water descends sub-vertically (1D flow) under the ridge, while
under the valley, oxygen-depleted water moves upward to the stream
and laterally out of the watershed in the subsurface (3D flow). Geochemical and mineralogical characterization indicates that the
transformation of Fe-rich chlorite at Shale Hills is initiated by the
oxidation of Fe(II). Next, the interlayer hydroxide sheet dissolves
to form hydroxy-interlayered vermiculite and then vermiculite. During
the transformation, Mg and Fe are released into solution and Fe is
reprecipitated as goethite in pore space. Delivery of oxygen to the
deep subsurface by infiltration of meteoric water is thought to control
the initial transformation of chlorite at Shale Hills. It is possible
that weathering of many Fe(II)-rich minerals is initiated by oxidation
as mediated by rates of subsurface oxygen delivery.
Title: Performance evaluation of CORDEX-Africa regional climate
models in simulating climate variables over Ethiopian main rift
valley: Evidence from Gidabo river basin for impact modeling studies
Authors: Girma, Rediet; Fürst, Christine; Moges, Awdenegest
Bibcode: 2022DyAtO..9901317G
Altcode:
Measuring the simulation skill of regional climate models (RCMs)
is vital in selecting the best performing model that can be used
for climate change studies. To that end, the performance of eleven
Coordinated Regional Climate Downscaling Experiment (CORDEX) Africa
RCMs were evaluated against observed datasets from 1991 to 2005
over Gidabo river basin (GRB), main Ethiopian rift valley. RCMs'
outputs were evaluated using coefficient of variation (CV), percent
of bias (PBIAS), Root Means Square Error (RMSE), Pearson's correlation
coefficient (r), revised R-squared (RR2), Taylor Skill Score
(TSS), Mann-Kendall (MK) trend test and Sen's slope estimator. The
results confirm the difference of RCMs in capturing the annual
and seasonal climate variables. In relation to the spatial pattern
of the rainfall, RACMO22T (EC-EARTH) strongly reproduced the mean
annual rainfall. CCLM4-8 (MPI) and mean ensemble reproduced the annual
patterns of the observed rainfall despite the fact with varying rainfall
amounts reproduced. The seasonal rainfall pattern was satisfactorily
captured by RACMO22T (EC-EARTH), CCLM4-8 (MPI) and REMO2009 (MPI). The
agreement between the observed and modeled rainfall is superior in
CCLM4-8 (MPI) and RACMO22T (EC-EARTH) at station level. CRCM5 (MPI)
satisfactory replicated the patterns of both minimum and maximum
temperature. RACMO22T (EC-EARTH) showed best performance in simulating
annual and seasonal rainfall trends in GRB. In overall, models that
performs better in replicating the observed climatology include RACMO22T
(EC-EARTH), CCLM4-8 (MPI), CRCM5 (MPI), CCLM4-8 (CNRM), and REMO2009
(EC-EARTH). The study underscored the use of the mean ensemble of model
simulation did not always guarantee better agreement with observation
than individual models. Therefore prior to climate impact study, it is
advisable to correct the systematic bias and employ the multi-model
ensemble of best performing models for climate change impact and
adaptation studies in the GRB.
Title: Gallium isotope constraints on the intense weathering of basalt
Authors: Yuan, Wei; Gong, Yingzeng; Chen, Jiubin; Wang, Zhengrong;
Huang, Fang; Yang, Xiaojuan; Chetelat, Benjamin; Teng, Henry; Schott,
Jacques
Bibcode: 2022GeCoA.333...22Y
Altcode:
Gallium (Ga) isotopes are potentially advantageous for characterizing
the surficial biogeochemical cycles of Ga and tracking the geochemical
behavior of the monoisotope element aluminum (Al) during chemical
weathering. To test the potential of Ga and its isotopes to trace
continental weathering, we studied Ga isotope compositions of a
strongly-weathered latosol profile developed from basalt on the
Leizhou Peninsula, Guangdong Province, South China. In the profile,
δ71GaSRM-994 values of latosol samples decrease
from ∼0.69‰ in unweathered basalts at the bottom to ∼0.51‰ in
shallow sections, while the Ga concentration increases from ∼19.9
μg/g in the bedrock to ∼42.7 μg/g in soil, indicating significant
enrichment of Ga and its isotope fractionation triggered by weathering
processes. Bulk samples analysis and sequential leaching of selected
weathering products suggest that the majority of Ga in these samples
occurs in the crystal lattice of Al-rich and Fe-rich minerals, with
the light Ga isotope (69Ga) enriched in latosol samples
relative to the coexisting solution. Interestingly, our results
show δ71Ga values of latosols display a bigger variation
(about 3-4 times of its analytical uncertainty) than their Ga/Al ratios
(about 1.5 times of its analytical uncertainty) throughout the profile,
indicating δ71Ga values may be a more sensitive proxy to
track the loss of Al3+ and involvement of Fe3+
during weathering process. Based on a simple Rayleigh model, the upper
limit of Ga isotope fractionation between solution and weathered basalt
(Δ71Gasolution-weathered rocks) is estimated
to be ∼1.50‰, implying that heavy Ga isotopes may be enriched
in surface river systems. This study highlights the potential of Ga
elemental and isotope geochemistry to trace continental weathering
and global Ga cycling.
Title: The effect of crystal fractionation on the geochemical
composition of syn-exhumation magmas: Implication for the formation
of high δ56Fe granites in collisional orogens
Authors: Ma, He-Zhi; Chen, Yi-Xiang; Zhou, Kun; Gao, Peng; Zheng,
Yong-Fei; Zha, Xiang-Ping; Xia, Xiao-Ping; Zhao, Zi-Fu; Huang, Fang
Bibcode: 2022GeCoA.332..156M
Altcode:
Syn-exhumation magmatism in collisional orogens is an important process
for crustal differentiation and crust-mantle interaction at convergent
plate boundaries. It is intriguing to elucidate which factors control
the geochemical composition of such magmatic products. To answer
this question, a combined study of whole-rock major-trace elements
and Nd-Fe isotopes, mineral O isotopes, and zircon U-Pb ages and
trace elements was carried out for syn-exhumation granites from
the Sulu ultrahigh-pressure (UHP) metamorphic belt in east-central
China. Several granitic plutons of Triassic age were newly found in
this typical collisional orogen, with a total exposure area of ∼10
km2, suggesting large-scale partial melting of the deeply
subducted continental crust in the terminal stage of continental
collision. Field observations indicate that the massive granites show
little deformation. The granites are high-K calc-alkaline and exhibit
enrichment in LILE and LREE but depletion in HFSE relative to HREE in
trace element distribution patterns. Zircons in these granites contain
relict magmatic cores characterized by steep HREE patterns with strong
negative Eu anomalies. These cores show middle Neoproterozoic U-Pb ages
of 724-779 Ma, consistent with the protolith age of UHP metaigneous
rocks in the Dabie-Sulu orogenic belt. Zircon rims exhibit oscillatory
zoning, and are characterized by Triassic U-Pb ages of 210-216 Ma,
low LREE contents and steep HREE patterns with significant negative
Eu anomalies, suggesting their growth from granitic magmas during
exhumation of the deeply subducted continental crust. The granites have
low δ18O values of 2.0-6.1‰ for quartz, 1.1-5.2‰ for
whole-rock, and 0.9-3.2‰ for zircon cores. The low δ18O
values and Neoproterozoic U-Pb ages of zircon cores in the granites
are characteristic feature of the deeply subducted continental
crust in the northern margin of the South China Block. One coesite
inclusion was found in the anatectic zircon rim, pointing to the deep
origin of anatectic melts at a subarc depth of >80 km. Whole-rock
SiO2 contents are correlated with major and trace elements,
which are ascribed to crystal fractionation of mainly biotite and
plagioclase during magma evolution. In particular, these granites
exhibit highly variable δ56Fe values from 0.05 to 0.30‰,
which are correlated with Fe3+/ΣFe, SiO2,
Al2O3, Nb/Ta and Eu/Eu*. This suggests that the
crystal fractionation of biotite would have controlled the Fe isotope
variation in the granites. Therefore, the syn-exhumation granites
experienced significant geochemical differentiation mainly through the
fractional crystallization during the magma evolution. A compilation
of syn-exhumation granites in the typical collisional orogens of the
world shows that such granites were mainly formed through dehydration
melting of hydrous minerals during decompressional exhumation. They
fall into the magnesian group with relatively low REE and HFSE (like
Ti, Nb and Zr) contents, distinct from the geochemical compositions
of A-type granites. Therefore, syn-exhumation granites record crustal
differentiation in the terminal stage of continental collision.
Title: Stress-based forecasting of induced seismicity with
instantaneous earthquake failure functions: Applications to the
Groningen gas reservoir
Authors: Smith, Jonathan D.; Heimisson, Elías R.; Bourne, Stephen J.;
Avouac, Jean-Philippe
Bibcode: 2022E&PSL.59417697S
Altcode:
In this study we use the Groningen gas field to test a new method
to assess stress changes due to gas extraction and forecast induced
seismicity. We take advantage of the detailed knowledge of the reservoir
geometry and production history, and of the availability of surface
subsidence measurements and high quality seismicity data. The subsurface
is represented as a homogeneous isotropic linear poroelastic half-space
subject to stress changes in three-dimensional space due to reservoir
compaction and pore pressure variations. The reservoir is represented
with cuboidal strain volumes. Stress changes within and outside the
reservoir are calculated using a convolution with semi-analytical Green
functions. The uniaxial compressibility of the reservoir is spatially
variable and constrained with surface subsidence data. We calculate
stress changes since the onset of gas production. Coulomb stress
changes are maximum near the top and bottom of the reservoir where the
reservoir is offset by faults. To assess earthquake probability, we
use the standard Mohr-Coulomb failure criterion assuming instantaneous
nucleation and a non-critical initial stress. The distribution of
initial strength excess, the difference between the initial Coulomb
stress and the critical Coulomb stress at failure, is treated as a
stochastic variable and estimated from the observations and the modelled
stress changes. The exponential rise of seismicity nearly 30 years after
the onset of production, provides constraints on the distribution of
initial strength. The lag and exponential onset of seismicity are well
reproduced assuming either a generalized Pareto distribution, which can
represent the tail of any distribution, or a Gaussian distribution,
to describe both the tail and body of the distribution. The Gaussian
distribution allows to test if the induced seismicity at Groningen has
transitioned to the steady-state where seismicity rate is proportional
to the stressing rate. We find no evidence that the system has reached
such a steady-state regime. The modeling framework is computationally
efficient making it possible to test the sensitivity to modeling
assumptions regarding the estimation of stress changes. The forecast
is found robust to uncertainties about the ability of the model to
represent accurately the physical processes. It does not require in
particular a priori knowledge of the location and orientation of the
faults that can be activated. The method presented here is in principle
applicable to induced seismicity in any setting provided deformation
and seismicity data are available to calibrate the model.
Title: 3D transdimensional seismic tomography of the inner core
Authors: Brett, Henry; Hawkins, Rhys; Waszek, Lauren; Lythgoe, Karen;
Deuss, Arwen
Bibcode: 2022E&PSL.59317688B
Altcode:
Body wave observations of the Earth's inner core show that it contains
strong seismic heterogeneity, both laterally and radially. Models of
inner core structure generated using body wave data are often limited
by their parameterisation. Thus, it is difficult to determine whether
features such as anisotropic hemispheres or an innermost inner core
truly exist with their simple shapes, or result only from the chosen
parameterisation and are in fact more complex features. To overcome this
limitation, we conduct seismic tomography using transdimensional Markov
Chain Monte Carlo on a high quality dataset of 5296 differential and
2344 absolute P-wave travel times. In a transdimensional approach,
the data defines the model space parameterisation, providing us
with both the mean value of each model parameter and its probability
distribution, allowing us to identify well versus poorly constrained
regions. We robustly recover many first order observations found in
previous studies without the imposition of a priori fixed geometry
including an isotropic top layer (with anisotropy less than 1%) which
is between 60 and 170 km thick, and separated into hemispheres with
a slow west and a faster east. Strong anisotropy (with a maximum of
7.2%) is found mainly in the west, with much weaker anisotropy in
the east. We observe for the first time that the western anisotropic
zone is largely confined to the northern hemisphere, a property which
would not be recognised in models assuming a simple hemispherical
parameterisation. We further find that the inner most inner core, in
which the slowest anisotropic velocity direction is tilted relative
to Earth's axis of rotation (ζ =55∘ ±16∘),
is offset by 400 km from the centre of the inner core and is restricted
to the eastern hemisphere. We propose that this anomalous anisotropy
might indicate the presence of a different phase of iron (either bcc
or fcc) compared to the rest of the inner core (hcp).
Title: Calibration Observations of ACIS-I0 with Cas A at a
Non-Standard Focal Plane Temperature of -105C
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6444C
Altcode:
These observations will be used to calibrate ACIS at a focal plane
temperature of -105C.
Title: A fuzzy-based flood warning system using 19-year remote
sensing time series data in the Google Earth Engine cloud platform
Authors: Rostami, Amirhossein; Akhoondzadeh, Mehdi; Amani, Meisam
Bibcode: 2022AdSpR..70.1406R
Altcode:
Many Flood Warning Systems (FWS) have been developed to date to
reduce flood risk and properly manage this natural disaster. This
study presents a novel method to create an FWS based on anomaly
detection in remote sensing climate data from western Lorestan, Iran,
from 2001-to 2019. To this end, the monthly time series of climate
products related to floods (e.g., precipitation, soil moisture, soil
and air temperatures, vegetation, snow, and evapotranspiration) were
first processed in Google Earth Engine (GEE). Then, three algorithms -
Median-Interquartile range (M-IQR), Multi-Layer Perceptron (MLP), and
Recurrent Neural Network (RNN) - were applied to detect anomalies in the
time series of each parameter. Finally, a rule-based Fuzzy Inference
System (FIS) was designed to estimate the potential of floods per
month by establishing the relationship between the observed anomalies
and the occurrence of floods. The results of the proposed Fuzzy-based
Flood Warning System (FFWS) using all three anomaly detection methods
accurately showed the very high potential for floods in March and April
2019 (i.e., actual flood events). Two other floods occurred in October
2015 and April 2016 were also considered for further evaluation of the
proposed method. The results indicated that the RNN method achieved
the highest performance in flood forecasting with the overall accuracy
and Kappa coefficient of 93.85% and 0.93, respectively. Moreover,
the potential of floods at the beginning of 2019 (i.e., January and
February) was also high, although not to the extent as in March and
April, indicating that the proposed method correctly identified the
potential of flooding in later months and can thus provide a warning
to help mitigate the impact of flood damage.
Title: Chandra and NuSTAR ToO observations of Swift X-ray transients
in the Galactic Center
Authors: Mori, Kaya
Bibcode: 2022cxo..prop.6286M
Altcode:
We propose Chandra and NuSTAR follow-up observations of new X-ray
transients and recurrent outbursts from the known VFXTs (very faint
X-ray transients), detected by Swift-XRT, at r < 50 pc from
the Galactic Center. The accurate source localization by Chandra
and broad-band spectral/timing data with NuSTAR provide the useful
diagnostic tools of understanding the nature of X-ray transients in the
Galactic Center, as demonstrated by four Swift transients followed up by
Chandra and NuSTAR including the transient magnetar SGR J1745-2900, one
VFXT and two new black hole transients. Detecting and characterizing new
X-ray transients, together with investigating quiescent X-ray binaries,
will probe the population and formation of X-ray binaries near Sgr A*.
Title: Investigating the Correlation Between Late-Time X-Rays &
Radio Emission in Tdes
Authors: Hajela, Aprajita
Bibcode: 2022cxo..prop.6325H
Altcode:
The tidal disruption of a star by a black hole provides a unique
opportunity to study accretion physics. Recently, delayed radio
flares have been discovered in several TDEs, peaking years after their
optical emission has faded. Various explanations have been proposed,
including off-axis jets entering our line of sight, delayed accretion
disk formation, or a state change in the accretion flow. To elucidate
the origin(s) of these flares, it has become crucial to acquire radio
and X-ray observations of these events at late-times (~ months to
years post-discovery) to study this previously unexplored phase in
the lifetime of TDEs.
Title: Twinkle -- a small satellite spectroscopy mission for the
next phase of exoplanet science
Authors: Stotesbury, Ian; Edwards, Billy; Lavigne, Jean-Francois;
Pesquita, Vasco; Veilleux, James J.; Windred, Philip; Al-Refaie,
Ahmed; Bradley, Lawrence; Ma, Sushuang; Savini, Giorgio; Tinetti,
Giovanna; Birnstiel, Til; Dodson-Robinson, Sally; Ercolano, Barbara;
Feliz, Dax; Gaudi, Scott; Hernitschek, Nina; Holdsworth, Daniel;
Jiang, Ing-Guey; Griffin, Matt; Lowson, Nataliea; Molaverdikhani,
Karan; Neilson, Hilding; Phillips, Caprice; Preibisch, Thomas; Sarkar,
Subhajit; Stassun, Keivan G.; Ward-Thompson, Derek; Wright, Duncan;
Yang, Ming; Yeh, Li-Chin; Zhou, Ji-Lin; Archer, Richard; Barrathwaj
Raman Mohan, Yoga; Joshua, Max; Tessenyi, Marcell; Tennyson, Jonathan;
Wilcock, Benjamin
Bibcode: 2022arXiv220903337S
Altcode:
With a focus on off-the-shelf components, Twinkle is the first in a
series of cost competitive small satellites managed and financed by
Blue Skies Space Ltd. The satellite is based on a high-heritage Airbus
platform that will carry a 0.45 m telescope and a spectrometer which
will provide simultaneous wavelength coverage from 0.5-4.5 $\rm{\mu
m}$. The spacecraft prime is Airbus Stevenage while the telescope
is being developed by Airbus Toulouse and the spectrometer by ABB
Canada. Scheduled to begin scientific operations in 2025, Twinkle
will sit in a thermally-stable, sun-synchronous, low-Earth orbit. The
mission has a designed operation lifetime of at least seven years and,
during the first three years of operation, will conduct two large-scale
survey programmes: one focused on Solar System objects and the other
dedicated to extrasolar targets. Here we present an overview of the
architecture of the mission, refinements in the design approach,
and some of the key science themes of the extrasolar survey.
Title: Calibration Observation of ACIS with GX 3+1 at a Non-Standard
Focal Plane Temperature of -105C
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6440C
Altcode:
This observation will be used to calibrate ACIS at a focal plane
temperature of -105C.
Title: Post-mission de-orbiting of Cartosat-2
Authors: Agarwal, Ankita; Mukherjee, Bulbul; Kandari, Amit;
Ramakrishna, B. N.; Anil Kumar, A. K.
Bibcode: 2022AdSpR..70.1312A
Altcode:
India has been voluntarily following the guidelines on space debris
mitigation recommended by UN-COPUOS (United Nations Committee on the
Peaceful Uses of Outer Space) and IADC (Inter-Agency Space Debris
coordination Committee) to the maximum possible extent towards safe
and sustainable operations in outer space. As a part of the ongoing
efforts for better compliance with these guidelines, post-mission
disposal of Low-Earth-Orbit (LEO) objects has been carried out in the
recent past. Cartosat-2, which was operational at 630 km altitude,
is the first satellite to be de-orbited at its end-of-life through a
series of perigee reduction orbit maneuvers to minimize its presence
in the LEO region. Consequently, the post-mission orbital lifetime was
reduced from more than 30 years to less than 5 years in compliance
with the 25-year rule recommended in IADC space debris mitigation
guidelines. The de-orbiting exercise utilizing left-over propellant
also achieved the objective of minimising any accidental break-up
risk. This paper outlines the relevant analyses and planning aspects
of post-mission de-orbiting for Cartosat-2. The lessons learnt and
recommendations on post-mission disposal for future LEO missions are
also presented.
Title: What happens after a stellar merger?
Authors: Guenther, Hans
Bibcode: 2022cxo..prop.6278G
Altcode:
A large fraction of all stars are in binary or multiple systems and
may have different evolutionary pathways than single stars. We propose
a 30 ks observation of the 1Gyr, first-ascent giant branch star TYC
4144-329-2, a suspected post-merger first-ascent giant branch star that
is surrounded by an IR-bright disk. It seems that this system falls
into an evolutionary sequence between BP Psc and TYC 2597-735-1, two
suspected merger remnants with outflows, and FK Com which no longer has
an IR disk. If the evolutionary sequence described above is correct,
TYC 4144-329-2 should show more X-ray activity than BP Psc and TYC
2597-735-1, but less than FK Com - a prediction easy to test with a
Chandra observation.
Title: Chondrule formation via impact jetting in the icy outer
solar system
Authors: Cashion, Melissa D.; Johnson, Brandon C.; Krot, Alexander N.;
Kretke, Katherine A.; Wakita, Shigeru; Davison, Thomas M.
Bibcode: 2022Icar..38415110C
Altcode:
Impact jetting during planetesimal collisions is a process that ejects
small amounts of highly shocked material during the earliest stages
of an impact. Jetting can produce melted and vaporized material
during relatively low velocity collisions and has previously been
presented as a mechanism for producing chondrules in the inner
solar system during impacts between rocky planetesimals. However,
chondrules are observed in both non‑carbonaceous and carbonaceous
chondrites, which are thought to have formed in the inner and outer
solar system, respectively. In this work, we use the iSALE2D hydrocode
to investigate the viability of jetting for producing chondrules in
the outer solar system, where ice-rich bodies begin to be incorporated
into the planetesimal population. We create mixed material equations
of state for ice mass fractions of 10-50% intimately combined with
dunite to emulate the compositions of ice-rich outer solar system
planetesimals. We account for collisions between a sphere and flat
target at 2-7 km/s. Our results indicate that the presence of ice
lowers the total mass of chondrule forming material jetting can
produce, but a significant mass of chondrules is likely to form
nonetheless even through collisions of bodies with relatively high
ice concentrations. For example, for collisions at 4 km/s, pure dunite
bodies create ~1% the mass of a 10-km-diameter projectile of chondrules,
while bodies that include 50% ice by mass produce ~0.004% the mass of an
impactor of chondrules. The presence of ice results in water vapor in
the jet plume which may generate an oxidizing environment that favors
the production of chondrules relatively enriched in 17O and
18O due to 16O-poor composition of water ice in
the outer solar system.
Title: Spherical multi-lacunarity reveals possible equatorial-polar
differences in crater densities on the dwarf planet Ceres
Authors: Dombard, Andrew J.; Tucker, Wesley S.; Joniak, Ronald;
Plotnick, Roy E.
Bibcode: 2022Icar..38415076D
Altcode:
The dwarf planet Ceres possesses a peculiar distribution of impact
craters. It has been previously noted that the largest craters expected
for Ceres are absent, while for smaller craters, the north polar region
is the most heavily cratered. It thus appears that some process(es)
have erased some of Ceres' craters, and the distribution of observed
craters could point to the nature of these processes. For instance,
a process tied to sunlight (e.g., relaxation or sublimation) could
impart a latitudinal dependence, while a more regional distribution
could point to a more endogenic process (e.g., cryovolcanism). Through
a combination of spherical multi-lacunarity analysis and kernel density
maps, we discover that the 20 largest craters (> 100 km across),
though statistically indistinguishable from random, are stochastically
concentrated in the south, while mid-size craters (20-70 km) show
clustering at spatial scales >130 km, roughly the same scale
that would be affected by emplacement of the 20 largest craters plus
ejecta. A mask made from these largest craters plus ejecta reveals
that a south polar region that matches the heavily cratered north
is almost completely covered by the largest craters. Crater counts
additionally reveal that this north polar region is older (i.e., more
heavily cratered) than an equatorial region not masked by the largest
craters, which in turn is about as cratered as the oldest of the 20
largest craters. Thus, it appears that there could be equator-polar
differences to Ceres' crater distribution, or at the very least,
that a latitudinal dependence cannot be discounted. Consequently,
latitudinal variations in sunlight might be a controlling factor in
the distribution of craters on Ceres.
Title: XOSS Transient Discovery Report for 2022-09-01
Authors: Zhang, M.; Gao, X.
Bibcode: 2022TNSTR2545....1Z
Altcode:
No abstract at ADS
Title: Pan-STARRS Transient Discovery Report for 2022-09-01
Authors: Chambers, K. C.; Boer, T. D.; Bulger, J.; Fairlamb, J.; Huber,
M.; Lin, C. C.; Lowe, T.; Magnier, E.; Schultz, A.; Wainscoat, R. J.;
Gao, H.; Smith, K. W.; Young, D. R.; Gillanders, J.; Srivastav, S.;
Fulton, M.; Smartt, S. J.; Sim, S.; Wright, D. E.
Bibcode: 2022TNSTR2543....1C
Altcode:
No abstract at ADS
Title: AGN Identification in MaNGA Coronal Line Galaxies
Authors: Negus, James
Bibcode: 2022cxo..prop.6361N
Altcode:
Coronal emission lines, which are highly ionized species of gas with
ionization potentials >100 eV, are promising tracers of AGN. However,
they are poorly studied and much of their origin remains a mystery. In a
study of coronal lines in MaNGA galaxies, we found that [Ne V] coronal
line detections correspond to WISE AGN detections, while [Fe VII]
coronal line detections do not, perhaps because [Fe VII] traces lower
luminosity AGN missed by WISE. Here we propose Chandra observations of
five [Fe VII] coronal line galaxies in MaNGA to determine whether the
source of the coronal line emission is AGN, AGN outflows, or outflows
and shocks associated with star formation or galaxy mergers.
Title: Highly heterogeneous mantle caused by recycling of oceanic
lithosphere from the mantle transition zone
Authors: Qian, Shengping; Salters, Vincent; McCoy-West, Alex J.; Wu,
Jonny; Rose-Koga, Estelle F.; Nichols, Alexander R. L.; Zhang, Le;
Zhou, Huaiyang; Hoernle, Kaj
Bibcode: 2022E&PSL.59317679Q
Altcode:
Geochemical heterogeneities observed in the mantle are
usually attributed to recycling of oceanic lithosphere through
subduction. However, it remains hotly debated where recycled material
stagnates, and how quickly it can be liberated back to surface. This
knowledge gap hinders our understanding of mantle circulation and the
chemical evolution of the Earth. Here we address these questions using a
combination of geochronology and geochemistry from South China Sea (SCS)
seamounts. The Shixingbei seamount lavas formed during active seafloor
spreading at c. 19.1 Ma show limited geochemical variability, whereas
the Zhenbei-Huangyan seamount chain formed during the post-spreading
stage at c. 7.8 Ma and displays a wide range of compositions. However,
melt inclusions in olivine and plagioclase from the Zhenbei-Huangyan
basalts show considerably greater isotopic variability than seen in
the whole rock compositions of both the SCS syn- and post-spreading
lavas. A previously unidentified third mantle source component (FOZO)
revealed by olivine-hosted melt inclusions along with both depleted
(DMM) and enriched (EMII) mantle components is required in the source
region to explain the observed isotopic and chemical variability. On
the basis of our results, the age of the recycled ocean crust and
sediments in this region are estimated to be c. 120 - 350 Ma. We infer
that these enriched components in the SCS lavas come from the mantle
transition zone. Variations in mantle source heterogeneity coupled with
melting process control spatial-temporal (spreading vs. post-spreading
stage) geochemical variations of lavas from the SCS and surrounding
areas. Together with the results from published studies, we propose
that marginal basins are one of the major locations on Earth where
oceanic and/or continental lithosphere is transferred into the upper
mantle and transition zone, representing an important source of upper
mantle heterogeneity. We provide a simple conceptual model linking
plate subduction and upper mantle heterogeneity and the volcanism in
the SCS and surrounding areas.
Title: Features of the primordial Universe in f(R)-gravity as viewed
in the Jordan frame
Authors: Bamonti, Nicola; Costantini, Andrea; Montani, Giovanni
Bibcode: 2022CQGra..39q5011B
Altcode: 2021arXiv210317063B
We analyze some features of the primordial Universe as viewed in the
Jordan frame formulation of the f(R)-gravity when the potential term
is negligible. We start formulating the Hamiltonian picture using
the three-metric determinant as a basic variable and we outline
that its conjugated momentum appears linearly only in the scalar
constraint. We construct the formalism to characterize the dynamics
of a generic inhomogeneous cosmological model and specialize it to
describe behaviors of the Bianchi Universes, both on a classical and
a quantum regime. We demonstrate that, when the potential term of the
additional scalar mode is negligible near to the initial singularity,
the Bianchi IX cosmology is no longer affected by the chaotic behavior,
typical in the vacuum of the Einsteinian dynamics. In fact, the presence
of the Kasner stability region and its attractive character are properly
characterized. Finally, we investigate the canonical quantization of
the Bianchi I model, using as time variable the non-minimally coupled
scalar field and showing that the existence of a conserved current is
outlined for the corresponding Wheeler-DeWitt equation. The behavior
of a localized wave-packet for the isotropic Universe is also evolved,
demonstrating that the singularity is still present in this revised
quantum dynamics.
Title: Dyke cooling upon intrusion: Subsequent shape change, cooling
regimes and the effect of further magma input
Authors: Loncar, Marco; Huppert, Herbert E.
Bibcode: 2022E&PSL.59317687L
Altcode:
Upon emplacement of a dyke, the magma may crystallise immediately and
block the dyke (blocking) or begin to melt the surrounding country
rock prior to crystallisation (meltback). A numerical model is used to
investigate the prevalence of these regimes and the change in shape
(of horizontal cross-section) of the dyke's solidus and mobile melt
extent (MME) isotherms. For static magma, the solidus narrows from its
initial shape throughout cooling while the MME initially narrows prior
to widening. Magma reinjection leads to widening of the MME after
each injection, with a lesser to no response in the solidus aspect
ratio. For static magma, the minimum dyke width at which meltback
occurs is inversely proportional to the country rock temperature (with
no meltback for country rock below specific temperatures determined
by the specific magma properties). Considering reinjection allows
for meltback at significantly lower country rock temperatures and a
power law relationship is determined between this meltback width and
the reinjection period. Injection of superheated magma gives rise
to further widening of the MME during cooling with no effect on the
solidus shape, as well as decreasing the country rock temperature
required for meltback.
Title: High-rate (20 Hz) single-frequency GPS/GALILEO variometric
approach for real-time structural health monitoring and rapid risk
assessment
Authors: Bezcioglu, Mert; Yigit, Cemal Ozer; Mazzoni, Augusto;
Fortunato, Marco; Dindar, Ahmet Anil; Karadeniz, Baris
Bibcode: 2022AdSpR..70.1388B
Altcode:
Real-time monitoring and the rapid risk assessment of the engineering
structures after a natural event is crucial to prevent further
disasters. Global Navigation Satellite System (GNSS) relative
positioning and Precise Point Positioning (PPP) have been widely used
in determining the seismic waveform and structural displacement. On
the other hand, variometric approach (VA) is a future-promising
method in capturing the real-time dynamic motions. VA technique has
been broadly used in real-time co-seismic displacement retrieval so
far. However, the usability of the high-rate single-frequency (SF)
variometric approach in real-time structural health monitoring has
not been investigated in the literature, yet. This paper examines
the ability of the SF-VA based on 20 Hz GPS-only and GPS/GALILEO
observations to capture high-frequency dynamic displacement and time
difference displacement. The dynamic harmonic motions with various
frequency and amplitude values were created using a single-axis shake
table. In addition to that 1995 Kobe earthquake's ground motion was also
tested on the shake table to evaluate the performance of SF-VA for GNSS
seismology applications. Displacement time and frequency series of SF-VA
were compared with a series of Linear Variable Differential Transformer
(LVDT) sensor installed to the shake-table. The comparisons show
that SF-VA can effectively capture the harmonic motions' vibrational
frequencies and displacement amplitudes. The observed amplitudes of
the displacement of harmonic movements are slightly different from the
LVDT values at the order of millimeters. Thus, it is found that the
SF-VA approach is a powerful and reliable tool in real-time structural
health monitoring and rapid risk assessment.
Title: Bayesian evidence comparison for distance scale estimates
Authors: Paranjape, Aseem; Sheth, Ravi K.
Bibcode: 2022arXiv220900668P
Altcode:
Constraints on cosmological parameters are often distilled from sky
surveys by fitting templates to summary statistics of the data that
are motivated by a fiducial cosmological model. However, recent work
has shown how to estimate the distance scale using templates that
are more generic: the basis functions used are not explicitly tied to
any one cosmological model. We describe a Bayesian framework for (i)
determining how many basis functions to use and (ii) comparing one basis
set with another. Our formulation provides intuition into how (a) one's
degree of belief in different basis sets, (b) the fact that the choice
of priors depends on basis set, and (c) the data set itself, together
determine the derived constraints. We illustrate our framework using
measurements in simulated datasets before applying it to real data.
Title: The population properties of spinning black holes using
Gravitational-wave Transient Catalog 3
Authors: Tong, Hui; Galaudage, Shanika; Thrane, Eric
Bibcode: 2022arXiv220902206T
Altcode:
Binary black holes formed via different pathways are predicted to have
distinct spin properties. Measuring these properties with gravitational
waves provides an opportunity to unveil the origins of binary black
holes. Recent work draws conflicting conclusions regarding the spin
distribution observed by LIGO--Virgo--KAGRA (LVK). Some analyses
suggest that a fraction of the observed black-hole spin vectors
are significantly misaligned (by $>90^\circ$) relative to the
orbital angular momentum. This has been interpreted to mean that
some binaries in the LVK dataset are assembled dynamically in dense
stellar environments. Other analyses find support for a sub-population
of binaries with negligible spin and no evidence for significantly
misaligned spin -- a result consistent with the field formation
scenario. In this work, we study the spin properties of binary black
holes in the third LVK gravitational-wave transient catalog. We
find that there is insufficient data to resolve the existence of
a sub-population of binaries with negligible black-hole spin (the
presence of this sub-population is supported by a modest Bayes factor
of 1.7). We find modest support for the existence of mergers with
extreme spin tilt angles $> 90^\circ$ (the presence of extreme-tilt
binaries is favored by a Bayes factor of 10.1). Only one thing is clear:
at least some of the LVK binaries formed in the field. At most $89\%$
of binaries are assembled dynamically (99\% credibility), though,
the true branching fraction could be much lower, even negligible.
Title: Keeping Tabs on Clusters in an Ultra-Diffuse Galaxy
Authors: Hensley, Kerry
Bibcode: 2022nova.pres.9825H
Altcode:
Ultra-diffuse galaxies are the size of normal galaxies but far fainter,
and many host an unusual abundance of globular clusters. A recent study
takes a closer look at how one such galaxys globular clusters came to
be where they are and what this might tell us about the galaxys dark
matter halo.Copious ClustersLeft: Inverted Hubble Space Telescope
image of UDG1. Right: Locations of objects identified in the Hubble
observations, separated into magnitude bins. The brightest objects (dark
red circles) are found closest to UDG1s center. Click to enlarge. [Bar
et al. 2022]Observations over the past several years have given rise
to numerous theories about the evolution of ultra-diffuse galaxies,
and the arrangement of these galaxies globular clusters spherical
clusters containing hundreds of thousands of stars can provide
a useful test of these theories. Previous investigations of the
ultra-diffuse galaxy NGC5846-UDG1, or UDG1, have shown that it has an
exceptional collection of globular clusters for a galaxy of its size:
researchers have found 54 candidate clusters, 11 of which have been
spectroscopically confirmed.UDG1s population of globular clusters is
also remarkable because its brightest clusters are concentrated near
the center of the galaxy. The arrangement is unlikely to be random
whats responsible for UDG1s globular cluster distribution?Projected
radial distance of UDG1s globular clusters as a function of mass,
binned three ways, compared to the predictions of simple dynamical
friction theory. [Bar et al. 2022]Influence of a Frictional ForceA
team led by Nitsan Bar (Weizmann Institute of Science, Israel)
hypothesized that the brightest and most massive globular clusters
would naturally migrate to UDG1s center because of gravitational
dynamical friction. Dynamical friction isnt the same as the friction
that allows us to warm chilly hands by rubbing them together; instead,
dynamical friction arises when objects interact gravitationally and
lose a bit of their momentum in the process. In the case of UDG1,
dynamical friction should cause the globular clusters to sink toward the
galaxys center, and since the most massive clusters should experience
the most friction, they should be found closest to the center.To test
this hypothesis, Bar and collaborators first used simple mathematical
expressions to calculate where globular clusters with various masses
would be located within UDG1 if dynamical friction is at work. Even
without capturing the nuances of the system, these simple calculations
matched observations fairly well, suggesting that dynamical friction
plays an important role in UDG1.A Test of Dark Matter DistributionsAs
a further test, the team performed detailed numerical simulations,
scattering globular clusters evenly throughout a UDG1-like galaxy and
allowing them to drift for 10 billion years under the influence of
dynamical friction, cluster mergers, and mass loss. These simulations
showed that dynamical friction could have caused globular clusters to
migrate to their current positions, likely from an initial arrangement
slightly more dispersed than the current arrangement.Density profiles of
three mass models tested. The Stars model is derived from the observed
stellar luminosity of UDG1, while the other two models incorporate a
massive, extended dark matter halo. [Adapted from Bar et al. 2022]Bar
and coauthors also explored the effects of changing the way mass
is distributed in UDG1s halo, which could give clues to the diffuse
galaxys dark matter distribution. The team found that UDG1 could be
situated in a massive dark matter halo, which would distinguish it from
other ultra-diffuse galaxies that are almost entirely lacking in dark
matter.More work remains to be done, and the question of UDG1s dark
matter is not yet settled. The authors suggest new avenues for both
theoretical and observational investigations: improved simulations of
globular cluster formation can refine model results, and future data
from Vera Rubin Observatory and the Nancy Grace Roman Space Telescope
should illuminate the faintest globular clusters in ultra-diffuse
galaxies.CitationDynamical Friction in Globular Cluster-rich
Ultra-diffuse Galaxies: The Case of NGC5846-UDG1, Nitsan Bar et al
2022 ApJL 932 L10. doi:10.3847/2041-8213/ac70dfThe post Keeping Tabs
on Clusters in an Ultra-Diffuse Galaxy appeared first on AAS Nova.
Title: Dissipative charged homologous model for cluster of stars in
f(R , T) gravity
Authors: Mumtaz, Saadia; Manzoor, Rubab; Saqlain, Muhammad; Ikram,
Ayesha
Bibcode: 2022PDU....3701096M
Altcode:
In this paper, we discuss homologous model for cluster of stars in
f(R , T) gravity. For this purpose, we use f(R , T) = R + K(-
T) n model to incorporate exotic terms in the system. The
quasi-static approximations are being imposed onto the shear-free
dissipative relativistic self-gravitating charged fluid. It is found
that non-dissipative case can easily be reduced to linear homology
law in the Newtonian regime. In dissipative scenario, this condition
exhibits that the linear homology law for a fluid element is applicable
only if we apply the homology conditions on temperature, emission rate
and charge associated to baryonic matter. For dark matter, it depends
upon the emission of gravitational dissipation. We also deduce that the
shear-free and homogeneous expansion rate conditions are equivalent to
the homology conditions only in the Newtonian limit. Furthermore, the
deviation from homology conditions leads to thermal peeling effects. We
use PSR J 1614 - 2230 data with f(R , T) field equations for which
the graphical analysis shows that the physical variables of baryonic
matter like density, pressures and dissipation are suppressed in the
presence of dark matter. Thus dark matter has a significant relevance
in the emergence of homologous evolution of stellar cluster.
Title: Localizing and Classifying Unidentified High-Energy X-Ray
Sources Discovered by Integral
Authors: Chakraborty, Priyanka
Bibcode: 2022cxo..prop.6344C
Altcode:
We propose 5 ksec Chandra ACIS-I observations for each of 9 unclassified
IGR sources newly discovered by INTEGRAL. We will localize the sources,
identify their multi-wavelength counterparts, measure their soft X-ray
spectra, and classify them. These will be the first observations of
these targets by Chandra or XMM-Newton.
Title: ZTF Transient Discovery Report for 2022-09-01
Authors: Fremling, C.
Bibcode: 2022TNSTR2547....1F
Altcode:
No abstract at ADS
Title: Infrared spectra of benzene ices: Reexamination and comparison
of two recent papers and the literature
Authors: Hudson, Reggie L.
Bibcode: 2022Icar..38415091H
Altcode:
Infrared spectroscopic results on benzene (C6H6)
ices from two recent papers, one published here, are compared to each
other and to literature results from 60 years ago. Qualitative and
quantitative differences are described, partly in terms of spectral
resolution, and errors in one paper are identified that, once corrected,
could bring the two recent publications into agreement with each
other. A solution is provided for an unexplained disagreement with
the literature noted by the authors of one paper. It is concluded
that the only accurate, extensive set of IR absorption coefficients,
band strengths, and optical constants now available for amorphous and
crystalline benzene are those recently published here by the author
and a colleague. Suggestions are made for future work to change this
situation.
Title: Sloshing-driven turbulence in the ICM: unique properties and
their X-ray measurements
Authors: Zhang, Congyao
Bibcode: 2022cxo..prop.6427Z
Altcode:
Turbulence plays a vital role in the intracluster medium. It could
prevent gas from cooling in cluster cores, promote gas mixing, and
excite diffuse radio emission. In observations, gas bulk motions
masquerade as turbulence and bias its measurements. In this study,
we aim to tackle this problem for sloshing motions that are nearly
universal in cool-core clusters. We propose to utilize numerically a
self-similar model of sloshing process in galaxy clusters to separate
the sloshing-driven turbulence and gas bulk motions unambiguously. Using
this model, we will (1) comprehend how turbulence is developed,
distributed, and dissipated in the sloshing process, and (2) explore
various strategies of measuring genuine turbulence when combining
high-resolution Chandra imaging and XRISM spectral data.
Title: Evidence for a cloud-cloud collision in Sh2-233 triggering
the formation of the high-mass protostar object IRAS 05358+3543
Authors: Yamada, Rin I.; Fukui, Yasuo; Sano, Hidetoshi; Tachihara,
Kengo; Bieging, John H.; Enokiya, Rei; Nishimura, Atsushi; Fujita,
Shinij; Kohno, Mikito; Tsuge, Kisetsu
Bibcode: 2022MNRAS.515.1012Y
Altcode: 2021arXiv210601852Y; 2022MNRAS.tmp.1113Y
We have carried out a new kinematical analysis of the molecular gas
in the Sh2-233 region by using the CO J = 2-1 data taken at ~0.5 pc
resolution. The molecular gas consists of a filamentary cloud of 5-pc
length with 1.5-pc width where two dense cloud cores are embedded. The
filament lies between two clouds, which have a velocity difference of
2.7 km s-1 and are extended over ~5 pc. We frame a scenario
that the two clouds are colliding with each other and compressed the gas
between them to form the filament in ~0.5 Myr which is perpendicular
to the collision. It is likely that the collision formed not only
the filamentary cloud but also the two dense cores. One of the dense
cores is associated with the high-mass protostellar candidate IRAS
05358+3543, a representative high-mass protostar. In the monolithic
collapse scheme of high mass star formation, a compact dense core of
100 M⊙ within a volume of 0.1 pc radius is assumed as
the initial condition, whereas the formation of such a core remained
unexplained in the previous works. We argue that the proposed collision
is a step which efficiently collects the gas of 100 M⊙ into
0.1 pc radius. This lends support for that the cloud-cloud collision
is an essential process in forming the compact high-mass dense core,
IRAS 05358+3543.
Title: Variations in GPS precipitable water vapor and rainfall during
the 2006-2019 Mei-yu season in Taiwan
Authors: Lien, Tzu-Yi; Yeh, Ta-Kang; Hong, Jing-Shan; Hsiao, Tung-Yuan
Bibcode: 2022AdSpR..70.1375L
Altcode:
The Mei-yu season contributes 26.3% of the annual precipitation
and provides important water resources to Taiwan. GPS meteorology
derives continuous, real-time and high spatial coverage of perceptible
water vapor (PWV), which supports weather forecasting for rainfall
indicators. This study analyzes the long-term spatial-temporal changes
in GPS PWV and rainfall data during the Mei-yu season from 2006 to
2019. The daily average data show that the Mei-yu season extended
in recent years. Both daily rainfall and PWV increase in mid-May and
rainfall reaches a maximum in early June, while PWV maintains stable
in June. The yearly results show that the trend of the accumulated
rainfall in the Mei-yu season is flat, and that PWV increases by 13%
over 14 years, which may be due to global warming as the trend of
temperature increases by 8%. Spatially, PWV is significantly higher
in southern Taiwan during the Mei-yu season, and rainfall increased
the most in both the central and southern mountain regions.
Title: Multiple families of synodic resonant periodic orbits in the
bicircular restricted four-body problem
Authors: Oshima, Kenta
Bibcode: 2022AdSpR..70.1325O
Altcode:
Periodic orbits in gravitational many-body problems have been
fundamental special solutions for analyzing phase-space flows not
only in autonomous systems but also in time-dependent non-autonomous
systems. The growing interest in cislunar space may require deeper
understandings of periodic orbits in the Earth-Moon system beyond the
simplified dynamics in the circular restricted three-body problem. The
present paper deals with two mechanisms of the generation of multiple
families of synodic resonant periodic orbits in the bicircular
restricted four-body problem through numerical examples adopting planar
and three-dimensional retrograde periodic orbits around the Earth. The
first part of the paper reveals complex interplays between a synodic
resonant periodic orbit and multi-revolutional orbits originated
from period-multiplying bifurcations. Extensions of continuation
curves beyond the usual limit find another 12 : 11 synodic resonant
planar retrograde periodic orbit around the Earth in addition to the
one already found in the previous work. The second part shows that a
doubly symmetric periodic orbit in the circular restricted three-body
problem can generate four families of synodic resonant periodic orbits
in the bicircular restricted four-body problem. This work identifies
linearly stable, 1 : 1 synodic resonant, three-dimensional retrograde
periodic orbits around the Earth and indicates their substantially
large stability regions under solar gravitational perturbations.
Title: Giant radio galaxies in the LOw-Frequency ARray Two-metre
Sky Survey Boötes deep field
Authors: Simonte, M.; Andernach, H.; Brüggen, M.; Schwarz, D. J.;
Prandoni, I.; Willis, A. G.
Bibcode: 2022MNRAS.515.2032S
Altcode: 2022arXiv220701648S; 2022MNRAS.tmp.1886S
Giant radio galaxies (GRGs) are radio galaxies that have
projected linear extents of more than 700 kpc or 1 Mpc, depending on
definition. We have carried out a careful visual inspection in search of
GRGs of the Boötes LOw-Frequency ARray Deep Field image at 150 MHz. We
identified 74 GRGs with a projected size larger than 0.7 Mpc of which 38
are larger than 1 Mpc. The resulting GRG sky density is about 2.8 (1.43)
GRGs per square degree for GRGs with linear size larger than 0.7 (1)
Mpc. We studied their radio properties and the accretion state of the
host galaxies using deep optical and infrared survey data and determined
flux densities for these GRGs from available survey images at both 54
MHz and 1.4 GHz to obtain integrated radio spectral indices. We show
the location of the GRGs in the P-D diagram. The accretion mode on to
the central black holes of the GRG hosts is radiatively inefficient
suggesting that the central engines are not undergoing massive accretion
at the time of the emission. Interestingly, 14 out of 35 GRGs for which
optical spectra are available show a moderate star-formation rate
(10-100 $\rm M_{\odot }\,yr^{-1}$). Based on the number density of
optical galaxies taken from the Dark Energy Spectroscopic Instrument
survey DR9 photometric redshift catalogue, we found no significant
differences between the environments of GRGs and other radio galaxies,
at least for redshift up to z = 0.7.
Title: Finite-time extended state observer based prescribed
performance fault tolerance control for spacecraft proximity
operations
Authors: Wang, Kun; Meng, Tao; Wang, Weijia; Song, Renting; Jin,
Zhonghe
Bibcode: 2022AdSpR..70.1270W
Altcode:
Relative motion control with six degrees of freedom (6-DOF) for
spacecraft proximity operations in prescribed performance control (PPC)
framework has become a hot issue in recent years, but actuator failure
is seldom involved in controller design. In this paper, we introduce
a complete thruster model to describe the actuator characteristics
for thruster-only spacecraft, considering efficiency loss, thrust
fluctuation and saturation. Besides, the barrier Lyapunov function
(BLF) method and homeomorphic mapping method are often used in the
PPC framework to constrain transformed errors. However, the two
methods have singularity and infinite control effort problem once
the constraints are not satisfied because of the actuator failure
or other disturbance. In this paper, a novel bounded BLF (BBLF) is
proposed to solve this problem. The proposed BBLF can still maintain
bounded control effort and guarantee the system stability even if the
transformed errors exceed the boundary. Further, the model uncertainty,
actuator output uncertainty and external disturbance are summarized as
lumped disturbances. A finite-time extended state observer (FTESO) is
constructed to estimate the lumped disturbances. Finally, based on the
estimated information from FTESO, an adaptive backstepping controller is
proposed to track the desired trajectory. Numerical simulation results
show the excellent dynamic response and steady-state accuracy of the
proposed control strategy.
Title: High-resolution Solar Image Reconstruction Based on Non-rigid
Alignment
Authors: Liu, Hui; Jin, Zhenyu; Xiang, Yongyuan; Ji, Kaifan
Bibcode: 2022RAA....22i5005L
Altcode: 2022arXiv220700268L
Suppressing the interference of atmospheric turbulence and
obtaining observation data with a high spatial resolution are an
issue to be solved urgently for ground observations. One way to
solve this problem is to perform a statistical reconstruction of
short-exposure speckle images. Combining the rapidity of Shift-Add
and the accuracy of speckle masking, this paper proposes a novel
reconstruction algorithm-NASIR (Non-rigid Alignment based Solar
Image Reconstruction). NASIR reconstructs the phase of the object
image at each frequency by building a computational model between
geometric distortion and intensity distribution and reconstructs the
modulus of the object image on the aligned speckle images by speckle
interferometry. We analyzed the performance of NASIR by using the
correlation coefficient, power spectrum, and coefficient of variation
of intensity profile in processing data obtained by the NVST (1 m New
Vacuum Solar Telescope). The reconstruction experiments and analysis
results show that the quality of images reconstructed by NASIR is close
to speckle masking when the seeing is good, while NASIR has excellent
robustness when the seeing condition becomes worse. Furthermore, NASIR
reconstructs the entire field of view in parallel in one go, without
phase recursion and block-by-block reconstruction, so its computation
time is less than half that of speckle masking. Therefore, we consider
NASIR is a robust and high-quality fast reconstruction method that
can serve as an effective tool for data filtering and quick look.
Title: Reionization time of the Local Group and Local-Group-like
halo pairs
Authors: Sorce, Jenny G.; Ocvirk, Pierre; Aubert, Dominique;
Gottlöber, Stefan; Shapiro, Paul R.; Dawoodbhoy, Taha; Yepes, Gustavo;
Ahn, Kyungjin; Iliev, Ilian T.; Lewis, Joseph S. W.
Bibcode: 2022MNRAS.515.2970S
Altcode: 2022arXiv220713102S; 2022MNRAS.tmp.1996S
Patchy cosmic reionization resulted in the ionizing UV background
asynchronous rise across the Universe. The latter might have left
imprints visible in present-day observations. Several numerical
simulation-based studies show correlations between the reionization
time and overdensities and object masses today. To remove the mass
from the study, as it may not be the sole important parameter, this
paper focuses solely on the properties of paired haloes within the same
mass range as the Milky Way. For this purpose, it uses CoDaII, a fully
coupled radiation hydrodynamics reionization simulation of the local
Universe. This simulation holds a halo pair representing the Local
Group, in addition to other pairs, sharing similar mass, mass ratio,
distance separation, and isolation criteria but in other environments,
alongside isolated haloes within the same mass range. Investigations of
the paired halo reionization histories reveal a wide diversity although
always inside-out, given our reionization model. Within this model,
haloes in a close pair tend to be reionized at the same time but being
in a pair does not bring to an earlier time their mean reionization. The
only significant trend is found between the total energy at z = 0 of
the pairs and their mean reionization time: Pairs with the smallest
total energy (bound) are reionized up to 50 Myr earlier than others
(unbound). Above all, this study reveals the variety of reionization
histories undergone by halo pairs similar to the Local Group, that
of the Local Group being far from an average one. In our model, its
reionization time is ~625 Myr against 660 ± 4 Myr (z ~ 8.25 against
7.87 ± 0.02) on average.
Title: Four bright eclipsing binaries with γ Doradus pulsating
components: CM Lac, MZ Lac, RX Dra, and V2077 Cyg
Authors: Southworth, John; Van Reeth, Timothy
Bibcode: 2022MNRAS.515.2755S
Altcode: 2022MNRAS.tmp.1990S; 2022arXiv220709169S
The study of pulsating stars in eclipsing binaries holds the promise
of combining two different ways of measuring the physical properties
of a star to obtain improved constraints on stellar theory. Gravity
(g) mode pulsations such as those found in γ Doradus stars can be
used to probe rotational profiles, mixing, and magnetic fields. Until
recently few γ Doradus stars in eclipsing binaries were known. We
have discovered g-mode pulsations in four detached eclipsing binary
systems from light curves obtained by the Transiting Exoplanet
Survey Satellite (TESS) and present an analysis of their eclipses and
pulsational characteristics. We find unresolved g-mode pulsations at
frequencies 1-1.5 d-1 in CM Lac, and measure the masses and
radii of the component stars from the TESS data and published radial
velocities. MZ Lac shows a much richer frequency spectrum, including
pressure modes and tidally excited g-modes. RX Dra is in the northern
continuous viewing zone of TESS so has a light-curve covering a full
year, but shows relatively few pulsation frequencies. For V2077 Cyg we
formally measure four pulsation frequencies, but the available data are
inadequate to properly resolve the g-mode pulsations. V2077 Cyg also
shows total eclipses, with which we obtain the first measurement of the
surface gravity of the faint secondary star. All four systems are bright
and good candidates for detailed study. Further TESS observations are
scheduled for all four systems, with much improved temporal baselines
in the cases of RX Dra and V2077 Cyg.
Title: Hard-X-ray-selected active galactic nuclei - II. Spectral
energy distributions in the 5-45 GHz domain
Authors: Panessa, Francesca; Chiaraluce, Elia; Bruni, Gabriele;
Dallacasa, Daniele; Laor, Ari; Baldi, Ranieri D.; Behar, Ehud; McHardy,
Ian; Tombesi, Francesco; Vagnetti, Fausto
Bibcode: 2022MNRAS.515..473P
Altcode: 2022arXiv220610424P; 2022MNRAS.tmp.1693P
A wide-frequency radio study of active galactic nuclei (AGN) is
crucial to evaluate the intervening radiative mechanisms responsible
for the observed emission and relate them with the underlying accretion
physics. We present wide-frequency (5-45 GHz), high-sensitivity (few
$\mathrm{{\mu }Jy\, beam^{-1}}$), (sub)-kpc Jansky Very Large Array
(JVLA) observations of a sample of 30 nearby ($0.003\, \le \, z\,
\le \, 0.3$) AGN detected by the International Gamma-Ray Astrophysics
Laboratory (INTEGRAL)/Imager on Board the INTEGRAL Satellite (IBIS)
at hard X-ray. We find a high detection fraction of radio emission at
all frequencies, i.e. ≥95 per cent at 5, 10, and 15 GHz and ≥80
per cent at 22 and 45 GHz. Two sources out of 30 remain undetected at
our high sensitivities. The nuclear radio morphology is predominantly
compact, sometimes accompanied by extended jet-like structures, or
more complex features. The radio spectral energy distributions (SEDs)
of the radio cores appear either as single or as a broken power law,
a minority of them exhibit a peaked component. The spectral slopes are
either flat/inverted or steep, up to a break/peak or over the whole
range. The sample mean SED shows a flat slope up to 15 GHz that steepens
between 15 and 22 GHz and becomes again flat above 22 GHz. Significant
radio-X-ray correlations are observed at all frequencies. About half of
the sample features extended emission, clearly resolved by the JVLA,
indicating low-power jets or large-scale outflows. The unresolved
cores, which often dominate the radio power, may be of jet, outflow,
and/or coronal origin, depending on the observed frequency.
Title: Calibration of NOMAD on ExoMars Trace Gas Orbiter: Part 3 -
LNO validation and instrument stability
Authors: Cruz Mermy, G.; Schmidt, F.; Thomas, I. R.; Daerden, F.;
Ristic, B.; Patel, M. R.; Lopez-Moreno, J. -J.; Bellucci, G.; Vandaele,
A. C.; The NOMAD Team
Bibcode: 2022P&SS..21805399C
Altcode:
The LNO channel is one of the 3 instruments of the NOMAD suite of
spectrometers onboard the ExoMars Trace Gas Orbiter currently orbiting
Mars. Designed to operate primarily at nadir at very high spectral
resolution in the 2.3 μm-3.8 μm spectral region, the instrument
observes the martian atmosphere and surface daily since March 2018. To
perform an accurate calibration of the instrument, in-flight measurement
needs to be integrated to account for potential change during the
cruise phase and later during the mission. In a companion article,
Thomas et al. this issue, PSS, 2021 proposed a method based on the use
of 6 observation sequences of the sun by LNO to derive a self-consistent
approach, assuming temporal stability. Here we report an alternative
concept of calibration, model the instrument using basic principle,
based on the comparison between each solar spectrum observed and a
reference solar spectrum. The method has the advantages to allows
testing of the temporal stability but also instrumental effects such
as temperature. It encompasses the main transfer functions of the
instrument related to the grating and the AOTF and the instrument
line shape using 9 free parameters which, once inverted, allow the
observations to be fitted with an acceptable Root Mean Square Error
(RMSE) around 0.5%. We propose to perform a continuum removal step
to reduce the spurious instrumental effect, allowing to directly
analyze the atmospheric lines. This methodology allows quantifying
the instrumental sensitivity and its dependence on temperature and
time. Once the temperature dependence was estimated and corrected,
we found no sign of aging of the detector. Finally, the parameters
are used to propose an efficient calibration procedure to convert the
LNO-NOMAD data from ADU to radiances with spectral calibration and
the instrument line shape. A comparison with the method reported in
Thomas et al. this issue, PSS, 2021 showed that both calibrations are
in agreement mostly within 3%.
Title: Findings of the unusual plasma bubble occurrences at dawn
during the recovery phase of a moderate geomagnetic storm over the
Brazilian sector
Authors: Carmo, C. S.; Denardini, C. M.; Figueiredo, C. A. O. B.;
Resende, L. C. A.; Moro, J.; Silva, R. P.; Nogueira, P. A. B.; Chen,
S. S.; Picanço, G. A. S.; Neto, P. F. Barbosa
Bibcode: 2022JASTP.23505908C
Altcode:
In this work, we observe for the first time the unusual pre-sunrise
Equatorial Plasma Bubbles (EPBs) during a moderate geomagnetic storm
recovery phase caused by the High-Speed Solar Wind Stream (HSS) on
February 17, 2015, over the Brazilian sector. Therefore, this study
aims to explain the generation mechanism of this uncommon event,
which started at 08:00 UT on February 18, 2015. We used Multiple
Global Navigation Satellite Systems (Multi-GNSS, GPS, and GLONASS)
data to produce two-dimensional maps of the Rate Of TEC index (ROTI)
that show EPB features elongated in magnetic meridians. Also, Digisonde
data from São Luís (2.53° S, 44.30° W, dip angle: 8.57°), Boa
Vista (12.81° N, 60.67° W, dip angle: 33.71°), and Campo Grande
(20.44° S, 54.64° W, dip angle: 25.98°), and magnetometer data at
São Luís and Eusébio (3.89° S, 38.45° W, dip angle: 17.96°). Our
analysis shows that the unusual pre-sunrise plasma bubbles lasted
longer after sunrise, around 1 h. Finally, we showed that these EPBs
are likely driven by a disturbance wind dynamo effect, which helps to
understand the role of the external factors in EPBs development.
Title: Novel extraction protocol for evaluating abundances and
structural features of amorphous SiO2
Authors: Pandey, Aditi; Nguyen-Vu, Monique; Schwab, Paul
Bibcode: 2022Icar..38415096P
Altcode:
Spectral data from satellite and rover missions on Mars identified
significant abundances of amorphous phases in most samples analyzed,
and SiO2 is the principal amorphous constituent in the Gale
crater. Identifying and quantifying these short-range ordered, highly
reactive phases is challenging but necessary to gain insight into
the evolution of these materials. Terrestrial analogs are frequently
employed to allow detailed analyses that cannot be performed on
Martian samples. Historically, chemical extraction techniques have been
extensively used to characterize amorphous materials in terrestrial
soils, but most automated systems are complex, expensive, and limited
to analyzing a single sample at one time. This study aims to develop
a cost-effective apparatus that will allow latitude in choosing
an extractant, process several samples simultaneously, enable rapid
sampling over time without interruption and provide the resolution for
quantitative differentiation of rapidly dissolving SiO2(a)
phases in natural samples. Dissolution rates as a function of time were
used as input for kinetic models to estimate the abundances of amorphous
phases. When 2 M Na2CO3 is used as the extractant,
dissolution rates differ significantly between secondary phases such
as opal and primary glass phases. A stronger base, NaOH, is necessary
for the complete dissolution of basaltic glass. Palagonitic tuffs from
Iceland (proposed analogs of Martian soils) with >90% (w/w) amorphous
composition were analyzed with 2 M Na2CO3 in the
proposed apparatus, and both primary glass and secondary SiO2
appear to be present. Using the kinetic model of the dissolution,
the palagonitic tuff has a composition of approximately 25% (w/w) of a
rapidly reacting amorphous phase and 13% (w/w) of the slower reacting
glass-like phase. The proposed high-efficiency analytical method
can be applied to screen multiple terrestrial analogs and archive
dissolution kinetics of many standard amorphous minerals. Although
this paper focuses on extracting SiO2(a), the same setup
can be applied to study time-based dissolution reactions using other
extractants such as ammonium oxalate oxalic acid.
Title: On the reliability of the inversion aimed to reconstruct
global lightning activity based on Schumann resonance measurements
Authors: Prácser, Ernő; Bozóki, Tamás
Bibcode: 2022JASTP.23505892P
Altcode:
The electromagnetic field generated by lightning is measured at
extremely low frequencies (< 100 Hz) in many places on Earth. These
measurements are called Schumann resonance (SR) measurements. From SR
measurements the location and intensity of global lightning activity
can be estimated by applying an inversion algorithm. In this paper,
we present an inversion approach based on singular value decomposition
(SVD) for this problem and we describe some quality features of the
applied inversion technique. The inversion algorithm is tested on
synthetic data and the reliability of the obtained results is examined
based on the described quality features. Our synthetic tests confirm
that the described quality features are very useful in determining
the reliability of inversion results. An important conclusion from the
synthetic tests is that the quality of the inversion is not adversely
affected by incorrect assumptions about the location of the lightning
sources.
Title: Meteors observations by the orbital telescope TUS
Authors: Ruiz-Hernandez, Oliver I.; Sharakin, Sergei; Klimov, Pavel;
Martínez-Bravo, Oscar M.
Bibcode: 2022P&SS..21805507R
Altcode:
The TUS (Tracking Ultraviolet Set-up) detector is the first fluorescence
telescope aimed to measuring Extensive Air Showers (EAS) from space
and operated till December 4th, 2017. Despite the main operation mode
with a 0.8 μs temporal resolution of the TUS detector was devoted for
EAS detection, also it was able to measure different slower luminescent
phenomena in the near ultraviolet range. One of the TUS operation modes
had 6.6 ms temporal resolution and was used to measure micro-meteors
and thunderstorm activity. The high sensitivity of the device due to
large area of an optical system, makes it a potentially powerful tool
for studying dim and fast glow in the Earth's atmosphere. In this
work we present the kinematics reconstruction of 13 events recorded
by the TUS during 250 h of operation, which possess the expected
characteristics produced by a meteor (characteristic linear track
and light curve). We discuss the possible source of them and their
luminosity. This experience of orbital meteor observations is useful for
planning similar research in the future more sensitive space missions.
Title: Sporadic micro-meteoroid source radiant distribution inferred
from the Arecibo 430 MHz radar observations
Authors: Li, Yanlin; Zhou, Qihou; Urbina, Julio; Huang, Tai-Yin
Bibcode: 2022MNRAS.515.2088L
Altcode: 2022MNRAS.tmp.1833L
This work presents the result of sporadic meteor radiant density
distribution using the Arecibo 430 MHz incoherent scatter radar (ISR)
located in Puerto Rico for the first time. Although numerous meteor
studies have been carried out using the Arecibo ISR, meteoroid radiant
density distribution has remained a mystery as the Arecibo radar cannot
measure vector velocity. A numerical orbital simulation algorithm
using dynamic programming and stochastic gradient descent is designed
to solve the sporadic meteoroid radiant density and the corresponding
speed distributions of the meteors observed at Arecibo. The data
set for the algorithm comprises over 250 000 meteors from Arecibo
observations between 2009 and 2017. Five of the six recognized sporadic
meteor sources can be identified from our result. There is no clearly
identifiable South Apex source. Instead, there is a broad distribution
between +/-30° ecliptic latitude, with the peak density located in the
North Apex direction. Our results also indicate that the Arecibo radar
is not sensitive to meteors travelling straight into or perpendicular
to the antenna beam but is most sensitive to meteors with an arrival
angle between 30° and 60°. Our analysis indicates that about 75 per
cent of meteoroids observed by the Arecibo radar travel in prograde
orbits when the impact probability is considered. Most of the retrograde
meteoroids travel in inclined low-eccentricity orbits.
Title: Calibration Observations of ACIS-I2 with Cas A at a
Non-Standard Focal Plane Temperature of -105C
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6443C
Altcode:
These observations will be used to calibrate ACIS at a focal plane
temperature of -105C.
Title: Unified formalism for the emergence of space from the first
law of thermodynamics
Authors: Hassan Basari V., T.; Krishna, P. B.; Mathew, Titus K.
Bibcode: 2022arXiv220900304H
Altcode:
We derive a unified expansion law for our universe from the first law
of thermodynamics on the apparent horizon, where entropic evolution
depicts the emergence of cosmic space. The derivation advances a
general form for degrees of freedom on the surface and bulk, which
provides a natural generalization for the expansion law proposed
by Padmanabhan. The derivation also provides justification for the
selection of Gibbons-Hawking temperature in the original expansion law
and for the use of areal volume in the non-flat FRW universe. Since
the unified expansion law exclusively depends on the form of entropy,
the method is applicable to obtain the expansion law in any gravity
theory without any additional ad hoc assumptions. From the general
expansion law, we have obtained the expansion law corresponding to
different theories of gravity like (n+1) Einstein, Gauss-Bonnet,
Lovelock, and Horava-Lifshitz. We also obtained the expansion law for
non-extensive entropy, like Tsallis entropy.
Title: Detection of the impact of a tropical cyclonic system on the
dynamics and energetics of the atmosphere using wind profiler radar
Authors: Sivan, C.; Rakesh, V.; Manoj, M. G.; Satheesan, K.; Abhilash,
S.; Mohanakumar, K.
Bibcode: 2022JASTP.23505896S
Altcode:
Rapid changes in the tropospheric circulation features associated
with the overhead passage of the Gaja cyclonic system over the 205
MHz Stratosphere Troposphere wind profiler radar observations at Kochi
(10.03° N, 76.33° E), India, have been studied. The severe cyclonic
system formed in the southeast Indian Peninsular region weakened
into a depression after landfall near the Tamil Nadu coast. On 16th
November 2018, the cyclonic system crossed the Western Ghats and
travelled westward at 33 knots over the ST radar site at Kochi in the
evening. Later it reached the Arabian Sea and intensified again into
a severe cyclone. Continuous observations of the vertical structure of
the wind pattern at 4-min intervals from the wind profiler radar have
been examined. The impact of the transit of the cyclonic system extends
up to a height of 13 km in the atmosphere. The vertical distribution of
turbulent kinetic energy in the atmosphere indicates a sudden disruption
in the tropospheric levels at the time of storm passage. The cyclonic
system traversed over the Western Ghats positioned at an altitude
of 2500 m. It crossed the radar site at the mean sea level after
passing a horizontal distance of 100 km. The abrupt changes in the
topographical conditions generate atmospheric gravity waves in the
leeward side of the Western Ghats, as observed from the ST radar,
are presented. During the period, changes in surface parameters
were evaluated using co-located automatic weather station (AWS)
data. Satellite information and Doppler weather radar observations
from Kochi have also supplemented the investigation.
Title: Sunspot numbers and proton events in solar cycles 19 to 24
Authors: Birch, M. J.; Bromage, B. J. I.
Bibcode: 2022JASTP.23605891B
Altcode:
In this study we compare the mean annual sunspot numbers for the six
most recent solar cycles (19 to 24) with the number of solar energetic
proton events occurring in those years. Though most of the individual
cycles exhibit quite strong correlations, when they are combined into
a generic solar cycle the result is very significant (ρ = 0.98). For
cycles 21 to 24 (when spacecraft observations have been regularly
available), we also investigate the variation in the source location
of the solar energetic proton events in relation to four peak flux
thresholds in orders of magnitude from ≥10 to ≥10,000 pfu. For
helio-latitudes within ±40° (the range within which active regions
usually occur) there is negligible variation in the helio-longitude of
the source regardless of the peak flux threshold. However, the effect
on the helio-longitude of varying the peak flux threshold is very
significant: the higher the threshold the closer is the median source
longitude to 0°, the variation being almost uniform from ≥10 pfu
(32°W) to ≥10,000 pfu (2°W). Finally, of the 10 events in cycles 19
to 24 with peak flux ≥10,000 pfu, all occurred between years 4 and 8
after solar minimum, all were the result of M- or X-class flares with
associated halo CMEs and shock fronts, and the three most intense events
(≥40,000 pfu) were all related to X-class flares which occurred in
the longitude range 10-28°E. These results support and extend previous
work by the cited authors, and have implications for solar-terrestrial
relations and the effects of space weather within geospace.
Title: A bright and spectrally multiplexed on-chip quantum light
source
Authors: Wang, Cheng
Bibcode: 2022SCPMA..6594263W
Altcode:
No abstract at ADS
Title: Tracking the Ulx Population Activity in the Circinus Galaxy
during the Ixpe Observation
Authors: Marinucci, Andrea
Bibcode: 2022cxo..prop.6357M
Altcode:
We propose two observations of the nuclear region of the Circinus
Galaxy, 10 ks long each, simultaneous to the IXPE (Imaging X-ray
Polarimeter Explorer) pointing of the source. We aim at monitoring
the flux level of the two Ultra Luminous X-ray sources (ULXs) CG X-1
and CG X-2, which might potentially contaminate the measurement of the
polarization signal from the Active Galactic Nucleus (AGN). With its
superior angular resolution, Chandra is the only X-ray observatory on
orbit which will allow us to disentangle the emission of CG X-1 and
CG X-2 from the one of the AGN. Since CG X-1 varies on timescales of
weeks, we require an ACIS-S observation at the beginning and another
one at the end of the IXPE pointing (which is about 20 days long).
Title: 2023 Spring Semester - Calibration Observations of Cas A
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6431C
Altcode:
Due to the continued fading of the ECS, the calibration team is
transferring the ACIS gain calibration to Cas A.
Title: Calibration Observations of ACIS-I1 with Cas A at a
Non-Standard Focal Plane Temperature of -105C
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6442C
Altcode:
These observations will be used to calibrate ACIS at a focal plane
temperature of -105C.
Title: Analysis of z<0.7 Cool Attitude Target quasars to calibrate
the Hubble diagram
Authors: Civano, Francesca
Bibcode: 2022cxo..prop.6425C
Altcode:
A new method has been proposed by Risaliti & Lusso (2016, 2019),
taking advantage of the large statistics provided by quasar surveys, to
constrain cosmological models with quasars in a completely unexplored
redshift range beyond which SN Ia are hardly detected. We want to
exploit the sample of z<0.7 quasars with pointed X-ray observations
that were recently observed as Chandra Cool Targets (CCTs) plus archival
sources drawn from the same CCT sample (48 sources total). The goal
is to analyze their X-ray properties and improve the calibration of
this new method for cosmological purposes at z<0.7 where samples
are scarce. We request fundings to support the analysis of this sample
and develop tools to automatically analyze future CCTs observations.
Title: Mid-Holocene high-resolution temperature and precipitation
gridded reconstructions over China: Implications for
elevation-dependent temperature changes
Authors: Chen, Weizhe; Xiao, Anguo; Braconnot, Pascale; Ciais,
Philippe; Viovy, Nicolas; Zhang, Rui
Bibcode: 2022E&PSL.59317656C
Altcode:
Driven by enhanced summer insolation in the Northern Hemisphere and
land-atmosphere feedbacks during the mid-Holocene (MH), most regions of
China were characterized by warmer and wetter summer than present. The
MH has been recognized as a benchmark period for climate simulations,
but proxy-based reconstructions and model results show some key
discrepancies in climate reconstructions. A lack of accurate gridded
climate data is a major obstacle to land surface modelling, which is
contributing to uncertainties in climate simulations. Here we developed
a monthly gridded dataset of temperature and precipitation for MH China
through applying eight interpolation methods to 159 pollen-based climate
reconstructions for January and July from previous studies. The gridded
dataset is consistent with these input records and other independent
climate reconstructions at 62 sites. Then, the temperature differences
between the MH and pre-industrial period are correlated with elevations
in China. Results show a significant elevation-dependent temperature
amplification of 0.59 °C/km for July during the MH relative to
pre-industrial period. In addition, our gridded reconstructions of the
MH climate were compared with climate simulations for the MH and for
the future medium-emission scenario. Most simulations significantly
underestimated the magnitude of climate anomalies during the MH in
China. Similar to the MH, a pronounced warming in winter and a strong
wetting in summer are projected in China at the end of this century
(i.e., 2091-2100), suggesting analogous seasonal changes during the
MH and future. This first high-resolution proxy-based gridded climate
dataset for MH China can be used in land surface modelling to improve
our understanding of terrestrial changes during the MH, which in turn
is expected to facilitate the climate simulations.
Title: Probing the rest-frame of the Universe with the near-IR cosmic
infrared background
Authors: Kashlinsky, A.; Atrio-Barandela, F.
Bibcode: 2022MNRAS.515L..11K
Altcode: 2022arXiv220600724K
While the cosmic microwave background (CMB) dipole is largely
assumed to be entirely kinematic, there is evidence that part of
it is primordial. Such a possibility arises in models implying a
tilt, interpreted as a dark flow, across the observable Universe. The
kinematic nature of the entire CMB dipole can be probed using the dipole
of cosmic backgrounds from galaxies after the last scattering. The
near-infrared (near-IR) cosmic infrared background (CIB) spectral
energy distribution leads to an amplified dipole compared with the
CMB. The CIB dipole is affected by galaxy clustering, decreasing
with fainter, more distant galaxies, and by Solar System emissions
and Galactic dust, which dominate the net CIB cosmological dipole in
the optical/near-IR. We propose a technique that enables an accurate
measurement of the kinematic near-IR CIB dipole. The CIB, effectively
the integrated galaxy light (IGL), would be reconstructed from resolved
galaxies in forthcoming space-borne wide surveys covering four bands,
0.9-2.5 μm. The galaxies will be subselected from the identified
magnitude range where the dipole component from galaxy clustering is
below the expected kinematic dipole. Using this technique, the dipole
can be measured in each of the bands at the statistical signal-to-noise
ratio S/N ≳50-100 with the forthcoming Euclid and Roman surveys,
isolating the CMB dipole's kinematic nature.
Title: AO-24 Big Dither Observation of Mkn421
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6435C
Altcode:
We continue to monitor the build-up of contamination on ACIS with
LETG/ACIS-S observations Mkn421.
Title: AO-23 Cold ECS Measurements
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6437C
Altcode:
Due to the lack of cold ECS data accumulated through June 2022, the
calibration team has requested and received approval for 30 ksec of
CECS time.
Title: Gravitational waves and electromagnetic radiation from charged
black hole binaries
Authors: Benavides-Gallego, Carlos A.; Han, Wen-Biao
Bibcode: 2022arXiv220900874B
Altcode:
It is still an open issue if astrophysical black holes have electric
charges or not. In this work, we analytically calculate gravitational
and electromagnetic waveforms in the frequency domain for charged black
hole binaries during the inspiral phase. In addition to the well-known
$f^{-7/6}$ waveforms, we also get a $-11/6$ power law gravitational
wave component. The phase of waveforms for charged binary is fully
derived. In the case of electromagnetic counterparts, we focus on
the electromagnetic dipole radiation, but we include the quadrupole
contribution to complete our discussion. We also obtain the chirp
property of the electromagnetic waves. In the case of dipole radiation,
the frequency-domain waves are proportional to $f^{-7/6}$, while
$f^{-1/6}$ appears in the quadrupole contribution. The frequency-domain
waveforms can be used to estimate the charges of black holes in the
current gravitational wave observations.
Title: Evolution of close binary systems parameter distributions
Authors: Belay Zeleke, Dugasa; Humne Negu, Seblu; Malkov, Oleg Yu.
Bibcode: 2022arXiv220900251B
Altcode:
In this paper, we investigate the orbital and stellar parameters
of low- and intermediate-mass close binary systems. We use models,
presented in the catalogue of (Han et al. 2000) and calculate
parameters of accretors. We also construct distributions of systems
along luminosity, semi-major axis and angular momentum, and make some
conclusions on their evolution with time. We made a comparison of the
results with observational data and it shows a good agreement. The set
of theoretical models published in (Han et al. 2000) quite adequately
describes the observational data and, consequently, can be used to
determine the evolutionary path of specific close binary systems,
their initial parameters values and final stages.
Title: AO-24 Calibration Observations of A1795
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6436C
Altcode:
These observations are used to monitor the contamination build-up
on ACIS
Title: Statistical validation of the detection of a sub-dominant
quasi-normal mode in GW190521
Authors: Capano, Collin D.; Abedi, Jahed; Kastha, Shilpa; Nitz,
Alexander H.; Westerweck, Julian; Cabero, Miriam; Nielsen, Alex B.;
Krishnan, Badri
Bibcode: 2022arXiv220900640C
Altcode:
One of the major aims of gravitational wave astronomy is to
observationally test the Kerr nature of black holes. The strongest such
test, with minimal additional assumptions, is provided by observations
of multiple ringdown modes, also known as black hole spectroscopy. For
the gravitational wave merger event GW190521, we have previously
claimed the detection of two ringdown modes emitted by the remnant
black hole. In this paper we provide further evidence for the detection
of multiple ringdown modes from this event. We analyze the recovery of
simulated gravitational wave signals designed to replicate the ringdown
properties of GW190521. We quantify how often our detection statistic
reports strong evidence for a sub-dominant $(\ell,m,n)=(3,3,0)$
ringdown mode, even when no such mode is present in the simulated
signal. We find this only occurs with a probability $\sim 0.02$, which
is consistent with a Bayes factor of $56 \pm 1$ (1$\sigma$ uncertainty)
found for GW190521. We also quantify our agnostic analysis of GW190521,
in which no relationship is assumed between ringdown modes, and find
that less than 1 in 500 simulated signals without a $(3,3,0)$ mode
yield a result as significant as GW190521. Conversely, we verify
that when simulated signals do have an observable $(3,3,0)$ mode
they consistently yield a strong evidence and significant agnostic
results. We also find that simulated GW190521-like signals with a
$(3,3,0)$ mode present yield tight constraints on deviations of that
mode from Kerr, whereas constraints on the $(2,2,1)$ overtone of the
dominant mode yield wide constraints that are not consistent with
Kerr. These results on simulated signals are similar to what we find
for GW190521. Our results strongly support our previous conclusion
that the gravitational wave signal from GW190521 contains an observable
sub-dominant $(\ell,m,n)=(3,3,0)$ mode.
Title: Carbon in the deep upper mantle and transition zone under
reduced conditions: Insights from high-pressure experiments and
machine learning models
Authors: Lei, Jiali; Sen, Sayan; Li, Yuan; ZhangZhou, J.
Bibcode: 2022GeCoA.332...88L
Altcode:
The storage of carbon in Earth's mantle is an important consideration
within the framework of the deep carbon cycle. In the deep (>250 km
depth) reduced mantle, carbon storage mechanisms differ greatly from
those in the oxidized shallow mantle. To investigate the stability
of carbon-bearing phases in Earth's deep mantle, we experimentally
constrained compositional effects on phase stability in the Fe-Ni-S-C
system at conditions relevant to the deep upper mantle and mantle
transition zone. Our experiments suggest that carbide is absent
at 10 GPa and 1450 °C in the Ni-poor (molar Ni/(Ni + Fe) = 0.2)
portion of the metal-sulfide-carbon ternary, with carbon occurring
as diamond or dissolved in the Fe-Ni-S-C melt. At 19 GPa and 1450 and
1600 °C, (Fe,Ni)7C3 saturates in the melt with
C-rich (4.78-9.47 wt%), S-poor (2.29-6.98 wt%) bulk compositions. In
comparison, Fe-Ni alloy only saturates with the C- and S-poor bulk
composition of 77.88 wt% Fe, 19.47 wt% Ni, 1.93 wt% S, and 0.72 wt%
C. Based on these results, we trained machine learning models to
predict carbon solubility in Fe-Ni-S-C melts. Compared to classical
regression models, machine learning models significantly improve the
accuracy of carbon solubility predictions. Combined, our experimental
and machine learning results suggest that diamond and Fe-Ni-S-C melt
are the primary hosts of carbon in the convecting deep upper mantle and
throughout most of the mantle transition zone. In the deepest parts
of the transition zone, however, carbide is likely to precipitate at
adiabatic temperatures in C-rich mantle sources.
Title: RVSPY -- Radial Velocity Survey for Planets around Young
Stars. Target characterization and high-cadence survey
Authors: Zakhozhay, O.; Launhardt, R.; Mueller, A.; Brems, S.;
Eigenthaler, P.; Gennaro, M.; Hempel, A.; Hempel, M.; Henning, Th.;
Kennedy, G.; Kim, S.; Kuerster, M.; Lachaume, R.; Manerikar, Y.;
Patel, J.; Pavlov, A.; Reffert, S.; Trifonov, T.
Bibcode: 2022arXiv220901125Z
Altcode:
We introduce our Radial Velocity Survey for Planets around Young stars
(RVSPY), characterise our target stars, and search for substellar
companions at orbital separations smaller than a few au from the host
star. We use the FEROS spectrograph to obtain high signal-to-noise
spectra and time series of precise radial velocities (RVs) of 111
stars most of which are surrounded by debris discs. Our target
stars have spectral types between early F and late K, a median age
of 400 Myr, and a median distance of 45 pc. We determine for all
target stars their basic stellar parameters and present the results
of the high-cadence RV survey and activity characterization. We
achieve a median single-measurement RV precision of 6 m/s and derive
the short-term intrinsic RV scatter of our targets (median 22 m/s),
which is mostly caused by stellar activity and decays with age from
>100 m/s at <20 Myr to <20 m/s at >500 Myr. We discover
six previously unknown close companions with orbital periods between 10
and 100 days, three of which are low-mass stars, and three are in the
brown dwarf mass regime. We detect no hot companion with an orbital
period <10 days down to a median mass limit of ~1 M_Jup for stars
younger than 500 Myr, which is still compatible with the established
occurrence rate of such companions around main-sequence stars. We
find significant RV periodicities between 1.3 and 4.5 days for 14
stars, which are, however, all caused by rotational modulation due to
starspots. We also analyse the TESS photometric time series data and
find significant periodicities for most of the stars. For 11 stars,
the photometric periods are also clearly detected in the RV data. We
also derive stellar rotation periods ranging from 1 to 10 days for
91 stars, mostly from TESS data. From the intrinsic activity-related
short-term RV jitter, we derive the expected mass-detection thresholds
for longer-period companions.
Title: YSE/Pan-STARRS Transient Discovery Report for 2022-09-01
Authors: Jones, D. O.; French, K. D.; Agnello, A.; Angus, C. R.;
Ansari, Z.; Arendse, N.; Gall, C.; Grillo, C.; Bruun, S. H.; Hede,
C.; Hjorth, J.; Izzo, L.; Korhonen, H.; Raimundo, S.; Ramanah,
D. K.; Sarangi, A.; Wojtak, R.; Pfister, H.; Auchettl, K.; Chambers,
K. C.; Huber, M. E.; Magnier, E. A.; Boer, T. J. L. D.; Fairlamb,
J. R.; Lin, C. C.; Wainscoat, R. J.; Lowe, T.; Gao, H.; Bulger, J.;
Schultz, A. S. B.; Engel, A.; Gagliano, A.; Narayan, G.; Soraisam,
M.; Wang, Q.; Rest, A.; Smartt, S. J.; Smith, K. W.; Alexander, K.;
Blanchard, P.; DeMarchi, L.; Hajela, A.; Jacobson-Galan, W.; Margutti,
R.; Matthews, D.; Stauffer, C.; Stroh, M.; Terreran, G.; Drout, M.;
Coulter, D. A.; Dimitriadis, G.; Foley, R. J.; Hung, T.; Kilpatrick,
C. D.; Rojas-Bravo, C.; Siebert, M. R.; Ramirez-Ruiz, E.
Bibcode: 2022TNSTR2546....1J
Altcode:
No abstract at ADS
Title: Non-solar abundance ratios trends of dEs in the Fornax Cluster
using newly defined high-resolution indices
Authors: Şen, Şeyda; Peletier, Reynier F.; Vazdekis, Alexandre
Bibcode: 2022MNRAS.515.3472S
Altcode: 2022MNRAS.tmp.2088S; 2022arXiv220615214S
We perform a detailed study of the stellar populations in a sample
of massive Fornax dwarf galaxies using a set of newly defined line
indices. Using data from the Integral Field Spectroscopic data, we
study abundance ratios of eight dEs with stellar mass ranging from
108 to 109.5 M⊙ in the Fornax
Cluster. We present the definitions of a new set of high-resolution
Lick-style indices to be used for stellar population studies of
unresolved small stellar systems. We identify 23 absorption features
and continuum regions, mainly dominated by 12 elements (Na, Ca, Sc,
Ti, V, Cr, Mn, Fe, Ni, Y, Ba, and Nd) in the wavelength range 4700-5400
Å and characterize them as a function of age, metallicity, and alpha
element abundance ratios. We analyse eight dEs and interpret the line
strengths, measured in our new high-resolution system of indices,
with the aid of stellar population models with high enough spectral
resolution. We obtain abundance ratio proxies for a number of elements
that have never been studied before for dwarf ellipticals outside the
Local Group. These proxies represent relative deviations from predicted
index strengths of base stellar population models built-up following
the abundance pattern of The Galaxy. The abundance proxy trend results
are compared to abundance ratios from resolved stars in the Local Group,
and indices from integrated light of larger early-type galaxies. We find
that all our dwarfs show a pattern of abundance ratios consistent with
the disc of the Milky Way, indicative of slow formation in comparison
to their high-mass counterparts.
Title: Spectropolarimetry of the tidal disruption event AT 2019qiz:
a quasi-spherical reprocessing layer
Authors: Patra, Kishore C.; Lu, Wenbin; Brink, Thomas G.; Yang, Yi;
Filippenko, Alexei V.; Vasylyev, Sergiy S.
Bibcode: 2022MNRAS.515..138P
Altcode: 2022MNRAS.tmp.1696P; 2022arXiv220609039P
We present optical spectropolarimetry of the tidal disruption
event (TDE) AT 2019qiz on days +0 and +29 relative to maximum
brightness. Continuum polarization, which informs the shape of the
electron-scattering surface, was found to be consistent with 0 per cent
at peak brightness. On day +29, the continuum polarization rose to ~1
per cent, making this the first reported spectropolarimetric evolution
of a TDE. These findings are incompatible with a naked eccentric disc
that lacks significant mass outflow. Instead, the spectropolarimetry
paints a picture wherein, at maximum brightness, high-frequency emission
from the accretion disc is reprocessed into the optical band by a
nearly spherical, optically thick, electron-scattering photosphere
located far away from the black hole. We estimate the radius of the
scattering photosphere to be $\sim 100\rm \, au$ at maximum brightness -
significantly larger than the tidal radius ($\sim 1\rm \, au$) and the
thermalization radius ($\sim 30\rm \, au$) where the optical continuum
is formed. A month later, as the fallback rate drops and the scattering
photosphere recedes, the continuum polarization increases, revealing
a moderately aspherical interior. We also see evidence for smaller
scale density variations in the scattering photosphere, inferred from
the scatter of the data in the Stokes q-u plane. On day +29, the H α
emission-line peak is depolarized to ~0.3 per cent (compared to ~1 per
cent continuum polarization), and displays a gradual rise towards the
line's redder wavelengths. This observation indicates the H α line
formed near the electron-scattering radius.
Title: Extreme giant molecular clouds in the luminous infrared galaxy
NGC 3256
Authors: Brunetti, Nathan; Wilson, Christine D.
Bibcode: 2022MNRAS.515.2928B
Altcode: 2022MNRAS.tmp.1891B; 2022arXiv220705174B
We present a cloud decomposition of 12CO (2-1) observations
of the merger and nearest luminous infrared galaxy, NGC 3256. 185
spatially and spectrally resolved clouds are identified across the
central ≍130 kpc2 at 90 pc resolution and completeness is
estimated. We compare our cloud catalogue from NGC 3256 to ten galaxies
observed in the PHANGS-ALMA survey. Distributions in NGC 3256 of cloud
velocity dispersions (median 23 km s-1), luminosities (1.5 ×
107 K km s-1 pc2), CO-estimated masses
(2.1 × 107 M⊙), mass surface densities (470
M⊙ pc-2), virial masses (5.4 × 107
M⊙), virial parameters (4.3), size-linewidth coefficients
(6.3 km2 s-2 pc-1), and internal
turbulent pressures ( 1.0 × 10 7K cm-3$\,
k_{\mathrm{B}}^{-1}$) are significantly higher than in the PHANGS-ALMA
galaxies. Cloud radii (median 88 pc) are slightly larger in NGC 3256
and free-fall times (4.1 Myr) are shorter. The distribution of cloud
eccentricities in NGC 3256 (median of 0.8) is indistinguishable
from many PHANGS-ALMA galaxies, possibly because the dynamical
state of clouds in NGC 3256 is similar to that of nearby spiral
galaxies. However, the narrower distribution of virial parameters
in NGC 3256 may reflect a narrower range of dynamical states than in
PHANGS-ALMA galaxies. No clear picture of cloud alignment is detected,
despite the large eccentricities. Correlations between cloud properties
point to high external pressures in NGC 3256 keeping clouds bound and
collapsing given such high velocity dispersions and star-formation
rates. A fit to the cloud mass function gives a high-mass power-law
slope of $-2.75^{+0.07}_{-0.01}$, near the average from PHANGS-ALMA
galaxies. We also compare our results to a pixel-based analysis of these
observations and find molecular-gas properties agree qualitatively,
though peak brightness temperatures are somewhat higher and virial
parameters and free-fall times are somewhat lower in this cloud-based
analysis.
Title: Cluster temperature profiles at high-z from resolved SZ and
X-ray measurements
Authors: Hughes, John P.
Bibcode: 2022cxo..prop.6400H
Altcode:
We propose a deep ACIS-S observation of HSC J0947-0119, a new,
massive, high-redshift (z=1.104) cluster discovered in the Subaru
Hyper Suprime-Cam (HSC) survey. The cluster is a significant
Sunyaev-Zel'dovitch (SZ) effect cluster, detected by ACT and with
a highly significant, resolved, SZ map from ALMA at an effective
resolution of 5" with signal extending over an arc minute. Our immediate
objective is to obtain a precise X-ray surface brightness profile for
use in conjunction with the ALMA SZ profile to measure gas temperature
and density profiles.
Title: Follow-ups of the most significant AGN ignition events detected
by eROSITA
Authors: Krumpe, Mirko
Bibcode: 2022cxo..prop.6379K
Altcode:
The eROSITA telescope is performing multiple all-sky X-ray surveys,
monitoring roughly half a million AGN, and identifying very rare AGN
ignition events as they occur. We request two ToO observations with
ACIS-S -- each 3x30 ks, each observation spaced 1.5 months apart --
to constrain the evolution of the various X-ray spectral components in
the most exceptional ignition events to be detected in future eROSITA
scans. We can thus track how the X-ray corona forms and adjusts to the
new accretion configuration. Joined with optical spectral monitoring
programs, we can determine how the different structural AGN components
(disk, BLR) respond as well and how the corona, disk, and BLR interact
with each other during AGN ignition.
Title: Dissecting the stormy weather in 3C 196.1
Authors: Ricci, Federica
Bibcode: 2022cxo..prop.6381R
Altcode:
We propose 48 ksec Chandra observation of the radio galaxy (RG)
3C196.1, BCG of the galaxy cluster CIZAJ0815.4-0308. The Chandra
archival observation of 3CR 196.1 shows a wealth of structures which is
indicative of complex RG/ICM interactions. Chandra 48 ksec data will
be combined with the archival observation to derive a high angular
resolution map of the inner core, characterize cavities and directly
probe kinetic feedback in action in this z=0.198 galaxy cluster. We
will also investigate the relation between extended emission line
region observed in the optical and spatially coincident with the inner
cavity around 3CR 196.1 a rare and unique case deserving deeper X-ray
observations.
Title: Chandra TOOs for Fermi Galactic Plane Transients
Authors: Torres-AlbÃÂ, Núria
Bibcode: 2022cxo..prop.6312T
Altcode:
Fermi detected hundreds of transients with short (sec to hr) and
long (months) variability timescales. However, transients on weekly
timescales are more challenging to detect. The Fermi All-sky Variability
Analysis (FAVA) allows us to systematically search the whole sky for
weekly transients. The novelty of FAVA resides in using the mission-long
data to provide an estimate of the average sky intensity against which
weekly data are compared. This makes FAVA an unbiased and fast tool
to find transients in the Galactic plane where the diffuse emission
is the brightest. FAVA detects 1 plane transient every 2 weeks. We
plan to use Chandra to follow up on 2 new transients. The population
of Galactic transients is undersampled and detecting even 1 source
will have a large impact
Title: Reconsideration of the anelasticity parameters of the martian
mantle: Preliminary estimates based on the latest geodetic parameters
and seismic models
Authors: Harada, Yuji
Bibcode: 2022Icar..38314917H
Altcode:
This study re-estimates the anelasticity parameters of the martian
mantle on the basis of both of the recent tidal and rotational
parameters and also the latest internal structure models obtained
from the in-situ seismic experiment. This study considers the
geodetically-derived tidal Love number, global quality factor, and
Chandler wobble period, together with the seismologically-derived
interior models based on the geophysical and geodynamical inversions. On
the assumption of simple power-law rheology, a grid search restricts
the ranges of the anelasticity parameters, namely, the frequency
exponent (α = 0 . 22 ± 0 . 13) and local quality factor normalization
(Q0 = 76 ± 9). The combination of the tidal and rotational
parameters with the seismic models constrains the frequency exponent
effectively.
Title: Very-high-energy flat spectral radio quasar candidates
Authors: Malik, Zahoor; Sahayanathan, Sunder; Shah, Zahir; Iqbal,
Naseer; Manzoor, Aaqib
Bibcode: 2022MNRAS.515.4505M
Altcode: 2022arXiv220403229M
The attenuation of very-high-energy (VHE) photons by the extragalactic
background light (EBL) prevents the observation of high-redshift flat
spectrum radio quasars (FSRQs). However, the correlation of the VHE
spectral index with source redshift suggests that the EBL intensity may
be less than what is predicted. This deviation can draw new constraints
on the opacity of the Universe to VHE gamma-rays. Therefore, more FSRQs
may fall above the sensitivity of the forthcoming VHE telescopes than
the ones predicted by the existing EBL models. In order to account for
the lower EBL intensity predicted by the index-redshift correlation,
we introduce a redshift-dependent correction factor to the opacity,
estimated from a commonly used cosmological EBL model. Considering
this modified opacity, we identify the plausible VHE FSRQ candidates
by linearly extrapolating the Fermi gamma-ray spectrum at 10 GeV to
the VHE regime. Our study suggests that among 744 FSRQs reported in
the Fermi Fourth Catalogue Data Release 2, 32 FSRQs will be detectable
by the Cherenkov Telescope Array Observatory (CTAO). Because FSRQs are
proven to be highly variable, we assume a scenario where the average
Fermi gamma-ray flux increases by a factor of 10, and this predicts
an additional 90 FSRQs that can be detected by the CTAO.
Title: Global Non-linearly Stable Large Data Solutions to the Einstein
Scalar Field System
Authors: Kilgore, Eric
Bibcode: 2022AnHP...23.3093K
Altcode: 2021arXiv210813377K
I study a class of global, causal geodesically complete solutions
to the spherically symmetric Einstein scalar field (SSESF) system
. Extending results of Luk-Oh (Quantitative Decay Rates for Dispersive
Solutions to the Einstein-Scalar Field System in Spherical Symmetry,
arXiv:1402.2984), Luk-Oh-Yang (Solutions to the Einstein-Scalar-Field
System in Spherical Symmetry with Large Bounded Variation Norms,
arXiv:1605.03893), I provide new bounds controlling higher derivatives
of both the metric components of the solution and the scalar field
itself for large data solutions to SSESF. Moreover, by constructing a
particular set of generalized wave-coordinates, I show that, assuming
sufficient regularity of the data, these solutions are globally
non-linearly stable to non-spherically symmetric perturbations by recent
results of Luk and Oh. In particular, I demonstrate the existence of
a large collection of non-trivial examples of large data, globally
nonlinearly stable, dispersive solutions to the Einstein scalar
field system.
Title: Removal of straylight from ExoMars NOMAD-UVIS observations
Authors: Mason, Jonathon P.; Patel, Manish R.; Leese, Mark R.;
Hathi, Brijen G.; Willame, Yannick; Thomas, Ian R.; Wolff, Michael
J.; Depiesse, Cédric; Holmes, James A.; Sellers, Graham; Marriner,
Charlotte; Ristic, Bojan; Daerden, Frank; Lopez-Moreno, Jose Juan;
Bellucci, Giancarlo; Vandaele, Ann Carine
Bibcode: 2022P&SS..21805432M
Altcode:
We present an in-flight straylight removal method for the Ultraviolet
and Visible Spectrometer (UVIS) channel of the Nadir and Occultation
for Mars Discovery (NOMAD) instrument aboard the ExoMars Trace Gas
Orbiter (TGO). The presence of a 'red-leak' straylight signal in the
UVIS instrument was discovered post-launch in ground calibration
measurements of spectral lamps; UVIS observations of lamps with
negligible UV light emission (RS12) showed a significant signal at UV
wavelengths. Subsequent analyses of nadir observations of the martian
atmosphere revealed that at UV wavelengths the red-leak straylight
was in excess of 300% of the true UV signal, jeopardising the primary
science observations of the instrument (retrievals of atmospheric
ozone). By modifying the UVIS readout method to obtain a region of
interest around the illuminated region on the Charge-Coupled Device
(CCD) detector, instead of a binned one-dimensional spectrum, and
utilising straylight profiles derived from measurements of the RS12
calibration lamp we show that the majority of the straylight at UV
wavelengths can be successfully removed for the nadir channel in a
self-consistent manner. The corrected UVIS radiances are compared
to coincident Mars Color Imager (MARCI) instrument observations with
residuals between the two instruments generally remaining within 15%.
