Author name code: shimizu
ADS astronomy entries on 2022-09-14
author:"Shimizu, Toshifumi"
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Title: Quiet Sun Center to Limb Variation of the Linear Polarization
Observed by CLASP2 Across the Mg II h and k Lines
Authors: Rachmeler, L. A.; Bueno, J. Trujillo; McKenzie, D. E.;
Ishikawa, R.; Auchère, F.; Kobayashi, K.; Kano, R.; Okamoto,
T. J.; Bethge, C. W.; Song, D.; Ballester, E. Alsina; Belluzzi,
L.; Pino Alemán, T. del; Ramos, A. Asensio; Yoshida, M.; Shimizu,
T.; Winebarger, A.; Kobelski, A. R.; Vigil, G. D.; Pontieu, B. De;
Narukage, N.; Kubo, M.; Sakao, T.; Hara, H.; Suematsu, Y.; Štěpán,
J.; Carlsson, M.; Leenaarts, J.
Bibcode: 2022ApJ...936...67R
Altcode: 2022arXiv220701788R
The CLASP2 (Chromospheric LAyer Spectro-Polarimeter 2) sounding rocket
mission was launched on 2019 April 11. CLASP2 measured the four Stokes
parameters of the Mg II h and k spectral region around 2800 Å along a
200″ slit at three locations on the solar disk, achieving the first
spatially and spectrally resolved observations of the solar polarization
in this near-ultraviolet region. The focus of the work presented here
is the center-to-limb variation of the linear polarization across these
resonance lines, which is produced by the scattering of anisotropic
radiation in the solar atmosphere. The linear polarization signals of
the Mg II h and k lines are sensitive to the magnetic field from the
low to the upper chromosphere through the Hanle and magneto-optical
effects. We compare the observations to theoretical predictions
from radiative transfer calculations in unmagnetized semiempirical
models, arguing that magnetic fields and horizontal inhomogeneities
are needed to explain the observed polarization signals and spatial
variations. This comparison is an important step in both validating and
refining our understanding of the physical origin of these polarization
signatures, and also in paving the way toward future space telescopes
for probing the magnetic fields of the solar upper atmosphere via
ultraviolet spectropolarimetry.
Title: GRAVITY faint: reducing noise sources in GRAVITY$^+$ with a
fast metrology attenuation system
Authors: Widmann, F.; Gillessen, S.; Ott, T.; Shimizu, T.; Eisenhauer,
F.; Fabricius, M.; Woillez, J.; Gonté, F.; Horrobin, M.; Shangguan,
J.; Yazici, S.; Perrin, G.; Paumard, T.; Brandner, W.; Kreidberg,
L.; Straubmeier, C.; Perraut, K.; Le Bouquin, J. -B.; Garcia, P.;
Hönig, S.; Defrère, D.; Bourdarot, G.; Drescher, A.; Feuchtgruber,
H.; Genzel, R.; Hartl, M.; Lutz, D.; More, N.; Rau, C.; Uysal, S.;
Wieprecht, E.
Bibcode: 2022arXiv220905593W
Altcode:
With the upgrade from GRAVITY to GRAVITY$^+$ the instrument will evolve
into an all-sky interferometer that can observe faint targets, such as
high redshift AGN. Observing the faintest targets requires reducing the
noise sources in GRAVITY as much as possible. The dominant noise source,
especially in the blue part of the spectrum, is the backscattering of
the metrology laser light onto the detector. To reduce this noise we
introduce two new metrology modes. With a combination of small hardware
changes and software adaptations, we can dim the metrology laser during
the observation without losing the phase referencing. For single beam
targets, we can even turn off the metrology laser for the maximum SNR
on the detector. These changes lead to an SNR improvement of over a
factor of two averaged over the whole spectrum and up to a factor of
eight in the part of the spectrum currently dominated by laser noise.
Title: A high angular resolution view of the PAH emission in Seyfert
galaxies using JWST/MRS data
Authors: García-Bernete, I.; Rigopoulou, D.; Alonso-Herrero,
A.; Donnan, F. R.; Roche, P. F.; Pereira-Santella, M.; Labiano,
A.; Peralta de Arriba, L.; Izumi, T.; Ramos Almeida, C.; Shimizu,
T.; Hönig, S.; García-Burillo, S.; Rosario, D. J.; Ward, M. J.;
Bellocchi, E.; Hicks, E. K. S.; Fuller, L.; Packham, C.
Bibcode: 2022arXiv220811620G
Altcode:
Polycyclic Aromatic Hydrocarbons (PAHs) are carbon-based molecules,
which are ubiquitous in a variety of astrophysical objects and
environments. In this work, we use JWST/MIRI MRS spectroscopy of 3
Seyferts to compare their nuclear PAH emission with that of star-forming
regions. This study represents the first of its kind using sub-arcsecond
angular resolution data of local luminous Seyferts (Lbol>10^44.89
erg/s) on a wide wavelength coverage (4.9-28.1 micron). We present an
analysis of their nuclear PAH properties by comparing the observed
ratios with PAH diagnostic model grids, derived from theoretical
spectra. Our results show that a suite of PAH features is present in
the innermost parts (~0.45 arcsec at 12 micron; in the inner ~142-245
pc) of luminous Seyfert galaxies. We find that the nuclear regions
of AGN lie at different positions of the PAH diagnostic diagrams,
whereas the SF regions are concentrated around the average values of SF
galaxies. In particular, we find that the nuclear PAH emission mainly
originates in neutral PAHs. In contrast, PAH emission originating in
the SF regions favours ionised PAH grains. The observed PAH ratios
in the nuclear region of AGN-dominated galaxy NGC 6552 indicate the
presence of larger-sized PAH molecules compared with those of the SF
regions. Therefore, our results provide evidence that the AGN have
a significant impact on the ionization state (and probably the size)
of the PAH grains on scales of ~142-245 pc.
Title: Direct Discovery of the Inner Exoplanet in the HD206893 System
Authors: Hinkley, S.; Lacour, S.; Marleau, G. D.; Lagrange, A. M.;
Wang, J. J.; Kammerer, J.; Cumming, A.; Nowak, M.; Rodet, L.; Stolker,
T.; Balmer, W. -O.; Ray, S.; Bonnefoy, M.; Mollière, P.; Lazzoni,
C.; Kennedy, G.; Mordasini, C.; Abuter, R.; Aigrain, S.; Amorim, A.;
Asensio-Torres, R.; Babusiaux, C.; Benisty, M.; Berger, J. -P.; Beust,
H.; Blunt, S.; Boccaletti, A.; Bohn, A.; Bonnet, H.; Bourdarot, G.;
Brandner, W.; Cantalloube, F.; Caselli, P.; Charnay, B.; Chauvin,
G.; Chomez, A.; Choquet, E.; Christiaens, V.; Clénet, Y.; Coudé du
Foresto, V.; Cridland, A.; Delorme, P.; Dembet, R.; de Zeeuw, P. T.;
Drescher, A.; Duvert, G.; Eckart, A.; Eisenhauer, F.; Feuchtgruber,
H.; Galland, F.; Garcia, P.; Garcia Lopez, R.; Gardner, T.; Gendron,
E.; Genzel, R.; Gillessen, S.; Girard, J. H.; Grandjean, A.; Haubois,
X.; Heißel, G.; Henning, Th.; Hippler, S.; Horrobin, M.; Houllé,
M.; Hubert, Z.; Jocou, L.; Keppler, M.; Kervella, P.; Kreidberg, L.;
Lapeyrère, V.; Le Bouquin, J. -B.; Léna, P.; Lutz, D.; Maire, A. -L.;
Mang, F.; Mérand, A.; Meunier, N.; Monnier, J. D.; Mordasini, C.;
Mouillet, D.; Nasedkin, E.; Ott, T.; Otten, G. P. P. L.; Paladini, C.;
Paumard, T.; Perraut, K.; Perrin, G.; Philipot, F.; Pfuhl, O.; Pourré,
N.; Pueyo, L.; Rameau, J.; Rickman, E.; Rubini, P.; Rustamkulov, Z.;
Samland, M.; Shangguan, J.; Shimizu, T.; Sing, D.; Straubmeier, C.;
Sturm, E.; Tacconi, L. J.; van Dishoeck, E. F.; Vigan, A.; Vincent,
F.; Ward-Duong, K.; Widmann, F.; Wieprecht, E.; Wiezorrek, E.; Woillez,
J.; Yazici, S.; Young, A.; Zicher, N.; the GRAVITY Collaboration
Bibcode: 2022arXiv220804867H
Altcode:
Long term precise radial velocity (RV) monitoring of HD206893, as well
as anomalies in the system proper motion, have suggested the presence of
an additional, inner companion in the system. In this work we describe
the results of a search for the companion responsible for this RV drift
and proper motion anomaly. Utilizing information from ongoing precision
RV measurements with the HARPS spectrograph, as well as Gaia host star
astrometry, we have undertaken a multi-epoch search for the purported
additional planet using the VLTI/GRAVITY instrument. We report a high
significance detection of the purported companion HD206893c over three
epochs, with clear evidence for Keplerian orbital motion. Our astrometry
with $\sim$50-100 $\mu$arcsec precision afforded by GRAVITY allows us
to derive a dynamical mass of 12.3$^{+1.1}_{-1.2}$ M$_{\rm Jup}$ and
an orbital separation of 3.53$^{+0.80}_{-0.70}$ au for HD206893c. Our
fits to the orbits of both companions in the system utilize both Gaia
astrometry and RVs to also provide a precise dynamical estimate of the
previously uncertain mass of the B component, and therefore derive an
age of 170 Myr. Importantly, we find that the bolometric luminosity of
the newly discovered HD206893c is anomalously high, and that standard
cooling curves are unable to simultaneously account for the brightness
of both members of the system at a common age of 170 Myr. However, we
find that incorporating an elevated helium abundance into our cooling
models in turn results in an enhanced level of deuterium burning in
the "c" companion, bringing the predicted luminosity in line with our
measured value. In addition to utilizing long-term RV information,
this effort is an early example of a direct imaging discovery of a
bona fide exoplanet that was guided in part with Gaia astrometry.
Title: Development of Fast and Precise Scan Mirror Mechanism for an
Airborne Solar Telescope
Authors: Oba, Takayoshi; Shimizu, Toshifumi; Katsukawa, Yukio; Kubo,
Masahito; Kawabata, Yusuke; Hara, Hirohisa; Uraguchi, Fumihiro;
Tsuzuki, Toshihiro; Tamura, Tomonori; Shinoda, Kazuya; Kodeki,
Kazuhide; Fukushima, Kazuhiko; Morales Fernández, José Miguel;
Sánchez Gómez, Antonio; Balaguer Jimenéz, María; Hernández
Expósito, David; Gandorfer, Achim
Bibcode: 2022arXiv220713864O
Altcode:
We developed a scan mirror mechanism (SMM) that enable a slit-based
spectrometer or spectropolarimeter to precisely and quickly map
an astronomical object. The SMM, designed to be installed in the
optical path preceding the entrance slit, tilts a folding mirror
and then moves the reflected image laterally on the slit plane,
thereby feeding a different one-dimensional image to be dispersed by
the spectroscopic equipment. In general, the SMM is required to scan
quickly and broadly while precisely placing the slit position across
the field-of-view (FOV). These performances are highly in demand for
near-future observations, such as studies on the magnetohydrodynamics of
the photosphere and the chromosphere. Our SMM implements a closed-loop
control system by installing electromagnetic actuators and gap-based
capacitance sensors. Our optical test measurements confirmed that the
SMM fulfils the following performance criteria: i) supreme scan-step
uniformity (linearity of 0.08%) across the wide scan range (${\pm}$1005
arcsec), ii) high stability (3${\sigma}$ = 0.1 arcsec), where the
angles are expressed in mechanical angle, and iii) fast stepping speed
(26 ms). The excellent capability of the SMM will be demonstrated
soon in actual use by installing the mechanism for a near-infrared
spectropolarimeter onboard the balloon-borne solar observatory for
the third launch, Sunrise III.
Title: A spectral solar irradiance monitor (SoSpIM) on the JAXA
Solar-C (EUVST) space mission
Authors: Harra, Louise K.; Watanabe, Kyoko; Haberreiter, Margit;
Hori, Tomoaki; Hara, Hirohisa; Kretzschmar, Matthieu; Woods, Thomas;
Shimizu, Toshifumi; Krucker, Samuel; Berghmans, David; Jin, Hidekatsu;
Dominique, Marie; Eparvier, Francis G.; Gissot, Samuel; Leng Yeo, Kok;
Pfiffner, Dany; Milligan, Ryan; Thiemann, Edward; Miyoshi, Yoshizumi;
Imada, Shinsuke; Kawate, Tomoko; Chamberlin, Phillip; Rozanov, Eugene;
Silvio Koller, -.; Barczynski, Krzysztof; Nozomu; Nishitani; Ieda,
Akimasa; Langer, Patrick; Meier, Leandro; Tye, Daniel; Alberti, Andrea
Bibcode: 2022cosp...44..834H
Altcode:
The JAXA Solar-C (EUVST) mission (Shimizu et al., 2020) is designed
to comprehensively understand how mass and energy are transferred
throughout the solar atmosphere. The EUV High-Throughput Spectroscopic
Telescope (EUVST) onboard does this by observing all the temperature
regimes of the atmosphere from the chromosphere to the corona
simultaneously. To enhance the EUVST scientific capabilities,
there will be a Solar Spectral Irradiance Monitor (SoSpIM). SoSpIM
will work hand-in-hand scientifically with EUVST, by providing the
full Sun irradiance at sub-second time cadence combined with the
spatially resolved spectroscopy from EUVST. The SoSPIM instrument
will specifically address two aspects. These are: · Understand how
the solar atmosphere becomes unstable, releasing the energy that
drives solar flares - achieved through probing fast time cadence
solar flare variations. · Measuring solar irradiance that impacts
the Earth's thermosphere and the mesosphere, linking to spatially
resolved measurements of the solar atmosphere with EUVST. SoSpIM will
provide high time resolution measurements in 2 channels (a) in the
corona through channel 1 (EUV) and (b) in the lower atmosphere through
channel 2 (Lyman alpha). Each channel impacts different layers of the
Earth's atmosphere.
Title: How Can Solar-C/SOSPIM Contribute to the Understanding of
Quasi-Periodic Pulsations in Solar Flares?
Authors: Dominique, Marie; Harra, Louise K.; Watanabe, Kyoko; Hara,
Hirohisa; Zhukov, Andrei; Shimizu, Toshifumi; Berghmans, David;
Dolla, Laurent; Gissot, Samuel; Pfiffner, Dany; Imada, Shinsuke;
Silvio Koller, -.; Meier, Leandro; Tye, Daniel; Alberti, Andrea
Bibcode: 2022cosp...44.2524D
Altcode:
Quasi-periodic pulsations (QPPs) refer to nearly-periodic oscillations
that are often observed in irradiance time series during solar flares
and have also been reported in several stellar flares. In the last
years, several statistical studies based on Soft X-ray measurements
have reached the conclusion that QPPs are present in most solar
flares of class M and above. Still, as of today, we are still unsure
of what causes QPPs. Several models could explain the presence of
QPPs with periods matching the ones observed. More detailed analysis
of the observational signatures of QPPs might help determine which
of those models are actually playing a role in the generation of
QPPs. However, as QPPs is a small timescale process (the period of
QPPs is often reported to be less than a minute), such an analysis
requires instruments with a good signal-to-noise and high sampling
rate. In this context, the spectral solar irradiance monitor SOSPIM,
that will be part of the JAXA SOLAR C mission and that will complement
the EUVST spectrograph measurements, could be a valuable asset. SOSPIM
will observe the solar chromosphere and corona in the Lyman-alpha
and EUV spectral ranges at high cadence. In this presentation, we
review the current knowledge of QPPs and describe what could be the
contribution of SOSPIM to push their understanding one step forward.
Title: Space-based instruments for small scale dynamics in the solar
upper atmosphere
Authors: Shimizu, Toshifumi
Bibcode: 2022cosp...44.2523S
Altcode:
Physical mechanisms on elemental small scales are believed
to be a key for understanding the formation mechanisms of the
hot and dynamic outer solar atmosphere and mechanisms of solar
eruptions. High resolution focus of space-based instruments will
be rich scientifically. Discoveries may be found on the elemental
small scales, such as the nature of magnetic stresses resulting
from braiding of magnetic field lines; the magnetic topology at the
footpoints of spicules, jets, and prominences; the transport of energy
via Alfvén waves; and the development and effects of turbulence
in all levels of the solar atmosphere. In the early 2020s, large
aperture telescopes, such as DKIST, have started their observations,
providing new diagnostics of magnetic and velocity fields in the
lower atmosphere with super high spatial resolution. In space, Parker
Solar Probe, Solar Orbiter, and BepiColomb are flying to explore the
inner heliosphere. New instruments are needed to link high resolution
information in the low atmosphere with observations from the inner
heliosphere. This means high resolution instruments for diagnosing the
upper atmosphere from the upper chromosphere to the corona and linking
to the inner heliosphere. Ideal state-of-art instruments for this
purpose will be realized in the latter half of 2020s: Solar-C (EUVST)
and MUSE. The combination of these two spacecraft with ground-based
DKIST would be the most powerful for dynamics in small-scales.
Title: An ALMA Observation of Time Variations in Chromospheric
Temperature of a Solar Plage Region
Authors: Abe, Masashi; Shimizu, Toshifumi; Shimojo, Masumi
Bibcode: 2022FrASS...9.8249A
Altcode:
Nanoflares and the shock formation of magnetohydrodynamic waves in the
solar chromosphere have been considered as key physical mechanisms
of the heating of the chromosphere and corona. To investigate
candidates of their signature in the mm-wavelength, a tiny active
region located on the solar disk was observed with the Atacama Large
millimeter and sub-millimeter Array (ALMA) at 3 mm, coordinated with
observatories on orbit including Hinode SOT spectro-polarimeter in
the Cycle 4 solar campaign (19 March 2017). ALMA's spatial resolution
was moderate, far from the best performance, but it provided stable
conditions that are suitable to investigate temporal variations in the
mm-wavelength. We determined that the noise level is less than 20 K
(σ) over 1 hour in the 20-s cadence time series of synthesized ALMA
images. The time variations with amplitudes above the noise level
were observed throughout the field of view, but variations exceeding
200 K, corresponding to energy input to the chromosphere on the order
of 1020-22 erg, were localized in two locations. One location was on
the polarity inversion line, where tiny concentrated magnetic patches
exist in weak field and a tiny magnetic flux may be emergent. The
other location was at the outer edge of a bipolar magnetic region,
which was under development with a successive series of magnetic flux
emergence. This observation suggests that nanoflare-class energy inputs
in the chromosphere can occur associated with emerging flux activities.
Title: First Light for GRAVITY Wide: Large Separation Fringe Tracking
for the Very Large Telescope Interferometer
Authors: GRAVITY+ Collaboration; :; Abuter, R.; Allouche, F.; Amorim,
A.; Bailet, C.; Bauböck, M.; Berger, J. -P.; Berio, P.; Bigioli,
A.; Boebion, O.; Bolzer, M. L.; Bonnet, H.; Bourdarot, G.; Bourget,
P.; Brandner, W.; Clénet, Y.; Courtney-Barrer, B.; Dallilar, Y.;
Davies, R.; Defrère, D.; Delboulbé, A.; Delplancke, F.; Dembet, R.;
de Zeeuw, P. T.; Drescher, A.; Eckart, A.; Édouard, C.; Eisenhauer,
F.; Fabricius, M.; Feuchtgruber, H.; Finger, G.; Förster Schreiber,
N. M.; Garcia, E.; Garcia, P.; Gao, F.; Gendron, E.; Genzel, R.; Gil,
J. P.; Gillessen, S.; Gomes, T.; Gonté, F.; Gouvret, C.; Guajardo, P.;
Guieu, S.; Hartl, M.; Haubois, X.; Haußmann, F.; Heißel, G.; Henning,
Th.; Hippler, S.; Hönig, S.; Horrobin, M.; Hubin, N.; Jacqmart,
E.; Jochum, L.; Jocou, L.; Kaufer, A.; Kervella, P.; Korhonen,
H.; Kreidberg, L.; Lacour, S.; Lagarde, S.; Lai, O.; Lapeyrère,
V.; Laugier, R.; Le Bouquin, J. -B.; Leftley, J.; Léna, P.; Lutz,
D.; Mang, F.; Marcotto, A.; Maurel, D.; Mérand, A.; Millour, F.;
More, N.; Nowacki, H.; Nowak, M.; Oberti, S.; Ott, T.; Pallanca, L.;
Paumard, T.; Perraut, K.; Perrin, G.; Petrov, R.; Pfuhl, O.; Pourré,
N.; Rabien, S.; Rau, C.; Robbe-Dubois, S.; Rochat, S.; Salman, M.;
Schöller, M.; Schubert, J.; Schuhler, N.; Shangguan, J.; Shimizu,
T.; Scheithauer, S.; Sevin, A.; Soulez, F.; Spang, A.; Stadler, E.;
Stadler, J.; Straubmeier, C.; Sturm, E.; Tacconi, L. J.; Tristram,
K. R. W.; Vincent, F.; von Fellenberg, S.; Uysal, S.; Widmann, F.;
Wieprecht, E.; Wiezorrek, E.; Woillez, J.; Yazici, S.; Young, A.;
Zins, G.
Bibcode: 2022arXiv220600684G
Altcode:
GRAVITY+ is the upgrade of GRAVITY and the Very Large Telescope
Interferometer (VLTI) with wide-separation fringe tracking, new
adaptive optics, and laser guide stars on all four 8~m Unit Telescopes
(UTs), for ever fainter, all-sky, high contrast, milliarcsecond
interferometry. Here we present the design and first results of the
first phase of GRAVITY+, called GRAVITY Wide. GRAVITY Wide combines
the dual-beam capabilities of the VLTI and the GRAVITY instrument to
increase the maximum separation between the science target and the
reference star from 2 arcseconds with the 8 m UTs up to several 10
arcseconds, limited only by the Earth's turbulent atmosphere. This
increases the sky-coverage of GRAVITY by two orders of magnitude,
opening up milliarcsecond resolution observations of faint objects, and
in particular the extragalactic sky. The first observations in 2019 -
2022 include first infrared interferometry of two redshift $z\sim2$
quasars, interferometric imaging on the binary system HD 105913A, and
repeated observations of multiple star systems in the Orion Trapezium
Cluster. We find the coherence loss between the science object and
fringe-tracking reference star well described by the turbulence
of the Earth's atmosphere. We confirm that the larger apertures of
the UTs result in higher visibilities for a given separation due to
larger overlap of the projected pupils on sky and give predictions
for visibility loss as a function of separation to be used for future
planning.
Title: CASPER: A mission to study the time-dependent evolution of
the magnetic solar chromosphere and transition regions
Authors: Orozco Suárez, D.; del Toro Iniesta, J. C.; Bailén, F. J.;
López Jiménez, A.; Balaguez Jiménez, M.; Bellot Rubio, L. R.;
Ishikawa, R.; Katsukawa, Y.; Kano, R.; Shimizu, T.; Trujillo Bueno,
J.; Asensio Ramos, A.; del Pino Alemán, T.
Bibcode: 2022ExA...tmp...26O
Altcode:
Our knowledge about the solar chromosphere and transition region (TR)
has increased in the last decade thanks to the huge scientific return
of space-borne observatories like SDO, IRIS, and Hinode, and suborbital
rocket experiments like CLASP1, CLASP2, and Hi-C. However, the magnetic
nature of those solar regions remain barely explored. The chromosphere
and TR of the Sun harbor weak fields and are in a low ionization stage
both having critical effects on their thermodynamic behavior. Relatively
cold gas structures, such as spicules and prominences, are located in
these two regions and display a dynamic evolution in high-resolution
observations that static and instantaneous 3D-magnetohydrodynamic (MHD)
models are not able to reproduce. The role of the chromosphere and TR
as the necessary path to a (largely unexplained) very hot corona calls
for the generation of observationally based, time-dependent models
of these two layers that include essential, up to now disregarded,
ingredients in the modeling such as the vector magnetic field. We
believe that the community is convinced that the origin of both the
heat and kinetic energy observed in the upper layers of the solar
atmosphere is of magnetic origin, but reliable magnetic field
measurements are missing. The access to sensitive polarimetric
measurements in the ultraviolet wavelengths has been elusive until
recently due to limitations in the available technology. We propose a
low-risk and high-Technology Readiness Level (TRL) mission to explore
the magnetism and dynamics of the solar chromosphere and TR. The mission
baseline is a low-Earth, Sun-synchronous orbit at an altitude between
600 and 800 km. The proposed scientific payload consists of a 30 cm
aperture telescope with a spectropolarimeter covering the hydrogen
Ly-alpha and the Mg II h&k ultraviolet lines. The instrument shall
record high-cadence, full spectropolarimetric observations of the
solar upper atmosphere. Besides the answers to a fundamental solar
problem the mission has a broader scientific return. For example,
the time-dependent modeling of the chromospheres of stars harboring
exoplanets is fundamental for estimating the planetary radiation
environment. The mission is based on technologies that are mature
enough for space and will provide scientific measurements that are
not available by other means.
Title: Kiloparsec view of a typical star-forming galaxy when the
Universe was $\sim$1 Gyr old II. Regular rotating disk and evidence
for baryon dominance on galactic scales
Authors: Herrera-Camus, R.; Förster Schreiber, N. M.; Price, S. H.;
Übler, H.; Bolatto, A. D.; Davies, R. L.; Fisher, D.; Genzel, R.;
Lutz, D.; Naab, T.; Nestor, A.; Shimizu, T.; Sternberg, A.; Tacconi,
L.; Tadaki, K.
Bibcode: 2022arXiv220300689H
Altcode:
We present a kinematic analysis of the main-sequence galaxy HZ4 at
$z=5.5$. Our study is based on deep, spatially resolved observations
of the [CII] 158 $\mu$m transition obtained with the Atacama Large
Millimeter/Submillimeter Array (ALMA). From the combined analysis
of the disk morphology, the two-dimensional velocity structure,
and forward-modeling of the one-dimensional velocity and velocity
dispersion profiles, we conclude that HZ4 has a regular rotating
disk in place. The intrinsic velocity dispersion in HZ4 is high
($\sigma_{0}=65.8^{+2.9}_{-3.3}$ km s$^{-1}$), and the ratio between
the rotational velocity and the intrinsic velocity dispersion is $V_{\rm
rot}/\sigma_{0}=2.2$. These values are consistent with the expectations
from the trends of increasing $\sigma_{0}$ and decreasing $V_{\rm
rot}/\sigma_{0}$ as a function of redshift observed in main-sequence
galaxies up to $z\approx4$. Galaxy evolution models suggest that the
high level of turbulence observed in HZ4 can only be achieved if, in
addition to stellar feedback, there is radial transport of gas within
the disk. Finally, we find that HZ4 is baryon dominated on galactic
scales ($\lesssim2\times R_{\rm e}$), with a dark matter fraction at one
effective radius of $f_{\rm DM}(R_{\rm e})=0.41^{+0.25}_{-0.22}$. This
value is comparable to the dark matter fractions found in lower
redshift galaxies that could be the descendants of HZ4: massive
($M_{\star}\approx10^{11}~M_{\odot}$), star-forming galaxies at
$z\sim2$, and passive, early type galaxies at $z\approx0$.
Title: Deep images of the Galactic center with GRAVITY
Authors: GRAVITY Collaboration; Abuter, R.; Aimar, N.; Amorim, A.;
Arras, P.; Bauböck, M.; Berger, J. P.; Bonnet, H.; Brandner, W.;
Bourdarot, G.; Cardoso, V.; Clénet, Y.; Davies, R.; de Zeeuw, P. T.;
Dexter, J.; Dallilar, Y.; Drescher, A.; Eisenhauer, F.; Enßlin, T.;
Förster Schreiber, N. M.; Garcia, P.; Gao, F.; Gendron, E.; Genzel,
R.; Gillessen, S.; Habibi, M.; Haubois, X.; Heißel, G.; Henning, T.;
Hippler, S.; Horrobin, M.; Jiménez-Rosales, A.; Jochum, L.; Jocou,
L.; Kaufer, A.; Kervella, P.; Lacour, S.; Lapeyrère, V.; Le Bouquin,
J. -B.; Léna, P.; Lutz, D.; Mang, F.; Nowak, M.; Ott, T.; Paumard,
T.; Perraut, K.; Perrin, G.; Pfuhl, O.; Rabien, S.; Shangguan, J.;
Shimizu, T.; Scheithauer, S.; Stadler, J.; Straub, O.; Straubmeier,
C.; Sturm, E.; Tacconi, L. J.; Tristram, K. R. W.; Vincent, F.; von
Fellenberg, S.; Waisberg, I.; Widmann, F.; Wieprecht, E.; Wiezorrek,
E.; Woillez, J.; Yazici, S.; Young, A.; Zins, G.
Bibcode: 2022A&A...657A..82G
Altcode: 2021arXiv211207477G
Stellar orbits at the Galactic Center provide a very clean probe of
the gravitational potential of the supermassive black hole. They can be
studied with unique precision, beyond the confusion limit of a single
telescope, with the near-infrared interferometer GRAVITY. Imaging is
essential to search the field for faint, unknown stars on short orbits
which potentially could constrain the black hole spin. Furthermore,
it provides the starting point for astrometric fitting to derive
highly accurate stellar positions. Here, we present GR, a
new imaging tool specifically designed for Galactic Center observations
with GRAVITY. The algorithm is based on a Bayesian interpretation of the
imaging problem, formulated in the framework of information field theory
and building upon existing works in radio-interferometric imaging. Its
application to GRAVITY observations from 2021 yields the deepest images
to date of the Galactic Center on scales of a few milliarcseconds. The
images reveal the complicated source structure within the central
100 mas around Sgr A*, where we detected the stars S29 and S55 and
confirm S62 on its trajectory, slowly approaching Sgr A*. Furthermore,
we were able to detect S38, S42, S60, and S63 in a series of exposures
for which we offset the fiber from Sgr A*. We provide an update on the
orbits of all aforementioned stars. In addition to these known sources,
the images also reveal a faint star moving to the west at a high angular
velocity. We cannot find any coincidence with any known source and,
thus, we refer to the new star as S300. From the flux ratio with S29,
we estimate its K-band magnitude as mK(S300) ≃ 19.0 −
19.3. Images obtained with CLEAN confirm the detection. To assess
the sensitivity of our images, we note that fiber damping reduces
the apparent magnitude of S300 and the effect increases throughout
the year as the star moves away from the field center. Furthermore,
we performed a series of source injection tests. Under favorable
circumstances, sources well below a magnitude of 20 can be recovered,
while 19.7 is considered the more universal limit for a good data set.
Title: Mass distribution in the Galactic Center based on
interferometric astrometry of multiple stellar orbits
Authors: GRAVITY Collaboration; Abuter, R.; Aimar, N.; Amorim, A.;
Ball, J.; Bauböck, M.; Berger, J. P.; Bonnet, H.; Bourdarot, G.;
Brandner, W.; Cardoso, V.; Clénet, Y.; Dallilar, Y.; Davies, R.;
de Zeeuw, P. T.; Dexter, J.; Drescher, A.; Eisenhauer, F.; Förster
Schreiber, N. M.; Foschi, A.; Garcia, P.; Gao, F.; Gendron, E.; Genzel,
R.; Gillessen, S.; Habibi, M.; Haubois, X.; Heißel, G.; Henning,
T.; Hippler, S.; Horrobin, M.; Jochum, L.; Jocou, L.; Kaufer, A.;
Kervella, P.; Lacour, S.; Lapeyrère, V.; Le Bouquin, J. -B.; Léna,
P.; Lutz, D.; Ott, T.; Paumard, T.; Perraut, K.; Perrin, G.; Pfuhl,
O.; Rabien, S.; Shangguan, J.; Shimizu, T.; Scheithauer, S.; Stadler,
J.; Stephens, A. W.; Straub, O.; Straubmeier, C.; Sturm, E.; Tacconi,
L. J.; Tristram, K. R. W.; Vincent, F.; von Fellenberg, S.; Widmann,
F.; Wieprecht, E.; Wiezorrek, E.; Woillez, J.; Yazici, S.; Young, A.
Bibcode: 2022A&A...657L..12G
Altcode:
Stars orbiting the compact radio source Sgr A* in the Galactic Center
serve as precision probes of the gravitational field around the closest
massive black hole. In addition to adaptive optics-assisted astrometry
(with NACO/VLT) and spectroscopy (with SINFONI/VLT, NIRC2/Keck and
GNIRS/Gemini) over three decades, we have obtained 30-100 μas
astrometry since 2017 with the four-telescope interferometric
beam combiner GRAVITY/VLTI, capable of reaching a sensitivity of
mK = 20 when combining data from one night. We present
the simultaneous detection of several stars within the diffraction
limit of a single telescope, illustrating the power of interferometry
in the field. The new data for the stars S2, S29, S38, and S55 yield
significant accelerations between March and July 2021, as these stars
pass the pericenters of their orbits between 2018 and 2023. This allows
for a high-precision determination of the gravitational potential around
Sgr A*. Our data are in excellent agreement with general relativity
orbits around a single central point mass, M• = 4.30 ×
106 M⊙, with a precision of about ±0.25%. We
improve the significance of our detection of the Schwarzschild
precession in the S2 orbit to 7σ. Assuming plausible density profiles,
the extended mass component inside the S2 apocenter (≈0.23″ or 2.4
× 104 RS) must be ≲3000 M⊙ (1σ),
or ≲0.1% of M•. Adding the enclosed mass determinations
from 13 stars orbiting Sgr A* at larger radii, the innermost radius
at which the excess mass beyond Sgr A* is tentatively seen is r ≈
2.5″ ≥ 10× the apocenter of S2. This is in full harmony with
the stellar mass distribution (including stellar-mass black holes)
obtained from the spatially resolved luminosity function.
Title: Simultaneous ALMA-Hinode-IRIS Observations on Footpoint
Signatures of a Soft X-Ray Loop-like Microflare
Authors: Shimizu, Toshifumi; Shimojo, Masumi; Abe, Masashi
Bibcode: 2021ApJ...922..113S
Altcode: 2021arXiv210911215S
Microflares have been considered to be among the major energy
input sources to form active solar corona. To investigate the
response of the low atmosphere to events, we conducted an Atacama
Large Millimeter/submillimeter Array (ALMA) observation at 3 mm,
coordinated with Interface Region Imaging Spectrograph (IRIS) and
Hinode observations, on 2017 March 19. During the observations, a soft
X-ray loop-type microflare (active region transient brightening) was
captured using the Hinode X-ray telescope in high temporal cadence. A
brightening loop footpoint is located within narrow fields of view of
ALMA, IRIS slit-jaw imager, and Hinode spectropolarimeter. Counterparts
of the microflare at the footpoint were detected in Si IV and ALMA
images, while the counterparts were less apparent in C II and Mg II
k images. Their impulsive time profiles exhibit the Neupert effect
pertaining to soft X-ray intensity evolution. The magnitude of thermal
energy measured using ALMA was approximately 100 times smaller than
that measured in the corona. These results suggest that impulsive
counterparts can be detected in the transition region and upper
chromosphere, where the plasma is thermally heated via impinging
nonthermal particles. Our energy evaluation indicates a deficit of
accelerated particles that impinge the footpoints for a small class
of soft X-ray microflares. The footpoint counterparts consist of
several brightening kernels, all of which are located in weak (void)
magnetic areas formed in patchy distribution of strong magnetic flux
at the photospheric level. The kernels provide a conceptual image in
which the transient energy release occurs at multiple locations on
the sheaths of magnetic flux bundles in the corona.
Title: The mass distribution in the Galactic Centre from
interferometric astrometry of multiple stellar orbits
Authors: GRAVITY Collaboration; Abuter, R.; Aimar, N.; Amorim, A.;
Ball, J.; Bauböck, M.; Berger, J. P.; Bonnet, H.; Bourdarot, G.;
Brandner, W.; Cardoso, V.; Clénet, Y.; Dallilar, Y.; Davies, R.;
de Zeeuw, P. T.; Dexter, J.; Drescher, A.; Eisenhauer, F.; Förster
Schreiber, N. M.; Foschi, A.; Garcia, P.; Gao, F.; Gendron, E.; Genzel,
R.; Gillessen, S.; Habibi, M.; Haubois, X.; Heißel, G.; Henning,
T.; Hippler, S.; Horrobin, M.; Jochum, L.; Jocou, L.; Kaufer, A.;
Kervella, P.; Lacour, S.; Lapeyrère, V.; Le Bouquin, J. -B.; Léna,
P.; Lutz, D.; Ott, T.; Paumard, T.; Perraut, K.; Perrin, G.; Pfuhl,
O.; Rabien, S.; Shangguan, J.; Shimizu, T.; Scheithauer, S.; Stadler,
J.; Stephens, A. W.; Straub, O.; Straubmeier, C.; Sturm, E.; Tacconi,
L. J.; Tristram, K. R. W.; Vincent, F.; von Fellenberg, S.; Widmann,
F.; Wieprecht, E.; Wiezorrek, E.; Woillez, J.; Yazici, S.; Young,
A.; Zins, G.
Bibcode: 2021arXiv211207478G
Altcode:
The stars orbiting the compact radio source Sgr A* in the Galactic
Centre are precision probes of the gravitational field around the
closest massive black hole. In addition to adaptive optics assisted
astrometry (with NACO / VLT) and spectroscopy (with SINFONI / VLT,
NIRC2 / Keck and GNIRS / Gemini) over three decades, since 2016/2017
we have obtained 30-100 mu-as astrometry with the four-telescope
interferometric beam combiner GRAVITY / VLTI reaching a sensitivity of
mK = 20 when combining data from one night. We present the simultaneous
detection of several stars within the diffraction limit of a single
telescope, illustrating the power of interferometry. The new data
for the stars S2, S29, S38 and S55 yield significant accelerations
between March and July 2021, as these stars pass the pericenters of
their orbits between 2018 and 2023. This allows for a high-precision
determination of the gravitational potential around Sgr A*. Our data
are in excellent agreement with general relativity orbits around a
single central point mass, M = 4.30 x 10^6 M_sun with a precision
of about +-0.25%. We improve the significance of our detection of
the Schwarzschild precession in the S2 orbit to 7 sigma. Assuming
plausible density profiles, an extended mass component inside S2's
apocentre (= 0.23" or 2.4 x 10^4 R_S) must be 3000 M_sun (1 sigma),
or 0.1% of M. Adding the enclosed mass determinations from 13 stars
orbiting Sgr A* at larger radii, the innermost radius at which the
excess mass beyond Sgr A* tentatively is seen is r = 2.5" >= 10x
the apocentre of S2. This is in full harmony with the stellar mass
distribution (including stellar-mass black holes) obtained from the
spatially resolved luminosity function.
Title: How Can Solar-C/SOSPIM Contribute to the Understanding of
Quasi-Periodic Pulsations in Solar Flares?
Authors: Dominique, Marie; Dolla, Laurent; Zhukov, Andrei; Alberti,
Andrea; Berghmans, David; Gissot, Samuel; Hara, Hirohisa; Harra,
Louise; Imada, Shinsuke; Koller, Silvio; Meier, Leandro; Pfiffner,
Daniel; Shimizu, Toshifumi; Tye, Daniel; Watanabe, Kyoko
Bibcode: 2021AGUFMSH25E2124D
Altcode:
Quasi-periodic pulsations (QPPs) refer to nearly-periodic oscillations
that are often observed in irradiance time series during solar flares
and have also been reported in several stellar flares. In the last
years, several statistical studies based on Soft X-ray measurements
have reached the conclusion that QPPs are present in most solar flares
of class M and above. Still, the mechanism at the origin of QPPs is
under debate. Are they caused by waves or periodic fluctuations of the
magnetic reconnection driving the flare? Analyzing the characteristics
of QPPs and their evolution during the flare could help identifying
their origin. However, QPPs sometimes exhibit very different
periodicities, and do not always happen during the same phase of the
flare. All this could point to the coexistence of QPPs with different
origin mechanism, and indicates the need for more observations. In this
context, the spectral solar irradiance monitor SOSPIM, that will be
part of the JAXA SOLAR C mission and that will complement the EUVST
spectrograph measurements, could be a valuable asset. SOSPIM will
observe the solar chromosphere and corona in the Lyman-alpha and EUV
spectral ranges at high cadence. In this presentation, we review the
current knowledge of QPPs and describe what could be the contribution
of SOSPIM to push their understanding one step forward.
Title: Rotation Curves in z 1-2 Star-forming Disks: Comparison
of Dark Matter Fractions and Disk Properties for Different Fitting
Methods
Authors: Price, S. H.; Shimizu, T. T.; Genzel, R.; Übler, H.;
Förster Schreiber, N. M.; Tacconi, L. J.; Davies, R. I.; Coogan,
R. T.; Lutz, D.; Wuyts, S.; Wisnioski, E.; Nestor, A.; Sternberg, A.;
Burkert, A.; Bender, R.; Contursi, A.; Davies, R. L.; Herrera-Camus,
R.; Lee, M. -J.; Naab, T.; Neri, R.; Renzini, A.; Saglia, R.; Schruba,
A.; Schuster, K.
Bibcode: 2021ApJ...922..143P
Altcode: 2021arXiv210902659P
We present a follow-up analysis examining the dynamics and structures
of 41 massive, large star-forming galaxies at z ~ 0.67 - 2.45 using
both ionized and molecular gas kinematics. We fit the galaxy dynamics
with models consisting of a bulge, a thick, turbulent disk, and an NFW
dark matter halo, using code that fully forward-models the kinematics,
including all observational and instrumental effects. We explore
the parameter space using Markov Chain Monte Carlo (MCMC) sampling,
including priors based on stellar and gas masses and disk sizes. We
fit the full sample using extracted 1D kinematic profiles. For a subset
of 14 well-resolved galaxies, we also fit the 2D kinematics. The MCMC
approach robustly confirms the results from least-squares fitting
presented in Paper I: the sample galaxies tend to be baryon-rich on
galactic scales (within one effective radius). The 1D and 2D MCMC
results are also in good agreement for the subset, demonstrating
that much of the galaxy dynamical information is captured along the
major axis. The 2D kinematics are more affected by the presence of
noncircular motions, which we illustrate by constructing a toy model
with constant inflow for one galaxy that exhibits residual signatures
consistent with radial motions. This analysis, together with results
from Paper I and other studies, strengthens the finding that massive,
star-forming galaxies at z ~ 1 - 2 are baryon-dominated on galactic
scales, with lower dark matter fractions toward higher baryonic surface
densities. Finally, we present details of the kinematic fitting code
used in this analysis.
Title: PSTEP: project for solar-terrestrial environment prediction
Authors: Kusano, Kanya; Ichimoto, Kiyoshi; Ishii, Mamoru; Miyoshi,
Yoshizumi; Yoden, Shigeo; Akiyoshi, Hideharu; Asai, Ayumi; Ebihara,
Yusuke; Fujiwara, Hitoshi; Goto, Tada-Nori; Hanaoka, Yoichiro;
Hayakawa, Hisashi; Hosokawa, Keisuke; Hotta, Hideyuki; Hozumi,
Kornyanat; Imada, Shinsuke; Iwai, Kazumasa; Iyemori, Toshihiko; Jin,
Hidekatsu; Kataoka, Ryuho; Katoh, Yuto; Kikuchi, Takashi; Kubo, Yûki;
Kurita, Satoshi; Matsumoto, Haruhisa; Mitani, Takefumi; Miyahara,
Hiroko; Miyoshi, Yasunobu; Nagatsuma, Tsutomu; Nakamizo, Aoi; Nakamura,
Satoko; Nakata, Hiroyuki; Nishizuka, Naoto; Otsuka, Yuichi; Saito,
Shinji; Saito, Susumu; Sakurai, Takashi; Sato, Tatsuhiko; Shimizu,
Toshifumi; Shinagawa, Hiroyuki; Shiokawa, Kazuo; Shiota, Daikou;
Takashima, Takeshi; Tao, Chihiro; Toriumi, Shin; Ueno, Satoru;
Watanabe, Kyoko; Watari, Shinichi; Yashiro, Seiji; Yoshida, Kohei;
Yoshikawa, Akimasa
Bibcode: 2021EP&S...73..159K
Altcode:
Although solar activity may significantly impact the global environment
and socioeconomic systems, the mechanisms for solar eruptions and
the subsequent processes have not yet been fully understood. Thus,
modern society supported by advanced information systems is at risk
from severe space weather disturbances. Project for solar-terrestrial
environment prediction (PSTEP) was launched to improve this situation
through synergy between basic science research and operational
forecast. The PSTEP is a nationwide research collaboration in Japan
and was conducted from April 2015 to March 2020, supported by a
Grant-in-Aid for Scientific Research on Innovative Areas from the
Ministry of Education, Culture, Sports, Science and Technology of
Japan. By this project, we sought to answer the fundamental questions
concerning the solar-terrestrial environment and aimed to build a
next-generation space weather forecast system to prepare for severe
space weather disasters. The PSTEP consists of four research groups and
proposal-based research units. It has made a significant progress in
space weather research and operational forecasts, publishing over 500
refereed journal papers and organizing four international symposiums,
various workshops and seminars, and summer school for graduate students
at Rikubetsu in 2017. This paper is a summary report of the PSTEP and
describes the major research achievements it produced.
Title: The GRAVITY young stellar object survey. VII. The inner dusty
disks of T Tauri stars
Authors: GRAVITY Collaboration; Perraut, K.; Labadie, L.; Bouvier, J.;
Ménard, F.; Klarmann, L.; Dougados, C.; Benisty, M.; Berger, J. -P.;
Bouarour, Y. -I.; Brandner, W.; Caratti O Garatti, A.; Caselli, P.;
de Zeeuw, P. T.; Garcia-Lopez, R.; Henning, T.; Sanchez-Bermudez,
J.; Sousa, A.; van Dishoeck, E.; Alécian, E.; Amorim, A.; Clénet,
Y.; Davies, R.; Drescher, A.; Duvert, G.; Eckart, A.; Eisenhauer,
F.; Förster-Schreiber, N. M.; Garcia, P.; Gendron, E.; Genzel, R.;
Gillessen, S.; Grellmann, R.; Heißel, G.; Hippler, S.; Horrobin,
M.; Hubert, Z.; Jocou, L.; Kervella, P.; Lacour, S.; Lapeyrère,
V.; Le Bouquin, J. -B.; Léna, P.; Lutz, D.; Ott, T.; Paumard, T.;
Perrin, G.; Scheithauer, S.; Shangguan, J.; Shimizu, T.; Stadler,
J.; Straub, O.; Straubmeier, C.; Sturm, E.; Tacconi, L.; Vincent,
F.; von Fellenberg, S.; Widmann, F.
Bibcode: 2021A&A...655A..73G
Altcode: 2021arXiv210911826T
Context. T Tauri stars are surrounded by dust and gas disks. As
material reservoirs from which matter is accreted onto the central
star and planets are built, these protoplanetary disks play a central
role in star and planet formation.
Aims: We aim at spatially
resolving at sub-astronomical unit (sub-au) scales the innermost
regions of the protoplanetary disks around a sample of T Tauri stars
to better understand their morphology and composition.
Methods:
Thanks to the sensitivity and the better spatial frequency coverage
of the GRAVITY instrument of the Very Large Telescope Interferometer,
we extended our homogeneous data set of 27 Herbig stars and collected
near-infrared K-band interferometric observations of 17 T Tauri stars,
spanning effective temperatures and luminosities in the ranges of
~4000-6000 K and ~0.4-10 L⊙, respectively. We focus on the
continuum emission and develop semi-physical geometrical models to fit
the interferometric data and search for trends between the properties
of the disk and the central star.
Results: As for those of their
more massive counterparts, the Herbig Ae/Be stars, the best-fit models
of the inner rim of the T Tauri disks correspond to wide rings. The
GRAVITY measurements extend the radius-luminosity relation toward the
smallest luminosities (0.4-10 L⊙). As observed previously,
in this range of luminosities, the R ∝ L1∕2 trend
line is no longer valid, and the K-band sizes measured with GRAVITY
appear to be larger than the predicted sizes derived from sublimation
radius computation. We do not see a clear correlation between the
K-band half-flux radius and the mass accretion rate onto the central
star. Besides, having magnetic truncation radii in agreement with the
K-band GRAVITY sizes would require magnetic fields as strong as a few
kG, which should have been detected, suggesting that accretion is not
the main process governing the location of the half-flux radius of
the inner dusty disk. The GRAVITY measurements agree with models that
take into account the scattered light, which could be as important as
thermal emission in the K band for these cool stars. The N-to-K band
size ratio may be a proxy for disentangling disks with silicate features
in emission from disks with weak and/or in absorption silicate features
(i.e., disks with depleted inner regions and/or with large gaps). The
GRAVITY data also provide inclinations and position angles of the inner
disks. When compared to those of the outer disks derived from ALMA
images of nine objects of our sample, we detect clear misalignments
between both disks for four objects.
Conclusions: The combination
of improved data quality with a significant and homogeneous sample
of young stellar objects allows us to revisit the pioneering works
done on the protoplanetary disks by K-band interferometry and to test
inner disk physics such as the inner rim morphology and location. GTO programs with run IDs: 0103.C-0347, 0102.C-0408, 0101.C-0311,
0100.C-0278, and 099.C-0667.
Title: The GRAVITY young stellar object survey. VIII. Gas and dust
faint inner rings in the hybrid disk of HD141569
Authors: GRAVITY Collaboration; Ganci, V.; Labadie, L.; Klarmann,
L.; de Valon, A.; Perraut, K.; Benisty, M.; Brandner, W.; Caratti O
Garatti, A.; Dougados, C.; Eupen, F.; Garcia Lopez, R.; Grellmann, R.;
Sanchez-Bermudez, J.; Wojtczak, A.; Garcia, P.; Amorim, A.; Bauböck,
M.; Berger, J. -P.; Caselli, P.; Clénet, Y.; Coudé Du Foresto, V.;
de Zeeuw, P. T.; Drescher, A.; Duvert, G.; Eckart, A.; Eisenhauer,
F.; Filho, M.; Gao, F.; Gendron, E.; Genzel, R.; Gillessen, S.;
Heissel, G.; Henning, T.; Hippler, S.; Horrobin, M.; Hubert, Z.;
Jiménez-Rosales, A.; Jocou, L.; Kervella, P.; Lacour, S.; Lapeyrère,
V.; Le Bouquin, J. -B.; Léna, P.; Ott, T.; Paumard, T.; Perrin, G.;
Pfuhl, O.; Heißel, G.; Rousset, G.; Scheithauer, S.; Shangguan, J.;
Shimizu, T.; Stadler, J.; Straub, O.; Straubmeier, C.; Sturm, E.;
van Dishoeck, E.; Vincent, F.; von Fellenberg, S. D.; Widmann, F.;
Woillez, J.
Bibcode: 2021A&A...655A.112G
Altcode: 2021arXiv210910070G
Context. The formation and evolution of planetary systems impact
the evolution of the primordial accretion disk in its dust and gas
content. HD 141569 is a peculiar object in this context as it is
the only known pre-main sequence star characterized by a hybrid
disk. Observations with 8 m class telescopes probed the outer-disk
structure showing a complex system of multiple rings and outer
spirals. Furthermore, interferometric observations attempted to
characterize its inner 5 au region, but derived limited constraints.
Aims: The goal of this work was to explore with new high-resolution
interferometric observations the geometry, properties, and dynamics of
the dust and gas in the internal regions of HD 141569.
Methods:
We observed HD 141569 on milliarcsecond scales with GRAVITY/VLTI in
the near-infrared (IR) at low (R ~ 20) and high (R ~ 4000) spectral
resolution. We interpreted the interferometric visibilities and
spectral energy distribution with geometrical models and through
radiative transfer techniques using the code MCMax to constrain the
dust emission. We analyzed the high spectral resolution quantities
(visibilities and differential phases) to investigate the properties of
the Brackett-γ (Brγ) line emitting region.
Results: Thanks to
the combination of three different epochs, GRAVITY resolves the inner
dusty disk in the K band with squared visibilities down to V2
~ 0.8. A differential phase signal is also detected in the region of
the Brγ line along most of the six baselines. Data modeling shows
that an IR excess of about 6% is spatially resolved and that the
origin of this emission is confined in a ring of material located at
a radius of ~1 au from the star with a width ≲0.3 au. The MCMax
modeling suggests that this emission could originate from a small
amount (1.4 × 10−8 M⊕) of quantum-heated
particles, while large silicate grain models cannot reproduce at the
same time the observational constraints on the properties of near-IR
and mid-IR fluxes. The high spectral resolution differential phases
in the Brγ line clearly show an S-shape that can be best reproduced
with a gaseous disk in Keplerian rotation, confined within 0.09 au (or
12.9 R⋆). This is also hinted at by the double-peaked Brγ
emission line shape, known from previous observations and confirmed by
GRAVITY. The modeling of the continuum and gas emission shows that the
inclination and position angle of these two components are consistent
with a system showing relatively coplanar rings on all scales.
Conclusions: With a new and unique observational dataset on HD 141569,
we show that the complex disk of this source is composed of a multitude
of rings on all scales. This aspect makes HD 141569 a potentially
unique source to investigate planet formation and disk evolution in
intermediate-mass pre-main sequence stars.
Title: VizieR Online Data Catalog: BAT AGN Spectroscopic
Survey. XVIII. Periodic var. (Liu+, 2020)
Authors: Liu, T.; Koss, M.; Blecha, L.; Ricci, C.; Trakhtenbrot,
B.; Mushotzky, R.; Harrison, F.; Ichikawa, K.; Kakkad, D.; Oh, K.;
Powell, M.; Privon, G. C.; Schawinski, K.; Shimizu, T. T.; Smith,
K. L.; Stern, D.; Treister, E.; Urry, C. M.
Bibcode: 2021yCat..18960122L
Altcode:
Theory predicts that a supermassive black hole binary (SMBHB)
could be observed as a luminous active galactic nucleus (AGN) that
periodically varies on the order of its orbital timescale. In X-rays,
periodic variations could be caused by mechanisms including relativistic
Doppler boosting and shocks. Here we present the first systematic search
for periodic AGNs using 941 hard X-ray light curves (14-195keV) from
the first 105 months of the Swift Burst Alert Telescope (BAT) survey
(2004-2013). We do not find evidence for periodic AGNs in Swift-BAT,
including the previously reported SMBHB candidate MCG+11-11-032. We
find that the null detection is consistent with the combination
of the upper-limit binary population in AGNs in our adopted model,
their expected periodic variability amplitudes, and the BAT survey
characteristics. We have also investigated the detectability of
SMBHBs against normal AGN X-ray variability in the context of the
extended ROentgen Survey with an Imaging Telescope Array (eROSITA)
survey. Under our assumptions of a binary population and the periodic
signals they produce, which have long periods of hundreds of days,
up to 13% true periodic binaries can be robustly distinguished from
normal variable AGNs with the ideal uniform sampling. However,
we demonstrate that realistic eROSITA sampling is likely to be
insensitive to long-period binaries because longer observing gaps
reduce their detectability. In contrast, large observing gaps do not
diminish the prospect of detecting binaries of short, few-day periods,
as 19% can be successfully recovered, the vast majority of which can
be identified by the first half of the survey. (1 data file).
Title: Constraining particle acceleration in Sgr A⋆
with simultaneous GRAVITY, Spitzer, NuSTAR, and Chandra observations
Authors: GRAVITY Collaboration; Abuter, R.; Amorim, A.; Bauböck,
M.; Baganoff, F.; Berger, J. P.; Boyce, H.; Bonnet, H.; Brandner, W.;
Clénet, Y.; Davies, R.; de Zeeuw, P. T.; Dexter, J.; Dallilar, Y.;
Drescher, A.; Eckart, A.; Eisenhauer, F.; Fazio, G. G.; Förster
Schreiber, N. M.; Foster, K.; Gammie, C.; Garcia, P.; Gao, F.;
Gendron, E.; Genzel, R.; Ghisellini, G.; Gillessen, S.; Gurwell,
M. A.; Habibi, M.; Haggard, D.; Hailey, C.; Harrison, F. A.;
Haubois, X.; Heißel, G.; Henning, T.; Hippler, S.; Hora, J. L.;
Horrobin, M.; Jiménez-Rosales, A.; Jochum, L.; Jocou, L.; Kaufer,
A.; Kervella, P.; Lacour, S.; Lapeyrère, V.; Le Bouquin, J. -B.;
Léna, P.; Lowrance, P. J.; Lutz, D.; Markoff, S.; Mori, K.; Morris,
M. R.; Neilsen, J.; Nowak, M.; Ott, T.; Paumard, T.; Perraut, K.;
Perrin, G.; Ponti, G.; Pfuhl, O.; Rabien, S.; Rodríguez-Coira, G.;
Shangguan, J.; Shimizu, T.; Scheithauer, S.; Smith, H. A.; Stadler,
J.; Stern, D. K.; Straub, O.; Straubmeier, C.; Sturm, E.; Tacconi,
L. J.; Vincent, F.; von Fellenberg, S. D.; Waisberg, I.; Widmann, F.;
Wieprecht, E.; Wiezorrek, E.; Willner, S. P.; Witzel, G.; Woillez,
J.; Yazici, S.; Young, A.; Zhang, S.; Zins, G.
Bibcode: 2021A&A...654A..22G
Altcode: 2021arXiv210701096A
We report the time-resolved spectral analysis of a bright near-infrared
and moderate X-ray flare of Sgr A⋆. We obtained light
curves in the M, K, and H bands in the mid- and near-infrared and in
the 2 − 8 keV and 2 − 70 keV bands in the X-ray. The observed
spectral slope in the near-infrared band is νLν ∝
ν0.5 ± 0.2; the spectral slope observed in the X-ray
band is νLν ∝ ν−0.7 ± 0.5. Using a fast
numerical implementation of a synchrotron sphere with a constant radius,
magnetic field, and electron density (i.e., a one-zone model), we tested
various synchrotron and synchrotron self-Compton scenarios. The observed
near-infrared brightness and X-ray faintness, together with the observed
spectral slopes, pose challenges for all models explored. We rule out
a scenario in which the near-infrared emission is synchrotron emission
and the X-ray emission is synchrotron self-Compton. Two realizations
of the one-zone model can explain the observed flare and its temporal
correlation: one-zone model in which the near-infrared and X-ray
luminosity are produced by synchrotron self-Compton and a model in
which the luminosity stems from a cooled synchrotron spectrum. Both
models can describe the mean spectral energy distribution (SED) and
temporal evolution similarly well. In order to describe the mean SED,
both models require specific values of the maximum Lorentz factor
γmax, which differ by roughly two orders of magnitude. The
synchrotron self-Compton model suggests that electrons are accelerated
to γmax ∼ 500, while cooled synchrotron model requires
acceleration up to γmax ∼ 5 × 104. The
synchrotron self-Compton scenario requires electron densities of
1010 cm−3 that are much larger than typical
ambient densities in the accretion flow. Furthermore, it requires a
variation of the particle density that is inconsistent with the average
mass-flow rate inferred from polarization measurements and can therefore
only be realized in an extraordinary accretion event. In contrast,
assuming a source size of 1 RS, the cooled synchrotron
scenario can be realized with densities and magnetic fields comparable
with the ambient accretion flow. For both models, the temporal evolution
is regulated through the maximum acceleration factor γmax,
implying that sustained particle acceleration is required to explain
at least a part of the temporal evolution of the flare.
Title: A geometric distance to the supermassive black Hole of NGC 3783
Authors: GRAVITY Collaboration; Amorim, A.; Bauböck, M.; Bentz,
M. C.; Brandner, W.; Bolzer, M.; Clénet, Y.; Davies, R.; de
Zeeuw, P. T.; Dexter, J.; Drescher, A.; Eckart, A.; Eisenhauer, F.;
Förster Schreiber, N. M.; Garcia, P. J. V.; Genzel, R.; Gillessen,
S.; Gratadour, D.; Hönig, S.; Kaltenbrunner, D.; Kishimoto, M.;
Lacour, S.; Lutz, D.; Millour, F.; Netzer, H.; Onken, C. A.; Ott,
T.; Paumard, T.; Perraut, K.; Perrin, G.; Petrucci, P. O.; Pfuhl,
O.; Prieto, M. A.; Rouan, D.; Shangguan, J.; Shimizu, T.; Stadler,
J.; Sternberg, A.; Straub, O.; Straubmeier, C.; Street, R.; Sturm,
E.; Tacconi, L. J.; Tristram, K. R. W.; Vermot, P.; von Fellenberg,
S.; Widmann, F.; Woillez, J.
Bibcode: 2021A&A...654A..85G
Altcode: 2021arXiv210714262G
The angular size of the broad line region (BLR) of the nearby
active galactic nucleus NGC 3783 has been spatially resolved by
recent observations with VLTI/GRAVITY. A reverberation mapping (RM)
campaign has also recently obtained high quality light curves and
measured the linear size of the BLR in a way that is complementary to
the GRAVITY measurement. The size and kinematics of the BLR can be
better constrained by a joint analysis that combines both GRAVITY
and RM data. This, in turn, allows us to obtain the mass of the
supermassive black hole in NGC 3783 with an accuracy that is about a
factor of two better than that inferred from GRAVITY data alone. We
derive MBH = 2.54−0.72+0.90
× 107 M⊙. Finally, and perhaps most
notably, we are able to measure a geometric distance to NGC 3783
of 39.9−11.9+14.5 Mpc. We are able to test
the robustness of the BLR-based geometric distance with measurements
based on the Tully-Fisher relation and other indirect methods. We find
the geometric distance is consistent with other methods within their
scatter. We explore the potential of BLR-based geometric distances to
directly constrain the Hubble constant, H0, and identify
differential phase uncertainties as the current dominant limitation
to the H0 measurement precision for individual sources.
Title: The GRAVITY young stellar object survey. VI. Mapping the
variable inner disk of HD 163296 at sub-au scales
Authors: GRAVITY Collaboration; Sanchez-Bermudez, J.; Caratti O
Garatti, A.; Garcia Lopez, R.; Perraut, K.; Labadie, L.; Benisty,
M.; Brandner, W.; Dougados, C.; Garcia, P. J. V.; Henning, Th.;
Klarmann, L.; Amorim, A.; Bauböck, M.; Berger, J. P.; Le Bouquin,
J. B.; Caselli, P.; Clénet, Y.; Coudé Du Foresto, V.; de Zeeuw,
P. T.; Drescher, A.; Duvert, G.; Eckart, A.; Eisenhauer, F.; Filho,
M.; Gao, F.; Gendron, E.; Genzel, R.; Gillessen, S.; Grellmann,
R.; Heissel, G.; Horrobin, M.; Hubert, Z.; Jiménez-Rosales, A.;
Jocou, L.; Kervella, P.; Lacour, S.; Lapeyrère, V.; Léna, P.; Ott,
T.; Paumard, T.; Perrin, G.; Pineda, J. E.; Rodríguez-Coira, G.;
Rousset, G.; Segura-Cox, D. M.; Shangguan, J.; Shimizu, T.; Stadler,
J.; Straub, O.; Straubmeier, C.; Sturm, E.; van Dishoeck, E.; Vincent,
F.; von Fellenberg, S. D.; Widmann, F.; Woillez, J.
Bibcode: 2021A&A...654A..97G
Altcode: 2021arXiv210702391S
Context. Protoplanetary disks drive some of the formation process
(e.g., accretion, gas dissipation, formation of structures) of
stars and planets. Understanding such physical processes is one
of the most significant astrophysical questions. HD 163296 is an
interesting young stellar object for which infrared and sub-millimeter
observations have shown a prominent circumstellar disk with gaps
plausibly created by forming planets.
Aims: This study aims
to characterize the morphology of the inner disk in HD 163296 with
multi-epoch, near-infrared interferometric observations performed
with GRAVITY at the Very Large Telescope Interferometer. Our goal
is to depict the K-band (λ0 ~ 2.2 μm) structure of the
inner rim with milliarcsecond (sub-au) angular resolution. Our data is
complemented with archival Precision Integrated-Optics Near-infrared
Imaging ExpeRiment (H-band; λ0 ~ 1.65 μm) data of the
source.
Methods: We performed a gradient descent parametric
model fitting to recover the sub-au morphology of our source.
Results: Our analysis shows the existence of an asymmetry in the disk
surrounding the central star of HD 163296. We confirm variability of
the disk structure in the inner ~2 mas (0.2 au). While variability of
the inner disk structure in this source has been suggested by previous
interferometric studies, this is the first time that it is confirmed
in the H- and K-bands by using a complete analysis of the closure
phases and squared visibilities over several epochs. Because of the
separation from the star, position changes, and the persistence of
this asymmetric structure on timescales of several years, we argue
that it is probably a dusty feature (e.g., a vortex or dust clouds)
made by a mixing of silicate and carbon dust and/or refractory grains,
inhomogeneously distributed above the mid-plane of the disk.
Title: LLAMA: Stellar populations in the nuclei of ultra-hard
X-ray-selected AGN and matched inactive galaxies
Authors: Burtscher, L.; Davies, R. I.; Shimizu, T. T.; Riffel,
R.; Rosario, D. J.; Hicks, E. K. S.; Lin, M. -Y.; Riffel, R. A.;
Schartmann, M.; Schnorr-Müller, A.; Storchi-Bergmann, T.; Orban de
Xivry, G.; Veilleux, S.
Bibcode: 2021A&A...654A.132B
Altcode: 2021arXiv210505309B
The relation between nuclear (≲50 pc) star formation and nuclear
galactic activity is still elusive; theoretical models predict a link
between the two, but it is unclear whether active galactic nuclei
(AGNs) should appear at the same time, before, or after nuclear star
formation activity. We present a study of this relation in a complete,
volume-limited sample of nine of the most luminous (log L14 − 195
keV > 1042.5 erg s−1) local AGNs (the
LLAMA sample), including a sample of 18 inactive control galaxies (six
star-forming; 12 passive) that are matched by Hubble type, stellar mass
(9.5 ≲ log M⋆/M⊙ ≲ 10.5), inclination,
and distance. This allows us to calibrate our methods on the control
sample and perform a differential analysis between the AGN and control
samples. We performed stellar population synthesis on VLT/X-shooter
spectra in an aperture corresponding to a physical radius of ≈150
pc. We find young (≲30 Myr) stellar populations in seven out of
nine AGNs and in four out of six star-forming control galaxies. In
the non-star-forming control population, in contrast, only two out of
12 galaxies show such a population. We further show that these young
populations are not indicative of ongoing star formation, providing
evidence for models that see AGN activity as a consequence of nuclear
star formation. Based on the similar nuclear star formation histories
of AGNs and star-forming control galaxies, we speculate that the latter
may turn into the former for some fraction of their time. Under this
assumption, and making use of the volume completeness of our sample,
we infer that the AGN phase lasts for about 5% of the nuclear starburst
phase. Spectra 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/654/A132
Title: The mass of β Pictoris c from β Pictoris b orbital motion
Authors: Lacour, S.; Wang, J. J.; Rodet, L.; Nowak, M.; Shangguan, J.;
Beust, H.; Lagrange, A. -M.; Abuter, R.; Amorim, A.; Asensio-Torres,
R.; Benisty, M.; Berger, J. -P.; Blunt, S.; Boccaletti, A.; Bohn, A.;
Bolzer, M. -L.; Bonnefoy, M.; Bonnet, H.; Bourdarot, G.; Brandner,
W.; Cantalloube, F.; Caselli, P.; Charnay, B.; Chauvin, G.; Choquet,
E.; Christiaens, V.; Clénet, Y.; Coudé Du Foresto, V.; Cridland,
A.; Dembet, R.; Dexter, J.; de Zeeuw, P. T.; Drescher, A.; Duvert,
G.; Eckart, A.; Eisenhauer, F.; Gao, F.; Garcia, P.; Garcia Lopez,
R.; Gendron, E.; Genzel, R.; Gillessen, S.; Girard, J. H.; Haubois,
X.; Heißel, G.; Henning, Th.; Hinkley, S.; Hippler, S.; Horrobin,
M.; Houllé, M.; Hubert, Z.; Jocou, L.; Kammerer, J.; Keppler, M.;
Kervella, P.; Kreidberg, L.; Lapeyrère, V.; Le Bouquin, J. -B.; Léna,
P.; Lutz, D.; Maire, A. -L.; Mérand, A.; Mollière, P.; Monnier,
J. D.; Mouillet, D.; Nasedkin, E.; Ott, T.; Otten, G. P. P. L.;
Paladini, C.; Paumard, T.; Perraut, K.; Perrin, G.; Pfuhl, O.;
Rickman, E.; Pueyo, L.; Rameau, J.; Rousset, G.; Rustamkulov,
Z.; Samland, M.; Shimizu, T.; Sing, D.; Stadler, J.; Stolker, T.;
Straub, O.; Straubmeier, C.; Sturm, E.; Tacconi, L. J.; van Dishoeck,
E. F.; Vigan, A.; Vincent, F.; von Fellenberg, S. D.; Ward-Duong,
K.; Widmann, F.; Wieprecht, E.; Wiezorrek, E.; Woillez, J.; Yazici,
S.; Young, A.; Gravity Collaboration
Bibcode: 2021A&A...654L...2L
Altcode: 2021arXiv210910671L
Aims: We aim to demonstrate that the presence and mass of
an exoplanet can now be effectively derived from the astrometry of
another exoplanet.
Methods: We combined previous astrometry
of β Pictoris b with a new set of observations from the GRAVITY
interferometer. The orbital motion of β Pictoris b is fit using Markov
chain Monte Carlo simulations in Jacobi coordinates. The inner planet,
β Pictoris c, was also reobserved at a separation of 96 mas, confirming
the previous orbital estimations.
Results: From the astrometry
of planet b only, we can (i) detect the presence of β Pictoris c and
(ii) constrain its mass to 10.04−3.10+4.53
MJup. If one adds the astrometry of β Pictoris c, the
mass is narrowed down to 9.15−1.06+1.08
MJup. The inclusion of radial velocity measurements does
not affect the orbital parameters significantly, but it does slightly
decrease the mass estimate to 8.89−0.75+0.75
MJup. With a semimajor axis of 2.68 ± 0.02 au, a period
of 1221 ± 15 days, and an eccentricity of 0.32 ± 0.02, the orbital
parameters of β Pictoris c are now constrained as precisely as those
of β Pictoris b. The orbital configuration is compatible with a
high-order mean-motion resonance (7:1). The impact of the resonance
on the planets' dynamics would then be negligible with respect to the
secular perturbations, which might have played an important role in
the eccentricity excitation of the outer planet.
Title: The Galaxy Activity, Torus, and Outflow Survey (GATOS). I. ALMA
images of dusty molecular tori in Seyfert galaxies
Authors: García-Burillo, S.; Alonso-Herrero, A.; Ramos Almeida,
C.; González-Martín, O.; Combes, F.; Usero, A.; Hönig, S.;
Querejeta, M.; Hicks, E. K. S.; Hunt, L. K.; Rosario, D.; Davies,
R.; Boorman, P. G.; Bunker, A. J.; Burtscher, L.; Colina, L.;
Díaz-Santos, T.; Gandhi, P.; García-Bernete, I.; García-Lorenzo,
B.; Ichikawa, K.; Imanishi, M.; Izumi, T.; Labiano, A.; Levenson,
N. A.; López-Rodríguez, E.; Packham, C.; Pereira-Santaella, M.;
Ricci, C.; Rigopoulou, D.; Rouan, D.; Shimizu, T.; Stalevski, M.;
Wada, K.; Williamson, D.
Bibcode: 2021A&A...652A..98G
Altcode: 2021arXiv210410227G
We present the first results of the Galaxy Activity, Torus, and Outflow
Survey (GATOS), a project aimed at understanding the properties of the
dusty molecular tori and their connection to the host galaxy in nearby
Seyfert galaxies. Our project expands the range of active galactic
nuclei (AGN) luminosities and Eddington ratios covered by previous
surveys of Seyferts conducted by the Atacama Large Millimeter Array
(ALMA), allowing us to study the gas feeding and feedback cycle
in a combined sample of 19 Seyferts. We used ALMA to obtain new
images of the emission of molecular gas and dust using the CO(3-2)
and HCO+(4-3) lines as well as their underlying continuum
emission at 870 μm with high spatial resolutions (0.1″ ∼ 7 −
13 pc) in the circumnuclear disks (CND) of ten nearby (D < 28 Mpc)
Seyfert galaxies selected from an ultra-hard X-ray survey. Our new
ALMA observations detect 870 μm continuum and CO line emission from
spatially resolved disks located around the AGN in all the sources. The
bulk of the 870 μm continuum flux can be accounted for by thermal
emission from dust in the majority of the targets. For most of the
sources, the disks show a preponderant orientation perpendicular
to the AGN wind axes, as expected for dusty molecular tori. The
median diameters and molecular gas masses of the tori are ∼42
pc and ∼6 × 105 M⊙, respectively. We
also detected the emission of the 4-3 line of HCO+ in
four GATOS targets. The order of magnitude differences found in the
CO/HCO+ ratios within our combined sample point to a very
different density radial stratification inside the dusty molecular
tori of these Seyferts. We find a positive correlation between the
line-of-sight gas column densities responsible for the absorption
of X-rays and the molecular gas column densities derived from CO
toward the AGN in our sources. Furthermore, the median values of
both column densities are similar. This suggests that the neutral gas
line-of-sight column densities of the dusty molecular tori imaged by
ALMA significantly contribute to the obscuration of X-rays. The radial
distributions of molecular gas in the CND of our combined sample show
signs of nuclear-scale molecular gas deficits. We also detect molecular
outflows in the sources that show the most extreme nuclear-scale gas
deficits in our sample. These observations find for the first time
supporting evidence that the imprint of AGN feedback is more extreme
in higher luminosity and/or higher Eddington ratio Seyfert galaxies.
Title: VizieR Online Data Catalog: X-shooter spectra of AGN and
inactive galaxies (Burtscher+, 2021)
Authors: Burtscher, L.; Davies, R. I.; Shimizu, T. T.; Riffel,
R.; Rosario, D. J.; Hicks, E. K. S.; Lin, M. -Y.; Riffel, R. A.;
Schartmann, M.; Schnorr-Mueller, A.; Storchi-Bergmann, T.; Orban de
Xivry, G.; Veilleux, S.
Bibcode: 2021yCat..36540132B
Altcode:
Spectra of all observations considered for this publication, i.e. all
49 observations mentioned in Table 2 of the paper. Please see Table
2 for the authors' judgement regarding the data quality of these
observations. For any questions regarding the data or its quality,
please contact Dr. Leonard Burtscher, burtscher(at)strw.leidenuniv.nl,
www.ileo.de or on Twitter as (at)LeoBurtscher. (2 data files).
Title: GRAVITY K-band spectroscopy of HD 206893 B. Brown dwarf
or exoplanet
Authors: Kammerer, J.; Lacour, S.; Stolker, T.; Mollière, P.;
Sing, D. K.; Nasedkin, E.; Kervella, P.; Wang, J. J.; Ward-Duong,
K.; Nowak, M.; Abuter, R.; Amorim, A.; Asensio-Torres, R.; Bauböck,
M.; Benisty, M.; Berger, J. -P.; Beust, H.; Blunt, S.; Boccaletti,
A.; Bohn, A.; Bolzer, M. -L.; Bonnefoy, M.; Bonnet, H.; Brandner,
W.; Cantalloube, F.; Caselli, P.; Charnay, B.; Chauvin, G.; Choquet,
E.; Christiaens, V.; Clénet, Y.; Coudé du Foresto, V.; Cridland,
A.; Dembet, R.; Dexter, J.; de Zeeuw, P. T.; Drescher, A.; Duvert,
G.; Eckart, A.; Eisenhauer, F.; Gao, F.; Garcia, P.; Garcia Lopez,
R.; Gendron, E.; Genzel, R.; Gillessen, S.; Girard, J.; Haubois,
X.; Heißel, G.; Henning, T.; Hinkley, S.; Hippler, S.; Horrobin,
M.; Houllé, M.; Hubert, Z.; Jocou, L.; Keppler, M.; Kreidberg, L.;
Lagrange, A. -M.; Lapeyrère, V.; Le Bouquin, J. -B.; Léna, P.;
Lutz, D.; Maire, A. -L.; Mérand, A.; Monnier, J. D.; Mouillet, D.;
Müller, A.; Ott, T.; Otten, G. P. P. L.; Paladini, C.; Paumard, T.;
Perraut, K.; Perrin, G.; Pfuhl, O.; Pueyo, L.; Rameau, J.; Rodet, L.;
Rousset, G.; Rustamkulov, Z.; Shangguan, J.; Shimizu, T.; Stadler, J.;
Straub, O.; Straubmeier, C.; Sturm, E.; Tacconi, L. J.; van Dishoeck,
E. F.; Vigan, A.; Vincent, F.; von Fellenberg, S. D.; Widmann, F.;
Wieprecht, E.; Wiezorrek, E.; Woillez, J.; Yazici, S.
Bibcode: 2021A&A...652A..57K
Altcode: 2021arXiv210608249K
Context. Near-infrared interferometry has become a powerful tool
for studying the orbital and atmospheric parameters of substellar
companions.
Aims: We aim to reveal the nature of the reddest
known substellar companion HD 206893 B by studying its near-infrared
colors and spectral morphology and by investigating its orbital
motion.
Methods: We fit atmospheric models for giant planets
and brown dwarfs and perform spectral retrievals with petitRADTRANS
and ATMO on the observed GRAVITY, SPHERE, and GPI spectra of HD 206893
B. To recover its unusual spectral features, first and foremost its
extremely red near-infrared color, we include additional extinction by
high-altitude dust clouds made of enstatite grains in the atmospheric
model fits. However, forsterite, corundum, and iron grains predict
similar extinction curves for the grain sizes considered here. We
also infer the orbital parameters of HD 206893 B by combining the ~100
μas precision astrometry from GRAVITY with data from the literature
and constrain the mass and position of HD 206893 C based on the Gaia
proper motion anomaly of the system.
Results: The extremely
red color and the very shallow 1.4 μm water absorption feature of
HD 206893 B can be fit well with the adapted atmospheric models and
spectral retrievals. By comparison with AMES-Cond evolutionary tracks,
we find that only some atmosphericmodels predict physically plausible
objects. Altogether, our analysis suggests an age of ~ 3-300 Myr and
a mass of ~ 5-30 MJup for HD 206893 B, which is consistent
with previous estimates but extends the parameter space to younger and
lower-mass objects. The GRAVITY astrometry points to an eccentric orbit
(e = 0.29−0.11+0.06) with a mutual inclination
of <34.4 deg with respectto the debris disk of the system.
Conclusions: While HD 206893 B could in principle be a planetary-mass
companion, this possibility hinges on the unknown influence of the
inner companion on the mass estimate of 10−4+5
MJup from radial velocity and Gaia as well as a relatively
small but significant Argus moving group membership probability of
~ 61%. However, we find that if the mass of HD 206893 B is <30
MJup, then the inner companion HD 206893 C should have a
mass between ~ 8-15 MJup. Finally, further spectroscopic
or photometric observations at higher signal-to-noise and longer
wavelengths are required to learn more about the composition and dust
cloud properties of HD 206893 B. Based on observations made with
ESO telescopes at Paranal Observatory under program IDs 1103.B-0626
and 1104.C-0651.
Title: The Galaxy Activity, Torus, and Outflow Survey
(GATOS). II. Torus and polar dust emission in nearby Seyfert galaxies
Authors: Alonso-Herrero, A.; García-Burillo, S.; Hönig, S. F.;
García-Bernete, I.; Ramos Almeida, C.; González-Martín, O.;
López-Rodríguez, E.; Boorman, P. G.; Bunker, A. J.; Burtscher, L.;
Combes, F.; Davies, R.; Díaz-Santos, T.; Gandhi, P.; García-Lorenzo,
B.; Hicks, E. K. S.; Hunt, L. K.; Ichikawa, K.; Imanishi, M.; Izumi,
T.; Labiano, A.; Levenson, N. A.; Packham, C.; Pereira-Santaella,
M.; Ricci, C.; Rigopoulou, D.; Roche, P.; Rosario, D. J.; Rouan, D.;
Shimizu, T.; Stalevski, M.; Wada, K.; Williamson, D.
Bibcode: 2021A&A...652A..99A
Altcode: 2021arXiv210700244A
We compare high angular resolution mid-infrared (mid-IR) and Atacama
Large Millimeter/submillimeter Array (ALMA) far-infrared (far-IR)
images of twelve nearby (median 21 Mpc) Seyfert galaxies selected from
the Galaxy Activity, Torus, and Outflow Survey (GATOS). The mid-IR
unresolved emission contributes more than 60% of the nuclear (diameters
of 1.5″ ∼ 150 pc) emission in most galaxies. By contrast, the ALMA
870 μm continuum emission is mostlyresolved with a median diameter
of 42 pc and typically along the equatorial direction of the torus
(Paper I). The Eddington ratios and nuclear hydrogen column densities
(NH) of half the sample are favorable to launching polar
and/or equatorial dusty winds, according to numerical simulations. Six
of these show mid-IR extended emission approximately in the polar
direction as traced by the narrow line region and perpendicular to
the ALMA emission. In a few galaxies, the nuclear NH might
be too high to uplift large quantities of dusty material along the
polar direction. Five galaxies have low NH and/or Eddington
ratios and thus polar dusty winds are not likely. We generated new
radiative transfer CAT3D-WIND disk+wind models and model images at
8, 12, and 700 μm. We tailored these models to the properties of
the GATOS Seyferts in this work. At low wind-to-disk cloud ratios,
the far-IR model images have disk- and ring-like morphologies. The
characteristic "X"-shape associated with dusty winds is seen better
in the far-IR at intermediate-high inclinations for the extended-wind
configurations. In most of the explored models, the mid-IR emission
mainly comes from the inner part of the disk and cone. Extended
biconical and one-sided polar mid-IR emission is seen in extended-wind
configurations and high wind-to-disk cloud ratios. When convolved to
the typical angular resolution of our observations, the CAT3D-WIND
model images reproduce qualitative aspects of the observed mid-
and far-IR morphologies. However, low to intermediate values of
the wind-to-disk ratio are required to account for the observed
large fractions of unresolved mid-IR emission in our sample. This
work and Paper I provide observational support for the torus+wind
scenario. The wind component is more relevant at high Eddington ratios
and/or active galactic nucleus luminosities, and polar dust emission
is predicted at nuclear column densities of up to ∼1024
cm−2. The torus or disk component, on the other hand,
prevails at low luminosities and/or Eddington ratios.
Title: MOLsphere and pulsations of the Galactic Center's red
supergiant GCIRS 7 from VLTI/GRAVITY
Authors: GRAVITY Collaboration; Rodríguez-Coira, G.; Paumard, T.;
Perrin, G.; Vincent, F.; Abuter, R.; Amorim, A.; Bauböck, M.; Berger,
J. P.; Bonnet, H.; Brandner, W.; Clénet, Y.; de Zeeuw, P. T.; Dexter,
J.; Drescher, A.; Eckart, A.; Eisenhauer, F.; Förster Schreiber,
N. M.; Gao, F.; Garcia, P.; Gendron, E.; Genzel, R.; Gillessen, S.;
Habibi, M.; Haubois, X.; Henning, T.; Hippler, S.; Horrobin, M.;
Jimenez-Rosales, A.; Jochum, L.; Jocou, L.; Kaufer, A.; Kervella, P.;
Lacour, S.; Lapeyrère, V.; Le Bouquin, J. B.; Léna, P.; Nowak, M.;
Ott, T.; Perraut, K.; Pfuhl, O.; Sanchez-Bermudez, J.; Shangguan, J.;
Scheithauer, S.; Stadler, J.; Straub, O.; Straubmeier, C.; Sturm, E.;
Tacconi, L. J.; Shimizu, T.; von Fellenberg, S.; Waisberg, I.; Widmann,
F.; Wieprecht, E.; Wiezorrek, E.; Woillez, J.; Yazici, S.; Zins, G.