Title: Monitoring the Building of the Corona in ESO 253-G003
Authors: Schartel, Norbert
Bibcode: 2022cxo..prop.6266S
Altcode:
The hot corona is central for our understanding of the X-ray
emission of active galactic nuclei (AGN). Beside its importance,
in fact, we have very little knowledge about the corona. The last
years established a new viewing angle as a few observations allowed
to observe the building of a hot corona, especially in the context
of tidal disruption events. Unfortunately, this observations had to
follow an opportunistic approach which substantially limits their
significance. Here we propose a systematic monitoring of the building
of a corona in ESO 253-G003. ESO 253-G003 shows a strongly periodic
disruption of its X-ray emission every ~114 days and subsequent recovery
of its X-ray emitting hot corona within 20 days. This offers a unique
opportunity to systematically monitor the raise of a coron
Title: HRC-I check out observation of Cas A
Authors: CXC Calibration
Bibcode: 2022cxo..prop.6271C
Altcode:
We request a HRC-I observation of Cas A in order to check the processing
electronics and detector degap over a 6 arcminute region.
Title: Dissolution and electrolysis of lunar regolith in ionic liquids
Authors: Rohde, Sebastian; Wiltsche, Helmar; Cowley, Aidan; Gollas,
Bernhard
Bibcode: 2022P&SS..21905534R
Altcode:
Oxygen extraction from lunar regolith is one of the key in-situ
resource utilization methods required for a permanent human presence
on the moon. In this work an electrolysis-based extraction method was
investigated, which works with innocuous chemicals and at moderate
temperatures. EAC-1 was utilized as lunar regolith simulant and the
ionic liquid 1-ethyl-3-methylimidazolium hydrogen sulfate was used as
electrolyte. The working principle of this method, which was pioneered
by Paley et al.2009, is envisaged as a three step process. First,
water is generated by the dissolution of regolith in the Brønsted
acidic ionic liquid. This water is electrolyzed, yielding oxygen and
hydrogen as an intermediate product. Finally, the ionic liquid is
regenerated by anodic oxidation of hydrogen and cathodic reduction
of the dissolved metal ions. A gravimetric investigation showed that
approximately 30 wt% of EAC-1 can be solubilized, if at least 6 g
of ionic liquid are used per gram of EAC-1. Phosphorous oxide was
found to be the most soluble compound with 82.0 ± 3.1% of the total
amount in solution, followed by MgO, Na2O, K2O,
Al2O3, iron oxides, TiO2 and CaO in
decreasing order as determined by inductively coupled plasma optical
emission spectrometry (ICP-OES). Cyclic voltammetry of the neat
ionic liquid revealed that reduction of H+ is the dominant
cathodic reaction of the electrolyte. The cyclic voltammogram of the
EAC-1 solution showed a Fe2+/Fe3+ redox peak pair,
yet no distinct current, which could be attributed to further reduction
of metal ions and electrodeposition. An investigation of the electrode
surfaces with SEM and EDX after potential controlled electrolysis
experiments at strongly negative cathodic potentials did not reveal any
signs of metal deposition and ionic liquid regeneration. Hence, more
work is required to enable the ionic liquid regeneration of this oxygen
extraction method by either inhibiting the hydrogen evolution reaction
in the ionic liquid electrolyte or facilitating metal deposition.
Title: Evolution of dipolar mixed-mode coupling factor in red giant
stars: impact of buoyancy spike
Authors: Jiang, C.; Cunha, M.; Christensen-Dalsgaard, J.; Zhang,
Q. S.; Gizon, L.
Bibcode: 2022MNRAS.515.3853J
Altcode: 2022arXiv220709878J; 2022MNRAS.tmp.1954J
Mixed modes observed in red giants allow for investigation of the
stellar interior structures. One important feature in these structures
is the buoyancy spike caused by the discontinuity of the chemical
gradient left behind during the first dredge-up. The buoyancy spike
emerges at the base of the convective zone in low-luminosity red
giants and later becomes a glitch when the g-mode cavity expands
to encompass the spike. Here, we study the impact of the buoyancy
spike on the dipolar mixed modes using stellar models with different
properties. We find that the applicability of the asymptotic formalisms
for the coupling factor, q, varies depending on the location of the
evanescent zone, relative to the position of the spike. Significant
deviations between the value of q inferred from fitting the oscillation
frequencies and either of the formalisms proposed in the literature are
found in models with a large frequency separation in the interval 5-15
μHz, with evanescent zones located in a transition region that may be
thin or thick. However, it is still possible to reconcile q with the
predictions from the asymptotic formalisms, by choosing which formalism
to use according to the value of q. For stars approaching the luminosity
bump, the buoyancy spike becomes a glitch and strongly affects the mode
frequencies. Fitting the frequencies without accounting for the glitch
leads to unphysical variations in the inferred q, but we show that this
is corrected when properly accounting for the glitch in the fitting.
Title: The halo model with beyond-linear halo bias: unbiasing
cosmological constraints from galaxy-galaxy lensing and clustering
Authors: Mahony, Constance; Dvornik, Andrej; Mead, Alexander; Heymans,
Catherine; Asgari, Marika; Hildebrandt, Hendrik; Miyatake, Hironao;
Nishimichi, Takahiro; Reischke, Robert
Bibcode: 2022MNRAS.515.2612M
Altcode: 2022MNRAS.tmp.1803M; 2022arXiv220201790M
We determine the error introduced in a joint halo model analysis
of galaxy-galaxy lensing and galaxy clustering observables when
adopting the standard approximation of linear halo bias. Considering
the Kilo-Degree Survey, we forecast that ignoring the non-linear halo
bias would result in up to 5σ offsets in the recovered cosmological
parameters describing structure growth, S8, and the matter
density parameter, Ωm. We include the scales $10^{-1.3}\lt
r_{\rm {p}} \ / h^{-1}\, \mathrm{Mpc}\lt 10$ in the data vector, and the
direction of these offsets are shown to depend on the freedom afforded
to the halo model through other nuisance parameters. We conclude that a
beyond-linear halo bias correction must therefore be included in future
cosmological halo model analyses of large-scale structure observables
on non-linear scales.
Title: Simulating the night-time astronomical seeing at Dome A using
Polar WRF
Authors: Yang, Qike; Wu, Xiaoqing; Wang, Zhiyuan; Hu, Xiaodan; Guo,
Yiming; Qing, Chun
Bibcode: 2022MNRAS.515.1788Y
Altcode: 2022MNRAS.tmp.1890Y
In Antarctica, excellent astronomical observing conditions have been
measured at Dome A during night-time (or polar winter). This study
investigates the performance of the Polar-optimized version of the
Weather Research and Forecasting (Polar WRF, PWRF hereafter) for
simulating the night-time astronomical seeing at Dome A. The seeing
values were estimated by a seeing model, which used the PWRF-simulated
wind speed and temperature as inputs. Furthermore, three methods
to obtain the boundary layer height in the seeing model have been
examined. The estimated seeing agrees well with 50-d measurements
from the KunLun Differential Image Motion Monitor at Dome A during
the night-time of 2019; the correlation coefficients range from 0.62
to 0.71. The PWRF-simulated meteorological parameters indicate that
low wind speed and strong temperature inversion (when a large gradient
Richardson number always occurs) near the ground can lead to good seeing
condition. The results suggest that the PWRF model could be a reliable
tool for scheduling observational astronomy at Dome A during night-time.
Title: High-z Universe probed via Lensing by QSOs (HULQ). II. Deep
GMOS spectroscopy of a QSO lens candidate
Authors: Taak, Y. C.; Im, M.; Kim, Y.; Hyun, M.; Paek, I.
Bibcode: 2022A&A...665A...5T
Altcode: 2022arXiv220710726T
Galaxies and their central supermassive black holes are known to
coevolve, but the physical background for this is unknown as of
yet. The High-z Universe probed via Lensing by QSOs (HULQ) project
aims to investigate this coevolution by using quasi-stellar object
(QSO) host galaxies acting as gravitational lenses (QSO lenses). We
present the results of the spectroscopic observation of the first QSO
lens candidate from the HULQ project, HULQ J0002+0239, which consists
of a QSO host galaxy at zd = 1.455 and four seemingly lensed
objects in a cross-like configuration. Deep optical spectra of two of
the possibly lensed objects with z ∼ 24.5 mag were obtained with the
Gemini Multi-Object Spectrograph on the Gemini North Telescope. Their
spectra reveal that the objects are newly discovered galaxies at z
= 0.29 and z = 1.11, and we conclude that HULQ J0002+0239 is not a
QSO lens. Our QSO lens search results are so far in agreement with
the predicted number of QSO lenses, and we discuss how the future
investigation of additional QSO lens candidates could tell us more about
the evolution of the black hole mass and host galaxy scaling relations.
Title: A Partial-sky Gibbs ILC Approach for the Estimation of CMB
Posterior over Large Angular Scales of the Sky
Authors: Sudevan, Vipin; Purkayastha, Ujjal; Saha, Rajib
Bibcode: 2022ApJ...936..106S
Altcode: 2021arXiv211007975S
In this article we present a formalism for incorporating the partial-sky
maps into the Gibbs ILC algorithm to estimate the joint posterior
density of the cosmic microwave background (CMB) signal and the
theoretical CMB angular power spectrum given the observed CMB maps. In
order to generate the partial-sky maps, we mask all the observed CMB
maps provided by the WMAP and Planck satellite full-sky mission using
a mask that removes 22% of the entire sky. The mask we use is based
on the strength of the thermal dust emissions in the Planck 353 GHz
map. While implementing the Gibbs ILC method on the partial-sky maps,
we convert the partial-sky-cleaned angular power spectrum into the
full-sky angular power spectrum using the mode-mode coupling matrix
estimated from the smoothed mask. The main products of our analysis are
a partial-sky cleaned best-fit CMB map and an estimate of the underlying
full-sky theoretical CMB angular power spectrum in the multipole range 2
≤ ℓ ≤ 32 along with their error estimates. We validate the method
by performing detailed Monte Carlo simulations after using realistic
models of foregrounds and detector noise consistent with the WMAP and
Planck frequency channels used in our analysis. We can estimate the
posterior density and full-sky theoretical CMB angular power spectrum
without any need to explicitly model the foreground components from
partial-sky maps using our method. Another important feature of this
method is that the power spectrum results along with the error estimates
can be directly used for cosmological parameter estimations.
Title: Discovery and analysis of three magnetic hot subdwarf stars:
evidence for merger-induced magnetic fields
Authors: Pelisoli, Ingrid; Dorsch, M.; Heber, U.; Gänsicke, B.;
Geier, S.; Kupfer, T.; Németh, P.; Scaringi, S.; Schaffenroth, V.
Bibcode: 2022MNRAS.515.2496P
Altcode: 2022arXiv220406575P; 2022MNRAS.tmp.1047P
Magnetic fields can play an important role in stellar evolution. Among
white dwarfs, the most common stellar remnant, the fraction of magnetic
systems is more than 20 per cent. The origin of magnetic fields in
white dwarfs, which show strengths ranging from 40 kG to hundreds
of MG, is still a topic of debate. In contrast, only one magnetic
hot subdwarf star has been identified out of thousands of known
systems. Hot subdwarfs are formed from binary interaction, a process
often associated with the generation of magnetic fields, and will evolve
to become white dwarfs, which makes the lack of detected magnetic hot
subdwarfs a puzzling phenomenon. Here we report the discovery of three
new magnetic hot subdwarfs with field strengths in the range 300-500
kG. Like the only previously known system, they are all helium-rich
O-type stars (He-sdOs). We analysed multiple archival spectra of
the three systems and derived their stellar properties. We find that
they all lack radial velocity variability, suggesting formation via
a merger channel. However, we derive higher than typical hydrogen
abundances for their spectral type, which are in disagreement with
current model predictions. Our findings suggest a lower limit to
the magnetic fraction of hot subdwarfs of $0.147^{+0.143}_{-0.047}$
per cent, and provide evidence for merger-induced magnetic fields
which could explain white dwarfs with field strengths of 50-150 MG,
assuming magnetic flux conservation.
Title: A Photometric Study of Two Contact Binaries: CRTS
J025408.1+265957 and CRTS J012111.1+272933
Authors: Ma, Shuo; Liu, Jin-Zhong; Zhang, Yu; Hu, Qingshun; Lü,
Guo-Liang
Bibcode: 2022RAA....22i5017M
Altcode: 2022arXiv220706255M
We performed new photometric observations for two contact binaries
(i.e., CRTS J025408.1+265957 and CRTS J012111.1+272933), which
were observed by the 1.0 m telescope at Xingjiang Astronomical
Observatory. From our light curves and several survey data, we
derived several sets of photometric solutions. We found that CRTS
J025408.1+265957 and CRTS J012111.1+272933 were A- and W-type W UMa,
respectively. The results imply that the spot migrates or disappears
in the two contact binaries, which were identified by chromospheric
activity emissions (e.g., H α emission) from LAMOST
spectra. From the O-C curves, the orbital periods of the two contact
binaries may be increasing, which is interpreted by the mass transfer
from the less massive component to the more massive one. With mass
transferring, the two contact binaries may evolve from the contact
configurations to semi-detached ones as predicted by the theory of
thermal relaxation oscillation.
Title: Multi-scale Analysis of the Relationships between Solar
Activity, CO2 and Global Surface Temperature
Authors: Li, Zhen; Chang, Lijun; Lou, Jiahui; Shen, Yi; Yan, Haoming
Bibcode: 2022RAA....22i5019L
Altcode:
To reveal whether the dynamics of solar activity precede those of global
temperature, especially in terms of global warming, the relationship
between total solar irradiance (TSI), which is treated as a proxy of
solar activity, and global surface temperature (GST) is investigated
in the frequency domain using wavelet coherence. The results suggest
that the effect of TSI on GST is mainly reflected on the characteristic
scale around 22 yr, and variations in TSI lead to changes in GST with
some delay effect as shown by the phase difference arrows. However, this
implicated relationship has been perturbed by excessive CO2
emissions since 1960. Through the combination of co-integration
analysis and wavelet coherence, the hidden relationship between TSI
and GST has been uncovered without the CO2 effect and the
results further indicate that TSI has a positive effect on GST at the
characteristic scale around 22 yr with a 3 yr lead.
Title: Probing the Mpc-scale environment of hyperluminous infrared
galaxies at 2<z<4
Authors: Gao, F.; Wang, L.; Ramos Padilla, A. F.; Clements, D.;
Farrah, D.; Huang, T.
Bibcode: 2022arXiv220903088G
Altcode:
Protoclusters are important for studying how halo mass and stellar
mass assemble in the early universe. Finding signposts of such
over-dense regions is a popular method to identify protocluster
candidates. Hyperluminous infrared galaxies (HLIRGs), are expected to
reside in overdense regions with massive halos. We study the Mpc-scale
environment of the largest HLIRG sample to date and investigate whether
they predominantly live in overdense regions. We first explore the
surface density of Herschel 250 $\mu$m sources around HLIRGs and
compare with that around random positions. Then, we compare the
spatial distribution of neighbours around HLIRGs with that around
randomly selected galaxies using a deep IRAC-selected catalogue with
good-quality photometric redshifts. We also use a redshift-matched
quasar sample and submillimeter galaxy (SMG) sample to validate our
method, as previous clustering studies have measured the host halo
masses of these populations. Finally, we adopt a Friends of Friends
(FOF) algorithm to seek (proto)clusters that host HLIRGs. We find
that HLIRGs tend to have more bright star-forming neighbours (with
250 $\mu$m flux density >10 mJy) within 100$\arcsec$ projected
radius than a random galaxy at a 3.7$\sigma$ significance. In our 3D
analysis, we find relatively weak excess of IRAC-selected sources
within 3 Mpc around HLIRGs compared with random galaxy neighbours,
mainly influenced by photometric redshift uncertainty and survey
depth. We find a more significant difference (at a 4.7$\sigma$
significance) in the number of Low Frequency Array (LOFAR)-detected
neighbours in the deepest EN1 field. HLIRGs at 3 < z < 4 show
stronger excess compared to HLIRGs at 2 < z < 3, consistent with
cosmic downsizing. Finally, we select and present a list of 30 most
promising protocluster candidates for future follow-up observations.
Title: Quantum interference in gravitational particle production
Authors: Basso, Edward; Chung, Daniel J. H.; Kolb, Edward W.; Long,
Andrew J.
Bibcode: 2022arXiv220901713B
Altcode:
Previous numerical investigations of gravitational particle
production during the coherent oscillation period of inflation
displayed unexplained fluctuations in the spectral density of the
produced particles. We argue that these features are due to the
quantum interference of the coherent scattering reactions that produce
the particles. We provide accurate analytic formulae to compute the
particle production amplitude for a conformally-coupled scalar field,
including the interference effect in the kinematic region where the
production can be interpreted as inflaton scattering into scalar final
states via graviton exchange.
Title: Type-B QPOs in a black hole source H1743-322 and its
association with Comptonizating region and Jet
Authors: Sripada, Harikrishna; Kandulapati, Sriram
Bibcode: 2022arXiv220901643S
Altcode:
The connection of type-B QPOs to the hot flow in the inner accretion
disk region is vaguely understood in black hole X-ray binaries. We
performed spectral and timing studies of twenty-three observations
where type-C and type-B QPOs with similar centroid frequencies (~ 6
Hz) occurred. Their spectral differences were used to understand the
production mechanism of type-B QPOs, along with the quasi-simultaneous
radio observations. Based on the spectral results, we did not notice
many variations in the Comptonization parameters and the inner disk
radius during type-C and type-B QPOs. We found that the structure of the
Comptonization region has to be different for observations associated
with type-C and type-B QPOs based on the CompTT model. Radio flux
density vs QPO width, soft to hard flux ratio, and QPO width vs inner
disk temperature, were found to follow certain trends, suggesting that
a jet could be responsible for the type-B QPOs in H1743-322. Further
studies are required to uniquely constrain this scenario. In a case
study where a gradual transition from type-C to type-B QPO was noticed,
we found that the spectral changes could be explained by the presence
of a jet or a vertically extended optically thick Comptonization
region. The geometrical Lense-Thirring precession model with a hot
flow and a jet in the inner region was incorporated to explain the
spectral and timing variations.
Title: Revisiting the Iconic Spitzer Phase Curve of 55 Cancri e:
Hotter Dayside, Cooler Nightside and Smaller Phase Offset
Authors: Mercier, Samson J.; Dang, Lisa; Gass, Alexander; Cowan,
Nicolas B.; Bell, Taylor J.
Bibcode: 2022arXiv220902090M
Altcode:
Thermal phase curves of short period exoplanets provide the best
constraints on the atmospheric dynamics and heat transport in their
atmospheres. The published Spitzer Space Telescope phase curve of
55 Cancri e, an ultra-short period super-Earth, exhibits a large
phase offset suggesting significant eastward heat recirculation,
unexpected on such a hot planet arXiv:1604.05725. We present our
re-reduction and analysis of these iconic observations using the open
source and modular Spitzer Phase Curve Analysis (SPCA) pipeline. In
particular, we attempt to reproduce the published analysis using
the same instrument detrending scheme as the original authors. We
retrieve the dayside temperature ($T_{\rm day} = 3771^{+669}_{-520}$
K), nightside temperature ($T_{\rm night} = 1045^{+302}_{-243}$ K),
and longitudinal offset of the planet's hot spot and quantify how they
depend on the reduction and detrending. Our re-analysis suggests that 55
Cancri e has a negligible hot spot offset of $-12^{+21}_{-18}$ degrees
east. The small phase offset and cool nightside are consistent with
the poor heat transport expected on ultra-short period planets. The
high dayside 4.5-micrometer brightness temperature is qualitatively
consistent with SiO emission from an inverted rock vapour atmosphere.
Title: The JWST Early Release Science Program for Direct Observations
of Exoplanetary Systems II: A 1 to 20 Micron Spectrum of the
Planetary-Mass Companion VHS 1256-1257 b
Authors: Miles, Brittany E.; Biller, Beth A.; Patapis, Polychronis;
Worthen, Kadin; Rickman, Emily; Hoch, Kielan K. W.; Skemer, Andrew;
Perrin, Marshall D.; Chen, Christine H.; Mukherjee, Sagnick; Morley,
Caroline V.; Moran, Sarah E.; Bonnefoy, Mickael; Petrus, Simon;
Carter, Aarynn L.; Choquet, Elodie; Hinkley, Sasha; Ward-Duong,
Kimberly; Leisenring, Jarron M.; Millar-Blanchaer, Maxwell A.; Pueyo,
Laurent; Ray, Shrishmoy; Stapelfeldt, Karl R.; Stone, Jordan M.; Wang,
Jason J.; Absil, Olivier; Balmer, William O.; Boccaletti, Anthony;
Bonavita, Mariangela; Booth, Mark; Bowler, Brendan P.; Chauvin, Gael;
Christiaens, Valentin; Currie, Thayne; Danielski, Camilla; Fortney,
Jonathan J.; Girard, Julien H.; Greenbaum, Alexandra Z.; Henning,
Thomas; Hines, Dean C.; Janson, Markus; Kalas, Paul; Kammerer, Jens;
Kenworthy, Matthew A.; Kervella, Pierre; Lagage, Pierre-Olivier;
Lew, Ben W. P.; Liu, Michael C.; Macintosh, Bruce; Marino, Sebastian;
Marley, Mark S.; Marois, Christian; Matthews, Elisabeth C.; Matthews,
Brenda C.; Mawet, Dimitri; McElwain, Michael W.; Metchev, Stanimir;
Meyer, Michael R.; Molliere, Paul; Pantin, Eric; Rebollido, Andreas
Quirrenbachm Isabel; Ren, Bin B.; Vasist, Malavika; Wyatt, Mark C.;
Zhou, Yifan; Briesemeister, Zackery W.; Bryan, Marta L.; Calissendorff,
Per; Catalloube, Faustine; Cugno, Gabriele; De Furio, Matthew; Dupuy,
Trent J.; Factor, Samuel M.; Faherty, Jacqueline K.; Fitzgerald,
Michael P.; Franson, Kyle; Gonzales, Eileen C.; Hood, Callie E.;
Howe, Alex R.; Kraus, Adam L.; Kuzuhara, Masayuki; Lawson, Kellen;
Lazzoni, Cecilia; Liu, Pengyu; Llop-Sayson, Jorge; Lloyd, James P.;
Martinez, Raquel A.; Mazoyer, Johan; Quanz, Sascha P.; Adams Redai,
Jea; Samland, Matthias; Schlieder, Joshua E.; Tamura, Motohide; Tan,
Xianyu; Uyama, Taichi; Vigan, Arthur; Vos, Johanna M.; Wagner, Kevin;
Wolff, Schuyler G.; Ygouf, Marie; Zhang, Keming; Zhang, Zhoujian
Bibcode: 2022arXiv220900620M
Altcode:
We present the highest fidelity spectrum to date of a planetary-mass
object. VHS 1256 b is a $<$20 M$_\mathrm{Jup}$ widely separated
($\sim$8", a = 150 au), young, brown dwarf companion that shares
photometric colors and spectroscopic features with the directly imaged
exoplanets HR 8799 c, d, and e. As an L-to-T transition object, VHS
1256 b exists along the region of the color-magnitude diagram where
substellar atmospheres transition from cloudy to clear. We observed VHS
1256 b with JWST's NIRSpec IFU and MIRI MRS modes for coverage from
1 $\mu$m to 20 $\mu$m at resolutions of $\sim$1,000 - 3,700. Water,
methane, carbon monoxide, carbon dioxide, sodium, and potassium are
observed in several portions of the JWST spectrum based on comparisons
from template brown dwarf spectra, molecular opacities, and atmospheric
models. The spectral shape of VHS 1256 b is influenced by disequilibrium
chemistry and clouds. We directly detect silicate clouds, the first
such detection reported for a planetary-mass companion.
Title: xGASS: The connection between angular momentum, mass and
atomic gas fraction in nearby galaxies
Authors: Hardwick, Jennifer A.; Cortese, Luca; Obreschkow, Danail;
Catinella, Barbara
Bibcode: 2022MNRAS.tmp.2337H
Altcode: 2022arXiv220901720H
We use a sample of 559 disc galaxies extracted from the eXtended
GALEX Arecibo SDSS Survey (xGASS) to study the connection between
baryonic angular momentum, mass and atomic gas fraction in the local
Universe. Baryonic angular momenta are determined by combining H I
and H2 integrated profiles with two-dimensional stellar
mass surface density profiles. In line with previous work, we confirm
that specific angular momentum and atomic gas fraction are tightly
correlated, but we find a larger scatter than previously observed. This
is most likely due to the wider range of galaxy properties covered
by our sample. We compare our findings with the predictions of the
analytical stability model developed by Obreschkow et al. and find that,
while the model provides a very good first-order approximation for the
connection between baryonic angular momentum, mass and gas fraction,
it does not fully match our data. Specifically, we find that at fixed
baryonic mass, the dependence of specific angular momentum on gas
fraction is significantly weaker, and at fixed gas fraction, the slope
of the angular momentum versus mass relation is shallower than what was
predicted by the model. The reasons behind this tension remain unclear,
but we speculate that multiple factors may simultaneously play a role,
all related to the fact that the model is not able to encapsulate the
full diversity of galaxy properties in our sample.
Title: Lithium niobate microresonator-based spectrally multiplexed
entangled photon pairs
Authors: Long, Gui-Lu
Bibcode: 2022SCPMA..6594261L
Altcode:
No abstract at ADS
Title: The structure at the centre of the giant radio galaxy GRS
J0844+4627: a compact symmetric object?
Authors: Marecki, A.; Sebastian, B.; Ishwara-Chandra, C. H.
Bibcode: 2022arXiv220901428M
Altcode:
We observed the core region of the giant radio galaxy GRS J0844+4627
with e-MERLIN at 1.52 and 5.07 GHz. These observations revealed
that the apparent single feature at the centre of GRS J0844+4627,
as seen by GMRT, consists of two components separated by 2.7 kpc in
projection. Follow-up observations at 1.66 GHz using the EVN unveiled
the complex morphologies of the two components. In particular, the
south-western component identified with the SDSS J084408.85+462744.2
galaxy morphologically resembles a compact symmetric object (CSO)
with a projected linear size of 115 pc. If the CSO hypothesis turns
out to be correct, then the overall radio structure of GRS J0844+4627
is triple-double. Given that CSOs are considered young objects, GRS
J0844+4627 would appear as a recently restarted active galaxy.
Title: Generalized disformal Horndeski theories: cosmological
perturbations and consistent matter coupling
Authors: Takahashi, Kazufumi; Minamitsuji, Masato; Motohashi, Hayato
Bibcode: 2022arXiv220902176T
Altcode:
Invertible disformal transformations are a useful tool to investigate
ghost-free scalar-tensor theories. By performing a higher-derivative
generalization of the invertible disformal transformation on
Horndeski theories, we construct a novel class of ghost-free
scalar-tensor theories, which we dub generalized disformal Horndeski
theories. Specifically, these theories lie beyond the quadratic/cubic
DHOST class. We explore cosmological perturbations to identify a
subclass where gravitational waves propagate at the speed of light and
clarify the conditions for the absence of ghost/gradient instabilities
for tensor and scalar perturbations. We also investigate the conditions
under which a matter field can be consistently coupled to these theories
without introducing unwanted extra degrees of freedom.
Title: Using Anisotropies as a Forensic Tool for Decoding Supernova
Remnants
Authors: Polin, Abigail; Duffell, Paul; Milisavljevic, Dan
Bibcode: 2022arXiv220902134P
Altcode:
We present a method for analyzing supernova remnants (SNRs)
by diagnosing the drivers responsible for structure at different
angular scales. First, we perform a suite of hydrodynamic models of
the Rayleigh-Taylor instability (RTI) as a supernova collides with
its surrounding medium. Using these models we demonstrate how power
spectral analysis can be used to attribute which scales in a SNR are
driven by RTI and which must be caused by intrinsic asymmetries in
the initial explosion. We predict the power spectrum of turbulence
driven by RTI and identify a dominant angular mode which represents
the largest scale that efficiently grows via RTI. We find that this
dominant mode relates to the density scale height in the ejecta, and
therefore reveals the density profile of the SN ejecta. If there is
significant structure in a SNR on angular scales larger than this mode,
then it is likely caused by anisotropies in the explosion. Structure on
angular scales smaller than the dominant mode exhibits a steep scaling
with wavenumber, possibly too steep to be consistent with a turbulent
cascade, and therefore might be determined by the saturation of RTI
at different length scales (although systematic 3D studies are needed
to investigate this). We also demonstrate, consistent with previous
studies, that this power spectrum is independent of the magnitude and
length scales of perturbations in the surrounding medium and therefore
this diagnostic is unaffected by ``clumpiness" in the CSM.
Title: Tracing the Milky Way warp and spiral arms with classical
Cepheids
Authors: Lemasle, B.; Lala, H. N.; Kovtyukh, V.; Hanke, M.; Prudil,
Z.; Bono, G.; Braga, V. F.; da Silva, R.; Fabrizio, M.; Fiorentino,
G.; Francois, P.; Grebel, E. K.; Kniazev, A.
Bibcode: 2022arXiv220902731L
Altcode:
Mapping the Galactic spiral structure is a difficult task since the Sun
is located in the Galactic plane and because of dust extinction. For
these reasons, molecular masers in radio wavelengths have been used
with great success to trace the Milky Way spiral arms. Recently, Gaia
parallaxes have helped in investigating the spiral structure in the
Solar extended neighborhood. In this paper, we propose to determine
the location of the spiral arms using Cepheids since they are bright,
young supergiants with accurate distances (they are the first ladder
of the extragalactic distance scale). They can be observed at very
large distances; therefore, we need to take the Galactic warp into
account. Thanks to updated mid-infrared photometry and to the most
complete catalog of Galactic Cepheids, we derived the parameters
of the warp using a robust regression method. Using a clustering
algorithm, we identified groups of Cepheids after having corrected
their Galactocentric distances from the (small) effects of the warp. We
derived new parameters for the Galactic warp, and we show that the
warp cannot be responsible for the increased dispersion of abundance
gradients in the outer disk reported in previous studies. We show that
Cepheids can be used to trace spiral arms, even at large distances from
the Sun. The groups we identify are consistent with previous studies
explicitly deriving the position of spiral arms using young tracers
(masers, OB(A) stars) or mapping overdensities of upper main-sequence
stars in the Solar neighborhood thanks to Gaia data.
Title: Hierarchical triple mergers: testing Hawking's area theorem
with the inspiral signals
Authors: Tang, Shao-Peng; Fan, Yi-Zhong; Wei, Da-Ming
Bibcode: 2022arXiv220903631T
Altcode:
Hawking's area theorem is one of the fundamental laws of black holes
(BHs), which has been tested at a confidence level of $\sim 95\%$
with gravitational wave (GW) observations by analyzing the inspiral
and ringdown portions of GW signals independently. In this work, we
propose to carry out the test in a new way with the hierarchical triple
merger (i.e., two successive BH mergers occurred sequentially within
the observation window of GW detectors), for which the properties of
the progenitor BHs and the remnant BH of the first coalescence can be
reliably inferred from the inspiral portions of the two mergers. As
revealed in our simulation, a test of the BH area law can be achieved
at the significance level of $\gtrsim 3\sigma$ for the hierarchical
triple merger events detected in LIGO/Virgo/KAGRA's O4/O5 runs. If
the hierarchical triple mergers contribute a $\gtrsim 0.1\%$ fraction
to the detected BBHs, a precision test of the BH area law with such
systems is achievable in the near future. Our method also provides
an additional criterion to establish the hierarchical triple merger
origin of some candidate events.
Title: Gravitational Lensing in a Universe with matter and
Cosmological Constant
Authors: Bessa, Pedro; Piattella, Oliver F.
Bibcode: 2022arXiv220904063B
Altcode:
We extend the results obtained in \cite{Piattella_2016, mcvittie_2015}
for gravitational lensing in the McVittie metric by including the
effect of the transition from the matter-dominated epoch of the
Universe to the $\Lambda$-dominated era. We derive a formula that
agrees with the previous results for the McVittie metric at lowest
order, and compare the lensing angle predictions obtained from the
Schwarzschild approximation, the McVittie model and higher order
corrections to the McVittie model. In doing this, we test if, beyond
the correction from the accelerated expansion of the Universe, there
is a need for including the matter content of the Universe in modeling
lens systems at the redshifts observerd in lens systems. We investigate
if there is a need for a modification of the lens equation from these
corrections, and if so, to which order and whether it is measurable. We
find that while the effect is of the same order as the one calculated
previously, there is no significant contribution to the bending angle,
as the 1st order effect is already of order $\mathcal{O}(\theta_O^4)$
in the observed angle.
Title: Jet kinematics in the transversely stratified jet of 3C 84. A
two-decade overview
Authors: Paraschos, G. F.; Krichbaum, T. P.; Kim, J. -Y.; Hodgson,
J. A.; Oh, J.; Ros, E.; Zensus, J. A.; Marscher, A. P.; Jorstad,
S. G.; Gurwell, M. A.; Lähteenmäki, A.; Tornikoski, M.; Kiehlmann,
S.; Readhead, A. C. S.
Bibcode: 2022A&A...665A...1P
Altcode: 2022arXiv220510281P
3C 84 (NGC 1275) is one of the brightest radio
sources in the millimetre radio bands, which led to a plethora of
very-long-baseline interferometry (VLBI) observations at numerous
frequencies over the years. They reveal a two-sided jet structure,
with an expanding but not well-collimated parsec-scale jet, pointing
southward. High-resolution millimetre-VLBI observations allow the study
and imaging of the jet base on a sub-parsec scale. This could facilitate
the investigation of the nature of the jet origin, also in view of the
previously detected two-railed jet structure and east-west oriented
core region seen with RadioAstron at 22 GHz. We produced VLBI images
of this core and inner jet region, observed over the past twenty years
at 15, 43, and 86 GHz. We determined the kinematics of the inner jet
and ejected features at 43 and 86 GHz and compared their ejection times
with radio and γ-ray variability. For the moving jet features, we find
an average velocity of βappavg = 0.055−0.22c
(μavg = 0.04 − 0.18 mas yr−1). From the
time-averaged VLBI images at the three frequencies, we measured the
transverse jet width along the bulk flow. On the ≤1.5 parsec scale,
we find a clear trend of the jet width being frequency dependent, with
the jet being narrower at higher frequencies. This stratification
is discussed in the context of a spine-sheath scenario, and we
compare it to other possible interpretations. From quasi-simultaneous
observations at 43 and 86 GHz, we obtain spectral index maps, revealing
a time-variable orientation of the spectral index gradient due to
structural variability of the inner jet.
Title: Convective inhibition with an ocean. I. Supercritical cores
on sub-Neptunes/super-Earths
Authors: Markham, S.; Guillot, T.; Stevenson, D.
Bibcode: 2022A&A...665A..12M
Altcode: 2022arXiv220704708M
Aims: In this work we generalize the notion of convective
inhibition to apply it to cases where there is an infinite reservoir
of condensible species (i.e., an ocean). We propose a new model for the
internal structure and thermal evolution of super-Earths with hydrogen
envelopes.
Methods: We derive the criterion for convective
inhibition in a generalized phase mixture from first principles
thermodynamics. We then investigate the global ocean case using a
water-hydrogen system, for which we have data, as an example. After
illustrating the relevant thermodynamics, we extend our arguments to
apply to a system of hydrogen and silicate vapor. We then employ a
simple atmospheric model to apply our findings to super-Earths and
to make predictions about their internal structures and thermal
evolution.
Results: For hydrogen envelope masses roughly
in the range 10−3−10−1 M⊕,
convective contact between the envelope and core may shut down because
of the compositional gradient that arises from silicate partial
vaporization. For envelope hydrogen masses that cause the associated
basal pressure to exceed the critical pressure of pure silicate (on the
order of a couple kilobars), the base of that envelope and the top of
the core lie on the critical line of the two-phase hydrogen-silicate
phase diagram. The corresponding temperature is much higher than
convective models would suggest. The core is then "supercritical"
in the sense that the temperature exceeds the critical temperature
for pure silicate. The core then cools inefficiently, with intrinsic
heat fluxes potentially comparable to the Earth's internal heat flux
today.
Conclusions: This low heat flux may allow the core to
remain in a high entropy supercritical state for billions of years,
but the details of this depend on the nature of the two-component
phase diagram at high pressure, something that is currently unknown. A
supercritical core thermodynamically permits the dissolution of large
quantities of hydrogen into the core.
Title: Gas Dynamics and Star Formation in NGC 6822
Authors: Park, Hye-Jin; Oh, Se-Heon; Wang, Jing; Zheng, Yun; Zhang,
Hong-Xin; De Blok, W. J. G.
Bibcode: 2022AJ....164...82P
Altcode: 2022arXiv220706698P
We present H I gas kinematics and star formation activities of NGC 6822,
a dwarf galaxy located in the Local Group at a distance of ~490 kpc. We
perform profile decomposition of line-of-sight velocity profiles of the
H I data cube (42.4″ × 12.0″ spatial, corresponding to ~100 pc;
1.6 km s-1 spectral) taken with the Australia Telescope
Compact Array. For this, we use a new tool, the so-called BAYGAUD,
which is based on Bayesian analysis techniques, allowing us to decompose
a line-of-sight velocity profile into an optimal number of Gaussian
components in a quantitative manner. We classify the decomposed H I
gas components of NGC 6822 into cool-bulk, warm-bulk, cool-non-bulk,
and warm-non-bulk motions with respect to their centroid velocities
and velocity dispersions. We correlate their gas surface densities
with corresponding star formation rate densities derived using both
the GALEX far-ultraviolet and WISE 22 μm data to examine the resolved
Kennicutt-Schmidt (K-S) law for NGC 6822. Of the decomposed H I gas
components, the cool-bulk component is likely to better follow the
linear extension of the K-S law for molecular hydrogen (H2)
at low gas surface densities where H I is not saturated.
Title: Call and Response: A Time-resolved Study of Chromospheric
Evaporation in a Large Solar Flare
Authors: Sellers, Sean G.; Milligan, Ryan O.; McAteer, R. T. James
Bibcode: 2022ApJ...936...85S
Altcode: 2022arXiv220814347S
We studied an X1.6 solar flare produced by NOAA Active Region 12602
on 2014 October 22. The entirety of this event was covered by RHESSI,
IRIS, and Hinode/EIS, allowing analysis of the chromospheric response
to a nonthermal electron driver. We derived the energy contained
in nonthermal electrons via RHESSI spectral fitting and linked the
time-dependent parameters of this call to the response in Doppler
velocity, density, and nonthermal width across a broad temperature
range. The total energy injected was 4.8 × 1030 erg and
lasted 352 s. This energy drove explosive chromospheric evaporation,
with a delineation in both Doppler and nonthermal velocities at
the flow reversal temperature, between 1.35 and 1.82 MK. The time
of peak electron injection (14:06 UT) corresponded to the time of
highest velocities. At this time, we found 200 km s-1
blueshifts in the core of Fe XXIV, which is typically assumed to be
at rest. Shortly before this time, the nonthermal electron population
had the shallowest spectral index (≍6), corresponding to the peak
nonthermal velocity in Si IV and Fe XXI. Nonthermal velocities in
Fe XIV, formed near the flow reversal temperature, were low and not
correlated with density or Doppler velocity. Nonthermal velocities in
ions with similar temperatures were observed to increase and correlate
with Doppler velocities, implying unresolved flows surrounding the flow
reversal point. This study provides a comprehensive, time-resolved
set of chromospheric diagnostics for a large X-class flare, along
with a time-resolved energy injection profile, ideal for further
modeling studies.
Title: Probing modified gravity with integrated Sachs-Wolfe CMB and
galaxy cross-correlations
Authors: Kable, Joshua A.; Benevento, Giampaolo; Frusciante, Noemi;
De Felice, Antonio; Tsujikawa, Shinji
Bibcode: 2022JCAP...09..002K
Altcode: 2021arXiv211110432K
We use the cross-correlation power spectrum of the integrated
Sachs-Wolfe (ISW) effect in the cosmic microwave background (CMB)
temperature anisotropy and galaxy fluctuations to probe the physics
of late-time cosmic acceleration. For this purpose, we focus on three
models of dark energy that belong to a sub-class of Horndeski theories
with the speed of gravity equivalent to that of light: Galileon Ghost
Condensate (GGC), Generalized Cubic Covariant Galileon (GCCG), and
K-mouflage. In the GGC and GCCG models, the existence of cubic-order
scalar self-interactions allows a possibility for realizing negative
ISW-galaxy cross-correlations, while the K-mouflage model predicts
a positive correlation similar to the Λ-cold-dark-matter (ΛCDM)
model. In our analysis, we fix the parameters of each model to
their best-fit values derived from a baseline likelihood analysis
with observational data from CMB, baryon acoustic oscillations, and
supernovae type Ia. Then we fit those best-fit models to the ISW-galaxy
cross-correlation power spectrum extracted from a collection of
photometric redshift surveys. We find that both GGC and GCCG best-fit
models degrade the fit to the ISW-galaxy cross-correlation data
compared to ΛCDM best-fit model. This is attributed to the fact that,
for their best-fit values constrained from the baseline likelihood, the
cubic-order scalar self-interaction gives rise to suppressed ISW tails
relative to ΛCDM. The K-mouflage best-fit model is largely degenerate
with the ΛCDM best-fit model and has a positively correlated ISW-galaxy
power close to that of ΛCDM.
Title: Probing the inner circumgalactic medium and quasar illumination
around the reddest 'extremely red quasar'
Authors: Lau, Marie Wingyee; Hamann, Fred; Gillette, Jarred; Perrotta,
Serena; Rupke, David S. N.; Wylezalek, Dominika; Zakamska, Nadia L.
Bibcode: 2022MNRAS.515.1624L
Altcode: 2022arXiv220306203L; 2022MNRAS.tmp.1757L
Dusty quasars might be in a young stage of galaxy evolution with
prominent quasar feedback. A recently discovered population of luminous,
extremely red quasars at z ~ 2-4 has extreme spectral properties
related to exceptionally powerful quasar-driven outflows. We present
Keck/KCWI observations of the reddest known ERQ, at z = 2.3184, with
extremely fast [O III] λ5007 outflow at ~6000 km s-1. The
Lyα halo spans ~100 kpc. The halo is kinematically quiet, with
velocity dispersion ~300 km s-1 and no broadening above
the dark matter circular velocity down to the spatial resolution ~6
kpc from the quasar. We detect spatially resolved He II λ1640 and
C IV λ1549 emissions with kinematics similar to the Lyα halo and
a narrow component in the [O III] λ5007. Quasar reddening acts as
a coronagraph, allowing views of the innermost halo. A narrow Lyα
spike in the quasar spectrum is inner halo emission, confirming the
broad C IV λ1549 in the unresolved quasar is blueshifted by 2240 km
s-1 relative to the halo frame. We propose the inner halo is
dominated by moderate-speed outflow driven in the past and the outer
halo dominated by inflow. The high central concentration of the halo
and the symmetric morphology of the inner region are consistent with
the ERQ being in earlier evolutionary stage than blue quasars. The
He II λ1640/Lyα ratio of the inner halo and the asymmetry level of
the overall halo are dissimilar to Type II quasars, suggesting unique
physical conditions for this ERQ that are beyond orientation differences
from other quasar populations. We find no evidence of mechanical quasar
feedback in the Lyα-emitting halo.
Title: A search for transit timing variations in the HATS-18
planetary system
Authors: Southworth, John; Barker, A. J.; Hinse, T. C.; Jongen,
Y.; Dominik, M.; Jørgensen, U. G.; Longa-Peña, P.; Sajadian, S.;
Snodgrass, C.; Tregloan-Reed, J.; Bach-Møller, N.; Bonavita, M.;
Bozza, V.; Burgdorf, M. J.; Figuera Jaimes, R.; Helling, Ch; Hitchcock,
J. A.; Hundertmark, M.; Khalouei, E.; Korhonen, H.; Mancini, L.;
Peixinho, N.; Rahvar, S.; Rabus, M.; Skottfelt, J.; Spyratos, P.
Bibcode: 2022MNRAS.515.3212S
Altcode: 2022arXiv220705873S; 2022MNRAS.tmp.1844S
HATS-18 b is a transiting planet with a large mass and a short orbital
period, and is one of the best candidates for the detection of orbital
decay induced by tidal effects. We present extensive photometry of
HATS-18 from which we measure 27 times of mid-transit. Two further
transit times were measured from data from the Transiting Exoplanet
Survey Satellite (TESS) and three more taken from the literature. The
transit timings were fitted with linear and quadratic ephemerides and an
upper limit on orbital decay was determined. This corresponds to a lower
limit on the modified stellar tidal quality factor of $Q_\star ^{\,
\prime } \gt 10^{5.11 \pm 0.04}$. This is at the cusp of constraining
the presence of enhanced tidal dissipation due to internal gravity
waves. We also refine the measured physical properties of the HATS-18
system, place upper limits on the masses of third bodies, and compare
the relative performance of TESS and the 1.54 m Danish Telescope in
measuring transit times for this system.
Title: New globular cluster candidates in the M81 group
Authors: Pan, Jiaming; Bell, Eric F.; Smercina, Adam; Price, Paul;
Slater, Colin T.; Bailin, Jeremy; de Jong, Roelof S.; D'Souza, Richard;
Jang, In Sung; Monachesi, Antonela
Bibcode: 2022MNRAS.515...48P
Altcode: 2022arXiv220607251P; 2022MNRAS.tmp.1611P
The study of outer halo globular cluster (GC) populations can give
insight into galaxy merging, GC accretion, and the origin of GCs. We
use archival Subaru Hyper Suprime-Cam (HSC) data in concert with
space-based GALEX, IRAC, and Gaia EDR3 data to select candidate GCs in
the outer halo of the M81 group for confirmation and future study. We
use a small sample of previously discovered GCs to tune our selection
criteria, finding that bright already-known GCs in the M81 group have
sizes that are typically slightly larger than the Subaru PSF in our
fields. In the optical bands, GCs appear to have colours that are
only slightly different from stars. The inclusion of archival IRAC
data yields dramatic improvements in colour separation, as the long
wavelength baseline aids somewhat in the separation from stars and
clearly separates GCs from many compact background galaxies. We show
that some previously spectroscopically identified GCs in the M81 group
are instead foreground stars or background galaxies. GCs close to M82
have radial velocities, suggesting that they fell into the M81 group
along with M82. The overall M81 GC luminosity function is similar to
the Milky Way and M31. M81's outer halo GCs are similar to the Milky
Way in their metallicities and numbers, and much less numerous than
M31's more metal-rich outer halo GC population. These properties reflect
differences in the three galaxies' merger histories, highlighting the
possibility of using outer halo GCs to trace merger history in larger
samples of galaxies.
Title: Inferring galaxy dark halo properties from visible matter
with machine learning
Authors: von Marttens, Rodrigo; Casarini, Luciano; Napolitano, Nicola
R.; Wu, Sirui; Amaro, Valeria; Li, Rui; Tortora, Crescenzo; Canabarro,
Askery; Wang, Yang
Bibcode: 2022MNRAS.tmp.2280V
Altcode: 2021arXiv211101185V
Next-generation surveys will provide photometric and spectroscopic data
of millions to billions of galaxies with unprecedented precision. This
offers a unique chance to improve our understanding of the galaxy
evolution and the unresolved nature of dark matter (DM). At galaxy
scales, the density distribution of DM is strongly affected by feedback
processes, which are difficult to fully account for in classical
techniques to derive galaxy masses. We explore the capability of
supervised Machine Learning (ML) algorithms to predict the DM content
of galaxies from 'luminous' observational-like parameters, using the
TNG100 simulation. In particular, we use, Photometric (magnitudes in
different bands), Structural (the stellar half-mass radius and three
different baryonic masses), and Kinematic (1D velocity dispersion and
the maximum rotation velocity) parameters to predict the total DM mass,
DM half-mass radius, DM mass inside one and two stellar half-mass
radii. We adopt the coefficient of determination, R2, as
a metric to evaluate the accuracy of these predictions. We find that
using all observational quantities together (Photometry, Structural,
and Kinematics) we reach high accuracy for all DM quantities (up to
R2 ~ 0.98). This first test shows that ML tools are promising
to predict the DM in real galaxies. The next steps will be to implement
the observational realism of the training sets, by closely selecting
samples which accurately reproduce the typical observed 'luminous'
scaling relations. The so-trained pipelines will be suitable for real
galaxy data collected from Rubin/LSST, Euclid, CSST, 4MOST, DESI,
to derive, e.g. the properties of their central DM fractions.
Title: Infrared spectroscopy of the 2019 eruption of the recurrent
nova V3890 Sgr: separation into equatorial and polar winds revealed
Authors: Evans, A.; Geballe, T. R.; Woodward, C. E.; Banerjee,
D. P. K.; Gehrz, R. D.; Starrfield, S.; Shahbandeh, M.
Bibcode: 2022MNRAS.tmp.2293E
Altcode: 2022arXiv220809356E
We present infrared spectroscopy of the 2019 eruption of the recurrent
nova V3890 Sgr, obtained over the period 5.1-46.3 days after the
eruption. The spectrum of the red giant became more prominent as the
flux declined, and by day 46.3 dominated the spectrum. Hydrogen and
helium emission lines consisted of a narrow component superposed on a
broad pedestal. The full width at half maximum of the narrow components
declined with time t as the eruption progressed, as t-0.74,
whereas those of the broad components remained essentially
constant. Conversely, the line fluxes of the narrow components of
Pa β remained roughly constant, while those of the broad components
declined by a factor ~30 over a period of ≲25 days. The behaviour of
the broad components is consistent with them arising in unencumbered
fast-flowing ejecta perpendicular to the binary plane, in material that
was ejected in a short ~3.3-day burst. The narrow components arise in
material that encounters the accumulated circumstellar material. The
outburst spectra were rich in coronal lines. There were two coronal
line phases, one that originated in gas ionised by supersoft X-ray
source, the other in shocked gas. From the relative fluxes of silicon
and sulphur coronal lines on day 23.4 - when the emitting gas was
shocked - we deduce that the temperature of the coronal gas was 9.3
× 105 K, and that the abundances are approximately solar.
Title: Cosmic-ray Convection-diffusion Anisotropy
Authors: Zhang, Yiran; Liu, Siming; Wu, Dejin
Bibcode: 2022arXiv220901412Z
Altcode:
Under nonuniform convection, the distribution of diffusive particles
can exhibit dipole and quadrupole anisotropy induced by the fluid
inertial and shear force, respectively. These convection-related
anisotropies, unlike the Compton-Getting effect, typically increase
with the cosmic-ray (CR) energy, and are thus candidate contributors
for the CR anisotropy. In consideration of the inertial effect, CR
observational data can be used to set an upper limit on the average
acceleration of the local interstellar medium in the equatorial plane
to be on the order of 100 $ \mu \text{m}/\text{s}^2 $. Using Oort
constants, the quadrupole anisotropy above 200 TeV may be modeled with
the shear effect arising from the Galactic differential rotation.
Title: A TESS search for substellar companions through pulsation
timing of $\delta$ Scuti stars. I. Discovery of companions around
Chang 134 and V393 Car
Authors: Vaulato, V.; Nascimbeni, V.; Piotto, G.
Bibcode: 2022arXiv220901220V
Altcode:
When searching for exoplanets, early-type, main-sequence pulsating stars
such as $\delta$ Scuti variables are one of the least explored class of
targets. Pulsation timing (PT) is an alternative technique to the most
effective search methods, which exploits the light-travel effect (LTE)
to infer the presence of additional massive bodies around a pulsating
star by measuring a periodic phase modulation of its signal. PT has been
already extremely successful in discovering and characterizing stellar
binaries when applied to high-precision light curves over large temporal
baselines, such as those delivered by the Kepler mission. In favorable
conditions, the sensitivity of PT can reach the planetary-mass regime,
with one such candidate already claimed. The advent of TESS, with its
nearly full-sky coverage and the availability of full-frame images,
opens a great opportunity to expand this field of research. In this
work, we present a pilot study aimed to understand the potential of PT
applied to TESS data, considerably different with respect to Kepler in
terms of photometric noise, sampling cadence and temporal baseline. We
focused on the most favourable class of $\delta$ Scuti, that is those
showing large pulsations and very simple frequency spectra. After the
development of a customized pipeline, for two targets we were able
to detect candidate companions within the (sub-)stellar mass regime:
Chang 134 ($43\pm 5$ $M_\mathrm{jup}$, $P\simeq 82$ d) and V393 Car
($\gtrsim 100$ $M_\mathrm{jup}$, $P\gtrsim 700$ d). Our results also
highlights the limiting factors of this technique and the importance of
an accurate absolute time calibration for future missions such as PLATO.
Title: Laboratory Constraints on the Neutron-Spin Coupling of
feV-scale Axions
Authors: Lee, Junyi; Lisanti, Mariangela; Terrano, William A.;
Romalis, Michael
Bibcode: 2022arXiv220903289L
Altcode:
Ultralight axion-like particles can contribute to the dark matter near
the Sun, leading to a distinct, stochastic signature in terrestrial
experiments. We search for such particles through their neutron-spin
coupling by re-analyzing approximately 40 days of data from a K-$^3$He
co-magnetometer with a new frequency-domain likelihood-based formalism
that properly accounts for stochastic effects over all axion coherence
times relative to the experimental time span. Assuming that axions make
up all of the dark matter in the Sun's vicinity, we find a median 95%
upper limit on the neutron-spin coupling of $2.4 \times 10^{-10}$
GeV$^{-1}$ for axion masses from 0.4 to 4 feV, which is about five
orders of magnitude more stringent than previous laboratory bounds in
that mass range. Although several peaks in the experiment's magnetic
power spectrum suggest the rejection of a white-noise null hypothesis,
further analysis of their lineshapes yields no positive evidence for
a dark matter axion.
Title: Search for pre-burst emission from binary neutron star mergers
with Spectrum-Roentgen-Gamma
Authors: Mereminskiy, I. A.; Lutovinov, A. A.; Postnov, K. A.; Arefiev,
V. A.; Lapshov, I. Yu.; Molkov, S. V.; Sazonov, S. Yu.; Semena, A. N.;
Tkachenko, A. Yu.; Shtykovsky, A. E.; Liu, Z.; Wilms, J.; Rau, A.;
Dauser, T.; Kreykenbohm, I.
Bibcode: 2022arXiv220900716M
Altcode:
Close binary systems consisting of two neutron stars (BNS) emit
gravitational waves, that allow them to merge on timescales shorter
than Hubble time. It is widely believed, that NS-NS mergers in
such systems power short gamma-ray bursts (GRB). Several mechanisms
which could lead to electromagnetic energy release prior to a merger
have been proposed. We estimate the ability to observe the possible
pre-burst emission with telescopes of Spectrum-Roentgen-Gamma. We also
investigate first such event, GRB210919A, which fell into the field
of view of the SRG telescopes less than two days before the burst.
Title: Novel cosmological bounds on thermally-produced axion-like
particles
Authors: Caloni, Luca; Gerbino, Martina; Lattanzi, Massimiliano;
Visinelli, Luca
Bibcode: 2022JCAP...09..021C
Altcode: 2022arXiv220501637C
We constrain the coupling of thermally-produced axion-like particles
(here axions) with photons and gluons, using data from the cosmic
microwave background (CMB) spectra and baryon acoustic oscillations. The
axion possesses an explicit soft breaking mass term and it is produced
thermally in the early Universe from either axion-photon or axion-gluon
processes, accounting for the recent progresses in the field. We
derive the most stringent bounds on the axion-gluon coupling to date on
the mass range considered 10-4 ≲ ma / eV ≲
100, superseding the current bounds from SN1987A. The bounds on the
axion-photon coupling are competitive with the results from the CAST
collaboration for the axion mass ma ≳ 3eV. We comment on
the forecast reaches that will be available given the sensitivity of
future CMB-S4 missions.
Title: Featured Image: First Images of a Substellar Companion in
the Hyades
Authors: Hensley, Kerry
Bibcode: 2022nova.pres.9810H
Altcode:
Images of the companion object (circled) taken over the course of
a year. The companion object is detected with a signal-to-noise
ratio ranging from 10 to 19. Click to enlarge. [Kuzuhara et
al. 2022]Astronomers have photographed a substellar object in orbit
around a star in the Hyades, the nearest star cluster to Earth,
for the first time. Previous data from the Gaia and Hipparcos
satellites showed the Sun-like star HIP 21152 accelerating under the
influence of an unseen companion. Now, a team led by Masayuki Kuzuhara
(Astrobiology Center of the National Institutes of Natural Sciences
and the National Astronomical Observatory of Japan) has obtained new
Subaru and Keck telescope images, shown above and to the right, of HIP
21152 and its surroundings. These images reveal HIP 21152s companion,
which Kuzuhara and collaborators determined to be a 27.8-Jupiter-mass
object orbiting the star at a distance of 17.5 au. Spectra of the
object suggest that it is a T dwarf with a temperature between 1200K
and 1300K. This discovery is exciting for a number of reasons, chief
among them the objects membership in the Hyades cluster; because the
age of the cluster is well known, the newly discovered object will
provide a useful reference point for studies of how substellar objects
evolve over time.CitationDirect-imaging Discovery and Dynamical Mass
of a Substellar Companion Orbiting an Accelerating Hyades Sun-like
Star with SCExAO/CHARIS, Masayuki Kuzuhara et al 2022 ApJL 934
L18. doi:10.3847/2041-8213/ac772fThe post Featured Image: First Images
of a Substellar Companion in the Hyades appeared first on AAS Nova.
Title: Where Do Eccentric Stellar Twins Come From?
Authors: Hensley, Kerry
Bibcode: 2022nova.pres.9837H
Altcode:
Across the Milky Way, pairs of nearly identical stars orbit each other,
separated by vast distances. What can recent survey data tell us about
how these systems form?Binary Star BreakthroughsBy studying binary
stars, astronomers hope to discern the details of star formation as well
as how repeated gravitational encounters can shape stellar systems after
theyve formed. Common though binary stars may be, theyre not without
their mysteries, and recent data have revealed intriguing details about
the binary stars in our galaxy.A view of the Milky Way containing
1.7 billion stars observed by the Gaia spacecraft. [ESA/Gaia/DPAC,
CC BY-SA 3.0 IGO]One finding is that widely separated binary systems
in which the stars have nearly the same mass wide twin binaries are
more common than expected. Twin binaries are expected to form from a
single disk of gas and dust, but these disks tend to be far smaller
than the present-day separations of these systems.If these distant
binary companions formed close together in a single disk before
being driven to their current locations by gravitational encounters,
these systems should have extremely elongated, or eccentric, orbits
and thanks to the Gaia spacecraft, we can test that prediction for
thousands of stars.Observed distributions of the measured vr angle for
wide twin (blue) and non-twin (orange) binaries. The black lines show
the simulated distributions for binary systems with eccentricities, e,
of 0 (solid line) and 0.90 (dashed line). [Hwang et al. 2022]Exploring
EccentricitiesWidely separated binary systems take more than a thousand
years to complete a single orbit, making it challenging to measure
the eccentricity of an individual system. Instead, Hsiang-Chih Hwang
(Institute for Advanced Study) used a statistical technique to study
nearly a million binary systems at once. Using stellar position
and velocity data from Gaia, the team measured the angle between two
vectors: one that describes the difference in the binary members motion
across the sky (v) and one that connects the two stars (r).By comparing
the angle between those vectors to theoretical predictions for stellar
populations with different eccentricities, the team determined that
twin binaries with orbital separations of 4001,000 au tend to have
extremely eccentric orbits. Specifically, there appear to be a high
number of systems with eccentricities between 0.95 and 1.0.Formation
PossibilitiesLeft: Angle distributions for twin binaries with orbital
separations of 4001,000 au (blue). A power-law model is shown in black
and the result for a simulated population of wide twin binaries in
which 18.9% of stars have eccentricities between 0.948 and 0.992 is
in red. Right: The modeled eccentricity distribution that corresponds
to the dashed red line in the left panel. Click to enlarge. [Hwang
et al. 2022]This finding suggests that wide twin binaries likely form
close together before being driven apart, but how these binary systems
attain their eccentric orbits is still unclear. Hwang and collaborators
explore several possibilities:An instantaneous kick could wrench a
close circular orbit into a highly eccentric one, but its not clear
what process could provide the kick.Wide, eccentric twin binary systems
might instead have three stars, with the third star being a close,
unresolved companion of one of the two widely separated stars. However,
previous research suggests that unresolved stellar companions are
not especially common among twin binaries.Interactions between a
young binary system and the disk surrounding it could increase the
systems eccentricity. This process would affect all close binaries
not just twin binaries but the results might be more apparent in the
twin binary population because twins are more common among close
binary systems.The formation of wide, eccentric twin binaries has
implications for single stars as well; Hwang and coauthors outline
the possibility that the same process that drives close binary systems
into highly eccentric orbits likely separates some systems entirely,
creating pairs of walkaway stars that meander in opposite directions
through the galaxy.CitationWide Twin Binaries are Extremely Eccentric:
Evidence of Twin Binary Formation in Circumbinary Disks, Hsiang-Chih
Hwang et al 2022 ApJL 933 L32. doi:10.3847/2041-8213/ac7c70The post
Where Do Eccentric Stellar Twins Come From? appeared first on AAS Nova.
Title: Multiwavelength modeling the SED of Luminous Supersoft X-ray
Sources in Large Magellanic Cloud and Small Magellanic Cloud
Authors: Skopal, Augustin
Bibcode: 2022arXiv220902524S
Altcode:
Classical supersoft X-ray sources (SSSs) are understood as close binary
systems in which a massive white dwarf (WD) accretes from its companion
at rates sustaining steady hydrogen burning on its surface generating
bolometric luminosities of $10^{36}-2\times10^{38}$ erg/s. Here, we
perform for the first time the global supersoft X-rays to near-infrared
(NIR) spectral energy distribution (SED) for the brightest SSSs
in LMC and SMC. We test a model in which the ultraviolet--NIR is
dominated by the emission from a compact (unresolved) circumstellar
nebula represented by the ionized gas out-flowing from the SSS. The SED
models correspond to luminosities of SSSs a few times $10^{38}-10^{39}$
erg/s, radiating at blackbody temperatures of $\approx 3\times 10^{5}$
K, and indicate nebular continuum, whose emission measure of $\gtrsim
2\times10^{60}$ cm$^{-3}$ corresponds to a wind mass-loss at rates
$\gtrsim 2\times 10^{-6}$ $M_{\odot}\,{\rm yr}^{-1}$. Such extreme
parameters suggest that the brightest SSSs could be unidentified
optical novae in a post-nova SSS state sustained at a high long-lasting
luminosity by resumed accretion, possibly at super-Eddington rates. New
observations and theoretical multiwavelength modeling of the global
SED of SSSs are needed to reliably determine their parameters, and
thus understand their proper stage in stellar evolution.
Title: Radiative reconnection-powered TeV flares from the black hole
magnetosphere in M87
Authors: Hakobyan, Hayk; Ripperda, Bart; Philippov, Alexander
Bibcode: 2022arXiv220902105H
Altcode:
Active Galactic Nuclei in general, and the supermassive black hole
in M87 in particular, show bright and rapid gamma-ray flares up to
energies of 100 GeV and above. For M87, the flares show multiwavelength
components, and the variability timescale is comparable to the dynamical
time of the event horizon, suggesting that the emission may come from
a compact region nearby the nucleus. However, the emission mechanism
for these flares is not well understood. Recent high-resolution general
relativistic magnetohydrodynamics simulations show the occurrence of
episodic magnetic reconnection events that can power flares nearby
the black hole event horizon. In this work we analyze the radiative
properties of the reconnecting current layer under the extreme plasma
conditions applicable to the black hole in M87 from first principles. We
show that abundant pair production is expected in the vicinity of
the reconnection layer, to the extent that the produced secondary
pair-plasma dominates the reconnection dynamics. Using analytic
estimates backed by two-dimensional particle-in-cell simulations we
demonstrate that even in the presence of strong synchrotron cooling,
reconnection can still produce a hard power-law distribution of pair
plasma imprinted in the outgoing synchrotron (up to few tens of MeV) and
the inverse-Compton signal (up to TeV). We produce synthetic radiation
spectra from our simulations, which can be directly compared with the
results of future multiwavelength observations of M87* flares.
Title: The Origin of the Doppler Flip in HD 100546: A Large-scale
Spiral Arm Generated by an Inner Binary Companion
Authors: Norfolk, Brodie J.; Pinte, Christophe; Calcino, Josh;
Hammond, Iain; van der Marel, Nienke; Price, Daniel J.; Maddison,
Sarah T.; Christiaens, Valentin; Gonzalez, Jean-François; Blakely,
Dori; Rosotti, Giovanni; Ginski, Christian
Bibcode: 2022ApJ...936L...4N
Altcode: 2022arXiv220802542N
Companions at subarcsecond separation from young stars are difficult to
image. However, their presence can be inferred from the perturbations
they create in the dust and gas of protoplanetary disks. Here we present
a new interpretation of SPHERE polarized observations that reveal
the previously detected inner spiral in the disk of HD 100546. The
spiral coincides with a newly detected 12CO inner spiral
and the previously reported CO emission Doppler flip, which has been
interpreted as the signature of an embedded protoplanet. Comparisons
with hydrodynamical models indicate that this Doppler flip is instead
the kinematic counterpart of the spiral, which is likely generated by
an inner companion inside the disk cavity.
Title: Broadband X-Ray Spectroscopy and Estimation of Spin of the
Galactic Black Hole Candidate GRS 1758-258
Authors: Jana, Arghajit; Chang, Hsiang-Kuang; Chatterjee, Arka; Naik,
Sachindra; Safi-Harb, Samar
Bibcode: 2022ApJ...936....3J
Altcode: 2022arXiv220801399J
We present the results of a broadband (0.5-78 keV) X-ray spectral
study of the persistent Galactic black hole X-ray binary GRS 1758-258
observed simultaneously by Swift and NuSTAR. Fitting with an absorbed
power-law model revealed a broad Fe line and reflection hump in the
spectrum. We used different flavors of the relativistic reflection
model for the spectral analysis. All models indicate the spin of the
black hole in GRS 1758-258 is >0.92. The source was in the low
hard state during the observation, with the hot electron temperature
of the corona estimated to be kT e ~ 140 keV. The black
hole is found to be accreting at ~1.5% of the Eddington limit during
the observation, assuming the black hole mass of 10 M ⊙
and distance of 8 kpc.
Title: pterodactyls: A Tool to Uniformly Search and Vet for Young
Transiting Planets in TESS Primary Mission Photometry
Authors: Fernandes, Rachel B.; Mulders, Gijs D.; Pascucci, Ilaria;
Bergsten, Galen J.; Koskinen, Tommi T.; Hardegree-Ullman, Kevin K.;
Pearson, Kyle A.; Giacalone, Steven; Zink, Jon; Ciardi, David R.;
O'Brien, Patrick
Bibcode: 2022AJ....164...78F
Altcode: 2022arXiv220603989F
Kepler's short-period exoplanet population has revealed evolutionary
features such as the Radius Valley and the Hot Neptune desert that
are likely sculpted by atmospheric loss over time. These findings
suggest that the primordial planet population is different from the
Gyr-old Kepler population, and motivates exoplanet searches around
young stars. Here, we present pterodactyls, a data reduction pipeline
specifically built to address the challenges in discovering exoplanets
around young stars and to work with TESS Primary Mission 30-minute
cadence photometry, since most young stars were not preselected
TESS two-minute cadence targets. pterodactyls builds on publicly
available and tested tools in order to extract, detrend, search, and
vet transiting young planet candidates. We search five clusters with
known transiting planets: the Tucana-Horologium Association, IC 2602,
Upper Centaurus Lupus, Ursa Major, and Pisces-Eridani. We show that
pterodactyls recovers seven out of the eight confirmed planets and
one out of the two planet candidates, most of which were initially
detected in two-minute cadence data. For these clusters, we conduct
injection-recovery tests to characterize our detection efficiency,
and compute an intrinsic planet occurrence rate of 49% ± 20% for
sub-Neptunes and Neptunes (1.8-6 R ⊕) within 12.5 days,
which is higher than Kepler's Gyr-old occurrence rates of 6.8% ±
0.3%. This potentially implies that these planets have shrunk with
time due to atmospheric mass loss. However, a proper assessment of the
occurrence of transiting young planets will require a larger sample
unbiased to planets already detected. As such, pterodactyls will be
used in future work to search and vet for planet candidates in nearby
clusters and moving groups.
Title: A 4~Kpc Molecular Gas Lane in Cygnus A
Authors: Carilli, C. L.; Perley, R. A.; Perley, D. A.; Dhawan, V.;
Decarli, R.; Evans, A.; Nyland, K.
Bibcode: 2022arXiv220901278C
Altcode:
We present the discovery of a 4 kpc molecular gas lane in the Cygnus A
host galaxy, using ALMA CO 2-1 observations. The gas lane is oriented
roughly perpendicular to the projected radio jet axis. The CO emission
generally follows the clumpy dust lanes seen in HST I-band images. The
total molecular gas mass is $30\times 10^8$ M$_\odot$ for Milky Way type
clouds, and $3.6 \times 10^8$ M$_\odot$ for starburst conditions. There
is a velocity change from the northern to southern CO peaks of about
$\pm 175$~km~s$^{-1}$, and an apparently smooth velocity gradient
between the peaks, although the emission in the central region is
weak. In the inner $\sim 0.5"$ projected distance from the radio core,
comparison of the CO velocities to those observed for H$_2$ 2.1218
$\mu$m emission shows higher velocities for the vibrationally excited
warm molecular gas than the cooler CO 2-1 line emitting gas at similar
projected radii. A possible explanation for these different projected
velocities at a given radius is that the cooler CO gas is distributed
in a clumpy ring at radius $\sim 1.5"$ to $2"$, while the warm H$_2$
2.12$\mu$m emitting gas is interior to this ring. Of course, the current
data cannot rule-out a clumpy, amorphous molecular gas distribution
linearly distributed perpendicular to the radio jet axis. We consider
surface brightness properties on scales down to $\sim 265$~pc, and
discuss the Cygnus A results in the context of other radio galaxies
with CO emission.
Title: Resolved velocity profiles of galactic winds at Cosmic Noon
Authors: C., Keerthi Vasan G.; Jones, Tucker; Sanders, Ryan L.; Ellis,
Richard S.; Stark, Daniel P.; Kacprzak, Glenn; Barone, Tania M.;
Tran, Kim-Vy H.; Glazebrook, Karl; Jacobs, Colin
Bibcode: 2022arXiv220905508C
Altcode:
We study the kinematics of the interstellar medium (ISM) viewed "down
the barrel" in 20 gravitationally lensed galaxies during Cosmic Noon
($z=1.5 - 3.5$). We use moderate-resolution spectra ($R\sim4000$) from
Keck/ESI and Magellan/MagE to spectrally resolve the ISM absorption
in these galaxies into $\sim$10 independent elements and use double
Gaussian fits to quantify the velocity structure of the gas. We find
that the bulk motion of gas in this galaxy sample is outflowing, with
average velocity centroid $\left=-148 $km$\,$s$^{-1}$
($\pm109 $km$\,$s$^{-1}$ scatter) measured with respect to the systemic
redshift. 16 out of the 20 galaxies exhibit a clear positive skewness,
with a blueshifted tail extending to $\sim -500$ km$\,$s$^{-1}$. The
velocity width is considerably larger in the lensed galaxy sample
compared to strong absorption systems viewed in quasar spectra which
probe larger impact parameters, suggesting that absorbing gas seen
in our sample is in close proximity to the host galaxies ($\lesssim
10$s of kpc). We examine scaling relations in outflow velocities
with galaxy stellar mass and star formation rate (SFR), finding
correlations consistent with a momentum-driven wind scenario. Our
measured outflow velocities are also comparable to those reported for
FIRE-2 and TNG50 cosmological simulations at similar redshift and galaxy
properties. We also consider implications for interpreting results from
lower-resolution spectra. We demonstrate that while velocity centroids
are accurately recovered at lower resolution, the skewness, velocity
width and probes of high velocity gas (e.g., $v_{95}$) are biased at
$R\lesssim2000$. This work represents the largest available sample of
well-resolved outflow velocity structure at $z>2$, and highlights the
need for good spectral resolution to recover accurate properties.
Title: Shape-based approach to attitude motion planning of
reconfigurable spacecraft
Authors: Gong, Shengping; Gong, Haoran; Shi, Peng
Bibcode: 2022AdSpR..70.1285G
Altcode:
Internal torques generated from shape reconfiguration can be helpful in
Micro-Satellite attitude control. The configuration-attitude-coupled
non-holonomic dynamics of a multi-body spacecraft is investigated. A
shape-based motion trajectory in the form of water drop curve is
proposed to synchronously reach target attitude and target shape
configuration. With the shape-based approach, the motion planning
problem is converted into a system of non-linear equations in three
unknowns. The advantages of this approach is demonstrated from the
views of simplicity, reachability, and efficiency. Simulations are
conducted to test the planning function, and the results are compared
with those obtained from the optimal control method.
Title: Discordance analysis on a high-resolution valley network map
of Mars: Assessing the effects of scale on the conformity of valley
orientation and surface slope direction
Authors: Bahia, Rickbir S.; Covey-Crump, Stephen; Jones, Merren A.;
Mitchell, Neil
Bibcode: 2022Icar..38315041B
Altcode:
Fluvial valleys incised into planetary surfaces display morphologies,
geometries and orientations that can be used to understand their
controlling processes. Comparisons between valley orientations and
topographic surface slope direction have been used to understand how
Martian surfaces have evolved (Luo and Stepinski, 2012; Black et al.,
2017); however, new insights from terrestrial studies have revealed
that the slope needs to be defined on a scale commensurate with the
length of valley (Lipp and Roberts, 2020). We propose and test a new
map-based framework for interpreting the difference between Martian
valley orientation and surface slope direction (discordance) at varying
spatial scales. Valleys and inverted channels were manually mapped in a
latitudinal strip from pole to pole between 20°E-20°W using High/Super
Resolution Stereo Colour Imager images (15 to 25 m per pixel). The
orientation of incisional valleys, associated with fluvial activity,
were compared with topographic slope direction at varying scales (463
m, 1 km, 10 km and 50 km). High-resolution mapping resulted in ~1.5
times the density (0.02 km/km2 on average) of the previous
valley map (Hynek et al., 2010), which raises the possibility that
water volumes necessary to carve valleys were greater than previously
thought. The distribution of valleys is similar to previous valley
maps, however there are areas where valleys were identified that have
previously remained undetected in low resolution images. The scale
over which one compares valley orientation to surface slope direction
has a clear effect on the apparent conformity between Martian valley
orientation and topographic slope direction, with smaller valleys
conforming more closely with smaller scale topography. To account
for scale we perform discordance analysis with the spatial scale
of surface slope direction varying based on valley length. When
scale is accounted for, there is a greater conformity between valley
orientation and surface slope direction, however only ~38% of valleys
display conformity, indicating other sources of high discordance. We
find that the source of the high values of discordance are likely a
result of a combination of valley immaturity, attesting to the arid
nature of the Late Noachian - Early Hesperian climate, but also the
palaeolake outburst and, possible, subglacial origin of some valley
networks. Considering a large proportion of valleys do not display
conformity with topography, we suggest that a discordance analysis of
the kind reported here is an important preliminary to any hydrodynamic
analysis that relies on topographic information.
Title: Pan-STARRS Transient Discovery Report for 2022-09-04
Authors: Chambers, K. C.; Boer, T. D.; Bulger, J.; Fairlamb, J.; Huber,
M.; Lin, C. C.; Lowe, T.; Magnier, E.; Schultz, A.; Wainscoat, R. J.;
Gao, H.; Smith, K. W.; Young, D. R.; Gillanders, J.; Srivastav, S.;
Fulton, M.; Smartt, S. J.; Sim, S.; Wright, D. E.
Bibcode: 2022TNSTR2577....1C
Altcode:
No abstract at ADS
Title: Transit Hunt for Young and Maturing Exoplanets (THYME). VIII. A
Pleiades-age Association Harboring Two Transiting Planetary Systems
from Kepler
Authors: Barber, Madyson G.; Mann, Andrew W.; Bush, Jonathan L.;
Tofflemire, Benjamin M.; Kraus, Adam L.; Krolikowski, Daniel M.;
Vanderburg, Andrew; Fields, Matthew J.; Newton, Elisabeth R.; Owens,
Dylan A.; Thao, Pa Chia
Bibcode: 2022AJ....164...88B
Altcode: 2022arXiv220608383B
Young planets provide a window into the early stages and evolution
of planetary systems. Ideal planets for such research are in coeval
associations, where the parent population can precisely determine
their ages. We describe a young association (MELANGE-3) in the Kepler
field, which harbors two transiting planetary systems (KOI-3876 and
Kepler-970). We identify MELANGE-3 by searching for kinematic and
spatial overdensities around Kepler planet hosts with high levels of
lithium. To determine the age and membership of MELANGE-3, we combine
new high-resolution spectra with archival light curves, velocities, and
astrometry of stars near KOI-3876 spatially and kinematically. We use
the resulting rotation sequence, lithium levels, and color-magnitude
diagram of candidate members to confirm the presence of a coeval 105
± 10 Myr population. MELANGE-3 may be part of the recently identified
Theia 316 stream. For the two exoplanet systems, we revise the stellar
and planetary parameters, taking into account the newly determined
age. Fitting the 4.5 yr Kepler light curves, we find that KOI-3876b
is a 2.0 ± 0.1 R ⊕ planet on a 19.58 day orbit, while
Kepler-970 b is a 2.8 ± 0.2 R ⊕ planet on a 16.73 day
orbit. KOI-3876 was previously flagged as an eclipsing binary, which
we rule out using radial velocities from APOGEE and statistically
validate the signal as planetary in origin. Given its overlap with the
Kepler field, MELANGE-3 is valuable for studies of spot evolution on
year timescales, and both planets contribute to the growing work on
transiting planets in young stellar associations.
Title: On the Origin of the Photospheric Magnetic Field
Authors: Schuck, Peter W.; Linton, Mark G.; Knizhnik, Kalman J.;
Leake, James E.
Bibcode: 2022ApJ...936...94S
Altcode:
This article presents results that challenge the paradigms that (1)
the convection zone is the source of the radial magnetic field in
the photosphere and (2) that coronal currents are neutralized from
the perspective of the photosphere. We demonstrate, using a new
analysis tool applied to simulations and observations, that bare
or partially dressed current channels are supported by the solar
corona and that fingerprints of these coronal current systems can be
detected in the photosphere. These coronal current channels can be a
significant source of the radial component of the magnetic field in
the photosphere. The roots of these coronal current channels in the
photosphere are the source of the magnetic field component parallel
to the polarity inversion line in active region NOAA 12673. These
analyses and observations transform our theoretical understanding of
coronal evolution and argue for a reexamination of the present paradigm
in which the convection zone is the sole source of the photospheric
magnetic field.
Title: YSE/Pan-STARRS Transient Discovery Report for 2022-09-06
Authors: Jones, D. O.; French, K. D.; Agnello, A.; Angus, C. R.;
Ansari, Z.; Arendse, N.; Gall, C.; Grillo, C.; Bruun, S. H.; Hede,
C.; Hjorth, J.; Izzo, L.; Korhonen, H.; Raimundo, S.; Ramanah,
D. K.; Sarangi, A.; Wojtak, R.; Pfister, H.; Auchettl, K.; Chambers,
K. C.; Huber, M. E.; Magnier, E. A.; Boer, T. J. L. D.; Fairlamb,
J. R.; Lin, C. C.; Wainscoat, R. J.; Lowe, T.; Gao, H.; Bulger, J.;
Schultz, A. S. B.; Engel, A.; Gagliano, A.; Narayan, G.; Soraisam,
M.; Wang, Q.; Rest, A.; Smartt, S. J.; Smith, K. W.; Alexander, K.;
Blanchard, P.; DeMarchi, L.; Hajela, A.; Jacobson-Galan, W.; Margutti,
R.; Matthews, D.; Stauffer, C.; Stroh, M.; Terreran, G.; Drout, M.;
Coulter, D. A.; Dimitriadis, G.; Foley, R. J.; Hung, T.; Kilpatrick,
C. D.; Rojas-Bravo, C.; Siebert, M. R.; Ramirez-Ruiz, E.
Bibcode: 2022TNSTR2598....1J
Altcode:
No abstract at ADS
Title: Binding Energy Evaluation Platform: A Database of Quantum
Chemical Binding Energy Distributions for the Astrochemical Community
Authors: Bovolenta, Giulia M.; Vogt-Geisse, Stefan; Bovino, Stefano;
Grassi, Tommaso
Bibcode: 2022ApJS..262...17B
Altcode: 2022arXiv220713095B
The quality of astrochemical models is highly dependent on reliable
binding energy (BE) values that consider the morphological and energetic
variety of binding sites on the surface of ice-grain mantles. Here,
we present the Binding Energy Evaluation Platform (BEEP) and database
that, using quantum chemical methods, produces full BE distributions of
molecules bound to an amorphous solid water (ASW) surface model. BEEP
is highly automatized and allows one to sample binding sites on a set
of water clusters and to compute accurate BEs. Using our protocol, we
computed 21 BE distributions of interstellar molecules and radicals on
an amorphized set of 15-18 water clusters of 22 molecules each. The
distributions contain between 225 and 250 unique binding sites. We
apply a Gaussian fit and report the mean and standard deviation for
each distribution. We compare with existing experimental results
and find that the low- and high-coverage experimental BEs coincide
well with the high-BE tail and mean value of our distributions,
respectively. Previously reported single BE theoretical values are
broadly in line with ours, even though in some cases significant
differences can be appreciated. We show how the use of different
BE values impacts a typical problem in astrophysics, such as the
computation of snow lines in protoplanetary disks. BEEP will be publicly
released so that the database can be expanded to other molecules or
ice models in a community effort.
Title: Widespread Detection of Two Components in the Hot
Circumgalactic Medium of the Milky Way
Authors: Bluem, Jesse; Kaaret, Philip; Kuntz, K. D.; Jahoda, Keith
M.; Koutroumpa, Dimitra; Hodges-Kluck, Edmund J.; Fuller, Chase A.;
LaRocca, Daniel M.; Zajczyk, Anna
Bibcode: 2022ApJ...936...72B
Altcode: 2022arXiv220802477B
Surrounding the Milky Way (MW) is the circumgalactic medium (CGM),
an extended reservoir of hot gas that has significant implications
for the evolution of the MW. We used the HaloSat all-sky survey to
study the CGM's soft X-ray emission in order to better define its
distribution and structure. We extend a previous HaloSat study of the
southern CGM (Galactic latitude b < -30°) to include the northern
CGM (b > 30°) and find evidence that at least two hot gas model
components at different temperatures are required to produce the
observed emission. The cooler component has a typical temperature of
kT ~0.18 keV, while the hotter component has a typical temperature of
kT ~0.7 keV. The emission measure in both the warm and hot components
has a wide range (~0.005-0.03, and ~0.0005-0.004 cm-6
pc, respectively), indicating that the CGM is clumpy. A patch of
relatively consistent CGM was found in the north, allowing for the CGM
spectrum to be studied in finer detail using a stacked spectrum. The
stacked spectrum is well described with a model including two hot
gas components at temperatures of kT = 0.166 ± 0.005 keV and kT =
${0.69}_{-0.05}^{+0.04}$ keV. As an alternative to adding a hot
component, a neon-enhanced single-temperature model of the CGM was
also tested and found to have worse fit statistics and poor residuals.
Title: Hidden Spectral Symmetries and Mode Stability of Subextremal
Kerr(-de Sitter) Black Holes
Authors: Casals, Marc; Teixeira da Costa, Rita
Bibcode: 2022CMaPh.394..797C
Altcode: 2022CMaPh.tmp..156C; 2021arXiv210513329C
We uncover hidden spectral symmetries of the Teukolsky equation
in Kerr(-de Sitter) black holes, recently conjectured by Aminov,
Grassi and Hatsuda (Ann. Henri Poincaré 23, 1951-1977, 2022, and
Gen. Relativ. Grav. 53(10):93, 2021) in the zero cosmological constant
case. Using these symmetries, we provide a new, simpler proof of mode
stability for subextremal Kerr black holes. We also present a partial
mode stability result for Kerr-de Sitter black holes.
Title: Can Cooling and Heating Functions Be Modeled with Homogeneous
Radiation Fields?
Authors: Robinson, David; Avestruz, Camille; Gnedin, Nickolay Y.
Bibcode: 2022ApJ...936...50R
Altcode: 2021arXiv210901674R
Cooling and heating functions describe how radiative processes impact
the thermal state of a gas as a function of its temperature and other
physical properties. In a most general case the functions depend on
the detailed distributions of ionic species and on the radiation
spectrum. Hence, these functions may vary on a very wide range of
spatial and temporal scales. In this paper, we explore cooling and
heating functions between 5 ≤ z ≤ 10 in simulated galaxies from the
Cosmic Reionization On Computers project. We compare three functions:
(1) the actual cooling and heating rates of hydrodynamic cells as
a function of cell temperature, (2) the median cooling and heating
functions computed using median interstellar medium (ISM) properties
(median ISM), and (3) the median of the cooling and heating functions
of all gas cells (instantaneous). We find that the median ISM and
instantaneous approaches to finding a median cooling and heating
function give identical results within the spread due to cell-to-cell
variation. However, the actual cooling (heating) rates experienced by
the gas at different temperatures in the simulations do not correspond
to either summarized cooling (heating) functions. In other words,
the thermodynamics of the gas in the simulations cannot be described
by a single set of a cooling plus a heating function with a spatially
constant radiation field that could be computed with common tools,
such as CLOUDY.
Title: Anisotropic Electron Heating in Turbulence-driven Magnetic
Reconnection in the Near-Sun Solar Wind
Authors: Franci, Luca; Papini, Emanuele; Micera, Alfredo; Lapenta,
Giovanni; Hellinger, Petr; Sarto, Daniele Del; Burgess, David;
Landi, Simone
Bibcode: 2022ApJ...936...27F
Altcode: 2022arXiv220508670F
We perform a high-resolution, 2D, fully kinetic numerical simulation of
a turbulent plasma system with observation-driven conditions, in order
to investigate the interplay between turbulence, magnetic reconnection,
and particle heating from ion to subelectron scales in the near-Sun
solar wind. We find that the power spectra of the turbulent plasma and
electromagnetic fluctuations show multiple power-law intervals down to
scales smaller than the electron gyroradius. Magnetic reconnection is
observed to occur in correspondence of current sheets with a thickness
of the order of the electron inertial length, which form and shrink
owing to interacting ion-scale vortices. In some cases, both ion and
electron outflows are observed (the classic reconnection scenario),
while in others-typically for the shortest current sheets-only
electron jets are present ("electron-only reconnection"). At the
onset of reconnection, the electron temperature starts to increase
and a strong parallel temperature anisotropy develops. This suggests
that in strong turbulence electron-scale coherent structures may play
a significant role for electron heating, as impulsive and localized
phenomena such as magnetic reconnection can efficiently transfer energy
from the electromagnetic fields to particles.
Title: The TESS-Keck Survey. XIII. An Eccentric Hot Neptune with a
Similar-mass Outer Companion around TOI-1272
Authors: MacDougall, Mason G.; Petigura, Erik A.; Fetherolf, Tara;
Beard, Corey; Lubin, Jack; Angelo, Isabel; Batalha, Natalie M.;
Behmard, Aida; Blunt, Sarah; Brinkman, Casey; Chontos, Ashley;
Crossfield, Ian J. M.; Dai, Fei; Dalba, Paul A.; Dressing, Courtney;
Fulton, Benjamin; Giacalone, Steven; Hill, Michelle L.; Howard,
Andrew W.; Huber, Daniel; Isaacson, Howard; Kane, Stephen R.;
Kosiarek, Molly; Mayo, Andrew; Močnik, Teo; Akana Murphy, Joseph
M.; Pidhorodetska, Daria; Polanski, Alex; Rice, Malena; Robertson,
Paul; Rosenthal, Lee J.; Roy, Arpita; Rubenzahl, Ryan A.; Scarsdale,
Nicholas; Turtelboom, Emma V.; Tyler, Dakotah; Van Zandt, Judah; Weiss,
Lauren M.; Esparza-Borges, Emma; Fukui, Akihiko; Isogai, Keisuke;
Kawauchi, Kiyoe; Mori, Mayuko; Murgas, Felipe; Narita, Norio; Nishiumi,
Taku; Palle, Enric; Parviainen, Hannu; Watanabe, Noriharu; Jenkins,
Jon M.; Latham, David W.; Ricker, George R.; Seager, S.; Vanderspek,
Roland K.; Winn, Joshua N.; Bieryla, Allyson; Caldwell, Douglas A.;
Dragomir, Diana; Fausnaugh, M. M.; Mireles, Ismael; Rodriguez, David R.
Bibcode: 2022AJ....164...97M
Altcode: 2022arXiv220614327M
We report the discovery of an eccentric hot Neptune and a non-transiting
outer planet around TOI-1272. We identified the eccentricity of the
inner planet, with an orbital period of 3.3 days and R p,b
= 4.1 ± 0.2 R ⊕, based on a mismatch between the observed
transit duration and the expected duration for a circular orbit. Using
ground-based radial velocity (RV) measurements from the HIRES instrument
at the Keck Observatory, we measured the mass of TOI-1272b to be M
p,b = 25 ± 2 M ⊕. We also confirmed a high
eccentricity of e b = 0.34 ± 0.06, placing TOI-1272b
among the most eccentric well-characterized sub-Jovians. We used these
RV measurements to also identify a non-transiting outer companion on
an 8.7 day orbit with a similar mass of M p,c sin i = 27 ±
3 M ⊕ and e c ≲ 0.35. Dynamically stable
planet-planet interactions have likely allowed TOI-1272b to avoid
tidal eccentricity decay despite the short circularization timescale
expected for a close-in eccentric Neptune. TOI-1272b also maintains
an envelope mass fraction of f env ≍ 11% despite its high
equilibrium temperature, implying that it may currently be undergoing
photoevaporation. This planet joins a small population of short-period
Neptune-like planets within the "Hot Neptune Desert" with a poorly
understood formation pathway.
Title: Extremely Low-mass White Dwarf Stars Observed in Gaia DR2
and LAMOST DR8
Authors: Wang, Kun; Németh, Péter; Luo, Yangping; Chen, Xiaodian;
Jiang, Qingquan; Cao, Xingmei
Bibcode: 2022ApJ...936....5W
Altcode: 2022arXiv220713401W
We present the first results from our ongoing project to study extremely
low-mass (ELM) white dwarfs (WDs) (M ≤ 0.3M ⊙) with the
Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST)
spectra. Based on the LAMOST DR8 spectral database, we analyzed 136
ELM WD candidates selected from Gaia DR2 data and 12 known objects
previously identified by the ELM Survey. The atmospheric parameters and
radial velocities of these stars were obtained by fitting the LAMOST
low-resolution spectra. After comparing the atmospheric parameters of
the 12 known objects from this work to the results reported by the ELM
Survey, we demonstrated the potential of LAMOST spectra in probing
into the nature of ELM WDs. Based on the atmospheric parameters and
Gaia EDR3 data, we identified 21 new high-probability ELM WDs with
masses M ≤ 0.3M ⊙ and parallax estimates that agree
to within a factor of 3. Two of them, J0338+4134 and J1129+4715,
show significant radial velocity variability and are very likely to
be binary systems containing at least one ELM WD.
Title: Degradation of rocks on the Moon: Insights on abrasion from
topographic diffusion, LRO/NAC and Apollo images
Authors: Rüsch, O.; Wöhler, C.
Bibcode: 2022Icar..38415088R
Altcode:
The efficiency of regolith production is key in understanding the
properties of airless surfaces. Debris aprons, of fillets, around
rocks are a ubiquitous morphology on many surfaces without atmosphere,
which origin and evolution are largely unknown. Here we develop a
model for the morphological evolution of the rock-fillet system on the
Moon that considers fillet material to be produced by the juxtaposed
rock under abrasion. We show that rocks of different cohesion have
fillets with distinct morphological evolution. Thus, a fillet around
a rock allows to disentangle rock cohesion from its surface exposure
age. By combing topographic diffusion modeling with images of blocks
of known age on the Moon, we find abrasion rates for m-sized rocks to
be higher than for cm-sized rocks. Artificial images constructed with
model topography indicate that rocks with fillet can be identified
in orbital images by a bright halo around a rock and by the fillet
shadows. Fillets around lunar rocks are consistent with abrasion by
isotropic micrometeoroid bombardment.
Title: Determining the orbit from five relative apparent positions
Authors: Emelyanov, N. V.; Kondratyev, B. P.
Bibcode: 2022Icar..38315060E
Altcode:
The article describes a new method for determining the orbit of
a satellite of a distant body by five measured apparent relative
positions. Objects can be components of a visual binary star. The
method is based on old ideas proposed back in the 19th century. In
1883, T.N. Thiele theoretically deduced and proposed an interesting
method for determining an orbit from three apparent relative positions
for a given sector (areal) velocity of the body in apparent orbit. In
this paper, this method is supplemented with analytical formulas for
determining the sectoral velocity of a satellite of a star or planet in
apparent orbit in five positions. Five relative positions are needed
to accurately determine the sector velocity of a body in a visible
orbit. Further, the parameters of the spatial orbit are determined by
three positions. The semi-major axis of the orbit and the mean motion
are determined independently. This makes it possible to determine
the total mass of the system under study. The proposed method is
first tested on a model example, and then its adequacy is shown for
the problem of determining the orbit of a visual binary star ZZ Tau
based on real observations. In this example, the method is tested,
its adequacy is shown. We also consider the application of the method
for determining the preliminary orbit of an asteroid satellite with
the aim of subsequent refinement of the orbit based on collection of
observations over a large time interval. The reliability of the method
has yet to be tested on specific problems. For convenience, an online
service has been developed on the Internet allowing to calculate the
orbit from the reader's observations.
Title: Dissimilar donuts in the sky? Effects of a pressure singularity
on the circular photon orbits and shadow of a cosmological black hole
Authors: Odintsov, S. D.; Oikonomou, V. K.
Bibcode: 2022EL....13959003O
Altcode: 2022arXiv220807972O
The black hole observations obtained so far indicate one thing:
similar "donuts" exist in the sky. But what if some of the observed
black hole shadows that will be obtained in the future are different
from the others? In this work the aim is to show that a difference in
the shadow of some observed black holes in the future might explain
the H 0-tension problem. In this letter we investigate
the possible effects of a pressure cosmological singularity on the
circular photon orbits and the shadow of galactic supermassive black
holes at cosmological redshifts. Since the pressure singularity is a
global event in the Universe, the effects of the pressure singularity
will be imposed on supermassive black holes at a specific redshift. As
we show, the pressure singularity affects the circular photon orbits
around cosmological black holes described by the McVittie metric,
and specifically, for some time before the time instance that the
singularity occurs, the photon orbits do not exist. We discuss the
possible effects of the absence of circular photon orbits on the
shadow of these black holes. Our idea indicates that if a pressure
singularity occurred in the near past, then this could have a direct
imprint on the shadow of supermassive galactic black holes at the
redshift corresponding to the time instance that the singularity
occurred in the past. Thus, if a sample of shadows is observed in
the future for redshifts $z\leq 0.01$ , and for a specific redshift
differences are found in the shadows, this could be an indication that
a pressure singularity occurred, and this global event might resolve
the H 0-tension as discussed in previous work. However,
the observation of several shadows at redshifts $z\leq 0.01$ is a
rather far future task.
Title: TRAPPIST comets production rates: C/2017 K2 (PanSTARR),
C/2022 E3 (ZTF), C/2022 P1 (NEOWISE), and 73P/SW-3
Authors: Jehin, E.; Donckt, M. Vander; Hmiddouch, S.; Manfroid, J.;
Hutsemekers, H.; Moulane, Y.
Bibcode: 2022ATel15591....1J
Altcode:
The authors report that they obtained from TRAPPIST robotic telescopes
(Jehin et al. 2011) recent observations using cometary HB narrowband
filters (Farnham et al. 2000) for the following comets and computed
preliminary production rates at 10.000 km using a Haser Model
(Vp=Vd=1km/s) (Haser 1957).
Title: Planar Carrollean dynamics, and the Carroll quantum equation
Authors: Marsot, L.
Bibcode: 2022JGP...17904574M
Altcode: 2021arXiv211008489M
We expand on the known result that the Carroll algebra in 2 + 1
dimensions admits two non-trivial central extensions by computing
the associated Lie group, which we call extended Carroll group. The
symplectic geometry associated to this group is then computed to
describe the motion of planar Carroll elementary particles, in
the free case, when coupled to an electromagnetic field, and to a
gravitational field. We compare to the motions of Carroll particles
in 3 + 1 dimensions in the same conditions, and also give the dynamics
of Carroll particles with spin. In an electromagnetic background, the
planar Carroll dynamics differ from the known Carroll ones due to 2 new
Casimir invariants, and turn out to be non-trivial. The coupling to
a gravitational field leaves the dynamics trivial, however. Finally,
we obtain the quantum equation obeyed by Carroll wave functions via
geometric quantization.
Title: MAXI/GSC detection of a new X-ray outburst from M15
Authors: Negoro, H.; Serino, M.; Nakajima, M.; Kobayashi, K.; Tanaka,
M.; Soejima, Y.; Mihara, T.; Kawamuro, T.; Yamada, S.; Tamagawa,
T.; Matsuoka, M.; Sakamoto, T.; Sugita, S.; Hiramatsu, H.; Yoshida,
A.; Tsuboi, Y.; Iwakiri, W.; Kohara, J.; Shidatsu, M.; Iwasaki, M.;
Kawai, N.; Niwano, M.; Hosokawa, R.; Imai, Y.; Ito, N.; Takamatsu, Y.;
Nakahira, S.; Ueno, S.; Tomida, H.; Ishikawa, M.; Kurihara, T.; Ueda,
Y.; Ogawa, S.; Setoguchi, K.; Yoshitake, T.; Inaba, K.; Yamauchi, M.;
Sato, T.; Hatsuda, R.; Fukuoka, R.; Hagiwara, Y.; Umeki, Y.; Yamaoka,
K.; Kawakubo, Y.; Sugizaki, M.