Bibcode: 2021A&A...651A..37G
Altcode: 2021arXiv210509832G
Context. GCIRS 7, the brightest star in the Galactic central parsec,
formed 6 ± 2 Myr ago together with dozens of massive stars in a
disk orbiting the central black-hole. It has been argued that GCIRS
7 is a pulsating body, on the basis of photometric variability.
Aims: Our goal is to confirm photospheric pulsations based on
interferometric size measurements to better understand how the mass loss
from these massive stars enriches the local interstellar medium.
Methods: We present the first medium-resolution (R = 500), K-band
spectro-interferometric observations of GCIRS 7, using the GRAVITY
instrument with the four auxiliary telescopes of the ESO VLTI. We
looked for variations using two epochs, namely 2017 and 2019.
Results: We find GCIRS 7 to be moderately resolved with a uniform-disk
photospheric diameter of θUD* = 1.55 ± 0.03
mas (RUD* = 1368 ± 26 R⊙) in the
K-band continuum. The narrow-band uniform-disk diameter increases
above 2.3 μm, with a clear correlation with the CO band heads in the
spectrum. This correlation is aptly modeled by a hot (TL =
2368 ± 37 K), geometrically thin molecular shell with a diameter of
θL = 1.74 ± 0.03 mas, as measured in 2017. The shell
diameter increased (θL = 1.89 ± 0.03 mas), while its
temperature decreased (TL = 2140 ± 42 K) in 2019. In
contrast, the photospheric diameter θUD* and the
extinction up to the photosphere of GCIRS 7 (AKS
= 3.18 ± 0.16) have the same value within uncertainties at the two
epochs.
Conclusions: In the context of previous interferometric
and photo-spectrometric measurements, the GRAVITY data allow for an
interpretation in terms of photospheric pulsations. The photospheric
diameter measured in 2017 and 2019 is significantly larger than
previously reported using the PIONIER instrument (θ* = 1.076
± 0.093 mas in 2013 in the H band). The parameters of the photosphere
and molecular shell of GCIRS 7 are comparable to those of other red
supergiants that have previously been studied using interferometry. The
extinction we measured here is lower than previous estimates in the
direction of GCIRS 7 but typical for the central parsec region. Based on observations made with ESO Telescopes at the La Silla
Paranal Observatory under the programme IDs 098.D-0250 and 103.B-0032.
Title: Instrumental design of the Solar Observing Satellite:
solar-C_EUVST
Authors: Suematsu, Yoshinori; Shimizu, Toshifumi; Hara, Hirohisa;
Kawate, Tomoko; Katsukawa, Yukio; Ichimoto, Kiyoshi; Imada, Shinsuke
Bibcode: 2021SPIE11852E..3KS
Altcode:
The EUV High-Throughput Spectroscopic Telescope (EUVST) of Solar-C
mission is a revolutionary spectrometer that is designed to provide
high-quality and high cadence spectroscopic data covering a wide
temperature range of the chromosphere to flaring corona to investigate
the energetics and dynamics of the solar atmosphere. The EUVST consists
of only two imaging optical components; a 28-cm clear aperture off-axis
parabolic primary mirror and a two-split ellipsoidal grating without a
blocking filter for visible light before the primary mirror to achieve
unprecedented high spatial and temporal resolution in EUV-UV imaging
spectroscopic observations. For this reason, about 53 W of sunlight
is absorbed by the multilayer coating on the mirror. We present an
instrumental design of the telescope, particularly, primary mirror
assembly which enables slit-scan observations for imaging spectroscopy,
an image stabilizing tip-tilt control, and a focus adjustment on
orbit, together with an optomechanical design of the primary mirror
and its supporting system which gives optically tolerant wavefront
error against a large temperature increase due to an absorption of
visible and IR lights.
Title: Kiloparsec view of a typical star-forming galaxy when the
Universe was ∼1 Gyr old. I. Properties of outflow, halo, and
interstellar medium
Authors: Herrera-Camus, R.; Förster Schreiber, N.; Genzel, R.;
Tacconi, L.; Bolatto, A.; Davies, R. L.; Fisher, D.; Lutz, D.; Naab,
T.; Shimizu, T.; Tadaki, K.; Übler, H.
Bibcode: 2021A&A...649A..31H
Altcode: 2021arXiv210105279H
We present new Atacama Large Millimeter/Submillimeter Array observations
of the [C II] 158 μm transition and the dust continuum in HZ4, a
typical star-forming galaxy when the Universe was only ∼1 Gyr old
(z ≈ 5.5). Our high ≈0.3″ spatial resolution allows us to study
the relationships between [C II] line emission, star formation rate, and
far-infrared emission on spatial scales of ∼2 kpc. In the central ∼4
kpc of HZ4, the [C II]/FIR is ∼3 × 10−3 on global scales
as well as on spatially resolved scales of ∼2 kpc, comparable to the
ratio observed in local moderate starburst galaxies such as M 82 or M
83. For the first time in an individual normal galaxy at this redshift,
we find evidence for outflowing gas from the central star-forming region
in the direction of the minor axis of the galaxy. The projected velocity
of the outflow is ∼400 km s−1, and the neutral gas-mass
outflow rate is ∼3 − 6 times higher than the star formation rate in
the central region. Finally, we detect a diffuse component of [C II]
emission, or [C II] halo, that extends beyond the star-forming disk
and has a diameter of ∼12 kpc. The outflow, which has a velocity
approximately half of the escape velocity of the system, most likely
partly fuels the [C II] extended emission. Together with the kinematic
analysis of HZ4 (presented in a forthcoming paper), the analysis
supports the hypothesis that HZ4 is a typical star-forming disk at
z ∼ 5 with interstellar medium conditions similar to present-day
galaxies forming stars at a similar level, driving a galactic outflow
that may already play a role in its evolution. The reduced images
and datacubes 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/649/A31
Title: VizieR Online Data Catalog: Completed KMOS3D
survey NIR obs. (Wisnioski+,
Authors: Wisnioski, E.; Schreiber, N. M. F.; Fossati, M.; Mendel,
J. T.; Wilman, D.; Genzel, R.; Bender, R.; Wuyts, S.; Davies, R. L.;
Ubler, H.; Bandara, K.; Beifiori, A.; Belli, S.; Brammer, G.; Chan, J.;
Davies, R. I.; Fabricius, M.; Galametz, A.; Lang, P.; Lutz, D.; Nelson,
E. J.; Momcheva, I.; Price, S.; Rosario, D.; Saglia, R.; Seitz, S.;
Shimizu, T.; Tacconi, L. J.; Tadaki, K.; van Dokkum, P. G.; Wuyts, E.
Bibcode: 2021yCat..18860124W
Altcode:
Observations with the multi-IFU K-band Multi Object Spectrograph (KMOS)
at the VLT took place in Visitor Mode over 75 guaranteed time nights
between 2013 October and 2018 April (ESO periods 92-101). The spectral
resolution of KMOS (R~3000-4000) varies for the 24 different IFUs. (3 data files).
Title: VizieR Online Data Catalog: BAT AGN Spectroscopic
Survey. XX. Molecular gas (Koss+, 2021)
Authors: Koss, M. J.; Strittmatter, B.; Lamperti, I.; Shimizu, T.;
Trakhtenbrot, B.; Saintonge, A.; Treister, E.; Cicone, C.; Mushotzky,
R.; Oh, K.; Ricci, C.; Stern, D.; Ananna, T. T.; Bauer, F. E.; Privon,
G. C.; Bar, R. E.; De Breuck, C.; Harrison, F.; Ichikawa, K.; Powell,
M. C.; Rosario, D.; Sanders, D. B.; Schawinski, K.; Shao, Li; Megan
Urry, C.; Veilleux, S.
Bibcode: 2021yCat..22520029K
Altcode:
Our AGN parent sample consists of 836 ultrahard-X-ray-selected
(14-195keV) AGN included in the 70-month Swift-BAT all-sky catalog
(Baumgartner+ 2013, J/ApJS/207/19). In total, 200 AGN galaxies
were newly observed: 165 with the Atacama Pathfinder Experiment
(APEX) and 35 with the James Clerk Maxwell Telescope (JCMT), while
13 were obtained from the literature (see col. Tel in table 2 and
Section 2.1.3). The APEX 12m antenna observations totalled 254hr
with 2288 400s long scans, taken over 67 days between 2016 March
and 2017 September. The observing programs involved were mainly an
ESO Large program (PI M. Koss, ~150hr), a follow-up ESO program
(PI B. Trakthenbrot, ~50hr), and Chilean time (PI E. Treister,
~75hr). In addition to our own programs, we also reduced data from
archival programs for six BAT AGN galaxies. We observed the CO(2-1)
transition (vrest=230.538GHz) using the Swedish Heterodyne
Facility Instrument (SHFI) with the eXtended Fast Fourier Transform
Spectrometer (XFFTS) backend (213-275GHz). JCMT observations of
the CO(2-1) molecular line were taken between 2011 February and 2013
April. Archival data for one additional galaxy were also reduced
(NGC 6240). We used the A3 (211-279GHz) receiver with the ACSIS
spectrometer with a beam size of 20.4" HPBW. The results for the
complementary sample of z<0.01 BAT AGN galaxies are presented in
Rosario+ (2018MNRAS.473.5658R). (2 data files).
Title: VizieR Online Data Catalog: [CCJ2015b] HZ4 [CII] 158um datacube
(Herrera-Camus+, 2021)
Authors: Herrera-Camus, R.; Foerster Schreiber, N.; Genzel, R.;
Tacconi, L.; Bolatto, A.; Davies, R. L.; Fisher, D.; Lutz, D.; Naab,
T.; Shimizu, T.; Tadaki, K.; Uebler, H.
Bibcode: 2021yCat..36490031H
Altcode:
Between November 2018 and April 2019 (Cycle 6), HZ4 (R.A. 9:58:28.5,
Dec. +2:03:06.7) was observed for 8.4hr in total (4.7hr on-source)
using ALMA as part of project 2018.1.01605.S (PI Herrera-Camus). The
observations were carried out in the C43-4 configuration. We centered
one spectral window on the [CII] line (νrest=1900.537GHz), which for
the source is redshifted to νobs=290.386GHz and falls in Band 7. (2 data files).
Title: The GRAVITY young stellar object survey. V. The orbit of the
T Tauri binary star WW Cha
Authors: GRAVITY Collaboration; Eupen, F.; Labadie, L.; Grellmann, R.;
Perraut, K.; Brandner, W.; Duchêne, G.; Köhler, R.; Sanchez-Bermudez,
J.; Garcia Lopez, R.; Caratti O Garatti, A.; Benisty, M.; Dougados,
C.; Garcia, P.; Klarmann, L.; Amorim, A.; Bauböck, M.; Berger,
J. P.; Caselli, P.; Clénet, Y.; Coudé Du Foresto, V.; de Zeeuw,
P. T.; Drescher, A.; Duvert, G.; Eckart, A.; Eisenhauer, F.; Filho,
M.; Ganci, V.; Gao, F.; Gendron, E.; Genzel, R.; Gillessen, S.;
Heissel, G.; Henning, Th.; Hippler, S.; Horrobin, M.; Hubert, Z.;
Jiménez-Rosales, A.; Jocou, L.; Kervella, P.; Lacour, S.; Lapeyrère,
V.; Le Bouquin, J. B.; Léna, P.; Ott, T.; Paumard, T.; Perrin,
G.; Pfuhl, O.; Rodríguez-Coira, G.; Rousset, G.; Scheithauer, S.;
Shangguan, J.; Shimizu, T.; Stadler, J.; Straub, O.; Straubmeier,
C.; Sturm, E.; van Dishoeck, E.; Vincent, F.; von Fellenberg, S. D.;
Widmann, F.; Woillez, J.; Wojtczak, A.
Bibcode: 2021A&A...648A..37G
Altcode: 2021arXiv210200122G
Context. Close young binary stars are unique laboratories for the
direct measurement of pre-main-sequence (PMS) stellar masses and
their comparison to evolutionary theoretical models. At the same
time, a precise knowledge of their orbital parameters when still
in the PMS phase offers an excellent opportunity for understanding
the influence of dynamical effects on the morphology and lifetime of
the circumstellar as well as circumbinary material.
Aims: The
young T Tauri star WW Cha was recently proposed to be a close binary
object with strong infrared and submillimeter excess associated
with circum-system emission, which makes it dynamically a very
interesting source in the above context. The goal of this work is
to determine the astrometric orbit and the stellar properties of WW
Cha using multi-epoch interferometric observations.
Methods:
We derive the relative astrometric positions and flux ratios of the
stellar companion in WW Cha from the interferometric model fitting of
observations made with the VLTI instruments AMBER, PIONIER, and GRAVITY
in the near-infrared from 2011 to 2020. For two epochs, the resulting
uv-coverage in spatial frequencies permits us to perform the first
image reconstruction of the system in the K band. The positions of nine
epochs are used to determine the orbital elements and the total mass of
the system. Combining the orbital solution with distance measurements
from Gaia DR2 and the analysis of evolutionary tracks, we constrain
the mass ratio.
Results: We find the secondary star orbiting
the primary with a period of T = 206.55 days, a semimajor axis of a =
1.01 au, and a relatively high eccentricity of e = 0.45. The dynamical
mass of Mtot = 3.20 M⊙ can be explained by
a mass ratio between ∼0.5 and 1, indicating an intermediate-mass T
Tauri classification for both components. The orbital angular momentum
vector is in close alignment with the angular momentum vector of the
outer disk as measured by ALMA and SPHERE, resulting in a small mutual
disk inclination. The analysis of the relative photometry suggests
the presence of infrared excess surviving in the system and likely
originating from truncated circumstellar disks. The flux ratio between
the two components appears variable, in particular in the K band,
and may hint at periods of triggered higher and lower accretion or
changes in the disks' structures.
Conclusions: The knowledge of
the orbital parameters, combined with a relatively short period, makes
WW Cha an ideal target for studying the interaction of a close young
T Tauri binary with its surrounding material, such as time-dependent
accretion phenomena. Finding WW Cha to be composed of two (probably
similar) stars led us to reevaluate the mass of WW Cha, which had been
previously derived under the assumption of a single star. This work
illustrates the potential of long baseline interferometry to precisely
characterize close young binary stars separated by a few astronomical
units. Finally, when combined with radial velocity measurements,
individual stellar masses can be derived and used to calibrate
theoretical PMS models. GRAVITY is developed in collaboration
by the Max Planck Institute for Extraterrestrial Physics, LESIA of
Paris Observatory, IPAG of Université Grenoble Alpes/CNRS, the Max
Planck Institute for Astronomy, the University of Cologne, the Centro
de Astrofísica e Gravitação, and the European Southern Observatory.
Title: The central parsec of NGC 3783: a rotating broad emission line
region, asymmetric hot dust structure, and compact coronal line region
Authors: GRAVITY Collaboration; Amorim, A.; Bauböck, M.; Brandner,
W.; Bolzer, M.; Clénet, Y.; Davies, R.; de Zeeuw, P. T.; Dexter, J.;
Drescher, A.; Eckart, A.; Eisenhauer, F.; Förster Schreiber, N. M.;
Gao, F.; Garcia, P. J. V.; Genzel, R.; Gillessen, S.; Gratadour, D.;
Hönig, S.; Kaltenbrunner, D.; Kishimoto, M.; Lacour, S.; Lutz, D.;
Millour, F.; Netzer, H.; Ott, T.; Paumard, T.; Perraut, K.; Perrin,
G.; Peterson, B. M.; Petrucci, P. O.; Pfuhl, O.; Prieto, M. A.; Rouan,
D.; Sanchez-Bermudez, J.; Shangguan, J.; Shimizu, T.; Schartmann,
M.; Stadler, J.; Sternberg, A.; Straub, O.; Straubmeier, C.; Sturm,
E.; Tacconi, L. J.; Tristram, K. R. W.; Vermot, P.; von Fellenberg,
S.; Waisberg, I.; Widmann, F.; Woillez, J.
Bibcode: 2021A&A...648A.117G
Altcode: 2021arXiv210200068G
Using VLTI/GRAVITY and SINFONI data, we investigate the subparsec
gas and dust structure around the nearby type 1 active galactic
nucleus (AGN) hosted by NGC 3783. The K-band coverage of GRAVITY
uniquely allows simultaneous analysis of the size and kinematics
of the broad line region (BLR), the size and structure of the
near-infrared(near-IR)-continuum-emitting hot dust, and the size of the
coronal line region (CLR). We find the BLR, probed through broad Brγ
emission, to be well described by a rotating, thick disc with a radial
distribution of clouds peaking in the inner region. In our BLR model,
the physical mean radius of 16 light-days is nearly twice the ten-day
time-lag that would be measured, which closely matches the ten-day
time-lag that has been measured by reverberation mapping. We measure a
hot dust full-width at half-maximum (FWHM) size of 0.74 mas (0.14 pc)
and further reconstruct an image of the hot dust, which reveals a faint
(5% of the total flux) offset cloud that we interpret as an accreting
or outflowing cloud heated by the central AGN. Finally, we directly
measure the FWHM size of the nuclear CLR as traced by the [Ca VIII] and
narrow Brγ line. We find a FWHM size of 2.2 mas (0.4 pc), fully in line
with the expectation of the CLR located between the BLR and narrow line
region. Combining all of these measurements together with larger scale
near-IR integral field unit and mid-IR interferometry data, we are able
to comprehensively map the structure and dynamics of gas and dust from
0.01 to 100 pc. GRAVITY is developed in a collaboration by the Max
Planck Institute for Extraterrestrial Physics, LESIA of Observatoire de
Paris/Université PSL/CNRS/Sorbonne Université/Université de Paris
and IPAG of Université Grenoble Alpes/CNRS, the Max Planck Institute
for Astronomy, the University of Cologne, the CENTRA - Centro de
Astrofisica e Gravitação, and the European Southern Observatory.
Title: Constraining the Nature of the PDS 70 Protoplanets with
VLTI/GRAVITY
Authors: Wang, J. J.; Vigan, A.; Lacour, S.; Nowak, M.; Stolker,
T.; De Rosa, R. J.; Ginzburg, S.; Gao, P.; Abuter, R.; Amorim, A.;
Asensio-Torres, R.; Bauböck, M.; Benisty, M.; Berger, J. P.; Beust,
H.; Beuzit, J. -L.; Blunt, S.; Boccaletti, A.; Bohn, A.; Bonnefoy,
M.; Bonnet, H.; Brandner, W.; Cantalloube, F.; Caselli, P.; Charnay,
B.; Chauvin, G.; Choquet, E.; Christiaens, V.; Clénet, Y.; Coudé
Du Foresto, V.; Cridland, A.; de Zeeuw, P. T.; Dembet, R.; Dexter,
J.; Drescher, A.; Duvert, G.; Eckart, A.; Eisenhauer, F.; Facchini,
S.; Gao, F.; Garcia, P.; Garcia Lopez, R.; Gardner, T.; Gendron,
E.; Genzel, R.; Gillessen, S.; Girard, J.; Haubois, X.; Heißel,
G.; Henning, T.; Hinkley, S.; Hippler, S.; Horrobin, M.; Houllé, M.;
Hubert, Z.; Jiménez-Rosales, A.; Jocou, L.; Kammerer, J.; Keppler, M.;
Kervella, P.; Meyer, M.; Kreidberg, L.; Lagrange, A. -M.; Lapeyrère,
V.; Le Bouquin, J. -B.; Léna, P.; Lutz, D.; Maire, A. -L.; Ménard,
F.; Mérand, A.; Mollière, P.; Monnier, J. D.; Mouillet, D.; Müller,
A.; Nasedkin, E.; Ott, T.; Otten, G. P. P. L.; Paladini, C.; Paumard,
T.; Perraut, K.; Perrin, G.; Pfuhl, O.; Pueyo, L.; Rameau, J.; Rodet,
L.; Rodríguez-Coira, G.; Rousset, G.; Scheithauer, S.; Shangguan,
J.; Shimizu, T.; Stadler, J.; Straub, O.; Straubmeier, C.; Sturm, E.;
Tacconi, L. J.; van Dishoeck, E. F.; Vincent, F.; von Fellenberg,
S. D.; Ward-Duong, K.; Widmann, F.; Wieprecht, E.; Wiezorrek, E.;
Woillez, J.; Gravity Collaboration
Bibcode: 2021AJ....161..148W
Altcode: 2021arXiv210104187W
We present K-band interferometric observations of the PDS 70
protoplanets along with their host star using VLTI/GRAVITY. We obtained
K-band spectra and 100 μas precision astrometry of both PDS 70 b
and c in two epochs, as well as spatially resolving the hot inner
disk around the star. Rejecting unstable orbits, we found a nonzero
eccentricity for PDS 70 b of 0.17 ± 0.06, a near-circular orbit
for PDS 70 c, and an orbital configuration that is consistent with
the planets migrating into a 2:1 mean motion resonance. Enforcing
dynamical stability, we obtained a 95% upper limit on the mass
of PDS 70 b of 10 MJup, while the mass of PDS 70 c was
unconstrained. The GRAVITY K-band spectra rules out pure blackbody
models for the photospheres of both planets. Instead, the models with
the most support from the data are planetary atmospheres that are
dusty, but the nature of the dust is unclear. Any circumplanetary
dust around these planets is not well constrained by the planets'
1-5 μm spectral energy distributions (SEDs) and requires longer
wavelength data to probe with SED analysis. However with VLTI/GRAVITY,
we made the first observations of a circumplanetary environment with
sub-astronomical-unit spatial resolution, placing an upper limit of
0.3 au on the size of a bright disk around PDS 70 b. ∗
Based on observations collected at the European Southern Observatory
under ESO programmes 0101.C-0281(B), 1103.B-0626(A), 2103.C-5018(A),
and 1104.C-0651(A).
Title: Improved GRAVITY astrometric accuracy from modeling optical
aberrations
Authors: GRAVITY Collaboration; Abuter, R.; Amorim, A.; Bauböck,
M.; Berger, J. P.; Bonnet, H.; Brandner, W.; Clénet, Y.; Davies,
R.; de Zeeuw, P. T.; Dexter, J.; Dallilar, Y.; Drescher, A.; Eckart,
A.; Eisenhauer, F.; Förster Schreiber, N. M.; Garcia, P.; Gao,
F.; Gendron, E.; Genzel, R.; Gillessen, S.; Habibi, M.; Haubois, X.;
Heißel, G.; Henning, T.; Hippler, S.; Horrobin, M.; Jiménez-Rosales,
A.; Jochum, L.; Jocou, L.; Kaufer, A.; Kervella, P.; Lacour, S.;
Lapeyrère, V.; Le Bouquin, J. -B.; Léna, P.; Lutz, D.; Nowak, M.;
Ott, T.; Paumard, T.; Perraut, K.; Perrin, G.; Pfuhl, O.; Rabien, S.;
Rodríguez-Coira, G.; Shangguan, J.; Shimizu, T.; Scheithauer, S.;
Stadler, J.; Straub, O.; Straubmeier, C.; Sturm, E.; Tacconi, L. J.;
Vincent, F.; von Fellenberg, S.; Waisberg, I.; Widmann, F.; Wieprecht,
E.; Wiezorrek, E.; Woillez, J.; Yazici, S.; Young, A.; Zins, G.
Bibcode: 2021A&A...647A..59G
Altcode: 2021arXiv210112098G
The GRAVITY instrument on the ESO VLTI pioneers the field of
high-precision near-infrared interferometry by providing astrometry at
the 10-100 μas level. Measurements at this high precision crucially
depend on the control of systematic effects. We investigate how
aberrations introduced by small optical imperfections along the path
from the telescope to the detector affect the astrometry. We develop
an analytical model that describes the effect of these aberrations on
the measurement of complex visibilities. Our formalism accounts for
pupil-plane and focal-plane aberrations, as well as for the interplay
between static and turbulent aberrations, and it successfully reproduces
calibration measurements of a binary star. The Galactic Center
observations with GRAVITY in 2017 and 2018, when both Sgr A* and the
star S2 were targeted in a single fiber pointing, are affected by these
aberrations at a level lower than 0.5 mas. Removal of these effects
brings the measurement in harmony with the dual-beam observations
of 2019 and 2020, which are not affected by these aberrations. This
also resolves the small systematic discrepancies between the derived
distance R0 to the Galactic Center that were reported
previously. GRAVITY is developed in a collaboration by the Max
Planck Institute for extraterrestrial Physics, LESIA of Observatoire de
Paris/Université PSL/CNRS/Sorbonne Université/Université de Paris
and IPAG of Université Grenoble Alpes/CNRS, the Max Planck Institute
for Astronomy, the University of Cologne, the CENTRA - Centro de
Astrofisica e Gravitação, and the European Southern Observatory.
Title: The KMOS3D Survey: Investigating the Origin of the
Elevated Electron Densities in Star-forming Galaxies at 1 ≲ z ≲ 3
Authors: Davies, Rebecca L.; Förster Schreiber, N. M.; Genzel, R.;
Shimizu, T. T.; Davies, R. I.; Schruba, A.; Tacconi, L. J.; Übler,
H.; Wisnioski, E.; Wuyts, S.; Fossati, M.; Herrera-Camus, R.; Lutz,
D.; Mendel, J. T.; Naab, T.; Price, S. H.; Renzini, A.; Wilman,
D.; Beifiori, A.; Belli, S.; Burkert, A.; Chan, J.; Contursi, A.;
Fabricius, M.; Lee, M. M.; Saglia, R. P.; Sternberg, A.
Bibcode: 2021ApJ...909...78D
Altcode: 2020arXiv201210445D
We investigate what drives the redshift evolution of the typical
electron density (ne) in star-forming galaxies, using
a sample of 140 galaxies drawn primarily from KMOS3D
(0.6 < z < 2.6) and 471 galaxies from SAMI (z < 0.113). We
select galaxies that do not show evidence of active galactic
nucleus activity or outflows to constrain the average conditions
within H II regions. Measurements of the [S II]λ6716/[S II]λ6731
ratio in four redshift bins indicate that the local ne
in the line-emitting material decreases from 187 ${}_{-132}^{+140}$
cm-3 at z ∼ 2.2 to 32 ${}_{-9}^{+4}$ cm-3 at z
∼ 0, consistent with previous results. We use the Hα luminosity to
estimate the rms ne averaged over the volumes of star-forming
disks at each redshift. The local and volume-averaged ne
evolve at similar rates, hinting that the volume filling factor of
the line-emitting gas may be approximately constant across 0 ≲
z ≲ 2.6. The KMOS3D and SAMI galaxies follow a roughly
monotonic trend between ne and star formation rate, but the
KMOS3D galaxies have systematically higher ne than
the SAMI galaxies at a fixed offset from the star-forming main sequence,
suggesting a link between the ne evolution and the evolving
main sequence normalization. We quantitatively test potential drivers
of the density evolution and find that ne(rms) $\simeq
{n}_{{{\rm{H}}}_{2}}$ , suggesting that the elevated ne
in high-z H II regions could plausibly be the direct result of higher
densities in the parent molecular clouds. There is also tentative
evidence that ne could be influenced by the balance between
stellar feedback, which drives the expansion of H II regions, and the
ambient pressure, which resists their expansion.
Title: The Diverse Molecular Gas Content of Massive Galaxies
Undergoing Quenching at z ∼ 1
Authors: Belli, Sirio; Contursi, Alessandra; Genzel, Reinhard; Tacconi,
Linda J.; Förster-Schreiber, Natascha M.; Lutz, Dieter; Combes,
Françoise; Neri, Roberto; García-Burillo, Santiago; Schuster,
Karl F.; Herrera-Camus, Rodrigo; Tadaki, Ken-ichi; Davies, Rebecca
L.; Davies, Richard I.; Johnson, Benjamin D.; Lee, Minju M.; Leja,
Joel; Nelson, Erica J.; Price, Sedona H.; Shangguan, Jinyi; Shimizu,
T. Taro; Tacchella, Sandro; Übler, Hannah
Bibcode: 2021ApJ...909L..11B
Altcode: 2021arXiv210207881B
We present a detailed study of the molecular gas content and stellar
population properties of three massive galaxies at 1 < z < 1.3
that are in different stages of quenching. The galaxies were selected
to have quiescent optical/near-infrared spectral energy distribution
and relatively bright emission at 24 μm, and show remarkably diverse
properties. CO emission from each of the three galaxies is detected in
deep NOEMA observations, allowing us to derive molecular gas fractions
Mgas/M* of 13%-23%. We also reconstruct the star
formation histories by fitting models to the observed photometry and
optical spectroscopy, finding evidence for recent rejuvenation in one
object, slow quenching in another, and rapid quenching in the third
system. To better constrain the quenching mechanism we explore the
depletion times for our sample and other similar samples at z ∼
0.7 from the literature. We find that the depletion times are highly
dependent on the method adopted to measure the star formation rate:
using the UV+IR luminosity we obtain depletion times about 6 times
shorter than those derived using dust-corrected [O II] emission. When
adopting the star formation rates from spectral fitting, which
are arguably more robust, we find that recently quenched galaxies
and star-forming galaxies have similar depletion times, while older
quiescent systems have longer depletion times. These results offer new,
important constraints for physical models of galaxy quenching.
Title: Mapping solar magnetic fields from the photosphere to the
base of the corona
Authors: Ishikawa, Ryohko; Bueno, Javier Trujillo; del Pino Alemán,
Tanausú; Okamoto, Takenori J.; McKenzie, David E.; Auchère,
Frédéric; Kano, Ryouhei; Song, Donguk; Yoshida, Masaki; Rachmeler,
Laurel A.; Kobayashi, Ken; Hara, Hirohisa; Kubo, Masahito; Narukage,
Noriyuki; Sakao, Taro; Shimizu, Toshifumi; Suematsu, Yoshinori; Bethge,
Christian; De Pontieu, Bart; Dalda, Alberto Sainz; Vigil, Genevieve D.;
Winebarger, Amy; Ballester, Ernest Alsina; Belluzzi, Luca; Štěpán,
Jiří; Ramos, Andrés Asensio; Carlsson, Mats; Leenaarts, Jorrit
Bibcode: 2021SciA....7.8406I
Altcode: 2021arXiv210301583I
Routine ultraviolet imaging of the Sun's upper atmosphere shows the
spectacular manifestation of solar activity; yet we remain blind to
its main driver, the magnetic field. Here we report unprecedented
spectropolarimetric observations of an active region plage and
its surrounding enhanced network, showing circular polarization in
ultraviolet (Mg II $h$ & $k$ and Mn I) and visible (Fe I) lines. We
infer the longitudinal magnetic field from the photosphere to the
very upper chromosphere. At the top of the plage chromosphere the
field strengths reach more than 300 gauss, strongly correlated with
the Mg II $k$ line core intensity and the electron pressure. This
unique mapping shows how the magnetic field couples the different
atmospheric layers and reveals the magnetic origin of the heating in
the plage chromosphere.
Title: Ionized outflows in local luminous AGN: Density and outflow
rate
Authors: Davies, R.; Baron, D.; Shimizu, T.; Netzer, H.
Bibcode: 2021IAUS..359..226D
Altcode:
We use the LLAMA survey to study the density and outflow rate of ionized
gas in a complete volume limited sample of local (<40 Mpc) luminous
(43.0 < log LAGN(erg/s) < 44.5) AGN selected by very
hard 14-195 keV X-rays. The detailed data available for this survey
enable us to measure the density of the outflowing ionized gas in
the central 300 pc of these AGN using three different and independent
methods (the standard [SII] doublet ratio; a method comparing [OII]
and [SII] ratios that include auroral and transauroral lines; and a
recently proposed method based on the ionization parameter). For each
method there is, as expected, a modest spread of densities among the
AGN in the sample. But remarkably, the median densities for each method
differ hugely, by an order of magnitude from below 400 cm-3
to almost 5000 cm-3. We discuss how the derived densities
can be reconciled, and what the impact is on the implied outflow rate.
Title: Detection of faint stars near Sagittarius A* with GRAVITY
Authors: GRAVITY Collaboration; Abuter, R.; Amorim, A.; Bauböck, M.;
Berger, J. P.; Bonnet, H.; Brandner, W.; Clénet, Y.; Dallilar, Y.;
Davies, R.; de Zeeuw, P. T.; Dexter, J.; Drescher, A.; Eisenhauer,
F.; Förster Schreiber, N. M.; Garcia, P.; Gao, F.; Gendron, E.;
Genzel, R.; Gillessen, S.; Habibi, M.; Haubois, X.; Heißel, G.;
Henning, T.; Hippler, S.; Horrobin, M.; Jiménez-Rosales, A.; Jochum,
L.; Jocou, L.; Kaufer, A.; Kervella, P.; Lacour, S.; Lapeyrère, V.;
Le Bouquin, J. -B.; Léna, P.; Lutz, D.; Nowak, M.; Ott, T.; Paumard,
T.; Perraut, K.; Perrin, G.; Pfuhl, O.; Rabien, S.; Rodríguez-Coira,
G.; Shangguan, J.; Shimizu, T.; Scheithauer, S.; Stadler, J.; Straub,
O.; Straubmeier, C.; Sturm, E.; Tacconi, L. J.; Vincent, F.; von
Fellenberg, S.; Waisberg, I.; Widmann, F.; Wieprecht, E.; Wiezorrek,
E.; Woillez, J.; Yazici, S.; Zins, G.
Bibcode: 2021A&A...645A.127G
Altcode: 2020arXiv201103058G
The spin of the supermassive black hole that resides at the Galactic
Center can, in principle, be measured by accurate measurements
of the orbits of stars that are much closer to Sgr A* than S2, the
orbit of which recently provided the measurement of the gravitational
redshift and the Schwarzschild precession. The GRAVITY near-infrared
interferometric instrument combining the four 8m telescopes of the VLT
provides a spatial resolution of 2-4 mas, breaking the confusion barrier
for adaptive-optics-assisted imaging with a single 8-10m telescope. We
used GRAVITY to observe Sgr A* over a period of six months in 2019 and
employed interferometric reconstruction methods developed in radio
astronomy to search for faint objects near Sgr A*. This revealed a
slowly moving star of magnitude 18.9 in the K-band within 30 mas of Sgr
A*. The position and proper motion of the star are consistent with the
previously known star S62, which is at a substantially greater physical
distance, but in projection passes close to Sgr A*. Observations in
August and September 2019 detected S29 easily, with K-magnitude of 16.6,
at approximately 130 mas from Sgr A*. The planned upgrades of GRAVITY,
and further improvements in the calibration, offer greater chances of
finding stars fainter than K-magnitude of 19.
Title: The ExoGRAVITY project: using single mode interferometry to
characterize exoplanets
Authors: Lacour, S.; Wang, J. J.; Nowak, M.; Pueyo, L.; Eisenhauer,
F.; Lagrange, A. -M.; Mollière, P.; Abuter, R.; Amorin, A.;
Asensio-Torres, R.; Bauböck, M.; Benisty, M.; Berger, J. P.; Beust,
H.; Blunt, S.; Boccaletti, A.; Bohn, A.; Bonnefoy, M.; Bonnet, H.;
Brandner, W.; Cantalloube, F.; Caselli, P.; Charnay, B.; Chauvin, G.;
Choquet, E.; Christiaens, V.; Clénet, Y.; Cridland, A.; de Zeeuw,
P. T.; Dembet, R.; Dexter, J.; Drescher, A.; Duvert, G.; Gao, F.;
Garcia, P.; Garcia Lopez, R.; Gardner, T.; Gendron, E.; Genzel, R.;
Gillessen, S.; Girard, J. H.; Haubois, X.; Heißel, G.; Henning,
T.; Hinkley, S.; Hippler, S.; Horrobin, M.; Houllé, M.; Hubert, Z.;
Jiménez-Rosales, A.; Jocou, L.; Kammerer, J.; Keppler, M.; Kervella,
P.; Kreidberg, L.; Lapeyrère, V.; Le Bouquin, J. -B.; Léna, P.;
Lutz, D.; Maire, A. -L.; Mérand, A.; Monnier, J. D.; Mouillet, D.;
Muller, A.; Nasedkin, E.; Ott, T.; Otten, G. P. P. L.; Paladini, C.;
Paumard, T.; Perraut, K.; Perrin, G.; Pfuhl, O.; Rameau, J.; Rodet,
L.; Rodriguez-Coira, G.; Rousset, G.; Shangguan, J.; Shimizu, T.;
Stadler, J.; Straub, O.; Straubmeier, C.; Sturm, E.; Stolker, T.;
van Dishoeck, E. F.; Vigan, A.; Vincent, F.; von Fellenberg, S. D.;
Ward-Duong, K.; Widmann, F.; Wieprecht, E.; Wiezorrek, E.; Woillez, J.
Bibcode: 2020SPIE11446E..0OL
Altcode: 2021arXiv210107098L
Combining adaptive optics and interferometric observations results in
a considerable contrast gain compared to single-telescope, extreme AO
systems. Taking advantage of this, the ExoGRAVITY project is a survey
of known young giant exoplanets located in the range of 0.1" to 2" from
their stars. The observations provide astrometric data of unprecedented
accuracy, being crucial for refining the orbital parameters of planets
and illuminating their dynamical histories. Furthermore, GRAVITY will
measure non-Keplerian perturbations due to planet-planet interactions
in multi-planet systems and measure dynamical masses. Over time,
repetitive observations of the exoplanets at medium resolution (R = 500)
will provide a catalogue of K-band spectra of unprecedented quality,
for a number of exoplanets. The K-band has the unique properties
that it contains many molecular signatures (CO, H2O,
CH4, CO2). This allows constraining precisely
surface gravity, metallicity, and temperature, if used in conjunction
with self-consistent models like Exo-REM. Further, we will use the
parameter-retrieval algorithm petitRADTRANS to constrain the C/O ratio
of the planets. Ultimately, we plan to produce the first C/O survey of
exoplanets, kick-starting the difficult process of linking planetary
formation with measured atomic abundances.
Title: SUNRISE Chromospheric Infrared spectroPolarimeter (SCIP)
for SUNRISE III: Scan mirror mechanism
Authors: Oba, Takayoshi; Shimizu, Toshifumi; Katsukawa, Yukio; Kubo,
Masahito; Uraguchi, Fumihiro; Tsuzuki, Toshihiro; Tamura, Tomonori;
Shinoda, Kazuya; Kodeki, Kazuhide; Fukushima, Kazuhiko; Gandorfer,
Achim; del Toro Iniesta, Jose Carlos
Bibcode: 2020SPIE11445E..4FO
Altcode:
The SUNRISE Chromospheric Infrared spectroPolarimeter (SCIP) is a
balloon-borne long-slit spectrograph for SUNRISE III to precisely
measure magnetic fields in the solar atmosphere. The scan mirror
mechanism (SMM) is installed in the optical path to the entrance slit
of the SCIP to move solar images focused on the slit for 2-dimensional
mapping. The SMM is required to have (1) the tilt stability better
than 0.035″ (3σ) on the sky angle for the diffraction-limited
spatial resolution of 0.2″, (2) step response shorter than 32 msec
for rapid scanning observations, and (3) good linearity (i.e. step
uniformity) over the entire field-of-view (60″x60″). To achieve
these performances, we have developed a flight-model mechanism
and its electronics, in which the mirror tilt is controlled by
electromagnetic actuators with a closed-loop feedback logic with
tilt angles from gap-based capacitance sensors. Several optical
measurements on the optical bench verified that the mechanism meets
the requirements. In particular, the tilt stability achives better
than 0.012″ (3σ). Thermal cycling and thermal vacuum tests have
been completed to demonstrate the performance in the vacuum and the
operational temperature range expected in the balloon flight. We
found a small temperature dependence in the step uniformity and this
dependence will be corrected to have 2-demensional maps with the
sub-arcsec spatial accuracy in the data post-processing.
Title: Sunrise Chromospheric Infrared spectroPolarimeter (SCIP)
for SUNRISE III: optical design and performance
Authors: Tsuzuki, Toshihiro; Katsukawa, Yukio; Uraguchi, Fumihiro;
Hara, Hirohisa; Kubo, Masahito; Nodomi, Yoshifumi; Suematsu, Yoshinori;
Kawabata, Yusuke; Shimizu, Toshifumi; Gandorfer, Achim; Feller, Alex;
Grauf, Bianca; Solanki, Sami; Carlos del Toro Iniesta, Jose
Bibcode: 2020SPIE11447E..AJT
Altcode:
The Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) is a
near-IR spectro-polarimeter instrument newly designed for Sunrise III,
which is a balloon-borne solar observatory equipped with a 1 m optical
telescope. To acquire high-quality 3D magnetic and velocity fields,
SCIP selects the two wavelength bands centered at 850 nm and 770 nm,
which contain many spectrum lines that are highly sensitive to magnetic
fields permeating the photosphere and chromosphere. To achieve high
spatial and spectral resolution (0.21 arcsec and 2 × 105),
SCIP optics adopt a quasi-Littrow configuration based on an echelle
grating and two high-order aspheric mirrors. Using different diffraction
orders of the echelle grating, dichroic beam splitter, and polarizing
beam-splitters, SCIP can obtain s- and p-polarization signals in the
two wavelength bands simultaneously within a relatively small space. We
established the wavefront error budget based on tolerance analysis,
surface figure errors, alignment errors, and environmental changes. In
addition, we performed stray light analysis, and designed light traps
and baffles needed to suppress unwanted reflections and diffraction
by the grating. In this paper, we present the details of this optical
system and its performance.
Title: Sunrise Chromospheric Infrared spectroPolarimeter (SCIP)
for SUNRISE III: polarization modulation unit
Authors: Kubo, Masahito; Shimizu, Toshifumi; Katsukawa, Yukio;
Kawabata, Yusuke; Anan, Tetsu; Ichimoto, Kiyoshi; Shinoda, Kazuya;
Tamura, Tomonori; Nodomi, Yoshifumi; Nakayama, Satoshi; Yamada, Takuya;
Tajima, Takao; Nakata, Shimpei; Nakajima, Yoshihito; Okutani, Kousei;
Feller, Alex; del Toro Iniesta, Jose Carlos
Bibcode: 2020SPIE11447E..A3K
Altcode:
Polarization measurements of the solar chromospheric lines at
high precision are key to present and future solar telescopes for
understanding magnetic field structures in the chromosphere. The
Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) for Sunrise
III is a spectropolarimeter with a polarimetric precision of 0.03 %
(1 σ). The key to high-precision polarization measurements using
SCIP is a polarization modulation unit that rotates a waveplate
continuously at a constant speed. The rotating mechanism is a DC
brushless motor originally developed for a future space mission, and
its control logic was originally developed for the sounding rocket
experiment CLASP. Because of our requirement on a speed of rotation
(0.512 s/rotation) that was 10 times faster than that of CLASP, we
optimized the control logic for the required faster rotation. Fast
polarization modulation is essential for investigating the fine-scale
magnetic field structures related to the dynamical chromospheric
phenomena. We have verified that the rotation performance can achieve
the polarization precision of 0.03 % (1 σ) required by SCIP and such
a significant rotation performance is maintained under thermal vacuum
conditions by simulating the environment of the Sunrise III balloon
flight. The waveplate was designed as a pair of two birefringent
plates made of quartz and sapphire to achieve a constant retardation
in a wide wavelength range. We have confirmed that the retardation
is almost constant in the 770 nm and 850nm wavelength bands of SCIP
under the operational temperature conditions.
Title: Sunrise Chromospheric Infrared spectroPolarimeter (SCIP)
for SUNRISE III: opto-mechanical analysis and design
Authors: Uraguchi, Fumihiro; Tsuzuki, Toshihiro; Katsukawa, Yukio;
Hara, Hirohisa; Iwamura, Satoru; Kubo, Masahito; Nodomi, Yoshifumi;
Suematsu, Yoshinori; Kawabata, Yusuke; Shimizu, Toshifumi; Gandorfer,
Achim; del Toro Iniesta, Jose Carlos
Bibcode: 2020SPIE11447E..ABU
Altcode:
The Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) is a
near-IR spectro-polarimeter instrument newly designed for Sunrise III,
a balloon-borne solar observatory with a 1-m diameter telescope. In
order to achieve the strict requirements the SCIP wavefront error, it is
necessary to quantify the errors due to environmen- tal effects such as
gravity and temperature variation under the observation conditions. We
therefore conducted an integrated opto-mechanical analysis incorporating
mechanical and thermal disturbances into a finite element model of
the entire SCIP structure to acquire the nodal displacements of each
optical element, then fed them back to the optical analysis software
in the form of rigid body motion and surface deformation fitted by
polynomials. This method allowed us to determine the error factors
having a significant influence on optical performance. For example,
no significant wavefront degradation was associated with the structural
mountings because the optical element mounts were well designed based
on quasi-kinematic constraints. In contrast, we found that the main
factor affecting wavefront degradation was the rigid body motions of
the optical elements, which must be mini- mized within the allowable
level. Based on these results, we constructed the optical bench using a
sandwich panel as the optical bench consisting of an aluminum-honeycomb
core and carbon fiber reinforced plastic skins with a high stiffness
and low coefficient of thermal expansion. We then confirmed that the
new opto-mechanical model achieved the wavefront error requirement. In
this paper, we report the details of this integrated opto-mechanical
analysis, including the wavefront error budgeting and the design of
the opto-mechanics.
Title: Significant Suppression of Star Formation in Radio-quiet AGN
Host Galaxies with Kiloparsec-scale Radio Structures
Authors: Smith, Krista Lynne; Koss, Michael; Mushotzky, Richard;
Wong, O. Ivy; Shimizu, T. Taro; Ricci, Claudio; Ricci, Federica
Bibcode: 2020ApJ...904...83S
Altcode: 2020arXiv201013806S
We conducted 22 GHz 1″ Jansky Very Large Array imaging of 100
radio-quiet X-ray-selected active galactic nuclei (AGN) from the
Swift-Burst Array Telescope (Swift-BAT) survey. We find AGN-driven
kiloparsec-scale radio structures inconsistent with pure star formation
in 11 AGN. The host galaxies of these AGN lie significantly below the
star-forming main sequence, indicating suppressed star formation. While
these radio structures tend to be physically small compared to the host
galaxy, the global star formation rate of the host is affected. We
evaluate the energetics of the radio structures interpreted first
as immature radio jets, and then as consequences of an AGN-driven
radiative outflow, and compare them to two criteria for successful
feedback: the ability to remove the CO-derived molecular gas mass from
the galaxy gravitational potential and the kinetic energy transfer to
molecular clouds leading to vcloud > σ*. In
most cases, the jet interpretation is insufficient to provide the energy
necessary to cause the star formation suppression. Conversely, the wind
interpretation provides ample energy in all but one case. We conclude
that it is more likely that the observed suppression of star formation
in the global host galaxy is due to interstellar medium interactions
of a radiative outflow, rather than a small-scale radio jet.
Title: Determining Subparsec Supermassive Black Hole Binary Orbits
with Infrared Interferometry
Authors: Dexter, Jason; Lutz, Dieter; Shimizu, T. Taro; Shangguan,
Jinyi; Davies, Richard I.; de Zeeuw, P. Tim; Sturm, Eckhard;
Eisenhauer, Frank; Förster-Schreiber, Natascha M.; Gao, Feng;
Genzel, Reinhard; Gillessen, Stefan; Pfuhl, Oliver; Tacconi, Linda J.;
Widmann, Felix
Bibcode: 2020ApJ...905...33D
Altcode: 2020arXiv201009735D
Radial-velocity monitoring has revealed the presence of moving
broad emission lines in some quasars, potentially indicating the
presence of a subparsec binary system. Phase-referenced, near-infrared
interferometric observations could map out the binary orbit by measuring
the photocenter difference between a broad emission line and the
hot dust continuum. We show that astrometric data over several years
may be able to detect proper motions and accelerations, confirming
the presence of a binary and constraining system parameters. The
brightness, redshifts, and astrometric sizes of current candidates are
well matched to the capabilities of the upgraded Very Large Telescope
Interferometer/GRAVITY+ instrument, and we identify a first sample
of 10 possible candidates. The astrometric signature depends on the
morphology and evolution of hot dust emission in supermassive black
hole binary systems. Measurements of the photocenter offset may reveal
binary motion whether the hot dust emission region is fixed to the
inner edge of the circumbinary disk, or moves in response to the
changing irradiation pattern from an accreting secondary black hole.
Title: The Solar-C (EUVST) mission: the latest status
Authors: Shimizu, Toshifumi; Imada, Shinsuke; Kawate, Tomoko; Suematsu,
Yoshinori; Hara, Hirohisa; Tsuzuki, Toshihiro; Katsukawa, Yukio; Kubo,
Masahito; Ishikawa, Ryoko; Watanabe, Tetsuya; Toriumi, Shin; Ichimoto,
Kiyoshi; Nagata, Shin'ichi; Hasegawa, Takahiro; Yokoyama, Takaaki;
Watanabe, Kyoko; Tsuno, Katsuhiko; Korendyke, Clarence M.; Warren,
Harry; De Pontieu, Bart; Boerner, Paul; Solanki, Sami K.; Teriaca,
Luca; Schuehle, Udo; Matthews, Sarah; Long, David; Thomas, William;
Hancock, Barry; Reid, Hamish; Fludra, Andrzej; Auchère, Frederic;
Andretta, Vincenzo; Naletto, Giampiero; Poletto, Luca; Harra, Louise
Bibcode: 2020SPIE11444E..0NS
Altcode:
Solar-C (EUVST) is the next Japanese solar physics mission to
be developed with significant contributions from US and European
countries. The mission carries an EUV imaging spectrometer with
slit-jaw imaging system called EUVST (EUV High-Throughput Spectroscopic
Telescope) as the mission payload, to take a fundamental step towards
answering how the plasma universe is created and evolves and how the
Sun influences the Earth and other planets in our solar system. In
April 2020, ISAS (Institute of Space and Astronautical Science) of JAXA
(Japan Aerospace Exploration Agency) has made the final down-selection
for this mission as the 4th in the series of competitively chosen
M-class mission to be launched with an Epsilon launch vehicle in mid
2020s. NASA (National Aeronautics and Space Administration) has selected
this mission concept for Phase A concept study in September 2019 and
is in the process leading to final selection. For European countries,
the team has (or is in the process of confirming) confirmed endorsement
for hardware contributions to the EUVST from the national agencies. A
recent update to the mission instrumentation is to add a UV spectral
irradiance monitor capability for EUVST calibration and scientific
purpose. This presentation provides the latest status of the mission
with an overall description of the mission concept emphasizing on key
roles of the mission in heliophysics research from mid 2020s.
Title: Sunrise Chromospheric Infrared SpectroPolarimeter (SCIP)
for sunrise III: system design and capability
Authors: Katsukawa, Y.; del Toro Iniesta, J. C.; Solanki, S. K.;
Kubo, M.; Hara, H.; Shimizu, T.; Oba, T.; Kawabata, Y.; Tsuzuki,
T.; Uraguchi, F.; Nodomi, Y.; Shinoda, K.; Tamura, T.; Suematsu,
Y.; Ishikawa, R.; Kano, R.; Matsumoto, T.; Ichimoto, K.; Nagata, S.;
Quintero Noda, C.; Anan, T.; Orozco Suárez, D.; Balaguer Jiménez,
M.; López Jiménez, A. C.; Cobos Carrascosa, J. P.; Feller, A.;
Riethmueller, T.; Gandorfer, A.; Lagg, A.
Bibcode: 2020SPIE11447E..0YK
Altcode:
The Sunrise balloon-borne solar observatory carries a 1 m aperture
optical telescope and provides us a unique platform to conduct
continuous seeing-free observations at UV-visible-IR wavelengths from
an altitude of higher than 35 km. For the next flight planned for
2022, the post-focus instrumentation is upgraded with new spectro-
polarimeters for the near UV (SUSI) and the near-IR (SCIP), whereas
the imaging spectro-polarimeter Tunable Magnetograph (TuMag) is capable
of observing multiple spectral lines within the visible wavelength. A
new spectro-polarimeter called the Sunrise Chromospheric Infrared
spectroPolarimeter (SCIP) is under development for observing near-IR
wavelength ranges of around 770 nm and 850 nm. These wavelength ranges
contain many spectral lines sensitive to solar magnetic fields and
SCIP will be able to obtain magnetic and velocity structures in the
solar atmosphere with a sufficient height resolution by combining
spectro-polarimetric data of these lines. Polarimetric measurements are
conducted using a rotating waveplate as a modulator and polarizing beam
splitters in front of the cameras. The spatial and spectral resolutions
are 0.2" and 2 105, respectively, and a polarimetric sensitivity of
0.03 % (1σ) is achieved within a 10 s integration time. To detect
minute polarization signals with good precision, we carefully designed
the opto-mechanical system, polarization optics and modulation, and
onboard data processing.
Title: Current Status of the Solar-C_EUVST Mission
Authors: Imada, S.; Shimizu, T.; Kawate, T.; Toriumi, S.; Katsukawa,
Y.; Kubo, M.; Hara, H.; Suematsu, Y.; Ichimoto, K.; Watanabe, T.;
Watanabe, K.; Yokoyama, T.; Warren, H.; Long, D.; Harra, L. K.;
Teriaca, L.
Bibcode: 2020AGUFMSH056..05I
Altcode:
Solar-C_EUVST (EUV High-Throughput Spectroscopic Telescope) is designed
to comprehensively understand the energy and mass transfer from the
solar surface to the solar corona and interplanetary space, and to
investigate the elementary processes that take place universally
in cosmic plasmas. As a fundamental step towards answering how the
plasma universe is created and evolves, and how the Sun influences
the Earth and other planets in our solar system, the proposed mission
is designed to comprehensively understand how mass and energy are
transferred throughout the solar atmosphere. Understanding the solar
atmosphere, which connects to the heliosphere via radiation, the solar
wind and coronal mass ejections, and energetic particles is pivotal
for establishing the conditions for life and habitability in the solar
system. The two primary science objectives for Solar-C_EUVST are :
I) Understand how fundamental processes lead to the formation of the
solar atmosphere and the solar wind, II) Understand how the solar
atmosphere becomes unstable, releasing the energy that drives solar
flares and eruptions. Solar-C_EUVST will, A) seamlessly observe all
the temperature regimes of the solar atmosphere from the chromosphere
to the corona at the same time, B) resolve elemental structures of the
solar atmosphere with high spatial resolution and cadence to track their
evolution, and C) obtain spectroscopic information on the dynamics of
elementary processes taking place in the solar atmosphere. In this
talk, we will first discuss the science target of the Solar-C_EUVST,
and then discuss the current status of the Solar-C_EUVST mission.
Title: Thermal design of the Solar-C (EUVST) telescope
Authors: Suematsu, Yoshinori; Shimizu, Toshifumi; Hara, Hirohisa;
Kawate, Tomoko; Katsukawa, Yukio; Ichimoto, Kiyoshi; Imada, Shinsuke;
Nagae, Kazuhiro; Yamazaki, Atsumu; Hattori, Tomoya
Bibcode: 2020SPIE11444E..3KS
Altcode:
The EUV High-Throughput Spectroscopic Telescope (EUVST) of Solar-C
mission consists of only two imaging optical components; a 28-cm clear
aperture off-axis parabolic primary mirror and a two-split ellipsoidal
grating without a blocking filter for visible light before the primary
mirror to achieve unprecedented high spatial and temporal resolution in
EUV-UV imaging spectroscopic observations. For this reason, about 60
W of sunlight is absorbed by the multilayer coating on the mirror. We
report a thermal design of telescope in which the temperature of the
primary mirror bonding part and underlying tip-tilt and slit-scanning
mechanisms is well lower than a glass transition temperature of adhesive
(about 60°C) and thermal deformation of the primary mirror is small,
although it is non-negligibly small.
Title: A sensitivity analysis of the updated optical design for
EUVST on the Solar-C mission
Authors: Kawate, Tomoko; Tsuzuki, Toshihiro; Shimizu, Toshifumi;
Imada, Shinsuke; Katsukawa, Yukio; Hara, Hirohisa; Suematsu, Yoshinori;
Ichimoto, Kiyoshi; Hattori, Tomoya; Narasaki, Shota; Warren, Harry P.;
Teriaca, Luca; Korendyke, Clarence M.; Brown, Charles M.; Auchere,
Frederic
Bibcode: 2020SPIE11444E..3JK
Altcode:
The EUV high-throughput spectroscopic telescope (EUVST) onboard the
Solar-C mission has the high spatial (0.4'') resolution over a wide
wavelength range in the vacuum ultraviolet. To achieve high spatial
resolution under a design constraint given by the JAXA Epsilon launch
vehicle, we further update the optical design to secure margins
needed to realize 0.4'' spatial resolution over a field of view of
100''×100''. To estimate the error budgets of spatial and spectral
resolutions due to installation and fabrication errors, we perform a
sensitivity analysis for the position and orientation of each optical
element and for the grating parameters by ray tracing with the Zemax
software. We obtain point spread functions (PSF) for rays from 9
fields and at 9 wavelengths on each detector by changing each parameter
slightly. A full width at half maximum (FWHM) of the PSF is derived at
each field and wavelength position as a function of the perturbation
of each optical parameter. Assuming a mount system of each optical
element and an error of each optical parameter, we estimate spatial
and spectral resolutions by taking installation and fabrication errors
into account. The results of the sensitivity analysis suggest that
budgets of the total of optical design and the assembly errors account
for 15% and 5.8% of our budgets of the spatial resolution in the long
wavelength and short wavelength bands, respectively. On the other hand,
the grating fabrication errors give a large degradation of spatial and
spectral resolutions, and investigations of compensators are needed
to relax the fabrication tolerance of the grating surface parameters.
Title: The spatially resolved broad line region of IRAS 09149-6206
Authors: GRAVITY Collaboration; Amorim, A.; Bauböck, M.; Brandner,
W.; Clénet, Y.; Davies, R.; de Zeeuw, P. T.; Dexter, J.; Eckart, A.;
Eisenhauer, F.; Förster Schreiber, N. M.; Gao, F.; Garcia, P. J. V.;
Genzel, R.; Gillessen, S.; Gratadour, D.; Hönig, S.; Kishimoto, M.;
Lacour, S.; Lutz, D.; Millour, F.; Netzer, H.; Ott, T.; Paumard, T.;
Perraut, K.; Perrin, G.; Peterson, B. M.; Petrucci, P. O.; Pfuhl,
O.; Prieto, M. A.; Rouan, D.; Shangguan, J.; Shimizu, T.; Schartmann,
M.; Stadler, J.; Sternberg, A.; Straub, O.; Straubmeier, C.; Sturm,
E.; Tacconi, L. J.; Tristram, K. R. W.; Vermot, P.; von Fellenberg,
S.; Waisberg, I.; Widmann, F.; Woillez, J.
Bibcode: 2020A&A...643A.154G
Altcode: 2020arXiv200908463G
We present new near-infrared VLTI/GRAVITY interferometric spectra that
spatially resolve the broad Brγ emission line in the nucleus of the
active galaxy IRAS 09149-6206. We use these data to measure the size
of the broad line region (BLR) and estimate the mass of the central
black hole. Using an improved phase calibration method that reduces
the differential phase uncertainty to 0.05° per baseline across the
spectrum, we detect a differential phase signal that reaches a maximum
of ∼0.5° between the line and continuum. This represents an offset
of ∼120 μas (0.14 pc) between the BLR and the centroid of the hot
dust distribution traced by the 2.3 μm continuum. The offset is well
within the dust sublimation region, which matches the measured ∼0.6
mas (0.7 pc) diameter of the continuum. A clear velocity gradient,
almost perpendicular to the offset, is traced by the reconstructed
photocentres of the spectral channels of the Brγ line. We infer the
radius of the BLR to be ∼65 μas (0.075 pc), which is consistent
with the radius-luminosity relation of nearby active galactic nuclei
derived based on the time lag of the Hβ line from reverberation mapping
campaigns. Our dynamical modelling indicates the black hole mass is
∼1 × 108 M⊙, which is a little below, but
consistent with, the standard MBH-σ* relation.
Title: Ionized outflows in local luminous AGN: what are the real
densities and outflow rates?
Authors: Davies, R.; Baron, D.; Shimizu, T.; Netzer, H.; Burtscher, L.;
de Zeeuw, P. T.; Genzel, R.; Hicks, E. K. S.; Koss, M.; Lin, M. -Y.;
Lutz, D.; Maciejewski, W.; Müller-Sánchez, F.; Orban de Xivry,
G.; Ricci, C.; Riffel, R.; Riffel, R. A.; Rosario, D.; Schartmann,
M.; Schnorr-Müller, A.; Shangguan, J.; Sternberg, A.; Sturm, E.;
Storchi-Bergmann, T.; Tacconi, L.; Veilleux, S.
Bibcode: 2020MNRAS.498.4150D
Altcode: 2020arXiv200306153D; 2020MNRAS.tmp.2061D
We report on the determination of electron densities, and their impact
on the outflow masses and rates, measured in the central few hundred
parsecs of 11 local luminous active galaxies. We show that the peak
of the integrated line emission in the active galactic nuclei (AGN)
is significantly offset from the systemic velocity as traced by the
stellar absorption features, indicating that the profiles are dominated
by outflow. In contrast, matched inactive galaxies are characterized by
a systemic peak and weaker outflow wing. We present three independent
estimates of the electron density in these AGN, discussing the merits
of the different methods. The electron density derived from the [S II]
doublet is significantly lower than that found with a method developed
in the last decade using auroral and transauroral lines, as well as
a recently introduced method based on the ionization parameter. The
reason is that, for gas photoionized by an AGN, much of the [S II]
emission arises in an extended partially ionized zone where the
implicit assumption that the electron density traces the hydrogen
density is invalid. We propose ways to deal with this situation and we
derive the associated outflow rates for ionized gas, which are in the
range 0.001-0.5 M⊙ yr-1 for our AGN sample. We
compare these outflow rates to the relation between $\dot{M}_{\rm out}$
and LAGN in the literature, and argue that it may need to
be modified and rescaled towards lower mass outflow rates.
Title: Rotation Curves in z ∼ 1-2 Star-forming Disks: Evidence
for Cored Dark Matter Distributions
Authors: Genzel, R.; Price, S. H.; Übler, H.; Förster Schreiber,
N. M.; Shimizu, T. T.; Tacconi, L. J.; Bender, R.; Burkert, A.;
Contursi, A.; Coogan, R.; Davies, R. L.; Davies, R. I.; Dekel, A.;
Herrera-Camus, R.; Lee, M. -J.; Lutz, D.; Naab, T.; Neri, R.; Nestor,
A.; Renzini, A.; Saglia, R.; Schuster, K.; Sternberg, A.; Wisnioski,
E.; Wuyts, S.
Bibcode: 2020ApJ...902...98G
Altcode: 2020arXiv200603046G
We report high-quality, Hα or CO rotation curves (RCs) to several
Re for 41 large, massive, star-forming disk galaxies
(SFGs) across the peak of cosmic galaxy evolution (z ∼ 0.67-2.45),
taken with the ESO-VLT, the LBT and IRAM-NOEMA. Most RC41 SFGs have
reflection-symmetric RCs plausibly described by equilibrium dynamics. We
fit the major axis position-velocity cuts using beam-convolved
forward modeling generated in three dimensions, with models that
include a bulge and turbulent disk component embedded in a dark matter
(DM) halo. We include priors for stellar and molecular gas masses,
optical light effective radii and inclinations, and DM masses from
abundance-matching scaling relations. Two-thirds or more of the z ≥
1.2 SFGs are baryon dominated within a few Re of typically
5.5 kpc and have DM fractions less than maximal disks (median $\langle
{f}_{\mathrm{DM}}({R}_{e})\rangle =0.12$ ). At lower redshift (z <
1.2), that fraction is less than one-third. DM fractions correlate
inversely with the baryonic angular momentum parameter, baryonic surface
density, and bulge mass. Inferred low DM fractions cannot apply to
the entire disk and halo but more plausibly reflect a flattened, or
cored, inner DM density distribution. The typical central "DM deficit"
in these cores relative to Navarro-Frenk-White (NFW) distributions is
∼30% of the bulge mass. The observations are consistent with rapid
radial transport of baryons in the first-generation massive gas-rich
halos forming globally gravitationally unstable disks and leading
to efficient build-up of massive bulges and central black holes. A
combination of heating due to dynamical friction and AGN feedback may
drive DM out of the initial cusps.
Title: On the Formation of Lyman β and the O I 1027 and 1028 Å
Spectral Lines
Authors: Hasegawa, Takahiro; Noda, Carlos Quintero; Shimizu, Toshifumi;
Carlsson, Mats
Bibcode: 2020ApJ...900...34H
Altcode: 2020arXiv200812556H
We study the potential of Lyman β and the O I 1027 and 1028
Å spectral lines to help in understanding the properties of the
chromosphere and transition region (TR). The oxygen transitions are
located in the wing of Lyman β, which is a candidate spectral line
for the solar missions Solar Orbiter/Spectral Imaging of the Coronal
Environment and Solar-C (EUVST). We examine the general spectroscopic
properties of the three transitions in the quiet Sun by synthesizing
them assuming nonlocal thermal equilibrium and taking into account
partial redistribution effects. We estimate the heights where the
spectral lines are sensitive to the physical parameters, computing the
response functions to temperature and velocity using a 1D semiempirical
atmospheric model. We also synthesize the intensity spectrum using the
3D enhanced network simulation computed with the BIFROST code. The
results indicate that Lyman β is sensitive to the temperature from
the middle chromosphere to the TR, while it is mainly sensitive to
the line-of-sight (LOS) velocity at the lower atmospheric layers,
around 2000 km above the optical surface. The O I lines form lower
in the middle chromosphere, being sensitive to the LOS velocities at
heights lower than those covered by Lyman β. The spatial distribution
of the intensity signals computed with the BIFROST atmosphere, as
well as the inferred velocities from the line core Doppler shift,
confirms the previous results. Therefore, these results indicate that
the spectral window at 1025 Å contains several spectral lines that
complement each other to seamlessly trace the thermal structure and
gas dynamics from the middle chromosphere to the lower TR.
Title: Chromospheric Magnetic Field: A Comparison of He I 10830 Å
Observations with Nonlinear Force-free Field Extrapolation
Authors: Kawabata, Yusuke; Asensio Ramos, Andrés; Inoue, Satoshi;
Shimizu, Toshifumi
Bibcode: 2020ApJ...898...32K
Altcode: 2020arXiv200600179K
The nonlinear force-free field (NLFFF) modeling has been extensively
used to infer the three-dimensional magnetic field in the solar
corona. One of the assumptions in the NLFFF extrapolation is that the
plasma beta is low, but this condition is considered to be incorrect in
the photosphere. We examine direct measurements of the chromospheric
magnetic field in two active regions through spectropolarimetric
observations at He I 10830 Å, which are compared with the potential
fields and NLFFFs extrapolated from the photosphere. The comparisons
allow quantitative estimation of the uncertainty in the NLFFF
extrapolation from the photosphere. Our analysis shows that observed
chromospheric magnetic field may have larger nonpotentiality compared to
the photospheric magnetic field. Moreover, the large nonpotentiality
in the chromospheric height may not be reproduced by the NLFFF
extrapolation from the photospheric magnetic field. The magnitude of
the underestimation of the nonpotentiality at chromospheric heights may
reach 30°-40° in shear signed angle in some locations. This deviation
may be caused by the non-force-freeness in the photosphere. Our study
suggests the importance of the inclusion of measured chromospheric
magnetic fields in the NLFFF modeling for the improvement of the
coronal extrapolation.
Title: The BAT AGN Spectroscopic Survey. XVIII. Searching for
Supermassive Black Hole Binaries in X-Rays
Authors: Liu, Tingting; Koss, Michael; Blecha, Laura; Ricci, Claudio;
Trakhtenbrot, Benny; Mushotzky, Richard; Harrison, Fiona; Ichikawa,
Kohei; Kakkad, Darshan; Oh, Kyuseok; Powell, Meredith; Privon, George
C.; Schawinski, Kevin; Shimizu, T. Taro; Smith, Krista Lynne; Stern,
Daniel; Treister, Ezequiel; Urry, C. Megan
Bibcode: 2020ApJ...896..122L
Altcode: 2019arXiv191202837L
Theory predicts that a supermassive black hole binary (SMBHB) could be
observed as a luminous active galactic nucleus (AGN) that periodically
varies on the order of its orbital timescale. In X-rays, periodic
variations could be caused by mechanisms including relativistic Doppler
boosting and shocks. Here we present the first systematic search for
periodic AGNs using 941 hard X-ray light curves (14-195 keV) from
the first 105 months of the Swift Burst Alert Telescope (BAT) survey
(2004-2013). We do not find evidence for periodic AGNs in Swift-BAT,
including the previously reported SMBHB candidate MCG+11-11-032. We
find that the null detection is consistent with the combination
of the upper-limit binary population in AGNs in our adopted model,
their expected periodic variability amplitudes, and the BAT survey
characteristics. We have also investigated the detectability of
SMBHBs against normal AGN X-ray variability in the context of the
extended ROentgen Survey with an Imaging Telescope Array (eROSITA)
survey. Under our assumptions of a binary population and the periodic
signals they produce, which have long periods of hundreds of days,
up to 13% true periodic binaries can be robustly distinguished from
normal variable AGNs with the ideal uniform sampling. However,
we demonstrate that realistic eROSITA sampling is likely to be
insensitive to long-period binaries because longer observing gaps
reduce their detectability. In contrast, large observing gaps do not
diminish the prospect of detecting binaries of short, few-day periods,
as 19% can be successfully recovered, the vast majority of which can
be identified by the first half of the survey.
Title: Extrapolation of Three-dimensional Magnetic Field Structure
in Flare-productive Active Regions with Different Initial Conditions
Authors: Kawabata, Y.; Inoue, S.; Shimizu, T.
Bibcode: 2020ApJ...895..105K
Altcode: 2020arXiv200500177K
Nonlinear force-free field (NLFFF) modeling has been extensively used
as a tool to infer three-dimensional (3D) magnetic field structure. In
this study, the dependency of the NLFFF calculation with respect to
the initial guess of the 3D magnetic field is investigated. While
major parts of the previous studies used the potential field as the
initial guess in NLFFF modeling, we adopt linear force-free fields
with different constant force-free alpha as the initial guesses. This
method enables us to investigate the uniqueness of the magnetic
field obtained by the NLFFF extrapolation with respect to the initial
guess. The dependence of the initial conditions on NLFFF extrapolation
is smaller in the strong magnetic field region. Therefore, the magnetic
field at lower heights (<10 Mm) tends to be less affected by the
initial conditions (correlation coefficient C > 0.9 with different
initial conditions); although, the Lorentz force is concentrated at
lower heights.
Title: A Solar Magnetic-fan Flaring Arch Heated by Nonthermal
Particles and Hot Plasma from an X-Ray Jet Eruption
Authors: Lee, Kyoung-Sun; Hara, Hirohisa; Watanabe, Kyoko; Joshi,
Anand D.; Brooks, David H.; Imada, Shinsuke; Prasad, Avijeet; Dang,
Phillip; Shimizu, Toshifumi; Savage, Sabrina L.; Moore, Ronald;
Panesar, Navdeep K.; Reep, Jeffrey W.
Bibcode: 2020ApJ...895...42L
Altcode: 2020arXiv200509875L
We have investigated an M1.3 limb flare, which develops as a magnetic
loop/arch that fans out from an X-ray jet. Using Hinode/EIS, we
found that the temperature increases with height to a value of over
107 K at the loop top during the flare. The measured Doppler
velocity (redshifts of 100-500 km s-1) and the nonthermal
velocity (≥100 km s-1) from Fe XXIV also increase with
loop height. The electron density increases from 0.3 × 109
cm-3 early in the flare rise to 1.3 × 109
cm-3 after the flare peak. The 3D structure of the loop
derived with Solar TErrestrial RElations Observatory/EUV Imager
indicates that the strong redshift in the loop-top region is due to
upflowing plasma originating from the jet. Both hard X-ray and soft
X-ray emission from the Reuven Ramaty High Energy Solar Spectroscopic
Imager were only seen as footpoint brightenings during the impulsive
phase of the flare, then, soft X-ray emission moved to the loop top in
the decay phase. Based on the temperature and density measurements and
theoretical cooling models, the temperature evolution of the flare arch
is consistent with impulsive heating during the jet eruption followed
by conductive cooling via evaporation and minor prolonged heating in
the top of the fan loop. Investigating the magnetic field topology and
squashing factor map from Solar Dynamics Observatory/HMI, we conclude
that the observed magnetic-fan flaring arch is mostly heated from low
atmospheric reconnection accompanying the jet ejection, instead of from
reconnection above the arch as expected in the standard flare model.
Title: From Nuclear to Circumgalactic: Zooming in on AGN-driven
Outflows at z ∼ 2.2 with SINFONI
Authors: Davies, Rebecca L.; Förster Schreiber, N. M.; Lutz, D.;
Genzel, R.; Belli, S.; Shimizu, T. T.; Contursi, A.; Davies, R. I.;
Herrera-Camus, R.; Lee, M. M.; Naab, T.; Price, S. H.; Renzini, A.;
Schruba, A.; Sternberg, A.; Tacconi, L. J.; Übler, H.; Wisnioski,
E.; Wuyts, S.
Bibcode: 2020ApJ...894...28D
Altcode: 2020arXiv200402891D
We use deep adaptive optics assisted integral field spectroscopy from
SINFONI on the VLT to study the spatially resolved properties of ionized
gas outflows driven by active galactic nuclei (AGNs) in three galaxies
at z ∼ 2.2—K20-ID5, COS4-11337, and J0901 + 1814. These systems
probe AGN feedback from nuclear to circumgalactic scales and provide
unique insights into the different mechanisms by which AGN-driven
outflows interact with their host galaxies. K20-ID5 and COS4-11337 are
compact star-forming galaxies with powerful ∼1500 km s-1
AGN-driven outflows that dominate their nuclear Hα emission. The
outflows do not appear to have any impact on the instantaneous star
formation activity of the host galaxies, but they carry a significant
amount of kinetic energy that could heat the halo gas and potentially
lead to a reduction in the rate of cold gas accretion onto the
galaxies. The outflow from COS4-11337 is propagating directly toward
its companion galaxy COS4-11363, at a projected separation of 5.4
kpc. COS4-11363 shows signs of shock excitation and recent truncation
of star formation activity, which could plausibly have been induced by
the outflow from COS4-11337. J0901 + 1814 is gravitationally lensed,
giving us a unique view of a compact (R = 470 ± 70 pc), relatively
low-velocity (∼650 km s-1) AGN-driven outflow. J0901 +
1814 has a similar AGN luminosity to COS4-11337, suggesting that the
difference in outflow properties is not related to the current AGN
luminosity and may instead reflect a difference in the evolutionary
stage of the outflow and/or the coupling efficiency between the AGN
ionizing radiation field and the gas in the nuclear regions.
Title: AGN feedback in a galaxy merger: multi-phase, galaxy-scale
outflows with a fast molecular gas blob ∼6 kpc away from IRAS
F08572+3915
Authors: Herrera-Camus, R.; Janssen, A.; Sturm, E.; Lutz, D.; Veilleux,
S.; Davies, R.; Shimizu, T.; González-Alfonso, E.; Rupke, D. S. N.;
Tacconi, L.; Genzel, R.; Cicone, C.; Maiolino, R.; Contursi, A.;
Graciá-Carpio, J.
Bibcode: 2020A&A...635A..47H
Altcode: 2019arXiv191106326H
To understand the role that active galactic nuclei (AGN) feedback
plays in galaxy evolution, we need in-depth studies of the multi-phase
structure and energetics of galaxy-wide outflows. In this work,
we present new, deep (∼50 h) NOEMA CO(1-0) line observations of
the molecular gas in the powerful outflow driven by the AGN in the
ultra-luminous infrared galaxy IRAS F08572+3915. We spatially resolve
the outflow, finding that its most likely configuration is a wide-angle
bicone aligned with the kinematic major axis of the rotation disk. The
molecular gas in the wind reaches velocities up to approximately ±1200
km s-1 and transports nearly 20% of the molecular gas mass
in the system. We detect a second outflow component located ∼6 kpc
northwest from the galaxy moving away at ∼900 km s-1,
which could be the result of a previous episode of AGN activity. The
total mass and energetics of the outflow, which includes contributions
from the ionized, neutral, and warm and cold molecular gas phases, is
strongly dominated by the cold molecular gas. In fact, the molecular
mass outflow rate is higher than the star formation rate, even if we
only consider the gas in the outflow that is fast enough to escape the
galaxy, which accounts for ∼40% of the total mass of the outflow. This
results in an outflow depletion time for the molecular gas in the
central ∼1.5 kpc region of only ∼3 Myr, a factor of ∼2 shorter
than the depletion time by star formation activity. A copy of
the reduced datacube is available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr
(ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/635/A47
Title: The resolved size and structure of hot dust in the immediate
vicinity of AGN
Authors: GRAVITY Collaboration; Dexter, J.; Shangguan, J.; Hönig,
S.; Kishimoto, M.; Lutz, D.; Netzer, H.; Davies, R.; Sturm, E.;
Pfuhl, O.; Amorim, A.; Bauböck, M.; Brandner, W.; Clénet, Y.; de
Zeeuw, P. T.; Eckart, A.; Eisenhauer, F.; Förster Schreiber, N. M.;
Gao, F.; Garcia, P. J. V.; Genzel, R.; Gillessen, S.; Gratadour, D.;
Jiménez-Rosales, A.; Lacour, S.; Millour, F.; Ott, T.; Paumard, T.;
Perraut, K.; Perrin, G.; Peterson, B. M.; Petrucci, P. O.; Prieto,
M. A.; Rouan, D.; Schartmann, M.; Shimizu, T.; Sternberg, A.;
Straub, O.; Straubmeier, C.; Tacconi, L. J.; Tristram, K.; Vermot,
P.; Waisberg, I.; Widmann, F.; Woillez, J.
Bibcode: 2020A&A...635A..92G
Altcode: 2019arXiv191000593G; 2020A&A...635A..92.
We use VLTI/GRAVITY near-infrared interferometry measurements of eight
bright type 1 AGN to study the size and structure of hot dust that
is heated by the central engine. We partially resolve each source,
and report Gaussian full width at half-maximum sizes in the range
0.3-0.8 mas. In all but one object, we find no evidence for significant
elongation or asymmetry (closure phases ≲1°). The narrow range
of measured angular sizes is expected given the similar optical flux
of our targets, and implies an increasing effective physical radius
with bolometric luminosity, as found from previous reverberation and
interferometry measurements. The measured sizes for Seyfert galaxies
are systematically larger than for the two quasars in our sample when
measured relative to the previously reported R ∼ L1/2
relationship, which is explained by emission at the sublimation
radius. This could be evidence of an evolving near-infrared emission
region structure as a function of central luminosity.
Title: The CO(3-2)/CO(1-0) Luminosity Line Ratio in Nearby
Star-forming Galaxies and Active Galactic Nuclei from xCOLD GASS,
BASS, and SLUGS
Authors: Lamperti, Isabella; Saintonge, Amélie; Koss, Michael;
Viti, Serena; Wilson, Christine D.; He, Hao; Shimizu, T. Taro; Greve,
Thomas R.; Mushotzky, Richard; Treister, Ezequiel; Kramer, Carsten;
Sanders, David; Schawinski, Kevin; Tacconi, Linda J.
Bibcode: 2020ApJ...889..103L
Altcode: 2019arXiv191201026L
We study the ${r}_{31}={L}_{\mathrm{CO}(3\mbox{--}2)}^{{\prime}
}/{L}_{\mathrm{CO}(1\mbox{--}0)}^{{\prime} }$ luminosity line ratio in
a sample of nearby (z < 0.05) galaxies: 25 star-forming galaxies
(SFGs) from the xCOLD GASS survey, 36 hard X-ray-selected active
galactic nucleus (AGN) host galaxies from the BAT AGN Spectroscopic
Survey, and 37 infrared-luminous galaxies from the SCUBA Local Universe
Galaxy Survey. We find a trend for r31 to increase with star
formation efficiency (SFE). We model r31 using the UCL-PDR
code and find that the gas density is the main parameter responsible for
the variation of r31, while the interstellar radiation field
and cosmic-ray ionization rate play only a minor role. We interpret
these results to indicate a relation between SFE and gas density. We do
not find a difference in the r31 value of SFGs and AGN host
galaxies, when the galaxies are matched in SSFR (<r31>
= 0.52 ± 0.04 for SFGs and <r31> = 0.53 ± 0.06
for AGN hosts). According to the results of the UCL-PDR models, the
X-rays can contribute to the enhancement of the CO line ratio, but
only for strong X-ray fluxes and for high gas density (nH
> 104 cm-3). We find a mild tightening of the
Kennicutt-Schmidt relation when we use the molecular gas mass surface
density traced by CO(3-2) (Pearson correlation coefficient R = 0.83),
instead of the molecular gas mass surface density traced by CO(1-0) (R =
0.78), but the increase in correlation is not statistically significant
(p-value = 0.06). This suggests that the CO(3-2) line can be reliably
used to study the relation between SFR and molecular gas for normal
SFGs at high redshift and to compare it with studies of low-redshift
galaxies, as is common practice.
Title: LLAMA: The MBH-σ⋆ relation of the
most luminous local AGNs
Authors: Caglar, Turgay; Burtscher, Leonard; Brandl, Bernhard;
Brinchmann, Jarle; Davies, Richard I.; Hicks, Erin K. S.; Koss,
Michael; Lin, Ming-Yi; Maciejewski, Witold; Müller-Sánchez,
Francisco; Riffel, Rogemar A.; Riffel, Rogério; Rosario, David
J.; Schartmann, Marc; Schnorr-Müller, Allan; Shimizu, T. Taro;
Storchi-Bergmann, Thaisa; Veilleux, Sylvain; Orban de Xivry, Gilles;
Bennert, Vardha N.
Bibcode: 2020A&A...634A.114C
Altcode: 2019arXiv191207734C
Context. The MBH-σ⋆ relation is considered a
result of coevolution between the host galaxies and their supermassive
black holes. For elliptical bulge hosting inactive galaxies, this
relation is well established, but there is still discussion concerning
whether active galaxies follow the same relation.
Aims: In
this paper, we estimate black hole masses for a sample of 19 local
luminous active galactic nuclei (AGNs; LLAMA) to test their location
on the MBH-σ⋆ relation. In addition, we test
how robustly we can determine the stellar velocity dispersion in the
presence of an AGN continuum and AGN emission lines, and as a function
of signal-to-noise ratio.
Methods: Supermassive black hole masses
(MBH) were derived from the broad-line-based relations
for Hα, Hβ, and Paβ emission line profiles for Type 1 AGNs. We
compared the bulge stellar velocity dispersion (σ⋆)
as determined from the Ca II triplet (CaT) with the dispersion
measured from the near-infrared CO (2-0) absorption features for
each AGN and find them to be consistent with each other. We applied
an extinction correction to the observed broad-line fluxes and we
corrected the stellar velocity dispersion by an average rotation
contribution as determined from spatially resolved stellar kinematic
maps.
Results: The Hα-based black hole masses of our sample
of AGNs were estimated in the range 6.34 ≤ log MBH
≤ 7.75 M⊙ and the σ⋆CaT estimates range
between 73 ≤ σ⋆CaT ≤ 227 km s-1. From
the so-constructed MBH - σ⋆ relation for
our Type 1 AGNs, we estimate the black hole masses for the Type 2
AGNs and the inactive galaxies in our sample.
Conclusions:
We find that our sample of local luminous AGNs is consistent with
the MBH-σ⋆ relation of lower luminosity AGNs
and inactive galaxies, after correcting for dust extinction and the
rotational contribution to the stellar velocity dispersion.
Title: An image of the dust sublimation region in the nucleus of
NGC 1068
Authors: GRAVITY Collaboration; Pfuhl, O.; Davies, R.; Dexter, J.;
Netzer, H.; Hönig, S.; Lutz, D.; Schartmann, M.; Sturm, E.; Amorim,
A.; Brandner, W.; Clénet, Y.; de Zeeuw, P. T.; Eckart, A.; Eisenhauer,
F.; Förster Schreiber, N. M.; Gao, F.; Garcia, P. J. V.; Genzel,
R.; Gillessen, S.; Gratadour, D.; Kishimoto, M.; Lacour, S.; Millour,
F.; Ott, T.; Paumard, T.; Perraut, K.; Perrin, G.; Peterson, B. M.;
Petrucci, P. O.; Prieto, M. A.; Rouan, D.; Shangguan, J.; Shimizu, T.;
Sternberg, A.; Straub, O.; Straubmeier, C.; Tacconi, L. J.; Tristram,
K. R. W.; Vermot, P.; Waisberg, I.; Widmann, F.; Woillez, J.
Bibcode: 2020A&A...634A...1G
Altcode: 2019arXiv191201361G; 2020A&A...634A...1.
We present near-infrared interferometric data on the Seyfert 2 galaxy
NGC 1068, obtained with the GRAVITY instrument on the European Southern
Observatory Very Large Telescope Interferometer. The extensive baseline
coverage from 5 to 60 Mλ allowed us to reconstruct a continuum image
of the nucleus with an unrivaled 0.2 pc resolution in the K-band. We
find a thin ring-like structure of emission with a radius r = 0.24
± 0.03 pc, inclination i = 70 ± 5°, position angle PA = -50 ±
4°, and h/r < 0.14, which we associate with the dust sublimation
region. The observed morphology is inconsistent with the expected
signatures of a geometrically and optically thick torus. Instead,
the infrared emission shows a striking resemblance to the 22 GHz
maser disc, which suggests they share a common region of origin. The
near-infrared spectral energy distribution indicates a bolometric
luminosity of (0.4-4.7) × 1045 erg s-1,
behind a large AK ≈ 5.5 (AV ≈ 90) screen
of extinction that also appears to contribute significantly to
obscuring the broad line region. The reconstructed image and
interferometric beam are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr
(ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/634/A1
Title: Locating Hot Plasma in Small Flares using Spectroscopic
Overlappogram Data from the Hinode EUV Imaging Spectrometer
Authors: Harra, Louise; Matthews, Sarah; Long, David; Hasegawa,
Takahiro; Lee, Kyoung-Sun; Reeves, Katharine K.; Shimizu, Toshifumi;
Hara, Hirohisa; Woods, Magnus
Bibcode: 2020SoPh..295...34H
Altcode: 2020arXiv200302908H
One of the key processes associated with the "standard" flare model is
chromospheric evaporation, a process during which plasma heated to high
temperatures by energy deposition at the flare footpoints is driven
upwards into the corona. Despite several decades of study, a number
of open questions remain, including the relationship between plasma
produced during this process and observations of earlier "superhot"
plasma. The Extreme ultraviolet Imaging Spectrometer (EIS) onboard
Hinode has a wide slot, which is often used as a flare trigger in the
He II emission-line band. Once the intensity passes a threshold level,
the study will switch to one focussed on the flaring region. However,
when the intensity is not high enough to reach the flare trigger
threshold, these datasets are then available during the entire flare
period and provide high-cadence spectroscopic observations over a
large field of view. We make use of data from two such studies of a
C4.7 flare and a C1.6 flare to probe the relationship between hot Fe
XXIV plasma and plasmas observed by the Reuven Ramaty High Energy Solar
Spectroscopic Imager (RHESSI) and the X-ray Telescope (XRT) to track
where the emission comes from and when it begins. The flare trigger
slot data used in our analysis has one-minute cadence. Although the
spatial and spectral information are merged in the wide-slot data,
it is still possible to extract when the hot plasma appears, through
the appearance of the Fe Xxiv spectral image. It is also possible
to derive spectrally pure Fe XXIV light curves from the EIS data,
and compare them with those derived from hard X-rays, enabling a full
exploration of the evolution of hot emission. The Fe XXIV emission
peaks just after the peak in the hard X-ray lightcurve; consistent with
an origin in the evaporation of heated plasma following the transfer
of energy to the lower atmosphere. A peak was also found for the C4.7
flare in the RHESSI peak temperature, which occurred before the hard
X-rays peaked. This suggests that the first peak in hot-plasma emission
is likely to be directly related to the energy-release process.
Title: BAT AGN Spectroscopic Survey - XIX. Type 1 versus type 2 AGN
dichotomy from the point of view of ionized outflows
Authors: Rojas, A. F.; Sani, E.; Gavignaud, I.; Ricci, C.; Lamperti,
I.; Koss, M.; Trakhtenbrot, B.; Schawinski, K.; Oh, K.; Bauer, F. E.;
Bischetti, M.; Boissay-Malaquin, R.; Bongiorno, A.; Harrison, F.;
Kakkad, D.; Masetti, N.; Ricci, F.; Shimizu, T.; Stalevski, M.; Stern,
D.; Vietri, G.
Bibcode: 2020MNRAS.491.5867R
Altcode: 2019MNRAS.tmp.3119R; 2019arXiv191112395R
We present a detailed study of ionized outflows in a large sample of
∼650 hard X-ray-detected active galactic neuclei (AGNs). Using optical
spectroscopy from the BAT AGN Spectroscopic Survey (BASS), we are able
to reveal the faint wings of the [O III] emission lines associated
with outflows covering, for the first time, an unexplored range of
low AGN bolometric luminosity at low redshift (z ∼0.05). We test
if and how the incidence and velocity of ionized outflow is related
to AGN physical parameters: black hole mass (M_{BH}), gas column
density (NH), Eddington ratio (λ _{Edd}), [O III], X-ray,
and bolometric luminosities. We find a higher occurrence of ionized
outflows in type 1.9 (55 per cent) and type 1 AGNs (46 per cent)
with respect to type 2 AGNs (24 per cent). While outflows in type 2
AGNs are evenly balanced between blue and red velocity offsets with
respect to the [O III] narrow component, they are almost exclusively
blueshifted in type 1 and type 1.9 AGNs. We observe a significant
dependence between the outflow occurrence and accretion rate, which
becomes relevant at high Eddington ratios [log(λ _{Edd}) ≳ -1.7]. We
interpret such behaviour in the framework of covering factor-Eddington
ratio dependence. We do not find strong trends of the outflow maximum
velocity with AGN physical parameters, as an increase with bolometric
luminosity can be only identified when including samples of AGNs at
high luminosity and high redshift taken from literature.
Title: Average Radial Structures of Gas Convection in the Solar
Granulation
Authors: Oba, T.; Iida, Y.; Shimizu, T.
Bibcode: 2020ApJ...890..141O
Altcode: 2020arXiv200103575O
Gas convection is observed in the solar photosphere as granulation,
I.e., having highly time-dependent cellular patterns, consisting
of numerous bright cells called granules and dark surrounding
channels called intergranular lanes. Many efforts have been made to
characterize the granulation, which may be used as an energy source
for various types of dynamical phenomena. Although the horizontal
gas flow dynamics in intergranular lanes may play a vital role,
they are poorly understood. This is because the Doppler signals can
be obtained only at the solar limb, where the signals are severely
degraded by a foreshortening effect. To reduce such a degradation, we
use Hinode's spectroscopic data, which are free from a seeing-induced
image degradation, and improve the image quality by correcting for
stray light in the instruments. The data set continuously covers from
the solar disk to the limb, providing a multidirectional line-of-sight
(LOS) diagnosis against the granulation. The obtained LOS flow-field
variation across the disk indicates a horizontal flow speed of 1.8-2.4
km s-1. We also derive the spatial distribution of the
horizontal flow speed, which is 1.6 km s-1 in granules and
1.8 km s-1 in intergranular lanes, and where the maximum
speed is inside intergranular lanes. This result newly suggests
the following sequence of horizontal flow: a hot rising gas parcel
is strongly accelerated from the granular center, even beyond the
transition from the granules to the intergranular lanes, resulting in
the fastest speed inside the intergranular lanes, and the gas may also
experience decelerations in the intergranular lane.
Title: Molecular outflows in local galaxies: Method comparison and
a role of intermittent AGN driving
Authors: Lutz, D.; Sturm, E.; Janssen, A.; Veilleux, S.; Aalto, S.;
Cicone, C.; Contursi, A.; Davies, R. I.; Feruglio, C.; Fischer, J.;
Fluetsch, A.; Garcia-Burillo, S.; Genzel, R.; González-Alfonso, E.;
Graciá-Carpio, J.; Herrera-Camus, R.; Maiolino, R.; Schruba, A.;
Shimizu, T.; Sternberg, A.; Tacconi, L. J.; Weiß, A.
Bibcode: 2020A&A...633A.134L
Altcode: 2019arXiv191105608L
We report new detections and limits from a NOEMA and ALMA CO(1-0)
search for molecular outflows in 13 local galaxies with high
far-infrared surface brightness, and combine these with local
universe CO outflow results from the literature. The CO line ratios
and spatial outflow structure of our targets provide some constraints
on the conversion steps from observables to physical quantities such
as molecular mass outflow rates. Where available, ratios between
outflow emission in higher J CO transitions and in CO(1-0) are
typically consistent with excitation Ri1 ≲ 1. However,
for IRAS 13120-5453, R31 = 2.10 ± 0.29 indicates optically
thin CO in the outflow. Like much of the outflow literature, we use
αCO(1 - 0) = 0.8, and we present arguments for using
C = 1 in deriving molecular mass outflow rates Ṁout =
CMoutvout/Rout. We compare the two main
methods for molecular outflow detection: CO millimeter interferometry
and Herschel OH-based spectroscopic outflow searches. For 26 sources
studied with both methods, we find an 80% agreement in detecting
vout ≳ 150 km s-1 outflows, and non-matches can
be plausibly ascribed to outflow geometry and signal-to-noise ratio. For
a published sample of 12 bright ultraluminous infrared galaxies with
detailed OH-based outflow modeling, CO outflows are detected in all but
one. Outflow masses, velocities, and sizes for these 11 sources agree
well between the two methods, and modest remaining differences may
relate to the different but overlapping regions sampled by CO emission
and OH absorption. Outflow properties correlate better with active
galactic nucleus (AGN) luminosity and with bolometric luminosity than
with far-infrared surface brightness. The most massive outflows are
found for systems with current AGN activity, but significant outflows
in nonAGN systems must relate to star formation or to AGN activity
in the recent past. We report scaling relations for the increase of
outflow mass, rate, momentum rate, and kinetic power with bolometric
luminosity. Short flow times of ∼106 yr and some sources
with resolved multiple outflow episodes support a role of intermittent
driving, likely by AGNs.
Title: Molecular gas inflows and outflows in ultraluminous infrared
galaxies at z ∼ 0.2 and one QSO at z = 6.1
Authors: Herrera-Camus, R.; Sturm, E.; Graciá-Carpio, J.; Veilleux,
S.; Shimizu, T.; Lutz, D.; Stone, M.; González-Alfonso, E.; Davies,
R.; Fischer, J.; Genzel, R.; Maiolino, R.; Sternberg, A.; Tacconi,
L.; Verma, A.
Bibcode: 2020A&A...633L...4H
Altcode: 2019arXiv191205548H
Aims: Our aim is to search for and characterize inflows and
outflows of molecular gas in four ultraluminous infrared galaxies
(ULIRGs; LIR > 1012L⊙) at z ∼
0.2-0.3 and one distant quasi-stellar object (QSO) at z = 6.13.
Methods: We used Herschel/PACS and ALMA Band 7 observations of
the hydroxyl molecule (OH) line at rest-frame wavelength 119 μm,
which in absorption can provide unambiguous evidence of inflows or
outflows of molecular gas in nuclear regions of galaxies. Our study
contributes to doubling the number of OH 119 μm observations of
luminous systems at z ∼ 0.2-0.3, and pushes the search for molecular
outflows based on the OH 119 μm transition to z ∼ 6.
Results:
We detect OH 119 μm high-velocity absorption wings in three of the
four ULIRGs. In two cases, IRAS F20036-1547 and IRAS F13352+6402, the
blueshifted absorption profiles indicate the presence of powerful and
fast (∼200-500 km s-1) molecular gas outflows. Consistent
with an inside-out quenching scenario, these outflows are depleting the
central reservoir of star-forming molecular gas at a rate similar to
that of intense star formation activity. For the starburst-dominated
system IRAS 10091+4704, we detect an inverted P Cygni profile that
is unique among ULIRGs and indicates the presence of a fast (∼400
km s-1) inflow of molecular gas at a rate of ∼100
M⊙ yr-1 towards the central region. Finally,
we tentatively detect (∼3σ) the OH 119 μm doublet in absorption
in the z = 6.13 QSO ULAS J131911+095051. The OH 119 μm feature is
blueshifted with a median velocity that suggests the presence of a
molecular outflow, although characterized by a modest molecular mass
loss rate of ∼200 M⊙ yr-1. This value is
comparable to the small mass outflow rates found in the stacking of
the [C II] spectra of other z ∼ 6 QSOs and suggests that ejective
feedback in this phase of the evolution of ULAS J131911+095051 has
subsided. Herschel is an ESA space observatory with science
instruments provided by European-led Principal Investigator consortia
and with important participation from NASA.
Title: VizieR Online Data Catalog: BAT AGN spectroscopic
survey. XI. IR photometry (Ichikawa+, 2019)
Authors: Ichikawa, K.; Ricci, C.; Ueda, Y.; Bauer, F. E.; Kawamuro,
T.; Koss, M. J.; Oh, K.; Rosario, D. J.; Shimizu, T. T.; Stalevski,
M.; Fuller, L.; Packham, C.; Trakhtenbrot, B.
Bibcode: 2020yCat..18700031I
Altcode:
Our initial sample is based on the sample of Ichikawa+ (2017,
J/ApJ/835/74), which contains the 606 non-blazar AGNs from the Swift/BAT
70 month catalog (Baumgartner+ 2013, J/ApJS/207/19) at galactic
latitudes (|b|>10°) for which secure spectroscopic redshifts are
available. In this study, we use the column density (NH)
and the absorption-corrected 14-150keV luminosity (L14-150)
tabulated in Ricci+ (2017, J/ApJS/233/17). (1 data file).
Title: VizieR Online Data Catalog: IRAS F08572+3915 CO(1-0) datacube
(Herrera-Camus+, 2020)
Authors: Herrera-Camus, R.; Janssen, A.; Sturm, E.; Lutz, D.; Veilleux,
S.; Davies, R.; Shimizu, T.; Gonzalez-Alfonso, E.; Rupke, D. S. N.;
Tacconi, L.; Genzel, R.; Cicone, C.; Maiolino, R.; Contursi, A.;
Gracia-Carpio, J.
Bibcode: 2020yCat..36350047H
Altcode:
In total, there have been three IRAM NOEMA (formerly Plateau de Bure
Interferometer) observing programs that target the CO(1-0) outflow
in IRAS F08572+3915 (May-Oct 2011, Feb-March 2013 and March 2015-Feb
2016). (2 data files).
Title: Tending the Fire: A molecular gas study of hard X-ray selected
AGN from the BASS survey.
Authors: Koss, M.; BASS Survey Team; Treister, E.; Cicone, C.; Shimizu,
T.; Saintonge, A.; Privon, G.; Sanders, D.; Schawinski, K.; Lamperti,
I.; Mushotzky, R.
Bibcode: 2020AAS...23532503K
Altcode:
Over the last 30 years the importance of host galaxy molecular gas
for growing black holes has been intensely debated. We have observed
a a volume-limited sample of 220 nearby AGN (0.01 < z < 0.05)
using the CO 2-1 line with the JCMT and APEX telescopes. The AGN
are selected from the Swift-BAT all sky hard X-ray survey. We compare
these AGN host galaxies to inactive galaxies selected with the IRAM 30m
COLD GASS survey to understand trends with host morphology and stellar
mass. We also study how molecular gas fraction is related to various AGN
properties (Eddington ratio, black hole mass, bolometric luminosity,
column density) from the BASS survey. Overall we find that AGN reside
in galaxies with higher overall gas fractions than inactive galaxies of
matched morphology and stellar mass, contain rare gas rich ellipticals,
and the highest Eddington ratio AGN have higher gas fractions.
Title: VizieR Online Data Catalog: NGC 1068 GRAVITY reconstructed
image (GRAVITY+, 2020)
Authors: GRAVITY Collaboration; Pfuhl, O.; Davies, R.; Dexter, J.;
Netzer, H.; Hoenig, S.; Lutz, D.; Schartmann, M.; Sturm, E.; Amorim,
A.; Brandner, W.; Clenet, Y.; de Zeeuw, P. T.; Eckart, A.; Eisenhauer,
F.; Foerster Schreiber, N. M.; Gao, F.; Garcia, P. J. V.; Genzel,
R.; Gillessen, S.; Gratadour, D.; Kishimoto, M.; Lacour, S.; Millour,
F.; Ott, T.; Paumard, T.; Perraut, K.; Perrin, G.; Peterson, B. M.;
Petrucci, P. O.; Prieto, M. A.; Rouan, D.; Shangguan, J.; Shimizu, T.;
Sternberg, A.; Straub, O.; Straubmeier, C.; Tacconi, L. J.; Tristram,
K. R. W.; Vermot, P.; Waisberg, I.; Widmann, F.; Woillez, J.
Bibcode: 2020yCat..36340001G
Altcode:
We present new 0.2pc resolution observations from the GRAVITY
interferometer on the VLT, which spatially resolve the hot dust
continuum in the central parsec of NGC 1068. (2 data files).
Title: GRAVITY and the Galactic Centre
Authors: GRAVITY Collaboration; Abuter, R.; Accardo, M.; Adler,
T.; Amorim, A.; Anugu, N.; Ávila, G.; Bauböck, M.; Benisty, M.;
Berger, J. -P.; Bestenlehner, J. M.; Beust, H.; Blind, N.; Bonnefoy,
M.; Bonnet, H.; Bourget, P.; Bouvier, J.; Brandner, W.; Brast,
R.; Buron, A.; Burtscher, L.; Cantalloube, F.; Caratti O Garatti,
A.; Caselli, P.; Cassaing, F.; Chapron, F.; Charnay, B.; Choquet,
É.; Clénet, Y.; Collin, C.; Coudé Du Foresto, V.; Davies, R.;
Deen, C.; Delplancke-Ströbele, F.; Dembet, R.; Derie, F.; de Wit,
W. -J.; Dexter, J.; de Zeeuw, T.; Dougados, C.; Dubus, G.; Duvert,
G.; Ebert, M.; Eckart, A.; Eisenhauer, F.; Esselborn, M.; Eupen, F.;
Fédou, P.; Ferreira, M. C.; Finger, G.; Förster Schreiber, N. M.;
Gao, F.; García Dabó, C. E.; Garcia Lopez, R.; Garcia, P. J. V.;
Gendron, É.; Genzel, R.; Gerhard, O.; Gil, J. P.; Gillessen, S.;
Gonté, F.; Gordo, P.; Gratadour, D.; Greenbaum, A.; Grellmann, R.;
Grözinger, U.; Guajardo, P.; Guieu, S.; Habibi, M.; Haguenauer, P.;
Hans, O.; Haubois, X.; Haug, M.; Haußmann, F.; Henning, T.; Hippler,
S.; Hönig, S. F.; Horrobin, M.; Huber, A.; Hubert, Z.; Hubin, N.;
Hummel, C. A.; Jakob, G.; Janssen, A.; Jimenez Rosales, A.; Jochum,
L.; Jocou, L.; Kammerer, J.; Karl, M.; Kaufer, A.; Kellner, S.;
Kendrew, S.; Kern, L.; Kervella, P.; Kiekebusch, M.; Kishimoto, M.;
Klarmann, L.; Klein, R.; Köhler, R.; Kok, Y.; Kolb, J.; Koutoulaki,
M.; Kulas, M.; Labadie, L.; Lacour, S.; Lagrange, A. -M.; Lapeyrère,
V.; Laun, W.; Lazareff, B.; Le Bouquin, J. -B.; Léna, P.; Lenzen,
R.; Lévêque, S.; Lin, C. -C.; Lippa, M.; Lutz, D.; Magnard, Y.;
Maire, A. -L.; Mehrgan, L.; Mérand, A.; Millour, F.; Mollière,
P.; Moulin, T.; Müller, A.; Müller, E.; Müller, F.; Netzer, H.;
Neumann, U.; Nowak, M.; Oberti, S.; Ott, T.; Pallanca, L.; Panduro,
J.; Pasquini, L.; Paumard, T.; Percheron, I.; Perraut, K.; Perrin, G.;
Peterson, B. M.; Petrucci, P. -O.; Pflüger, A.; Pfuhl, O.; Phan Duc,
T.; Pineda, J. E.; Plewa, P. M.; Popovic, D.; Pott, J. -U.; Prieto,
A.; Pueyo, L.; Rabien, S.; Ramírez, A.; Ramos, J. R.; Rau, C.; Ray,
T.; Riquelme, M.; Rodríguez-Coira, G.; Rohloff, R. -R.; Rouan, D.;
Rousset, G.; Sanchez-Bermudez, J.; Schartmann, M.; Scheithauer,
S.; Schöller, M.; Schuhler, N.; Segura-Cox, D.; Shangguan, J.;
Shimizu, T. T.; Spyromilio, J.; Sternberg, A.; Stock, M. R.; Straub,
O.; Straubmeier, C.; Sturm, E.; Suárez Valles, M.; Tacconi, L. J.;
Thi, W. -F.; Tristram, K. R. W.; Valenzuela, J. J.; van Boekel, R.;
van Dishoeck, E. F.; Vermot, P.; Vincent, F.; von Fellenberg, S.;
Waisberg, I.; Wang, J. J.; Wank, I.; Weber, J.; Weigelt, G.; Widmann,
F.; Wieprecht, E.; Wiest, M.; Wiezorrek, E.; Wittkowski, M.; Woillez,
J.; Wolff, B.; Yang, P.; Yazici, S.; Ziegler, D.; Zins, G.
Bibcode: 2019Msngr.178...26G
Altcode:
On a clear night, our home galaxy, the Milky Way, is visible as a
starry ribbon across the sky. Its core is located in the constellation
of Sagittarius, approximately where the bright glow is interrupted
by the darkest dust filaments. There, hidden, lies a massive black
hole. To peer through the obscuring clouds and see the stars and gas
near the black hole we use GRAVITY. The main GRAVITY results are the
detection of gra- vitational redshift, the most precise mass- distance
measurement, the test of the equivalence principle, and the detection
of orbital motion near the black hole.
Title: An Image of the Dust Sublimation Region in the Nucleus of
NGC 1068
Authors: GRAVITY Collaboration; Abuter, R.; Accardo, M.; Adler,
T.; Amorim, A.; Anugu, N.; Ávila, G.; Bauböck, M.; Benisty, M.;
Berger, J. -P.; Bestenlehner, J. M.; Beust, H.; Blind, N.; Bonnefoy,
M.; Bonnet, H.; Bourget, P.; Bouvier, J.; Brandner, W.; Brast,
R.; Buron, A.; Burtscher, L.; Cantalloube, F.; Caratti O Garatti,
A.; Caselli, P.; Cassaing, F.; Chapron, F.; Charnay, B.; Choquet,
É.; Clénet, Y.; Collin, C.; Coudé Du Foresto, V.; Davies, R.;
Deen, C.; Delplancke-Ströbele, F.; Dembet, R.; Derie, F.; de Wit,
W. -J.; Dexter, J.; de Zeeuw, T.; Dougados, C.; Dubus, G.; Duvert,
G.; Ebert, M.; Eckart, A.; Eisenhauer, F.; Esselborn, M.; Eupen, F.;
Fédou, P.; Ferreira, M. C.; Finger, G.; Förster Schreiber, N. M.;
Gao, F.; García Dabó, C. E.; Garcia Lopez, R.; Garcia, P. J. V.;
Gendron, É.; Genzel, R.; Gerhard, O.; Gil, J. P.; Gillessen, S.;
Gonté, F.; Gordo, P.; Gratadour, D.; Greenbaum, A.; Grellmann, R.;
Grözinger, U.; Guajardo, P.; Guieu, S.; Habibi, M.; Haguenauer, P.;
Hans, O.; Haubois, X.; Haug, M.; Haußmann, F.; Henning, T.; Hippler,
S.; Hönig, S. F.; Horrobin, M.; Huber, A.; Hubert, Z.; Hubin, N.;
Hummel, C. A.; Jakob, G.; Janssen, A.; Jimenez Rosales, A.; Jochum,
L.; Jocou, L.; Kammerer, J.; Karl, M.; Kaufer, A.; Kellner, S.;
Kendrew, S.; Kern, L.; Kervella, P.; Kiekebusch, M.; Kishimoto, M.;
Klarmann, L.; Klein, R.; Köhler, R.; Kok, Y.; Kolb, J.; Koutoulaki,
M.; Kulas, M.; Labadie, L.; Lacour, S.; Lagrange, A. -M.; Lapeyrère,
V.; Laun, W.; Lazareff, B.; Le Bouquin, J. -B.; Léna, P.; Lenzen,
R.; Lévêque, S.; Lin, C. -C.; Lippa, M.; Lutz, D.; Magnard, Y.;
Maire, A. -L.; Mehrgan, L.; Mérand, A.; Millour, F.; Mollière,
P.; Moulin, T.; Müller, A.; Müller, E.; Müller, F.; Netzer, H.;
Neumann, U.; Nowak, M.; Oberti, S.; Ott, T.; Pallanca, L.; Panduro,
J.; Pasquini, L.; Paumard, T.; Percheron, I.; Perraut, K.; Perrin, G.;
Peterson, B. M.; Petrucci, P. -O.; Pflüger, A.; Pfuhl, O.; Phan Duc,
T.; Pineda, J. E.; Plewa, P. M.; Popovic, D.; Pott, J. -U.; Prieto,
A.; Pueyo, L.; Rabien, S.; Ramírez, A.; Ramos, J. R.; Rau, C.; Ray,
T.; Riquelme, M.; Rodríguez-Coira, G.; Rohloff, R. -R.; Rouan, D.;
Rousset, G.; Sanchez-Bermudez, J.; Schartmann, M.; Scheithauer,
S.; Schöller, M.; Schuhler, N.; Segura-Cox, D.; Shangguan, J.;
Shimizu, T. T.; Spyromilio, J.; Sternberg, A.; Stock, M. R.; Straub,
O.; Straubmeier, C.; Sturm, E.; Suárez Valles, M.; Tacconi, L. J.;
Thi, W. -F.; Tristram, K. R. W.; Valenzuela, J. J.; van Boekel, R.;
van Dishoeck, E. F.; Vermot, P.; Vincent, F.; von Fellenberg, S.;
Waisberg, I.; Wang, J. J.; Wank, I.; Weber, J.; Weigelt, G.; Widmann,
F.; Wieprecht, E.; Wiest, M.; Wiezorrek, E.; Wittkowski, M.; Woillez,
J.; Wolff, B.; Yang, P.; Yazici, S.; Ziegler, D.; Zins, G.
Bibcode: 2019Msngr.178...24G
Altcode:
The superb resolution of the Very Large Telescope Interferometer
(VLTI) and the unrivalled sensitivity of GRAVITY have allowed us to
reconstruct the first detailed image of the dust sublimation region in
an active galaxy. In the nearby archetypal Seyfert 2 galaxy NGC 1068,
the 2 µm continuum emission traces a highly inclined thin ring-like
structure with a radius of 0.24 pc. The observed morphology challenges
the picture of a geometrically and optically thick torus.
Title: Spatially Resolved Accretion-Ejection in Compact Binaries
with GRAVITY
Authors: GRAVITY Collaboration; Abuter, R.; Accardo, M.; Adler,
T.; Amorim, A.; Anugu, N.; Ávila, G.; Bauböck, M.; Benisty, M.;
Berger, J. -P.; Bestenlehner, J. M.; Beust, H.; Blind, N.; Bonnefoy,
M.; Bonnet, H.; Bourget, P.; Bouvier, J.; Brandner, W.; Brast,
R.; Buron, A.; Burtscher, L.; Cantalloube, F.; Caratti O Garatti,
A.; Caselli, P.; Cassaing, F.; Chapron, F.; Charnay, B.; Choquet,
É.; Clénet, Y.; Collin, C.; Coudé Du Foresto, V.; Davies, R.;
Deen, C.; Delplancke-Ströbele, F.; Dembet, R.; Derie, F.; de Wit,
W. -J.; Dexter, J.; de Zeeuw, T.; Dougados, C.; Dubus, G.; Duvert,
G.; Ebert, M.; Eckart, A.; Eisenhauer, F.; Esselborn, M.; Eupen, F.;
Fédou, P.; Ferreira, M. C.; Finger, G.; Förster Schreiber, N. M.;
Gao, F.; García Dabó, C. E.; Garcia Lopez, R.; Garcia, P. J. V.;
Gendron, É.; Genzel, R.; Gerhard, O.; Gil, J. P.; Gillessen, S.;
Gonté, F.; Gordo, P.; Gratadour, D.; Greenbaum, A.; Grellmann, R.;
Grözinger, U.; Guajardo, P.; Guieu, S.; Habibi, M.; Haguenauer, P.;
Hans, O.; Haubois, X.; Haug, M.; Haußmann, F.; Henning, T.; Hippler,
S.; Hönig, S. F.; Horrobin, M.; Huber, A.; Hubert, Z.; Hubin, N.;
Hummel, C. A.; Jakob, G.; Janssen, A.; Jimenez Rosales, A.; Jochum,
L.; Jocou, L.; Kammerer, J.; Karl, M.; Kaufer, A.; Kellner, S.;
Kendrew, S.; Kern, L.; Kervella, P.; Kiekebusch, M.; Kishimoto, M.;
Klarmann, L.; Klein, R.; Köhler, R.; Kok, Y.; Kolb, J.; Koutoulaki,
M.; Kulas, M.; Labadie, L.; Lacour, S.; Lagrange, A. -M.; Lapeyrère,
V.; Laun, W.; Lazareff, B.; Le Bouquin, J. -B.; Léna, P.; Lenzen,
R.; Lévêque, S.; Lin, C. -C.; Lippa, M.; Lutz, D.; Magnard, Y.;
Maire, A. -L.; Mehrgan, L.; Mérand, A.; Millour, F.; Mollière,
P.; Moulin, T.; Müller, A.; Müller, E.; Müller, F.; Netzer, H.;
Neumann, U.; Nowak, M.; Oberti, S.; Ott, T.; Pallanca, L.; Panduro,
J.; Pasquini, L.; Paumard, T.; Percheron, I.; Perraut, K.; Perrin, G.;
Peterson, B. M.; Petrucci, P. -O.; Pflüger, A.; Pfuhl, O.; Phan Duc,
T.; Pineda, J. E.; Plewa, P. M.; Popovic, D.; Pott, J. -U.; Prieto,
A.; Pueyo, L.; Rabien, S.; Ramírez, A.; Ramos, J. R.; Rau, C.; Ray,
T.; Riquelme, M.; Rodríguez-Coira, G.; Rohloff, R. -R.; Rouan, D.;
Rousset, G.; Sanchez-Bermudez, J.; Schartmann, M.; Scheithauer,
S.; Schöller, M.; Schuhler, N.; Segura-Cox, D.; Shangguan, J.;
Shimizu, T. T.; Spyromilio, J.; Sternberg, A.; Stock, M. R.; Straub,
O.; Straubmeier, C.; Sturm, E.; Suárez Valles, M.; Tacconi, L. J.;
Thi, W. -F.; Tristram, K. R. W.; Valenzuela, J. J.; van Boekel, R.;
van Dishoeck, E. F.; Vermot, P.; Vincent, F.; von Fellenberg, S.;
Waisberg, I.; Wang, J. J.; Wank, I.; Weber, J.; Weigelt, G.; Widmann,
F.; Wieprecht, E.; Wiest, M.; Wiezorrek, E.; Wittkowski, M.; Woillez,
J.; Wolff, B.; Yang, P.; Yazici, S.; Ziegler, D.; Zins, G.
Bibcode: 2019Msngr.178...29G
Altcode:
The GRAVITY instrument at the Very Large Telescope Interferometer has
led to the first spatially resolved observations of X-ray binaries at
scales comparable to the binary orbit, providing unprecedented spatial
information on their accretion-ejection mechanisms. In particular,
observations of the hypercritical accretor SS433 have revealed a
variety of spatial structures at the heart of this exotic microquasar,
including bipolar outflows, super-Keplerian equatorial outflows and
extended baryonic jets photoionised by collimated ultraviolet radiation.
Title: The KMOS3D Survey: Data Release and Final Survey
Paper
Authors: Wisnioski, E.; Förster Schreiber, N. M.; Fossati, M.;
Mendel, J. T.; Wilman, D.; Genzel, R.; Bender, R.; Wuyts, S.; Davies,
R. L.; Übler, H.; Bandara, K.; Beifiori, A.; Belli, S.; Brammer, G.;
Chan, J.; Davies, R. I.; Fabricius, M.; Galametz, A.; Lang, P.; Lutz,
D.; Nelson, E. J.; Momcheva, I.; Price, S.; Rosario, D.; Saglia, R.;
Seitz, S.; Shimizu, T.; Tacconi, L. J.; Tadaki, K.; van Dokkum, P. G.;
Wuyts, E.
Bibcode: 2019ApJ...886..124W
Altcode: 2019arXiv190911096W
We present the completed KMOS3D survey, an integral field
spectroscopic survey of 739 {log}({M}\star /{M}⊙
)> 9 galaxies at 0.6 < z < 2.7 using the K-band
Multi Object Spectrograph (KMOS) at the Very Large Telescope. The
KMOS3D survey provides a population-wide census of
kinematics, star formation, outflows, and nebular gas conditions both
on and off the star-forming galaxy main sequence through the spatially
resolved and integrated properties of Hα, [N II], and [S II] emission
lines. We detect Hα emission for 91% of galaxies on the main sequence
of star formation and 79% overall. The depth of the survey has allowed
us to detect galaxies with star formation rates below 1 M ⊙
yr-1, as well as to resolve 81% of detected galaxies with
≥3 resolution elements along the kinematic major axis. The detection
fraction of Hα is a strong function of both color and offset from the
main sequence, with the detected and nondetected samples exhibiting
different spectral energy distribution shapes. Comparison of Hα and
UV+IR star formation rates reveal that dust attenuation corrections may
be underestimated by 0.5 dex at the highest masses ({log}({M}\star
/{M}⊙ )> 10.5). We confirm our first year results
of a high rotation-dominated fraction (monotonic velocity gradient
and v rot/{σ }0> \sqrt{3.36}) of 77% for
the full KMOS3D sample. The rotation-dominated fraction
is a function of both stellar mass and redshift, with the strongest
evolution measured over the redshift range of the survey for galaxies
with {log}({M}\star /{M}⊙ )< 10.5. With this
paper, we include a final data release of all 739 observed objects (http://www.mpe.mpg.de/ir/KMOS3D).
Based on observations obtained at the Very Large Telescope (VLT) of
the European Southern Observatory (ESO), Paranal, Chile (ESO program IDS
092A-0091, 093.A-0079, 093.A-0079, 094.A-0217, 095.A-0047, 096.A-0025,
097.A-0028, 098.A-0045, 099.A-0013, 0100.A-0039, and 0101.A-0022).
Title: Hunting Exoplanets with Single-Mode Optical Interferometry
Authors: GRAVITY Collaboration; Abuter, R.; Accardo, M.; Adler,
T.; Amorim, A.; Anugu, N.; Ávila, G.; Bauböck, M.; Benisty, M.;
Berger, J. -P.; Bestenlehner, J. M.; Beust, H.; Blind, N.; Bonnefoy,
M.; Bonnet, H.; Bourget, P.; Bouvier, J.; Brandner, W.; Brast,
R.; Buron, A.; Burtscher, L.; Cantalloube, F.; Caratti O Garatti,
A.; Caselli, P.; Cassaing, F.; Chapron, F.; Charnay, B.; Choquet,
É.; Clénet, Y.; Collin, C.; Coudé Du Foresto, V.; Davies, R.;
Deen, C.; Delplancke-Ströbele, F.; Dembet, R.; Derie, F.; de Wit,
W. -J.; Dexter, J.; de Zeeuw, T.; Dougados, C.; Dubus, G.; Duvert,
G.; Ebert, M.; Eckart, A.; Eisenhauer, F.; Esselborn, M.; Eupen, F.;
Fédou, P.; Ferreira, M. C.; Finger, G.; Förster Schreiber, N. M.;
Gao, F.; García Dabó, C. E.; Garcia Lopez, R.; Garcia, P. J. V.;
Gendron, É.; Genzel, R.; Gerhard, O.; Gil, J. P.; Gillessen, S.;
Gonté, F.; Gordo, P.; Gratadour, D.; Greenbaum, A.; Grellmann, R.;
Grözinger, U.; Guajardo, P.; Guieu, S.; Habibi, M.; Haguenauer, P.;
Hans, O.; Haubois, X.; Haug, M.; Haußmann, F.; Henning, T.; Hippler,
S.; Hönig, S. F.; Horrobin, M.; Huber, A.; Hubert, Z.; Hubin, N.;
Hummel, C. A.; Jakob, G.; Janssen, A.; Jimenez Rosales, A.; Jochum,
L.; Jocou, L.; Kammerer, J.; Karl, M.; Kaufer, A.; Kellner, S.;
Kendrew, S.; Kern, L.; Kervella, P.; Kiekebusch, M.; Kishimoto, M.;
Klarmann, L.; Klein, R.; Köhler, R.; Kok, Y.; Kolb, J.; Koutoulaki,
M.; Kulas, M.; Labadie, L.; Lacour, S.; Lagrange, A. -M.; Lapeyrère,
V.; Laun, W.; Lazareff, B.; Le Bouquin, J. -B.; Léna, P.; Lenzen,
R.; Lévêque, S.; Lin, C. -C.; Lippa, M.; Lutz, D.; Magnard, Y.;
Maire, A. -L.; Mehrgan, L.; Mérand, A.; Millour, F.; Mollière,
P.; Moulin, T.; Müller, A.; Müller, E.; Müller, F.; Netzer, H.;
Neumann, U.; Nowak, M.; Oberti, S.; Ott, T.; Pallanca, L.; Panduro,
J.; Pasquini, L.; Paumard, T.; Percheron, I.; Perraut, K.; Perrin, G.;
Peterson, B. M.; Petrucci, P. -O.; Pflüger, A.; Pfuhl, O.; Phan Duc,
T.; Pineda, J. E.; Plewa, P. M.; Popovic, D.; Pott, J. -U.; Prieto,
A.; Pueyo, L.; Rabien, S.; Ramírez, A.; Ramos, J. R.; Rau, C.; Ray,
T.; Riquelme, M.; Rodríguez-Coira, G.; Rohloff, R. -R.; Rouan, D.;
Rousset, G.; Sanchez-Bermudez, J.; Schartmann, M.; Scheithauer,
S.; Schöller, M.; Schuhler, N.; Segura-Cox, D.; Shangguan, J.;
Shimizu, T. T.; Spyromilio, J.; Sternberg, A.; Stock, M. R.; Straub,
O.; Straubmeier, C.; Sturm, E.; Suárez Valles, M.; Tacconi, L. J.;
Thi, W. -F.; Tristram, K. R. W.; Valenzuela, J. J.; van Boekel, R.;
van Dishoeck, E. F.; Vermot, P.; Vincent, F.; von Fellenberg, S.;
Waisberg, I.; Wang, J. J.; Wank, I.; Weber, J.; Weigelt, G.; Widmann,
F.; Wieprecht, E.; Wiest, M.; Wiezorrek, E.; Wittkowski, M.; Woillez,
J.; Wolff, B.; Yang, P.; Yazici, S.; Ziegler, D.; Zins, G.
Bibcode: 2019Msngr.178...47G
Altcode:
The GRAVITY instrument was primarily conceived for imaging and
astrometry of the Galactic centre. However, its sensitivity and
astrometric capabilities have also enabled interferometry to reach
a new domain of astrophysics: exoplanetology. In March 2019, the
GRAVITY collaboration published the first spectrum and astrometry of an
exoplanet obtained by optical interferometry. In this article, we show
how this observation is paving the way to even more exciting discoveries
— finding new planets, and characterising their atmospheres.
Title: Spatially Resolving the Inner Gaseous Disc of the Herbig Star
51 Oph through its CO Ro-vibration Emission
Authors: GRAVITY Collaboration; Abuter, R.; Accardo, M.; Adler,
T.; Amorim, A.; Anugu, N.; Ávila, G.; Bauböck, M.; Benisty, M.;
Berger, J. -P.; Bestenlehner, J. M.; Beust, H.; Blind, N.; Bonnefoy,
M.; Bonnet, H.; Bourget, P.; Bouvier, J.; Brandner, W.; Brast,
R.; Buron, A.; Burtscher, L.; Cantalloube, F.; Caratti O Garatti,
A.; Caselli, P.; Cassaing, F.; Chapron, F.; Charnay, B.; Choquet,
É.; Clénet, Y.; Collin, C.; Coudé Du Foresto, V.; Davies, R.;
Deen, C.; Delplancke-Ströbele, F.; Dembet, R.; Derie, F.; de Wit,
W. -J.; Dexter, J.; de Zeeuw, T.; Dougados, C.; Dubus, G.; Duvert,
G.; Ebert, M.; Eckart, A.; Eisenhauer, F.; Esselborn, M.; Eupen, F.;
Fédou, P.; Ferreira, M. C.; Finger, G.; Förster Schreiber, N. M.;
Gao, F.; García Dabó, C. E.; Garcia Lopez, R.; Garcia, P. J. V.;
Gendron, É.; Genzel, R.; Gerhard, O.; Gil, J. P.; Gillessen, S.;
Gonté, F.; Gordo, P.; Gratadour, D.; Greenbaum, A.; Grellmann, R.;
Grözinger, U.; Guajardo, P.; Guieu, S.; Habibi, M.; Haguenauer, P.;
Hans, O.; Haubois, X.; Haug, M.; Haußmann, F.; Henning, T.; Hippler,
S.; Hönig, S. F.; Horrobin, M.; Huber, A.; Hubert, Z.; Hubin, N.;
Hummel, C. A.; Jakob, G.; Janssen, A.; Jimenez Rosales, A.; Jochum,
L.; Jocou, L.; Kammerer, J.; Karl, M.; Kaufer, A.; Kellner, S.;
Kendrew, S.; Kern, L.; Kervella, P.; Kiekebusch, M.; Kishimoto, M.;
Klarmann, L.; Klein, R.; Köhler, R.; Kok, Y.; Kolb, J.; Koutoulaki,
M.; Kulas, M.; Labadie, L.; Lacour, S.; Lagrange, A. -M.; Lapeyrère,
V.; Laun, W.; Lazareff, B.; Le Bouquin, J. -B.; Léna, P.; Lenzen,
R.; Lévêque, S.; Lin, C. -C.; Lippa, M.; Lutz, D.; Magnard, Y.;
Maire, A. -L.; Mehrgan, L.; Mérand, A.; Millour, F.; Mollière,
P.; Moulin, T.; Müller, A.; Müller, E.; Müller, F.; Netzer, H.;
Neumann, U.; Nowak, M.; Oberti, S.; Ott, T.; Pallanca, L.; Panduro,
J.; Pasquini, L.; Paumard, T.; Percheron, I.; Perraut, K.; Perrin, G.;
Peterson, B. M.; Petrucci, P. -O.; Pflüger, A.; Pfuhl, O.; Phan Duc,
T.; Pineda, J. E.; Plewa, P. M.; Popovic, D.; Pott, J. -U.; Prieto,
A.; Pueyo, L.; Rabien, S.; Ramírez, A.; Ramos, J. R.; Rau, C.; Ray,
T.; Riquelme, M.; Rodríguez-Coira, G.; Rohloff, R. -R.; Rouan, D.;
Rousset, G.; Sanchez-Bermudez, J.; Schartmann, M.; Scheithauer,
S.; Schöller, M.; Schuhler, N.; Segura-Cox, D.; Shangguan, J.;
Shimizu, T. T.; Spyromilio, J.; Sternberg, A.; Stock, M. R.; Straub,
O.; Straubmeier, C.; Sturm, E.; Suárez Valles, M.; Tacconi, L. J.;
Thi, W. -F.; Tristram, K. R. W.; Valenzuela, J. J.; van Boekel, R.;
van Dishoeck, E. F.; Vermot, P.; Vincent, F.; von Fellenberg, S.;
Waisberg, I.; Wang, J. J.; Wank, I.; Weber, J.; Weigelt, G.; Widmann,
F.; Wieprecht, E.; Wiest, M.; Wiezorrek, E.; Wittkowski, M.; Woillez,
J.; Wolff, B.; Yang, P.; Yazici, S.; Ziegler, D.; Zins, G.
Bibcode: 2019Msngr.178...40G
Altcode:
Near-infrared interferometry gives us the opportunity to
spatially resolve the circumstellar environment of young stars at
sub-astronomical-unit (au) scales, which a standalone telescope could
not reach. In particular, the sensitivity of GRAVITY on the VLTI allows
us to spatially resolve the CO overtone emission at 2.3 microns. In
this article, we present a new method of using the model of the CO
spectrum to reconstruct the differential phase signal and extract the
geometry and size of the emitting region.
Title: Spatially Resolving the Quasar Broad Emission Line Region
Authors: GRAVITY Collaboration; Abuter, R.; Accardo, M.; Adler,
T.; Amorim, A.; Anugu, N.; Ávila, G.; Bauböck, M.; Benisty, M.;
Berger, J. -P.; Bestenlehner, J. M.; Beust, H.; Blind, N.; Bonnefoy,
M.; Bonnet, H.; Bourget, P.; Bouvier, J.; Brandner, W.; Brast,
R.; Buron, A.; Burtscher, L.; Cantalloube, F.; Caratti O Garatti,
A.; Caselli, P.; Cassaing, F.; Chapron, F.; Charnay, B.; Choquet,
É.; Clénet, Y.; Collin, C.; Coudé Du Foresto, V.; Davies, R.;
Deen, C.; Delplancke-Ströbele, F.; Dembet, R.; Derie, F.; de Wit,
W. -J.; Dexter, J.; de Zeeuw, T.; Dougados, C.; Dubus, G.; Duvert,
G.; Ebert, M.; Eckart, A.; Eisenhauer, F.; Esselborn, M.; Eupen, F.;
Fédou, P.; Ferreira, M. C.; Finger, G.; Förster Schreiber, N. M.;
Gao, F.; García Dabó, C. E.; Garcia Lopez, R.; Garcia, P. J. V.;
Gendron, É.; Genzel, R.; Gerhard, O.; Gil, J. P.; Gillessen, S.;
Gonté, F.; Gordo, P.; Gratadour, D.; Greenbaum, A.; Grellmann, R.;
Grözinger, U.; Guajardo, P.; Guieu, S.; Habibi, M.; Haguenauer, P.;
Hans, O.; Haubois, X.; Haug, M.; Haußmann, F.; Henning, T.; Hippler,
S.; Hönig, S. F.; Horrobin, M.; Huber, A.; Hubert, Z.; Hubin, N.;
Hummel, C. A.; Jakob, G.; Janssen, A.; Jimenez Rosales, A.; Jochum,
L.; Jocou, L.; Kammerer, J.; Karl, M.; Kaufer, A.; Kellner, S.;
Kendrew, S.; Kern, L.; Kervella, P.; Kiekebusch, M.; Kishimoto, M.;
Klarmann, L.; Klein, R.; Köhler, R.; Kok, Y.; Kolb, J.; Koutoulaki,
M.; Kulas, M.; Labadie, L.; Lacour, S.; Lagrange, A. -M.; Lapeyrère,
V.; Laun, W.; Lazareff, B.; Le Bouquin, J. -B.; Léna, P.; Lenzen,
R.; Lévêque, S.; Lin, C. -C.; Lippa, M.; Lutz, D.; Magnard, Y.;
Maire, A. -L.; Mehrgan, L.; Mérand, A.; Millour, F.; Mollière,
P.; Moulin, T.; Müller, A.; Müller, E.; Müller, F.; Netzer, H.;
Neumann, U.; Nowak, M.; Oberti, S.; Ott, T.; Pallanca, L.; Panduro,
J.; Pasquini, L.; Paumard, T.; Percheron, I.; Perraut, K.; Perrin, G.;
Peterson, B. M.; Petrucci, P. -O.; Pflüger, A.; Pfuhl, O.; Phan Duc,
T.; Pineda, J. E.; Plewa, P. M.; Popovic, D.; Pott, J. -U.; Prieto,
A.; Pueyo, L.; Rabien, S.; Ramírez, A.; Ramos, J. R.; Rau, C.; Ray,
T.; Riquelme, M.; Rodríguez-Coira, G.; Rohloff, R. -R.; Rouan, D.;
Rousset, G.; Sanchez-Bermudez, J.; Schartmann, M.; Scheithauer,
S.; Schöller, M.; Schuhler, N.; Segura-Cox, D.; Shangguan, J.;
Shimizu, T. T.; Spyromilio, J.; Sternberg, A.; Stock, M. R.; Straub,
O.; Straubmeier, C.; Sturm, E.; Suárez Valles, M.; Tacconi, L. J.;
Thi, W. -F.; Tristram, K. R. W.; Valenzuela, J. J.; van Boekel, R.;
van Dishoeck, E. F.; Vermot, P.; Vincent, F.; von Fellenberg, S.;
Waisberg, I.; Wang, J. J.; Wank, I.; Weber, J.; Weigelt, G.; Widmann,
F.; Wieprecht, E.; Wiest, M.; Wiezorrek, E.; Wittkowski, M.; Woillez,
J.; Wolff, B.; Yang, P.; Yazici, S.; Ziegler, D.; Zins, G.
Bibcode: 2019Msngr.178...20A
Altcode:
The angular resolution of the Very Large Telescope Interferometer
(VLTI) and the excellent sensitivity of GRAVITY have led to the
first detection of spatially resolved kinematics of high velocity
atomic gas near an accreting super- massive black hole, revealing
rotation on sub-parsec scales in the quasar 3C 273 at a distance of
550 Mpc. The observations can be explained as the result of circular
orbits in a thick disc configuration around a 300 million solar mass
black hole. Within an ongoing Large Programme, this capability will
be used to study the kinematics of atomic gas and its relation to hot
dust in a sample of quasars and Seyfert galaxies. We will measure a
new radius-luminosity relation from spatially resolved data and test
the current methods used to measure black hole mass in large surveys.
Title: Multiple Star Systems in the Orion Nebula
Authors: GRAVITY Collaboration; Abuter, R.; Accardo, M.; Adler,
T.; Amorim, A.; Anugu, N.; Ávila, G.; Bauböck, M.; Benisty, M.;
Berger, J. -P.; Bestenlehner, J. M.; Beust, H.; Blind, N.; Bonnefoy,
M.; Bonnet, H.; Bourget, P.; Bouvier, J.; Brandner, W.; Brast,
R.; Buron, A.; Burtscher, L.; Cantalloube, F.; Caratti O Garatti,
A.; Caselli, P.; Cassaing, F.; Chapron, F.; Charnay, B.; Choquet,
É.; Clénet, Y.; Collin, C.; Coudé Du Foresto, V.; Davies, R.;
Deen, C.; Delplancke-Ströbele, F.; Dembet, R.; Derie, F.; de Wit,
W. -J.; Dexter, J.; de Zeeuw, T.; Dougados, C.; Dubus, G.; Duvert,
G.; Ebert, M.; Eckart, A.; Eisenhauer, F.; Esselborn, M.; Eupen, F.;
Fédou, P.; Ferreira, M. C.; Finger, G.; Förster Schreiber, N. M.;
Gao, F.; García Dabó, C. E.; Garcia Lopez, R.; Garcia, P. J. V.;
Gendron, É.; Genzel, R.; Gerhard, O.; Gil, J. P.; Gillessen, S.;
Gonté, F.; Gordo, P.; Gratadour, D.; Greenbaum, A.; Grellmann, R.;
Grözinger, U.; Guajardo, P.; Guieu, S.; Habibi, M.; Haguenauer, P.;
Hans, O.; Haubois, X.; Haug, M.; Haußmann, F.; Henning, T.; Hippler,
S.; Hönig, S. F.; Horrobin, M.; Huber, A.; Hubert, Z.; Hubin, N.;
Hummel, C. A.; Jakob, G.; Janssen, A.; Jimenez Rosales, A.; Jochum,
L.; Jocou, L.; Kammerer, J.; Karl, M.; Kaufer, A.; Kellner, S.;
Kendrew, S.; Kern, L.; Kervella, P.; Kiekebusch, M.; Kishimoto, M.;
Klarmann, L.; Klein, R.; Köhler, R.; Kok, Y.; Kolb, J.; Koutoulaki,
M.; Kulas, M.; Labadie, L.; Lacour, S.; Lagrange, A. -M.; Lapeyrère,
V.; Laun, W.; Lazareff, B.; Le Bouquin, J. -B.; Léna, P.; Lenzen,
R.; Lévêque, S.; Lin, C. -C.; Lippa, M.; Lutz, D.; Magnard, Y.;
Maire, A. -L.; Mehrgan, L.; Mérand, A.; Millour, F.; Mollière,
P.; Moulin, T.; Müller, A.; Müller, E.; Müller, F.; Netzer, H.;
Neumann, U.; Nowak, M.; Oberti, S.; Ott, T.; Pallanca, L.; Panduro,
J.; Pasquini, L.; Paumard, T.; Percheron, I.; Perraut, K.; Perrin, G.;
Peterson, B. M.; Petrucci, P. -O.; Pflüger, A.; Pfuhl, O.; Phan Duc,
T.; Pineda, J. E.; Plewa, P. M.; Popovic, D.; Pott, J. -U.; Prieto,
A.; Pueyo, L.; Rabien, S.; Ramírez, A.; Ramos, J. R.; Rau, C.; Ray,
T.; Riquelme, M.; Rodríguez-Coira, G.; Rohloff, R. -R.; Rouan, D.;
Rousset, G.; Sanchez-Bermudez, J.; Schartmann, M.; Scheithauer,
S.; Schöller, M.; Schuhler, N.; Segura-Cox, D.; Shangguan, J.;
Shimizu, T. T.; Spyromilio, J.; Sternberg, A.; Stock, M. R.; Straub,
O.; Straubmeier, C.; Sturm, E.; Suárez Valles, M.; Tacconi, L. J.;
Thi, W. -F.; Tristram, K. R. W.; Valenzuela, J. J.; van Boekel, R.;
van Dishoeck, E. F.; Vermot, P.; Vincent, F.; von Fellenberg, S.;
Waisberg, I.; Wang, J. J.; Wank, I.; Weber, J.; Weigelt, G.; Widmann,
F.; Wieprecht, E.; Wiest, M.; Wiezorrek, E.; Wittkowski, M.; Woillez,
J.; Wolff, B.; Yang, P.; Yazici, S.; Ziegler, D.; Zins, G.
Bibcode: 2019Msngr.178...36G
Altcode:
GRAVITY observations reveal that most massive stars in the
Orion Trapezium cluster live in multiple systems. Our deep,
milliarcsecond-resolution interferometry fills the gap at 1-100
astronomical units (au), which is not accessible to traditional imaging
and spectroscopy, but is crucial to uncovering the mystery of high-mass
star formation.The new observations find a significantly higher
companion fraction than earlier studies of mostly OB associations. The
observed distribution of mass ratios declines steeply with mass and
follows a Salpeter power-law initial mass function. The observations
therefore exclude stellar mergers as the dominant formation mechanism
for massive stars in Orion.
Title: Images at the Highest Angular Resolution with GRAVITY: The
Case of η Carinae
Authors: GRAVITY Collaboration; Abuter, R.; Accardo, M.; Adler,
T.; Amorim, A.; Anugu, N.; Ávila, G.; Bauböck, M.; Benisty, M.;
Berger, J. -P.; Bestenlehner, J. M.; Beust, H.; Blind, N.; Bonnefoy,
M.; Bonnet, H.; Bourget, P.; Bouvier, J.; Brandner, W.; Brast,
R.; Buron, A.; Burtscher, L.; Cantalloube, F.; Caratti O Garatti,
A.; Caselli, P.; Cassaing, F.; Chapron, F.; Charnay, B.; Choquet,
É.; Clénet, Y.; Collin, C.; Coudé Du Foresto, V.; Davies, R.;
Deen, C.; Delplancke-Ströbele, F.; Dembet, R.; Derie, F.; de Wit,
W. -J.; Dexter, J.; de Zeeuw, T.; Dougados, C.; Dubus, G.; Duvert,
G.; Ebert, M.; Eckart, A.; Eisenhauer, F.; Esselborn, M.; Eupen, F.;
Fédou, P.; Ferreira, M. C.; Finger, G.; Förster Schreiber, N. M.;
Gao, F.; García Dabó, C. E.; Garcia Lopez, R.; Garcia, P. J. V.;
Gendron, É.; Genzel, R.; Gerhard, O.; Gil, J. P.; Gillessen, S.;
Gonté, F.; Gordo, P.; Gratadour, D.; Greenbaum, A.; Grellmann, R.;
Grözinger, U.; Guajardo, P.; Guieu, S.; Habibi, M.; Haguenauer, P.;
Hans, O.; Haubois, X.; Haug, M.; Haußmann, F.; Henning, T.; Hippler,
S.; Hönig, S. F.; Horrobin, M.; Huber, A.; Hubert, Z.; Hubin, N.;
Hummel, C. A.; Jakob, G.; Janssen, A.; Jimenez Rosales, A.; Jochum,
L.; Jocou, L.; Kammerer, J.; Karl, M.; Kaufer, A.; Kellner, S.;
Kendrew, S.; Kern, L.; Kervella, P.; Kiekebusch, M.; Kishimoto, M.;
Klarmann, L.; Klein, R.; Köhler, R.; Kok, Y.; Kolb, J.; Koutoulaki,
M.; Kulas, M.; Labadie, L.; Lacour, S.; Lagrange, A. -M.; Lapeyrère,
V.; Laun, W.; Lazareff, B.; Le Bouquin, J. -B.; Léna, P.; Lenzen,
R.; Lévêque, S.; Lin, C. -C.; Lippa, M.; Lutz, D.; Magnard, Y.;
Maire, A. -L.; Mehrgan, L.; Mérand, A.; Millour, F.; Mollière,
P.; Moulin, T.; Müller, A.; Müller, E.; Müller, F.; Netzer, H.;
Neumann, U.; Nowak, M.; Oberti, S.; Ott, T.; Pallanca, L.; Panduro,
J.; Pasquini, L.; Paumard, T.; Percheron, I.; Perraut, K.; Perrin, G.;
Peterson, B. M.; Petrucci, P. -O.; Pflüger, A.; Pfuhl, O.; Phan Duc,
T.; Pineda, J. E.; Plewa, P. M.; Popovic, D.; Pott, J. -U.; Prieto,
A.; Pueyo, L.; Rabien, S.; Ramírez, A.; Ramos, J. R.; Rau, C.; Ray,
T.; Riquelme, M.; Rodríguez-Coira, G.; Rohloff, R. -R.; Rouan, D.;
Rousset, G.; Sanchez-Bermudez, J.; Schartmann, M.; Scheithauer,
S.; Schöller, M.; Schuhler, N.; Segura-Cox, D.; Shangguan, J.;
Shimizu, T. T.; Spyromilio, J.; Sternberg, A.; Stock, M. R.; Straub,
O.; Straubmeier, C.; Sturm, E.; Suárez Valles, M.; Tacconi, L. J.;
Thi, W. -F.; Tristram, K. R. W.; Valenzuela, J. J.; van Boekel, R.;
van Dishoeck, E. F.; Vermot, P.; Vincent, F.; von Fellenberg, S.;
Waisberg, I.; Wang, J. J.; Wank, I.; Weber, J.; Weigelt, G.; Widmann,
F.; Wieprecht, E.; Wiest, M.; Wiezorrek, E.; Wittkowski, M.; Woillez,
J.; Wolff, B.; Yang, P.; Yazici, S.; Ziegler, D.; Zins, G.
Bibcode: 2019Msngr.178...31G
Altcode:
The main goal of an interferometer is to probe the physics of
astronomical objects at the highest possible angular resolution. The
most intuitive way of doing this is by reconstructing images from the
interferometric data. GRAVITY at the Very Large Telescope Interferometer
(VLTI) has proven to be a fantastic instrument in this endeavour. In
this article, we describe the reconstruction of the wind-wind collision
cavity of the massive binary η Car with GRAVITY across two spectral
lines: HeI and Brγ.
Title: The multiphase gas structure and kinematics in the
circumnuclear region of NGC 5728
Authors: Shimizu, T. Taro; Davies, R. I.; Lutz, D.; Burtscher, L.;
Lin, M.; Baron, D.; Davies, R. L.; Genzel, R.; Hicks, E. K. S.; Koss,
M.; Maciejewski, W.; Müller-Sánchez, F.; Orban de Xivry, G.; Price,
S. H.; Ricci, C.; Riffel, R.; Riffel, R. A.; Rosario, D.; Schartmann,
M.; Schnorr-Müller, A.; Sternberg, A.; Sturm, E.; Storchi-Bergmann,
T.; Tacconi, L.; Veilleux, S.
Bibcode: 2019MNRAS.490.5860S
Altcode: 2019MNRAS.tmp.2449S; 2019arXiv190703801S
We report on our combined analysis of HST, VLT/MUSE, VLT/SINFONI, and
ALMA observations of the local Seyfert 2 galaxy, NGC 5728 to investigate
in detail the feeding and feedback of the active galactic nucleus
(AGN). The data sets simultaneously probe the morphology, excitation,
and kinematics of the stars, ionized gas, and molecular gas over a
large range of spatial scales (10 pc to 10 kpc). NGC 5728 contains a
large stellar bar that is driving gas along prominent dust lanes to the
inner 1 kpc where the gas settles into a circumnuclear ring. The ring
is strongly star forming and contains a substantial population of young
stars as indicated by the lowered stellar velocity dispersion and gas
excitation consistent with H II regions. We model the kinematics of
the ring using the velocity field of the CO (2-1) emission and stars
and find it is consistent with a rotating disc. The outer regions
of the disc, where the dust lanes meet the ring, show signatures of
inflow at a rate of 1 M⊙ yr-1. Inside the
ring, we observe three molecular gas components corresponding to the
circular rotation of the outer ring, a warped disc, and the nuclear
stellar bar. The AGN is driving an ionized gas outflow that reaches
a radius of 250 pc with a mass outflow rate of 0.08 M⊙
yr-1 consistent with its luminosity and scaling relations
from previous studies. While we observe distinct holes in CO emission
which could be signs of molecular gas removal, we find that largely
the AGN is not disrupting the structure of the circumnuclear region.
Title: Probing the Discs of Herbig Ae/Be Stars at Terrestrial Orbits
Authors: GRAVITY Collaboration; Abuter, R.; Accardo, M.; Adler,
T.; Amorim, A.; Anugu, N.; Ávila, G.; Bauböck, M.; Benisty, M.;
Berger, J. -P.; Bestenlehner, J. M.; Beust, H.; Blind, N.; Bonnefoy,
M.; Bonnet, H.; Bourget, P.; Bouvier, J.; Brandner, W.; Brast,
R.; Buron, A.; Burtscher, L.; Cantalloube, F.; Caratti O Garatti,
A.; Caselli, P.; Cassaing, F.; Chapron, F.; Charnay, B.; Choquet,
É.; Clénet, Y.; Collin, C.; Coudé Du Foresto, V.; Davies, R.;
Deen, C.; Delplancke-Ströbele, F.; Dembet, R.; Derie, F.; de Wit,
W. -J.; Dexter, J.; de Zeeuw, T.; Dougados, C.; Dubus, G.; Duvert,
G.; Ebert, M.; Eckart, A.; Eisenhauer, F.; Esselborn, M.; Eupen, F.;
Fédou, P.; Ferreira, M. C.; Finger, G.; Förster Schreiber, N. M.;
Gao, F.; García Dabó, C. E.; Garcia Lopez, R.; Garcia, P. J. V.;
Gendron, É.; Genzel, R.; Gerhard, O.; Gil, J. P.; Gillessen, S.;
Gonté, F.; Gordo, P.; Gratadour, D.; Greenbaum, A.; Grellmann, R.;
Grözinger, U.; Guajardo, P.; Guieu, S.; Habibi, M.; Haguenauer, P.;
Hans, O.; Haubois, X.; Haug, M.; Haußmann, F.; Henning, T.; Hippler,
S.; Hönig, S. F.; Horrobin, M.; Huber, A.; Hubert, Z.; Hubin, N.;
Hummel, C. A.; Jakob, G.; Janssen, A.; Jimenez Rosales, A.; Jochum,
L.; Jocou, L.; Kammerer, J.; Karl, M.; Kaufer, A.; Kellner, S.;
Kendrew, S.; Kern, L.; Kervella, P.; Kiekebusch, M.; Kishimoto, M.;
Klarmann, L.; Klein, R.; Köhler, R.; Kok, Y.; Kolb, J.; Koutoulaki,
M.; Kulas, M.; Labadie, L.; Lacour, S.; Lagrange, A. -M.; Lapeyrère,
V.; Laun, W.; Lazareff, B.; Le Bouquin, J. -B.; Léna, P.; Lenzen,
R.; Lévêque, S.; Lin, C. -C.; Lippa, M.; Lutz, D.; Magnard, Y.;
Maire, A. -L.; Mehrgan, L.; Mérand, A.; Millour, F.; Mollière,
P.; Moulin, T.; Müller, A.; Müller, E.; Müller, F.; Netzer, H.;
Neumann, U.; Nowak, M.; Oberti, S.; Ott, T.; Pallanca, L.; Panduro,
J.; Pasquini, L.; Paumard, T.; Percheron, I.; Perraut, K.; Perrin, G.;
Peterson, B. M.; Petrucci, P. -O.; Pflüger, A.; Pfuhl, O.; Phan Duc,
T.; Pineda, J. E.; Plewa, P. M.; Popovic, D.; Pott, J. -U.; Prieto,
A.; Pueyo, L.; Rabien, S.; Ramírez, A.; Ramos, J. R.; Rau, C.; Ray,
T.; Riquelme, M.; Rodríguez-Coira, G.; Rohloff, R. -R.; Rouan, D.;
Rousset, G.; Sanchez-Bermudez, J.; Schartmann, M.; Scheithauer,
S.; Schöller, M.; Schuhler, N.; Segura-Cox, D.; Shangguan, J.;
Shimizu, T. T.; Spyromilio, J.; Sternberg, A.; Stock, M. R.; Straub,
O.; Straubmeier, C.; Sturm, E.; Suárez Valles, M.; Tacconi, L. J.;
Thi, W. -F.; Tristram, K. R. W.; Valenzuela, J. J.; van Boekel, R.;
van Dishoeck, E. F.; Vermot, P.; Vincent, F.; von Fellenberg, S.;
Waisberg, I.; Wang, J. J.; Wank, I.; Weber, J.; Weigelt, G.; Widmann,
F.; Wieprecht, E.; Wiest, M.; Wiezorrek, E.; Wittkowski, M.; Woillez,
J.; Wolff, B.; Yang, P.; Yazici, S.; Ziegler, D.; Zins, G.
Bibcode: 2019Msngr.178...38G
Altcode:
More than 4000 exoplanets are known to date in systems that differ
greatly from our Solar System. In particular, inner exoplanets tend
to follow orbits around their parent star that are much more compact
than that of Earth. These systems are also extremely diverse, covering
a range of intrinsic properties. Studying the main physi- cal processes
at play in the innermost regions of the protoplanetary discs is crucial
to understanding how these planets form and migrate so close to their
host. With GRAVITY, we focused on the study of near-infrared emission
of a sample of young intermediate- mass stars, the Herbig Ae/Be stars.
Title: VizieR Online Data Catalog: AGN global star-forming properties
(Shimizu+, 2017)
Authors: Shimizu, T. T.; Mushotzky, R. F.; Melendez, M.; Koss, M. J.;
Barger, A. J.; Cowie, L. L.
Bibcode: 2019yCat..74663161S
Altcode:
Using our high-quality Herschel photometry from Melendez
et al. (2014. Cat. J/ApJ/794/152) and Shimizu et al. (2016,
Cat. J/ApJ/794/152) combined with archival WISE 12 and 22um photometry,
we have constructed and modelled the SEDs for over 300 AGN. Our sample
is unique given its nearly unbiased selection based on ultrahard X-ray
detection, as well as its local nature that eliminates possible biases
and source confusion. (1 data file).
Title: Achievements of Hinode in the first eleven years
Authors: Hinode Review Team; Al-Janabi, Khalid; Antolin, Patrick;
Baker, Deborah; Bellot Rubio, Luis R.; Bradley, Louisa; Brooks,
David H.; Centeno, Rebecca; Culhane, J. Leonard; Del Zanna, Giulio;
Doschek, George A.; Fletcher, Lyndsay; Hara, Hirohisa; Harra,
Louise K.; Hillier, Andrew S.; Imada, Shinsuke; Klimchuk, James A.;
Mariska, John T.; Pereira, Tiago M. D.; Reeves, Katharine K.; Sakao,
Taro; Sakurai, Takashi; Shimizu, Toshifumi; Shimojo, Masumi; Shiota,
Daikou; Solanki, Sami K.; Sterling, Alphonse C.; Su, Yingna; Suematsu,
Yoshinori; Tarbell, Theodore D.; Tiwari, Sanjiv K.; Toriumi, Shin;
Ugarte-Urra, Ignacio; Warren, Harry P.; Watanabe, Tetsuya; Young,
Peter R.
Bibcode: 2019PASJ...71R...1H
Altcode:
Hinode is Japan's third solar mission following Hinotori (1981-1982)
and Yohkoh (1991-2001): it was launched on 2006 September 22 and is in
operation currently. Hinode carries three instruments: the Solar Optical
Telescope, the X-Ray Telescope, and the EUV Imaging Spectrometer. These
instruments were built under international collaboration with the
National Aeronautics and Space Administration and the UK Science and
Technology Facilities Council, and its operation has been contributed
to by the European Space Agency and the Norwegian Space Center. After
describing the satellite operations and giving a performance evaluation
of the three instruments, reviews are presented on major scientific
discoveries by Hinode in the first eleven years (one solar cycle long)
of its operation. This review article concludes with future prospects
for solar physics research based on the achievements of Hinode.
Title: Development of Solar-C_EUVST structural design
Authors: Suematsu, Yoshinori; Shimizu, Toshifumi; Hara, Hirohisa;
Katsukawa, Yukio; Kawate, Tomoko; Ichimoto, Kiyoshi; Imada, Shinsuke
Bibcode: 2019SPIE11118E..1OS
Altcode:
The Solar-C_EUVST is a mission designed to provide high-quality solar
spectroscopic data covering a wide temperature range of the chromosphere
to flaring corona. To fulfill a high throughput requirement, the
instrument consists of only two optical components; a 28-cm primary
mirror and a segmented toroidal grating which have high reflective
coatings in EUV-UV range. We present a mission payload structural
design which accommodates long focal length optical components and
a launcher condition/launch environment (JAXA Epsilon). We also
present a mechanical design of primary mirror assembly which enables
slit-scan observations, an image stabilizing tip-tilt control, and a
focus adjustment on orbit, together with an optomechanical design of
the primary mirror and its supporting system which gives optically
tolerant wavefront error against a large temperature increase due to
an absorption of visible and IR lights.
Title: Concept study of Solar-C_EUVST optical design
Authors: Kawate, Tomoko; Shimizu, Toshifumi; Imada, Shinsuke; Tsuzuki,
Toshihiro; Katsukawa, Yukio; Hara, Hirohisa; Suematsu, Yoshinori;
Ichimoto, Kiyoshi; Warren, Harry; Teriaca, Luca; Korendyke, Clarence
M.; Brown, Charles
Bibcode: 2019SPIE11118E..1NK
Altcode:
The main characteristics of Solar-C_EUVST are the high temporal and
high spatial resolutions over a wide temperature coverage. In order
to realize the instrument for meeting these scientific requirements
under size constraints given by the JAXA Epsilon vehicle, we examined
four-dimensional optical parameter space of possible solutions of
geometrical optical parameters such as mirror diameter, focal length,
grating magnification, and so on. As a result, we have identified
the solution space that meets the EUVST science objectives and rocket
envelope requirements. A single solution was selected and used to define
the initial optical parameters for the concept study of the baseline
architecture for defining the mission concept. For this solution, we
optimized the grating and geometrical parameters by ray tracing of the
Zemax software. Consequently, we found an optics system that fulfills
the requirement for a 0.4" angular resolution over a field of view of
100" (including margins) covering spectral ranges of 170-215, 463-542,
557-637, 690-850, 925-1085, and 1115-1275 A. This design achieves an
effective area 10 times larger than the Extreme-ultraviolet Imaging
Spectrometer onboard the Hinode satellite, and will provide seamless
observations of 4.2-7.2 log(K) plasmas for the first time. Tolerance
analyses were performed based on the optical design, and the moving
range and step resolution of focus mechanisms were identified. In
the presentation, we describe the derivation of the solution space,
optimization of the optical parameters, and show the results of ray
tracing and tolerance analyses.
Title: The Solar-C_EUVST mission
Authors: Shimizu, Toshifumi; Imada, Shinsuke; Kawate, Tomoko;
Ichimoto, Kiyoshi; Suematsu, Yoshinori; Hara, Hirohisa; Katsukawa,
Yukio; Kubo, Masahito; Toriumi, Shin; Watanabe, Tetsuya; Yokoyama,
Takaaki; Korendyke, Clarence M.; Warren, Harry P.; Tarbell, Ted; De
Pontieu, Bart; Teriaca, Luca; Schühle, Udo H.; Solanki, Sami; Harra,
Louise K.; Matthews, Sarah; Fludra, A.; Auchère, F.; Andretta, V.;
Naletto, G.; Zhukov, A.
Bibcode: 2019SPIE11118E..07S
Altcode:
Solar-C EUVST (EUV High-Throughput Spectroscopic Telescope) is a
solar physics mission concept that was selected as a candidate for
JAXA competitive M-class missions in July 2018. The onboard science
instrument, EUVST, is an EUV spectrometer with slit-jaw imaging
system that will simultaneously observe the solar atmosphere from the
photosphere/chromosphere up to the corona with seamless temperature
coverage, high spatial resolution, and high throughput for the first
time. The mission is designed to provide a conclusive answer to the
most fundamental questions in solar physics: how fundamental processes
lead to the formation of the solar atmosphere and the solar wind, and
how the solar atmosphere becomes unstable, releasing the energy that
drives solar flares and eruptions. The entire instrument structure
and the primary mirror assembly with scanning and tip-tilt fine
pointing capability for the EUVST are being developed in Japan, with
spectrograph and slit-jaw imaging hardware and science contributions
from US and European countries. The mission will be launched and
installed in a sun-synchronous polar orbit by a JAXA Epsilon vehicle in
2025. ISAS/JAXA coordinates the conceptual study activities during the
current mission definition phase in collaboration with NAOJ and other
universities. The team is currently working towards the JAXA final
down-selection expected at the end of 2019, with strong support from
US and European colleagues. The paper provides an overall description
of the mission concept, key technologies, and the latest status.
Title: Design of all-reflective space-borne 1-m aperture solar
optical telescope
Authors: Suematsu, Y.; Hara, H.; Katsukawa, Y.; Kano, R.; Shimizu,
T.; Ichimoto, K.
Bibcode: 2019SPIE11180E..0RS
Altcode:
A 1-m aperture optical telescope is planned for a future Japanese solar
mission. The telescope is designed to provide high spatial resolution
data of solar lower atmosphere from the photosphere to the uppermost
chromosphere with enhanced spectroscopic and spectro-polarimetric
capabilities covering a wide wavelength region from UV to near IR where
many useful spectral lines and continua exist for physical diagnosis of
the solar magnetized atmosphere. We designed an allreflective telescope
to fulfill the scientific and engineering requirements. From a thermal
view point, a Gregorian telescope is the most suitable. To avoid
chromatic aberration, a tri-aspheric-mirror collimator coupling to
the Gregorian was designed to give a diffraction-limited performance
over the FOV by allowing a field curvature. The field curvature can
be compensated by an off-axis Ritchey Chretien reimaging optics at an
entrance of focal plane instrument, which has an opposite sign in the
field curvature to the Gregorian. We also briefly studied structural
design of all-reflective 1-m aperture solar optical telescope for the
space solar mission.
Title: UFSS (ultra fine sun sensor): CCD sun sensor with sub-arc
second accuracy for the next solar observing satellite SOLAR-C
Authors: Tsuno, K.; Wada, S.; Ogawa, T.; Shimizu, T.; Hasegawa, T.;
Kubo, M.; Murao, H.; Mizumoto, S.; Fujishima, S.; Toyonaga, K.
Bibcode: 2019SPIE11180E..4OT
Altcode:
The Ultra Fine Sun Sensor (UFSS) on board the HINODE solar observing
satellite is one of the most successful sun sensors. It is the linear
CCD sun sensor with a special detection method using multiple slits,
called the periodic reticle. The angular resolution of 0.14 arcsec
in the noise equivalent angle (NEA) and 1 arcsec stability were
achieved by the sensor head, of 1.2 kg weight. The concept of the
detection method and processing algorithm of the Sun's direction
is described. The system is modeled and the dynamic response of the
system is characterized by the first-order lag system. By utilizing
this characteristic, a resolution improvement three times higher can be
expected by adjusting the parameters with a small modification to the
HINODE UFSS processing algorithm. The design for a new UFSS for the
next generation solar observation satellite, SOLAR-C, shall include
these modifications. The thermomechanical design is also reviewed to
improve stability and a design policy is obtained.
Title: Chromospheric polarimetry through multiline observations of
the 850 nm spectral region III: Chromospheric jets driven by twisted
magnetic fields
Authors: Quintero Noda, C.; Iijima, H.; Katsukawa, Y.; Shimizu,
T.; Carlsson, M.; de la Cruz Rodríguez, J.; Ruiz Cobo, B.; Orozco
Suárez, D.; Oba, T.; Anan, T.; Kubo, M.; Kawabata, Y.; Ichimoto,
K.; Suematsu, Y.
Bibcode: 2019MNRAS.486.4203Q
Altcode: 2019MNRAS.tmp.1081N; 2019arXiv190409151Q
We investigate the diagnostic potential of the spectral lines at 850
nm for understanding the magnetism of the lower atmosphere. For that
purpose, we use a newly developed 3D simulation of a chromospheric
jet to check the sensitivity of the spectral lines to this phenomenon
as well as our ability to infer the atmospheric information through
spectropolarimetric inversions of noisy synthetic data. We start
comparing the benefits of inverting the entire spectrum at 850 nm versus
only the Ca II 8542 Å spectral line. We found a better match of the
input atmosphere for the former case, mainly at lower heights. However,
the results at higher layers were not accurate. After several tests,
we determined that we need to weight more the chromospheric lines
than the photospheric ones in the computation of the goodness of the
fit. The new inversion configuration allows us to obtain better fits and
consequently more accurate physical parameters. Therefore, to extract
the most from multiline inversions, a proper set of weights needs to
be estimated. Besides that, we conclude again that the lines at 850
nm, or a similar arrangement with Ca II 8542 Å plus Zeeman-sensitive
photospheric lines, pose the best-observing configuration for examining
the thermal and magnetic properties of the lower solar atmosphere.
Title: The Evolution and Origin of Ionized Gas Velocity Dispersion
from z ∼ 2.6 to z ∼ 0.6 with KMOS3D
Authors: Übler, H.; Genzel, R.; Wisnioski, E.; Förster Schreiber,
N. M.; Shimizu, T. T.; Price, S. H.; Tacconi, L. J.; Belli, S.;
Wilman, D. J.; Fossati, M.; Mendel, J. T.; Davies, R. L.; Beifiori,
A.; Bender, R.; Brammer, G. B.; Burkert, A.; Chan, J.; Davies, R. I.;
Fabricius, M.; Galametz, A.; Herrera-Camus, R.; Lang, P.; Lutz, D.;
Momcheva, I. G.; Naab, T.; Nelson, E. J.; Saglia, R. P.; Tadaki, K.;
van Dokkum, P. G.; Wuyts, S.
Bibcode: 2019ApJ...880...48U
Altcode: 2019arXiv190602737U
We present the 0.6 < z < 2.6 evolution of the ionized gas
velocity dispersion in 175 star-forming disk galaxies based on
data from the full KMOS3D integral field spectroscopic
survey. In a forward-modeling Bayesian framework including instrumental
effects and beam-smearing, we fit simultaneously the observed galaxy
velocity and velocity dispersion along the kinematic major axis to
derive the intrinsic velocity dispersion σ 0. We find
a reduction of the average intrinsic velocity dispersion of disk
galaxies as a function of cosmic time, from σ 0 ∼ 45 km
s-1 at z ∼ 2.3 to σ 0 ∼ 30 km s-1
at z ∼ 0.9. There is substantial intrinsic scatter ({σ }{σ
0,{int}}≈ 10 {km} {{{s}}}-1) around
the best-fit σ 0-z relation beyond what can be accounted
for from the typical measurement uncertainties (δσ 0
≈ 12 km s-1), independent of other identifiable galaxy
parameters. This potentially suggests a dynamic mechanism such as
minor mergers or variation in accretion being responsible for the
scatter. Putting our data into the broader literature context, we find
that ionized and atomic+molecular velocity dispersions evolve similarly
with redshift, with the ionized gas dispersion being ∼10-15 km
s-1 higher on average. We investigate the physical driver of
the on average elevated velocity dispersions at higher redshift and find
that our galaxies are at most marginally Toomre-stable, suggesting that
their turbulent velocities are powered by gravitational instabilities,
while stellar feedback as a driver alone is insufficient. This picture
is supported through comparison with a state-of-the-art analytical
model of galaxy evolution. Based on observations collected at
the Very Large Telescope (VLT) of the European Southern Observatory
(ESO), Paranal, Chile, under ESO program IDs 092.A-0091, 093.A-0079,
094.A-0217, 095.A-0047, 096.A-0025, 097.A-0028, 098.A-0045, 099.A-0013,
0100.A-0039, and 0101.A-0022.
Title: Structure and dynamics of the hot flaring loop-top source
observed by Hinode, SDO, RHESSI, and STEREO
Authors: Lee, Kyoung-Sun; Hara, Hirohisa; Watanabe, Kyoko; Joshi,
Anand D.; Imada, Shinsuke; Brooks, David H.; Dang, Phillip; Shimizu,
Toshifumi; Savage, Sabrina
Bibcode: 2019AAS...23421605L
Altcode:
We have investigated an M1.3 flare on 2014 January 13 around
21:48 UT observed at the west limb using the Hinode, SDO, RHESSI,
and STEREO. Especially, the Hinode/EIS scanned the flaring loop
covering the loop-top region over the limb, which is a good target to
investigate the dynamics of the flaring loop with their height. Using
the multi-wavelength observations from the Hinode/EIS and SDO/AIA,
we found a very hot emission above the loop-top observed in Fe XXIV
and 131Å channel. Measuring the intensity, Doppler velocity and line
width for the flaring loop, we found that hot emission observed at
the cusp-like shape of the loop-top region which shows strong redshift
about 500 km s-1 in Doppler velocity and strong enhancement
of the non-thermal velocity (line width enhancement) larger than 100
km s-1. Combining with the STEREO observation, we have
examined the 3D structure with loop tilt angle and have investigated
the velocity distribution of the loop-top region. With the loop tilt
angle, we could identify the strong redshift at the loop-top region
may indicate an up-flow along the loop-top region. From RHESSI hard
X-ray (HXR), and soft X-ray (SXR) emission, we found that the footpoint
brightening region at the beginning of the flare has a both HXR (25-50
keV) and SXR (12-25 keV) emission in which imply that the region has
non-thermal emission or accelerated particles. Then, within 10 minutes
the soft X-ray (SXR) emission observed near the cusp shape region at
loop top. The temporal variation of the HXR and SXR emissions and the
Doppler velocity variation of the hot plasma component at the loop-top
imply that the strong flow in a hot component near loop-top could be
the evaporation flows which detected at the corona along the tilted
loop. Moreover, The temporal evolution of the temperature observed
by SDO/AIA and Hinode/EIS also shows the cooling process of the flare
plasma which is consistent with the impulsively heated flare model.