Bibcode: 2022ATel15586....1N
Altcode:
At 21:46 UT on 2022 August 26, the MAXI/GSC nova alert system triggered
on a new X-ray outburst probably from an X-ray source in the globular
cluster M15. The X-ray flux averaged over 13 scan transits from 22:33
on August 25 and 21:46 August 26 scan was 28 +- 5 mCrab (4.0-10.0keV,
1 sigma error).
Title: From Maximum Force Via the Hoop Conjecture to Inverse Square
Gravity
Authors: Schiller, Christoph
Bibcode: 2022GrCo...28..305S
Altcode:
The equivalence of maximum force $c4/4G$ and the field
equations of general relativity provides a simple derivation of inverse
square gravity. The derivation confirms the hoop conjecture and suggests
a lack of gravitational physics beyond general relativity. Possible
loopholes are pointed out.
Title: New XMM-Newton observations of faint, evolved supernova
remnants in the Large Magellanic Cloud
Authors: Kavanagh, P. J.; Sasaki, M.; Filipović, M. D.; Points,
S. D.; Bozzetto, L. M.; Haberl, F.; Maggi, P.; Maitra, C.
Bibcode: 2022MNRAS.515.4099K
Altcode: 2022MNRAS.tmp..786K; 2021arXiv211100446K
The Large Magellanic Cloud (LMC) hosts a rich population of supernova
remnants (SNRs), our knowledge of which is the most complete of any
galaxy. However, there remain many candidate SNRs, identified through
optical and radio observations where additional X-ray data can confirm
their SNR nature and provide details on their physical properties. In
this paper, we present XMM-Newton observations that provide the first
deep X-ray coverage of ten objects, comprising eight candidates and
two previously confirmed SNRs. We perform multifrequency studies
using additional data from the Magellanic Cloud Emission Line Survey
(MCELS) to investigate their broad-band emission and used Spitzer data
to understand the environment in which the objects are evolving. We
confirm seven of the eight candidates as bona-fide SNRs. We used
a multifrequency morphological study to determine the position and
size of the remnants. We identify two new members of the class of
evolved Fe-rich remnants in the Magellanic Clouds (MCs), several SNRs
well into their Sedov-phase, one SNR likely projected towards a H II
region, and a faint, evolved SNR with a hard X-ray core which could
indicate a pulsar wind nebula. Overall, the seven newly confirmed
SNRs represent a ~10-per cent increase in the number of LMC remnants,
bringing the total number to 71, and provide further insight into the
fainter population of X-ray SNRs.
Title: July 2022 report CAMS BeNeLux
Authors: Roggemans, P.
Bibcode: 2022eMetN...7..364R
Altcode:
A summary of the activity of the CAMS BeNeLux network during the month
of July 2022 is presented. July 2022 allowed to register 29558 meteors
of which 15972 multiple-station meteors, with a total number of 4499
orbits. A maximum of 100 cameras was operational at 30 camera stations
during this month.
Title: On the inconsistency of [C/Fe] abundances and the fractions
of carbon-enhanced metal-poor stars among various stellar surveys
Authors: Arentsen, Anke; Placco, Vinicius M.; Lee, Young Sun; Aguado,
David S.; Martin, Nicolas F.; Starkenburg, Else; Yoon, Jinmi
Bibcode: 2022MNRAS.515.4082A
Altcode: 2022MNRAS.tmp.1956A; 2022arXiv220604081A
Carbon-enhanced metal-poor (CEMP) stars are a unique resource for
Galactic archaeology because they probe the properties of the First
Stars, early chemical evolution, and binary interactions at very
low metallicity. Comparing the fractions and properties of CEMP
stars in different Galactic environments can provide us with unique
insights into the formation and evolution of the Milky Way halo and
its building blocks. In this work, we investigate whether directly
comparing fractions of CEMP stars from different literature samples
of very metal-poor ($\rm {[Fe/H]}\,\lt\, -2.0$) stars is valid. We
compiled published CEMP fractions and samples of Galactic halo stars
from the past 25 years, and find that they are not all consistent with
each other. Focusing on giant stars, we find significant differences
between various surveys when comparing their trends of [Fe/H] versus
[C/Fe] and their distributions of CEMP stars. To test the role of
the analysis pipelines for low-resolution spectroscopic samples,
we re-analysed giant stars from various surveys with the SSPP and
FERRE pipelines. We found systematic differences in [C/Fe] of ~0.1-0.4
dex, partly independent of degeneracies with the stellar atmospheric
parameters. These systematics are likely due to the different pipeline
approaches, different assumptions in the employed synthetic grids,
and/or the comparison of different evolutionary phases. We conclude
that current biases in (the analysis of) very metal-poor samples limit
the conclusions one can draw from comparing different surveys. We
provide some recommendations and suggestions that will hopefully aid
the community to unlock the full potential of CEMP stars for Galactic
archaeology.
Title: Accreting neutron stars: heating of the upper layers of the
inner crust
Authors: Shchechilin, N. N.; Gusakov, M. E.; Chugunov, A. I.
Bibcode: 2022MNRAS.515L...6S
Altcode: 2022MNRAS.tmpL..57S; 2022arXiv220207486S
Neutron stars in low-mass X-ray binaries are thought to be heated up
by accretion-induced exothermic nuclear reactions in the crust. The
energy release and the location of the heating sources are important
ingredients of the thermal evolution models. Here, we present
thermodynamically consistent calculations of the energy release in
three zones of the stellar crust: at the outer-inner crust interface,
in the upper layers of the inner crust (up to the density ρ ≤ 2
× 1012 g cm-3), and in the underlying crustal
layers. We consider three representative models of thermonuclear ashes
(superburst, extreme rp, and Kepler ashes). The energy release in
each zone is parametrized by the pressure at the outer-inner crust
interface, Poi, which encodes all uncertainties related
to the physics of the deepest inner-crust layers. Our calculations
allow us to set new theoretical lower limits on the net energy release
(per accreted baryon): Q ≳ 0.28 MeV for extreme rp ashes and Q ≳
0.43-0.51 MeV for superburst and Kepler ashes. Our results can be
directly incorporated into numerical codes and provide an opportunity
to constrain Poi by comparing thermal evolution models of
accreting neutron stars with observations.
Title: Towards a classification scheme for the rocky planets based
on equilibrium thermodynamic considerations
Authors: Bertolami, Orfeu; Francisco, Frederico
Bibcode: 2022MNRAS.515.1037B
Altcode: 2022MNRAS.tmp.1631B; 2021arXiv211211404B
A classification scheme for rocky planets is proposed, based on a
description of the Earth System in terms of the Landau-Ginzburg Theory
of phase transitions. Three major equilibrium states can be identified
and the associated planetary states or phases are: Earth-like Holocene
state; hot Venus-like state; cold Mars-like state. The scheme is based
on an approach proposed to understand the Earth transition from the
Holocene to the Anthropocene, driven by the impact of the human action
on the Earth System. In this work, we identity the natural conditions
that cause transformations on the planets forcing them into one of the
states identified above. We discuss how the parameters that describe
these transformations can be related with exoplanets observables. In
analysing the relevant physical parameters, we were stroke by the
similarities between Earth and Venus, and how likely is that the
Anthropocene transition may lead to hot-house Earth scenario.
Title: Modelling the galaxy-halo connection with machine learning
Authors: Delgado, Ana Maria; Wadekar, Digvijay; Hadzhiyska, Boryana;
Bose, Sownak; Hernquist, Lars; Ho, Shirley
Bibcode: 2022MNRAS.515.2733D
Altcode: 2021arXiv211102422D; 2022MNRAS.tmp.1879D
To extract information from the clustering of galaxies on non-linear
scales, we need to model the connection between galaxies and haloes
accurately and in a flexible manner. Standard halo occupation
distribution (HOD) models make the assumption that the galaxy
occupation in a halo is a function of only its mass, however, in
reality; the occupation can depend on various other parameters
including halo concentration, assembly history, environment,
and spin. Using the IllustrisTNG hydrodynamical simulation as our
target, we show that machine learning tools can be used to capture
this high-dimensional dependence and provide more accurate galaxy
occupation models. Specifically, we use a random forest regressor to
identify which secondary halo parameters best model the galaxy-halo
connection and symbolic regression to augment the standard HOD model
with simple equations capturing the dependence on those parameters,
namely the local environmental overdensity and shear, at the location
of a halo. This not only provides insights into the galaxy formation
relationship but also, more importantly, improves the clustering
statistics of the modelled galaxies significantly. Our approach
demonstrates that machine learning tools can help us better understand
and model the galaxy-halo connection, and are therefore useful for
galaxy formation and cosmology studies from upcoming galaxy surveys.
Title: Detectability of wandering intermediate-mass black holes in
the Milky Way galaxy from radio to x-rays
Authors: Seepaul, Bryan S.; Pacucci, Fabio; Narayan, Ramesh
Bibcode: 2022MNRAS.515.2110S
Altcode: 2022arXiv220412498S; 2022MNRAS.tmp.1835S
Intermediate-mass black holes (IMBHs, $10^{3\!-\!6} \, {\rm M_\odot
}$), are typically found at the centre of dwarf galaxies and might
be wandering, thus far undetected, in the Milky Way (MW). We use
model spectra for advection-dominated accretion flows to compute
the typical fluxes, in a range of frequencies spanning from radio to
X-rays, emitted by a putative population of $10^5 \, {\rm M_\odot }$
IMBHs wandering in five realistic volume-weighted MW environments. We
predict that $\sim 27{{\ \rm per\ cent}}$ of the wandering IMBHs can
be detected in the X-ray with Chandra, $\sim 37{{\ \rm per\ cent}}$ in
the near-infrared with the Roman Space Telescope, $\sim 49{{\ \rm per\
cent}}$ in the sub-mm with CMB-S4, and $\sim 57{{\ \rm per\ cent}}$
in the radio with ngVLA. We find that the brightest fluxes are emitted
by IMBHs passing through molecular clouds or cold neutral medium,
where they are always detectable. We propose criteria to facilitate
the selection of candidates in multiwavelength surveys. Specifically,
we compute the X-ray to optical ratio (αox) and the optical
to sub-mm ratio, as a function of the accretion rate of the IMBH. We
show that at low rates the sub-mm emission of IMBHs is significantly
higher than the optical, UV, and X-ray emission. Finally, we place
upper limits on the number N• of these objects in the MW:
N• < 2000 and N• < 100, based on our
detectability expectations and current lack of detections in molecular
clouds and cold neutral medium, respectively. These predictions will
guide future searches of IMBHs in the MW, which will be instrumental
to understanding their demographics and evolution.
Title: Deep extragalactic visible legacy survey (DEVILS): the
emergence of bulges and decline of disc growth since z = 1
Authors: Hashemizadeh, Abdolhosein; Driver, Simon P.; Davies, Luke
J. M.; Robotham, Aaron S. G.; Bellstedt, Sabine; Foster, Caroline;
Holwerda, Benne W.; Jarvis, Matt; Phillipps, Steven; Siudek,
Malgorzata; Thorne, Jessica E.; Windhorst, Rogier A.; Wolf, Christian
Bibcode: 2022MNRAS.515.1175H
Altcode: 2022arXiv220300185H; 2022MNRAS.tmp.1160H
We present a complete structural analysis of the ellipticals
(E), diffuse bulges (dB), compact bulges (cB), and discs
(D) within a redshift range 0 < z < 1, and stellar mass
log10(M*/M⊙) ≥ 9.5 volume-limited
sample drawn from the combined DEVILS and HST-COSMOS region. We use
the PROFIT code to profile over ~35 000 galaxies for which visual
classification into single or double component was pre-defined in
Paper-I. Over this redshift range, we see a growth in the total
stellar mass density (SMD) of a factor of 1.5. At all epochs we
find that the dominant structure, contributing to the total SMD, is
the disc, and holds a fairly constant share of $\sim 60{{\ \rm per\
cent}}$ of the total SMD from z = 0.8 to z = 0.2, dropping to $\sim
30{{\ \rm per\ cent}}$ at z = 0.0 (representing $\sim 33{{\ \rm per\
cent}}$ decline in the total disc SMD). Other classes (E, dB, and
cB) show steady growth in their numbers and integrated stellar mass
densities. By number, the most dramatic change across the full mass
range is in the growth of diffuse bulges. In terms of total SMD, the
biggest gain is an increase in massive elliptical systems, rising from
20 per cent at z = 0.8 to equal that of discs at z = 0.0 (30 per cent)
representing an absolute mass growth of a factor of 2.5. Overall, we
see a clear picture of the emergence and growth of all three classes
of spheroids over the past 8 Gyr, and infer that in the later half
of the Universe's timeline spheroid-forming processes and pathways
(secular evolution, mass-accretion, and mergers) appear to dominate
mass transformation over quiescent disc growth.
Title: Sub-surface alteration and related change in reflectance
spectra of space-weathered materials
Authors: Chrbolková, Kateřina; Halodová, Patricie; Kohout, Tomáš;
Ďurech, Josef; Mizohata, Kenichiro; Malý, Petr; Dědič, Václav;
Penttilä, Antti; Trojánek, František; Jarugula, Rajesh
Bibcode: 2022A&A...665A..14C
Altcode: 2022arXiv220708473C
Context. Airless planetary bodies are studied mainly by remote sensing
methods. Reflectance spectroscopy is often used to derive their
compositions. One of the main complications for the interpretation of
reflectance spectra is surface alteration by space weathering caused
by irradiation by solar wind and micrometeoroid particles.
Aims: We aim to evaluate the damage to the samples from H+
and laser irradiation and relate it to the observed alteration
in the spectra.
Methods: We used olivine (OL) and pyroxene
(OPX) pellets irradiated by 5 keV H+ ions and individual
femtosecond laser pulses and measured their visible (VIS) and
near-infrared (NIR) spectra. We observed the pellets with scanning and
transmission electron microscopy. We studied structural, mineralogical,
and chemical modifications in the samples. Finally, we connected the
material observations to changes in the reflectance spectra.
Results: In both minerals, H+ irradiation induces partially
amorphous sub-surface layers containing small vesicles. In OL pellets,
these vesicles are more tightly packed than in OPX ones. Any related
spectral change is mainly in the VIS spectral slope. Changes due
to laser irradiation are mostly dependent on the material's melting
temperature. Of all the samples, only the laser-irradiated OL contains
nanophase Fe particles, which induce detectable spectral slope change
throughout the measured spectral range. Our results suggest that
spectral changes at VIS-NIR wavelengths are mainly dependent on the
thickness of (partially) amorphous sub-surface layers. Furthermore,
amorphisation smooths micro-roughness, increasing the contribution
of volume scattering and absorption over surface scattering.
Conclusions: Soon after exposure to the space environment, the
appearance of partially amorphous sub-surface layers results in
rapid changes in the VIS spectral slope. In later stages (onset of
micrometeoroid bombardment), we expect an emergence of nanoparticles to
also mildly affect the NIR spectral slope. An increase in the dimensions
of amorphous layers and vesicles in the more space-weathered material
will only cause band-depth variation and darkening.
Title: ELUCID. VII. Using Constrained Hydro Simulations to Explore
the Gas Component of the Cosmic Web
Authors: Li, Renjie; Wang, Huiyuan; Mo, H. J.; Huang, Shuiyao; Katz,
Neal; Luo, Xiong; Cui, Weiguang; Li, Hao; Yang, Xiaohu; Jiang, Ning;
Zhang, Yuning
Bibcode: 2022ApJ...936...11L
Altcode: 2022arXiv220608384L
Using reconstructed initial conditions in the Sloan Digital Sky Survey
(SDSS) survey volume, we carry out constrained hydrodynamic simulations
in three regions representing different types of the cosmic web: the
Coma cluster of galaxies; the SDSS Great Wall; and a large low-density
region at z ~ 0.05. These simulations, which include star formation
and stellar feedback but no active galactic nucleus formation and
feedback, are used to investigate the properties and evolution of
intergalactic and intracluster media. About half of the warm-hot
intergalactic gas is associated with filaments in the local cosmic
web. Gas in the outskirts of massive filaments and halos can be heated
significantly by accretion shocks generated by mergers of filaments
and halos, respectively, and there is a tight correlation between
the gas temperature and the strength of the local tidal field. The
simulations also predict some discontinuities associated with shock
fronts and contact edges, which can be tested using observations of the
thermal Sunyaev-Zel'dovich effect and X-rays. A large fraction of the
sky is covered by Lyα and O VI absorption systems, and most of the
O VI systems and low-column-density H I systems are associated with
filaments in the cosmic web. The constrained simulations, which follow
the formation and heating history of the observed cosmic web, provide an
important avenue to interpret observational data. With full information
about the origin and location of the cosmic gas to be observed, such
simulations can also be used to develop observational strategies.
Title: Mining S-PLUS for Metal-poor Stars in the Milky Way
Authors: Placco, Vinicius M.; Almeida-Fernandes, Felipe; Arentsen,
Anke; Lee, Young Sun; Schoenell, William; Ribeiro, Tiago; Kanaan,
Antonio
Bibcode: 2022ApJS..262....8P
Altcode: 2022arXiv220609003P
This work presents the medium-resolution (R ~ 1500) spectroscopic
follow-up of 522 low-metallicity star candidates from the
Southern Photometric Local Universe Survey (S-PLUS). The objects
were selected from narrowband photometry, taking advantage of the
metallicity-sensitive S-PLUS colors. The follow-up observations were
conducted with the Blanco and Gemini South telescopes, using the COSMOS
and GMOS spectrographs, respectively. The stellar atmospheric parameters
(T eff, $\mathrm{log}\,g$ , and [Fe/H]), as well as carbon
and α-element abundances, were calculated for the program stars in
order to assess the efficacy of the color selection. Results show
that ${92}_{-3}^{+2} \% $ of the observed stars have [Fe/H] ≤ -1.0,
${83}_{-3}^{+3} \% $ have [Fe/H] ≤ -2.0, and ${15}_{-3}^{+3} \% $
have [Fe/H] ≤ -3.0, including two ultra metal-poor stars ([Fe/H] ≤
-4.0). The 80th percentile for the metallicity cumulative distribution
function of the observed sample is [Fe/H] = -2.04. The sample also
includes 68 carbon-enhanced metal-poor stars. Based on the calculated
metallicities, further S-PLUS color cuts are proposed, which can
increase the fractions of stars with [Fe/H] ≤ -1.0 and ≤ -2.0 to
98% and 88%, respectively. Such high success rates enable targeted
high-resolution spectroscopic follow-up efforts, as well as provide
selection criteria for fiber-fed multiplex spectroscopic surveys.
Title: The Physical Properties of Massive Green Valley Galaxies as
a Function of Environments at 0.5 < z < 2.5 in 3D-HST/Candels
Fields
Authors: Chang, Wenjun; Fang, Guanwen; Gu, Yizhou; Lin, Zesen; Lu,
Shiying; Kong, Xu
Bibcode: 2022ApJ...936...47C
Altcode: 2022arXiv220810014C
To investigate the effects of environment in the quenching phase, we
study the empirical relations for green valley (GV) galaxies between
overdensity and other physical properties (i.e., effective radius r
e , Sérsic indices n, and specific star formation rate
(sSFR)). Based on five 3D-HST/CANDELS fields, we construct a large
sample of 2126 massive (M ⋆ > 1010 M
☉) GV galaxies at 0.5 < z < 2.5 and split it into
the higher overdensity quarter and the lower overdensity quarter. The
results shows that GV galaxies in denser environments have higher
n values and lower sSFR at 0.5 < z < 1, while there is no
discernible distinction at 1 < z < 2.5. No significant enlarging
or shrinking is found for GV galaxies in different environments within
the same redshift bin. This suggests that a dense environment would
promote the growth of bulges and suppress star formation activity
of GV galaxies at 0.5 < z < 1.5 but would not affect the
galaxy size. We also study the dependence of the fraction of three
populations (blue cloud, GV, and red sequence) on both environments and
M ⋆. At a given M ⋆, blue cloud fraction goes
down with increasing environment density, while red sequence fraction
is opposite. For the most massive GV galaxies, a sharp drop appears
in the denser environment. Coupled with the mass dependence of three
fractions in different redshift bins, our result implies that stellar
mass and environments jointly promote the quenching process. Such a dual
effect is also confirmed by recalculating the new effective GV fraction
as the number of GV galaxies over the number of nonquiescent galaxies.
Title: Long-term Evolution of Nonthermal Emission from Type Ia and
Core-collapse Supernova Remnants in a Diversified Circumstellar Medium
Authors: Kobashi, Ryosuke; Yasuda, Haruo; Lee, Shiu-Hang
Bibcode: 2022ApJ...936...26K
Altcode: 2022arXiv220706203K
The contribution of galactic supernova remnants (SNRs) to the
origin of cosmic rays (CRs) is an important open question in
modern astrophysics. Broadband nonthermal emission is a useful
proxy for probing the energy budget and production history of CRs in
SNRs. We conduct hydrodynamic simulations to model the long-term SNR
evolution from explosion all the way to the radiative phase (or 3 ×
105 yr at maximum) and compute the time evolution of the
broadband nonthermal spectrum to explore its potential applications on
constraining the surrounding environments, as well as the natures and
mass-loss histories, of the SNR progenitors. A parametric survey is
performed on the ambient environments separated into two main groups,
namely, a homogeneous medium with a uniform gas density and one with
the presence of a circumstellar structure created by the stellar wind
of a massive red supergiant progenitor star. Our results reveal a
highly diverse evolution history of the nonthermal emission closely
correlated to the environmental characteristics of an SNR. Up to
the radiative phase, the roles of CR reacceleration and ion-neutral
wave damping on the spectral evolution are investigated. Finally,
we make an assessment of the future prospect of SNR observations by
the next-generation hard X-ray space observatory FORCE and predict
what we can learn from their comparison with our evolution models.
Title: TauRunner: A public Python program to propagate neutral and
charged leptons
Authors: Safa, Ibrahim; Lazar, Jeffrey; Pizzuto, Alex; Vasquez,
Oswaldo; Argüelles, Carlos A.; Vandenbroucke, Justin
Bibcode: 2022CoPhC.27808422S
Altcode: 2021arXiv211014662S
In the past decade IceCube's observations have revealed a flux
of astrophysical neutrinos extending to 107 GeV . The
forthcoming generation of neutrino observatories promises to grant
further insight into the high-energy neutrino sky, with sensitivity
reaching energies up to 1012 GeV . At such high energies, a
new set of effects becomes relevant, which was not accounted for in the
last generation of neutrino propagation software. Thus, it is important
to develop new simulations which efficiently and accurately model
lepton behavior at this scale. We present TauRunner, a Python-based
package that propagates neutral and charged leptons. TauRunner
supports propagation between 10 GeV and 1012 GeV . The
package accounts for all relevant secondary neutrinos produced in
charged-current tau neutrino interactions. Additionally, tau energy
losses of taus produced in neutrino interactions are taken into account,
and treated stochastically. Finally, TauRunner is broadly adaptable to
divers experimental setups, allowing for user-specified trajectories
and propagation media, neutrino cross sections, and initial spectra.
Title: Role of terrestrial versus marine sources of humic dissolved
organic matter on the behaviors of trace elements in seawater
Authors: Chen, Xiaoyu; Kwon, Hyeong Kyu; Joung, Dongjoo; Baek,
Cheolmin; Park, Tae Gyu; Son, Moonho; Kim, Guebuem
Bibcode: 2022GeCoA.333..333C
Altcode:
We investigated the behaviors of dissolved trace elements (Mn, Fe,
Ni, Cu, Zn, and Cd) associated with humic dissolved organic matter
(DOMH) of varying origins in the surface waters of two
Korean coastal regions (Jinhae Bay [JH] and offshore Tongyeong
[TY]). Both regions displayed intensive scavenging and settling of
the particle-reactive Ce and 234Th tracers. However, in JH,
where DOMH is mainly terrestrial-derived, the concentrations
of trace elements (Fe, Ni, and Cu) were negatively correlated with
salinity and positively correlated with DOMH. This indicates
that terrestrial DOMH could form complexes with dissolved
trace elements, and this complexation likely deters the adsorptive
removal of trace elements by settling particles. Similar interactions
between trace elements (Mn, Fe, and Cu) and DOMH were also
discovered in TY, where most DOMH originated from marine
biological production. Our study reveals that both terrestrial and
marine DOMH would complex with dissolved trace elements,
stabilizing them in the dissolved phase in coastal waters. Therefore,
DOMH-trace element complexation in coastal waters could play
a key role in regulating the cycling and transport of trace elements
in the ocean.
Title: Characteristics of Nanoflare Heating in a Coronal Bright Point
Authors: Hahn, Michael; Ho, Brandon; Savin, Daniel Wolf
Bibcode: 2022ApJ...936..113H
Altcode:
We have obtained constraints on the nanoflare energy distribution
and timing for the heating of a coronal bright point. Observations
of the bright point were made using the Extreme Ultraviolet Imaging
Spectrometer on Hinode in slot mode, which collects a time series of
monochromatic images of the region leading to unambiguous temperature
diagnostics. The Enthalpy-Based Thermal Evolution of Loops model was
used to simulate nanoflare heating of the bright point and generate
a time series of synthetic intensities. The nanoflare heating in
the model was parameterized in terms of the power-law index α of
the nanoflare energy distribution, which is ∝ E -α ;
average nanoflare frequency f; and the number N of magnetic strands
making up the observed loop. By comparing the synthetic and observed
light curves, we inferred the region of the model parameter space (α,
f, N) that was consistent with the observations. Broadly, we found
that N and f are inversely correlated with one another, while α is
directly correlated with either N or f. These correlations are likely
a consequence of the region requiring a certain fixed energy input,
which can be achieved in various ways by trading off among the different
parameters. We also find that a value of α > 2 generally gives the
best match between the model and observations, which indicates that
the heating is dominated by low-energy events. Our method of using
monochromatic images, focusing on a relatively simple structure,
and constraining nanoflare parameters on the basis of statistical
properties of the intensity provides a versatile approach to better
understand the nature of nanoflares and coronal heating.
Title: ATLAS Transient Discovery Report for 2022-09-02
Authors: Tonry, J.; Denneau, L.; Weiland, H.; Lawrence, A.; Siverd,
R.; Erasmus, N.; Koorts, W.; Anderson, J.; Jordan, A.; Suc, V.; Smith,
K. W.; Srivastav, S.; Young, D. R.; Smartt, S. J.; Gillanders, J.;
Fulton, M.; McCollum, M.; Moore, T.; Shingles, L.; Rest, A.; Chen,
T. W.; Pacheco, D.; Nicholl, M.; Stubbs, C.; Rest, S.
Bibcode: 2022TNSTR2552....1T
Altcode:
No abstract at ADS
Title: Quantum Corrections to Pair Production of Charged Black Holes
in de Sitter Space
Authors: Wang, Yu-Peng; Ma, Liang; Pang, Yi
Bibcode: 2022arXiv220900772W
Altcode:
We compute pair production rate of charged black holes in de Sitter
space in four dimensional Einstein-Maxwell theory with 4-derivative
corrections. We find that the probability measure of producing a
pair of generic dyonically charged black holes is still given by
the sum of two entropies, one of which is associated with the black
hole outer horizon and the other is associated with the cosmological
horizon. Specializing to examples of smooth configurations, we show that
the 4-derivative couplings break the symmetry between the production
rate of the purely electric black hole and that of the purely magnetic
black hole. Although electromagnetic duality is no longer a symmetry,
it induces a transformation on the 4-derivative couplings, mapping
the physical quantities of a purely electric black hole to those of a
purely magnetic black hole and vice versa. We also observe that under
the same transformation, unitarity constraints on the 4-derivative
couplings remain invariant.
Title: New, late-type spectroscopic binaries with X-ray emission
Authors: Frasca, A.; Catanzaro, G.; Busà, I.; Guillout, P.;
Alonso-Santiago, J.; Ferrara, C.; Giarrusso, M.; Munari, M.; Leone, F.
Bibcode: 2022MNRAS.515.3716F
Altcode: 2022arXiv220700505F; 2022MNRAS.tmp.1795F
In this paper, we present a spectroscopic study of six double-lined
binaries, five of which were recently discovered in a high-resolution
spectroscopic survey of optical counterparts of stellar X-ray
sources. Thanks to high-resolution spectra acquired with CAOS
spectropolarimeter during 7 yr, we were able to measure the radial
velocities of their components and determine their orbital elements. We
have applied our code COMPO2 to determine the spectral types and
atmospheric parameters of the components of these spectroscopic binaries
and found that two of these systems are composed of main-sequence stars,
while the other four contain at least one evolved (giant or subgiant)
component, similar to other well-known RS CVn systems. The subtraction
of a photospheric template built up with spectra of non-active stars
of the same spectral type as those of the components of each system
has allowed us to investigate the chromospheric emission that fills in
the H α cores. We found that the colder component is normally the one
with the largest H α emission. None of the systems show a detectable
Li Iλ6708 line, with the exception of TYC 4279-1821-1, which exhibits
high photospheric abundances in both components. Photometric time-series
from the literature allowed us to assess that the five systems with a
nearly circular orbit have also photometric periods close or equal to
the orbital ones, indicating spin-orbit synchronization. For the system
with a highly eccentric orbit, a possible pseudo-synchronization with
the periastron velocity is suggested.
Title: A search for monochromatic light towards the Galactic Centre
Authors: Marcy, Geoffrey W.; Tellis, Nathaniel K.; Wishnow, Edward H.
Bibcode: 2022MNRAS.515.3898M
Altcode: 2022arXiv220813561M; 2022MNRAS.tmp.1853M
A region 140 square degrees towards the Galactic Centre was searched
for monochromatic optical light, both pulses shorter than 1 s and
continuous emission. A novel instrument was constructed that obtains
optical spectra of every point within 6 square deg every second,
able to distinguish lasers from astrophysical sources. The system
consists of a modified Schmidt telescope, a wedge prism over the 0.28-m
aperture, and a fast CMOS camera with 9500 × 6300 pixels. During 2021,
a total of 34 800 exposures were obtained and analysed for monochromatic
sources, both subsecond pulses and continuous in time. No monochromatic
light was found. A benchmark laser with a 10-m aperture and located
100 light years (ly) away would be detected if it had a power more
than ~60 megawatt (MW) during 1 s, and from 1000 ly away, 6000 MW is
required. This non-detection of optical lasers adds to previous optical
SETI non-detections from more than 5000 nearby stars of all masses, from
the Solar gravitational lens focal points of Alpha Centauri, and from
all-sky searches for broadband optical pulses. These non-detections,
along with those of broadband pulses, constitute a growing SETI desert
in the optical domain.
Title: For how long are particles accelerated in shells of recurrent
novae?
Authors: Bednarek, W.
Bibcode: 2022MNRAS.515.1644B
Altcode: 2022arXiv220701306B
Galactic novae are at present a well established class of γ-ray
sources. We wonder for how long the mechanism of acceleration of
electrons operates in the shells of novae. In order to put constraints
on the time-scale of the electron acceleration, we consider a specific
model for the injection and propagation of electrons within the shell
of the recurrent nova RS Ophiuchi. We calculate the equilibrium spectra
of electrons within the nova shell and the γ-ray fluxes produced by
these electrons in the Comptonization of the soft radiation from the
red giant within a nova binary system and also radiation from the nova
photosphere. We investigate a two-component time-dependent model in
which a spherically ejected nova shell propagates freely in the polar
region of a nova binary system. However, the shell is significantly
decelerated in the dense equatorial region of the binary system. We
discuss the conditions under which electrons can produce γ-rays that
might be detectable by present and/or future γ-ray observatories. It
is concluded that freely expanding shells of novae in the optimal case
(strongly magnetized shell and efficiency of acceleration of electrons
of the order of 10 per cent) can produce TeV γ-rays within the
sensitivity of the Cherenkov Telescope Array within 1-2 yr of explosion
only. On the other hand, decelerated shells of novae have a chance to be
detected during the whole recurrence period of RS Ophiuchi, i.e. ~15 yr.
Title: The kinematics and ionization structure of the extended
emission-line region of QSO E1821+643
Authors: Rosborough, Sara A.; Robinson, A.; Seelig, T.
Bibcode: 2022MNRAS.515.3319R
Altcode: 2022MNRAS.tmp.1937R; 2022arXiv220803418R
The most luminous quasars are created by major, gas-rich mergers and
E1821+643, an optically luminous quasar situated at the centre of a
cool-core cluster, appears to be in the late stages of the post-merger
blowout phase. This quasar is also identified as a gravitational
recoil candidate, in which the supermassive black hole (SMBH) has
received a recoil kick due to anisotropic emission of gravitational
waves during the coalescence of a progenitor SMBH binary. We analyse
long-slit spectra of the extended, ionized gas surrounding E1821+643
to study its kinematics and ionization. We have identified three
kinematically distinct components, which we associate, respectively,
with a wide-angle polar wind from the nucleus, kinematically undisturbed
gas, and a redshifted arc-like structure of gas, at a distance of 3-4
arcsec (13-18 kpc) from the nucleus. The latter component coincides
with the northern and eastern extremities of an arc of [O III] emission
seen in HST images. This feature could trace a tidal tail originating
from a merger with a gas-rich galaxy to the south-east of the nucleus,
whose presence has been inferred by Aravena et al. from the detection
of CO emission. Alternatively, the arc could be the remnant of a shell
of gas swept up by a powerful quasar wind. The emission-line ratios
of the extended gas are consistent with photoionization by the quasar,
but a contribution from radiative shocks cannot be excluded.
Title: Revealing the dust grain polarization properties as a function
of extinction and distance towards NGC 1893
Authors: Bijas, N.; Eswaraiah, Chakali; Wang, Jia-Wei; Jose, Jessy;
Chen, Wen-Ping; Li, Di; Lai, Shih-Ping; Ojha, D. K.
Bibcode: 2022MNRAS.515.3352B
Altcode: 2022arXiv220703173B
Dust polarization observations at optical wavelengths help us to
understand the dust grain properties and trace the plane-of-the-sky
component of the magnetic field. In this study, we make use of
the I-band polarization data acquired from AIMPOL along with the
distances (d) and extinction (AV) data to study the
variation of polarization fraction (P) as a function of AV
and d towards the star-forming region, NGC 1893. We employ a broken
power-law fit and Bayesian analysis on extinction (AV) versus
polarization efficiency (P/AV) and distance (d) versus rate
of polarization (P/d). We find that P/AV shows a break at
an extinction of ~0.9 mag, whereas P/d exhibits a break at a distance
of ~1.5 kpc. Based on these, we categorize the dust towards NGC 1893
into two populations: (i) foreground dust confined to AV
< ~1 mag and distance up to ~2 kpc and (ii) Perseus spiral arm
dust towards NGC 1893 characterized with AV > ~1 mag and
distance beyond ~2 kpc. Foreground dust exhibits higher polarization
efficiency but a lower polarization rate, whereas Perseus dust shows
a lower polarization efficiency but a slightly higher polarization
rate. Hence, we suggest that while polarization efficiency reveals
the dust grain alignment, the rate of polarization infers about the
distribution of dust grains towards NGC 1893. Further, we also shed a
light on the spatial variation of intrinsic polarization and magnetic
field orientation, and other parameters within the intracluster medium
of NGC 1893.
Title: A LAsMA Survey of the Milky Way: Effects of Feedback on
Molecular Clouds
Authors: Mazumdar, Parichay
Bibcode: 2022PhDT.........4M
Altcode:
The advent of radio and (sub) millimetre astronomy has opened the world
of molecular clouds (MCs) to astronomers' wonder. At the turn of the
21st century, MC surveys have helped us better understand them. How
MCs form, their morphology, physical conditions, and many other aspects
are active research areas. This dissertation takes another step toward
understanding MCs by conducting the first large-scale high-resolution
survey of giant molecular clouds (GMCs) in the Milky Way (LAsMAGal),
covering 12CO and 13CO (3-2) lines simultaneously. Part I and II
provide an overview of the background knowledge related to molecular
clouds and the star-formation theory and introduce the new 7-pixel
receiver (LAsMA) used for the survey. The commissioning tests done on
the instruments are also presented in part II. In Part III, we
examine if LAsMAGal is feasible and test observing strategies. The test
observations showed 4 fold improvement in noise levels compared to the
SEDIGISM 13CO (2-1) survey (the most relevant survey towards the planned
region for LAsMAGal). Part IV presents LAsMAGal data towards the
G305 star-forming GMC used to study feedback effects from the central
cluster of OB stars. The distribution of CO excitation was compared to
that of 8-micron emission imaged with Spitzer (dominated by UV-excited
emission from polycyclic aromatic hydrocarbons). A 13CO J=3-2/2-1 (line
ratio) excitation map was obtained by combining LAsMAGal and SEDIGISM
data. Line profiles along radially outward directions showed a factor
of 2-3 increase in gas excitation temperature as well as line ratio at
the GMC edge facing the center of the complex. Excitation temperature,
line ratio and column density showed a positive correlation with
8-micron flux. Centroid velocities and stacked line profiles were
examined to investigate the feedback effect on gas dynamics. The
velocity probability distribution function displayed exponential wings,
indicating turbulence driven by strong stellar winds. Stacked spectra
in regions with stronger feedback had higher skewness than regions with
weaker feedback. Therefore, feedback from the stellar cluster in G305
shows demonstrable effects on the gas excitation and dynamics of the
GMC. The next chapter investigates the effects of feedback on
star formation in G305. First, the region is decomposed into clumps
using dendrogram analysis. Their surface mass densities positively
correlated with incident 8-micron flux. Clumps were categorized into
"mostly inside" (> 67%), "partly inside" (< 10% and > 67%),
and "outside" (< 10%) subsamples based on their overlap with an
8 micron flux mask. The 3 subsamples had a statistically significant
difference in surface mass densities. The "mostly inside" subsample
also showed the highest level of fragmentation proving G305 clumps
are triggered. Then, G305 clumps were compared with the Galactic
average taken from a distance-limited sample of ATLASGAL 870 mm dust
continuum and CHIMPS 13CO (3-2) clumps. The G305 clump population
was statistically different from the average Galactic population,
ruling out redistribution due to feedback. Finally, the cumulative
distribution functions (CDFs) of the clump masses and L/M ratios in
G305 were compared to values of the Galactic sample. The CDFs were
flatter in G305, indicating that clumps are heavier and more efficient
at forming stars in G305, driving triggered star formation in this
GMC. The final part of the thesis updates the current status of
LAsMAGal. The reduction pipeline is also presented, followed by the
maps of the regions observed so far. Finally, a summary of the work
is given in the final chapter."
Title: On the Nature of the Mass-gap Object in the GW190814 Event
Authors: Lopes, Luiz L.; Menezes, Debora P.
Bibcode: 2022ApJ...936...41L
Altcode: 2021arXiv211102247L
In this work, we conduct an extensive study of the conditions that
allow the mass-gap object in the GW190814 event to be faced as a
degenerate star instead of a black hole. We begin by revisiting some
parameterizations of quantum hadrodynamics and then study under which
conditions hyperons are present in such a massive star. Afterward,
using a vector MIT-based model, we study whether self-bound quark
stars, satisfying the Bodmer-Witten conjecture, fulfill all the
observational constraints. Finally, we study hybrid stars within a
Maxwell construction and check for what values of the bag, as well
as the vector interaction, a quark core star with only nucleons,
and with nucleons admixed with hyperons can reach at least 2.50
M ⊙. We conclude that, depending on the choice of
parameters, none of the possibilities can be completely ruled out,
i.e., the mass-gap object can be a hadronic (either nucleonic or
hyperonic), a quark, or a hybrid star, although some cases are more
probable than others.
Title: Black-hole analog in vehicular traffic
Authors: de Souza, Luanna K.; Matsas, George E. A.
Bibcode: 2022AmJPh..90..692D
Altcode: 2022arXiv220211791D
We propose here a simple black-hole analog in vehicular-traffic
dynamics. The corresponding causal diagram is determined by the
propagation of the tail light flashes emitted by a convoy of cars
on a highway. In addition to being a new black-hole analog, this
illustrates how causal diagrams, so common in general relativity,
may be useful in areas as unexpected as vehicular-traffic dynamics.
Title: The Velocity Map Asymmetry of Ionized Gas in MaNGA. I. The
Catalog and General Properties
Authors: Feng, Shuai; Shen, Shi-Yin; Yuan, Fang-Ting; Dai, Y. Sophia;
Masters, Karen L.
Bibcode: 2022ApJS..262....6F
Altcode: 2022arXiv220706050F
The SDSS-IV MaNGA survey has measured two-dimensional maps of
emission-line velocities for a statistically powerful sample of nearby
galaxies. The asymmetric features of these kinematics maps reflect the
nonrotational component of a galaxy's internal motion of ionized gas. In
this study, we present a catalog of kinematic asymmetry measurements
of the Hα velocity map of a sample of 5353 MaNGA galaxies. Based on
this catalog, we find that "special" galaxies (e.g., merging galaxies,
barred galaxies, and active galactic nucleus host galaxies) contain
more galaxies with highly asymmetric velocity maps. However, we notice
that more than half of galaxies with high kinematic asymmetry in our
sample are quite "regular." For those "regular" galaxies, kinematic
asymmetry shows a significant anticorrelation with stellar mass at
$\mathrm{log}{M}_{\star }\lt 9.7$ , while such a trend becomes very
weak at $\mathrm{log}{M}_{\star }\gt 9.7$ . Moreover, at a given
stellar mass, the kinematic asymmetry shows weak correlations with
photometric morphology, star formation rate, and environment, while
it is independent of H I gas content. We also have quantified the
observational effects in the kinematic asymmetry measurement. We find
that both the signal-to-noise ratio of Hα flux and disk inclination
angle contribute to the measures of kinematic asymmetry, while the
physical spatial resolution is an irrelevant factor inside the MaNGA
redshift coverage.
Title: Manifestation of Gravitational Settling in Coronal Mass
Ejections Measured in the Heliosphere
Authors: Rivera, Yeimy J.; Raymond, John C.; Landi, Enrico; Lepri,
Susan T.; Reeves, Katharine K.; Stevens, Michael L.; Alterman, B. L.
Bibcode: 2022ApJ...936...83R
Altcode:
Elemental composition in the solar wind reflects the fractionation
processes at the Sun. In coronal mass ejections (CMEs) measured in
the heliosphere, the elemental composition can vary between plasma
of high and low ionization states as indicated by the average Fe
charge state, <QFe>. It is found that CMEs with
higher ionized plasma, <QFe> greater than 12, are
significantly more enriched in low first ionization potential (FIP)
elements compared to their less ionized, <QFe> less
than 12, counterparts. In addition, the CME elemental composition
has been shown to vary along the solar cycle. However, the processes
driving changes in elemental composition in the plasma are not well
understood. To gain insight into this variation, this work investigates
the effects of gravitational settling in the ejecta to examine how
that process can modify signatures of the FIP effect found in CMEs. We
examine the absolute abundances of C, N, O, Ne, Mg, Si, S, and Fe in
CMEs between 1998 and 2011. Results show that the ejecta exhibits some
gravitational settling effects in approximately 33% of all CME periods
in plasma where the Fe abundance of the ejecta compared to the solar
wind (Fe/HCME:Fe/HSW) is depleted compared to
the C abundance (C/HCME:C/HSW). We also find
gravitational settling is most prominent in CMEs during solar minimum;
however, it occurs throughout the solar cycle. This study indicates
that gravitational settling, along with the FIP effect, can become
important in governing the compositional makeup of CME source regions.
Title: ZTF Transient Classification Report for 2022-09-02
Authors: Schulze, S.; Meynardie, W.; Chu, M.; Fremling, C.
Bibcode: 2022TNSCR2562....1S
Altcode:
No abstract at ADS
Title: Shape Modeling of Dimorphos for the Double Asteroid Redirection
Test (DART)
Authors: Terik Daly, R.; Ernst, Carolyn M.; Barnouin, Olivier S.;
Gaskell, Robert W.; Palmer, Eric E.; Nair, Hari; Espiritu, Ray C.;
Hasnain, Sarah; Waller, Dany; Stickle, Angela M.; Nolan, Michael C.;
Trigo-Rodríguez, Josep M.; Dotto, Elisabetta; Lucchetti, Alice;
Pajola, Maurizio; Ieva, Simone; Michel, Patrick
Bibcode: 2022PSJ.....3..207T
Altcode:
The Double Asteroid Redirection Test (DART) is the first planetary
defense test mission. It will demonstrate the kinetic impactor technique
by intentionally colliding the DART spacecraft with the near-Earth
asteroid Dimorphos. The main DART spacecraft is accompanied by the
Italian Space Agency Light Italian CubeSat for Imaging of Asteroids
(LICIACube). Shape modeling efforts will estimate the volume of
Dimorphos and constrain the nature of the impact site. The DART
mission uses stereophotoclinometry (SPC) as its primary shape modeling
technique. DART is essentially a worst-case scenario for any image-based
shape modeling approach because images taken by the camera on board the
DART spacecraft, called the Didymos Reconnaissance and Asteroid Camera
for Optical navigation (DRACO), possess little stereo and no lighting
variation; they simply zoom in on the asteroid. LICIACube images add
some stereo, but the images are substantially lower in resolution than
the DRACO images. Despite the far-from-optimal imaging conditions,
our tests indicate that we can identify the impact site to an accuracy
and precision better than 10% the size of the spacecraft core, estimate
the volume of Dimorphos to better than 25%, and measure tilts at the
impact site over the scale of the spacecraft with an accuracy better
than 7°. In short, we will know with excellent accuracy where the
DART spacecraft hit, with reasonable knowledge of local tilt, and
determine the volume well enough that uncertainties in the density
of Dimorphos will be comparable to or dominate the uncertainty in
the estimated mass. The tests reported here demonstrate that SPC is
a robust technique for shape modeling, even with suboptimal images.
Title: Quantitatively study on wave-turbulence interactions by
laboratory experiments
Authors: Ma, Hongyu; Dai, Dejun; Jiang, Shumin; Huang, Chuanjiang;
Deng, Jia; Qiao, Fangli
Bibcode: 2022DyAtO..9901302M
Altcode:
Ocean turbulent mixing influences the air-sea exchanges of heat,
momentum and mass. The surface gravity waves play a key role
in turbulence generation in the upper ocean. How wave energy
is transferred to ocean turbulence through the wave-turbulence
interactions remains an open question. In order to study this question,
laboratory experiments were carried out in a wave tank to investigate
the wave-turbulence interactions. Based on their power spectra,
the turbulence intensities before and after the wave-turbulence
interactions were compared quantitatively, and the experimental
results indicate that the background turbulence energy among 7 and
20 Hz of its power spectrum increased approximately by 23.3% through
wave-turbulence interaction. Using the Holo-Hilbert spectral analysis
method, the results clearly show that the turbulence was modulated by
surface waves and then enhanced through the wave-turbulence interaction
process. When the surface wave is strong with a wave height of 7 cm,
the modulation occurs in both the wave trough and crest phases. In
addition, the intensity of the wave-turbulence interaction increases
with the wave height and is proportional to Hs2 .
Title: MAXI/GSC detection of increased flux in a region including
4U 0923-31, CXO J092418.2-314217, and 3MAXI J0924-316
Authors: Kawamuro, T.; Mihara, T.; Negoro, H.; Serino, M.; Nakajima,
M.; Kobayashi, K.; Tanaka, M.; Soejima, Y.; Yamada, S.; Tamagawa,
T.; Matsuoka, M.; Sakamoto, T.; Sugita, S.; Hiramatsu, H.; Yoshida,
A.; Tsuboi, Y.; Iwakiri, W.; Kohara, J.; Shidatsu, M.; Iwasaki, M.;
Kawai, N.; Niwano, M.; Hosokawa, R.; Imai, Y.; Ito, N.; Takamatsu, Y.;
Nakahira, S.; Ueno, S.; Tomida, H.; Ishikawa, M.; Kurihara, T.; Ueda,
Y.; Ogawa, S.; Setoguchi, K.; Yoshitake, T.; Inaba, K.; Yamauchi, M.;
Sato, T.; Hatsuda, R.; Fukuoka, R.; Hagiwara, Y.; Umeki, Y.; Yamaoka,
K.; Kawakubo, Y.; Sugizaki, M.
Bibcode: 2022ATel15583....1K
Altcode:
The MAXI/GSC nova alert system triggered on a significant 4--10 keV
enhancement of 20 +- 4 mCrab (1 sigma error) averaged over scans
on 2022 August 31. Its position was constrained to be (R.A., Dec) =
(141.003 deg, -31.700 deg) = (09h24m00s, -31d41m59s) (J2000) with a 90%
C.L. elliptical error region, whose long and short radii are 0.62 deg
and 0.42 deg, respectively.
Title: Comprehensive Search of Stable Isomers of Alanine and Alanine
Precursors in Prebiotic Syntheses
Authors: Shoji, Mitsuo; Watanabe, Natsuki; Hori, Yuta; Furuya, Kenji;
Umemura, Masayuki; Boero, Mauro; Shigeta, Yasuteru
Bibcode: 2022AsBio..22.1129S
Altcode:
Enantiomeric excesses of L-amino acids have been detected in meteorites;
however, their molecular mechanism and prebiotic syntheses are still a
matter of debate. To elucidate the origin of homochirality, alanine and
the chiral precursors formed in prebiotic processes were investigated
with regard to their stabilities among their isomers by employing
the minimum energy principle, namely, the abundancy of a molecule in
the interstellar medium is directly correlated to the stability among
isomers. To facilitate the search for possible isomers, we developed a
new isomer search algorithm, the random connection method, and performed
a thorough search for all the stable isomers within a given chemical
formula. We found that alanine and most of its precursors are located
at higher energy by more than 5.7 kcal mol−1, with respect
to the most stable isomer that consists of a linear-chain structure,
whereas only the 2-aminopropanenitrile is the most stable isomer among
all others possible. The inherent stability of the α-amino nitrile
suggests that the 2-aminopropanenitrile is the dominant contribution
in the formation of the common enantiomeric excess over α-amino acids.
Title: Fe-Rich Fossil Vents as Mars Analog Samples: Identification of
Extinct Chimneys in Miocene Marine Sediments Using Raman Spectroscopy,
X-Ray Diffraction, and Scanning Electron Microscopy-Energy Dispersive
X-Ray Spectroscopy
Authors: Demaret, Lucas; Hutchinson, Ian B.; Ingley, Richard; Edwards,
Howell G. M.; Fagel, Nathalie; Compere, Philippe; Javaux, Emmanuelle
J.; Eppe, Gauthier; Malherbe, Cédric
Bibcode: 2022AsBio..22.1081D
Altcode:
On Earth, the circulation of Fe-rich fluids in hydrothermal environments
leads to characteristic iron mineral deposits, reflecting the pH
and redox chemical conditions of the hydrothermal system, and is
often associated with chemotroph microorganisms capable of deriving
energy from chemical gradients. On Mars, iron-rich hydrothermal
sites are considered to be potentially important astrobiological
targets for searching evidence of life during exploration missions,
such as the Mars 2020 and the ExoMars 2022 missions. In this study,
an extinct hydrothermal chimney from the Jaroso hydrothermal system
(SE Spain), considered an interesting geodynamic and mineralogical
terrestrial analog for Mars, was analyzed using Raman spectroscopy,
X-ray diffraction, and scanning electron microscopy coupled with energy
dispersive X-ray spectroscopy. The sample consists of a fossil vent
in a Miocene shallow-marine sedimentary deposit composed of a marl
substrate, an iron-rich chimney pipe, and a central space filled
with backfilling deposits and vent condensates. The iron crust is
particularly striking due to the combined presence of molecular and
morphological indications of a microbial colonization, including mineral
microstructures (e.g., stalks, filaments), iron oxyhydroxide phases
(altered goethite, ferrihydrite), and organic signatures (carotenoids,
organopolymers). The clear identification of pigments by resonance
Raman spectroscopy and the preservation of organics in association with
iron oxyhydroxides by Raman microimaging demonstrate that the iron
crust was indeed colonized by microbial communities. These analyses
confirm that Raman spectroscopy is a powerful tool for documenting the
habitability of such historical hydrothermal environments. Finally,
based on the results obtained, we propose that the ancient iron-rich
hydrothermal pipes should be recognized as singular terrestrial
Mars analog specimens to support the preparatory work for robotic in
situ exploration missions to Mars, as well as during the subsequent
interpretation of data returned by those missions.
Title: XOSS Transient Discovery Report for 2022-09-06
Authors: Zhang, M.; Ye, Q.; Gao, X.; Sun, G.; Team, T. K.
Bibcode: 2022TNSTR2597....1Z
Altcode:
No abstract at ADS
Title: ZTF Transient Discovery Report for 2022-09-06
Authors: Fremling, C.
Bibcode: 2022TNSTR2599....1F
Altcode:
No abstract at ADS
Title: Chandra Follow-up of a Super-Eddington Tidal Disruption
Event Candidate
Authors: Lin, Dacheng
Bibcode: 2022cxo..prop.6360L
Altcode:
Tidal disruption events (TDEs) were long thought to be great targets for
study of super-Eddington accretion onto massive black holes. However,
although >100 candidates have been discovered, the evidence for
super-Eddington accretion in TDEs remains weak. Promising evidence was
found in a recent decade-long candidate, with quasi-soft X-ray spectra
(kT~0.3 keV) in the peak followed by super-soft X-ray spectra (kT~0.15
keV) in the decay. Now there is another ongoing TDE candidate discovered
by SRG/eROSITA showing similar interesting spectral evolution. We
request a 20 ks Chandra observation of this new event in Cycle 24
in order to establish it as a strong super-Eddington TDE candidate,
by checking its nuclear origin and confirming its spectral evolution
as expected for a super-Eddington TDE.
Title: June 2022 report CAMS BeNeLux
Authors: Roggemans, P.
Bibcode: 2022eMetN...7..362R
Altcode:
A summary of the activity of the CAMS BeNeLux network during the month
of June 2022 is presented. 14179 meteors were registered of which 7739
multiple-station events, resulting in 2228 orbits. June 2022 was the
second best month of June in the 11 years of the network.
Title: The 2022 encounter of the outburst material from comet
73P/Schwassmann-Wachmann 3
Authors: Ye, Quanzhi; Vaubaillon, Jérémie
Bibcode: 2022MNRAS.515L..45Y
Altcode: 2022arXiv220512473Y; 2022MNRAS.tmpL..64Y
The encounter of the meteoric material from 73P/Schmassmann-Wachmann 3
produced during the comet's 1995 outburst in May 2022 provides a rare
and valuable opportunity to understand a fragmenting comet. Here,
we explore various ejection configurations and their impact on the
meteor outburst detected in the early hours of UT 2022 May 31. We show
that the dust must have been ejected ~4 to 5× faster than calculated
by water-ice sublimation model to best match the observed meteor
activity. As only a small subset of particles with a narrow range of
cross-section is expected to have reached the Earth, the large spread
of meteor brightness likely indicates the presence of large but porous
meteoroids in the trail. Other effects such as an enhanced lunar sodium
tail and a visible glow from the meteoroid trail may have also occurred
during the encounter.
Title: Astrochemical model to study the abundances of branched
carbon-chain molecules in a hot molecular core with realistic
binding energies
Authors: Srivastav, Satyam; Sil, Milan; Gorai, Prasanta; Pathak,
Amit; Sivaraman, Bhalamurugan; Das, Ankan
Bibcode: 2022MNRAS.515.3524S
Altcode: 2022arXiv220803531S; 2022MNRAS.tmp.2077S
Straight-chain (normal-propyl cyanide, $\rm {n-C_3H_7CN}$) and
branched-chain (iso-propyl cyanide, $\rm {i-C_3H_7CN}$) alkyl cyanides
are recently identified in the massive star-forming regions (Sgr B2(N)
and Orion). These branched-chain molecules indicate that the key
amino acids (side-chain structures) may also be present in a similar
region. The process by which this branching could propagate towards
the higher order (butyl cyanide, $\rm {C_4H_9CN}$) is an active field
of research. Since the grain catalysis process could have formed a
major portion of these species, considering a realistic set of binding
energies are indeed essential. We employ quantum chemical calculations
to estimate the binding energy of these species considering water
as a substrate because water is the principal constituent of this
interstellar ice. We find significantly lower binding energy values
for these species than were previously used. It is noticed that the
use of realistic binding energy values can significantly change the
abundance of these species. The branching is more favourable for the
higher order alkyl cyanides with the new binding energies. With the
inclusion of our new binding energy values and one essential destruction
reaction ($\rm {i-C_3H_7CN+H \rightarrow CH_3C(CH_3)CN + H_2}$, having
an activation barrier of 947 K), abundances of $\rm {t-C_4H_9CN}$
dramatically increased.
Title: iMaNGA: mock MaNGA galaxies based on IllustrisTNG and MaStar
SSPs - I. Construction and analysis of the mock data cubes
Authors: Nanni, Lorenza; Thomas, Daniel; Trayford, James; Maraston,
Claudia; Neumann, Justus; Law, David R.; Hill, Lewis; Pillepich,
Annalisa; Yan, Renbin; Chen, Yanping; Lazarz, Dan
Bibcode: 2022MNRAS.515..320N
Altcode: 2022MNRAS.tmp.1487N; 2022arXiv220311575N
Galaxy formation and evolution simulations are essential tools to probe
poorly known astrophysics processes, but particular care is needed to
compare simulations with galaxy observations, as observed data need
to be modelled as well. We present a method to generate mock galaxies
from the hydro-dynamical IllustrisTNG simulations which are suited to
compare with integral field spectroscopic observation of galaxies from
the SDSS-IV/Mapping Nearby Galaxies at Apache Point Observatory (MaNGA)
survey. First, we include the same instrumental effects and procedures
as adopted in the acquisition and analysis of real data. Furthermore,
we generate the galaxy spectra from the simulations using new stellar
population models based on the MaNGA stellar library (MaStar). In this
way, our mock data cubes have the same spatial sampling, cover the
same wavelength range (3600-10 300 Å), and share the same spectral
resolution (R ≍ 1800) and flux calibration of real MaNGA galaxy
spectra. In this first paper, we demonstrate the method over an
early- and a late-type simulated galaxy from TNG50. We analyse the
correspondent mock MaNGA-like data cubes with the same full spectral
fitting code, FIREFLY, which was used for the observed spectra. We
find that the intrinsic and recovered age and metallicity gradients
are consistent within 1σ, with residuals over all tassels consistent
with 0 at the 68 ${{\ \rm per\ cent}}$ confidence level. We also
perform the challenging test at comparing intrinsic and recovered
star formation histories, finding a close resemblance between input
and output. In follow-up papers, we will present a full simulated
MaNGA-like catalogue (≍10 000 galaxies) with a comprehensive
comparison of TNG50 simulations to MaNGA observational results.
Title: Von Zeipel - Lidov - Kozai cycles in action: Kepler triples
with eclipse depth variations: KICs 6964043, 5653126, 5731312,
and 8023317
Authors: Borkovits, T.; Rappaport, S. A.; Toonen, S.; Moe, M.; Mitnyan,
T.; Csányi, I.
Bibcode: 2022MNRAS.515.3773B
Altcode: 2022MNRAS.tmp.1895B; 2022arXiv220705517B
We report the results of the photodynamical analyses of four compact,
tight triple stellar systems, KICs 6964043, 5653126, 5731312, and
8023317, based largely on Kepler and TESS data. All systems display
remarkable eclipse timing and eclipse depth variations, the latter
implying a non-aligned outer orbit. Moreover, KIC 6964043 is also
a triply eclipsing system. We combined photometry, ETV curves, and
archival spectral energy distribution data to obtain the astrophysical
parameters of the constituent stars and the orbital elements with
substantial precision. KICs 6964043 and 5653126 were found to be nearly
flat with mutual inclinations imut = 4${_{.}^{\circ}}$1
and 12${_{.}^{\circ}}$3, respectively, while KICs 5731312 and 8023317
(imut = 39${_{.}^{\circ}}$4 and 55${_{.}^{\circ}}$7,
respectively) are found to lie in the high imut regime of
the von Zeipel-Kozai-Lidov (ZKL) theorem. We show that, currently, both
high inclination triples exhibit observable unusual retrograde apsidal
motion. Moreover, the eclipses will disappear in all but one of the
four systems within a few decades. Short-term numerical integrations
of the dynamical evolution reveal that both high inclination triples
are currently subject to ongoing, large amplitude (Δe ~ 0.3) inner
eccentricity variations on centuries-long time-scales, in accord with
the ZKL theorem. Longer-term integrations predict that two of the four
systems may become dynamically unstable on ~ Gyr time-scales, while in
the other two triples common envelope phases and stellar mergers may
occur. Finally, we investigate the dynamical properties of a sample of
71 KIC/TIC triples statistically, and find that the mutual inclinations
and outer mass ratios are anticorrelated at the 4σ level. We discuss
the implications for the formation mechanisms of compact triples.
Title: Inhomogeneity within Local Interstellar Clouds
Authors: Linsky, Jeffrey L.; Redfield, Seth; Ryder, Diana;
Chasan-Taber, Adina
Bibcode: 2022AJ....164..106L
Altcode: 2022arXiv220402428L
Analysis of interstellar absorption lines observed in high-resolution
Hubble Space Telescope spectra of nearby stars provides temperatures,
turbulent velocities, and kinetic properties of warm interstellar
clouds. A new analysis of 97 interstellar-velocity components reveals
a wide range of temperatures and turbulent velocities within the
Local Interstellar Cloud (LIC) and the nearby Cluster of Interstellar
Clouds (CLIC). These variations appear to be random with Gaussian
distributions. We find no trends of these properties with stellar
distance or angles from the Galactic Center, magnetic field, the
main source of extreme-UV radiation (the star ϵ CMa), the center of
the LIC, or the direction of inflowing interstellar matter into the
heliosphere. The spatial scale for temperature variations in the LIC is
likely smaller than 5100 au, a distance that the Sun will traverse in
1000 yr. Essentially all velocity components align with known warm
clouds. We find that within 4 pc of the Sun, space is completely
filled with partially ionized clouds, but at larger distances space
is only partially filled with partially ionized clouds. We find that
the neutral hydrogen number density in the LIC and likely other warm
clouds in the CLIC is about 0.10 cm-3 rather than the 0.20
cm-3 density that may be representative of only the immediate
environment of the LIC. The ≤3000-12,000 K temperature range for the
gas is wider than the predictions of thermal equilibrium theoretical
models of the warm neutral medium and warm ionized medium, and the
high degree of inhomogeneity within clouds argues against simple
theoretical models. *All of the data presented in this paper were
obtained from the Mikulski Archive for Space Telescopes (MAST) at the
Space Telescope Science Institute. The specific observations analyzed
can be accessed via https://doi.org/10.17909/gabn-m136. STScI is
operated by the Association of Universities for Research in Astronomy,
Inc., under NASA contract NAS5-26555. Support to MAST for these data
is provided by the NASA office of Space Science via grant No. NAG5-7584
and by other grants and contracts.
Title: Solar jets observed with the Interface Region Imaging
Spectrograph (IRIS)
Authors: Schmieder, Brigitte; Joshi, Reetika; Chandra, Ramesh
Bibcode: 2022AdSpR..70.1580S
Altcode: 2021arXiv211109002S
Solar jets are impulsive, collimated plasma ejections that are
triggered by magnetic reconnection. They are observed for many decades
in various temperatures and wavelengths, therefore their kinematic
characteristics, such as velocity and recurrence, have been extensively
studied. Nevertheless, the high spatial resolution of the Interface
Region Imaging Spectrograph (IRIS) launched in 2013 allowed us to
make a step forward in the understanding of the relationship between
surges and hot jets. In this paper we report on several results of
recent studies of jets observed by IRIS. Cool and hot plasma have
been detected with ejections of cool blobs having a speed reaching
300 km s-1 during the impulsive phase of jet formation
and slow velocity surges surrounding hot jets after the reconnection
phase. Plasma characteristics of solar jets, such as the emission
measure, temperature, and density have been quantified. A multi-layer
atmosphere at the reconnection site based on observed IRIS spectra has
been proposed. IRIS evidenced bidirectional flows at reconnection sites,
and tilt along the spectra which were interpreted as the signature of
twist in jets. The search of possible sites for reconnection could be
achieved by the analysis of magnetic topology. Combining Solar Dynamics
Observatory/Helioseismic Magnetic Imager (SDO/HMI) vector magnetograms
and IRIS observations, it was found that reconnection site could be
located at null points in the corona as well as in bald patch regions
low in the photosphere. In one case study a magnetic sketch could
explain the initiation of a jet starting in a bald patch transformed
to a current sheet in a dynamical way, and the transfer of twist from
a flux rope to the jet during the magnetic reconnection process.
Title: Implementation and validation of the FRi3D flux rope model
in EUHFORIA
Authors: Maharana, Anwesha; Isavnin, Alexey; Scolini, Camilla; Wijsen,
Nicolas; Rodriguez, Luciano; Mierla, Marilena; Magdalenić, Jasmina;
Poedts, Stefaan
Bibcode: 2022AdSpR..70.1641M
Altcode: 2022arXiv220706707M
The "Flux Rope in 3D" (FRi3D, Isavnin, 2016), a coronal mass ejection
(CME) model with global three-dimensional (3D) geometry, has been
implemented in the space weather forecasting tool EUHFORIA (Pomoell
and Poedts, 2018). By incorporating this advanced flux rope model in
EUHFORIA, we aim to improve the modelling of CME flank encounters and,
most importantly, the magnetic field predictions at Earth. After using
synthetic events to showcase FRi3D's capabilities of modelling CME
flanks, we optimize the model to run robust simulations of real events
and test its predictive capabilities. We perform observation-based
modelling of the halo CME event that erupted on 12 July 2012. The
geometrical input parameters are constrained using the forward
modelling tool included in FRi3D with additional flux rope geometry
flexibilities as compared to the pre-existing models. The magnetic
field input parameters are derived using the differential evolution
algorithm to fit FRi3D parameters to the in situ data at 1 AU. An
observation-based approach to constrain the density of CMEs is adopted,
in order to achieve a better estimation of mass corresponding to
the FRi3D geometry. The CME is evolved in EUHFORIA's heliospheric
domain and a comparison of FRi3D's predictive performance with the
previously implemented spheromak CME in EUHFORIA is presented. For
this event, FRi3D improves the modelling of the total magnetic
field magnitude and Bz at Earth by ∼ 30 % and ∼ 70 %
, respectively. Moreover, we compute the expected geoeffectiveness of
the storm at Earth using an empirical Dst model and find that the FRi3D
model improves the predictions of minimum Dst by ∼ 20 % as compared
to the spheromak CME model. Finally, we discuss the limitations of
the current implementation of FRi3D in EUHFORIA and propose possible
improvements.
Title: Polarized Synchrotron Foreground Assessment for CMB Experiments
Authors: Weiland, Janet L.; Addison, Graeme E.; Bennett, Charles L.;
Halpern, Mark; Hinshaw, Gary
Bibcode: 2022ApJ...936...24W
Altcode: 2022arXiv220311445W
Polarized Galactic synchrotron emission is an undesirable foreground for
cosmic microwave background experiments observing at frequencies <150
GHz. We perform a combined analysis of observational data at 1.4, 2.3,
23, 30, and 33 GHz to quantify the spatial variation of the polarized
synchrotron spectral index, β pol, on ~3.°5 scales. We
compare results from different data combinations to address limitations
and inconsistencies present in these public data, and form a composite
map of β pol. Data quality masking leaves 44% sky coverage
(73% for ∣b∣ > 45°). Generally -3.2 < β pol
≲ -3 in the inner Galactic plane and spurs, but the Fan Region in
the outer galaxy has a flatter index. We find a clear spectral index
steepening with increasing latitude south of the Galactic plane with
Δβ pol = 0.4, and a smaller steepening of 0.25 in the
north. Near the south Galactic pole the polarized synchrotron spectral
index is β pol ≍ -3.4. Longitudinal spectral index
variations of Δβ pol ~ 0.1 about the latitudinal mean
are also detected. Within the BICEP2/Keck survey footprint, we find
consistency with a constant value, β pol = -3.25 ± 0.04
(statistical) ±0.02 (systematic). We compute a map of the frequency at
which synchrotron and thermal dust emission contribute equally to the
total polarized foreground. The limitations and inconsistencies among
data sets encountered in this work make clear the value of additional
independent surveys at multiple frequencies, especially between 10
and 20 GHz, provided these surveys have sufficient sensitivity and
control of instrumental systematic errors.
Title: An Improved Method for Coupling Hydrodynamics with
Astrophysical Reaction Networks
Authors: Zingale, M.; Katz, M. P.; Nonaka, A.; Rasmussen, M.
Bibcode: 2022ApJ...936....6Z
Altcode: 2022arXiv220601285Z
Reacting astrophysical flows can be challenging to model, because of the
difficulty in accurately coupling hydrodynamics and reactions. This can
be particularly acute during explosive burning or at high temperatures
where nuclear statistical equilibrium is established. We develop a
new approach, based on the ideas of spectral deferred corrections
(SDC) coupling of explicit hydrodynamics and stiff reaction sources
as an alternative to operator splitting, that is simpler than the
more comprehensive SDC approach we demonstrated previously. We apply
the new method to a double-detonation problem with a moderately sized
astrophysical nuclear reaction network and explore the time step size
and reaction network tolerances, to show that the simplified-SDC
approach provides improved coupling with decreased computational
expense compared to traditional Strang operator splitting. This is
all done in the framework of the Castro hydrodynamics code, and all
algorithm implementations are freely available.
Title: Exosphere-mediated migration of volatile species on airless
bodies across the solar system
Authors: Steckloff, Jordan K.; Goldstein, David; Trafton, Laurence;
Varghese, Philip; Prem, Parvathy
Bibcode: 2022Icar..38415092S
Altcode: 2022arXiv220512805S
Surface-bound exospheres facilitate volatile migration across the
surfaces of nearly airless bodies. However, such transport requires that
the body can both form and retain an exosphere. To form a sublimation
exosphere requires the surface of a body to be sufficiently warm for
surface volatiles to sublime; to retain an exosphere, the ballistic
escape and photodestruction rates and other loss mechanisms must be
sufficiently low. Here we construct a simple free molecular model of
exospheres formed by volatile desorption or sublimation. We consider the
conditions for forming and retaining exospheres for common volatile
species across the Solar System, and explore how three processes
(desorption/sublimation, ballistic loss, and photodestruction)
shape exospheric dynamics on airless bodies. Our model finds that the
CO2 exosphere of Callisto is much too dense to be sustained
by impact-delivered volatiles, but could be maintained by only ~7
ha (~0.07 km2) of exposed CO2 ice distributed
across Callisto (and refreshed through mass wasting). We use our model
to predict the peak surface locations of Callisto's CO2
exosphere along with other Galilean moons, which could be tested
by JUICE observations. Our model finds that to maintain Iapetus'
two-tone appearance, its dark Cassini Regio likely has unresolved
exposures of water ice, perhaps in sub-resolution impact craters,
that amount to up to approximately ~0.06% of its surface. In the
Uranian system, we find that the CO2 deposits on Ariel,
Umbriel, Titania, and Oberon are unlikely to have been delivered
via impacts, but are consistent with both a magnetospheric origin,
(as has been previously suggested) or sourced endogenously. We suggest
that the leading/trailing CO2 asymmetries on these moons
could result from exosphere-mediated volatile transport, and may be a
seasonal equinox feature that could be largely erased by pole-to-pole
volatile migration during the Uranian solstices. We calculate that
~2.4-6.4 mm thick layer of CO2 (depending the moon) could
migrate about the surface of Uranus' large moons during a seasonal
cycle. Our model also confirms that water migration to Mercury's polar
cold traps is inefficient without self-shield against photodestroying
UV light, and that Callisto's bright spires could be formed/maintained
by exospherically deposited H2O.
Title: DeepAdversaries: examining the robustness of deep learning
models for galaxy morphology classification
Authors: Ćiprijanović, Aleksandra; Kafkes, Diana; Snyder, Gregory;
Sánchez, F. Javier; Perdue, Gabriel Nathan; Pedro, Kevin; Nord,
Brian; Madireddy, Sandeep; Wild, Stefan M.
Bibcode: 2022MLS&T...3c5007C
Altcode: 2021arXiv211214299C
With increased adoption of supervised deep learning methods for work
with cosmological survey data, the assessment of data perturbation
effects (that can naturally occur in the data processing and
analysis pipelines) and the development of methods that increase model
robustness are increasingly important. In the context of morphological
classification of galaxies, we study the effects of perturbations
in imaging data. In particular, we examine the consequences of using
neural networks when training on baseline data and testing on perturbed
data. We consider perturbations associated with two primary sources: (a)
increased observational noise as represented by higher levels of Poisson
noise and (b) data processing noise incurred by steps such as image
compression or telescope errors as represented by one-pixel adversarial
attacks. We also test the efficacy of domain adaptation techniques
in mitigating the perturbation-driven errors. We use classification
accuracy, latent space visualizations, and latent space distance to
assess model robustness in the face of these perturbations. For deep
learning models without domain adaptation, we find that processing
pixel-level errors easily flip the classification into an incorrect
class and that higher observational noise makes the model trained
on low-noise data unable to classify galaxy morphologies. On the
other hand, we show that training with domain adaptation improves
model robustness and mitigates the effects of these perturbations,
improving the classification accuracy up to 23% on data with higher
observational noise. Domain adaptation also increases up to a factor
of ${\approx}2.3$ the latent space distance between the baseline and
the incorrectly classified one-pixel perturbed image, making the model
more robust to inadvertent perturbations. Successful development and
implementation of methods that increase model robustness in astronomical
survey pipelines will help pave the way for many more uses of deep
learning for astronomy.
Title: Likely Supernova at z > 1 in the MACS J0257.1-2325
Galaxy-Cluster Field
Authors: Kelly, P.; Oguri, M.; Zitrin, A.; Diego, J.; Koekemoer, A.
Bibcode: 2022TNSAN.188....1K
Altcode:
No abstract at ADS
Title: ZTF Transient Classification Report for 2022-09-07
Authors: Fremling, C.; Neill, D.; Sharma, Y.
Bibcode: 2022TNSCR2610....1F
Altcode:
No abstract at ADS
Title: ZTF Transient Classification Report for 2022-09-05
Authors: Fremling, C.; Neill, D.; Sharma, Y.
Bibcode: 2022TNSCR2589....1F
Altcode:
No abstract at ADS
Title: Meteorite petrology versus genetics: Toward a unified binominal
classification
Authors: Jacquet, Emmanuel
Bibcode: 2022M&PS...57.1774J
Altcode:
The current meteorite taxonomy, a result of two centuries of meteorite
research and tradition, entangles textural and genetic terms in a
less than consistent fashion, with some taxa (like "shergottites")
representing varied lithologies from a single putative parent body
while others (like "pallasites") subsume texturally similar objects of
multifarious solar system origins. The familiar concept of "group" as
representative of one primary parent body is also difficult to define
empirically. It is proposed that the classification becomes explicitly
binominal throughout the meteorite spectrum, with classes referring
to petrographically defined primary rock types, whereas groups retain
a genetic meaning, but no longer tied to any assumption on the number
of represented parent bodies. The classification of a meteorite would
thus involve both a class and a group, in a two-dimensional fashion
analogous to the way Van Schmus and Wood decoupled primary and secondary
properties in chondrites. Since groups would not substantially differ,
at first, from those in current use de facto, the taxonomic treatment of
"normal" meteorites, whose class would bring no new information, would
hardly change. Yet classes combined with high- or low-level groups
would provide a standardized grid to characterize petrographically
and/or isotopically unusual or anomalous meteorites—which make up
the majority of represented meteorite parent bodies—for example, in
relation to the carbonaceous/noncarbonaceous dichotomy. In the longer
term, the mergers of genetically related groups, a more systematic
treatment of lithology mixtures, and the chondrite/achondrite transition
can further simplify the nomenclature.
Title: Galaxy And Mass Assembly: Galaxy Zoo spiral arms and star
formation rates
Authors: Porter-Temple, R.; Holwerda, B. W.; Hopkins, A. M.; Porter,
L. E.; Henry, C.; Geron, T.; Simmons, B.; Masters, K.; Kruk, S.
Bibcode: 2022MNRAS.515.3875P
Altcode: 2022arXiv220805036P
Understanding the effect spiral structure has on star formation
properties of galaxies is important to complete our picture of spiral
structure evolution. Previous studies have investigated connections
between spiral arm properties and star formation, but the effect that
the number of spiral arms has on this process is unclear. Here, we
use the Galaxy And Mass Assembly (GAMA) survey paired with the citizen
science visual classifications from the Galaxy Zoo project to explore
galaxies' spiral arm number and how it connects to the star formation
process. We use the votes from the GAMA-Kilo Degree Survey Galaxy Zoo
classification to investigate the link between spiral arm number and
stellar mass, star formation rate, and specific star formation rate
(sSFR). We find that galaxies with fewer spiral arms have lower stellar
masses and higher sSFRs, while those with more spiral arms tend towards
higher stellar masses and lower sSFRs, and conclude that galaxies are
less efficient at forming stars if they have more spiral arms. We note
how previous studies' findings may indicate a cause for this connection
in spiral arm strength or opacity.
Title: S-PLUS: exploring wide field properties of multiple populations
in galactic globular clusters at different metallicities
Authors: Hartmann, Eduardo A.; Bonatto, Charles J.; Chies-Santos,
Ana L.; Alonso-García, Javier; Bastian, Nate; Overzier, Roderik;
Schoenell, William; Coelho, Paula R. T.; Branco, Vinicius; Kanaan,
Antonio; Mendes de Oliveira, Claudia; Ribeiro, Tiago
Bibcode: 2022MNRAS.515.4191H
Altcode: 2022MNRAS.tmp.1379H; 2022arXiv220211449H
Multiple stellar populations (MSPs) are a ubiquitous phenomenon in
Galactic globular clusters (GCs). By probing different spectral ranges
affected by different absorption lines using the multiband photometric
survey S-PLUS, we study four GCs - NGC 104, NGC 288, NGC 3201, and NGC
7089 - that span a wide range of metallicities. With the combination
of broad and narrow-band photometry in 12 different filters from 3485A
(u) to 9114A (z), we identified MSPs along the rectified red-giant
branch in colour-magnitude diagrams and separated them using a K-means
clustering algorithm. Additionally, we take advantage of the large
Field of View of the S-PLUS detector to investigate radial trends in
our sample. We report on six colour combinations that can be used to
successfully identify two stellar populations in all studied clusters
and show that they can be characterized as Na-rich and Na-poor. For both
NGC 288 and NGC 7089, their radial profiles show a clear concentration
of 2P population. This directly supports the formation theories that
propose an enrichment of the intra-cluster medium and subsequent star
formation in the more dense central regions. However, in the case of
NGC 3201, the trend is reversed. The 1P is more centrally concentrated,
in direct contradiction with previous literature studies. NGC 104
shows a well-mixed population. We also constructed radial profiles
up to 1 half-light radius of the clusters with HST data to highlight
that radial differences are lost in the inner regions of the GCs and
that wide-field studies are essential when studying this.
Title: Spin transfer from dark matter to gas during halo formation
Authors: Li, Jie; Obreschkow, Danail; Power, Chris; Lagos, Claudia
del P.
Bibcode: 2022MNRAS.515..437L
Altcode: 2022arXiv220610079L; 2022MNRAS.tmp.1695L
In the protogalactic density field, diffuse gas and collision-less
cold dark matter (DM) are often assumed sufficiently mixed that both
components experience identical tidal torques. However, haloes in
cosmological simulations consistently end up with a higher specific
angular momentum (sAM) in gas, even in simulations without radiative
cooling and galaxy formation physics. We refine this result by analysing
the spin distributions of gas and DM in ~50 000 well-resolved haloes
in a non-radiative cosmological simulation from the SURFS suite. The
sAM of the halo gas on average ends up ~40 per cent above that of
the DM. This can be pinned down to an excess AM in the inner halo
(<50 per cent virial radius), paralleled by a more coherent
rotation pattern in the gas. We uncover the leading driver for this
AM difference through a series of control simulations of a collapsing
ellipsoidal top-hat, where gas and DM are initially well mixed. These
runs reveal that the pressurized inner gas shells collapse more slowly,
causing the DM ellipsoid to spin ahead of the gas ellipsoid. The
arising torque generally transfers AM from the DM to the gas. The
amount of AM transferred via this mode depends on the initial spin,
the initial axes ratios, and the collapse factor. These quantities
can be combined in a single dimensionless parameter, which robustly
predicts the AM transfer of the ellipsoidal collapse. This simplistic
model can quantitatively explain the average AM excess of the gas
found in the more complex non-radiative cosmological simulation.
Title: Dynamical fates of S-type planetary systems in embedded
cluster environments
Authors: Ellithorpe, Elizabeth A.; Kaib, Nathan A.
Bibcode: 2022MNRAS.515.2914E
Altcode: 2022MNRAS.tmp.1889E; 2022arXiv220705759E
The majority of binary star systems that host exoplanets will spend
the first portion of their lives within a star-forming cluster
that may drive dynamical evolution of the binary-planet system. We
perform numerical simulations of S-type planets, with masses and
orbital architecture analogous to the Solar system's four gas giants,
orbiting within the influence of a $0.5\, \mathrm{M}_{\odot }$ binary
companion. The binary-planet system is integrated simultaneously with
an embedded stellar cluster environment. ~10 per cent of our planetary
systems are destabilized when perturbations from our cluster environment
drive the binary periastron towards the planets. This destabilization
occurs despite all of our systems being initialized with binary orbits
that would allow stable planets in the absence of the cluster. The
planet-planet scattering triggered in our systems typically results in
the loss of lower mass planets and the excitement of the eccentricities
of surviving higher mass planets. Many of our planetary systems that go
unstable also lose their binary companions prior to cluster dispersal
and can therefore masquerade as hosts of eccentric exoplanets that
have spent their entire histories as isolated stars. The cluster-driven
binary orbital evolution in our simulations can also generate planetary
systems with misaligned spin-orbit angles. This is typically done as
the planetary system precesses as a rigid disc under the influence
of an inclined binary, and those systems with the highest spin-orbit
angles should often retain their binary companion and possess multiple
surviving planets.
Title: Tracing a decade of activity towards a yellow hypergiant. The
spectral and spatial morphology of IRC+10420 at au scales
Authors: Koumpia, Evgenia; Oudmaijer, R. D.; de Wit, W. -J.; Mérand,
A.; Black, J. H.; Ababakr, K. M.
Bibcode: 2022MNRAS.515.2766K
Altcode: 2022arXiv220705812K; 2022MNRAS.tmp.1944K
The fate of a massive star during the latest stages of its evolution is
highly dependent on its mass-loss history and geometry, with the yellow
hypergiants (YHGs) being key objects. We present near-IR interferometric
observations of the famous YHG IRC+10420 and blue spectra taken between
1994 and 2019. Our 2.2-μm GRAVITY/VLTI observations attain a spatial
resolution of ~5 stellar radii and spatially resolve the hot emission
in the K-band tracing the gas via Na I doublet emission and the Br γ
emission. Our geometric modelling reveals a compact neutral zone (Na I)
which is slightly larger than the continuum but within an extended Br
γ emitting region. Our study confirms an hour-glass geometry of the
wind, but we find no signature of a companion at 7-800 au separations
at the contrast limit of our observations (3.7 mag at 3σ) to explain
this geometry. We report an evolution of the ejecta over 7 yr, and
constrain the opening angle of the hour-glass to be <10°. Lastly,
we present the first blue optical spectra of IRC+10420 since 1994. The
multi-epoch data indicate that the spectral type, and thus temperature,
of the object has essentially remained constant during the intervening
years. Therefore, the observed increase in temperature of 2000 K in
less than two decades prior to 1994 is now halted. This suggests that
this YHG has 'hit' the White Wall in the HR-diagram preventing it from
evolving blue-wards, and will likely undergo a major mass-loss event
in the near future.
Title: Radio emission from simulated tidal disruption events
Authors: Spaulding, Alexandra; Chang, Philip
Bibcode: 2022MNRAS.515.1699S
Altcode: 2022MNRAS.tmp.1878S
Several tidal disruption events such as ASASSN-14li and XMMSL1 J0740-85
have recently been observed in the radio. While the radio emission of
some tidal disruption events are attributed to a relativistic jet, a
few others are associated with a non-relativistic outflow. This outflow
can either be due to a spherical wind or unbound tidal debris. We
explore this latter hypothesis in this paper. We show that the maximum
velocity of the unbound debris is a function of the impact parameter,
such that smaller impact parameters (closer approaches) produce
larger maximum velocities. We then model this outflow which expands
and shocks the local interstellar medium and compute the peak radio
flux and frequency as functions of the impact parameter. Moreover,
multiple epochs of observations can put additional constraints on
the profile of the local interstellar medium. We apply this analysis
to four tidal disruption events whose radio emission is attributed
to a non-relativistic outflow and show that the velocities of the
unbound material are consistent with our simulated events. We also
place constraints on the density profile of three of the four tidal
disruption events with multiple epochs of observations.
Title: Hidden cooling flows in clusters of galaxies
Authors: Fabian, A. C.; Ferland, G. J.; Sanders, J. S.; McNamara,
B. R.; Pinto, C.; Walker, S. A.
Bibcode: 2022MNRAS.515.3336F
Altcode: 2022MNRAS.tmp.1940F; 2022arXiv220704951F
The radiative cooling time of the hot gas at the centres of cool
cores in clusters of galaxies drops down to 10 Myr and below. The
observed mass cooling rate of such gas is very low, suggesting that
active galactic nucleus feedback is very tightly balanced or that the
soft X-ray emission from cooling is somehow hidden from view. We use
an intrinsic absorption model in which the cooling and coolest gas
are closely interleaved to search for hidden cooling flows in the
Centaurus, Perseus, and A1835 clusters of galaxies. We find hidden
mass cooling rates of between 10 and $500\,{{\rm M_{\odot }}\,{\rm
yr}^{-1}}$ as the cluster mass increases, with the absorbed emission
emerging in the far-infrared (FIR) band. Good agreement is found
between the hidden cooling rate and observed FIR luminosity in the
Centaurus Cluster. The limits on the other two clusters allow for
considerable hidden cooling. The implied total mass of cooled gas is
much larger than the observed molecular masses. We discuss its fate
including possible further cooling and collapse into undetected very
cold clouds, low-mass stars, and substellar objects.
Title: Quasi-periodic eruptions from galaxy nuclei
Authors: King, Andrew
Bibcode: 2022MNRAS.515.4344K
Altcode: 2022arXiv220604698K; 2022MNRAS.tmp.1590K
I consider quasi-periodic eruptions (QPEs) from galaxy nuclei. All
the known cases fit naturally into a picture of accretion from white
dwarfs (WDs) in highly eccentric orbits about the central black holes
which decay through gravitational wave emission. I argue that ESO
243-39 HLX-1 is a QPE source at an earlier stage of this evolution,
with a correspondingly longer period, more extreme eccentricity,
and a significantly more massive WD donor. I show explicitly that
mass transfer in QPE systems is always highly stable, despite recent
claims to the contrary in the literature. This stability may explain
the alternating long-short eruptions seen in some QPE sources. As the
WD orbit decays, the eruptions occupy larger fractions of the orbit
and become brighter, making searches for quasi-periodicities in bright
low-mass galaxy nuclei potentially fruitful.
Title: HORuS transmission spectroscopy and revised planetary
parameters of KELT-7 b
Authors: Tabernero, H. M.; Zapatero Osorio, M. R.; Allende Prieto,
C.; González-Álvarez, E.; Sanz-Forcada, J.; López-Gallifa, A.;
Montes, D.; del Burgo, C.; González Hernández, J. I.; Rebolo, R.
Bibcode: 2022MNRAS.515.1247T
Altcode: 2022arXiv220611548T; 2022MNRAS.tmp.1869T
We report on the high-resolution spectroscopic observations of two
planetary transits of the hot Jupiter KELT-7b (Mp = 1.28
± 0.17MJup, Teq = 2028 K) observed with the
High Optical Resolution Spectrograph (HORuS) mounted on the 10.4-m
Gran Telescopio Canarias (GTC). A new set of stellar parameters are
obtained for the rapidly rotating parent star from the analysis of
the spectra. Using the newly derived stellar mass and radius, and the
planetary transit data of the Transiting Exoplanet Survey Satellite
(TESS) together with the HORuS velocities and the photometric and
spectroscopic data available in the literature, we update and improve
the ephemeris of KELT-7b. Our results indicate that KELT-7 has an angle
λ = -10.55 ± 0.27 deg between the sky projections of the star's spin
axis and the planet's orbital axis. By combining this angle and our
newly derived stellar rotation period of 1.38 ± 0.05 d, we obtained a
3D obliquity ψ = 12.4 ± 11.7 deg (or 167.6 deg), thus reinforcing that
KELT-7 is a well-aligned planetary system. We search for the presence of
Hα, Li I, Na I, Mg I, and Ca II features in the transmission spectrum
of KELT-7b but we are only able to determine upper limits of 0.08-1.4
per cent on their presence after accounting for the contribution of
the stellar variability to the extracted planetary spectrum. We also
discuss the impact of stellar variability on the planetary data. Our
results reinforce the importance of monitoring the parent star when
performing high-resolution transmission spectroscopy of the planetary
atmosphere in the presence of stellar activity.
Title: Incorporation of 16O-rich anhydrous silicates in
the protolith of highly hydrated asteroid Ryugu
Authors: Liu, Ming-Chang; McCain, Kaitlyn A.; Matsuda, Nozomi;
Yamaguchi, Akira; Kimura, Makoto; Tomioka, Naotaka; Ito, Motoo; Uesugi,
Masayuki; Imae, Naoya; Shirai, Naoki; Ohigashi, Takuji; Greenwood,
Richard C.; Uesugi, Kentaro; Nakato, Aiko; Yogata, Kasumi; Yuzawa,
Hayato; Kodama, Yu; Hirahara, Kaori; Sakurai, Ikuya; Okada, Ikuo;
Karouji, Yuzuru; Nakazawa, Satoru; Okada, Tatsuaki; Saiki, Takanao;
Tanaka, Satoshi; Terui, Fuyuto; Yoshikawa, Makoto; Miyazaki, Akiko;
Nishimura, Masahiro; Yada, Toru; Abe, Masanao; Usui, Tomohiro;
Watanabe, Sei-ichiro; Tsuda, Yuichi
Bibcode: 2022NatAs.tmp..189L
Altcode:
The abundant phyllosilicate and carbonate minerals characterizing most
of the returned particles from asteroid Ryugu suggest a history of
extensive aqueous alteration on its parent body, similar to the rare
mineralogically altered, but chemically primitive, CI (Ivuna-type)
chondrite meteorites. Particle C0009 differs mineralogically from other
Ryugu particles examined so far by containing anhydrous silicates at
a level of ~0.5 vol%, and thus can help shed light on the unaltered
original materials that constituted Ryugu's protolith. In situ oxygen
isotope measurements of the most Mg-rich olivine and pyroxene in C0009
reveal two populations of Δ17O: −25‰ to −15‰ and
−8‰ to −3‰. The former and the latter populations correlate well
with silicate morphologies similar to those seen in amoeboid olivine
aggregates and chondrule phenocrysts, respectively, both of which
are abundant in less aqueously altered carbonaceous chondrites. This
result also highlights the presence of olivine with Δ17O
close to the solar value in either a CI chondrite or an asteroid
with CI-chondrite characteristics, and provides strong evidence that
amoeboid olivine aggregates and Mg-rich chondrules accreted into Ryugu's
protolith. Our data also raise the possibility that the protoliths of
CI and other carbonaceous chondrites incorporated similar anhydrous
silicates.
Title: The Open Cluster Chemical Abundances and Mapping
Survey. VI. Galactic Chemical Gradient Analysis from APOGEE DR17
Authors: Myers, Natalie; Donor, John; Spoo, Taylor; Frinchaboy, Peter
M.; Cunha, Katia; Price-Whelan, Adrian M.; Majewski, Steven R.; Beaton,
Rachael L.; Zasowski, Gail; O'Connell, Julia; Ray, Amy E.; Bizyaev,
Dmitry; Chiappini, Cristina; García-Hernández, D. A.; Geisler, Doug;
Jönsson, Henrik; Lane, Richard R.; Longa-Peña, Penélope; Minchev,
Ivan; Minniti, Dante; Nitschelm, Christian; Roman-Lopes, A.
Bibcode: 2022AJ....164...85M
Altcode: 2022arXiv220613650M
The goal of the Open Cluster Chemical Abundances and Mapping
(OCCAM) survey is to constrain key Galactic dynamic and chemical
evolution parameters by the construction and analysis of a large,
comprehensive, uniform data set of infrared spectra for stars in
hundreds of open clusters. This sixth contribution from the OCCAM
survey presents analysis of SDSS/APOGEE Data Release 17 (DR17) results
for a sample of stars in 150 open clusters, 94 of which we designate
to be "high-quality" based on the appearance of their color-magnitude
diagram. We find the APOGEE DR17-derived [Fe/H] values to be in good
agreement with those from previous high-resolution spectroscopic open
cluster abundance studies. Using a subset of the high-quality sample,
the Galactic abundance gradients were measured for 16 chemical elements,
including [Fe/H], for both Galactocentric radius (R GC)
and guiding center radius (R guide). We find an overall
Galactic [Fe/H] versus R GC gradient of -0.073 ± 0.002
dex kpc-1 over the range of 6 > R GC
< 11.5 kpc, and a similar gradient is found for [Fe/H] versus
R guide. Significant Galactic abundance gradients are
also noted for O, Mg, S, Ca, Mn, Na, Al, K, and Ce. Our large sample
additionally allows us to explore the evolution of the gradients in
four age bins for the remaining 15 elements.
Title: Chemical Abundances of Young Massive Clusters in NGC 1313
Authors: Hernandez, Svea; Winch, Autumn; Larsen, Søren; James,
Bethan L.; Jones, Logan
Bibcode: 2022AJ....164...89H
Altcode: 2022arXiv220702219H
We analyze spectroscopic observations of five young massive
clusters (YMCs) in the barred spiral galaxy NGC 1313 to obtain
detailed abundances from their integrated light. Our sample of
YMCs was observed with the X-shooter spectrograph on the Very Large
Telescope. We make use of theoretical isochrones to generate synthetic
integrated-light spectra, iterating on the individual elemental
abundances until converging on the best fit to the observations. We
measure abundance ratios for [Ca/Fe], [Ti/Fe], [Mg/Fe], [Cr/Fe], and
[Ni/Fe]. We estimate an Fe abundance gradient of -0.124 ± 0.034 dex
kpc-1, and a slightly shallower α gradient of -0.093 ±
0.009 dex kpc-1. This is in contrast to previous metallicity
studies that focused on the gas-phase abundances, which have found NGC
1313 to be the highest-mass barred galaxy known not to have a radial
abundance gradient. We propose that the gradient discrepancy between
the different studies originates from the metallicity calibrations used
to study the gas-phase abundances. We also observe an age-metallicity
trend that supports a scenario of constant star formation throughout the
galaxy, with a possible burst in star formation in the southwest region
where YMC NGC 1313-379 is located. ∗ Based on observations
made with ESO telescopes at the La Silla Paranal Observatory under
program ID 084.B-0468(A).
Title: Flux emergence and generation of flare-productive active
regions
Authors: Toriumi, Shin
Bibcode: 2022AdSpR..70.1549T
Altcode: 2021arXiv210509961T
Solar flares and coronal mass ejections are among the most prominent
manifestations of the magnetic activity of the Sun. The strongest
events of them tend to occur in active regions (ARs) that are large,
complex, and dynamically evolving. However, it is not clear what the
key observational features of such ARs are, and how these features
are produced. This article answers these fundamental questions based
on morphological and magnetic characteristics of flare-productive ARs
and their evolutionary processes, i.e., large-scale flux emergence and
subsequent AR formation, which have been revealed in observational
and theoretical studies. We also present the latest modeling of
flare-productive ARs achieved using the most realistic flux emergence
simulations in a very deep computational domain. Finally, this review
discusses the future perspective pertaining to relationships of flaring
solar ARs with the global-scale dynamo and stellar superflares.
Title: High-frequency Radio Imaging of 3CR 403.1 with the Sardinia
Radio Telescope
Authors: Missaglia, Valentina; Murgia, Matteo; Massaro, Francesco;
Paggi, Alessandro; Jimenez-Gallardo, Ana; Forman, William R.; Kraft,
Ralph P.; Balmaverde, Barbara
Bibcode: 2022ApJ...936...10M
Altcode: 2022arXiv220713711M
We present multifrequency observations of the radio source 3CR 403.1, a
nearby (z = 0.055), extended (~0.5 Mpc) radio galaxy hosted in a small
galaxy group. Using new high-frequency radio observations from the
Sardinia Radio Telescope (SRT), augmented with archival low-frequency
radio observations, we investigated radio spectral and polarimetric
properties of 3CR 403.1. From the MHz-to-GHz spectral analysis,
we computed the equipartition magnetic field in the lobes to be B
eq = 2.4 μG and the age of the source to be ~100 Myr. From
the spectral analysis of the diffuse X-ray emission we measured
the temperature and density of the intracluster medium (ICM). From
the SRT observations, we discovered two regions where the radio flux
density is below the background value. We computed the Comptonization
parameter both from the radio and from the X-ray observations to test
whether the Sunyaev-Zel'dovich effect is occurring here and found a
significant tension between the two estimates. If the negative signal is
considered as real, then we speculate that the discrepancy between the
two values could be partially caused by the presence of a nonthermal
bath of mildly relativistic ghost electrons. From the polarimetric
radio images, we find a net asymmetry of the Faraday rotation between
the two prominent extended structures of 3CR 403.1 and constrain the
magnetic field strength in the ICM to be 1.8-3.5 μG. The position of
3CR 403.1 in the magnetic field-gas density plane is consistent with
the trend reported in the literature between central magnetic field
and central gas density.