Title: Comparison of Scattering Polarization Signals Observed by
CLASP: Possible Indication of the Hanle Effect
Authors: Ishikawa, R.; Trujillo Bueno, J.; Uitenbroek, H.; Kubo, M.;
Tsuneta, S.; Goto, M.; Kano, R.; Narukage, N.; Bando, T.; Katsukawa,
Y.; Ishikawa, S.; Giono, G.; Suematsu, Y.; Hara, H.; Shimizu, T.;
Sakao, T.; Winebarger, A.; Kobayashi, K.; Cirtain, J.; Champey, P.;
Auchère, F.; Štěpán, J.; Belluzzi, L.; Asensio Ramos, A.; Manso
Sainz, R.; De Pomtieu, B.; Ichimoto, K.; Carlsson, M.; Casini, R.
Bibcode: 2019ASPC..526..305I
Altcode:
The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP; Kano et
al. 2012; Kobayashi et al. 2012; Kubo et al. 2014) observed, for the
first time, the linear polarization produced by scattering processes
in the hydrogen Lyman-α (121.57 nm) and Si III (120.56 nm) lines of
the solar disk radiation. The complexity of the observed scattering
polarization (i.e., conspicuous spatial variations in Q/I and U/I
at spatial scales of 10″-20″ and the absence of center-to- limb
variation at the Lyman-α center; see Kano et al. 2017) motivated us
to search for possible hints of the operation of the Hanle effect by
comparing: (a) the Lyman-α line center signal, for which the critical
field strength (BH) for the onset of the Hanle effect is
53 G, (b) the Lyman-α wing, which is insensitive to the Hanle effect,
and (c) the Si III line, whose BH = 290 G. We focus on four
regions with different total unsigned photospheric magnetic fluxes
(estimated from SDO/HMI observations), and compare the corresponding
U/I spatial variations in the Lyman-α wing, Lyman-α center, and Si III
line. The U/I signal in the Lyman-α wing shows an antisymmetric spatial
distribution, which is caused by the presence of a bright structure in
all the selected regions, regardless of the total unsigned photospheric
magnetic flux. In an internetwork region, the Lyman-α center shows an
antisymmetric spatial variation across the selected bright structure,
but it does not show it in other more magnetized regions. In the Si III
line, the spatial variation of U/I deviates from the above-mentioned
antisymmetric shape as the total unsigned photospheric magnetic flux
increases. We argue that a plausible explanation of this differential
behavior is the operation of the Hanle effect. This work, presented
in an oral contribution at this Workshop, has been published on The
Astrophysical Journal (Ishikawa et al. 2017).
Title: The KMOS3D Survey: Demographics and Properties of
Galactic Outflows at z = 0.6-2.7
Authors: Förster Schreiber, N. M.; Übler, H.; Davies, R. L.;
Genzel, R.; Wisnioski, E.; Belli, S.; Shimizu, T.; Lutz, D.; Fossati,
M.; Herrera-Camus, R.; Mendel, J. T.; Tacconi, L. J.; Wilman, D.;
Beifiori, A.; Brammer, G. B.; Burkert, A.; Carollo, C. M.; Davies,
R. I.; Eisenhauer, F.; Fabricius, M.; Lilly, S. J.; Momcheva, I.; Naab,
T.; Nelson, E. J.; Price, S. H.; Renzini, A.; Saglia, R.; Sternberg,
A.; van Dokkum, P.; Wuyts, S.
Bibcode: 2019ApJ...875...21F
Altcode: 2018arXiv180704738F
We present a census of ionized gas outflows in 599 normal galaxies
at redshift 0.6 < z < 2.7, mostly based on integral field
spectroscopy of Hα, [N II], and [S II] line emission. The sample
fairly homogeneously covers the main sequence of star-forming galaxies
with masses 9.0 < log(M */M ⊙) < 11.7,
and probes into the regimes of quiescent galaxies and starburst
outliers. About one-third exhibits the high-velocity component
indicative of outflows, roughly equally split into winds driven by star
formation (SF) and active galactic nuclei (AGNs). The incidence of
SF-driven winds correlates mainly with SF properties. These outflows
have typical velocities of ∼450 km s-1, local electron
densities of n e ∼ 380 cm-3, modest mass loading
factors of ∼0.1-0.2 at all galaxy masses, and energetics compatible
with momentum driving by young stellar populations. The SF-driven winds
may escape from log(M */M ⊙) ≲ 10.3 galaxies,
but substantial mass, momentum, and energy in hotter and colder outflow
phases seem required to account for low galaxy formation efficiencies
in the low-mass regime. Faster AGN-driven outflows (∼1000-2000 km
s-1) are commonly detected above log(M */M
⊙) ∼ 10.7, in up to ∼75% of log(M */M
⊙) ≳ 11.2 galaxies. The incidence, strength, and
velocity of AGN-driven winds strongly correlates with stellar mass and
central concentration. Their outflowing ionized gas appears denser
(n e ∼ 1000 cm-3), and possibly compressed
and shock-excited. These winds have comparable mass loading factors
as the SF-driven winds but carry ∼10 (∼50) times more momentum
(energy). The results confirm our previous findings of high-duty-cycle,
energy-driven outflows powered by AGN above the Schechter mass, which
may contribute to SF quenching. Based on observations obtained
at the Very Large Telescope of the European Southern Observatory,
Paranal, Chile (ESO program IDs 073.B-9018, 074.A-9011, 075.A-0466,
076.A-0527, 077.A-0527, 078.A-0600, 079.A-0341, 080.A-0330, 080.A-0339,
080.A-0635, 081.A-0672, 081.B-0568, 082.A-0396, 183.A-0781, 087.A-0081,
088.A-0202, 088.A-0209, 090.A-0516, 091.A-0126, 092.A-0082, 092.A-0091,
093.A-0079, 093.A-0110, 093.A-0233, 094.A-0217, 094.A-0568, 095.A-0047,
096.A-0025, 097.A-0028, 098.A-0045, 099.A-0013, 0100.A-0039). Also based
on observations taken at the Large Binocular Telescope on Mt. Graham
in Arizona.
Title: Kiloparsec Scale Properties of Star Formation Driven Outflows
at z ∼ 2.3 in the SINS/zC-SINF AO Survey
Authors: Davies, R. L.; Förster Schreiber, N. M.; Übler, H.; Genzel,
R.; Lutz, D.; Renzini, A.; Tacchella, S.; Tacconi, L. J.; Belli, S.;
Burkert, A.; Carollo, C. M.; Davies, R. I.; Herrera-Camus, R.; Lilly,
S. J.; Mancini, C.; Naab, T.; Nelson, E. J.; Price, S. H.; Shimizu,
T. T.; Sternberg, A.; Wisnioski, E.; Wuyts, S.
Bibcode: 2019ApJ...873..122D
Altcode: 2018arXiv180810700D
We investigate the relationship between star formation activity and
outflow properties on kiloparsec scales in a sample of 28 star-forming
galaxies at z ∼ 2-2.6, using adaptive optics assisted integral field
observations from SINFONI on the Very Large Telescope. The narrow
and broad components of the Hα emission are used to simultaneously
determine the local star formation rate surface density ({{{Σ
}}}SFR}), and the outflow velocity {v}out}
and mass outflow rate {\dot{M}}out}, respectively. We find
clear evidence for faster outflows with larger mass loading factors
at higher {{{Σ }}}SFR}. The outflow velocities scale as
{v}out} ∝ {{{Σ }}}SFR} 0.34±0.10,
which suggests that the outflows may be driven by a combination of
mechanical energy released by supernova explosions and stellar winds,
as well as radiation pressure acting on dust grains. The majority of
the outflowing material does not have sufficient velocity to escape
from the galaxy halos, but will likely be re-accreted and contribute
to the chemical enrichment of the galaxies. In the highest {{{Σ
}}}SFR} regions the outflow component contains an average
of ∼45% of the Hα flux, while in the lower {{{Σ }}}SFR}
regions only ∼10% of the Hα flux is associated with outflows. The
mass loading factor, η = {\dot{M}}out}/SFR, is positively
correlated with {{{Σ }}}SFR} but is relatively low
even at the highest {{{Σ }}}SFR}: η ≲ 0.5 ×
(380 cm-3/n e ). This may be in tension
with the η ≳ 1 required by cosmological simulations, unless a
significant fraction of the outflowing mass is in other gas phases
and has sufficient velocity to escape the galaxy halos. Based on
observations collected at the European Organisation for Astronomical
Research in the Southern Hemisphere under ESO Programme IDs 075.A-0466,
079.A-0341, 080.A-0330, 080.A-0339, 080.A-0635, 081.A-0672, 081.B-0568,
183.A-0781, 087.A-0081, and 088.A-0209.
Title: BAT AGN Spectroscopic Survey. XI. The Covering Factor of Dust
and Gas in Swift/BAT Active Galactic Nuclei
Authors: Ichikawa, Kohei; Ricci, Claudio; Ueda, Yoshihiro; Bauer,
Franz E.; Kawamuro, Taiki; Koss, Michael J.; Oh, Kyuseok; Rosario,
David J.; Shimizu, T. Taro; Stalevski, Marko; Fuller, Lindsay; Packham,
Christopher; Trakhtenbrot, Benny
Bibcode: 2019ApJ...870...31I
Altcode: 2018arXiv181102568I
We quantify the luminosity contribution of active galactic nuclei
(AGNs) to the 12 μm, mid-infrared (MIR; 5-38 μm), and total IR
(5-1000 μm) emission in the local AGNs detected in the all-sky 70
month Swift/Burst Alert Telescope (BAT) ultrahard X-ray survey. We
decompose the IR spectral energy distributions (SEDs) of 587 objects
into the AGN and starburst components using templates for an AGN
torus and a star-forming galaxy. This enables us to recover the
emission from the AGN torus including the low-luminosity end, down
to {log}({L}14-150/{erg} {{{s}}}-1)≃ 41,
which typically has significant host galaxy contamination. The
sample demonstrates that the luminosity contribution of the AGN
to the 12 μm, the MIR, and the total IR bands is an increasing
function of the 14-150 keV luminosity. We also find that for the
most extreme cases, the IR pure-AGN emission from the torus can
extend up to 90 μm. The total IR AGN luminosity obtained through
the IR SED decomposition enables us to estimate the fraction
of the sky obscured by dust, i.e., the dust covering factor. We
demonstrate that the median dust covering factor is always smaller
than the median X-ray obscuration fraction above an AGN bolometric
luminosity of {log}({L}bol}({AGN)}/{erg}
{{{s}}}-1)≃ 42.5. Considering that the X-ray obscuration
fraction is equivalent to the covering factor coming from both the
dust and gas, this indicates that an additional neutral gas component,
along with the dusty torus, is responsible for the absorption of
X-ray emission.
Title: Molecular and Ionized Gas Phases of an AGN-driven Outflow in
a Typical Massive Galaxy at z ≈ 2
Authors: Herrera-Camus, R.; Tacconi, L.; Genzel, R.; Förster
Schreiber, N.; Lutz, D.; Bolatto, A.; Wuyts, S.; Renzini, A.; Lilly,
S.; Belli, S.; Übler, H.; Shimizu, T.; Davies, R.; Sturm, E.; Combes,
F.; Freundlich, J.; García-Burillo, S.; Cox, P.; Burkert, A.; Naab,
T.; Colina, L.; Saintonge, A.; Cooper, M.; Feruglio, C.; Weiss, A.
Bibcode: 2019ApJ...871...37H
Altcode: 2018arXiv180707074H
Nuclear outflows driven by accreting massive black holes are one of the
main feedback mechanisms invoked at high-z to reproduce the distinct
separation between star-forming disk galaxies and quiescent spheroidal
systems. Yet our knowledge of feedback at high-z remains limited by the
lack of observations of the multiple gas phases in galaxy outflows. In
this work, we use new deep, high spatial resolution ALMA CO(3-2)
and archival Very Large Telescope/SINFONI Hα observations to study
the molecular and ionized components of the active galactic nucleus
(AGN)-driven outflow in zC400528, a massive main-sequence galaxy at
z = 2.3 in the process of quenching. We detect a powerful molecular
outflow that shows a positive velocity gradient before a turnover
and extends for at least ∼10 kpc from the nuclear region, about
three times the projected size of the ionized wind. The molecular
gas in the outflow does not reach velocities high enough to escape
the galaxy and is therefore expected to be reaccreted. Keeping in
mind the various assumptions involved in the analysis, we find that
the mass and energetics of the outflow are dominated by the molecular
phase. The AGN-driven outflow in zC400528 is powerful enough to deplete
the molecular gas reservoir on a timescale comparable to that needed to
exhaust it by star formation. This suggests that the nuclear outflow is
one of the main quenching engines at work in the observed suppression
of the central star formation activity in zC400528.
Title: Study of the polarization produced by the Zeeman effect in
the solar Mg I b lines
Authors: Quintero Noda, C.; Uitenbroek, H.; Carlsson, M.; Orozco
Suárez, D.; Katsukawa, Y.; Shimizu, T.; Ruiz Cobo, B.; Kubo, M.; Oba,
T.; Kawabata, Y.; Hasegawa, T.; Ichimoto, K.; Anan, T.; Suematsu, Y.
Bibcode: 2018MNRAS.481.5675Q
Altcode: 2018arXiv181001067Q; 2018MNRAS.tmp.2566Q
The next generation of solar observatories aim to understand the
magnetism of the solar chromosphere. Therefore, it is crucial to
understand the polarimetric signatures of chromospheric spectral
lines. For this purpose, we here examine the suitability of the three
Fraunhofer Mg I b1, b2, and b4 lines
at 5183.6, 5172.7, and 5167.3 Å, respectively. We start by describing
a simplified atomic model of only six levels and three line transitions
for computing the atomic populations of the 3p-4s (multiplet number
2) levels involved in the Mg I b line transitions assuming non-local
thermodynamic conditions and considering only the Zeeman effect using
the field-free approximation. We test this simplified atom against
more complex ones finding that, although there are differences in the
computed profiles, they are small compared with the advantages provided
by the simple atom in terms of speed and robustness. After comparing
the three Mg I lines, we conclude that the most capable one is the
b2 line as b1 forms at similar heights and always
shows weaker polarization signals, while b4 is severely
blended with photospheric lines. We also compare Mg I b2
with the K I D1 and Ca II 8542 Å lines finding that the
former is sensitive to the atmospheric parameters at heights that
are in between those covered by the latter two lines. This makes Mg I
b2 an excellent candidate for future multiline observations
that aim to seamlessly infer the thermal and magnetic properties of
different features in the lower solar atmosphere.
Title: Statistical Relation between Solar Flares and Coronal Mass
Ejections with Respect to Sigmoidal Structures in Active Regions
Authors: Kawabata, Yusuke; Iida, Yusuke; Doi, Takafumi; Akiyama,
Sachiko; Yashiro, Seiji; Shimizu, Toshifumi
Bibcode: 2018ApJ...869...99K
Altcode: 2018arXiv181010808K
Statistical dependences among features of coronal mass ejections
(CMEs), solar flares, and sigmoidal structures in soft-X-ray images
were investigated. We applied analysis methods to all the features
in the same way in order to investigate the reproducibility of
the correlations among them, which may be found from previous
statistical studies. Samples of 211 M-class and X-class flares,
observed between 2006 and 2015 by the Hinode/X-ray telescope, Solar and
Heliospheric Observatory/Large Angle and Spectrometric Coronagraph,
and Geostationary Operational Environmental Satellite, were examined
statistically. Five kinds of analysis were performed: occurrence
rate analysis, linear-correlation analysis, association analysis,
the Kolmogorov-Smirnov test, and the Anderson-Darling test. These give
three main results. First, the sigmoidal structure and long-duration
events (LDEs) have a stronger dependence on CME occurrence than large
X-ray-class events in on-disk events. Second, for the limb events,
a significant dependence exists between LDEs and CME occurrence,
and between X-ray-class events and CME occurrence. Third, 32.4% of
on-disk flare events have sigmoidal structure and are not accompanied
by CMEs. However, the occurrence probability of CMEs without sigmoidal
structure is very small, 8.8%, in on-disk events. While the first and
second results are consistent with previous studies, we provide for
the first time a difference between the on-disk and limb events. The
third result, that non-sigmoidal regions produce fewer eruptive events,
is also different from previous results. We suggest that sigmoidal
structures in soft X-ray images will be a helpful feature for CME
prediction in on-disk flare events.
Title: Flare-related Recurring Active Region Jets: Evidence for Very
Hot Plasma
Authors: Mulay, Sargam M.; Matthews, Sarah; Hasegawa, Takahiro;
Del Zanna, Giulio; Mason, Helen; Shimizu, Toshifumi
Bibcode: 2018SoPh..293..160M
Altcode:
We present a study of two active region jets (AR jets) that are
associated with two C-class X-ray flares. The recurrent, homologous
jets originated from the northern periphery of a sunspot. We
confirm flare-like temperatures at the footpoints of these jets using
spectroscopic observations of Fe XXIII (263.76 Å) and Fe XXIV (255.11
Å) emission lines. The emission measure loci method was used to obtain
an isothermal temperature, and the results show a decrease (17.7 to 13.6
MK) in the temperature during the decay phase of the C 3.0 flare. The
electron number densities at the footpoints were found to range from
1.7 ×1010 to 2.0 ×1011cm−3 using
the Fe XIV line pair ratio. Nonthermal velocities were found to range
from 34 - 100 km/s for Fe XXIV and 51 - 89 km/s for Fe XXIII. The
plane-of-sky velocities were calculated to be 462 ±21 and 228 ±23
km/s for the two jets using the Atmospheric Imaging Assembly (AIA)
171 Å channel. The AIA light curves of the jet footpoint regions
confirmed the temporal and spatial correlation between the two X-ray
flares and the jet footpoint emission. The Gamma-ray Burst Monitor (GBM)
also confirmed superhot plasma of 27 (25) MK with a nonthermal energy
of 2.38 ×1026 (2.87 ×1027) ergs−1
in the jet footpoint region during the rise (peak) phase of one of the
flares. The temperatures of the jet footpoint regions obtained from
EIS agree very well (within an uncertainty of 20%) with temperatures
obtained from the Geostationary Environmental Operational Satellite
(GOES) flux ratios. These results provide clear evidence for very hot
plasma (>10 MK) at the footpoints of the flare-related jets, and
they confirm the heating and cooling of the plasma during the flares.
Title: Witnessing the Early Growth and Life Cycle of Galaxies with
KMOS3D
Authors: Förster Schreiber, N. M.; Wilman, D.; Wisnioski, E. S.;
Fossati, M.; Mendel, J. T.; Bender, R.; Genzel, R.; Beifiori, A.;
Belli, S.; Brammer, G.; Burkert, A.; Chan, J.; Davies, R. I.; Davies,
R. L.; Fabricius, M.; Galametz, A.; Herrera-Camus, R.; Lang, P.; Lutz,
D.; Momcheva, I.; Naab, T.; Nelson, E. J.; Price, S. H.; Renzini, A.;
Saglia, R.; Seitz, S.; Shimizu, T.; Sternberg, A.; Tacconi, L. J.;
Tadaki, K. -i.; Übler, H.; van Dokkum, P. G.; Wuyts, S.
Bibcode: 2018Msngr.174...28S
Altcode:
Near-infrared integral field unit (IFU) spectrographs are powerful
tools for investigating galaxy evolution. We report on our recently
completed multi- year KMOS3D survey of Hα, [N II] and
[SII] line emission of galaxies at redshift z 0.7-2.7 with the
K-band Multi-Object Spectrograph (KMOS) at the Very Large Telescope
(VLT). With deep observations of 745 targets spanning over two orders
of magnitude in galaxy mass, five billion years of cosmic time, and all
levels of star formation, KMOS3D provides an unparalleled
population-wide census of spatially-resolved kinematics, star formation,
outflows and nebular gas conditions. The dataset sheds new light on the
physical mechanisms driving the early growth and lifecycle of galaxies,
and provides a rich legacy for the astronomical community.
Title: The LiteBIRD Satellite Mission: Sub-Kelvin Instrument
Authors: Suzuki, A.; Ade, P. A. R.; Akiba, Y.; Alonso, D.; Arnold,
K.; Aumont, J.; Baccigalupi, C.; Barron, D.; Basak, S.; Beckman,
S.; Borrill, J.; Boulanger, F.; Bucher, M.; Calabrese, E.; Chinone,
Y.; Cho, S.; Crill, B.; Cukierman, A.; Curtis, D. W.; de Haan, T.;
Dobbs, M.; Dominjon, A.; Dotani, T.; Duband, L.; Ducout, A.; Dunkley,
J.; Duval, J. M.; Elleflot, T.; Eriksen, H. K.; Errard, J.; Fischer,
J.; Fujino, T.; Funaki, T.; Fuskeland, U.; Ganga, K.; Goeckner-Wald,
N.; Grain, J.; Halverson, N. W.; Hamada, T.; Hasebe, T.; Hasegawa,
M.; Hattori, K.; Hattori, M.; Hayes, L.; Hazumi, M.; Hidehira, N.;
Hill, C. A.; Hilton, G.; Hubmayr, J.; Ichiki, K.; Iida, T.; Imada, H.;
Inoue, M.; Inoue, Y.; Irwin, K. D.; Ishino, H.; Jeong, O.; Kanai, H.;
Kaneko, D.; Kashima, S.; Katayama, N.; Kawasaki, T.; Kernasovskiy,
S. A.; Keskitalo, R.; Kibayashi, A.; Kida, Y.; Kimura, K.; Kisner,
T.; Kohri, K.; Komatsu, E.; Komatsu, K.; Kuo, C. L.; Kurinsky, N. A.;
Kusaka, A.; Lazarian, A.; Lee, A. T.; Li, D.; Linder, E.; Maffei,
B.; Mangilli, A.; Maki, M.; Matsumura, T.; Matsuura, S.; Meilhan, D.;
Mima, S.; Minami, Y.; Mitsuda, K.; Montier, L.; Nagai, M.; Nagasaki,
T.; Nagata, R.; Nakajima, M.; Nakamura, S.; Namikawa, T.; Naruse,
M.; Nishino, H.; Nitta, T.; Noguchi, T.; Ogawa, H.; Oguri, S.; Okada,
N.; Okamoto, A.; Okamura, T.; Otani, C.; Patanchon, G.; Pisano, G.;
Rebeiz, G.; Remazeilles, M.; Richards, P. L.; Sakai, S.; Sakurai, Y.;
Sato, Y.; Sato, N.; Sawada, M.; Segawa, Y.; Sekimoto, Y.; Seljak, U.;
Sherwin, B. D.; Shimizu, T.; Shinozaki, K.; Stompor, R.; Sugai, H.;
Sugita, H.; Suzuki, J.; Tajima, O.; Takada, S.; Takaku, R.; Takakura,
S.; Takatori, S.; Tanabe, D.; Taylor, E.; Thompson, K. L.; Thorne, B.;
Tomaru, T.; Tomida, T.; Tomita, N.; Tristram, M.; Tucker, C.; Turin,
P.; Tsujimoto, M.; Uozumi, S.; Utsunomiya, S.; Uzawa, Y.; Vansyngel,
F.; Wehus, I. K.; Westbrook, B.; Willer, M.; Whitehorn, N.; Yamada,
Y.; Yamamoto, R.; Yamasaki, N.; Yamashita, T.; Yoshida, M.
Bibcode: 2018JLTP..193.1048S
Altcode: 2018JLTP..tmp..124S; 2018arXiv180106987S
Inflation is the leading theory of the first instant of the
universe. Inflation, which postulates that the universe underwent
a period of rapid expansion an instant after its birth, provides
convincing explanation for cosmological observations. Recent
advancements in detector technology have opened opportunities to
explore primordial gravitational waves generated by the inflation
through "B-mode" (divergent-free) polarization pattern embedded in the
cosmic microwave background anisotropies. If detected, these signals
would provide strong evidence for inflation, point to the correct
model for inflation, and open a window to physics at ultra-high
energies. LiteBIRD is a satellite mission with a goal of detecting
degree-and-larger-angular-scale B-mode polarization. LiteBIRD will
observe at the second Lagrange point with a 400 mm diameter telescope
and 2622 detectors. It will survey the entire sky with 15 frequency
bands from 40 to 400 GHz to measure and subtract foregrounds. The
US LiteBIRD team is proposing to deliver sub-Kelvin instruments
that include detectors and readout electronics. A lenslet-coupled
sinuous antenna array will cover low-frequency bands (40-235
GHz) with four frequency arrangements of trichroic pixels. An
orthomode-transducer-coupled corrugated horn array will cover
high-frequency bands (280-402 GHz) with three types of single frequency
detectors. The detectors will be made with transition edge sensor
(TES) bolometers cooled to a 100 milli-Kelvin base temperature by an
adiabatic demagnetization refrigerator. The TES bolometers will be read
out using digital frequency multiplexing with Superconducting QUantum
Interference Device (SQUID) amplifiers. Up to 78 bolometers will be
multiplexed with a single SQUID amplifier. We report on the sub-Kelvin
instrument design and ongoing developments for the LiteBIRD mission.
Title: First high-resolution look at the quiet Sun with ALMA at 3mm
Authors: Nindos, A.; Alissandrakis, C. E.; Bastian, T. S.; Patsourakos,
S.; De Pontieu, B.; Warren, H.; Ayres, T.; Hudson, H. S.; Shimizu,
T.; Vial, J. -C.; Wedemeyer, S.; Yurchyshyn, V.
Bibcode: 2018A&A...619L...6N
Altcode: 2018arXiv181005223N
We present an overview of high-resolution quiet Sun observations,
from disk center to the limb, obtained with the Atacama Large
millimeter and sub-millimeter Array (ALMA) at 3 mm. Seven quiet-Sun
regions were observed at a resolution of up to 2.5″ by 4.5″. We
produced both average and snapshot images by self-calibrating the ALMA
visibilities and combining the interferometric images with full-disk
solar images. The images show well the chromospheric network, which,
based on the unique segregation method we used, is brighter than the
average over the fields of view of the observed regions by ∼305
K while the intranetwork is less bright by ∼280 K, with a slight
decrease of the network/intranetwork contrast toward the limb. At 3
mm the network is very similar to the 1600 Å images, with somewhat
larger size. We detect, for the first time, spicular structures,
rising up to 15″ above the limb with a width down to the image
resolution and brightness temperature of ∼1800 K above the local
background. No trace of spicules, either in emission or absorption,
is found on the disk. Our results highlight the potential of ALMA for
the study of the quiet chromosphere.
Title: CLASP Constraints on the Magnetization and Geometrical
Complexity of the Chromosphere-Corona Transition Region
Authors: Trujillo Bueno, J.; Štěpán, J.; Belluzzi, L.; Asensio
Ramos, A.; Manso Sainz, R.; del Pino Alemán, T.; Casini, R.; Ishikawa,
R.; Kano, R.; Winebarger, A.; Auchère, F.; Narukage, N.; Kobayashi,
K.; Bando, T.; Katsukawa, Y.; Kubo, M.; Ishikawa, S.; Giono, G.; Hara,
H.; Suematsu, Y.; Shimizu, T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.;
Cirtain, J.; Champey, P.; De Pontieu, B.; Carlsson, M.
Bibcode: 2018ApJ...866L..15T
Altcode: 2018arXiv180908865T
The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a
suborbital rocket experiment that on 2015 September 3 measured
the linear polarization produced by scattering processes in the
hydrogen Lyα line of the solar disk radiation. The line-center
photons of this spectral line radiation mostly stem from the
chromosphere-corona transition region (TR). These unprecedented
spectropolarimetric observations revealed an interesting surprise,
namely that there is practically no center-to-limb variation (CLV) in
the Q/I line-center signals. Using an analytical model, we first show
that the geometric complexity of the corrugated surface that delineates
the TR has a crucial impact on the CLV of the Q/I and U/I line-center
signals. Second, we introduce a statistical description of the solar
atmosphere based on a 3D model derived from a state-of-the-art radiation
magnetohydrodynamic simulation. Each realization of the statistical
ensemble is a 3D model characterized by a given degree of magnetization
and corrugation of the TR, and for each such realization we solve the
full 3D radiative transfer problem taking into account the impact
of the CLASP instrument degradation on the calculated polarization
signals. Finally, we apply the statistical inference method presented
in a previous paper to show that the TR of the 3D model that produces
the best agreement with the CLASP observations has a relatively weak
magnetic field and a relatively high degree of corrugation. We emphasize
that a suitable way to validate or refute numerical models of the upper
solar chromosphere is by confronting calculations and observations
of the scattering polarization in ultraviolet lines sensitive to the
Hanle effect.
Title: BAT AGN Spectroscopic Survey - XII. The relation between
coronal properties of active galactic nuclei and the Eddington ratio
Authors: Ricci, C.; Ho, L. C.; Fabian, A. C.; Trakhtenbrot, B.; Koss,
M. J.; Ueda, Y.; Lohfink, A.; Shimizu, T.; Bauer, F. E.; Mushotzky,
R.; Schawinski, K.; Paltani, S.; Lamperti, I.; Treister, E.; Oh, K.
Bibcode: 2018MNRAS.480.1819R
Altcode: 2018MNRAS.tmp.1793R; 2018arXiv180904076R
The bulk of the X-ray emission in active galactic nuclei (AGNs) is
produced very close to the accreting supermassive black hole (SMBH),
in a corona of hot electrons which up scatters optical and ultraviolet
photons from the accretion flow. The cut-off energy (EC) of
the primary X-ray continuum emission carries important information on
the physical characteristics of the X-ray emitting plasma, but little
is currently known about its potential relation with the properties
of accreting SMBHs. Using the largest broad-band (0.3-150 keV) X-ray
spectroscopic study available to date, we investigate how the corona
is related to the AGN luminosity, black hole mass and Eddington
ratio (λEdd). Assuming a slab corona the median values
of the temperature and optical depth of the Comptonizing plasma are
kTe = 105 ± 18 keV and τ = 0.25 ± 0.06, respectively. When
we properly account for the large number of EC lower limits,
we find a statistically significant dependence of the cut-off energy on
the Eddington ratio. In particular, objects with λEdd >
0.1 have a significantly lower median cut-off energy (EC =
160 ± 41 keV) than those with λEdd ≤ 0.1 (EC
= 370 ± 51 keV). This is consistent with the idea that radiatively
compact coronae are also cooler, because they tend to avoid the region
in the temperature-compactness parameter space where runaway pair
production would dominate. We show that this behaviour could also
straightforwardly explain the suggested positive correlation between
the photon index (Γ) and the Eddington ratio, being able to reproduce
the observed slope of the Γ-λEdd trend.
Title: A Statistical Inference Method for Interpreting the CLASP
Observations
Authors: Štěpán, J.; Trujillo Bueno, J.; Belluzzi, L.; Asensio
Ramos, A.; Manso Sainz, R.; del Pino Alemán, T.; Casini, R.; Kano, R.;
Winebarger, A.; Auchère, F.; Ishikawa, R.; Narukage, N.; Kobayashi,
K.; Bando, T.; Katsukawa, Y.; Kubo, M.; Ishikawa, S.; Giono, G.; Hara,
H.; Suematsu, Y.; Shimizu, T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.;
Cirtain, J.; Champey, P.; De Pontieu, B.; Carlsson, M.
Bibcode: 2018ApJ...865...48S
Altcode: 2018arXiv180802725S
On 2015 September 3, the Chromospheric Lyman-Alpha SpectroPolarimeter
(CLASP) successfully measured the linear polarization produced by
scattering processes in the hydrogen Lyα line of the solar disk
radiation, revealing conspicuous spatial variations in the Q/I and U/I
signals. Via the Hanle effect, the line-center Q/I and U/I amplitudes
encode information on the magnetic field of the chromosphere-corona
transition region, but they are also sensitive to the three-dimensional
structure of this corrugated interface region. With the help of a simple
line-formation model, here we propose a statistical inference method
for interpreting the Lyα line-center polarization observed by CLASP.
Title: Sunrise Chromospheric Infrared spectroPolarimeter (SCIP)
for the SUNRISE balloon-borne solar observatory
Authors: Suematsu, Yoshinori; Katsukawa, Yukio; Hara, Hirohisa;
Ichimoto, Kiyoshi; Shimizu, Toshifumi; Kubo, Masahito; Barthol,
Peter; Riethmueller, Tino; Gandorfer, Achim; Feller, Alex; Orozco
Suárez, David; Del Toro Iniesta, Jose Carlos; Kano, Ryouhei; Ishikawa,
Shin-nosuke; Ishikawa, Ryohko; Tsuzuki, Toshihiro; Uraguchi, Fumihiro;
Quintero Noda, Carlos; Tamura, Tomonori; Oba, Takayoshi; Kawabata,
Yusuke; Nagata, Shinichi; Anan, Tetsu; Cobos Carrascosa, Juan Pedro;
Lopez Jimenez, Antonio Carlos; Balaguer Jimenez, Maria; Solanki, Sami
Bibcode: 2018cosp...42E3285S
Altcode:
The SUNRISE balloon-borne solar observatory carries a 1 m aperture
optical telescope, and allows us to perform seeing-free continuous
observations at visible-IR wavelengths from an altitude higher than
35 km. In the past two flights, in 2009 and 2013, observations mainly
focused on fine structures of photospheric magnetic fields. For the
third flight planned for 2021, we are developing a new instrument
for conducting spectro-polarimetry of spectral lines formed over a
larger height range in the solar atmosphere from the photosphere to
the chromosphere. Targets of the spectro-polarimetric observation
are (1) to determine 3D magnetic structure from the photosphere to
the chromosphere, (2) to trace MHD waves from the photosphere to the
chromosphere, and (3) to reveal the mechanism driving chromospheric
jets, by measuring height- and time-dependent velocities and magnetic
fields. To achieve these goals, a spectro-polarimeter called SCIP
(Sunrise Chromospheric Infrared spectroPolarimeter) is designed to
observe near-infrared spectrum lines sensitive to solar magnetic
fields. The spatial and spectral resolutions are 0.2 arcsec and
200,000, respectively, while 0.03% polarimetric sensitivity is
achieved within a 10 sec integration time. The optical system employs
an Echelle grating and off-axis aspheric mirrors to observe the two
wavelength ranges centered at 850 nm and 770 nm simultaneously by
two cameras. Polarimetric measurements are performed using a rotating
waveplate and polarization beam-splitters in front of the cameras. For
detecting minute polarization signals with good precision, we carefully
assess the temperature dependence of polarization optics, and make
the opto-structural design that minimizes the thermal deformation
of the spectrograph optics. Another key technique is to attain good
(better than 30 msec) synchronization among the rotating phase of
the waveplate, read-out timing of cameras, and step timing of a
slit-scanning mirror. On-board accumulation and data processing are
also critical because we cannot store all the raw data read-out from the
cameras. We demonstrate that we can reduce the data down to almost 10%
with loss-less image compression and without sacrificing polarimetric
information in the data. The SCIP instrument is developed by internal
collaboration among Japanese institutes including Japan Aerospace
Exploration Agency (JAXA), the Spanish Sunrise consortium, and the
German Max Planck Institute for Solar System Research (MPS) with a
leadership of the National Astronomical Observatory of Japan (NAOJ).
Title: Current State of UV Spectro-Polarimetry and its Future
Direction
Authors: Ishikawa, Ryohko; Sakao, Taro; Katsukawa, Yukio; Hara,
Hirohisa; Ichimoto, Kiyoshi; Shimizu, Toshifumi; Kubo, Masahito;
Auchere, Frederic; De Pontieu, Bart; Winebarger, Amy; Kobayashi,
. Ken; Kano, Ryouhei; Narukage, Noriyuki; Trujillo Bueno, Javier;
Song, Dong-uk; Manso Sainz, Rafael; Asensio Ramos, Andres; Leenaarts,
Jorritt; Carlsson, Mats; Bando, Takamasa; Ishikawa, Shin-nosuke;
Tsuneta, Saku; Belluzzi, Luca; Suematsu, Yoshinori; Giono, Gabriel;
Yoshida, Masaki; Goto, Motoshi; Del Pino Aleman, Tanausu; Stepan,
Jiri; Okamoto, Joten; Tsuzuki, Toshihiro; Uraguchi, Fumihiro; Champey,
Patrick; Alsina Ballester, Ernest; Casini, Roberto; McKenzie, David;
Rachmeler, Laurel; Bethge, Christian
Bibcode: 2018cosp...42E1564I
Altcode:
To obtain quantitative information on the magnetic field in low beta
regions (i.e., upper chromosphere and above) has been increasingly
important to understand the energetic phenomena of the outer
solar atmosphere such as flare, coronal heating, and the solar wind
acceleration. In the UV range, there are abundant spectral lines that
originate in the upper chromosphere and transition region. However,
the Zeeman effect in these spectral lines does not give rise to easily
measurable polarization signals because of the weak magnetic field
strength and the larger Doppler broadening compared with the Zeeman
effect. Instead, the Hanle effect in UV lines is expected to be a
suitable diagnostic tool of the magnetic field in the upper atmospheric
layers. To investigate the validity of UV spectro-polarimetry and
the Hanle effect, the Chromospheric Lyman-Alpha Spectro-Polarimeter
(CLASP), which is a NASA sounding- rocket experiment, was launched at
White Sands in US on September 3, 2015. During its 5 minutes ballistic
flight, it successfully performed spectro-polarimetric observations
of the hydrogen Lyman-alpha line (121.57 nm) with an unprecedentedly
high polarization sensitivity of 0.1% in this wavelength range. CLASP
observed the linear polarization produced by scattering process in VUV
lines for the first time and detected the polarization signals which
indicate the operation of the Hanle effect. Following the success
of CLASP, we are confident that UV spectro-polarimetry is the way
to proceed, and we are planning the second flight of CLASP (CLASP2:
Chromospheric LAyer SpectroPolarimeter 2). For this second flight we
will carry out spectro-polarimetry in the Mg II h and k lines around
280 nm, with minimum modifications of the CLASP1 instrument. The linear
polarization in the Mg II k line is induced by scattering processes and
the Hanle effect, being sensitive to magnetic field strengths of 5 to 50
G. In addition, the circular polarizations in the Mg II h and k lines
induced by the Zeeman effect can be measurable in at least plage and
active regions. The combination of the Hanle and Zeeman effects could
help us to more reliably infer the magnetic fields of the upper solar
chromosphere. CLASP2 was selected for flight and is being developed for
launch in the spring of 2019.Based on these sounding rocket experiments
(CLASP1 and 2), we aim at establishing the strategy and refining the
instrument concept for future space missions to explore the enigmatic
atmospheric layers via UV spectro-polarimetry.
Title: Recommendations from the NGSPM-SOT report and mission
opportunities in Japan
Authors: Shimizu, Toshifumi
Bibcode: 2018tess.conf41001S
Altcode:
A study report on the future of solar physics for the decade of
2020 was published by the Next Generation Solar Physics Mission
(NGSPM)'s Science Objectives Team (SOT), an advisory team consisting
of 14 scientists, chartered by NASA, JAXA, and ESA. The report lists
scientific objectives in all the research areas related to solar physics
and provides priorities for next generation solar physics missions to be
realized in the mid 2020s. The report is based on extensive reviews of
the broad interests of the heliophysics research community, following
a public call for white papers in the fall of 2016 which resulted
in 34 submissions covering a wide variety of topics. Three top-level
science objectives are identified: I) Formation mechanisms of the hot
and dynamic outer solar atmosphere, II) Mechanisms of large-scale solar
eruptions and foundations for predictions, and III) Mechanisms driving
the solar cycle and irradiance variation. There are two broad avenues,
both with distinct merits, for future research: physical mechanisms
on elemental scales, versus global processes affecting/involving large
fractions of the solar interior and/or atmosphere. With the resources
available for a NGSPM in the next decade, the team chose to focus its
recommendations on the study of fundamental physical processes at high
spatial and temporal resolution through all temperature regimes of the
solar atmosphere. For this study, the SOT identified a minimum set of
, i.e., three kinds of instruments with which NGSPM can address the
greatest number of sub-objectives and maximize the science return of the
mission. The team recommends that these instruments be realized with
a single platform. If the single-platform approach is not possible,
a combination of two or three spacecraft is recommended. In response
to the NGSPM report, the Japanese solar physics community has been
making efforts to realize a part of such instruments in the mid
2020s and submitted the Solar-C_EUVST mission proposal to ISAS/JAXA
in reply to 2017 Announcement of Opportunity for competitive M-class
mission launched by an Epsilon rocket. This mission carries an EUV
high-throughput spectroscopic telescope (EUVST) and aims to mainly cover
topics I) and II). This talk will briefly discuss recommendations in
the NGSPM-SOT report and Japanese efforts to the recommendations.
Title: BAT AGN Spectroscopic Survey. VIII. Type 1 AGN with Massive
Absorbing Columns
Authors: Shimizu, T. Taro; Davies, Richard I.; Koss, Michael;
Ricci, Claudio; Lamperti, Isabella; Oh, Kyuseok; Schawinski, Kevin;
Trakhtenbrot, Benny; Burtscher, Leonard; Genzel, Reinhard; Lin,
Ming-yi; Lutz, Dieter; Rosario, David; Sturm, Eckhard; Tacconi, Linda
Bibcode: 2018ApJ...856..154S
Altcode: 2017arXiv171009117S
We explore the relationship between X-ray absorption and optical
obscuration within the BAT AGN Spectroscopic Survey (BASS), which has
been collecting and analyzing the optical and X-ray spectra for 641
hard X-ray selected (E > 14 keV) active galactic nuclei (AGNs). We
use the deviation from a linear broad Hα-to-X-ray relationship as an
estimate of the maximum optical obscuration toward the broad line region
(BLR) and compare the A V to the hydrogen column densities
({N}{{H}}) found through systematic modeling of their X-ray
spectra. We find that the inferred columns implied by A V
toward the BLR are often orders of magnitude less than the columns
measured toward the X-ray emitting region, indicating a small-scale
origin for the X-ray absorbing gas. After removing 30% of Sy 1.9s that
potentially have been misclassified due to outflows, we find that 86%
(164/190) of the Type 1 population (Sy 1-1.9) are X-ray unabsorbed as
expected based on a single obscuring structure. However, 14% (26/190),
of which 70% (18/26) are classified as Sy 1.9, are X-ray absorbed,
suggesting that the BLR itself is providing extra obscuration toward
the X-ray corona. The fraction of X-ray absorbed Type 1 AGNs remains
relatively constant with AGN luminosity and Eddington ratio, indicating
a stable BLR covering fraction.
Title: Solar polarimetry in the K I D2 line : A novel
possibility for a stratospheric balloon
Authors: Quintero Noda, C.; Villanueva, G. L.; Katsukawa, Y.; Solanki,
S. K.; Orozco Suárez, D.; Ruiz Cobo, B.; Shimizu, T.; Oba, T.; Kubo,
M.; Anan, T.; Ichimoto, K.; Suematsu, Y.
Bibcode: 2018A&A...610A..79Q
Altcode: 2018arXiv180101655Q
Of the two solar lines, K I D1 and D2, almost
all attention so far has been devoted to the D1 line, as
D2 is severely affected by an O2 atmospheric
band. This, however, makes the latter appealing for balloon and space
observations from above (most of) the Earth's atmosphere. We estimate
the residual effect of the O2 band on the K I D2
line at altitudes typical for stratospheric balloons. Our aim is to
study the feasibility of observing the 770 nm window. Specifically,
this paper serves as a preparation for the third flight of the Sunrise
balloon-borne observatory. The results indicate that the absorption
by O2 is still present, albeit much weaker, at the expected
balloon altitude. We applied the obtained O2 transmittance
to K I D2 synthetic polarimetric spectra and found that in
the absence of line-of-sight motions, the residual O2 has
a negligible effect on the K I D2 line. On the other hand,
for Doppler-shifted K I D2 data, the residual O2
might alter the shape of the Stokes profiles. However, the residual
O2 absorption is sufficiently weak at stratospheric levels
that it can be divided out if appropriate measurements are made,
something that is impossible at ground level. Therefore, for the
first time with Sunrise III, we will be able to perform polarimetric
observations of the K I D2 line and, consequently, we will
have improved access to the thermodynamics and magnetic properties of
the upper photosphere from observations of the K I lines.
Title: LLAMA: nuclear stellar properties of Swift-BAT AGN and matched
inactive galaxies
Authors: Lin, Ming-Yi; Davies, R. I.; Hicks, E. K. S.; Burtscher,
L.; Contursi, A.; Genzel, R.; Koss, M.; Lutz, D.; Maciejewski, W.;
Müller-Sánchez, F.; Orban de Xivry, G.; Ricci, C.; Riffel, R.;
Riffel, R. A.; Rosario, D.; Schartmann, M.; Schnorr-Müller, A.;
Shimizu, T.; Sternberg, A.; Sturm, E.; Storchi-Bergmann, T.; Tacconi,
L.; Veilleux, S.
Bibcode: 2018MNRAS.473.4582L
Altcode: 2017arXiv171004098L
In a complete sample of local 14-195 keV selected active galactic nuclei
(AGNs) and inactive galaxies, matched by their host galaxy properties,
we study the spatially resolved stellar kinematics and luminosity
distributions at near-infrared wavelengths on scales of 10-150 pc,
using SINFONI on the VLT. In this paper, we present the first half of
the sample, which comprises 13 galaxies, eight AGNs and five inactive
galaxies. The stellar velocity fields show a disc-like rotating
pattern, for which the kinematic position angle is in agreement with
the photometric position angle obtained from large scale images. For
this set of galaxies, the stellar surface brightness of the inactive
galaxy sample is generally comparable to the matched sample of AGN,
but extends to lower surface brightness. After removal of the bulge
contribution, we find a nuclear stellar light excess with an extended
nuclear disc structure, which exhibits a size-luminosity relation. While
we expect the excess luminosity to be associated with a dynamically
cooler young stellar population, we do not typically see a matching drop
in dispersion. This may be because these galaxies have pseudo-bulges
in which the intrinsic dispersion increases towards the centre. And
although the young stars may have an impact in the observed kinematics,
their fraction is too small to dominate over the bulge and compensate
the increase in dispersion at small radii, so no dispersion drop is
seen. Finally, we find no evidence for a difference in the stellar
kinematics and nuclear stellar luminosity excess between these active
and inactive galaxies.
Title: Ionized and Molecular Gas Kinematics in a z = 1.4 Star-forming
Galaxy
Authors: Übler, H.; Genzel, R.; Tacconi, L. J.; Förster Schreiber,
N. M.; Neri, R.; Contursi, A.; Belli, S.; Nelson, E. J.; Lang, P.;
Shimizu, T. T.; Davies, R.; Herrera-Camus, R.; Lutz, D.; Plewa, P. M.;
Price, S. H.; Schuster, K.; Sternberg, A.; Tadaki, K.; Wisnioski,
E.; Wuyts, S.
Bibcode: 2018ApJ...854L..24U
Altcode: 2018arXiv180202135U
We present deep observations of a z = 1.4 massive, star-forming galaxy
(SFG) in molecular and ionized gas at comparable spatial resolution (CO
3-2, NOrthern Extended Millimeter Array (NOEMA); Hα, Large Binocular
Telescope (LBT)). The kinematic tracers agree well, indicating that
both gas phases are subject to the same gravitational potential
and physical processes affecting the gas dynamics. We combine the
one-dimensional velocity and velocity dispersion profiles in CO and Hα
to forward-model the galaxy in a Bayesian framework, combining a thick
exponential disk, a bulge, and a dark matter halo. We determine the
dynamical support due to baryons and dark matter, and find a dark matter
fraction within one effective radius of {f}DM}(≤slant
{R}e)={0.18}-0.04+0.06. Our result
strengthens the evidence for strong baryon-dominance on galactic
scales of massive z ∼ 1-3 SFGs recently found based on ionized gas
kinematics alone. Based on observations carried out with the IRAM
Interferometer NOEMA. IRAM is supported by INSU/CNRS (France), MPG
(Germany), and IGN (Spain). Based on observations carried out with the
LBT. The LBT is an international collaboration among institutions in
the United States, Italy, and Germany. LBT Corporation partners are:
LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck
Society, The Leibniz Institute for Astrophysics Potsdam, and Heidelberg
University; The University of Arizona on behalf of the Arizona Board
of Regents; Istituto Nazionale di Astrofisica, Italy; The Ohio State
University, and The Research Corporation, on behalf of The University
of Notre Dame, University of Minnesota and University of Virginia.
Title: LLAMA: normal star formation efficiencies of molecular gas
in the centres of luminous Seyfert galaxies
Authors: Rosario, D. J.; Burtscher, L.; Davies, R. I.; Koss, M.; Ricci,
C.; Lutz, D.; Riffel, R.; Alexander, D. M.; Genzel, R.; Hicks, E. H.;
Lin, M. -Y.; Maciejewski, W.; Müller-Sánchez, F.; Orban de Xivry,
G.; Riffel, R. A.; Schartmann, M.; Schawinski, K.; Schnorr-Müller,
A.; Saintonge, A.; Shimizu, T.; Sternberg, A.; Storchi-Bergmann, T.;
Sturm, E.; Tacconi, L.; Treister, E.; Veilleux, S.
Bibcode: 2018MNRAS.473.5658R
Altcode: 2017arXiv171004224R
Using new Atacama Pathfinder Experiment and James Clerk Maxwell
Telescope spectroscopy of the CO 2→1 line, we undertake a controlled
study of cold molecular gas in moderately luminous (Lbol =
1043-44.5 erg s-1) active galactic nuclei (AGN)
and inactive galaxies from the Luminous Local AGN with Matched Analogs
(LLAMA) survey. We use spatially resolved infrared photometry of the
LLAMA galaxies from 2MASS, the Wide-field Infrared Survey Explorer
the Infrared Astronomical Satellite and the Herschel Space Observatory
(Herschel), corrected for nuclear emission using multicomponent spectral
energy distribution fits, to examine the dust-reprocessed star formation
rates, molecular gas fractions and star formation efficiencies (SFEs)
over their central 1-3 kpc. We find that the gas fractions and central
SFEs of both active and inactive galaxies are similar when controlling
for host stellar mass and morphology (Hubble type). The equivalent
central molecular gas depletion times are consistent with the discs
of normal spiral galaxies in the local Universe. Despite energetic
arguments that the AGN in LLAMA should be capable of disrupting the
observable cold molecular gas in their central environments, our
results indicate that nuclear radiation only couples weakly with this
phase. We find a mild preference for obscured AGN to contain higher
amounts of central molecular gas, which suggests connection between
AGN obscuration and the gaseous environment of the nucleus. Systems
with depressed SFEs are not found among the LLAMA AGN. We speculate
that the processes that sustain the collapse of molecular gas into
dense pre-stellar cores may also be a prerequisite for the inflow of
material on to AGN accretion discs.
Title: Local Swift-BAT active galactic nuclei prefer circumnuclear
star formation
Authors: Lutz, D.; Shimizu, T.; Davies, R. I.; Herrera-Camus, R.;
Sturm, E.; Tacconi, L. J.; Veilleux, S.
Bibcode: 2018A&A...609A...9L
Altcode: 2017arXiv170900857L; 2017A&A...609A...9L
We use Herschel data to analyze the size of the far-infrared 70 μm
emission for z < 0.06 local samples of 277 hosts of Swift-BAT
selected active galactic nuclei (AGN), and 515 comparison galaxies
that are not detected by BAT. For modest far-infrared luminosities 8.5
<log (LFIR [L⊙]) < 10.5, we find large
scatter of half light radii Re,70 for both populations,
but a typical Re,70≲ 1 kpc for the BAT hosts that is only
half that of comparison galaxies of same far-infrared luminosity. The
result mostly reflects a more compact distribution of star formation
(and hence gas) in the AGN hosts, but compact AGN heated dust may
contribute in some extremely AGN dominated systems. Our findings are
in support of an AGN-host coevolution where accretion onto the central
black hole and star formation are fed from the same gas reservoir,
with more efficient black hole feeding if that reservoir is more
concentrated. The significant scatter in the far-infrared sizes
emphasizes that we are mostly probing spatial scales much larger than
those of actual accretion, and that rapid accretion variations can
smear the distinction between the AGN and comparison categories. Large
samples are hence needed to detect structural differences that
favor feeding of the black hole. No size difference between AGN
host and comparison galaxies is observed at higher far-infrared
luminosities log(LFIR [L⊙]) > 10.5 (star
formation rates ≳6 M⊙ yr-1), possibly
because these are typically reached in more compact regions. Full Table A.1 is only available at the CDS via anonymous ftp to
http://cdsarc.u-strasbg.fr
(http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/609/A9
Title: A Brief History of Hinode: Toward the Success in Orbit
Authors: Shimizu, Toshifumi
Bibcode: 2018ASSL..449....3S
Altcode:
No abstract at ADS
Title: First Ten Years of Hinode Solar On-Orbit Observatory
Authors: Shimizu, Toshifumi; Imada, Shinsuke; Kubo, Masahito
Bibcode: 2018ASSL..449.....S
Altcode:
No abstract at ADS
Title: Pointing stability of Hinode and requirements for the next
Solar mission Solar-C
Authors: Katsukawa, Y.; Masada, Y.; Shimizu, T.; Sakai, S.; Ichimoto,
K.
Bibcode: 2017SPIE10565E..28K
Altcode:
It is essential to achieve fine pointing stability in a space mission
aiming for high resolutional observations. In a future Japanese
solar mission SOLAR-C, which is a successor of the HINODE (SOLAR-B)
mission, we set targets of angular resolution better than 0.1 arcsec
in the visible light and better than 0.2 - 0.5 arcsec in EUV and
X-rays. These resolutions are twice to five times better than those of
corresponding instruments onboard HINODE. To identify critical items
to achieve the requirements of the pointing stability in SOLAR-C, we
assessed in-flight performance of the pointing stability of HINODE that
achieved the highest pointing stability in Japanese space missions. We
realized that one of the critical items that have to be improved in
SOLAR-C is performance of the attitude stability near the upper limit
of the frequency range of the attitude control system. The stability
of 0.1 arcsec (3σ) is required in the EUV and X-ray telescopes
of SOLAR-C while the HINODE performance is slightly worse than the
requirement. The visible light telescope of HINODE is equipped with
an image stabilization system inside the telescope, which achieved
the stability of 0.03 arcsec (3σ) by suppressing the attitude jitter
in the frequency range lower than 10 Hz. For further improvement, it
is expected to suppress disturbances induced by resonance between the
telescope structures and disturbances of momentum wheels and mechanical
gyros in the frequency range higher than 100 Hz.
Title: Instrument design and on-orbit performance of the solar
optical telescope aboard hinode (Solar-B)
Authors: Suematsu, Yoshinori; Ichimoto, Kiyoshi; Katsukawa, Yukio;
Tsuneta, Saku; Shimizu, Toshifumi
Bibcode: 2017SPIE10566E..2ZS
Altcode:
The Solar Optical Telescope (SOT) aboard Solar-B satellite (Hinode)
is designed to perform high-precision photometric and polarimetric
observations of the solar lower atmosphere in visible light spectra
(388-668 nm) with a spatial resolution of 0.2 to 0.3 arcsec. The
SOT consists of two components; the optical telescope assembly (OTA)
consisting of a 50-cm aperture Gregorian telescope with a collimating
lens unit and an active tip-tilt mirror for an image-stabilization and
an accompanying focal plane package (FPP) housing two filtergraphs and a
spectro-polarimeter. Since its first-light observation on 25 Oct. 2006,
the image-stabilization system has been working with performance
better than 0.01 arcsec rms and the SOT has been continuously
providing unprecedented solar data of high spatial resolution. Since
the opto-mechanical and -thermal performance of the OTA is crucial
to attain unprecedented high-quality solar observations, we here
describe in detail the instrument design and on-orbit diffraction-limit
performance of the OTA, the largest state-of-the-art solar telescope
yet flown in space.
Title: Instrument design of 1.5-m aperture solar optical telescope
for the Solar-C Mission
Authors: Suematsu, Yoshinori; Katsukawa, Yukio; Shimizu, Toshifumi;
Ichimoto, Kiyoshi
Bibcode: 2017SPIE10564E..0TS
Altcode:
A 1.5 m aperture optical telescope is planned for the next Japanese
solar mission SOLAR-C as one of major three observing instruments. The
optical telescope is designed to provide high-angular-resolution
investigation of lower atmosphere from the photosphere to the uppermost
chromosphere with enhanced spectroscopic and spectropolarimetric
capability covering a wide wavelength region from 280 nm to 1100
nm. The opto-mechanical and -thermal performance of the telescope is
crucial to attain high-quality solar observations and we present a
study of optical and structural design of the large aperture space
solar telescope, together with conceptual design of its accompanying
focal plane instruments: wide-band and narrow-band filtergraphs and
a spectro-polarimeter for high spatial and temporal observations in
the solar photospheric and chromospheric lines useful for sounding
physical condition of dynamical phenomena.
Title: Chromospheric polarimetry through multiline observations of
the 850-nm spectral region - II. A magnetic flux tube scenario
Authors: Quintero Noda, C.; Kato, Y.; Katsukawa, Y.; Oba, T.; de la
Cruz Rodríguez, J.; Carlsson, M.; Shimizu, T.; Orozco Suárez, D.;
Ruiz Cobo, B.; Kubo, M.; Anan, T.; Ichimoto, K.; Suematsu, Y.
Bibcode: 2017MNRAS.472..727Q
Altcode: 2017arXiv170801333Q
In this publication, we continue the work started in Quintero Noda et
al., examining this time a numerical simulation of a magnetic flux
tube concentration. Our goal is to study if the physical phenomena
that take place in it, in particular, the magnetic pumping, leaves
a specific imprint on the examined spectral lines. We find that the
profiles from the interior of the flux tube are periodically doppler
shifted following an oscillation pattern that is also reflected in
the amplitude of the circular polarization signals. In addition, we
analyse the properties of the Stokes profiles at the edges of the flux
tube discovering the presence of linear polarization signals for the Ca
II lines, although they are weak with an amplitude around 0.5 per cent
of the continuum intensity. Finally, we compute the response functions
to perturbations in the longitudinal field, and we estimate the field
strength using the weak-field approximation. Our results indicate
that the height of formation of the spectral lines changes during the
magnetic pumping process, which makes the interpretation of the inferred
magnetic field strength and its evolution more difficult. These results
complement those from previous works, demonstrating the capabilities and
limitations of the 850-nm spectrum for chromospheric Zeeman polarimetry
in a very dynamic and complex atmosphere.
Title: Optical and thermal design of 1.5-m aperture solar UV visible
and IR observing telescope for Solar-C mission
Authors: Suematsu, Y.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.;
Horiuchi, T.; Matsumoto, Y.; Takeyama, N.
Bibcode: 2017SPIE10565E..0RS
Altcode:
The next Japanese solar mission, SOLAR-C, which has been envisaged
after successful science operation of Hinode (SOLAR-B) mission, is
perusing two plans: plan-A and plan-B, and under extensive study from
science objectives as well as engineering point of view. The plan-A
aims at performing out-of-ecliptic observations for investigating, with
helioseismic approach, internal structure and dynamo mechanisms of the
Sun. It also explores polar regions where fast solar wind is believed
to originate. A baseline orbit for plan-A is a circular orbit of 1 AU
distance from the Sun with its inclination at around or greater than
40 degrees. The plan-B aims to study small-scale plasma processes and
structures in the solar atmosphere which attract researchers' growing
interest, followed by many Hinode discoveries [1], for understanding
fully dynamism and magnetic nature of the atmosphere. With plan-B,
high-angular-resolution investigation of the entire solar atmosphere
(from the photosphere to the corona, including their interface layers,
i.e., chromosphere and transition region) is to be performed with
enhanced spectroscopic and spectro-polarimetric capability as compared
with Hinode, together with enhanced sensitivity towards ultra-violet
wavelengths. The orbit of plan-B is either a solar synchronous polar
orbit of altitude around 600 km or a geosynchronous orbit to ensure
continuous solar observations. After the decision of any one of the
two plans, the SOLAR-C will be proposed for launch in mid-2010s. In
this paper, we will present a basic design of one of major planned
instrumental payload for the plan-B: the Solar Ultra-violet Visible
and near IR observing Telescope (hereafter referred to as SUVIT). The
basic concept in designing the SUVIT is to utilize as much as possible
a heritage of successful telescope of the Solar Optical Telescope
(SOT) aboard Hinode [2]. Major differences of SUVIT from SOT are
the three times larger aperture of 1.5 m, which enables to collect
one order of magnitude more photons than SOT, relatively shorter
telescope length of 2.8 m to accommodate a launcher's nosecone size
for possible dual-satellite-launch configuration, and much wider
observing wavelength from UV (down to 250 nm) through near IR (up
to 1100 nm). The large aperture is essentially important to attain
scientific goals of the plan-B, especially for accurate diagnostics of
the dynamic solar chromosphere as revealed by Hinode, although this
make it difficult to design the telescope because of ten times more
solar heat load introduced into the telescope. The SUVIT consists of
two optically separable components; the telescope assembly (TA) and
an accompanying focal plane package equipped with filtergraphs and
spectrographs. Opto-mechanical and -thermal performance of the TA is
crucial to attain high-quality solar observations and here we present
a status of feasible study in its optical and thermal designing for
diffraction-limited performance at visible wavelength in a reasonably
wide field of view.
Title: The Small-scale Structure of Photospheric Convection Retrieved
by a Deconvolution Technique Applied to Hinode/SP Data
Authors: Oba, T.; Riethmüller, T. L.; Solanki, S. K.; Iida, Y.;
Quintero Noda, C.; Shimizu, T.
Bibcode: 2017ApJ...849....7O
Altcode: 2017arXiv170906933O
Solar granules are bright patterns surrounded by dark channels, called
intergranular lanes, in the solar photosphere and are a manifestation of
overshooting convection. Observational studies generally find stronger
upflows in granules and weaker downflows in intergranular lanes. This
trend is, however, inconsistent with the results of numerical
simulations in which downflows are stronger than upflows through the
joint action of gravitational acceleration/deceleration and pressure
gradients. One cause of this discrepancy is the image degradation caused
by optical distortion and light diffraction and scattering that takes
place in an imaging instrument. We apply a deconvolution technique to
Hinode/SP data in an attempt to recover the original solar scene. Our
results show a significant enhancement in both the convective upflows
and downflows but particularly for the latter. After deconvolution,
the up- and downflows reach maximum amplitudes of -3.0 km s-1
and +3.0 km s-1 at an average geometrical height of roughly
50 km, respectively. We found that the velocity distributions after
deconvolution match those derived from numerical simulations. After
deconvolution, the net LOS velocity averaged over the whole field of
view lies close to zero as expected in a rough sense from mass balance.
Title: VizieR Online Data Catalog: Local Swift-BAT AGN observed with
Herschel (Lutz+, 2018)
Authors: Lutz, D.; Shimizu, T.; Davies, R. I.; Herrera Camus, R.;
Sturm, E.; Tacconi, L. J.; Veilleux, S.
Bibcode: 2017yCat..36090009L
Altcode:
Table A.1 lists the basic properties of the BAT AGN and reference
samples, and the derived far-infrared sizes. For guidance, part of
the table and related notes are also included in an appendix to the
paper. (1 data file).
Title: Solar polarimetry through the K I lines at 770 nm
Authors: Quintero Noda, C.; Uitenbroek, H.; Katsukawa, Y.; Shimizu,
T.; Oba, T.; Carlsson, M.; Orozco Suárez, D.; Ruiz Cobo, B.; Kubo,
M.; Anan, T.; Ichimoto, K.; Suematsu, Y.
Bibcode: 2017MNRAS.470.1453Q
Altcode: 2017arXiv170510002Q
We characterize the K I D1 & D2 lines in
order to determine whether they could complement the 850 nm window,
containing the Ca II infrared triplet lines and several Zeeman sensitive
photospheric lines, that was studied previously. We investigate the
effect of partial redistribution on the intensity profiles, their
sensitivity to changes in different atmospheric parameters, and
the spatial distribution of Zeeman polarization signals employing a
realistic magnetohydrodynamic simulation. The results show that these
lines form in the upper photosphere at around 500 km, and that they
are sensitive to the line-of-sight velocity and magnetic field strength
at heights where neither the photospheric lines nor the Ca II infrared
lines are. However, at the same time, we found that their sensitivity
to the temperature essentially comes from the photosphere. Then, we
conclude that the K I lines provide a complement to the lines in the
850 nm window for the determination of atmospheric parameters in the
upper photosphere, especially for the line-of-sight velocity and the
magnetic field.
Title: Non-potential Field Formation in the X-shaped Quadrupole
Magnetic Field Configuration
Authors: Kawabata, Y.; Inoue, S.; Shimizu, T.
Bibcode: 2017ApJ...842..106K
Altcode: 2017arXiv170502560K
Some types of solar flares are observed in X-shaped quadrupolar field
configuration. To understand the magnetic energy storage in such
a region, we studied non-potential field formation in an X-shaped
quadrupolar field region formed in the active region NOAA 11967, which
produced three X-shaped M-class flares on 2014 February 2. Nonlinear
force-free field modeling was applied to a time series of vector
magnetic field maps from the Solar Optical Telescope on board Hinode
and the Helioseismic and Magnetic Imager on board the Solar Dynamics
Observatory. Our analysis of the temporal three-dimensional magnetic
field evolution shows that the sufficient free energy had already
been stored more than 10 hr before the occurrence of the first M-class
flare and that the storage was observed in a localized region. In this
localized region, quasi-separatrix layers (QSLs) started to develop
gradually from 9 hr before the first M-class flare. One of the flare
ribbons that appeared in the first M-class flare was co-spatial with
the location of the QSLs, suggesting that the formation of the QSLs is
important in the process of energy release. These QSLs do not appear
in the potential field calculation, indicating that they were created
by the non-potential field. The formation of the QSLs was associated
with the transverse photospheric motion of the pre-emerged flux and the
emergence of a new flux. This observation indicates that the occurrence
of the flares requires the formation of QSLs in the non-potential
field in which free magnetic energy is stored in advance.
Title: Indication of the Hanle Effect by Comparing the Scattering
Polarization Observed by CLASP in the Lyα and Si III 120.65 nm Lines
Authors: Ishikawa, R.; Trujillo Bueno, J.; Uitenbroek, H.; Kubo, M.;
Tsuneta, S.; Goto, M.; Kano, R.; Narukage, N.; Bando, T.; Katsukawa,
Y.; Ishikawa, S.; Giono, G.; Suematsu, Y.; Hara, H.; Shimizu, T.;
Sakao, T.; Winebarger, A.; Kobayashi, K.; Cirtain, J.; Champey, P.;
Auchère, F.; Štěpán, J.; Belluzzi, L.; Asensio Ramos, A.; Manso
Sainz, R.; De Pontieu, B.; Ichimoto, K.; Carlsson, M.; Casini, R.
Bibcode: 2017ApJ...841...31I
Altcode:
The Chromospheric Lyman-Alpha Spectro-Polarimeter is a sounding
rocket experiment that has provided the first successful measurement
of the linear polarization produced by scattering processes in
the hydrogen Lyα line (121.57 nm) radiation of the solar disk. In
this paper, we report that the Si III line at 120.65 nm also shows
scattering polarization and we compare the scattering polarization
signals observed in the Lyα and Si III lines in order to search for
observational signatures of the Hanle effect. We focus on four selected
bright structures and investigate how the U/I spatial variations vary
between the Lyα wing, the Lyα core, and the Si III line as a function
of the total unsigned photospheric magnetic flux estimated from Solar
Dynamics Observatory/Helioseismic and Magnetic Imager observations. In
an internetwork region, the Lyα core shows an antisymmetric spatial
variation across the selected bright structure, but it does not show
it in other more magnetized regions. In the Si III line, the spatial
variation of U/I deviates from the above-mentioned antisymmetric
shape as the total unsigned photospheric magnetic flux increases. A
plausible explanation of this difference is the operation of the Hanle
effect. We argue that diagnostic techniques based on the scattering
polarization observed simultaneously in two spectral lines with very
different sensitivities to the Hanle effect, like Lyα and Si III,
are of great potential interest for exploring the magnetism of the
upper solar chromosphere and transition region.
Title: The role of host galaxy for the environmental dependence of
active nuclei in local galaxies
Authors: Davies, Richard I.; Hicks, E. K. S.; Erwin, P.; Burtscher,
L.; Contursi, A.; Genzel, R.; Janssen, A.; Koss, M.; Lin, M. -Y.;
Lutz, D.; Maciejewski, W.; Müller-Sánchez, F.; Orban de Xivry,
G.; Ricci, C.; Riffel, R.; Riffel, R. A.; Rosario, D.; Schartmann,
M.; Schnorr-Müller, A.; Shimizu, T.; Sternberg, A.; Sturm, E.;
Storchi-Bergmann, T.; Tacconi, L.; Veilleux, S.
Bibcode: 2017MNRAS.466.4917D
Altcode: 2017MNRAS.tmp...69D; 2016arXiv161009890D
We discuss the environment of local hard X-ray selected active galaxies,
with reference to two independent group catalogues. We find that
the fraction of these AGN in S0 host galaxies decreases strongly
as a function of galaxy group size (halo mass) - which contrasts
with the increasing fraction of galaxies of S0 type in denser
environments. However, there is no evidence for an environmental
dependence of AGN in spiral galaxies. Because most AGN are found in
spiral galaxies, this dilutes the signature of environmental dependence
for the population as a whole. We argue that the differing results
for AGN in disc-dominated and bulge-dominated galaxies are related
to the source of the gas fuelling the AGN, and so may also impact the
luminosity function, duty cycle and obscuration. We find that there is
a significant difference in the luminosity function for AGN in spiral
and S0 galaxies, and tentative evidence for some difference in the
fraction of obscured AGN.
Title: Polarization Calibration of the Chromospheric Lyman-Alpha
SpectroPolarimeter for a 0.1% Polarization Sensitivity in the VUV
Range. Part II: In-Flight Calibration
Authors: Giono, G.; Ishikawa, R.; Narukage, N.; Kano, R.; Katsukawa,
Y.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.;
Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.;
Tsuneta, S.; Shimizu, T.; Sakao, T.; Cirtain, J.; Champey, P.; Asensio
Ramos, A.; Štěpán, J.; Belluzzi, L.; Manso Sainz, R.; De Pontieu,
B.; Ichimoto, K.; Carlsson, M.; Casini, R.; Goto, M.
Bibcode: 2017SoPh..292...57G
Altcode:
The Chromospheric Lyman-Alpha SpectroPolarimeter is a sounding
rocket instrument designed to measure for the first time the linear
polarization of the hydrogen Lyman-α line (121.6 nm). The instrument
was successfully launched on 3 September 2015 and observations were
conducted at the solar disc center and close to the limb during the
five-minutes flight. In this article, the disc center observations are
used to provide an in-flight calibration of the instrument spurious
polarization. The derived in-flight spurious polarization is consistent
with the spurious polarization levels determined during the pre-flight
calibration and a statistical analysis of the polarization fluctuations
from solar origin is conducted to ensure a 0.014% precision on the
spurious polarization. The combination of the pre-flight and the
in-flight polarization calibrations provides a complete picture of
the instrument response matrix, and a proper error transfer method
is used to confirm the achieved polarization accuracy. As a result,
the unprecedented 0.1% polarization accuracy of the instrument in the
vacuum ultraviolet is ensured by the polarization calibration.
Title: Herschel far-infrared photometry of the Swift Burst Alert
Telescope active galactic nuclei sample of the local universe -
III. Global star-forming properties and the lack of a connection to
nuclear activity
Authors: Shimizu, T. Taro; Mushotzky, Richard F.; Meléndez, Marcio;
Koss, Michael J.; Barger, Amy J.; Cowie, Lennox L.
Bibcode: 2017MNRAS.466.3161S
Altcode: 2016arXiv161203941S
We combine the Herschel Space Observatory PACS (Photoconductor Array
Camera and Spectrometer) and SPIRE (Spectral and Photometric Imaging
Receiver) photometry with archival WISE (Wide-field Infrared Survey
Explorer) photometry to construct the spectral energy distributions
(SEDs) for over 300 local (z < 0.05), ultrahard X-ray (14-195
keV) selected active galactic nuclei (AGN) from the Swift Burst
Alert Telescope (BAT) 58-month catalogue. Using a simple analytical
model that combines an exponentially cutoff power law with a single
temperature modified blackbody, we decompose the SEDs into a host
galaxy and AGN component. We calculate dust masses, dust temperatures,
and star formation rates (SFRs) for our entire sample and compare them
to a stellar mass-matched sample of local non-AGN galaxies. We find AGN
host galaxies have systematically higher dust masses, dust temperatures,
and SFRs due to the higher prevalence of late-type galaxies to host
an AGN, in agreement with previous studies of the Swift/BAT AGN. We
provide a scaling to convert X-ray luminosities into 8-1000 μm AGN
luminosities, as well as determine the best mid-to-far IR colours for
identifying AGN-dominated galaxies in the IR regime. We find that
for nearly 30 per cent of our sample, the 70 μm emission contains
a significant contribution from the AGN (>0.5), especially at
higher luminosities (L14 - 195 keV > 1042.5
erg s-1). Finally, we measure the local SFR-AGN luminosity
relationship, finding a slope of 0.18, large scatter (0.37 dex), and
no evidence for an upturn at high AGN luminosity. We conclude with a
discussion on the implications of our results within the context of
galaxy evolution with and without AGN feedback.
Title: Discovery of Scattering Polarization in the Hydrogen Lyα
Line of the Solar Disk Radiation
Authors: Kano, R.; Trujillo Bueno, J.; Winebarger, A.; Auchère, F.;
Narukage, N.; Ishikawa, R.; Kobayashi, K.; Bando, T.; Katsukawa, Y.;
Kubo, M.; Ishikawa, S.; Giono, G.; Hara, H.; Suematsu, Y.; Shimizu,
T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.; Goto, M.; Belluzzi, L.;
Štěpán, J.; Asensio Ramos, A.; Manso Sainz, R.; Champey, P.;
Cirtain, J.; De Pontieu, B.; Casini, R.; Carlsson, M.
Bibcode: 2017ApJ...839L..10K
Altcode: 2017arXiv170403228K
There is a thin transition region (TR) in the solar atmosphere where
the temperature rises from 10,000 K in the chromosphere to millions
of degrees in the corona. Little is known about the mechanisms that
dominate this enigmatic region other than the magnetic field plays a
key role. The magnetism of the TR can only be detected by polarimetric
measurements of a few ultraviolet (UV) spectral lines, the Lyα line
of neutral hydrogen at 121.6 nm (the strongest line of the solar UV
spectrum) being of particular interest given its sensitivity to the
Hanle effect (the magnetic-field-induced modification of the scattering
line polarization). We report the discovery of linear polarization
produced by scattering processes in the Lyα line, obtained with
the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) rocket
experiment. The Stokes profiles observed by CLASP in quiet regions of
the solar disk show that the Q/I and U/I linear polarization signals are
of the order of 0.1% in the line core and up to a few percent in the
nearby wings, and that both have conspicuous spatial variations with
scales of ∼10 arcsec. These observations help constrain theoretical
models of the chromosphere-corona TR and extrapolations of the
magnetic field from photospheric magnetograms. In fact, the observed
spatial variation from disk to limb of polarization at the line core
and wings already challenge the predictions from three-dimensional
magnetohydrodynamical models of the upper solar chromosphere.
Title: Chromospheric polarimetry through multiline observations of
the 850-nm spectral region
Authors: Quintero Noda, C.; Shimizu, T.; Katsukawa, Y.; de la Cruz
Rodríguez, J.; Carlsson, M.; Anan, T.; Oba, T.; Ichimoto, K.;
Suematsu, Y.
Bibcode: 2017MNRAS.464.4534Q
Altcode: 2016arXiv161006651Q
Future solar missions and ground-based telescopes aim to understand the
magnetism of the solar chromosphere. We performed a supporting study in
Quintero Noda et al. focused on the infrared Ca II 8542 Å line and we
concluded that it is one of the best candidates because it is sensitive
to a large range of atmospheric heights, from the photosphere to the
middle chromosphere. However, we believe that it is worth trying to
improve the results produced by this line observing additional spectral
lines. In that regard, we examined the neighbourhood solar spectrum
looking for spectral lines which could increase the sensitivity to
the atmospheric parameters. Interestingly, we discovered several
photospheric lines which greatly improve the photospheric sensitivity
to the magnetic field vector. Moreover, they are located close to a
second chromospheric line which also belongs to the Ca II infrared
triplet, I.e. the Ca II 8498 Å line, and enhances the sensitivity to
the atmospheric parameters at chromospheric layers. We conclude that the
lines in the vicinity of the Ca II 8542 Å line not only increase its
sensitivity to the atmospheric parameters at all layers, but also they
constitute an excellent spectral window for chromospheric polarimetry.
Title: Height-dependent Velocity Structure of Photospheric Convection
in Granules and Intergranular Lanes with Hinode/SOT
Authors: Oba, T.; Iida, Y.; Shimizu, T.
Bibcode: 2017ApJ...836...40O
Altcode: 2016arXiv161206175O
The solar photosphere is the visible surface of the Sun, where many
bright granules, surrounded by narrow dark intergranular lanes,
are observed everywhere. The granular pattern is a manifestation of
convective motion at the photospheric level, but its velocity structure
in the height direction is poorly understood observationally. Applying
bisector analysis to a photospheric spectral line recorded by the
Hinode Solar Optical Telescope, we derived the velocity structure
of the convective motion in granular regions and intergranular
lanes separately. The amplitude of motion of the convective material
decreases from 0.65 to 0.40 km s-1 as the material rises in
granules, whereas the amplitude of motion increases from 0.30 to 0.50
km s-1 as it descends in intergranular lanes. These values
are significantly larger than those obtained in previous studies
using bisector analysis. The acceleration of descending materials
with depth is not predicted from the convectively stable condition in
a stratified atmosphere. Such convective instability can be developed
more efficiently by radiative cooling and/or a gas pressure gradient,
which can control the dynamical behavior of convective material
in intergranular lanes. Our analysis demonstrated that bisector
analysis is a useful method for investigating the long-term dynamic
behavior of convective material when a large number of pixels
is available. In addition, one example is the temporal evolution
of granular fragmentation, in which downflowing material develops
gradually from a higher layer downward.
Title: UV/EUV High-Throughput Spectroscopic Telescope: A Next
Generation Solar Physics Mission white paper
Authors: Imada, S.; Shimizu, T.; Kawate, T.; Hara, H.; Watanabe, T.
Bibcode: 2017arXiv170104972I
Altcode:
The origin of the activity in the solar corona is a long-standing
problem in solar physics. Recent satellite observations, such as Hinode,
Solar Dynamics Observatory (SDO), Interface Region Imaging Spectrograph
(IRIS), show the detail characteristics of the solar atmosphere and
try to reveal the energy transfer from the photosphere to the corona
through the magnetic fields and its energy conversion by various
processes. However, quantitative estimation of energy transfer along
the magnetic field is not enough. There are mainly two reason why it is
difficult to observe the energy transfer from photosphere to corona; 1)
spatial resolution gap between photosphere (a few 0.1 arcsec) and corona
(a few arcsec), 2) lack in temperature coverage. Furthermore, there
is not enough observational knowledge of the physical parameters in
the energy dissipation region. There are mainly three reason why it is
difficult to observe in the vicinity of the energy dissipation region;
1) small spatial scale, 2) short time scale, 3) low emission. It is
generally believed that the energy dissipation occurs in the very small
scale and its duration is very short (10 second). Further, the density
in the dissipation region might be very low. Therefore, the high spatial
and temporal resolution UV/EUV spectroscopic observation with wide
temperature coverage is crucial to estimate the energy transport from
photosphere to corona quantitatively and diagnose the plasma dynamics
in the vicinity of the energy dissipation region. Main Science Target
for the telescope is quantitative estimation for the energy transfer
from the photosphere to the corona, and clarification of the plasma
dynamics in the vicinity of the energy dissipation region, where is the
key region for coronal heating, solar wind acceleration, and/or solar
flare, by the high spatial and temporal resolution UV/EUV spectroscopy.
Title: Discovery of Ubiquitous Fast-Propagating Intensity Disturbances
by the Chromospheric Lyman Alpha Spectropolarimeter (CLASP)
Authors: Kubo, M.; Katsukawa, Y.; Suematsu, Y.; Kano, R.; Bando,
T.; Narukage, N.; Ishikawa, R.; Hara, H.; Giono, G.; Tsuneta, S.;
Ishikawa, S.; Shimizu, T.; Sakao, T.; Winebarger, A.; Kobayashi, K.;
Cirtain, J.; Champey, P.; Auchère, F.; Trujillo Bueno, J.; Asensio
Ramos, A.; Štěpán, J.; Belluzzi, L.; Manso Sainz, R.; De Pontieu,
B.; Ichimoto, K.; Carlsson, M.; Casini, R.; Goto, M.
Bibcode: 2016ApJ...832..141K
Altcode:
High-cadence observations by the slit-jaw (SJ) optics system of the
sounding rocket experiment known as the Chromospheric Lyman Alpha
Spectropolarimeter (CLASP) reveal ubiquitous intensity disturbances
that recurrently propagate in either the chromosphere or the transition
region or both at a speed much higher than the speed of sound. The
CLASP/SJ instrument provides a time series of two-dimensional images
taken with broadband filters centered on the Lyα line at a 0.6 s
cadence. The multiple fast-propagating intensity disturbances appear in
the quiet Sun and in an active region, and they are clearly detected in
at least 20 areas in a field of view of 527″ × 527″ during the 5
minute observing time. The apparent speeds of the intensity disturbances
range from 150 to 350 km s-1, and they are comparable
to the local Alfvén speed in the transition region. The intensity
disturbances tend to propagate along bright elongated structures away
from areas with strong photospheric magnetic fields. This suggests
that the observed fast-propagating intensity disturbances are related
to the magnetic canopy structures. The maximum distance traveled by
the intensity disturbances is about 10″, and the widths are a few
arcseconds, which are almost determined by a pixel size of 1.″03. The
timescale of each intensity pulse is shorter than 30 s. One possible
explanation for the fast-propagating intensity disturbances observed
by CLASP is magnetohydrodynamic fast-mode waves.
Title: Hinode and IRIS Observations of the Magnetohydrodynamic Waves
Propagating from the Photosphere to the Chromosphere in a Sunspot
Authors: Kanoh, Ryuichi; Shimizu, Toshifumi; Imada, Shinsuke
Bibcode: 2016ApJ...831...24K
Altcode: 2016arXiv160803910K
Magnetohydrodynamic (MHD) waves have been considered as energy
sources for heating the solar chromosphere and the corona. Although
MHD waves have been observed in the solar atmosphere, there are a
lack of quantitative estimates on the energy transfer and dissipation
in the atmosphere. We performed simultaneous Hinode and Interface
Region Imaging Spectrograph observations of a sunspot umbra to
derive the upward energy fluxes at two different atmospheric layers
(photosphere and lower transition region) and estimate the energy
dissipation. The observations revealed some properties of the observed
periodic oscillations in physical quantities, such as their phase
relations, temporal behaviors, and power spectra, making a conclusion
that standing slow-mode waves are dominant at the photosphere with
their high-frequency leakage, which is observed as upward waves at
the chromosphere and the lower transition region. Our estimates of
upward energy fluxes are 2.0× {10}7 erg cm-2
s-1 at the photospheric level and 8.3× {10}4
erg cm-2 s-1 at the lower transition region
level. The difference between the energy fluxes is larger than the
energy required to maintain the chromosphere in the sunspot umbrae,
suggesting that the observed waves can make a crucial contribution to
the heating of the chromosphere in the sunspot umbrae. In contrast,
the upward energy flux derived at the lower transition region level is
smaller than the energy flux required for heating the corona, implying
that we may need another heating mechanism. We should, however, note
a possibility that the energy dissipated at the chromosphere might be
overestimated because of the opacity effect.
Title: VizieR Online Data Catalog: PACS observations of Herschel-BAT
sample (Melendez+, 2014)
Authors: Melendez, M.; Mushotzky, R. F.; Shimizu, T. T.; Barger,
A. J.; Cowie, L. L.
Bibcode: 2016yCat..17940152M
Altcode:
The sample presented in this work was selected from the low-redshift
(z<0.05) 58 month Swift/BAT survey with a median redshift of z~0.025
(http://swift.gsfc.nasa.gov/results/bs58mon/). The 58 month Swift/BAT
is an almost uniform hard X-ray all-sky survey and reaches a flux
level of 1.1x10-11 erg/s/cm2 over 50% of the
sky and 1.48x10-11erg/s/cm2 over 90% of the sky
(Baumgartner et al. 2013, Cat. J/ApJS/207/19). Source identifications
are based primarily on the X-ray imaging data and a correlation with
optical images and catalogs. In some cases, the identifications are
based on positional coincidences with previously known AGNs. The
main advantage of the BAT AGN sample is that the selection process is
completely independent of optical, IR, or radio properties of the host
galaxy. Our final sample of galaxies includes 149 Seyfert 1 galaxies
(1/1.2/1.5), 157 Seyfert 2 galaxies (1.8/1.9/2.0), 6 LINERs, and 1
unclassified Seyfert galaxy, ESO 464-G016. (1 data file).
Title: VizieR Online Data Catalog: SPIRE observations of Herschel-BAT
sample (Shimizu+, 2016)
Authors: Shimizu, T. T.; Melendez, M.; Mushotzky, R. F.; Koss, M. J.;
Barger, A. J.; Cowie, L. L.
Bibcode: 2016yCat..74563335S
Altcode:
We selected our sample of 313 AGN from the 58 month Swift/BAT Catalogue
(https://swift.gsfc.nasa.gov/results/bs58mon) (Baumgartner et al., 2012,
in prep.), imposing a redshift cutoff of z<0.05. All different types
of AGN were chosen only excluding Blazars/BL Lac objects which most
likely introduce complicated beaming effects. To determine their AGN
type, for 252 sources we used the classifications from the BAT AGN
Spectroscopic Survey (Koss et al., in preparation) which compiled
and analysed optical spectra for the Swift/BAT 70 month catalogue
(Berney et al., 2015MNRAS.454.3622B). (2 data files).
Title: Analysis of a spatially deconvolved solar pore
Authors: Quintero Noda, C.; Shimizu, T.; Ruiz Cobo, B.; Suematsu,
Y.; Katsukawa, Y.; Ichimoto, K.
Bibcode: 2016MNRAS.460.1476Q
Altcode: 2016arXiv160501796Q; 2016MNRAS.tmp..847Q
Solar pores are active regions with large magnetic field strengths
and apparent simple magnetic configurations. Their properties
resemble the ones found for the sunspot umbra although pores do
not show penumbra. Therefore, solar pores present themselves as an
intriguing phenomenon that is not completely understood. We examine
in this work a solar pore observed with Hinode/SP using two state
of the art techniques. The first one is the spatial deconvolution
of the spectropolarimetric data that allows removing the stray
light contamination induced by the spatial point spread function
of the telescope. The second one is the inversion of the Stokes
profiles assuming local thermodynamic equilibrium that let us to
infer the atmospheric physical parameters. After applying these
techniques, we found that the spatial deconvolution method does not
introduce artefacts, even at the edges of the magnetic structure,
where large horizontal gradients are detected on the atmospheric
parameters. Moreover, we also describe the physical properties of
the magnetic structure at different heights finding that, in the
inner part of the solar pore, the temperature is lower than outside,
the magnetic field strength is larger than 2 kG and unipolar, and
the line-of-sight velocity is almost null. At neighbouring pixels,
we found low magnetic field strengths of same polarity and strong
downward motions that only occur at the low photosphere, below the
continuum optical depth log τ = -1. Finally, we studied the spatial
relation between different atmospheric parameters at different heights
corroborating the physical properties described before.
Title: LiteBIRD: lite satellite for the study of B-mode polarization
and inflation from cosmic microwave background radiation detection
Authors: Ishino, H.; Akiba, Y.; Arnold, K.; Barron, D.; Borrill,
J.; Chendra, R.; Chinone, Y.; Cho, S.; Cukierman, A.; de Haan, T.;
Dobbs, M.; Dominjon, A.; Dotani, T.; Elleflot, T.; Errard, J.; Fujino,
T.; Fuke, H.; Funaki, T.; Goeckner-Wald, N.; Halverson, N.; Harvey,
P.; Hasebe, T.; Hasegawa, M.; Hattori, K.; Hattori, M.; Hazumi, M.;
Hidehira, N.; Hill, C.; Hilton, G.; Holzapfel, W.; Hori, Y.; Hubmayr,
J.; Ichiki, K.; Imada, H.; Inatani, J.; Inoue, M.; Inoue, Y.; Irie,
F.; Irwin, K.; Ishitsuka, H.; Jeong, O.; Kanai, H.; Karatsu, K.;
Kashima, S.; Katayama, N.; Kawano, I.; Kawasaki, T.; Keating, B.;
Kernasovskiy, S.; Keskitalo, R.; Kibayashi, A.; Kida, Y.; Kimura,
N.; Kimura, K.; Kisner, T.; Kohri, K.; Komatsu, E.; Komatsu, K.; Kuo,
C. -L.; Kuromiya, S.; Kusaka, A.; Lee, A.; Li, D.; Linder, E.; Maki,
M.; Matsuhara, H.; Matsumura, T.; Matsuoka, S.; Matsuura, S.; Mima,
S.; Minami, Y.; Mitsuda, K.; Nagai, M.; Nagasaki, T.; Nagata, R.;
Nakajima, M.; Nakamura, S.; Namikawa, T.; Naruse, M.; Nishibori, T.;
Nishijo, K.; Nishino, H.; Noda, A.; Noguchi, T.; Ogawa, H.; Ogburn,
W.; Oguri, S.; Ohta, I.; Okada, N.; Okamoto, A.; Okamura, T.; Otani,
C.; Pisano, G.; Rebeiz, G.; Richards, P.; Sakai, S.; Sakurai, Y.;
Sato, Y.; Sato, N.; Segawa, Y.; Sekiguchi, S.; Sekimoto, Y.; Sekine,
M.; Seljak, U.; Sherwin, B.; Shimizu, T.; Shinozaki, K.; Shu, S.;
Stompor, R.; Sugai, H.; Sugita, H.; Suzuki, J.; Suzuki, T.; Suzuki,
A.; Tajima, O.; Takada, S.; Takakura, S.; Takano, K.; Takatori, S.;
Takei, Y.; Tanabe, D.; Tomaru, T.; Tomita, N.; Turin, P.; Uozumi,
S.; Utsunomiya, S.; Uzawa, Y.; Wada, T.; Watanabe, H.; Westbrook,
B.; Whitehorn, N.; Yamada, Y.; Yamamoto, R.; Yamasaki, N.; Yamashita,
T.; Yoshida, T.; Yoshida, M.; Yotsumoto, K.
Bibcode: 2016SPIE.9904E..0XI
Altcode:
LiteBIRD is a next generation satellite aiming for the detection
of the Cosmic Microwave Background (CMB) B-mode polarization
imprinted by the primordial gravitational waves generated in the
era of the inflationary universe. The science goal of LiteBIRD is
to measure the tensor-to-scaler ratio r with a precision of δr
< 10-3♢, offering us a crucial test of the major
large-single-field slow-roll inflation models. LiteBIRD is planned
to conduct an all sky survey at the sun-earth second Lagrange point
(L2) with an angular resolution of about 0.5 degrees to cover the
multipole moment range of 2 <= l <= 200. We use focal plane
detector arrays consisting of 2276 superconducting detectors to measure
the frequency range from 40 to 400 GHz with the sensitivity of 3.2
μK·arcmin. including the ongoing studies.
Title: Development of a near-infrared detector and a fiber-optic
integral field unit for a space solar observatory SOLAR-C
Authors: Katsukawa, Yukio; Kamata, Yukiko; Anan, Tetsu; Hara,
Hirohisa; Suematsu, Yoshinori; Bando, Takamasa; Ichimoto, Kiyoshi;
Shimizu, Toshifumi
Bibcode: 2016SPIE.9904E..5IK
Altcode:
We are developing a high sensitivity and fast readout near-infrared
(NIR) detector and an integral field unit (IFU) for making
spectro-polarimetric observations of rapidly varying chromospheric
spectrum lines, such as He I 1083 nm and Ca II 854 nm, in the
next space-based solar mission SOLAR-C. We made tests of a 1.7 μm
cutoff H2RG detector with the SIDECAR ASIC for the application in
SOLAR-C. It's important to verify its perfor- mance in the temperature
condition around -100 °C, which is hotter than the typical temperature
environment used for a NIR detector. We built a system for testing the
detector between -70 °C and -140 °C. We verified linearity, read-out
noise, and dark current in both the slow and fast readout modes. We
found the detector has to be cooled down lower than -100 °C because
of significant increase of the number of hot pixels in the hotter
environment. The compact and polarization maintenance IFU was designed
using fiber-optic ribbons consisting of rectangular cores which exhibit
good polarization maintenance. A Silicone adhesive DC-SE9187L was used
to hold the fragile fiber-optic ribbons in a metal housing. Polarization
maintenance property was confirmed though polarization calibration
as well as temperature control are required to suppress polarization
crosstalk and to achieve the polarization accuracy in SOLAR-C.
Title: In-flight performance of the polarization modulator in the
CLASP rocket experiment
Authors: Ishikawa, Shin-nosuke; Shimizu, Toshifumi; Kano, Ryohei;
Bando, Takamasa; Ishikawa, Ryoko; Giono, Gabriel; Beabout, Dyana L.;
Beabout, Brent L.; Nakayama, Satoshi; Tajima, Takao
Bibcode: 2016SPIE.9905E..2UI
Altcode:
We developed a polarization modulation unit (PMU), a motor system
to rotate a waveplate continuously. In polarization measurements,
the continuous rotating waveplate is an important element as well as
a polarization analyzer to record the incident polarization in a time
series of camera exposures. The control logic of PMU was originally
developed for the next Japanese solar observation satellite SOLAR-C by
the SOLAR-C working group. We applied this PMU for the Chromospheric
Lyman-alpha SpectroPolarimeter (CLASP). CLASP is a sounding rocket
experiment to observe the linear polarization of the Lyman-alpha
emission (121.6 nm vacuum ultraviolet) from the upper chromosphere and
transition region of the Sun with a high polarization sensitivity of
0.1 % for the first time and investigate their vector magnetic field
by the Hanle effect. The driver circuit was developed to optimize the
rotation for the CLASP waveplate (12.5 rotations per minute). Rotation
non- uniformity of the waveplate causes error in the polarization
degree (i.e. scale error) and crosstalk between Stokes components. We
confirmed that PMU has superior rotation uniformity in the ground
test and the scale error and crosstalk of Stokes Q and U are less than
0.01 %. After PMU was attached to the CLASP instrument, we performed
vibration tests and confirmed all PMU functions performance including
rotation uniformity did not change. CLASP was successfully launched on
September 3, 2015, and PMU functioned well as designed. PMU achieved
a good rotation uniformity, and the high precision polarization
measurement of CLASP was successfully achieved.
Title: Analysis of spatially deconvolved polar faculae
Authors: Quintero Noda, C.; Suematsu, Y.; Ruiz Cobo, B.; Shimizu,
T.; Asensio Ramos, A.
Bibcode: 2016MNRAS.460..956Q
Altcode: 2016MNRAS.tmp..838Q; 2016arXiv160500330Q
Polar faculae are bright features that can be detected in
solar limb observations and they are related to magnetic field
concentrations. Although there are a large number of works studying
them, some questions about their nature as their magnetic properties
at different heights are still open. Thus, we aim to improve the
understanding of solar polar faculae. In that sense, we infer
the vertical stratification of the temperature, gas pressure,
line-of-sight velocity and magnetic field vector of polar faculae
regions. We performed inversions of the Stokes profiles observed
with Hinode/Spectropolarimeter after removing the stray light
contamination produced by the spatial point spread function of the
telescope. Moreover, after solving the azimuth ambiguity, we transform
the magnetic field vector to local solar coordinates. The obtained
results reveal that the polar faculae are constituted by hot plasma with
low line-of-sight velocities and single polarity magnetic fields in the
kilogauss range that are nearly perpendicular to the solar surface. We
also found that the spatial location of these magnetic fields is
slightly shifted respect to the continuum observations towards the
disc centre. We believe that this is due to the hot wall effect that
allows detecting photons that come from deeper layers located closer
to the solar limb.
Title: Spectropolarimetric capabilities of Ca II 8542 Å line
Authors: Quintero Noda, C.; Shimizu, T.; de la Cruz Rodríguez, J.;
Katsukawa, Y.; Ichimoto, K.; Anan, T.; Suematsu, Y.
Bibcode: 2016MNRAS.459.3363Q
Altcode: 2016MNRAS.tmp..667Q; 2016arXiv160404957Q
The next generation of space- and ground-based solar missions aim
to study the magnetic properties of the solar chromosphere using the
infrared Ca II lines and the He I 10830 Å line. The former seem to be
the best candidates to study the stratification of magnetic fields in
the solar chromosphere and their relation to the other thermodynamical
properties underlying the chromospheric plasma. The purpose of this
work is to provide a detailed analysis of the diagnostic capabilities
of the Ca II 8542 Å line, anticipating forthcoming observational
facilities. We study the sensitivity of the Ca II 8542 Å line
to perturbations applied to the physical parameters of reference
semi-empirical 1D model atmospheres using response functions and we
make use of 3D magnetohydrodynamics simulations to examine the expected
polarization signals for moderate magnetic field strengths. Our results
indicate that the Ca II 8542 Å line is mostly sensitive to the layers
enclosed in the range log τ = [0, -5.5], under the physical conditions
that are present in our model atmospheres. In addition, the simulated
magnetic flux tube generates strong longitudinal signals in its centre
and moderate transversal signals, due to the vertical expansion of
magnetic field lines, in its edge. Thus, observing the Ca II 8542 Å
line we will be able to infer the 3D geometry of moderate magnetic
field regions.
Title: Spectro-polarimetric observation in UV with CLASP to probe
the chromosphere and transition region
Authors: Kano, Ryouhei; Ishikawa, Ryohko; Winebarger, Amy R.; Auchère,
Frédéric; Trujillo Bueno, Javier; Narukage, Noriyuki; Kobayashi,
Ken; Bando, Takamasa; Katsukawa, Yukio; Kubo, Masahito; Ishikawa,
Shin-Nosuke; Giono, Gabriel; Hara, Hirohisa; Suematsu, Yoshinori;
Shimizu, Toshifumi; Sakao, Taro; Tsuneta, Saku; Ichimoto, Kiyoshi;
Goto, Motoshi; Cirtain, Jonathan W.; De Pontieu, Bart; Casini, Roberto;
Manso Sainz, Rafael; Asensio Ramos, Andres; Stepan, Jiri; Belluzzi,
Luca; Carlsson, Mats
Bibcode: 2016SPD....4710107K
Altcode:
The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a NASA
sounding-rocket experiment that was performed in White Sands in
the US on September 3, 2015. During its 5-minute ballistic flight,
CLASP successfully made the first spectro-polarimetric observation in
the Lyman-alpha line (121.57 nm) originating in the chromosphere and
transition region. Since the Lyman-alpha polarization is sensitive
to magnetic field of 10-100 G by the Hanle effect, we aim to infer
the magnetic field information in such upper solar atmosphere with
this experiment.The obtained CLASP data showed that the Lyman-alpha
scattering polarization is about a few percent in the wings and
the order of 0.1% in the core near the solar limb, as it had been
theoretically predicted, and that both polarization signals have a
conspicuous spatio-temporal variability. CLASP also observed another
upper-chromospheric line, Si III (120.65 nm), whose critical field
strength for the Hanle effect is 290 G, and showed a measurable
scattering polarization of a few % in this line. The polarization
properties of the Si III line could facilitate the interpretation of
the scattering polarization observed in the Lyman-alpha line.In this
presentation, we would like to show how the upper chromosphere and
transition region are seen in the polarization of these UV lines and
discuss the possible source of these complicated polarization signals.
Title: Development of the Universal Tunable Filter and High-resolution
Imaging Observation with the Fuxian Solar Observatory
Authors: Hagino, M.; Ichimoto, K.; Ueno, S.; Kimura, G.; Otsuji, K.;
Kitai, R.; Zhong, L.; Xu, Z.; Shinoda, K.; Hara, H.; Suematsu, Y.;
Shimizu, T.
Bibcode: 2016ASPC..504..103H
Altcode:
We have developed a new narrow-band universal tunable filter to perform
imaging spectroscopy of the solar chromosphere. The development stage
of the filter has been almost finished and we shifted to the scientific
observation phase by using large grand-based telescopes. Using the
filter, a series of high-resolution images were obtained with the 1m
vacuum solar telescope at the Fuxian Solar Observatory. We succeeded in
observing several flares and fine structures of the chromospheric layer.
Title: Analysis of horizontal flows in the solar granulation
Authors: Quintero Noda, C.; Shimizu, T.; Suematsu, Y.
Bibcode: 2016MNRAS.457.1703Q
Altcode: 2016arXiv160103814Q
Solar limb observations sometimes reveal the presence of a satellite
lobe in the blue wing of the Stokes I profile from pixels belonging to
granules. The presence of this satellite lobe has been associated in
the past to strong line-of-sight gradients and, as the line-of-sight
component is almost parallel to the solar surface, to horizontal
granular flows. We aim to increase the knowledge about these horizontal
flows studying a spectropolarimetric observation of the north solar
pole. We will make use of two state of the art techniques, the spatial
deconvolution procedure that increases the quality of the data removing
the stray light contamination, and spectropolarimetric inversions that
will provide the vertical stratification of the atmospheric physical
parameters where the observed spectral lines form. We inverted the
Stokes profiles using a two component configuration, obtaining that
one component is strongly blueshifted and displays a temperature
enhancement at upper photospheric layers while the second component has
low redshifted velocities and it is cool at upper layers. In addition,
we examined a large number of cases located at different heliocentric
angles, finding smaller velocities as we move from the centre to the
edge of the granule. Moreover, the height location of the enhancement
on the temperature stratification of the blueshifted component also
evolves with the spatial location on the granule being positioned on
lower heights as we move to the periphery of the granular structure.
Title: Herschel far-infrared photometry of the Swift Burst Alert
Telescope active galactic nuclei sample of the local universe -
II. SPIRE observations
Authors: Shimizu, T. Taro; Meléndez, Marcio; Mushotzky, Richard F.;
Koss, Michael J.; Barger, Amy J.; Cowie, Lennox L.
Bibcode: 2016MNRAS.456.3335S
Altcode: 2015arXiv151202733S
We present far-infrared (FIR) and submillimetre photometry from
the Herschel Space Observatory's Spectral and Photometric Imaging
Receiver (SPIRE) for 313 nearby (z < 0.05) active galactic nuclei
(AGN). We selected AGN from the 58 month Swift Burst Alert Telescope
(BAT) catalogue, the result of an all-sky survey in the 14-195 keV
energy band, allowing for a reduction in AGN selection effects due to
obscuration and host galaxy contamination. We find 46 per cent (143/313)
of our sample is detected at all three wavebands and combined with
our Photoconductor Array Camera and Spectrometer (PACS) observations
represents the most complete FIR spectral energy distributions of local,
moderate-luminosity AGN. We find no correlation among the 250, 350, and
500 μm luminosities with 14-195 keV luminosity, indicating the bulk
of the FIR emission is not related to the AGN. However, Seyfert 1s do
show a very weak correlation with X-ray luminosity compared to Seyfert
2s and we discuss possible explanations. We compare the SPIRE colours
(F250/F350 and F350/F500)
to a sample of normal star-forming galaxies, finding the two samples are
statistically similar, especially after matching in stellar mass. But
a colour-colour plot reveals a fraction of the Herschel-BAT AGN are
displaced from the normal star-forming galaxies due to excess 500
μm emission (E500). Our analysis shows E500
is strongly correlated with the 14-195 keV luminosity and 3.4/4.6 μm
flux ratio, evidence the excess is related to the AGN. We speculate
these sources are experiencing millimetre excess emission originating
in the corona of the accretion disc.
Title: Hinode magnetic-field observations of solar flares for
exploring the energy storage and trigger mechanisms
Authors: Shimizu, Toshifumi; Inoue, Satoshi; Kawabata, Yusuke
Bibcode: 2016IAUS..320..175S
Altcode:
The spectro-polarimeter in the Hinode Solar Optical Telescope (SOT)
is one of the powerful instruments for the most accurate measurements
of vector magnetic fields on the solar surface. The magnetic field
configuration and possible candidates for flare trigger are briefly
discussed with some SOT observations of solar flare events, which
include X5.4/X1.3 flares on 7 March 2012, X1.2 flare on 7 January
2014 and two M-class flares on 2 February 2014. Especially, using an
unique set of the Hinode and SDO data for the X5.4/X1.3 flares on 7
March 2012, we briefly reviewed remarkable properties observed in the
spatial distribution of the photospheric magnetic flux, chromospheric
flare ribbons, and the 3D coronal magnetic field structure inferred
by non-linear force-free field modeling with the Hinode photospheric
magnetic field data.
Title: Development of a Precise Polarization Modulator for UV
Spectropolarimetry
Authors: Ishikawa, S.; Shimizu, T.; Kano, R.; Bando, T.; Ishikawa,
R.; Giono, G.; Tsuneta, S.; Nakayama, S.; Tajima, T.
Bibcode: 2015SoPh..290.3081I
Altcode: 2015arXiv150905716I; 2015SoPh..tmp..120I
We developed a polarization modulation unit (PMU) to rotate a
waveplate continuously in order to observe solar magnetic fields
by spectropolarimetry. The non-uniformity of the PMU rotation may
cause errors in the measurement of the degree of linear polarization
(scale error) and its angle (crosstalk between Stokes-Q and -U ),
although it does not cause an artificial linear polarization signal
(spurious polarization). We rotated a waveplate with the PMU to obtain
a polarization modulation curve and estimated the scale error and
crosstalk caused by the rotation non-uniformity. The estimated scale
error and crosstalk were <0.01 % for both. This PMU will be used as
a waveplate motor for the Chromospheric Lyman-Alpha SpectroPolarimeter
(CLASP) rocket experiment. We confirm that the PMU performs and
functions sufficiently well for CLASP.
Title: 3D magnetic field configuration of small-scale reconnection
events in the solar plasma atmosphere
Authors: Shimizu, T.
Bibcode: 2015PhPl...22j1207S
Altcode: 2015arXiv150805481S
The outer solar atmosphere, i.e., the corona and the chromosphere,
is replete with small energy-release events, which are accompanied
by transient brightening and jet-like ejections. These events are
considered to be magnetic reconnection events in the solar plasma, and
their dynamics have been studied using recent advanced observations
from the Hinode spacecraft and other observatories in space and on
the ground. These events occur at different locations in the solar
atmosphere and vary in their morphology and amount of the released
energy. The magnetic field configurations of these reconnection
events are inferred based on observations of magnetic fields at
the photospheric level. Observations suggest that these magnetic
configurations can be classified into two groups. In the first group,
two anti-parallel magnetic fields reconnect to each other, yielding
a 2D emerging flux configuration. In the second group, helical or
twisted magnetic flux tubes are parallel or at a relative angle to each
other. Reconnection can occur only between anti-parallel components
of the magnetic flux tubes and may be referred to as component
reconnection. The latter configuration type may be more important
for the larger class of small-scale reconnection events. The two
types of magnetic configurations can be compared to counter-helicity
and co-helicity configurations, respectively, in laboratory plasma
collision experiments.
Title: Moonraker and Tetris: Japanese Microrovers for Lunar Cave
Exploration
Authors: Yoshida, K.; Britton, N.; Walker, J.; Shimizu, T.; Tanaka,
T.; Hakamada, T.
Bibcode: 2015LPICo1883.9036Y
Altcode:
A Japanese team HAKUTO is developing a robotic system for exploration
of Lunar lava tubes. Motivated by Google Lunar XPRIZE that requires
500 m travel on any surface of Moon, but the team plans to go down
into a skylight in Lacus Mortis.
Title: Decreased specific star formation rates in AGN host galaxies
Authors: Shimizu, T. Taro; Mushotzky, Richard F.; Meléndez, Marcio;
Koss, Michael; Rosario, David J.
Bibcode: 2015MNRAS.452.1841S
Altcode: 2015arXiv150607039S
We investigate the location of an ultra-hard X-ray selected sample
of active galactic nuclei (AGN) from the Swift Burst Alert Telescope
(BAT) catalogue with respect to the main sequence (MS) of star-forming
galaxies using Herschel-based measurements of the star formation rate
(SFR) and M*'s from Sloan Digital Sky Survey photometry where
the AGN contribution has been carefully removed. We construct the MS
with galaxies from the Herschel Reference Survey and Herschel Stripe 82
Survey using the exact same methods to measure the SFR and M*
as the Swift/BAT AGN. We find that a large fraction of the Swift/BAT
AGN lie below the MS indicating decreased specific SFR (sSFR) compared
to non-AGN galaxies. The Swift/BAT AGN are then compared to a high-mass
galaxy sample (CO Legacy Database for GALEX Arecibo SDSS Survey, COLD
GASS), where we find a similarity between the AGN in COLD GASS and
the Swift/BAT AGN. Both samples of AGN lie firmly between star-forming
galaxies on the MS and quiescent galaxies far below the MS. However,
we find no relationship between the X-ray luminosity and distance from
the MS. While the morphological distribution of the BAT AGN is more
similar to star-forming galaxies, the sSFR of each morphology is more
similar to the COLD GASS AGN. The merger fraction in the BAT AGN is much
higher than the COLD GASS AGN and star-forming galaxies and is related
to distance from the MS. These results support a model in which bright
AGN tend to be in high-mass star-forming galaxies in the process of
quenching which eventually starves the supermassive black hole itself.
Title: CLASP: A UV Spectropolarimeter on a Sounding Rocket for
Probing theChromosphere-Corona Transition Regio
Authors: Ishikawa, Ryohko; Kano, Ryouhei; Winebarger, Amy; Auchere,
Frederic; Trujillo Bueno, Javier; Bando, Takamasa; Narukage,
Noriyuki; Kobayashi, Ken; Katsukawa, Yukio; Kubo, Masahito; Ishikawa,
Shin-nosuke; Giono, Gabriel; Tsuneta, Saku; Hara, Hirohisa; Suematsu,
Yoshinori; Shimizu, Toshifumi; Sakao, Taro; Ichimoto, Kiyoshi;
Cirtain, Jonathan; De Pontieu, Bart; Casini, Roberto; Manso Sainz,
Rafael; Asensio Ramos, Andres; Stepan, Jiri; Belluzzi, Luca
Bibcode: 2015IAUGA..2254536I
Altcode:
The wish to understand the energetic phenomena of the outer solar
atmosphere makes it increasingly important to achieve quantitative
information on the magnetic field in the chromosphere-corona
transition region. To this end, we need to measure and model the
linear polarization produced by scattering processes and the Hanle
effect in strong UV resonance lines, such as the hydrogen Lyman-alpha
line. A team consisting of Japan, USA, Spain, France, and Norway has
been developing a sounding rocket experiment called the Chromospheric
Lyman-alpha Spectro-Polarimeter (CLASP). The aim is to detect the
scattering polarization produced by anisotropic radiation pumping in
the hydrogen Lyman-alpha line (121.6 nm), and via the Hanle effect to
try to constrain the magnetic field vector in the upper chromosphere
and transition region. In this talk, we will present an overview
of our CLASP mission, its scientific objectives, ground tests made,
and the latest information on the launch planned for the Summer of 2015.
Title: Hinode magnetic-field observations of solar flares for
exploring the energy storage and trigger mechanisms
Authors: Shimizu, Toshifumi; Inoue, Satoshi; Kawabata, Yusuke
Bibcode: 2015IAUGA..2252467S
Altcode:
Solar flares abruptly release the free energy stored as a non-potential
magnetic field in the corona and may be accompanied by eruptions of
the coronal plasma. Magnetic reconnection is considered as a physical
process in which the magnetic energy is converted to kinetic energy,
thermal energy, and particle acceleration, but the location of
magnetic reconnection is difficult to identify directly because of
low emission measure at the reconnection region. We are still lack of
observational knowledge on the 3D magnetic configuration and physical
conditions for leading to flare trigger. Accurate measurements of
vector magnetic fields at the solar photosphere, provided by the Solar
Optical Telescope onboard Hinode, help us in exploring how the free
energy is stored in the solar atmosphere and how the release of the
energy is triggered. This presentation will review the magnetic field
configuration and possible candidates for flare trigger primarily based
on Hinode observations of some large flare events, which may include
X5.4/X1.3 flares on 7 March 2012, X1.2 flare on 7 January 2014 and two
M-class flares on 2 February 2014. The 7 March 2012 events were observed
in an active region with delta-type sunspots, showing a strong shear
in the entire magnetic system. For the sheared magnetic structure,
the inclusion of a small-scale trigger field was identified near the
polarity inversion line with excitation of a high-speed material
flow in the horizontally oriented magnetic field formed nearly in
parallel to the polarity inversion line. The observations suggest that
gas dynamics at the solar surface play a vital role of leading to the
onset of flares. The 7 January 2014 event is an exceptional event which
most scientists would not be able to predict its occurrence. The flare
unexpectedly happened apart from the sheared magnetic field region. The
M-class flares on 2 February 2014 were observed in the magnetic field
configuration, in which four magnetic domains were distributed on the
solar surface and a null point might be formed in the coronal magnetic
field originating from the four magnetic domains.
Title: Hinode SOT Plate Scale Reinvestigated by G-Band Images on
the 2012 Transit of Venus
Authors: Kanao, M.; Shimizu, T.; Imamura, T.; Nakamura, M.
Bibcode: 2015SoPh..290.1491K
Altcode: 2015SoPh..tmp...40K
The Hinode Solar Optical Telescope (SOT) successfully observed the
transit of Venus with an unprecedented high spatial resolution on 5 -
6 June 2012, providing images of the aureole refracted by the atmosphere
of Venus and the dark Venus disk against the bright solar surface. The
transit of Venus provided a unique opportunity for calibrating the plate
scale of SOT images. With the examination of the radius of the dark
Venus disk, we determined the plate scale of G-band 430.5 nm images
with high accuracy: 0.05369±0.00005 arcsec pixel−1. The
radius was defined at the intensity level of the 0.5 transmittance
and compared with the angular radius of Venus including the thickness
of the atmosphere determined with the measurements of SPICAV onboard
Venus Express. Thanks to the high spatial resolution, SOT images show
that the dark Venus can be well represented by an ellipse. We observed
7.6 km difference in altitude between the equator and the polar regions.
Title: High-speed photospheric material flow observed at the polarity
inversion line of a δ-type sunspot producing an X5.4 flare on 2012
March 7
Authors: Shimizu, Toshifumi; Lites, Bruce W.; Bamba, Yumi
Bibcode: 2014PASJ...66S..14S
Altcode: 2014arXiv1406.1617S; 2014PASJ..tmp..101S
Solar flares abruptly release the free energy stored as a non-potential
magnetic field in the corona and may be accompanied by eruptions
of the coronal plasma. Formation of a non-potential magnetic field
and the mechanisms for triggering the onset of flares are still
poorly understood. In particular, photospheric dynamics observed
near those polarity inversion lines that are sites of major flare
production have not been well observed with high spatial resolution
spectro-polarimetry. This paper reports on a remarkable high-speed
material flow observed along the polarity inversion line located between
flare ribbons at the main energy release side of an X5.4 flare on 2012
March 7. Observations were carried out by the spectro-polarimeter of
the Solar Optical Telescope on board Hinode. The high-speed material
flow was observed in the horizontally oriented magnetic field formed
nearly parallel to the polarity inversion line. This flow persisted from
at least six hours before the onset of the flare, and continued for at
least several hours after the onset of the flare. Observations suggest
that the observed material flow represents neither the emergence nor
convergence of the magnetic flux. Rather, it may be considered to be
material flow working both to increase the magnetic shear along the
polarity inversion line and to develop magnetic structures favorable
for the onset of the eruptive flare.
Title: A Sounding Rocket Experiment for the Chromospheric Lyman-Alpha
Spectro-Polarimeter (CLASP)
Authors: Kubo, M.; Kano, R.; Kobayashi, K.; Bando, T.; Narukage, N.;
Ishikawa, R.; Tsuneta, S.; Katsukawa, Y.; Ishikawa, S.; Suematsu, Y.;
Hara, H.; Shimizu, T.; Sakao, T.; Ichimoto, K.; Goto, M.; Holloway,
T.; Winebarger, A.; Cirtain, J.; De Pontieu, B.; Casini, R.; Auchère,
F.; Trujillo Bueno, J.; Manso Sainz, R.; Belluzzi, L.; Asensio Ramos,
A.; Štěpán, J.; Carlsson, M.
Bibcode: 2014ASPC..489..307K
Altcode:
A sounding-rocket experiment called the Chromospheric Lyman-Alpha
Spectro-Polarimeter (CLASP) is presently under development to measure
the linear polarization profiles in the hydrogen Lyman-alpha (Lyα)
line at 121.567 nm. CLASP is a vacuum-UV (VUV) spectropolarimeter to aim
for first detection of the linear polarizations caused by scattering
processes and the Hanle effect in the Lyα line with high accuracy
(0.1%). This is a fist step for exploration of magnetic fields in
the upper chromosphere and transition region of the Sun. Accurate
measurements of the linear polarization signals caused by scattering
processes and the Hanle effect in strong UV lines like Lyα are
essential to explore with future solar telescopes the strength
and structures of the magnetic field in the upper chromosphere and
transition region of the Sun. The CLASP proposal has been accepted by
NASA in 2012, and the flight is planned in 2015.
Title: Herschel Far-infrared Photometry of the Swift Burst Alert
Telescope Active Galactic Nuclei Sample of the Local Universe. I. PACS
Observations
Authors: Meléndez, M.; Mushotzky, R. F.; Shimizu, T. T.; Barger,
A. J.; Cowie, L. L.
Bibcode: 2014ApJ...794..152M
Altcode: 2014arXiv1408.5889M
Far-Infrared (FIR) photometry from the Photodetector Array Camera
and Spectrometer on the Herschel Space Observatory is presented for
313 nearby, hard X-ray selected galaxies from the 58 month Swift Burst
Alert Telescope (BAT) Active Galactic Nuclei catalog. The present data
do not distinguish between the FIR luminosity distributions at 70 and
160 μm for Seyfert 1 and Seyfert 2 galaxies. This result suggests that
if the FIR emission is from the nuclear obscuring material surrounding
the accretion disk, then it emits isotropically, independent of
orientation. Alternatively, a significant fraction of the 70 and 160
μm luminosity could be from star formation, independent of active
galactic nucleus (AGN) type. Using a non-parametric test for partial
correlation with censored data, we find a statistically significant
correlation between the AGN intrinsic power (in the 14-195 keV band)
and the FIR emission at 70 and 160 μm for Seyfert 1 galaxies. We find
no correlation between the 14-195 keV and FIR luminosities in Seyfert
2 galaxies. The observed correlations suggest two possible scenarios:
(1) if we assume that the FIR luminosity is a good tracer of star
formation, then there is a connection between star formation and
the AGN at sub-kiloparsec scales, or (2) dust heated by the AGN has
a statistically significant contribution to the FIR emission. Using
a Spearman rank-order analysis, the 14-195 keV luminosities for the
Seyfert 1 and 2 galaxies are weakly statistically correlated with the
F 70/F 160 ratios. Herschel is an ESA space
observatory with science instruments provided by European-led Principal
Investigator consortia and with important participation from NASA.
Title: Large aperture solar optical telescope and instruments for
the SOLAR-C mission
Authors: Suematsu, Y.; Katsukawa, Y.; Hara, H.; Kano, R.; Shimizu,
T.; Ichimoto, K.
Bibcode: 2014SPIE.9143E..1PS
Altcode:
A large aperture solar optical telescope and its instruments
for the SOLAR-C mission are under study to provide the critical
physical parameters in the lower solar atmosphere and to resolve the
mechanism of magnetic dynamic events happening there and in the upper
atmosphere as well. For the precise magnetic field measurements and
high angular resolution in wide wavelength region, covering FOV of 3
arcmin x3 arcmin, an entrance aperture of 1.4 m Gregorian telescope is
proposed. Filtergraphs are designed to realize high resolution imaging
and pseudo 2D spectro-polarimetry in several magnetic sensitive lines of
both photosphere and chromosphere. A full stokes polarimetry is carried
out at three magnetic sensitive lines with a four-slit spectrograph
of 2D image scanning mechanism. We present a progress in optical and
structural design of SOLAR-C large aperture optical telescope and its
observing instruments which fulfill science requirements.
Title: Development of a universal tunable filter for future solar
observations
Authors: Hagino, M.; Ichimoto, K.; Kimura, G.; Nakatani, Y.; Kawate,
T.; Shinoda, K.; Suematsu, Y.; Hara, H.; Shimizu, T.
Bibcode: 2014SPIE.9151E..5VH
Altcode:
We have developed a new narrowband tunable filter to perform imaging
spectroscopy of the solar chromosphere. Using Liquid Crystal Variable
Retarders (LCVRs) as the tuning elements for wavelength, wide-band
polarizers and super achromatic half-wave plates, it is possible to make
high speed tuning (about 0.1Sec), to exclude mechanical drives (and oil
tank), and to cover a wide wavelength range (510-100nm). This filter
builds up with seven stages each consisting of a pair of calcites,
LCVR, half-wave plates and linear polarizer. The full width at half
maximum (FWHM) of the filter transmission is about 0.025nm at 656.3nm.We
demonstrate that the concept of the universal tunable filter using the
LCVR's as tuning elements is highly promising for future application
to space mission and ground based observations.
Title: New developments in rotating and linear motion mechanisms
used in contamination sensitive space telescopes
Authors: Shimizu, Toshifumi; Watanabe, Kyoko; Nakayama, Satoshi;
Tajima, Takao; Obara, Shingo; Imada, Shinsuke; Nishizuka, Naoto;
Ishikawa, Shin-nosuke; Hara, Hirohisa
Bibcode: 2014SPIE.9151E..38S
Altcode:
We have been developing a rotating mechanism and a linear motion
mechanism for their usage in contamination sensitive space
telescopes. They both are needed for ~1.4 meter optical telescope
and its focal plane instrument onboard SOLAR-C, the next-generation
spaceborne solar observatory following Hinode. Highly reliable long life
performance, low outgassing properties, and low level of micro-vibration
are required along with their scientific performance. With the
proto-type mechanisms, the long life performance and outgassing
properties of the mechanisms have been evaluated in vacuum chambers. The
level of micro-vibration excited during the operations of the rotating
mechanism was measured by operating it on the Kestler table. This
paper provides the overall descriptions of our mechanism developments.
Title: Do Most Active Galactic Nuclei Live in High Star Formation
Nuclear Cusps?
Authors: Mushotzky, Richard F.; Shimizu, T. Taro; Meléndez, Marcio;
Koss, Michael
Bibcode: 2014ApJ...781L..34M
Altcode: 2013arXiv1312.7766M
We present early results of the Herschel PACS (70 and 160 μm) and
SPIRE (250, 350, and 500 μm) survey of 313 low redshift (z < 0.05),
ultra-hard X-ray (14-195 keV) selected active galactic nuclei (AGNs)
from the 58 month Swift/Burst Alert Telescope catalog. Selection of
AGNs from ultra-hard X-rays avoids bias from obscuration, providing
a complete sample of AGNs to study the connection between nuclear
activity and star formation in host galaxies. With the high angular
resolution of PACS, we find that >35% and >20% of the sources are
"point-like" at 70 and 160 μm respectively and many more have their
flux dominated by a point source located at the nucleus. The inferred
star formation rates (SFRs) of 0.1-100 M ⊙ yr-1
using the 70 and 160 μm flux densities as SFR indicators are consistent
with those inferred from Spitzer Ne II fluxes, but we find that 11.25
μm polycyclic aromatic hydrocarbon data give ~3× lower SFR. Using
GALFIT to measure the size of the far-infrared emitting regions, we
determined the SFR surface density (M ⊙ yr-1
kpc-2) for our sample, finding that a significant fraction
of these sources exceed the threshold for star formation driven winds
(0.1 M ⊙ yr-1 kpc-2). Herschel
is an ESA space observatory with science instruments provided by
European-led Principal Investigator consortia and with important
participation from NASA.
Title: White-Light Emission and related Chromospheric Response in
an X1.8-class Flare on 2012 October 23
Authors: Watanabe, Kyoko; Shimizu, Toshifumi; Imada, Shinsuke
Bibcode: 2014cosp...40E3604W
Altcode:
In association with strong solar flares, we sometimes observe
enhancements of visible continuum radiation, which is known as a
”white-light flare”. Because many observed events show a close
correlation between the time profiles and locations of white-light
emission, and the hard X-rays and/or radio emission, there is some
consensus that the origin of white-light emission is non-thermal
electrons. Generally, white-light emission is emitted from near the
photosphere, however, non-thermal electrons are almost thermalized
by the time they reach the lower chromosphere - and cannot reach
the photosphere. So, still there is a problem concerning how the
energy of non-thermal electrons propagates to the photosphere,
and produces white-light emission. On October 23, 2012, white-light
emission was observed by Hinode/SOT in association with the X1.8 class
flare. Although the main phenomena of this solar flare occurred in a
very compact region and the two Ca II H ribbons are separated by less
than only 5 arcseconds, the white-light kernels are clearly observed
along the Ca II H ribbons. Moreover, hard X-ray, and gamma-ray emission
is present up to about 1 MeV, observed by the RHESSI satellite, and
most of this emission is associated with the white-light kernels. The
Hinode/EIS was also scanning over this flaring active region before the
flare, and the flare occurred during the scan. Over the white-light
kernel, strong red shifts were observed in FeXII etc. before the
flare. In this paper, we will report the observed white-light emission,
and chromospheric response obtained by the EUV observations. We also
discuss the relationship between the downflows over the white-light
kernel and the strength of the white-light emission, and try to show
a possible prediction of how white-light emission can be produced by
the transportation of non-thermal electrons.
Title: Sunspot Bright Points
Authors: Choudhary, Debi Prasad; Shimizu, Toshifumi
Bibcode: 2013SoPh..288..171C
Altcode: 2010arXiv1001.2354P
We used the flux-calibrated images from the Broad-band Filter
Imager and Stokes Polarimeter data obtained with the Solar Optical
Telescope onboard the Hinode spacecraft to study the properties of
bright points in and around sunspots. The selected bright points are
smaller in diameter than 150 km with contrasts exceeding about 3 %
in the ratio of sunspot images obtained with the G-band (430.5 nm)
and Ca II H (396.85 nm) filters. The bright points are classified as
umbral dot, peripheral umbral dot, penumbral grains, and G-band bright
point depending on their location. The bright points are preferentially
located around the penumbral boundary and in the fast decaying parts of
the umbra. The color temperature of the bright points is in the range
of 4600 K to 6600 K with cooler ones located in the central part of the
umbra. The temperature increases as a function of distance from the
center outward. The G-band, CN-band (388.35 nm), and Ca II H fluxes
of the bright points as a function of their blue-band (450.55 nm)
brightness increase continuously in a nonlinear fashion unlike their
red (668.4 nm) and green (555.05 nm) counterparts. This is consistent
with a model in which the localized heating of the flux tube depletes
the molecular concentration, resulting in the reduced opacity that
leads to the exposition of deeper and hotter layers. The light curve
of the bright points shows that the enhanced brightness at these
locations lasts for about 15 to 60 min with the least contrast for
the points outside the sunspot. The umbral dots near the penumbral
boundary are associated with elongated filamentary structures. The
spectropolarimeter observations show that the filling factor decreases
as the G-band brightness increases. We discuss the results using the
model in which the G-band bright points are produced in the cluster
of flux tubes that a sunspot consists of.
Title: Multi-wavelength Observations of the Spatio-temporal Evolution
of Solar Flares with AIA/SDO. II. Hydrodynamic Scaling Laws and
Thermal Energies
Authors: Aschwanden, Markus J.; Shimizu, Toshifumi
Bibcode: 2013ApJ...776..132A
Altcode: 2013arXiv1308.5198A
In this study we measure physical parameters of the same set of 155
M- and X-class solar flares observed with AIA/SDO as analyzed in
Paper I, by performing a differential emission measure analysis to
determine the flare peak emission measure EM p , peak
temperature Tp , electron density np , and
thermal energy E th, in addition to the spatial scales L,
areas A, and volumes V measured in Paper I. The parameter ranges
for M- and X-class flares are log (EM p ) = 47.0-50.5,
Tp = 5.0-17.8 MK, np = 4 × 109-9 ×
1011 cm-3, and thermal energies of E th
= 1.6 × 1028-1.1 × 1032 erg. We find that these
parameters obey the Rosner-Tucker-Vaiana (RTV) scaling law T_p^2 \propto
n_p L and HvpropT 7/2 L -2 during the peak time
tp of the flare density np , when energy balance
between the heating rate H and the conductive and radiative loss rates
is achieved for a short instant and thus enables the applicability
of the RTV scaling law. The application of the RTV scaling law
predicts power-law distributions for all physical parameters, which
we demonstrate with numerical Monte Carlo simulations as well as with
analytical calculations. A consequence of the RTV law is also that
we can retrieve the size distribution of heating rates, for which we
find N(H)vpropH -1.8, which is consistent with the magnetic
flux distribution N(Φ)vpropΦ-1.85 observed by Parnell
et al. and the heating flux scaling law FH vpropHLvpropB/L
of Schrijver et al.. The fractal-diffusive self-organized criticality
model in conjunction with the RTV scaling law reproduces the observed
power-law distributions and their slopes for all geometrical and
physical parameters and can be used to predict the size distributions
for other flare data sets, instruments, and detection algorithms.
Title: Emission Height and Temperature Distribution of White-light
Emission Observed by Hinode/SOT from the 2012 January 27 X-class
Solar Flare
Authors: Watanabe, Kyoko; Shimizu, Toshifumi; Masuda, Satoshi;
Ichimoto, Kiyoshi; Ohno, Masanori
Bibcode: 2013ApJ...776..123W
Altcode: 2013arXiv1308.5059W
White-light emissions were observed from an X1.7 class solar flare on
2012 January 27, using three continuum bands (red, green, and blue) of
the Solar Optical Telescope on board the Hinode satellite. This event
occurred near the solar limb, and so differences in the locations of the
various emissions are consistent with differences in heights above the
photosphere of the various emission sources. Under this interpretation,
our observations are consistent with the white-light emissions occurring
at the lowest levels of where the Ca II H emission occurs. Moreover, the
centers of the source regions of the red, green, and blue wavelengths
of the white-light emissions are significantly displaced from each
other, suggesting that those respective emissions are emanating from
progressively lower heights in the solar atmosphere. The temperature
distribution was also calculated from the white-light data, and we found
the lower-layer emission to have a higher temperature. This indicates
that high-energy particles penetrated down to near the photosphere,
and deposited heat into the ambient lower layers of the atmosphere.
Title: Evidence for Hot Fast Flow above a Solar Flare Arcade
Authors: Imada, S.; Aoki, K.; Hara, H.; Watanabe, T.; Harra, L. K.;
Shimizu, T.
Bibcode: 2013ApJ...776L..11I
Altcode: 2013arXiv1309.3401I
Solar flares are one of the main forces behind space weather
events. However, the mechanism that drives such energetic phenomena is
not fully understood. The standard eruptive flare model predicts that
magnetic reconnection occurs high in the corona where hot fast flows are
created. Some imaging or spectroscopic observations have indicated the
presence of these hot fast flows, but there have been no spectroscopic
scanning observations to date to measure the two-dimensional structure
quantitatively. We analyzed a flare that occurred on the west solar
limb on 2012 January 27 observed by the Hinode EUV Imaging Spectrometer
(EIS) and found that the hot (~30MK) fast (>500 km s-1)
component was located above the flare loop. This is consistent with
magnetic reconnection taking place above the flare loop.
Title: Chromospheric Lyman Alpha SpectroPolarimeter: CLASP
Authors: Kobayashi, Ken; Kano, R.; Trujillo Bueno, J.; Winebarger,
A. R.; Cirtain, J. W.; Bando, T.; De Pontieu, B.; Ishikawa, R.;
Katsukawa, Y.; Kubo, M.; Narukage, N.; Sakao, T.; Tsuneta, S.;
Auchère, F.; Asensio Ramos, A.; Belluzzi, L.; Carlsson, M.; Casini,
R.; Hara, H.; Ichimoto, K.; Manso Sainz, R.; Shimizu, T.; Stepan,
J.; Suematsu, Y.; Holloway, T.
Bibcode: 2013SPD....44..142K
Altcode:
The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a VUV
spectropolarimeter optimized for measuring the linear polarization of
the Lyman-alpha line (121.6 nm). The Lyman-alpha line is predicted to
show linear polarization caused by atomic scattering in the chromosphere
and modified by the magnetic field through the Hanle effect. The
Hanle effect is sensitive to weaker magnetic fields than Zeeman
effect, and is not canceled by opposing fields, making it sensitive
to tangled or unresolved magnetic field structures. These factors make
the Hanle effect a valuable tool for probing the magnetic field in the
chromosphere above the quiet sun. To meet this goal, CLASP is designed
to measure linear polarization with 0.1% polarization sensitivity
at 0.01 nm spectral resolution and 10" spatial resolution. CLASP is
scheduled to be launched in 2015.
Title: The First Hard X-Ray Power Spectral Density Functions of
Active Galactic Nucleus
Authors: Shimizu, T. Taro; Mushotzky, Richard F.
Bibcode: 2013ApJ...770...60S
Altcode: 2013arXiv1304.7002S
We present results of our power spectral density (PSD) analysis of
30 active galactic nuclei (AGNs) using the 58 month light curves from
Swift's Burst Alert Telescope (BAT) in the 14-150 keV band. PSDs were
fit using a Monte Carlo based algorithm to take into account windowing
effects and measurement error. All but one source were found to be
fit very well using an unbroken power law with a slope of ~ - 1,
consistent at low frequencies with previous studies in the 2-10 keV
band, with no evidence of a break in the PSD. For five of the highest
signal-to-noise ratio sources, we tested the energy dependence of
the PSD and found no significant difference in the PSD at different
energies. Unlike previous studies of X-ray variability in AGNs, we do
not find any significant correlations between the hard X-ray variability
and different properties of the AGN including luminosity and black hole
mass. The lack of break frequencies and correlations seem to indicate
that AGNs are similar to the high state of Galactic black holes.
Title: Hinode observations of flares and active region emergence
Authors: Shimizu, Toshifumi
Bibcode: 2013JPhCS.440a2002S
Altcode:
After observing the quiet Sun during a long and deep minimum, Hinode's
observing priority is now the active Sun, i.e., flares and active
regions. Because of its small field-of-view instruments and telemetry
restrictions, capturing major flares with good observing coverage
needs challenging efforts on operation plannings for Hinode and we
have been using the latest available AIA and HMI full-Sun images for
targeting. Also, capturing the initial phase of large-scale emerging
flux activities is not easy for Hinode without having the forecast of
flux emergence before they are visible on the surface. Nevertheless,
Hinode has some good examples of observations of such events. In this
paper, we briefly discuss two specific observations; X-class flares
in March 2012 and a large-scale flux emergence in December 2009. The
Stokes polarimetry data for the flares presented in this paper reveals
significant gas flows along the neutral line of the sheared magnetic
distributions and the change of magnetic field inclination at the areas
where penumbral development and disappearance was observed with the
occurrence of the flares. The flux emergence and the sunspot formation
presented were well monitored by the Hinode three telescopes from the
beginning through the end of the emergence, Of particular interest is
the finding of a precursory signature in the chromosphere preceding
the appearance of sunspot penumbra.
Title: The Northern Galactic Cap AGN from the 58-month BAT Catalogue:
A Comprehensive X-ray Spectral Study
Authors: Vasudevan, Ranjan; Brandt, W. N.; Mushotzky, R.; Winter,
L. M.; Baumgartner, W. H.; Shimizu, T.; Nousek, J. A.; Schneider,
D. P.; Gandhi, P.
Bibcode: 2013HEAD...1310906V
Altcode:
The all-sky hard X-ray Swift/BAT survey has provided the most complete
census of local AGN activity to date, unbiased to all but the most
heavy absorption levels. Continual monitoring in the 14--195 keV band
has allowed the assembly of hard X-ray detected AGN catalogues after 9,
22, 36, 58 and 70 months of operation, increasing the sample size by
probing to fainter fluxes. The seminal study of Winter et al. (2009)
presented a comprehensive X-ray analysis of the AGN in the 9-month
catalogue, providing their absorption and luminosity distributions,
characterising the spectral shape for each source in the catalogue,
and allowing the determination of sample-wide properties for an
unbiased AGN sample. We present a timely revision of this exercise for
the latest publicly available 58-month BAT catalogue (flux limit 4 x
10^-12 erg/s/cm^2 in the 14-195 keV band), focusing on the Northern
Galactic Cap (b>50 degrees). This sky area has excellent potential
for further dedicated study due to a wide range of multi-wavelength data
that are already available, and we propose it as a low-redshift analogue
to the ‘deep field’ observations of AGN at higher redshifts. We
consistently fit all the 100 objects in this sky region with a suite
of models to determine the best fitting column densities, luminosities
and spectral features (Iron lines, soft excesses and warm absorber
edges). Comparison with previous works on the 9-month and 36-month
catalogues now allows a better understanding of whether the deepening
exposure of the BAT catalogue uncovers progressively different AGN
properties. We find that ~60% of the sample is absorbed above logNH=22,
9% is Compton thick, and Compton reflection is significant for the
sample overall (average reflection amplitude <R> = 2.7). The
sample is complete down to fluxes 4 times fainter than the 9-month
catalogue in the 2--10 keV band. We emphasise the utility of this
Northern Galactic Cap sample for a wide variety of future studies on
AGN, and outline one such current project on the stacked emission from
this sample and the connections with X-ray background synthesis models.
Title: The Hinode Spectro-Polarimeter
Authors: Lites, B. W.; Akin, D. L.; Card, G.; Cruz, T.; Duncan, D. W.;
Edwards, C. G.; Elmore, D. F.; Hoffmann, C.; Katsukawa, Y.; Katz, N.;
Kubo, M.; Ichimoto, K.; Shimizu, T.; Shine, R. A.; Streander, K. V.;
Suematsu, A.; Tarbell, T. D.; Title, A. M.; Tsuneta, S.
Bibcode: 2013SoPh..283..579L
Altcode:
The joint Japan/US/UK Hinode mission includes the first large-aperture
visible-light solar telescope flown in space. One component of the
Focal Plane Package of that telescope is a precision spectro-polarimeter
designed to measure full Stokes spectra with the intent of using those
spectra to infer the magnetic-field vector at high precision in the
solar photosphere. This article describes the characteristics of the
flight hardware of the HinodeSpectro-Polarimeter, and summarizes its
in-flight performance.
Title: Properties of a Decaying Sunspot
Authors: Balthasar, H.; Beck, C.; Gömöry, P.; Muglach, K.; Puschmann,
K. G.; Shimizu, T.; Verma, M.
Bibcode: 2013CEAB...37..435B
Altcode: 2013arXiv1301.1562B
A small decaying sunspot was observed with the Vacuum Tower Telescope
(VTT) on Tenerife and the Japanese Hinode satellite. We obtained
full Stokes scans in several wavelengths covering different heights
in the solar atmosphere. Imaging time series from Hinode and the
Solar Dynamics Observatory (SDO) complete our data sets. The spot is
surrounded by a moat flow, which persists also on that side of the
spot where the penumbra already had disappeared. Close to the spot,
we find a chromospheric location with downflows of more than 10 km
s^{-1} without photospheric counterpart. The height dependence of
the vertical component of the magnetic field strength is determined
in two different ways that yielded different results in previous
investigations. Such a difference still exists in our present data,
but it is not as pronounced as in the past.
Title: Next space solar observatory SOLAR-C: mission instruments
and science objectives
Authors: Katsukawa, Y.; Watanabe, T.; Hara, H.; Ichimoto, K.; Kubo,
M.; Kusano, K.; Sakao, T.; Shimizu, T.; Suematsu, Y.; Tsuneta, S.
Bibcode: 2012IAUSS...6E.207K
Altcode:
SOLAR-C, the fourth space solar mission in Japan, is under study with a
launch target of fiscal year 2018. A key concept of the mission is to
view the photosphere, chromosphere, and corona as one system coupled
by magnetic fields along with resolving the size scale of fundamental
physical processes connecting these atmospheric layers. It is especially
important to study magnetic structure in the chromosphere as an
interface layer between the photosphere and the corona. The SOLAR-C
satellite is equipped with three telescopes, the Solar UV-Visible-IR
Telescope (SUVIT), the EUV/FUV High Throughput Spectroscopic Telescope
(EUVS/LEMUR), and the X-ray Imaging Telescope (XIT). Observations
with SUVIT of photospheric and chromospheric magnetic fields make it
possible to infer three dimensional magnetic structure extending from
the photosphere to the chromosphere and corona.This helps to identify
magnetic structures causing magnetic reconnection, and clarify how
waves are propagated, reflected, and dissipated. Phenomena indicative
of or byproducts of magnetic reconnection, such as flows and shocks,
are to be captured by SUVIT and by spectroscopic observations using
EUVS/LEMUR, while XIT observes rapid changes in temperature distribution
of plasma heated by shock waves.
Title: Instrument Design of the Large Aperture Solar UV Visible and
IR Observing Telescope (SUVIT) for the SOLAR-C Mission
Authors: Suematsu, Y.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.;
Takeyama, N.
Bibcode: 2012ASPC..463..439S
Altcode:
We present an instrumental design of one major solar observation payload
planned for the SOLAR-C mission: the Solar Ultra-violet Visible and
near IR observing Telescope (SUVIT). The SUVIT is designed to provide
high-angular-resolution investigation of the lower solar atmosphere,
from the photosphere to the uppermost chromosphere, with enhanced
spectroscopic and spectro-polarimetric capability in wide wavelength
regions from 280 nm (Mg II h&k lines) to 1100 nm (He I 1083 nm
line) with 1.5 m class aperture and filtergraphic and spectrographic
instruments.
Title: Hinode observations of the Venus corona during the 2012
transit of Venus
Authors: Kanao, M.; Yamazaki, A.; Imada, S.; Shimizu, T.; Sakao, T.;
Kasaba, Y.; Sakanoi, T.; Kagitani, M.; Nakamura, M.
Bibcode: 2012AGUFM.P11D1851K
Altcode:
The Hinode satellite successfully observed the transit of Venus on
5th June 2012 with the highest spatial resolution. This presentation
will focus on UV and soft X-ray data acquired with the EUV Imaging
Spectrometer (EIS) and the X-ray Telescope (XRT) onboard Hinode. We
expected the EUV and X-ray emissions from the charge exchange reaction
by the solar wind impacting on the neutral particles in Venus upper
atmosphere. The neutral particles escape through the photoreaction, the
solar wind pick-up process, and so on, in connection with the solar wind
and the solar radiation. However, there are few precedent observations
of the escaping hydrogen and oxygen, ranging from a few eV to a few keV
because of difficulty in the groundbased observations. The atmosphere
loss can be estimated based on the two-dimensional image of the neutral
particle density. Our estimation was made for 18.4nm (OVI), 19.3nm (OV)
and 25.6nm (HII), which intensity and line profiles can be recorded with
EIS, and 1.72-2.18nm (OVII), 1.60-1.90nm(OVIII), 2.85-3.37nm (CVI),
3.50-4.03 nm (CV), which are located in XRT's broadband range. Multi
wavelength observation could clarify the collision velocities between
the solar wind and Venus neutral particles. Before the transit of Venus,
for science planning purpose, we estimated the EUV and X-ray emission
intensities by using typical solar wind parameters (the proton density
10/cc and the solar wind velocity 400 km/sec) with a Venus atmosphere
model. The photon production rate of the X-ray emission is estimated
to be 1.1 x 10^25 photons/s, and that of the OVI emission line (18.4nm)
is 6.9 x 10^23 photons/s. These values are much lower than the emissions
from the solar corona, but unexpected signals may be observed dureing
the transit. In this presentation, we will present the calculation
results on intensity distribution of the Venus corona and some X-ray
and EUV data acquired during the transit. Also we briefly compare
the observed intensities in dark Venus feature with the calculation
results and discuss the signification of the difference.
Title: Science and Instrument Design of 1.5-m Aperture Solar Optical
Telescope for the SOLAR-C Mission
Authors: Suematsu, Y.; Katsukawa, Y.; Ichimoto, K.; Shimizu, T.
Bibcode: 2012IAUSS...6E.208S
Altcode:
We present science cases and a design of one of major instruments for
SOLAR-C mission; 1.5-m-class aperture solar ultra-violet visible and
near IR observing Telescope (SUVIT). The SOLAR-C mission aims at fully
understanding dynamism and magnetic nature of the solar atmosphere by
observing small-scale plasma processes and structures. The SUVIT is
designed to provide high-angular-resolution investigation of lower
atmosphere from the photosphere to the uppermost chromosphere with
enhanced spectroscopic and spectro-polarimetric capability covering
a wide wavelength region from 280 nm (Mg II h&k) to 1100 nm (He
I 1083 nm), using focal plane instruments: wide-band and narrow-band
filtergraphs and a spectrograph for high-precision spectro-polarimetry
in the solar photospheric and chromospheric lines. We will discuss
about instrument design to realize the science cases.
Title: Emission Height and Temperature Distribution of White-Light
Emission from the 2011 January 27 Flare Observed by Hinode/SOT
Authors: Watanabe, K.; Shimizu, T.; Masuda, S.; Ichimoto, K.
Bibcode: 2012AGUFMSH52B..03W
Altcode:
White light flares are flares that show an emission enhancement in
the visible continuum. White-light emissions are well correlated
with hard X-ray and radio emissions in time profile and emission
location. This seems to imply that the origin of white-light emission
is accelerated particles, in particular non-thermal elections. However,
this is hard to understand in terms of the expected respective emission
heights. Theoretically, white-light emissions are generated near the
photosphere, but non-thermal electrons of energy ~50-100 keV should
deposit their energy in the lower chromosphere, more than 500 km
above the photosphere. Thus there should be ~500 km difference in
the white-light and X-ray emission heights, which seems at odds with
the observations. We investigate this question with observations
of a near-limb X1.7 flare of 27 January 2012, using three continuum
bands (red, green, and blue) of the Hinode Solar Optical Telescope
(SOT). The near-limb location allowed us to determine the heights of the
emissions. We found the white-light emissions to be located low down,
apparently at the photosphere, with the Ca II H emission originating
from higher up. We also calculated the temperature distribution from the
three white-light continuum bands, and found the lower layer to have
higher temperature. These findings suggest that high energy particles
penetrate to near the photosphere, heating the ambient atmosphere from
very low (near photospheric) layers.
Title: Three-dimensional instability of two-dimensional fast magnetic
reconnection in comparison with Petschek and Sweet-Parker models
Authors: Shimizu, T.; Kondoh, K.
Bibcode: 2012AGUFMSM13B2372S
Altcode:
Petschek and Sweet-Parker models are known as the controversial
two-dimensional MHD models discussed in the magnetic reconnection
problem of space plasma physics for more than 40 years. Recently, we
numerically found that two-dimensional Petschek reconnection process is
unstable for a three-dimensional resistive perturbation, resulting in
intermittent and random three-dimensional fast magnetic reconnection. In
this presentation, we discuss that such three-dimensional instability
is not caused (i.e. stable) in the Sweet Parker reconnection
process, where the magnetic diffusion region is not localized in
the jet direction. In real space plasmas, many observations suggest
that three-dimensionally localized fast magnetic reconnection is
ubiquitously caused in approximately one-dimensional current sheet,
such as a geomagneto-tail. Our study shows that Petschek reconnection
model plays a crucial role there, rather than Sweet Parker model.
Title: LEMUR: Large European module for solar Ultraviolet
Research. European contribution to JAXA's Solar-C mission
Authors: Teriaca, Luca; Andretta, Vincenzo; Auchère, Frédéric;
Brown, Charles M.; Buchlin, Eric; Cauzzi, Gianna; Culhane, J. Len;
Curdt, Werner; Davila, Joseph M.; Del Zanna, Giulio; Doschek, George
A.; Fineschi, Silvano; Fludra, Andrzej; Gallagher, Peter T.; Green,
Lucie; Harra, Louise K.; Imada, Shinsuke; Innes, Davina; Kliem,
Bernhard; Korendyke, Clarence; Mariska, John T.; Martínez-Pillet,
Valentin; Parenti, Susanna; Patsourakos, Spiros; Peter, Hardi; Poletto,
Luca; Rutten, Robert J.; Schühle, Udo; Siemer, Martin; Shimizu,
Toshifumi; Socas-Navarro, Hector; Solanki, Sami K.; Spadaro, Daniele;
Trujillo-Bueno, Javier; Tsuneta, Saku; Dominguez, Santiago Vargas;
Vial, Jean-Claude; Walsh, Robert; Warren, Harry P.; Wiegelmann,
Thomas; Winter, Berend; Young, Peter
Bibcode: 2012ExA....34..273T
Altcode: 2011ExA...tmp..135T; 2011arXiv1109.4301T
The solar outer atmosphere is an extremely dynamic environment
characterized by the continuous interplay between the plasma and the
magnetic field that generates and permeates it. Such interactions play a
fundamental role in hugely diverse astrophysical systems, but occur at
scales that cannot be studied outside the solar system. Understanding
this complex system requires concerted, simultaneous solar observations
from the visible to the vacuum ultraviolet (VUV) and soft X-rays, at
high spatial resolution (between 0.1'' and 0.3''), at high temporal
resolution (on the order of 10 s, i.e., the time scale of chromospheric
dynamics), with a wide temperature coverage (0.01 MK to 20 MK,
from the chromosphere to the flaring corona), and the capability of
measuring magnetic fields through spectropolarimetry at visible and
near-infrared wavelengths. Simultaneous spectroscopic measurements
sampling the entire temperature range are particularly important. These
requirements are fulfilled by the Japanese Solar-C mission (Plan B),
composed of a spacecraft in a geosynchronous orbit with a payload
providing a significant improvement of imaging and spectropolarimetric
capabilities in the UV, visible, and near-infrared with respect to
what is available today and foreseen in the near future. The Large
European Module for solar Ultraviolet Research (LEMUR), described
in this paper, is a large VUV telescope feeding a scientific payload
of high-resolution imaging spectrographs and cameras. LEMUR consists
of two major components: a VUV solar telescope with a 30 cm diameter
mirror and a focal length of 3.6 m, and a focal-plane package composed
of VUV spectrometers covering six carefully chosen wavelength ranges
between 170 Å and 1270 Å. The LEMUR slit covers 280'' on the Sun with
0.14'' per pixel sampling. In addition, LEMUR is capable of measuring
mass flows velocities (line shifts) down to 2 km s - 1 or
better. LEMUR has been proposed to ESA as the European contribution
to the Solar C mission.
Title: Design of large aperture solar optical telescope for the
SOLAR-C mission
Authors: Suematsu, Y.; Katsukawa, Y.; Hara, H.; Shimizu, T.;
Ichimoto, K.
Bibcode: 2012SPIE.8442E..25S
Altcode:
A large aperture optical telescope is planned for the next Japanese
solar mission SOLAR-C as one of major three observing instruments. The
optical telescope is designed to provide high-angular-resolution
investigation of lower atmosphere from the photosphere to the uppermost
chromosphere with enhanced spectroscopic and spectro-polarimetric
capability covering a wide wavelength region from 280 nm to 1100
nm. The opto-mechanical and -thermal performance of the telescope is
crucial to attain high-quality solar observations and we present a
study of optical and structural design of the large aperture space
solar telescope, together with conceptual design of its accompanying
focal plane instruments: wide-band and narrow-band filtergraphs and
a spectro-polarimeter for high spatial and temporal observations in
the solar photospheric and chromospheric lines useful for sounding
physical condition of dynamical phenomena.
Title: Chromospheric Lyman-alpha spectro-polarimeter (CLASP)
Authors: Kano, Ryouhei; Bando, Takamasa; Narukage, Noriyuki; Ishikawa,
Ryoko; Tsuneta, Saku; Katsukawa, Yukio; Kubo, Masahito; Ishikawa,
Shin-nosuke; Hara, Hirohisa; Shimizu, Toshifumi; Suematsu, Yoshinori;
Ichimoto, Kiyoshi; Sakao, Taro; Goto, Motoshi; Kato, Yoshiaki; Imada,
Shinsuke; Kobayashi, Ken; Holloway, Todd; Winebarger, Amy; Cirtain,
Jonathan; De Pontieu, Bart; Casini, Roberto; Trujillo Bueno, Javier;
Štepán, Jiří; Manso Sainz, Rafael; Belluzzi, Luca; Asensio Ramos,
Andres; Auchère, Frédéric; Carlsson, Mats
Bibcode: 2012SPIE.8443E..4FK
Altcode:
One of the biggest challenges in heliophysics is to decipher the
magnetic structure of the solar chromosphere. The importance of
measuring the chromospheric magnetic field is due to both the key role
the chromosphere plays in energizing and structuring the outer solar
atmosphere and the inability of extrapolation of photospheric fields to
adequately describe this key boundary region. Over the last few years,
significant progress has been made in the spectral line formation
of UV lines as well as the MHD modeling of the solar atmosphere. It
is found that the Hanle effect in the Lyman-alpha line (121.567 nm)
is a most promising diagnostic tool for weaker magnetic fields in
the chromosphere and transition region. Based on this groundbreaking
research, we propose the Chromospheric Lyman-Alpha Spectro-Polarimeter
(CLASP) to NASA as a sounding rocket experiment, for making the first
measurement of the linear polarization produced by scattering processes
and the Hanle effect in the Lyman-alpha line (121.567 nm), and making
the first exploration of the magnetic field in the upper chromosphere
and transition region of the Sun. The CLASP instrument consists
of a Cassegrain telescope, a rotating 1/2-wave plate, a dual-beam
spectrograph assembly with a grating working as a beam splitter, and
an identical pair of reflective polarization analyzers each equipped
with a CCD camera. We propose to launch CLASP in December 2014.
Title: A Laboratory Experiment of Magnetic Reconnection: Outflows,
Heating, and Waves in Chromospheric Jets
Authors: Nishizuka, N.; Hayashi, Y.; Tanabe, H.; Kuwahata, A.; Kaminou,
Y.; Ono, Y.; Inomoto, M.; Shimizu, T.
Bibcode: 2012ApJ...756..152N
Altcode: 2014arXiv1412.7903N
Hinode observations have revealed intermittent recurrent plasma
ejections/jets in the chromosphere. These are interpreted as a result
of non-perfectly anti-parallel magnetic reconnection, i.e., component
reconnection, between a twisted magnetic flux tube and the pre-existing
coronal/chromospheric magnetic field, though the fundamental physics of
component reconnection is not revealed. In this paper, we experimentally
reproduced the magnetic configuration and investigated the dynamics of
plasma ejections, heating, and wave generation triggered by component
reconnection in the chromosphere. We set plasma parameters as in the
chromosphere (density 1014 cm-3, temperature 5-10
eV, i.e., (5-10) × 104 K, and reconnection magnetic field
200 G) using argon plasma. Our experiment shows bi-directional outflows
with the speed of 5 km s-1 at maximum, ion heating in the
downstream area over 30 eV, and magnetic fluctuations mainly at 5-10
μs period. We succeeded in qualitatively reproducing chromospheric
jets, but quantitatively, we still have some differences between
observations and experiments such as in jet velocity, total energy,
and wave frequency. Some of them can be explained by the scale gap
between solar and laboratory plasma, while the others are probably due
to the difference in microscopy and macroscopy, collisionality, and the
degree of ionization, which have not been achieved in our experiment.
Title: The SOLAR-C Mission: Plan B Payload Concept
Authors: Shimizu, T.; Sakao, T.; Katsukawa, Y.; Group, J. S. W.
Bibcode: 2012ASPC..454..449S
Altcode:
The telescope concepts for the SOLAR-C Plan B mission as of the time of
the Hinode-3 meeting were briefly presented for having comments from
the international solar physics community. The telescope candidates
are 1) near IR-visible-UV telescope with 1.5m aperture and enhanced
spectro-polarimetric capability, 2) UV/EUV high throughput spectrometer,
and 3) next generation X-ray telescope.
Title: Magnetic Properties and Behaviors of a Sunspot Light Bridge
in Terms of Magnetic Reconnection
Authors: Shimizu, T.
Bibcode: 2012ASPC..454..177S
Altcode:
The sunspot light bridge formed in the south-east of the well-developed
sunspot in active region 10953 is one of interesting regions to
understand magnetic environment responsible for exciting long-lasting
occurrence of magnetic reconnection events. Temporal evolution of
magnetic and velocity field properties over 4 days was studied and
briefly discussed in this presentation, leading to a conclusion that
the amount of twist may be one of key parameters for the occurrence
of magnetic reconnection at the low atmosphere and the resulting
dynamical behaviors.
Title: A New Method of Determining the Pattern Speed of the LMC
Authors: Shimizu, T.; Yoshii, Y.
Bibcode: 2012ASPC..458..341S
Altcode:
We focus on the idea proposed by de Vaucouleurs that constellation III
would be regarded as the Lagrange point in a rotating non-axisymmetric
bar potential. Based on this idea, we identify the center of
constellation III with the Lagrange point L4 and have determined the
pattern speed of the LMC as 21 ± 3km/s/kpc. Using this pattern speed,
we estimate the velocity with which the constellation III captures
matter around, and we find that the estimated value of velocity is
consistent with the observation. In this presentation, using the LMC
we describe our method of determining a pattern speed and present the
dynamics around each of the Lagrange points in detail.
Title: Precursor of Sunspot Penumbral Formation Discovered with
Hinode SOT Observation
Authors: Shimizu, T.; Ichimoto, K.; Suematsu, Y.
Bibcode: 2012ASPC..456...43S
Altcode:
We newly found a precursory signature of sunspot penumbral formation
in Ca II H images. The precursor is a dark annular zone (width 3"-5")
around the umbra (pore), which was formed soon after the pore formation
and existed until the penumbral formation. The penumbra was developed
as if to fill the annular zone. Pre-existing ambient magnetic field
islands were moved to be distributed at the outer edge of the annular
zone and did not come into the zone. The observations indicate that
the annular zone is different from sunspot moat flow region and that
the zone is visible only in chromospheric Ca II H images, not in
photospheric G-band images. We conclude that the annular zone reflects
the formation of a magnetic canopy overlying the region surrounding
the umbra at the chromospheric level, much before the formation of the
penumbra at the photospheric level. We can predict the region and size
of the penumbra, by looking at the appearance of dark zone around pores.
Title: The Fifth Hinode Science Meeting
Authors: Golub, L.; De Moortel, I.; Shimizu, T.
Bibcode: 2012ASPC..456.....G
Altcode:
No abstract at ADS
Title: Precursor of Sunspot Penumbral Formation Discovered with
Hinode Solar Optical Telescope Observations
Authors: Shimizu, Toshifumi; Ichimoto, Kiyoshi; Suematsu, Yoshinori
Bibcode: 2012ApJ...747L..18S
Altcode: 2012arXiv1202.1025S
We present observations of a precursory signature that would be helpful
for understanding the formation process of sunspot penumbrae. The Hinode
Solar Optical Telescope successfully captured the entire evolution of a
sunspot from the pore to a large well-developed sunspot with penumbra
in an emerging flux region appearing in NOAA Active Region 11039. We
found an annular zone (width 3''-5'') surrounding the umbra (pore)
in Ca II H images before the penumbra formed around the umbra. The
penumbra developed as if to fill the annular zone. The annular zone
shows weak magnetogram signals, meaning less magnetic flux or highly
inclined fields there. Pre-existing ambient magnetic field islands were
distributed at the outer edge of the annular zone and did not come into
the zone. There are no strong systematic flow patterns in the zone,
but we occasionally observed small magnetic flux patches streaming
out. The observations indicate that the annular zone is different from
the sunspot moat flow region and that it represents the structure in the
chromosphere. We conclude that the annular zone reflects the formation
of a magnetic canopy overlying the region surrounding the umbra at the
chromospheric level, long before the formation of the penumbra at the
photospheric level. The magnetic field structure in the chromosphere
needs to be considered in the formation process of the penumbrae.
Title: Horizontal flow fields observed in Hinode G-band
images. II. Flow fields in the final stages of sunspot decay
Authors: Verma, M.; Balthasar, H.; Deng, N.; Liu, C.; Shimizu, T.;
Wang, H.; Denker, C.
Bibcode: 2012A&A...538A.109V
Altcode: 2011arXiv1112.1589V
Context. Generation and dissipation of magnetic fields is a fundamental
physical process on the Sun. In comparison to flux emergence and the
initial stages of sunspot formation, the demise of sunspots still
lacks a comprehensive description.
Aims: The evolution of
sunspots is most commonly discussed in terms of their intensity and
magnetic field. Here, we present additional information about the
three-dimensional flow field in the vicinity of sunspots towards
the end of their existence.
Methods: We present a subset of
multi-wavelengths observations obtained with the Japanese Hinode
mission, the Solar Dynamics Observatory (SDO), and the Vacuum Tower
Telescope (VTT) at Observatorio del Teide, Tenerife, Spain during the
time period 2010 November 18-23. Horizontal proper motions were derived
from G-band and Ca ii H images, whereas line-of-sight velocities were
extracted from VTT echelle Hα λ656.28 nm spectra and Fe i λ630.25 nm
spectral data of the Hinode/Spectro-Polarimeter, which also provided
three-dimensional magnetic field information. The Helioseismic and
Magnetic Imager on board SDO provided continuum images and line-of-sight
magnetograms, in addition to the high-resolution observations for the
entire disk passage of the active region.
Results: We perform
a quantitative study of photospheric and chromospheric flow fields
in and around decaying sunspots. In one of the trailing sunspots of
active region NOAA 11126, we observe moat flow and moving magnetic
features (MMFs), even after its penumbra had decayed. We also detect
a superpenumbral structure around this pore. We find that MMFs follow
well-defined, radial paths from the spot all the way to the border of
a supergranular cell surrounding the spot. In contrast, flux emergence
near the other sunspot prevents the establishment of similar well
ordered flow patterns, which could be discerned around a tiny pore of
merely 2 Mm diameter. After the disappearance of the sunspots/pores,
a coherent patch of abnormal granulation remained at their location,
which was characterized by more uniform horizontal proper motions, low
divergence values, and smaller photospheric Doppler velocities. This
region, thus, differs significantly from granulation and other areas
covered by G-band bright points. We conclude that this peculiar flow
pattern is a signature of sunspot decay and the dispersal of magnetic
flux.
Title: Dynamical Behaviors of the Solar Chromosphere Observed with
Hinode Dynamics in Sunspot Light Bridges and Magnetic Reconnection
Processes
Authors: Shimizu, Toshifumi; Imada, Shinsuke
Bibcode: 2012ASSP...33...23S
Altcode: 2012msdp.book...23S
The Hinode's Solar Optical Telescope has revealed that the solar
chromosphere is full of dynamical nature and much more dynamic than
our thought. Observations of chromospheric dynamics in sunspot light
bridges provides a new insight on the magnetic field topology for
causing magnetic reconnection in the solar atmosphere and the process
to supply and maintain the twisted flux in light bridges.
Title: One-dimensional Modeling for Temperature-dependent Upflow in
the Dimming Region Observed by Hinode/EUV Imaging Spectrometer
Authors: Imada, S.; Hara, H.; Watanabe, T.; Murakami, I.; Harra,
L. K.; Shimizu, T.; Zweibel, E. G.
Bibcode: 2011ApJ...743...57I
Altcode: 2011arXiv1108.5031I
We previously found a temperature-dependent upflow in the dimming region
following a coronal mass ejection observed by the Hinode EUV Imaging
Spectrometer (EIS). In this paper, we reanalyzed the observations along
with previous work on this event and provided boundary conditions for
modeling. We found that the intensity in the dimming region dramatically
drops within 30 minutes from the flare onset, and the dimming region
reaches the equilibrium stage after ~1 hr. The temperature-dependent
upflows were observed during the equilibrium stage by EIS. The
cross-sectional area of the flux tube in the dimming region does not
appear to expand significantly. From the observational constraints,
we reconstructed the temperature-dependent upflow by using a new method
that considers the mass and momentum conservation law and demonstrated
the height variation of plasma conditions in the dimming region. We
found that a super-radial expansion of the cross-sectional area is
required to satisfy the mass conservation and momentum equations. There
is a steep temperature and velocity gradient of around 7 Mm from
the solar surface. This result may suggest that the strong heating
occurred above 7 Mm from the solar surface in the dimming region. We
also showed that the ionization equilibrium assumption in the dimming
region is violated, especially in the higher temperature range.
Title: The Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP)j
Authors: Kobayashi, K.; Tsuneta, S.; Trujillo Bueno, J.; Bando, T.;
Belluzzi, L.; Casini, R.; Carlsson, M.; Cirtain, J. W.; De Pontieu,
B.; Hara, H.; Ichimoto, K.; Ishikawa, R.; Kano, R.; Katsukawa, Y.;
Kim, T.; Kubo, M.; Manso Sainz, R.; Narukage, N.; Asensio Ramos,
A.; Robinson, B.; Sakao, T.; Shimizu, T.; Stepan, J.; Suematsu, Y.;
Watanabe, H.; West, E.; Winebarger, A. R.
Bibcode: 2011AGUFM.P14C..05K
Altcode:
We present an overview of the Chromospheric Lyman-Alpha
SpectroPolarimeter (CLASP) program. CLASP is a proposed sounding rocket
experiment currently under development as collaboration between Japan,
USA and Spain. The aim is to achieve the first measurement of magnetic
field in the upper chromosphere and transition region of the Sun
through the detection and measurement of Hanle effect polarization
of the Lyman alpha line. The Hanle effect (i.e. the magnetic field
induced modification of the linear polarization due to scattering
processes in spectral lines) is believed to be a powerful tool for
measuring the magnetic field in the upper chromosphere, as it is more
sensitive to weaker magnetic fields than the Zeeman effect, and also
sensitive to magnetic fields tangled at spatial scales too small to be
resolved. The Lyman-alpha (121.567 nm) line has been chosen because
it is a chromospheric/transition-region line, and because the Hanle
effect polarization of the Lyman-alpha line is predicted to be sensitive
to 10-250 Gauss, encompassing the range of interest. Hanle effect is
predicted to be observable as linear polarization or depolarization,
depending on the geometry, with a fractional polarization amplitude
varying between 0.1% and 1% depending on the strength and orientation of
the magnetic field. This quantification of the chromospheric magnetic
field requires a highly sensitive polarization measurement. The
CLASP instrument consists of a large aperture (287 mm) Cassegrain
telescope mated to a polarizing beamsplitter and a matched pair
of grating spectrographs. The polarizing beamsplitter consists
of a continuously rotating waveplate and a linear beamsplitter,
allowing simultaneous measurement of orthogonal polarizations and
in-flight self-calibration. Development of the instrument is underway,
and prototypes of all optical components have been tested using a
synchrotron beamline. The experiment is proposed for flight in 2014.
Title: Three-dimensional shock formation in the spontaneous fast
reconnection evolution
Authors: Kondoh, K.; Ugai, M.; Shimizu, T.
Bibcode: 2011AGUFMSM23B2040K
Altcode:
Shock structure associated with magnetic reconnection is studied using
three-dimensional magneto-hydro-dynamics simulations on the basis
of the spontaneous fast reconnection model. In the two-dimensional
reconnection, the angle between the slow shock pair (thickness of
the plasma sheet) is smaller (thinner) in the region with higher
reconnection rate. On the other hand, in the three-dimensional
reconnection, the reconnection rate in the diffusion region is not
uniform in the direction of sheet current, and the angle between
the shock pair at the center of the diffusion region should be
smallest. However, the profile of the angle in the direction of sheet
current is not satisfied with this relationship. It is shown that this
structure is caused by the inflow from the direction of the positive and
negative sheet current and the inflow of the magnetic flux accompanied
with it.