Title: Evidence for Corotation Origin of Super-metal-rich Stars in
LAMOST-Gaia: Multiple Ridges with a Similar Slope in the ϕ versus
L z Plane
Authors: Chen, Yuqin; Zhao, Gang; Zhang, Haopeng
Bibcode: 2022ApJ...936L...7C
Altcode: 2022arXiv220813353C
Super-metal-rich (SMR) stars in the solar neighborhood are thought to
be born in the inner disk and come to their present location by radial
migration, which is most intense at the corotation resonance (CR)
of the Galactic bar. In this work, we show evidence for the CR origin
of SMR stars in the Large Sky Area Multi-Object Fiber Spectroscopic
Telescope and Gaia by detecting six ridges and undulations in the ϕ
versus L z space coded by median V R, following a
similar slope of -8 km s-1 kpc deg-1. The slope is
predicted by Monario et al.'s model for CR of a large and slow Galactic
bar. For the first time, we show the variation in the angular momentum
with azimuths from -10° to 20° for two outer and broad undulations
with negative V R around - 18 km s-1 following
this slope. The wave-like pattern with large amplitude outside CR and
a wide peak of the second undulation indicate that minor merger of
the Sagittarius dwarf galaxy with the disk might play a role besides
the significant impact of the CR of the Galactic bar.
Title: Automated Crater detection from Co-registered optical images,
elevation maps and slope maps using deep learning
Authors: Tewari, Atal; Verma, Vinay; Srivastava, Pradeep; Jain,
Vikrant; Khanna, Nitin
Bibcode: 2022P&SS..21805500T
Altcode:
Craters are topographic structures resulting from impactors striking
the surface of planetary bodies. This paper proposes a novel way
of simultaneously utilizing optical images, digital elevation maps
(DEMs), and slope maps for automatic crater detection on the lunar
surface. The proposed system utilizes Mask R-CNN by tuning it for the
crater detection task. Two catalogs, namely, Head-LROC and Robbins,
are used for performance evaluation, and extensive analysis of detection
results for the lunar surface is performed for both of these catalogs. A
recall value of 93.94% is obtained for the Head-LROC catalog, which
has relatively strict crater markings. For the Robbins catalog,
an exhaustive crater catalog based on relatively liberal marking,
F1-score of the proposed system ranges from 64.27% to 81.33%,
for different crater size ranges. The proposed system's generalization
capability for crater detection on different terrains with different
input data types is also evaluated. Experimental results show that the
proposed system trained on the lunar surface can also detect craters
on the Martian surface. This model is trained by simultaneously using
lunar surface's optical images and DEMs with their corresponding slope
maps; however, it is tested on an entirely different input data type,
thermal IR images from the Martian surface.
Title: ZTF Transient Discovery Report for 2022-09-07
Authors: Fremling, C.
Bibcode: 2022TNSTR2608....1F
Altcode:
No abstract at ADS
Title: Effect of the Heliospheric State on CME Evolution
Authors: Dagnew, Fithanegest Kassa; Gopalswamy, Nat; Tessema, Solomon
Belay; Akiyama, Sachiko; Yashiro, Seiji
Bibcode: 2022ApJ...936..122D
Altcode:
The culmination of solar cycle 24 by the end of 2019 has created
the opportunity to compare the differing properties of coronal mass
ejections (CMEs) between two whole solar cycles: solar cycle 23 (SC 23)
and solar cycle 24 (SC 24). We report on the width evolution of limb
CMEs in SCs 23 and 24 in order to test the suggestion by Gopalswamy et
al. that CME flux ropes attain pressure balance at larger heliocentric
distances in SC 24. We measure CME width as a function of heliocentric
distance for a significantly large number of limb CMEs (~1000) and
determine the distances where the CMEs reach constant width in each
cycle. We introduced a new parameter, the transition height (hc) of a
CME, defined as the critical heliocentric distance beyond which the CME
width stabilizes to a quasi-constant value. Cycle and phase-to-phase
comparisons are based on this new parameter. We find that the average
value of hc in SC 24 is 62% higher than that in SC 23. SC 24 CMEs
attain their peak width at larger distances from the Sun than SC 23
CMEs do. The enhanced transition height in SC 24 is new observational
ratification of the anomalous expansion. The anomalous expansion of
SC 24 CMEs, which is caused by the weak state of the heliosphere,
accounts for the larger heliocentric distance where the pressure
balance between CME flux rope and the ambient medium is attained.
Title: The Late-time X-ray Behavior of Short Gamma-ray Bursts:
Implications for Energetics and Rates
Authors: Fong, Wen-fai
Bibcode: 2022cxo..prop.6302F
Altcode:
The distribution of jet angles for short gamma-ray bursts (SGRBs)
is critical to constrain because it directly affects the true energy
scale and event rate. The event rate is of particular interest in
the gravitational wave era. Our current knowledge of the jet angle
distribution comes almost exclusively from X-ray observations at >1
day after the burst. Here, we propose for Chandra TOO observations
to monitor an SGRB afterglow and constrain its collimation, either
from the detection of a jet break, or the non-detection of a break to
place a lower limit of >5-25 deg. A precise calculation of the jet
angle also requires broad-band afterglow observations, which will be
leveraged to provide the tightest constraints on the jet angle.
Title: Correction to: Models of binary neutron star remnants with
tabulated equations of state
Authors: Iosif, Panagiotis; Stergioulas, Nikolaos
Bibcode: 2022MNRAS.tmp.2308I
Altcode:
No abstract at ADS
Title: A truncated inner disc in the Seyfert 1 galaxy WKK 4438
Authors: Gallo, L. C.; Buhariwalla, M. Z.; Jiang, J.; D'Ammando, F.;
Walton, D. J.
Bibcode: 2022MNRAS.515.2208G
Altcode: 2022MNRAS.tmp.1820G; 2022arXiv220702340G
Understanding whether and when the accretion disc extends down to
the innermost stable circular orbit is important since it is the
fundamental assumption behind measuring black hole spin. Here, we
examine the 2013 and 2018 NuSTAR and Swift data ($0.5\!-\!50{\rm
\, keV}$) of the narrow-line Seyfert 1 galaxy, WKK 4438. The X-ray
emission can be fitted well with models depicting a corona and blurred
reflection originating from a disc around a low-spin (a*
≍ 0) black hole. However, such models result in unconventional values
for some of the parameters (e.g. inverted emissivity profile and high
coronal height). Alternatively, equally good fits can be achieved if
the disc is truncated at $\sim 10{\, r_{\rm g}}$ and the black hole is
spinning at the Thorne limit (a* = 0.998). In these cases,
the model parameters are consistent with the interpretation that the
corona is centrally located close to the black hole and illuminating
the disc at a larger distance.
Title: Combined spectroscopy and intensity interferometry to determine
the distances of the blue supergiants P Cygni and Rigel
Authors: de Almeida, E. S. G.; Hugbart, M.; Domiciano de Souza,
A.; Rivet, J. -P.; Vakili, F.; Siciak, A.; Labeyrie, G.; Garde, O.;
Matthews, N.; Lai, O.; Vernet, D.; Kaiser, R.; Guerin, W.
Bibcode: 2022MNRAS.515....1D
Altcode: 2022MNRAS.tmp.1599D; 2022arXiv220400372D
In this paper, we report on spatial intensity interferometry
measurements within the Hα line on two stars: the Luminous Blue
Variable supergiant P Cygni and the late-type B supergiant Rigel. The
experimental setup was upgraded to allow simultaneous measurement of
two polarization channels, instead of one in our previous setup, and
the zero baseline correlation function on-sky to validate independent
estimates obtained from the stellar spectrum and the instrumental
spectral throughput. Combined with simultaneous spectra measurements
and based on radiative transfer models calculated with the code CMFGEN,
we were able to fit our measured visibility curves to extract the
stellar distances. Our distance determinations for both P Cygni (1.61
± 0.18 kpc) and Rigel (0.26 ± 0.02 kpc) agree very well with the
values provided by astrometry with the Gaia and Hipparcos missions,
respectively. This result for Rigel was obtained by adopting a
stellar luminosity of L⋆ = 123 000 L⊙,
which is reported in the literature as being consistent with the
Hipparcos distance to Rigel. However, due to the lack of consensus on
Rigel's luminosity, we also explore how the adoption of the stellar
luminosity in our models affects our distance determination for
Rigel. In conclusion, we support, in an independent way, the distance
to Rigel as the one provided by the Hipparcos mission, when taking
the luminosity of 123 000 L⊙ at face value. This study
is the first successful step towards extending the application of the
Wind Momentum Luminosity Relation method for distance calibration from
an LBV supergiant to a more normal late-type B supergiant.
Title: Main belt asteroid collision histories: Cratering, ejecta,
erosion, catastrophic dispersions, spins, binaries, tops, and wobblers
Authors: Holsapple, Keith A.
Bibcode: 2022P&SS..21905529H
Altcode:
This is a study of the collisional history of the asteroids in the
main asteroid belt. Over the ∼4.5 Byr of the belt existence, every
asteroid collided with others a multitude of times, producing cratering,
erosion, spin, fragmentation, reshaping, and occasional catastrophic
disruption and dispersion. Extensive information for asteroid orbits,
sizes, shapes, composition, and rotation states of those asteroids is
now available. Those are a result of their history, but to interpret
them requires understanding the processes. That understanding can
be achieved by simulations of the history. A simulation needs
robust models of the dynamical and collisional events. Such models have
evolved substantially in the last few decades. Here I present extensive
current models, a method, and a code "SSAH" (Stochastic Simulations
of Asteroid Histories) for statistical recreations of the collisional
history of the main belt. Although there are still significant gaps
in our understanding of the necessary models, the code exposes those
and gives a framework upon which existing and improved models can be
tested. The results reveal new paradigms for asteroid histories,
including the distribution of spins; the irrelevance of material
strength spin limits; the 'uncommon' spins of such asteroids as
the rapid rotating 2001 OE84, and of large slow spinning, tumbling
object Mathilde; the "V-shape" in the spin versus diameter plot;
the non-Maxwellian distributions of spins; the numbers of expected
binaries and of tumblers, and more. They suggest a reassessment of
the importance of the role of the YORP processes. The intent
here is to provide current models, simulate the histories, note the
uncertainties, and provide a framework for future improvements. The
SSAH code is freely available for the use of others here, or directly
from the author at holsapple@aa.washington.edu.
Title: Integrated mass-loss of evolved stars in M4 using
asteroseismology
Authors: Howell, Madeline; Campbell, Simon W.; Stello, Dennis; De
Silva, Gayandhi M.
Bibcode: 2022MNRAS.515.3184H
Altcode: 2022arXiv220702406H; 2022MNRAS.tmp.1975H
Mass-loss remains a major uncertainty in stellar modelling. In
low-mass stars, mass-loss is most significant on the red giant branch
(RGB), and will impact the star's evolutionary path and final stellar
remnant. Directly measuring the mass difference of stars in various
phases of evolution represents one of the best ways to quantify
integrated mass-loss. Globular clusters (GCs) are ideal objects
for this. M4 is currently the only GC for which asteroseismic data
exist for stars in multiple phases of evolution. Using K2 photometry,
we report asteroseismic masses for 75 red giants in M4, the largest
seismic sample in a GC to date. We find an integrated RGB mass-loss of
$\Delta \overline{M} = 0.17 \pm 0.01 ~\mathrm{M}_{\odot }$, equivalent
to a Reimers' mass-loss coefficient of ηR = 0.39. Our
results for initial mass, horizontal branch mass, ηR,
and integrated RGB mass-loss show remarkable agreement with previous
studies, but with higher precision using asteroseismology. We also
report the first detections of solar-like oscillations in early
asymptotic giant branch (EAGB) stars in GCs. We find an average mass
of $\overline{M}_{\text{EAGB}}=0.54 \pm 0.01 ~\mathrm{M}_{\odot
}$, significantly lower than predicted by models. This suggests
larger-than-expected mass-loss on the horizontal branch. Alternatively,
it could indicate unknown systematics in the scaling relations for
the EAGB. We discover a tentative mass bimodality in the RGB sample,
possibly due to the multiple populations. In our red horizontal branch
sample, we find a mass distribution consistent with a single value. We
emphasize the importance of seismic studies of GCs since they could
potentially resolve major uncertainties in stellar theory.
Title: Stratospheric clouds do not impede JWST transit spectroscopy
for exoplanets with Earth-like atmospheres
Authors: Doshi, Dhvani; Cowan, Nicolas B.; Huang, Yi
Bibcode: 2022MNRAS.515.1982D
Altcode: 2022arXiv220700015D; 2022MNRAS.tmp.1797D
The James Webb Space Telescope (JWST) will provide an opportunity to
investigate the atmospheres of potentially habitable planets. Aerosols
significantly mute molecular features in transit spectra because they
prevent light from probing the deeper layers of the atmosphere. Earth
occasionally has stratospheric/high tropospheric clouds at 15-20 km
that could substantially limit the observable depth of the underlying
atmosphere. We use solar occultations of Earth's atmosphere to
create synthetic JWST transit spectra of Earth analogues orbiting
dwarf stars. Unlike previous investigations, we consider both clear
and cloudy sightlines from the SCISAT satellite. We find that the
maximum difference in effective thickness of the atmosphere between
a clear and globally cloudy atmosphere is 8.5 km at 2.28 $\mu$m,
with a resolution of 0.02 $\mu$m. After incorporating the effects of
refraction and Pandexo's noise modelling, we find that JWST would not
be able to detect Earth-like stratospheric clouds if an exo-Earth was
present in the TRAPPIST-1 system, as the cloud spectrum differs from
the clear spectrum by a maximum of 10 ppm. These stratospheric clouds
are also not robustly detected by TauREx when performing spectral
retrieval for a cloudy TRAPPIST-1 planet. However, if an Earth-sized
planet were to orbit in a white dwarf's habitable zone, then we predict
that JWST's NIRSpec would be able to detect its stratospheric clouds
after only four transits. We conclude that stratospheric clouds would
not impede JWST transit spectroscopy or the detection of biosignatures
for Earth-like atmospheres.
Title: Morphological decomposition of TNG50 galaxies: methodology
and catalogue
Authors: Zana, Tommaso; Lupi, Alessandro; Bonetti, Matteo; Dotti,
Massimo; Rosas-Guevara, Yetli; Izquierdo-Villalba, David; Bonoli,
Silvia; Hernquist, Lars; Nelson, Dylan
Bibcode: 2022MNRAS.515.1524Z
Altcode: 2022arXiv220604693Z; 2022MNRAS.tmp.1668Z
We present MORDOR (MORphological DecOmposeR), a new algorithm for
structural decomposition of simulated galaxies based on stellar
kinematics. The code measures the properties of up to five structural
components (a thin/cold and a thick/warm disc, a classical and a
secular bulge, and a spherical stellar halo), and determines the
properties of a stellar bar (if present). A comparison with other
algorithms presented in the literature yields overall good agreement,
with MORDOR displaying a higher flexibility in correctly decomposing
systems and identifying bars in crowded environments (e.g. with ongoing
fly-bys, often observable in cosmological simulations). We use MORDOR
to analyse galaxies in the TNG50 simulation and find the following:
(i) the thick disc component undergoes the strongest evolution in
the binding energy-circularity plane, as expected when disc galaxies
decrease their turbulent-rotational support with cosmic time; (ii)
smaller galaxies (with stellar mass, $10^{9} \lesssim M_{*}/~\rm
M_{\odot }\le 5 \times 10^{9}$) undergo a major growth in their disc
components after z ~ 1, whereas (iii) the most massive galaxies
($5 \times 10^{10} \lt M_{*}/~\rm M_{\odot }\le 5\times 10^{11}$)
evolve towards more spheroidal dominated objects down to z = 0 due to
frequent gravitational interactions with satellites; (iv) the fraction
of barred galaxies grows rapidly at high redshift and stabilizes below
z ~ 2, except for the most massive galaxies that show a decrease in
the bar occupation fraction at low redshift; (v) galaxies with $M_{*}
\sim 10^{11}~~\rm M_{\odot }$ exhibit the highest relative occurrence
of bars at z = 0, in agreement with observational studies. We publicly
release MORDOR and the morphological catalogue of TNG50 galaxies.
Title: Simulating radio synchrotron emission in star-forming galaxies:
small-scale magnetic dynamo and the origin of the far-infrared-radio
correlation
Authors: Pfrommer, Christoph; Werhahn, Maria; Pakmor, Rüdiger;
Girichidis, Philipp; Simpson, Christine M.
Bibcode: 2022MNRAS.515.4229P
Altcode: 2022MNRAS.tmp.1815P; 2021arXiv210512132P
In star-forming galaxies, the far-infrared (FIR) and radio-continuum
luminosities obey a tight empirical relation over a large range of
star-formation rates (SFR). To understand the physics, we examine
magnetohydrodynamic galaxy simulations, which follow the genesis
of cosmic ray (CR) protons at supernovae and their advective and
anisotropic diffusive transport. We show that gravitational collapse
of the proto-galaxy generates a corrugated accretion shock, which
injects turbulence and drives a small-scale magnetic dynamo. As the
shock propagates outwards and the associated turbulence decays, the
large velocity shear between the supersonically rotating cool disc
with respect to the (partially) pressure-supported hot circumgalactic
medium excites Kelvin-Helmholtz surface and body modes. Those interact
non-linearly, inject additional turbulence and continuously drive
multiple small-scale dynamos, which exponentially amplify weak seed
magnetic fields. After saturation at small scales, they grow in scale
to reach equipartition with thermal and CR energies in Milky Way-mass
galaxies. In small galaxies, the magnetic energy saturates at the
turbulent energy while it fails to reach equipartition with thermal
and CR energies. We solve for steady-state spectra of CR protons,
secondary electrons/positrons from hadronic CR-proton interactions
with the interstellar medium, and primary shock-accelerated electrons
at supernovae. The radio-synchrotron emission is dominated by primary
electrons, irradiates the magnetized disc and bulge of our simulated
Milky Way-mass galaxy and weakly traces bubble-shaped magnetically
loaded outflows. Our star-forming and star-bursting galaxies with
saturated magnetic fields match the global FIR-radio correlation (FRC)
across four orders of magnitude. Its intrinsic scatter arises due to
(i) different magnetic saturation levels that result from different
seed magnetic fields, (ii) different radio synchrotron luminosities
for different specific SFRs at fixed SFR, and (iii) a varying radio
intensity with galactic inclination. In agreement with observations,
several 100-pc-sized regions within star-forming galaxies also obey
the FRC, while the centres of starbursts substantially exceed the FRC.
Title: Combined effects of disc winds and turbulence-driven accretion
on planet populations
Authors: Alessi, Matthew; Pudritz, Ralph E.
Bibcode: 2022MNRAS.515.2548A
Altcode: 2022MNRAS.tmp.1726A; 2022arXiv220701626A
Recent surveys show that protoplanetary discs have lower levels of
turbulence than expected based on their observed accretion rates. A
viable solution to this is that magnetized disc winds dominate angular
momentum transport. This has several important implications for planet
formation processes. We compute the physical and chemical evolution
of discs and the formation and migration of planets under the combined
effects of angular momentum transport by turbulent viscosity and disc
winds. We take into account the critical role of planet traps to limit
Type I migration in all of these models and compute thousands of planet
evolution tracks for single planets drawn from a distribution of initial
disc properties and turbulence strengths. We do not consider multiplanet
models nor include N-body planet-planet interactions. Within this
physical framework we find that populations with a constant value disc
turbulence and winds strength produce mass-semimajor axis distributions
in the M-a diagram with insufficient scatter to compare reasonably
with observations. However, populations produced as a consequence
of sampling discs with a distribution of the relative strengths of
disc turbulence and winds fit much better. Such models give rise
to a substantial super Earth population at orbital radii 0.03-2 au,
as well as a clear separation between the produced hot Jupiter and
warm Jupiter populations. Additionally, this model results in a good
comparison with the exoplanetary mass-radius distribution in the M-R
diagram after post-disc atmospheric photoevaporation is accounted for.
Title: On the asymptotic behaviour of cosmic density-fluctuation
power spectra
Authors: Konrad, Sara; Bartelmann, Matthias
Bibcode: 2022MNRAS.515.2578K
Altcode: 2021arXiv211007427K; 2022MNRAS.tmp.1836K
We study the small-scale asymptotic behaviour of the cosmic
density-fluctuation power spectrum in the Zel'dovich approximation. For
doing so, we extend Laplace's method in arbitrary dimensions and use it
to prove that this power spectrum necessarily develops an asymptotic
tail proportional to k-3, irrespective of the cosmological
model and the power spectrum of the initial matter distribution. The
exponent -3 is set only by the number of spatial dimensions. We derive
the complete asymptotic series of the power spectrum and compare
the leading and next-to-leading-order terms to derive characteristic
scales for the onset of non-linear structure formation, independent
of the cosmological model and the type of dark matter. Combined
with earlier results on the mean-field approximation for including
particle interactions, this asymptotic behaviour is likely to remain
valid beyond the Zel'dovich approximation. Due to their insensitivity
to cosmological assumptions, our results are generally applicable to
particle distributions with positions and momenta drawn from a Gaussian
random field. We discuss an analytically solvable toy model to further
illustrate the formation of the k-3 asymptotic tail.
Title: Testing viable extensions of Einstein-Gauss-Bonnet gravity
Authors: Odintsov, Sergei D.; Sáez-Chillón Gómez, Diego; Sharov,
German S.
Bibcode: 2022PDU....3701100O
Altcode: 2022arXiv220708513O
Some models within the framework of Gauss-Bonnet gravities are
considered in the presence of a non-minimally coupled scalar field. By
imposing a particular constraint on the scalar field coupling, a
class of these theories called Einstein-Gauss-Bonnet gravity keeps the
correct speed of propagation for gravitational waves. The cosmological
evolution for this viable class of models is studied and compared
with observational data (BAO, CMB, Sne Ia,..), where we obtain the
corresponding bounds for these theories and show that such theories
fit well the data and provide a well-behaved cosmological evolution
in comparison to the standard model of cosmology. Some statistical
parameters show that the goodness of the fits are slightly better than
those for ΛCDM model.
Title: Monitoring Earth using SDR Earth Imager
Authors: Sharif, Radwan; Tanyer, S. Gokhun; Harrison, Stephen;
Driessen, Peter; Herring, Rodney
Bibcode: 2022JASTP.23505907S
Altcode:
To obtain information about Earth disturbances to the ionosphere of the
atmosphere, a Software Defined Radio (SDR) Earth Imager was constructed
at the Dominion Radio Astrophysical Observatory (DRAO). This imager
used radio waves reflected from the Earth's ionization layer to phase
image waves on/in the ionosphere. Two sets of waves were found, one
having a constant frequency and another having a large spike. The
constant frequency waves represent a continuously active ionospheric
disturbance such as a power generating station. The large spike waves
were randomly occurring outliers. Candidates for the spike waves are
lightning strikes and/or earthquakes. Having the capability to detect
these waves opens up the possibility of measuring the power, energy
and location of their disturbance.
Title: Quantifying Earth's radiogenic heat budget
Authors: Sammon, Laura G.; McDonough, William F.
Bibcode: 2022E&PSL.59317684S
Altcode:
Earth's internal heat drives its dynamic engine, causing mantle
convection, plate tectonics, and the geodynamo. These renewing
and protective processes, which make Earth habitable, are fueled
by primordial and radiogenic heat. For the past two decades,
particle physicists have measured the flux of geoneutrinos, electron
antineutrinos emitted during β- decay. These ghost-like
particles provide a direct measure of the amount of heat producing
elements (HPE: Th & U) in the Earth and in turn define the planet's
absolute concentration of the refractory elements. The geoneutrino
flux has contributions from the lithosphere and mantle. Detector
sensitivity follows a 1/r2 (source detector separation
distance) dependence. Accordingly, an accurate geologic model of
the Near-Field Lithosphere (NFL, closest 500 km) surrounding each
experiment is required to define the mantle's contribution. Because
of its proximity to the detector and enrichment in HPEs, the local
lithosphere contributes ∼50% of the signal and has the greatest
effect on interpreting the mantle's signal. We re-analyzed the
upper crustal compositional model used by Agostini et al. (2020)
for the Borexino experiment. We documented the geology of the western
Near-Field region as rich in potassic volcanism, including some centers
within 50 km of the detector. In contrast, the Agostini study did not
include these lithologies and used only a HPE-poor, carbonate-rich,
model for upper crustal rocks in the surrounding ∼150 km of the
Borexino experiment. Consequently, we report 3× higher U content
for the local upper crust, which produces a 200% decrease in Earth's
radiogenic heat budget, when compared to their study. Results from
the KamLAND and Borexino geoneutrino experiments are at odds with
one another and predict mantle compositional heterogeneity that is
untenable. Combined analyses of the KamLAND and Borexino experiments
using our revised local models strongly favor an Earth with ∼20 TW
present-day total radiogenic power. The next generation of geoneutrino
detectors (SNO+, counting; and JUNO, under construction) will better
constrain the HPE budget of the Earth.
Title: Negative polarization properties of regolith
simulants. Systematic experimental evaluation of composition effects
Authors: Spadaccia, S.; Patty, C. H. L.; Capelo, H. L.; Thomas, N.;
Pommerol, A.
Bibcode: 2022A&A...665A..49S
Altcode: 2022arXiv220708767S
Context. Polarization phase curves of asteroids and other small airless
bodies are influenced by the compositional and physical properties of
their regolith. The mixing of minerals composing the regolith influences
the negative polarization at small phase angles because it changes the
multiple scattering properties of the medium.
Aims: This work
aims to demonstrate experimentally how the mixing effect influences
the polarization phase curve at small phase angles for different
mineralogies relevant for asteroids, and to determine how different
aggregate sizes affect the negative polarization.
Methods: We
prepared a set of binary and ternary mixtures with different common
minerals on asteroids and one set of the same mixture with different
aggregate sizes. We measured their reflected light at 530 nm with full
Stokes polarimetry at phase angles ranging from 0.8° to 30°.
Results: The mixing effect of the mixtures with both bright and dark
minerals significantly changes the behavior of the phase curves in terms
of minimum polarization, phase angle of the minimum, and inversion angle
with respect to the mineral components that are mixed together. The
changes in phase curve could explain the polarization observation of
particular classes of asteroids (F and L class) and other asteroids with
peculiar polarization curves or photometric properties. Furthermore,
we demonstrate that the negative polarization is invariant to the
presence of dust aggregates up to centimeter sizes.
Title: Cometary Activities of the Hyperbolic Asteroid A/2021 X2
Observed at Lulin Observatory
Authors: Cheng, Yu-Chi; Wu, Ya-Lin
Bibcode: 2022ATel15597....1C
Altcode:
We report ongoing cometary activities of the hyperbolic asteroid A/2021
X2 (hereafter X2) from our optical imaging in August. A weak coma and
a faint diffuse tail were observed on the 9th, 20th, 21st, and 24th
of August when the heliocentric distance of X2 varied between 3.01 and
3.03 au. The FWHM of X2 is around 2.5" which is twice the mean seeing
during the observation.
Title: Nonlinear Color-Metallicity Relations of Globular
Clusters. XI. Nonlinearity Effect Revealed by NGC 5128 (Centaurus A)
and NGC 4594 (Sombrero) Galaxies
Authors: Kim, Hak-Sub; Yoon, Suk-Jin; Lee, Sang-Yoon; Han, Sang-Il
Bibcode: 2022ApJ...936...15K
Altcode: 2022arXiv220902738K
Metallicity distributions (MDs) of globular clusters (GCs) provide
crucial clues for the assembly and star formation history of their host
galaxies. GC colors, when GCs are old, have been used as a proxy of GC
metallicities. Bimodal GC color distributions (CDs) observed in most
early-type galaxies have been interpreted as bimodal MDs for decades,
suggesting the presence of merely two GC subpopulations within single
galaxies. However, the conventional view has been challenged by a
new theory that nonlinear metallicity-to-color conversion can cause
bimodal CDs from unimodal MDs. The unimodal MDs seem natural given
that MDs involved many thousand protogalaxies. The new theory has
been tested and corroborated by various observational and theoretical
studies. Here we examine the nonlinear nature of GC color-metallicity
relations (CMRs) using photometric and spectroscopic GC data of NGC
5128 (Centaurus A) and NGC 4594 (Sombrero), in comparison with stellar
population simulations. We find that, with a slight offset in color,
the overall shapes of observed and modeled CMRs agree well for all
available colors. Diverse color-depending morphologies of GC CDs of the
two galaxies are well reproduced based on their observed spectroscopic
MDs via our CMR models. The results corroborate the nonlinear CMR
interpretation of the GC color bimodality, shedding further light on
theories of galaxy formation.
Title: SWASTi-SW: Space Weather Adaptive Simulation Framework for
Solar Wind and Its Relevance to the Aditya-L1 Mission
Authors: Mayank, Prateek; Vaidya, Bhargav; Chakrabarty, D.
Bibcode: 2022ApJS..262...23M
Altcode: 2022arXiv220713708M
Solar wind streams, acting as a background, govern the propagation
of space weather drivers in the heliosphere, which induce geomagnetic
storm activities. Therefore, predictions of the solar wind parameters
are the core of space weather forecasts. This work presents an
indigenous three-dimensional (3D) solar wind model (SWASTi-SW). This
numerical framework for forecasting the ambient solar wind is based
on a well-established scheme that uses a semiempirical coronal model
and a physics-based inner heliospheric model. This study demonstrates
a more generalized version of the Wang-Sheeley-Arge relation, which
provides a speed profile input to the heliospheric domain. Line-of-sight
observations of GONG and Helioseismic and Magnetic Imager magnetograms
are used as inputs for the coronal model, which in turn provides the
solar wind plasma properties at 0.1 au. These results are then used as
an initial boundary condition for the magnetohydrodynamics model of
the inner heliosphere to compute the solar wind properties up to 2.1
au. Along with the validation run for multiple Carrington rotations,
the effect of variation of specific heat ratio and study of the stream
interaction region (SIR) are also presented. This work showcases the
multidirectional features of SIRs and provides synthetic measurements
for potential observations from the Solar Wind Ion Spectrometer
subsystem of the Aditya Solar wind Particle Experiment payload on
board ISRO's upcoming solar mission Aditya-L1.
Title: Understanding the relation between thermal Sunyaev-Zeldovich
decrement and halo mass using the SIMBA and TNG simulations
Authors: Yang, Tianyi; Cai, Yan-Chuan; Cui, Weiguang; Davé, Romeel;
Peacock, John A.; Sorini, Daniele
Bibcode: 2022MNRAS.tmp.2318Y
Altcode: 2022arXiv220211430Y
The relation between the integrated thermal Sunyaev-Zeldovich (tSZ)
y-decrement versus halo mass (Y-M) can potentially constrain galaxy
formation models, if theoretical and observational systematics
can be properly assessed. We investigate the Y-M relation in the
SIMBA and IllustrisTNG-100 cosmological hydrodynamic simulations,
quantifying the effects of feedback, line-of-sight projection, and
beam convolution. We find that SIMBA's AGN jet feedback generates
strong deviations from self-similar expectations for the Y-M relation,
especially at $M_{\rm 500}\lesssim 10^{13}M_\odot$. In SIMBA, this is
driven by suppressed in-halo y contributions owing to lowered halo
baryon fractions. IllustrisTNG results more closely resemble SIMBA
without jets. Projections of line-of-sight structures weaken these
model differences slightly, but they remain significant - particularly
at group and lower halo masses. In contrast, beam smearing at Planck
resolution makes the models indistinguishable, and both models appear
to agree well with Planck data down to the lowest masses probed. We
show that the arcminute resolution expected from forthcoming facilities
would retain the differences between model predictions, and thereby
provide strong constraints on AGN feedback.
Title: GASP XXXIX: MeerKAT hunts Jellyfish in A2626
Authors: Deb, Tirna; Verheijen, Marc A. W.; Poggianti, Bianca M.;
Moretti, Alessia; van der Hulst, J. M.; Vulcani, Benedetta; Ramatsoku,
Mpati; Serra, Paolo; Healy, Julia; Gullieuszik, Marco; Bacchini,
Cecilia; Ignesti, Alessandro; Müller, Ancla; Zabel, Nikki; Luber,
Nicholas; Jaffë, Yara L.; Gitti, Myriam
Bibcode: 2022MNRAS.tmp.2319D
Altcode: 2022arXiv220812950D
We present MeerKAT H I observations of six jellyfish candidate galaxies
(JFCGs) in the galaxy cluster, A2626. Two of the six galaxies JW100
and JW103, that were identified as JFCGs from B-band images, are
confirmed as jellyfish galaxies (JFGs). Both of the JFGs have low H I
content, reside in the cluster core, and move at very high velocities
(~ 3σcl). The other JFCGs, identified as non-jellyfish
galaxies, are H I rich, with H I morphologies revealing warps,
asymmetries, and possible tidal interactions. Both the A2626 JFGs and
three other confirmed JFGs from the GASP sample show that these galaxies
are H I stripped but not yet quenched. We detect H I, Hα, and CO(2-1)
tails of similar extent (~ 50 kpc) in JW100. Comparing the multi-phase
velocity channels, we do not detect any H I or CO(2-1) emission in the
northern section of the tail where Hα emission is present, possibly
due to prolonged interaction between the stripped gas and the ICM. We
also observe an anti-correlation between H I and CO(2-1), which hints
at an efficient conversion of H I to H2 in the southern part
of the tail. We find that both RPS and H I-to-H2 conversion
are significant depletion channels for atomic gas. H I-to-H2
conversion is more efficient in the disc than in the tail.
Title: H I 21-cm absorption in radio-loud AGN with double-peaked
[O III] emission
Authors: Dutta, Rajeshwari; Srianand, Raghunathan
Bibcode: 2022MNRAS.tmp.2294D
Altcode: 2022arXiv220902717D
Different physical processes in galaxy evolution, such as galaxy
mergers that lead to coalescence of dual Active Galactic Nuclei
(AGN) and outflows emanating from the narrow line region, can
leave their imprint on the optical spectra of AGN in the form of
double-peaked narrow emission lines. To investigate the neutral gas
in the centres of such AGN, we have conducted a pilot survey of H I
21-cm absorption, using the upgraded Giant Metrewave Radio Telescope
(uGMRT), in radio-loud AGN whose optical spectra show double-peaked
[O III] emission lines at z ≤ 0.4 (median z ≍ 0.14). Among the
eight sources for which we could obtain clean spectra, we detect H I
21-cm absorption in three sources (detection rate of $38^{+36}_{-20}$%)
and find tentative indication of absorption in two other sources. The
detection rate of H I 21-cm absorption is tentatively higher for the
systems that show signatures of interaction or tidal disturbance (≳
50%) in the ground-based optical images than that for the systems that
appear single and undisturbed (≍25%). This is consistent with the
high incidence of H I 21-cm absorption observed in z ≤ 0.2 galaxy
mergers. Higher spatial resolution spectroscopy is required to confirm
the origin of the H I absorbing gas, i.e. either gas infalling onto the
radio-loud AGN, outflowing gas ejected by the AGN, or gas in rotation
on the galactic-scale or circumnuclear discs.
Title: ALETHEIA: Hunting for Low-mass Dark Matter with Liquid
Helium TPCs
Authors: Liao, Junhui; Gao, Yuanning; Jiang, Zhen; Liang, Zhuo; OuYang,
Zebang; Peng, Zhaohua; Zhang, Fengshou; hang, Lei; Zhou, Jiangfeng
Bibcode: 2022arXiv220902320L
Altcode:
Dark Matter (DM) is one of the most critical questions to be
understood and answered in fundamental physics today. Observations
with varied astronomical and cosmological technologies already
pinned down that DM exists in the Universe, the Milky Way, and the
Solar System. Nevertheless, understanding DM under the language of
elementary physics is still in progress. DM direct detection tests
the interactive cross-section between galactic DM particles and an
underground detector's nucleons. Although Weakly Interactive Massive
Particles (WIMPs) are the most discussed DM candidates, the null-WIMPs
conclusion has been consistently addressed by the most convincing
experiments in the field. Relatively, the low-mass WIMPs region ($\sim$
10 MeV/c$^2$ - 10 GeV/c$^2$) has not been fully exploited compared to
high-mass WIMPs ($\sim$ 10 GeV/c$^2$ - 10 TeV/c$^2$). The ALETHEIA (A
Liquid hElium Time projection cHambEr In dArk matter) experiment aims to
hunt for low-mass WIMPs with liquid helium-filled TPCs (Time Projection
Chambers). In this paper, we go through the physics motivation of the
project, the detector's design, the R\&D plan, and the progress
we have made since the project has been launched in the summer of 2020.
Title: A giant umbrella-like stellar stream around the tidal ring
galaxy NGC 922
Authors: Martinez-Delgado, David; Roca-Fabrega, Santi; Miro-Carretero,
Juan; Gomez-Flechoso, Maria Angeles; Roman, Javier; Donatiello,
Giuseppe; Schmidt, Judy; Lang, Dustin; Akhlaghi, Mohammad
Bibcode: 2022arXiv220901583M
Altcode:
Tidal ring galaxies are observed rarely in the local universe due
to their intrinsically transient nature. The tidal ring structures
are the result of strong interactions between gas-rich stellar disks
and smaller galactic systems and do not last longer than ~500~Myr
therefore, these are perfect scenarios where to find the debris of
recently accreted dwarf galactic systems. We present new deep images of
the NGC 922 tidal ring galaxy and its surroundings from the DESI Legacy
survey data and from our observations with an amateur telescope. These
observations are compared with results from high-resolution N-body
simulations designed to reproduce an alternative formation scenario
for this peculiar galaxy. Our new observations unveil that the low
surface brightness stellar tidal structures around NGC 922 are much
more complex than reported in previous works. In particular, the
formerly detected tidal spike-like structure at the northeast of the
central galaxy disk is not connected with the dwarf companion galaxy
PGC3080368, which has been suggested as the intruder triggering the ring
formation of NGC 922. The deep images reveal that this tidal structure
is mainly composed by a fainter giant umbrella-like shape and thus it
was formed from the tidal disruption of a different satellite. Using
the broad-band g, r and z DESI LS images, we measured the photometric
properties of this stellar stream, estimating a total absolute magnitude
in r-band of Mr= -17.0 +/- 0.03 magn and a total stellar mass for the
stream between 6.9-8.5X10^8 Mo. We perform a set of N-body simulations
to reproduce the observed NGC 922-intruder interaction, suggesting a
new scenario for the formation of its tidal ring from the in-fall of
a gas rich satellite around 150 Myr ago.
Title: TDCOSMO XI. Automated Modeling of 9 Strongly Lensed Quasars
and Comparison Between Lens Modeling Software
Authors: Ertl, S.; Schuldt, S.; Suyu, S. H.; Schmidt, T.; Treu, T.;
Birrer, S.; Shajib, A. J.; Sluse, D.
Bibcode: 2022arXiv220903094E
Altcode:
To use strong gravitational lenses as an astrophysical or cosmological
probe, models of their mass distributions are often needed. We present
a new, time-efficient automation code for uniform modeling of strongly
lensed quasars with GLEE, a lens modeling software, for high-resolution
multi-band data. By using the observed positions of the lensed quasars
and the spatially extended surface brightness distribution of the
lensed quasar host galaxy, we obtain a model of the mass distribution
of the lens galaxy. We apply this uniform modeling pipeline to a
sample of nine strongly lensed quasars with HST WFC 3 images. The
models show in most cases well reconstructed light components and a
good alignment between mass and light centroids. We find that the
automated modeling code significantly reduces the user input time
during the modeling process. The preparation time of required input
files is reduced significantly. This automated modeling pipeline can
efficiently produce uniform models of extensive lens system samples
which can be used for further cosmological analysis. A blind test
through a comparison with the results of an independent automated
modeling pipeline based on the modeling software Lenstronomy reveals
important lessons. Quantities such as Einstein radius, astrometry, mass
flattening and position angle are generally robustly determined. Other
quantities depend crucially on the quality of the data and the accuracy
of the PSF reconstruction. Better data and/or more detailed analysis
will be necessary to elevate our automated models to cosmography
grade. Nevertheless, our pipeline enables the quick selection of lenses
for follow-up monitoring and further modeling, significantly speeding
up the construction of cosmography-grade models. This is an important
step forward to take advantage of the orders of magnitude increase in
the number of lenses expected in the coming decade.
Title: Constraints on the positron emission from pulsar populations
with AMS-02 data
Authors: Manconi, Silvia
Bibcode: 2022arXiv220905118M
Altcode:
Electron and positron fluxes in cosmic rays are currently measured
with unprecedented precision by AMS-02 up to TeV energies, and
represent unique probes for the local properties of our Galaxy. The
interpretation of their spectra is at present still debated, especially
for the excess of positrons above 10 GeV. The hypothesis that pulsars
can significantly contribute to this excess has been consolidated
after the observation of gamma-ray halos at TeV energies of a few
degree size around Geminga and Monogem pulsars. However, the spatial
and energetic Galactic distribution of pulsars and the details of the
positron production, acceleration and release from these sources are not
yet fully understood. I will describe how we can use the high-precision
AMS-02 positron data to constrain the main properties of the Galactic
pulsar population and of the positron acceleration needed to explain
the observed fluxes. This is achieved by simulating a large number of
Galactic pulsar populations, following the most recent self-consistent
modelings for the pulsar spin-down and evolution properties, calibrated
on catalog observations. By fitting the positron AMS-02 data together
with a secondary component due to collisions of primary cosmic rays
with the interstellar medium, we determine the physical parameters
of the pulsars dominating the positron flux, and assess the impact of
different assumptions on radial distributions, spin-down properties,
Galactic propagation scenarios and positron emission time.
Title: Bracketing the direct detection exclusion plot for a WIMP of
spin one half in non-relativistic effective theory
Authors: Kang, Sunghyun; Jeong, Injun; Scopel, Stefano
Bibcode: 2022arXiv220903646K
Altcode:
Assuming a standard Maxwellian velocity distribution for the WIMPs
in the halo of our Galaxy we use the null results of an exhaustive
set of 6 direct detection experiments to calculate the maximal
variation of the exclusion plot for each Wilson coefficient of
the most general Galilean-invariant effective Hamiltonian for a
WIMP of spin one half due to interferences. We consider 56 Wilson
coefficients $c_i^{p,n}$ and $\alpha_i^{n,p}$ for WIMP-proton
and WIMP-neutron contact interactions ${\cal O}_i^{p,n}$ and
the corresponding long range interaction ${\cal O}_i^{p,n}/q^2$,
parameterized by a massless propagator $1/q^2$. For each coupling we
provide a different exclusion plot when the following set of operators
is allowed to interfere: proton-neutron, i.e. $c_i^{p}$-$c_i^{n}$ or
$\alpha_i^{p}$-$\alpha_i^{n}$; contact-contact or long range-long range,
i.e. $c_i^{p,n}$-$c_j^{p,n}$ or $\alpha_i^{p,n}$-$\alpha_j^{p,n}$;
contact-long range, i.e. $c_i^{p,n}$-$\alpha_j^{p,n}$. For each of the
56 Wilson coefficients $c_i^{p,n}$ and $\alpha_j^{p,n}$ and for the
largest number of interfering operators the exclusion plot variation
can reach 3 orders of magnitude and reduces to a factor as small as a
few for the Wilson coefficients of the effective interactions where
the WIMP couples to the nuclear spin, thanks to the combination of
experiments using proton-odd and neutron-odd targets. Some of the
conservative bounds require an extremely high level of cancellation,
putting into question the reliability of the result. We analyze
this issue in a systematic way, showing that it affects some of the
couplings driven by the operators ${\cal O}_{1}$, ${\cal O}_{3}$,
${\cal O}_{11}$, ${\cal O}_{12}$ and ${\cal O}_{15}$, especially when
interferences among contact and long range interactions are considered.
Title: Inspirals from the innermost stable circular orbit of Kerr
black holes: Exact solutions and universal radial flow
Authors: Mummery, Andrew; Balbus, Steven
Bibcode: 2022arXiv220903579M
Altcode:
We present exact solutions of test particle orbits spiralling inward
from the innermost stable circular orbit (ISCO) of a Kerr black
hole. Our results are valid for any allowed value of the angular
momentum $a$-parameter of the Kerr metric. These solutions are of
considerable physical interest. In particular, the radial 4-velocity of
these orbits is both remarkably simple and, with the radial coordinate
scaled by its ISCO value, universal in form, otherwise completely
independent of the black hole spin.
Title: Group velocity of obliquely propagating Alfvén waves in a
magnetized dusty plasma
Authors: De Toni, L. B.; Gaelzer, R.; Ziebell, L. F.
Bibcode: 2022arXiv220903784D
Altcode:
In this work we investigate the characteristics of the group velocity
of obliquely propagating Alfvén waves in a dusty plasma typical of a
stellar wind. The dispersion relation is derived with the aid of the
kinetic theory for a magnetized dusty plasma consisting of electrons
and ions, with distribution of momenta described by a Maxwellian
function. The dust particles are considered to be immobile and have
all the same size; they are electrically charged by absorption of
plasma particles via inelastic collisions and by photoionization. We
numerically solve the dispersion relation and calculate the components
of group velocity (along and transverse to the magnetic field) for the
normal modes, namely the compressional and shear Alfvén waves (CAW
and SAW). The results show that the direction of the group velocity of
CAWs is greatly modified with the wave-vector direction. On the other
hand, SAWs will present group velocity propagating practically along
the magnetic field. The changes in dust parameters, such as number
density and equilibrium electrical charge, may significantly change
the waves' characteristics. It is seen that for sufficiently high dust
to ion number density ratio, the SAWs may present perpendicular group
velocity propagating in opposite direction to the perpendicular phase
velocity, in a small interval of wavenumber values; we also notice that
this interval may change, or even vanish, when the flux of radiation
incident on the dust is altered, changing the equilibrium electrical
charge of the grains.
Title: CHAOS VII: A Large-Scale Direct Abundance Study in M33
Authors: Rogers, Noah S. J.; Skillman, Evan D.; Pogge, Richard
W.; Berg, Danielle A.; Croxall, Kevin V.; Bartlett, Jordan;
Arellano-Córdova, Karla Z.; Moustakas, John
Bibcode: 2022arXiv220903962R
Altcode:
The dispersion in chemical abundances provides a very strong constraint
on the processes that drive the chemical enrichment of galaxies. Due to
its proximity, the spiral galaxy M33 has been the focus of numerous
chemical abundance surveys to study the chemical enrichment and
dispersion in abundances over large spatial scales. The CHemical
Abundances Of Spirals (CHAOS) project has observed $\sim$100 H II
regions in M33 with the Large Binocular Telescope (LBT), producing
the largest homogeneous sample of electron temperatures (T$_e$) and
direct abundances in this galaxy. Our LBT observations produce a robust
oxygen abundance gradient of $-$0.037 $\pm$ 0.007 dex/kpc and indicate
a relatively small (0.043 $\pm$ 0.015 dex) intrinsic dispersion in
oxygen abundance relative to this gradient. The dispersions in N/H
and N/O are similarly small and the abundances of Ne, S, Cl, and
Ar relative to O are consistent with the solar ratio as expected
for $\alpha$-process or $\alpha$-process-dependent elements. Taken
together, the ISM in M33 is chemically well-mixed and homogeneously
enriched from inside-out with no evidence of significant abundance
variations at a given radius in the galaxy. Our results are compared
to those of the numerous studies in the literature, and we discuss
possible contaminating sources that can inflate abundance dispersion
measurements. Importantly, if abundances are derived from a single T$_e$
measurement and T$_e$-T$_e$ relationships are relied on for inferring
the temperature in the unmeasured ionization zone, this can lead to
systematic biases which increase the measured dispersion up to 0.11 dex.
Title: Uncovering the process that transports magnetic helicity to
coronal mass ejection flux ropes
Authors: Pal, Sanchita
Bibcode: 2022AdSpR..70.1601P
Altcode:
Magnetic helicity, an intrinsic property of eruptive helical flux
ropes (FRs) forming coronal mass ejections (CMEs), plays an important
role in determining CME geoeffectiveness. In the solar atmosphere and
heliosphere, helicity remains conserved in a closed volume. Considering
this fact as a basis of our study, we perform a quantitative comparison
between total magnetic helicity and twisted flux in interplanetary
CMEs and those transported to CMEs via magnetic reconnection at low
corona. At the source, twisted/poloidal flux (ϕpcme)
of CMEs is directly estimated from total reconnection flux, and CME
helicity (Hcme) is obtained by combining reconnection flux
information with CME physical parameters. At 1 AU, the twisted/poloidal
flux (ϕpmc) and helicity (Hmc) of CMEs
are obtained from in situ observations. Considering uncertainties
steaming from FR length, reconnection flux and CME physical parameter
estimations, poloidal flux and helicity of CMEs at 1 AU are found to
be highly relevant (ϕpmc/ϕpcme = 0.4-1.5,
Hmc/Hcme = 0.3-1) to low-corona magnetic
reconnection at the wake of CMEs. This result remains unchanged despite
CME association with pre-existing FRs. We show that a significant
reduction in CME helicity during its heliospheric propagation may
result from a high rate of FR erosion in the interplanetary medium. Our
event analysis confirms that CME's intrinsic magnetic properties are
transported to CME FRs during magnetic reconnection at sheared coronal
arcades. A one-to-one correspondence between the chirality of 1-AU
CMEs and their pre-eruptive structures complies with the fact that
the sense of field line rotations in FRs may remain unchanged during
coronal reconnection at the source. By connecting intrinsic magnetic
properties of FRs through Sun-Earth medium, this study provides
important implications for the origin of geoeffectiveness in CMEs.
Title: Likelihood-free Inference with the Mixture Density Network
Authors: Wang, Guo-Jian; Cheng, Cheng; Ma, Yin-Zhe; Xia, Jun-Qing
Bibcode: 2022ApJS..262...24W
Altcode: 2022arXiv220700185W
In this work, we propose using the mixture density network (MDN) to
estimate cosmological parameters. We test the MDN method by constraining
parameters of the ΛCDM and wCDM models using Type Ia supernovae and
the power spectra of the cosmic microwave background. We find that
the MDN method can achieve the same level of accuracy as the Markov
Chain Monte Carlo method, with a slight difference of ${ \mathcal
O }({10}^{-2}\sigma )$ . Furthermore, the MDN method can provide
accurate parameter estimates with ${ \mathcal O }({10}^{3})$ forward
simulation samples, which are useful for complex and resource-consuming
cosmological models. This method can process either one data set
or multiple data sets to achieve joint constraints on parameters,
extendable for any parameter estimation of complicated models in a
wider scientific field. Thus, the MDN provides an alternative way for
likelihood-free inference of parameters.
Title: An Updated Metal-dependent Theoretical Scenario for Classical
Cepheids
Authors: De Somma, Giulia; Marconi, Marcella; Molinaro, Roberto;
Ripepi, Vincenzo; Leccia, Silvio; Musella, Ilaria
Bibcode: 2022ApJS..262...25D
Altcode: 2022arXiv220611154D
To properly quantify the possible residual systematic errors affecting
the classical Cepheid distance scale, a detailed theoretical scenario
is recommended. By extending the set of nonlinear, convective
pulsation models published for Z = 0.02 to Z = 0.004, Z = 0.008, and
Z = 0.03, we provide a detailed homogeneous, nonlinear model grid
taking into account simultaneous variations of the mass-luminosity
relation, the efficiency of superadiabatic convection, and the
chemical composition. The dependence of the inferred period-radius,
period-mass-radius, and period-mass-luminosity-temperature relations
on the input parameters is discussed for both the fundamental and
first overtone modes. The trend of the instability strip getting
redder as the metallicity increases is confirmed for the additional
mass-luminosity assumptions and mixing length values. From the
obtained multifilter light curves, we derive the mean magnitudes and
colors, and in turn the period-luminosity-color and period-Wesenheit
relations, for each assumed chemical composition, mass-luminosity
relation, and efficiency of superadiabatic convection. Application to
a well-studied sample of Cepheids in the Large Magellanic Cloud allows
us to constrain the dependence of the inferred distance modulus on the
assumed mass-luminosity relation, and the inclusion of the metallicity
term in the derivation of the period-Wesenheit relations allows us,
for each assumed mass-luminosity relation, to predict the metallicity
dependence of the Cepheid distance scale. The obtained metal-dependent,
period-Wesenheit relations are compared with recent results in the
literature and applied to a sample of Gaia Early Data Release 3
Galactic Cepheids with known metal abundances to derive individual
parallaxes. The comparison of these predictions with Gaia results is
finally discussed.
Title: The Formation of the Stripped-envelope Type IIb Supernova
Progenitors: Rotation, Metallicity, and Overshooting
Authors: Long, Gang; Song, Hanfeng; Meynet, Georges; Maeder, Andre;
Zhang, Ruiyu; Qin, Ying; Ekströmt, Sylvia; Georgy, Cyril; Zhao, Liuyan
Bibcode: 2022ApJS..262...26L
Altcode: 2022arXiv220811329L
Type IIb supernovae (SNe) are believed to originate from core-collapse
progenitors having kept only a very thin hydrogen envelope. We aim
to explore how some physical factors, such as rotation, metallicity,
overshooting, and the initial orbital period in binaries significantly
affect the Roche lobe overflow and the formation of Type IIb SNe (also
denoted SNe IIb). It is found that binaries are the main channel that
are capable of producing Type IIb SNe progenitors in the mass range for
initial masses below 20 M ⊙. The formation of Type IIb SNe
progenitors is extremely sensitive to the initial orbital period. A less
massive hydrogen envelope mass indicates a smaller radius and higher
effective temperatures, and vice versa. Binary systems with initial
periods between 300 and 720 days produce Type IIb progenitors that are
a red supergiant. Those with an initial period between 50 and 300 days
produce yellow supergiant progenitors, and those with initial periods
shorter than 50 days blue supergiant progenitors. Both rapid rotation
and larger overshooting can enlarge the carbon-oxygen core mass and lead
to higher core temperature and lower central density at the precollapse
phase. They are also beneficial to surface nitrogen enrichment but
restrict the efficiency of the first dredge-up. SN IIb progenitors with
low metallicity have smaller hydrogen envelope masses and radii than
their high-metallicity counterparts. Ultrastripped binary models have
systematically higher core mass fraction 12C left, which
has an important influence on the compactness of Type IIb progenitors.
Title: The Rate and Spatial Distribution of Novae in M31 as Determined
by a 20 Year Survey
Authors: Rector, Travis A.; Shafter, Allen W.; Burris, William A.;
Walentosky, Matthew J.; Viafore, Kendall D.; Strom, Allison L.;
Cool, Richard J.; Sola, Nicole A.; Crayton, Hannah; Pilachowski,
Catherine A.; Jacoby, George H.; Corbett, Danielle L.; Rene, Michelle;
Hernandez, Denise
Bibcode: 2022ApJ...936..117R
Altcode: 2022arXiv220705689R
A long-term (1995-2016) survey for novae in the nearby Andromeda
galaxy (M31) was conducted as part of the Research-Based Science
Education initiative. During the course of the survey 180 nights
of observation were completed at Kitt Peak, Arizona. A total of 262
novae were either discovered or confirmed, 40 of which have not been
previously reported. Of these, 203 novae form a spatially complete
sample detected by the KPNO/WIYN 0.9 m telescope within a $20^{\prime}
\times 20^{\prime} $ field centered on the nucleus of M31. An additional
50 novae are part of a spatially complete sample detected by the
KPNO 4 m telescope within a larger $36^{\prime} \times 36^{\prime} $
field. Consistent with previous studies, it is found that the spatial
distribution of novae in both surveys follows the bulge light of
M31 somewhat more closely than the overall background light of the
galaxy. After correcting for the limiting magnitude and the spatial
and temporal coverage of the surveys, a final nova rate in M31 is
found to be $R={40}_{-4}^{+5}$ yr-1, which is considerably
lower than recent estimates. When normalized to the K-band luminosity
of M31, this value yields a luminosity-specific nova rate, ν
K = 3.3 ± 0.4 yr ${}^{-1}\,{[{10}^{10}\,{L}_{\odot ,K}]}^{-1}$
. By scaling the M31 nova rate using the relative infrared luminosities
of M31 and our Galaxy, a nova rate of ${R}_{{\rm{G}}}={28}_{-4}^{+5}$
yr-1 is found for the Milky Way.
Title: Modeling the Luminosity-dependent Pulse Profile and Emission
Geometry of SMC X-2 during a Giant Outburst
Authors: Roy, Ankur; Cappallo, Rigel; Laycock, Silas G. T.;
Christodoulou, Dimitris M.; Vasilopoulos, Georgios; Bhattacharya,
Sayantan
Bibcode: 2022ApJ...936...90R
Altcode:
One of the brightest X-ray pulsars in the Small Magellanic Cloud is
SMC X-2. During its most recent major outburst in 2015, this transient
pulsar displayed significant changes in both its accretion state and
magnetosphere, particularly when it entered the low-luminosity regime
of subcritical accretion. Polestar is a pulse-profile modeling code
that helps in delineating the geometry of the emission as the source
evolves past outburst and toward lower-luminosity states. Applying
Polestar to XMM-Newton and NuSTAR pulse profiles, we constrained the
most likely inclination of the spin axis of the pulsar to be i =
87° ± 4°. As the X-ray luminosity declined, an increase in the
pulsed fraction was detected from Swift observations, which suggests
a transition from fan- to pencil-beam emission during the later stages
of the outburst. Additionally, we also performed analysis of the OGLE
IV light curves, which showed strong modulation in the optical profiles
during the outburst.
Title: Extragalactic Magnetism with SOFIA (SALSA Legacy
Program). IV. Program Overview and First Results on the Polarization
Fraction
Authors: Lopez-Rodriguez, Enrique; Mao, Sui Ann; Beck, Rainer;
Borlaff, Alejandro S.; Ntormousi, Evangelia; Tassis, Konstantinos;
Dale, Daniel A.; Roman-Duval, Julia; Subramanian, Kandaswamy;
Martin-Alvarez, Sergio; Marcum, Pamela M.; Clark, Susan E.; Reach,
William T.; Harper, Doyal A.; Zweibel, Ellen G.
Bibcode: 2022ApJ...936...92L
Altcode: 2022arXiv220501105L
We present the first data release of the Survey on extragALactic
magnetiSm with SOFIA (SALSA Legacy Program) with a set of 14 nearby
(<20 Mpc) galaxies with resolved imaging polarimetric observations
using HAWC+ from 53 to 214 μm at a resolution of 5″-18″
(90 pc-1 kpc). We introduce the definitions of and background on
extragalactic magnetism and present the scientific motivation and
sample selection of the program. Here we focus on the general trends
in the emissive polarization fraction. Far-infrared polarimetric
observations trace the thermal polarized emission of magnetically
aligned dust grains across the galaxy disks with polarization fractions
of P = 0%-15% in the cold, T d = [19, 48] K, and dense,
${\mathrm{log}}_{10}({N}_{{\rm{H}}{\rm\small{I}}+{{\rm{H}}}_{2}}[{\mathrm{cm}}^{-2}])=[19.96,22.91]$
, interstellar medium. The spiral galaxies show a median <P 154
μm> = 3.3% ± 0.9% across the disks. We report the first
polarized spectrum of starburst galaxies showing a minimum within
89-154 μm. The falling 53-154 μm polarized spectrum may be due to a
decrease in the dust grain alignment efficiency produced by variations
in dust temperatures along the line of sight in the galactic outflow. We
find that the starburst galaxies and the star-forming regions within
normal galaxies have the lowest polarization fractions. We find that 50%
(seven out of 14) of the galaxies require a broken power law in the P -
${N}_{{\rm{H}}{\rm\small{I}}+{{\rm{H}}}_{2}}$ and P - T d
relations with three different trends. Group 1 has a relative increase
of anisotropic random B-fields produced by compression or shear of
B-fields in the galactic outflows, starburst rings, and inner bars
of galaxies, and groups 2 and 3 have a relative increase of isotropic
random B-fields driven by star-forming regions in the spiral arms and/or
an increase of dust grain alignment efficiency caused by shock-driven
regions or evolutionary stages of a galaxy. *SALSA provides a software
repository at https://github.com/galmagfields/hawc and publicly
available data at http://galmagfields.com/.
Title: ePESSTO+ spectroscopic classification of optical transients
Authors: Pineda-Garcia, J.; Gutiérrez, C.; Kravtsov, T.; Pessi, T.;
Ihanec, N.; Reguitti, A.; Smartt, S. J.; Anderson, J.; Chen, T. W.;
Gromadzki, M.; Inserra, C.; Kankare, E.; Müller-Bravo, T.; Nicholl,
M.; Yaron, O.; Young, D.; Tonry, J.; Denneau, L.; Heinze, A.; Weiland,
H.; Stalder, B.; Rest, A.; Smith, K. W.; Fulton, M.; Gillanders, J.;
Moore, T.; Srivastav, S.
Bibcode: 2022TNSAN.186....1P
Altcode:
This report includes classifications of 2 Type Ia's, 1 Type II, 1 Type
IIn, and 2 blue continua spectra.
Title: Kasner cosmology in bumblebee gravity
Authors: Neves, Juliano C. S.
Bibcode: 2022arXiv220900589N
Altcode:
Kasner cosmology is a vacuum and anisotropically expanding spacetime in
the general relativity context. Here I explore such a cosmological model
in another context, the bumblebee model, where the Lorentz symmetry is
spontaneously broken. By using the bumblebee context it is possible
to justify the anisotropic feature of the Kasner cosmology. Thus,
the origin of the anisotropy in this cosmological model could be in
the Lorentz symmetry breaking.
Title: TDCOSMO X: A key test of systematics in the hierarchical
method of time-delay cosmography
Authors: Gomer, Matthew R.; Sluse, Dominique; van de Vyvere, Lyne;
Birrer, Simon; Courbin, Frederic
Bibcode: 2022arXiv220902076G
Altcode:
The largest source of systematic errors in the time-delay cosmography
method likely arises from the lens model mass distribution, where an
inaccurate choice of model could in principle bias the value of $H_0$. A
Bayesian hierarchical framework has been proposed which combines lens
systems with kinematic data, constraining the mass profile shape at a
population level. The framework has been previously validated on a small
sample of lensing galaxies drawn from hydro-simulations. The goal of
this work is to expand the validation to a more general set of lenses
consistent with observed systems, as well as confirm the capacity of
the method to combine two lens populations: one which has time delay
information and one which lacks time delays and has systematically
different image radii. For this purpose, we generate samples of
analytic lens mass distributions made of baryons+dark matter and fit the
subsequent mock images with standard power-law models. Corresponding
kinematics data are also emulated. The hierarchical framework applied
to an ensemble of time-delay lenses allows us to correct the $H_0$ bias
associated with model choice, finding $H_0$ within $1.5\sigma$ of the
fiducial value. We then combine this set with a sample of corresponding
lens systems which have no time delays and have a source at lower $z$,
resulting in a systematically smaller image radius relative to their
effective radius. The hierarchical framework successfully accounts for
this effect, recovering a value of $H_0$ which is both more precise
($\sigma\sim2\%$) and more accurate ($0.7\%$ median offset) than
the time-delay set alone. This result confirms that non-time-delay
lenses can nonetheless contribute valuable constraining power to the
determination of $H_0$ via their kinematic constraints, assuming they
come from the same global population as the time-delay set.
Title: Subtracting Compact Binary Foregrounds to Search for
Subdominant Gravitational-Wave Backgrounds in Next-Generation
Ground-Based Observatories
Authors: Zhou, Bei; Reali, Luca; Berti, Emanuele; Çalışkan, Mesut;
Creque-Sarbinowski, Cyril; Kamionkowski, Marc; Sathyaprakash, B. S.
Bibcode: 2022arXiv220901310Z
Altcode:
Stochastic gravitational-wave backgrounds (SGWBs) derive from the
superposition of numerous individually unresolved gravitational-wave
(GW) signals. Detecting SGWBs provides us with invaluable information
about astrophysics, cosmology, and fundamental physics. In this paper,
we study SGWBs from binary black-hole (BBH) and binary neutron-star
(BNS) coalescences in a network of next-generation ground-based GW
observatories (Cosmic Explorer and Einstein Telescope) and determine
how well they can be measured; this then limits how well we can
observe other subdominant astrophysical and cosmological SGWBs. We
simulate all-Universe populations of BBHs and BNSs and calculate
the corresponding SGWBs, which consist of a superposition of (i)
undetected signals, and (ii) the residual background from imperfect
removal of resolved sources. The sum of the two components sets the
sensitivity for observing other SGWBs. Our results show that, even
with next-generation observatories, the residual background is large
and limits the sensitivity to other SGWBs. The main contributions
to the residual background arise from uncertainties in inferring
the coalescence phase and luminosity distance of the detected
signals. Alternative approaches to signal subtraction would need to
be explored to minimize the BBH and BNS foreground in order to observe
SGWBs from other subdominant astrophysical and cosmological sources.
Title: How to delay death and look further into the future if you
fall into a black hole
Authors: Toporensky, A. V.; Popov, S. B.
Bibcode: 2022arXiv220904823T
Altcode:
In this note, we present a pedagogical illustration of peculiar
properties of motion in the vicinity and inside black holes. We discuss
how a momentary impulse can modify the lifetime of an object radially
falling into a Schwarzschild black hole down to singularity. The well
known upper limit for a proper time spent within a horizon, in fact,
requires an infinitely powerful kick. We calculate the proper time
interval (perceived as personal lifetime of a falling observer) till
the contact with the singularity, as well as the time interval in
the Lema\^itre frame (which reflects how far into the future of the
outer world a falling observer can look), for different values of the
kick received by the falling body. We discuss the ideal strategy to
increase both time intervals by the engine with a finite power. This
example is suitable for university seminars for undergraduate students
specializing in General Relativity and related astrophysical subjects.
Title: The Great Flare of 2021 November 19 on AD Leo. Simultaneous
XMM-Newton and TESS observations
Authors: Stelzer, B.; Caramazza, M.; Raetz, St.; Argiroffi, C.;
Coffaro, M.
Bibcode: 2022arXiv220905068S
Altcode:
We present a detailed analysis of a superflare on the active M dwarf
star AD Leonis. The event presents a rare case of a stellar flare
observed simultaneously in X-rays (with XMM-Newton) and in optical (with
the Transiting Exoplanet Survey Satellite, TESS). The radiated energy
both in the 0.2-12 keV X-ray band ($1.26 \pm 0.01 \cdot 10^{33}$ erg)
and the bolometric value ($E_{F,bol} = 5.57 \pm 0.03 \cdot 10^{33}$ erg)
put this event at the lower end of the superflare class. The exceptional
photon statistics deriving from the proximity of AD Leo has enabled
measurements in the 1-8 AA GOES band for the peak flux (X1445 class)
and integrated energy ($E_{F,GOES} = 4.30 \pm 0.05 \cdot 10^{32}$
erg), making possible a direct comparison with data on flares from
our Sun. From extrapolations of empirical relations for solar flares
we estimate that a proton flux of at least $10^5\,{cm^{-2} s^{-1}
sr^{-1}}$ accompanied the radiative output. With a time lag of 300s
between the peak of the TESS white-light flare and the GOES band flare
peak as well as a clear Neupert effect this event follows very closely
the standard (solar) flare scenario. Time-resolved spectroscopy during
the X-ray flare reveals, in addition to the time evolution of plasma
temperature and emission measure, a temporary increase of electron
density and elemental abundances, and a loop that extends in the
corona by 13% of the stellar radius ($4 \cdot 10^9$ cm). Independent
estimates of the footprint area of the flare from TESS and XMM-Newton
data suggest a high temperature of the optical flare (25000 K), but we
consider more likely that the optical and X-ray flare areas represent
physically distinct regions in the atmosphere of AD Leo.
Title: Extended radio halo of the supernova remnant CTB87 (G74.9+1.2)
Authors: Reich, Wolfgang; Reich, Patricia; Kothes, Roland
Bibcode: 2022arXiv220901618R
Altcode:
Breaks in the radio spectra of supernova remnants (SNRs) reflect
the maximum energy of either shock-accelerated electrons or - in the
case of pulsar wind nebulae - of electrons injected by the central
pulsar. Otherwise, the break may result from energy losses due to
synchrotron aging or it is caused by energy-dependent diffusion. A
spectral steepening of the plerionic SNR CTB87 at around 11 GHz was
observed in the eighties, but a recent analysis of CTB87's energetic
properties based on new radio data raised doubt on it. CTB87 consists
of a central compact component surrounded by a diffuse centrally peaked
almost circular halo. Missing faint halo emission due to insufficient
sensitivity of early high-frequency observations may be be the reason
for the reported spectral break. We intend to clarify the high-frequency
spectrum of CTB87 by new sensitive observations. We used the broad-band
2-cm receiver at the Effelsberg 100-m telescope for sensitive continuum
observations of CTB87 and its halo in two frequency bands. The new 2-cm
maps of CTB87 show halo emission with a diameter of about 17' or 30 pc
for a distance of 6.1 kpc in agreement with lower-frequency data. The
measured flux densities are significantly higher than those reported
earlier. The new 2-cm data establish the high-frequency continuation of
CTB87's low-frequency spectrum. Any significant high-frequency spectral
bend or break is constrained to frequencies well above about 18 GHz. The
extended halo of CTB87 has a faint counterpart in gamma-rays (VER
J2016+37) and thus indicates a common origin of the emitting electrons.
Title: MOA-2020-BLG-135Lb: A New Neptune-class Planet for the Extended
MOA-II Exoplanet Microlens Statistical Analysis
Authors: Ishitani Silva, Stela; Ranc, Clément; Bennett, David
P.; Bond, Ian A.; Zang, Weicheng; Abe, Fumio; Barry, Richard K.;
Bhattacharya, Aparna; Fujii, Hirosane; Fukui, Akihiko; Hirao, Yuki;
Itow, Yoshitaka; Kirikawa, Rintaro; Kondo, Iona; Koshimoto, Naoki;
Matsubara, Yutaka; Matsumoto, Sho; Miyazaki, Shota; Muraki, Yasushi;
Olmschenk, Greg; Okamura, Arisa; Rattenbury, Nicholas J.; Satoh, Yuki;
Sumi, Takahiro; Suzuki, Daisuke; Toda, Taiga; Tristram, Paul. J.;
Vandorou, Aikaterini; Yama, Hibiki; Petric, Andreea; Burdullis,
Todd; Fouqué, Pascal; Mao, Shude; Penny, Matthew T.; Zhu, Wei;
CFHT Microlensing Collaboration; Rau, Gioia
Bibcode: 2022AJ....164..118I
Altcode: 2022arXiv220403672I
We report the light-curve analysis for the event MOA-2020-BLG-135,
which leads to the discovery of a new Neptune-class
planet, MOA-2020-BLG-135Lb. With a derived mass ratio of
$q={1.52}_{-0.31}^{+0.39}\times {10}^{-4}$ and separation s ≍ 1,
the planet lies exactly at the break and likely peak of the exoplanet
mass-ratio function derived by the Microlensing Observations in
Astrophysics (MOA) Collaboration. We estimate the properties of
the lens system based on a Galactic model and considering two
different Bayesian priors: one assuming that all stars have an
equal planet-hosting probability and the other that planets are more
likely to orbit more-massive stars. With a uniform host mass prior,
we predict that the lens system is likely to be a planet of mass
${m}_{\mathrm{planet}}={11.3}_{-6.9}^{+19.2}{M}_{\oplus }$ and a host
star of mass ${M}_{\mathrm{host}}={0.23}_{-0.14}^{+0.39}{M}_{\odot }$
, located at a distance ${D}_{L}={7.9}_{-1.0}^{+1.0}\ \mathrm{kpc}$
. With a prior that holds that planet occurrence scales in
proportion to the host-star mass, the estimated lens system
properties are ${m}_{\mathrm{planet}}={25}_{-15}^{+22}{M}_{\oplus
}$ , ${M}_{\mathrm{host}}={0.53}_{-0.32}^{+0.42}{M}_{\odot }$ , and
${D}_{L}={8.3}_{-1.0}^{+0.9}\ \mathrm{kpc}$ . This planet qualifies
for inclusion in the extended MOA-II exoplanet microlens sample.
Title: Flares and rotation of M dwarfs with habitable zones accessible
to TESS planet detections
Authors: Stelzer, B.; Bogner, M.; Magaudda, E.; Raetz, St.
Bibcode: 2022A&A...665A..30S
Altcode: 2022arXiv220703794S
Context. More than 4000 exoplanets have been discovered to date,
providing the search for a place capable of hosting life with a large
number of targets. With the Transiting Exoplanet Survey Satellite
(TESS) having completed its primary mission in July 2020, the number of
planets confirmed by follow-up observations is growing further. Crucial
for planetary habitability is not only a suitable distance of the
planet to its host star, but also the star's properties. Stellar
magnetic activity, and especially flare events, expose planets to
a high photon flux and potentially erode their atmospheres. Here
especially the poorly constrained high-energy UV and X-ray domain
is relevant.
Aims: We characterize the magnetic activity of M
dwarfs to provide the planet community with information on the energy
input from the star; in particular, in addition to the frequency of
optical flares directly observed with TESS, we aim at estimating the
corresponding X-ray flare frequencies, making use of the small pool
of known events observed simultaneously in both wavebands.
Methods: We identified 112 M dwarfs with a TESS magnitude ≤11.5 for
which TESS can probe the full habitable zone for transits. These 112
stars have 1276 two-minute cadence TESS LCs from the primary mission,
which we searched for rotational modulation and flares. We study the
link between rotation and flares and between flare properties, for
example the flare amplitude-duration relation and cumulative flare
energy frequency distributions (FFDs). Assuming that each optical
flare is associated with a flare in the X-ray band, and making use
of published simultaneous Kepler/K2 and XMM-Newton flare studies,
we estimate the X-ray energy released by our detected TESS flare
events. Our calibration also involves the relation between flare
energies in the TESS and K2 bands.
Results: We detected more than
2500 optical flare events on a fraction of about 32% of our targets
and found reliable rotation periods only for 12 stars, which is a
fraction of about 11%. For these 12 targets, we present cumulative
FFDs and FFD power law fits. We construct FFDs in the X-ray band by
calibrating optical flare energies to the X-rays. In the absence of
directly observed X-ray FFDs for main-sequence stars, our predictions
can serve for estimates of the high-energy input to the planet of a
typical fast-rotating early- or mid-M dwarf. Full Tables 2, A.1,
A.2 and A.3 are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr
(ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/665/A30
Title: A Magnetogram-matching Method for Energizing Magnetic Flux
Ropes Toward Eruption
Authors: Titov, V. S.; Downs, C.; Török, T.; Linker, J. A.
Bibcode: 2022ApJ...936..121T
Altcode: 2022arXiv220503982T
We propose a new "helicity-pumping" method for energizing coronal
equilibria that contain a magnetic flux rope (MFR) toward an
eruption. We achieve this in a sequence of magnetohydrodynamics
relaxations of small line-tied pulses of magnetic helicity, each of
which is simulated by a suitable rescaling of the current-carrying
part of the field. The whole procedure is "magnetogram-matching"
because it involves no changes to the normal component of the field
at the photospheric boundary. The method is illustrated by applying
it to an observed force-free configuration whose MFR is modeled
with our regularized Biot-Savart law method. We find that, in spite
of the bipolar character of the external field, the MFR eruption is
sustained by two reconnection processes. The first, which we refer to
as breakthrough reconnection, is analogous to breakout reconnection
in quadrupolar configurations. It occurs at a quasi-separator inside a
current layer that wraps around the erupting MFR and is caused by the
photospheric line-tying effect. The second process is the classical
flare reconnection, which develops at the second quasi-separator inside
a vertical current layer that is formed below the erupting MFR. Both
reconnection processes work in tandem with the magnetic forces of the
unstable MFR to propel it through the overlying ambient field, and their
interplay may also be relevant for the thermal processes occurring in
the plasma of solar flares. The considered example suggests that our
method will be beneficial for both the modeling of observed eruptive
events and theoretical studies of eruptions in idealized magnetic
configurations.
Title: TIC 5724661: A Long-period Binary with a Pulsating sdB Star
and δ Scuti Variable
Authors: Jayaraman, Rahul; Rappaport, Saul A.; Nelson, Lorne; Kurtz,
Donald W.; Dufresne, George; Handler, Gerald; Senhadji, Abdel; Latham,
David W.; Zhou, George; Bieryla, Allyson; Ricker, George R.
Bibcode: 2022ApJ...936..123J
Altcode: 2021arXiv211112098J
Using TESS 20 s cadence data, we have discovered an unusual combination
of pulsating stars in what we infer to be a binary system. The binary
consists of a standard δ Scuti star with pulsations over the range
32-41 day-1; this is in a likely wide orbit with a hot
subdwarf-B (sdB) star, which itself has a large-amplitude p-mode
pulsation at 524 day-1. We establish constraints on the
period of the putative binary by using radial velocity measurements of
the δ Scuti star and show that any sdB companion star must orbit with
a period greater than approximately thirty days. Our identification
of this sdB binary serves as an important addition to the relatively
small number of sdB binaries known to have orbital periods longer
than a few days. We model such a binary using MESA and find that this
system could be formed through stable, nonconservative mass transfer
from either a low-mass or an intermediate-mass progenitor, without
undergoing a common-envelope phase.
Title: The covariance of squeezed bispectrum configurations
Authors: Biagetti, Matteo; Castiblanco, Lina; Noreña, Jorge;
Sefusatti, Emiliano
Bibcode: 2022JCAP...09..009B
Altcode: 2021arXiv211105887B
We measure the halo bispectrum covariance in a large set of N-body
simulations and compare it with theoretical expectations. We find
a large correlation among (even mildly) squeezed halo bispectrum
configurations. A similarly large correlation can be found between
squeezed triangles and the long-wavelength halo power spectrum. This
shows that the diagonal Gaussian contribution fails to describe,
even approximately, the full covariance in these cases. We compare
our numerical estimate with a model that includes, in addition to the
Gaussian one, only the non-Gaussian terms that are large for squeezed
configurations. We find that accounting for these large terms in the
modeling greatly improves the agreement of the full covariance with
simulations. We apply these results to a simple Fisher matrix forecast,
and find that constraints on primordial non-Gaussianity are degraded
by a factor of ~ 2 when a non-Gaussian covariance is assumed instead
of the diagonal, Gaussian approximation.
Title: A measurement of small-scale features using ionospheric
scintillation. Comparison with refractive shift measurements
Authors: Waszewski, A.; Morgan, J.; Jordan, C. H.
Bibcode: 2022PASA...39...36W
Altcode: 2022arXiv220713252W
We present a study of scintillation induced by the mid-latitude
ionosphere. By implementing methods currently used in Interplanetary
Scintillation studies to measure amplitude scintillation at low
frequencies, we have proven it is possible to use the Murchison
Widefield Array to study ionospheric scintillation in the weak regime,
which is sensitive to structures on scales ${∼}300$ m at our observing
frequency of 154 MHz, where the phase variance on this scale was $0.06
\textrm{rad}2$ in the most extreme case observed. Analysing
over 1000 individual 2-min observations, we compared the ionospheric
phase variance with that inferred with previous measurements of
refractive shifts, which are most sensitive to scales almost an order
of magnitude larger. The two measurements were found to be highly
correlated (Pearson correlation coefficient 0.71). We observed that for
an active ionosphere, the relationship between these two metrics is
in line with what would be expected if the ionosphere's structure is
described by Kolmogorov turbulence between the relevant scales of 300
and 2000 m. In the most extreme ionospheric conditions, the refractive
shifts were sometimes found to underestimate the small-scale variance
by a factor of four or more, and it is these ionospheric conditions
that could have significant effects on radio astronomy observations.
Title: Characterization of the MASCOT landing area by Hayabusa2
Authors: Schröder, Stefan; Sakatani, Naoya; Honda, Rie; Tatsumi, Eri;
Yokota, Yasuhiro; Domingue, Deborah; Cho, Yuichiro; Kameda, Shingo;
Kitazato, Kohei; Kouyama, Toru; Matsuoka, Moe; Miura, Akira; Morota,
Tomokatsu; Okada, Tatsuaki; Sawada, Hirotaka; Senshu, Hiroki; Shimaki,
Yuri; Sugita, Seiji; Tanaka, Satoshi; Yabuta, Hikaru; Yamada, Manabu;
Grott, Matthias; Hamm, Maximilian; Ho, Tra-Mi; Jaumann, Ralf; Mottola,
Stefano; Otto, Katharina; Schmitz, Nicole; Scholten, Frank
Bibcode: 2022arXiv220900856S
Altcode:
Context. After landing on C-type asteroid Ryugu, MASCOT imaged brightly
colored, submillimeter-sized inclusions in a small rock. Hayabusa2
successfully returned a sample of small particles from the surface of
Ryugu, but none of these appear to harbor such inclusions. The samples
are considered representative of Ryugu. Aims. To understand the apparent
discrepancy between MASCOT observations and Ryugu samples, we assess
whether the MASCOT landing site, and the rock by implication, is perhaps
atypical for Ryugu. Methods. We analyzed observations of the MASCOT
landing area acquired by three instruments on board Hayabusa2: a camera
(ONC), a near-infrared spectrometer (NIRS3), and a thermal infrared
imager (TIR). We compared the landing area properties thus retrieved
with those of the average Ryugu surface. Results. We selected several
areas and landforms in the landing area for analysis: a small crater,
a collection of smooth rocks, and the landing site itself. The crater
is relatively blue and the rocks are relatively red. The spectral
and thermophysical properties of the landing site are very close to
those of the average Ryugu surface. The spectral properties of the
MASCOT rock are probably close to average, but its thermal inertia
may be somewhat higher. Conclusions. The MASCOT rock can also be
considered representative of Ryugu. Some of the submillimeter-sized
particles in the returned samples stand out because of their atypical
spectral properties. Such particles may be present as inclusions in
the MASCOT rock.
Title: Tracing the contraction of the pre-stellar core L1544 with
HC$^{17}$O$^+$ $J$ = 1-0 emission
Authors: Ferrer Asensio, J.; Spezzano, S.; Caselli, P.; Alves, F. O.;
Sipilä, O.; Redaelli, E.; Bizzocchi, L.; Lique, F.; Mullins, A.
Bibcode: 2022arXiv220902489F
Altcode:
Spectral line profiles of several molecules observed towards
the pre-stellar core L1544 appear double-peaked. For abundant
molecular species this line morphology has been linked to
self-absorption. However, the physical process behind the double-peaked
morphology for less abundant species is still under debate. In
order to understand the cause behind the double-peaked spectra of
optically thin transitions and their link to the physical structure
of pre-stellar cores, we present high-sensitivity and high-spectral
resolution HC$^{17}$O$^+$ $J =$1-0 observations towards the dust peak in
L1544. We observed the HC$^{17}$O$^+$ (1-0) spectrum with the Institut
de Radioastronomie Millimétrique (IRAM) 30m telescope. By using new
state-of-the-art collisional rate coefficients, a physical model for
the core and the fractional abundance profile of HC$^{17}$O$^+$, the
hyperfine structure of this molecular ion is modelled for the first
time with the radiative transfer code LOC applied to the predicted
chemical structure of a contracting pre-stellar core. We applied
the same analysis to the chemically related C$^{17}$O molecule. The
observed HC$^{17}$O$^+$(1-0) and C$^{17}$O(1-0) lines have been
successfully reproduced with a non-local thermal equilibrium (LTE)
radiative transfer model applied to chemical model predictions for a
contracting pre-stellar core. An upscaled velocity profile (by 30%)
is needed to reproduce the HC$^{17}$O$^+$(1-0) observations. The double
peaks observed in the HC$^{17}$O$^+$(1-0) hyperfine components are due
to the contraction motions at densities close to the critical density
of the transition ($\sim$10$^{5}$ cm$^{-3}$) and to the fact that the
HCO$^{+}$ fractional abundance decreases toward the centre.
Title: Multiwavelength Survey of Dark Globule DC 314.8-5.1: Point
Source Identification and Diffuse Emission Characterization
Authors: Kosmaczewski, E.; Stawarz, L.; Cheung, C. C.; Bamba, A.;
Karska, A.; Rocha, W. R. M.
Bibcode: 2022arXiv220902372K
Altcode:
We present an analysis of the multi-wavelength observations of
the dark globule, DC 314.8-5.1, using the optical survey Gaia,
the near-infrared survey 2MASS, mid-infrared survey WISE along with
dedicated imaging with the Spitzer Space Telescope, and finally X-ray
data obtained with the Swift-XRT telescope. The main goal of this
analysis was to identify possible pre-main sequence stars and young
stellar objects (YSOs) associated with the globule. For this purpose,
we studied the infrared colors of all point sources coinciding within
the boundaries of the cloud, as inferred from the optical extinction
maps. After removing the sources with spectra of non-stellar types,
we investigated the Gaia parallaxes for the YSO candidates, finding
that none of them are physically related to DC 314.8-5.1. In addition,
we probed the presence of pre-main sequence stars lacking infrared
counterparts with Swift-XRT, and found no candidates down to a
luminosity level $\lesssim 10^{31}$erg cm$^{-1}$ in the 0.5-10 keV
range. Our detailed inspection of the gathered data confirm a very
young, ``pre-stellar core'' evolutionary stage of the cloud. As such,
DC 314.8-5.1 constitutes a compact reservoir of cold dust and gas,
enabling for a truly unique insight into a primordial form of the
interstellar medium. Based on the archival Planck and IRAS data, we
identify the presence of a hot dust, with temperatures reaching even up
to 200 K, in addition to the dominant dust component at 14 K. Finally,
we comment on the mass estimates for the globule.
Title: An Analytical Study of the Primordial
Gravitational-Wave-Induced Contribution to the Large-Scale Structure
of the Universe
Authors: Bari, Pritha; Bertacca, Daniele; Bartolo, Nicola; Ricciardone,
Angelo; Giardiello, Serena; Matarrese, Sabino
Bibcode: 2022arXiv220905329B
Altcode:
The imprint of gravitational waves (GWs) on large-scale structures
(LSS) is a useful and promising way to detect or to constrain
them. Tensor fossils have been largely studied in the literature as
an indirect way to detect primordial GWs. In this paper we analyze
a new effect induced by primordial GWs: a correction to the density
contrast of the underlying matter distribution of LSS, as well as its
radiation counterpart, induced by the energy density fluctuation of
the gravitational radiation. We perform our derivation of the full
analytical solution of the density contrast for waves entering the
horizon during radiation dominance. We account for two phases in the
radiation era, depending on the main contributor to the perturbed energy
density of the Universe. By comparing the density contrast of cold
dark matter and radiation-sourced by linear gravitational waves only-
we conclude that the former overcomes the latter at some time in the
radiation era, a behaviour analogous to their linear counterpart. Then
we conclude by discussing the case of density perturbations produced
by GWs entering the Hubble radius during the matter era as well as
their evolution in the late dark-energy dominated phase.
Title: Resilience of small PAHs in interstellar clouds: Efficient
stabilization of cyanonaphthalene by fast radiative cooling
Authors: Stockett, Mark H.; Bull, James N.; Cederquist, Henrik;
Indrajith, Suvasthika; Ji, MingChao; Navarro Navarrete, José E.;
Schmidt, Henning T.; Zettergren, Henning; Zhu, Boxing
Bibcode: 2022arXiv220905229S
Altcode:
After decades of speculation and searching, astronomers have
recently identified specific Polycyclic Aromatic Hydrocarbons (PAHs)
in space. Remarkably, the observed abundance of cyanonaphthalene
(CNN, C10H7CN) in the Taurus Molecular Cloud (TMC-1) is six orders of
magnitude higher than expected from astrophysical modeling. Here, we
report absolute unimolecular dissociation and radiative cooling rate
coefficients of the 1-CNN isomer in its cationic form. These results
are based on measurements of the time-dependent neutral product emission
rate and Kinetic Energy Release distributions produced from an ensemble
of internally excited 1-CNN + studied in an environment similar to
that in interstellar clouds. We find that Recurrent Fluorescence -
radiative relaxation via thermally populated electronic excited states
- efficiently stabilizes 1-CNN+ , owing to a large enhancement of the
electronic transition probability by vibronic coupling. Our results
help explain the anomalous abundance of CNN in TMC-1 and challenge
the widely accepted picture of rapid destruction of small PAHs in space.
Title: The locations of features in the mass distribution of
merging binary black holes are robust against uncertainties in the
metallicity-dependent cosmic star formation history
Authors: van Son, L. A. C.; de Mink, S. E.; Chruslinska, M.; Conroy,
C.; Pakmor, R.; Hernquist, L.
Bibcode: 2022arXiv220903385V
Altcode:
New observational facilities are probing astrophysical transients such
as stellar explosions and gravitational wave (GW) sources at ever
increasing redshifts, while also revealing new features in source
property distributions. To interpret these observations, we need
to compare them to predictions from stellar population models. Such
models require the metallicity-dependent cosmic star formation history
($\mathcal{S}(Z,z)$) as an input. Large uncertainties remain in
the shape and evolution of this function. In this work, we propose
a simple analytical function for $\mathcal{S}(Z,z)$. Variations of
this function can be easily interpreted, because the parameters link
to its shape in an intuitive way. We fit our analytical function to
the star-forming gas of the cosmological TNG100 simulation and find
that it is able to capture the main behaviour well. As an example
application, we investigate the effect of systematic variations in
the $\mathcal{S}(Z,z)$ parameters on the predicted mass distribution
of locally merging binary black holes (BBH). Our main findings are: I)
the locations of features are remarkably robust against variations in
the metallicity-dependent cosmic star formation history, and II) the
low mass end is least affected by these variations. This is promising
as it increases our chances to constrain the physics that governs the
formation of these objects.
Title: A measurement of circumgalactic gas around nearby galaxies
using fast radio bursts
Authors: Wu, Xiaohan; McQuinn, Matthew
Bibcode: 2022arXiv220904455W
Altcode:
The distribution of gas in the circumgalactic medium (CGM) of galaxies
of all types is poorly constrained. Foreground CGMs contribute an extra
amount to the dispersion measure (DM) of fast radio bursts (FRB). We
measure this DM excess for the CGMs of $10^{11}-10^{13}\ M_\odot$
halos using the CHIME/FRB first data release, a halo mass range that
is challenging to probe in any other way. Because of the uncertainty
in the FRBs' angular coordinates, only for nearby galaxies is the
localization sufficient to confidently associate them with intersecting
any foreground halo. Thus we stack on galaxies within 80 Mpc, optimizing
the stacking scheme to approximately minimize the stack's variance and
marginalize over uncertainties in FRB locations. The sample has 20-30
FRBs intersecting halos with masses of $10^{11}-10^{12}\ M_\odot$
and also of $10^{12}-10^{13}\ M_\odot$, and these intersections
allow a marginal $1-2\,\sigma$ detection of the DM excess in both
mass bins. The $10^{11}-10^{12}\ M_\odot$ halos bin also shows a DM
excess at 1-2 virial radii. By comparing data with different models
for the CGM gas profile, we find that all models are favored by the
data up to 2-$\sigma$ level compared to the null hypothesis of no DM
excess. With 2000-3000 more bursts from a future CHIME data release,
we project a 4-$\sigma$ detection of the CGM. Distinguishing between
viable CGM models by stacking FRBs with CHIME-like localization would
require tens of thousands of bursts.
Title: Absolute dimensions and apsidal motion of the eclipsing
binaries V889 Aquilae and V402 Lacertae
Authors: Baroch, D.; Giménez, A.; Morales, J. C.; Ribas, I.; Herrero,
E.; Perdelwitz, V.; Jordi, C.; Granzer, T.; Allende Prieto, C.
Bibcode: 2022A&A...665A..13B
Altcode: 2022arXiv220613121B
Context. Double-lined eclipsing binaries allow the direct determination
of masses and radii, which are key for testing stellar models. With
the launch of the TESS mission, many well-known eclipsing binaries
have been observed at higher photometric precision, permitting the
improvement of the absolute dimension determinations.
Aims:
Using TESS data and newly obtained spectroscopic observations, we aim
to determine the masses and radii of the eccentric eclipsing binary
systems V889 Aql and V402 Lac, together with their apsidal motion
parameters.
Methods: We simultaneously modelled radial velocity
curves and times of eclipse for each target to precisely determine
the orbital parameters of the systems, which we used to analyse the
light curves and then obtain their absolute dimensions. We compared
the obtained values with those predicted by theoretical models.
Results: We determined masses and radii of the components of
both systems with relative uncertainties lower than 2%. V889 Aql is
composed of two stars with masses 2.17 ± 0.02 M⊙ and
2.13 ± 0.01 M⊙ and radii 1.87 ± 0.04 R⊙
and 1.85 ± 0.04 R⊙. We find conclusive evidence of
the presence of a third body orbiting V889 Aql with a period of 67
yr. Based on the detected third light and the absence of signal in
the spectra, we suggest that this third body could in turn be a binary
composed of two ∼1.4 M⊙ stars. V402 Lac is composed of
two stars with masses 2.80 ± 0.05 M⊙ and 2.78 ± 0.05
M⊙ and radii 2.38 ± 0.03 R⊙ and 2.36 ±
0.03 R⊙. The times of minimum light are compatible with
the presence of a third body for this system too, although its period
is not yet fully sampled. In both cases we have found a good agreement
between the observed apsidal motion rates and the model predictions.
Title: Ultra-sensitive THz microwave kinetic inductance detectors
for future space telescopes
Authors: Baselmans, J. J. A.; Facchin, F.; Pascual Laguna, A.; Bueno,
J.; Thoen, D. J.; Murugesan, V.; Llombart, N.; de Visser, P. J.
Bibcode: 2022A&A...665A..17B
Altcode: 2022arXiv220708647B
Aims: Future actively cooled space-borne observatories for the
far-infrared, loosely defined as a 1-10 THz band, can potentially
reach a sensitivity limited only by background radiation from the
Universe. This will result in an increase in observing speed of many
orders of magnitude. A spectroscopic instrument on such an observatory
requires large arrays of detectors with a sensitivity expressed as a
noise equivalent power NEP = 3 × 10−20 W/√Hz.
Methods: We present the design, fabrication, and characterisation of
microwave kinetic inductance detectors (MKIDs) for this frequency range
reaching the required sensitivity. The devices are based on thin-film
NbTiN resonators which use lens-antenna coupling to a submicron-width
aluminium transmission line at the shorted end of the resonator
where the radiation is absorbed. We optimised the MKID geometry for
a low NEP by using a small aluminium volume of ≈1 µm3
and fabricating the aluminium section on a very thin (100 nm) SiN
membrane. Both methods of optimisation also reduce the effect of excess
noise by increasing the responsivity of the device, which is further
increased by reducing the parasitic geometrical inductance of the
resonator.
Results: We measure the sensitivity of eight MKIDs
with respect to the power absorbed in the detector using a thermal
calibration source filtered in a narrow band around 1.5 THz. We obtain
a NEPexp(Pabs) = 3.1 ± 0.9 × 10−20
W/√Hz at a modulation frequency of 200 Hz averaged over all measured
MKIDs. The NEP is limited by quasiparticle trapping.
Conclusions:
The measured sensitivity is sufficient for spectroscopic observations
from future, actively cooled space-based observatories. Moreover, the
presented device design and assembly can be adapted for frequencies
up to ≈10 THz and can be readily implemented in kilopixel arrays.
Title: Binary black hole mergers from young massive clusters in the
pair-instability supernova mass gap
Authors: Banerjee, Sambaran
Bibcode: 2022A&A...665A..20B
Altcode: 2021arXiv210914612B
Context. The recent discovery of the binary black hole (BBH)
merger event GW190521, between two black holes (BHs) of ≈100
Msamp, in addition to other massive BBH merger events
involving BHs within the pair-instability supernova (PSN) mass
gap have sparked widespread debate on the origin of such extreme
gravitational-wave (GW) events. GW190521 simultaneously triggers two
critical questions: how BHs can appear within the `forbidden' PSN gap
and, if they do, how they get to participate in general-relativistic
(GR) mergers.
Aims: In this study, I investigate whether
dynamical interactions in young massive clusters (YMCs) serve as a
viable scenario for assembling PSN-gap BBH mergers.
Methods:
To that end, I explore a grid of 40 new evolutionary models of a
representative YMC of initial mass and size Mcl = 7.5
× 104 Msamp (N ≈ 1.28 × 105)
and rh = 2 pc, respectively. The model grid ranges
over metallicity 0.0002 ≤ Z ≤ 0.02 and comprises initial
cluster configurations of King central concentration parameters
W0 = 7 and 9. In each model, all BH progenitor stars
are initially in primordial binaries following observationally
motivated distributions. All cluster models are evolved with the
direct, relativistic N-body code NBODY7, incorporating up-to-date
remnant formation, BH natal spin, and GR merger recoil schemes.
Results: Binary black hole mergers from these model cluster
computations agree well with the masses and effective spin parameters,
χeff, of the events from the latest gravitational-wave
transient catalogue (GWTC). In particular, GW190521-like, that is to
say ≈200 Msamp, low χeff events are produced
via a dynamical merger among BHs derived from star-star merger
products. GW190403_051519-like, that is PSN-gap, highly asymmetric,
high χeff events result from mergers involving BHs that are
spun up via matter accretion or a binary interaction. The resulting
present-day, differential intrinsic merger rate density, within the
PSN gap, accommodates that from GWTC well.
Conclusions: This
study demonstrates that, subject to model uncertainties, the tandem
of massive binary evolution and dynamical interactions in ≲100
Myr-old, low metallicity YMCs in the Universe can plausibly produce GR
mergers involving PSN-gap BHs and in rates consistent with that from
up-to-date GW observations. Such clusters can produce extreme events
similar to GW190521 and GW190403_051519. The upper limit of the models'
GW190521-type event rate is within the corresponding LIGO-Virgo-KAGRA
(LVK)-estimated rate limits, although the typical model rate lies below
LVK's lower limit. The present YMC models yield a merger rate density
of 0−3.8 × 10−2 yr−1 Gpc−3
for GW190521-type events. They produce GW190403_051519-like events
at a rate within 0−1.6 × 10−1 yr−1
Gpc−3 and their total BBH-merger yield within the PSN gap
is 0−8.4 × 10−1 yr−1 Gpc−3.
Title: Independent Evidence for Earlier Formation Epochs of Fossil
Groups of Galaxies through the Intracluster Light: The Case for
RX J100742.53+380046.6
Authors: Dupke, Renato A.; Jimenez-Teja, Yolanda; Su, Yuanyuan;
R. Carrasco, Eleazar; M. Koekemoer, Anton; M. Batalha, Rebeca; Johnson,
Lucas; Irwin, Jimmy; MIller, Eric; Dimauro, Paola; de Oliveira,
Nícolas O. L.; Vilchez, Jose
Bibcode: 2022ApJ...936...59D
Altcode: 2022arXiv220700603D
Fossil groups (FG) of galaxies still present a puzzle to theories
of structure formation. Despite the low number of bright galaxies,
they have relatively high velocity dispersions and ICM temperatures
often corresponding to cluster-like potential wells. Their measured
concentrations are typically high, indicating early formation epochs
as expected from the originally proposed scenario for their origin as
being older undisturbed systems. This is, however, in contradiction with
the typical lack of expected well developed cool cores. Here, we apply
a cluster dynamical indicator recently discovered in the intracluster
light fraction (ICLf) to a classic FG, RX J1000742.53+380046.6, to
assess its dynamical state. We also refine that indicator to use as
an independent age estimator. We find negative radial temperature and
metal abundance gradients, the abundance achieving supersolar values
at the hot core. The X-ray flux concentration is consistent with that
of cool core systems. The ICLf analysis provides an independent probe
of the system's dynamical state and shows that the system is very
relaxed, more than all clusters, where the same analysis has been
performed. The specific ICLf is about 6 times higher, than any of
the clusters previously analyzed, which is consistent with an older
noninteractive galaxy system that had its last merging event within
the last ~5 Gyr. The specific ICLf is predicted to be an important
new tool to identify fossil systems and to constrain the relative age
of clusters.
Title: Properties of the radius valley around low mass stars:
Predictions from the core-powered mass-loss mechanism
Authors: Gupta, Akash; Nicholson, Lorraine; Schlichting, Hilke E.
Bibcode: 2022MNRAS.tmp.2307G
Altcode: 2022arXiv220514020G
In recent years, analyzing the bimodality in the size distribution of
small planets, i.e. the 'radius valley', has given us unprecedented
insight into the planet formation process. Here we explore the
properties of the radius valley for low mass stars, assuming
that the core-powered mass-loss is the dominant process shaping
the small exoplanet population. We show that the slope of radius
valley in the planet size-orbital period space, to first-order,
does not vary with stellar mass and has a negative slope of
dlogRp/dlogP ≃ -0.11 even for stars as small as 0.1
M⊙, as observed in latest studies. Furthermore, we find
that the slope of the radius valley in the planet size-stellar mass
space is dlogRp/dlogM* ≃ (3ζ - 2)/36 where
ζ is given by the stellar mass-luminosity relation $L_\ast \propto
M_\ast ^\zeta$. Because ζ is ≳ 2 and increases with stellar mass,
we predict that the radius valley has a positive slope in the planet
size-stellar mass space across FGKM dwarfs. This slope, however,
decreases (increases) in magnitude towards lower (higher) mass
stars, due to the variation of ζ with stellar mass. While around 1.0
M⊙ stars the slope is dlogRp/dlogM*
~ 0.37, it is as low as ~0.13 around 0.1 M⊙ stars. In
addition, we find that the radius valley is narrower and less empty
around lower mass stars. Finally, we show that predictions for the
radius valley for core-powered mass-loss and photoevaporation become
increasingly distinct for lower mass stars.
Title: Jet Formation Mechanism of the Gamma-Ray-emitting Narrow-line
Seyfert 1 Galaxies
Authors: Chen, Yongyun; Gu, Qiusheng; Fan, Junhui; Yu, Xiaoling;
Xiong, Dingrong; Ding, Nan; Guo, Xiaotong; Ge, Xue
Bibcode: 2022RAA....22i5006C
Altcode:
We use a large sample of gamma-ray narrow-line Seyfert 1 galaxies
(γ-NLS1s) to study the jet formation mechanisms. We find that the
jet power of γ-NLS1s is lower than the maximum jet power of the
Blandford-Payne (BP) mechanism. At the same time, we find that there
is a significant correlation between jet power and accretion disk
luminosity. Moreover, the contribution rates of the accretion to the
jet power are larger than that of black hole mass to jet power. These
results further suggest that the jet of γ NLS1s is mainly produced
by the BP mechanism.
Title: Boosting Jittering Jets by Neutrino Heating in Core Collapse
Supernovae
Authors: Soker, Noam
Bibcode: 2022RAA....22i5007S
Altcode: 2022arXiv220205556S
I estimate the energy that neutrino heating adds to the outflow that
jets induce in the collapsing core material in core collapse supernovae
(CCSNe), and find that this energy crudely doubles the energy that
the jets deposit into the outer core. I consider the jittering jets
explosion mechanism where there are several stochastic jet-launching
episodes, each lasting for about 0.01-0.1 s. The collapsing core
material passes through the stalled shock at about 100 km and
then slowly flows onto the proto-neutron star (NS). I assume that
the proto-NS launches jittering jets, and that the jets break out
from the stalled shock. I examine the boosting process by which the
high-pressure gas inside the stalled shock, the gain region material,
expands alongside the jets and does work on the material that the jets
shock, the cocoon. This work is crudely equal to the energy that the
original jets carry. I argue that the coupling between instabilities,
stochastic rotation, magnetic fields, and jittering jets leads to
most CCSN explosions. In other cases, the pre-collapse core is rapidly
rotating and therefore ordered rotation replaces stochastic rotation
and fixed jets replace jittering jets.
Title: Chinese Sunspot Drawings and Their Digitization-(VII) Sunspot
Penumbra to Umbra Area Ratio Using the Hand-Drawing Records from
Yunnan Observatories
Authors: Hou, Jia-Wei; Zeng, Shu-Guang; Zheng, Sheng; Luo, Xiao-Yu;
Deng, Lin-Hua; Li, Yang-Yang; Chen, Yan-Qing; Lin, Gang-Hua; Feng,
Yong-Li; Tao, Jin-Ping
Bibcode: 2022RAA....22i5012H
Altcode:
The ratio of penumbral to umbra area of sunspots plays a crucial
role in the solar physics fields, especially for understanding the
origin and evolution of the solar activity cycle. By analyzing the
recently digitized sunspot drawings observed from Yunnan Observatories
(1957-2021), we investigate the long-term variation of the penumbral
to umbra area ratio of sunspots. An automatic extraction method,
based on the maximum between-class variance and the morphological
discrimination, is used to accurately extract penumbra and umbra and to
calculate the ratio over six solar cycles (cycle 19-24). The expected
value of the ratio of penumbra to umbra area is found to be 6.63 ±
0.98, and it does not exhibit any systematic variation with sunspot
latitudes and phases. The average ratio fluctuates from 5 to 7.5 per
year and the overall trend has decreased after 1999 compared to the
previous one. The ratio of sunspot penumbra to umbra area satisfies
the log-normal distribution, implying that its variation is related
to the evolution of the photospheric magnetic field. Our results are
consistent with previous works.
Title: A Catalog of Molecular Clumps and Cores with Infall Signatures
Authors: Yu, Shuling; Jiang, Zhibo; Yang, Yang; Chen, Zhiwei; Feng,
Haoran
Bibcode: 2022RAA....22i5014Y
Altcode: 2022arXiv220613908Y
The research of infall motion is a common means to study molecular
cloud dynamics and the early process of star formation. Many works
had been done in-depth research on infall. We searched the literature
related to infall study of molecular cloud since 1994, summarized the
infall sources identified by the authors. A total of 456 infall sources
are cataloged. We classify them into high-mass and low-mass sources,
in which the high-mass sources are divided into three evolutionary
stages: prestellar, protostellar and H II region. We divide the sources
into clumps and cores according to their sizes. The H2
column density values range from 1.21 × 1021 to 9.75
× 1024 cm-2, with a median value of 4.17 ×
1022 cm-2. The H2 column densities
of high-mass and low-mass sources are significantly separated. The
median value of infall velocity for high-mass clumps is 1.12 km
s-1, and the infall velocities of low-mass cores are
virtually all less than 0.5 km s-1. There is no obvious
difference between different stages of evolution. The mass infall rates
of low-mass cores are between 10-7 and 10-4 M
⊙yr-1, and those of high-mass clumps are between
10-4 and 10-1 M ⊙yr-1
with only one exception. We do not find that the mass infall rates
vary with evolutionary stages.
Title: Investigating the UV-excess in Star Clusters with N-body
Simulations: Predictions for Future CSST Observations
Authors: Pang, Xiaoying; Shu, Qi; Wang, Long; Kouwenhoven, M. B. N.
Bibcode: 2022RAA....22i5015P
Altcode: 2022arXiv220700772P
We study the origin of the UV-excess in star clusters by performing
N-body simulations of six clusters with N = 10 k and N = 100 k (single
stars & binary systems) and metallicities of Z = 0.01, 0.001 and
0.0001, using PETAR. All models initially have a 50% primordial binary
fraction. Using GalevNB we convert the simulated data into synthetic
spectra and photometry for the China Space Station Telescope (CSST) and
Hubble Space Telescope (HST). From the spectral energy distributions we
identify three stellar populations that contribute to the UV-excess:
(1) second asymptotic giant branch stars, which contribute to the UV
flux at early times; (2) naked helium stars and (3) white dwarfs,
which are long-term contributors to the FUV spectra. Binary stars
consisting of a white dwarf and a main sequence star are cataclysmic
variable (CV) candidates. The magnitude distribution of CV candidates
is bimodal up to 2 Gyr. The bright CV population is particularly bright
in FUV - NUV. The FUV - NUV color of our model clusters is 1-2 mag
redder than the UV-excess globular clusters in M87 and in the Milky
Way. This discrepancy may be induced by helium enrichment in observed
clusters. Our simulations are based on simple stellar evolution; we
do not include the effects of variations in helium and light elements
or multiple stellar populations. A positive radial color gradient is
present in CSST NUV - y for main sequence stars in all models with a
color difference of 0.2-0.5 mag, up to 4 half-mass radii. The CSST NUV -
g color correlates strongly with HST FUV - NUV for NUV - g > 1 mag,
with the linear relation FUV - NUV =(1.09 ± 0.12) × (NUV - g) + (-1.01
± 0.22). This allows for conversion of future CSST NUV - g colors into
HST FUV - NUV colors, which are sensitive to UV-excess features. We find
that CSST will be able to detect UV-excess in Galactic/extragalactic
star clusters with ages >200 Myr. *Supported by the research grants
from the China Manned Space Project with No. CMS-CSST-2021-A08.
Title: Rethinking the role of the giant planet instability in
terrestrial planet formation models
Authors: Clement, Matthew S.; Deienno, Rogerio; Izidoro, Andre
Bibcode: 2022arXiv220900706C
Altcode:
Advances in computing power and numerical methodologies over the past
several decades sparked a prolific output of dynamical investigations
of the late stages of terrestrial planet formation. Among other
peculiar inner solar system qualities, the ability of simulations to
reproduce the small mass of Mars within the planets' geochemically
inferred accretion timescale of <10 Myr after the appearance of
calcium aluminum-rich inclusions (CAIs) is arguably considered the
gold standard for judging evolutionary hypotheses. At present, a
number of independent models are capable of consistently generating
Mars-like planets and simultaneously satisfying various important
observational and geochemical constraints. However, all models must
still account for the effects of the epoch of giant planet migration
and orbital instability; an event which dynamical and cosmochemical
constraints indicate occurred within the first 100 Myr after nebular
gas dispersal. If the instability occurred in the first few Myr of
this window, the disturbance might have affected the bulk of Mars'
growth. In this manuscript, we turn our attention to a scenario where
the instability took place after t=50 Myr. Specifically, we simulate the
instability's effects on three nearly-assembled terrestrial systems that
were generated via previous embryo accretion models and contain three
large proto-planets with orbits interior to a collection of ~Mars-mass
embryos and debris. While the instability consistently triggers a
Moon-forming impact and efficiently removes excessive material from
the Mars-region in our models, we find that our final systems are
too dynamically excited and devoid of Mars and Mercury analogs. Thus,
we conclude that, while possible, our scenario is far more improbable
than one where the instability either occurred earlier, or at a time
where Earth and Venus' orbits were far less dynamically excited.
Title: A UV census of the environments of stripped-envelope supernovae
Authors: Sun, Ning-Chen; Maund, Justyn R.; Crowther, Paul A.
Bibcode: 2022arXiv220905283S
Altcode:
This paper reports an environmental analysis of 41 uniformly-selected
stripped-envelope supernovae (SESNe) based on deep ultraviolet-optical
images acquired by the Hubble Space Telescope. Young stellar
populations are detected in most SN environments and their ages are
derived with a hierarchical Bayesian approach. The age distributions are
indistinguishable between Type IIb and Type Ib while that for Type Ic is
systematically younger. This suggests that the Type Ic SN progenitors
are more massive while the Type IIb and Type Ib SNe have very similar
progenitor masses. Our result supports a hybrid envelope-stripping
mechanism, in which the hydrogen envelopes of the SESN progenitors
are stripped via a mass-insensitive process (e.g. binary interaction)
while the helium envelopes are stripped via a mass-sensitive process
(e.g. stellar wind of the post-binary interaction progenitor). We
also provide progenitor constraints for three Type Ibn SNe and two
broad-lined Type Ic SNe. All these results demonstrate the importance
of the very diverse mass-loss processes in the origins of SESNe.
Title: Axisymmetric, stationary collisionless gas configurations
surrounding black holes
Authors: Gabarrete, Carlos; Sarbach, Olivier
Bibcode: 2022arXiv220905327G
Altcode:
The properties of a stationary gas cloud surrounding a black hole
are discussed, assuming that the gas consists of collisionless,
identical massive particles that follow spatially bound geodesic
orbits in the Schwarzschild spacetime. Several models for the
one-particle distribution function are considered, and the essential
formulae that describe the relevant macroscopic observables, like the
current density four-vector and the stress-energy-momentum tensor are
derived. This is achieved by rewriting these observables as integrals
over the constants of motion and by a careful analysis of the range of
integration. In particular, we provide configurations with finite total
mass and angular momentum. Differences between these configurations
and their nonrelativistic counterparts in a Newtonian potential are
analyzed. Finally, our configurations are compared to their hydrodynamic
analogues, the "polish doughnuts".
Title: Effects of finite sizes of atomic nuclei on shear modulus
and torsional oscillations in neutron stars
Authors: Sotani, Hajime; Togashi, Hajime; Takano, Masatoshi
Bibcode: 2022arXiv220905416S
Altcode:
The shear modulus of neutron star matter is one of the important
properties for determining torsional oscillations in neutron stars. We
take into account the effects of finite sizes of spherical nuclei on
the shear modulus and examine the frequencies of crustal torsional
oscillations. The shear modulus decreases owing to the finite-size
effect, which in turn decreases the frequencies of torsional
oscillations. In particular, the finite-size effect becomes more
crucial for oscillations with a larger azimuthal quantum number and for
neutron star models with a weaker density dependence of nuclear symmetry
energy. In practice, when one identifies the quasi-periodic oscillations
from a neutron star, where the magnetic effect is negligible, with
crustal torsional oscillations, the finite-size effect can be more
significant at frequencies higher than $\sim 100$ Hz.
Title: Broadband study and the discovery of pulsations from the
Be/X-ray binary eRASSU J052914.9-662446 in the Large Magellanic Cloud
Authors: Maitra, C.; Kaltenbrunner, D.; Haberl, F.; Buckley, D. A. H.;
Monageng, I. M.; Udalski, A.; Carpano, S.; Coley, J. B.; Doroshenko,
V.; Ducci, L.; Malacaria, C.; König, O.; Santangelo, A.; Vasilopoulos,
G.; Wilms, J.
Bibcode: 2022arXiv220901664M
Altcode:
Context. The Magellanic Clouds are our nearest star-forming
galaxies. While the population of high-mass X-ray binaries (HMXBs)
in the Small Magellanic Cloud (SMC) is relatively well studied,
our knowledge about the Large Magellanic Cloud (LMC) is far from
complete given its large angular extent and insufficient coverage with
X-ray observations. Aims. We conducted a search for new HMXBs in the
LMC using data from eROSITA, the soft X-ray instrument on board the
Spektrum-Roentgen-Gamma (SRG) satellite. Methods. After confirming the
nature of eRASSU J052914.9-662446 as a hard X-ray source positionally
coincident with an early type star, we followed it up with optical
spectroscopic observations from South African Large Telescope (SALT)
and a dedicated NuSTAR observation. Results. We study the broadband
timing and spectral behaviour of the newly discovered HMXB eRASSU
J052914.9-662446 through eROSITA, Swift and NuSTAR data in X-rays and
the Optical Gravitational Lensing Experiment (OGLE) and SALT RSS data at
optical wavelength. We report on detection of the spin period at 1412 s
and suggest an orbital period of the system of ~151 days, and thereby
establish eRASSU J052914.9-662446 as an accreting pulsar. Further,
through optical spectroscopic observations and the existence of H
alpha emission the source is identified as a Be X-ray binary pulsar
in the LMC. We also investigate the variability of the source in the
optical and X-ray regime over the last decades and provide estimates
on the possible magnetic field strength of the neutron star.
Title: BeyondPlanck IV. On end-to-end simulations in CMB analysis --
Bayesian versus frequentist statistics
Authors: Brilenkov, M.; Fornazier, K. S. F.; Hergt, L. T.; Hoerning,
G. A.; Marins, A.; Murokoshi, T.; Rahman, F.; Stutzer, N. -O.;
Zhou, Y.; Abdalla, F. B.; Andersen, K. J.; Aurlien, R.; Banerji, R.;
Basyrov, A.; Battista, A.; Bersanelli, M.; Bertocco, S.; Bollanos,
S.; Colombo, L. P. L.; Eriksen, H. K.; Eskilt, J. R.; Foss, M. K.;
Franceschet, C.; Fuskeland, U.; Galeotta, S.; Galloway, M.; Gerakakis,
S.; Gjerlow, E.; Hensley, B.; Herman, D.; Hoang, T. D.; Ieronymaki,
M.; Ihle, H. T.; Jewell, J. B.; Karakci, A.; Keihanen, E.; Keskitalo,
R.; Maggio, G.; Maino, D.; Maris, M.; Paradiso, S.; Partridge, B.;
Reinecke, M.; Suur-Uski, A. -S.; Svalheim, T. L.; Tavagnacco, D.;
Thommesen, H.; Tomasi, M.; Watts, D. J.; Wehus, I. K.; Zacchei, A.
Bibcode: 2022arXiv220904437B
Altcode:
End-to-end simulations play a key role in the analysis of any
high-sensitivity CMB experiment, providing high-fidelity systematic
error propagation capabilities unmatched by any other means. In this
paper, we address an important issue regarding such simulations,
namely how to define the inputs in terms of sky model and instrument
parameters. These may either be taken as a constrained realization
derived from the data, or as a random realization independent from
the data. We refer to these as Bayesian and frequentist simulations,
respectively. We show that the two options lead to significantly
different correlation structures, as frequentist simulations, contrary
to Bayesian simulations, effectively include cosmic variance,
but exclude realization-specific correlations from non-linear
degeneracies. Consequently, they quantify fundamentally different
types of uncertainties, and we argue that they therefore also have
different and complementary scientific uses, even if this dichotomy is
not absolute. Before BeyondPlanck, most pipelines have used a mix of
constrained and random inputs, and used the same hybrid simulations for
all applications, even though the statistical justification for this
is not always evident. BeyondPlanck represents the first end-to-end
CMB simulation framework that is able to generate both types of
simulations, and these new capabilities have brought this topic to
the forefront. The Bayesian BeyondPlanck simulations and their uses
are described extensively in a suite of companion papers. In this
paper we consider one important applications of the corresponding
frequentist simulations, namely code validation. That is, we generate
a set of 1-year LFI 30 GHz frequentist simulations with known inputs,
and use these to validate the core low-level BeyondPlanck algorithms;
gain estimation, correlated noise estimation, and mapmaking.
Title: Investigation of a Machine learning methodology for the SKA
pulsar search pipeline
Authors: Bhat, Shashank Sanjay; Thiagaraj, Prabu; Stappers, Ben;
Ghalame, Atul; Saha, Snehanshu; Sudarshan, T. S. B; Hosenie, Zaffirah
Bibcode: 2022arXiv220904430B
Altcode:
The SKA pulsar search pipeline will be used for real time
detection of pulsars. Modern radio telescopes such as SKA will be
generating petabytes of data in their full scale of operation. Hence
experience-based and data-driven algorithms become indispensable for
applications such as candidate detection. Here we describe our findings
from testing a state of the art object detection algorithm called
Mask R-CNN to detect candidate signatures in the SKA pulsar search
pipeline. We have trained the Mask R-CNN model to detect candidate
images. A custom annotation tool was developed to mark the regions
of interest in large datasets efficiently. We have successfully
demonstrated this algorithm by detecting candidate signatures on a
simulation dataset. The paper presents details of this work with a
highlight on the future prospects.
Title: The Effects Of Relativistic Hidden Sector Particles on the
Matter Power Spectrum
Authors: Ganjoo, Himanish; Erickcek, Adrienne L.; Lin, Weikang; Mack,
Katherine J.
Bibcode: 2022arXiv220902735G
Altcode:
If dark matter resides in a hidden sector minimally coupled to the
Standard Model, another particle within the hidden sector might dominate
the energy density of the early universe temporarily, causing an early
matter-dominated era (EMDE). During an EMDE, matter perturbations
grow more rapidly than they would in a period of radiation domination,
which leads to the formation of microhalos much earlier than they would
form in standard cosmological scenarios. These microhalos boost the
dark matter annihilation signal, but this boost is highly sensitive
to the small-scale cut-off in the matter power spectrum. If the dark
matter is sufficiently cold, this cut-off is set by the relativistic
pressure of the particle that dominates the hidden sector. We determine
the evolution of dark matter density perturbations in this scenario,
obtaining the power spectrum at the end of the EMDE. We analyze the
suppression of perturbations due to the relativistic pressure of the
dominant hidden sector particle and express the cut-off scale and peak
scale for which the matter power spectrum is maximized in terms of
the properties of this particle. We also supply transfer functions to
relate the matter power spectrum with a small-scale cut-off resulting
from the pressure of the dominant hidden sector particle to the matter
power spectrum that results from a cold hidden sector. These transfer
functions facilitate the quick computation of accurate matter power
spectra in EMDE scenarios with initially hot hidden sectors and allow us
to identify which models significantly enhance the microhalo abundance.
Title: Cosmic-ray measurements with an array of Cherenkov telescopes
using reconstruction of longitudinal profiles of air showers
Authors: Delgado Giler, Andrés G.; de Souza, Vitor
Bibcode: 2022arXiv220904045D
Altcode:
We present a method to reconstruct the longitudinal profile of electrons
in showers using Cherenkov telescopes. We show how the Cherenkov
light collected by an array of telescopes can be transformed into the
number of electrons as a function of atmospheric depth. This method is
validated using air shower and simplified telescope simulations. The
reconstruction of the depth in which the shower has the maximum number
of electrons ($\mathrm{X_{max}}$) opens the possibility of cosmic
ray composition studies with Cherenkov telescopes in the energy range
from 10 to 100 TeV. A resolution of less than 16 $\mathrm{g/cm^{2}}$
in the $\mathrm{X_{max}}$ reconstruction is obtained.
Title: OMC-2 FIR 4 under the microscope: Shocks, filaments, and a
highly collimated jet at 100 au scales
Authors: Chahine, L.; López-Sepulcre, A.; Podio, L.; Codella, C.;
Neri, R.; Mercimek, S.; De Simone, M.; Caselli, P.; Ceccarelli, C.;
Bouvier, M.; Sakai, N.; Fontani, F.; Yamamoto, S.; Alves, F. O.;
Lattanzi, V.; Evans, L.; Favre, C.
Bibcode: 2022arXiv220903696C
Altcode:
Star-forming molecular clouds are characterised by the ubiquity of
intertwined filaments. The filaments have been observed in both high-
and low-mass star-forming regions, and are thought to split into
collections of sonic fibres. The locations where filaments converge
are termed hubs, and these are associated with the young stellar
clusters. However, the observations of filamentary structures within
hubs at distances require a high angular resolution that limits the
number of such studies conducted so far. The integral shaped filament
of the Orion A molecular cloud is noted for harbouring several hubs
within which no filamentary structures have been observed so far. The
goal of our study is to investigate the nature of the filamentary
structures within one of these hubs, which is the chemically rich hub
OMC-2 FIR 4, and to analyse their emission with high density and shock
tracers. We observed the OMC-2 FIR 4 proto-cluster using Band 6 of
the ALMA in Cycle 4 with an angular resolution of ~0.26"(100 au). We
analysed the spatial distribution of dust, the shock tracer SiO,
and dense gas tracers (i.e., CH$_{3}$OH, CS, and H$^{13}$CN). We also
studied gas kinematics using SiO and CH3OH maps. Our observations for
the first time reveal interwoven filamentary structures within OMC-2
FIR 4 that are probed by several tracers. Each filamentary structure
is characterised by a distinct velocity as seen from the emission
peak of CH$_{3}$OH lines. They also show transonic and supersonic
motions. SiO is associated with filaments and also with multiple
bow-shock features. In addition, for the first time, we reveal a highly
collimated SiO jet (~1$^{\circ}$) with a projected length of ~5200 au
from the embedded protostar VLA15. Our study shows that multi-scale
observations of these regions are crucial for understanding the
accretion processes and flow of material that shapes star formation.
Title: New recursions for tree-level correlators in (Anti) de
Sitter space
Authors: Armstrong, Connor; Gomez, Humberto; Lipinski Jusinskas,
Renann; Lipstein, Arthur; Mei, Jiajie
Bibcode: 2022arXiv220902709A
Altcode:
We present for the first time classical multiparticle solutions in Anti
de Sitter space (AdS) involving scalars, gluons, and gravitons. They
are recursively defined through multiparticle currents which
reduce to Berends-Giele currents in the flat space limit. This
construction exposes a compact definition of tree-level boundary
correlators using a general prescription that removes unphysical
boundary contributions. Similarly to the flat space perturbiner,
a convenient gauge choice leads to a scalar basis for all degrees of
freedom, while the tensor structure is exclusively captured by field
theory vertices. This provides a fully automated way to compute AdS
boundary correlators to any multiplicity and cosmological wavefunction
coefficients after Wick-rotating to de Sitter space.
Title: Empirical constraints on the turbulence in QSO host nebulae
from velocity structure function measurements
Authors: Chen, Mandy C.; Chen, Hsiao-Wen; Rauch, Michael; Qu, Zhijie;
Johnson, Sean D.; Li, Jennifer I-Hsiu; Schaye, Joop; Rudie, Gwen C.;
Zahedy, Fakhri S.; Boettcher, Erin; Cooksey, Kathy L.; Cantalupo,
Sebastiano
Bibcode: 2022arXiv220904344C
Altcode:
We present the first empirical constraints on the turbulent velocity
field of the diffuse circumgalactic medium around four luminous QSOs at
$z\!\approx\!0.5$--1.1. Spatially extended nebulae of $\approx\!50$--100
physical kpc in diameter centered on the QSOs are revealed in
[OII]$\lambda\lambda\,3727,3729$ and/or [OIII]$\lambda\,5008$ emission
lines in integral field spectroscopic observations obtained using MUSE
on the VLT. We measure the second- and third-order velocity structure
functions (VSFs) over a range of scales, from $\lesssim\!5$ kpc to
$\approx\!20$--50 kpc, to quantify the turbulent energy transfer between
different scales in these nebulae. While no constraints on the energy
injection and dissipation scales can be obtained from the current data,
we show that robust constraints on the power-law slope of the VSFs can
be determined after accounting for the effects of atmospheric seeing,
spatial smoothing, and large-scale bulk flows. Out of the four QSO
nebulae studied, one exhibits VSFs in spectacular agreement with the
Kolmogorov law, expected for isotropic, homogeneous, and incompressible
turbulent flows. The other three fields exhibit a shallower decline
in the VSFs from large to small scales but with loose constraints,
in part due to a limited dynamic range in the spatial scales in
seeing-limited data. For the QSO nebula consistent with the Kolmogorov
law, we determine a turbulence energy cascade rate of $\approx\!0.2$
cm$^{2}$ s$^{-3}$. We discuss the implication of the observed VSFs in
the context of QSO feeding and feedback in the circumgalactic medium.
Title: Cold dense quark matter with phenomenological medium effects: a
self-consistent formulation of the quark-mass density-dependent model
Authors: Lugones, G.; Grunfeld, A. G.
Bibcode: 2022arXiv220903455L
Altcode:
We revisit the quark-mass density-dependent model -- a phenomenological
equation of state for deconfined quark matter in the high-density
low-temperature regime -- and show that thermodynamic inconsistencies
that have plagued the model for decades, can be solved if the model
is formulated in the canonical ensemble instead of the grand canonical
one. Within the new formulation, the minimum of the energy per baryon
occurs at zero pressure, and the Euler's relation is verified. Adopting
a typical mass-formula, we first analyze in detail a simple model with
one particle species. We show that a ``bag'' term that produces quark
confinement naturally appears in the pressure (and not in the energy
density) due to density dependence of the quark masses. Additionally,
the chemical potential gains a new term as in other models with
quark repulsive interactions. Then, we extend the formalism to the
astrophysically realistic case of charge-neutral three-flavor quark
matter in equilibrium under weak interactions, focusing on two different
mass formulae: a flavor dependent and a flavor blind one. For these
two models, we derive the equation of state and analyze its behavior
for several parameter choices. We systematically analyze the parameter
space and identify the regions corresponding to self-bound 2-flavor
and 3-flavor quark matter, hybrid matter and causal behavior.
Title: First Sample of H$\alpha$+[O III] $\lambda$5007 Line Emitters
at $z > 6$ through JWST/NIRCam Slitless Spectroscopy: Physical
Properties and Line Luminosity Functions
Authors: Sun, Fengwu; Egami, Eiichi; Pirzkal, Nor; Rieke, Marcia;
Baum, Stefi; Boyer, Martha; Boyett, Kristan; Bunker, Andrew J.;
Cameron, Alex J.; Curti, Mirko; Eisenstein, Daniel J.; Gennaro, Mario;
Greene, Thomas P.; Jaffe, Daniel; Kelly, Doug; Koekemoer, Anton M.;
Kumari, Nimisha; Maiolino, Roberto; Maseda, Michael; Perna, Michele;
Rest, Armin; Robertson, Brant E.; Schlawin, Everett; Smit, Renske;
Stansberry, John; Sunnquist, Ben; Tacchella, Sandro; Williams,
Christina C.; Willmer, Christopher N. A.
Bibcode: 2022arXiv220903374S
Altcode:
We present a sample of four emission-line galaxies at $z=6.11-6.35$
that were serendipitously discovered using the commissioning data for
the JWST/NIRCam wide-field slitless spectroscopy (WFSS) mode. One of
them (at $z=6.11$) has been reported previously while the others
are new discoveries. These sources are selected by the secure
detections of both [O III] $\lambda$5007 and H$\alpha$ lines with
other fainter lines tentatively detected in some cases (e.g., [O II]
$\lambda$3727, [O III] $\lambda$4959 and [N II] $\lambda$6583). In
the [O III]/H$\beta$ - [N II]/H$\alpha$ Baldwin-Phillips-Terlevich
diagram, these galaxies occupy the same parameter space as that of
$z\sim2$ star-forming galaxies, indicating that they have been enriched
rapidly to sub-solar metallicities ($\sim$0.6 $Z_{\odot}$), similar to
galaxies with comparable stellar masses at much lower redshifts. The
detection of strong H$\alpha$ lines suggests a higher ionizing photon
production efficiency within galaxies in the early Universe. We find
brightening of the [O III] $\lambda$5007 line luminosity function (LF)
from $z=3$ to 6, and no or weak redshift evolution of the H$\alpha$
line LF from $z=2$ to 6. Both LFs are under-predicted at $z\sim6$
by a factor of $\sim$10 in certain cosmological simulations. This
further indicates a global Ly$\alpha$ photon escape fraction of 5-7%
at $z\sim6$, much lower than previous estimates through the comparison
of the UV-derived star-formation rate density and Ly$\alpha$ luminosity
density. Our sample recovers $88^{+164}_{-57}$% of $z=6.0-6.6$ galaxies
in the survey volume with stellar masses greater than $5\times10^8$
$M_{\odot}$, suggesting the ubiquity of strong H$\alpha$ and [O III]
line emitters in the Epoch of Reionization, which will be further
uncovered in the era of JWST.
Title: Radical addition and H abstraction reactions in
C2H2, C2H4, and
C2H6: A gateway for ethyl- and vinyl-bearing
molecules in the interstellar medium
Authors: Molpeceres, G.; Rivilla, V. M.
Bibcode: 2022A&A...665A..27M
Altcode: 2022arXiv220600350M
Context. Recent interstellar detections include a significant number
of molecules containing vinyl (C2H3) and ethyl
(C2H5) groups in their structure. For several
of these molecules, there is no clear experimental or theoretical
evidence that supports their formation from simpler precursors.
Aims: We carried out a systematic search of viable reactions starting
from closed-shell hydrocarbons containing two carbon atoms (ethane,
C2H6; ethylene, C2H4; and
acetylene, C2H2), with the goal of determining
viable chemical routes for the formation of vinyl and ethyl molecules
on top of interstellar dust grains.
Methods: We used density
functional theory calculations in combination with semiclassical
instantem theory to derive the rate coefficients for the radical-neutral
surface reactions. The effect of a surface was modeled through
an implicit surface approach, profiting from the weak interaction
between the considered hydrocarbons and the dust surfaces.
Results: Our results show that both H and OH radicals are key in
converting acetylene and ethylene into more complex radicals that are
liable to continue reacting and to form interstellar complex organic
molecules. The relevant reactions, for example OH additions, present
rate constants above 101 s−1 that are likely
competitive with OH diffusion on grains. Similarly, H atom addition
to acetylene and ethylene is a very fast process, with rate constants
above 104 s−1 in all cases, and is greatly
enhanced by quantum tunneling. Hydrogen abstraction reactions are
less relevant, but may play a role in specific cases involving the OH
radical. Reactions with other radicals NH2 and CH3
are likely to have much less impact on the chemistry of ethyl- and
vinyl-bearing molecules.
Conclusions: The effective formation
at low temperatures of four radicals (C2H3,
C2H5, C2H2OH, and
C2H4OH) through our proposed mechanism opens the
gate for the formation of complex organic molecules, and indicates a
potential prevalence of OH-bearing molecules on the grain. Following
our suggested reaction pathway, we explain the formation of many of the
newly detected molecules, and propose new molecules for detection. Our
results reinforce the recent view on the importance of the OH radical
in interstellar surface chemistry.
Title: Variability-selected Intermediate-mass Black Hole Candidates
in Dwarf Galaxies from ZTF and WISE
Authors: Ward, Charlotte; Gezari, Suvi; Nugent, Peter; Bellm, Eric C.;
Dekany, Richard; Drake, Andrew; Duev, Dmitry A.; Graham, Matthew J.;
Kasliwal, Mansi M.; Kool, Erik C.; Masci, Frank J.; Riddle, Reed L.
Bibcode: 2022ApJ...936..104W
Altcode: 2021arXiv211013098W
While it is difficult to observe the first black hole seeds in the
early universe, we can study intermediate-mass black holes (IMBHs)
in local dwarf galaxies for clues about their origins. In this paper
we present a sample of variability-selected active galactic nuclei
(AGN) in dwarf galaxies using optical photometry from the Zwicky
Transient Facility (ZTF) and forward-modeled mid-IR photometry of
time-resolved Wide-field Infrared Survey Explorer (WISE) co-added
images. We found that 44 out of 25,714 dwarf galaxies had optically
variable AGN candidates and 148 out of 79,879 dwarf galaxies had mid-IR
variable AGN candidates, corresponding to active fractions of 0.17%
± 0.03% and 0.19% ± 0.02%, respectively. We found that spectroscopic
approaches to AGN identification would have missed 81% of our ZTF IMBH
candidates and 69% of our WISE IMBH candidates. Only nine candidates
have been detected previously in radio, X-ray, and variability searches
for dwarf galaxy AGN. The ZTF and WISE dwarf galaxy AGN with broad
Balmer lines have virial masses of 105 M ⊙
< M BH < 107 M ⊙, but for
the rest of the sample, BH masses predicted from host galaxy mass
range between 105.2 M ⊙ < M BH
< 107.25 M ⊙. We found that only 5 of
152 previously reported variability-selected AGN candidates from
the Palomar Transient Factory in common with our parent sample were
variable in ZTF. We also determined a nuclear supernova fraction of
0.05% ± 0.01% yr-1 for dwarf galaxies in ZTF. Our ZTF and
WISE IMBH candidates show the promise of variability searches for the
discovery of otherwise hidden low-mass AGN.
Title: Investigation of the Broadband Emission of the Gamma-Ray
Binary HESS J0632+057 Using an Intrabinary Shock Model
Authors: Kim, Jinyoung; An, Hongjun; Mori, Kaya
Bibcode: 2022ApJ...936...32K
Altcode: 2022arXiv220801189K
We investigated a wealth of X-ray and gamma-ray spectral energy
distribution (SED) and multiband light-curve (LC) data of the gamma-ray
binary HESS J0632+057 using a phenomenological intrabinary shock (IBS)
model. Our baseline model assumes that the IBS is formed by colliding
winds from a putative pulsar and its Be companion and that particles
accelerated in the IBS emit broadband radiation via synchrotron (SY)
and inverse Compton upscattering (ICS) processes. Adopting the latest
orbital solution and system geometry, we reproduced the global X-ray
and TeV LC features, two broad bumps at ϕ ~ 0.3 and ~0.7, with the SY
and ICS model components. We found that these TeV LC peaks originate
from ICS emission caused by the enhanced seed photon density near
periastron and superior conjunction or Doppler-beamed emission of
bulk-accelerated particles in the IBS at inferior conjunction. While
our IBS model successfully explained most of the observed SED and LC
data, we found that phase-resolved SED data in the TeV band require
an additional component associated with ICS emission from preshock
particles (produced by the pulsar wind). This finding indicates a
possibility of delineating the IBS emission components and determining
the bulk Lorentz factors of the pulsar wind at certain orbital phases.
Title: Type-B QPOs in a black hole source H1743-322 and its
association with Comptonizating region and Jet
Authors: Harikrishna, S.; Sriram, K.
Bibcode: 2022MNRAS.tmp.2333H
Altcode:
The connection of type-B QPOs to the hot flow in the inner accretion
disk region is vaguely understood in black hole X-ray binaries. We
performed spectral and timing studies of twenty-three observations
where type-C and type-B QPOs with similar centroid frequencies (~ 6
Hz) occurred. Their spectral differences were used to understand the
production mechanism of type-B QPOs, along with the quasi-simultaneous
radio observations. Based on the spectral results, we did not notice
many variations in the Comptonization parameters and the inner disk
radius during type-C and type-B QPOs. We found that the structure of the
Comptonization region has to be different for observations associated
with type-C and type-B QPOs based on the CompTT model. Radio flux
density vs QPO width, soft to hard flux ratio, and QPO width vs inner
disk temperature, were found to follow certain trends, suggesting that
a jet could be responsible for the type-B QPOs in H1743-322. Further
studies are required to uniquely constrain this scenario. In a case
study where a gradual transition from type-C to type-B QPO was noticed,
we found that the spectral changes could be explained by the presence
of a jet or a vertically extended optically thick Comptonization
region. The geometrical Lense-Thirring precession model with a hot
flow and a jet in the inner region was incorporated to explain the
spectral and timing variations.
Title: New Close Binary Central Stars of Planetary Nebulae from Gaia
DR3 Epoch Photometry
Authors: Chornay, Nicholas; Walton, Nicholas A.
Bibcode: 2022RNAAS...6..177C
Altcode: 2022arXiv220900352C
Close binary interactions perform a key role in the formation and
shaping of planetary nebulae (PNe). However only a small fraction
of Galactic PNe are known to host close binary systems. Many such
systems are detectable through photometric variability. We searched
recently published epoch photometry data from Gaia DR3 for planetary
nebula central stars with periodic photometric variability indicative
of binarity, uncovering four previously unknown close binaries.
Title: The X-ray polarimetry view of the accreting pulsar Cen X-3
Authors: Tsygankov, Sergey S.; Doroshenko, Victor; Poutanen, Juri;
Heyl, Jeremy; Mushtukov, Alexander A.; Caiazzo, Ilaria; Di Marco,
Alessandro; Forsblom, Sofia V.; González-Caniulef, Denis; Klawin,
Moritz; La Monaca, Fabio; Malacaria, Christian; Marshall, Herman L.;
Muleri, Fabio; Ng, Mason; Suleimanov, Valery F.; Sunyaev, Rashid
A.; Turolla, Roberto; Agudo, Iván; Antonelli, Lucio A.; Bachetti,
Matteo; Baldini, Luca; Baumgartner, Wayne H.; Bellazzini, Ronaldo;
Bianchi, Stefano; Bongiorno, Stephen D.; Bonino, Raffaella; Brez,
Alessandro; Bucciantini, Niccolò; Capitanio, Fiamma; Castellano,
Simone; Cavazzuti, Elisabetta; Ciprini, Stefano; Costa, Enrico;
De Rosa, Alessandra; Del Monte, Ettore; Di Gesu, Laura; Di Lalla,
Niccolò; Donnarumma, Immacolata; Dovčiak, Michal; Ehlert, Steven
R.; Enoto, Teruaki; Evangelista, Yuri; Fabiani, Sergio; Ferrazzoli,
Riccardo; Garcia, Javier A.; Gunji, Shuichi; Hayashida, Kiyoshi;
Iwakiri, Wataru; Jorstad, Svetlana G.; Karas, Vladimir; Kitaguchi,
Takao; Kolodziejczak, Jeffery J.; Krawczynski, Henric; Latronico,
Luca; Liodakis, Ioannis; Maldera, Simone; Manfreda, Alberto; Marin,
Frédéric; Marinucci, Andrea; Marscher, Alan P.; Matt, Giorgio;
Mitsuishi, Ikuyuki; Mizuno, Tsunefumi; Ng, C. -Y.; O'Dell, Stephen
L.; Omodei, Nicola; Oppedisano, Chiara; Papitto, Alessandro; Pavlov,
George G.; Peirson, Abel L.; Perri, Matteo; Pesce-Rollins, Melissa;
Petrucci, Pierre-Olivier; Pilia, Maura; Possenti, Andrea; Puccetti,
Simonetta; Ramsey, Brian D.; Rankin, John; Ratheesh, Ajay; Romani,
Roger W.; Sgrò, Carmelo; Slane, Patrick; Soffitta, Paolo; Spandre,
Gloria; Tamagawa, Toru; Tavecchio, Fabrizio; Taverna, Roberto; Tawara,
Yuzuru; Tennant, Allyn F.; Thomas, Nicolas E.; Tombesi, Francesco;
Trois, Alessio; Vink, Jacco; Weisskopf, Martin C.; Wu, Kinwah; Xie,
Fei; Zane, Silvia
Bibcode: 2022arXiv220902447T
Altcode:
Cen X-3 is the first X-ray pulsar discovered 50 years ago. Radiation
from such objects is expected to be highly polarized due to
birefringence of plasma and vacuum associated with propagation of
photons in presence of the strong magnetic field. Here we present
results of the observations of Cen X-3 performed with the Imaging
X-ray Polarimetry Explorer. The source exhibited significant flux
variability and was observed in two states different by a factor of
~20 in flux. In the low-luminosity state no significant polarization
was found either in pulse phase-averaged (with the 3$\sigma$ upper
limit of 12%) or phase-resolved data (the 3$\sigma$ upper limits are
20-30%). In the bright state the polarization degree of 5.8$\pm$0.3%
and polarization angle of $49.6°\pm1.5°$ with significance of about
20$\sigma$ was measured from the spectro-polarimetric analysis of the
phase-averaged data. The phase-resolved analysis showed a significant
anti-correlation between the flux and the polarization degree as well as
strong variations of the polarization angle. The fit with the rotating
vector model indicates a position angle of the pulsar spin axis of about
49$°$ and a magnetic obliquity of 17$°$. The detected relatively
low polarization can be explained if the upper layers of the neutron
star surface are overheated by the accreted matter and the conversion
of the polarization modes occurs within the transition region between
the upper hot layer and a cooler underlying atmosphere. A fraction of
polarization signal can also be produced by reflection of radiation
from the neutron star surface and the accretion curtain.
Title: Measuring cosmic filament spin with the kinetic
Sunyaev-Zel'dovich effect
Authors: Zheng, Yi; Cai, Yan-Chuan; Zhu, Weishan; Neyrinck, Mark;
Wang, Peng; Li, Shaohong
Bibcode: 2022arXiv220904464Z
Altcode:
The spin of intergalactic filaments has been predicted from simulations,
and supported by tentative evidence from redshift-space filament shapes
in a galaxy redshift survey: generally, a filament is redshifted
on one side of its axis, and blueshifted on the other. Here, we
investigate whether filament spins could have a measurable kinetic
Sunyaev-Zel'dovich (kSZ) signal, from CMB photons scattering off
of moving ionized gas; this pure velocity information is rather
complementary to filament redshift-space shapes. We develop a technique
to measure the kSZ dipole by combining galaxy redshift surveys with
CMB experiments. We base our S/N analyses first on an existing filament
catalogue, making simple assumptions about how ionised gas follows the
galaxies and matter in each filament, and its combination with Planck
data. We then investigate the detectability of the kSZ dipole using the
combination of DESI or SKA-2 with next-stage CMB experiments. We find
that the gas halos of filament galaxies co-rotating with filaments
induce a stronger kSZ dipole signal than that from the diffuse
filamentary gas, but both signals seem too small to detect in near-term
surveys such as DESI+future CMB experiments. But the combination of
SKA-2 with future CMB experiments could give a more than $10\sigma$
detection. The gain comes mainly from an increased area overlap and
an increased number of filaments, but also the low noise and high
resolution in future CMB experiments are important to capture signals
from filaments small on the sky. Successful detection of the signals
may help to find the gravitomagnetic effect in large-scale structure
and advance our understanding on baryons in the cosmic web.
Title: A characterization method for low-frequency environmental
noise in LIGO
Authors: Valdes, Guillermo; Hines, Adam; Nelson, Andrea; Zhang, Yanqi;
Guzman, Felipe
Bibcode: 2022arXiv220904452V
Altcode:
We present a method to characterize the noise in ground-based
gravitational-wave observatories such as the Laser Gravitational-Wave
Observatory (LIGO). This method uses linear regression algorithms
such as the least absolute shrinkage and selection operator (LASSO)
to identify noise sources and analyzes the detector output versus noise
witness sensors to quantify the coupling of such noise. Our method can
be implemented with currently available resources at LIGO, which avoids
extra coding or direct experimentation at the LIGO sites. We present
two examples to validate and estimate the coupling of elevated ground
motion at frequencies below 10 Hz with noise in the detector output.
Title: No room to hide: implications of cosmic-ray upscattering for
GeV-scale dark matter
Authors: Alvey, James; Bringmann, Torsten; Kolesova, Helena
Bibcode: 2022arXiv220903360A
Altcode:
The irreducible upscattering of cold dark matter by cosmic rays opens
up the intriguing possibility of detecting even light dark matter
in conventional direct detection experiments or underground neutrino
detectors. The mechanism also significantly enhances sensitivity to
models with very large nuclear scattering rates, where the atmosphere
and rock overburden efficiently stop standard non-relativistic dark
matter particles before they could reach the detector. In this article,
we demonstrate that cosmic-ray upscattering essentially closes the
window for strongly interacting dark matter in the (sub-)GeV mass
range. Arriving at this conclusion crucially requires a detailed
treatment of both nuclear form factors and inelastic dark matter-nucleus
scattering, as well as including the full momentum-transfer
dependence of scattering amplitudes. We illustrate the latter point by
considering three generic situations where such a momentum-dependence
is particularly relevant, namely for interactions dominated by the
exchange of light vector or scalar mediators, respectively, and for
dark matter particles of finite size. As a final concrete example,
we apply our analysis to a putative hexaquark state, which has been
suggested as a viable baryonic dark matter candidate. Once again,
we find that the updated constraints derived in this work close a
significant part of otherwise unconstrained parameter space.
Title: Smallest scale clumpy star formation in Stephan's Quintet
revealed from UV and IR imaging
Authors: Joseph, Prajwel; George, Koshy; Subramanian, Smitha; Mondal,
Chayan; Subramaniam, Annapurni
Bibcode: 2022arXiv220903439J
Altcode:
The spatial distribution and physical sizes of star forming clumps at
the smallest scales provide valuable information on hierarchical star
formation (SF). In this context, we report the sites of ongoing SF at
~120 pc along the interacting galaxies in Stephan's Quintet (SQ) compact
group using AstroSat-UVIT and JWST data. Since ultraviolet radiation is
a direct tracer of recent SF, we identified star forming clumps in this
compact group from the FUV imaging which we used to guide us to detect
star forming regions on JWST IR images. The FUV imaging reveals star
forming regions within which we detect smaller clumps from the higher
spatial resolution images of JWST, likely produced by PAH molecules and
dust ionised by FUV emission from young massive stars. This analysis
reveals the importance of FUV imaging data in identifying star forming
regions in the highest spatial resolution IR imaging available.
Title: The Einasto model for dark matter haloes
Authors: Baes, Maarten
Bibcode: 2022arXiv220903639B
Altcode:
Context: The Einasto model has become one of the most popular models
for describing the density profile of dark matter haloes. There have
been relatively few comprehensive studies on the dynamical structure of
the Einasto model, mainly because only a limited number of properties
can be calculated analytically. Aims: We want to systematically
investigate the photometric and dynamical structure of the family of
Einasto models over the entire model parameter space. Methods: We used
the SpheCow code to explore the properties of the Einasto model. We
systematically investigated how the most important properties change
as a function of the Einasto index $n$. We considered both isotropic
models and radially anisotropic models with an Osipkov-Merritt orbital
structure. Results: We find that all Einasto models with $n<\tfrac12$
have a formal isotropic or Osipkov-Merritt distribution function that
is negative in parts of phase space, and hence cannot be supported by
such orbital structures. On the other hand, all models with larger
values of $n$ can be supported by an isotropic orbital structure,
or by an Osipkov-Merritt anisotropy, as long as the anisotropy radius
is larger than a critical value. This critical anisotropy radius is a
decreasing function of $n$, indicating that less centrally concentrated
models allow for a larger degree of radial anisotropy. Conclusions:
Studies of the structure and dynamics of models for galaxies and
dark matter haloes should not be restricted to completely analytical
models. Numerical codes such as SpheCow can help open up the range
of models that are systematically investigated. This applies to the
Einasto model discussed here, but also to other proposed models for
dark matter haloes, including different extensions to the Einasto model.
Title: Phase transitions in TGFT: a Landau-Ginzburg analysis of
Lorentzian quantum geometric models
Authors: Marchetti, Luca; Oriti, Daniele; Pithis, Andreas G. A.;
Thürigen, Johannes
Bibcode: 2022arXiv220904297M
Altcode:
In the tensorial group field theory (TGFT) approach to quantum
gravity, the basic quanta of the theory correspond to discrete
building blocks of geometry. It is expected that their collective
dynamics gives rise to continuum spacetime at a coarse grained
level, via a process involving a phase transition. In this work we
show for the first time how phase transitions for realistic TGFT
models can be realized using Landau-Ginzburg mean-field theory. More
precisely, we consider models generating 4-dimensional Lorentzian
triangulations formed by spacelike tetrahedra whose quantum geometry
is encoded in non-local degrees of freedom on the non-compact group
$\mathrm{SL}(2,\mathbb{C})$ and subject to gauge and simplicity
constraints. Further we include $\mathbb{R}$-valued variables which
may be interpreted as discretized scalar fields typically employed as
a matter reference frame. We apply the Ginzburg criterion finding that
fluctuations around the non-vanishing mean-field vacuum remain small
at large correlation lengths regardless of the combinatorics of the
non-local interaction validating the mean-field theory description
of the phase transition. This work represents a first crucial step
to understand phase transitions in compelling TGFT models for quantum
gravity and paves the way for a more complete analysis via functional
renormalization group techniques. Moreover, it supports the recent
extraction of effective cosmological dynamics from TGFTs in the context
of a mean-field approximation.
Title: Discovery of Line Pressure Broadening and Direct Constraint
on Gas Surface Density in a Protoplanetary Disk
Authors: Yoshida, Tomohiro C.; Nomura, Hideko; Tsukagoshi, Takashi;
Furuya, Kenji; Ueda, Takahiro
Bibcode: 2022arXiv220903367Y
Altcode:
The gas surface density profile of protoplanetary disks is one
of the most fundamental physical properties to understand planet
formation. However, it is challenging to determine the surface
density profile observationally, because the H$_2$ emission cannot be
observed in low-temperature regions. We analyzed the Atacama Large
Millimeter/submillimeter Array (ALMA) archival data of the \co line
toward the protoplanetary disk around TW Hya and discovered extremely
broad line wings due to the pressure broadening. In conjunction with a
previously reported optically thin CO isotopologue line, the pressure
broadened line wings enabled us to directly determine the midplane
gas density for the first time. The gas surface density at $\sim5$
au from the central star reaches $\sim 10^3\ {\rm g\ cm^{-2}}$,
which suggests that the inner region of the disk has enough mass to
form a Jupiter-mass planet. Additionally, the gas surface density
drops at the inner cavity by $\sim2$ orders of magnitude compared to
outside the cavity. We also found a low CO abundance of $\sim 10^{-6}$
with respect to H$_2$, even inside the CO snowline, which suggests
conversion of CO to less volatile species. Combining our results with
previous studies, the gas surface density jumps at $r\sim 20$ au,
suggesting that the inner region ($3<r<20$ au) might be the
magnetorotational instability dead zone. This study sheds light on
direct gas-surface-density constraint without assuming the CO/H$_2$
ratio using ALMA.
Title: A long gamma-ray burst from a merger of compact objects
Authors: Troja, E.; Fryer, C. L.; O'Connor, B.; Ryan, G.; Dichiara,
S.; Kumar, A.; Ito, N.; Gupta, R.; Wollaeger, R.; Norris, J. P.;
Kawai, N.; Butler, N.; Aryan, A.; Misra, K.; Hosokawa, R.; Murata,
K. L.; Niwano, M.; Pandey, S. B.; Kutyrev, A.; van Eerten, H. J.;
Chase, E. A.; Hu, Y. -D.; Caballero-Garcia, M. D.; Castro-Tirado, A. J.
Bibcode: 2022arXiv220903363T
Altcode:
Gamma-ray bursts (GRBs) are flashes of high-energy radiation arising
from energetic cosmic explosions. Bursts of long (>2 s) duration
are produced by the core-collapse of massive stars, those of short
(< 2 s) duration by the merger of two neutron stars (NSs). A third
class of events with hybrid high-energy properties was identified,
but never conclusively linked to a stellar progenitor. The lack of
bright supernovae rules out typical core-collapse explosions, but
their distance scales prevent sensitive searches for direct signatures
of a progenitor system. Only tentative evidence for a kilonova has
been presented. Here we report observations of the exceptionally
bright GRB211211A that classify it as a hybrid event and constrain
its distance scale to only 346 Mpc. Our measurements indicate that
its lower-energy (from ultraviolet to near-infrared) counterpart is
powered by a luminous (~1E42 erg/s) kilonova possibly formed in the
ejecta of a compact binary merger.
Title: Advancing Theory and Modeling Efforts in Heliophysics
Authors: Guo, Fan; Antiochos, Spiro; Cassak, Paul; Chen, Bin; Chen,
Xiaohang; Dong, Chuanfei; Downs, Cooper; Giacalone, Joe; Haggerty,
Colby C.; Ji, Hantao; Karpen, Judith; Klimchuk, James; Li, Wen; Li,
Xiaocan; Oka, Mitsuo; Reeves, Katharine K.; Swisdak, Marc; Tu, Weichao
Bibcode: 2022arXiv220903611G
Altcode:
Heliophysics theory and modeling build understanding from fundamental
principles to motivate, interpret, and predict observations. Together
with observational analysis, they constitute a comprehensive scientific
program in heliophysics. As observations and data analysis become
increasingly detailed, it is critical that theory and modeling develop
more quantitative predictions and iterate with observations. Advanced
theory and modeling can inspire and greatly improve the design of
new instruments and increase their chance of success. In addition,
in order to build physics-based space weather forecast models, it is
important to keep developing and testing new theories, and maintaining
constant communications with theory and modeling. Maintaining a
sustainable effort in theory and modeling is critically important
to heliophysics. We recommend that all funding agencies join forces
and consider expanding current and creating new theory and modeling
programs--especially, 1. NASA should restore the HTMS program to its
original support level to meet the critical needs of heliophysics
science; 2. a Strategic Research Model program needs to be created to
support model development for next-generation basic research codes;
3. new programs must be created for addressing mission-critical theory
and modeling needs; and 4. enhanced programs are urgently required
for training the next generation of theorists and modelers.
Title: Inference of gravitational field superposition from quantum
measurements
Authors: Overstreet, Chris; Curti, Joseph; Kim, Minjeong; Asenbaum,
Peter; Kasevich, Mark A.; Giacomini, Flaminia
Bibcode: 2022arXiv220902214O
Altcode:
Experiments are beginning to probe the interaction of quantum particles
with gravitational fields beyond the uniform-field regime. In standard
quantum mechanics, the gravitational field in such experiments is
written as a superposition state. We empirically demonstrate that
alternative theories of gravity can avoid gravitational superposition
states only by decoupling the gravitational field energy from the
quantum particle's time evolution. Furthermore, such theories
must specify a preferred quantum reference frame in which the
equations of motion are valid. To the extent that these properties
are theoretically implausible, recent experiments provide indirect
evidence that gravity has quantum features. Proposed experiments with
superposed gravitational sources would provide even stronger evidence
that gravity is nonclassical.
Title: Athena synergies in the multi-messenger and transient universe
Authors: Piro, Luigi; Ahlers, Markus; Coleiro, Alexis; Colpi, Monica;
de Oña Wilhelmi, Emma; Guainazzi, Matteo; Jonker, Peter G.; Namara,
Paul Mc; Nichols, David A.; O'Brien, Paul; Troja, Eleonora; Vink,
Jacco; Aird, James; Amati, Lorenzo; Anand, Shreya; Bozzo, Enrico;
Carrera, Francisco J.; Fabian, Andrew C.; Fryer, Christopher;
Hall, Evan; Korobkin, Oleg; Korol, Valeriya; Mangiagli, Alberto;
Martínez-Núñez, Silvia; Nissanke, Samaya; Osborne, Julien; Padovani,
Paolo; Rossi, Elena M.; Ryan, Geoffrey; Sesana, Alberto; Stratta,
Giulia; Tanvir, Niel; van Eerten, Hendrik
Bibcode: 2022ExA...tmp...67P
Altcode:
In this paper we explore the scientific synergies between Athena
and some of the key multi-messenger facilities that should be
operative concurrently with Athena. These facilities include LIGO A+,
Advanced Virgo+ and future detectors for ground-based observation of
gravitational waves (GW), LISA for space-based observations of GW,
IceCube and KM3NeT for neutrino observations, and CTA for very high
energy observations. These science themes encompass pressing issues
in astrophysics, cosmology and fundamental physics such as: the
central engine and jet physics in compact binary mergers, accretion
processes and jet physics in Super-Massive Binary Black Holes (SMBBHs)
and in compact stellar binaries, the equation of state of neutron
stars, cosmic accelerators and the origin of Cosmic Rays (CRs),
the origin of intermediate and high-Z elements in the Universe, the
Cosmic distance scale and tests of General Relativity and the Standard
Model. Observational strategies for implementing the identified science
topics are also discussed. A significant part of the sources targeted
by multi-messenger facilities is of transient nature. We have thus also
discussed the synergy of Athena with wide-field high-energy facilities,
taking THESEUS as a case study for transient discovery. This discussion
covers all the Athena science goals that rely on follow-up observations
of high-energy transients identified by external observatories, and
includes also topics that are not based on multi-messenger observations,
such as the search for missing baryons or the observation of early
star populations and metal enrichment at the cosmic dawn with Gamma-Ray
Bursts (GRBs).
Title: On generally covariant mathematical formulation of Feynman
integral in Lorentz signature
Authors: László, András
Bibcode: 2022CQGra..39r5004L
Altcode: 2022arXiv220111408L
It is widely accepted that the Feynman integral is one of the most
promising methodologies for defining a generally covariant formulation
of nonperturbative interacting quantum field theories (QFTs) without a
fixed prearranged causal background. Recent literature suggests that if
the spacetime metric is not fixed, e.g. because it is to be quantized
along with the other fields, one may not be able to avoid considering
the Feynman integral in the original Lorentz signature, without Wick
rotation. Several mathematical phenomena are known, however, which
are at some point showstoppers to a mathematically sound definition of
Feynman integral in Lorentz signature. The Feynman integral formulation,
however, is known to have a differential reformulation, called to be the
master Dyson-Schwinger (MDS) equation for the field correlators. In
this paper it is shown that a particular presentation of the MDS
equation can be cast into a mathematically rigorously defined form:
the involved function spaces and operators can be strictly defined
and their properties can be established. Therefore, MDS equation can
serve as a substitute for the Feynman integral, in a mathematically
sound formulation of constructive QFT, in arbitrary signature,
without a fixed background causal structure. It is also shown that
even in such a generally covariant setting, there is a canonical way
to define the Wilsonian regularization of the MDS equation. The main
result of the paper is a necessary and sufficient condition for the
regularized MDS solution space to be nonempty, for conformally invariant
Lagrangians. This theorem also provides an iterative approximation
algorithm for obtaining regularized MDS solutions, and is guaranteed to
be convergent whenever the solution space is nonempty. The algorithm
could eventually serve as a method for putting Lorentz signature QFTs
onto lattice, in the original metric signature.
Title: Exotic image formation in strong gravitational lensing by
clusters of galaxies - III. Statistics with HUDF
Authors: Meena, Ashish Kumar; Bagla, Jasjeet Singh
Bibcode: 2022MNRAS.515.4151M
Altcode: 2021arXiv210711955M; 2022MNRAS.tmp.1039M
We study the image formation near point singularities (swallowtail
and umbilics) in the simulated strongly lensed images of Hubble Ultra
Deep Field (HUDF) by the Hubble Frontier Fields (HFF) clusters. In this
work, we only consider nearly half of the brightest (a total of 5271)
sources in the HUDF region. For every HFF cluster, we constructed 11
realizations of strongly lensed HUDF with an arbitrary translation of
the cluster centre within the central region of HUDF and an arbitrary
rotation. In each of these realizations, we visually identify the
characteristic/exotic image formation corresponding to the different
point singularities. We find that our current results are consistent
with our earlier results based on different approaches. We also study
time delay in these exotic image formations and compare it with typical
five-image geometries. We find that the typical time delay in exotic
image formations is an order of magnitude smaller than the typical
time delay in a generic five-image geometry.
Title: A general study of decaying scalar dark matter: existing
limits and projected radio signals at the SKA
Authors: Dutta, Koushik; Ghosh, Avirup; Kar, Arpan; Mukhopadhyaya,
Biswarup
Bibcode: 2022JCAP...09..005D
Altcode: 2022arXiv220406024D
We consider a decaying scalar dark matter (DM) with mass m χ
in the range 10 GeV - 10 TeV and vary the branching ratios of all
possible two-body SM final states (excluding and including νν̅)
in the range 0%-100% to derive constraints on the total decay width
Γ using the data collected by several astrophysical and cosmological
observations. We find that, Γ ≲ 10-26 - 10-27
s-1 (excluding νν̅) and Γ ≲ 10-24 -
10-26 s-1 (including νν̅) are allowed,
depending on the values of m χ, which are most robust upper
limits on Γ for a generic decaying scalar DM. We then investigate the
prospect of the upcoming Square Kilometre Array (SKA) radio telescope
in detecting the DM decay induced radio signals originating inside
the dwarf spheroidal (dSph) galaxies. We have classified the DM
parameter space, allowed by the existing observations, independently
of the branching ratio of each individual two-body SM final state,
based on the detectability at the SKA. Excluding the νν̅ decay
mode, we find that, throughout the DM mass range considered, Γ ≳
10-30 s-1 - 10-29 s-1 is
detectable for all possible branching ratio combinations at the SKA
(assuming 100 hours of observation time), with conservative choices
for the relevant astrophysical parameters. On the other hand, when
arbitrary branching ratios are allowed also for the νν̅ decay mode,
DM decays can be probed independently of the branching ratio of each SM
final state for Γ ≳ 2 × 10-29 s-1, provided
DM masses are greater than a few hundreds of GeV.
Title: Neutrino masses and mass hierarchy: evidence for the normal
hierarchy
Authors: Jimenez, Raul; Pena-Garay, Carlos; Short, Kathleen; Simpson,
Fergus; Verde, Licia
Bibcode: 2022JCAP...09..006J
Altcode: 2022arXiv220314247J
The latest cosmological constraints on the sum of neutrino masses, in
combination with the latest laboratory measurements on oscillations,
provide "decisive" Bayesian evidence for the normal neutrino mass
hierarchy. We show that this result holds across very different
prior alternatives by exploring two extremes on the range of prior
choices. In fact, while the specific numerical value for the Evidence
depends on the choice of prior, the Bayesian odds remain greater than
140:1 across very different prior choices. For Majorana neutrinos this
has important implications for the upper limit of the neutrino-less
double beta decay half life and thus for the technology and resources
needed for future double beta decay experiments.
Title: The redshift evolution of extragalactic magnetic fields
Authors: Pomakov, V. P.; O'Sullivan, S. P.; Brüggen, M.; Vazza, F.;
Carretti, E.; Heald, G. H.; Horellou, C.; Shimwell, T.; Shulevski,
A.; Vernstrom, T.
Bibcode: 2022MNRAS.515..256P
Altcode: 2022MNRAS.tmp.1763P
Faraday rotation studies of distant radio sources can constrain
the evolution and the origin of cosmic magnetism. We use data from
the LOFAR Two-Metre Sky Survey: Data Release 2 (LoTSS DR2) to study
the dependence of the Faraday rotation measure (RM) on redshift. By
focusing on radio sources that are close in terms of their projection
on the sky, but physically unrelated ('random pairs'), we measure the
RM difference, ΔRM, between the two sources. Thus, we isolate the
extragalactic contribution to ΔRM from other contributions. We present
a statistical analysis of the resulting sample of random pairs and find
a median absolute RM difference |ΔRM| =(1.79 ± 0.09) ${\rm rad\,
m}^{-2}$, with |ΔRM| uncorrelated both with respect to the redshift
difference of the pair and the redshift of the nearer source, and a
median excess of random pairs over physical pairs of (1.65 ± 0.10)
${\rm rad\, m}^{-2}$. We seek to reproduce this result with Monte
Carlo simulations assuming a non-vanishing seed cosmological magnetic
field and a redshift evolution of the comoving magnetic field strength
that varies as (1 + z)-γ. We find the best-fitting results
B0 ≡ Bcomoving(z = 0) ≲ (2.0 ± 0.2) nG and
γ ≲ 4.5 ± 0.2 that we conservatively quote as upper limits due to
an unmodelled but non-vanishing contribution of local environments to
the RM difference. A comparison with cosmological simulations shows
our results to be incompatible with primordial magnetogenesis scenarios
with uniform seed fields of order nG.
Title: Constraining IGM enrichment and metallicity with the C IV
forest correlation function
Authors: Tie, Suk Sien; Hennawi, Joseph F.; Kakiichi, Koki; Bosman,
Sarah E. I.
Bibcode: 2022MNRAS.515.3656T
Altcode: 2022MNRAS.tmp.2079T; 2022arXiv220110571T; 2022arXiv220110571S
The distribution and abundance of metals in the diffuse intergalactic
medium (IGM) have implications for galaxy formation and evolution
models, and has been argued to be sensitive to the Universe's
reionization history. However, reduced sensitivity in the near-IR
implies that probing IGM metals at z > 4 is currently out of reach
with the traditional method of detecting individual absorbers. We
present a new technique based on clustering analysis that enables the
detection of these weak IGM absorbers. We investigate the two-point
correlation function (2PCF) of the ${\rm C\, {\small IV}}$ forest as a
probe of IGM metallicity and enrichment topology by simulating the z
= 4.5 IGM with models of inhomogeneous metal distributions. The 2PCF
of the ${\rm C\, {\small IV}}$ forest demonstrates a clear peak at a
characteristic separation corresponding to the doublet separation of the
${\rm C\, {\small IV}}$ line.The peak amplitude scales quadratically
with metallicity, while enrichment topology affects both the shape
and amplitude of the 2PCF. For models consistent with the distribution
of metals at z ~ 3, we find that we can constrain [C/H] to within 0.2
dex, log$\, M_{\rm {min}}$ to within 0.4 dex, and R to within 15 per
cent. We show that CGM absorbers can be reliably identified and masked,
thus recovering the underlying IGM signal. The auto-correlation of
the metal-line forest presents a compelling avenue to constrain the
IGM metallicity and enrichment topology with high precision at z >
4, thereby pushing such measurements into the Epoch of Reionization.
Title: The effect of modified dispersion relations on the
thermodynamics of Schwarzschild black hole surrounded by quintessence
Authors: Hamil, B.; Lütfüoğlu, B. C.
Bibcode: 2022arXiv220900954H
Altcode:
In this manuscript, we investigate the effects of a modified dispersion
relation on the thermodynamics of Schwarzschild black hole surrounded
by the quintessence matter. We find that the MDR-correction states
the same lower bound on the horizon, while the quintessence matter
specifies the upper bound to the horizon depending on the state
parameter. Due to MDR-correction and quintessence matter presence,
we observe modifications in equation of state and specific heat
functions of black hole. We show that a remnant can occur according
to quintessence matter, and the black hole's stability depends only
on the modified dispersion relation.
Title: Boosting the 21 cm forest signals by the clumpy substructures
Authors: Kadota, Kenji; Villanueva-Domingo, Pablo; Ichiki, Kiyotomo;
Hasegawa, Kenji
Bibcode: 2022arXiv220901305K
Altcode:
We study the contribution of subhalos to the 21 cm forest signal. The
halos can host the substructures and including the effects of those
small scale clumps can potentially boost the 21 cm optical depth
in favor of detecting the 21 cm forest signals. We estimate the
boost factor representing the ratio of the optical depth due to the
subhalo contribution and that due to the host halo alone (without
subhalos). Even though the optical depth boost factor is negligible for
a small host halo with the mass of order $10^5 M_{\odot}$, the subhalo
contribution can enhance the optical depth by an order of magnitude for
a host halo of order $10^7 M_{\odot}$. The resultant 21 cm absorption
line abundance which is obtained by integrating over the halo mass
range relevant for the 21 cm forest signal can be enhanced by up to of
order $10\%$ due to the substructures. The larger boost factor for a
larger host halo would be of particular interest for the 21 cm forest
detection because the the contribution of the larger host halos to the
21 cm forest signals is smaller due to their higher temperature and less
abundance than the smaller host halos. The subhalos hence can well help
the larger host halos more important for the signal estimation which,
without considering the subhalos, may not give appreciable contribution
to 21 cm forest signals.
Title: Symphony: Cosmological Zoom-in Simulation Suites over Four
Decades of Host Halo Mass
Authors: Nadler, Ethan O.; Mansfield, Philip; Wang, Yunchong;
Du, Xiaolong; Adhikari, Susmita; Banerjee, Arka; Benson, Andrew;
Darragh-Ford, Elise; Mao, Yao-Yuan; Wagner-Carena, Sebastian; Wechsler,
Risa H.; Wu, Hao-Yi
Bibcode: 2022arXiv220902675N
Altcode:
We present Symphony, a compilation of $262$ cosmological, cold dark
matter-only zoom-in simulations spanning four decades of host halo mass,
from $10^{11}~M_{\mathrm{\odot}}$ to $10^{15}~M_{\mathrm{\odot}}$. This
compilation includes three existing simulation suites at the cluster
and Milky Way-mass scales, and two new suites: $39$ Large Magellanic
Cloud-mass ($10^{11}~M_{\mathrm{\odot}}$) and $49$ strong-lens-analog
($10^{13}~M_{\mathrm{\odot}}$) group-mass hosts. Across the entire
host halo mass range, the highest-resolution regions in these
simulations are resolved with a dark matter particle mass of $\approx
3\times 10^{-7}$ times the host virial mass and a Plummer-equivalent
gravitational softening length of $\approx 9\times 10^{-4}$ times
the host virial radius, on average. We measure correlations between
subhalo abundance and host concentration, formation time, and maximum
subhalo mass, all of which peak at the Milky Way host halo mass
scale. Subhalo abundances are $\approx 50\%$ higher in clusters than
in lower-mass hosts at fixed sub-to-host halo mass ratios. Subhalo
radial distributions are approximately self-similar as a function
of host mass and are less concentrated than hosts' underlying dark
matter distributions. We compare our results to the semi-analytic
model $\mathrm{\texttt{Galacticus}}$, which predicts subhalo mass
functions with a higher normalization at the low-mass end and radial
distributions that are slightly more concentrated than Symphony. We
use $\mathrm{\texttt{UniverseMachine}}$ to model halo and subhalo
star formation histories in Symphony, and we demonstrate that these
predictions resolve the formation histories of the halos that host
nearly all currently observable satellite galaxies in the Universe. To
promote open use of Symphony, data products are publicly available
at http://phil-mansfield.github.io/symphony.
Title: The size--mass and other structural parameter ($n, \mu_z,
R_z$) relations for local bulges/spheroids from multicomponent
decompositions
Authors: Hon, Dexter S. -H.; Graham, Alister W.; Sahu, Nandini
Bibcode: 2022arXiv220901550H
Altcode:
We analyse the bulge/spheroid size-(stellar mass), $R_{\rm
e,Sph}-M_{\rm *,Sph}$, relation and spheroid structural parameters
for 202 local (predominantly $\lesssim 110~\rm Mpc$) galaxies
spanning $ M_*\sim 3\times10^{9}-10^{12}~\rm M_{\odot}$ and $
0.1 \lesssim R_{\rm e, Sph}\lesssim32~\rm kpc$ from multicomponent
decomposition. The correlations between the spheroid Sérsic index
($n_{\rm Sph}$), central surface brightness ($\mu_{\rm 0, Sph}$),
effective half-light radius ($R_{\rm e, Sph}$), absolute magnitude
($\mathfrak{M}_{\rm Sph}$) and stellar mass ($M_{\rm *,Sph}$) are
explored. We also investigate the consequences of using different
scale radii, $R_{z,\rm Sph}$, encapsulating a different fraction ($z$,
from 0 to 1) of the total luminosity. The correlation strengths for
projected mass densities, $\Sigma_z$ and $\langle \Sigma \rangle_z$,
vary significantly with the choice of $z$. Spheroid size ($R_{\rm
z, Sph}$) and mass ($M_{\rm *,Sph}$) are strongly correlated for
all light fractions $z$. We find: $\log(R_{\rm e,Sph}/\rm kpc) =
0.88\log(M_{\rm *,Sph}/\rm M_{\odot})-9.15$ with a small scatter of
$\Delta_{rms} = 0.24~\rm dex$. This result is discussed relative to
the \textit{curved} size-mass relation for early-type galaxies due to
their discs yielding larger galaxy radii at lower masses. Moreover,
the slope of our spheroid size-mass relation is a factor of $\sim3$,
steeper than reported bulge size-mass relations, and with bulge sizes
at $M_{\rm *,sph}\sim 3\times10^9~M_\odot$ which are 2 to 3 times
smaller. Finally, we show that the local spheroids align well with
quiescent galaxies at $z\sim1.25$--$2.25$. In essence, local spheroids
and high-$z$ quiescent galaxies appear structurally similar, likely
dictated by the virial theorem.
Title: Simulation of the Solar Energetic Particle Event on 2020 May
29 Observed by Parker Solar Probe
Authors: Cheng, Lei; Zhang, Ming; Lario, David; Balmaceda, Laura A.;
Kwon, Ryun Young; Cohen, Christina
Bibcode: 2022arXiv220902566C
Altcode:
This paper presents a stochastic three-dimensional (3D) focused
transport simulation of solar energetic particles (SEPs) produced by
a data-driven coronal mass ejection (CME) shock propagating through
a data-driven model of coronal and heliospheric magnetic fields. The
injection of SEPs at the CME shock is treated using diffusive shock
acceleration of post-shock superthermal solar wind ions. A time backward
stochastic simulation is employed to solve the transport equation to
obtain the SEP time-intensity profile at any location, energy, and pitch
angle. The model is applied to a SEP event on 2020 May 29, observed by
STEREO-A close to 1 au and by Parker Solar Probe (PSP) when it was about
0.33 au away from the Sun. The SEP event was associated with a very slow
CME with a plane-of-sky speed of 337 km/s at a height below 6 $\rm R_S$
as reported in the SOHO/LASCO CME catalog. We compute the time profiles
of particle flux at PSP and STEREO-A locations, and estimate both the
spectral index of the proton energy spectrum for energies between 2
and 16 MeV and the equivalent path length of the magnetic field lines
experienced by the first arriving SEPs. We found that the simulation
results are well correlated with observations. The SEP event could be
explained by the acceleration of particles by a weak CME shock in the
low solar corona that is not magnetically connected to the observers.
Title: The Fermi Gamma Ray Sky: summary of recent Observations
Authors: Principe, Giacomo
Bibcode: 2022arXiv220903652P
Altcode:
The Fermi Gamma-ray Space Telescope was launched more than 13 years
ago and since then it has dramatically changed our knowledge of the
gamma-ray sky. With more than three billions photons from the whole sky,
collected in the energy range between 20 MeV and more than 300 GeV,
and beyond 6,000 detected sources, LAT observations have been crucial
to improving our understanding of particle acceleration and gamma-ray
production in astrophysical sources. In this proceeding, I will review
recent science highlights from the LAT. I will focus on the recent
source catalog release, as well as on the main transient phenomena
seen with the LAT with multi-wavelength and multi-messenger connection.
Title: Exoplanet Atmosphere Retrievals in 3D Using Phase Curve Data
with ARCiS: Application to WASP-43b
Authors: Chubb, Katy L.; Min, Michiel
Bibcode: 2022A&A...665A...2C
Altcode: 2022arXiv220609738C
Aims: Our goal is to create a retrieval framework which
encapsulates the three-dimensional (3D) nature of exoplanet atmospheres,
and to apply it to observed emission phase curve and transmission
spectra of the `hot Jupiter' exoplanet WASP-43b.
Methods: We
present our 3D framework, which is freely available as a stand-alone
module from GitHub. We use the atmospheric modelling and Bayesian
retrieval package ARCiS (ARtful modelling Code for exoplanet Science)
to perform a series of eight 3D retrievals on simultaneous transmission
(HST/WFC3) and phase-dependent emission (HST/WFC3 and Spitzer/IRAC)
observations of WASP-43b as a case study. Via these retrieval setups,
we assess how input assumptions affect our retrieval outcomes. In
particular we look at constraining equilibrium chemistry vs. a free
molecular retrieval, the case of no clouds vs. parametrised clouds,
and using Spitzer phase data that have been reduced from two different
literature sources. For the free chemistry retrievals, we retrieve
abundances of H2O, CH4, CO, CO2,
AlO, and NH3 as a function of phase, with many more
species considered for the equilibrium chemistry retrievals.
Results: We find consistent super-solar C/O (0.6-0.9) and super-solar
metallicities (1.7-2.9 dex) for all retrieval setups that assume
equilibrium chemistry. We find that atmospheric heat distribution,
hotspot shift (≈15.6° vs. 4.5° for the different Spitzer
datasets), and temperature structure are very influenced by the
choice of Spitzer emission phase data. We see some trends in molecular
abundances as a function of phase, in particular for CH4 and
H2O. Comparisons are made with other studies of WASP-43b,
including global climate model (GCM) simulations, available in the
literature.
Conclusions: The parametrised 3D setup we have
developed provides a valuable tool to analyse extensive observational
datasets such as spectroscopic phase curves. We conclude that further
near-future observations with missions such as the James Webb Space
Telescope and Ariel will greatly improve our understanding of the
atmospheres of exoplanets such as WASP-43b. This is particularly evident
from the effect that the current phase-dependent Spitzer emission data
has on retrieved atmospheres.
Title: INTEGRAL follow up of the new outburst from SAX J1808.4-3658
Authors: Ferrigno, C.; Sanna, A.; Bozzo, E.; Savchenko, V.; Burderi,
L.; Riggio, A.; Di Salvo, T.; Altamirano, D.; Chenevez, J.; Kuulkers,
E.; Sanchez-Fernandez, C.
Bibcode: 2022ATel15601....1F
Altcode:
On August 19, 2022, the MAXI/GSC nova alert system reported X-ray
activity in the direction of the known accreting millisecond X-ray
pulsar SAX J1808.4-3658 (Atel #15563).
Title: 3D Selection of 167 Substellar Companions to Nearby Stars
Authors: Feng, Fabo; Butler, R. Paul; Vogt, Steven S.; Clement,
Matthew S.; Tinney, C. G.; Cui, Kaiming; Aizawa, Masataka; Jones,
Hugh R. A.; Bailey, J.; Burt, Jennifer; Carter, B. D.; Crane, Jeffrey
D.; Dotti, Francesco Flammini; Holden, Bradford; Ma, Bo; Ogihara,
Masahiro; Oppenheimer, Rebecca; O'Toole, S. J.; Shectman, Stephen A.;
Wittenmyer, Robert A.; Wang, Sharon X.; Wright, D. J.; Xuan, Yifan
Bibcode: 2022ApJS..262...21F
Altcode: 2022arXiv220812720F
We analyze 5108 AFGKM stars with at least five high-precision radial
velocity points, as well as Gaia and Hipparcos astrometric data,
utilizing a novel pipeline developed in previous work. We find 914
radial velocity signals with periods longer than 1000 days. Around
these signals, 167 cold giants and 68 other types of companions are
identified, through combined analyses of radial velocity, astrometry,
and imaging data. Without correcting for detection bias, we estimate
the minimum occurrence rate of the wide-orbit brown dwarfs to be 1.3%,
and find a significant brown-dwarf valley around 40 M Jup. We
also find a power-law distribution in the host binary fraction beyond
3 au, similar to that found for single stars, indicating no preference
of multiplicity for brown dwarfs. Our work also reveals nine substellar
systems (GJ 234 B, GJ 494 B, HD 13724 b, HD 182488 b, HD 39060 b and c,
HD 4113 C, HD 42581 d, HD 7449 B, and HD 984 b) that have previously
been directly imaged, and many others that are observable at existing
facilities. Depending on their ages, we estimate that an additional
10-57 substellar objects within our sample can be detected with current
imaging facilities, extending the imaged cold (or old) giants by an
order of magnitude.
Title: Could the 'Wow' signal have originated from a stochastic
repeating beacon?
Authors: Kipping, David; Gray, Robert
Bibcode: 2022MNRAS.515.1122K
Altcode: 2022arXiv220608374K; 2022MNRAS.tmp.1778K
The famous 'Wow' signal detected in 1977 remains arguably the most
compelling SETI signal ever found. The original Big Ear data require
that the signal turned on/off over the span of ~3 min (time difference
between the dual antennae), yet persisted for 72 s (duration of
a single beam sweep). Combined with the substantial and negative
follow-up efforts, these observations limit the allowed range of
signal repeat schedules, to the extent that one might question the
credibility of the signal itself. Previous work has largely excluded
the hypothesis of a strictly periodic repeating source, for periods
shorter than 40 h. However, a non-periodic, stochastic repeater remains
largely unexplored. Here, we employ a likelihood emulator using the
Big Ear observing logs to infer the probable signal properties under
this hypothesis. We find that the maximum a-posteriori solution has a
likelihood of 32.3 per cent, highly compatible with the Big Ear data,
with a broad 2σ credible interval of signal duration 72 s<T <
77 min and mean repeat rate 0.043 d-1 < λ < 59.8
d-1. We extend our analysis to include 192 h of subsequent
observations from META, Hobart, and ATA, which drops the peak likelihood
to 1.78 per cent, and thus in tension with the available data at
the 2.4σ level. Accordingly, the Wow signal cannot be excluded as
a stochastic repeater with available data, and we estimate that 62 d
of accumulated additional observations would be necessary to surpass
3σ confidence.
Title: Environmental cluster effects and galaxy evolution: The H I
properties of the Abell clusters A85/A496/A2670
Authors: López-Gutiérrez, M. M.; Bravo-Alfaro, H.; van Gorkom,
J. H.; Caretta, C. A.; Durret, F.; Núñez-Beltrán, L. M.; Jaffé,
Y. L.; Hirschmann, M.; Pérez-Millán, D.
Bibcode: 2022MNRAS.tmp.2331L
Altcode: 2022arXiv220900764L
We study the impact of local environment on the transformation
of spiral galaxies in three nearby (z < 0.08) Abell clusters:
A85/A496/A2670. These systems were observed in H I with the Very
Large Array, covering a volume extending beyond the virial radius
and detecting 10, 58, 38 galaxies, respectively. High fractions
(0.40-0.86) of bright spirals [log(M*/M⊙)
= 9 - 10] are not detected in H I. We provide further evidence of
environmental effects consisting in significant fractions (0.10-0.33)
of abnormal objects and a number of red (passive) spirals, suggesting
an ongoing process of quenching. Ram-pressure profiles, and the sample
of the brightest spirals used as test particles for environmental
effects, indicate that ram-pressure plays an important role in
stripping and transforming late-types. Phase-space diagrams and our
search for substructures helped to trace the dynamical stage of the
three systems. This was used to compare the global cluster effects
vs. pre-processing, finding that the former is the dominating mechanism
in the studied clusters. By contrasting the global distribution of H
I normal vs. H I disturbed spirals in the combined three clusters,
we confirm the expected correlation of disturbed objects located,
on average, at shorter projected radii. However, individual clusters
do not necessarily follow this trend and we show that A496 and A2670
present an atypical behavior. In general we provide conclusive evidence
about the dependence of the transformation of infalling spirals on
the ensemble of cluster properties like mass, ICM density, dynamical
stage and surrounding large-scale structure.
Title: Could kilomasers pinpoint supermassive stars?
Authors: Nowak, Katarzyna; Krause, Martin. G. H.; Schaerer, Daniel
Bibcode: 2022arXiv220902712N
Altcode:
A strong nuclear kilomaser, W1, has been found in the nearby galaxy
NGC 253, associated with a forming super star cluster. Kilomasers could
arise from the accretion disc around supermassive stars (>10^3 Msun),
hypothetical objects that have been proposed as polluters responsible
for the chemical peculiarities in globular clusters. The supermassive
stars would form via runaway collisions, simultaneously with the
cluster. Their discs are perturbed by stellar flybys, inspiralling and
colliding stars. This raises the question if an accretion disc would
at all be able to survive in such a dynamic environment and mase water
lines. We investigated what the predicted maser spectrum of such a disc
would look like using 2D hydrodynamic simulations and compared this to
the W1 kilomaser. We derived model maser spectra from the simulations by
using a general maser model for appropriate disc temperatures. All our
model discs survived. The model maser spectra for the most destructive
case for the simulations of M = 1000 Msun are a reasonable match with
the W1 kilomaser spectrum in terms of scaling, flux values and some of
the signal trends. Details in the spectrum suggest that a star of a
few 1000 Msun might fit even better, with 10,000 Msun clearly giving
too large velocities. Our investigations thus support the hypothesis
that kilomasers could pinpoint supermassive stars.
Title: AGN feedback in NGC 3982
Authors: Joseph, Prajwel; George, Koshy; Paul, K. T.
Bibcode: 2022arXiv220904914J
Altcode:
The energetic feedback from supermassive black holes can influence
star formation at the centres of galaxies. Observational evidence
for AGN impact on star formation can be searched in galaxies by
combining ultraviolet imaging and optical integral field unit data. The
ultraviolet flux directly traces recent star formation, and the integral
field unit data can reveal dust attenuation, gas ionisation mechanisms,
and gas/stellar kinematics from the central regions of the galaxy
disk. A pilot study on NGC 3982 shows star formation suppression in the
central regions of the galaxy, likely due to negative AGN feedback, and
enhanced star formation in the outer regions. The case of NGC 3982 could
be observational evidence of AGN feedback operating in a Seyfert galaxy.
Title: Vacuum polarization on three-dimensional anti-de Sitter
space-time with Robin boundary conditions
Authors: Namasivayam, Sivakumar; Winstanley, Elizabeth
Bibcode: 2022arXiv220901133N
Altcode:
We study a quantum scalar field, with general mass and coupling to the
scalar curvature, propagating on three-dimensional global anti-de Sitter
space-time. We determine the vacuum and thermal expectation values
of the square of the field, also known as the vacuum polarisation
(VP). We consider values of the scalar field mass and coupling for
which there is a choice of boundary conditions giving well-posed
classical dynamics. We apply Dirichlet, Neumann and Robin (mixed)
boundary conditions to the field at the space-time boundary. We find
finite values of the VP when the parameter governing the Robin boundary
conditions is below a certain critical value. For all couplings, the
vacuum expectation values of the VP with either Neumann or Dirichlet
boundary conditions are constant and respect the maximal symmetry of
the background space-time. However, this is not the case for Robin
boundary conditions, when both the vacuum and thermal expectation
values depend on the space-time location. At the space-time boundary,
we find that both the vacuum and thermal expectation values of the VP
with Robin boundary conditions converge to the result when Neumann
boundary conditions are applied, except in the case of Dirichlet
boundary conditions.
Title: The Cosmic Ultraviolet Baryon Survey (CUBS) V: On the
Thermodynamic Properties of the Cool Circumgalactic Medium at $z
< 1$
Authors: Qu, Zhijie; Chen, Hsiao-Wen; Rudie, Gwen C.; Zahedy, Fakhri
S.; Johnson, Sean D.; Boettcher, Erin; Cantalupo, Sebastiano; Chen,
Mandy C.; Cooksey, Kathy L.; DePalma, David; Faucher-Giguère,
Claude-André; Rauch, Michael; Schaye, Joop; Simcoe, Robert A.
Bibcode: 2022arXiv220901228Q
Altcode:
This paper presents a systematic study of the photoionization
and thermodynamic properties of the cool circumgalactic medium
(CGM) as traced by rest-frame ultraviolet absorption lines around
26 galaxies at redshift $z\lesssim1$. The study utilizes both
high-quality far-ultraviolet and optical spectra of background QSOs
and deep galaxy redshift surveys to characterize the gas density,
temperature, and pressure of individual absorbing components and to
resolve their internal non-thermal motions. The derived gas density
spans more than three decades, from $\log (n_{\rm H}/{\rm cm^{-3}})
\approx -4$ to $-1$, while the temperature of the gas is confined in
a narrow range of $\log (T/{\rm K})\approx 4.3\pm 0.3$. In addition, a
weak anti-correlation between gas density and temperature is observed,
consistent with the expectation of the gas being in photoionization
equilibrium. Furthermore, decomposing the observed line widths into
thermal and non-thermal contributions reveals that more than 30%
of the components at $z\lesssim 1$ exhibit line widths driven by
non-thermal motions, in comparison to $<20$% found at $z\approx
2$-3. Attributing the observed non-thermal line widths to intra-clump
turbulence, we find that massive quenched galaxies on average exhibit
higher non-thermal broadening/turbulent energy in their CGM compared
to star-forming galaxies at $z\lesssim 1$. Finally, strong absorption
features from multiple ions covering a wide range of ionization energy
(e.g., from Mg II to O IV) can be present simultaneously in a single
absorption system with kinematically aligned component structure,
but the inferred pressure in different phases may differ by a factor
of $\approx 10$.
Title: The Role of Strong Magnetic Fields in Stabilizing Highly
Luminous, Thin Disks
Authors: Mishra, Bhupendra; Fragile, P. Chris; Anderson, Jessica;
Blankenship, Aidan; Li, Hui; Nalewajko, Krzysztof
Bibcode: 2022arXiv220903317M
Altcode:
We present a set of three-dimensional, global, general
relativistic radiation magnetohydrodynamic simulations of thin,
radiation-pressure-dominated accretion disks surrounding a non-rotating,
stellar-mass black hole. The simulations are initialized using the
Shakura-Sunyaev model with a mass accretion rate of $\dot{M} = 3
L_\mathrm{Edd}/c^2$ (corresponding to $L=0.17 L_\mathrm{Edd}$). Our
previous work demonstrated that such disks are thermally unstable when
accretion is driven by an $\alpha$-viscosity. In the present work, we
test the hypothesis that strong magnetic fields can both drive accretion
through the magneto-rotational instability and restore stability to
such disks. We test four initial magnetic field configurations: 1)
a zero-net-flux case with a single, radially extended set of magnetic
field loops (dipole); 2) a zero-net-flux case with two radially extended
sets of magnetic field loops of opposite polarity stacked vertically
(quadrupole); 3) a zero-net-flux case with multiple radially concentric
rings of alternating polarity (multi-loop); and 4) a net-flux, vertical
magnetic field configuration (vertical). In all cases, the fields
are initially weak, with the gas-to-magnetic pressure ratio $\gtrsim
100$. Based on the results of these simulations, we find that the dipole
and multi-loop configurations remain thermally unstable like their
$\alpha$-viscosity counterpart, in our case collapsing vertically on the
local thermal timescale and never fully recovering. The vertical case,
on the other hand, stabilizes and remains so for the duration of our
tests (many thermal timescales). The quadrupole case is intermediate,
showing signs of both stability and instability. The key stabilizing
criteria is, $P_\mathrm{mag} \gtrsim 0.5P_\mathrm{tot}$ with strong
toroidal fields near the disk midplane. We also report a comparison
of our models to the standard Shakura-Sunyaev disk.
Title: Regular black holes in three dimensions and the zero point
length
Authors: Jusufi, Kimet
Bibcode: 2022arXiv220904433J
Altcode:
In this paper, by means of regularisation procedure via $r\to
\sqrt{r^2+l_0^2}$ (where $l_0$ can play the role of zero point length),
we first modify the gravitational and electromagnetic potentials in
two dimensions and then we solve the Einstein field equations to end
up with an exact and regular black hole solution in three dimensions
with a negative cosmological constant. We show that, the black hole
solution is asymptotically AdS, non-singular at the origin and, under
specific conditions, it has a flat de Sitter core at the origin. As
a special case, we obtain the charged Banados-Teitelboim-Zanelli
(BTZ) solution. Finally, using a dimensional continuation and the NJ
algorithm, we end up with a legitimate rotating black hole solution
in three dimensions.
Title: The Fundamental Plane Is Not a Plane: Warped Nature of the
Fundamental Plane of Early-type Galaxies and Its Implication for
Galaxy Formation
Authors: Yoon, Yongmin; Park, Changbom
Bibcode: 2022ApJ...936...22Y
Altcode: 2022arXiv220807656Y
Based on 16,283 early-type galaxies (ETGs) in 0.025 ≤ z
spec < 0.055 from Sloan Digital Sky Survey data,
we show that the fundamental plane (FP) of ETGs is not a plane in
the strict sense but is a curved surface with a twisted shape whose
orthogonal direction to the surface is shifted as the central velocity
dispersion (σ 0) or mean surface brightness within the
half-light radius (μ e ) changes. When ETGs are divided
into subsamples according to σ 0, the coefficient of μ
e of the FP increases, whereas the zero-point of the FP
decreases at higher σ 0. Taking the z band as an example,
the coefficient of μ e rises from 0.28 to 0.36 as σ
0 increases from ~100 to ~300 km s-1. At the same
time, the zero-point of the FP falls from -7.5 to -9.0 in the same σ
0 range. The consistent picture on the curved nature of
the FP is also reached by inspecting changes in the FP coefficients
for ETG subsamples with different μ e . By examining
scaling relations that are projections of the FP, we suggest that the
warped nature of the FP may originate from dry merger effects that
are imprinted more prominently in ETGs with higher masses.
Title: Albedo variegation on Comet 67P/Churyumov-Gerasimenko
Authors: Davidsson, Björn J. R.; Buratti, Bonnie J.; Hicks, Michael D.
Bibcode: 2022MNRAS.tmp.2313D
Altcode:
We here study the level of albedo variegation on the nucleus of Comet
67P/Churyumov-Gerasimenko. This is done by fitting the parameters of
a standard photometric phase function model to disk-average radiance
factor data in images acquired by the Rosetta/OSIRIS Narrow Angle
Camera in the orange filter. Local discrepancies between the observed
radiance factor and the disk-average solution are interpreted as a
proxy $\mathcal {W}$ of the local single-scattering albedo. We find a
wide range $0.02 \lesssim \mathcal {W}\lesssim 0.09$ around an average
of $\mathcal {W}=0.055$. The observed albedo variegation is strongly
correlated with nucleus morphology - smooth terrain is brighter, and
consolidated terrain is darker, than average. Furthermore, we find
that smooth terrain darken prior to morphological changes, and that
stratigraphically low terrain (with respect to the centre of each
nucleus lobe) is brighter than stratigraphically high terrain. We
propose that the observed albedo variegation is due to differences
in porosity and the coherent effect: compaction causes small brighter
particles to act collectively as larger optically effective particles,
that are darker. Accordingly, we consider the dark consolidated terrain
materials more compacted than smooth terrain materials, and darkening
of the latter is due to subsidence.
Title: Statistical investigation of the kinematic and thermal
properties of supra-arcade downflows observed during a solar flare
Authors: Tan, Guangyu; Hou, Yijun; Tian, Hui
Bibcode: 2022MNRAS.tmp.2292T
Altcode: 2022arXiv220814737T
Supra-arcade downflows (SADs) are dark structures descending towards
post-reconnection flare loops observed in extreme ultraviolet or X-ray
observations and are closely related to magnetic reconnection during
solar flares. Due to the lack of statistical study on SADs in a single
flare, evolutions of kinematic and thermal properties of SADs during
the flare process still remain obscure. In this work, we identified 81
SADs in a flare that occurred on 2013 May 22 using observations of the
Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory
(SDO). The kinematic properties of each SAD, including the appearance
time, height, projective velocity, and acceleration were recorded. We
found that the appearance heights of SADs become larger during the
flare, which is likely due to the lift of the bottom of the plasma
sheet. In the flare decay phase, the region where SADs mainly appear
moves from the north part to the south side possibly related to
a secondary eruption in the south side. The trajectories of most
SADs can be fitted by one or two deceleration processes, while some
special ones have positive accelerations during the descent. For the
thermal properties, we selected 54 SADs, whose front and body could be
clearly distinguished from the surrounding during the entire descent,
to perform Differential Emission Measure analysis. It is revealed that
the temperatures of the SAD front and body tend to increase during
their downward courses, and the relationship between the density and
temperature indicates that the heating is mainly caused by adiabatic
compression.