Title: Magnetic Reconnection in Non-equilibrium Ionization Plasma
Authors: Imada, S.; Murakami, I.; Watanabe, T.; Hara, H.; Shimizu, T.
Bibcode: 2011ApJ...742...70I
Altcode: 2011arXiv1108.5026I
We have studied the effect of time-dependent ionization and
the recombination processes on magnetic reconnection in the solar
corona. Petschek-type steady reconnection, in which the magnetic energy
is mainly converted at the slow-mode shocks, was assumed. We carried out
the time-dependent ionization calculation in the magnetic reconnection
structure. We only calculated the transient ionization of iron;
the other species were assumed to be in ionization equilibrium. The
intensity of line emissions at specific wavelengths was also calculated
for comparison with Hinode or other observations in future. We found
the following: (1) iron is mostly in non-equilibrium ionization in the
reconnection region; (2) the intensity of line emission estimated by
the time-dependent ionization calculation is significantly different
from that determined from the ionization equilibrium assumption;
(3) the effect of time-dependent ionization is sensitive to the
electron density in the case where the electron density is less than
1010 cm-3 (4) the effect of thermal conduction
lessens the time-dependent ionization effect; and (5) the effect of
radiative cooling is negligibly small even if we take into account
time-dependent ionization.
Title: Three dimensional MHD spontaneous fast reconnection for the
shear field effect and oblique neutral line formation
Authors: Shimizu, T.; Kondoh, K.; Ugai, M.
Bibcode: 2011AGUFMSM51B2088S
Altcode:
Three-dimensional MHD instability for the spontaneous fast magnetic
reconnection was studied under the shear field condition and the
formation of oblique neutral line, in order to apply to space plasma
observations in THEMIS and Cluster. In our previous studies under the
current-driven anomalous resistivity, it was shown that one-dimensional
current sheet (the Harris sheet) is unstable for three-dimensional
resistive perturbation, resulting in three-dimensionally localized,
intermittent and random fast reconnection process. In space plasmas,
one-dimensional current sheet will be ubiquitous and is believed
to be a source region of explosive plasma phenomena, such as solar
flares and geomagnetic substorms. However, it was unclear how the 3D
fast reconnection is localized in such 1D current sheet. According to
our studies, the 3D fast reconnection can be triggered by any weak 3D
effect, such as waves and plasma flows stagnating in the current sheet,
and then is nonlinearly developed. Finally, the fast reconnection
process becomes unsteady, intermittent and random. In recent, it was
reported that the intermittent and snake-like plasma downflow jets often
observed in solar flares, e.g. TRACE EUV data, can be well explained by
our three-dimensional fast reconnection model. Then, we are now trying
to apply our model to the geomagnetic substorms observed in THEMIS,
Cluster and GEOTAIL. In comparison with solar flare observations, the
observation data obtained in geomagnetic substorms is more fine, and
hence, we can explore the details of how the 3D fast reconnection is
caused. In this presentation, we report how our 3D fast reconnection
model is modified by the shear field effect and oblique formation
of active neutral lines, collaborating with observation data and MHD
numerical study.
Title: Extinction law in ultraluminous infrared galaxies at z∼ 1
Authors: Shimizu, T.; Kawara, K.; Sameshima, H.; Ienaka, N.; Nozawa,
T.; Kozasa, T.
Bibcode: 2011MNRAS.418..625S
Altcode: 2011arXiv1107.5381S; 2011MNRAS.tmp.1436S
We analyse the multiwavelength photometric and spectroscopic data of
12 ultraluminous infrared galaxies (ULIRGs) at z∼ 1 and compare them
with models of stars and dust in order to study the extinction law and
star formation in young infrared (IR) galaxies. Five extinction curves,
namely the Milky Way (MW), the pseudo-MW which is MW-like without
the 2175 Å feature, the Calzetti and two supernova (SN) dust curves
are applied to the data by combining with various dust distributions,
namely the uniform dust screen, the clumpy dust screen, the internal
dust geometry, and the composite geometry with a combination of dust
screen and internal dust. Employing a minimum χ2 method,
we find that the foreground dust screen geometry, especially combined
with the 8-40 M⊙ SN extinction curve, provides a good
approximation to the real dust geometry, whereas internal dust is only
significant in two galaxies. The SN extinction curves, which are flatter
than the others, reproduce the data of eight (67 per cent) galaxies
better. Dust masses are estimated to be in excess of ∼108
M⊙. The inferred ages of the galaxies are small, eight
of which range from 10 to 650 Myr. The SN-origin dust is the most
plausible to account for the vast amount of dust masses and the flat
slope of the observed extinction law. The inferred dust mass per SN
ranges from 0.01 to 0.4 M⊙ per SN.
Title: Focal plane instrument for the Solar UV-Vis-IR Telescope
aboard SOLAR-C
Authors: Katsukawa, Yukio; Suematsu, Yoshinori; Shimizu, Toshifumi;
Ichimoto, Kiyoshi; Takeyama, Norihide
Bibcode: 2011SPIE.8148E..0EK
Altcode: 2011SPIE.8148E..13K
It is presented the conceptual design of a focal plane instrument for
the Solar UV-Vis-IR Telescope (SUVIT) aboard the next Japanese solar
mission SOLAR-C. A primary purpose of the telescope is to achieve
precise as well as high resolution spectroscopic and polarimetric
measurements of the solar chromosphere with a big aperture of 1.5 m,
which is expected to make a significant progress in understanding basic
MHD processes in the solar atmosphere. The focal plane instrument
consists of two packages: A filtergraph package is to get not only
monochromatic images but also Dopplergrams and magnetograms using a
tunable narrow-band filter and interference filters. A spectrograph
package is to perform accurate spectro-polarimetric observations for
measuring chromospheric magnetic fields, and is employing a Littrow-type
spectrograph. The most challenging aspect in the instrument design is
wide wavelength coverage from 280 nm to 1.1 μm to observe multiple
chromospheric lines, which is to be realized with a lens unit including
fluoride glasses. A high-speed camera for correlation tracking of
granular motion is also implemented in one of the packages for an
image stabilization system, which is essential to achieve high spatial
resolution and high polarimetric accuracy.
Title: LEMUR (Large European Module for solar Ultraviolet Research):
a VUV imaging spectrograph for the JAXA Solar-C Mission
Authors: Korendyke, Clarence M.; Teriaca, Luca; Doschek, George A.;
Harra, Louise K.; Schühle, Udo H.; Shimizu, Toshifumi
Bibcode: 2011SPIE.8148E..0IK
Altcode: 2011SPIE.8148E..17K
LEMUR is a VUV imaging spectrograph with 0.28" resolution. Incident
solar radiation is imaged onto the spectrograph slit by a single
mirror telescope consisting of a 30-cm steerable f/12 off-axis
paraboloid mirror. The spectrograph slit is imaged and dispersed by
a highly corrected grating that focuses the solar spectrum over the
detectors. The mirror is coated with a suitable multilayer with B4C
top-coating providing a reflectance peak around 18.5 nm besides the
usual B4C range above 500Å. The grating is formed by two halves, one
optimized for performances around 185Å and the other above 500Å. Three
intensified CCD cameras will record spectra above 50 nm while a large
format CCD array with an aluminum filter will be used around 185Å.
Title: Overview of Chromospheric Lyman-Alpha SpectroPolarimeter
(CLASP)
Authors: Narukage, Noriyuki; Tsuneta, Saku; Bando, Takamasa; Kano,
Ryouhei; Kubo, Masahito; Ishikawa, Ryoko; Hara, Hirohisa; Suematsu,
Yoshinori; Katsukawa, Yukio; Watanabe, Hiroko; Ichimoto, Kiyoshi;
Sakao, Taro; Shimizu, Toshifumi; Kobayashi, Ken; Robinson, Brian; Kim,
Tony; Winebarger, Amy; West, Edward; Cirtain, Jonathan; De Pontieu,
Bart; Casini, Roberto; Trujillo Bueno, Javier; Stepan, Jiri; Manso
Sainz, Rafael; Belluzzi, Luca; Asensio Ramos, Andres; Carlsson, Mats
Bibcode: 2011SPIE.8148E..0HN
Altcode: 2011SPIE.8148E..16N
The solar chromosphere is an important boundary, through which all of
the plasma, magnetic fields and energy in the corona and solar wind
are supplied. Since the Zeeman splitting is typically smaller than
the Doppler line broadening in the chromosphere and transition region,
it is not effective to explore weak magnetic fields. However, this is
not the case for the Hanle effect, when we have an instrument with
high polarization sensitivity (~ 0.1%). "Chromospheric Lyman- Alpha
SpectroPolarimeter (CLASP)" is the sounding rocket experiment to detect
linear polarization produced by the Hanle effect in Lyman-alpha line
(121.567 nm) and to make the first direct measurement of magnetic
fields in the upper chromosphere and lower transition region. To
achieve the high sensitivity of ~ 0.1% within a rocket flight (5
minutes) in Lyman-alpha line, which is easily absorbed by materials,
we design the optical system mainly with reflections. The CLASP
consists of a classical Cassegrain telescope, a polarimeter and a
spectrometer. The polarimeter consists of a rotating 1/2-wave plate
and two reflecting polarization analyzers. One of the analyzer also
works as a polarization beam splitter to give us two orthogonal linear
polarizations simultaneously. The CLASP is planned to be launched in
2014 summer.
Title: The SOLAR-C mission: current status
Authors: Shimizu, Toshifumi; Tsuneta, Saku; Hara, Hirohisa; Ichimoto,
Kiyoshi; Kusano, Kanya; Sakao, Taro; Sekii, Takashi; Suematsu,
Yoshinori; Watanabe, Tetsuya
Bibcode: 2011SPIE.8148E..0BS
Altcode: 2011SPIE.8148E..10S
Two mission concepts (plan A: out-of-ecliptic mission and plan B:
high resolution spectroscopic mission) have been studied for the next
Japanese-led solar mission Solar-C, which will follow the scientific
success of the Hinode mission. The both mission concepts are concluded
as equally important and attractive for the promotion of space solar
physics. In the meantime we also had to make efforts for prioritizing
the two options, in order to proceed to next stage of requesting the
launch of Solar-C mission at the earliest opportunity. This paper
briefly describes the two mission concepts and the current status
on our efforts for prioritizing the two options. More details are
also described for the plan B option as the first-priority Solar-C
mission. The latest report from the Solar-C mission concept studies
was documented as "Interim Report on the Solar-C Mission Concept."
Title: Short telescope design of 1.5-m aperture solar UV visible
and IR telescope aboard Solar-C
Authors: Suematsu, Y.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.;
Horiuchi, T.; Matsumoto, Y.; Takeyama, N.
Bibcode: 2011SPIE.8148E..0DS
Altcode: 2011SPIE.8148E..12S
We present an optical and thermal design of one of major instrumental
payload planned for SOLAR-C mission/Plan-B (high resolution
spectroscopic option): the telescope assembly of Solar Ultra-violet
Visible and near IR observing Telescope (SUVIT). To accommodate a
launcher's nosecone size, a wide observing wavelength coverage from UV
(down to 280 nm) through near IR (up to 1100 nm), and an 0.1 arcsec
resolution in the field of 200 arcsec diameter, a short telescope
design was made for a 1.5 m aperture solar Gregorian telescope with
the compact design of three-mirror collimator unit.
Title: VizieR Online Data Catalog: Synthetic supernova extinction
curves (Kawara+, 2011)
Authors: Kawara, K.; Hirashita, H.; Nozawa, T.; Kozasa, T.; Oyabu,
S.; Matsuoka, Y.; Shimizu, T.; Sameshima, H.; Ienaka, N.
Bibcode: 2011yCat..74121070K
Altcode:
Synthetic spectra of stellar populations reddened by dust are modelled
to reproduce the data of SST J1604+4304. This is a young IR galaxy at z=
1.135 with the characteristic of ULIRGs. (1 data file).
Title: Modeling and verification of the diffraction-limited visible
light telescope aboard the solar observing satellite HINODE
Authors: Katsukawa, Y.; Suematsu, Y.; Tsuneta, S.; Ichimoto, K.;
Shimizu, T.
Bibcode: 2011SPIE.8336E..0FK
Altcode: 2011SPIE.8336E..14K
HINODE, Japanese for "sunrise", is a spacecraft dedicated for
observations of the Sun, and was launched in 2006 to study the Sun's
magnetic fields and how their explosive energies propagate through the
different atmospheric layers. The spacecraft carries the Solar Optical
Telescope (SOT), which has a 50 cm diameter clear aperture and provides
a continuous series of diffraction-limited visible light images from
space. The telescope was developed through international collaboration
between Japan and US. In order to achieve the diffraction-limited
performance, thermal and structural modeling of the telescope was
extensively used in its development phase to predict how the optical
performance changes dependent on the thermal condition in orbit. Not
only the modeling, we devoted many efforts to verify the optical
performance in ground tests before the launch. The verification in
the ground tests helped us to find many issues, such as temperature
dependent focus shifts, which were not identified only through the
thermal-structural modeling. Another critical issue was micro-vibrations
induced by internal disturbances of mechanical gyroscopes and momentum
wheels for attitude control of the spacecraft. Because the structural
modeling was not accurate enough to predict how much the image quality
was degraded by the micro-vibrations, we measured their transmission
in a spacecraft-level test.
Title: Long-term Evolution of Magnetic and Dynamical Properties in
A Sunspot Light Bridge
Authors: Shimizu, Toshifumi
Bibcode: 2011ApJ...738...83S
Altcode:
Sunspot light bridges (LBs)—long bright lanes appearing in
umbra—sometimes show dynamical behaviors such as plasma ejections,
brightenings, and fast gas flows in the photosphere and lower
chromosphere, but we have not understood what causes these dynamics. The
Hinode Solar Optical Telescope successfully captured the entire period
of the evolution of an LB formed at the southeast of the well-developed
sunspot in NOAA Active Region 10953, allowing us to track how magnetic
and dynamical properties change with time for 3.5 days. The LB produced
chromospheric upward ejections intermittently and recurrently on 2007
April 30, and fewer upward ejections were observed on May 1. We found
that G-band intensity features morphologically changed from cellar or
patchy on April 30 to filamentary on May 1, although there were small
changes in the magnetic flux density and inclination. This suggests that
the chromospheric activity is related to the change of morphology in
the photosphere. Fast gas flows and a pair of strong enhanced vertical
electrical currents were also observed in the photosphere after the
filamentary structures were dominant. The end of a large Hα filament
(or prominence) was extended very close to the LB on May 1, suggesting
that the filamentary structures formed along the LB may be magnetically
connected to the large Hα filament and the gas flows may originate
far from the LB region, although other mechanisms cannot be ruled out.
Title: Magnetic field evolution of active regions and sunspots in
connection with chromospheric and coronal activities
Authors: Shimizu, Toshifumi
Bibcode: 2011IAUS..273..157S
Altcode:
Ca II H imaging observations by the Hinode Solar Optical Telescope
(SOT) have revealed that the chromosphere is extremely dynamic and
that ejections and jets are well observed in moat region around
sunspots. X-ray and EUV observations show frequent occurrence of
microflaring activities around sunspots; small emerging flux or
moving magnetic features approaching opposite pre-existing magnetic
flux can be identified on the footpoints for half of microflares
studied, while no encounters of opposite polarities are observed at
footpoints for the others even with SOT high spatial magnetorams
(Kano et al. 2010). Another observations tell the involvement of
twisted magnetic fields in the microflares accompanied by no polarity
encounters at the footpoints. Some type of sunspot light bridges shows
recurrent occurrence of chromospheric ejections, and photospheric
vector magnetic field data suggests that twsited magnetic flux tubes
lying along light bridge play vital roles in producing such ejections
(Shimizu et al. 2009). This presentation reviewed observational findings
from these studies. We will need to understand the 3D configuration
of magnetic fields for better understanding of activity triggers in
the solar atmosphere.
Title: What determines the penumbral size and Evershed flow speed?
Authors: Deng, Na; Shimizu, Toshifumi; Choudhary, Debi Prasad;
Wang, Haimin
Bibcode: 2011IAUS..273..216D
Altcode: 2011arXiv1102.3164D
Using Hinode SP and G-band observations, we examined the relationship
between magnetic field structure and penumbral length as well as
Evershed flow speed. The latter two are positively correlated with
magnetic inclination angle or horizontal field strength within 1.5
kilogauss, which is in agreement with recent magnetoconvective
simulations of Evershed effect. This work thus provides direct
observational evidence supporting the magnetoconvection nature of
penumbral structure and Evershed flow in the presence of strong and
inclined magnetic field.
Title: Bright Points In And Around Sunspots
Authors: Prasad Choudhary, Debi; Deng, N.; Shimizu, T.
Bibcode: 2011SPD....42.1714P
Altcode: 2011BAAS..43S.1714P
We used the flux calibrated images through the Broad Band Filter
Imager and Stokes Polarimeter data obtained with the Solar Optical
Telescope onboard the Hinode spacecraft to study the properties of
sunspot bright points. The isolated bright points were selected and
classified as umbral dot, peripheral umbral dot, penumbral grains and
G-band bright point depending on their location. Most of the bright
points are smaller than about 150 km, and not uniformly distributed
over the umbra but preferentially located around the penumbral boundary
and in the fast decaying parts of umbra. The color temperature of
the bright points, derived using the continuum irradiance, are in the
range of 4600 K to 6600 K with cooler ones located in the umbra. The
temperature increases as a function of distance from the center to
outside. The G-band, CN-band and CaII H flux of the bright points
as a function of their blue band brightness increase continuously
in a nonlinear fashion unlike their red and green counterpart. The
scatter in CaII H irradiance is higher compared to the G-band and
CN-band irradiance. The light curve of the bright points show that
the enhanced brightness at these locations last for about 15 to 60
minutes. The umbral dots near the penumbral boundary are associated
with elongated filamentary structures. The G-band brightness closely
follows their magnetic filling factor. Generally, the umbral dots have
higher magnetic field and larger Doppler velocity compared to their
counterpart outside the spot. These results are consistent with the
model in which the upward intruding plasma through the nonmagnetic
columns between the fluxtubes of sunspot produce the bright points and
heat the matter inside of adjacent tubes. The heated plasma flows in
the direction of reduced gas pressure. Similar localized heating of
penumbra leads to the origin of penumbral grains.
Title: Observations of On-Disk Type I and II Spicules
Authors: Deng, Na; Denker, C.; Verma, M.; Shimizu, T.; Liu, C.;
Wang, H.
Bibcode: 2011SPD....42.1737D
Altcode: 2011BAAS..43S.1737D
A coordinated observing campaign was carried out during 2010
November 16-30 using German Vacuum Tower Telescope (VTT) and Hinode
to investigate properties of small-scale spicules on the solar
disk. The high-spectral resolution Echelle spectrograph at the VTT
on Tenerife acquired spectra of the chromospheric halpha (656.28 nm)
and photospheric Fe I (656.92 nm) lines in a region centered on a
small pore. Hinode mission provides high-cadence vector magnetograms,
G-band and Ca II H images, EIS and XRT observations of the same
region. We present statistical properties of spicules (type I and II),
such as spectral characteristics, velocities, spatial distribution and
temporal evolution, paying particular attention to type II spicules or
chromospheric jets. We investigate the photospheric magnetic structure,
flow field and their evolution attempting to find the origin of
chromospheric jets. The vertical extent of identified chromospheric
jets in the transition region and corona will be studied using EIS
and XRT observations in conjunction with SDO observations.
Title: Supernova dust for the extinction law in a young infrared
galaxy at z∼ 1
Authors: Kawara, K.; Hirashita, H.; Nozawa, T.; Kozasa, T.; Oyabu,
S.; Matsuoka, Y.; Shimizu, T.; Sameshima, H.; Ienaka, N.
Bibcode: 2011MNRAS.412.1070K
Altcode: 2010MNRAS.tmp.1877K; 2010arXiv1011.0511K
We apply the supernova (SN) extinction curves to reproduce the
observed properties of SST J1604+4304 which is a young infrared
(IR) galaxy at z∼ 1. The SN extinction curves used in this work
were obtained from models of unmixed ejecta of Type II supernovae
for the Salpeter initial mass function with a mass range from 8 to
30 M⊙ or 8 to 40 M⊙. The effect of dust
distributions on the attenuation of starlight is investigated by
performing the χ2 fitting method against various dust
distributions. These are the commonly used uniform dust screen,
the clumpy dust screen and the internal dust geometry. We add to
these geometries three scattering properties, namely, no scattering,
isotropic scattering and forward-only scattering. Judging from the
χ2 values, we find that the uniform screen models with
any scattering property provide good approximations to the real dust
geometry. Internal dust is inefficient to attenuate starlight and thus
cannot be the dominant source of the extinction. We show that the SN
extinction curves reproduce the data of SST J1604+4304 comparable to
or better than the Calzetti extinction curve. The Milky Way extinction
curve is not in satisfactory agreement with the data unless several
dusty clumps are in the line of sight. This trend may be explained by
the abundance of SN-origin dust in these galaxies; SN dust is the most
abundant in the young IR galaxy at z∼ 1, abundant in local starbursts
and less abundant in the Galaxy. If dust in SST J1604+4304 is dominated
by SN dust, the dust production rate is ∼0.1 M⊙ per SN.
Title: Magnetic Reconnection in the Solar Atmopshere Observed
by Hinode
Authors: Imada, Shinsuke; Isobe, Hiroaki; Shimizu, Toshifumi
Bibcode: 2011sswh.book...63I
Altcode:
No abstract at ADS
Title: Three-dimensional MHD instability of spontaneous fast magnetic
reconnection in geomagnetotail
Authors: Shimizu, T.; Ogino, T.; Kondoh, K.
Bibcode: 2010AGUFMSM51C1827S
Altcode:
In recent multi-satellite observations such as THEMIS, various plasma
dynamics related to the fast magnetic reconnection in geomagnetotail is
actively studied. However, the three-dimensional structure of the fast
magnetic reconnection itself is still unclear. According to our previous
MHD studies, it has been revealed that two-dimensional spontaneous fast
magnetic reconnection which can be quasi-steady state is unstable in
three-dimensional perturbation, resulting in intermittent and unsteady
three-dimensional fast magnetic reconnection even in one-dimensional
current sheet. Those studies were successfully applied for solar flare
observations such as TRACE EUV image data and, now, is tried to be
applied for the geomagnetotail dynamics. In geomagnetotail, since the
current sheet has a three-dimensional structure and may be disturbed
by various geomagnetosphere’s three-dimensional plasma convections,
the three-dimensional instability of fast magnetic reconnection process
may be largely modified from the ideal and simple geometry models. In
this study, using global three-dimensional MHD simulation including
various interactions between solar winds and geomagnetosphere, it is
visually shown that how the three-dimensional spontaneous fast magnetic
reconnection is caused in geomagnetotail.
Title: Ionization non-equilibrium plasma during magnetic reconnection
in solar corona
Authors: Imada, S.; Murakami, I.; Watanabe, T.; Hara, H.; Shimizu, T.
Bibcode: 2010AGUFMSH31A1788I
Altcode:
Hinode can provide us both of the stored magnetic field energy in
corona before magnetic reconnection and the most part of energy post
reconnection stage. On the other hand, there is not enough observational
knowledge of the physical parameters in the reconnection region. The
inflow into the reconnection region, the temperature of the plasma in
the reconnection region, and the temperatures and densities of the
plasma jets predicted by reconnection, have not been quantitatively
measured in sufficient. EIS on Hinode may provide some answers if
solar cycle 24 ever produces a solar maximum. But it is important
to answer why the most observation cannot detect the predicted flow
or temperature in the reconnection region. One of the reasons why we
cannot observe inside the magnetic reconnection region is due to its
darkness. Generally we can see the bright cusp-like structure during
solar flare, although the reconnection region is faint/blind. One may
think that the temperature in the reconnection region is enough higher
than that of cusp-like flare loops. Thus the wavelength of emission
from reconnection region is different from flare loops. However, this
is not entirely true. Magnetic reconnection causes rapid heating. Thus
ionization cannot reach to the equilibrium stage. We have calculated
the ionization process in the down stream of Petschek type magnetic
reconnection. From our result, we can clearly see that plasma cannot
reach the ionization equilibrium in the down stream of slow-mode
shock. The typical emissions from magnetic reconnection region are
FeIXX or FeXX, although the plasma temperature is equal to 40MK. The
typical temperature and density of post flare loops are 10 MK and 10^11
/cc, and the dominant emissions from post flare loops are from FeIXX
to FeXXIII. Thus the wavelength of emission from reconnection region
is not so much different from post flare loops. We will discuss how
the emissions from reconnection region looks like by using several
ionization calculations of magnetic reconnection.
Title: Experimental Simulation of Magnetic Reconnection in the
Sunspot Light Bridge
Authors: Hayashi, Yoshinori; Tanabe, Hiroshi; Inomoto, Michiaki; Ono,
Yasushi; Shimizu, Toshifumi; Imada, Shinsuke; Nishizuka, Naoto
Bibcode: 2010APS..DPPCP9122H
Altcode:
Intermittent and recurrent chromospheric plasma ejections were
discovered in the sunspot light bridge (LB) by the Solar Optical
Telescope of the Hinode satellite (Shimizu et al. 2009, ApJ, 696,
L66). Strong current was observed under the jet, suggesting existence
of twisted flux tube in the vertical background field. The magnetic
reconnection between the flux tube and the vertical field is considered
to cause the plasma ejection. It is left unsolved why the intermittent
reconnection continuing more than one day. Note that the magnetic
configuration of LB is similar to the spheromak plasma maintained
by vertical field in the laboratory. We formed spheromak in the TS-4
device and drove magnetic reconnection with center solenoid coil. We
measured 2D magnetic profile of the reconnecting field lines between
the spheromak and the solenoid coil by the magnetic probe array and
local temperature, density and plasma flow at the reconnection point
by the Langmuir probes and ion Doppler spectroscopy. We will discuss
about the LB reconnection by comparing the laboratory experiment with
the satellite observation.
Title: Hinode Observation of Photospheric Magnetic Activities
Triggering X-ray Microflares Around a Well-developed Sunspot
Authors: Kano, R.; Shimizu, T.; Tarbell, T. D.
Bibcode: 2010ApJ...720.1136K
Altcode:
Microflares, which are small energetic events in the solar corona, are
an example of dynamical phenomena suitable for understanding energy
release processes in the solar corona. We identified 55 microflares
around a well-developed sunspot surrounded by a moat with high-cadence
X-ray images from the Hinode X-ray Telescope, and searched for their
photospheric counterparts in line-of-sight magnetograms taken with the
Hinode Solar Optical Telescope. We found opposite magnetic polarities
encountering each other around the footpoints of 28 microflares,
while we could not find such encounters around the footpoints of the
other 27 microflares. Emerging magnetic fluxes in the moat were the
dominant origin causing the encounters of opposite polarities (21 of
28 events). Unipolar moving magnetic features (MMFs) with negative
polarities the same as the sunspot definitely caused the encounters of
opposite polarities for five microflares. The decrease of magnetic flux,
i.e., magnetic flux cancellation, was confirmed at the encountering site
in typical examples of microflares. Microflares were not isotropically
distributed around the spot; the microflares with emerging magnetic
fluxes (EMFs) were observed in the direction where magnetic islands
with the same polarity as the spot were located at the outer boundary
of the moat, while the microflares with negative MMFs were observed
in the direction where magnetic islands with polarity opposite to the
spot were located at the outer boundary of the moat. We also found that
EMFs in the moat had a unique orientation in which those with the same
polarity as the spot is closer to the spot than the other one that had
the opposite polarity to the spot. These observational results lead
to two magnetic configurations including magnetic reconnection for
triggering energy release at least in half of the microflares around
the spot, and suggest that the global magnetic structures around the
spot strongly affect what kinds of polarity encounters are formed in
the sunspot moat.
Title: Quiescent Prominence Dynamics Observed with the Hinode Solar
Optical Telescope. I. Turbulent Upflow Plumes
Authors: Berger, Thomas E.; Slater, Gregory; Hurlburt, Neal; Shine,
Richard; Tarbell, Theodore; Title, Alan; Lites, Bruce W.; Okamoto,
Takenori J.; Ichimoto, Kiyoshi; Katsukawa, Yukio; Magara, Tetsuya;
Suematsu, Yoshinori; Shimizu, Toshifumi
Bibcode: 2010ApJ...716.1288B
Altcode:
Hinode/Solar Optical Telescope (SOT) observations reveal two new
dynamic modes in quiescent solar prominences: large-scale (20-50 Mm)
"arches" or "bubbles" that "inflate" from below into prominences, and
smaller-scale (2-6 Mm) dark turbulent upflows. These novel dynamics are
related in that they are always dark in visible-light spectral bands,
they rise through the bright prominence emission with approximately
constant speeds, and the small-scale upflows are sometimes observed to
emanate from the top of the larger bubbles. Here we present detailed
kinematic measurements of the small-scale turbulent upflows seen in
several prominences in the SOT database. The dark upflows typically
initiate vertically from 5 to 10 Mm wide dark cavities between the
bottom of the prominence and the top of the chromospheric spicule
layer. Small perturbations on the order of 1 Mm or less in size
grow on the upper boundaries of cavities to generate plumes up to
4-6 Mm across at their largest widths. All plumes develop highly
turbulent profiles, including occasional Kelvin-Helmholtz vortex
"roll-up" of the leading edge. The flows typically rise 10-15 Mm before
decelerating to equilibrium. We measure the flowfield characteristics
with a manual tracing method and with the Nonlinear Affine Velocity
Estimator (NAVE) "optical flow" code to derive velocity, acceleration,
lifetime, and height data for several representative plumes. Maximum
initial speeds are in the range of 20-30 km s-1, which
is supersonic for a ~10,000 K plasma. The plumes decelerate in the
final few Mm of their trajectories resulting in mean ascent speeds
of 13-17 km s-1. Typical lifetimes range from 300 to 1000
s (~5-15 minutes). The area growth rate of the plumes (observed as
two-dimensional objects in the plane of the sky) is initially linear
and ranges from 20,000 to 30,000 km2 s-1 reaching
maximum projected areas from 2 to 15 Mm2. Maximum contrast of
the dark flows relative to the bright prominence plasma in SOT images
is negative and ranges from -10% for smaller flows to -50% for larger
flows. Passive scalar "cork movies" derived from NAVE measurements show
that prominence plasma is entrained by the upflows, helping to counter
the ubiquitous downflow streams in the prominence. Plume formation
shows no clear temporal periodicity. However, it is common to find
"active cavities" beneath prominences that can spawn many upflows in
succession before going dormant. The mean flow recurrence time in these
active locations is roughly 300-500 s (5-8 minutes). Locations remain
active on timescales of tens of minutes up to several hours. Using a
column density ratio measurement and reasonable assumptions on plume
and prominence geometries, we estimate that the mass density in the
dark cavities is at most 20% of the visible prominence density, implying
that a single large plume could supply up to 1% of the mass of a typical
quiescent prominence. We hypothesize that the plumes are generated from
a Rayleigh-Taylor instability taking place on the boundary between
the buoyant cavities and the overlying prominence. Characteristics,
such as plume size and frequency, may be modulated by the strength
and direction of the cavity magnetic field relative to the prominence
magnetic field. We conclude that buoyant plumes are a source of
quiescent prominence mass as well as a mechanism by which prominence
plasma is advected upward, countering constant gravitational drainage.
Title: The Relationship Among Magnetic Field Configuration, Penumbral
Size, and Evershed Flow Speed
Authors: Deng, Na; Shimizu, T.; Choudhary, D.
Bibcode: 2010AAS...21640308D
Altcode: 2010BAAS...41..879D
Recent observations (e.g., Wang et al. 2004; Deng et al. 2005) have
shown that there is a sudden penumbral decay associated with major
flares during which the overall magnetic field inclination in penumbra
changes due to magnetic reconnection. We propose that the size (i.e.,
length) of sunspot penumbra is related to the localized magnetic field
configuration. In order to test this hypothesis, we study 11 sunspots
close to disk center with different sizes, which were observed by
Hinode/SOT at the late phase of solar cycle 23. We notice that even
for typical alpha sunspots near the disc center, the penumbral length
is different in different sectors in the same spot. Since the Evershed
flow is coupled with penumbra, we also study the properties of Evershed
flow, such as its speed, at different location of a sunspot. The SP
data is used to study the magnetic field parameters (e.g., strength,
inclination) in different penumbral sectors that show distinct penumbral
length. The Evershed flow is measured both by Doppler shift from SP
observation and by Local Correlation Tracking based on time series of
BFI data. We aim to find the relationship among magnetic field topology,
penumbral size, and Evershed flow speed.
Title: Velocity and Magnetic Structure of Sunspot Umbral Dots
Authors: Prasad Choudhary, Debi; MacDonald, G. A.; Deng, N.;
Shimizu, T.
Bibcode: 2010AAS...21640111P
Altcode: 2010BAAS...41..858P
The Doppler velocity measurements of umbral dots obtained with
Spectropolarimeter (SP) on board Hinode Solar Optical Telescope is
used to study the sunspot structure. The SP observations, each more
than an hour long, were carried out at 2-minute cadence with 25 slit
positions at penumbral boundary of a sunspot on 2-3 February 2007. These
observations record the formation and decay of at least four umbral
dots. The Doppler velocity observed in and around the umbral dots
using Stokes profiles show unidirectional velocities of about 700 to
1200 meters per second. The Stokes-V profiles at these locations show
asymmetry of about 1 to 5 % compared to the surroundings. We discuss the
formation mechanisms of umbral dots and their implication for sunspot
structure using these observations. This work is supported by
NASA grant NNX08AQ32G and NSF grant ATM 05-48260.
Title: G-band and Hard X-ray Emissions of the 2006 December 14 Flare
Observed by Hinode/SOT and Rhessi
Authors: Watanabe, Kyoko; Krucker, Säm; Hudson, Hugh; Shimizu,
Toshifumi; Masuda, Satoshi; Ichimoto, Kiyoshi
Bibcode: 2010ApJ...715..651W
Altcode: 2010arXiv1004.4259W
We report on G-band emission observed by the Solar Optical Telescope on
board the Hinode satellite in association with the X1.5-class flare on
2006 December 14. The G-band enhancements originate from the footpoints
of flaring coronal magnetic loops, coinciding with nonthermal hard
X-ray bremsstrahlung sources observed by the Reuven Ramaty High Energy
Solar Spectroscopic Imager. At the available 2 minute cadence, the
G-band and hard X-ray intensities are furthermore well correlated in
time. Assuming that the G-band enhancements are continuum emission from
a blackbody, we derived the total radiative losses of the white-light
flare (white-light power). If the G-band enhancements additionally have
a contribution from lines, the derived values are overestimates. We
compare the white-light power with the power in hard X-ray producing
electrons using the thick-target assumption. Independent of the cutoff
energy of the accelerated electron spectrum, the white-light power and
the power of accelerated electrons are roughly proportional. Using
the observed upper limit of ~30 keV for the cutoff energy, the hard
X-ray producing electrons provide at least a factor of 2 more power
than needed to produce the white-light emission. For electrons above
40 keV, the powers roughly match for all four of the time intervals
available during the impulsive phase. Hence, the flare-accelerated
electrons contain enough energy to produce the white-light flare
emissions. The observed correlation in time, space, and power strongly
suggests that electron acceleration and white-light production in solar
flares are closely related. However, the results also call attention
to the inconsistency in apparent source heights of the hard X-ray
(chromosphere) and white-light (upper photosphere) sources.
Title: Tomographic All-sky Imaging Above 200 keV With BATSE
Authors: Wheaton, William A.; Case, G. L.; Cherry, M. L.; Ling, J. C.;
Lo, M. W.; Roland, J. M.; Shimizu, T.
Bibcode: 2010HEAD...11.3501W
Altcode: 2010BAAS...42..714W
We describe a tomographic method of mapping the gamma-ray sky above 200
keV with earth-occultation data from BATSE, the Burst And Transient
Source Experiment on the Compton Gamma-Ray Observatory (CGRO). The
method combines good sensitivity with 0.5° angular resolution over
the whole sky. Our previous occultation analysis of the BATSE data
indicates the presence of a significant number of unmodeled cosmic
sources. The Earth's horizon cuts the sky in a cycle that repeats with
the 51 day precession of the CGRO orbit plane, which is reflected in
periodic effects due to the uncatalogued sources. Such cycles are then a
natural data unit for all-sky mapping by a tomographic method using the
Radon transform. Because the airmass profile of the horizon is nearly
independent of energy, we obtain 0.5° angular resolution over the
entire low-energy gamma-ray region. To improve sensitivity, we subtract
a phenomenological model for the non-cosmic gamma-ray background from
the raw count data before performing the imaging analysis, which uses a
simple planar approximation to the inverse Radon transform on a tiling
of the sky. We present images in four broad energy bands (23-98
keV, 98-230 keV, 230-595 keV and 595-1800 keV) centered on selected
sources to illustrate the power of this approach. Our preliminary
results tentatively show several sources in the 230-595 keV and
595-1800 keV bands, which will be presented. We easily image the Crab
in the 595-1800 keV band in a single precession cycle. With 64 cycles
in the 9 year CGRO data set, we expect a flux-complete survey of the
entire sky, with multiple independent sky maps achieving a combined
sensitivity typically less than 125 mCrab near 1 MeV. This work has
been supported by grants from NASA, JPL, and LSU.
Title: The SOLAR-C mission: study status update
Authors: Shimizu, Toshifumi
Bibcode: 2010cosp...38.1950S
Altcode: 2010cosp.meet.1950S
The SOLAR-C working group (WG) in ISAS/JAXA with Solar-C project
office in NAOJ has been studying the next solar mission, the so-called
Solar-C, as the post-Hinode mission. Two concepts have been studied:
The Plan A mission will perform out-of-the-ecliptic magnetic and
helioseismic observations of the polar and the quatorial regions
to investigate properties of the polar region, meridional flow and
magnetic structure inside the Sun down to the bottom of the convection
zone. This kind of exploration may give better understanding of the
mechanism responsible for creating the solar magnetic cycle. The Plan
B mission will perform high spatial resolution, high throughput, high
cadence spectroscopic and polarimetric and UV observations, from the
photosphere to the corona, to investigate the magnetism of the Sun
and its role in heating and dynamism of the solar atmospheres. Deeper
investigations of magnetic reconnec-tion in the solar plasma is one
of key observations for understanding dynamism and heating of the
solar plasma, and it is our desire that the following observations
are realized with the com-bination of the instrument candidates. 1)
Precise spectroscopic and polarimetric observations for understanding
dynamic nature of magnetic fields, especially in the upper atmospheres
(chro-mosphere and, the corona if possible). 2) High time resolution,
high throughput spectroscopic observations for understanding nature of
dynamics. 3) Seamless observations over the entire atmosphere, i.e.,
from photosphere to corona, for understanding the entire pictures
of heating and dynamics. 4) High spatial resolution observations for
resolving elementary structures and physical process responsible for
various MHD behaviors in the solar atmosphere. Three model payloads have
been studied: 1.5m near IR-visible-UV telescope, high throughput UV/EUV
spectrograph, and X-ray telescope with photon counting mode. Studies
are in good progress in 2009, with studies by sub-working groups,
which are organized with participation of many scientists from US and
countries in Europe. The WG plans to propose a single mission plan to
ISAS/JAXA at the time of the next call for proposal of the next JAXA
science mission. We will report our latest mission concept and study
status in the presentation.
Title: Magnetohydrodynamics Study of Three-Dimensional Fast Magnetic
Reconnection for Intermittent Snake-Like Downflows in Solar Flares
Authors: Shimizu, T.; Kondo, K.; Ugai, M.; Shibata, K.
Bibcode: 2009ApJ...707..420S
Altcode:
Three-dimensional instability of the spontaneous fast magnetic
reconnection is studied with magnetohydrodynamics (MHD)
simulation, where the two-dimensional model of the spontaneous
fast magnetic reconnection is destabilized in three dimensions. In
two-dimensional models, every plasma condition is assumed to be
uniform in the sheet current direction. In that case, it is well
known that the two-dimensional fast magnetic reconnection can be
caused by current-driven anomalous resistivity, when an initial
resistive disturbance is locally put in a one-dimensional current
sheet. In this paper, it is studied whether the two-dimensional fast
magnetic reconnection can be destabilized or not when the initial
resistive disturbance is three dimensional, i.e., that which has weak
fluctuations in the sheet current direction. According to our study,
the two-dimensional fast magnetic reconnection is developed to the
three-dimensional intermittent fast magnetic reconnection which is
strongly localized in the sheet current direction. The resulting fast
magnetic reconnection repeats to randomly eject three-dimensional
magnetic loops which are very similar to the intermittent downflows
observed in solar flares. In fact, in some observations of solar flares,
the current sheet seems to be approximately one dimensional, but the
fast magnetic reconnection is strongly localized in the sheet current
direction, i.e., fully three dimensional. In addition, the observed
plasma downflows as snake-like curves. It is shown that those observed
features are consistent with our numerical MHD study.
Title: Hinode Observation of the Vector Magnetic Fields in a Sunspot
Light Bridge Accompanied by Chromospheric Plasma Ejections
Authors: Shimizu, T.
Bibcode: 2009ASPC..415..148S
Altcode:
This article briefly discusses vector magnetic fields of of a sunspot
light bridge (LB) where chromospheric plasma ejections (or it is
called surges) occurred intermittently and recurrently for more than 1
day. Obliquely oriented magnetic fields with strong vertical electric
current density higher than 100 mA/m2 are clearly observed
along the light bridge, suggesting a twisted magnetic flux (current
carrying) loop lying along the bridge. The magnetic field structure of
the light bridge is modeled to explain observed recurrent ejections
in terms of magnetic reconnections at the low atmosphere. Details of
our findings will be described in a more complete paper (Shimizu et
al. 2009).
Title: Radiation Transfer Analysis on Heating Mechanism of
Magnetohydrodynamic Emerging Magnetic Flux Tube
Authors: Kato, Y.; Magara, T.; Shimizu, T.
Bibcode: 2009ASPC..415..272K
Altcode:
In spite of the large number of magnetohydrodynamic (MHD) simulations
of emerging flux tubes in the solar atmosphere, radiation properties of
the phenomenon remain poorly understood. This is because heating at the
footpoints of the emerging magnetic field lines is significant and the
effects associated with heat conduction and evaporation have largely
been neglected. In this study, we have performed three-dimensional
(3-D) multi-wavelength radiation transfer calculations on a MHD model
of an emerging flux tube in order to examine the MHD model and also to
identify a possible heating mechanism for explaining the properties of
observed X-ray coronal loops. It is found that the current dissipation
model is difficult for reproducing the structure of X-ray loops observed
by Hinode XRT and Yohkoh SXT. This suggests that alternative models
of the heating process should be incorporated into our MHD models. We
left unresolved issues of the heating process as future work.
Title: Initial Results of New Tomographic Imaging of the Gamma-Ray
Sky with BATSE
Authors: Case, G. L.; Cherry, M. L.; Ling, J. C.; Lo, M.; Shimizu,
T.; Wheaton, Wm. A.
Bibcode: 2009arXiv0912.3815C
Altcode:
We describe an improved method of mapping the gamma-ray sky by applying
the Linear Radon Transform to data from BATSE on NASA's CGRO. Based
on a method similar to that used in medical imaging, we use the
relatively sharp (~0.25 deg) limb of the Earth to collimate BATSE's
eight Large Area Detectors (LADs). Coupling this to the ~51-day
precession cycle of the CGRO orbit, we can complete a full survey
of the sky, localizing point sources to < 1 deg accuracy. This
technique also uses a physical model for removing many sources of
gamma-ray background, which allows us to image strong gamma-ray sources
such as the Crab up to ~2 MeV with only a single precession cycle. We
present the concept of the Radon Transform technique as applied to
the BATSE data for imaging the gamma-ray sky and show sample images
in three broad energy bands (23-98 keV, 98-230 keV, and 230-595 keV)
centered on the positions of selected sources from the catalog of 130
known sources used in our Enhanced BATSE Occultation Package (EBOP)
analysis system. Any new sources discovered during the sky survey will
be added to the input catalog for EBOP allowing daily light curves and
spectra to be generated. We also discuss the adaptation of tomographic
imaging to the Fermi GBM occultation project.
Title: Magnetic Flux Budget in a Decaying Active Region
Authors: Kubo, M.; Lites, B. W.; Shimizu, T.; Ichimoto, K.
Bibcode: 2009ASPC..415..359K
Altcode:
We investigate the sunspot decay process in terms of the magnetic flux
budget of a decaying sunspot. This article is based on results in Kubo
et al. 2008. Please see this paper for further details.
Title: The self-organization of neutral lines in three-dimensional
and random fast magnetic reconnection
Authors: Shimizu, T.
Bibcode: 2009AGUFMSH23A1532S
Altcode:
Three-dimensional, multiple, spontaneous, and intermittent fast
magnetic reconnection was studied in numerical MHD simulations as a
three-dimensional instability of the typical two-dimensional spontaneous
fast magnetic reconnection model. In this model, the current-driven
anomalous resistivity is assumed and the fast reconnection process
is initiated by a three-dimensional resistive perturbation in the
one-dimensional current sheet. The resulting fast reconnection process
is strongly localized in the sheet current direction, intermittently
enhanced, and simultaneously occurs in some places of the current
sheet. As a result, magnetic loops, i.e. plasmoids, are repeatedly
and randomly ejected. This numerical result is very similar to the
intermittent downflows often observed in EUV imager of solar flares. In
this paper, in the viewpoint of three-dimensional instability of the
reconnection process, the three-dimensional structures and dynamics
of neutral lines which can be caused in the one-dimensional current
sheet are reported through the numerical and analytical MHD studies.
Title: Evolution of fine magnetic structures in sunspot light bridges
as observed with Hinode/SOT
Authors: Shimizu, T.
Bibcode: 2009AGUFMSH53B..08S
Altcode:
Sunspot light bridges are one of the fundamental magnetic structures
in sunspots, possibly related to fragmentation of magnetic flux in
sunspots. One of the interesting and important observational aspects
that some light bridges show chromospheric activities along the
structure, such as long-lasting plasma ejections or surge activities
(Roy 1973, Asai et al. 2001, Bharti et al. 2007, Shimizu et al. 2009)
and brightness enhancements (Berger and Berdyugina 2003). Moreover,
X-ray transient brightenings of coronal loops (microflares) may
have one loop footpoint near along sunspot light bridges. What are
magnetic structures and activities for causing activities in the
chromosphere and corona? Precise vector magnetic field measurements
with high spatial resolution can give observational hints to this
question. This presentation will discuss high-resolution vector
magnetic field measurements of sunspot light bridges, some of which
showed remarkable chromospheric activities. One good example is a
sunspot light bridge observed at the south-east side of the leading
sunspot in NOAA Active Region 10953. Long-lasting plasma ejections were
intermittently and recurrently observed in the chromosphere for more
than 1 days, starting from 20UT on April 29, 2007 and observed through
April 30. The light bridge showed several number of brightenings in
the chromosphere on May 1. During these three days, SOT successfully
captured long-term evolution of fine magnetic structures in the light
bridge with Stokes Polarimeter. The magnetic field data suggests that
magnetic flux tubes were trapped below a cusp-shaped magnetic structure
along the light bridge. The flux tubes were highly twisted on April
30 and less twisted on May 1. Chromospheric ejections and heating,
and their different behaviors between on April 30 and May 1 may be
explained with evolution of fine magnetic structures along the light
bridge. Many observational features can be well explained in terms of
magnetic reconnections between the trapped flux tubes and pre-existing
vertically oriented umbral fields.
Title: Hinode Mission Status
Authors: Shimizu, T.
Bibcode: 2009ASPC..415....1S
Altcode:
The Hinode mission status was briefly explained in this
presentation. The Hinode spacecraft has been operated for two
years after the launch on 23 September 2006 (JST). All the three
telescopes are continuing to observe the Sun with the expected
excellent performance. The Sun has been quiet for most of the latest
one year and Hinode's observations were mainly focused on the quiet Sun
studies. Spacecraft functions are good except for an anomaly in X-band
telemetry downlink. The X-band downlink anomaly gives a restriction to
the volume of science data but we have almost established scientific
operations baseline since the transition to S-band backup high-speed
downlink.
Title: Magnetic Flux Budget of a Decaying Sunspot
Authors: Kubo, Masahito; Lites, Bruce W.; Shimizu, Toshifumi;
Ichimoto, Kiyoshi
Bibcode: 2009shin.confE...9K
Altcode:
Numerous small magnetic elements called moving magnetic features (MMFs)
are generally observed in the moat region that surrounds a sunspot. We
attempt to address a basic question how much magnetic flux is carried
away from a sunspot by MMFs and is subsequently removed from the
photosphere. This is essential for understanding decay of sunspots
and distribution of magnetic flux on the Sun. We estimate the magnetic
flux budget in a decaying sunspot and its surrounding moat region by
using a time series of the spatial distribution of vector magnetic
fields in the photosphere. Spectropolarimetric measurements with the
Solar Optical Telescope aboard the Hinode satellite allow us, for
the first time, to know an accurate flux change without any effects
of atmospheric seeing. The amount of magnetic flux that decreases
in the sunspot and (inner) moat region is very similar to magnetic
flux transported to the outer boundary of the moat region. The flux
loss rates of magnetic elements with positive and negative polarities
balance each other around the outer boundary of the moat region. These
results suggest that most of the magnetic flux in the sunspot is
transported to the outer boundary of the moat region as MMFs, and
then the transported flux is removed from the photosphere by apparent
collisions of opposite-polarity magnetic elements (called
Title: Magnetic field strength of active region filaments
Authors: Kuckein, C.; Centeno, R.; Martínez Pillet, V.; Casini, R.;
Manso Sainz, R.; Shimizu, T.
Bibcode: 2009A&A...501.1113K
Altcode: 2009arXiv0904.4876K
Aims: We study the vector magnetic field of a filament observed over a
compact active region neutral line.
Methods: Spectropolarimetric
data acquired with TIP-II (VTT, Tenerife, Spain) of the 10 830
Å spectral region provide full Stokes vectors that were analyzed
using three different methods: magnetograph analysis, Milne-Eddington
inversions, and PCA-based atomic polarization inversions.
Results:
The inferred magnetic field strengths in the filament are around 600-700
G by all these three methods. Longitudinal fields are found in the
range of 100-200 G whereas the transverse components become dominant,
with fields as high as 500-600 G. We find strong transverse fields
near the neutral line also at photospheric levels.
Conclusions:
Our analysis indicates that strong (higher than 500 G, but below kG)
transverse magnetic fields are present in active region filaments. This
corresponds to the highest field strengths reliably measured in these
structures. The profiles of the helium 10 830 Å lines observed in
this active region filament are dominated by the Zeeman effect.
Title: A New View of Fine Scale Dynamics and Magnetism of Sunspots
Revealed by Hinode/SOT
Authors: Ichimoto, K.; Suematsu, Y.; Katsukawa, Y.; Tsuneta, S.;
Shimojo, M.; Shimizu, T.; Shine, R. A.; Tarbell, T. D.; Berger, T.;
Title, A. M.; Lites, B. W.; Kubo, M.; Yokoyama, T.; Nagata, S.
Bibcode: 2009ASPC..405..167I
Altcode:
The Solar Optical Telescope on-board Hinode is providing a new view of
the fine scale dynamics in sunspots with its high spatial resolution and
unprecedented image stability. We present three features related to the
Evershed flow each of which raises a new puzzle in sunspot dynamics;
i.e., twisting appearance of penumbral filaments, the source and sink
of individual Evershed flow channels, and the net circular polarization
in penumbrae with its spatial relation to the Evershed flow channels.
Title: Has Hinode Revealed the Missing Turbulent Flux of the
Quiet Sun?
Authors: Lites, B. W.; Kubo, M.; Socas-Navarro, H.; Berger, T.; Frank,
Z.; Shine, R.; Tarbell, T.; Title, A. M.; Ichimoto, K.; Katsukawa,
Y.; Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2009ASPC..405..173L
Altcode:
The Hinode Spectro-Polarimeter has revealed the presence of surprisingly
strong horizontal magnetic fields nearly everywhere in the quiet
solar atmosphere. These horizontal fields, along with measures of the
vertical fields, may be the signature of the ``hidden turbulent flux''
of the quiet Sun. The measured horizontal fields average at least to
55 Gauss: nearly 5 times that of the measured longitudinal apparent
flux density. The nature of these fields are reviewed, and discussed
in the light of recent magneto-convection numerical simulations of
the quiet Sun.
Title: Hinode Observation of the Magnetic Fields in a Sunspot Light
Bridge Accompanied by Long-Lasting Chromospheric Plasma Ejections
Authors: Shimizu, Toshifumi; Katsukawa, Yukio; Kubo, Masahito; Lites,
Bruce W.; Ichimoto, Kiyoshi; Suematsu, Yoshinori; Tsuneta, Saku;
Nagata, Shin'ichi; Shine, Richard A.; Tarbell, Theodore D.
Bibcode: 2009ApJ...696L..66S
Altcode:
We present high-resolution magnetic field measurements of a sunspot
light bridge (LB) that produced chromospheric plasma ejections
intermittently and recurrently for more than 1 day. The observations
were carried out with the Hinode Solar Optical Telescope on 2007
April 29 and 30. The spectro-polarimeter reveals obliquely oriented
magnetic fields with vertical electric current density higher than
100 mA m-2 along the LB. The observations suggest that
current-carrying highly twisted magnetic flux tubes are trapped below
a cusp-shaped magnetic structure along the LB. The presence of trapped
current-carrying flux tubes is essential for causing long-lasting
chromospheric plasma ejections at the interface with pre-existing
vertically oriented umbral fields. A bidirectional jet was clearly
detected, suggesting magnetic reconnections occurring at very low
altitudes, slightly above the height where the vector magnetic fields
are measured. Moreover, we found another strong vertical electric
current on the interface between the current-carrying flux tube
and pre-existing umbral field, which might be a direct detection
of the currents flowing in the current sheet formed at the magnetic
reconnection sites.
Title: Three-dimensional non-linear instability of spontaneous fast
magnetic reconnection
Authors: Shimizu, T.; Kondoh, K.; Ugai, M.
Bibcode: 2009EP&S...61..569S
Altcode: 2009EP&S...61L.569S
Three-dimensional instability of spontaneous fast magnetic reconnection
is studied using MHD (magnetohydro- dynamic) simulation. Previous
two-dimensional MHD studies have demonstrated that, if a current-driven
anomalous resistivity is assumed, two-dimensional fast magnetic
reconnection occurs and two-dimensional largescale magnetic loops,
i.e., plasmoids, are ejected from the reconnection region. In most
two-dimensional MHD studies, the structure of the current sheet is
initially one-dimensinal. On the other hand, in recent space plasma
observations, fully three-dimensional magnetic loops frequently appear
even in the almost one-dimensional current sheet. This suggests that the
classical two-dimensional fast magnetic reconnection may be unstable to
any three-dimensional perturbation, resulting in three-dimensional fast
magnetic reconnection. In this paper, we show that a three-dimensional
resistive perturbation destabilizes two-dimensional fast magnetic
reconnection and results in three-dimensional fast magnetic
reconnection. The resulting three-dimensional fast reconnection
repeatedly ejects three-dimensional magnetic loops downstream. The
obtained numerical results are similar to the pulsating downflows
observed in solar flares. According to the Fourier analysis of the
ejected magnetic loops, the time evolution of this three-dimensional
instability is fully non-linear.
Title: Magnetic Flux Budget of a Decaying Sunspot
Authors: Kubo, Masahito; Lites, B. W.; Shimizu, T.; Ichimoto, K.
Bibcode: 2009SPD....40.0905K
Altcode:
We estimate how much magnetic flux is lost in a decaying sunspot
and how much magnetic flux is carried away from the sunspot through
its surrounding moat region. A time series of spectropolarimetric
measurements with the Solar Optical Telescope aboard Hinode allows us,
for the first time, to investigate an accurate flux change without
any effects of atmospheric seeing. The amount of magnetic flux that
decreases in the sunspot and moat region is almost equal to that of
magnetic flux transported to the outer boundary of the moat region. The
flux loss rates of magnetic elements with positive and negative
polarities are balanced each other around the outer boundary of the
moat region. These results suggest that most of the magnetic flux in
the sunspot is transported to the outer boundary of the moat region
as moving magnetic features, and then removed from the photosphere by
flux cancellation around the moat boundary.
Title: BATSE Soft Gamma Rays Tomographic Sky Imaging with Radon
Transforms
Authors: Ling, J. C.; Case, G. L., II; Lo, M.; Shimizu, T.; Reddick,
R.; Wheaton, W. A.; Cherry, M.
Bibcode: 2009AAS...21440712L
Altcode:
We present preliminary results of tomographic imaging of the 20 keV
to 1800 keV gamma-ray sky using Radon Transforms and data from the
BATSE experiment on the Compton Gamma Ray Observatory. The method uses
Earth occultation, with the 0.2 degree angular response characteristic
of the atmospheric limb, together with the all-sky coverage of the
BATSE instrument to produce 2-dimensional maps of the sky from the
count data from the eight BATSE detectors. We have initially used
the Linear Radon Transform (LRT), though this limits us to imaging
small ( 4x4o) regions of the sky where the earth limb can
be approximated as a straight line. As the orbit of the spacecraft
precesses over a 51-day period, the earth limb sweeps across the sky at
different orientations, though never sampling the full 180o
range of angles. The large and complex variation of the background
counting rate common to all high-energy instruments in low-earth
orbit is subtracted from the raw data prior to the imaging steps
using our earlier work in modeling the background variability (Ling
et al. 2000). Summing the 16 BATSE LAD energy channels into four
broad bands (23-98 keV, 98-230 keV, 230-595 keV, and 595-1798 keV),
we are able to detect and position the Crab Nebula and the nearby
transient GRO J0422+32 using only a single 51 day precession cycle,
with source location accuracy of the order of 1o in each
band. We confirm earlier work by Zhang et al (1993) for applying
the LRT technique to the BATSE data, extend their work to cover more
source regions, and produce images at higher energies. We also discuss
the extension of our method to Generalized Radon Transforms, e.g. the
Spherical Cap Radon Transform, which would allow us to image larger
regions of the sky.
Title: Precision Co-alignment Of Hinode SOT And XRT Images
Authors: Slater, Gregory L.; Shimizu, T.
Bibcode: 2009SPD....40.1521S
Altcode:
In order to fully exploit the high spatial resolution of the
SOT and XRT telescopes of the Hinode solar observatory, routine
sub-arcsecond alignment between images from the two instruments
is important. Algorithms have been developed to precisely align
SOT and XRT image series to within 1 arcsec. The effectiveness of
the algorithms is currently being tested on data taken throughout the
Hinode mission. The results of these tests will be presented, as well
as the status of efforts to generate absolute pointing coordinates
for SOT and XRT images.
Title: Modeling of substorms and flares by the fast reconnection
mechanism
Authors: Ugai, M.; Kondoh, K.; Shimizu, T.
Bibcode: 2009EP&S...61..561U
Altcode: 2009EP&S...61L.561U
The 3D spontaneous fast reconnection model is applied to well-known
signatures of geomagnetic substorms and solar flares. First, it
is applied to the traveling compression regions (TCRs) associated
with plasmoids propagating down the tail plasma sheet, known as
a definite signature of geomagnetic substorms, and the in-situ
satellite observations can be precisely explained, both qualitatively
and quantitatively. Then, it is demonstrated that the magnetospheric
current wedge drastically evolves through field-aligned currents to
link the tail current to the auroral electrojet. It is also found
that the well-known morphological features of two-ribbon flares
can be explained by the fast reconnection model. In particular, the
joule heating, associated with the flare current wedge, is shown to
be important for the two-ribbon heating. Therefore, it is suggested
that both solar flares and geomagnetic substorms result from the same
physical mechanism, i.e., the fast reconnection mechanism.
Title: Prominence Formation Associated with an Emerging Helical
Flux Rope
Authors: Okamoto, Takenori J.; Tsuneta, Saku; Lites, Bruce W.; Kubo,
Masahito; Yokoyama, Takaaki; Berger, Thomas E.; Ichimoto, Kiyoshi;
Katsukawa, Yukio; Nagata, Shin'ichi; Shibata, Kazunari; Shimizu,
Toshifumi; Shine, Richard A.; Suematsu, Yoshinori; Tarbell, Theodore
D.; Title, Alan M.
Bibcode: 2009ApJ...697..913O
Altcode: 2009arXiv0904.0007O
The formation and evolution process and magnetic configuration of
solar prominences remain unclear. In order to study the formation
process of prominences, we examine continuous observations of a
prominence in NOAA AR 10953 with the Solar Optical Telescope on
the Hinode satellite. As reported in our previous Letter, we find
a signature suggesting that a helical flux rope emerges from below
the photosphere under a pre-existing prominence. Here we investigate
more detailed properties and photospheric indications of the emerging
helical flux rope, and discuss their relationship to the formation of
the prominence. Our main conclusions are: (1) a dark region with absence
of strong vertical magnetic fields broadens and then narrows in Ca II
H-line filtergrams. This phenomenon is consistent with the emergence
of the helical flux rope as photospheric counterparts. The size of the
flux rope is roughly 30,000 km long and 10,000 km wide. The width is
larger than that of the prominence. (2) No shear motion or converging
flows are detected, but we find diverging flows such as mesogranules
along the polarity inversion line. The presence of mesogranules may
be related to the emergence of the helical flux rope. (3) The emerging
helical flux rope reconnects with magnetic fields of the pre-existing
prominence to stabilize the prominence for the next several days. We
thus conjecture that prominence coronal magnetic fields emerge in
the form of helical flux ropes that contribute to the formation and
maintenance of the prominence.
Title: HINODE: New Space-borne Observatory for Investigating the Sun
Authors: Shimizu, Toshifumi
Bibcode: 2009TrSpT...7..Tm1S
Altcode:
This paper gives an overview of the Hinode satellite, which was
launched in September 2006 and is now observing the Sun with high
spatial resolution and high performance never achieved so far. The
primary aims of Hinode are to investigate magnetic activity of the Sun
including its generation, energy transfer and release of the magnetic
energy by simultaneously observing the solar surface (photosphere) and
the corona. Some results from the Hinode observations are presented
with emphasis on the supreme performance of the spacecraft and its
onboard telescopes.
Title: Erratum: "Magnetic Flux Loss and Flux Transport in a Decaying
Active Region" (ApJ, 686, 1447 [2008])
Authors: Kubo, M.; Lites, B. W.; Shimizu, T.; Ichimoto, K.
Bibcode: 2008ApJ...689.1456K
Altcode:
No abstract at ADS
Title: The Magnetic Landscape of the Sun's Polar Region
Authors: Tsuneta, S.; Ichimoto, K.; Katsukawa, Y.; Lites, B. W.;
Matsuzaki, K.; Nagata, S.; Orozco Suárez, D.; Shimizu, T.; Shimojo,
M.; Shine, R. A.; Suematsu, Y.; Suzuki, T. K.; Tarbell, T. D.; Title,
A. M.
Bibcode: 2008ApJ...688.1374T
Altcode: 2008arXiv0807.4631T
We present observations of the magnetic landscape of the polar region
of the Sun that are unprecedented in terms of spatial resolution,
field of view, and polarimetric precision. They were carried out with
the Solar Optical Telescope aboard Hinode. Using a Milne-Eddington
inversion, we find many vertically oriented magnetic flux tubes
with field strengths as strong as 1 kG scattered in latitude between
70° and 90°. They all have the same polarity, consistent with the
global polarity of the polar region. The field vectors are observed to
diverge from the centers of the flux elements, consistent with a view
of magnetic fields that are expanding and fanning out with height. The
polar region is also found to have ubiquitous horizontal fields. The
polar regions are the source of the fast solar wind, which is channeled
along unipolar coronal magnetic fields whose photospheric source is
evidently rooted in the strong-field, vertical patches of flux. We
conjecture that vertical flux tubes with large expansion around the
photospheric-coronal boundary serve as efficient chimneys for Alfvén
waves that accelerate the solar wind.
Title: Three-dimensional instability of spontaneous fast magnetic
reconnection
Authors: Shimizu, T.; Kondo, K.; Ugai, M.
Bibcode: 2008AGUFMSM21B..06S
Altcode:
MHD numerical study for spontaneous fast magnetic reconnection is
presented. As well-known in two- dimensional numerical MHD studies,
if a current-driven anomalous resistivity is assumed, one-dimensional
current sheet is destabilized by a resistive perturbation, resulting in
two-dimensional fast magnetic reconnection. In this paper, it is shown
that such a two-dimensional fast magnetic reconnection process can be
moreover destabilized by a three-dimensional resistive perturbation,
resulting in three-dimensional fast magnetic reconnection which is
strongly localized in sheet current direction. The three-dimensional
fast magnetic reconnection process intermittently and randomly ejects
three-dimensional plasmoids downstream. This numerical study is
applicable for magnetic reconnection problems in geo-magnetotail and
solar flares, in which three-dimensional plasmoids are intermittently
ejected from one-dimensional current sheet. It fact, this numerical
result is very similar to the intermittent downflow observed in solar
flares by TRACE"fs EUV instrument.
Title: The SOLAR-C mission
Authors: Shimizu, T.
Bibcode: 2008AGUFMSH52A..07S
Altcode:
Solar-physics community in Japan has so far developed 3 solar missions,
i.e., Hinotori, Yohkoh, and Hinode, over past 25 years. Japan has
started the conceptual studies for realizing the forth mission (SOLAR-C)
in the coming decade. Two mission concepts are now under study. Plan
A is to perform magnetic, helioseismic, and X-ray observations of
the solar polar regions from out of the ecliptic to investigate
properties of the polar region, magnetic and flow structures inside
the Sun down to the bottom of the convection zone. Plan B is to perform
high throughput, high cadence spectroscopic/polarimetric and EUV/X-ray
observations with high spatial resolution, focusing on chromosphere and
transition region as interface layer from the photosphere to corona, to
investigate magnetism of the Sun and its roles in heating and dynamics
of solar atmosphere. JAXA SOLAR-C working group, organized in ISAS of
JAXA with participation of japanese researchers, refines both plans,
compare science, technology, and other constraints, and will prioritize
the two plans. We recognize that success of Hinode and Yohkoh is due
to strong international collaborations. The working group hopes strong
international support for realizing the SOLAR-C mission and invites
US and European participation to the SOLAR-C program, following our
remarkable history of collaboration. International SOLAR-C science
definition meeting will be held this November at ISAS with participants
from US and European countries. This presentation will report on the
mission concept and current study status, including discussions in
the international Solar-C science definition meeting.
Title: White Light Flare Observations from the Solar Optical Telescope
onboard Hinode
Authors: Watanabe, K.; Shimizu, T.
Bibcode: 2008AGUFMSH41B1620W
Altcode:
In association with solar flares, we sometimes observe emission of white
light continuum, which is referred to as a "gwhite light flare"h. White
light flares are very infrequent, and the processes causing them are
still unclear. Since close correlations of white light and hard X-ray
emission were reported in many events (e.g. Hudson et al., 2006),
the mechanism seems to involve emission of white light by nonthermal
electron beams. The Solar Optical Telescope (SOT) is capable making
observations in white light. We used SOT G-band observations to search
for white-light flare counterparts to flares of GOES X-ray class C and
higher. Among 155 solar flares over the first two years of the Hinode
mission, we found eight white-light flare events. The white-light
events tended to occur in larger events, however two occurred in
C-class flares. The white light emission was located inside the
flare ribbon emission, where the ribbons were observed in SOT Ca II
H images. The amount of white-light emission is correlated with the
emission in GOES soft X-rays and RHESSI hard X-rays. The location of
the white light emission is located at almost the same place as the
hard X-ray emission. However, just a weak correlation was seen between
white light emission and magnetic field strength observed by the SOT
Spectro Polarimeter. We consider these observations in terms of hard
X-ray production and particle acceleration scenarios.
Title: Magnetic Flux Loss and Flux Transport in a Decaying Active
Region
Authors: Kubo, M.; Lites, B. W.; Shimizu, T.; Ichimoto, K.
Bibcode: 2008ApJ...686.1447K
Altcode: 2008arXiv0807.4340K
We estimate the temporal change of magnetic flux normal to the solar
surface in a decaying active region by using a time series of the
spatial distribution of vector magnetic fields in the photosphere. The
vector magnetic fields are derived from full spectropolarimetric
measurements with the Solar Optical Telescope aboard Hinode. We compare
a magnetic flux loss rate to a flux transport rate in a decaying sunspot
and its surrounding moat region. The amount of magnetic flux that
decreases in the sunspot and moat region is very similar to magnetic
flux transported to the outer boundary of the moat region. The flux
loss rates [(dF/dt)loss] of magnetic elements with positive
and negative polarities balance each other around the outer boundary of
the moat region. These results suggest that most of the magnetic flux
in the sunspot is transported to the outer boundary of the moat region
as moving magnetic features, and then removed from the photosphere by
flux cancellation around the outer boundary of the moat region.
Title: Magnetic Fields of the Quiet Sun: A New Quantitative
Perspective From Hinode
Authors: Lites, B. W.; Kubo, M.; Socas-Navarro, H.; Berger, T.; Frank,
Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Katsukawa, Y.;
Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2008ASPC..397...17L
Altcode:
This article summarizes results of studies presented in two papers
already published: Lites et al. (2007a); Lites et al. (2007b). Please
see these for further details.
Title: On-orbit Performance of the Solar Optical Telescope aboard
Hinode
Authors: Ichimoto, K.; Katsukawa, Y.; Tarbell, T.; Shine, R. A.;
Hoffmann, C.; Berger, T.; Cruz, T.; Suematsu, Y.; Tsuneta, S.; Shimizu,
T.; Lites, B. W.
Bibcode: 2008ASPC..397....5I
Altcode: 2008arXiv0804.3248I
On-orbit performance of the Solar Optical Telescope (SOT) aboard Hinode
is described with some attention to its unpredicted aspects. In general,
SOT reveals an excellent performance and has been providing outstanding
data. Some unexpected features exist, however, in behaviours of the
focus position, throughput and structural stability. Most of them are
recovered by the daily operation i.e., frequent focus adjustment,
careful heater setting and corrections in data analysis. The
tunable filter contains air bubbles which degrade the data quality
significantly. Schemes for tuning the filter without disturbing the
bubbles have been developed and tested, and some useful procedures
to obtain Dopplergrams and magnetograms are now available. October
and March, when the orbit of satellite becomes nearly perpendicular
to the direction towards the Sun, provide a favourable condition for
continuous runs of the narrow-band filter imager.
Title: High Resolution Observations of Spicules with Hinode/SOT
Authors: Suematsu, Y.; Ichimoto, K.; Katsukawa, Y.; Shimizu, T.;
Okamoto, T.; Tsuneta, S.; Tarbell, T.; Shine, R. A.
Bibcode: 2008ASPC..397...27S
Altcode:
High time cadence unprecedented images at the limb with Ca II H line
filtergraph from the Solar Optical Telescope (SOT) aboard Hinode
have revealed that a spicule consists of highly dynamic multi-threads
(typically twin) as thin as a few tenths of an arcsecond, and shows
prominent lateral movement or oscillation with rotation on its axis
during its life. This multi-thread structure and lateral motion indicate
that the spicules can be driven by magnetic reconnection at unresolved
spatial scales at their footpoints.
Title: Evolution of Magnetic Fields at the Boundary of the Penumbra
Authors: Kubo, M.; Ichimoto, K.; Shimizu, T.; Lites, B. W.; Tsuneta,
S.; Suematsu, Y.; Katsukawa, Y.; Nagata, S.; Tarbell, T.; Shine,
R. A.; Title, A. M.
Bibcode: 2008ASPC..397...79K
Altcode:
The formation of moving magnetic features (MMFs) separating from the
penumbra were successfully observed with the Solar Optical Telescope
(SOT) aboard the Hinode satellite. We find that bright features in
the outer penumbra are located at the penumbral spines, which have
magnetic fields more vertical than the surroundings, or located at the
MMFs separating from the spines. This suggests that convection in the
outer penumbra is related to the disintegration of the sunspot.
Title: Erratum: The Analysis of Penumbral Fine Structure Using an
Advanced Inversion Technique
Authors: Jurcák, Jan; Bellot Rubio, Luis; Ichimoto, Kiyoshi;
Katsukawa, Yukio; Lites, Bruce; Nagata, Shin'ichi; Shimizu, Toshifumi;
Suematsu, Yoshinori; Tarbell, Theodore D.; Title, Alan M.; Tsuneta,
Saku
Bibcode: 2008PASJ...60..933J
Altcode:
In the article [PASJ 59, S601-S606 (2007)], the word ''CSIC'' was
omitted from the affiliation of Dr. Luis Bellot Rubio. The correct
affiliation is : 2Instituto de Astrofísica de Andalucía
(CSIC), Apdo. de Correos 3004, 18080 Granada, Spain
Title: Vertical Temperature Structures of the Solar Corona Derived
with the Hinode X-Ray Telescope
Authors: Kano, Ryouhei; Sakao, Taro; Narukage, Noriyuki; Tsuneta,
Saku; Kotoku, Jun'ichi; Bando, Takamasa; Deluca, Edward; Lundquist,
Loraine; Golub, Leon; Hara, Hirohisa; Matsuzaki, Keiichi; Shimojo,
Masumi; Shibasaki, Kiyoto; Shimizu, Toshifumi; Nakatani, Ichiro
Bibcode: 2008PASJ...60..827K
Altcode:
We obtained temperature structures in faint coronal features
above and near the solar limb with the X-Ray Telescope aboard the
Hinode satellite by accurately correcting the scattered X-rays
from surrounding bright regions with occulted images during
the solar eclipses. Our analysis yields a polar coronal hole
temperature of about 1.0MK and an emission measure in the range of
1025.5-1026.0cm-5. In addition,
our methods allow us to measure the temperature and emission
measure of two distinct quiet-Sun structures: radial (plume-like)
structures near the boundary of the coronal-hole and diffuse quiet
Sun regions at mid-latitudes. The radial structures appear to have
increasing temperature with height during the first 100Mm, and
constant temperatures above 100Mm. For the diffuse quiet-Sun region
the temperatures are the highest just above the limb, and appear
to decrease with height. These differences may be due to different
magnetic configurations.
Title: Frequent Occurrence of High-Speed Local Mass Downflows on
the Solar Surface
Authors: Shimizu, Toshifumi
Bibcode: 2008AstHe.101..414S
Altcode:
New spectro-polarimetric measurements have been carried out with the
Solar Optical Telescope onboard the Hinode satellite, revealing the
frequent appearance of polarization signals indicating high-speed,
probably supersonic, downflows that are associated with at least
three different configurations of magnetic fields in the solar
photosphere. The excitation of supersonic mass flows are one of the
key observational features of the dynamical evolution occurring in
magnetic-field fine structures on the solar surface. Furthermore,
understanding the origins of observed supersonic flows may help to
understand complicated interactions between plasma flows and magnetic
fields in the astrophysical plasma.
Title: Disintegration of Magnetic Flux in Decaying Sunspots as
Observed with the Hinode SOT
Authors: Kubo, M.; Lites, B. W.; Ichimoto, K.; Shimizu, T.; Suematsu,
Y.; Katsukawa, Y.; Tarbell, T. D.; Shine, R. A.; Title, A. M.; Nagata,
S.; Tsuneta, S.
Bibcode: 2008ApJ...681.1677K
Altcode: 2008arXiv0806.0415K
Continuous observations of sunspot penumbrae with the Solar Optical
Telescope aboard Hinode clearly show that the outer boundary of the
penumbra fluctuates around its averaged position. The penumbral outer
boundary moves inward when granules appear in the outer penumbra. We
discover that such granules appear one after another while moving
magnetic features (MMFs) are separating from the penumbral "spines"
(penumbral features that have fields that are stronger and more vertical
than those of their surroundings). These granules that appear in the
outer penumbra often merge with bright features inside the penumbra
that move with the spines as they elongate toward the moat region. This
suggests that convective motions around the penumbral outer boundary are
related to the disintegration of magnetic flux in the sunspot. We also
find that dark penumbral filaments frequently elongate into the moat
region in the vicinity of MMFs that detach from penumbral spines. Such
elongating dark penumbral filaments correspond to nearly horizontal
fields extending from the penumbra. Pairs of MMFs with positive and
negative polarities are sometimes observed along the elongating dark
penumbral filaments. This strongly supports the notion that such
elongating dark penumbral filaments have magnetic fields with a "sea
serpent"-like structure. Evershed flows, which are associated with the
penumbral horizontal fields, may be related to the detachment of the
MMFs from the penumbral spines, as well as to the formation of the MMFs
along the dark penumbral filaments that elongate into the moat region.
Title: Polarization Calibration of the Solar Optical Telescope
onboard Hinode
Authors: Ichimoto, K.; Lites, B.; Elmore, D.; Suematsu, Y.; Tsuneta,
S.; Katsukawa, Y.; Shimizu, T.; Shine, R.; Tarbell, T.; Title, A.;
Kiyohara, J.; Shinoda, K.; Card, G.; Lecinski, A.; Streander, K.;
Nakagiri, M.; Miyashita, M.; Noguchi, M.; Hoffmann, C.; Cruz, T.
Bibcode: 2008SoPh..249..233I
Altcode: 2008SoPh..tmp...69I
The Solar Optical Telescope (SOT) onboard Hinode aims to obtain vector
magnetic fields on the Sun through precise spectropolarimetry of
solar spectral lines with a spatial resolution of 0.2 - 0.3 arcsec. A
photometric accuracy of 10−3 is achieved and, after the
polarization calibration, any artificial polarization from crosstalk
among Stokes parameters is required to be suppressed below the level
of the statistical noise over the SOT's field of view. This goal was
achieved by the highly optimized design of the SOT as a polarimeter,
extensive analyses and testing of optical elements, and an end-to-end
calibration test of the entire system. In this paper we review both
the approach adopted to realize the high-precision polarimeter of the
SOT and its final polarization characteristics.
Title: Image Stabilization System for Hinode (Solar-B) Solar Optical
Telescope
Authors: Shimizu, T.; Nagata, S.; Tsuneta, S.; Tarbell, T.; Edwards,
C.; Shine, R.; Hoffmann, C.; Thomas, E.; Sour, S.; Rehse, R.; Ito,
O.; Kashiwagi, Y.; Tabata, M.; Kodeki, K.; Nagase, M.; Matsuzaki,
K.; Kobayashi, K.; Ichimoto, K.; Suematsu, Y.
Bibcode: 2008SoPh..249..221S
Altcode:
The Hinode Solar Optical Telescope (SOT) is the first space-borne
visible-light telescope that enables us to observe magnetic-field
dynamics in the solar lower atmosphere with 0.2 - 0.3 arcsec spatial
resolution under extremely stable (seeing-free) conditions. To achieve
precise measurements of the polarization with diffraction-limited
images, stable pointing of the telescope (<0.09 arcsec, 3σ) is
required for solar images exposed on the focal plane CCD detectors. SOT
has an image stabilization system that uses image displacements
calculated from correlation tracking of solar granules to control
a piezo-driven tip-tilt mirror. The system minimizes the motions
of images for frequencies lower than 14 Hz while the satellite and
telescope structural design damps microvibration in higher frequency
ranges. It has been confirmed from the data taken on orbit that
the remaining jitter is less than 0.03 arcsec (3σ) on the Sun. This
excellent performance makes a major contribution to successful precise
polarimetric measurements with 0.2 - 0.3 arcsec resolution.
Title: The Solar Optical Telescope for the Hinode Mission: An Overview
Authors: Tsuneta, S.; Ichimoto, K.; Katsukawa, Y.; Nagata, S.; Otsubo,
M.; Shimizu, T.; Suematsu, Y.; Nakagiri, M.; Noguchi, M.; Tarbell,
T.; Title, A.; Shine, R.; Rosenberg, W.; Hoffmann, C.; Jurcevich,
B.; Kushner, G.; Levay, M.; Lites, B.; Elmore, D.; Matsushita, T.;
Kawaguchi, N.; Saito, H.; Mikami, I.; Hill, L. D.; Owens, J. K.
Bibcode: 2008SoPh..249..167T
Altcode: 2008SoPh..tmp...74T; 2007arXiv0711.1715T
The Solar Optical Telescope (SOT) aboard the Hinode satellite
(formerly called Solar-B) consists of the Optical Telescope Assembly
(OTA) and the Focal Plane Package (FPP). The OTA is a 50-cm
diffraction-limited Gregorian telescope, and the FPP includes the
narrowband filtergraph (NFI) and the broadband filtergraph (BFI), plus
the Stokes Spectro-Polarimeter (SP). The SOT provides unprecedented
high-resolution photometric and vector magnetic images of the
photosphere and chromosphere with a very stable point spread function
and is equipped with an image-stabilization system with performance
better than 0.01 arcsec rms. Together with the other two instruments
on Hinode (the X-Ray Telescope (XRT) and the EUV Imaging Spectrometer
(EIS)), the SOT is poised to address many fundamental questions about
solar magnetohydrodynamics. This paper provides an overview; the
details of the instrument are presented in a series of companion papers.
Title: Frequent Occurrence of High-Speed Local Mass Downflows on
the Solar Surface
Authors: Shimizu, T.; Lites, B. W.; Katsukawa, Y.; Ichimoto, K.;
Suematsu, Y.; Tsuneta, S.; Nagata, S.; Kubo, M.; Shine, R. A.; Tarbell,
T. D.
Bibcode: 2008ApJ...680.1467S
Altcode: 2008arXiv0804.1167S
We report on new spectropolarimetric measurements with simultaneous
filter imaging observation, revealing the frequent appearance of
polarization signals indicating high-speed, probably supersonic,
downflows that are associated with at least three different
configurations of magnetic fields in the solar photosphere. The
observations were carried out with the Solar Optical Telescope on
board the Hinode satellite. High-speed downflows are excited when a
moving magnetic feature is newly formed near the penumbral boundary of
sunspots. Also, a new type of downflows is identified at the edge of
sunspot umbra that lack accompanying penumbral structures. These may
be triggered by the interaction of magnetic fields swept by convection
with well-concentrated magnetic flux. Another class of high-speed
downflows are observed in quiet Sun and sunspot moat regions. These are
closely related to the formation of small concentrated magnetic flux
patches. High-speed downflows of all types are transient time-dependent
mass motions. These findings suggest that the excitation of supersonic
mass flows are one of the key observational features of the dynamical
evolution occurring in magnetic-field fine structures on the solar
surface.
Title: Cooperative Observation of Ellerman Bombs between the Solar
Optical Telescope aboard Hinode and Hida/Domeless Solar Telescope
Authors: Matsumoto, Takuma; Kitai, Reizaburo; Shibata, Kazunari;
Nagata, Shin'ichi; Otsuji, Kenichi; Nakamura, Tahei; Watanabe, Hiroko;
Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto, Kiyoshi; Shimizu,
Toshifumi; Katsukawa, Yukio; Tarbell, Theodore D.; Lites, Bruce W.;
Shine, Richard A.; Title, Alan M.
Bibcode: 2008PASJ...60..577M
Altcode:
High-resolution CaIIH broad-band filter images of NOAA10933 on 2007
January 5 were obtained by the Solar Optical Telescope aboard the Hinode
satellite. Many small-scale (∼1") bright points were observed outside
the sunspot and inside the emerging flux region. We identified some of
these bright points with Ellerman bombs (EBs) by using Hα images taken
by the Domeless Solar Telescope at Hida observatory. The sub-arcsec
structures of two EBs seen in CaIIH were studied in detail. Our
observation showed the following two aspects: (1) The CaIIH bright
points identified with EBs were associated with the bipolar magnetic
field structures, as reported by previous studies. (2)The structure
of the CaIIH bright points turned out to consist of the following two
parts: a central elongated bright core (0.7" × 0.5") located along
the magnetic neutral line and a diffuse halo (1.2"×1.8").