Title: Binaries with possible compact components discovered from
the LAMOST Time-Domain Survey of four $K$2 plates
Authors: Xue, Li; Song, Wang; Xinlin, Zhao; Zhongrui, Bai; Hailong,
Yuan; Haotong, Zhang; Jifeng, Liu
Bibcode: 2022arXiv220900765X
Altcode:
Time-domain (TD) spectroscopic data from the Large Sky Area Multi-Object
Fiber Spectroscopic Telescope (LAMOST) can provide accurate and
high-cadence radial velocities (RVs). In this work, we search for
binaries with compact components with RV monitoring method by using the
LAMOST TD survey of four $K$2 plates. Three binary systems including an
unseen white dwarf or neutron star are found. For each binary system,
we estimate the stellar parameters of the visible star and orbital
parameters, and finally calculate the binary mass function and the
minimum mass of the unseen star. No obvious double-lined feature is
seen from the LAMOST medium-resolution spectra of the three sources. In
addition, we found no X-ray counterpart for all these sources but
UV companions for two of them. Spectral disentangling also shows no
additional component with optical absorption spectra, supporting that
these systems contain compact objects.
Title: Jet-ISM interaction in NGC 1167 / B2 0258+35, A LINER with
an AGN past
Authors: Fabbiano, G.; Paggi, A.; Morganti, R.; Balokovic, M.; Elvis,
A.; Mukherjee, D.; Meenakshi, M.; Siemiginowska, A.; Murthy, S. M.;
Oosterloo, T. A.; Wagner, A. Y.; Bicknell, G.
Bibcode: 2022arXiv220902549F
Altcode:
We report the results of joint Chandra/ACIS - NuSTAR deep observations
of NGC 1167, the host galaxy of the young radio jet B2 0258+35. In the
ACIS data we detect X-ray emission, extended both along and orthogonal
to the jet. At the end of the SE radio jet, we find lower-energy X-ray
emission that coincides with a region of CO turbulence and fast outflow
motions. This suggests that the hot Interstellar Medium (ISM) may be
compressed by the jet and molecular outflow, resulting in more efficient
cooling. Hydrodynamic simulations of jet-ISM interaction tailored to
NGC 1167 are in agreement with this conclusion and with the overall
morphology and spectra of the X-ray emission. The faint hard nuclear
source detected with Chandra and the stringent NuSTAR upper limits on
the harder X-ray emission show that the active galactic nucleus (AGN) in
NGC 1167 is in a very low-accretion state. However, the characteristics
of the extended X-ray emission are more consonant to those of luminous
Compton Thick AGNs, suggesting that we may be observing the remnants
of a past high accretion rate episode, with sustained strong activity
lasting ~ 2 x 103 yr. We conclude that NGC1167 is presently a LINER,
but was an AGN in the past, given the properties of the extended X-ray
emission and their similarity with those of CT AGN extended emission.
Title: Spectroscopic Classifications of Optical Transients with the
Lick Shane telescope
Authors: Jones, D. O.; Tinyanont, S.; Foley, R. J.
Bibcode: 2022ATel15595....1J
Altcode:
We report the following classifications of optical transients from
spectroscopic observations with the Kast spectrograph on the Shane
telescope. The targets were supplied by ALeRCE (selected from the ZTF
data stream).
Title: The Internal Proper Motion Kinematics of NGC 346: Past
Formation and Future Evolution
Authors: Sabbi, E.; Zeidler, P.; Marel, R. P. van der; Nota,
A.; Anderson, J.; Gallagher, J. S.; Lennon, D. J.; Smith, L. J.;
Gennaro, M.
Bibcode: 2022ApJ...936..135S
Altcode: 2022arXiv220903215S
We investigate the internal kinematics of the young star-forming region
NGC 346 in the Small Magellanic Cloud (SMC). We used two epochs of deep
F555W and F814W Hubble Space Telescope Advanced Camera for Surveys
observations with an 11 yr baseline to determine proper motions and
study the kinematics of different populations, as identified by their
color-magnitude diagram and spatial distribution characteristics. The
proper motion field of the young stars shows a complex structure with
spatially coherent patterns. NGC 346's upper main sequence and pre-main
sequence stars follow very similar motion patterns, with the outer parts
of the cluster being characterized both by outflows and inflows. The
proper motion field in the inner ~10 pc shows a combination of rotation
and inflow, indicative of inspiraling motion. The rotation velocity in
this regions peaks at ~3 km s-1, whereas the inflow velocity
peaks at ~1 km s-1. Subclusters and massive young stellar
objects in NGC 346 are found at the interface of significant changes in
the coherence of the proper motion field. This suggests that turbulence
is the main star formation driver in this region. Similar kinematics
observed in the metal-poor NGC 346 and in the Milky Way's star-forming
regions suggest that the differences in the cooling conditions due to
different amounts of metallicity and dust density between the SMC and
our galaxy are too small to alter significantly the process of star
cluster assembly and growth. The main characteristics of our findings
are consistent with various proposed star cluster formation models.
Title: The Internal Line-of-Sight Kinematics of NGC 346: The Rotation
of the Core Region
Authors: Zeidler, Peter; Sabbi, Elena; Nota, Antonella
Bibcode: 2022ApJ...936..136Z
Altcode: 2022arXiv220903237Z
We present the stellar radial velocity analysis of the central
$1^{\prime} \times 1^{\prime} $ of the young massive Small Magellanic
Cloud star cluster NGC 346. Using VLT/MUSE integral field spectroscopy
in combination with Hubble Space Telescope photometry, we extract 103
spectra of cluster member stars suited to measure accurate line-of-sight
kinematics. The cluster member stars show two distinct velocity groups
at ${v}_{1}=-{3.3}_{-0.2}^{+0.3}\,\mathrm{km}\,{{\rm{s}}}^{-1}$
and ${v}_{2}={2.6}_{-0.1}^{+0.1}\,\mathrm{km}\,{{\rm{s}}}^{-1}$
, relative to the systemic velocity of (165.5 ±
0.2) km s-1, and hint at a third group at
${v}_{3}={9.4}_{-0.1}^{+0.1}\,\mathrm{km}\,{{\rm{s}}}^{-1}$ . We
show that there is neither a correlation between the velocity
groups and the spatial location of the stars, nor their locus on
optical color-magnitude diagrams, which makes the stellar velocity
a key parameter to separate individual stellar components in such
a young star cluster. Velocity group 2 shows clear rotation with
Ω2 =(-0.4 ± 0.1) Myr-1, corresponding to
(-4.9 ± 0.7) km s-1 at radial distance of 10 pc from the
center, a possible remnant of the formation process of NGC 346 through
the hierarchical collapse of the giant molecular cloud. The ionizing
gas has lost any natal kinematic imprint and shows clear expansion,
driven by far-ultraviolet fluxes and stellar winds of the numerous
OB stars in the cluster center. The size of this expanding bubble
and its expansion velocity of 7.9 km s-1 are in excellent
agreement with the estimate that the latest star formation episode
occurred about two million years ago.
Title: Mid-IR detection of GX 339-4 with VLT/VISIR, and upcoming
JWST observation
Authors: Russell, David M.; Gandhi, Poshak; Alabarta, Kevin; Baglio,
M. Cristina; Belloni, Tomaso; Casella, Piergiorgio; Ceccobello,
Chiara; Trigo, Maria Diaz; Gallo, Elena; Homan, Jeroen; Koljonen,
Karri; Markoff, Sera; Miller-Jones, James C. A.; O'Brien, Kieran S.;
Rodriguez, Jérôme; Russell, Thomas D.; Saikia, Payaswini; Shahbaz,
Tariq; Silvakoff, Gregory; Soria, Roberto; Tetarenko, Alexandra
Bibcode: 2022ATel15596....1R
Altcode:
A new outburst from the recurrent transient X-ray binary, GX 339-4,
was detected in 2022 August. The X-ray flux increased from 23 to 28
August in MAXI (2-20 keV) and Swift/BAT (15-50 keV; ATel #15577), and
a brightening in more sensitive Swift/XRT observations was reported
to have started around 6 August (ATel #15578).
Title: Constraints on the Spindown of Fully Convective M Dwarfs
Using Wide Field Binaries
Authors: Pass, Emily K.; Charbonneau, David; Irwin, Jonathan M.;
Winters, Jennifer G.
Bibcode: 2022ApJ...936..109P
Altcode: 2022arXiv220615318P
M dwarfs remain active over longer timescales than their Sunlike
counterparts, with potentially devastating implications for the
atmospheres of their planets. However, the age at which fully
convective M dwarfs transition from active and rapidly rotating to
quiescent and slowly rotating is poorly understood, as these stars
remain rapidly rotating in the oldest clusters that are near enough
for a large sample of low-mass M dwarfs to be studied. To constrain
the spindown of these low-mass stars, we measure photometric rotation
periods for field M dwarfs in wide binary systems, primarily using
the Transiting Exoplanet Survey Satellite and MEarth. Our analysis
includes M-M pairs, which are coeval but of unknown age, as well as M
dwarfs with white dwarf or Sunlike primaries, for which we can estimate
ages using techniques like white-dwarf cooling curves, gyrochronology,
and lithium abundance. We find that the epoch of spindown is strongly
dependent on mass. Fully convective M dwarfs initially spin down slowly,
with the population of 0.2-0.3 M ⊙ rapid rotators evolving
from P rot < 2 days at 600 Myr to 2 < P rot
< 10 days at 1-3 Gyr before rapidly spinning down to long rotation
periods at older ages. However, we also identify some variability
in the spindown of fully convective M dwarfs, with a small number of
stars having substantially spun down by 600 Myr. These observations
are consistent with models of magnetic morphology-driven spindown,
where angular momentum loss is initially inefficient until changes in
the magnetic field allow spindown to progress rapidly.
Title: Updated Photometry of the Yellow Supergiant Progenitor and
Late-time Observations of the Type IIb Supernova SN 2016gkg
Authors: Kilpatrick, Charles D.; Coulter, David A.; Foley, Ryan J.;
Piro, Anthony L.; Rest, Armin; Rojas-Bravo, César; Siebert, Matthew R.
Bibcode: 2022ApJ...936..111K
Altcode: 2021arXiv211203308K
We present Hubble Space Telescope (HST) observations of the Type IIb
supernova (SN) SN 2016gkg at 652, 1698, and 1795 days from explosion
with the Advanced Camera for Surveys (ACS) and Wide Field Camera 3
(WFC3). Comparing to pre-explosion imaging from 2001 obtained with
the Wide Field Planetary Camera 2, we demonstrate that SN 2016gkg is
now fainter than its candidate counterpart in the latest WFC3 imaging,
implying that the counterpart has disappeared and confirming that it
was the SN progenitor star. We show the latest light curve and Keck
spectroscopy of SN 2016gkg, which imply that SN 2016gkg is declining
more slowly than the expected rate for 56Co decay during
its nebular phase. We find that this emission is too luminous to be
powered by other radioisotopes and infer that SN 2016gkg is entering a
new phase in its evolution where it is powered primarily by interaction
with circumstellar matter. Finally, we reanalyze the progenitor star
spectral energy distribution and late-time limits in the context of
binary evolution models. Including emission from a potential companion
star, we find that all such predicted companion stars would be fainter
than our limiting magnitudes.
Title: Classical OBe Stars as Post-supernova Runaways: Confirming
Binary Origins
Authors: Dallas, Matthew M.; Oey, M. S.; Castro, Norberto
Bibcode: 2022ApJ...936..112D
Altcode: 2022arXiv220810408D
Massive binaries play an important role in fields ranging from
gravitational-wave astronomy to stellar evolution. We provide several
lines of evidence that classical OBe stars in the Small Magellanic
Cloud (SMC) obtain their rapid rotation from mass and angular momentum
transfer in massive binaries, which predicts that the subsequent
supernovae should often eject OBe stars into the field. We find that
(1) OBe stars have a higher field frequency than OB stars; (2) our
cumulative distribution function (CDF) of stellar distances from O
stars shows that OBe stars are indeed much more isolated than ordinary
OB stars of corresponding spectral types; (3) the CDFs of OBe stars
approach that of high-mass X-ray binaries (HMXBs), which are confirmed
post-supernova objects; and (4) Oe stars are as isolated from clusters
as Be stars, implying that their final masses are relatively independent
of their initial masses, consistent with major mass transfer. Lastly,
we also find that the spatial distribution of supergiant OBe stars
differs from that of classical OBe stars, consistent with the different
mechanisms responsible for their emission-line spectra.
Title: Supernova Precursor Emission and the Origin of Pre-explosion
Stellar Mass Loss
Authors: Matsumoto, Tatsuya; Metzger, Brian D.
Bibcode: 2022ApJ...936..114M
Altcode: 2022arXiv220608377M
A growing number of core-collapse supernovae (SNe) that show evidence
for interaction with dense circumstellar medium (CSM) are accompanied
by "precursor" optical emission rising weeks to months prior to the
explosion. The precursor luminosities greatly exceed the Eddington
limit of the progenitor star, implying that they are accompanied by
substantial mass loss. Here, we present a semi-analytic model for SN
precursor light curves, which we apply to constrain the properties and
mechanisms of the pre-explosion mass loss. We explore two limiting
mass-loss scenarios: (1) an "eruption" arising from shock breakout
following impulsive energy deposition below the stellar surface;
and (2) a steady "wind," due to sustained heating of the progenitor
envelope. The eruption model, which resembles a scaled-down version
of Type IIP SNe, can explain the luminosities and timescales of
well-sampled precursors, for ejecta masses ~ 0.1-1 M ⊙
and velocities ~ 100-1000 km s-1. By contrast, the steady
wind scenario cannot explain the highest precursor luminosities ≳
1041 erg s-1, under the constraint that the total
ejecta mass does not exceed the entire progenitor mass (though the less
luminous SN 2020tlf precursor can be explained by a mass-loss rate ~
1 M ⊙ yr-1). However, shock interaction between
the wind and pre-existing (earlier ejected) CSM may boost its radiative
efficiency and mitigate this constraint. In both the eruption and wind
scenarios, the precursor ejecta forms compact (≲1015
cm) optically thick CSM at the time of core collapse; though only
directly observable via rapid post-explosion spectroscopy (≲ a few
days before being overtaken by the SN ejecta), this material can boost
the SN luminosity via shock interaction.
Title: Overview of the Remote Sensing Observations from PSP Solar
Encounter 10 with Perihelion at 13.3 R ⊙
Authors: Howard, Russell A.; Stenborg, Guillermo; Vourlidas, Angelos;
Gallagher, Brendan M.; Linton, Mark G.; Hess, Phillip; Rich, Nathan
B.; Liewer, Paulett C.
Bibcode: 2022ApJ...936...43H
Altcode: 2022arXiv220712175H
The closest perihelion pass of Parker Solar Probe (PSP), so far,
occurred between 2021 November 16 and 26 and reached ~13.29 R
☉ from Sun center. This pass resulted in very unique
observations of the solar corona by the Wide-field Instrument for Solar
PRobe (WISPR). WISPR observed at least 10 coronal mass ejections (CMEs),
some of which were so close that the structures appear distorted. All
of the CMEs appeared to have a magnetic flux rope (MFR) structure, and
most were oriented such that the view was along the axis orientation,
revealing very complex interiors. Two CMEs had a small MFR develop in
the interior, with a bright circular boundary surrounding a very dark
interior. Trailing the larger CMEs were substantial outflows of small
blobs and flux-rope-like structures within striated ribbons, lasting
for many hours. When the heliospheric plasma sheet was inclined,
as it was during the days around perihelion on 2021 November 21, the
outflow was over a very wide latitude range. One CME was overtaken
by a faster one, with a resultant compression of the rear of the
leading CME and an unusual expansion in the trailing CME. The small
Thomson surface creates brightness variations of structures as they
pass through the field of view. In addition to this dynamic activity,
a brightness band from excess dust along the orbit of asteroid/comet
3200 Phaethon is also seen for several days.
Title: Wide-band Timing of GMRT-discovered Millisecond Pulsars
Authors: Sharma, Shyam S.; Roy, Jayanta; Bhattacharyya, Bhaswati;
Levin, Lina; Stappers, Ben W.; Pennucci, Timothy T.; Schult, Levi;
Singh, Shubham; Kaninghat, Aswathy
Bibcode: 2022ApJ...936...86S
Altcode: 2022arXiv220104386S
Modeling of frequency-dependent effects, contributed by the turbulence
in the free electron density of interstellar plasma, is required to
enable the detection of the expected imprints from the stochastic
gravitational-wave (GW) background in pulsar timing data. In
this work, we present an investigation of temporal variations of
interstellar medium for a set of millisecond pulsars (MSPs) with
the upgraded Giant Metrewave Radio Telescope (GMRT) aided by large
fractional bandwidth at lower observing frequencies. Contrary to
the conventional narrowband analysis using a frequency-invariant
template profile, we applied PulsePortraiture-based wide-band timing
analysis while correcting for the evolution of the pulsar profile with
frequency. Implementation of the PulsePortraiture-based wide-band
timing method for the GMRT-discovered MSPs to probe the dispersion
measure (DM) variations resulted in a DM precision of 10-4
pc cm-3. In general, we achieve similar DM and timing
precision from wide-band timing compared to the narrowband timing
with matching temporal variations of DMs. This wide-band timing study
of newly discovered MSPs over a wide frequency range highlights the
effectiveness of profile modeling at low frequencies and probes the
potential of using them in a pulsar timing array.
Title: Antenna beam characterization for the global 21-cm experiment
LEDA and its impact on signal model parameter reconstruction
Authors: Spinelli, M.; Kyriakou, G.; Bernardi, G.; Bolli, P.;
Greenhill, L. J.; Fialkov, A.; Garsden, H.
Bibcode: 2022MNRAS.515.1580S
Altcode: 2022MNRAS.tmp.1775S; 2022arXiv220612158S
Cosmic dawn, the onset of star formation in the early universe, can in
principle be studied via the 21-cm transition of neutral hydrogen, for
which a sky-averaged absorption signal, redshifted to MHz frequencies,
is predicted to be O(10-100) mK. Detection requires separation of
the 21-cm signal from bright chromatic foreground emission due to
Galactic structure, and the characterization of how it couples to
instrumental response. In this work, we present characterization of
antenna gain patterns for the Large-aperture Experiment to detect
the Dark Ages (LEDA) via simulations, assessing the effects of the
antenna ground-plane geometries used, and measured soil properties. We
then investigate the impact of beam pattern uncertainties on the
reconstruction of a Gaussian absorption feature. Assuming the pattern
is known and correcting for the chromaticity of the instrument,
the foregrounds can be modelled with a log-polynomial, and the 21-cm
signal identified with high accuracy. However, uncertainties on the soil
properties lead to percentage changes in the chromaticity that can bias
the signal recovery. The bias can be up to a factor of two in amplitude
and up to few per cent in the frequency location. These effects do not
appear to be mitigated by larger ground planes, conversely gain patterns
with larger ground planes exhibit more complex frequency structure,
significantly compromising the parameter reconstruction. Our results,
consistent with findings from other antenna design studies, emphasize
the importance of chromatic response and suggest caution in assuming
log-polynomial foreground models in global signal experiments.
Title: GRMHD simulations of accreting neutron stars with non-dipole
fields
Authors: Das, Pushpita; Porth, Oliver; Watts, Anna L.
Bibcode: 2022MNRAS.515.3144D
Altcode: 2022MNRAS.tmp.1755D; 2022arXiv220400249D
NASA's NICER telescope has recently provided evidence for non-dipolar
magnetic field structures in rotation-powered millisecond pulsars. These
stars are assumed to have gone through a prolonged accretion spin-up
phase, begging the question of what accretion flows on to stars with
complex magnetic fields would look like. We present results from a suite
of general relativistic magnetohydrodynamic simulations of accreting
neutron stars for dipole, quadrupole, and quadrudipolar stellar
field geometries. This is a first step towards simulating realistic
hotspot shapes in a general relativistic framework to understand
hotspot variability in accreting millisecond pulsars. We find that
the location and size of the accretion columns resulting in hotspots
changes significantly depending on initial stellar field strength and
geometry. We also find that the strongest contributions to the stellar
torque are from disc-connected field lines and the pulsar wind, leading
to spin-down in almost the entire parameter regime explored here. We
further analyse angular momentum transport in the accretion disc due
to large-scale magnetic stresses, turbulent stresses, and wind and
compressible effects which we identify with convective motions. The disc
collimates the initial open stellar flux forming jets. For dipoles,
the disc-magnetosphere interaction can either enhance or reduce jet
power compared to the isolated case. However for quadrupoles, the
disc always leads to an enhanced net open flux making the jet power
comparable to the dipolar case. We discuss our results in the context
of observed neutron star jets and provide a viable mechanism to explain
radio power both in the low- and high-magnetic field case.
Title: Tungsten versus Selenium as a potential source of kilonova
nebular emission observed by Spitzer
Authors: Hotokezaka, Kenta; Tanaka, Masaomi; Kato, Daiji; Gaigalas,
Gediminas
Bibcode: 2022MNRAS.515L..89H
Altcode: 2022arXiv220400737H; 2022MNRAS.tmpL..80H
Infrared emission lines arising from transitions between fine structure
levels of heavy elements are expected to produce kilonova nebular
emission. For the kilonova in GW170817, strong emission at $4.5\, {\rm
\mu m}$ at late times was detected by the Spitzer Space Telescope but
no source was detected at $3.6\, {\rm \mu m}$. This peculiar spectrum
indicates that strong line emitters exist around $4.5\, {\rm \mu m}$
and the absence of strong lines around $3.6\, {\rm \mu m}$. To model
the spectrum we prepare a line list based on the selection rules in LS
coupling from the experimentally calibrated energy levels in the NIST
database. This method enables to generate the synthetic spectra with
accurate line wavelengths. We find that the spectrum is sensitive to the
abundance pattern whether or not the first r-process peak elements are
included. In both cases, the synthetic spectra can match the observed
data, leading to two possible interpretations. If the first peak
elements are abundant, a Se III line dominates the flux. If otherwise,
W III with Os III, Rh III, and Ce IV can be the main sources. Observing
nebular spectra for the future kilonova in a wider wavelength range
can provide more conclusive elemental identification.
Title: Molecular fraction in the Galactic Center: The Central
Molecular and H I Zones
Authors: Sofue, Yoshiaki
Bibcode: 2022MNRAS.tmp.2273S
Altcode: 2022arXiv220812858S
By mapping the molecular fraction of the Galactic Center (GC), we
quantitatively address the question of how much molecular and central
the CMZ (Central Molecular Zone) is. For this purpose we analyse the
CO and H I-line archival data, and determine the column- (surface-) and
volume-molecular fractions, $f_{\rm mol}^\Sigma$ and $f_{\rm mol}^\rho$,
which are the ratio of column-mass density of H2 projected
on the sky to that of total gas (H2 + H I) from the line
intensities, and the ratio of volume-mass densities of H2
to total gas from the brightness temperature, respectively. It is
shown that $f_{\rm mol}^\Sigma$ is as high as ~0.9 - 0.95 in the
CMZ, and $f_{\rm mol}^\rho$ is 0.93 - 0.98 in the GC Arms I and II
attaining the highest value of ~0.98 toward Sgr B2. The expanding
molecular ring (EMR, or the parallelogram) has a slightly smaller
$f_{\rm mol}^\rho$ as ~0.9 - 0.93. We define the CMZ as the region with
$f_{\rm mol}^\Sigma \ge 0.8-0.9$ between the shoulders of plateau-like
distribution of H2 column density from l = -1○.1
to +1○.8 having Gaussian vertical distribution with a
half thickness of ±0○.2. The CMZ is embedded in the
Central H I Zone (CHZ), which is defined as an H I disc between l ~
-2○ and +2○.5, b = -0○.5 and
+0○.5. Based on the analysis, we discuss the origin of
CMZ and interstellar physics such as the volume filling factors of
molecular and H I gases inferred from the difference between $f_{\rm
mol}^\Sigma$ and $f_{\rm mol}^\rho$.
Title: Galaxy cluster photons alter the ionization state of the
nearby warm-hot intergalactic medium
Authors: Štofanová, Lýdia; Simionescu, Aurora; Wijers, Nastasha A.;
Schaye, Joop; Kaastra, Jelle S.
Bibcode: 2022MNRAS.515.3162S
Altcode: 2022MNRAS.tmp.1781S; 2022arXiv220710069S
The physical properties of the faint and extremely tenuous plasma in the
far outskirts of galaxy clusters, the circumgalactic media of normal
galaxies, and filaments of the cosmic web remain one of the biggest
unknowns in our story of large-scale structure evolution. Modelling the
spectral features due to emission and absorption from this very diffuse
plasma poses a challenge, as both collisional and photoionization
processes must be accounted for. In this paper, we study the ionization
by photons emitted by the intracluster medium in addition to the
photoionization by the cosmic ultraviolet/X-ray background on gas in the
vicinity of galaxy clusters. For near-massive clusters such as A2029,
the ionization parameter can no longer describe the ionization balance
uniquely. The ionization fractions (in particular of C IV, C V, C VI,
N VII, O VI, O VII, O VIII, Ne VIII, Ne IX, and Fe XVII) obtained by
taking into account the photoionization by the cosmic background are
either an upper or lower limit to the ionization fraction calculated as
a function of distance from the emission from the cluster. Using a toy
model of a cosmic web filament, we predict how the cluster illumination
changes the column densities for two different orientations of the line
of sight. For lines of sight passing close to the cluster outskirts,
O VI can be suppressed by a factor of up to 4.5, O VII by a factor of
2.2, C V by a factor of 3, and Ne VIII can be boosted by a factor of 2,
for low-density gas.
Title: Physical properties of accretion shocks toward the Class I
protostellar system Oph-IRS 44
Authors: de la Villarmois, E. Artur; Guzmán, V. V.; Jørgensen,
J. K.; Kristensen, L. E.; Bergin, E. A.; Harsono, D.; Sakai, N.;
van Dishoeck, E. F.; Yamamoto, S.
Bibcode: 2022arXiv220902827D
Altcode:
(Abridged) Physical processes such as accretion shocks are thought to be
common in the protostellar phase, where the envelope component is still
present, and they can release molecules from the dust to the gas phase,
altering the original chemical composition of the disk. Consequently,
the study of accretion shocks is essential for a better understanding
of the physical processes at disk scales and their chemical output. The
purpose of this work is to assess the characteristics of accretion
shocks traced by sulfur-related species. We present ALMA high angular
resolution observations (0.1") of the Class I protostar Oph-IRS
44. The continuum emission at 0.87 mm is observed, together with
sulfur-related species such as SO, SO$_{2}$, and $^{34}$SO$_{2}$. Six
lines of SO$_{2}$, two lines of $^{34}$SO$_{2}$, and one line of SO are
detected toward IRS 44. The emission of all the detected lines peaks at
~0.1" (~14 au) from the continuum peak and we find infalling-rotating
motions inside 30 au. However, only redshifted emission is seen
between 50 and 30 au. Colder and more quiescent material is seen
toward an offset region located at a distance of ~400 au from the
protostar, and we do not find evidence of a Keplerian profile in these
data. Accretion shocks are the most plausible explanation for the high
temperatures, high densities, and velocities found for the SO$_{2}$
emission. When material enters the disk--envelope system, it generates
accretion shocks that increase the dust temperature and desorb SO$_{2}$
molecules from dust grains. High-energy SO$_{2}$ transitions (~200 K)
seem to be the best tracers of accretion shocks that can be followed
up by future higher angular resolution ALMA observations and compared
to other species to assess their importance in releasing molecules
from the dust to the gas phase.
Title: A census of OBe stars in nearby metal-poor dwarf galaxies
reveals a high fraction of extreme rotators
Authors: Schootemeijer, A.; Lennon, D. J.; Garcia, M.; Langer, N.;
Hastings, B.; Schuermann, C.
Bibcode: 2022arXiv220904943S
Altcode:
The Early Universe, together with many nearby dwarf galaxies, is
deficient in heavy elements. The evolution of massive stars in such
environments is thought to be affected by rotation. Extreme rotators
amongst them tend to form decretion disks and manifest themselves as
OBe stars. We use a combination of U B, GAIA, Spitzer, and Hubble
Space Telescope photometry to identify the complete populations of
massive OBe stars - one hundred to thousands in number - in five nearby
dwarf galaxies. This allows us to derive the galaxy-wide fractions of
main sequence stars that are OBe stars (f_OBe), and how it depends on
absolute magnitude, mass, and metallicity (Z). We find f_OBe = 0.22
in the Large Magellanic Cloud (0.5 Z_Sun), increasing to f_OBe = 0.31
in the Small Magellanic Cloud (0.2 Z_Sun). In the so far unexplored
metallicity regime below 0.2 Z_Sun, in Holmberg I, Holmberg II,
and Sextans A, we also obtain high OBe star fractions of 0.27, 0.27,
and 0.27, respectively. These high OBe star fractions, and the strong
contribution in the stellar mass range which dominates the production
of supernovae, shed new light on the formation channel of OBe stars,
as well as on the preference of long-duration gamma-ray bursts and
superluminous supernovae to occur in metal-poor galaxies.
Title: Self-force regularization of a point particle for generic
orbits in Kerr spacetime: electromagnetic and gravitational cases
Authors: Heffernan, Anna
Bibcode: 2022arXiv220905450H
Altcode:
The self-force is the leading method in modelling waveforms for
extreme mass ratio inspirals, a key target of ESA's future space-based
gravitational wave detector LISA. In modelling these systems, one
approximates the smaller body as a point particle leading to problematic
singularities that need to be removed. Modelling of this singular
structure has settled on the Detweiler-Whiting singular field as the
gold standard. As a solution to the governing wave equation itself,
on removal, it leaves a smooth regular field that is a solution to
the homogeneous wave equation, much like its well established flat
spacetime counterpart. The mode-sum method enables subtraction of this
singularity mode by mode via a spherical harmonic decomposition. The
more modes one has, the faster the convergence in the $\ell$-sum, making
these expressions highly beneficial, especially considering the heavy
computational burden of waveform production. Until recently, only the
two leading orders were known for generic orbits in Kerr spacetime. In
a previous paper, we produced the next non-zero parameter for a scalar
charged particle in curved spacetime, laying the groundwork for the
electromagnetic and gravitational case which we present here.
Title: Phantom cosmologies from QCD ghost dark energy
Authors: Cruz, Miguel; Lepe, Samuel; Soto, Germán E.
Bibcode: 2022arXiv220904584C
Altcode:
We review a dynamical dark energy model scarcely studied in the
literature and we introduce two possible generalizations. We discuss
separately the behavior of the original model and a minimal extension
of it by exploring some early and late times limits, we find that the
cosmic components are related by their parameters state. In order to
have access to the phantom regime we present two dark energy densities
inspired from the holographic approach and from the emergent entropic
forces model in the early universe. For the first case we obtain a
Type III singularity and in the second proposal we have a transition
from decelerated to accelerated cosmic expansion that starts as phantom
type. However, the final stage of the universe is a de Sitter state.
Title: Gravitational waves from rapid structure formation on
microscopic scales before matter-radiation equality
Authors: Flores, Marcos M.; Kusenko, Alexander; Sasaki, Misao
Bibcode: 2022arXiv220904970F
Altcode:
The existence of scalar fields can be probed by observations of
stochastic gravitational waves. Scalar fields mediate attractive
forces, usually stronger than gravity, on the length scales shorter
than their Compton wavelengths, which can be non-negligible in the
early universe, when the horizon size is small. These attractive
forces exhibit an instability similar to the gravitational instability,
only stronger. They can, therefore, lead to the growth of structures
in some species. We identify a gravitational waves signature of such
processes and show that it can be detected by the future gravitational
waves experiments.
Title: Searching for X-ray nuclear sources in Virgo dwarfs in
stripping
Authors: Sun, Ming
Bibcode: 2022cxo..prop.6362S
Altcode:
Over the last 10 - 15 years, a population of dwarf galaxies hosting
massive black holes with masses of 10^4 - 10^6.5 M_Sun has been
strongly suggested from observations. However, it is also clear that
strong AGN in local dwarfs are rare. Dwarf galaxies in galaxy clusters
are subject to ram pressure stripping (RPS) that can have an initial
positive effect on star formation and AGN accretion, as suggested by
studies of more massive galaxies. In this proposal, we select a sample
of dwarf galaxies undergoing RPS in the Virgo cluster. New Chandra
observations are proposed to search for X-ray AGN and X-ray binaries
(including ULXs) in these dwarfs. Joint HST observations are also
requested. This survey also complements previous Chandra surveys on
massive Virgo galaxies with a similar depth.
Title: The Cosmological Black Hole
Authors: Roupas, Zacharias
Bibcode: 2022arXiv220904813R
Altcode:
We briefly review the recent novel solution of General Relativity,
we call the cosmological black hole, firstly discovered in [Roupas,
Z. Eur. Phys. J. C 82, 255 (2022)]. A dark energy universe and a
Schwartzschild black hole are matched on a common dual event horizon
which is finitely thick due to quantum indeterminacy. The system
gets stabilized by a finite tangential pressure applied on the dual
horizon. The fluid entropy of the system at a Tolman temperature
identified with the cosmological horizon temperature is calculated to
be equal with the Bekenstein-Hawking entropy.
Title: BICEP/Keck data and quadratic gravity
Authors: Salvio, Alberto
Bibcode: 2022JCAP...09..027S
Altcode: 2022arXiv220200684S
The recent results of the BICEP and Keck collaborations have
put stringent bounds on many inflationary models, including some
well-motivated ones. This is certainly the case when gravity remains
described by Einstein's theory up to the inflationary scale, but can be
avoided by introducing quadratic-in-curvature terms that are effective
at that scale. Recently it has also been shown that these terms can
UV complete gravity respecting stability and unitarity. Here the
predictions of such quadratic gravity are computed and compared with
the BICEP/Keck constraints by focusing on some of the inflationary
scenarios that are best-motivated from the particle physics point of
view and are already ruled out in Einstein gravity: (critical) Higgs
inflation and natural inflation. The first scenario can be considered
as the most economical option as the inflaton is identified with the
only known elementary scalar field in the Standard Model and the near
criticality of the Standard Model is used to remain in the perturbative
regime. In the second one a pseudo-Nambu-Goldstone boson contributes
to the inflationary dynamics and its potential is naturally flat. It
is shown that in both scenarios one can restore the agreement with
the observational constraints in quadratic gravity.
Title: Vector dark radiation and gravitational-wave polarization
Authors: Miravet, Alfredo D.; Maroto, Antonio L.
Bibcode: 2022JCAP...09..014M
Altcode: 2022arXiv220307125M
We consider conformal vector models which could play the role of a
cosmological dark radiation component. We analyse the propagation of
gravitational waves in the presence of this vector background and find
a suppression in the tensor transfer function at large scales. We also
find that although the cosmological background metric is isotropic,
anisotropies are imprinted in the tensor power spectrum. In addition,
the presence of the background vector fields induces a net polarization
of the gravitational wave background and, for certain configurations
of the vector field, a linear to circular polarization conversion. We
also show that this kind of effects are also present for vector models
with more general potential terms.
Title: Effects of Radiative Diffusion on the Dynamical Corotation
Torque in Three-Dimensional Protoplanetary Disks
Authors: Yun, Han-Gyeol; Kim, Woong-Tae; Bae, Jaehan; Han, Cheongho
Bibcode: 2022arXiv220905417Y
Altcode:
The dynamical corotation torque arising from the deformation of the
horseshoe orbits, along with the vortensity gradient in the background
disk, is important for determining orbital migration rate and direction
of low-mass planets. Previous two-dimensional studies predicted that
the dynamical corotation torque is positive, decelerating the inward
planet migration. In contrast, recent three-dimensional studies have
shown that buoyancy resonance makes the dynamical corotation torque
negative, accelerating the inward migration. In this paper, we study
the dependence of the dynamical corotation torque on the thermal
transport using three-dimensional simulations. We first show that our
results are consistent with previous three-dimensional studies when the
disk is fully adiabatic. In more realistic radiative disks, however,
radiative diffusion suppresses the buoyancy resonance significantly,
especially at high-altitude regions, and yields a positive dynamical
corotation torque. This alleviates the issue of a rapid migration
caused by the negative dynamical corotation torque in the adiabatic
disks. Our results suggest that radiative diffusion together with
stellar irradiation and accretion heating is needed to accurately
describe the migration of low-mass planets.
Title: Flare Kernels May be Smaller than You Think: Modelling the
Radiative Response of Chromospheric Plasma Adjacent to a Solar Flare
Authors: Osborne, Christopher M. J.; Fletcher, Lyndsay
Bibcode: 2022arXiv220903238O
Altcode:
Numerical models of solar flares typically focus on the behaviour
of directly-heated flare models, adopting magnetic field- aligned,
plane-parallel methodologies. With high spatial- and spectral-resolution
ground-based optical observations of flares, it is essential also
to understand the response of the plasma surrounding these strongly
heated volumes. We investigate the effects of the extreme radiation
field produced by a heated column of flare plasma on an adjacent slab
of chromospheric plasma, using a two-dimensional radiative transfer
model and considering the time-dependent solution to the atomic level
populations and electron density throughout this model. The outgoing
spectra of H$\alpha$ and Ca II 854.2 nm synthesised from our slab show
significant spatial-, time-, and wavelength-dependent variations (both
enhancements and reductions) in the line cores, extending on order 1 Mm
into the non-flaring slab due to the incident transverse radiation field
from the flaring boundary. This may lead to significant overestimates of
the sizes of directly-heated flare kernels, if line-core observations
are used. However, the radiation field alone is insufficient to drive
any significant changes in continuum intensity, due to the typical
photospheric depths at which they forms, so continuum sources will not
have an apparent increase in size. We show that the line formation
regions near the flaring boundary can be driven upwards in altitude
by over 1 Mm despite the primary thermodynamic parameters (other than
electron density) being held horizontally uniform. This work shows
that in simple models these effects are significant and should be
considered further in future flare modelling and interpretation.
Title: Gravitationally induced entanglement dynamics of photon pairs
and quantum memories
Authors: Barzel, Roy; Gündoğan, Mustafa; Krutzik, Markus; Rätzel,
Dennis; Lämmerzahl, Claus
Bibcode: 2022arXiv220902099B
Altcode:
We investigate the effect of gravitationally induced entanglement
dynamics -- the basis of a mechanism of universal decoherence -- for
photonic states in a quantum field theoretical framework. We discuss the
prospects of witnessing the effect by use of quantum memories and delay
lines via Hong-Ou-Mandel interference. This would represent a genuine
quantum test of general relativity, combining a multi-particle effect
predicted by the quantum theory of light and the general relativistic
effect of gravitational time dilation.
Title: A simple and accurate prescription for the tidal disruption
radius of a star and the peak accretion rate in tidal disruption
events
Authors: Coughlin, Eric R.; Nixon, Chris
Bibcode: 2022arXiv220903982C
Altcode:
A star destroyed by a supermassive black hole (SMBH) in a tidal
disruption event (TDE) enables the study of SMBHs. We propose that the
distance within which a star is completely destroyed by a SMBH, defined
$r_{\rm t, c}$, is accurately estimated by equating the SMBH tidal field
(including numerical factors) to the maximum gravitational field in the
star. We demonstrate that this definition accurately reproduces the
critical $\beta_{\rm c} = r_{\rm t}/r_{\rm t, c}$, where $r_{\rm t}
= R_{\star}\left(M_{\bullet}/M_{\star}\right)^{1/3}$ is the standard
tidal radius with $R_{\star}$ and $M_{\star}$ the stellar radius and
mass and $M_{\bullet}$ the SMBH mass, for multiple stellar progenitors
at various ages, and can be reasonably approximated by $\beta_{\rm
c} \simeq \left[\rho_{\rm c}/(4\rho_{\star})\right]^{1/3}$, where
$\rho_{\rm c}$ ($\rho_{\star}$) is the central (average) stellar
density. We also calculate the peak fallback rate and time at which the
fallback rate peaks, finding excellent agreement with hydrodynamical
simulations, and also suggest that the partial disruption radius --
the distance at which any mass is successfully liberated from the star
-- is $\beta_{\rm partial} \simeq 4^{-1/3} \simeq 0.6$. For given
stellar and SMBH populations, this model yields, e.g., the fraction
of partial TDEs, the peak luminosity distribution of TDEs, and the
number of directly captured stars.
Title: Tunneling of Bell Particles, Page Curve and Black Hole
Information
Authors: Chu, Chong-Sun; Miao, Rong-Xin
Bibcode: 2022arXiv220903610C
Altcode:
We propose that the quantum states of black hole responsible for the
Bekenstein-Hawking entropy are given by a thin shell of Bell particles
located at the region just underneath the horizon. We argue that the
configuration can be stabilized by a new kind of degeneracy pressure
which is suggested by noncommutative geometry. We utilize the work
of Parikh and Wilczek to include the effect of tunneling on the Bell
particles. We show that partially tunneled Bell particles give the
Page curve for the Hawking radiation, and the entirety of information
initially stored in the black hole is returned to the outside via the
Hawking radiation. In view of entropic force, the location of these
Bell states is naturally related to the island and the quantum extremal
surface. Also, the thin shell of Bell particles may be interpreted as
a firewall.
Title: Combining Hipparcos and Gaia data for the study of binaries:
the BINARYS tool
Authors: Leclerc, A.; Babusiaux, C.; Arenou, F.; van Leeuwen, F.;
Bonnefoy, M.; Delfosse, X.; Forveille, T.; Le Bouquin, J. -B.;
Rodet, L.
Bibcode: 2022arXiv220904210L
Altcode:
Orbital motion in binary and planetary systems is the main source of
precise stellar and planetary mass measurements, and joint analysis
of data from multiple observational methods can both lift degeneracies
and improve precision. We set out to measure the masses of individual
stars in binary systems using all the information brought by the
Hipparcos and Gaia absolute astrometric missions. We present BINARYS,
a tool which uses the Hipparcos and Gaia absolute astrometric data
and combines it with relative astrometry and/or radial velocity
measurements to determine the orbit of a binary system. It rigorously
combines the Hipparcos and Gaia data (here EDR3), and it can use the
Hipparcos Transit Data as needed for binaries where Hipparcos detect
significant flux from the secondary component. It also support the
case where Gaia resolved the system, giving an astrometric solution
for both components. We determine model-independent individual masses
for the first time for three systems: the two mature binaries Gl~494
($M_1=0.584 \pm 0.003 M_{\odot}$ and $M_2=87 \pm 1 M_{\textrm{Jup}}$)
and HIP~88745 ($M_1=0.96 \pm 0.02 M_{\odot}$ and $M_2= 0.60^{+
0.02 }_{- 0.01 } M_{\odot}$), and the younger AB Dor member GJ~2060
($M_1=0.60 ^{+ 0.06}_{- 0.05} M_{\odot}$ and $M_2=0.45 ^{+ 0.06}_{-
0.05}M_{\odot}$). The latter provides a rare test of evolutionary
model predictions at young ages in the low stellar-mass range and sets
a lower age limit of 100~Myr for the moving group.
Title: Accumulation of elastic strain toward crustal fracture in
magnetized neutron stars
Authors: Kojima, Yasufumi
Bibcode: 2022arXiv220904136K
Altcode:
This study investigates elastic deformation driven by the Hall drift
in a magnetized neutron-star crust. Although the dynamic equilibrium
initially holds without elastic displacement, the magnetic-field
evolution changes the Lorentz force over a secular timescale, which
inevitably causes the elastic deformation to settle in a new force
balance. Accordingly, elastic energy is accumulated, and the crust
is eventually fractured beyond a particular threshold. We assume that
the magnetic field is axially symmetric, and we explicitly calculate
the breakup time, maximum elastic energy stored in the crust, and
spatial shear-stress distribution. For the barotropic equilibrium
of a poloidal dipole field expelled from the interior core without a
toroidal field, the breakup time corresponds to a few years for the
magnetars with a magnetic field strength of $\sim 10^{15}$G; however,
it exceeds 1 Myr for normal radio pulsars. The elastic energy stored
in the crust before the fracture ranges from $10^{41}$ to $10^{45}$
erg, depending on the spatial-energy distribution. Generally, a large
amount of energy is deposited in a deep crust. The energy released at
fracture is typically $\sim 10^{41}$ erg when the rearrangement of
elastic displacements occurs only in the fragile shallow crust. The
amount of energy is comparable to the outburst energy on the magnetars.
Title: COOL-LAMPS III: Discovery of a 25".9 Separation Quasar Lensed
by a Merging Galaxy Cluster
Authors: Martinez, Michael N.; Napier, Kate A.; Cloonan, Aidan P.;
Sukay, Ezra; Gozman, Katya; Merz, Kaiya; Khullar, Gourav; Lin, Jason
J.; Matthews Acuña, Owen S.; Medina, Elisabeth; Sanchez, Jorge A.;
Sisco, Emily E.; Kavin Stein, Daniel J.; Tavangar, Kiyan; Remolina
Gonzàlez, Juan; Mahler, Guillaume; Sharon, Keren; Dahle, Håkon;
Gladders, Michael D.
Bibcode: 2022arXiv220903972M
Altcode:
In the third paper from the COOL-LAMPS Collaboration, we report
the discovery of COOL J0542-2125, a gravitationally lensed quasar
at $z=1.84$, observed as three images due to an intervening massive
galaxy cluster at $z=0.61$. The lensed quasar images were identified
in a search for lens systems in recent public optical imaging data and
have separations on the sky up to 25".9, wider than any previously known
lensed quasar. The galaxy cluster acting as a strong lens appears to
be in the process of merging, with two sub-clusters separated by $\sim
1$ Mpc in the plane of the sky, and their central galaxies showing
a radial velocity difference of $\sim 1000$ km/s. Both cluster cores
show strongly lensed images of an assortment of background sources,
as does the region between them. A preliminary strong lens model
implies masses of $M(<250\ \rm{kpc}) = 1.79^{+0.16} _{-0.01} \times
10^{14} M_{\odot}$ and $M(<250\ \rm{kpc}) = 1.48^{+0.04}_{-0.10}
\times 10^{14} M_{\odot}$ for the East and West sub-clusters,
respectively. This line of sight is also coincident with a ROSAT
ALL-sky Survey source, centered between the two confirmed cluster
halos reminiscent of other major cluster-scale mergers.
Title: The Demographics of Kepler's Earths and super-Earths into
the Habitable Zone
Authors: Bergsten, Galen J.; Pascucci, Ilaria; Mulders, Gijs D.;
Fernandes, Rachel B.; Koskinen, Tommi T.
Bibcode: 2022arXiv220904047B
Altcode:
Understanding the occurrence of Earth-sized planets in the
habitable zone of Sun-like stars is essential to the search for
Earth analogues. Yet a lack of reliable Kepler detections for such
planets has forced many estimates to be derived from the close-in
($2<P_{\mathrm{orb}}<100$ days) population, whose radii may
have evolved differently under the effect of atmospheric mass loss
mechanisms. In this work, we compute the intrinsic occurrence rates
of close-in super-Earths ($\sim1-2\,R_\oplus$) and sub-Neptunes
($\sim2-3.5\,R_\oplus$) for FGK stars ($0.56-1.63\,M_\odot$) as
a function of orbital period and find evidence of two regimes:
where super-Earths are more abundant at short orbital periods, and
where sub-Neptunes are more abundant at longer orbital periods. We
fit a parametric model in five equally populated stellar mass bins
and find that the orbital period of transition between these two
regimes scales with stellar mass, like $P_\mathrm{trans} \propto
M_*^{1.7\pm0.2}$. These results suggest a population of former
sub-Neptunes contaminating the population of Gyr-old close-in
super-Earths, indicative of a population shaped by atmospheric
loss. Using our model to constrain the long-period population of
intrinsically rocky planets, we estimate an occurrence rate of
$\Gamma_\oplus = 15^{+6}_{-4}\%$ for Earth-sized habitable zone
planets, and predict that sub-Neptunes may be $\sim$twice as common as
super-Earths in the habitable zone (when normalized over the natural log
orbital period and radius range used). Finally, we discuss our results
in the context of future missions searching for habitable zone planets.
Title: Muons in the aftermath of Neutron Star Mergers and their
impact on Trapped Neutrinos
Authors: Loffredo, Eleonora; Perego, Albino; Logoteta, Domenico;
Branchesi, Marica
Bibcode: 2022arXiv220904458L
Altcode:
In the upcoming years, present and next-generation gravitational wave
observatories will detect a larger number of Binary Neutron Star
(BNS) mergers with increasing accuracy. In this context, improving
BNS merger numerical simulations is crucial to correctly interpret
the data and constrain the Equation of State (EOS) of Neutron Stars
(NSs). State-of-the-art simulations of BNS mergers do not include
muons. However, muons are known to be relevant in the microphysics of
cold NSs and are expected to have a significant role in mergers, where
the typical thermodynamics conditions favor their production. Our work
aims at investigating the impact of muons on the merger remnant. We
post-process the outcome of four numerical relativity simulations,
performed with three different baryonic EOSs and two mass ratios,
considering the first $15$ milliseconds after the merger. We compute
the abundance of muons in the remnant and analyse how muons affect
the trapped neutrino component and the fluid pressure. We find that
the net fraction of muons is between $30 \%$ and $70 \%$ the one of
electrons, depending on the baryonic EOS. Muons change the flavour
hierarchy of trapped (anti)neutrinos, so that muon anti-neutrinos
are the most abundant, followed by electron anti-neutrinos. Finally,
muons modify the neutron to proton ratio inducing variations of the
remnant pressure up to $7\%$. This work demonstrates that muons have
a non-negligible effect on the outcome of BNS merger simulations,
and they should be included to improve simulations accuracy.
Title: Supersymmetric Kundt four manifolds and their spinorial
evolution flows
Authors: Murcia, Ángel; Shahbazi, C. S.
Bibcode: 2022arXiv220904396M
Altcode:
We investigate the differential geometry and topology of
four-dimensional Lorentzian manifolds $(M,g)$ equipped with a real
Killing spinor $\varepsilon$, where $\varepsilon$ is defined as a
section of a bundle of irreducible real Clifford modules satisfying
the Killing spinor equation with non-zero real constant. Such triples
$(M,g,\varepsilon)$ are precisely the supersymmetric configurations of
minimal four-dimensional supergravity and necessarily belong to the
class Kundt of space-times, hence we refer to them as supersymmetric
Kundt configurations. We characterize a class of Lorentzian metrics
on $\mathbb{R}^2\times X$, where $X$ is a two-dimensional oriented
manifold, to which every supersymmetric Kundt configuration is locally
isometric, proving that $X$ must be an elementary hyperbolic Riemann
surface when equipped with the natural induced metric. This yields
a class of space-times that vastly generalize the Siklos class of
space-times describing gravitational waves in AdS$_4$. Furthermore,
we study the Cauchy problem posed by a real Killing spinor and we prove
that the corresponding evolution problem is equivalent to a system of
differential flow equations, the real Killing spinorial flow equations,
for a family of functions and coframes on any Cauchy hypersurface
$\Sigma\subset M$. Using this formulation, we prove that the evolution
flow defined by a real Killing spinor preserves the Hamiltonian and
momentum constraints of the Einstein equation with negative curvature
and is therefore compatible with the latter. Moreover, we explicitly
construct all left-invariant evolution flows defined by a Killing
spinor on a simply connected three-dimensional Lie group, classifying
along the way all solutions to the corresponding constraint equations,
some of which also satisfy the constraint equations associated to the
Einstein condition.
Title: Probing the Density Fine Structuring of the Solar Corona with
Comet Lovejoy
Authors: Nisticò, Giuseppe; Zimbardo, Gaetano; Perri, Silvia;
Nakariakov, Valery M.; Duckenfield, Timothy J.; Druckmueller, Miloslav
Bibcode: 2022arXiv220904051N
Altcode:
The passage of sungrazing comets in the solar corona can be a powerful
tool to probe the local plasma properties. Here, we carry out a
study of the striae pattern appearing in the tail of sungrazing Comet
Lovejoy, as observed by the Atmospheric Imaging Assembly (AIA) aboard
the Solar Dynamics Observatory (SDO) during the inbound and outbound
phases of the comet orbit. We consider the images in EUV in the 171
Å bandpass, where emission from oxygen ions O$^{4+}$ and O$^{5+}$
is found. The striae are described as due to a beam of ions injected
along the local magnetic field, with the initial beam velocity decaying
because of collisions. Also, ion collisional diffusion contributes to
ion propagation. Both the collision time for velocity decay and the
diffusion coefficient for spatial spreading depend on the ambient plasma
density. A probabilistic description of the ion beam density along the
magnetic field is developed, where the beam position is given by the
velocity decay and the spreading of diffusing ions is described by
a Gaussian probability distribution. Profiles of emission intensity
along the magnetic field are computed and compared with the profiles
along the striae observed by AIA, showing a good agreement for most
considered striae. The inferred coronal densities are then compared
with a hydrostatic model of the solar corona. The results confirm that
the coronal density is strongly spatially structured.
Title: Can the Production Cross-Section Uncertainties Explain the
Cosmic Fluorine Anomaly?
Authors: Zhao, Meng-Jie; Bi, Xiao-Jun; Fang, Kun
Bibcode: 2022arXiv220903799Z
Altcode:
The stable secondary-to-primary flux ratios of cosmic rays (CRs),
represented by the boron-to-carbon ratio (B/C), are the main probes
of the Galactic CR propagation. However, the fluorine-to-silicon
ratio (F/Si) predicted by the CR diffusion coefficient inferred
from B/C is significantly higher than the latest measurement of
AMS-02. This anomaly is commonly attributed to the uncertainties of the
F production cross sections. In this work, we give a careful test to
this interpretation. We consider four different cross-section parametric
models. Each model is constrained by the latest cross-section data. We
perform combined fits to the B/C, F/Si, and cross-section data with
the same propagation framework. Two of the cross-section models have
good overall goodness of fit with $\chi^2/n_{d.o.f.}\sim1$. However,
the goodness of fit of the cross-section part is poor with
$\chi^2_{\rm{cs}}/n_{\rm{cs}}\gtrsim2$ for these models. The best-fitted
F production cross sections are systematically larger than the
measurements, while the fitted cross sections for B production are
systematically lower than the measurements. This indicates that the F
anomaly can hardly be interpreted by neither the random errors of the
cross-section measurements nor the differences between the existing
cross-section models. We then propose that the spatially dependent
diffusion model could help to explain B/C and F/Si consistently. In
this model, the average diffusion coefficient of the Ne-Si group is
expected to be larger than that of the C-O group.
Title: Searching for Cataclysmic Variable Stars in Unidentified
X-Ray Sources
Authors: Takata, J.; Wang, X. F.; Kong, A. K. H.; Mao, J.; Hou, X.;
Hu, C. -P.; Lin, L. C. -C.; Li, K. L.; Hui, C. Y.
Bibcode: 2022ApJ...936..134T
Altcode: 2022arXiv220801833T
We carry out a photometric search for new cataclysmic variable
stars (CVs), with the goal of identification for candidates of AR
Scorpii-type binary systems. We select GAIA sources that are likely
associated with unidentified X-ray sources, and analyze the light curves
taken by the Zwicky Transient Facility, Transiting Exoplanet Survey
Satellite, and Lulin One-meter Telescope in Taiwan. We investigate
eight sources as candidates for CVs, among which six sources are new
identifications. Another two sources have been recognized as CVs in
previous studies, but no detailed investigations have been done. We
identify two eclipsing systems that are associated with an unidentified
XMM-Newton or Swift source, and one promising candidate for polar
associated with an unidentified ASKA source. Two polar candidates may
locate in the so-called period gap of a CV, and the other six candidates
have an orbital period shorter than that of the period gap. Although
we do not identify a promising candidate for AR Scorpii-type binary
systems, our study suggests that CV systems that have X-ray emission and
do not show frequent outbursts may have been missed in previous surveys.
Title: Antaeus: A Retrograde Group of Tidal Debris in the Milky
Way's Disk Plane
Authors: Oria, Pierre-Antoine; Tenachi, Wassim; Ibata, Rodrigo; Famaey,
Benoit; Yuan, Zhen; Arentsen, Anke; Martin, Nicolas; Viswanathan,
Akshara
Bibcode: 2022ApJ...936L...3O
Altcode: 2022arXiv220610404O
We present the discovery of a wide retrograde moving group in the disk
plane of the Milky Way using action-angle coordinates derived from
the Gaia DR3 catalog. The structure is identified from a sample of its
members that are currently almost at the pericenter of their orbit and
are passing through the solar neighborhood. The motions of the stars
in this group are highly correlated, indicating that the system is
probably not phase mixed. With a width of at least 1.5 kpc and with a
probable intrinsic spread in metallicity, this structure is most likely
the wide remnant of a tidal stream of a disrupted ancient dwarf galaxy
(age ~12 Gyr, <[Fe/H]> ~ -1.74). The structure presents many
similarities (e.g., in energy, angular momentum, metallicity, and
eccentricity) with the Sequoia merging event. However, it possesses
extremely low vertical action J z , which makes it unique
even among Sequoia dynamical groups. As the low J z may
be attributable to dynamical friction, we speculate that these stars
may be the remnants of the dense core of the Sequoia progenitor.
Title: Bridging the Bondi and Event Horizon Scales: 3D GRMHD
Simulations Reveal X-shaped Radio Galaxy Morphology
Authors: Lalakos, Aretaios; Gottlieb, Ore; Kaaz, Nicholas; Chatterjee,
Koushik; Liska, Matthew; Christie, Ian M.; Tchekhovskoy, Alexander;
Zhuravleva, Irina; Nokhrina, Elena
Bibcode: 2022ApJ...936L...5L
Altcode: 2022arXiv220208281L
X-shaped radio galaxies (XRGs) produce misaligned X-shaped jet pairs
and make up ≲10% of radio galaxies. XRGs are thought to emerge
in galaxies featuring a binary supermassive black hole (SMBH), SMBH
merger, or large-scale ambient medium asymmetry. We demonstrate that
XRG morphology can naturally form without such special, preexisting
conditions. Our 3D general-relativistic magnetohydrodynamic (GRMHD)
simulation for the first time follows magnetized rotating gas
from outside the SMBH sphere of influence of radius R B
to the SMBH of gravitational radius R g at the largest
scale separation, R B/R g = 103, to
date. Initially, our axisymmetric system of constant-density hot gas
contains a weak vertical magnetic field and rotates in the equatorial
plane of a rapidly spinning SMBH. We seed the gas with small-scale 2%
level pressure perturbations. Infalling gas forms an accretion disk, and
the SMBH launches relativistically magnetized collimated jets reaching
well outside R B. Under the pressure of the infalling gas,
the jets intermittently turn on and off, erratically wobble, and inflate
pairs of cavities in different directions, resembling an X-shaped jet
morphology. Synthetic X-ray images reveal multiple pairs of jet-powered
shocks and cavities. Large-scale magnetic flux accumulates on the SMBH,
becomes dynamically important, and leads to a magnetically arrested
disk state. The SMBH accretes at 2% of the Bondi rate ( $\dot{M}\simeq
2.4\times {10}^{-3}{M}_{\odot }\,{\mathrm{yr}}^{-1}$ for M87*) and
launches twin jets at η = 150% efficiency. These jets are powerful
enough (P jets ≃ 2 × 1044 erg s-1)
to escape along the SMBH spin axis and end the short-lived intermittent
jet state, whose transient nature can account for the rarity of XRGs.
Title: Exploring KSZ velocity reconstruction with N-body simulations
and the halo model
Authors: Giri, Utkarsh; Smith, Kendrick M.
Bibcode: 2022JCAP...09..028G
Altcode: 2020arXiv201007193G
KSZ velocity reconstruction is a recently proposed method for
mapping the largest-scale modes of the universe, by applying a
quadratic estimator v̂ r to the small-scale CMB and
a galaxy catalog. We implement kSZ velocity reconstruction in an
N-body simulation pipeline and explore its properties. We find that
the reconstruction noise can be larger than the analytic prediction
which is usually assumed. We revisit the analytic prediction and find
additional noise terms which explain the discrepancy. The new terms are
obtained from a six-point halo model calculation, and are analogous to
the N (1) and N (3/2) biases in CMB lensing. We
implement an MCMC pipeline which estimates fNL from N-body
kSZ simulations, and show that it recovers unbiased estimates of
fNL , with statistical errors consistent with a Fisher
matrix forecast. Overall, these results confirm that kSZ velocity
reconstruction will be a powerful probe of cosmology in the near future,
but new terms should be included in the noise power spectrum.
Title: Ranking Theoretical Supernovae Explosion Models from
Observations of the Intracluster Gas
Authors: Batalha, Rebeca M.; Dupke, Renato A.; Jiménez-Teja, Yolanda
Bibcode: 2022ApJS..262...27B
Altcode: 2022arXiv220700601B
The intracluster medium (ICM) is a reservoir of heavy elements
synthesized by different supernovae (SNe) types over cosmic
history. Different enrichment mechanisms contribute a different
relative metal production, predominantly caused by different SNe type
dominance. Using spatially resolved X-ray spectroscopy, one can probe
the contribution of each metal-enrichment mechanism. However, a large
variety of physically feasible supernova (SN) explosion models make
the analysis of the ICM enrichment history more uncertain. This paper
presents a nonparametric probability distribution function analysis
to rank different theoretical SNe yields models by comparing their
performance against observations. Specifically, we apply this new
methodology to rank 7192 combinations of core-collapse SN and Type Ia
SN models using eight abundance ratios from Suzaku observations of 18
galaxy systems (clusters and groups) to test their predictions. This
novel technique can compare many SN models and maximize spectral
information extraction, considering all the individual measurable
abundance ratios and their uncertainties. We find that Type II SNe with
nonzero initial metallicity progenitors in general performed better
than pair-instability SN and hypernova models, and that 3D SNIa models
(with a white dwarf progenitor central density of 2.9 × 109
g cm-3) performed best among all tested SN model pairs.
Title: GROWTH on S190426c II: GROWTH-India Telescope search for
an optical counterpart with a custom image reduction and candidate
vetting pipeline
Authors: Kumar, Harsh; Bhalerao, Varun; Anupama, G. C.; Barway,
Sudhanshu; Coughlin, Michael W.; De, Kishalay; Deshmukh, Kunal; Dutta,
Anirban; Goldstein, Daniel A.; Jassani, Adeem; Joharle, Simran;
Karambelker, Viraj; Khandagale, Maitreya; Kumar, Brajesh; Saraogi,
Divita; Sharma, Yashvi; Shenoy, Vedant; singer, Leo; Singh, Avinash;
Waratkar, Gaurav
Bibcode: 2022MNRAS.tmp.2347K
Altcode: 2022arXiv220902077K
S190426c / GW190426_152155 was the first probable neutron star - black
hole merger candidate detected by the LIGO-Virgo Collaboration. We
undertook a tiled search for optical counterparts of this event
using the 0.7m GROWTH-India Telescope. Over a period of two weeks, we
obtained multiple observations over a 22.1 deg2 area, with
a 17.5 per cent probability of containing the source location. Initial
efforts included obtaining photometry of sources reported by various
groups, and a visual search for sources in all galaxies contained in
the region. Subsequently, we have developed an image subtraction and
candidate vetting pipeline with $\sim 94{{\%}}$ efficiency for transient
detection. Processing the data with this pipeline, we find several
transients, but none that are compatible with kilonova models. We
present the details of our observations, working of our pipeline,
results from the search, and our interpretations of the non-detections
that will work as a pathfinder during the O4 run of LVK.
Title: Low-J Transitions in {\tilde{A}}(2) {\Pi
}(0,0,0)-{\tilde{X}}(2) {{\Sigma }}(+) (0,0,0) Band of
Buffer-gas-cooled CaOH
Authors: Takahashi, Yuiki; Baba, Masaaki; Enomoto, Katsunari; Hiramoto,
Ayami; Iwakuni, Kana; Kuma, Susumu; Tobaru, Reo; Miyamoto, Yuki
Bibcode: 2022ApJ...936...97T
Altcode: 2022arXiv220802370T
Calcium monohydroxide radical (CaOH) is receiving an increasing amount
of attention from the astrophysics community as it is expected to be
present in the atmospheres of hot rocky super-Earth exoplanets as well
as interstellar and circumstellar environments. Here, we report the
high-resolution laboratory absorption spectroscopy on low-J transitions
in ${\tilde{A}}^{2}{\rm{\Pi }}(0,0,0)-{\tilde{X}}^{2}{{\rm{\Sigma
}}}^{+}(0,0,0)$ band of buffer-gas-cooled CaOH. In total, 40 transitions
out of the low-J states were assigned, including 27 transitions that
have not been reported in previous literature. The determined rotational
constants for both ground and excited states are in excellent agreement
with previous literature, and the measurement uncertainty for the
absolute transition frequencies was improved by more than a factor of
3. This will aid future interstellar, circumstellar, and atmospheric
identifications of CaOH. The buffer-gas-cooling method employed here
is a particularly powerful method to probe low-J transitions and is
easily applicable to other astrophysical molecules.
Title: FORGE: the f(R)-gravity cosmic emulator project -
I. Introduction and matter power spectrum emulator
Authors: Arnold, Christian; Li, Baojiu; Giblin, Benjamin;
Harnois-Déraps, Joachim; Cai, Yan-Chuan
Bibcode: 2022MNRAS.515.4161A
Altcode: 2021arXiv210904984A
We present a large suite of cosmological simulations, the FORGE (F-of-R
Gravity Emulator) simulation suite, which is designed to build accurate
emulators for cosmological observables in galaxy clustering, weak
gravitational lensing, and galaxy clusters for the f(R)-gravity model. A
total of 200 simulations explore the cosmological parameter space around
a standard Planck cosmology with a Latin hypercube, for 50 combinations
of $\bar{f}_{R0}$, Ωm, σ8, and h with all other
parameters fixed. For each parameter combination, or node, we ran four
independent simulations, one pair using 10243 particles in
$500\, h^{-1}\, \mathrm{Mpc}$ simulation boxes to cover small scales,
and another pair using 5123 simulation particles in $1.5\,
h^{-1}\, \mathrm{Gpc}$ boxes for larger scales. Each pair of initial
conditions is selected such that sample variance on large scales is
minimized on average. In this work we present an accurate emulator
for the matter power spectrum in f(R) gravity trained on FORGE. We
have verified, using the cross-validation technique, that the emulator
accuracy is better than $2.5{{\, \rm per\, cent}}$ for the majority of
nodes, particularly around the centre of the explored parameter space,
up to scales of $k = 10\, h \, \mathrm{Mpc}^{-1}$. We have also checked
the power spectrum emulator against simulations that are not part of our
training set and found excellent agreement. Due to its high accuracy on
small scales, the FORGE matter power spectrum emulator is well suited
for weak-lensing analysis and can play a key tool in constraining f(R)
gravity using current and future observational data.
Title: Baryon acoustic oscillations from H I intensity mapping:
The importance of cross-correlations in the monopole and quadrupole
Authors: Rubiola, Andrea; Cunnington, Steven; Camera, Stefano
Bibcode: 2022MNRAS.tmp.2317R
Altcode: 2021arXiv211111347R
Cosmological parameter estimation in the post-reionisation era
via neutral hydrogen radio emission (H I), is among the key science
goals of the forthcoming SKA Observatory (SKAO). This paper explores
detection capability for baryon acoustic oscillations (BAO) with a suite
of 100 simulations introducing the main limitations from foreground
contamination and poor angular resolution caused by the radio telescope
beam. Such broad single-dish beam representing a serious challenge for
BAO detection with H I intensity mapping, we investigate a multipole
expansion approach as a means for mitigating such limitations. We
also showcase the gains made from cross-correlating the H I intensity
mapping data with an overlapping spectroscopic galaxy survey, aiming
to test potential synergies between the SKA Project and other future
cosmological experiments at optical/near-infrared wavelengths. For our ~
4 000 deg2 data set at z = 0.9, replicating the essential
features of an SKAO H I intensity mapping survey, we were able to
achieve a ~ 4.5σ detection of BAO features in auto-correlation despite
the dominant beam effect. Cross-correlation with an overlapping galaxy
survey can increase this to a ~ 6σ detection. Furthermore, including
the power spectrum quadrupole besides the monopole in a joint fit
can approximately double the BAO detection significance. Despite not
implementing a radial-only P(k∥) analysis in favour of
the three-dimensional P(k) and its multipoles, we were still able to
obtain robust constraints on the radial Alcock-Paczynski parameter,
whereas the perpendicular parameter remains unconstrained and prior
dominated due to beam effects.
Title: Deep learning-based super-resolution and de-noising for
XMM-newton images
Authors: Sweere, Sam F.; Valtchanov, Ivan; Lieu, Maggie; Vojtekova,
Antonia; Verdugo, Eva; Santos-Lleo, Maria; Pacaud, Florian; Briassouli,
Alexia; Pérez, Daniel Cámpora
Bibcode: 2022MNRAS.tmp.2335S
Altcode: 2022arXiv220501152S
The field of artificial intelligence based image enhancement has
been rapidly evolving over the last few years and is able to produce
impressive results on non-astronomical images. In this work we present
the first application of Machine Learning based super-resolution (SR)
and de-noising (DN) to enhance X-ray images from the European Space
Agency's XMM-Newton telescope. Using XMM-Newton images in band [0.5,2]
keV from the European Photon Imaging Camera pn detector (EPIC-pn), we
develop XMM-SuperRes and XMM-DeNoise - deep learning-based models that
can generate enhanced SR and DN images from real observations. The
models are trained on realistic XMM-Newton simulations such that
XMM-SuperRes will output images with two times smaller point-spread
function and with improved noise characteristics. The XMM-DeNoise model
is trained to produce images with 2.5× the input exposure time from 20
to 50 ks. When tested on real images, DN improves the image quality
by $8.2{{\%}}$, as quantified by the global peak-signal-to-noise
ratio. These enhanced images allow identification of features that
are otherwise hard or impossible to perceive in the original or in
filtered/smoothed images with traditional methods. We demonstrate the
feasibility of using our deep learning models to enhance XMM-Newton
X-ray images to increase their scientific value in a way that could
benefit the legacy of the XMM-Newton archive.
Title: Primordial dusty rings and episodic outbursts in protoplanetary
discs
Authors: Kadam, Kundan; Vorobyov, Eduard; Basu, Shantanu
Bibcode: 2022MNRAS.tmp.2336K
Altcode: 2022arXiv220812105K
We investigate the formation and evolution of 'primordial' dusty rings
occurring in the inner regions of protoplanetary discs, with the help
of long-term, coupled dust-gas, magnetohydrodynamic simulations. The
simulations are global and start from the collapse phase of the parent
cloud core, while the dead zone is calculated via an adaptive α
formulation by taking into account the local ionization balance. The
evolution of the dusty component includes its growth and back reaction
on to the gas. Previously, using simulations with only a gas component,
we showed that dynamical rings form at the inner edge of the dead
zone. We find that when dust evolution as well as magnetic field
evolution in the flux-freezing limit are included, the dusty rings
formed are more numerous and span a larger radial extent in the inner
disc, while the dead zone is more robust and persists for a much longer
time. We show that these dynamical rings concentrate enough dust mass to
become streaming unstable, which should result in rapid planetesimal
formation even in the embedded phases of the system. The episodic
outbursts caused by the magnetorotational instability have significant
impact on the evolution of the rings. The outbursts drain the inner
disc of grown dust, however, the period between bursts is sufficiently
long for the planetesimal growth via streaming instability. The
dust mass contained within the rings is large enough to ultimately
produce planetary systems with the core accretion scenario. The low
mass systems rarely undergo outbursts and thus, the conditions around
such stars can be especially conducive for planet formation.
Title: Constraints on the Very High Energy Gamma-Ray Emission from
Short GRBs with HAWC
Authors: Albert, A.; Alfaro, R.; Alvarez, C.; Arteaga-Velázquez,
J. C.; Arunbabu, K. P.; Rojas, D. Avila; Solares, H. A. Ayala;
Babu, R.; Belmont-Moreno, E.; Brisbois, C.; Caballero-Mora, K. S.;
Capistrán, T.; Carramiñana, A.; Casanova, S.; Chaparro-Amaro, O.;
Cotti, U.; Cotzomi, J.; de León, S. Coutiño; León, C. de; De la
Fuente, E.; Hernandez, R. Diaz; Dichiara, S.; Dingus, B. L.; DuVernois,
M. A.; Durocher, M.; Díaz-Vélez, J. C.; Engel, K.; Espinoza,
C.; Fan, K. L.; Fraija, N.; Galván-Gámez, A.; García-González,
J. A.; Garfias, F.; González, M. M.; Goodman, J. A.; Harding, J. P.;
Hernandez, S.; Hona, B.; Huang, D.; Hueyotl-Zahuantitla, F.; Humensky,
T. B.; Hüntemeyer, P.; Iriarte, A.; Joshi, V.; Kaufmann, S.; Lara,
A.; Lee, W. H.; Vargas, H. León; Linnemann, J. T.; Longinotti,
A. L.; Luis-Raya, G.; Malone, K.; Marinelli, S. S.; Martinez,
O.; Martínez-Castro, J.; Matthews, J. A.; Miranda-Romagnoli, P.;
Morales-Soto, J. A.; Moreno, E.; Mostafá, M.; Nayerhoda, A.; Nellen,
L.; Newbold, M.; Noriega-Papaqui, R.; Peisker, A.; Araujo, Y. Pérez;
Pérez-Pérez, E. G.; Ren, Z.; Rho, C. D.; Rosa-González, D.;
Rosenberg, M.; Sacahui, J. R.; Salazar, H.; Greus, F. Salesa; Sandoval,
A.; Serna-Franco, J.; Smith, A. J.; Springer, R. W.; Surajbali, P.;
Tibolla, O.; Tollefson, K.; Torres, I.; Torres-Escobedo, R.; Turner,
R.; Villaseñor, L.; Wang, X.; Willox, E.; Zepeda, A.; Zhou, H.;
HAWC Collaboration
Bibcode: 2022ApJ...936..126A
Altcode: 2022arXiv220801075A
Many gamma-ray bursts (GRBs) have been observed from radio wavelengths,
and a few at very high energies (VHEs, >100 GeV). The High Altitude
Water Cherenkov (HAWC) gamma-ray observatory is well suited to study
transient phenomena at VHEs owing to its large field of view and duty
cycle. These features allow for searches of VHE emission and can probe
different model assumptions of duration and spectra. In this paper,
we use data collected by HAWC between 2014 December and 2020 May to
search for emission in the energy range from 80 to 800 GeV coming
from a sample of 47 short GRBs that triggered the Fermi, Swift, and
Konus satellites during this period. This analysis is optimized to
search for delayed and extended VHE emission within the first 20 s of
each burst. We find no evidence of VHE emission, either simultaneous
or delayed, with respect to the prompt emission. Upper limits (90%
confidence level) derived on the GRB fluence are used to constrain
the synchrotron self-Compton forward-shock model. Constraints for
the interstellar density as low as 10-2 cm-3
are obtained when assuming z = 0.3 for bursts with the highest keV
fluences such as GRB 170206A and GRB 181222841. Such a low density makes
observing VHE emission mainly from the fast-cooling regime challenging.
Title: Computing optical meteor flux using global meteor network data
Authors: Vida, Denis; Blaauw Erskine, Rhiannon C.; Brown, Peter G.;
Kambulow, Jonathon; Campbell-Brown, Margaret; Mazur, Michael J.
Bibcode: 2022MNRAS.515.2322V
Altcode: 2022arXiv220611365V; 2022MNRAS.tmp.1701V
Meteor showers and their outbursts are the dominant source of
meteoroid impact risk to spacecraft on short time-scales. Meteor
shower prediction models depend on historical observations to produce
accurate forecasts. However, the current lack of quality and persistent
world-wide monitoring at optical meteoroid sizes has left some recent
major outbursts poorly observed. A novel method of computing meteor
shower flux is developed and applied to Global Meteor Network data. The
method is verified against previously published observations of the
Perseids and the Geminids. The complete mathematical and algorithmic
details of computing meteor shower fluxes from video observations
are described. As an example application of our approach, the flux
measurements of the 2021 Perseid outburst, the 2020-2022 Quadrantids,
and 2020-2021 Geminids are presented. The flux of the 2021 Perseids
reached similar levels to the 1991-1994 and 2016 outbursts (ZHR ~
280). The flux of the Quadrantids shows high year-to-year variability
in the core of the stream while the longer lasting background activity
is less variable, consistent with an age difference between the two
components. The Geminids show a double peak in flux near the time
of peak.
Title: Transparency of fast radio burst waves in magnetar
magnetospheres
Authors: Qu, Yuanhong; Kumar, Pawan; Zhang, Bing
Bibcode: 2022MNRAS.515.2020Q
Altcode: 2022arXiv220410953Q; 2022MNRAS.tmp.1840Q
At least some fast radio bursts (FRBs) are produced by magnetars. Even
though mounting observational evidence points towards a magnetospheric
origin of FRB emission, the question of the location for FRB
generation continues to be debated. One argument suggested against
the magnetospheric origin of bright FRBs is that the radio waves
associated with an FRB may lose most of their energy before escaping the
magnetosphere because the cross-section for e± to scatter
large-amplitude electromagnetic waves in the presence of a strong
magnetic field is much larger than the Thompson cross-section. We have
investigated this suggestion and find that FRB radiation travelling
through the open field line region of a magnetar's magnetosphere does
not suffer much loss due to two previously ignored factors. First,
the plasma in the outer magnetosphere ($r \gtrsim 10^9$ cm), where the
losses are potentially most severe, is likely to be flowing outwards
at a high Lorentz factor γp ≥ 103. Secondly,
the angle between the wave vector and the magnetic field vector,
θB, in the outer magnetosphere is likely of the order of 0.1
radian or smaller due in part to the intense FRB pulse that tilts open
magnetic field lines so that they get aligned with the pulse propagation
direction. Both these effects reduce the interaction between the FRB
pulse and the plasma substantially. We find that a bright FRB with
an isotropic luminosity $L_{\rm frb} \gtrsim 10^{42} \, {\rm erg \
s^{-1}}$ can escape the magnetosphere unscathed for a large section
of the γp - θB parameter space, and therefore
conclude that the generation of FRBs in magnetar magnetosphere passes
this test.
Title: Consistency study of high- and low-accreting Mg II quasars:
no significant effect of the Fe II to Mg II flux ratio on the
radius-luminosity relation dispersion
Authors: Khadka, Narayan; Zajaček, Michal; Panda, Swayamtrupta;
Martínez-Aldama, Mary Loli; Ratra, Bharat
Bibcode: 2022MNRAS.515.3729K
Altcode: 2022arXiv220505813K; 2022MNRAS.tmp.1823K
We use observations of 66 reverberation-measured Mg II quasars
(QSOs) in the redshift range 0.36 ≤ z ≤ 1.686 - a subset of the
78 QSOs we previously studied that also have ${\cal R}_{\rm {Fe\,
{\small II}}}$ (flux ratio parameter of UV Fe II to Mg II that is
used as an accretion-rate proxy) measurements - to simultaneously
constrain cosmological model parameters and QSO two-parameter and
three-parameter radius-luminosity (R-L) relation parameters in six
different cosmological models. We find that these QSO R-L relation
parameters are independent of the assumed cosmological model and so
these QSOs are standardizable through the R-L relations. Also: (1) With
the two-parameter R-L relation, we find that the low-${\cal R}_{\rm
{Fe\, {\small II}}}$ and high-${\cal R}_{\rm {Fe\, {\small II}}}$
data subsets obey the same R-L relation within the error bars. (2)
Extending the two-parameter R-L relation to a three-parameter one does
not result in the hoped-for reduction in the intrinsic dispersion of
the R-L relation. (3) Neither of the three-parameter R-L relations
provide a significantly better fit to the measurements than does
the two-parameter R-L relation. These are promising results for the
ongoing development of Mg II cosmological probes. The first and third
of these results differ significantly from those we found elsewhere
from analyses of reverberation-measured H β QSOs.
Title: Clash of Titans: a MUSE dynamical study of the extreme cluster
merger SPT-CL J0307-6225
Authors: Hernández-Lang, D.; Zenteno, A.; Diaz-Ocampo, A.; Cuevas, H.;
Clancy, J.; Prado, P. H.; Aldás, F.; Pallero, D.; Monteiro-Oliveira,
R.; Gómez, F. A.; Ramirez, Amelia; Wynter, J.; Carrasco, E. R.;
Hau, G. K. T.; Stalder, B.; McDonald, M.; Bayliss, M.; Floyd, B.;
Garmire, G.; Katzenberger, A.; Kim, K. J.; Klein, M.; Mahler, G.;
Nilo Castellon, J. L.; Saro, A.; Somboonpanyakul, T.
Bibcode: 2022MNRAS.tmp.2299H
Altcode: 2021arXiv211115443H
We present MUSE spectroscopy, Megacam imaging, and Chandra X-ray
emission for SPT-CL J0307-6225, a z=0.58 major merging galaxy cluster
with a large BCG-SZ centroid separation and a highly disturbed X-ray
morphology. The galaxy density distribution shows two main overdensities
with separations of 0.144 and 0.017 arcmin to their respective BCGs. We
characterize the central regions of the two colliding structures, namely
0307-6225N and 0307-6225S, finding velocity derived masses of M200,
N = 2.44 ± 1.41 × 1014 M⊙ and M200,
S = 3.16 ± 1.88 × 1014 M⊙, with a
line-of-sight velocity difference of |Δv| = 342 km s-1. The
total dynamically derived mass is consistent with the SZ derived mass
of 7.63 h$_{70}^{-1}$ ± 1.36 × 1014 M⊙. We
model the merger using the Monte Carlo Merger Analysis Code, estimating
a merging angle of 36$^{+14}_{-12}$ degrees with respect to the plane
of the sky. Comparing with simulations of a merging system with a mass
ratio of 1:3, we find that the best scenario is that of an ongoing
merger that began 0.96$^{+0.31}_{-0.18}$ Gyr ago. We also characterize
the galaxy population using Hδ and [OII] λ3727 Å lines. We find
that most of the emission-line galaxies belong to 0307-6225S, close
to the X-ray peak position, with a third of them corresponding to
red-cluster sequence galaxies, and the rest to blue galaxies with
velocities consistent with recent periods of accretion. Moreover, we
suggest that 0307-6225S suffered a previous merger, evidenced through
the two equally bright BCGs at the center with a velocity difference
of ~674 km s-1.
Title: REXCOR: a model of the X-ray spectrum of active galactic
nuclei that combines ionized reflection and a warm corona
Authors: Xiang, X.; Ballantyne, D. R.; Bianchi, S.; De Rosa, A.;
Matt, G.; Middei, R.; Petrucci, P. -O.; Różańska, A.; Ursini, F.
Bibcode: 2022MNRAS.515..353X
Altcode: 2022MNRAS.tmp.1593X; 2022arXiv220606825X
The X-ray spectra of active galactic nuclei (AGNs) often exhibit an
excess of emission above the primary power law at energies ≲2 keV. Two
models for the origin of this 'soft excess' are ionized relativistic
reflection from the inner accretion disc and Comptonization of thermal
emission in a warm corona. Here, we introduce REXCOR, a new AGN X-ray
(0.3-100 keV) spectral fitting model that self-consistently combines the
effects of both ionized relativistic reflection and the emission from a
warm corona. In this model, the accretion energy liberated in the inner
disc is distributed between a warm corona, a lamppost X-ray source,
and the accretion disc. The emission and ionized reflection spectrum
from the inner 400 rg of the disc is computed, incorporating
the effects of relativistic light-bending and blurring. The resulting
spectra predict a variety of soft excess shapes and sizes that depend on
the fraction of energy dissipated in the warm corona and lamppost. We
illustrate the use of REXCOR by fitting to the joint XMM-Newton and
NuSTAR observations of the Seyfert 1 galaxies HE 1143-1820 and NGC 4593,
and find that both objects require a warm corona contribution to the
soft excess. Eight REXCOR table models, covering different values of
accretion rate, lamppost height, and black hole spin, are publicly
available through the XSPEC website. Systematic use of REXCOR will
provide insight into the distribution of energy in AGN accretion flows.
Title: How to Deploy a 10-km Interferometric Radio Telescope on the
Moon with Just Four Tethered Robots
Authors: McGarey, Patrick; Nesnas, Issa A.; Rajguru, Adarsh; Bezkrovny,
Matthew; Jamnejad, Vahraz; Lux, Jim; Sunada, Eric; Teitelbaum,
Lawrence; Miller, Alexander; Squyres, Steve W.; Hallinan, Gregg;
Hegedus, Alex; Burns, Jack O.
Bibcode: 2022arXiv220902216M
Altcode:
The Far-side Array for Radio Science Investigations of the Dark
ages and Exoplanets (FARSIDE) is a proposed mission concept to
the lunar far side that seeks to deploy and operate an array of
128 dual-polarization, dipole antennas over a region of 100 square
kilometers. The resulting interferometric radio telescope would provide
unprecedented radio images of distant star systems, allowing for the
investigation of faint radio signatures of coronal mass ejections
and energetic particle events and could also lead to the detection of
magnetospheres around exoplanets within their parent star's habitable
zone. Simultaneously, FARSIDE would also measure the "Dark Ages" of the
early Universe at a global 21-cm signal across a range of red shifts
(z approximately 50-100). Each discrete antenna node in the array is
connected to a central hub (located at the lander) via a communication
and power tether. Nodes are driven by cold=operable electronics that
continuously monitor an extremely wide-band of frequencies (200 kHz
to 40 MHz), which surpass the capabilities of Earth-based telescopes
by two orders of magnitude. Achieving this ground-breaking capability
requires a robust deployment strategy on the lunar surface, which
is feasible with existing, high TRL technologies (demonstrated or
under active development) and is capable of delivery to the surface
on next-generation commercial landers, such as Blue Origin's Blue
Moon Lander. This paper presents an antenna packaging, placement,
and surface deployment trade study that leverages recent advances
in tethered mobile robots under development at NASA's Jet Propulsion
Laboratory, which are used to deploy a flat, antenna-embedded, tape
tether with optical communication and power transmission capabilities.
Title: Neutrino pair condensate and its application to cosmology
and astrophysics
Authors: Yoshimura, M.
Bibcode: 2022arXiv220902985Y
Altcode:
Left-handed neutrinos interact attractively by Z-boson exchange. The
Ginzburg-Landau mean field calculation and the Bogoliubov transformation
suggest that the attractive force leads to neutrino pair condensate
and neutrino super-fluidity. Neutrinos, as defined by quasi-particle
in the super-fluid phase, behave as massless fermions. When the result
of super-fluid formation is applied to the early universe, horizon
scale pair condensate may become a component of dark energy. A further
accretion of other fermions from thermal cosmic medium gives a seed
of primordial neutron stars consisting of proton, neutron, electron,
and neutrino in beta-equilibrium, surrounded by left-handed neutrino
pair condensate. This possibility may provide a mechanism of giving
a part or the whole of the dark matter in the present universe, if a
properly chosen small fraction condenses to neutrino super-fluid and
primordial neutron star not to over-close the universe. The proposal
can be verified by measuring neutrino burst at primordial neutron
star formation and by detecting super-fluid relic neutrinos in atomic
experiments at laboratories.
Title: A MUSE view of the massive merging galaxy cluster ACT-CL
J0102-4915 (El Gordo) at z = 0.87: robust strong lensing model and
data release
Authors: Caminha, G. B.; Grillo, C.; Rosati, P.; Liu, A.; Acebron,
A.; Bergamini, P.; Caputi, K. I.; Mercurio, A.; Tozzi, P.; Vanzella,
E.; Demarco, R.; Frye, B.; Rosani, G.; Sharon, K.
Bibcode: 2022arXiv220902718C
Altcode:
We present a detailed strong lensing analysis of the massive and
distant ($z=0.870$) galaxy cluster ACT-CL J0102$-$4915 (ACT0102,
also known as El Gordo), taking advantage of new spectroscopic data
from the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large
Telescope, and archival imaging from the Hubble Space Telescope. Thanks
to the MUSE data, we measure secure redshifts for 374 single objects,
including 23 multiply lensed galaxies, and 167 cluster members of
ACT0102. The observed positions of 56 multiple images, along with their
new spectroscopic redshift measurements, are used as constraints for
our strong lensing model. Remarkably, some multiple images are detected
out to a large projected distance of $\approx 1$ Mpc from the brightest
cluster galaxy, allowing us to estimate a projected total mass value
of $1.84_{-0.04}^{+0.03} \times 10^{15}\, \rm M_{\odot}$ within that
radius. We find that we need two extended cluster mass components, the
mass contributions from the cluster members and the additional lensing
effect of a foreground ($z=0.633$) group of galaxies, to predict the
positions of all multiple images with a root mean square offset of
$0.75"$. The main cluster-scale mass component is centered very closely
to the brightest cluster galaxy and the other extended mass component
is located in the north-west region of the cluster. These two mass
components have very similar values of mass projected within 300 kpc
from their centers, namely $2.29_{-0.10}^{+0.09}\times10^{14}\,\rm
M_{\odot}$ and $2.10_{-0.09}^{+0.08}\times10^{14}\,\rm M_{\odot}$,
in agreement with the major merging scenario of ACT0102. We make
publicly available the lens model, including the magnification maps
and posterior distributions of the model parameter values, as well as
the full spectroscopic catalogue containing all redshift measurements
obtained with MUSE.
Title: Observation of Turbulent Magnetohydrodynamic Cascade in the
Jovian Magnetosheath
Authors: Andrés, N.; Bandyopadhyay, R.; McComas, D. J.; Szalay,
J. R.; Allegrini, F.; Ebert, R. W.; Gershman, D. J.; Connerney,
J. E. P.; Bolton, S. J.
Bibcode: 2022arXiv220905386A
Altcode:
We present the first estimation of the energy cascade rate in Jupiter's
magnetosheath (MS). We use in-situ observations from the Jovian Auroral
Distributions Experiment (JADE) and the magnetometer investigation
(MAG) instruments onboard the Juno spacecraft, in concert with two
recent compressible models to investigate the cascade rate in the
magnetohydrodynamic (MHD) scales. While a high level of compressible
density fluctuations is observed in the Jovian MS, a constant energy
flux exists in the MHD inertial range. The compressible isothermal
and polytropic energy cascade rates increase in the MHD range when
density fluctuations are present. We find that the energy cascade
rate in Jupiter's magnetosheath is at least two orders of magnitude
(100 times) smaller than the corresponding typical value in the Earth's
magnetosheath.
Title: Is there evidence for CIDER in the Universe?
Authors: Barros, Bruno J.; Castelão, Diogo; da Fonseca, Vitor;
Barreiro, Tiago; Nunes, Nelson J.; Tereno, Ismael
Bibcode: 2022arXiv220904468B
Altcode:
In this work we analyze the full linear behaviour of the constrained
interacting dark energy (CIDER) model, which is a conformally coupled
quintessence model tailored to mimic a $\Lambda$CDM expansion. We
compute the matter and temperature anisotropies power spectra and
test the model against recent observational data. We shed light on
some particular subtleties of the background behaviour that were
not fully captured in previous works, and study the physics of the
linear cosmological observables. One novelty found was that matter
perturbations are enhanced at large scales when compared with the ones
of the standard $\Lambda$CDM. The reason and impact of this trend on
the cosmological observables and on the physics of the early Universe
are considered. We find that the introduction of the coupling parameter
alleviates the $\sigma_8$ tension between early and late time probes
although Planck data favours the $\Lambda$CDM limit of the model.
Title: A PeVatron Candidate: Modelling the Boomerang Nebula in
X-ray Band
Authors: Liang, Xuan-Han; Li, Chao-Ming; Wu, Qi-Zuo; Pan, Jia-Shu;
Liu, Ruo-Yu
Bibcode: 2022arXiv220903809L
Altcode:
Pulsar wind nebula (PWN) Boomerang and the associated supernova remnant
(SNR) G106.3+2.7 are among candidates for the ultra-high-energy (UHE)
gamma-ray counterparts published by LHAASO. Although the centroid of the
extended source, LHAASO J2226+6057, deviates from the pulsar's position
by about $0.3^\circ$, the source partially covers the PWN. Therefore, we
cannot totally exclude the possibility that a part of the UHE emission
comes from the PWN. Previous studies mainly focus on whether the SNR
is a PeVatron, while neglecting the energetic PWN. Here, we explore
the possibility of the Boomerang Nebula being a PeVatron candidate by
studying its X-ray radiation. By modelling the diffusion of relativistic
electrons injected in the PWN, we fit the radial profiles of the X-ray
surface brightness and the photon index. The solution with a magnetic
field $B=140\mu$G can well reproduce the observed profiles and implies
a severe suppression of IC scattering of electrons. Therefore, a proton
component need be introduced to account for the UHE emission, in light
of recent LHAASO's measurement on Crab Nebula, if future observations
reveal part of the UHE emission originating from the PWN. In this sense,
Boomerang Nebula would be a hadronic PeVatron.
Title: Hemispherical asymmetry of primordial power spectra
Authors: Sravan Kumar, K.; Marto, João
Bibcode: 2022arXiv220903928S
Altcode:
Although the cosmic microwave background (CMB) is largely understood
to be homogeneous and isotropic, the hemispherical asymmetry anomaly
seems to breakdown the isotropy, since the difference between the
power spectrum in the two hemispheres of the CMB is of the order of
$10^{-2}$ at large angular scales. We argue that the existence of an
anisotropic power spectrum can simply be explained by considering the
existence of two distinct power spectra in the two hemispheres of the
CMB. We achieve this by proposing a double vacuum structure for (single
field) inflationary quantum fluctuations based on discrete spacetime
transformations ($\mathcal{P}\mathcal{T}$) in a gravitational context,
first in de Sitter and finally in quasi de Sitter. As a result we obtain
inflationary quantum fluctuations that are produced in pairs with which
we are able to reproduce the amplitude of the observed dipolar asymmetry
at different scales of $ 10^{-4} {\rm Mpc^{-1}}\lesssim k\lesssim 1 {\rm
Mpc^{-1}}$ fixing the pivot scale $k=0.05 \, {\rm Mpc}^{-1}$ for $N=55$
e-foldings of inflation. We also predict that a similar hemispherical
asymmetry should arise for the primordial gravitational waves (PGWs)
as well and we compute the power asymmetry of PGW spectra at various
wave numbers. In our framework we do not introduce any new parameters.
Title: What drives decayless kink oscillations in active region
coronal loops on the Sun?
Authors: Mandal, Sudip; Chitta, Lakshmi P.; Antolin, Patrick; Peter,
Hardi; Solanki, Sami K.; Auchère, Frédéric; Berghmans, David;
Zhukov, Andrei N.; Teriaca, Luca; Cuadrado, Regina A.; Schühle,
Udo; Parenti, Susanna; Buchlin, Éric; Harra, Louise; Verbeeck, Cis;
Kraaikamp, Emil; Long, David M.; Rodriguez, Luciano; Pelouze, Gabriel;
Schwanitz, Conrad; Barczynski, Krzysztof; Smith, Phil J.
Bibcode: 2022arXiv220904251M
Altcode:
We study here the phenomena of decayless kink oscillations in a system
of active region (AR) coronal loops. Using high resolution observations
from two different instruments, namely the Extreme Ultraviolet Imager
(EUI) on board Solar Orbiter and the Atmospheric Imaging Assembly
(AIA) on board the Solar Dynamics Observatory, we follow these AR
loops for an hour each on three consecutive days. Our results show
significantly more resolved decayless waves in the higher-resolution
EUI data compared with the AIA data. Furthermore, the same system of
loops exhibits many of these decayless oscillations on Day-2, while on
Day-3, we detect very few oscillations and on Day-1, we find none at
all. Analysis of photospheric magnetic field data reveals that at most
times, these loops were rooted in sunspots, where supergranular flows
are generally absent. This suggests that supergranular flows, which
are often invoked as drivers of decayless waves, are not necessarily
driving such oscillations in our observations. Similarly, our findings
also cast doubt on other possible drivers of these waves, such as a
transient driver or mode conversion of longitudinal waves near the loop
footpoints. In conclusion, through our analysis we find that none of
the commonly suspected sources proposed to drive decayless oscillations
in active region loops seems to be operating in this event and hence,
the search for that elusive wave driver needs to continue.
Title: Detection of gravitational waves using parametric resonance
in Bose-Einstein condensates
Authors: Robbins, Matthew P. G.; Afshordi, Niayesh; Jamison, Alan O.;
Mann, Robert B.
Bibcode: 2022CQGra..39q5009R
Altcode: 2021arXiv210103691R
An interesting proposal for detecting gravitational waves involves
quantum metrology of Bose-Einstein condensates (BECs). We consider
a forced modulation of the speed of sound of a BEC, whose modulation
frequency matches that of an incoming continuous gravitational wave. The
speed of sound modulation induces parametric resonance in the BEC, which
in turn enhances sensitivity of the BEC to gravitational waves. We
find that such a BEC detector could potentially be used to detect
gravitational waves across several orders of magnitude in frequency,
with the sensitivity depending on the speed of sound, size of the
condensate, and frequency of the phonons. We discuss the sensitivity
of a possible BEC experiment and comment on the current technological
limitations. We also comment on the noise sources as well as what is
necessary for such a detector to become feasible.
Title: Fracturing and pore-fluid distribution in the Marlborough
region, New Zealand from body-wave tomography: Implications for
regional understanding of the Kaikōura area
Authors: Heath, Benjamin A.; Eberhart-Phillips, Donna; Lanza,
Federica; Thurber, Clifford; Savage, Martha K.; Okada, Tomomi;
Matsumoto, Satoshi; Iio, Yoshihisa; Bannister, Stephen
Bibcode: 2022E&PSL.59317666H
Altcode:
Relative to more mature fault zones, immature fault zones that
have accumulated smaller total displacement are characterized by
less efficient strain localization and more complicated earthquake
ruptures. How differences in maturation are reflected in regional-scale
upper-crustal fracturing is not well known. Recently, complicated
earthquake ruptures associated with immature fault zones, such as the
2016 Kaikōura earthquake in New Zealand, have occurred in areas that
are in regional proximity (<100 km away) to more mature faults. Here
we examine whether inefficient strain localization in less mature fault
zones is associated with a broader distribution and anomalously elevated
concentration of fractures over distances of tens of kilometers. We
use regional seismic arrival-time tomography in a broad area around
the Kaikōura earthquake to investigate lateral variations in Vp
and Vp/Vs. Focusing on the extensively faulted but compositionally
uniform Torlesse-Pahau terrane in the Marlborough region where the
earthquake occurred, we attribute lateral variations in Vp and Vp/Vs
to differences in concentration of fluid-filled fractures. Using
numerical models relating seismic velocities and fracturing, we
solve for the lateral variation in concentration of ∼0.01 aspect
ratio fluid-filled fractures. We find that areas near the Kaikōura
rupture have >3% elevated fracture porosity compared to the adjacent
area to the north. The elevated regional fracturing in the Kaikōura
area is interpreted to result from more distributed deformation, and
broader distribution of earthquakes, due to inefficient localization of
strain from a regionally uniform strain rate field, highlighting the
relationship between relative maturity of upper-crustal fault zones
and lateral variability of regional upper-crustal properties. When earthquakes occur in immature fault zones (areas that have
accumulated small total displacement), they tend to rupture multiple
poorly developed faults of diverse orientations. In contrast, more
mature fault zones are associated with more developed, smoother faults
and more localized earthquake activity. How these differences in
maturation are reflected in the regional distribution of fractures
is not well known. Here we use the arrival times of P and S waves
from earthquakes to constrain seismic velocities (Vp and Vp/Vs)
and use numerical models to relate seismic velocities to fracture
concentration. We focus on the Marlborough region of the South Island,
New Zealand, where immature fault zones recently ruptured during the
2016 Kaikōura earthquake but which also has more mature fault zones
<100 km away. We find elevated fracture concentrations (3% higher
fracture porosity), indicative of more distributed deformation along
immature fault zones relative to more mature fault zones. In immature
settings, fracturing is not as effectively localized along individual
fault traces, leading to a broadly distributed fracture network.