Title: The Solar Optical Telescope of Solar-B ( Hinode): The Optical
Telescope Assembly
Authors: Suematsu, Y.; Tsuneta, S.; Ichimoto, K.; Shimizu, T.; Otsubo,
M.; Katsukawa, Y.; Nakagiri, M.; Noguchi, M.; Tamura, T.; Kato, Y.;
Hara, H.; Kubo, M.; Mikami, I.; Saito, H.; Matsushita, T.; Kawaguchi,
N.; Nakaoji, T.; Nagae, K.; Shimada, S.; Takeyama, N.; Yamamuro, T.
Bibcode: 2008SoPh..249..197S
Altcode: 2008SoPh..tmp...26S
The Solar Optical Telescope (SOT) aboard the Solar-B satellite (Hinode)
is designed to perform high-precision photometric and polarimetric
observations of the Sun in visible light spectra (388 - 668 nm)
with a spatial resolution of 0.2 - 0.3 arcsec. The SOT consists of
two optically separable components: the Optical Telescope Assembly
(OTA), consisting of a 50-cm aperture Gregorian with a collimating lens
unit and an active tip-tilt mirror, and an accompanying Focal Plane
Package (FPP), housing two filtergraphs and a spectro-polarimeter. The
optomechanical and optothermal performance of the OTA is crucial to
attain unprecedented high-quality solar observations. We describe in
detail the instrument design and expected stable diffraction-limited
on-orbit performance of the OTA, the largest state-of-the-art solar
telescope yet flown in space.
Title: The Analysis of Hinode/XRT Observations
Authors: Deluca, E. E.; Weber, M.; Savcheva, A.; Saar, S.; Testa,
P.; Cirtain, J. W.; Sakao, T.; Noriyuki, N.; Kano, R.; Shimizu, T.
Bibcode: 2008AGUSMSP51B..02D
Altcode:
This poster will present the current state of Hinode/XRT analysis
software. We will give an overview of the XRT Analysis Guide. We will
include a detailed discussion of the following topics: Co-alignment
with SOT and EIS Spot removal for dynamics studies Filter calibration
for thermal studies Dark calibrations Sample data sets will be
discussed and links to the data products will be provided.
Title: Emergence of a helical flux rope and prominence formation
Authors: Okamoto, T. J.; Tsuneta, S.; Lites, B. W.; Kubo, M.; Yokoyama,
T.; Berger, T. E.; Ichimoto, K.; Katsukawa, Y.; Nagata, S.; Shibata,
K.; Shimizu, T.; Shine, R. A.; Suematsu, Y.; Tarbell, T. D.; Title,
A. M.
Bibcode: 2008AGUSMSP43B..06O
Altcode:
We report a discovery about emergence of a helical flux rope. The
episode may be related to the formation and evolution of an active
region prominence. Statistical studies by previous authors indicate that
numerous prominences have the inverse-polarity configuration suggesting
the helical magnetic configurations. There are two theoretical
models about formation of such a coronal helical magnetic field in
association with prominences: flux rope model and sheared-arcade
model. We have so far no clear observational evidence to support
either model. In order to find a clue about the formation of the
prominence, we had continuous observations of NOAA AR 10953 with the
SOT during 2007 April 28 to May 9. A prominence was located over the
polarity inversion line in the south-east of the main sunspot. These
observations provided us with a time series of vector magnetic fields
on the photosphere under the prominence. We found four new features:
(1) The abutting opposite-polarity regions on the two sides along
the polarity inversion line first grew laterally in size and then
narrowed. (2) These abutting regions contained vertically-weak,
but horizontally-strong magnetic fields. (3) The orientations of
the horizontal magnetic fields along the polarity inversion line on
the photosphere gradually changed with time from a normal- polarity
configuration to an inverse-polarity one. (4) The horizontal-magnetic
field region was blueshifted. These indicate that helical flux rope
emerges from below the photosphere into the corona along the polarity
inversion line under the prominence. We suggest that this supply of a
helical magnetic flux possibly into the corona is related to formation
and maintenance of active-region prominences.
Title: Photospheric Signature of Penumbral Microjets
Authors: Katsukawa, Y.; Jurcak, J.; Ichimoto, K.; Suemtasu, Y.;
Tsuneta, S.; Shimizu, T.; Berger, T. E.; Shine, R. A.; Tarbell, T. D.;
Lites, B. W.
Bibcode: 2008AGUSMSP53A..03K
Altcode:
HINODE Solar Optical Telescope (SOT) discovered ubiquitous occurrence
of fine-scale jetlike activities in penumbral chromospheres, which
are referred to as penumbral microjets. The microjets' small width
of 400 km and short duration of less than 1 min make them difficult
to identify in existing ground-based observations. The apparent
rise velocity is faster than 50km/s and is roughly comparable to
the Alfven speed in the sunspot chromosphere. These properties of
penumbral microjets suggest that magnetic reconnection in uncombed
magnetic field configuration is the most possible cause of penumbral
microjets. In order to understand magnetic configuration associated with
penumbral microjets and prove the chromospheric magnetic reconnection
hypothesis, we investigated relationship between penumbral microjets
seen in CaIIH images and photospheric magnetic fields measured by
the HINODE spectro-polarimeter. We found the inclination angles of
penumbral microjets measured in CaII H images are roughly consistent
with inclination angles of relatively vertical magnetic field
component in uncombed magnetic field configuration. In addition,
strong and transient downflows are observed in the photosphere near
the boundary of a horizontal flux tube associated with a penumbral
microjet. The size of the downflow region is about 300km, which is
close to the width of penumbral microjets seen in CaII H images. The
downflow velocity of several km/s might be a result of an outflow of
chromospheric magnetic reconnection and suffer deceleration due to
the higher density in the photosphere.
Title: Disintegration of Magnetic Flux in Decaying Sunspots as
Observed with the Hinode/SOT
Authors: Kubo, M.; Lites, B. W.; Ichimoto, K.; Shimizu, T.; Suematsu,
Y.; Katsukawa, Y.; Tarbell, T. D.; Shine, R. A.; Title, A. M.; Nagata,
S.; Tsuneta, S.
Bibcode: 2008AGUSMSP31B..01K
Altcode:
Continuous observations of sunspot penumbrae with the Solar Optical
Telescope aboard Hinode clearly show that the outer boundary of the
penumbra fluctuates around its averaged position. The penumbral outer
boundary moves inward when granules appear in the outer penumbra. We
discover that such granules appear one after another while moving
magnetic features (MMFs) are separating from the penumbral "spines"
(penumbral features having fields that are stronger and more vertical
than their surroundings). These granules that appear in the outer
penumbra often merge with bright features inside the penumbra that move
with spines as they elongate toward the moat region. This suggests that
convective motions around the penumbral outer boundary are related to
disintegration of magnetic flux in the sunspot. We also find that dark
penumbral filaments frequently elongate into the moat region in the
vicinity of MMFs that detach from penumbral spines. Such elongating
dark penumbral filaments correspond to nearly horizontal fields
extending from the penumbra. Pairs of MMFs with positive and negative
polarities are sometimes observed along the elongating dark penumbral
filaments. This strongly supports the notion that such elongating dark
penumbral filaments have magnetic fields with a "sea serpent"-like
structure. Evershed flows, which are associated with the penumbral
horizontal fields, may be related to detachment of the MMFs from the
penumbral spines, as well as to the formation of the MMFs along the
dark penumbral filaments that elongate into the moat region.
Title: Formation of Solar Magnetic Flux Tubes with Kilogauss Field
Strength Induced by Convective Instability
Authors: Nagata, Shin'ichi; Tsuneta, Saku; Suematsu, Yoshinori;
Ichimoto, Kiyoshi; Katsukawa, Yukio; Shimizu, Toshifumi; Yokoyama,
Takaaki; Tarbell, Theodore D.; Lites, Bruce W.; Shine, Richard A.;
Berger, Thomas E.; Title, Alan M.; Bellot Rubio, Luis R.; Orozco
Suárez, David
Bibcode: 2008ApJ...677L.145N
Altcode:
Convective instability has been a mechanism used to explain
the formation of solar photospheric flux tubes with kG field
strength. However, the turbulence of the Earth's atmosphere has
prevented ground-based observers from examining the hypothesis
with precise polarimetric measurement on the subarcsecond scale
flux tubes. Here we discuss observational evidence of this scenario
based on observations with the Solar Optical Telescope (SOT) aboard
Hinode. The cooling of an equipartition field strength flux tube
precedes a transient downflow reaching 6 km s-1 and the
intensification of the field strength to 2 kG. These observations
agree very well with the theoretical predictions.
Title: Transient horizontal magnetic fields in solar plage regions
Authors: Ishikawa, R.; Tsuneta, S.; Ichimoto, K.; Isobe, H.; Katsukawa,
Y.; Lites, B. W.; Nagata, S.; Shimizu, T.; Shine, R. A.; Suematsu,
Y.; Tarbell, T. D.; Title, A. M.
Bibcode: 2008A&A...481L..25I
Altcode: 2008arXiv0802.1769I
Aims:We report the discovery of isolated, small-scale emerging
magnetic fields in a plage region with the Solar Optical Telescope
aboard Hinode.
Methods: Spectro-polarimetric observations were
carried out with a cadence of 34 s for the plage region located near
disc center. The vector magnetic fields are inferred by Milne-Eddington
inversion.
Results: The observations reveal widespread occurrence
of transient, spatially isolated horizontal magnetic fields. The
lateral extent of the horizontal magnetic fields is comparable to
the size of photospheric granules. These horizontal magnetic fields
seem to be tossed about by upflows and downflows of the granular
convection. We also report an event that appears to be driven by the
magnetic buoyancy instability. We refer to buoyancy-driven emergence
as type 1 and convection-driven emergence as type 2. Although both
events have magnetic field strengths of about 600 G, the filling
factor of type 1 is a factor of two larger than that of type 2.
Conclusions: Our finding suggests that the granular convection in
the plage regions is characterized by a high rate of occurrence of
granular-sized transient horizontal fields.
Title: Net circular polarization of sunspots in high spatial
resolution
Authors: Ichimoto, K.; Tsuneta, S.; Suematsu, Y.; Katsukawa, Y.;
Shimizu, T.; Lites, B. W.; Kubo, M.; Tarbell, T. D.; Shine, R. A.;
Title, A. M.; Nagata, S.
Bibcode: 2008A&A...481L...9I
Altcode:
Context: Net circular polarization (NCP) of spectral lines in
sunspots has been most successfully explained by the presense of
discontinuities in the magnetic field inclination and flow velocity
along the line-of-sight in the geometry of the embedded flux tube model
of penumbrae (Δγ-effect).
Aims: The fine scale structure of
NCP in a sunspot is examined with special attention paid to spatial
relations of the Evershed flow to confirm the validity of the present
interpretation of the NCP of sunspots.
Methods: High resolution
spectro-polarimetric data of a positive-polarity sunspot obtained
by the Solar Optical Telescope aboard Hinode are analysed.
Results: A positive NCP is associated with the Evershed flow
channels in both limb-side and disk center-side penumbrae and with
upflows in the penumbra at disk center. The negative NCP in the disk
center-side penumbra is generated in inter-Evershed flow channels.
Conclusions: The first result is apparently inconsistent with the
current explanation of NCP with the Δγ-effect but rather suggests a
positive correlation between the magnetic field strength and the flow
velocity as the cause of the NCP. The second result serves as strong
evidence for the presence of gas flows in inter-Evershed flow channels.
Title: Hinode SOT Observations of Solar Quiescent Prominence Dynamics
Authors: Berger, Thomas E.; Shine, Richard A.; Slater, Gregory L.;
Tarbell, Theodore D.; Title, Alan M.; Okamoto, Takenori J.; Ichimoto,
Kiyoshi; Katsukawa, Yukio; Suematsu, Yoshinori; Tsuneta, Saku; Lites,
Bruce W.; Shimizu, Toshifumi
Bibcode: 2008ApJ...676L..89B
Altcode:
We report findings from multihour 0.2'' resolution movies of
solar quiescent prominences (QPs) observed with the Solar Optical
Telescope (SOT) on the Hinode satellite. The observations verify
previous findings of filamentary downflows and vortices in QPs. SOT
observations also verify large-scale transverse oscillations in QPs,
with periods of 20-40 minutes and amplitudes of 2-5 Mm. The upward
propagation speed of several waves is found to be ~10 km s-1,
comparable to the sound speed of a 10,000 K plasma, implying that
the waves are magnetoacoustic in origin. Most significantly, Hinode
SOT observations reveal that dark, episodic upflows are common in
QPs. The upflows are 170-700 km in width, exhibit turbulent flow,
and rise with approximately constant speeds of ~20 km s-1
from the base of the prominence to heights of ~10-20 Mm. The upflows
are visible in both the Ca II H-line and Hα bandpasses of SOT. The new
flows are seen in about half of the QPs observed by SOT to date. The
dark upflows resemble buoyant starting plumes in both their velocity
profile and flow structure. We discuss thermal and magnetic mechanisms
as possible causes of the plumes.
Title: Emergence of a Helical Flux Rope under an Active Region
Prominence
Authors: Okamoto, Takenori J.; Tsuneta, Saku; Lites, Bruce W.; Kubo,
Masahito; Yokoyama, Takaaki; Berger, Thomas E.; Ichimoto, Kiyoshi;
Katsukawa, Yukio; Nagata, Shin'ichi; Shibata, Kazunari; Shimizu,
Toshifumi; Shine, Richard A.; Suematsu, Yoshinori; Tarbell, Theodore
D.; Title, Alan M.
Bibcode: 2008ApJ...673L.215O
Altcode: 2008arXiv0801.1956O
Continuous observations were obtained of NOAA AR 10953 with the Solar
Optical Telescope (SOT) on board the Hinode satellite from 2007 April
28 to May 9. A prominence was located over the polarity inversion
line (PIL) to the southeast of the main sunspot. These observations
provided us with a time series of vector magnetic fields on the
photosphere under the prominence. We found four features: (1) The
abutting opposite-polarity regions on the two sides along the PIL first
grew laterally in size and then narrowed. (2) These abutting regions
contained vertically weak but horizontally strong magnetic fields. (3)
The orientations of the horizontal magnetic fields along the PIL on
the photosphere gradually changed with time from a normal-polarity
configuration to an inverse-polarity one. (4) The horizontal magnetic
field region was blueshifted. These indicate that helical flux rope
was emerging from below the photosphere into the corona along the PIL
under the preexisting prominence. We suggest that this supply of a
helical magnetic flux to the corona is associated with evolution and
maintenance of active region prominences.
Title: The Horizontal Magnetic Flux of the Quiet-Sun Internetwork
as Observed with the Hinode Spectro-Polarimeter
Authors: Lites, B. W.; Kubo, M.; Socas-Navarro, H.; Berger, T.; Frank,
Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Katsukawa, Y.;
Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2008ApJ...672.1237L
Altcode:
Observations of very quiet Sun using the Solar Optical
Telescope/Spectro-Polarimeter (SOT/SP) aboard the Hinode spacecraft
reveal that the quiet internetwork regions are pervaded by horizontal
magnetic flux. The spatial average horizontal apparent flux density
derived from wavelength-integrated measures of Zeeman-induced linear
polarization is BTapp = 55 Mx cm -2, as
compared to the corresponding average vertical apparent flux density of
| BLapp| = 11 Mx cm -2. Distributions
of apparent flux density are presented. Magnetic fields are organized on
mesogranular scales, with both horizontal and vertical fields showing
"voids" of reduced flux density of a few granules spatial extent. The
vertical fields are concentrated in the intergranular lanes, whereas the
stronger horizontal fields are somewhat separated spatially from the
vertical fields and occur most commonly at the edges of the bright
granules. High-S/N observations from disk center to the limb help
to constrain possible causes of the apparent imbalance between |
BLapp| and BTapp, with
unresolved structures of linear dimension on the surface smaller by at
least a factor of 2 relative to the SOT/SP angular resolution being one
likely cause of this discrepancy. Other scenarios for explaining this
imbalance are discussed. The horizontal fields are likely the source of
the "seething" fields of the quiet Sun discovered by Harvey et al. The
horizontal fields may also contribute to the "hidden" turbulent flux
suggested by studies involving Hanle effect depolarization of scattered
radiation.
Title: Hinode Observations of Flux Emergence in Quiet and Active
Regions
Authors: Lites, B. W.; Centeno, R.; Kubo, M.; Socas-Navarro, H. Berger,
T.; Frank, Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.;
Katsukawa, Y.; Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2008ASPC..383...71L
Altcode:
We review briefly the observational understanding of emergence of
flux in both the quiet Sun and active regions in the light of first
results from the joint Japan/US/UK Hinode mission. That spacecraft
is now providing us with our first continuous, high resolution
measurements of the photospheric vector magnetic field, along with
high resolution observations of the thermal and dynamic properties
of the chromosphere and corona. This review is intended to present a
few very early results and to highlight the potential for discovery
offered by this extraordinary new mission. The discovery of ubiquitous
horizontal magnetic flux in the quiet internetwork regions is presented.
Title: Mangetic field properties at the footpoints of solar
microflares (active-region transient brightenings)
Authors: Shimizu, T.; Kano, R.; Katsukawa, Y.; Kubo, M.; Deluca, E.;
Ichimoto, K.; Lites, B.; Nagata, S.; Sakao, T.; Shine, R.; Suematsu,
Y.; Tarbell, T.; Title, A.; Tsuneta, S.
Bibcode: 2007AGUFMSH52C..06S
Altcode:
Solar active regions produce numerous numbers of small-scale explosive
energy releases, i.e., microflares, which are captured by imaging
observations in soft X-rays as transient brightenings of small-scale
coronal loops. Thanks to advanced performance of X-Ray Telescope (XRT)
onboard the Hinode satellite, we can investigate finer structure
of the brightening X-ray sources in more details than we did with
Yohkoh data. One of important questions on microflares is what causes
microflares. The simultaneous visible-light observations by the Solar
Optical Telescope (SOT) allow us to explore magnetic activities
and magnetic field configuration at the photospheric footpoints
of brightening loops, giving key observations to investigate the
question. For our investigations of corona-photosphere magnetic
coupling, we have established co-alignment between SOT and XRT
with accuracy better than 1 arcsec (Shimizu et al. 2007, PASJ in
press). It turns out that Ca II H observations are very useful
to identify the exact positions of footpoints of X-ray transient
brightening loops. Small "Kernels" are sometimes observed in Ca II H
and they may be signature of highly accelerated non-thermal particles
impinging on chromosphere. As already shown in Shimizu et al.(2002),
frequent transient brightenings are observed at the locations where
emerging activities are on going. However, another type of brightening
triggering mechanism should exist to explain some observed multiple-loop
brightenings. In the multiple-loop brightenings, multiple loops are
magnetically in parallel with each other and no apparent magnetic
activities, such as emerging and canceling, are observed at and near
the footpoints. This paper will present SOT observations of some
microflares observed with XRT.
Title: Small-Scale Jetlike Features in Penumbral Chromospheres
Authors: Katsukawa, Y.; Berger, T. E.; Ichimoto, K.; Lites, B. W.;
Nagata, S.; Shimizu, T.; Shine, R. A.; Suematsu, Y.; Tarbell, T. D.;
Title, A. M.; Tsuneta, S.
Bibcode: 2007Sci...318.1594K
Altcode:
We observed fine-scale jetlike features, referred to as penumbral
microjets, in chromospheres of sunspot penumbrae. The microjets
were identified in image sequences of a sunspot taken through a Ca II
H-line filter on the Solar Optical Telescope on board the Japanese solar
physics satellite Hinode. The microjets’ small width of 400 kilometers
and short duration of less than 1 minute make them difficult to identify
in existing observations. The microjets are possibly caused by magnetic
reconnection in the complex magnetic configuration in penumbrae and
have the potential to heat the corona above a sunspot.
Title: Chromospheric Alfvénic Waves Strong Enough to Power the
Solar Wind
Authors: De Pontieu, B.; McIntosh, S. W.; Carlsson, M.; Hansteen,
V. H.; Tarbell, T. D.; Schrijver, C. J.; Title, A. M.; Shine, R. A.;
Tsuneta, S.; Katsukawa, Y.; Ichimoto, K.; Suematsu, Y.; Shimizu, T.;
Nagata, S.
Bibcode: 2007Sci...318.1574D
Altcode:
Alfvén waves have been invoked as a possible mechanism for the heating
of the Sun's outer atmosphere, or corona, to millions of degrees and
for the acceleration of the solar wind to hundreds of kilometers per
second. However, Alfvén waves of sufficient strength have not been
unambiguously observed in the solar atmosphere. We used images of
high temporal and spatial resolution obtained with the Solar Optical
Telescope onboard the Japanese Hinode satellite to reveal that the
chromosphere, the region sandwiched between the solar surface and
the corona, is permeated by Alfvén waves with strong amplitudes on
the order of 10 to 25 kilometers per second and periods of 100 to
500 seconds. Estimates of the energy flux carried by these waves and
comparisons with advanced radiative magnetohydrodynamic simulations
indicate that such Alfvén waves are energetic enough to accelerate
the solar wind and possibly to heat the quiet corona.
Title: Chromospheric Anemone Jets as Evidence of Ubiquitous
Reconnection
Authors: Shibata, Kazunari; Nakamura, Tahei; Matsumoto, Takuma; Otsuji,
Kenichi; Okamoto, Takenori J.; Nishizuka, Naoto; Kawate, Tomoko;
Watanabe, Hiroko; Nagata, Shin'ichi; UeNo, Satoru; Kitai, Reizaburo;
Nozawa, Satoshi; Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto, Kiyoshi;
Shimizu, Toshifumi; Katsukawa, Yukio; Tarbell, Theodore D.; Berger,
Thomas E.; Lites, Bruce W.; Shine, Richard A.; Title, Alan M.
Bibcode: 2007Sci...318.1591S
Altcode: 2008arXiv0810.3974S
The heating of the solar chromosphere and corona is a long-standing
puzzle in solar physics. Hinode observations show the ubiquitous
presence of chromospheric anemone jets outside sunspots in active
regions. They are typically 3 to 7 arc seconds = 2000 to 5000 kilometers
long and 0.2 to 0.4 arc second = 150 to 300 kilometers wide, and their
velocity is 10 to 20 kilometers per second. These small jets have an
inverted Y-shape, similar to the shape of x-ray anemone jets in the
corona. These features imply that magnetic reconnection similar to that
in the corona is occurring at a much smaller spatial scale throughout
the chromosphere and suggest that the heating of the solar chromosphere
and corona may be related to small-scale ubiquitous reconnection.
Title: Twisting Motions of Sunspot Penumbral Filaments
Authors: Ichimoto, K.; Suematsu, Y.; Tsuneta, S.; Katsukawa, Y.;
Shimizu, T.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Lites, B. W.;
Kubo, M.; Nagata, S.
Bibcode: 2007Sci...318.1597I
Altcode:
The penumbra of a sunspot is composed of numerous thin, radially
extended, bright and dark filaments carrying outward gas flows
(the Evershed flow). Using high-resolution images obtained by the
Solar Optical Telescope aboard the solar physics satellite Hinode, we
discovered a number of penumbral bright filaments revealing twisting
motions about their axes. These twisting motions are observed only
in penumbrae located in the direction perpendicular to the symmetry
line connecting the sunspot center and the solar disk center, and
the direction of the twist (that is, lateral motions of intensity
fluctuation across filaments) is always from limb side to disk-center
side. Thus, the twisting feature is not an actual twist or turn of
filaments but a manifestation of dynamics of penumbral filaments with
three-dimensional radiative transfer effects.
Title: Magnetic Field Properties of Flux Cancellation Sites
Authors: Kubo, M.; Shimizu, T.
Bibcode: 2007ApJ...671..990K
Altcode:
It has been frequently observed in longitudinal magnetograms that
magnetic elements disappear when a magnetic polarity element approaches
and collides with another polarity element. We examine 12 collision
events observed with the Advanced Stokes Polarimeter. We find formation
of new magnetic connection between the colliding opposite polarity
elements both in the photosphere and in the corona. In some cases,
the opposite polarity elements to be collided appear at different
times and at widely separated positions. Magnetic fields horizontal to
the solar surface are spontaneously formed on the polarity inversion
line (PIL) between such colliding elements, and transient bright X-ray
loops connecting the opposite polarity elements appear. We suggest that
formation of the coronal loops and the photospheric horizontal fields
are due to magnetic reconnection between the colliding field lines,
possibly at multiple locations with different heights. We also find that
a global change in the direction of the photospheric horizontal fields
between the colliding elements occurs in association with formation
and disappearance of Hα dark filaments. Initial horizontal fields
perpendicular to the PIL become parallel to the PIL, when dark filaments
are observed along the PIL. They return to being perpendicular to the
PIL at around the time of the disappearance of the dark filament. This work was completed while the author was affiliated with the
National Astronomical Observatory of Japan and University of Tokyo.
Title: Continuous Plasma Outflows from the Edge of a Solar Active
Region as a Possible Source of Solar Wind
Authors: Sakao, Taro; Kano, Ryouhei; Narukage, Noriyuki; Kotoku,
Jun'ichi; Bando, Takamasa; DeLuca, Edward E.; Lundquist, Loraine L.;
Tsuneta, Saku; Harra, Louise K.; Katsukawa, Yukio; Kubo, Masahito;
Hara, Hirohisa; Matsuzaki, Keiichi; Shimojo, Masumi; Bookbinder, Jay
A.; Golub, Leon; Korreck, Kelly E.; Su, Yingna; Shibasaki, Kiyoto;
Shimizu, Toshifumi; Nakatani, Ichiro
Bibcode: 2007Sci...318.1585S
Altcode:
The Sun continuously expels a huge amount of ionized material into
interplanetary space as the solar wind. Despite its influence on the
heliospheric environment, the origin of the solar wind has yet to
be well identified. In this paper, we report Hinode X-ray Telescope
observations of a solar active region. At the edge of the active region,
located adjacent to a coronal hole, a pattern of continuous outflow of
soft-x-ray emitting plasmas was identified emanating along apparently
open magnetic field lines and into the upper corona. Estimates of
temperature and density for the outflowing plasmas suggest a mass
loss rate that amounts to ~1/4 of the total mass loss rate of the
solar wind. These outflows may be indicative of one of the solar wind
sources at the Sun.
Title: Hinode SOT observations of plume upflows and cascading
downflows in quiescent solar prominences
Authors: Berger, T.; Shine, R.; Slater, G.; Tarbell, T.; Title, A.;
Lites, B.; Tsuneta, S.; Okamoto, T. J.; Ichimoto, K.; Katsukawa, Y.;
Sekii, T.; Suematsu, Y.; Shimizu, T.
Bibcode: 2007AGUFMSH53A1065B
Altcode:
We present several Hinode SOT filtergram movies of quiescent solar
prominences that show newly discovered "plume-like" upflows and
cascading "waterfall-like" downflows that persist for the entire
multi-hour duration of the observations. The flow speeds are on the
order of 10 km/sec with typical widths of 400-700 km. Preliminary
calculations show that if the upflows are buoyancy driven, the
associated thermal perturbation is on the order of 10,000 K, sufficient
to explain the dark appearance of the upflows in the interference
filter passbands. In addition we observe rotational vortices and
body oscillations within the prominences. These new observations
challenge current magnetostatic models of solar prominences by showing
that prominence plasmas are in constant motion, often in directions
perpendicular to the magnetic field lines proposed by the models. TRACE,
Hinode/EIS, and Hinode/XRT observations are used to investigate the
differential topology of the flows across temperature regimes.
Title: Coronal Transverse Magnetohydrodynamic Waves in a Solar
Prominence
Authors: Okamoto, T. J.; Tsuneta, S.; Berger, T. E.; Ichimoto, K.;
Katsukawa, Y.; Lites, B. W.; Nagata, S.; Shibata, K.; Shimizu, T.;
Shine, R. A.; Suematsu, Y.; Tarbell, T. D.; Title, A. M.
Bibcode: 2007Sci...318.1577O
Altcode: 2008arXiv0801.1958O
Solar prominences are cool 104 kelvin plasma clouds
supported in the surrounding 106 kelvin coronal plasma by
as-yet-undetermined mechanisms. Observations from Hinode show fine-scale
threadlike structures oscillating in the plane of the sky with periods
of several minutes. We suggest that these represent Alfvén waves
propagating on coronal magnetic field lines and that these may play
a role in heating the corona.
Title: Quiet-Sun Internetwork Magnetic Fields from the Inversion of
Hinode Measurements
Authors: Orozco Suárez, D.; Bellot Rubio, L. R.; del Toro Iniesta,
J. C.; Tsuneta, S.; Lites, B. W.; Ichimoto, K.; Katsukawa, Y.; Nagata,
S.; Shimizu, T.; Shine, R. A.; Suematsu, Y.; Tarbell, T. D.; Title,
A. M.
Bibcode: 2007ApJ...670L..61O
Altcode: 2007arXiv0710.1405O
We analyze Fe I 630 nm observations of the quiet Sun at disk center
taken with the spectropolarimeter of the Solar Optical Telescope aboard
the Hinode satellite. A significant fraction of the scanned area,
including granules, turns out to be covered by magnetic fields. We
derive field strength and inclination probability density functions from
a Milne-Eddington inversion of the observed Stokes profiles. They show
that the internetwork consists of very inclined, hG fields. As expected,
network areas exhibit a predominance of kG field concentrations. The
high spatial resolution of Hinode's spectropolarimetric measurements
brings to an agreement the results obtained from the analysis of
visible and near-infrared lines.
Title: Center-to-Limb Variation of Stokes V Asymmetries in Solar
Pores Observed with the Hinode Spectro-Polarimeter
Authors: Morinaga, Shuji; Nagata, Shin'ichi; Ichimoto, Kiyoshi;
Suematsu, Yoshinori; Tsuneta, Saku; Katsukawa, Yukio; Shimizu,
Toshifumi; Shine, Richard A.; Tarbell, Theodore D.; Title, Alan M.;
Lites, Bruce; Kubo, Masahito; Sakurai, Takashi
Bibcode: 2007PASJ...59S.613M
Altcode:
Here we present spectro-polarimetric measurements of several pores
and the surrounding regions taken with the Solar Optical Telescope
aboard Hinode at various viewing angles. We analyzed the Stokes V
area asymmetry, and confirmed that it is depressed at the center of
the pores, while it shows large positive values (a blue lobe larger
than a red lobe) in the surrounding area; this is consistent with a
previous report. In addition to this ring of positive asymmetry, we
found regions of alternating positive and negative area asymmetries
when weak V regions were observed near the solar limb. The positive
asymmetry occurs on the disk-center side and the negative asymmetry
on the limb side of the magnetic concentrations. These center-to-limb
variations of the Stokes V area asymmetry can be interpreted as being
a systematic inflow of plasma into the magnetic concentrations from
their surroundings.
Title: Initial Results on Line-of-Sight Field Calibrations of SP/NFI
Data Taken by SOT/Hinode
Authors: Chae, Jongchul; Moon, Yong-Jae; Park, Young-Deuk; Ichimoto,
Kiyoshi; Sakurai, Takashi; Suematsu, Yoshinori; Tsuneta, Saku;
Katsukawa, Yukio; Shimizu, Toshifumi; Shine, Richard A.; Tarbell,
Theodore D.; Title, Alan M.; Lites, Bruce; Kubo, Masahito; Nagata,
Shin'ichi; Yokoyama, Takaaki
Bibcode: 2007PASJ...59S.619C
Altcode:
We present initial results on the line-of-sight field calibration
of the two kinds of Stokes I and V data taken by the Solar Optical
Telescope on the satellite Hinode: spectral profiles of Stokes I and V
parameters recorded on the Spectro-polarimeter (SP), and monochromatic
images of the same parameters recorded on the Narrow-band Filter Imager
(NFI). By applying the center-of-gravity method to the SP data of
AR10930 taken on 2006 December 11, we determined the line-of-sight field
at every location in the active region. As a result, we found that the
line-of-sight field strength ranges up to 2kG in plages, even without
taking into account the filling factor, and up to 3.5kG or higher values
inside the umbra of the major sunspot. We calibrated the NFI data in
reference to the field determined from the SP data. In regions outside
the sunspots and the penumbral regions, we adopted a linear relation,
B|| = βV / I, between the circular polarization, V / I,
and the line-of-sight field strength, B||, and obtained β =
23.5kG in regions outside the sunspots, and β = 12.0kG in penumbral
regions. In umbral regions of sunspots, a first-order polynomial was
adopted to model the reversal of the polarization signal over the
field strength.
Title: Response of the Solar Atmosphere to Magnetic Flux Emergence
from Hinode Observations
Authors: Li, Hui; Sakurai, Takashi; Ichimito, Kiyoshi; Suematsu,
Yoshinori; Tsuneta, Saku; Katsukawa, Yukio; Shimizu, Toshifumi; Shine,
Richard A.; Tarbell, Theodore D.; Title, Alan M.; Lites, Bruce; Kubo,
Masahito; Nagata, Shin'ichi; Kotoku, Jun; Shibasaki, Kiyoto; Saar,
Steven H.; Bobra, Monica
Bibcode: 2007PASJ...59S.643L
Altcode:
No abstract at ADS
Title: Initial Helioseismic Observations by Hinode/SOT
Authors: Sekii, Takashi; Kosovichev, Alexander G.; Zhao, Junwei;
Tsuneta, Saku; Shibahashi, Hiromoto; Berger, Thomas E.; Ichimoto,
Kiyoshi; Katsukawa, Yukio; Lites, Bruce; Nagata, Shin'ichi; Shimizu,
Toshifumi; Shine, Richard A.; Suematsu, Yoshinori; Tarbell, Theodore
D.; Title, Alan M.
Bibcode: 2007PASJ...59S.637S
Altcode: 2007arXiv0709.1806S
Results from initial helioseismic observations by the Solar Optical
Telescope on-board Hinode are reported. It has been demonstrated
that intensity oscillation data from the Broadband Filter Imager
can be used for various helioseismic analyses. The k - ω power
spectra, as well as the corresponding time-distance cross-correlation
function, which promise high-resolution time-distance analysis below
the 6-Mm travelling distance, were obtained for G-band and CaII-H
data. Subsurface supergranular patterns were observed from our first
time-distance analysis. The results show that the solar oscillation
spectrum is extended to much higher frequencies and wavenumbers, and
the time-distance diagram is extended to much shorter travel distances
and times than were observed before, thus revealing great potential
for high-resolution helioseismic observations from Hinode.
Title: Magnetic Feature and Morphological Study of X-Ray Bright
Points with Hinode
Authors: Kotoku, Jun'ichi; Kano, Ryouhei; Tsuneta, Saku; Katsukawa,
Yukio; Shimizu, Toshifumi; Sakao, Taro; Shibazaki, Kiyoto; Deluca,
Edward E.; Korreck, Kelly E.; Golub, Leon; Bobra, Monica
Bibcode: 2007PASJ...59S.735K
Altcode:
We observed X-ray bright points (XBPs) in a quiet region of the Sun
with the X-Ray Telescope (XRT) aboard the Hinode satellite on 2006
December 19. XRT's high-resolution X-ray images revealed many XBPs with
complicated structure and evolving dramatically with time. Almost all
of the dynamic eruptions in the quiet region were composed of XBPs,
and they had either loop or multiloop shapes, as is observed in larger
flares. Brightening XBPs had strong magnetic fields with opposite
polarities near their footpoints. While we have found a possible
example of associated magnetic cancellation, other XBPs brighten and
fade without any associated movement of the photospheric magnetic field.
Title: Hinode Observations of Horizontal Quiet Sun Magnetic Flux
and the ``Hidden Turbulent Magnetic Flux''
Authors: Lites, Bruce; Socas-Navarro, Hector; Kubo, Masahito; Berger,
Thomas; Frank, Zoe; Shine, Richard A.; Tarbell, Theodore D.; Title,
Alan M.; Ichimoto, Kiyoshi; Katsukawa, Yukio; Tsuneta, Saku; Suematsu,
Yoshinori; Shimizu, Toshifumi
Bibcode: 2007PASJ...59S.571L
Altcode:
We present observations of magnetic fields of the very quiet Sun
near disk center using the Spectro-Polarimeter of the Solar Optical
Telescope aboard the Hinode satellite. These observations reveal for
the first time the ubiquitous presence of horizontal magnetic fields in
the internetwork regions. The horizontal fields are spatially distinct
from the vertical fields, demonstrating that they are not arising mainly
from buffeting of vertical flux tubes by the granular convection. The
horizontal component has an average ``apparent flux density'' of
55Mxcm-2 (assuming the horizontal field structures are
spatially resolved), in contrast to the average apparent vertical flux
density of 11Mxcm-2. The vertical fields reside mainly in
the intergranular lanes, whereas the horizontal fields occur mainly
over the bright granules, with a preference to be near the outside
edge of the bright granules. The large apparent imbalance of vertical
and horizontal flux densities is discussed, and several scenarios are
presented to explain this imbalance.
Title: Strategy for the Inversion of Hinode Spectropolarimetric
Measurements in the Quiet Sun
Authors: Orozco Suárez, David; Bellot Rubio, Luis R.; Del Toro
Iniesta, Jose Carlos; Tsuneta, Saku; Lites, Bruce; Ichimoto, Kiyoshi;
Katsukawa, Yukio; Nagata, Shin'ichi; Shimizu, Toshifumi; Shine,
Richard A.; Suematsu, Yoshinori; Tarbell, Theodore D.; Title, Alan M.
Bibcode: 2007PASJ...59S.837O
Altcode: 2007arXiv0709.2033O
In this paper we propose an inversion strategy for the analysis of
spectropolarimetric measurements taken by Hinode in the quiet Sun. The
Spectro-Polarimeter of the Solar Optical Telescope aboard Hinode records
the Stokes spectra of the FeI line pair at 630.2nm with unprecendented
angular resolution, high spectral resolution, and high sensitivity. We
discuss the need to consider a local stray-light contamination to
account for the effects of telescope diffraction. The strategy is
applied to observations of a wide quiet Sun area at disk center. Using
these data we examine the influence of noise and initial guess models
in the inversion results. Our analysis yields the distributions of
magnetic field strengths and stray-light factors. They show that quiet
Sun internetwork regions consist mainly of hG fields with stray-light
contamination of about 0.8.
Title: Hinode Calibration for Precise Image Co-Alignment between
SOT and XRT (2006 November-2007 April)
Authors: Shimizu, Toshifumi; Katsukawa, Yukio; Matsuzaki, Keiichi;
Ichimoto, Kiyoshi; Kano, Ryohei; Deluca, Edward E.; Lundquist,
Loraine L.; Weber, Mark; Tarbell, Theodore D.; Shine, Richard A.;
Sôma, Mitsuru; Tsuneta, Saku; Sakao, Taro; Minesugi, Kenji
Bibcode: 2007PASJ...59S.845S
Altcode: 2007arXiv0709.4098S
To understand the physical mechanisms for activity and heating in
the solar atmosphere, the magnetic coupling from the photosphere
to the corona is an important piece of information from the Hinode
observations, and therefore precise positional alignment is required
among the data acquired by different telescopes. The Hinode spacecraft
and its onboard telescopes were developed to allow us to investigate
magnetic coupling with co-alignment accuracy better than 1". Using
the Mercury transit observed on 2006 November 8 and co-alignment
measurements regularly performed on a weekly basis, we have determined
the information necessary for precise image co-alignment, and have
confirmed that co-alignment better than 1" can be realized between
Solar Optical Telescope (SOT) and X-Ray Telescope (XRT) with our
baseline co-alignment method. This paper presents results from the
calibration for precise co-alignment of CCD images from SOT and XRT.
Title: Hinode Observations of a Vector Magnetic Field Change
Associated with a Flare on 2006 December 13
Authors: Kubo, Masahito; Yokoyama, Takaaki; Katsukawa, Yukio; Lites,
Bruce; Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto, Kiyoshi; Shimizu,
Toshifumi; Nagata, Shin'ichi; Tarbell, Theodore D.; Shine, Richard A.;
Title, Alan M.; Elmore David
Bibcode: 2007PASJ...59S.779K
Altcode: 2007arXiv0709.2397K
Continuous observations of the flare productive active region 10930
were successfully carried out with the Solar Optical Telescope aboard
the Hinode spacecraft during 2006 December 6 to 19. We focused on the
evolution of photospheric magnetic fields in this active region, and the
magnetic field properties at the site of the X3.4 class flare, using
a time series of vector field maps with high spatial resolution. The
X3.4 class flare occurred on 2006 December 13 at the apparent
collision site between the large, opposite polarity umbrae. Elongated
magnetic structures with alternatingly positive and negative polarities
resulting from flux emergence appeared one day before the flare in the
collision site penumbra. Subsequently, the polarity inversion line
at the collision site became very complicated. The number of bright
loops in CaII H increased during the formation of these elongated
magnetic structures. Flare ribbons and bright loops evolved along
the polarity inversion line and one footpoint of the bright loop was
located in a region having a large departure of the field azimuth angle
with respect to its surroundings. SOT observations with high spatial
resolution and high polarization precision revealed temporal change in
the fine structure of magnetic fields at the flare site: some parts of
the complicated polarity inversion line then disappeared, and in those
regions the azimuth angle of the photospheric magnetic field changed by
about 90°, becoming more spatially uniform within the collision site.
Title: The Analysis of Penumbral Fine Structure Using an Advanced
Inversion Technique
Authors: Jurcák, Jan; Bellot Rubio, Luis; Ichimoto, Kiyoshi;
Katsukawa, Yukio; Lites, Bruce; Nagata, Shin'ichi; Shimizu, Toshifumi;
Suematsu, Yoshinori; Tarbell, Theodore D.; Title, Alan M.; Tsuneta,
Saku
Bibcode: 2007PASJ...59S.601J
Altcode: 2007arXiv0707.1560J
We present a method to study the penumbral fine structure using data
obtained by the spectropolarimeter on board Hinode. For the first
time, the penumbral filaments can be considered as being resolved in
spectropolarimetric measurements. This enables us to use inversion
codes with only one-component model atmospheres, and thus to assign
the obtained stratifications of the plasma parameters directly to the
penumbral fine structure. This approach was applied to the limb-side
part of the penumbra in the active region NOAA10923. Preliminary results
show a clear dependence of the plasma parameters on the continuum
intensity in the inner penumbra, i.e., a weaker and horizontal magnetic
field along with an increased line-of-sight velocity are found in the
low layers of the bright filaments. The results in the mid penumbra
are ambiguous, and future analyses are necessary to unveil the magnetic
field structure and other plasma parameters there.
Title: Fine-Scale Structures of the Evershed Effect Observed by the
Solar Optical Telescope aboard Hinode
Authors: Ichimoto, Kiyoshi; Shine, Richard A.; Lites, Bruce; Kubo,
Masahito; Shimizu, Toshifumi; Suematsu, Yoshinori; Tsuneta, Saku;
Katsukawa, Yukio; Tarbell, Theodore D.; Title, Alan M.; Nagata,
Shin'ichi; Yokoyama, Takaaki; Shimojo, Masumi
Bibcode: 2007PASJ...59S.593I
Altcode:
The small-scale structure of the Evershed effect is being studied
using data obtained by the Spectropolarimeter and the Broadband Filter
Imager of the Solar Optical Telescope aboard Hinode. We find that the
Evershed flow starts at the leading edge of inwardly migrating bright
penumbral grains, and turns to nearly a horizontal flow preferentially
in the dark lanes of the penumbra. A number of small elongated regions
that have an upward motion of ∼ 1kms-1 are found in the
deep photosphere distributed over the penumbra. They are cospatial
with bright grains and have relatively horizontal magnetic fields. A
number of patches having a strong downward motion associated with the
opposite magnetic polarity from the sunspot are also found in the mid
and outer penumbra. They could be identified as foot points of the
Evershed flow channels, though the identification of individual pairs
is not straightforward. Our results provide strong support for some
recent findings from ground-based high-resolution observations, and
are in general agreement with the well-known picture of the uncombed
structure of the penumbra, in which the penumbrae consist of rising
flux tubes carrying nearly horizontal Evershed flows embedded in more
vertical background magnetic fields.
Title: Flare Ribbons Observed with G-band and FeI 6302Å, Filters
of the Solar Optical Telescope on Board Hinode
Authors: Isobe, Hiroaki; Kubo, Masahito; Minoshima, Takashi; Ichimoto,
Kiyoshi; Katsukawa, Yukio; Tarbell, Theodore D.; Tsuneta, Saku; Berger,
Thomas E.; Lites, Bruce; Nagata, Shin'ichi; Shimizu, Toshifumi; Shine,
Richard A.; Suematsu, Yoshinori; Title, Alan M.
Bibcode: 2007PASJ...59S.807I
Altcode: 2007arXiv0711.3946I
The Solar Optical Telescope (SOT) on board the Hinode satellite observed
an X3.4 class flare on 2006 December 13. A typical two-ribbon structure
was observed, not only in the chromospheric CaII H line, but also in
the G-band and FeI 6302Å line. The high-resolution, seeing-free images
achieved by SOT revealed, for the first time, sub-arcsec fine structures
of the ``white light'' flare. The G-band flare ribbons on sunspot
umbrae showed a sharp leading edge, followed by a diffuse inside,
as well as a previously known core-halo structure. The underlying
structures, such as umbral dots, penumbral filaments, and granules,
were visible in the flare ribbons. Assuming that the sharp leading
edge was directly heated by a particle beam and the diffuse parts were
heated by radiative back-warming, we estimated the depth of the diffuse
flare emission using an intensity profile of the flare ribbon. We found
that the depth of the diffuse emission was about 100km or less from
the height of the source of radiative back-warming. The flare ribbons
were also visible in the Stokes-V images of FeI 6302Å, as a transient
polarity reversal. This is probably related to a ``magnetic transient''
reported in the literature. The intensity increase in Stokes-I images
indicates that the FeI 6302Å line was significantly deformed by the
flare, which may cause such a magnetic transient.
Title: Small-Scale Magnetic-Flux Emergence Observed with Hinode
Solar Optical Telescope
Authors: Otsuji, Kenichi; Shibata, Kazunari; Kitai, Reizaburo; Ueno,
Satoru; Nagata, Shin'ichi; Matsumoto, Takuma; Nakamura, Tahei;
Watanabe, Hiroko; Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto,
Kiyoshi; Shimizu, Toshifumi; Katsukawa, Yukio; Tarbell, Theodore D.;
Lites, Bruce; Shine, Richard A.; Title Alan M.
Bibcode: 2007PASJ...59S.649O
Altcode: 2007arXiv0709.3207O
We observed small-scale magnetic-flux emergence in a sunspot moat region
by the Solar Optical Telescope (SOT) aboard the Hinode satellite. We
analyzed filtergram images observed at wavelengths of Fe 6302Å, G band,
and CaII H. In Stokes I images of Fe 6302Å, emerging magnetic flux was
recognized as dark lanes. In the G band, they showed to be their shapes
almost the same as in Stokes I images. These magnetic fluxes appeared
as dark filaments in CaII H images. Stokes V images of Fe 6302Å showed
pairs of opposite polarities at footpoints of each filament. These
magnetic concentrations were identified to correspond to bright points
in G band/CaII H images. From an analysis of time-sliced diagrams, we
derived the following properties of emerging flux, which are consistent
with those of previous studies: (1) Two footpoints separate each other
at a speed of 4.2kms-1 during the initial phase of evolution,
and decrease to about 1kms-1 10minutes later. (2) CaII H
filaments appear almost simultaneously with the formation of dark lanes
in Stokes I in an observational cadence of 2minutes. (3) The lifetime
of the dark lanes in the Stokes I and G band is 8minutes, while that
of Ca filament is 12minutes. An interesting phenomena was observed,
that an emerging flux tube expanded laterally in the photosphere with a
speed of 3.8kms-1. A discussion on the horizontal expansion
of the flux tube is given with refernce to previous simulation studies.
Title: Observations of Sunspot Oscillations in G Band and CaII H
Line with Solar Optical Telescope on Hinode
Authors: Nagashima, Kaori; Sekii, Takashi; Kosovichev, Alexander G.;
Shibahashi, Hiromoto; Tsuneta, Saku; Ichimoto, Kiyoshi; Katsukawa,
Yukio; Lites, Bruce; Nagata, Shin'ichi; Shimizu, Toshifumi; Shine,
Richard A.; Suematsu, Yoshinori; Tarbell, Theodore D.; Title, Alan M.
Bibcode: 2007PASJ...59S.631N
Altcode: 2007arXiv0709.0569N
Exploiting high-resolution observations made by the Solar Optical
Telescope on board Hinode, we investigate the spatial distribution
of the power spectral density of the oscillatory signal in and around
the active region NOAA 10935. The G-band data show that in the umbra
the oscillatory power is suppressed in all frequency ranges. On
the other hand, in CaII H intensity maps oscillations in the umbra,
so-called umbral flashes, are clearly seen with the power peaking around
5.5mHz. The CaII H power distribution shows the enhanced elements with
the spatial scale of the umbral flashes over most of the umbra, but
there is a region with suppressed power at the center of the umbra. The
origin and property of this node-like feature remain unexplained.
Title: Hinode SP Vector Magnetogram of AR10930 and Its
Cross-Comparison with MDI
Authors: Moon, Yong-Jae; Kim, Yeon-Han; Park, Young-Deuk; Ichimoto,
Kiyoshi; Sakurai, Takashi; Chae, Jongchul; Cho, Kyung Suk; Bong,
Suchan; Suematsu, Yoshinori; Tsuneta, Saku; Katsukawa, Yukio; Shimojo,
Masumi; Shimizu, Toshifumi; Shine, Richard A.; Tarbell, Theodore D.;
Title, Alan M.; Lites, Bruce; Kubo, Masahito; Nagata, Shin'ichi;
Yokoyama, Takaaki
Bibcode: 2007PASJ...59S.625M
Altcode:
We present one Hinode Spectropolarimeter (SP) magnetogram of AR 10930
that produced several major flares. The inversion from Stokes profiles
to magnetic field vectors was made using the standard Milne-Eddington
code. We successfully applied the Uniform Shear Method for resolving
the 180° ambiguity to the magnetogram. The inversion gave very strong
magnetic field strengths (near 4500 gauss) for a small portion of area
in the umbra. Considering that the observed V-profile of 6301.5Å was
well-fitted as well as a direct estimation of the Zeeman splitting
results in 4300-4600 gauss, we think that the field strengths
should not be far from the actual value. A cross-comparison of the
Hinode SP and SOHO MDI high resolution flux densities shows that the
MDI flux density could be significantly underestimated by about a
factor of two. In addition, it has a serious negative correlation
(the so-called Zeeman saturation effect) with the Hinode SP flux
density for umbral regions. Finally, we could successfully obtain
a recalibrated MDI magnetogram that has been corrected for the
Zeeman saturation effect using not only a pair of MDI intensity and
magnetogram data simultaneously observed, but also the relationship
from the cross-comparison between the Hinode SP and MDI flux densities.
Title: Formation Process of a Light Bridge Revealed with the Hinode
Solar Optical Telescope
Authors: Katsukawa, Yukio; Yokoyama, Takaaki; Berger, Thomas E.;
Ichimoto, Kiyoshi; Kubo, Masahito; Lites, Bruce; Nagata, Shin'ichi;
Shimizu, Toshifumi; Shine, Richard A.; Suematsu, Yoshinori; Tarbell,
Theodore D.; Title, Alan M.; Tsuneta, Saku
Bibcode: 2007PASJ...59S.577K
Altcode: 2007arXiv0709.2527K
The Solar Optical Telescope (SOT) on-board Hinode successfully and
continuously observed the formation process of a light bridge in a
matured sunspot of the NOAA active region 10923 for several days with
high spatial resolution. During its formation, many umbral dots were
observed to be emerging from the leading edges of penumbral filaments,
and rapidly intruding into the umbra. The precursor of the light bridge
formation was also identified as a relatively slow inward motion of
the umbral dots, which emerged not near the penumbra, but inside the
umbra. The spectro-polarimeter on SOT provided physical conditions in
the photosphere around the umbral dots and the light bridges. We found
that the light bridges and the umbral dots had significantly weaker
magnetic fields associated with upflows relative to the core of the
umbra, which implies that there was hot gas with weak field strength
penetrating from the subphotosphere to near the visible surface inside
those structures. There needs to be a mechanism to drive the inward
motion of the hot gas along the light bridges. We suggest that the
emergence and the inward motion are triggered by a buoyant penumbral
flux tube as well as subphotospheric flow crossing the sunspot.
Title: Umbral Fine Structures in Sunspots Observed with Hinode Solar
Optical Telescope
Authors: Kitai, Reizaburo; Watanabe, Hiroko; Nakamura, Tahei; Otsuji,
Ken-ichi; Matsumoto, Takuma; UeNo, Satoru; Nagata, Shin'ichi; Shibata,
Kazunari; Muller, Richard; Ichimoto, Kiyoshi; Tsuneta, Saku; Suematsu,
Yoshinori; Katsukawa, Yukio; Shimizu, Toshifumi; Tarbell, Theodore D.;
Shine, Richard A.; Title, Alan M.; Lites, Bruce
Bibcode: 2007PASJ...59S.585K
Altcode: 2007arXiv0711.3266K
A high resolution imaging observation of a sunspot umbra was made with
the Hinode Solar Optical Telescope. Filtergrams at wavelengths of the
blue and green continua were taken during three consecutive days. The
umbra consisted of a dark core region, several diffuse components,
and numerous umbral dots. We derived basic properties of umbral dots
(UDs), especially their temperatures, lifetimes, proper motions,
spatial distribution, and morphological evolution. The brightness
of UDs is confirmed to depend on the brightness of their surrounding
background. Several UDs show fission and fusion. Thanks to the stable
condition of the space observation, we could for the first time follow
the temporal behavior of these events. The derived properties of the
internal structure of the umbra are discussed from the viewpoint of
magnetoconvection in a strong magnetic field.
Title: On Connecting the Dynamics of the Chromosphere and Transition
Region with Hinode SOT and EIS
Authors: Hansteen, Viggo H.; de Pontieu, Bart; Carlsson, Mats;
McIntosh, Scott; Watanabe, Tetsuya; Warren, Harry P.; Harra, Louise K.;
Hara, Hirohisa; Tarbell, Theodore D.; Shine, Dick; Title, Alan M.;
Schrijver, Carolus J.; Tsuneta, Saku; Katsukawa, Yukio; Ichimoto,
Kiyoshi; Suematsu, Yoshinori; Shimizu, Toshifumi
Bibcode: 2007PASJ...59S.699H
Altcode: 2007arXiv0711.0487H
We use coordinated Hinode SOT/EIS observations that include
high-resolution magnetograms, chromospheric, and transition region
(TR) imaging, and TR/coronal spectra in a first test to study how
the dynamics of the TR are driven by the highly dynamic photospheric
magnetic fields and the ubiquitous chromospheric waves. Initial
analysis shows that these connections are quite subtle and require a
combination of techniques including magnetic field extrapolations,
frequency-filtered time-series, and comparisons with synthetic
chromospheric and TR images from advanced 3D numerical simulations. As a
first result, we find signatures of magnetic flux emergence as well as
3 and 5mHz wave power above regions of enhanced photospheric magnetic
field in both chromospheric, transition region, and coronal emission.
Title: Can High Frequency Acoustic Waves Heat the Quiet Sun
Chromosphere?
Authors: Carlsson, Mats; Hansteen, Viggo H.; de Pontieu, Bart;
McIntosh, Scott; Tarbell, Theodore D.; Shine, Dick; Tsuneta, Saku;
Katsukawa, Yukio; Ichimoto, Kiyoshi; Suematsu, Yoshinori; Shimizu,
Toshifumi; Nagata, Shin'ichi
Bibcode: 2007PASJ...59S.663C
Altcode: 2007arXiv0709.3462C
We use Hinode/SOT Ca II H-line and blue continuum broadband observations
to study the presence and power of high frequency acoustic waves at
high spatial resolution. We find that there is no dominant power at
small spatial scales; the integrated power using the full resolution of
Hinode (0.05'' pixels, 0.16'' resolution) is larger than the power in
the data degraded to 0.5'' pixels (TRACE pixel size) by only a factor
of 1.2. At 20 mHz the ratio is 1.6. Combining this result with the
estimates of the acoustic flux based on TRACE data of Fossum &
Carlsson (2006), we conclude that the total energy flux in acoustic
waves of frequency 5-40 mHz entering the internetwork chromosphere of
the quiet Sun is less than 800 W m$^{-2}$, inadequate to balance the
radiative losses in a static chromosphere by a factor of five.
Title: Formation of Moving Magnetic Features and Penumbral Magnetic
Fields with Hinode/SOT
Authors: Kubo, Masahito; Ichimoto, Kiyoshi; Shimizu, Toshifumi;
Tsuneta, Saku; Suematsu, Yoshinori; Katsukawa, Yukio; Nagata,
Shin'ichi; Tarbell, Theodore D.; Shine, Richard A.; Title, Alan M.;
Frank, Zoe A.; Lites, Bruce; Elmore, David
Bibcode: 2007PASJ...59S.607K
Altcode: 2007arXiv0709.1853K
Vector magnetic fields of moving magnetic features (MMFs) were well
observed with the Solar Optical Telescope (SOT) aboard the Hinode
satellite. We focused on the evolution of three MMFs with the SOT in
this study. We found that an MMF having relatively vertical fields
with the same polarity as the sunspot was detached from the penumbra
around the granules appearing in the outer penumbra. This suggests
that granular motions in the outer penumbra are responsible for
disintegration of the sunspot. Two MMFs with polarity opposite to
the sunspot are located around the outer edge of horizontal fields
extending from the penumbra. This is evidence that the MMFs with
polarity opposite to the sunspot are the prolongation of penumbral
horizontal fields. Redshifts larger than the sonic velocity in the
photosphere are detected for some of the MMFs with polarity opposite
to the sunspot.
Title: A Tale of Two Spicules: The Impact of Spicules on the Magnetic
Chromosphere
Authors: de Pontieu, Bart; McIntosh, Scott; Hansteen, Viggo H.;
Carlsson, Mats; Schrijver, Carolus J.; Tarbell, Theodore D.; Title,
Alan M.; Shine, Richard A.; Suematsu, Yoshinori; Tsuneta, Saku;
Katsukawa, Yukio; Ichimoto, Kiyoshi; Shimizu, Toshifumi; Nagata,
Shin'ichi
Bibcode: 2007PASJ...59S.655D
Altcode: 2007arXiv0710.2934D
We use high-resolution observations of the Sun in CaIIH (3968Å)
from the Solar Optical Telescope on Hinode to show that there are
at least two types of spicules that dominate the structure of the
magnetic solar chromosphere. Both types are tied to the relentless
magnetoconvective driving in the photosphere, but have very different
dynamic properties. ``Type-I'' spicules are driven by shock waves
that form when global oscillations and convective flows leak into
the upper atmosphere along magnetic field lines on 3--7minute
timescales. ``Type-II'' spicules are much more dynamic: they form
rapidly (in ∼ 10s), are very thin (≤ 200 km wide), have lifetimes
of 10-150s (at any one height), and seem to be rapidly heated to
(at least) transition region temperatures, sending material through
the chromosphere at speeds of order 50--150kms-1. The
properties of Type II spicules suggest a formation process that is
a consequence of magnetic reconnection, typically in the vicinity
of magnetic flux concentrations in plage and network. Both types of
spicules are observed to carry Alfvén waves with significant amplitudes
of order 20kms-1.
Title: Magnetic Correspondence between Moving Magnetic Features and
Penumbral Magnetic Fields
Authors: Kubo, M.; Shimizu, T.
Bibcode: 2007ASPC..369..145K
Altcode:
We investigate vector magnetic fields of moving magnetic features
(MMFs) around a mature sunspot with the Advanced Stokes Polarimeter
and SOHO/MDI. In addition to the classical isolated MMFs identified by
visually inspecting the time sequence of MDI magnetograms, we focus
on any diffuse moving magnetic features that are not recognized
as classical MMFs. This feature is called non-isolated MMFs. The
non-isolated MMFs occupy most of the moat region surrounding the
sunspot, and have nearly horizontal magnetic fields with both
polarities. We find that the isolated MMFs located on the lines
extrapolated from the horizontal component of the penumbral uncombed
structure have magnetic fields similar to the non-isolated MMFs. This
suggests that such MMFs are part of horizontal fields extended from
the penumbra. The isolated MMFs located on the lines extrapolated from
the vertical component of the uncombed structure have vertical fields
with polarity same as the sunspot. Our observation shows that such
MMFs are detached from the vertical component of the penumbra. Their
flux transport rate is estimated to be 1-3 times larger than a flux
loss rate of the sunspot. The isolated vertical MMFs alone can be
responsible for decaying the sunspot.
Title: Estimate on SOT Light Level in Flight with Throughput
Measurements in SOT Sun Tests
Authors: Shimizu, T.; Kubo, M.; Tarbell, T. D.; Berger, T. E.;
Suematsu, Y.; Ichimoto, K.; Katsukawa, Y.; Miyashita, M.; Noguchi,
M.; Nakagiri, M.; Tsuneta, S.; Elmore, D. F.; Lites, B. W.
Bibcode: 2007ASPC..369...51S
Altcode:
The SOT (Solar Optical Telescope, e.g., Shimizu 2004) optical
system consists of 50cm-aperture optical telescope (OTA) and focal
plane instrument (FPP). The solar light into the telescope penetrates
through many optical elements located in OTA and FPP before illuminating
CCDs. Natural solar light was fed to the integrated SOT in sun tests for
verifying various optical aspects including the confirmation of photon
throughput. CCD exposures provide the number of photons accumulated
in an exposure duration with a clean-room test condition. To estimate
the absolute intensity of the solar light at the telescope entrance
in the clean-room test condition, we developed a pinhole-PSD sensor
for simultaneous monitoring the solar light outside the clean room
and measured the transmission of light through two flat mirrors of
the heliostat and clean-room entrance window glass as a function of
wavelength. The PSD sensor was pre-calibrated with continuous monitoring
the solar light in a day long under a clear constant sky condition,
determining the earth atmospheric attenuation and the PSD output for
the solar light on orbit. These throughput measurements have provided
an estimate on photon throughput for the SOT flight model. The results
confirm suitable number of photons without saturation for proper CCD
exposures in flight.
Title: Supersonic Downflows in the Photosphere Discovered in Sunspot
Moat Regions
Authors: Shimizu, T.; Martinez-Pillet, V.; Collados, M.; Ruiz-Cobo,
B.; Centeno, R.; Beck, C.; Katsukawa, Y.
Bibcode: 2007ASPC..369..113S
Altcode:
This paper reports on our new findings from the International
Time Program observations at the Canaries islands, Spain, in July
2005. We have found small-scale photospheric events with extremely
red-shifted Stokes V signals in sunspot moat regions. A preliminary
estimate of the physical conditions for an observed Stokes V profile
indicates the presence of a downward motion with a supersonic speed
in the order of 10 km/s. With the currently evaluated observational
information, we interprete the supersonic flows as downward motion from
magnetic reconnection occurring at the upper chromosphere or lower
photosphere. With coordinated observations of the Solar-B onboard
telescopes, Stokes measurements by the SOT spectro-polarimeter would
give new information for further understanding the nature of these
events with strongly red-shifted Stokes V, and for discussing the
physical conditions involving in possible magnetic reconnections in
the lower solar atmosphere.
Title: Performance Characteristics of the Solar-B Spectro-Polarimeter
Authors: Lites, B. W.; Elmore, D. F.; Streander, K. V.; Hoffmann,
C. M.; Tarbell, T. D.; Title, A. M.; Shine, R. A.; Ichimoto, K.;
Tsuneta, S.; Shimizu, T.; Suematsu, Y.
Bibcode: 2007ASPC..369...55L
Altcode:
The Focal Plane Package (FPP) of the Solar Optical Telescope (SOT)
includes the first precision Spectro-Polarimeter (SP) for solar space
observations. The FPP/SP will provide high precision measures of
the vector magnetic field in the solar photosphere. Here we present
some as-built performance specifications for the entire system of
telescope + polarimeter. The FPP-SP system represents significant
gains in several aspects over existing spectro-polarimetric systems;
notably, angular resolution, polarimetric accuracy, spectral purity,
and most importantly, temporal continuity of stable, high angular
resolution. In this short summary of the poster, a few of the
performance characteristics of the SP are presented.
Title: Calibration of the SOT Polarization
Authors: Ichimoto, K.; Suematsu, Y.; Shimizu, T.; Katsukawa, Y.;
Noguchi, M.; Nakagiri, M.; Miyashita, M.; Tsuneta, S.; Tarbell, T. D.;
Shine, R. A.; Hoffmann, C. M.; Cruz, T.; Lites, B. W.; Elmore, D. F.
Bibcode: 2007ASPC..369...39I
Altcode:
Calibration of SOT polarization property was performed using natural
sunlight and well calibrated sheet polarizer (linear and circular)
placed on the entrance of the telescope. The polarimeter response
matrices were determined for the spectropolarimeter (SP) and the
narrowband filter imager (NFI), and it is shown that they are well
behave as predicted and constant over the field of view. The crosstalk
between I,Q,U,V will be suppressed to the negligible level at the
photometric accuracy of 10^{-3} after the calibration with the obtained
matrices. The sensitivity of SOT on linear and circular polarizations
at each wavelength observed by NFI are also obtained.
Title: Examinations of the Relative Alignment of the Instruments
on SOT
Authors: Okamoto, T. J.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.;
Suematsu, Y.; Tsuneta, S.; Tarbell, T. D.
Bibcode: 2007ASPC..369...47O
Altcode:
We report the results of the examination about the relative alignment
among the instruments on SOT. We employ a test data set obtained in the
natural sun-light test in May 2005, which has had a grid pattern over
the entire FOV. SOT has the filtergraph (FG) and the spectro-polarimeter
(SP). The FG consists of six broadband filter imagers (BFI) and six
narrowband filter imagers (NFI). We examined the displacements among
the images taken with different filters to an accuracy of better than
0.1 pixel corresponding to 0.02''. It is important to know relative
displacements and plate scales of these instruments for accurate
alignment of observational data. We note that the values measured in
our work are relative and it is needed to decide the absolute values
with another way.
Title: Vector Spectropolarimetry of Dark-cored Penumbral Filaments
with Hinode
Authors: Bellot Rubio, L. R.; Tsuneta, S.; Ichimoto, K.; Katsukawa,
Y.; Lites, B. W.; Nagata, S.; Shimizu, T.; Shine, R. A.; Suematsu,
Y.; Tarbell, T. D.; Title, A. M.; del Toro Iniesta, J. C.
Bibcode: 2007ApJ...668L..91B
Altcode: 2007arXiv0708.2791B
We present spectropolarimetric measurements of dark-cored penumbral
filaments taken with Hinode at a resolution of 0.3". Our observations
demonstrate that dark-cored filaments are more prominent in polarized
light than in continuum intensity. Far from disk center, the Stokes
profiles emerging from these structures are very asymmetric and show
evidence for magnetic fields of different inclinations along the
line of sight, together with strong Evershed flows of at least 6-7 km
s-1. In sunspots closer to disk center, dark-cored penumbral
filaments exhibit regular Stokes profiles with little asymmetries due
to the vanishing line-of-sight component of the horizontal Evershed
flow. An inversion of the observed spectra indicates that the magnetic
field is weaker and more inclined in the dark cores as compared with
the surrounding bright structures. This is compatible with the idea
that dark-cored filaments are the manifestation of flux tubes carrying
hot Evershed flows.
Title: Emergence of Small-Scale Magnetic Loops in the Quiet-Sun
Internetwork
Authors: Centeno, R.; Socas-Navarro, H.; Lites, B.; Kubo, M.; Frank,
Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Tsuneta, S.;
Katsukawa, Y.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2007ApJ...666L.137C
Altcode: 2007arXiv0708.0844C
We study the emergence of magnetic flux at very small spatial
scales (less than 2") in the quiet-Sun internetwork. To this aim,
a time series of spectropolarimetric maps was taken at disk center
using the instrument SP/SOT on board Hinode. The LTE inversion of
the full Stokes vector measured in the Fe I 6301 and 6302 Å lines
allows us to retrieve the magnetic flux and topology in the region
of study. In the example presented here, the magnetic flux emerges
within a granular structure. The horizontal magnetic field appears
prior to any significant amount of vertical field. As time goes on,
the traces of the horizontal field disappear, while the vertical dipoles
drift-carried by the plasma motions-toward the surrounding intergranular
lanes. These events take place within typical granulation timescales.
Title: The Hinode (Solar-B) Mission: An Overview
Authors: Kosugi, T.; Matsuzaki, K.; Sakao, T.; Shimizu, T.; Sone,
Y.; Tachikawa, S.; Hashimoto, T.; Minesugi, K.; Ohnishi, A.; Yamada,
T.; Tsuneta, S.; Hara, H.; Ichimoto, K.; Suematsu, Y.; Shimojo, M.;
Watanabe, T.; Shimada, S.; Davis, J. M.; Hill, L. D.; Owens, J. K.;
Title, A. M.; Culhane, J. L.; Harra, L. K.; Doschek, G. A.; Golub, L.
Bibcode: 2007SoPh..243....3K
Altcode:
The Hinode satellite (formerly Solar-B) of the Japan Aerospace
Exploration Agency's Institute of Space and Astronautical Science
(ISAS/JAXA) was successfully launched in September 2006. As the
successor to the Yohkoh mission, it aims to understand how magnetic
energy gets transferred from the photosphere to the upper atmosphere
and results in explosive energy releases. Hinode is an observatory
style mission, with all the instruments being designed and built to
work together to address the science aims. There are three instruments
onboard: the Solar Optical Telescope (SOT), the EUV Imaging Spectrometer
(EIS), and the X-Ray Telescope (XRT). This paper provides an overview
of the mission, detailing the satellite, the scientific payload, and
operations. It will conclude with discussions on how the international
science community can participate in the analysis of the mission data.
Title: Chromospheric Micro-jets Discovered Above Sunspot Penumbrae
Authors: Katsukawa, Yukio; Tsuneta, S.; Suematsu, Y.; Ichimoto, K.;
Shimizu, T.; Kubo, M.; Nagata, S.; Berger, T.; Tarbell, T.; Shine,
R.; Title, A.
Bibcode: 2007AAS...210.9413K
Altcode: 2007BAAS...39..219K
The Solar Optical Telescope (SOT) aboard HINODE allows us to observe
dynamical activities in the solar photosphere and the chromosphere
with high and stable image quality of 0.2 arcseconds. This superior
performance of SOT provides new findings of fine-scale transient
activities occurring in the chromosphere. In this paper, we report
discovery of fine-scale jet-like phenomena ubiquitously observed
above sunspot penumbrae. The jets are identified in image sequences
of a sunspot taken through a Ca II H line filter at 3968A. The Ca II
H line is sensitive to about 10^4 K plasma in the chromosphere. Their length is typically between 3000 and 10000km, and their
width is smaller than 500km. It is notable that their lifetime
is shorter than 1 minute. Those small spatial and temporal scale
possibly makes it difficult to identify the phenomena in existing
ground-based observations. The jets are easily identified when a
sunspot is located far from the disk center, and motion of the bright
features suggests that mass is erupted from lower chromosphere to upper
atmosphere. Velocities of the motion are estimated to be 50 to 100 km/s
from their lateral motion of intensity patterns. The velocities are much
faster than sound speeds in the chromosphere. A possible cause of such
high-speed jets is magnetic reconnection at the lower chromosphere
resulted from fluted magnetic configuration in penumbrae which is
suggested by vector magnetic field measurements in the photosphere.
Title: Hinode Data Calibration For Precise Image Co-alignment:
XRT vs. SOT
Authors: Shimizu, Toshifumi; DeLuca, E. E.; Lundquist, L.; Sakao,
T.; Kubo, M.; Narukage, N.; Kano, R.; Katsukawa, Y.; Ichimoto, K.;
Suematsu, Y.; Tsuneta, S.; Tarbell, T.; Shine, D.; Hinode Team
Bibcode: 2007AAS...210.9417S
Altcode: 2007BAAS...39Q.220S
From late October in 2006, Hinode solar optical telescope (SOT) has
started to produce series of 0.2-0.3 arcsec visible-light images,
revealing dynamical behaviors of solar magnetic fields on the
solar surface. Simultaneously, Hinode X-ray telescope (XRT) has been
providing 1 arcsec resolution X-ray images of the solar corona, giving
the location of heating and dynamics occuring in the corona. Precise
image co-alignment of SOT data on XRT data with sub-arcsec accuracy is
required to provide new information regarding connecting the corona to
the photosphere. This presentation will give an introduction of Hinode
between-telescopes' image co-alignment to SPD participants. For active
region observations with sunspots, sunspots can be used as fiducial to
co-align the data from the two telescopes each other. Satellite jitter
in order of 1 arcsec or less is included in the series of XRT data,
whereas image stabilization system (correlation tracker) removes the
satellite jitter from the series of SOT images. Telescope pointings show
orbital variation in order of a few arcsec, which can be well predicted
from Hinode orbit information. Modeling co-alignment is under study
and it is the only precise method for quiet Sun and limb observations.
Title: Magnetic Patches in Internetwork Quiet Sun
Authors: De Wijn, Alfred; Lites, B.; Berger, T.; Shine, R.; Title,
A.; Katsukawa, Y.; Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Hinode Team
Bibcode: 2007AAS...210.9412D
Altcode: 2007BAAS...39Q.219D
We study strong flux elements in the quiet sun in the context of
the nature of quiet-sun magnetism, its coupling to chromospheric,
transition-region and coronal fields, and the nature of a local
turbulent dynamo. Strong, kilogauss flux elements show up intermittently
as small bright points in G-band and Ca II H images. Although
bright points have been extensively studied in the magnetic network,
internetwork magnetism has only come under scrutiny in recent years. A
full spectrum of field strengths seems to be ubiquitously present in
the internetwork at small spatial scales, with the stronger elements
residing in intergranular lanes. De Wijn et al. (2005) found that bright
points in quiet sun internetwork areas appear recurrently with varying
intensity and horizontal motion within long-lived patches that outline
cell patterns on mesogranular scales. They estimate that the "magnetic
patches" have a mean lifetime of nine hours, much longer than granular
timescales. We use multi-hour sequences of G-band and Ca II H images
as well as magnetograms recorded by the Hinode satellite to follow up
on their results. The larger field of view, the longer sequences, the
addition of magnetograms, and the absence of atmospheric seeing allows
us to better constrain the patch lifetime, to provide much improved
statistics on IBP lifetime, to compare IBPs to network bright points,
and to study field polarity of IBPs in patches and between nearby
patches. Hinode is an international project supported by JAXA,
NASA, PPARC and ESA. We are grateful to the Hinode team for all their
efforts in the design, build and operation of the mission.
Title: Hinode/SOT Observations Of Apparent "Thermal Plume" Motions
In A Solar Prominence
Authors: Berger, Thomas; Tarbell, T.; Slater, G.; Tsuneta, S.;
Suematsu, Y.; Ichimoto, K.; Katsukawa, Y.; Shimizu, T.; Kubo, M.;
Nagata, S.
Bibcode: 2007AAS...210.9433B
Altcode: 2007BAAS...39..222B
We present 396.8 nm Ca II H-line observations of a large
hedgerow, or "sheet", prominence seen on the solar western limb
on 30-November-2006. The 16 second cadence observations show dark
channels rising vertically at speeds of approximately 10 km/sec to
heights of about 15 Mm above the limb. Many of the motions end in
vortical overturning near the top of the sheet . Bright downflows of
similar speed are also seen within the sheet, often in association
with a dark channel that has risen to the top of the sheet. The dark
channels are suggestive of hot material rising in thermal plumes
within the prominence sheet. Similarly, the bright material motions
appear to be density enhanced regions of turbulent downflow. Current
models of sheet prominences do not include the observed dynamics. In
these models, the prominence plasma is in a low-beta state and is
constrained to move only along magnetic field lines. However the
motions observed here are extremely complex, implying either that the
magnetic field lines are undergoing turbulent motion, thus tangling
and reconnecting constantly, or that the plasma is not constrained
by the field and is in a high-beta convective state. We measure the
motion of several representative "plumes" and downflows, estimate the
density and temperature of the prominence plasma, and suggest several
avenues for further investigation. This work was supported by
NASA under the Hinode/SOT contract NNM07AA01C.
Title: High Resolution Observation of Spicules in Ca II H with
Hinode/SOT
Authors: Suematsu, Yoshinori; Katsukawa, Y.; Ichimoto, K.; Tsuneta, S.;
Okamoto, T.; Nagata, S.; Shimizu, T.; Tarbell, T.; Shine, R.; Title, A.
Bibcode: 2007AAS...210.9411S
Altcode: 2007BAAS...39..219S
High cadence observation with a Ca II H broadband filtergraph
(passband of 0.25 nm) of the Solar Optical Telescope (SOT) aboard
HINODE has revealed dynamical nature of solar limb spicules. Thanks to a
diffraction-limited and low-scattered light property of the instrument,
we can track the detailed evolution of individual spicules for the first
time with a spatial resolution of 0.2 arcsec. The spicules in Ca II
H are typically several arcsec tall and have multi-thread structure;
each threads are a few tenth of arcsec wide. It should be stressed
that most spicules do not show a simple up-and-down motion along a
rigid path line. They start with bright structure emanating from Ca II
H bright region, get widen and diffused with time and ascent, showing
expansion with lateral or even helical motion in tall events. Small and
short lived spicules tend to fade out after ascent. We will present
new findings of spicule dynamics in different magnetic environments
and discuss about long standing controversy of its motion and evolution.
Title: Hinode/SOT Observation of Fine Structure of the Evershed Flow
Authors: Ichimoto, Kiyoshi; Suematsu, Y.; Tsuneta, S.; Katsukawa, Y.;
Shimojo, M.; Kubo, M.; Shimizu, T.; Shine, R.; Tarbell, T.; Title,
A.; Lites, B.; Elmore, D.; Yokoyama, T.; Nagaka, S.
Bibcode: 2007AAS...210.9408I
Altcode: 2007BAAS...39..218I
Small scale structure of the Evershed effect was studied using the
Spectropolarimeter (SP) and Broadband Filter Imager (BFI) of SOT aboard
Hinode. SP maps and high cadence continuum images of BFI coverting
entire sunspots are used to investigate the spatial distribution of
the flow field, brightness and magnetic fields. It is revealed that the
Evershed flow starts at the front edge of inwardly migrating penumbral
grains with an upward velocity component and turns to nearly holizontal
flow preferentially in dark lanes (or dark core of filaments) of the
penumbra. Our results are in general agreement with the well known
uncombed penumbral concept in which the Evershed flow takes place
in nearly holizontal field channels. We discovered a number of tiny
elongated regions in deep photosphere in which there is an obvious
upward motion of 1-1.5km/s distributing over the penumbra. They
could be identified as the 'foot points' of the individual Evershed
flow channels. Cross-correlation among the flow speed, intensity,
magnetic field strength and inclination, and distribution of string
down flows in and around the penumbra will also be discussed.
Title: Continuous Upflow of Plasmas at the Edge of an Active Region
as Revealed by the X-ray Telescope (XRT) aboard Hinode
Authors: Sakao, Taro; Kano, R.; Narukage, N.; Kotoku, J.; Bando, T.;
DeLuca, E. E.; Lundquist, L. L.; Golub, L.; Kubo, M.; Katsukawa, Y.;
Tsuneta, S.; Hara, H.; Matsuzaki, K.; Shimojo, M.; Shibasaki, K.;
Shimizu, T.; Nakatani, I.
Bibcode: 2007AAS...210.7205S
Altcode: 2007BAAS...39Q.179S
We present X-ray imaging observations with Hinode X-Ray Telescope (XRT)
of an active region NOAA AR 10942 made in the period of 20-22 February
2007. A prominent feature that drew our particular attention is that
there revealed continuous upflow of soft-X-ray-emitting plasmas along
apparently-open field lines towards the outer corona emanating from the
edge of the active region. The field lines are originated from
an ensamble of small spots of following polarity, and are located at
a border between the active region and an adjacent equatorial coronal
hole(s) located to the east. The upflow was observed to be continuous
throughout the three days of observation intervals with projected
velocity of 140 km/s, accompanied with undulating motion of the field
lines. We assert that these upflowing plasmas would be a possible
source of slow solar wind material, which supports a foresighted
notion which grew out of interplanetary scintillation observations
that slow solar wind most likely has its origin in the vicinity of
active regions with large flux expansion (Kojima et al. 1999). A
preliminaty analysis indicates that the temperature of the upflowing
material near the base of the field lines is 1.3 MK with number density
of 2 × 109 /cm3. Assuming that all the material
is to escape to the interplanetary space, this leads to a mass loss
rate of 2 × 1011 g/s which amounts to a good fraction of
the total mass loss rate for solar wind. It is noteworthy that, even
apart from this unique upflow, we see continuous (up)flows of plasmas
anywhere around (surrounding) the active region. Details of the
upflow will be presented and their possible implication to slow solar
wind discussed.
Title: Magnetic Flux Emergence In The Quiet Sun Photosphere
Authors: Centeno, Rebecca; Lites, B.; Socas-Navarro, H.; Frank,
Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Tsuneta, S.;
Katsukawa, Y.; Suematsu, Y.; Kubo, M.; Shimizu, T.
Bibcode: 2007AAS...210.9406C
Altcode: 2007BAAS...39..218C
We study the emergence of magnetic flux at very small spacial scales
(less than 1 arcsec) in the quiet Sun internetwork. To this aim, several
time series of spectropolarimetric maps were taken at disk center using
the instrument SP/SOT on board Hinode. The LTE inversion of the full
Stokes vector measured in the Fe I 6301 and 6302 lines will allow us
to retrieve the magnetic flux and topology in the region of study. We
find that the magnetic flux emerges typically within the granular
structures. In many cases, the horizontal magnetic field appears
prior to any significant amount of vertical field. As time goes on,
the traces of the horizontal field dissapear while the the vertical
dipoles drift -carried by the plasma motions- towards the surrounding
intergranular lanes. Sometimes they stay trapped there for a while
but they eventually either disappear by disgregation/cancelation
or agregate to other magnetic field concentrations giving rise to
larger flux elements. The time scale of these events is of the order
of 10-20 minutes.
Title: Formation of Moving Magnetic Features and Penumbral Magnetic
Fields
Authors: Kubo, Masahito; Ichimoto, K.; Shimizu, T.; Tsuneta, S.;
Suematsu, Y.; Katsukawa, Y.; Nagata, S.; Lites, B. W.; Frank, Z.;
Tarbell, T. D.; Shine, R. A.; Title, A. M.
Bibcode: 2007AAS...210.9410K
Altcode: 2007BAAS...39..218K
We investigate the formation process of Moving Magnetic Features
(MMFs) observed with Hinode/SOT. Moving magnetic features are small
magnetic elements moving outward in the moat region surrounding
mature sunspots. We derive vector magnetic fields of MMFs around
simple sunspots near the disk center. Most of MMFs with polarity
opposite to the sunspot have large redshift around the penumbral outer
boundary. We find that some of them have Doppler velocities of about
10 km/s and such large Doppler motion is observed only in the Stokes
V profile. The Stokes Q and U profiles in the same pixel do not have
any significant Doppler motions. Horizontal magnetic fields of the
penumbra frequently extend to the moat region and the MMFs having
horizontal fields with polarity same as the sunspot are formed. The
MMFs with polarity opposite to the sunspot appear around the outer
edge of the extending penumbral fields. We also find penumbral spines,
which have more vertical magnetic fields than the surroundings, branch
off at their outer edge and MMFs having relatively vertical fields
with polarity same as the sunspot are detached from the outer edge
of the branch. The branch of penumbral spine is formed when granular
cells in the moat region go into the penumbra.