Title: A numerical study of the 1/2, 2/1, and 1/1 retrograde mean
motion resonances in planetary systems
Authors: Caritá, Gabriel Antonio; Cefali Signor, Alan; Morais,
Maria Helena Moreira
Bibcode: 2022MNRAS.515.2280C
Altcode: 2022MNRAS.tmp.1551C; 2022arXiv220604526C
We present a numerical study on the stability of the 1/2, 2/1, and 1/1
retrograde mean motion resonances in the three-body problem composed
of a solar mass star, a Jupiter mass planet, and an additional
body with zero mass (elliptic restricted three-body problem) or
masses corresponding to either Neptune, Saturn, or Jupiter (planetary
three-body problem). For each system, we obtain stability maps using the
n-body numerical integrator REBOUND and computing the chaos indicator
mean exponential growth factor of nearby orbits (MEGNO). We show
that families of periodic orbits exist in all configurations and they
correspond to the libration of either a single resonant argument or all
resonant arguments (fixed points). We compare the results obtained in
the elliptic restricted three-body problem with previous results in the
literature, and we show the differences and similarities between the
phase space topology for these retrograde resonances in the circular
restricted, elliptic restricted, and planetary three-body problems.
Title: Filament Leg--Leg Reconnection as a Source of Prominent
Supra-Arcade Downflows
Authors: Dudik, Jaroslav; Aulanier, Guillaume; Kasparova, Jana;
Karlicky, Marian; Zemanova, Alena; Lorincik, Juraj; Druckmuller,
Miloslav
Bibcode: 2022arXiv220900306D
Altcode:
We report on interaction of the legs of the erupting filament
of 2012 August 31 and associated prominent supra-arcade downflows
(P-SADs) as observed by the Atmospheric Imaging Assembly onboard the
Solar Dynamics Observatory. We employ a number of image processing
techniques to enhance weak interacting features. As the filament erupts,
both legs stretch outwards. The positive-polarity leg also untwists
and splits into two parts. The first part runs into the conjugate
(negative-polarity) leg, tearing it apart. The second part then
converges into the remnant of the conjugate leg, after which both
weaken and finally disappear. All these episodes of interaction of
oppositely-oriented filament legs are followed by appearance of P-SADs,
seen in the on-disk projection to be shaped as loop-tops, along with
many weaker SADs. All SADs are preceded by hot supra-arcade downflowing
loops. This observed evolution is consistent with the three-dimensional
rr-rf (leg-leg) reconnection, where the erupting flux rope reconnects
with itself. In our observations, as well as in some models, the
reconnection in this geometry is found to be long-lasting. It plays
a substantial role in the evolution of the flux rope of the erupting
filament and leads to prominent supra-arcade downflows.
Title: Pre-landslide topographic reconstruction in Baetis Chaos,
mars using a CaSSIS Digital Elevation Model
Authors: Guimpier, A.; Conway, S. J.; Pajola, M.; Lucchetti, A.;
Simioni, E.; Re, C.; Noblet, A.; Mangold, N.; Thomas, N.; Cremonese,
G.; CaSSIS Team
Bibcode: 2022P&SS..21805505G
Altcode:
Planview detailed morphological analysis of martian landslides is
usually performed using orbital imagery such as from the ConTeXt camera
(CTX) at 6 m/pix, the Colour and Stereo Surface Imaging System (CaSSIS)
at 4.5 m/pix or the High-Resolution Imaging Science Experiment (HiRISE)
at 0.25-0.5 m/pix. However, topographic information is key to fully
understand a landslide's formation mechanism and its mobility, by
estimating the material volumes mobilised and the spatial distribution
of erosion and deposition. Digital Elevation Models (DEM) are required
to carry out these analyses; nevertheless, there is currently a gap
in landslide-volume studies between those using Mars Orbiter Laser
Altimeter (MOLA) dataset at ∼450 m/pix or HRSC at 50-200 m/pix and
those using HiRISE data at 1-2 m/pix, which is only partially filled
by CTX elevation data at ∼20 m/pix. The CaSSIS camera on board
the ESA/Trace Gas Obiter (TGO) can be used to produce DEMs, but so
far, such data have not yet been used to conduct a landslide volume
analysis. Here, we use three reconstruction methods (semi-automatic,
morphology-based and tilted) on a CaSSIS DEM to estimate the initial
topography and hence the volume and the distribution of erosion and
deposition of a 6 km long landslide in Baetis Chaos. Despite the
complex topography of the surrounding area due to the presence of an
ejecta deposit beneath the landslide, we were able to estimate the
landslide's volume and mass distribution. Using a tilted plane as part
of estimating the initial topography produced the best results. We
evaluated the success by considering the quantifiable balance between
erosion and deposition (given the uncertainties) and more subjectively
by considering whether the volume distribution matched with what
was expected based on the morphology in images alone. Therefore, we
recommend the use of this method for individual landslide studies in
complex topography where detailed knowledge of the deposit-thickness
distribution is required. The semi-automatic reconstruction method
produces satisfactory volume estimates and would be better suited to
studies where hundreds of landslides are present. We found that CaSSIS
data can be used to successfully conduct such analyses, providing
additional DEM coverage to study martian medium-scale landslides or
other landforms of similar scale (5-15 km) with the notable benefit
that it provides single-pass stereo image acquisition.
Title: Large-scale expansion of OB stars in Cygnus
Authors: Quintana, Alexis L.; Wright, Nicholas J.
Bibcode: 2022MNRAS.515..687Q
Altcode: 2022arXiv220515611Q; 2022MNRAS.tmp.1468Q
The proper motions (PMs) of OB stars in Cygnus have recently been
found to exhibit two large-scale kinematic patterns suggestive
of expansion. We perform a 3D traceback on these OB stars, the
newly identified OB associations and related open clusters in the
region. We find that there are two groups of stars, associations and
clusters and that they were each more compact in the past, reaching
their closest approach $7.9^{+3.0}_{-1.8}$ and $8.5^{+0.8}_{-2.8}$ Myr
ago. We consider two main scenarios for the driver of these large-scale
expansion patterns: feedback-driven expansion from a previous generation
of massive stars, and expansion as a result of the turbulent velocity
field in the primordial molecular cloud. While it is tempting to
attribute such large-scale expansion patterns to feedback processes,
we find that the observed kinematics are fully consistent with the
turbulent origin, and therefore that the injection of further energy or
momentum from feedback is not required. Similar conclusions may be drawn
for other star forming regions with large-scale expansion patterns.
Title: Predicting fault reactivation and macroscopic failure in
discrete element method simulations of restraining and releasing
step overs
Authors: McBeck, J.; Ben-Zion, Y.; Renard, F.
Bibcode: 2022E&PSL.59317667M
Altcode:
To assist the identification of precursors to ruptures in segmented
fault networks, we build discrete element method simulations of two
parallel faults that are underlapping or overlapping, in releasing
or restraining steps. We use machine learning models to predict
the timing of the reactivation of the faults, and the timing of
macroscopic failure identified from the peak shear stress acting
on the boundaries. The machine learning models use the evolving
three-dimensional components of the strain and velocity fields to
make these predictions. The models depend on the same characteristics,
regardless of the preexisting geometry: the component of the velocity
vector parallel to the applied loading direction, vx, the
shear strain component εxy, and the second invariant of the
strain deviator tensor, J2. The results suggest that crustal
monitoring of strike-slip systems in which the loading is approximately
parallel to the fault strike, with releasing and restraining steps
and overlapping and underlapping faults, may focus on the same set
of strain and velocity components. However, the results indicate that
the key characteristics that control the timing of fault reactivation
depend on the distance from the preexisting faults. When the models
use data within one fault half-length of the preexisting fault, the
predictions primarily depend on εxy and vx,
whereas when they use data outside this region, they primarily depend
on vx. Monitoring efforts that focus on the near-fault
deformation field may benefit from tracking information that helps
estimate εxy and vx, in contrast to monitoring
efforts further from the main faults. Models developed with data
further from the faults perform worse than models developed with all
of the data, but better than models developed with near fault data,
consistent with observations of distributed and subsequently localizing
low-magnitude seismicity.
Title: A faster growth of perturbations in an early matter dominated
epoch: primordial black holes and gravitational waves
Authors: Das, Subinoy; Maharana, Anshuman; Muia, Francesco
Bibcode: 2022MNRAS.515...13D
Altcode: 2021arXiv211211486D; 2022MNRAS.tmp.1579D
We present a scenario for fast growth of cosmological perturbations;
δ(t) ~ a(t)s, a(t) being the scale factor, with s >
10 for the numerical examples reported in this article. The basic
ingredients of the scenario are an early matter dominated era and
the dark fermion, which experiences a scalar mediated force during
the epoch. Both of these arise in string/supergravity models. The
fast growth occurs for sub-horizon density perturbations of the
dark fermion. The fast growth has a rich set of phenomenological
implications. We outline implications for the formation of primordial
black holes and the production of gravitational waves. Primordial
black holes in the sublunar mass range (which are ideal dark matter
candidates) can be produced. Gravitational waves can be produced in
a wide range of frequencies due to second-order scalar perturbations
and due to evaporation and merger of primordial black holes.
Title: A 2-hr binary period for the black hole transient MAXI
J0637-430
Authors: Soria, Roberto; Ma, Ruican; Tao, Lian; Zhang, Shuang-Nan
Bibcode: 2022MNRAS.515.3105S
Altcode: 2022arXiv220701631S; 2022MNRAS.tmp.1828S
We revisit various sets of published results from X-ray and optical
studies of the Galactic black hole (BH) candidate MAXI J0637-430,
which went into outburst in 2019. Combining the previously reported
values of peak outburst luminosity, best-fitting radii of inner and
outer accretion disc, viewing angle, exponential decay time-scale,
and peak-to-peak separation of the He II λ4686 disc emission line,
we improve the constraints on the system parameters. We estimate a
heliocentric distance d ≍ (8.7 ± 2.3) kpc, a projected Galactocentric
distance R ≍ (13.2 ± 1.8) kpc and a height |z| ≍ (3.1 ± 0.8)
kpc from the Galactic plane. It is the currently known Milky Way BH
candidate located farthest from the Galactic Centre. We infer a BH
mass M1 ≍ (5.1 ± 1.6)M⊙, a spin parameter
a* ≲ 0.25, a donor star mass M2 ≍ (0.25 ±
0.07)M⊙, a peak Eddington ratio λ ≍ 0.17 ± 0.11 and
a binary period $P_{\rm orb} \approx 2.2^{+0.8}_{-0.6}$ hr. This is
the shortest period measured or estimated so far for any Galactic BH
X-ray binary. If the donor star is a main-sequence dwarf, such a period
corresponds to the evolutionary stage where orbital shrinking is driven
by gravitational radiation and the star has regained contact with its
Roche lobe (low end of the period gap). The three Galactic BHs with
the shortest period (≲3 hr) are also those with the highest vertical
distance from the Galactic plane (≳2 kpc). This is probably because
binaries with higher binding energies can survive faster natal kicks.
Title: 2001 SN263 - the contribution of their irregular
shapes on the neighbourhood dynamics
Authors: Valvano, G.; Winter, O. C.; Sfair, R.; Machado Oliveira,
R.; Borderes-Motta, G.
Bibcode: 2022MNRAS.515..606V
Altcode: 2022MNRAS.tmp.1769V; 2022arXiv220701726V
The first proposed Brazilian mission to deep space, the ASTER mission,
has the triple asteroid system (153591) 2001 SN263 as a
target. One of the mission's main goals is to analyse the physical
and dynamical structures of the system to understand its origin and
evolution. This work aims to analyse how the asteroid's irregular
shape interferes with the stability around the system. The results show
that the irregular shape of the bodies plays an important role in the
dynamics nearby the system. For instance, the perturbation due to the
(153591) 2001 SN263 Alpha's shape affects the stability in
the (153591) 2001 SN263 Gamma's vicinity. Similarly, the
(153591) 2001 SN263 Beta's irregularity causes a significant
instability in its nearby environment. As expected, the prograde
case is the most unstable, while the retrograde scenario presents
more stability. Additionally, we investigate how the solar radiation
pressure perturbs particles of different sizes orbiting the triple
system. We found that particles with a 10-50 cm radius could survive
the radiation pressure for the retrograde case. Meanwhile, to resist
solar radiation, the particles in prograde orbit must be larger than
the particles in retrograde orbits, at least one order of magnitude.
Title: Water vapor and cloud microphysical characteristics of a
sea-effect snowstorm in Shandong Peninsula, China
Authors: Li, Jianhua; Gao, Wenhua; Li, Feng
Bibcode: 2022JASTP.23505910L
Altcode:
Sea-effect snowfall is a special form of snow in the coastal areas of
the Bohai Sea in China. However, a quantitative understanding of its
water vapor and cloud microphysical mechanisms is still lacking. In
this study, the Weather Research and Forecasting model version
4.0 with three microphysics schemes was employed to investigate a
sea-effect snowstorm that occurred in the north of Shandong Peninsula
on 9-10 January 2018. The simulated snowfall amount, temperature and
humidity profiles, and radar reflectivity were in general agreement
with the observations. The moisture budget revealed that the water
vapor came completely from evaporation of the surface of Bohai Sea. The
largest water vapor sink term was the moisture advection, followed by
the deposition and condensation (accounting for only 15% of the sea
surface evaporation). This phenomenon is analogous to heating water
in a kettle and then the water vapor drifting away with the wind. In
the main snowfall area, the total water vapor transport was positive
(i.e., inflow) below the height of 1.5 km, and was almost zero above
3.0 km. The period of maximum moisture inflow in the low layer was
about 30 min ahead of the maximum surface snowfall. In addition, the
hydrometeor distributions in this sea-effect snowstorm were relatively
simple compared to those in non-sea-effect snowstorm; the snow content
was the most (0.09 g kg-1), followed by the supercooled
cloud water (0.01 g kg-1), owing to the weak convection
in it. Snow growth was dominated by the vapor deposition, and the
process of rimming accounted for only 1/4 of the vapor deposition. The
evidently weaker vapor condensation than vapor deposition is quite
different from that in summertime heavy rainfall.
Title: Swampland conjectures in hybrid metric-Palatini gravity
Authors: Sadeghi, J.; Noori Gashti, S.; Darabi, F.
Bibcode: 2022PDU....3701090S
Altcode: 2022arXiv220709793S
In this paper, we study a hybrid combination of Einstein-Hilbert action
with curvature scalar R, and a function f(R) in Palatini gravity within
the context of inflationary scenario, from the Swampland conjecture
point of view. This hybrid model has been paid attention in recent
cosmological studies, and its applications have been widely studied in
the literature. In this regard, using the Swampland conjecture (using
(C1) as the first component of dS swampland conjecture,
which is obtained from the first derivative of the potential upon the
potential and (C2) as the second component which is acquired
from the second derivative of the potential upon the potential), we
investigate the cosmological implications of the present gravity theory,
with a suitable potential, in the framework of inflationary scenario
to obtain cosmological quantities such as slow-roll parameter, scalar
spectral index (ns) , tensor-to-scalar ratio (rs),
and then compare them with the cosmological observations. Moreover,
we compare the compatibility or incompatibility of the model with
observable data, such as Planck, by applying Swampland conjecture
to rs -ns , C1,2 -ns
and C1,2 -rs plots.
Title: Semiquantum private comparison of size relationship based on
<italic>d</italic>-level single-particle states
Authors: GENG, MaoJie; XU, TianJie; CHEN, Ying; YE, TianYu
Bibcode: 2022SSPMA..52C0311G
Altcode: 2022arXiv220104787G
In this paper, we propose a novel semiquantum private comparison
(SQPC) protocol of size relationship based on d-level single-particle
states. The designed protocol can compare the size relationship of
different privacy messages from two classical users with the help of a
semi-honest third party (TP), who is permitted to misbehave on her own
but cannot be in collusion with anyone else. The correctness analysis
shows that this protocol can gain correct comparison results. The
security analysis turns out that this protocol can resist famous outside
attacks and participant attacks. Moreover, this protocol can guarantee
that TP does not know the accurate comparison results. Compared
with the only existing SQPC protocol of size relationship (Quantum
Inf. Process. 20:124 (2021)), this protocol takes advantage over it on
the aspects of initial quantum resource, TP's measurement operations
and TP's knowledge about the comparison results.
Title: Arecibo observations of a burst storm from FRB 20121102A
in 2016
Authors: Hewitt, D. M.; Snelders, M. P.; Hessels, J. W. T.; Nimmo,
K.; Jahns, J. N.; Spitler, L. G.; Gourdji, K.; Hilmarsson, G. H.;
Michilli, D.; Ould-Boukattine, O. S.; Scholz, P.; Seymour, A. D.
Bibcode: 2022MNRAS.515.3577H
Altcode: 2022MNRAS.tmp.1885H; 2021arXiv211111282H
FRB 20121102A is the first known fast radio burst (FRB) from which
repeat bursts were detected, and one of the best-studied FRB sources
in the literature. Here we report on the analysis of 478 bursts
(333 previously unreported) from FRB 20121102A using the 305-m
Arecibo telescope - detected during approximately 59 hours of
observations between December 2015 and October 2016. The majority
of bursts are from a burst storm around September 2016. This is the
earliest available sample of a large number of FRB 20121102A bursts,
and it thus provides an anchor point for long-term studies of the
source's evolving properties. We observe that the bursts separate
into two groups in the width-bandwidth-energy parameter space, which
we refer to as the low-energy bursts (LEBs) and high-energy bursts
(HEBs). The LEBs are typically longer duration and narrower bandwidth
than the HEBs, reminiscent of the spectro-temporal differences observed
between the bursts of repeating and non-repeating FRBs. We fit the
cumulative burst rate-energy distribution with a broken power law
and find that it flattens out toward higher energies. The sample
shows a diverse zoo of burst morphologies. Notably, burst emission
seems to be more common at the top than the bottom of our 1150-1730
MHz observing band. We also observe that bursts from the same day
appear to be more similar to each other than to those of other days,
but this observation requires confirmation. The wait times and burst
rates that we measure are consistent with previous studies. We discuss
these results, primarily in the context of magnetar models.
Title: Phantom scalar field counterpart to Curzon-Chazy spacetime
Authors: Polcar, Lukáš; Svítek, Otakar
Bibcode: 2022CQGra..39r5002P
Altcode: 2021arXiv211211738P
We derive and analyze phantom scalar field counterpart to Curzon-Chazy
spacetime. Such solution contains a wormhole throat while the region
inside the throat behaves like a one-directional time machine. We
describe its conformal structure and non-scalar singularity hidden
inside the wormhole. We examine the results provided by different
definitions of mass of the spacetime to understand their value in the
presence of phantom matter. The electromagnetic generalization of this
spacetime is as well briefly considered.
Title: Photonic integration on rare earth ion-doped thin-film
lithium niobate
Authors: Chen, Yuping
Bibcode: 2022SCPMA..6594231C
Altcode:
No abstract at ADS
Title: Seismogenesis of the 2021 Mw 7.1 earthquake
sequence near the northeastern Japan revealed by double-difference
seismic tomography
Authors: Tan, Yuyang; Xing, Huilin; Jin, Zongwei; Wang, Jianchao;
Pang, Shuo; Guo, Hao; Zhang, Haijiang; Gao, Lei
Bibcode: 2022E&PSL.59417738T
Altcode:
Recently, a Mw 7.1 earthquake struck the Pacific coast of
northeastern Japan on 2021/02/13. To investigate the cause of this
earthquake and its aftershocks, we applied a Vp/Vs model-consistency
constrained double-difference (DD) seismic tomography method to the
earthquake arrival time data from the dense seismic networks in Japan
to image the velocity structures at the hypocenter areas. Compared
to the conventional DD tomography, the new method can determine the
Vp/Vs model with high resolution and precision. The reliability of
the seismic tomography results is testified by checkerboard resolution
test. The velocity profiles show that the oceanic crust and uppermost
part of the oceanic mantle are characterized by low Vs and high
Vp/Vs due to hydration reaction, while the lower oceanic mantle
is associated with high Vs and low Vp/Vs anomalies that are likely
caused by serpentine dehydration. The mainshock of the Mw
7.1 earthquake sequence is located at the boundary between the low
velocity layer and underlying high velocity zone. The aftershocks are
mainly distributed within the low velocity layer. The rupture plane
inferred from the aftershock distribution and mainshock focal mechanism
solution has penetrated ∼10 km into the slab and extended ∼50 km
along a direction nearly parallel to the trench. These observations
have suggested that the Mw 7.1 earthquake sequence occurs
as a result of reactivation of a pre-existing fault likely created
at the outer-rise before subduction. The association of the mainshock
with the velocity anomaly edge suggests that this earthquake sequence
is probably caused by dehydration of the mantle serpentines, which
increases the pore pressure on the fault. Besides, the variation of
rock mechanics at the hypocenter area of the mainshock also facilitates
the nucleation of the whole earthquake sequence.
Title: Cryptic sulfur cycling during the formation of giant gypsum
deposits
Authors: Guibourdenche, L.; Cartigny, P.; Dela Pierre, F.; Natalicchio,
M.; Aloisi, G.
Bibcode: 2022E&PSL.59317676G
Altcode:
Salt giants are large-scale, basin-wide deposits formed sporadically
in the geological past, from the early Paleozoic to the late
Cenozoic. Their role as sinks for seawater dissolved ions is well
known, however the biogeochemical conditions that accompany salt
giant formation and their effects on carbon cycling remain poorly
constrained. Here we show that massive gypsum deposits of the
Mediterranean salt giant - the youngest salt giant on Earth - formed
in a particularly dynamic biogeochemical environment controlled by
orbitally-driven climate oscillations at the precessional scale. Using
multiple sulfur isotopes combined with a steady-state sulfur cycle
model, we show that, prior to gypsum precipitation, more than 80% of
its constituting sulfate was first microbially reduced into sulfide,
possibly stored as elemental sulfur, and then almost completely
microbially reoxidized back to sulfate. This "cryptic" sulfur cycling
contemporaneous to gypsum precipitation implies both negligible net
sulfate consumption and sulfide production, despite a significant
benthic flux of organic carbon remineralized through microbial sulfate
reduction. This is the first known evidence of cryptic sulfur cycling
in the geological past.
Title: Barium isotopes reveal the role of deep magmatic fluids in
magmatic-hydrothermal evolution and tin enrichment in granites
Authors: Deng, Gengxin; Jiang, Dingsheng; Zhang, Rongqing; Huang,
Jian; Zhang, Xingchao; Huang, Fang
Bibcode: 2022E&PSL.59417724D
Altcode:
Although deep magmatic fluids are important for the shallow
magmatic-hydrothermal evolution and transport/enrichment of ore-forming
elements in transcrustal magmatic system, it is still difficult to
identify the influences of such fluids by using conventional geochemical
indicators. Here we report Ba isotope compositions for granites from the
Jurassic Qitianling batholith in the Nanling Range, South China that
hosts several large tin deposits. This composite batholith consists
of three stages of granites with an age range of ∼15 Ma and sharp
contacts between each other, which suggest an underlying long-lived
crystal mush-dominated transcrustal magmatic system. The small variation
of δ 138 / 134Ba in the first-stage less evolved granites
(-0.24-0.37‰) indicates that fractional crystallization in deep
crystal mush of this system does not cause significant Ba isotope
fractionation. In contrary, the latter-two stage highly differentiated
granites show more variable and overall lower δ 138 / 134Ba
(-1.79-0.14‰), which cannot be explained by K-feldspar-controlled
fractional crystallization in shallow crystal mush. Instead, the
distinctively low Ba contents (<100 μg/g) and magmatic-hydrothermal
evolution features of the latter-two stage granites suggest that their
low δ 138 / 134Ba are due to modification by magmatic
fluids. Further modeling demonstrates that exsolved fluids from deep
crystal mush can explain the light Ba isotope compositions of the
latter-two stage granites. Because these ascending deep magmatic
fluids can efficiently scavenge Sn and other fluid-mobile elements
then transport to shallow level, we propose that these fluids could
provide critical materials for the Sn-polymetallic mineralization.
Title: Linking granulites, intraplate magmatism, and bi-mineralic
eclogites with a thermodynamic-petrological model of melt-solid
interaction at the base of anorogenic lower continental crust
Authors: Emo, Robert B.; Kamber, Balz S.
Bibcode: 2022E&PSL.59417742E
Altcode:
This study reports results from thermodynamic phase equilibrium
and trace element modelling of mafic magmatic underplating and
solid-liquid interaction in the lower continental crust (LCC) in
intraplate settings. The arrival of underplating basalt sills into thin
(∼30 km at 8 kbar) and thicker (∼45 km at 12 kbar) andesitic and
basaltic LCC precursors was simulated with heating and batch-melting
to yield refractory residues. Continued magmatic invasion of the LCC
was then modelled at the same pressures with hybridisation between
the residual solids and basaltic and picritic liquids (at 80:20 and
50:50 proportions). The first finding is that hybridisation with
basalt increases the stability fields of 2-pyroxene-plagioclase and
garnet-clinopyroxene-plagioclase granulites, by far the dominant LCC
xenoliths found in anorogenic settings. The second finding pertains
to situations when the liquid proportion of the hybrid system is
lower than the fraction of the incoming mafic liquid. The resulting
liquids share many characteristics with silicic volcanic rocks in
continental flood basalt (CFB) provinces, including low Al and high
Ti-concentrations. Stoichiometric melting reactions from 80:20 residual
andesite:basalt hybridisation reproduce trace element patterns of
silicic eruptives with potential for decoupling of Sr-Nd-Pb isotope
systematics, as found in CFB rhyolites and LCC xenoliths. Incongruent
melting of hornblende and garnet (the A in AFC) from the residual solid
and dominant peritectic fractional crystallisation of plagioclase (the
FC in AFC) from the liquid occur. A notable feature of LCC-picrite
hybridisation is that solid residues after felsic liquid extraction,
when subjected to higher pressure, are buffered to olivine and
quartz-free compositions. Consequently, if these high-pressure granulite
residues delaminated, they would convert to the bi-mineralic high-Mg
eclogites found as xenoliths in kimberlites. The modelled residues
also have the Sr-enrichment and positive Eu-anomalies of eclogite
xenoliths. Solid-liquid interaction in intraplate settings has been
and remains a significant process in crustal growth and evolution.
Title: Unified formalism for the emergence of space from the first
law of thermodynamics
Authors: T., Hassan Basari V.; Krishna, P. B.; Mathew, Titus K.
Bibcode: 2022arXiv220900304T
Altcode:
We derive a unified expansion law for our universe from the first law
of thermodynamics on the apparent horizon, where entropic evolution
depicts the emergence of cosmic space. The derivation advances a
general form for degrees of freedom on the surface and bulk, which
provides a natural generalization for the expansion law proposed
by Padmanabhan. The derivation also provides justification for the
selection of Gibbons-Hawking temperature in the original expansion law
and for the use of areal volume in the non-flat FRW universe. Since
the unified expansion law exclusively depends on the form of entropy,
the method is applicable to obtain the expansion law in any gravity
theory without any additional ad hoc assumptions. From the general
expansion law, we have obtained the expansion law corresponding to
different theories of gravity like (n+1) Einstein, Gauss-Bonnet,
Lovelock, and Horava-Lifshitz. We also obtained the expansion law for
non-extensive entropy, like Tsallis entropy.
Title: Ubiquitous dendritic olivine constructs initial crystal
framework of mafic magma chamber
Authors: Xing, Chang-Ming; Wang, Christina Yan; Charlier, Bernard;
Namur, Olivier
Bibcode: 2022E&PSL.59417710X
Altcode:
Layered intrusions are fossilized mafic magma chambers in the Earth's
crust. The pathways that led to crystallization and solidification
of layered intrusions have been hotly debated as the growth model of
primocrysts (the earliest-formed crystals) in mafic magma chambers
remains enigmatic. In this study, we carried out high-resolution
elemental mapping of mm-scale olivine primocrysts from the Sept Iles
layered intrusion (Canada), the third largest one in the world,
with a focus on phosphorus (P) zoning of olivine. Our results
reveal that complex P zoning of olivine with intense dissolution
textures is ubiquitous in the ∼4.7 km-thick Layered Series of the
intrusion. The P-rich zones of olivine are featured with dendritic,
hopper and sector-zoned patterns, which are attributed to significant
magma undercooling. Thermal modeling based on a 1-D conductive
cooling model suggests that initially hot parental magma intruding
into cold country rocks would result in high degrees of undercooling
(-ΔT >60 °C) in the margins (i.e., floor, roof and sidewalls) of
magma chamber, facilitating rapid growth of dendritic olivine, which
may be then spread within the magma chamber by dynamic convection and
crucial to construct initial crystal framework of a solidifying magma
chamber. Additionally, diffusion modeling based on the P gradients in
olivine suggests a minimum cooling rate of 2.7 to 3.3×10-3
°C/year in the center of the intrusion, similar to the averaged
cooling rate of other layered intrusions (e.g., Bushveld, Stillwater
and Skaergaard) reported in previous studies. This indicates that
rapid cooling (ca. 10-2 to 10-3 °C/year)
at high temperature (>800 °C) may be predominant regardless of
the size of magma chambers. Our study demonstrates that P zoning of
olivine is powerful in decoding crystallization and thermal histories
of mafic-ultramafic intrusions.
Title: Can we accurately estimate sediment budgets on Mars?
Authors: Sankey, Joel B.; Kasprak, Alan; Chojnacki, Matthew; Titus,
Timothy N.; Caster, Joshua; DeBenedetto, Geoffrey P.
Bibcode: 2022E&PSL.59317682S
Altcode:
Sediment budgets are fundamentally important for planetary
science. However, only one primary method, based on remote sensing,
is currently available for determining extraterrestrial sediment
budgets. For determining sediment budgets on Earth, both in-situ and
remote sensing methods are available. Despite the widespread use of the
two methods, there has been surprisingly little research on how well
the sediment budgets produced by these two approaches reconcile with
one another, which highlights the lack of quantitative understanding of
errors for sediment budgets measured with remote sensing in planetary
research. Therefore, there is a general need to expand our knowledge
of sediment budgets. Here we use a background review and analog
case study of an aeolian dunefield in Grand Canyon, Earth to frame a
path forward for addressing shortcomings of remote sensing sediment
budgets on Mars. We estimate a 53% percent difference in the sediment
budget determined with remote sensing relative to in-situ methods
for a simple endmember scenario of a dunefield within a unimodal
wind directional regime and no external sediment supply. However,
when we incorporated key sources of uncertainty in remote sensing
change detection following methods commonly used by geomorphologists
on Earth, the estimates of sediment budget differences relative to the
in-situ method spanned a much larger range, from 3% to 138%. Our case
study also suggests that sediment budget errors could be much larger
under more complex wind direction, sediment supply, and physiographic
settings, and that variability in those landscape characteristics might
be used to better estimate errors for dunefield sediment budgets. We
conclude that by comparing sediment budgets derived from in-situ
measurements of sediment fluxes and from remote sensing measurements
at many more analog sites on Earth, the aeolian research community,
and the geomorphology discipline, could gain an understanding of the
errors of the remote sensing method, which is used by investigators on
other planetary bodies such as Mars. This could improve the ability to
quantify sediment budgets on Mars - and, in the future, other planetary
environments where high-resolution topographic data are available -
as well as directly improve our ability to interpret extraterrestrial
landscape evolution related to climate, weather, and geologic history.
Title: The relationship between surface weather over North America
and the Mid-Latitude Seasonal Oscillation
Authors: Manthos, Zachary H.; Pegion, Kathleen V.; Dirmeyer, Paul A.;
Stan, Cristiana
Bibcode: 2022DyAtO..9901314M
Altcode:
The influence of the 120-day Mid-Latitude Seasonal Oscillation (MLSO)
on near surface circulation, temperature and precipitation over North
America is investigated as an independent mode and in combination with
the El Niño-Southern Oscillation (ENSO), as well as the North Atlantic
Oscillation (NAO) and Pacific North American (PNA) teleconnection
patterns. Empirical evidence based on frequency ratios such as anomalous
warm over cold days and wet over dry days and composite analysis reveal
an influence of the MLSO during both boreal winter and summer. During
winter, above (below) normal MLSO conditions can cause below (above)
average temperatures across the US. During summer, the below normal MLSO
conditions can cause strong above average temperatures across the US,
whereas the below normal MLSO conditions can cause weak temperature
anomalies of both signs. The influence of MLSO on the surface air
temperature anomalies is more significant and stronger than the
effect on precipitation. It is also found that the MLSO plays a role
in exciting variability when interacting with other modes, exerting
influence over the same region. Expected patterns of temperature and
precipitation associated with well-known climate modes show alterations
when they are further decomposed to account for the MLSO influence.
Title: Dust impact and attitude analysis for JAXA's probe on the
Comet Interceptor mission
Authors: Machuca, P.; Ozaki, N.; Sánchez, J. P.; Felicetti, L.
Bibcode: 2022AdSpR..70.1189M
Altcode:
Comet Interceptor (Comet-I), to be launched in 2029 as a piggyback to
ESA's ARIEL mission, is aimed to perform the first fly-by of a pristine
long-period comet. The mission will be composed of a main spacecraft,
SC A (ESA), and two small probes to be released prior to the fly-by, SC
B1 (JAXA) and SC B2 (ESA). This work analyzes the attitude performance
of JAXA's 24U-sized spacecraft through the dust environment of a
yet-to-be-discovered target comet. Main challenges to the mission are
associated to the high levels of uncertainty and extremity of fly-by
conditions: highly-active dust environment, uncertain fly-by altitude
(750 ± 250 km (1σ), as of 2021), and large and unknown relative
fly-by speeds (15-70 km/s). A Monte Carlo analysis is performed to
characterize the effect of dust particle impacts on the attitude of SC
B1, and to evaluate the likelihood of satisfying pointing and angular
velocity requirements of the science camera. Analysis initially shows
that particles of mass 10-8-10-5 kg represent
the most relevant source of perturbation due to their transferred
angular momentum and likelihood of being encountered, and saturation
of reaction wheels is shown unlikely given the large fly-by speeds and
short fly-by durations (20 min-2 h). More detailed analysis ultimately
suggests a probability larger than 90% of satisfying science camera
requirements despite the extreme, uncertain fly-by conditions, dust
environment, and component inaccuracies (star tracker, gyroscopes,
and reaction wheels). Results also show that upgrading the reaction
wheel that is implemented along the camera line-of-sight can improve,
but only marginally, attitude performance, and proper alignment of
solar arrays parallel to the incoming flow of particles is shown
essential to maximize probability of success.
Title: New and improved orbits of historical comets: Late 4th and
5th century
Authors: Martínez, M. J.; Marco, F. J.; Sicoli, P.; Gorelli, R.
Bibcode: 2022Icar..38415112M
Altcode:
Since as early as the 19th century, many scholars have devoted
themselves to the calculation of sets of orbital elements for particular
historical comets. In many cases, these studies have led to proposing
orbits that have given satisfactory answers to contemporary observations
or later reports about these celestial bodies. As new records or
improved translations of existing sources appear, the already calculated
orbits can be refined, or even new ones can be achieved. In this paper
we focus on historical observations from Eastern and European countries
in the late 4th and 5th centuries to suggest new determinations of
orbital elements for some of these comets, or, where appropriate, to
discuss or improve existing ones. We will also carry out a separate
study of comets from the years AD422-423 and AD467, which have been
suggested as the parent comets of the Kreutz system of sungrazer comets.
Title: Structure formation in dark matter particle production
cosmology
Authors: Safari, Z.; Rezazadeh, K.; Malekolkalami, B.
Bibcode: 2022PDU....3701092S
Altcode: 2022arXiv220105195S
We investigate a cosmological scenario in which the dark matter
particles can be created during the evolution of the Universe. By
regarding the Universe as an open thermodynamic system and
using non-equilibrium thermodynamics, we examine the mechanism
of gravitational particle production. In this setup, we study
the large-scale structure (LSS) formation of the Universe in the
Newtonian regime of perturbations and derive the equations governing
the evolution of the dark matter overdensities. Then, we implement the
cosmological data from Planck 2018 CMB measurements, SNe Ia and BAO
observations, as well as the Riess et al. (2019) local measurement
for H0 to provide some cosmological constraints for the
parameters of our model. We see that the best case of our scenario
(χtot2 = 3834 . 40) fits the observational data
better than the baseline ΛCDM model (χtot2
= 3838 . 00) at the background level. We moreover estimate the
growth factor of linear perturbations and show that the best
case of our model (χfσ82 =
39.85) fits the LSS data significantly better than the ΛCDM model
(χfσ82 = 45.29). Consequently,
our model also makes a better performance at the level of the linear
perturbations compared to the standard cosmological model. Although
the improvement in χtot for Model 2 compared to ΛCDM at
the background level may arise somewhat from the additional degree of
freedom, the better consistency of this model at the level of linear
perturbations results mainly from the impact of particle production
on the sound speed at low redshifts.
Title: The quiet chromosphere: Phase relation with the solar cycle
Authors: Li, K. J.; Feng, W.
Bibcode: 2022AdSpR..70.1539L
Altcode:
The solar chromosphere was daily observed in the Ca II K line from
1915 August 10 to 1985 July 7, and correspondingly, 938 synoptic
maps are measured. The valuable database is utilized to explore
phase relationship of long-term evolution of the quiet chromosphere
and sunspot numbers. Temporal change of the quiet chromosphere is
found to be in anti-phase with the solar cycle on the whole, as
the small-scale magnetic elements whose flux is in a span of (2.9 -
32.0) ×1018 (Mx) do. The abnormal heating of the quiet
chromosphere is accordingly suggested to be related mainly to the
magnetic elements, and they may likely function in reducing chromosphere
material loss.
Title: The fate of delaminated cratonic lithosphere
Authors: Peng, Lihang; Liu, Lijun; Liu, Liang
Bibcode: 2022E&PSL.59417740P
Altcode:
Cratonic lithosphere delamination has been frequently suggested in
recent studies. However, the fate of the delaminated Sub-Cratonic
Lithospheric Mantle (SCLM) has not been thoroughly investigated. Here,
we use 2D numerical models to study the evolution of initially
delaminated SCLM whose density is initially larger than that of the
ambient mantle. Our simulations reveal that after the dense lithospheric
segments sink into the hot mantle, the increasing thermal buoyancy
and/or removal of the dense components reverse their trajectory, and
most of these segments eventually relaminate to the base of the above
lithosphere. The time needed for the relamination process to complete is
100-300 Myr since initial delamination, with the exact value depending
on the buoyancy of the SCLM and the mantle viscosity. Both delamination
and relamination could generate a rapid hundred-meter to kilometer
scale surface uplift. After the relamination, the subsequent cooling
of the SCLM causes gradual subsidence by ∼2 km. This model provides a
novel explanation for the observed Phanerozoic vertical motion of many
cratons. According to our models, the delamination-to-relamination
evolution mode could occur repeatedly during the past one billion
years, as could reconcile the apparent long-term intactness of cratonic
crusts and the temporal variations of cratonic topography. In addition,
some delaminated lithosphere segments could relaminate to the base of
the oceanic plate, providing a mechanism for the presence of ancient
continental compositions within some oceanic basalts.
Title: A CO Survey of the Entire Northern Sky
Authors: Dame, T. M.; Thaddeus, P.
Bibcode: 2022ApJS..262....5D
Altcode:
We present a very large extension of the Galactic plane CO survey
of Dame et al. to the entire northern sky (δ > -17°). The
extension was carried out with the same telescope as was used for the
plane survey, the CfA 1.2 m, and perfectly meshes with its irregular
boundaries in latitude. A total of 382,202 CO(1-0) spectra uniformly
sample the high-latitude sky with a true-angle spacing of 0.°25 or
better. The final reduced and folded spectra have a uniform sensitivity
of 0.18 K in 0.65 km s-1 channels and provide a velocity
coverage of ±47.1 km s-1. We describe the observational
techniques and the data reduction and provide various summary maps of
the spatial and velocity distributions of CO emission over the northern
sky, and a catalog of the molecular clouds we found there. We also
describe the CO spectral line data cubes that we have made available
online.
Title: Calibration of NOMAD on ESA's ExoMars Trace Gas Orbiter:
Part 1 - The Solar Occultation channel
Authors: Thomas, Ian R.; Aoki, Shohei; Trompet, Loïc; Robert,
Séverine; Depiesse, Cédric; Willame, Yannick; Erwin, Justin T.;
Vandaele, Ann Carine; Daerden, Frank; Mahieux, Arnaud; Neefs, Eddy;
Ristic, Bojan; Hetey, Laszlo; Berkenbosch, Sophie; Clairquin, Roland;
Beeckman, Bram; Patel, Manish R.; Lopez-Moreno, Jose Juan; Bellucci,
Giancarlo; The NOMAD Team
Bibcode: 2022P&SS..21805411T
Altcode:
Nadir and Occultation for MArs Discovery (NOMAD) is a 3-channel
spectrometer suite that is currently orbiting Mars onboard ESA's
ExoMars Trace Gas Orbiter, measuring the composition of the Martian
atmosphere in unprecedented detail. Of the three channels, two
operate in the infrared: the Solar Occultation (SO) channel observes
gas species in the 2.2-4.3 μm spectral region in solar occultation
mode, while the Limb, Nadir and Occultation (LNO) channel observes
in the 2.2-3.8 μm spectral region and can operate in limb-, nadir-
and solar occultation-pointing modes. The Ultraviolet-VISible (UVIS)
channel operates in the UV-visible region, from 200 to 650 nm. Both infrared channels have a spectral resolution typically an order
of magnitude better than previous instruments orbiting Mars, to measure
molecular absorption lines and therefore determine the abundances of
constituents of the Martian atmosphere and the processes that govern
their distribution and transport. To maximise the full potential of
the instrument, a wide range of calibration measurements were made
prior to launch and continue to be made in-flight. This work, part 1,
addresses the aspects of the SO channel calibration that are not covered
elsewhere, namely: the SO channel ground calibration setup, boresight
pointing vector determination, detector characterisation, detector
illumination pattern and saturation levels, and an investigation of
the instrument line shape. An accompanying paper, part 2, addresses
similar aspects for LNO, the other infrared channel in NOMAD (Thomas
et al., 2021, this issue).
Title: Research progress in lithium niobate on insulator lasers
Authors: Luo, Qiang; Bo, Fang; Kong, Yongfa; Zhang, Guoquan; Xu,
Jingjun
Bibcode: 2022SSPMA..52C4221L
Altcode:
No abstract at ADS
Title: Mass-Velocity Dispersion Relation by Using the Gaia Data and
Its Effect on Interpreting Short-duration and Degenerate Microlensing
Events
Authors: Sajadian, Sedighe; Rahvar, Sohrab; Kazemian, Fatemeh
Bibcode: 2022AJ....164..112S
Altcode: 2021arXiv210310593S
Gravitational microlensing, the lensing of stars in the Milky Way with
other stars, has been used for exploring compact dark matter objects,
exoplanets, and black holes. The duration of microlensing events,
the so-called Einstein crossing time, is a function of distance,
mass, and velocities of lens objects. Lenses with different ages
and masses might have various characteristic velocities inside the
Galaxy and this might lead to our misinterpretation of microlensing
events. In this work, we use the Gaia archived data to find a relation
between the velocity dispersion and mass, and the age of stars. This
mass-velocity dispersion relation confirms the known age-velocity
relation for early-type and massive stars, and additionally reveals a
dependence of stellar velocity dispersion on the mass for low-mass and
late-type stars at a 2σ-3σ level. By considering this correlation, we
simulate short-duration microlensing events due to brown dwarfs. From
this simulation, we conclude that lens masses are underestimated by
~2.5%-5.5% while modeling short-duration and degenerate microlensing
events with the Bayesian analysis.
Title: Dense Gas and Star Formation in Nearby Infrared-bright
Galaxies: APEX Survey of HCN and HCO+ J = 2 → 1
Authors: Zhou, Jing; Zhang, Zhi-Yu; Gao, Yu; Wang, Junzhi; Shi, Yong;
Gu, Qiusheng; Yang, Chentao; Wang, Tao; Tan, Qing-Hua
Bibcode: 2022ApJ...936...58Z
Altcode: 2022arXiv220713724Z
Both Galactic and extragalactic studies of star formation suggest
that stars form directly from dense molecular gas. To trace such
high volume density gas, HCN and HCO+ J = 1 → 0 have
been widely used for their high dipole moments, relatively high
abundances, and often being the strongest lines after CO. However, HCN
and HCO+ J = 1 → 0 emission could arguably be dominated
by the gas components at low volume densities. The HCN J = 2 →
1 and HCO+ J = 2 → 1 transitions, with more suitable
critical densities (1.6 × 106 and 2.8 × 105
cm-3) and excitation requirements, would trace typical dense
gas closely related to star formation. Here we report new observations
of HCN J = 2 → 1 and HCO+ J = 2 → 1 toward 17 nearby
infrared-bright galaxies with the APEX 12 m telescope. The correlation
slopes between the luminosities of HCN J = 2 → 1 and HCO+
J = 2 → 1 and total infrared emission are 1.03 ± 0.05 and 1.00
± 0.05, respectively. The correlations of their surface densities,
normalized with the area of radio/submillimeter continuum, show even
tighter relations (slopes: 0.99 ± 0.03 and 1.02 ± 0.03). The eight
active galactic nucleus (AGN)-dominated galaxies show no significant
difference from the 11 star-formation-dominated galaxies in the above
relations. The average HCN/HCO+ ratios are 1.15 ± 0.26
and 0.98 ± 0.42 for AGN- and star-formation-dominated galaxies,
respectively, without obvious dependencies on infrared luminosity,
dust temperature, or infrared pumping. The Magellanic Clouds roughly
follow the same correlations, expanding to 8 orders of magnitude. On the
other hand, ultraluminous infrared galaxies with AGNs systematically lie
above the correlations, indicating potential biases introduced by AGNs.
Title: Radiogenic chromium isotope evidence for the earliest planetary
volcanism and crust formation in the Solar system
Authors: Zhu, Ke; Becker, Harry; Li, Shi-Jie; Fan, Yan; Liu, Xiao-Ning;
Elliott, Tim
Bibcode: 2022MNRAS.515L..39Z
Altcode: 2022MNRAS.tmpL..65Z
Erg Chech (EC) 002 is a meteorite with andesitic composition,
potentially recording the lava crystallization and crust formation
of its parent body. Nucleosynthetic Cr isotope composition
(ɛ54Cr = -0.35 ± 0.06) for EC 002 suggests
a non-carbonaceous region of the Solar system, and possibly
represents the crustal composition of the brachinite parent body. The
53Mn-to-53Cr decay system shows it crystallized
at 4566.6 ± 0.6 Ma, i.e. 0.7 ± 0.6 Ma after Solar system formation
(only considering the cogenetic matrix fractions with similar
ɛ54Cr values). This age represents the earliest recorded
evidence for planetary melting and volcanism in the Solar system,
suggesting that the planetary crust formation occurred very early,
only within the first few hundred thousand years of Solar system
history. However, the 53Mn-53Cr age does not
overlap with 26Al-26Mg dating results, which
might indicate that non-carbonaceous achondrites have lower initial
26Al/27Al than the canonical value defined by
refractory inclusions in carbonaceous chondrites.
Title: A Bayesian Analysis of Physical Parameters for 783 Kepler
Close Binaries: Extreme-mass-ratio Systems and a New Mass Ratio
versus Period Lower Limit
Authors: Kobulnicky, Henry A.; Molnar, Lawrence A.; Cook, Evan M.;
Henderson, Lauren E.
Bibcode: 2022ApJS..262...12K
Altcode: 2022arXiv220201187K
Contact binary star systems represent the long-lived penultimate
phase of binary evolution. Population statistics of their physical
parameters inform an understanding of binary evolutionary pathways
and end products. We use light curves and new optical spectroscopy to
conduct a pilot study of ten (near) contact systems in the long-period
(P > 0.5 days) tail of close binaries in the Kepler field. We use
PHOEBE light-curve models to compute Bayesian probabilities on five
principal system parameters. Mass ratios and third-light contributions
measured from spectra agree well with those inferred from the light
curves. Pilot study systems have extreme mass ratios q < 0.32. Most
are triples. Analysis of the unbiased sample of 783 0.15 d < P <
2 days (near) contact binaries results in 178 probable contact systems,
114 probable detached systems, and 491 ambiguous systems for which we
report best-fitting and 16th-/50th-/84th-percentile parameters. Contact
systems are rare at periods P > 0.5 days, as are systems with q >
0.8. There exists an empirical mass ratio lower limit ${q}_{\min }(P)$
≍ 0.05-0.15 below which contact systems are absent, supporting a
new set of theoretical predictions obtained by modeling the evolution
of contact systems under the constraints of mass and angular momentum
conservation. Premerger systems should lie at long periods and near
this mass ratio lower limit, which rises from q = 0.044 for P = 0.74
days to q = 0.15 at P = 2.0 days. These findings support a scenario
whereby nuclear evolution of the primary (more massive) star drives
mass transfer to the primary, thus moving systems toward extreme q and
larger P until the onset of the Darwin instability at ${q}_{\min }$
precipitates a merger.
Title: Rapid Radiolytic Degradation of Amino Acids in the Martian
Shallow Subsurface: Implications for the Search for Extinct Life
Authors: Pavlov, Alexander A.; McLain, Hannah L.; Glavin, Daniel
P.; Roussel, Anaïs; Dwork2in, Jason P.; Elsila, Jamie E.; Yocum,
Katarina M.
Bibcode: 2022AsBio..22.1099P
Altcode:
Amino acids are fundamental to life as we know them as the monomers
of proteins and enzymes. They are also readily synthesized under a
variety of plausible prebiotic conditions and are common in carbon-rich
meteorites. Thus, they represent a reasonable class of organics to
target in the search for prebiotic chemistry or chemical evidence of
life on Mars. However, regardless of their origin, amino acids and
other organic molecules present in near-surface regolith and rocks on
Mars can be degraded by exposure to cosmic rays that can penetrate to
a depth of a few meters. We exposed several pure amino acids in dry and
hydrated silicate mixtures and in mixtures of silicates with perchlorate
salts to gamma radiation at various temperatures and radiation doses
representative of the martian near-subsurface. We found that irradiation
of amino acids mixed with dry silica powder increased the rate of
amino acid radiolysis, with the radiolysis constants of amino acids
in silicate mixtures at least a factor of 10 larger compared with the
radiolysis constants of amino acids alone. The addition of perchlorate
salts to the silicate samples or hydration of silicate samples further
accelerated the rate of amino acid destruction during irradiation and
increased the radiolysis constants by a factor of ∼1.5. Our results
suggest that even low-molecular-weight amino acids could degrade in just
∼20 million years in the top 10 cm of the martian surface regolith
and rock, and even faster if the material contains elevated abundances
of hydrated silicate minerals or perchlorates. We did not detect
evidence of amino acid racemization after gamma radiation exposure
of the samples, which indicates that the chirality of some surviving
amino acids may still be preserved. Our experimental results suggest
serious challenges for the search of ancient amino acids and other
potential organic biosignatures in the top 2 m of the martian surface.
Title: Pan-STARRS Transient Discovery Report for 2022-09-08
Authors: Chambers, K. C.; Boer, T. D.; Bulger, J.; Fairlamb, J.; Huber,
M.; Lin, C. C.; Lowe, T.; Magnier, E.; Schultz, A.; Wainscoat, R. J.;
Gao, H.; Smith, K. W.; Young, D. R.; Gillanders, J.; Srivastav, S.;
Fulton, M.; Smartt, S. J.; Sim, S.; Wright, D. E.
Bibcode: 2022TNSTR2615....1C
Altcode:
No abstract at ADS
Title: Distinguishing between ΛCDM and f(R) gravity models using
halo ellipticity correlations in simulations
Authors: Chuang, Yao-Tsung; Okumura, Teppei; Shirasaki, Masato
Bibcode: 2022MNRAS.515.4464C
Altcode: 2022MNRAS.tmp.1917C; 2021arXiv211101417C
There is a growing interest in utilizing intrinsic alignment (IA) of
galaxy shapes as a geometric and dynamical probe of cosmology. In this
paper, we present the first measurements of IA in a modified gravity
model using the gravitational shear-intrinsic ellipticity correlation
(GI) and intrinsic ellipticity-ellipticity correlation (II) functions
of dark-matter haloes from f(R) gravity simulations. By comparing
them with the same statistics measured in Lambda cold dark matter
(ΛCDM) simulations, we find that the IA statistics in different
gravity models show distinguishable features, with a trend similar to
the case of conventional galaxy clustering statistics. Thus, the GI
and II correlations are found to be useful in distinguishing between
the ΛCDM and f(R) gravity models. More quantitatively, IA statistics
enhance detectability of the imprint of f(R) gravity on large-scale
structures by $\sim 40{{\ \rm per\ cent}}$ when combined with the
conventional halo clustering in redshift space. We also find that the
correlation between the axial ratio and orientation of haloes becomes
stronger in f(R) gravity than that in ΛCDM. Our results demonstrate the
usefulness of IA statistics as a probe of gravity beyond a consistency
test of ΛCDM and general relativity.
Title: TeraHertz desorption emission spectroscopy (THz DES) of space
relevant ices
Authors: Auriacombe, Olivier; Rea, S.; Ioppolo, S.; Oldfield, M.;
Parkes, S.; Ellison, B.; Fraser, H. J.
Bibcode: 2022MNRAS.515.2698A
Altcode: 2022MNRAS.tmp.1971A; 2022arXiv220703356A
We present an experimental instrument that performs laboratory-based
gas-phase Terahertz Desorption Emission Spectroscopy (THz-DES)
experiments in support of astrochemistry. The measurement system
combines a terahertz heterodyne radiometer that uses room temperature
semiconductor mixer diode technology previously developed for the
purposes of Earth observation, with a high-vacuum desorption gas cell
and high-speed digital sampling circuitry to enable high spectral
and temporal resolution spectroscopy of molecular species with
thermal discrimination. During use, molecules are condensed on to a
liquid nitrogen cooled metal finger to emulate ice structures that
may be present in space. Following deposition, thermal desorption
is controlled and initiated by means of a heater and monitored via
a temperature sensor. The 'rest frequency' spectral signatures of
molecules released into the vacuum cell environment are detected by
the heterodyne radiometer in real-time and characterized with high
spectral resolution. To demonstrate the viability of the instrument,
we have studied Nitrous Oxide (N2O). This molecule strongly
emits within the terahertz (sub-millimetre wavelength) range and
provide a suitable test gas and we compare the results obtained with
more traditional techniques such as quadrupole mass spectrometry. The
results obtained allow us to fully characterize the measurement method
and we discuss its potential use as a laboratory tool in support of
astrochemical observations of molecular species in the interstellar
medium and the Solar System.
Title: Non-LTE abundances of zinc in different spectral type stars
and the Galactic [Zn/Fe] trend based on quantum-mechanical data on
inelastic processes in zinc-hydrogen collisions
Authors: Sitnova, T. M.; Yakovleva, S. A.; Belyaev, A. K.; Mashonkina,
L. I.
Bibcode: 2022MNRAS.515.1510S
Altcode: 2022MNRAS.tmp.1813S; 2022arXiv220505819S
We present a new model atom of Zn I-Zn II based on the most up-to-date
photoionization cross-sections, electron-impact excitation rates,
and rate coefficients for the Zn I + H I and Zn II + H-
collisions. The latter were calculated using the multichannel quantum
asymptotic treatment based on the Born-Oppenheimer approach. Non-LTE
analysis was performed for the first time for lines of Zn I and Zn II
in the ultraviolet (UV) spectra of two very metal-poor reference stars:
HD 84937 and HD 140283. We found consistent non-LTE abundance from the
resonance Zn I 2138 Å line, the subordinate lines, and the lines of Zn
II. In both stars, non-LTE leads to 0.17 dex higher average abundance
from Zn I, while, for Zn II lines, non-LTE corrections are minor and do
not exceed 0.06 dex. Using lines of Zn I in the high-resolution spectra,
we determined the non-LTE abundances for a sample of 80 stars in the
-2.5 ≤ [Fe/H] ≤ 0.2 metallicity range. The [Zn/Fe] versus [Fe/H]
diagram reveals a dip, with [Zn/Fe] ≃ 0.3 in the most metal-poor
stars, a close-to-solar value for [Fe/H] ~-1.2, and increasing [Zn/Fe]
up to 0.3 in the thick disc stars. The close-to-solar metallicity
stars have subsolar [Zn/H] ≃ -0.1, on average. Non-LTE abundances of
zinc were derived for the first time for seven reference F- to B-type
stars. We provide a grid of the non-LTE abundance corrections.
Title: Modelling magnetically channeled winds in 3D - I. Isothermal
simulations of a magnetic O supergiant
Authors: Subramanian, Sethupathy; Balsara, Dinshaw S.; ud-Doula,
Asif; Gagné, Marc
Bibcode: 2022MNRAS.515..237S
Altcode: 2022MNRAS.tmp.1716S
In this paper we present the first set of 3D magnetohydrodynamic
(MHD) simulations performed with the RIEMANN GEOMESH code. We study
the dynamics of the magnetically channeled winds of magnetic massive
stars in full three dimensions using a code that is uniquely suited to
spherical problems. Specifically, we perform isothermal simulations
of a smooth wind on a rotating star with a tilted, initially
dipolar field. We compare the mass-loss, angular momentum loss,
and magnetospheric dynamics of a template star (with the properties
that are reminiscent of the O4 supergiant ζ Pup) over a range of
rotation rates, magnetic field strengths, and magnetic tilt angles. The
simulations are run up to a quasi-steady state and the results are
observed to be consistent with the existing literature, showing the
episodic centrifugal breakout events of the mass outflow, confined
by the magnetic field loops that form the closed magnetosphere of the
star. The catalogued results provide perspective on how angular-momentum
loss varies for different configurations of rotation rate, magnetic
field strength, and large magnetic tilt angles. In agreement with
previous 2D MHD studies, we find that high magnetic confinement
reduces the overall mass-loss rate, and higher rotation increases the
mass-loss rate. This and future studies will be used to estimate the
angular-momentum evolution, spin-down time, and mass-loss evolution
of magnetic massive stars as a function of magnetic field strength,
rotation rate, and dipole tilt.
Title: The growth and migration of massive planets under the influence
of external photoevaporation
Authors: Winter, Andrew J.; Haworth, Thomas J.; Coleman, Gavin A. L.;
Nayakshin, Sergei
Bibcode: 2022MNRAS.515.4287W
Altcode: 2022arXiv220602818W; 2022MNRAS.tmp.1515W
The formation of gas giant planets must occur during the first few
Myr of a star's lifetime, when the protoplanetary disc still contains
sufficient gas to be accreted on to the planetary core. The majority
of protoplanetary discs are exposed to strong ultraviolet irradiation
from nearby massive stars, which drives winds and depletes the mass
budget for planet formation. It remains unclear to what degree external
photoevaporation affects the formation of massive planets. In this work,
we present a simple one dimensional model for the growth and migration
of a massive planet under the influence of external FUV fields. We find
that even moderate FUV fluxes $F_\mathrm{FUV}\gtrsim 100 \, G_0$ have a
strong influence on planet mass and migration. By decreasing the local
surface density and shutting off accretion on to the planet, external
irradiation suppresses planet masses and halts migration early. The
distribution of typical stellar birth environments can therefore
produce an anticorrelation between semi-major axis and planet mass,
which may explain the apparent decrease in planet occurrence rates at
orbital periods Porb ≳ 103 d. Even moderate
fluxes FFUV strongly suppress giant planet formation and
inward migration for any initial semi-major axis if the stellar host
mass $M_*\lesssim 0.5\, {\rm M}_\odot$, consistent with findings that
massive planet occurrence is much lower around such stars. The outcomes
of our prescription for external disc depletion show significant
differences to the current approximation adopted in state-of-the-art
population synthesis models, motivating future careful treatment of
this important process.
Title: Dust masses for a large sample of core-collapse supernovae
from optical emission line asymmetries: dust formation on 30-year
time-scales
Authors: Niculescu-Duvaz, Maria; Barlow, M. J.; Bevan, A.; Wesson,
R.; Milisavljevic, D.; De Looze, I.; Clayton, G. C.; Krafton, K.;
Matsuura, M.; Brady, R.
Bibcode: 2022MNRAS.515.4302N
Altcode: 2022MNRAS.tmp.1865N; 2022arXiv220414179N
Modelling the red-blue asymmetries seen in the broad emission lines of
core-collapse supernovae (CCSNe) is a powerful technique to quantify
total dust mass formed in the ejecta at late times (>5 yr after
outburst) when ejecta dust temperatures become too low to be detected
by mid-infrared (IR) instruments. Following our success in using
the Monte Carlo radiative transfer code DAMOCLES to measure the
dust mass evolution in SN 1987A and other CCSNe, we present the most
comprehensive sample of dust mass measurements yet made with DAMOCLES,
for CCSNe aged between 4 and 60 yr after outburst. Our sample comprises
multi-epoch late-time optical spectra taken with the Gemini/Gemini
Multi-Object Spectrographs (GMOS) and Very Large Telescope (VLT)
X-Shooter spectrographs, supplemented by archival spectra. For the 14
CCSNe that we have modelled, we confirm a dust mass growth with time
that can be fit by a sigmoid curve that is found to saturate beyond an
age of ~30 yr, at a mass of 0.23$^{+0.17}_{-0.12}$ M⊙. For
an expanded sample including dust masses found in the literature for a
further 11 CCSNe and six CCSN remnants, the dust mass at saturation is
found to be 0.42$^{+0.09}_{-0.05}$ M⊙. Uncertainty limits
for our dust masses were determined from a Bayesian analysis using
the affine invariant Markov chain Monte Carlo ensemble sampler EMCEE
with DAMOCLES. The best-fitting line profile models for our sample
all required grain radii between 0.1 and 0.5 $\mu$m. Our results
are consistent with CCSNe forming enough dust in their ejecta to
significantly contribute to the dust budget of the Universe.
Title: Fragmented atomic shell around S187 H II region and its
interaction with molecular and ionized gas
Authors: Zemlyanukha, Petr; Zinchenko, Igor I.; Dombek, Evgeny;
Pirogov, Lev E.; Topchieva, Anastasiia; Joncas, Gilles; Dewangan,
Lokesh K.; Ojha, Devendra K.; Ghosh, Swarna K.
Bibcode: 2022MNRAS.515.2445Z
Altcode: 2022MNRAS.tmp.1945Z; 2022arXiv220705507Z
The environment of S187, a nearby H II region (1.4 ± 0.3 kpc),
is analyzed. A surrounding shell has been studied in the H I line,
molecular lines, and also in infrared and radio continua. We report the
first evidence of a clumpy H I environment in its photodissociation
region. A background radio galaxy enables the estimation of the
properties of cold atomic gas. The estimated atomic mass fraction of
the shell is ~260 M⊙, the median spin temperature is ~50
K, the shell size is ~4 pc with typical wall width around 0.2 pc. The
atomic shell consists of ~100 fragments. The fragment sizes correlate
with mass with a power-law index of 2.39-2.50. The S187 shell has a
complex kinematical structure, including the expanding quasi-spherical
layer, molecular envelope, an atomic sub-bubble inside the shell and two
dense cores (S187 SE and S187 NE) at different stages of evolution. The
atomic sub-bubble inside the shell is young, contains a Class II young
stellar object and OH maser in the centre and the associated YSOs
in the walls of the bubble. S187 SE and S187 NE have similar masses
(~1200 and ~900 M⊙, respectively). S187 SE is embedded
into the atomic shell and has a number of associated objects, including
high-mass protostars, outflows, maser sources, and other indicators
of ongoing star formation. No YSOs inside S187 NE were detected,
but indications of compression and heating by the H II region exist.
Title: MOA-2019-BLG-008Lb: A New Microlensing Detection of an Object
at the Planet/Brown Dwarf Boundary
Authors: Bachelet, E.; Tsapras, Y.; Gould, Andrew; Street, R. A.;
Bennett, David P.; Hundertmark, M. P. G.; Bozza, V.; Bramich, D. M.;
Cassan, A.; Dominik, M.; Horne, K.; Mao, S.; Saha, A.; Wambsganss, J.;
Zang, Weicheng; ROME/REA Collaboration; Abe, Fumio; Barry, Richard;
Bennett, David P.; Bhattacharya, Aparna; Bond, Ian A.; Fukui, Akihiko;
Fujii, Hirosane; Hirao, Yuki; Itow, Yoshitaka; Kirikawa, Rintaro;
Kondo, Iona; Koshimoto, Naoki; Matsubara, Yutaka; Matsumoto, Sho;
Miyazaki, Shota; Muraki, Yasushi; Olmschenk, Greg; Ranc, Clément;
Okamura, Arisa; Rattenbury, Nicholas J.; Satoh, Yuki; Sumi, Takahiro;
Suzuki, Daisuke; Silva, Stela Ishitani; Toda, Taiga; Tristram,
Paul. J.; Vandorou, Aikaterini; Yama, Hibiki; MOA Collaboration;
Albrow, Michael D.; Chung, Sun-Ju; Han, Cheongho; Hwang, Kyu-Ha;
Jung, Youn Kil; Ryu, Yoon-Hyun; Shin, In-Gu; Shvartzvald, Yossi;
Yee, Jennifer C.; Cha, Sang-Mok; Kim, Dong-Jin; Kim, Seung-Lee; Lee,
Chung-Uk; Lee, Dong-Joo; Lee, Yongseok; Park, Byeong-Gon; Pogge,
Richard W.; KMTNet Collaboration; Udalski, Andrzej; Mróz, Przemek;
Poleski, Radosław; Skowron, Jan; Szymański, Michał K.; Soszyński,
Igor; Pietrukowicz, Paweł; Kozłowski, Szymon; Ulaczyk, Krzysztof;
Rybicki, Krzysztof A.; Iwanek, Patryk; Wrona, Marcin; Gromadzki,
Mariusz; OGLE Collaboration
Bibcode: 2022AJ....164...75B
Altcode: 2022arXiv220507522B
We report on the observations, analysis and interpretation of the
microlensing event MOA-2019-BLG-008. The observed anomaly in the
photometric light curve is best described through a binary lens
model. In this model, the source did not cross caustics and no
finite-source effects were observed. Therefore, the angular Einstein
ring radius θ E cannot be measured from the light
curve alone. However, the large event duration, t E ~ 80
days, allows a precise measurement of the microlensing parallax π
E. In addition to the constraints on the angular radius θ
* and the apparent brightness I s of the source,
we employ the Besançon and GalMod galactic models to estimate the
physical properties of the lens. We find excellent agreement between
the predictions of the two galactic models: the companion is likely
a resident of the brown dwarf desert with a mass M p ~
30 M Jup, and the host is a main-sequence dwarf star. The
lens lies along the line of sight to the Galactic bulge, at a distance
of ≤4 kpc. We estimate that in about 10 yr the lens and source will
be separated by ~55 mas, and it will be possible to confirm the exact
nature of the lensing system by using high-resolution imaging from
ground- or space-based observatories.
Title: The modified KdV equation for a nonlinear evolution problem
with perturbation technique
Authors: Asghar, Saleem; Haider, Jamil Abbas; Muhammad, Noor
Bibcode: 2022IJMPB..3650160A
Altcode:
This paper examines nonlinear partial differential equation (PDE)
solutions. Scientists and engineers have struggled to solve nonlinear
differential equations. Nonlinear equations arrive in nearly all
problems in nature. There are no well-established techniques for
solving all nonlinear equations, and efforts have been made to enhance
approaches for a specific class of problems. Keeping this in mind, we
shall investigate the perturbation method’s efficiency in solving
nonlinear PDEs. Several techniques work well for diverse issues. We
recognize that there may be several solutions to a given nonlinear
issue. Methods include homotropy analysis, tangent hyperbolic function,
factorization and trial function. However, some of these strategies
do not cover all nonlinear issue solutions. In this paper, we use
the perturbation technique to solve the zeroth-order Airy equation
and also find the Bessel function in the first-order nonhomogeneous
differential equation by using self-similar solutions that appears in
modified Korteweg-de Vries (KdV) equation. This approach will be used
for nonlinear equations in physics and applied mathematics.
Title: Detection of the third innermost radiation belt on LEO
CORONAS-Photon satellite around 2009 solar minimum
Authors: Dudnik, Oleksiy V.; Sylwester, Janusz; Kowaliński, Mirosław;
Podgórski, Piotr; Phillips, Kenneth J. H.
Bibcode: 2022AdSpR..70.1441D
Altcode: 2022arXiv220804154D
We analyze variations of high energy charged particle populations
filling various magnetospheric regions under, inside and outside of the
Van Allen inner and outer electron radiation belts in May 2009. The
study is based on the experimental data obtained from the STEP-F and
the SphinX instruments placed close to each other aboard the low-Earth
circular orbit CORONAS-Photon satellite. Data analysis of particle
fluencies collected from the highly sensitive STEP-F device indicates
the presence of a persistent electron belt at L ≈ 1.6, i.e., beneath
the well-known Van Allen electron inner radiation belt of the Earth's
magnetosphere. The electron energy spectrum in this "new" belt is much
steeper than that of the inner belt, so that the electrons with energies
Ee ≥ 400 keV were almost not recorded on L ≈ 1.6 outside
the South Atlantic Anomaly (SAA). We introduce the concept of effective
lowest threshold energies for X-ray detectors used in the solar soft
X-ray spectrophotometer SphinX and define their values for two regions:
the SAA and in the Van Allen outer belt. Different values of lowest
threshold energies are directly associated with different slopes
of particle energy spectra. Cross-analyses of data obtained from the
STEP-F and SphinX instruments initially built for various purposes made
it possible to detect the highly anisotropic character of the spatial
electron distribution in radiation belts in both Southern and Northern
hemispheres. We detected also the presence of low-energy electrons at
all latitudes during the main phase of a weak geomagnetic storm.
Title: Gemini-LIGHTS: Herbig Ae/Be and Massive T Tauri Protoplanetary
Disks Imaged with Gemini Planet Imager
Authors: Rich, Evan A.; Monnier, John D.; Aarnio, Alicia; Laws,
Anna S. E.; Setterholm, Benjamin R.; Wilner, David J.; Calvet,
Nuria; Harries, Tim; Miller, Chris; Davies, Claire L.; Adams, Fred
C.; Andrews, Sean M.; Bae, Jaehan; Espaillat, Catherine; Greenbaum,
Alexandra Z.; Hinkley, Sasha; Kraus, Stefan; Hartmann, Lee; Isella,
Andrea; McClure, Melissa; Oppenheimer, Rebecca; Pérez, Laura M.;
Zhu, Zhaohuan
Bibcode: 2022AJ....164..109R
Altcode: 2022arXiv220605815R
We present the complete sample of protoplanetary disks from the Gemini-
Large Imaging with the Gemini Planet Imager Herbig/T Tauri Survey, which
observed bright Herbig Ae/Be stars and T Tauri stars in near-infrared
polarized light to search for signatures of disk evolution and ongoing
planet formation. The 44 targets were chosen based on their near-
and mid-infrared colors, with roughly equal numbers of transitional,
pre-transitional, and full disks. Our approach explicitly did not favor
well-known, "famous" disks or those observed by the Atacama Large
Millimeter/submillimeter Array, resulting in a less-biased sample
suitable to probe the major stages of disk evolution during planet
formation. Our optimized data reduction allowed polarized flux as low
as 0.002% of the stellar light to be detected, and we report polarized
scattered light around 80% of our targets. We detected point-like
companions for 47% of the targets, including three brown dwarfs (two
confirmed, one new), and a new super-Jupiter-mass candidate around V1295
Aql. We searched for correlations between the polarized flux and system
parameters, finding a few clear trends: the presence of a companion
drastically reduces the polarized flux levels, far-IR excess correlates
with polarized flux for nonbinary systems, and systems hosting disks
with ring structures have stellar masses <3 M⊙. Our
sample also included four hot, dusty "FS CMa" systems, and we detected
large-scale ( >100 au) scattered light around each, signs of extreme
youth for these enigmatic systems. Science-ready images are publicly
available through multiple distribution channels using a new FITS file
standard that has been jointly developed with members of the Very Large
Telescope Spectro-polarimetric High-contrast Exoplanet Research team.
Title: The California Legacy Survey. III. On the Shoulders of
(Some) Giants: The Relationship between Inner Small Planets and
Outer Massive Planets
Authors: Rosenthal, Lee J.; Knutson, Heather A.; Chachan, Yayaati;
Dai, Fei; Howard, Andrew W.; Fulton, Benjamin J.; Chontos, Ashley;
Crepp, Justin R.; Dalba, Paul A.; Henry, Gregory W.; Kane, Stephen R.;
Petigura, Erik A.; Weiss, Lauren M.; Wright, Jason T.
Bibcode: 2022ApJS..262....1R
Altcode: 2021arXiv211203399R
We use a high-precision radial velocity survey of FGKM stars to study
the conditional occurrence of two classes of planets: close-in small
planets (0.023-1 au, 2-30 M ⊕) and distant giant planets
(0.23-10 au, 30-6000 M ⊕). We find that ${41}_{-13}^{+15}
\% $ of systems with a close-in, small planet also host an outer
giant, compared to ${17.6}_{-1.9}^{+2.4} \% $ for stars irrespective
of small planet presence. This implies that small planet hosts may
be enhanced in outer giant occurrences compared to all stars with
1.7σ significance. Conversely, we estimate that ${42}_{-13}^{+17}
\% $ of cold giant hosts also host an inner small planet, compared
to ${27.6}_{-4.8}^{+5.8} \% $ of stars irrespective of cold giant
presence. We also find that more massive and close-in giant planets
are not associated with small inner planets. Specifically, our
sample indicates that small planets are less likely to have outer
giant companions more massive than approximately 120 M ⊕
and within 0.3-3 au, than to have less massive or more distant giant
companions, with ~2.2σ confidence. This implies that massive gas giants
within 0.3-3 au may suppress inner small planet formation. Additionally,
we compare the host-star metallicity distributions for systems
with only small planets and those with both small planets and cold
giants. In agreement with previous studies, we find that stars in our
survey that only host small planets have a metallicity distribution
that is consistent with the broader solar-metallicity-median sample,
while stars that host both small planets and gas giants are distinctly
metal rich with ~2.3σ confidence.
Title: Simulation Study of Network Reconfiguration and Load-balancing
Method for the Xinjiang Astronomical Observatory Data Center
Authors: Wang, Jie; Zhang, Hailong; Wang, Na; Ye, Xinchen; Wang,
Wanqiong; Li, Jia; Zhang, Meng; Zhang, Yazhou; Du, Xu
Bibcode: 2022RAA....22i5022W
Altcode:
The Xinjiang Astronomical Observatory Data Center faces issues related
to delay-affected services. As a result, these services cannot be
implemented in a timely manner due to the overloading of transmission
links. In this paper, the software-defined network technology is
applied to the Xinjiang Astronomical Observatory Data Center Network
(XAO-DCN). Specifically, a novel reconfiguration method is proposed to
realise the software-defined Xinjiang Astronomical Observatory Data
Center Network (SDXAO-DCN), and a network model is constructed. To
overcome the congestion problem, a traffic load-balancing algorithm
is designed for fast transmission of the service traffic by combining
three factors: network structure, congestion level and transmission
service. The proposed algorithm is compared with current commonly
load-balancing algorithms which are used in data center to verify its
efficiency. Simulation experiments show that the algorithm improved
transmission performance and transmission quality for the SDXAO-DCN.
Title: Probing the velocity and spectral evolution along the eastern
lobe of the microquasar SS 433
Authors: Tsuji, Naomi
Bibcode: 2022cxo..prop.6297T
Altcode:
We propose to perform Chandra ACIS-I observations of the non-thermal
knots located in the eastern lobe of W50 associated with the Galactic
microquasar SS 433. These knots are the likely counterparts of the
recently detected VHE gamma-ray emission by HAWC, making the SS 433/W50
system a unique jet-driven PeVatron candidate. Chandra will provide the
first high-resolution X-ray imaging data of our proposed region aimed
to achieve: (1) proper motion measurement of the knots to determine
the velocity profile in the eastern jet, and (2) spatially-resolved
X-ray spectroscopy to characterize the spectral evolution along the
jet. These observables uniquely obtained by new Chandra observations
will test our model predictions for the jet dynamics, knot formation,
and particle acceleration processes.
Title: ATLAS Transient Discovery Report for 2022-09-04
Authors: Tonry, J.; Denneau, L.; Weiland, H.; Lawrence, A.; Siverd,
R.; Erasmus, N.; Koorts, W.; Anderson, J.; Jordan, A.; Suc, V.; Smith,
K. W.; Srivastav, S.; Young, D. R.; Smartt, S. J.; Gillanders, J.;
Fulton, M.; McCollum, M.; Moore, T.; Shingles, L.; Rest, A.; Chen,
T. W.; Pacheco, D.; Nicholl, M.; Stubbs, C.; Rest, S.
Bibcode: 2022TNSTR2574....1T
Altcode:
No abstract at ADS
Title: MASTER Transient Discovery Report for 2022-09-05
Authors: Kechin, Y.; Lipunov, V.; Kornilov, V.; Gorbovskoy, E.;
Zhirkov, K.; Tyurina, N.; Balanutsa, P.; Kuznetsov, A.; Vlasenko,
D.; Antipov, G.; Zimnukhov, D.; Senik, V.; Minkina, E.; Chasovnikov,
A.; Topolev, V.; Kuvshinov, D.; Cheryasov, D.; Kechin, Y.; Podesta,
R.; Lopez, C.; Podesta, F.; Francile, C.; Rebolo, R.; Serra, M.;
Buckley, D.; Gres, O. A.; Budnev, N. M.; Carrasco, L.; Valdes, J. R.;
Chavushyan, V.; Alvarez, V. M. P.; Martinez, J.; Corella, A. R.;
Rodriguez, L. H.; Tlatov, A.; Dormidontov, D.; Gabovich, A.; Yurkov, V.
Bibcode: 2022TNSTR2584....1K
Altcode:
No abstract at ADS
Title: Intermediate- and high-velocity clouds in the Milky Way -
II. Evidence for a Galactic fountain with collimated outflows and
diffuse inflows
Authors: Marasco, Antonino; Fraternali, Filippo; Lehner, Nicolas;
Howk, J. Christopher
Bibcode: 2022MNRAS.515.4176M
Altcode: 2022MNRAS.tmp.1300M; 2022arXiv220205852M
We model the kinematics of the high- and intermediate-velocity clouds
(HVCs and IVCs) observed in absorption towards a sample of 55 Galactic
halo stars with accurate distance measurements. We employ a simple
model of a thick disc whose main free parameters are the gas azimuthal,
radial, and vertical velocities (vϕ, vR, and
vz), and apply it to the data by fully accounting for the
distribution of the observed features in the distance-velocity space. We
find that at least two separate components are required to reproduce the
data. A scenario where the HVCs and the IVCs are treated as distinct
populations provides only a partial description of the data, which
suggests that a pure velocity-based separation may give a biased vision
of the gas physics at the Milky Way's disc-halo interface. Instead, the
data are better described by a combination of an inflow component and an
outflow component, both characterized by rotation with vϕ
comparable to that of the disc and vz of $50\!-\!100\,
{\rm km\, s}^{-1}$. Features associated with the inflow appear to be
diffused across the sky, while those associated with the outflow are
mostly confined within a bicone pointing towards (l = 220°, b = +40°)
and (l = 40°, b = -40°). Our findings indicate that the lower ($|z|
\lesssim 10\, {\rm kpc}$) Galactic halo is populated by a mixture of
diffuse inflowing gas and collimated outflowing material, which are
likely manifestations of a galaxy-wide gas cycle triggered by stellar
feedback, that is, the galactic fountain.
Title: Investigating the X-ray polarization of lamp-post coronae
in BHXRBs
Authors: Zhang, Wenda; Dovčiak, Michal; Bursa, Michal; Karas,
Vladimír; Matt, Giorgio; Ursini, Francesco
Bibcode: 2022MNRAS.515.2882Z
Altcode: 2022arXiv220703228Z; 2022MNRAS.tmp.1852Z
High-sensitivity X-ray polarimetric observations of black hole X-ray
binaries, which will soon become available with the launches of
space-borne X-ray observatories with sensitive X-ray polarimeters,
will be able to put independent constraints on the black hole as well
as the accretion flow, and possibly break degeneracies that cannot
be resolved by spectral/timing observations alone. In this work,
we perform a series of general relativistic Monte Carlo radiative
transfer simulations to study the expected polarization properties of
X-ray radiation emerging from lamp-post coronae in black hole X-ray
binaries. We find that the polarization degree of the coronal emission
of black hole X-ray binaries is sensitive to the spin of the black hole,
the height of the corona, and the dynamics of the corona.
Title: Solenoidal turbulent modes and star formation efficiency in
Galactic plane molecular clouds
Authors: Rani, Raffaele; Moore, Toby J. T.; Eden, David J.; Rigby,
Andrew J.
Bibcode: 2022MNRAS.515..271R
Altcode: 2022arXiv220613442R; 2022MNRAS.tmp.1767R
It is speculated that the high star formation efficiency observed
in spiral-arm molecular clouds is linked to the prevalence of
compressive (curl-free) turbulent modes, while the shear-driven
solenoidal (divergence-free) modes appear to be the main cause of
the low star formation efficiency that characterizes clouds in the
Central Molecular Zone. Similarly, analysis of the Orion B molecular
cloud has confirmed that, although turbulent modes vary locally and at
different scales within the cloud, the dominant solenoidal turbulence
is compatible with its low star formation rate. This evidence points
to intercloud and intracloud fluctuations of the solenoidal modes being
an agent for the variability of star formation efficiency. We present a
quantitative estimation of the relative fractions of momentum density in
the solenoidal modes of turbulence in a large sample of plane molecular
clouds in the 13CO/C18O (J = 3 → 2) Heterodyne
Inner Milky Way Plane Survey (CHIMPS). We find a negative correlation
between the solenoidal fraction and star formation efficiency. This
feature is consistent with the hypothesis that solenoidal modes prevent
or slow down the collapse of dense cores. In addition, the relative
power in the solenoidal modes of turbulence (solenoidal fraction)
appears to be higher in the Inner Galaxy declining with a shallow
gradient with increasing Galactocentric distance. Outside the Inner
Galaxy, the slowly, monotonically declining values suggest that the
solenoidal fraction is unaffected by the spiral arms.
Title: Mg II in the JWST era: a probe of Lyman continuum escape?
Authors: Katz, Harley; Garel, Thibault; Rosdahl, Joakim; Mauerhofer,
Valentin; Kimm, Taysun; Blaizot, Jérémy; Michel-Dansac, Léo;
Devriendt, Julien; Slyz, Adrianne; Haehnelt, Martin
Bibcode: 2022MNRAS.515.4265K
Altcode: 2022arXiv220511534K; 2022MNRAS.tmp.1388K; 2022MNRAS.tmp.1395K
Limited constraints on the evolution of the Lyman Continuum (LyC) escape
fraction represent one of the primary uncertainties in the theoretical
determination of the reionization history. Due to the intervening
intergalactic medium, the possibility of observing LyC photons directly
in the epoch of reionization is highly unlikely. For this reason,
multiple indirect probes of LyC escape have been identified, some
of which are used to identify low-redshift LyC leakers (e.g. O32),
while others are primarily useful at z > 6 (e.g. [O III]/[C III]
far-infrared emission). The flux ratio of the resonant Mg II doublet
emission at 2796$\mathring{\rm A}$ and 2803$\mathring{\rm A}$ as well as
the Mg II optical depth have recently been proposed as ideal diagnostics
of LyC leakage that can be employed at z > 6 with JWST. Using
state-of-the-art cosmological radiation hydrodynamics simulations
post-processed with CLOUDY and resonant-line radiative transfer, we test
whether Mg II is indeed a useful probe of LyC leakage. Our simulations
indicate that the majority of bright, star-forming galaxies with high
LyC escape fractions are expected to be Mg II emitters rather than
absorbers at z = 6. However, we find that the Mg II doublet flux ratio
is a more sensitive indicator of dust rather than neutral hydrogen,
limiting its use as a LyC leakage indicator to only galaxies in the
optically thin regime. Given its resonant nature, we show that Mg II
will be an exciting probe of the complex kinematics in high-redshift
galaxies in upcoming JWST observations.
Title: Palomar Gattini-IR discovery and classification of a new
highly reddened Galactic nova PGIR22akgylf in the active TESS field
Authors: De, K.; Soria, R.; Agusti, M. Badenas; Kong, M.; Karambelkar,
V.; Hankins, M.; Kasliwal, M. M.; Sokoloski, J.; Ashley, M.; Babul,
A.; Lau, R. M.; Moore, A.; Ofek, E. O.; Sharma, M.; Simcoe, R.; Soon,
J.; Soria, R.; Travouillon, T.; Vanderburg, A.
Bibcode: 2022ATel15587....1D
Altcode:
We report the discovery and spectroscopic classification of the highly
reddened transient PGIR22akgylf / AT 2022sfe in the ongoing TESS
Sector 55. The transient was identified in regular survey operations
of Palomar Gattini-IR (De et al. 2020; Moore & Kasliwal 2019).
Title: On the utility of flux rope models for CME magnetic structure
below 30 R⊙
Authors: Lynch, Benjamin J.; Al-Haddad, Nada; Yu, Wenyuan; Palmerio,
Erika; Lugaz, Noé
Bibcode: 2022AdSpR..70.1614L
Altcode: 2022arXiv220502144L
We present a comprehensive analysis of the three-dimensional magnetic
flux rope structure generated during the Lynch et al. (2019, ApJ
880:97) magnetohydrodynamic (MHD) simulation of a global-scale, 360
° -wide streamer blowout coronal mass ejection (CME) eruption. We
create both fixed and moving synthetic spacecraft to generate time
series of the MHD variables through different regions of the flux
rope CME. Our moving spacecraft trajectories are derived from the
spatial coordinates of Parker Solar Probe's past encounters 7 and 9 and
future encounter 23. Each synthetic time series through the simulation
flux rope ejecta is fit with three different in situ flux rope models
commonly used to characterize the large-scale, coherent magnetic field
rotations observed in a significant fraction of interplanetary CMEs
(ICMEs). We present each of the in situ flux rope model fits to the
simulation data and discuss the similarities and differences between
the model fits and the MHD simulation's flux rope spatial orientations,
field strengths and rotations, expansion profiles, and magnetic flux
content. We compare in situ model properties to those calculated with
the MHD data for both classic bipolar and unipolar ICME flux rope
configurations as well as more problematic profiles such as those
with a significant radial component to the flux rope axis orientation
or profiles obtained with large impact parameters. We find general
agreement among the in situ flux rope fitting results for the classic
profiles and much more variation among results for the problematic
profiles. We also examine the force-free assumption for a subset of
the flux rope models and quantify properties of the Lorentz force
within MHD ejecta intervals. We conclude that the in situ flux rope
models are generally a decent approximation to the field structure,
but all the caveats associated with in situ flux rope models will
still apply (and perhaps moreso) at distances below 30R⊙
. We discuss our results in the context of future PSP observations of
CMEs in the extended corona.
Title: An Atlas of Convection in Main-sequence Stars
Authors: Jermyn, Adam S.; Anders, Evan H.; Lecoanet, Daniel; Cantiello,
Matteo
Bibcode: 2022ApJS..262...19J
Altcode: 2022arXiv220600011J
Convection is ubiquitous in stars and occurs under many different
conditions. Here we explore convection in main-sequence stars through
two lenses: dimensionless parameters arising from stellar structure and
parameters that emerge from the application of mixing length theory. We
first define each quantity in terms familiar to both the 1D stellar
evolution community and the hydrodynamics community. We then explore
the variation of these quantities across different convection zones,
different masses, and different stages of main-sequence evolution. We
find immense diversity across stellar convection zones. Convection
occurs in thin shells, deep envelopes, and nearly spherical cores;
it can be efficient or inefficient, rotationally constrained or not,
transsonic or deeply subsonic. This atlas serves as a guide for future
theoretical and observational investigations by indicating which
regimes of convection are active in a given star, and by describing
appropriate model assumptions for numerical simulations.
Title: Spectral Energy Distributions in Three Deep-drilling Fields
of the Vera C. Rubin Observatory Legacy Survey of Space and Time:
Source Classification and Galaxy Properties
Authors: Zou, Fan; Brandt, W. N.; Chen, Chien-Ting; Leja, Joel;
Ni, Qingling; Yan, Wei; Yang, Guang; Zhu, Shifu; Luo, Bin; Nyland,
Kristina; Vito, Fabio; Xue, Yongquan
Bibcode: 2022ApJS..262...15Z
Altcode: 2022arXiv220606432Z
W-CDF-S, ELAIS-S1, and XMM-LSS will be three Deep-Drilling Fields (DDFs)
of the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST),
but their extensive multiwavelength data have not been fully utilized
as done in the COSMOS field, another LSST DDF. To prepare for future
science, we fit source spectral energy distributions (SEDs) from X-ray
to far-infrared in these three fields mainly to derive galaxy stellar
masses and star formation rates. We use CIGALE v2022.0, a code that has
been regularly developed and evaluated, for the SED fitting. Our catalog
includes 0.8 million sources covering 4.9 deg2 in W-CDF-S,
0.8 million sources covering 3.4 deg2 in ELAIS-S1, and 1.2
million sources covering 4.9 deg2 in XMM-LSS. Besides fitting
normal galaxies, we also select candidates that may host active galactic
nuclei (AGNs) or are experiencing recent star formation variations and
use models specifically designed for these sources to fit their SEDs;
this increases the utility of our catalog for various projects in
the future. We calibrate our measurements by comparison with those in
well-studied smaller regions and briefly discuss the implications of our
results. We also perform detailed tests of the completeness and purity
of SED-selected AGNs. Our data can be retrieved from a public website.
Title: New Class of Laboratory Astrophysics Experiments: Application
to Radiative Accretion Processes around Neutron Stars
Authors: Tranchant, V.; Charpentier, N.; Van Box Som, L.; Ciardi,
A.; Falize, É.
Bibcode: 2022ApJ...936...14T
Altcode:
Extreme radiative phenomena, where the radiation energy density and flux
strongly influence the medium, are common in the universe. Nevertheless,
because of limited or nonexistent observational and experimental data,
the validity of theoretical and numerical models for some of these
radiation-dominated regimes remains to be assessed. Here, we present
the theoretical framework of a new class of laboratory astrophysics
experiments that can take advantage of existing high-power laser
facilities to study supersonic radiation-dominated waves. Based
on an extension of Lie symmetry theory we show that the stringent
constraints imposed on the experiments by current scaling theories can
in fact be relaxed, and that astrophysical phenomena can be studied
in the laboratory even if the ratio of radiation energy density to
thermal energy and systems' microphysics are different. The validity
of this approach holds until the hydrodynamic response of the studied
system starts to play a role. These equivalence symmetries concepts are
demonstrated using a combination of simulations for conditions relevant
to Type I X-ray burst and of equivalent laboratory experiments. These
results constitute the starting point of a new general approach
expanding the catalog of astrophysical systems that can be studied in
the laboratory.
Title: Adakite generation as a result of fluid-fluxed melting at
normal lower crustal pressures
Authors: Wang, Xiangsong; Sun, Min; Weinberg, Roberto F.; Cai, Keda;
Zhao, Guochun; Xia, Xiaoping; Li, Pengfei; Liu, Xijun
Bibcode: 2022E&PSL.59417744W
Altcode:
Adakites with continental origin have K-rich compositions distinctive
from the sodic, subduction-related adakites and are generally considered
as partial melting products of thickened mafic lower crust at high
pressure conditions (above 1.5 GPa; >50 km depth). In order to
compare the geochemical differences and to constrain their source
compositions and partial melting conditions, we compiled published
data for the sodic adakites related to subduction processes in the
Central Asian Orogenic Belt (CAOB) and the potassic adakite-like
rocks related to continental collision in the Lhasa Terranes (LT)
of the Tibetan Plateau. Based on the spatial similarity of Sr-Nd
isotopes and nature of inherited zircons, the origin of the CAOB
sodic adakites is best explained by fluid-fluxed melting of low-K arc
basalts, while the LT potassic adakites are best explained as generated
by fluid-fluxed melting of rocks similar to the voluminous high-K
Linzizong mafic volcanic successions (LVS). The phase equilibria
and trace-element modeling reveal that these low Mg#
mafic sources would expand garnet stability to pressures as low as
7-8 kbar and fluid-fluxed melting (X(H2O) = 2-3 wt%)
would significantly decrease the modal content of plagioclase,
resulting in melts with "high pressure" signature (e.g., high Sr/Y
and La/Yb). This paper provides an alternative model for the origin
of sodic or potassic continental adakites arguing that they originate
from fluid-fluxed melting at garnet amphibolite facies at normal lower
crustal pressures (10-11 kbar). Our findings highlight the importance
of the source composition and fluid content in generating the "high
pressure" signatures of adakites, which may also explain the origin
of Archean tonalite-trondhjemite-granodiorites (TTGs).
Title: ZTF Transient Discovery Report for 2022-09-02
Authors: Taubenberger, S.; Chen, T.
Bibcode: 2022TNSTR2557....1T
Altcode:
No abstract at ADS
Title: On Planet Formation around Supermassive Black Holes and Grain
Disruption Barriers by Radiative Torques
Authors: Giang, Nguyen Chau; Hoang, Thiem; Tram, Le Ngoc; Dieu, Nguyen
Duc; Diep, Pham Ngoc; Phuong, Nguyen Thi; Tuan, Bui Van; Truong, Bao
Bibcode: 2022ApJ...936..108G
Altcode:
It has recently been suggested that planets can form by dust coagulation
in the tori of active galactic nuclei (AGN) with low luminosities of
L bol ≲ 1042 erg s-1, constituting
a new class of exoplanets orbiting supermassive black holes called
blanets. However, large dust grains in the AGN torus may be rotationally
disrupted by the radiative torque disruption (RATD) mechanism due to AGN
radiation feedback, which would prevent blanet formation. To test this
scenario, we adopt a simple smooth and a clumpy dust/gas distribution
inside the torus region to study the effect of RATD on the evolution
of composite dust grains in the midplane of the torus. We found that
grain growth and then blanet formation are possible in the smooth torus
model. However, in the clumpy torus model, grain growth will be strongly
constrained by RATD, assuming the gas density distribution as adopted
by Wada et al. We also found that icy grain mantles inside clumps
are quickly detached from the grain cores by rotational desorption,
reducing the sticking coefficient between icy grains and the coagulation
efficiency. The grain rotational disruption and ice desorption occur
on timescales much shorter than the growth time up to a factor of
~104, which are the new barriers that grain growth must
overcome to form blanets. Further studies with more realistic AGN
models are required to constrain better the effect of RATD on grain
growth and blanet formation hypothesis around low-luminosity AGN.
Title: Near anti-helion meteor shower outburst recorded by Global
Meteor Network
Authors: Roggemans, P.; Šegon, D.; Vida, D.; Greaves, J.; Sekiguchi,
T.; Angelsky, A.; Davydov, A.
Bibcode: 2022eMetN...7..293R
Altcode:
An outburst near the anti-helion source has been registered by
the cameras of the Global Meteor Network on 2022 August 15–16
and August 16–17. The shower meteors radiated from a very compact
radiant centered at α = 325.3 ± 0.4° an δ = –11.5 ± 0.4° with
a geocentric velocity vg = 23.9 ± 0.3 km/s, with M2022-Q1 as temporary
identification, likely recorded before as the August delta Capricornids
(ADC#00199). The flux plot indicates that the activity lasted ~15
hours with the main peak activity at λʘ = 143.71° corresponding
to 2022 August 16, 22h04m UT with a ZHR of about 10. The mean orbit
could be derived from 123 very similar orbits. Another set of 5 paired
meteors recorded by the RMS network in Ukraine confirms the orbit
obtained by GMN. The observed outburst matches very well with the
forecast by Mikhail Maslov who predicted that a young trail of comet
45P/Honda-Mrkos-Pajdusakova ejected in 1980 could encounter the Earth
at 2022 August 16, at 23h40m UT.
Title: Cometary dust analogues for physics experiments
Authors: Lethuillier, A.; Feller, C.; Kaufmann, E.; Becerra, P.;
Hänni, N.; Diethelm, R.; Kreuzig, C.; Gundlach, B.; Blum, J.;
Pommerol, A.; Kargl, G.; Laddha, S.; Denisova, K.; Kührt, E.; Capelo,
H. L.; Haack, D.; Zhang, X.; Knollenberg, J.; Molinski, N. S.; Gilke,
T.; Sierks, H.; Tiefenbacher, P.; Güttler, C.; Otto, K. A.; Bischoff,
D.; Schweighart, M.; Hagermann, A.; Jäggi, N.
Bibcode: 2022MNRAS.515.3420L
Altcode: 2022MNRAS.tmp.1711L; 2021arXiv211005832L
The CoPhyLab (Cometary Physics Laboratory) project is designed to study
the physics of comets through a series of earth-based experiments. For
these experiments, a dust analogue was created with physical properties
comparable to those of the non-volatile dust found on comets. This
'CoPhyLab dust' is planned to be mixed with water and CO2
ice and placed under cometary conditions in vacuum chambers to study
the physical processes taking place on the nuclei of comets. In order
to develop this dust analogue, we mixed two components representative
for the non-volatile materials present in cometary nuclei. We chose
silica dust as a representative for the mineral phase and charcoal for
the organic phase, which also acts as a darkening agent. In this paper,
we provide an overview of known cometary analogues before presenting
measurements of eight physical properties of different mixtures of
the two materials and a comparison of these measurements with known
cometary values. The physical properties of interest are particle
size, density, gas permeability, spectrophotometry, and mechanical,
thermal, and electrical properties. We found that the analogue dust
that matches the highest number of physical properties of cometary
materials consists of a mixture of either 60 per cent/40 per cent or
70 per cent/30 per cent of silica dust/charcoal by mass. These best-fit
dust analogue will be used in future CoPhyLab experiments.
Title: Research progress on the effects of microgravity and space
radiation on astronauts' health and nursing measures
Authors: Cao, Xinhua
Bibcode: 2022OAst...31..300C
Altcode:
With the development of human space technology, more and more astronauts
fly into space. With the rapid development of commercial aerospace,
more ordinary people will go to space for sightseeing. However, it
should not be ignored that microgravity, space radiation, relative
geometry, and orbit of space stations have various effects on the
health of astronauts. In recent years, scholars in various countries
have made considerable research progress in this field. This article
analyzes the research history and current situation of this field,
including the individual effects of space radiation, microgravity,
orbit, and relative geometry, as well as their comprehensive effects. In
addition, various nursing measures have been investigated.
Title: KIC 2857323: A Double-mode High-amplitude δ Scuti Star with
Amplitude Decline of the First Overtone Mode
Authors: Yang, Tao-Zhi; Zuo, Zhao-Yu; Sun, Xiao-Ya; Tang, Rui-Xuan;
Esamdin, Ali
Bibcode: 2022ApJ...936...48Y
Altcode:
We investigate the pulsating behavior of KIC 2857323 using
high-precision observations from the Kepler mission. Fourier analysis
of 4 yr time-series data reveals five independent frequencies for the
light variation. Among them, two strong frequencies f 1
and f 3 with a period ratio of 0.774 identify this star as a
double-mode (i.e., the fundamental mode F0 and first overtone mode F1)
high-amplitude δ Scuti star (HADS). Seismic modeling using the two
radial modes F0 and F1 indicates that KIC 2857323 is a main-sequence
star with mass M = 1.78 ± 0.02 M ⊙ and metallicity Z from
0.009 to 0.012. We analyze the phase and amplitude variations of F0 and
F1 using the phase modulation method and find that the first overtone
mode F1 shows a slow decline in amplitude. We discuss several possible
causes for the amplitude variation and speculate that the amplitude
decline in this star may be due to pulsation energy loss. We note that
KIC 2857323 is the first double-mode HADS to show amplitude decline
and warrants further study to ascertain its nature.
Title: Unified neutron star EOSs and neutron star structures in
RMF models
Authors: Xia, Cheng-Jun; Maruyama, Toshiki; Li, Ang; Yuan Sun, Bao;
Long, Wen-Hui; Zhang, Ying-Xun
Bibcode: 2022CoTPh..74i5303X
Altcode: 2022arXiv220812893X
In the framework of the Thomas-Fermi approximation, we systematically
study the EOSs and microscopic structures of neutron star matter
in a vast density range with n b ≍ 10-10-2
fm-3, where various covariant density functionals are
adopted, i.e., those with nonlinear self couplings (NL3, PK1, TM1,
GM1, MTVTC) and density-dependent couplings (DD-LZ1, DDME-X, PKDD,
DD-ME2, DD2, TW99). It is found that the EOSs generally coincide
with each other at n b ≲ 10-4 fm-3
and 0.1 fm-3 ≲ n b ≲ 0.3 fm-3,
while in other density regions they are sensitive to the effective
interactions between nucleons. By adopting functionals with a larger
slope of symmetry energy L, the curvature parameter K sym
and neutron drip density generally increases, while the droplet size,
proton number of nucleus, core-crust transition density, and onset
density of non-spherical nuclei, decrease. All functionals predict
neutron stars with maximum masses exceeding the two-solar-mass limit,
while those of DD2, DD-LZ1, DD-ME2, and DDME-X predict optimum neutron
star radii according to the observational constraints. Nevertheless, the
corresponding skewness coefficients J are much larger than expected,
while only the functionals MTVTC and TW99 meet the start-of-art
constraints on J. More accurate measurements on the radius of
PSR J0740 + 6620 and the maximum mass of neutron stars are thus
essential to identify the functional that satisfies all constraints
from nuclear physics and astrophysical observations. Approximate linear
correlations between neutron stars' radii at M = 1.4M ⊙ and
2M ⊙, the slope L and curvature parameter K sym
of symmetry energy are observed as well, which are mainly attributed to
the curvature-slope correlations in the functionals adopted here. The
results presented here are applicable for investigations of the
structures and evolutions of compact stars in a unified manner.
Title: Probing Magnetic Fields in Protoplanetary Disk Atmospheres
through Polarized Near-IR Light Scattered by Aligned Grains
Authors: Yang, Haifeng; Li, Zhi-Yun
Bibcode: 2022AJ....164...99Y
Altcode: 2022arXiv220303213Y
Magnetic fields play essential roles in protoplanetary disks. Magnetic
fields in the disk atmosphere are of particular interest, as they
are connected to the wind-launching mechanism. In this work, we
study the polarization of the light scattered off of magnetically
aligned grains in the disk atmosphere, focusing on the deviation of
the polarization orientation from the canonical azimuthal direction,
which may be detectable in near-IR polarimetry with instruments such as
VLT/SPHERE. We show with a simple disk model that the polarization can
even be oriented along the radial (rather than azimuthal) direction,
especially in highly inclined disks with toroidally dominated magnetic
fields. This polarization reversal is caused by the anisotropy in
the polarizability of aligned grains and is thus a telltale sign of
such grains. We show that the near-IR light is scattered mostly by
μm-sized grains or smaller at the τ = 1 surface and such grains can be
magnetically aligned if they contain superparamagnetic inclusions. For
comparison with observations, we generate synthetic maps of the ratios
of U ϕ /I and Q ϕ /I, which can be used to
infer the existence of (magnetically) aligned grains through a negative
Q ϕ (polarization reversal) and/or a significant level of
U ϕ /I. We show that two features observed in the existing
data, an asymmetric distribution of U ϕ with respect to
the disk minor axis and a spatial distribution of U ϕ
that is predominantly positive or negative, are incompatible with
scattering by spherical grains in an axisymmetric disk. They provide
indirect evidence for scattering by aligned nonspherical grains.
Title: Evidence that Earth's magnetotail affects dielectric breakdown
weathering on the Moon
Authors: Jordan, A. P.; Case, A. W.; Wilson, J. K.; Huang, C. -L.
Bibcode: 2022Icar..38315011J
Altcode:
The standard view of space weathering on the Moon is that the solar
wind and micrometeoroid impacts alter the optical properties of
lunar soil. A third process-dielectric breakdown driven by solar
energetic particles (SEPs)-has also been suggested to contribute to
space weathering. It has been difficult to determine the relative
roles of these processes. The Earth's magnetotail, however, provides
a way to distinguish between them, because it affects only charged
particles. Earth's magnetotail blocks the solar wind, and here we
show that it also likely reduces the flux of SEPs traveling across
the tail and impacting the tail-facing hemisphere of the Moon when it
is entering or leaving. Consequently, we make two predictions that
distinguish how the tail affects dielectric breakdown weathering
patterns from how it affects solar wind weathering patterns. First,
the magnetotail should create two minima in the total amount of
breakdown weathering that has occurred: one near ≳ 60∘
and a deeper one near ≲ - 60∘ longitude. Second, the
tail should create east-west asymmetries in the breakdown weathering
of crater walls, with the greatest asymmetries occurring at ±
75∘ longitude. Although the first prediction has proven
difficult to test, we find that the second prediction is supported
by observations. Therefore, we conclude that investigations of space
weathering must consider, not only micrometeoroid and solar wind
bombardment, but also dielectric breakdown.
Title: Structure of deformations in Jackiw-Teitelboim black holes
with matter
Authors: Bak, Dongsu; Kim, Chanju; Yi, Sang-Heon
Bibcode: 2022arXiv220901394B
Altcode:
We consider Jackiw-Teitelboim gravity with a massless matter field
and turn on bulk excitations leading to a nontrivial vev of the
corresponding dual boundary operator. To leading order, we realize the
corresponding deformation of thermofield double state by explicitly
identifying their Hilbert space. The deformed state can be prepared with
an operator insertion at the mid-point of the Euclidean time evolution
in the context of Hartle-Hawking construction. We show that the inserted
operators form an SL(2,{\bf R}) representation. We construct a specific
orthonormal basis that is directly related to the operator basis of
the vev deformations. If we include the higher order corrections, the
bulk geometry is no longer left-right symmetric. We argue that the mode
coefficients in the bulk deformation cannot be fully recovered from the
data collected along the boundary cutoff trajectories. It implies that
the bulk contains more information than the cutoff boundary, and this
might be responsible for nontrivial behind-horizon degrees of freedom.
Title: Loop Quantum Gravity: A Demystified View
Authors: Vyas, Rakshit P.; Joshi, Mihir J.
Bibcode: 2022GrCo...28..228V
Altcode:
An attempt is made to demystify loop quantum gravity (LQG) in a
concise and lucid way. LQG is a background-independent as well as
non-perturbative approach of the theory of quantum gravity. Since LQG is
one of the supposed candidates of a theory of quantum gravity, firstly,
prerequisite concepts that are needed for LQG are outlined. Since LQG
belongs to the canonical quantization approach, the ADM formalism
along with the metric formulation is introduced. Thereafter,
other associated concepts regarding the connection formulation
are given, such as tetrads, spin connection, and the Palatini
action. Afterwards, a modification of the connection formulation, i.e.,
the Ashtekar formulation, a basis for the current framework of LQG,
is presented. Thereafter, the kinematic and dynamical framework,
i.e., spin network and spin foam, respectively, are explained;
here, the geometrical observables such as area and volume are
quantized. Applications of LQG, such as the black hole entropy problem
and loop quantum cosmology, are also briefly introduced. This article
targets on beginners and novice who wants to enter this research field.
Title: Global SN Project Transient Classification Report for
2022-09-06
Authors: Hosseinzadeh, G.; Li, W.; Arcavi, I.; Lam, M.; Keinan, I.
Bibcode: 2022TNSCR2601....1H
Altcode:
No abstract at ADS
Title: ALeRCE/ZTF Transient Discovery Report for 2022-09-05
Authors: Munoz-Arancibia, A.; Bauer, F. E.; Forster, F.; Pignata,
G.; Mourao, A.; Hernandez-Garcia, L.; Galbany, L.; Silva-Farfan,
J.; Hoshino, R.; Camacho, E.; Arredondo, J.; Cabrera-Vives, G.;
Carrasco-Davis, R.; Estevez, P. A.; Huijse, P.; Reyes, A. M. E.;
Reyes, I.; Sanchez-Saez, P.; Rodriguez-Mancini, D.; Catelan, M.;
Eyheramendy, S.; Graham, M. J.
Bibcode: 2022TNSTR2582....1M
Altcode:
No abstract at ADS
Title: The H α luminosity and stellar mass dependent clustering of
star-forming galaxies at 0.7 < z < 1.5 with 3D-HST
Authors: Clontz, Callie; Wake, David; Zheng, Zheng
Bibcode: 2022MNRAS.515.2224C
Altcode: 2022arXiv220702871C; 2022MNRAS.tmp.1873C
We present measurements of the dependence of the clustering amplitude
of galaxies on their star formation rate (SFR) and stellar mass
(M*) at 0.7 < z < 1.5 to assess the extent to which
environment affects these properties. While these relations are well
determined in the local Universe, they are much more poorly known at
earlier times. For this analysis, we make use of the near-infrared
HST WFC3 grism spectroscopic data in the five CANDELS fields obtained
as part of the 3D-HST survey. We make projected two-point correlation
function measurements using ~6000 galaxies with accurate redshifts,
M*, and H α luminosities. We find a strong dependence of
clustering amplitude on H α luminosity and thus SFR. However, at fixed
M*, the clustering dependence on H α luminosity is largely
eliminated. We model the clustering of these galaxies within the halo
occupation distribution framework using the conditional luminosity
function model and the newly developed conditional stellar mass and H
α luminosity distribution model. These show that galaxies with higher
SFRs tend to live in higher mass haloes, but this is largely driven
by the relationship between SFR and M*. Finally, we show
that the small residual correlation between clustering amplitude and
H α luminosity at fixed M* is likely being driven by a
broadening of the SFR-M* relationship for satellite galaxies.
Title: On the origin of diffuse radio emission in Abell 85 - insights
from new GMRT observations
Authors: Rahaman, Majidul; Raja, Ramij; Datta, Abhirup; Burns, Jack
O.; Rapetti, David
Bibcode: 2022MNRAS.515.2245R
Altcode: 2022MNRAS.tmp.1834R; 2022arXiv220700061R
Extended, steep, and ultra-steep spectrum radio emission in a galaxy
cluster is usually associated with recent mergers. Simulations show that
radio phoenixes are aged radio galaxy lobes whose emission reactivates
when a low Mach shock compresses it. A85 hosts a textbook example of
a radio phoenix at about 320 kpc southwest of the cluster centre. We
present a new high-resolution 325 MHz GMRT radio map illustrating this
radio phoenix's complex and filamentary structure. The full extent
of the radio structure is revealed for the first time from these
radio images of A85. Using archival Chandra X-ray observations, we
applied an automated 2D shock finder to the X-ray surface brightness
and Adaptive Circular Binning temperature maps that confirmed a bow
shock at the location of the radio phoenix. We also compared the Mach
number from the X-ray data with the radio-derived Mach number in the
same region using multifrequency radio observations and find that they
are consistent within the 1σ error level.
Title: Solar Coronal Mass Ejections Plasma Diagnostics Expressed as
Potential Stellar CME Signatures
Authors: Wilson, Maurice L.; Raymond, John C.
Bibcode: 2022AJ....164..108W
Altcode: 2022arXiv220512985W
Solar coronal mass ejections (CMEs) have a strong association with
solar flares that is not fully understood. This characteristic of our
Sun's magnetic activity may also occur on other stars, but the lack
of successfully detected stellar CMEs makes it difficult to perform
statistical studies that might show a similar association between
CMEs and flares. Because of the potentially strong association, the
search for stellar CMEs often starts with a successful search for
superflares on magnetically active stars. Regardless of the flare's
presence, we emphasize the utility of searching for CME-specific
spectroscopic signatures when attempting to find and confirm stellar
CME candidates. We use solar CMEs as examples of why a multitude
of ultraviolet emission lines, when detected simultaneously, can
substantially improve the credibility of spectroscopically discovered
stellar CME candidates. We make predictions on how bright CME-related
emission lines can be if they are derived from distant stars. We
recommend the use of three emission lines in particular (C IV 1550 Å,
O VI 1032 Å, and C III 977 Å) due to their potentially bright signal
and convenient diagnostic capabilities that can be used to confirm if
an observational signature truly derives from a stellar CME.
Title: Distributed YSOs in the Perseus Molecular Cloud from the Gaia
and LAMOST Surveys
Authors: Wang, Xiao-Long; Fang, Min; Gao, Yu; Zhang, Hong-Xin; Herczeg,
Gregory J.; Ma, Hong-Jun; Chen, En; Zhou, Xing-Yu
Bibcode: 2022ApJ...936...23W
Altcode: 2022arXiv220713368W
Identifying the young optically visible population in a star-forming
region is essential for fully understanding the star formation event. In
this paper, we identify 211 candidate members of the Perseus molecular
cloud based on Gaia astrometry. We use LAMOST spectra to confirm
that 51 of these candidates are new members, bringing the total
census of known members to 856. The newly confirmed members are less
extincted than previously known members. Two new stellar aggregates
are identified in our updated census. With the updated member list,
we obtain a statistically significant distance gradient of 4.84 pc
deg-1 from west to east. Distances and extinction corrected
color-magnitude diagrams indicate that NGC 1333 is significantly younger
than IC 348 and the remaining cloud regions. The disk fraction in NGC
1333 is higher than elsewhere, consistent with its youngest age. The
star formation scenario in the Perseus molecular cloud is investigated
and the bulk motion of the distributed population is consistent with
the cloud being swept away by the Per-Tau Shell.
Title: The First Fall is the Hardest: The Importance of Peculiar
Galaxy Dynamics at Infall Time for Tidal Stripping Acting at the
Centers of Groups and Clusters
Authors: Smith, Rory; Calderón-Castillo, Paula; Shin, Jihye; Raouf,
Mojtaba; Ko, Jongwan
Bibcode: 2022AJ....164...95S
Altcode: 2022arXiv220705099S
Using dark-matter-only N-body cosmological simulations, we measure
the pericentre distance of dark matter halos on their first infall
into group and cluster halos. We find that the pericentre distance (R
peri) is an important parameter as it significantly affects
the strength of tidal mass loss in dense environments, and likely
other environmental mechanisms as well. We examine what determines
the R peri value and find that, for most infallers, the
dominant parameter is V ⊥, the tangential component of
the orbital velocity as the halo enters the group/cluster halo for the
first time. This means that the strength of tidal stripping acting near
the cores of groups/clusters are strongly influenced by the external
peculiar velocity field of the large-scale structure surrounding them,
which differs between clusters and is sensitive to the mass ratio
of infaller to host. We find that filament feeding also partially
contributes to feeding in low-V ⊥ halos. Dynamical friction
can also play a role in reducing R peri but this is only
significant for those few relatively massive infallers (>10% of
the mass of their host). These results highlight how the response of
galaxies to dense environments will sensitively depend on dynamics
inherited from far outside those dense environments.
Title: Erratum: "Molecules with ALMA at Planet-forming Scales (MAPS):
A Circumplanetary Disk Candidate in Molecular-line Emission in the
AS 209 Disk" (2022, ApJL, 934, L20)
Authors: Bae, Jaehan; Teague, Richard; Andrews, Sean M.; Benisty,
Myriam; Facchini, Stefano; Galloway-Sprietsma, Maria; Loomis, Ryan A.;
Aikawa, Yuri; Alarcón, Felipe; Bergin, Edwin; Bergner, Jennifer B.;
Booth, Alice S.; Cataldi, Gianni; Cleeves, L. Ilsedore; Czekala,
Ian; Guzmán, Viviana V.; Huang, Jane; Ilee, John D.; Kurtovic,
Nicolas T.; Law, Charles J.; Le Gal, Romane; Liu, Yao; Long, Feng;
Ménard, Françcois; Öberg, Karin I.; Pérez, Laura M.; Qi, Chunhua;
Schwarz, Kamber R.; Sierra, Anibal; Walsh, Catherine; Wilner, David
J.; Zhang, Ke
Bibcode: 2022ApJ...936L..16B
Altcode:
No abstract at ADS
Title: Detection of an optical outburst from Swift J1943.4+0228
Authors: Wang, Yuankun; Bellm, Eric C.
Bibcode: 2022ATel15600....1W
Altcode:
We report an optical brightening of the Galactic X-ray transient Swift
J1942.4+0228 (Krimm et al. 2012, ATel #4049) with the Zwicky Transient
Facility (ZTF; Bellm et al. 2019, Graham et. al 2019).
Title: Ultramassive black holes formed by triple quasar mergers at
$z\sim 2$
Authors: Ni, Yueying; DiMatteo, Tiziana; Chen, Nianyi; Croft, Rupert;
Bird, Simeon
Bibcode: 2022arXiv220901249N
Altcode:
The origin of rare and elusive ultramassive black holes (UMBH,
with MBH > 1e10 Msun) is an open question. Using the large volume
cosmological hydrodynamic simulation ASTRID, we report on the formation
of an extremely massive UMBH with MBH ~ 1e11 Msun at z~2. The UMBH is
assembled as a result of two successive mergers of massive galaxies
each with stellar mass M* > 3e11 Msun that also produces a bright,
rare triple quasar system powered by three ~10^9 Msun black holes. The
second merger of supermassive black holes (SMBHs) follows the first
after 150 Myrs. The merger events lead to sustained Eddington accretion
onto the central SMBH, forming an UMBH in the center of a massive
compact stellar core with M* > 2e12 Msun. The strong feedback of
the UMBH quenches the surrounding star formation to < 10 Msun/yr
in the inner 50 kpc/h region. There are two more UMBHs with MBH >
5e10 Msun at z>2 in ASTRID which are also produced by major mergers
of galaxies, and their progenitors can be observed as quasar triplets
of lower luminosity. The rarely observed quasar multiples can be the
cradle of UMBHs at high redshift, and likely end up in the center of
the most massive clusters.
Title: ATLAS Transient Discovery Report for 2022-09-06
Authors: Tonry, J.; Denneau, L.; Weiland, H.; Lawrence, A.; Siverd,
R.; Erasmus, N.; Koorts, W.; Anderson, J.; Jordan, A.; Suc, V.; Smith,
K. W.; Srivastav, S.; Young, D. R.; Smartt, S. J.; Gillanders, J.;
Fulton, M.; McCollum, M.; Moore, T.; Shingles, L.; Rest, A.; Chen,
T. W.; Pacheco, D.; Nicholl, M.; Stubbs, C.; Rest, S.
Bibcode: 2022TNSTR2592....1T
Altcode:
No abstract at ADS
Title: Bolide fragmentation: What parts of asteroid 2008
TC3 survived to the ground?
Authors: Jenniskens, Peter; Robertson, Darrel; Goodrich, Cyrena A.;
Shaddad, Muawia H.; Kudoda, Ayman; Fioretti, Anna M.; Zolensky,
Michael E.
Bibcode: 2022M&PS...57.1641J
Altcode:
Asteroid 2008 TC3 impacted the Earth's atmosphere with a
known shape and orientation. Over 600 meteorites were recovered at
recorded locations, including meteorites of nonureilite type. From
where in the asteroid did these stones originate? Here, we reconstruct
the meteor lightcurve and study the breakup dynamics of asteroid 2008
TC3 in 3-D hydrodynamic modeling. Two fragmentation regimes
are found that explain the lightcurve and strewn field. As long as
the asteroid created a wake vacuum, the fragments tended to move
into that shadow, where they mixed with small relative velocities and
surviving meteorites fell along a narrow strip on the ground. But when
the surviving part of the backside and bottom of the asteroid finally
collapsed at 33 km altitude, it created an end flare and dust cloud,
while fragments were dispersed radially with much higher relative speed
due to shock-shock interactions with a distorted shock front. Stones
that originated in this final collapse tended to survive in a larger
size and fell over a wider area at locations on the ground. Those
locations to some extent still trace back to the fragment's original
position in the asteroid. We classified the stones from this "large
mass" area and used this information to glean some insight into the
relative location of recovered ureilites and ordinary and enstatite
chondrites in 2008 TC3.
Title: The irreducible mass and the horizon area of LIGO's black holes
Authors: Gerosa, Davide; Fabbri, Cecilia Maria; Sperhake, Ulrich
Bibcode: 2022CQGra..39q5008G
Altcode: 2022arXiv220208848G
The mass of a Kerr black hole (BH) can be separated into irreducible
and rotational components-the former is a lower limit to the energy
that cannot be possibly extracted from the event horizon and is
related to its area. Here we compute the irreducible masses of the
stellar-mass BHs observed by gravitational-wave interferometers LIGO
and Virgo. Using single-event data, we present a re-parameterization of
the posterior distribution that explicitly highlights the irreducible
and rotational contributions to the total energy. We exploit the
area law to rank the black-hole mergers observed to date according to
their irreversibility, thus providing a guide to selecting events for
targeted tests of general relativity. Using population fits, we compute
the rate by which the total area of black-hole horizons increases due
to the observable mergers.
Title: A Multifluid Dust Module in Athena++: Algorithms and Numerical
Tests
Authors: Huang, Pinghui; Bai, Xue-Ning
Bibcode: 2022ApJS..262...11H
Altcode: 2022arXiv220601023H
We describe the algorithm, implementation, and numerical tests
of a multifluid dust module in the Athena++ magnetohydrodynamic
code. The module can accommodate an arbitrary number of dust species
interacting with the gas via aerodynamic drag (characterized by the
stopping time), with a number of numerical solvers. In particular, we
describe two second-order accurate, two-stage, fully implicit solvers
that are stable in stiff regimes, including short stopping times and
high dust mass loading, and they are paired with the second-order
explicit van Leer and Runge-Kutta gas dynamics solvers in Athena++,
respectively. Moreover, we formulate a consistent treatment of dust
concentration diffusion with dust back-reaction, which incorporates
momentum diffusion and ensures Galilean invariance. The new formulation
and stiff drag solvers are implemented to be compatible with most of the
existing features of Athena++, including different coordinate systems,
mesh refinement, and shearing box and orbital advection. We present a
large suite of test problems, including the streaming instability in
linear and nonlinear regimes, as well as local and global settings,
which demonstrate that the code achieves the desired performance. This
module will be particularly useful for studies of dust dynamics and
planet formation in protoplanetary disks.
Title: The microstructure and Ruppeiner geometry of charged anti-de
Sitter black holes in Gauss-Bonnet gravity: from the critical point
to the triple point
Authors: Wei, Shao-Wen; Liu, Yu-Xiao
Bibcode: 2022CoTPh..74i5402W
Altcode: 2021arXiv210714523W
Ruppeiner geometry has been successfully applied in the study of the
black hole microstructure by combining with the small-large black
hole phase transition, and the potential interactions among the
molecular-like constituent degrees of freedom are uncovered. In this
paper, we will extend the study to the triple point, where three black
hole phases coexist acting as a typical feature of black hole systems
quite different from the small-large black hole phase transition. For
the six-dimensional charged Gauss-Bonnet anti-de Sitter black hole,
we thoroughly investigate the swallow tail behaviors of the Gibbs free
energy and the equal area laws. After obtaining the black hole triple
point in a complete parameter space, we exhibit its phase structures
both in the pressure-temperature and temperature-horizon radius
diagrams. Quite different from the liquid-vapor phase transition,
a double peak behavior is present in the temperature-horizon radius
phase diagram. Then we construct the Ruppeiner geometry and calculate
the corresponding normalized curvature scalar. Near the triple point,
we observe multiple negatively divergent behaviors. Positive curvature
scalar is observed for the small black hole with high temperature,
which indicates that the repulsive interaction dominates among
the microstructure. Furthermore, we consider the variation of the
curvature scalar along the coexisting intermediate and large black
hole curves. Combining with the observation for different fluids, the
result suggests that this black hole system behaves more like the argon
or methane. Our study provides a first and preliminary step towards
understanding black hole microstructure near the triple point, as well
as uncovering the particular properties of the Gauss-Bonnet gravity.
Title: When null energy condition meets ADM mass
Authors: Yang, Run-Qiu; Li, Li; Cai, Rong-Gen
Bibcode: 2022CoTPh..74i5403Y
Altcode: 2022arXiv220508246Y
We give a conjecture on the lower bound of the ADM mass M by using the
null energy condition. The conjecture includes a Penrose-like inequality
$3M\geqslant \kappa { \mathcal A }/(4\pi )+\sqrt{{ \mathcal A }/4\pi
}$ and the Penrose inequality $2M\geqslant \sqrt{{ \mathcal A }/4\pi
}$ with ${ \mathcal A }$ the event horizon area and κ the surface
gravity. Both the conjecture in the static spherically symmetric case
and the Penrose inequality for a dynamical spacetime with spherical
symmetry are proved by imposing the null energy condition. We then
generalize the conjecture to a general dynamical spacetime. Our results
raise a new challenge for the famous unsettled question in general
relativity: in what general case can the null energy condition replace
other energy conditions to ensure the Penrose inequality?
Title: Global Modeling of Nebulae with Particle Growth, Drift, and
Evaporation Fronts. II. The Influence of Porosity on Solids Evolution
Authors: Estrada, Paul R.; Cuzzi, Jeffrey N.; Umurhan, Orkan M.
Bibcode: 2022ApJ...936...42E
Altcode: 2022arXiv220712626E
Incremental particle growth in turbulent protoplanetary nebulae
is limited by a combination of barriers that can slow or stall
growth. Moreover, particles that grow massive enough to decouple
from the gas are subject to inward radial drift, which could lead
to the depletion of most disk solids before planetesimals can
form. Compact particle growth is probably not realistic. Rather,
it is more likely that grains grow as fractal aggregates, which may
overcome this so-called radial drift barrier because they remain
more coupled to the gas than compact particles of equal mass. We
model fractal aggregate growth and compaction in a viscously evolving
solar-like nebula for a range of turbulent intensities α t
= 10-5-10-2. We do find that radial drift is
less influential for porous aggregates over much of their growth
phase; however, outside the water snowline fractal aggregates can
grow to much larger masses with larger Stokes numbers more quickly
than compact particles, leading to rapid inward radial drift. As
a result, disk solids outside the snowline out to ~10-20 au are
depleted earlier than in compact growth models, but outside ~20 au
material is retained much longer because aggregate Stokes numbers there
remain lower initially. Nevertheless, we conclude even fractal models
will lose most disk solids without the intervention of some leapfrog
planetesimal forming mechanism such as the streaming instability (SI),
though conditions for the SI are generally never satisfied, except for
a brief period at the snowline for α t = 10-5.
Title: Characterizing the 3D Kinematics of Young Stars in the
Radcliffe Wave
Authors: Tu, Alan J.; Zucker, Catherine; Speagle, Joshua S.; Beane,
Angus; Goodman, Alyssa; Alves, João; Faherty, Jacqueline; Burkert,
Andreas
Bibcode: 2022ApJ...936...57T
Altcode: 2022arXiv220806469T
We present an analysis of the kinematics of the Radcliffe Wave,
a 2.7 kpc long sinusoidal band of molecular clouds in the solar
neighborhood recently detected via 3D dust mapping. With Gaia DR2
astrometry and spectroscopy, we analyze the 3D space velocities of
~1500 young stars along the Radcliffe Wave in action-angle space,
using the motion of the wave's newly born stars as a proxy for its gas
motion. We find that the vertical angle of young stars-corresponding
to their orbital phase perpendicular to the Galactic plane-varies
significantly as a function of position along the structure, in a
pattern potentially consistent with a wavelike oscillation. This kind
of oscillation is not seen in a control sample of older stars from
Gaia occupying the same volume, disfavoring formation channels caused
by long-lived physical processes. We use a "wavy midplane" model to
try to account for the trend in vertical angles seen in young stars,
and find that while the best-fit parameters for the wave's spatial
period and amplitude are qualitatively consistent with the existing
morphology defined by 3D dust, there is no evidence for additional
velocity structure. These results support more recent and/or transitory
processes in the formation of the Radcliffe Wave, which would primarily
affect the motion of the wave's gaseous material. Comparisons of our
results with new and upcoming simulations, in conjunction with new
stellar radial velocity measurements in Gaia DR3, should allow us to
further discriminate between various competing hypotheses.
Title: ALMA Detection of Parsec-scale Blobs at the Head of a
Kiloparsec-scale Jet in the Nearby Seyfert Galaxy NGC 1068
Authors: Michiyama, Tomonari; Inoue, Yoshiyuki; Doi, Akihiro;
Khangulyan, Dmitry
Bibcode: 2022ApJ...936L...1M
Altcode: 2022arXiv220808533M
We present Atacama Large Millimeter/submillimeter Array observations at
≍100 GHz with 0.″05 (3 pc) resolution of the kiloparsec-scale jet
seen in the nearby Seyfert galaxy NGC 1068, and we report the presence
of parsec-scale blobs at the head of the jet. The combination of the
detected radio flux (≍0.8 mJy), spectral index (≍0.5), and blob size
(≍10 pc) suggests a strong magnetic field of B ≍ 240 μG. Such a
strong magnetic field most likely implies magnetic field amplification
by streaming cosmic rays. The estimated cosmic-ray power of the jet may
exceed the limit set by the star formation activity in this galaxy. This
result suggests that even modest-power jets can increase the galactic
cosmic-ray content while propagating through the galactic bulge.
Title: Constraining the X-ray Features of the Double Radio Relic
Cluster ZWCL1856+6616 with High-Resolution Chandra Observation
Authors: Finner, Kyle
Bibcode: 2022cxo..prop.6395F
Altcode:
The supersonic collision of two galaxy subclusters induces shocks
into the intracluster medium. Radio relics are synchrotron emission
from charged particles that are accelerated in the shocks. The
shocks in galaxy clusters are weak ($M<3$) and have low particle
acceleration efficiency, which is insufficient to produce the observed
radio relics. To understand the shock - radio relic connection, a
clear understanding of the cluster merger scenario is required. ZwCl
1856.8+6616 is a low-mass merging cluster that is rich with features
such as double radio relics, slingshot tails, and a possible X-ray
cavity. We propose an additional 223 ks Chandra observation to detect
the X-ray shocks, confirm and investigate the slingshot tails, and
probe the X-ray cavity.
Title: Swift XRT observations of the high redshift (z=2.1) flat
spectrum radio quasar 4C+01.02
Authors: Agarwal, Sushmita; Shukla, Amit
Bibcode: 2022ATel15588....1A
Altcode:
The high redshift (z~2.1) flat spectrum radio quasar
(FSRQ) 4C+01.02 (ICRS coordinate. (ep=J2000):
RA 01 08 38.77, Dec +01 35 00.3) was observed by
Fermi-LAT in gamma-ray ( > 100 MeV) in high activity state
(https://fermi.gsfc.nasa.gov/FTP/glast/data/lat/catalogs/asp/current/lightcurves/4C+01.02
86400 1yr.png).
Title: Map-based cosmology inference with lognormal cosmic shear maps
Authors: Boruah, Supranta S.; Rozo, Eduardo; Fiedorowicz, Pier
Bibcode: 2022MNRAS.tmp.2305B
Altcode:
Most cosmic shear analyses to date have relied on summary statistics
(e.g. ξ+ and ξ-). These types of analyses are
necessarily sub-optimal, as the use of summary statistics is lossy. In
this paper, we forward-model the convergence field of the Universe as
a lognormal random field conditioned on the observed shear data. This
new map-based inference framework enables us to recover the joint
posterior of the cosmological parameters and the convergence field of
the Universe. Our analysis properly accounts for the covariance in the
mass maps across tomographic bins, which significantly improves the
fidelity of the maps relative to single-bin reconstructions. We verify
that applying our inference pipeline to Gaussian random fields recovers
posteriors that are in excellent agreement with their analytical
counterparts. At the resolution of our maps - and to the extent that
the convergence field can be described by the lognormal model - our map
posteriors allow us to reconstruct all summary statistics (including
non-Gaussian statistics). We forecast that a map-based inference
analysis of LSST-Y10 data can improve cosmological constraints in
the σ8-Ωm plane by $\approx 30\%$ relative
to the currently standard cosmic shear analysis. This improvement
happens almost entirely along the $S_8=\sigma _8\Omega _{\rm m}^{1/2}$
directions, meaning map-based inference fails to significantly improve
constraints on S8.
Title: ZTF Transient Discovery Report for 2022-09-05
Authors: Fremling, C.
Bibcode: 2022TNSTR2587....1F
Altcode:
No abstract at ADS
Title: Radio meteors June 2022
Authors: Verbelen, F.
Bibcode: 2022eMetN...7..336V
Altcode:
An overview of the radio observations during June 2022 is given.
Title: Spectroscopic study of five SB1 stars with CP components
Authors: Catanzaro, G.; Colombo, C.; Ferrara, C.; Giarrusso, M.
Bibcode: 2022MNRAS.515.4350C
Altcode:
In this paper, we present the results of a spectroscopic campaign
devoted to ascertaining the actual nature of a sample of five objects
reported as chemically peculiar stars in the Catalogue of Ap, HgMn and
Am stars (2009, A&A, 498, 961). Spectroscopic observations were
obtained with Catania Astrophysical Observatory Spectropolarimeter. For
each of the objects, we derive the effective temperature, gravity,
rotational and radial velocities, and chemical abundances using
the spectral synthesis method. All the targets were found to be
SB1 systems. Our abundance analysis led us to classify HD 40788 and
HD 187959 as marginal Am stars and HD 202431 as an Am star, and to
confirm HD 134793 as an SrEuCr Ap star and, finally, HD 189652 as a
normal star. Finally, we confirm that Am stars can possibly be used
as an accurate tool to date stellar populations in galaxies.
Title: Multiwavelength temporal and spectral study of TeV blazar
1ES 1727+502 during 2014-2021
Authors: Prince, Raj; Khatoon, Rukaiya; Majumdar, Pratik; Czerny,
Bożena; Gupta, Nayantara
Bibcode: 2022MNRAS.515.2633P
Altcode: 2022MNRAS.tmp.1817P; 2022arXiv220612506P
One of the most important questions in blazar physics is the origin of
broad-band emission and fast-flux variation. In this work, we studied
the broad-band temporal and spectral properties of a TeV blazar 1ES
1727+502 and explore the one-zone synchrotron self-Compton (SSC) model
to fit the broad-band spectral energy distribution (SED). We collected
the long-term (2014-2021) multiband data that include both the low-
and high-flux states of the source. The entire light curve is divided
into three segments of different flux states and the best-fitting
parameters obtained by broad-band SED modelling corresponding to three
flux states were then compared. The TeV blazar 1ES 1727+502 has been
observed to show the brightest flaring episode in the X-ray followed
by the optical-UV and γ-rays. The fractional variability estimated
during various segments behaves differently in multiple wavebands,
suggesting a complex nature of emission in this source. This source
has shown a range of variability time from days scale to month scale
during this long period of observations between 2014 and 2021. A
'harder-when-brighter' trend is not prominent in the X-ray but seen
in the optical-UV and an opposite trend is observed in the γ-ray. The
complex nature of correlation among various bands is observed. The SED
modelling suggests that the one-zone SSC emission model can reproduce
the broad-band spectrum in the energy range from optical-UV to very
high energy γ-ray.
Title: Lyman alpha and Lyman continuum emission of Mg II-selected
star-forming galaxies
Authors: Izotov, Y. I.; Chisholm, J.; Worseck, G.; Guseva, N. G.;
Schaerer, D.; Prochaska, J. X.
Bibcode: 2022MNRAS.515.2864I
Altcode: 2022arXiv220704483I; 2022MNRAS.tmp.1882I
We present observations with the Cosmic Origins Spectrograph onboard
the Hubble Space Telescope of seven compact low-mass star-forming
galaxies at redshifts, z, in the range 0.3161-0.4276, with various
O3Mg2 = [O III] λ5007/Mg II λ2796+2803 and
Mg2 = Mg II λ2796/Mg II λ2803 emission-line ratios. We aim
to study the dependence of leaking Lyman continuum (LyC) emission on
the characteristics of Mg II emission together with the dependencies
on other indirect indicators of escaping ionizing radiation. LyC
emission with escape fractions fesc(LyC) = 3.1-4.6 per
cent is detected in four galaxies, whereas only 1σ upper limits of
fesc(LyC) in the remaining three galaxies were derived. A
strong narrow Lyα emission line with two peaks separated by $V_{\rm
sep}\, \sim$ 298-592 km s-1 was observed in four galaxies
with detected LyC emission and very weak Lyα emission is observed
in galaxies with LyC non-detections. Our new data confirm the tight
anticorrelation between fesc(LyC) and Vsep
found for previous low-redshift galaxy samples. Vsep
remains the best indirect indicator of LyC leakage among all
considered indicators. It is found that escaping LyC emission is
detected predominantly in galaxies with Mg$_2\, \gtrsim$ 1.3. A
tendency of an increase of fesc(LyC) with increasing of
both the O3Mg2 and Mg2 is possibly
present. However, there is substantial scatter in these relations not
allowing their use for reliable prediction of fesc(LyC).
Title: Virial masses of late-type galaxies from the SDSS DR16
Authors: Nigoche-Netro, A.; de la Fuente, E.; Diaz, R. J.; Agüero,
M. P.; Kemp, S. N.; Marquez-Lugo, R. A.; Lagos, P.; Ruelas-Mayorga,
A.; López-Contreras, N. L.
Bibcode: 2022MNRAS.515.2351N
Altcode: 2022MNRAS.tmp.1808N; 2022arXiv220704322N
Motivated by the challenges of calculating the dynamical masses of
late-type galaxies (LTGs) and the enormous amount of data from the
Sloan Digital Sky Survey (SDSS), we calculate virial masses of a sample
of approximately 126 000 LTGs from the sixteenth data release of the
SDSS. The virial mass estimations were made considering Newtonian
mechanics, virial equilibrium and velocity dispersion from stars
and gas. The procedure gave as a result seven mass estimations for
each galaxy. The calculated masses were calibrated using a sample of
spiral galaxies with velocity rotation curves. Considering the results
from the calibration, we find that the correlation between virial and
dynamical (rotation curve) masses is stronger for high inclination
values. Therefore, the calibration relies more on the available data
for higher inclination angle galaxies. We also show that if we have a
heterogeneous sample of galaxies one must take into consideration the
size and colour of these galaxies by using the following variables:
Sersic index n, concentration index, and colour of the stars. For
relatively smaller and bluer LTGs, the gas velocity dispersion provides
a more consistent mass calculation, while for LTGs that are relatively
larger and redder the stellar velocity dispersion provides a better
correlated mass calculation.
Title: Over-expansion of coronal mass ejections modelled using 3D
MHD EUHFORIA simulations
Authors: Verbeke, Christine; Schmieder, Brigitte; Démoulin, Pascal;
Dasso, Sergio; Grison, Benjamin; Samara, Evangelia; Scolini, Camilla;
Poedts, Stefaan
Bibcode: 2022AdSpR..70.1663V
Altcode: 2022arXiv220703168V
Coronal mass ejections (CMEs) are large scale eruptions observed close
to the Sun. They are travelling through the heliosphere and possibly
interacting with the Earth environment creating interruptions or even
damaging new technology instruments. Most of the time their physical
conditions (velocity, density, pressure) are only measured in situ
at one point in space, with no possibility to have information on
the variation of these parameters during their journey from Sun to
Earth. Our aim is to understand the evolution of internal physical
parameters of a set of three particular fast halo CMEs. These
CMEs were launched between 15 and 18 July 2002. Surprisingly, the
related interplanetary CMEs (ICMEs), observed near Earth, have a low,
and in one case even very low, plasma density. We use the EUropean
Heliosphere FORecasting Information Asset (EUHFORIA) model to simulate
the propagation of the CMEs in the background solar wind by placing
virtual spacecraft along the Sun--Earth line. We set up the initial
conditions at 0.1 au, first with a cone model and then with a linear
force free spheromak model. A relatively good agreement between
simulation results and observations concerning the speed, density and
arrival times of the ICMEs is obtained by adapting the initial CME
parameters. In particular, this is achieved by increasing the initial
magnetic pressure so that a fast expansion is induced in the inner
heliosphere. This implied the develop First, we show that a magnetic
configuration with an out of force balance close to the Sun mitigates
the EUHFORIA assumptions related to an initial uniform velocity. Second,
the over-expansion of the ejected magnetic configuration in the inner
heliosphere is one plausible origin for the low density observed
in some ICMEs at 1 au. The in situ observed very low density has a
possible coronal origin of fast expansion for two of the three ICMEs.
Title: A void in the Hubble tension? The end of the line for the
Hubble bubble
Authors: Camarena, David; Marra, Valerio; Sakr, Ziad; Clarkson, Chris
Bibcode: 2022CQGra..39r4001C
Altcode: 2022arXiv220505422C
The Universe may feature large-scale inhomogeneities beyond the
standard paradigm, implying that statistical homogeneity and isotropy
may be reached only on much larger scales than the usually assumed
~100 Mpc. This means that we are not necessarily typical observers and
that the Copernican principle could be recovered only on super-Hubble
scales. Here, we do not assume the validity of the Copernican principle
and let cosmic microwave background, baryon acoustic oscillations,
type Ia supernovae, local H 0, cosmic chronometers,
Compton y-distortion and kinetic Sunyaev-Zeldovich observations
constrain the geometrical degrees of freedom of the local structure,
which we parametrize via the ΛLTB model-basically a non-linear radial
perturbation of a FLRW metric. In order to quantify if a non-Copernican
structure could explain away the Hubble tension, we pay careful
attention to computing the Hubble constant in an inhomogeneous Universe,
and we adopt model selection via both the Bayes factor and the Akaike
information criterion. Our results show that, while the ΛLTB model can
successfully explain away the H 0 tension, it is favored with
respect to the ΛCDM model only if one solely considers supernovae in
the redshift range that is used to fit the Hubble constant, that is,
0.023 < z < 0.15. If one considers all the supernova sample,
then the H 0 tension is not solved and the support for the
ΛLTB model vanishes. Combined with other data sets, this solution to
the Hubble tension barely helps. Finally, we have reconstructed our
local spacetime. We have found that data are best fit by a shallow void
with δ L ≍ -0.04 and ${r}_{\mathrm{L}}^{\text{out}}\approx
300$ Mpc, which, interestingly, lies on the border of the 95% credible
region relative to the standard model expectation.
Title: The Isotopic Abundances of Galactic Cosmic Rays with Atomic
Number 29 ≤ Z ≤ 38
Authors: Binns, W. R.; Wiedenbeck, M. E.; Rosenvinge, T. T. von;
Israel, M. H.; Christian, E. R.; Cummings, A. C.; Nolfo, G. A. de;
Leske, R. A.; Mewaldt, R. A.; Stone, E. C.
Bibcode: 2022ApJ...936...13B
Altcode:
The Cosmic Ray Isotope Spectrometer (CRIS) on the Advanced Composition
Explorer spacecraft has been operating successfully in a halo orbit
about the L1 Lagrange point since late 1997. We report here the
isotopic composition of the Galactic cosmic ray (GCR) elements with
29 ≤ Z ≤ 38 derived from more than 20 years of CRIS data. Using a
model of cosmic-ray transport in the Galaxy and the solar system (SS),
we have derived from these observations the isotopic composition of
the accelerated material at the GCR source (GCRS). Comparison of the
isotopic fractions of these elements in the GCRS with corresponding
fractions in the solar system gives no indication of GCRS enrichment in
r-process isotopes. Since a large fraction of core-collapse supernovae
(CCSNe) occur in OB associations, the fact that GCRs do not contain
enhanced abundances of r-process nuclides indicates that CCSNe are
not the principal source of lighter (Z ≤ 38) r-process nuclides in
the solar system. This conclusion supports recent work that points to
binary neutron-star mergers, rather than supernovae, as the principal
source of galactic r-process isotopes.
Title: Synthetic Polarization Maps of an Outflow Zone from
Magnetohydrodynamic Simulations
Authors: Bino, Gianfranco; Basu, Shantanu; Machida, Masahiro N.;
Tritsis, Aris; Sharkawi, Mahmoud; Kadam, Kundan; Das, Indrani
Bibcode: 2022ApJ...936...29B
Altcode: 2022arXiv220701743B
The canonical theory of star formation in a magnetized environment
predicts the formation of hourglass-shaped magnetic fields during the
prestellar collapse phase. In protostellar cores, recent observations
reveal complex and strongly distorted magnetic fields in the inner
regions that are sculpted by rotation and outflows. We conduct
resistive, nonideal magnetohydrodynamic simulations of a protostellar
core and employ the radiative transfer code POLARIS to produce synthetic
polarization segment maps. A comparison of our mock-polarization maps
based on the toroidal-dominated magnetic field in the outflow zone with
the observed polarization vectors of SiO lines in Orion Source I shows a
reasonable agreement when the magnetic axis is tilted at an angle θ =
15° with respect to the plane of the sky and if the SiO lines have a
net polarization parallel to the local magnetic field. Although the
observed polarization is from SiO lines and our synthetic maps are
due to polarized dust emission, a comparison is useful and allows us
to resolve the ambiguity of whether the line polarization is parallel
or perpendicular to the local magnetic field direction.
Title: Earliest evidence of nebular shock waves recorded in a
calcium-aluminum-rich Inclusion
Authors: Mane, Prajkta; Wallace, Shawn; Bose, Maitrayee; Wallace,
Paul; Wadhwa, Meenakshi; Weber, Juliane; Zega, Thomas J.
Bibcode: 2022GeCoA.332..369M
Altcode:
Calcium-aluminum-rich inclusions (CAIs) and chondrules are among the
most predominant chondritic components contained within primitive
meteorites. As CAIs are the first solids to form in the solar
nebula, they contain a record of its earliest chemical and physical
processes. Here we combine electron backscatter diffraction (EBSD) and
26Al-26Mg chronology techniques to determine
the crystallographic properties and ages of CAI components that
provide temporal as well as spatial constraints on their origins and
subsequent processing in the solar protoplanetary disk. We find evidence
of shock deformation within a CAI, suggesting that it was deformed as
a free-floating object soon after the CAI formation at the beginning
of the Solar System. Our results suggest that even though CAIs and
chondrules formed in distinct environments and on different timescales,
they were likely affected by similar shock processes that operated over
large temporal (0 to ∼4 Ma) and spatial (0.2 to at least 2 to 3 au)
extents. Our results imply that nebular shock events were active on a
wider scale in the solar protoplanetary disk than previously recognized.
Title: A Reliable Calibration of H II Galaxies Hubble Diagram with
Cosmic Chronometers and Artificial Neural Network
Authors: Zhang, Jian-Chen; Jiao, Kang; Zhang, Tingting; Zhang,
Tong-Jie; Yu, Bo
Bibcode: 2022ApJ...936...21Z
Altcode: 2022arXiv220803960Z
The L-σ relation of H II galaxies (HIIGx) calibrated by a distance
indicator is a reliable standard candle for measuring the Hubble
constant H 0. The most straightforward calibration
technique anchors them with the first tier of distance ladders
from the same galaxies. Recently another promising method that
uses the cosmological model-independent cosmic chronometers as
a calibrator has been proposed. We promote this technique by
removing the assumptions about the cosmic flatness and using a
nonparametric artificial neural network for the data reconstruction
process. We observe a correlation between the cosmic curvature density
parameter and the slope of the L-σ relation, thereby improving the
reliability of the calibration. Using the calibrated HIIGx Hubble
diagram, we obtain a Type Ia supernovae Hubble diagram free of the
conventional assumption about H 0. Finally we get a value of
${H}_{0}={65.9}_{-2.9}^{+3.0}\,\mathrm{km}\,{{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$
, which is compatible with the latest Planck 18 measurement.
Title: ALeRCE/ZTF Transient Discovery Report for 2022-09-02
Authors: Munoz-Arancibia, A.; Bauer, F. E.; Forster, F.; Pignata,
G.; Mourao, A.; Hernandez-Garcia, L.; Galbany, L.; Silva-Farfan,
J.; Hoshino, R.; Camacho, E.; Arredondo, J.; Cabrera-Vives, G.;
Carrasco-Davis, R.; Estevez, P. A.; Huijse, P.; Reyes, A. M. E.;
Reyes, I.; Sanchez-Saez, P.; Rodriguez-Mancini, D.; Catelan, M.;
Eyheramendy, S.; Graham, M. J.
Bibcode: 2022TNSTR2550....1M
Altcode:
No abstract at ADS
Title: ALeRCE/ZTF Transient Discovery Report for 2022-09-06
Authors: Munoz-Arancibia, A.; Bauer, F. E.; Pignata, G.; Forster,
F.; Mourao, A.; Hernandez-Garcia, L.; Galbany, L.; Silva-Farfan,
J.; Hoshino, R.; Camacho, E.; Arredondo, J.; Cabrera-Vives, G.;
Carrasco-Davis, R.; Estevez, P. A.; Huijse, P.; Reyes, A. M. E.;
Reyes, I.; Sanchez-Saez, P.; Rodriguez-Mancini, D.; Catelan, M.;
Eyheramendy, S.; Graham, M. J.
Bibcode: 2022TNSTR2591....1M
Altcode:
No abstract at ADS
Title: Transient Discovery Report for 2022-09-07
Authors: Nishimura, K.
Bibcode: 2022TNSTR2605....1N
Altcode:
No abstract at ADS
Title: The Von Zeipel-Lidov-Kozai Effect inside Mean Motion Resonances
with Applications to Trans-Neptunian Objects
Authors: Lei, Hanlun; Li, Jian; Huang, Xiumin; Li, Muzi
Bibcode: 2022AJ....164...74L
Altcode: 2022arXiv220712954L
Secular dynamics inside mean motion resonances (MMRs) plays an essential
role in governing the dynamical structure of the trans-Neptunian
region and sculpting the orbital distribution of trans-Neptunian
objects (TNOs). In this study, semianalytical developments are made
to explore the von Zeipel-Lidov-Kozai resonance inside MMRs. To
this end, a semi-secular model is formulated from averaging theory
and then a single-degree-of-freedom integrable model is achieved
based on the adiabatic invariance approximation. In particular,
we introduce a modified adiabatic invariant, which is continuous
around the separatrices of MMRs. During long-term evolution, both the
resonant Hamiltonian and the adiabatic invariant remain unchanged,
thus phase portraits can be produced by plotting level curves of the
adiabatic invariant with a given Hamiltonian. The phase portraits
provide global pictures to predict long-term behaviors of the
eccentricity, inclination, and argument of pericenter. Applications
to some representative TNOs inside MMRs (2018 VO137, 2005
SD278, 2015 PD312, Pluto, 2004 HA79,
1996 TR66, and 2014 SR373) show good agreements
between the numerically propagated trajectories under the full N-body
model and the level curves arising in phase portraits. Interestingly,
2018 VO137 and 2005 SD278 exhibit switching
behaviors during their long-term evolution and currently they are
inside 2:5 MMR with Neptune.
Title: Generalized proofs of the first law of entanglement entropy
Authors: Taylor, Marika; Too, Linus
Bibcode: 2022AVSQS...4c3801T
Altcode: 2021arXiv211200972T
In this paper, we develop generalized proofs of the holographic first
law of entanglement entropy using holographic renormalization. These
proofs establish the holographic first law for non-normalizable
variations of the bulk metric; hence, relaxing the boundary conditions
imposed on variations in earlier works. Boundary and counterterm
contributions to conserved charges computed via covariant phase space
analysis have been explored previously. Here, we discuss in detail how
counterterm contributions are treated in the covariant phase approach
to proving the first law. Our methodology would be applicable to
generalizing other holographic information analyses to wider classes
of gravitational backgrounds.
Title: Measuring Elemental Abundances of JWST Target Stars for
Exoplanet Characterization. I. FGK Stars
Authors: Kolecki, Jared R.; Wang, Ji
Bibcode: 2022AJ....164...87K
Altcode: 2021arXiv211202031K
With the launch of the JWST, we will obtain more precise data for
exoplanets than ever before. However, these data can only inform
and revolutionize our understanding of exoplanets when placed in the
larger context of planet-star formation. Therefore, gaining a deeper
understanding of their host stars is equally important and synergistic
with the upcoming JWST data. We present detailed chemical abundance
profiles of 17 FGK stars that will be observed in exoplanet-focused
Cycle 1 JWST observer programs. The elements analyzed (C, N, O, Na, Mg,
Si, S, K, and Fe) were specifically chosen as being informative to the
composition and formation of planets. Using archival high-resolution
spectra from a variety of sources, we perform an LTE equivalent width
analysis to derive these abundances. We look to literature sources to
correct the abundances for non-LTE effects, especially for O, S, and
K, where the corrections are large (often >0.2 dex). With these
abundances and the ratios thereof, we will begin to paint clearer
pictures of the planetary systems analyzed by this work. With our
analysis, we can gain insight into the composition and extent of
migration of Hot Jupiters, as well as the possibility of carbon-rich
terrestrial worlds.
Title: Extra-tidal star candidates in globular clusters of the
Sagittarius dwarf spheroidal galaxy
Authors: Kundu, Richa; Navarrete, Camila; Sbordone, Luca;
Carballo-Bello, Julio A.; Fernández-Trincado, José G.; Minniti,
Dante; Singh, Harinder P.
Bibcode: 2022A&A...665A...8K
Altcode: 2022arXiv220605287K
Context. Globular clusters (GCs) associated with the Sagittarius dwarf
spheroidal galaxy (Sgr dSph) have evolved under the gravitational
potential of both Sgr dSph and the Milky Way. The effects of
these potentials are most pronounced in the extra-tidal regions
as compared to the central regions of the GCs.
Aims: We
aim to study the extra-tidal regions of the GCs that are possibly
associated with Sgr dSph, namely Arp 2, Terzan 8, NGC 5634, NGC
6284, Terzan 7, NGC 2419, NGC 4147, M 54 and Pal 12, using data
from the Gaia early data release 3.
Methods: We selected the
extra-tidal candidates based on their angular distances from the
cluster centre in the RA-Dec plane, proper motions of the clusters
and the individual extra-tidal star candidates, and their positions
on the colour-magnitude diagrams of the clusters.
Results:
We found extra-tidal candidates for the nine studied GCs. For eight
of them, the surface density of candidate extra-tidal stars in the
vicinity of the clusters is in significant excess with respect to
more distant surrounding fields. No extended extra-tidal features
beyond 5 tidal radii were detected for any of the clusters.
Conclusions: We publish a list of the most probable extra-tidal
candidates that we determined using Gaia astrometric and photometric
data. Our analysis shows that the clusters that are associated with
Sgr dSph are more likely affected by the gravitational potential of
the Sgr, as the distribution of extra-tidal stars is elongated in the
same direction as the local stream. NGC 4147 is the only exception. We
found some high-probability candidate extra-tidal stars in several of
the analysed clusters. We failed to detect any coherent large-scale
tidal tail around them. Tables containing list of extra-tidal
star candidates are only available at the CDS via anonymous ftp to
cdsarc.u-strasbg.fr
(ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/665/A8
Title: Self-adjoint extensions for a p4-corrected
Hamiltonian of a particle on a finite interval
Authors: Dilem, B. B.; Fabris, J. C.; Nogueira, J. A.
Bibcode: 2022AnPhy.44468994D
Altcode: 2022arXiv220400687D
In the present paper we deal with the issue of finding the self-adjoint
extensions of a p4-corrected Hamiltonian. The importance
of this subject lies on the application of the concepts of quantum
mechanics to the minimal-length scale scenario which describes an
effective theory of quantum gravity. We work in a finite one dimensional
interval and we give the explicit U(4) parametrization that leads to
the self-adjoint extensions. Once the parametrization is known, we
can choose appropriate U(4) matrices to model physical problems. As
examples, we discuss the infinite square-well, periodic conditions,
anti-periodic conditions and periodic conditions up to a prescribed
phase. We hope that the parametrization we found will contribute to
model other interesting physical situations in further works.
Title: Public Release of A-SLOTH: Ancient Stars and Local Observables
by Tracing Halos
Authors: Hartwig, Tilman; Magg, Mattis; Chen, Li-Hsin; Tarumi, Yuta;
Bromm, Volker; Glover, Simon C. O.; Ji, Alexander P.; Klessen, Ralf
S.; Latif, Muhammad A.; Volonteri, Marta; Yoshida, Naoki
Bibcode: 2022ApJ...936...45H
Altcode: 2022arXiv220600223H
The semianalytical model A-SLOTH (Ancient Stars and Local Observables
by Tracing Halos) is the first public code that connects the formation
of the first stars and galaxies to observables. After several
successful projects with this model, we publish the source code
(https://gitlab.com/thartwig/asloth) and describe the public version
in this paper. The model is based on dark matter merger trees that
can either be generated based on Extended Press-Schechter theory or be
imported from dark matter simulations. On top of these merger trees,
A-SLOTH applies analytical recipes for baryonic physics to model the
formation of both metal-free and metal-poor stars and the transition
between them with unprecedented precision and fidelity. A-SLOTH
samples individual stars and includes radiative, chemical, and
mechanical feedback. It is calibrated based on six observables,
such as the optical depth to Thomson scattering, the stellar mass
of the Milky Way and its satellite galaxies, the number of extremely
metal-poor stars, and the cosmic star formation rate density at high
redshift. A-SLOTH has versatile applications with moderate computational
requirements. It can be used to constrain the properties of the
first stars and high-z galaxies based on local observables, predicts
properties of the oldest and most metal-poor stars in the Milky Way,
can serve as a subgrid model for larger cosmological simulations,
and predicts next-generation observables of the early universe, such
as supernova rates or gravitational wave events.
Title: Additions to the Spectrum of Fe IX in the 110-200 Å Region
Authors: Ryabtsev, Alexander N.; Kononov, Edward Y.; Young, Peter R.
Bibcode: 2022ApJ...936...60R
Altcode: 2022arXiv220615354R
The spectrum of eight-times ionized iron, Fe IX, was studied in the
110-200 Å region. A low inductance vacuum spark and a 3 m grazing
incidence spectrograph were used for the excitation and recording of
the spectrum. Previous analyses of Fe IX have been greatly extended and
partly revised. The number of known lines in the 3p 53d-3p
54f and 3p 53d-3p 43d 2
transition arrays is extended to 25 and 81, respectively. Most of
the identifications of the Fe IX lines from the 3p 53d-3p
43d 2 transition array in the solar spectrum
have been confirmed and several new identifications are suggested.
Title: Exploring the Link between the X-Ray Power Spectra and Energy
Spectra of Active Galactic Nuclei
Authors: Yang, Haonan; Jin, Chichuan; Yuan, Weimin
Bibcode: 2022ApJ...936...36Y
Altcode: 2022arXiv220712151Y
Active galactic nuclei (AGN) are generally considered the scaled-up
counterparts of X-ray binaries (XRBs). It is known that the power
spectral density (PSD) of the X-ray emission of XRBs shows significant
evolution with spectral state. It is not clear whether AGN follow a
similar evolutionary trend, however, though their X-ray emission and the
PSD are both variable. In this work, we study a sample of nine AGN with
multiple long observations with XMM-Newton, which exhibit significant
X-ray spectral variation. We perform Bayesian PSD analysis to measure
the PSD shape and variation. We find that a large change in the X-ray
energy spectrum (mainly the change in flux state) is often accompanied
by a large change in the PSD shape. The emergence of a high-frequency
break in the PSD also depends on the spectral state. Among the four
sources with significant high-frequency PSD breaks detected, three show
the break only in the high-flux state, while the remaining one shows
it only in the low-flux state. Moreover, the X-ray rms variability in
different spectral states of an AGN is found to vary by as much as 1.0
dex. These results suggest that the different variability properties
observed are likely caused by different physical processes dominating
different spectral states. Our results also indicate that the intrinsic
PSD variation can introduce a significant fraction of the dispersion
as reported for the correlations between various X-ray variability
properties and the black hole mass.
Title: Satellite mass functions and the faint end of the galaxy
mass-halo mass relation in LCDM
Authors: Santos-Santos, Isabel M. E.; Sales, Laura V.; Fattahi,
Azadeh; Navarro, Julio F.
Bibcode: 2022MNRAS.515.3685S
Altcode: 2022MNRAS.tmp.1952S; 2021arXiv211101158S
The abundance of the faintest galaxies provides insight into the nature
of dark matter and the process of dwarf galaxy formation. In the LCDM
scenario, low-mass haloes are so numerous that the efficiency of dwarf
formation must decline sharply with decreasing halo mass in order to
accommodate the relative scarcity of observed dwarfs and satellites in
the Local Group. The nature of this decline contains important clues
to the mechanisms regulating the onset of galaxy formation in the
faintest systems. We explore here two possible models for the stellar
mass (M*)-halo mass (M200) relation at the faint
end, motivated by some of the latest LCDM cosmological hydrodynamical
simulations. One model includes a sharp mass threshold below which
no luminous galaxies form, as expected if galaxy formation proceeds
only in systems above the hydrogen-cooling limit. In the second model,
M* scales as a steep power law of M200 with no
explicit cut-off, as suggested by recent semi-analytical work. Although
both models predict satellite numbers around Milky Way-like galaxies
consistent with current observations, they predict vastly different
numbers of ultrafaint dwarfs and of satellites around isolated dwarf
galaxies. Our results illustrate how the satellite mass function around
dwarfs may be used to probe the M*-M200 relation
at the faint end and to elucidate the mechanisms that determine which
low-mass haloes 'light up' or remain dark in the LCDM scenario.
Title: Microfluidic Chromatography for Enhanced Amino Acid Detection
at Ocean Worlds
Authors: Van Volkenburg, Tessa; Benzing, Jennifer Skerritt; Craft,
Kathleen L.; Ohiri, Korine; Kilhefner, Ashley; Irons, Kristen;
Bradburne, Christopher
Bibcode: 2022AsBio..22.1116V
Altcode:
Increasing interest in the detection of biogenic signatures, such as
amino acids, on icy moons and bodies within our solar system has led
to the development of compact in situ instruments. Given the expected
dilute biosignatures and high salinities of these extreme environments,
purification of icy samples before analysis enables increased detection
sensitivity. Herein, we outline a novel compact cation exchange method
to desalinate proteinogenic amino acids in solution, independent of
the type and concentration of salts in the sample. Using a modular
microfluidic device, initial experiments explored operational limits
of binding capacity with phenylalanine and three model cations,
Na+, Mg2+, and Ca2+. Phenylalanine
recovery (94-17%) with reduced conductivity (30-200 times) was seen
at high salt-to-amino-acid ratios between 25:1 and 500:1. Later
experiments tested competition between mixtures of 17 amino acids and
other chemistries present in a terrestrial ocean sample. Recoveries
ranged from 11% to 85% depending on side chain chemistry and cation
competition, with concentration shown for select high affinity amino
acids. This work outlines a nondestructive amino acid purification
device capable of coupling to multiple downstream analytical techniques
for improved characterization of icy samples at remote ocean worlds.
Title: ANTARES/ZTF Transient Discovery Report for 2022-09-02
Authors: Aleo, P.; Lee, C.; Malanchev, K.; Matheson, T.; Narayan,
G.; Saha, A.; Scheidegger, C.; Scott, A.; Soraisam, M.; Stubens, C.;
Wolf, N.
Bibcode: 2022TNSTR2551....1A
Altcode:
No abstract at ADS
Title: Redshift in Varying Speed of Light Cosmology
Authors: Eaves, R. E.
Bibcode: 2022MNRAS.tmp.2346E
Altcode:
In standard cosmology, redshift is related to scale factor by z =
a-1 - 1. Varying speed of light cosmologies also have
applied this relationship, in which c does not explicitly appear, with
the assumption that ℏ∝c. Measured redshift is not a comparison of
an observed spectrum with the spectrum as it was emitted at a distant
location, but a comparison with a reference spectrum generated more
locally. This distinction suggests decomposition into two parts: (a)
change during the flight of a photon, and (b) difference in physics
at the time of emission and at the time of observation of a photon
associated with an electron transition between specific bound states of
an atom. Based on atomic units consistent with data and a relativistic
atomic model, redshift is given by z = β(θ)θa-1 - 1,
where θ = c/c0, with c0 the present value
of c, and β is a function of the atomic parameters describing
the transition. The modified form appears to have a modest effect
(a difference in scale factor < 2 %) for redshifts that are not
much greater than 10. However, the modification can have a major
effect for an early universe with c significantly larger than the
present. The simplified form z = θa-1 - 1, which results
from a non-relativistic model, provides an approximation for redshift
that is not transition-specific.
Title: The effect and properties of drifts in the heliosphere
Authors: Raath, J. L.; Ferreira, S. E. S.; Kopp, A.
Bibcode: 2022A&A...665A...4R
Altcode:
We investigate the properties of drifts and their effect on cosmic
ray modulation in the heliosphere using a numerical modulation model
based on the solution of a set of stochastic differential equations
that was derived from the Parker transport equation. The illustrative
capabilities of the numerical model are exploited to yield a better
understanding of the physical modulation processes involved. Various
studies have indicated that drifts need to be scaled down towards
solar maximum conditions and the present study looks at how this can
be achieved. Drifts are scaled down directly by multiplying the drift
coefficient by a factor of less than unity as well as indirectly through
the drift-diffusion relation, that is, by modifying the diffusion
coefficient so as to cause a change in the drift effects through
altered gradients in particle intensity. Contour plots of particle
exit positions and exit energies are presented for both of these
cases, and it is illustrated that drifts in the model lead to larger
energy losses. This is explained with the aid of figures indicating
the relative amount of time spent by pseudo-particles in different
regions of the heliosphere during the modulation process. These figures
also indicate that an increase in diffusion leads to a suppression or
reduction of drift effects. Finally, the figures also show that drift
effects are reduced as a function of increasing particle energy; even
though the drift coefficient increases with particle energy, the total
drift effect, taking into account the contribution from the increased
diffusion associated with larger energies, causes drift effects to be
reduced with an increase in energy.
Title: An EUV Jet Driven by a Series of Transition Region Microjets
Authors: Wei, Hengyuan; Huang, Zhenghua; Fu, Hui; Xiong, Ming; Xia,
Lidong; Zhang, Chao; Deng, Kaiwen; Li, Haiyi
Bibcode: 2022ApJ...936...51W
Altcode: 2022arXiv220800112W
Jets are one of the most common eruptive events in the solar atmosphere,
and they are believed to be important in the context of coronal
heating and solar wind acceleration. We present an observational study
on a sequence of jets with the data acquired with the Solar Dynamics
Observatory and the Interface Region Imaging Spectrograph. This sequence
is peculiar in that an extreme-ultraviolet (EUV) jet, ~29″ long
and with a dome-like base, appears to be a consequence of a series of
transition region (TR) microjets that are a few arcsecs in length. We
find that the occurrence of any TR microjets is always associated
with the change of geometry of microloops at the footpoints of the
microjets. A bundle of TR flux ropes is seen to link a TR microjet
to the dome-like structure at the base of the EUV jet. This bundle
rises as a response to the TR microjets, with the rising motion
eventually triggering the EUV jet. We propose a scenario involving a
set of magnetic reconnections, in which the series of TR microjets are
associated with the processes to remove the constraints to the TR flux
ropes and thus allows them to rise and trigger the EUV jet. Our study
demonstrates that small-scale dynamics in the lower solar atmosphere
are crucial in understanding the energy and mass connection between
the corona and the solar lower atmosphere, even though many of them
might not pump mass and energy to the corona directly.
Title: A 30 kpc Spatially Extended Clumpy and Asymmetric Galactic
Outflow at z 1.7
Authors: Shaban, Ahmed; Bordoloi, Rongmon; Chisholm, John; Sharma,
Soniya; Sharon, Keren; Rigby, Jane R.; Gladders, Michael G.; Bayliss,
Matthew B.; Barrientos, L. Felipe; Lopez, Sebastian; Tejos, Nicolas;
Ledoux, Cédric; Florian, Michael K.
Bibcode: 2022ApJ...936...77S
Altcode: 2021arXiv210913264S
We image the spatial extent of a cool galactic outflow with
fine-structure Fe II* emission and resonant Mg II emission in a
gravitationally lensed star-forming galaxy at z = 1.70347. The Fe II*
and Mg II (continuum-subtracted) emissions span out to radial distances
of ~14.33 and 26.5 kpc, respectively, with maximum spatial extents
of ~21 kpc for Fe II* emission and ~30 kpc for Mg II emission. Mg II
emission is patchy and covers a total area of ~184 kpc2,
constraining the minimum area covered by the outflowing gas to be
~13% of the total area. Mg II emission is asymmetric and shows ~21%
more extended emission along the decl. direction. We constrain the
covering fractions of the Fe II* and Mg II emission as a function of
radial distance and characterize them with a power-law model. The
Mg II 2803 emission line shows two kinematically distinct emission
components and may correspond to two distinct shells of outflowing
gas with a velocity separation of Δv ~ 400 km s-1. By
using multiple images with different magnifications of the galaxy in
the image plane, we trace the Fe II* and Mg II emissions around three
individual star-forming regions. In all cases, both the Fe II* and Mg
II emissions are more spatially extended compared to the star-forming
regions traced by the [O II] emission. These findings provide robust
constraints on the spatial extent of the outflowing gas and, combined
with outflow velocity and column density measurements, will give
stringent constraints on mass-outflow rates of the galaxy.
Title: Gas Column Density Distribution of Molecular Clouds in the
Third Quadrant of the Milky Way
Authors: Ma, Yuehui; Wang, Hongchi; Zhang, Miaomiao; Wang, Chen; Zhang,
Shaobo; Liu, Yao; Li, Chong; Zheng, Yuqing; Yuan, Lixia; Yang, Ji
Bibcode: 2022ApJS..262...16M
Altcode: 2022arXiv220603963M
We have obtained column density maps for an unbiased sample of 120
molecular clouds in the third quadrant of the Milky Way midplane
(b ≤ ∣5∣°) within the Galactic longitude range from 195° to
225°, using the high-sensitivity 12CO and 13CO
(J = 1 - 0) data from the Milky Way Imaging Scroll Painting (MWISP)
project. The probability density functions of the molecular hydrogen
column density of the clouds, N-pdfs, are fitted with both a lognormal
(LN) function and a lognormal plus power-law (LN+PL) function. The
molecular clouds are classified into three categories according to
their shapes of N-pdfs, i.e., LN, LN+PL, and UN (unclear). About 72% of
the molecular clouds fall into the LN category, while 18% and 10% fall
into the LN+PL and UN categories, respectively. A PL scaling relation,
${\sigma }_{s}\propto {N}_{{{\rm{H}}}_{2}}^{0.44}$ , exists between the
width of the N-pdf, σ s , and the average column density,
${N}_{{{\rm{H}}}_{2}}$ , of the molecular clouds. However, σ s
shows no correlation with the mass of the clouds. A correlation
is found between the dispersion of normalized column density, σ
N/<N>, and the sonic Mach number, ${ \mathcal M }$
, of molecular clouds. Overall, as predicted by numerical simulations,
the N-pdfs of the molecular clouds with active star formation activity
tend to have N-pdfs with PL high-density tails.
Title: Application of historic datasets to understanding open solar
flux and the 20th-century grand solar maximum. 1. Geomagnetic,
ionospheric, and sunspot observations
Authors: Lockwood, Mike; Owens, Mathew J.; Barnard, Luke A.; Scott,
Chris J.; Frost, Anna M.; Yu, Bingkun; Chi, Yutian
Bibcode: 2022FrASS...9.0775L
Altcode:
We updated annual mean reconstructions of near-Earth interplanetary
conditions and (signed) open solar flux FS for the past 186
years. Furthermore, we added observations for solar cycle 24 to refine
regressions and improved allowance for orthogardenhose and folded
(a.k.a., switchback) heliospheric flux from studies using strahl
electrons. We also improved the allowance made for the annual mean
gardenhose angle of the interplanetary magnetic field. We used both
multiple regression with interplanetary magnetic field B and solar wind
speed VSW and linear regression with the function BVSWn and demonstrated
that the latter gives correlations that are not significantly lower
than those given by the former. We conducted a number of tests of the
geomagnetic indices used, of which by far the most important is that all
four usable pairings of indices produce almost identical results for
B, VSW, and FS. All reconstructions were given full 2σ uncertainties
using a Monte Carlo technique that generates an ensemble of 1 million
members for each pairing of indices. The long-term variations of
near-Earth interplanetary field B and open solar flux FS were found to
closely match those of the international sunspot numbers but VSW show
a significantly different variation. This result explains why of the
two peaks of 20th-century grand solar maximum, the range geomagnetic
indices give a larger second peak, whereas the diurnal variation indices
give a first peak that is larger, as it is for sunspots. We found that
the increase in solar cycle averages of FS was between 2.46 × 1014
Wb in 1906 and 4.10 × 1014 Wb in 1949, the peak of the grand maximum,
and hence, the rise in open flux was by a factor of 67%.
Title: Meteor observations May–June 2022 from Any Martin Rieux
Northern France
Authors: Miskotte, K.
Bibcode: 2022eMetN...7..351M
Altcode:
An overview of visual meteor observations made by the author from
Any Martin Rieux (Northern France) in late May and early June is
presented. Among other things, extra attention was paid to the meteor
shower tau Herculids, which was expected to show a possible outburst
during the night of May 30–31, 2022.
Title: Radio meteors July 2022.
Authors: Verbelen, F.
Bibcode: 2022eMetN...7..343V
Altcode:
An overview of the radio observations during July 2022 is given.
Title: Radio detection of SAX J1808.4-3658 with MeerKAT
Authors: Gasealahwe, Kelebogile; Eijnden, Jakob van den; Motta, Sara;
Fender, Rob; Woudt, Patrick; Miller-Jones, James; Monageng, Itumeleng
Bibcode: 2022ATel15584....1G
Altcode:
SAX J1808.4-3658 is an accreting millisecond X-ray pulsar, that was
reported to be in outburst on 19 August 2022 by NICER (ATel #15559)
and MAXI (ATel #15563).
Title: MeerLICHT Transient Discovery Report for 2022-09-08
Authors: Groot, P.
Bibcode: 2022TNSTR2613....1G
Altcode:
No abstract at ADS
Title: Exploring the Origin of Lenticular Galaxies with Chandra/acis
Authors: Serrano Borlaff, Alejandro
Bibcode: 2022cxo..prop.6420S
Altcode:
Recent studies suggest that low stellar-mass S0 galaxies are formed
via secular processes, while massive S0 are preferentially formed
through galactic mergers. This hypothesis can be contrasted based
on the diffuse X-ray emission from hot gas halos. Due to the long
timescales required to cool the hot gas phase, extended soft-band
X-ray emission will be preferentially associated with galaxies that
formed through mergers rather than those that evolved passively. The
key focus of this archive proposal is a systematic search of extended
hot gas halos on disk galaxies using ACIS observations of the Chandra
Catalog of Nearby Galaxies. We will test the differences of this
emission (or their absence) as a function of the morphological type
(S0s vs. spirals), stellar mass, and environment density.
Title: Effects of dark matter on shadows and rings of Brane-World
black holes illuminated by various accretions
Authors: Zeng, Xiao-Xiong; He, Ke-Jian; Li, Guo-Ping
Bibcode: 2022SCPMA..6590411Z
Altcode:
In this study, by taking the accretions into account, the observed
shadows and rings cast by the Brane-World black hole were numerically
investigated when the observer was located at the cosmological
horizon. The results showed that the radius rp of the photon
sphere increased with the cosmological parameter α and dark matter
parameter β, while the impact parameter bp decreased with
α and increased with β. For thin disk accretion, the total observed
intensity is mainly composed of direct emission. Simultaneously,
the lensing ring and photon ring have only small and negligible
contributions, respectively. We also found that shadows and rings
exhibit different and exciting features when the disk is located at
different positions. For static and infalling spherical accretions,
it is evident that the size of shadows is always the same for both
accretions. This implies that shadows are only related to space-time
geometry in this case. The luminosity of the shadow and photon sphere is
closely associated with the Doppler effect and the emissivity per unit
volume j(ve). In addition, the influence of dark matter and
cosmological constant on the observed intensity of shadows and rings
is carefully emphasized throughout this paper. Finally, we obtained
the burring images of shadows and rings using the nominal resolution
of the event horizon telescope. We also studied the upper limits of
the X-clod dark matter parameter β using the data of the shadow of M87.
Title: Fe5S2 identified as a host of sulfur
in Earth and planetary cores
Authors: Zurkowski, Claire C.; Lavina, Barbara; Case, Abigail; Swadba,
Kellie; Chariton, Stella; Prakapenka, Vitali; Campbell, Andrew J.
Bibcode: 2022E&PSL.59317650Z
Altcode:
Cosmochemical considerations suggest that sulfur is a candidate
light alloying element in rocky planetary cores, such that the
high pressure-temperature (P-T) Fe-S phase relations likely play
a key role in planetary core crystallization thermodynamics. The
iron-saturated Fe-S phase relations were investigated to 200 GPa and
3250 K using combined powder and single-crystal X-ray diffraction
techniques in a laser-heated diamond anvil cell. Upon heating at
120 GPa, I-4 Fe3S is observed to break down to form
iron and a novel hexagonal Fe5S2 sulfide with
the Ni5As2 structure (P63cm, Z =
6). To 200 GPa, Fe5S2 and Fe are observed to
coexist at high temperatures while Fe2S polymorphs are
identified with Fe at lower temperatures. An updated Fe-rich Fe-S phase
diagram is presented. As this hexagonal Fe5S2
expresses complex Fe-Fe coordination and atomic positional disorder,
crystallization of Fe5S2 may contribute to
intricate elastic and electrical properties in Earth and planetary
cores as they crystallize over time. Models of a fully crystallized
Fe-rich Fe-S liquid in Earth's and Venus' core establish that
Fe5S2 is likely the only sulfide to crystallize
and may deposit in the outer third of the planets' cores as they
cool. Fe5S2 could further serve as a host
for Ni and Si as has been observed in the related meteoritic phase
perryite, (Fe, Ni)8(P, Si)3, adding intricacies
to elemental partitioning during core crystallization. The stability
of Fe5S2 presented here is key to understanding
the role of sulfur in the crystallization sequences that drive the
geodynamics and dictate the structures of Earth and rocky planetary
cores.
Title: Confirmation of the First Helium Star Stripped by a Black Hole
Authors: Ludwig, Bethany
Bibcode: 2022cxo..prop.6307L
Altcode:
In a search for stars stripped of their H-rich envelopes in binaries,
we have discovered a candidate stripped star - black hole (BH)
system. The star appears to be an isolated, ~8Msun, helium star but
radial velocities reveals an orbit of 75 days, suggesting a companion
mass of >2.2 Msun. With no signs of the presence of a main sequence
star in the optical spectrum, it is likely this dark companion is a
BH. If true, this system would be the first discovered in a population
of X-ray faint BH X-ray binaries with helium-rich donors, yielding
legacy value. They are also expected to be progenitors of merging
compact objects with extreme mass ratio, such as NSBH systems or the
gravitational wave event GW190814. A 50ks deep Chandra exposure will
reveal the true nature of this dark companion.
Title: Field-free spin-orbit torque-induced perpendicularmagnetization
switching in YIG/Ta/CoTb/Pt
Authors: Meng, Dequan; He, Wenqing; Zhang, Yu; Liu, Gengshuo; You,
Long; Wan, Caihua; Liang, Shiheng
Bibcode: 2022SSPMA..52C7011M
Altcode:
No abstract at ADS
Title: Global Modeling of Nebulae with Particle Growth, Drift, and
Evaporation Fronts. III. Redistribution of Refractories and Volatiles
Authors: Estrada, Paul R.; Cuzzi, Jeffrey N.
Bibcode: 2022ApJ...936...40E
Altcode: 2022arXiv220712629E
Formation of the first planetesimals remains an unsolved problem. Growth
by sticking must initiate the process, but multiple studies have
revealed a series of barriers that can slow or stall growth, most
of them due to nebula turbulence. In a companion paper, we study
the influence of these barriers on models of fractal aggregate and
solid, compact particle growth in a viscously evolving solar-like
nebula for a range of turbulent intensities α t =
10-5-10-2. Here, we examine how the disk
composition in these same models changes with time. We find that
advection and diffusion of small grains and vapor, and radial inward
drift for larger compact particles and fractal aggregates, naturally
lead to diverse outcomes for planetesimal composition. Larger particles
can undergo substantial inward radial migration due to gas drag before
being collisionally fragmented or partially evaporating at various
temperatures. This leads to enhancement of the associated volatile in
both vapor inside, and solids outside, their respective evaporation
fronts, or snowlines. In cases of lower α t, we see narrow
belts of volatile or supervolatile material develop in the outer
nebula, which could be connected to the bands of pebbles seen by the
Atacama Large Millimeter/submillimeter Array. Volatile bands, which
migrate inwards as the disk cools, can persist over long timescales
as their gas phase continues to advect or diffuse outward across its
evaporation front. These belts could be sites where supervolatile-rich
planetesimals form, such as the rare CO-rich and water-poor comets;
giant planets formed just outside the H2O snowline may be
enhanced in water.
Title: Dark Matter Admixed Neutron Star Properties in the Light of
X-Ray Pulse Profile Observations
Authors: Miao, Zhiqiang; Zhu, Yaofeng; Li, Ang; Huang, Feng
Bibcode: 2022ApJ...936...69M
Altcode: 2022arXiv220405560M
The distribution of the dark matter (DM) in DM-admixed neutron stars
(DANSs) is supposed to result in either a dense dark core or an extended
dark halo, subject to the DM fraction of the DANS (f χ )
and the DM properties, such as the mass (m χ ) and the
strength of the self-interaction (y). In this paper, we perform an
in-depth analysis of the formation criterion for dark cores/dark halos,
and point out that the relative distribution of these two components
is essentially determined by the ratio of the central enthalpy of
the DM component to that of the baryonic matter component inside
the DANSs. For the critical case where the radii of the DM and the
baryonic matter are the same, we further derive an analytical formula
to describe the dependence of ${f}_{\chi }^{\mathrm{crit}}$ on m
χ and y for a given DANS mass. The relative distribution of the
two components in DANSs can lead to different observational effects. We
here focus on the modification of the pulsar pulse profile, due to the
extra light-bending effect in the case of a dark halo existence, and
conduct the first investigation into the dark halo effects on the pulse
profile. We find that the peak flux deviation is strongly dependent on
the ratio of the halo mass to the radius of the DM component. Last, we
perform Bayesian parameter estimation on the DM particle properties,
based on the recent X-ray observations of PSR J0030+0451 and PSR
J0740+6620 by the Neutron Star Interior Composition Explorer.
Title: Osaka Feedback Model. II. Modeling Supernova Feedback Based
on High-resolution Simulations
Authors: Oku, Yuri; Tomida, Kengo; Nagamine, Kentaro; Shimizu, Ikkoh;
Cen, Renyue
Bibcode: 2022ApJS..262....9O
Altcode: 2022arXiv220100970O
Feedback from supernovae (SNe) is an essential mechanism that
self-regulates the growth of galaxies, and a better model of SN feedback
is still needed in galaxy-formation simulations. In the first part of
this paper, using an Eulerian hydrodynamic code ATHENA++, we find the
universal scaling relations for the time evolution of momentum and
radius for a superbubble, when the momentum and time are scaled by
those at the shell-formation time. In the second part of this paper,
we develop a SN feedback model based on the ATHENA++ simulation results
utilizing Voronoi tessellation around each star particle, and implement
it into the GADGET3-OSAKA smoothed particle hydrodynamic code. Our
feedback model was demonstrated to be isotropic and conservative in
terms of energy and momentum. We examined the mass/energy/metal loading
factors and find that our stochastic thermal feedback model produced
galactic outflow that carries metals high above the galactic plane but
with weak suppression of star formation. Additional mechanical feedback
further suppressed star formation and brought the simulation results
into better agreement with the observations of the Kennicutt-Schmidt
relation, with all the results being within the uncertainties of
observed data. We argue that both thermal and mechanical feedback
are necessary for the SN feedback model of galaxy evolution when an
individual SN bubble is unresolved.
Title: Optimal sensor fusion method for active vibration isolation
systems in ground-based gravitational-wave detectors
Authors: Tsang, T. T. L.; Li, T. G. F.; Dehaeze, T.; Collette, C.
Bibcode: 2022CQGra..39r5007T
Altcode: 2021arXiv211114355T
Sensor fusion is a technique used to combine sensors with different
noise characteristics into a super sensor that has superior noise
performance. To achieve sensor fusion, complementary filters are used
in current gravitational-wave detectors to combine relative displacement
sensors and inertial sensors for active seismic isolation. Complementary
filters are a set of digital filters, which have transfer functions
that are summed to unity. Currently, complementary filters are
shaped and tuned manually rather than being optimized. They can be
sub-optimal and hard to reproduce for future detectors. In this paper,
${\mathcal{H}}_{\infty }$ optimization is proposed for synthesizing
optimal complementary filters. The complementary filter design problem
is converted into an optimization problem that seeks minimization of
an objective function equivalent to the maximum difference between
the super sensor noise and the lower bound in logarithmic scale. The
method is exemplified with three cases, which simulate the sensor fusion
between a relative displacement sensor and an inertial sensor. In all
cases, the ${\mathcal{H}}_{\infty }$ complementary filters suppress the
super sensor noise equally close to the lower bound at all frequencies
in logarithmic scale. The ${\mathcal{H}}_{\infty }$ filters also provide
better suppression of sensor noises compared to complementary filters
pre-designed using traditional methods.
Title: YSE/Pan-STARRS Transient Discovery Report for 2022-09-04
Authors: Jones, D. O.; French, K. D.; Agnello, A.; Angus, C. R.;
Ansari, Z.; Arendse, N.; Gall, C.; Grillo, C.; Bruun, S. H.; Hede,
C.; Hjorth, J.; Izzo, L.; Korhonen, H.; Raimundo, S.; Ramanah,
D. K.; Sarangi, A.; Wojtak, R.; Pfister, H.; Auchettl, K.; Chambers,
K. C.; Huber, M. E.; Magnier, E. A.; Boer, T. J. L. D.; Fairlamb,
J. R.; Lin, C. C.; Wainscoat, R. J.; Lowe, T.; Gao, H.; Bulger, J.;
Schultz, A. S. B.; Engel, A.; Gagliano, A.; Narayan, G.; Soraisam,
M.; Wang, Q.; Rest, A.; Smartt, S. J.; Smith, K. W.; Alexander, K.;
Blanchard, P.; DeMarchi, L.; Hajela, A.; Jacobson-Galan, W.; Margutti,
R.; Matthews, D.; Stauffer, C.; Stroh, M.; Terreran, G.; Drout, M.;
Coulter, D. A.; Dimitriadis, G.; Foley, R. J.; Hung, T.; Kilpatrick,
C. D.; Rojas-Bravo, C.; Siebert, M. R.; Ramirez-Ruiz, E.
Bibcode: 2022TNSTR2578....1J
Altcode:
No abstract at ADS
Title: GaiaAlerts Transient Discovery Report for 2022-09-02
Authors: Hodgkin, S. T.; Breedt, E.; Delgado, A.; Harrison, D. L.;
Leeuwen, M. V.; Rixon, G.; Wevers, T.; Yoldas, A.; Ihanec, N.;
Kruszyńska, K.; Rybicki, K. A.; Wyrzykowski, Ł.; Kostrzewa-Rutkowska,
Z.; Eappachen, D.; Marton, G.
Bibcode: 2022TNSTR2553....1H
Altcode:
No abstract at ADS
Title: Equation of state of neutron-rich matter in d-dimensions
Authors: Cai, Bao-Jun; Li, Bao-An
Bibcode: 2022AnPhy.44469062C
Altcode: 2022arXiv220615314C
Nuclear systems under constraints, with high degrees of symmetries
and/or collectivities may be considered as moving effectively in
spaces with reduced spatial dimensions. We first derive analytical
expressions for the nucleon specific energy E0(ρ) , pressure
P0(ρ) , incompressibility coefficient K0(ρ) and
skewness coefficient J0(ρ) of symmetric nucleonic matter
(SNM), the quadratic symmetry energy Esym(ρ) , its slope
parameter L(ρ) and curvature coefficient Ksym(ρ) as well as
the fourth-order symmetry energy Esym,4(ρ) of neutron-rich
matter in general d spatial dimensions (abbreviated as " dD") in
terms of the isoscalar and isovector parts of the isospin-dependent
single-nucleon potential according to the generalized Hugenholtz-Van
Hove (HVH) theorem. The equation of state (EOS) of nuclear matter in
dD can be linked to that in the conventional 3-dimensional (3D) space
by the ϵ-expansion which is a perturbative approach successfully
used previously in treating second-order phase transitions and
related critical phenomena in solid state physics and more recently
in studying the EOS of cold atoms. The ϵ-expansion of nuclear EOS in
dD based on a reference dimension df = d - ϵ is shown to
be effective with - 1 ≲ ϵ ≲ 1 starting from 1 ≲df
≲ 3 in comparison with the exact expressions derived using the
HVH theorem. Moreover, the EOS of SNM (with/without considering its
potential part) is found to be reduced (enhanced) in lower (higher)
dimensions, indicating in particular that the many-nucleon system tends
to be more bounded but saturate at higher densities in spaces with
lower dimensions. The symmetry energy perturbed from its counterpart
in 3D is found to strongly depend on the momentum-dependence of the
nucleon isovector potential. Moreover, the specific structure of the
fourth-order symmetry energy in dD is also analyzed generally, and it
is found to be naturally small, confirming the parabolic approximation
for the EOS of neutron-rich matter from an even wider viewpoint. The
links between the EOSs in 3D and dD spaces from the ϵ-expansion
provide new perspectives to the EOS of neutron-rich matter. Further
studies and potential applications of these links in nuclear physics
and/or astrophysics are discussed.
Title: Prominence oscillations activated by an EUV wave
Authors: Devi, Pooja; Chandra, Ramesh; Joshi, Reetika; Chen, P. F.;
Schmieder, Brigitte; Uddin, Wahab; Moon, Yong-Jae
Bibcode: 2022AdSpR..70.1592D
Altcode: 2022arXiv220213147D
Prominence oscillations are one of interesting phenomena in the solar
atmosphere, which can be utilized to infer the embedded magnetic field
magnitude. We present here the transverse oscillations of two different
prominences located at the East solar limb on 2011 February 11 using the
multi-wavebands data of the Atmospheric Imaging Assembly (AIA) on-board
the Solar Dynamics Observatory (SDO) satellite. A prominence eruption
was observed towards the east direction with an average speed of ≈
275 km s-1. The eruption is fitted with the combination of
a linear and an exponential functions of time. An extreme ultraviolet
(EUV) wave event was associated with the prominence eruption. This EUV
wave triggered the oscillations of both prominences on the East limb. We
computed the period of each prominence using the wavelet analysis
method. The oscillation period varies from 14 to 22 min. The magnetic
field of the prominences was derived, which ranges from 14 to 20 G.
Title: Shadow thermodynamics of an AdS black hole in regular spacetime
Authors: Guo, Sen; Li, Guan-Ru; Li, Guo-Ping
Bibcode: 2022ChPhC..46i5101G
Altcode: 2022arXiv220504957G
The dependence of the black hole (BH) shadow and thermodynamics may
be structured in regular spacetime. Taking a regular Bardeen-AdS BH
as an example, the relationship between the shadow radius and event
horizon radius is derived. It is found that these two radii display
a positive correlation, implying that the BH temperature can be
rewritten as a function of shadow radius in regular spacetime. By
analyzing the phase transition curves under the shadow context,
we find that the shadow radius can replace the event horizon radius
to present the BH phase transition process, and the phase transition
grade can also be revealed by the shadow radius, indicating that the
shadow radius may serve as a probe for phase structure in regular
spacetime. Utilizing the temperature-shadow radius function, the
thermal profile of the Bardeen-AdS BH is established. Moreover, the
temperature exhibits an N-type change trend in the $ P\lt{P}_{\rm{c}} $
situation. These results suggest that the phase transition process of
a regular AdS BH can be completely presented in the thermal profile,
and the relationship between the BH shadow and thermodynamics can
also be established in regular spacetime. *Supported by the National
Natural Science Foundation of China (11903025)
Title: X-Ray Redshifts of Obscured Chandra Source Catalog Active
Galactic Nuclei
Authors: Sicilian, Dominic; Civano, Francesca; Cappelluti, Nico;
Buchner, Johannes; Peca, Alessandro
Bibcode: 2022ApJ...936...39S
Altcode: 2022arXiv220313825S
We have computed obscured active galactic nuclei (AGN) redshifts
using the XZ method, adopting a broad treatment in which we employed a
wide-ranging data set and worked primarily at the XZ counts sensitivity
threshold, culminating with a redshift catalog containing 121 sources
that lack documented redshifts. We considered 363 obscured AGN from
the Chandra Source Catalog Release 2.0, 59 of which were selected
using multiwavelength criteria while 304 were X-ray selected. One
third of the data set had crossmatched spectroscopic or photometric
redshifts. These sources, dominated by low-z and low-N H
AGN, were supplemented by 1000 simulations to form a data set for
testing the XZ method. We used a multilayer perceptron neural network
to examine and predict cases in which XZ fails to reproduce the
known redshift, yielding a classifier that can identify and discard
poor redshift estimates. This classifier demonstrated a statistically
significant ~3σ improvement over the existing XZ redshift information
gain filter. We applied the machine-learning model to sources with no
documented redshifts, resulting in the 121 source new redshift catalog,
all of which were X-ray selected. Our neural network's performance
suggests that nearly 90% of these redshift estimates are consistent with
hypothetical spectroscopic or photometric measurements, strengthening
the notion that redshifts can be reliably estimated using only X-rays,
which is valuable to current and future missions such as Athena. We
have also identified a possible Compton-thick candidate that warrants
further investigation.
Title: Seasonality in Mars atmospheric methane driven by microseepage,
barometric pumping, and adsorption
Authors: Klusman, Ronald W.; Luo, Yangcheng; Chen, Pin; Yung, Yuk L.;
Tallapragada, Sindhoora
Bibcode: 2022Icar..38315079K
Altcode:
Measurements of atmospheric methane by the Curiosity rover's SAM-TLS
instrument are providing evidence of seasonality with bimodal peaks
in concentration. Given methane's short atmospheric lifetime relative
to geological timescales, its presence implies a replenishing source,
and the observed seasonality demands the proposition of a modulation
mechanism. This paper focuses on the modulation mechanism. Our modeling
study shows that barometric pumping driven by seasonal variation of
atmospheric pressure, along with adsorption and desorption of methane
in the shallow subsurface driven by temperature change, can explain
the observed bimodal peaks in the seasonal variations of methane
concentration. In the model, an active, continuous, steady-state
deep source of methane is assumed, and carbon dioxide serves as the
carrier gas for producing seasonal variation in the upper part of
the sedimentary column for methane and other possible trace gaseous
constituents. Our work also presents a comprehensive flow chart for
modeling the microseepage of methane on Mars from first principles.
Title: VizieR Online Data Catalog: Galactic post-AGB stars in Gaia
DR3 (Oudmaijer+, 2022)
Authors: Oudmaijer, R. D.; Jones, E. R. M.; Vioque, M.
Bibcode: 2022yCat..75169061O
Altcode:
The catalogue of post-AGB stars with parallax information, their
astrometric data and derived parameters used in this article
are available in this table (i.e. the 249 sources from Vickers et
al. (2015MNRAS.447.1673V, Cat. J/MNRAS/447/1673) for which parallax
information is available). (1 data file).
Title: Spherically Symmetric Solutions of a Chiral Self-Gravitating
Model in \boldsymbol{f(R,\square R)} Gravity
Authors: Chervon, S. V.; Fomin, I. V.; Chaadaev, A. A.
Bibcode: 2022GrCo...28..296C
Altcode:
We construct a chiral self-gravitating model corresponding to modified
$f(R,\square R)$ gravity following by application of the Lagrange
multipliers method and a conformal transformation to obtain the
model in the Einstein frame. Killing symmetries of the target space
are found. Using a special case of a scaling transformation, we find
examples of exact solutions with zero and constant potentials. A linear
dependence between the fields leads to new solutions for the model.
Title: Spore Survival During Abrasive Saltation on Mars: A Reply to
the Comment by Minns et al.
Authors: Bak, Ebbe Norskov; Bregnhøj, Mikkel; Nørnberg, Per; Jensen,
Svend J. Knak; Thøgersen, Jan; Finster, Kai
Bibcode: 2022AsBio..22.1032B
Altcode:
No abstract at ADS
Title: Did you check for ravens?