Title: Ubiquitous Horizontal Magnetic Fields in the Quiet Solar
Photosphere as Revealed by HINODE Meaurements
Authors: Lites, Bruce W.; Socas Navarro, H.; Berger, T.; Frank,
Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Katsukawa,
Y.; Tsuneta, S.; Suematsu, Y.; Kubo, M.; Shimizu, T.; Nagata, S.;
Hinode Team
Bibcode: 2007AAS...210.6303L
Altcode: 2007BAAS...39..171L
Measurements with the HINODE Spectro-Polarimeter (SP) of the quiet
Sun allow characterization of the weak, mixed-polarity magnetic
flux at the highest angular resolution to date (0.3"), and with good
polarimetric sensitivity(0.025% relative to the continuum). The image
stabilization of the HINODE spacecraft allows long integrations with
degradation of the image quality only by the evolution of the solar
granulation. From the Stokes V profile measurements we find an average
solar "Apparent Flux Density" of 14 Mx cm-2, with significant Stokes V
signals at every position on the disk at all times. However, there are
patches of meso-granular size (5-15") where the flux is very weak. At
this high sensitivity, transverse fields produce measurable Stokes
Q,U linear polarization signals over a majority of the area, with
apparent transverse flux densities in the internetwork significantly
larger than the corresponding longitudinal flux densities. When viewed
at the center of the solar disk, the Stokes V signals (longitudinal
fields) show a preference for occurrence in the intergranular lanes,
and the Q,U signals occur preferably over the granule interiors,
but neither association is exclusive. Hinode is an international
project supported by JAXA, NASA, PPARC and ESA. We are grateful to the
Hinode team for all their efforts in the design, build and operation
of the mission.
Title: Attempt to detect Aflven waves with Solar Optical Telescope
aboard Hinode
Authors: Tsuneta, Saku; Suematsu, Y.; Ichimoto, K.; Katsukawa, Y.;
Shimizu, T.; Nagata, S.; Orozco Suárez, D.; Lites, B.; Shine, D.;
Tarbell, T.; Title, A.
Bibcode: 2007AAS...210.9428T
Altcode: 2007BAAS...39..222T
Flux tube on the sun may carry linear and torsional Alfven waves
generated by photospheric motion. Photospheric motion of 2 km/s would
provide magnetic fluctuation of 40G for 1KG tube and for the Alfven
speed of 50km/s. This may be close to the detection limit of the Stokes
Q and U signals for flux tubes located in the sun center. However,
for flux tubes located near the limb, the fluctuation would be seen in
the Stokes V signal, and can be detectable. We also may be able
to confirm the 90 degree phase shift between magnetic fluctuation and
velocity fluctuation, which is easier to observe for flux tubes near
the limb. Detection of waves would be important in terms of coronal
heating and solar wind acceleration. An attempt to detect waves along
flux tubes will be reported.
Title: Discovery Of Cool Cloud-like Structures In The Corona With
Hinode Solar Optical Telescope
Authors: Okamoto, Takenori; Tsuneta, S.; Katsukawa, Y.; Ichimoto,
K.; Suematsu, Y.; Shimizu, T.; Nagata, S.; Shibata, K.; Tarbell, T.;
Shine, R.; Berger, T.; Lites, B.; Myers, D.
Bibcode: 2007AAS...210.9426O
Altcode: 2007BAAS...39..221O
A solar observation satellite Hinode (Japanese for sun rise) was
launched in September 2006.Hinode carried 3 advanced solar telescopes,
visible light telescope, EUV imaging spectrometer, and X-ray telescope
to simultaneously observe the photosphere, chromosphere, transition
region, and corona. In the performance verification phase of the Hinode
spacecraft with its telescopes, we observed an active region AR10921
near the west limb of the solar disk on November 9 2006. At this point,
we planned to observe spicules on the limb with a broadband filter
dedicated to Ca II H line (3968A). Ca II-H emission line (3968A) comes
from plasma with temperature of approx. 10(4) K, which is much lower
than the coronal temperature of 10(6-7) K. In addition to spectacular
spicules, we find a large cloud-like structure located 10,000-20,000
km above the limb. The cloud has a very complex fine structure with
dominant horizontal thread-like structure. Some features are moving
horizontally and also have clear vertical oscillatory motions. The
periods and amplitudes of these oscillations are 130-250 seconds and
200-850 km, respectively. The vertical oscillatory motion sometimes
has a coherence length as long as 16,000 km. We conclude that from
various observational features this vertical oscillation is a signature
of Alfven waves propagating along the horizontal magnetic fields. We
will discuss their origin and implications.
Title: Hinode/SOT Observations of Sunspot Penumbral Dynamics and
Evolution
Authors: Shine, Richard A.; Hagenaar, M.; Tarbell, T.; Title, A.;
Lites, B.; Ichimoto, K.; Tsuneta, S.; Katsakawa, Y.; Suematsu, Y.;
Nagata, S.; Kubo, M.; Shimizu, T.
Bibcode: 2007AAS...210.9407S
Altcode: 2007BAAS...39..218S
The Solar Optical Telescope (SOT) on the Hinode satellite (launched
October 2006) has obtained long and nearly continuous time series of
several large sunspots including those in NOAA AR's 10923, 10925,
and 10930. Here we use high resolution movies taken primarily with
the broad band Ca II (396.8nm) and G band (430.5nm) channels and
magnetograms taken with the 630.2nm narrow band channel to study
the details and short term evolution of penumbral fine structures
as well as the long term evolution of the sunspots. We compute flow
maps and use space/time slices to track motions of Evershed clouds,
penumbral grains, and visualize oscillations. The data contain examples
of penumbral formation and disintegration including "orphan" penumbra
(i.e., penumbra without an obvious umbra). There is also an interesting
instance of "colliding" penumbra in AR 10930 as two sunspots of opposite
polarity converged. The zone of apparent shear was associated with
several flares. This work was supported by NASA contract NNM07AA01C
Title: Optical Performance of the Solar Optical Telescope aboard
HINODE
Authors: Suematsu, Yoshinori; Ichimoto, K.; Katsukawa, Y.; Otsubo,
M.; Tsuneta, S.; Nakagiri, M.; Noguchi, M.; Tamura, T.; Kato, Y.;
Hara, H.; Miyashita, M.; Shimizu, T.; Kubo, M.; Sakamoto, Y.
Bibcode: 2007AAS...210.9402S
Altcode: 2007BAAS...39Q.217S
The Solar Optical Telescope (SOT) carried by HINODE was designed
to perform a high-precision polarimetric observation of the Sun
in visible light spectra with a spatial resolution of 0.2 - 0.3
arcseconds. The SOT is a sophistcated instrument and consists of two
separate optical parts; the Optical Telescope Assembly (OTA) which is
50 cm aperture Gregorian telescope feeding the light into following
observing instruments which is called the focal plane package (FPP)
made of two filtergraphs and a spectro-polarimeter. The performance
of the OTA is important because a spatial resolution and its temporal
stability is mainly determined by this component. To keep the OTA in
moderate temperature and optical thermal deformation small, it equipped
newly designed components such as a heat dump and a secondary field stop
aluminum mirror with high reflectivity silver coating and a temperature
low-sensitive apochromatic collimataing lens unit with a UV/IR cut
coating on the first surface. In addition, the SOT has an active image
stabilization system consisting of correlation tracker, tip-tilt mirror
and its controller against satellite pointing jitter. It was confirmed
that this system freezes residual motion to the 0.01 arcsecond level
on orbit. The image of sub-arcsecond G-band (430.5 nm) bright points
clearly indicates that the SOT achieves the diffraction-limit on orbit;
this is also confirmed using a phase diversity method. In this paper,
we describe details of the design and on-orbit performance of the OTA.
Title: Magnetic Landscape Of Solar Polar Region With Solar Optical
Telescope Aboard Hinode
Authors: Tsuneta, Saku; Suematsu, Y.; Ichimoto, K.; Shimizu, T.;
Katsukawa, Y.; Nagata, S.; Orozco Suárez, D.; Lites, B.; Shine, D.;
Tarbell, T.; Title, A.
Bibcode: 2007AAS...210.9405T
Altcode: 2007BAAS...39..218T
Solar polar region is the final destination for remnant magnetic
fields due to meridional flow and granular diffusion, and is very
important for the global solar dynamo. Hinode satellite carried out
high-resolution spectro-polarimetric observations for the Northern
pole on 2006 November 22 as a part of its performance verification
program. We find ubiquitous isolated (positive and negative) patches
in the Stokes V map (i.e. fields horizontal to local surface) all over
the Arctic circle. The Q (vertical to local surface) map indicates
scattered vertical flux tubes, which have bipolar feature in the U and
V maps. This suggests canopy-like structure of the strong isolated flux
tubes. This will be compared with equatorial landscape with similar
distance from the sun center. Strong flux tube and weaker ubiquitous
horizontal fields as represented by Stokes V would have implication
to the current understanding of the global and local dynamo.
Title: Vector Magnetic Fields of Moving Magnetic Features and Flux
Removal from a Sunspot
Authors: Kubo, M.; Shimizu, T.; Tsuneta, S.
Bibcode: 2007ApJ...659..812K
Altcode:
Moving magnetic features (MMFs) are small photospheric magnetic
elements moving outward in the zone (moat region) surrounding mature
sunspots. Vector magnetic fields and horizontal motion of the classical
MMFs (called isolated MMFs hereafter) are investigated using coordinated
ASP and MDI observations. Their magnetic and velocity properties
are compared to nearby magnetic features, including moat fields
surrounding the isolated MMFs and penumbral uncombed structure. The
moat fields are defined as nonisolated MMFs because they also move
outward from sunspots. The nonisolated MMFs have nearly horizontal
magnetic fields of both polarities. We find that the isolated MMFs
located on the lines extrapolated from the horizontal component of the
uncombed structure have magnetic fields similar to the nonisolated
MMFs. This suggests that the MMFs with nearly horizontal fields are
intersections of horizontal fields extended from the penumbra with the
photospheric surface. We find clear evidence that the isolated MMFs
located on the lines extrapolated from the vertical component of the
uncombed structure have vertical field lines with polarity same as the
sunspot. This correspondence shows that such MMFs are detached from
the spine (vertical) component of the penumbra. We estimate that the
magnetic flux carried by the vertical MMFs is about 1-3 times larger
than the flux loss of the sunspot. We suggest that the isolated vertical
MMFs alone can transport sufficient magnetic flux and are responsible
for the disappearance and disintegration of the sunspot.
Title: Magnetic Field Diagnostic Capability of Solar-B/SOT:
Filtergraph Instrument
Authors: Ichimoto, K.; Suematsu, Y.; Shimizu, T.; Katsukawa, Y.;
Tsuneta, S.; Tarbell, T. D.; Shine, R. A.; Hoffmann, C. M.; Title,
A. M.; Lites, B. W.; Elmore, D. F.; Streander, K. V.
Bibcode: 2006ASPC..358..189I
Altcode:
The Narrowband Filter Instrument (NFI) of the Solar Optical Telescope
onboard Solar-B provides 2D magnetograms/Dopplergrams with a tunable
Lyot filter (width ∼ 0.1 Å) in 6 selected wavelength bands, and
spatial sampling of 0.08 arcsec/px. The Zeeman-effect sensitivity of
NFI and the detection limits of weak magnetic fields are evaluated for
2 photospheric and 3 chromospheric lines. Magnetic-field retrievability
from the NFI observables is studied using synthetic Stokes profiles
of Fe I 5250 Å. We find that, with optimized wavelength sampling at 4
positions, the inferred magnetic field is sufficiently accurate under
the hypothesis of constant magnetic field and velocity along the LOS.
Title: Adiabatic expansion acceleration process in spontaneous fast
magnetic reconnection
Authors: Shimizu, T.; Kondoh, K.; Ugai, M.
Bibcode: 2006AdSpR..37.1283S
Altcode:
MHD study for the adiabatic expansion acceleration process associated
with the spontaneous fast magnetic reconnection is reported. When
the fast reconnection process steadily generates a plasmoid in the
downstream, the adiabatic expansion acceleration region appears
between the reconnection jet and plasmoid. It is pointed out that
the appearance of the acceleration region is required to steadily
keep the reconnection process. The reconnection jet and plasmoid is
generally high beta but the plasma pressure in the acceleration region
is extremely low, when the reconnection jet is supersonic. This feature
may become a signature to detect where the Petschek reconnection is
steadily caused in the current sheet of the geomagnetotail.
Title: Three dimensional computer simulation of magnetic loop
associated with magnetic reconnection
Authors: Kondoh, K.; Ugai, M.; Shimizu, T.
Bibcode: 2006AdSpR..37.1301K
Altcode:
The dynamics of large-scale magnetic loop in three dimensions is
studied by MHD simulations. The spontaneous fast reconnection model
is used in this study. Once a current-driven anomalous resistivity is
ignited in a local region in a current sheet, the fast reconnection
mechanism spontaneously evolves. As a result, large magnetic loop is
developed, and very localized high pressure region appears outside of
the magnetic loop. Near the region between magnetic loop and the high
pressure region, very large vortex flow appears, and then, the high
pressure region more and more localized due to this vortex. On the other
hand, we suggest that the spatial size of initial disturbance to the
direction of current is very important to evolve of three dimensional
fast reconnection processes.
Title: Three Dimensional Analysis of Shock Structure around Magnetic
Loop Associated with Spontaneous Fast Magnetic Reconnection
Authors: Kondoh, K.; Ugai, M.; Shimizu, T.
Bibcode: 2005ESASP.596E..72K
Altcode: 2005ccmf.confE..72K
No abstract at ADS
Title: MHD Shock Wave Structure in Supersonic Magnetic Reconnection
Authors: Shimizu, T.; Kondo, K.; Ugai, M.
Bibcode: 2005ESASP.596E..25S
Altcode: 2005ccmf.confE..25S
No abstract at ADS
Title: A long-time chopper for direct measurement of
4He(12C,16O)γ reaction cross section
Authors: Oba, H.; Sagara, K.; Shimizu, T.; Oshiro, M.; Maeda, T.;
Ikeda, N.
Bibcode: 2005NuPhA.758..407O
Altcode:
Direct measurement of the
4He(12C,16O)γ reaction cross
section by detecting 16O recoils is in progress at
Kyushu University tandem laboratory (KUTL). A long-time chopper
(LTC) has been developed to reject backgrounds from 16O
recoils which have time (energy) spread. In the measurement of
4He(12C,16O)γ cross section at
Ecm = 2.4 MeV, LTC was found to reduce the backgrounds by
about three orders of magnitude.
Title: Contamination evaluation and thermal vacuum bakeout for
SOLAR-B visible-light and X-ray telescope
Authors: Tamura, Tomonori; Hara, Hirohisa; Tsuneta, Saku; Ichimoto,
Kiyoshi; Kumagai, Kazuyoshi; Nakagiri, Masao; Shimizu, Toshifumi;
Sakao, Taro; Kano, Ryouhei
Bibcode: 2005RNAOJ...8...21T
Altcode:
In the development of space telescopes, we are concerned about molecular
outgassing materials from telescope components. In particular, for
solar telescopes in space, the deposition of the outgassing materials
may lead to the increase of solar absorptance at a mirror surface
and it causes the thermal distortion due to the resultant temperature
increase. The mirror reflectivity at vacuum ultraviolet wavelengths
is very sensitive to molecular contamination. We have extensively
evaluated reflectance at 121.6nm (Lyman-alpha) of the contamination
witness mirrors exposed to the telescope testing environments in the
SOLAR-B visible-light telescope program. Thermal vacuum bakeout of
flight components is very effective process to reduce the outgassing
rate. We have severe contamination control program during the assembly
and testing of the SOLAR-B telescope up to launch of the satellite.
Title: Completion of Solar-B/Optical Telescope flight model
Authors: Suematsu, Yoshinori; Ichimoto, Kiyosi; Shimizu, Toshifumi;
Otsubo, Masashi; Nakagiri, Masao; Noguchi, Motokazu; Tamura, Tomonori;
Katsukawa, Yukio; Kato, Yoshihiro; Hara, Hirohisa; Miyashita, Masakuni;
Tsuneta, Saku; Kubo, Masahito; Sakamoto, Yasushi
Bibcode: 2005ARAOJ...7...52S
Altcode:
No abstract at ADS
Title: Supersonic and Subsonic Expansion Acceleration Mechanisms in
Fast Magnetic Reconnection
Authors: Shimizu, T.; Ugai, M.
Bibcode: 2005fmpp.conf..139S
Altcode:
No abstract at ADS
Title: Solar-B/Optical Telescope flight model is coming up
Authors: Suematsu, Yoshinori; Ichimoto, Kiyoshi; Shimizu, Toshifumi;
Otsubo, Masashi; Nakagiri, Masao; Noguchi, Motokazu; Tamura, Tomonori;
Kato, Yoshihiro; Hara, Hirohisa; Miyashita, Masakuni; Tsuneta, Saku;
Katsukawa, Yukio; Kubo, Masahito; Sakamoto, Yasushi
Bibcode: 2005naoj.book....4S
Altcode:
No abstract at ADS
Title: Computer Simulations on the Spontaneous Fast Reconnection
Evolution in Three Dimensions
Authors: Kondoh, K.; Ugai, M.; Shimizu, T.
Bibcode: 2005fmpp.conf..135K
Altcode:
No abstract at ADS
Title: The first build-up of the Solar-B flight models
Authors: Hara, Hirohisa; Ichimoto, Kiyoshi; Otsubo, Masashi; Katsukawa,
Yukio; Kato, Yoshihiro; Kano, Ryohei; Kumagai, Kazuyoshi; Shibasaki,
Kiyoto; Shimizu, Toshifumi; Shimojo, Masumi; Suematsu, Yoshinori;
Tamura, Tomonori; Tsuneta, Saku; Noguchi, Motokazu; Nakagiri, Masao;
Miyashita, Masakuni; Watanabe, Tesuya; Kosuchi, Takeo; Sakao, Taro;
Matsuzaki, Keiichi; Kitakoshi, Yasunori; Kubo, Masahito; Sakamoto,
Yasushi
Bibcode: 2005ARAOJ...7...46H
Altcode:
No abstract at ADS
Title: Vector Magnetic Field of Moving Magnetic Features around a
Well-Developed Sunspot
Authors: Kubo, M.; Shimizu, T.
Bibcode: 2004ASPC..325..143K
Altcode:
No abstract at ADS
Title: SolarB Solar Optical Telescope (SOT)
Authors: Shimizu, T.
Bibcode: 2004ASPC..325....3S
Altcode:
The SolarB Solar Optical Telescope (SOT) will be the largest telescope
with highest performance ever to observe the Sun at visible wavelengths
from space. The telescope itself (Optical Telescope Assembly, OTA)
along with its focal plane package (FPP), is optimized for measurement
of the vector magnetic field and associated dynamics in the solar
photosphere and chromosphere. FPP observations are controlled using
commands from the sequence tables in Mission Data Processor (MDP). This
paper describes scientific capabilities of the instrument.
Title: Test particle simulation of MHD shock structure in fast
magnetic reconnection
Authors: Shimizu, T.
Bibcode: 2004AGUFMSM53B0411S
Altcode:
Test fluid particles are traced on the time-developed MHD simulation
field data, in order to study MHD shock waves formed in fast
magnetic reconnection. In general, when fast magnetic reconnection is
steadily caused in the uniform current sheet, high speed plasma jet
is generated by a pair of slow shocks and a plasmoid is formed in the
downstream. According to our MHD simulations, when the plasmoid continue
to propagate in the current sheet, the slow shock may be separated into
two regions, i.e. reconnection jet region and plasmoid region. The
reconnection jet is generated by the former slow shock. While, the
propagation of the plasmoid is driven by the latter slow shock around
the plasmoid. In addition, if the reconnection jet is supersonic,
the slow shock in the jet region partially collapses, and then,
intermediate waves and expansion waves appear in the jet region. The
details of these MHD wave structures which are new features for the
fast magnetic reconnection on the basis of MHD theory are reported by
using test particle simulation technique.
Title: Image stabilization system on SOLAR-B Solar Optical Telescope
Authors: Shimizu, Toshifumi; Nagata, Shin'ichi; Edwards, Chris;
Tarbell, Theodore; Kashiwagi, Yasuhiro; Kodeki, Kazuhide; Ito,
Osamu; Miyagawa, Hiroyuki; Nagase, Masayuki; Inoue, Syunsaku; Kaneko,
Kazumasa; Sakamoto, Yasushi; Ichimoto, Kiyoshi; Tsuneta, Saku; Miki,
Shiro; Endo, Makoto; Tabata, Masaki; Nakaoji, Toshitaka; Matsuzaki,
Keiichi; Kobayashi, Ken; Otsubo, Masashi; Suematsu, Yoshinori; Kumagai,
Kazuyoshi; Noguchi, Motokazu; Tamura, Tomonori; Nakagiri, Masao
Bibcode: 2004SPIE.5487.1199S
Altcode:
Extremely stable pointing of the telescope is required for images on the
CCD cameras to accurately measure the nature of magnetic field on the
sun. An image stabilization system is installed to the Solar Optical
Telescope onboard SOLAR-B, which stabilizes images on the focal plane
CCD detectors in the frequency range lower than about 20Hz. The system
consists of a correlation tracker and a piezo-based tip-tilt mirror with
servo control electronics. The correlation tracker is a high speed CCD
camera with a correlation algorithm on the flight computer, producing
a pointing error from series of solar granule images. Servo control
electronics drives three piezo actuators in the tip-tilt mirror. A
unique function in the servo control electronics can put sine wave
form signals in the servo loop, allowing us to diagnose the transfer
function of the servo loop even on orbit. The image stabilization
system has been jointly developed by collaboration of National
Astronomical Observatory of Japan/Mitsubishi Electronic Corp. and
Lockheed Martin Advanced Technology Center Solar and Astrophysics
Laboratory. Flight model was fabricated in summer 2003, and we measured
the system performance of the flight model on a laboratory environment
in September 2003, confirming that the servo stability within 0-20 Hz
bandwidth is 0.001-0.002 arcsec rms level on the sun.
Title: The Solar Optical Telescope onboard the Solar-B
Authors: Ichimoto, Kiyoshi; Tsuneta, Saku; Suematsu, Yoshinori;
Shimizu, Toshifumi; Otsubo, Masashi; Kato, Yoshihiro; Noguchi,
Motokazu; Nakagiri, Masao; Tamura, Tomonori; Katsukawa, Yukio; Kubo,
Masahito; Sakamoto, Yasushi; Hara, Hirohisa; Minesugi, Kenji; Ohnishi,
Akira; Saito, Hideo; Kawaguchi, Noboru; Matsushita, Tadashi; Nakaoji,
Toshitaka; Nagae, Kazuhiro; Sakamoto, Joji; Hasuyama, Yoshihiro;
Mikami, Izumi; Miyawaki, Keizo; Sakurai, Yasushi; Kaido, Nobuaki;
Horiuchi, Toshihida; Shimada, Sadanori; Inoue, Toshio; Mitsutake,
Masaaki; Yoshida, Norimasa; Takahara, Osamu; Takeyama, Norihide;
Suzuki, Masaharu; Abe, Shunichi
Bibcode: 2004SPIE.5487.1142I
Altcode:
The solar optical telescope onboard the Solar-B is aimed to perform a
high precision polarization measurements of the solar spectral lines
in visible wavelengths to obtain, for the first time, continuous
sets of high spatial resolution (~0.2arcsec) and high accuracy
vector-magnetic-field map of the sun for studying the mechanisms
driving the fascinating activity phenomena occurring in the solar
atmosphere. The optical telescope assembly (OTA) is a diffraction
limited, aplanatic Gregorian telescope with an aperture of Φ500mm. With
a collimating lens unit and an active folding mirror, the OTA provides
a pointing-stabilized parallel beam to the focal plane package (FPP)
with a field of view of about 360x200arcsec. In this paper we identify
the key technical issues of OTA for achieving the mission goal and
describe the basic concepts in its optical, mechanical and thermal
designs. The strategy to verify the in-orbit performance of the
telescope is also discussed.
Title: Design and Performance of Tip-Tilt Mirror System for Solar
Telescope
Authors: Kodeki, Kazuhide; Fukushima, Kazuhiko; Hara, Hirohisa; Inoue,
Masao; Kano, Ryouhei; Kashiwase, Toshio; Nagata, Shin'ichi; Sakao,
Taro; Shimizu, Toshifumi; Tsuneta, Saku; Yoshida, Tsuyoshi
Bibcode: 2004JSpRo..41..868K
Altcode:
No abstract at ADS
Title: The dynamics of plasmoid in asymmetric spontaneous fast
reconnection
Authors: Kondoh, K.; Ugai, M.; Shimizu, T.
Bibcode: 2004AdSpR..33..794K
Altcode:
The spontaneous fast reconnection evolution is studied in asymmetric
magnetic field configuration. In particular, it is investigated how
shear flow influences in magnetosheath region to the propagation of
plasmoid results from magnetic reconnection using two-dimensional
magnetohydrodynamic simulations. According to the fast reconnection
development, the resulting large-scale plasmoids swell and
propagate. Once the plasmoid fully develops, the propagation speed
becomes almost constant in both the symmetric and asymmetric magnetic
field configuration. An asymmetric plasmoid swells predominantly
in the region of a weaker magnetic field and propagates along the
field lines. The associated shock structure standing at the plasma
boundary is the ordinary slow shock irrespective of the intensity of
shear flow. However, velocity of plasmoid is proportional to shear
flow velocity.
Title: Multi-wavelength observations of microflares and emerging
flux with YOHKOH/SXT
Authors: Shimizu, Toshifumi
Bibcode: 2004IAUS..223..345S
Altcode: 2005IAUS..223..345S
Soft X-ray observations by Yohkoh SXT have revealed that transient
brightenings of small coronal loops frequently occur in active
regions. Their estimated energy is 10^{24} sim 10^{28} ergs and
non-thermal behaviors may be observed in the large member of
the brightenings. They are considered as soft X-ray signatures of
microflares observed in hard X-rays. Lower coronal temperature plasma
(1-2MK) produced by Yohkoh transient brightenings is simultaneously
observed in EUV wavelengths by TRACE and SoHO EIT/CDS. Moreover, EUV
observations have shown a lot of tinier transient brightenings without
accompanying SXT transient brightenings. Coordinated observations with
photospheric observations show that the location of Yohkoh transient
brightenings is well localized in active regions, i.e., in emerging flux
regions, around well-developed sunspots, and in the coronal bundles
connecting the leading plage to the following plage regions. In
some Yohkoh events, small-scale emergence of magnetic flux is well
associated with their occurrence, suggesting that emerging flux plays
a key role in triggering transient energy release in the corona. This
paper reviews multi-wavelength observations coordinated with Yohkoh SXT
observations for investigating the nature of SXT transient brightenings
(SXR microflares) and their associated emerging flux. Finally, Solar-B
space observatory is briefly introduced as a next powerful tool for
multi-wavelength investigations.
Title: Core-Collapse Supernovae Induced by Anisotropic Neutrino
Radiation
Authors: Motizuki, Y.; Madokoro, H.; Shimizu, T.
Bibcode: 2004EAS....11..163M
Altcode: 2004astro.ph..6303M
We demonstrate the important role of anisotropic neutrino radiation
on the mechanism of core-collapse supernova explosions. Through a
newparameter study with a fixed radiation field of neutrinos, we
show thatprolate explosions caused by globally anisotropic neutrino
radiationrepresent the most effective mechanism of increasing the
explosionenergy when the total neutrino luminosity is given. This is
suggestive ofthe fact that the expanding materials of SN 1987A have
a prolategeometry.
Title: Comparison of supersonic and subsonic expansion accelerations
associated with fast magnetic reconnection
Authors: Shimizu, T.; Ugai, M.
Bibcode: 2004AdSpR..33..789S
Altcode:
Supersonic and subsonic expansion acceleration mechanisms associated
with spontaneous fast magnetic reconnection process are compared by
two-dimensional magnetohydrodynamic (MHD) simulations and test fluid
(non-charged) particle simulations. When the Petschek reconnection
process is steadily established, the reconnection jet generated by
a pair of slow shocks becomes either supersonic (Case 1) or subsonic
(Case 2), depending on the upstream plasma condition. For Case 1, the
jet generated by the slow shocks can be further accelerated by the
adiabatic supersonic expansion process. Finally, the jet encounters
a fast shock in front of the plasmoid. For Case 2, the jet generated
by slow shocks can be further accelerated by the adiabatic subsonic
expansion process. The acceleration of Case 1 is stronger than that
of Case 2. In Case 2, a fast shock is not formed. In both cases, it is
important that the propagation of the plasmoid is driven by slow shocks
formed around the plasmoid itself, rather than the reconnection jet.
Title: Plasmoid Formation and Heating in Supersonic and Subsonic
Reconnections
Authors: Shimizu, T.; Ugai, M.
Bibcode: 2004cosp...35..567S
Altcode: 2004cosp.meet..567S
The supersonic and subsonic magnetic reconnections in the closed
boundary system were studied in MHD simulations. Theoretically, when
the upstream magnetic field region is high beta (i.e. larger than
0.5), the reconnection jet is subsonic. Nevertheless, the jet can
be temporally supersonic, i.e. superfast, in the stationary frame,
when the jet region is sufficiently long. As a result, a fast shock
is formed in front of the plasmoid. This is caused by the plasmoid
(plasma loop) propagation. The fast shock is much weaker than that
of supersonic magnetic reconnection. The differences between the
supersonic and subsonic reconnections are discussed in the view of
plasma acceleration and heating.
Title: The evoluton of vector magnetic fields in an emerging flux
region
Authors: Kubo, Masahito; Shimizu, Toshifumi; Tsuneta, Saku; Lites,
B. W.
Bibcode: 2004naoj.book...41K
Altcode:
No abstract at ADS
Title: Digestive enzyme expression and epithelial structure of small
intestine in neonatal rats after 16 days spaceflight
Authors: Miyake, M.; Yamasaki, M.; Hazama, A.; Ijiri, K.; Shimizu, T.
Bibcode: 2004cosp...35.1119M
Altcode: 2004cosp.meet.1119M
It is important to assure whether digestive system can develop
normally in neonates during spaceflight. Because the small intestine
changes its function and structure drastically around weaning known as
redifferentiation. Lactase expression declines and sucrase increases
in small intestine for digestion of solid food before weaning. In this
paper, we compared this enzyme transition and structural development of
small intestine in neonatal rats after spaceflight. To find digestive
genes differentially expressed in fight rats, DNA membrane macroarray
was also used. Eight-day old rats were loaded to Space Shuttle
Columbia, and housed in the animal facility for 16 days in space
(STS-90, Neurolab mission). Two control groups (AGC; asynchronous
ground control and VIV; vivarium) against flight group (FLT) were
prepared. There was no difference in structure (crypt depth) and cell
differentiation of epithelium between FLT and AGC by immunohistochemical
analysis. We found that the amount of sucrase mRNA compared to lactase
was decreased in FLT by RT-PCR. It reflected the enzyme transition
was inhibited. Increase of 5 genes (APO A-I, APO A-IV, ACE, aFABP and
aminopeptidase M) and decrease of carboxypeptidase-D were detected in
FLT using macroarray. We think nutrition differences (less nourishment
and late weaning) during spaceflight may cause inhibition of enzyme
transition at least partly. The weightlessness might contribute to
the inhibition through behavioral change.
Title: The Evolution of Vector Magnetic Fields in an Emerging
Flux Region
Authors: Kubo, M.; Shimizu, T.; Lites, B. W.
Bibcode: 2003ApJ...595..465K
Altcode:
Collaborative observations of NOAA Active Region 9231 were carried out
during 9 days in 2000 November using the Advanced Stokes Polarimeter
(ASP), Yohkoh/SXT, TRACE, and SOHO/MDI, in order to record the
evolution of the photospheric magnetic field and its related coronal
response. During this period an emerging flux region (EFR) appeared in
the photosphere near the well-developed leading sunspot of this region,
and subsequently bright bundles of coronal loops formed between the
main concentrations of opposite magnetic polarity. The structure of
the photospheric field comprising the EFR is classified into three
regions: (1) the main bipolar magnetic flux of the EFR; (2) two small,
rapidly emerging bipoles within the EFR; and (3) the remainder of
the EFR excluding the other two regions. Two small, rapidly emerging
bipoles are observed within a few hours of their first appearance at
the photosphere. Examination of the vector magnetic field, its filling
factor, and Doppler motion within the EFR shows that the young emerging
magnetic field is nearly horizontal, the intrinsic field strength is
weaker than that of the surrounding magnetic field (~500 G), and the
weak field has a high filling factor (>80%) and upward motion (<1
km s-1). At both ends of the horizontal field structure we
find that the magnetic field strength increases to about 1500 G and
the filling factor drops to about 40% as the magnetic field becomes
vertical in orientation during its first 12 hr. This field strength
is typical of the field within the main bipolar magnetic flux, but
the filling factor increases to 80% during the following 2 days. The
process for organizing magnetic field configuration including convective
collapse and flux concentration provides one possible explanation
of the evolution of the field strength and the filling factor in the
EFR. In addition, aymmetric surface distributions of magnetic field
inclination were observed in the horizontal magnetic field area in the
EFR. These asymmetric distributions were also observed in the small,
young, emerging bipoles. This may mean that the magnetic field of the
EFR is affected by the preexisting magnetic environment surrounding
the EFR and that the emerging magnetic loops are deformed before or
at the time they reach the photospheric level.
Title: Spatial and Temporal Properties of Hot and Cool Coronal Loops
Authors: Nagata, Shin'ichi; Hara, Hirohisa; Kano, Ryouhei; Kobayashi,
Ken; Sakao, Taro; Shimizu, Toshifumi; Tsuneta, Saku; Yoshida, Tsuyoshi;
Gurman, Joseph B.
Bibcode: 2003ApJ...590.1095N
Altcode:
A suite of images from the XUV Doppler Telescope (XDT), the Yohkoh Soft
X-ray Telescope (SXT), and the Extreme-Ultraviolet Imaging Telescope
(EIT) on the Solar and Heliospheric Observatory (SOHO) allow us to
see the whole (T>1 MK) temperature evolution of coronal loops. The
detailed morphological comparison of an active region shows that hot
loops seen in SXT (T>3 MK) and cool loops seen in the the EIT 195
Å band (T~1.5 MK) are located in almost alternating manner. The
anticoincidence of the hot and the cool loops is conserved for a
duration much longer than the estimated cooling timescale. However, both
hot and cool loops have counterparts in the intermediate-temperature
images. The cross-correlation coefficients are higher for neighboring
temperature pairs and lower for pairs with larger temperature
differences. These results suggest that loops are not isothermal but
rather have a differential emission measure distribution of modest but
finite width that peaks at different temperatures for different loops.
Title: Development of the Solar-B spacecraft
Authors: Tsuneta, Saku; Ichimoto, Kiyoshi; Suematsu, Yoshinori;
Shimizu, Toshifumi; Hara, Hirohisa; Kano, Ryohei; Nagata, Shin'ichi;
Tamura, Tomonori; Nakagiri, Masao; Noguchi, Motokazu; Kato, Yoshihiro;
Watanabe, Tetsuya; Hanaoka, Yoichiro; Sawa, Masaki; Otsubo, Masashi;
Kosugi, Takeo; Yamada, Takahiro; Sakao, Taro; Matsuzaki, Keiichi;
Minesugi, Kenji; Onishi, Akira; Katsukawa, Yukio; Kobayashi, Ken;
Kubo, Masahito
Bibcode: 2003naoj.book....3T
Altcode:
No abstract at ADS
Title: Development of Solar-B solar optical telescope
Authors: Suematsu, Yoshinori; Ichimoto, Kiyoshi; Shimizu, Toshifumi;
Nagata, Shin'ichi; Tamura, Tomonori; Tsuneta, Saku; Noguchi, Motokazu;
Kato, Yoshihiro; Nakagiri, Masao; Otsubo, Masashi; Hanaoka, Yoichiro;
Katsukawa, Yukio; Kobayashi, Ken; Kubo, Masahito
Bibcode: 2003naoj.book....5S
Altcode:
No abstract at ADS
Title: Development of image stabilization system for solar optical
telescope onboard Solar-B satellite
Authors: Nagata, Shinichi; Shimizu, Toshifumi; Ichimoto, Kiyoshi;
Tsuneta, Saku; Matsuzaki, Keiichi; Kobayashi, Ken
Bibcode: 2003naoj.book....8N
Altcode:
No abstract at ADS
Title: Converging Flows in the Penumbra of a δ Sunspot
Authors: Lites, B. W.; Socas-Navarro, H.; Skumanich, A.; Shimizu, T.
Bibcode: 2002ApJ...575.1131L
Altcode:
Doppler velocities in the penumbra of a δ-configuration sunspot
observed near the limb indicate flows that converge upon the
line separating locally positive and negative polarity magnetic
field (the polarity inversion line). These flows persist for many
hours. Observations of this region with the Advanced Stokes Polarimeter
(ASP) reveal a convex vector field geometry with magnetic lines of
force arching upward from positive polarity, then downward to negative
polarity. The straightforward interpretation of the combined Doppler
velocity and vector field information leads to an untenable physical
situation: were flows directed from both footpoints toward the tops
of arched magnetic lines of force, mass would rapidly load the tops of
the arches. However, there is no observational evidence of the dynamics
that such a loading would require. To better understand this apparent
contradiction, we perform two-component analyses of the observed Stokes
spectral profiles in the vicinity of the polarity inversion line, in
order to extract information about unresolved structure of the magnetic
field and its associated flows. Fits to the observed profiles, obtained
by use of two different inversion techniques, suggest strongly that, as
in penumbrae of simple sunspots, the field geometry in the convergence
zone is ``fluted.'' However, unlike in simple sunspots, which have only
an outward-directed Evershed flow in the more horizontal of the field
components, at each spatial point our analysis reveals flows in the two
components that are oppositely directed. We interpret these observations
as indicative of an interleaved system of field lines in the vicinity
of the polarity reversal, whereby the convergent streams are able to
slip past one another and return downward into the solar interior.
Title: Photospheric Magnetic Activities Responsible for Soft
X-Ray Pointlike Microflares. I. Identifications of Associated
Photospheric/Chromospheric Activities
Authors: Shimizu, T.; Shine, R. A.; Title, A. M.; Tarbell, T. D.;
Frank, Z.
Bibcode: 2002ApJ...574.1074S
Altcode:
By combining Yohkoh soft X-ray images with high-resolution magnetograms
simultaneously obtained at La Palma, we studied photospheric magnetic
signatures responsible for soft X-ray microflares (active-region
transient brightenings). In order to have a reliable correspondence
between the photosphere and the corona, we studied 16 pointlike
transient brightenings with X-ray source size less than 10" occurring
during periods when the seeing was excellent at La Palma, although a
lot of transient brightenings were in forms of multiple- or single-loop
structures. In half of the studied events, small-scale emergences
of magnetic flux loops are found in the vicinity of the transient
brightenings. Six events of that half show that a small-scale flux
emergence accompanies the X-ray brightening 5-30 minutes prior to
its onset. In the other half of the studied events, no apparent
evolutionary change of magnetic flux elements is found associated
with the transient brightenings. Many of these events are found in
rather strong magnetic fields, such as sunspots and pores, implying
that small-scale changes of magnetic flux are obscured or suppressed
by strong magnetic fields. The horizontal plasma flows derived from
local cross-correlation tracking of granules in continuum images are
suppressed at the feet of some X-ray transient brightenings.
Title: Superfast expansion acceleration mechanism in the spontaneous
fast magnetic reconnection
Authors: Shimizu, T.; Ugai, M.
Bibcode: 2002AdSpR..29.1081S
Altcode:
Thermodynamic supersonic (superfast) plasma expansion acceleration
generated in the spontaneous fast magnetic reconnection process is
studied in 2-dimensional magnetohydrodynamic (MHD) simulations. In
contrast to the Petschek reconnection model, the reconnection outflow
jet is found to exceed steadily the Alfven velocity measured in
the upstream magnetic field region. In our MHD simulation for the
symmetric anti-parallel magnetic field model, the final velocity of
the plasma jet is observed to reach 1.4 times of the Alfven velocity,
which is maintained until the jet encounters a fast shock generated
in front of the magnetic loop (plasmoid). Also in asymmetric magnetic
field models, in which the current sheet is put between two straight
magnetic field regions with different intensities, the supersonic plasma
acceleration mechanism is detected. Especially, in the asymmetric model
in which uniform plasma density is initially assumed, the supersonic
acceleration region tends to shift to the side of the higher intensity
magnetic field region. In addition, the plasma jet region consists of
two jet layers which have different Mach numbers and almost the same
jet velocity. It means that the reconnection jet almost have reached
a steady state. Hence, the generation of the superfast jet can be
predicted by the Rankine Hugoniot relation for the slow shock. Once
the superfast jet and magnetic loop are generated, the thermodynamic
supersonic expansion acceleration can occur due to the change of the
pressure balance around the magnetic loop.
Title: MHD wave structures in the plasmoid associated with the fast
magnetic reconnection
Authors: Shimizu, T.; Ugai, M.
Bibcode: 2002cosp...34E1147S
Altcode: 2002cosp.meetE1147S
Numerical MHD study of fast magnetic reconnection is shown in the
view of MHD waves generated in the reconnection jet and associated
plasmoid. In this reconnection model, the reconnection jet generated
by slow shocks is further accelerated by the thermodynamic expansion
acceleration mechanism. Depending on the beta value and plasma
density in the upstream magnetic regions, either supersonic or
subsonic expansion accelerations is caused with different MHD wave
structures. Finally, when the resulting jet encounters a plasmoid, the
slow shock intensity is changed and survives around the plasmoid. It
is remarkable that the slow shock around the plasmoid is dominant to
determine the plasmoid propagation speed, rather than the reconnection
jet.
Title: Solar-B
Authors: Shimizu, T.; Solar-B Team
Bibcode: 2002AdSpR..29.2009S
Altcode:
Following the successful Yohkoh satellite which is continuously
operating since August 1991, the solar physics community in Japan
is now preparing for a Japan's next solar physics mission, Solar-B,
whose primary objective is to study the connection of the dynamics
and heating in the solar corona with the magnetic field at the
solar surface. Solar-B will carry a medium-sized optical telescope
with capability of measuring vector magnetic fields at the solar
surface, together with two X-ray/EUV imaging telescopes capable of
measuring the dynamics and physical conditions of hot plasma in the
solar corona. These telescopes are prepared under the international
collaborations with U.S.A. (NASA) and U.K. (PPARC). ISAS schedules
to launch Solar-B as its 22nd science satellite in summer 2005. The
Solar-B program is now in the proto-model manifacture/test phase and
the baseline design of the satellite as well as the three telescopes
is defined.
Title: Connection between Photospheric Magnetic Fields and Coronal
Structure/Dynamics [Invited]
Authors: Shimizu, T.
Bibcode: 2002mwoc.conf...29S
Altcode:
Continuous observations of the solar X-ray corona with Yohkoh Soft X-ray
Telescope (SXT) have been revealing that dynamical phenomena, such as
coronal jets and microflares (transient loop brightenings) are common
in the corona, especially in the active-region corona. Moreover, the
heating of the corona is about two order of magnitude more significant
in the active regions than in the quiet regions. Since observations of
magnetic fields at the photosphere show that magnetic fields are much
more concentrated into active regions, it has been widely believed that
magnetic fields would be responsible for the heating of the corona as
well as dynamics in the corona. A lot of complicated magnetic activities
are observed at the photosphere; newly emerging magnetic fields,
marging to the same-polarity magnetic fields, cancelling magnetic fields
with the opposite-polarity magnetic fields, developing the shear in
magnetic field structure, and so on. How are these magnetic activities
associated with the dynamics and heating well observed in the coronaNULL
A lot of investigations have been made by comparing Yohkoh observations
with observations of photospheric magnetic fields. This paper reviews
some of investigations made in the last decade. Solar-B is now under
development for the launch scheduled in 2005. Its primary objective
is to study the connection of the dynamics and heating observed in
the solar corona with the magnetic field at the solar surface. For
great advances in understanding the magnetic connection between the
photosphere and the corona with Solar-B, it is significant important
to review the recent knowledges obtained in the Yohkoh era.
Title: The dynamics of plasmoid in symmetric and asymmetric
spontaneous fast reconnection
Authors: Kondoh, K.; Ugai, M.; Shimizu, T.
Bibcode: 2002cosp...34E2129K
Altcode: 2002cosp.meetE2129K
The spontaneous fast reconnection evolution is studied in symmetric
and asymmetric magnetic field configuration. In particularly, it is
investigated what determines the propagation speed of plasmoid using
2 dimensional MHD simulations. According to the fast reconnection
development, the resulting large- scale plasmoids swell and
propagate. Once the plasmoid fully develops, the propagation speed
becomes almost constant in symmetric and asymmetric magnetic field
configuration. In asymmetric magnetic field configuration, an asymmetric
plasmoid swells predominantly in the region of a weaker magnetic field
and propagates along the field lines. It is remarkable that the slow
shocks around the plasmoid determine the propagation speed in the both
of symmetric and asymmetric magnetic field configuration.
Title: The MHD study of the shock waves in the fast magnetic
reconnection with the thermodynamic supersonic expansion acceleration
process
Authors: Shimizu, T.; Ugai, M.
Bibcode: 2001AGUFMSM11B0814S
Altcode:
The structure of the slow and intermediate shock waves in the fast
magnetic reconnection process is studied in MHD simulations and
analytic research. Unlike the Petschek reconnection model, in this fast
reconnection process a thermodynamic supersonic expansion acceleration
mechanism works to accelerate the reconnection jet generated by slow
shocks, and hence, the resulting jet can exceed the Alfven velocity
measured in the upstream field region. The MHD simulation shows that
the thermodynamic acceleration process destroys a pair of the slow
shock associated with the Petschek reconnection model, and eventually
generates a pair of intermediate shocks. But, according to more exact
researches, just after the formation of the intermediate shock, the
structure of the intermediate shock may start to be gradually deformed
into the usual intermediate wave, slow shock and slow expansion waves,
because the intermediate shock has not the steepening effect which is
usually required for shock wave. We comprehensively discuss the fast
reconnection process and the plasmoid (magnetic loop) formed by the
reconnection process in the view of the MHD wave analysis.
Title: Converging Flows in the Penumbra of a δ-Sunspot
Authors: Lites, B. W.; Socas-Navarro, H.; Skumanich, A.; Shimizu, T.
Bibcode: 2001ASPC..248..143L
Altcode: 2001mfah.conf..143L
No abstract at ADS
Title: Thermo-dynamic plasma expansion acceleration in asymmetric
spontaneous fast magnetic reconnection - conditions required for
the onset
Authors: Shimizu, T.; Ugai, M.
Bibcode: 2001sps..proc..347S
Altcode:
One of the onset conditions for the thermodynamic supersonic
(superfast) plasma expansion acceleration generated in the spontaneous
fast magnetic reconnection process is studied by 2-dimensional
magnetohydrodynamic (MHD) simulations and the Rankine Hugoniot
analysis. In this reconnection model, the reconnection outflow jet can
steadily exceed the Alfven velocity measured in the upstream magnetic
field region. Note that this high speed jet cannot be explained by
the Petsheck reconnection model. According to our previous studies
(Shimizu and Ugai, 2000), the plasma jet is generated by a combination
of the slow shock acceleration and adiabatic supersoinc expansion
acceleration. The former acceleration is the same as that of the
Petsheck model and the jet can become superfast, i,e, supersonic. The
latter is caused by the adiabatic expansion of the supersonic plasma
jet. The expansion process is caused by the swelling of the plasmoid
(magnetic loop) associated with the reconnection process. In this
paper, in addition to the symmetric reconnection field case, asymmetric
cases, in general, will also be studied. It is shown that the condition
required to generate the supersonic jet by slow shocks is determined by
the plasma density and beta value in the upstream field region. Once
the supersonic jet is generated, the adiabatic supersonic expansion
acceleration is caused just upstream side of the swelling plasmoid. 1
MHD simulation Figure 1 is obtained in an asymmetric magnetic field
case starting from an initial asymmetric anti-parallel magnetic field
in which no plasma flow and uniform plasma density are initially
set. Figure 1a shows the magnetic field lines
Title: NSA Characteristics of the Semi-Anechoic Chamber Composed of
Absorbers with Different Absorbing Characteristics
Authors: Hamaura, R.; Shimizu, T.; Takiguchi, Y.; Tokuda, M.
Bibcode: 2001aprs.conf..301H
Altcode:
No abstract at ADS
Title: On the Detection of Solar Coronal High-Velocity Fields Using
the XUV Doppler Telescope
Authors: Kobayashi, Ken; Hara, Hirohisa; Kano, Ryohei; Nagata,
Shin'ichi; Sakao, Taro; Shimizu, Toshifumi; Tsuneta, Saku; Yoshida,
Tsuyoshi; Harrison, Richard
Bibcode: 2000PASJ...52.1165K
Altcode:
The XUV Doppler Telescope (XDT) is a sounding rocket experiment
designed to detect flows in the solar corona using filter ratios. The
XDT, successfully launched on 1998 January 31, is a normal incidence
telescope composed of narrow-bandpass multilayer mirrors and capable
of obtaining images 2 Å\ above and 2 Å\ below the Fe XIV 211 Å\
(T = 1.7 MK) emission line. It has the potential to make a velocity map
of the entire solar disk with just a few minutes of observation. The
image ratio maps show features that translate to Doppler shifts of
200 km s-1 or more, including several `redshift' features
located near footpoints of coronal loops. However, no corresponding
velocity features were seen by the Solar and Heliospheric Observatory
(SOHO) Coronal Diagnostic Spectrometer (CDS) in the Mg IX 368 Å (T =
1 MK) line, suggesting that the features are not caused by Doppler
shift. Instead, the features seem to be related to contamination
of lower temperature (T < 1 MK) emission lines and the nearby
density-sensitive Fe XIII lines. We conclude that while no flows were
positively identified by the XDT, this observing technique is capable
of detecting flows of 1000 km s^{-1} independently, and 200 km s^{-1}$
when combined with simultaneous plasma diagnostic observation.
Title: Thermo-Dynamic Plasma Acceleration Mechanism in the Spontaneous
Fast Magnetic Reconnection Model
Authors: Shimizu, T.; Ugai, M.
Bibcode: 2000ASPC..206..183S
Altcode: 2000hesp.conf..183S
No abstract at ADS
Title: Initial Results from the XUV Doppler Telescope
Authors: Kano, R.; Hara, H.; Kobayashi, K.; Kumagai, K.; Nagata, S.;
Sakao, T.; Shimizu, T.; Tsuneta, S.; Yoshida, T.
Bibcode: 2000AdSpR..25.1739K
Altcode:
We developed a unique telescope to obtain simultaneous XUV images and
the velocity maps by measuring the line-of-sight Doppler shifts of the
Fe XIV 211A&ring line (T = 1.8 MK): the Solar XUV Doppler Telescope
(hereafter XDT). The telescope was launched by the Institute of Space
and Astronautical Science with the 22nd S520 rocket on January 31,
1998, and took 14 XUV whole sun images during 5 minutes. Simultaneous
observations of XDT with Yohkoh (SXT), SOHO (EIT, CDS, LASCO and MDI)
were successfully carried out. The images taken with EIT, XDT and SXT
are able to cover the wide temperature ranging from 1 to 10 MK, and
clearly show the multi-temperature nature of the solar corona. Indeed,
we notice that both the cool (1-2 MK) loops observed with EIT and
XDT, and the hot (>3 MK) loops observed with SXT exist in the same
active regions but in a spatially exclusive way. The XDT red-blue ratio
between longer- and shorter-wavelength bands of Fe XIV 211A&ring
line indicates a possible down-flow of 1.8 MK plasma near the footpoints
of multiple cool loops
Title: Weak Transient Activities in the Corona
Authors: Shimizu, T.
Bibcode: 1999spro.proc..123S
Altcode:
Weak transient activities of small-scale coronal loops have been
reported from Yohkoh and SoHO observations: Active-region transient
brightenings (ARTBs), XBP flares, network flares, coronal flashes, and
EUV transient brightenings. They are called with different terminology,
but no significant differences can be found except for the sizes
of energy and the locations where they are observed on the Sun. No
differences except for the sizes of energy can be also found between
ARTBs and standard flares; The frequency distribution of ARTBs as a
function of energy is well represented by a single power-law with
a slope similar to that of standard flares, and relatively strong
ARTBs are populated by non-thermal electrons. With these observations,
although more observations are still required, we currently conclude
that weak transient activities of small-scale coronal loops observed
not only in active regions but also in quiet regions are just small
flares (microflares or nanoflares in terminology), which are located
in lower energy extension of standard flares. No reliable evidences
suggesting that microflares or nanoflares entirely explain the heating
of the corona have been found. However, weak temporal variations seen
in quasi-steady long loops are found to be well correlated with the
heating level, suggesting that they may be an X-ray signature of the
heating process responsible for the heating of the corona.
Title: Solar-B (The Next Japanese Solar Mission)
Authors: Shimizu, T.; Solar-B Working Group
Bibcode: 1999spro.proc..459S
Altcode:
Our view of the solar corona has been revolutionized by Yohkoh. Yohkoh
has shown that the hot corona is extremely dynamic, with magnetic
reconnection, rapid heating, and mass ejection being common
phenomena. The next vital step is to understand magnetic origins of
coronal dynamics and heating. Solar-B, Japan's next solar physics
mission, is designed to study the connection of the dynamics and
heating observed in the corona with the magnetic field at the solar
surface. Solar-B will carry a medium-sized optical telescope capable
of measuring vector magnetic fields on the solar surface, together
with two X-ray/EUV imaging instruments for the solar corona. The
Solar-B program is now in the conceptual design study phase. ISAS,
in collaboration with NASA (U.S.A.) and PPARC (U.K.), plans to launch
Solar-B as its 22nd science satellite in summer 2004.
Title: Narrow-Bandpass Multilayer Mirrors for an Extreme-Ultraviolet
Doppler Telescope
Authors: Hara, Hirohisa; Nagata, Shin'ichi; Kano, Ryouhei; Kumagai,
Kazuyoshi; Sakao, Taro; Shimizu, Toshifumi; Tsuneta, Saku; Yoshida,
Tsuyoshi; Ishiyama, Wakana; Oshino, Tetsuya; Murakami, Katsuhiko
Bibcode: 1999ApOpt..38.6617H
Altcode:
No abstract at ADS
Title: The XUV Doppler Telescope (XDT)
Authors: Sakao, T.; Tsuneta, S.; Hara, H.; Shimizu, T.; Kano, R.;
Kumagai, K.; Yoshida, T.; Nagata, S.; Kobayashi, K.
Bibcode: 1999SoPh..187..303S
Altcode:
We present an overview and instrumental details of the solar XUV Doppler
Telescope (XDT) launched in January 1998 with the S520CN-22 sounding
rocket of the Institute of Space and Astronautical Science. The XDT
observes nearly single-temperature solar corona at 1.8 MK with angular
resolution of ≈ 5'' pixel size, together with the ability to detect
the coronal velocity field with a full-Sun field of view. By use of
normal incidence optics whose primary and secondary mirrors are coated
with multilayer materials in two sectors, the XDT takes images of the
Sun in a set of shorter and longer wavelength bands around the Fe xiv
211.3 Å emission line. Summation of a pair of images in the two bands
provides an image of the 1.8 MK-corona while the difference between
the two provides velocity images of the Fe xiv-emitting plasma. A brief
description on the observation sequence together with the flight result
is also given.
Title: Development and flight performance of tip-tilt mirror system
for a sounding rocket observation of the Sun.
Authors: Shimizu, T.; Yoshida, T.; Tsuneta, S.; Sakao, T.; Kano,
R.; Hara, H.; Nagata, S.; Kodeki, K.; Inoue, M.; Fukushima, K.;
Kashiwase, T.
Bibcode: 1999RNAOJ...4...43S
Altcode: 1999RNOAJ...4...43S
A tip-tilt mirror (TTM) system was developed for the XUV Doppler
telescope (XDT) on board an ISAS sounding rocket. The spatial resolution
of the telescope is about 5″ whereas the pointing stability is
only ±0.3° with the rocket pointing control system. To achieve
better than 5″stability on the focal plane of the telescope, the
TTM system controls the tilt of the secondary mirror with fixed-coil
magnetic actuators. The control signal to stabilize focal-plane images
is supplied by the position-sensitive detector (PSD) of a pin-hole
telescope equipped inside XDT. Closed-loop controls are made with
the on-board software on the DSP processor. The sounding rocket was
successfully launched on 31 January 1998 from the Kagoshima Space
Center of ISAS. TTM worked perfectly during the flight, and achieved
better than 5″stability on the focal plane during CCD exposures.
Title: a Relativistic Description of Gentry's New Redshift
Interpretation
Authors: Shimizu, T.; Watanabe, K.
Bibcode: 1999MPLA...14..779S
Altcode: 1999astro.ph..2278S
We obtain a new expression of the Friedmann-Robertson-Walker metric,
which is an analogue of a static chart of the de Sitter space-time. The
reduced metric contains two functions, M(T, R) and Ψ(T, R), which are
interpreted as, respectively, the mass function and the gravitational
potential. We find that, near the coordinate origin, the reduced metric
can be approximated in a static form and that the approximated metric
function, Ψ(R) satisfies the Poisson equation. Moreover, when the
model parameters of the Friedmann-Robertson-Walker metric are suitably
chosen, the approximated metric coincides with exact solutions of
the Einstein equation with the perfect fluid matter. We then solve
the radial geodesics on the approximated space-time to obtain the
distance-redshift relation of geodesic sources observed by the comoving
observer at the origin. We find that the redshift is expressed in
terms of a peculiar velocity of the source and the metric function,
Ψ(R), evaluated at the source position, and one may think that this
is a new interpretation of Gentry's new redshift interpretation.
Title: Why is the corona hot? Micro- and nano-flares and the solar
corona.
Authors: Shimizu, T.
Bibcode: 1998AstHe..91..399S
Altcode:
The solar corona is the upper atmosphere which consists of faint, hot
(>2 million K degree) plasma. Why is the corona so hot? This is one
of fundamental questions in astrophysics. Micro- and nano-flares have
been recently considered as a mechanism for energy dissipation in the
corona. The soft X-ray telescope on board the Yohkoh satellite enables
one for the first time to investigate micro- and nano-flares. This
article introduces some observational results of micro- and nano-flares,
and discusses their implications for heating of the corona.
Title: Development of the tip-tilt mirror system for the solar
XUV telescope
Authors: Kodeki, Kazuhide; Fukushima, Kazuhiko; Kashiwase, Toshio;
Inoue, Masao; Shimizu, Toshifumi; Yoshida, Tsuyoshi; Sakao, Taro;
Hara, Hirohisa; Nagata, Shin'ichi; Kano, Ryouhei; Tsuneta, Saku
Bibcode: 1998SPIE.3356..922K
Altcode:
This paper describes the design and prelaunch performance of the
tip-tilt mirror (TTM) system developed for the XUV Cassegrain telescope
aboard the ISAS sounding rocket experiment. The spatial resolution
of the telescope is about 5 arcsec, whereas the rocket pointing is
only controlled to be within +/- 0.5 degree around the target without
stability control. The TTM is utilized to stabilize the XUV image
on the focal planes by tilting the secondary mirror with two-axes
fixed-coil type actuators. The two position- sensitive detectors in
the telescope optics and in the TTM mechanical structure from the
normal and local closed-loop modes. The TTM has four grain modes with
automatic transition among the modes. The low gain mode is used in
the initial acquisition, and in case the TTM loses the tracking. The
high gain mode is used in the normal tracking mode. This arrangement
provides us with the wide initial acquisition angle with single TTM
system as well as the high pointing accuracy once the tracking is
established. The TTM has a launch-lock mechanism against the launch
vibration of 16G. The closed-loop control with command and telemetry
interface is done by the flight software against the launch vibration
of 16G. The closed-loop control with command and telemetry interface
is done by the flight software on the DSP processor. The use of the
fast processor brings in the significant reduction in the weight and
size of the control- electronics, more flexible control system, and
shorter design and testing period.
Title: XUV Doppler Telescope Aboard Sounding Rocket
Authors: Yoshida, T.; Kano, R.; Nagata, S.; Hara, H.; Sakao, T.;
Shimizu, T.; Tsuneta, S.
Bibcode: 1998ASSL..229..383Y
Altcode: 1998opaf.conf..383Y
No abstract at ADS
Title: Scientific Objectives of the Solar-B Mission
Authors: Shimizu, T.
Bibcode: 1998ESASP.417..169S
Altcode: 1998cesh.conf..169S
No abstract at ADS
Title: Test Particle Simulations of Proton Accelerations in
Spontaneous Fast Magnetic Reconnection
Authors: Shimizu, T.; Ugai, M.
Bibcode: 1998ASSL..238..723S
Altcode: 1998subs.conf..723S
No abstract at ADS
Title: Deep Survey of Solar Nano-Flares with YOHKOH
Authors: Shimizu, T.; Tsuneta, S.
Bibcode: 1998ASSL..229...27S
Altcode: 1998opaf.conf...27S
No abstract at ADS
Title: Deep Survey of Solar Nanoflares with Yohkoh
Authors: Shimizu, Toshifumi; Tsuneta, Saku
Bibcode: 1997ApJ...486.1045S
Altcode:
Short timescale variability fainter than transient brightenings
(microflares) is found in the solar position-dependent light curves
observed with the Yohkoh Soft X-Ray Telescope. The time variability is
found almost everywhere in active regions and X-ray bright points,
while no significant variability is found in quiet regions. An
intensity correlation is found between the magnitudes of the time
variability and the intensities of the persistent corona. The time
variability is apparently related to the heating mechanism of the
persistent active-region corona. The intensity correlation can be
explained with the idea that the persistent corona is made of extremely
numerous nanoflares, larger ones of which are observed as the time
variability. The alternative explanation is that a common parameter
controls both the persistent corona and the time variability.
Title: XUV Doppler telescope with multilayer optics
Authors: Hara, Hirohisa; Kano, Ryouhei; Nagata, Shin'ichi; Sakao, Taro;
Shimizu, Toshifumi; Tsuneta, Saku; Yoshida, Tsuyoshi; Kosugi, Takeo
Bibcode: 1997SPIE.3113..420H
Altcode:
We present an overview of a sounding-rocket experiment, which is
scheduled to be launched by the Institute of Space and Astronautical
Science (ISAS) in January 1998, the rising phase of the 11-year activity
cycle of the sun. The purpose of this experiment is (1) to obtain
whole-sun images taken in an XUV emission line, Fe XIV 211 angstrom,
using the normal incidence multilayer optics with a high spectral
resolution of (lambda) /(Delta) (lambda) approximately equals 40, and
(2) to carry out the velocity-field measurement with detection limit
as high as 100 km/s.
Title: Development of multilayer mirrors for the XUV Doppler telescope
Authors: Nagata, Shin'ichi; Hara, Hirohisa; Sakao, Taro; Shimizu,
Toshifumi; Tsuneta, Saku; Yoshida, Tsuyoshi; Ishiyama, Wakana;
Murakami, Katsuhiko; Oshino, Tetsuya
Bibcode: 1997SPIE.3113..193N
Altcode:
We present the development status of the normal incidence XUV multilayer
mirrors for XUV Doppler telescope, which observes coronal velocity
fields of the whole sun. The telescope has two narrow band-pass
multilayer mirrors tuned to slightly longer and shorter wavelengths
around the Fe XIV line at 211.3 Angstrom. From the intensity difference
of the images taken with these two bands, we can obtain Dopplergram of
1.8 MK plasma of the whole sun. It is required that the multilayer has
high wavelength-resolution ((lambda) /(Delta) (lambda) approximately
30 per mirror), anti-reflection coating for intense He II 304 angstrom
emission line and high d-spacing uniformity of approximately 1%.
Title: Neutral-Line Magnetic Shear and Enhanced Coronal Heating in
Solar Active Regions
Authors: Falconer, D. A.; Moore, R. L.; Porter, J. G.; Gary, G. A.;
Shimizu, T.
Bibcode: 1997ApJ...482..519F
Altcode:
By examining the magnetic structure at sites in the bright coronal
interiors of active regions that are not flaring but exhibit persistent
strong coronal heating, we establish some new characteristics of
the magnetic origins of this heating. We have examined the magnetic
structure of these sites in five active regions, each of which was well
observed by both the Yohkoh SXT and the Marshall Space Flight Center
Vector Magnetograph and showed strong shear in its magnetic field along
part of at least one neutral line (polarity inversion). Thus, we can
assess whether this form of nonpotential field structure in active
regions is a characteristic of the enhanced coronal heating and vice
versa. From 27 orbits' worth of Yohkoh SXT images of the five active
regions, we have obtained a sample of 94 persistently bright coronal
features (bright in all images from a given orbit), 40 long (>~20,000
km) neutral-line segments having strong magnetic shear throughout
(shear angle greater than 45°), and 39 long neutral-line segments
having weak magnetic shear throughout (shear angle less than 45°). From
this sample, we find that (1) all of our persistently bright coronal
features are rooted in magnetic fields that are stronger than 150 G,
(2) nearly all (95%) of these enhanced coronal features are rooted near
neutral lines (closer than 10,000 km), (3) a great majority (80%) of the
bright features are rooted near strong-shear portions of neutral lines,
(4) a great majority (85%) of long strong-shear segments of neutral
lines have persistently bright coronal features rooted near them, (5)
a large minority (40%) of long weak-shear segments of neutral lines
have persistently bright coronal features rooted near them, and (6)
the brightness of a persistently bright coronal feature often changes
greatly over a few hours. From these results, we conclude that most
persistent enhanced heating of coronal loops in active regions (1)
requires the presence of a polarity inversion in the magnetic field
near at least one of the loop footpoints, (2) is greatly aided by the
presence of strong shear in the core magnetic field along that neutral
line, and (3) is controlled by some variable process that acts in this
magnetic environment. We infer that this variable process is low-lying
reconnection accompanying flux cancellation.
Title: Nonthermal Radio Emission from Solar Soft X-Ray Transient
Brightenings
Authors: Gary, Dale E.; Hartl, Michael D.; Shimizu, Toshifumi
Bibcode: 1997ApJ...477..958G
Altcode:
We compare microwave total power spectral data from the Owens Valley
Radio Observatory Solar Array with soft X-ray transient brightenings
observed with the Yohkoh soft X-ray telescope. We find that the
transient brightenings are clearly detected in microwaves in 12
of 34 events (35%), possibly detected in another 17 of 34 events
(50%), and only five of 34 events (15%) had no apparent microwave
counterpart. Comparing the radio and soft X-ray characteristics, we
find that (1) the soft X-ray peak is delayed relative to the microwave
peak in 16 of 20 events, (2) the microwave flux is correlated with
the flux seen in soft X-rays, (3) when radio fluence is used instead
of radio flux (24 events) the correlation increases substantially,
(4) the microwave spectra in the range 1-18 GHz vary greatly from
event to event, (5) the microwave spectra often peak in the range 5-10
GHz (13 of 16 events), and (6) the microwave spectra of some events
show narrowband spectra with a steep low-frequency slope. We
conclude that the emission from at least some events is the result of
a nonthermal population of electrons, and that transient brightenings
as a whole can therefore be identified as microflares, the low-energy
extension of the general flare energy distribution. Soft X-ray transient
brightenings, and therefore microflares, cannot heat the corona.
Title: Gauge Dependence of Post-Newtonian Approximation in General
Relativity
Authors: Shimizu, T.
Bibcode: 1997gwd..conf..327S
Altcode:
No abstract at ADS
Title: Japanese sounding rocket experiment with the solar XUV
Doppler telescope
Authors: Sakao, Taro; Tsuneta, Saku; Hara, Hirohisa; Kano, Ryouhei;
Yoshida, Tsuyoshi; Nagata, Shin'ichi; Shimizu, Toshifumi; Kosugi,
Takeo; Murakami, Katsuhiko; Wasa, Wakuna; Inoue, Masao; Miura,
Katsuhiro; Taguchi, Koji; Tanimoto, Kazuo
Bibcode: 1996SPIE.2804..153S
Altcode:
We present an overview of an ongoing Japanese sounding rocket project
with the Solar XUV Doppler telescope. The telescope employs a pair
of normal incidence multilayer mirrors and a back-thinned CCD, and is
designed to observe coronal velocity field of the whole sun by measuring
line- of-sight Doppler shifts of the Fe XIV 211 angstroms line. The
velocity detection limit is estimated to be better than 100 km/s. The
telescope will be launched by the Institute of Space and Astronautical
Science in 1998, when the solar activity is going to be increasing
towards the cycle 23 activity maximum. Together with the overview of
the telescope, the current status of the development of each telescope
components including multilayer mirrors, telescope structure, image
stabilization mechanism, and focal plane assembly, are reviewed. The
observation sequence during the flight is also briefly described.
Title: Microflaring in Sheared Core Magnetic Fields and Episodic
Heating in Large Coronal Loops
Authors: Porter, J. G.; Falconer, D. A.; Moore, R. L.; Harvey, K. L.;
Rabin, D. M.; Shimizu, T.
Bibcode: 1996AAS...188.7018P
Altcode: 1996BAAS...28..941P
We have previously reported that large, outstandingly-bright coronal
loops within an active region or stemming from an active region have
one end rooted around a magnetic island of included polarity that is
itself a site of locally enhanced coronal heating (X-ray bright point)
[Porter et al 1996, in Proceedings of the Yohkoh Solar/Stellar IAU
Symposium, ed. Y. Uchida, T. Kosugi, H.S. Hudson (Kluwer: Dordrecht), in
press]. This suggests that exceptional magnetic structure in and around
the magnetic island fosters magnetic activity, such as microflaring,
that results in the enhanced coronal heating in both the compact core
field around the island and in the body of large loops that extend
from this site. We have also reported that enhanced coronal heating
in active regions goes hand-in-hand with strong magnetic shear in
the core magnetic fields along polarity neutral lines (Falconer et al
1995, BAAS, 27(2), 976). Here, by combining MSFC vector magnetograms
with an NSO full-disk magnetogram and Yohkoh SXT coronal images, we
examine the incidence of sheared core fields, enhanced coronal heating,
and microflaring in two active regions having several good examples
of enhanced extended coronal loops. It appears that the localized
microflaring activity in sheared core fields is basically similar
whether the core field is on the neutral line around an island of
included polarity or on the main neutral line of an entire bipolar
active region. This suggests that the enhanced coronal heating in an
extended loop stemming from near a polarity inversion line requires a
special field configuration at its foot to plug it into the activity at
the neutral line, rather than a different kind of activity in the core
field on the neutral line. We also examine whether the waxing and waning
of the coronal brightness of extended loops shows any correlation with
the vigor or frequency of microflaring at the feet. This research was
supported by the Solar Physics Branch of NASA's Office of Space Science.
Title: Evidence that Strong Coronal Heating Results from Photospheric
Magnetic Flux Cancellation
Authors: Moore, R. L.; Falconer, D. A.; Porter, J. G.; Gary, G. A.;
Shimizu, T.
Bibcode: 1996AAS...188.8604M
Altcode: 1996BAAS...28..963M
Soft X-ray images of the Sun's corona, such as those from the Yohkoh
SXT, show that the sites of strongest persistent (non-flare) coronal
heating are located within the strong (>100 gauss) magnetic fields
in sunspot regions and are limited to only certain places within these
stong-field domains, covering only a fraction of the total area. We have
examined the structure of the magnetic field at these sites in 5 active
regions by superposing Yohkoh SXT coronal X-ray images on MSFC vector
magnetograms. We find: (1) nearly all of the enhanced (outstandingly
bright) coronal features that persist for tens of minutes are rooted
near polarity neutral lines in the photospheric magnetic flux; (2) in
most cases the core magnetic field closely straddling the neutral line
at the root of the strong heating is strongly sheared; (3) the enhanced
coronal X-ray brightness in the low-lying core fields shows spatial
substructure that fluctuates on time scales of minutes, in the manner
of microflaring; and (4) large parts of extensive enhanced coronal
features often last for no more than a few hours. From these results,
it appears that most enhanced coronal heating in active regions is a
consequence of some process that (1) acts only in the presence of a
photospheric polarity neutral line, (2) is episodic on times of about
an hour, (3) usually gives stronger coronal heating in the presence of
stronger magnetic shear, but is not required to act by the presence of
magnetic shear, and (4) is often accompanied by microflaring in the
core field. We point out that magnetic flux cancellation (driven by
photospheric flows at the neutral line) is a process that plausibly
meets all these requirements. The flux cancellation might directly
drive microflaring, or trigger microflaring in the sheared core field,
or both. The microflaring might directly produce the enhanced coronal
heating in the core fields as well as generate MHD waves that propagate
up into the enhanced extended coronal loops to provide the strong
coronal heating in these.
Title: Nonthermal Microwave Emission from Soft X-ray Transient
Brightenings.
Authors: Gary, D. E.; Hartl, M.; Shimizu, T.
Bibcode: 1996AAS...188.2609G
Altcode: 1996BAAS...28..858G
Soft X-ray transient brightenings (TBs) are small enhancements,
generally associated with active region loops, that last for 5-10
min. Shimizu et al. (1994) has shown that the rate of energy release in
TBs has the same form as that for flares, and if they are interpreted
as tiny flares they would extend the flare energy release rate to lower
energy by two orders of magnitude. However, in initial investigation of
radio counterparts of TBs near 15 GHz (Gopalswamy et al 1995; White et
al. 1995) showed no conclusive evidence for nonthermal electrons, which
brings into question whether TBs are flare-like energy releases. The
presence of nonthermal electrons is most easily seen at somewhat lower
radio frequencies, which led us to search for such emission in radio
data from the OVRO Solar Array in the range 1-18 GHz. Using soft X-ray
observations from Yohkoh, we identified 34 transient brightenings in
solar active region AR7172 observed from 20-29 May 1992. A comparison
with radio data from OVRO yielded the following new results: 1) enhanced
radio emission can be positively associated with TBs in 12 events (35%),
with another 17 (50%) showing a possible association; 2) a number of
the positive associations show radio peaks that occur near the onset
of the soft X-ray enhancement, with a Neupert-Effect-like relationship
(mean delay of the soft X-ray peak relative to the microwave peak is
2.5 min); 3) the radio power spectra of those events intense enough
to give good spectra indicate the presence of a nonthermal electron
population; 4) the correlation between peak radio flux and peak soft
X-ray flux is weak. For the 7 events with the clearest Neupert-Effect
relationship, there is a much higher correlation between integrated
radio flux and peak soft X-ray flux. Together these results suggest
that TBs are the analog of solar flares extended below the subflare
energy range. We may now state that the low-energy extension of flare
events is not sufficient to heat the corona, but the study of TBs can
shed light on flare processes that may be masked in larger flares.
Title: Small-Scale Horizontal Magnetic Fields in the Solar Photosphere
Authors: Lites, B. W.; Leka, K. D.; Skumanich, A.; Martinez Pillet,
V.; Shimizu, T.
Bibcode: 1996ApJ...460.1019L
Altcode:
We present recent observations of quiet regions near the center
of the solar disk using the Advanced Stokes Polarimeter. These
observations reveal a component of the solar magnetic field heretofore
unobserved: isolated, small-scale (typically 1"-2" or smaller),
predominantly horizontal magnetic flux structures in the solar
photosphere. These features occur in isolation of the well-known,
nearly vertical flux concentrations usually seen in the photospheric
"network." Hence we ascribe this horizontal flux to the photospheric
"internetwork." They reveal themselves by the distinct signature
of the Stokes Q and U polarization profiles, which are symmetric
about the line center. The polarization signals are weak, with peak
amplitudes typically ∼0.1%-0.2% of the continuum intensity in the
resolved spectral profiles, but they are well above the noise level
of these observations (≍0.05%). Such magnetic fields are weak
(significantly less than 1000 G) and largely horizontal owing to
the absence, or near absence, of accompanying Stokes V polarization
when observed at the center of the solar disk. These horizontal field
elements are often associated with blueshifted Stokes line profiles,
and they often occur between regions of opposite polarity (but weak)
Stokes V profiles. The horizontal elements are short-lived, typically
lasting ∼5 minutes. Our observations suggest that we are viewing the
emergence of small, concentrated loops of flux, carried upward either
by granular convection or magnetic buoyancy. Even though these entities
show weak field strengths, they also seem to be fairly common, implying
that they could carry the order of 1024 Mx of magnetic flux
to the surface on a daily basis. However, further observational study
is needed to identify the specific nature of this phenomenon.
Title: Signatures of Global Mode Alfven Resonance Heating in
Coronal Loops
Authors: Ofman, L.; Davila, J. M.; Shimizu, T.
Bibcode: 1996ApJ...459L..39O
Altcode:
The Yohkoh Soft X-Ray Telescope (SXT) observations of active region
coronal loops transient brightening is analyzed, and the scaling of
the thermal energy release with loop lengths is found to be Eth ~
L1.60+/-0.09. The numerically determined scaling of the global
mode heating rate for the resonant absorption of Alfven waves,
H ~ L, is found to agree with the heating rate deduced from the
observed thermal energy scaling, provided that the magnetic field
scales as B ~ L-0.70+/-0.05 and the waves are driven with a omega -1
spectrum. Previous analytical and numerical studies have shown that the
heating due to resonant absorption of Alfven waves is most efficient at
the global mode frequency. In agreement with these studies, we suggest
that coronal loop transient X-ray brightenings occur when a given
length coronal loop is perturbed at its global mode frequency by random
footpoint motions, which results in more efficient heating of the loop.
Title: Gravitational collapse of rotating stellar cores and supernovae
Authors: Sato, K.; Shimizu, T. M.; Yamada, S.
Bibcode: 1996NuPhA.606..118S
Altcode:
As is well known, massive stars, which would be the progenitor of
type II supernovae, are rapid rotators. It is obviously necessary to
investigate the effects of rotation on gravitational collapse of stellar
cores and supernova explosions. We review (i) rotational core collapse,
(ii) jet-like explosion induced by rotation and asymmetric neutrino
emission from proto-neutron-stars, and (iii) explosive nucleosynthesis
when an asymmetric jet-like explosion occurs, based on our recent work.
Title: YOHKOH Observations Related to Coronal Heating (Invited)
Authors: Shimizu, T.
Bibcode: 1996ASPC..111...59S
Altcode: 1997ASPC..111...59S
Yohkoh observations of microflares (transient brightenings) and
nanoflares are presented. The frequency distribution of transient
brightenings is found to be a power law with an index of 1.5 - 1.6
in the energy range greater than 1027erg. Short time-scale
variability fainter than transient brightenings is found in the soft
X-ray position-dependent light curves. Time variability is found
almost everywhere in active regions and X-ray bright points, while no
significant variability is found in the quiet Sun.
Title: Heating of Active Region Corona by Transient Brightenings
(Microflares)
Authors: Shimizu, T.; Tsuneta, T.; Title, A.; Tarbell, T.; Shine,
R.; Frank, Z.
Bibcode: 1996mpsa.conf...37S
Altcode: 1996IAUCo.153...37S
No abstract at ADS
Title: Computer Simulations on the Spontaneous Fast Reconnection
Mechanism
Authors: Ugai, M.; Shimizu, T.; Obayashi, T.
Bibcode: 1996mpsa.conf..583U
Altcode: 1996IAUCo.153..583U
No abstract at ADS
Title: Magnetic Roots of Enhanced High Coronal Loops
Authors: Porter, J. C.; Falconer, D. A.; Moore, R. L.; Harvey, K. L.;
Rabin, D. M.; Shimizu, T.
Bibcode: 1996mpsa.conf..429P
Altcode: 1996IAUCo.153..429P
No abstract at ADS
Title: The Radio Properties of Solar Active Region Soft X-Ray
Transient Brightenings
Authors: White, S. M.; Kundu, M. R.; Shimizu, T.; Shibasaki, K.;
Enome, S.
Bibcode: 1995ApJ...450..435W
Altcode:
We present the results of a search for radio emission from active-region
transient brightenings identified in Yohkoh soft X-ray telescope
observations of active region AR 7260. We present detailed observations
of four events in which 17 GHz radio emission is clearly detected in
observations by the Nobeyama radioheliograph. The time profiles of
the 17 GHz data are very similar to those of the soft X-ray fluxes,
and the 17 GHz flux is very close to that expected from plasma with
the temperature and emission measure derived for the soft X-ray
emitting material from filter ratios. No impulsive nonthermal radio
emission was detected from any of the four events, although each was
at least GOES class B 1 in soft X-rays. Weak hard X-rays may have been
detected by GRO/BATSE from the strongest of the events, but not from
two others. These negative results leave open the possibility that
there is a difference between active region transient brightenings
and solar flares, in that the former do not convert a significant
amount of the released energy into accelerated electrons. However,
confirmation of this hypothesis will require a larger sample of events.
Title: Coordinated Observation of the Solar Corona Using the Norikura
Coronagraph and the YOHKOH Soft X-Ray Telescope
Authors: Ichimoto, K.; Hara, H.; Takeda, A.; Kumagai, K.; Sakurai,
T.; Shimizu, T.; Hudson, H. S.
Bibcode: 1995ApJ...445..978I
Altcode:
Spectroscopic observations of coronal emission lines were carried
out at the Norikura Solar Observatory in cooperation with the soft
X-ray telescope on board the Yohkoh satellite to study the plasma
distributions at different temperatures. Intensity and velocity
distributions in Fe XIV wavelength 5303 (green), Fe X wavelength
6374 (red), and Ca XV wavelength 5694 (yellow) lines are compared
with the soft X-ray images. It is found that the soft X-ray images
closely resemble those of the yellow line that represents a rather
high temperature component of the corona. On the other hand the
low-temperature component seen in the green and the red lines shows
quite a different distribution from that of the high-temperature
component; the low-temperature component consists of many thin loops
or streaks, while the high-temperature component is more diffuse. We
find that the active elements of the cool component, i.e., complex
loop systems, rapid changes of small structures, and localized large
plasma motions, all tend to be cospatial with the hot component.
Title: YOHKOH SXT/HXT Observations of a Two-Loop Interaction Solar
Flare on 1992 December 9
Authors: Inda-Koide, Mika; Sakai, Jun-Ichi; Koide, Shinji; Kosugi,
Takeo; Sakao, Taro; Shimizu, Toshifumi
Bibcode: 1995PASJ...47..323I
Altcode:
Observations with the Soft X-ray and Hard X-ray Telescopes aboard Yohkoh
of a simple solar flare on 1992 December 9 are discussed. The soft X-ray
morphology suggests evidence of a loop-loop interaction mechanism:
the images reveal two parallel magnetic loops prior to the flare,
and their merging just before onset of the hard X-ray burst. This
flare therefore provides a chance to examine the two-loop interaction
model for solar flares. It is found (1) that the observed soft X-ray
behavior of the two loops in the preflare phase well matches to the
two-loop interaction model between strong and weak current loops and
(2) that the observed time scale of the two-loop coalescence is almost
equal to that estimated from explosive-reconnection theory. In the
impulsive phase, it is found (3) that the loop-top portion near to the
interaction region first brightens in the 14--23 keV hard X-rays and (4)
that the 23--33 keV hard X-ray emission around the peak time originates
dominantly from two compact sources at the two ends of the merging
loops. These hard X-ray observations are explained by high-energy
electrons that are produced in the two current loop interaction.
Title: Energetics and Occurrence Rate of Active-Region Transient
Brightenings and Implications for the Heating of the Active-Region
Corona
Authors: Shimizu, Toshifumi
Bibcode: 1995PASJ...47..251S
Altcode:
Frequent transient brightenings have been discovered in solar
active regions using the Yohkoh Soft X-ray Telescope. We examine the
possibility that these transient brightenings have much contribution
to heating of the active-region corona. Imaging observations provide
the following physical conditions: temperature, 4--8 MK; emission
measure, 10(44.5) --10(47.5) cm(-3) ; electron density, 2 times 10(9)
--2 times 10(10) cm(-3) ; gas pressure, 5--20 dyne cm(-2) ; loop
length, 5 times 10(3) --4 times 10(4) km; loop width, 2 times 10(3)
--7 times 10(3) km; and duration, 2--7 min. The energy involved in
the observed transient brightenings is estimated to range from 10(25)
to 10(29) erg. The frequency distribution as a function of the energy
can be represented by a single power-law with an index of 1.5--1.6 in
the energy range greater than 10(27) erg, although the distribution
deviates from a power-law in the energy range less than 10(27) erg
due to the instrument dead time and/or obscuration by bright coronal
features. The single power-law of the frequency distribution thus
appears to extend from the solar flare range down to an energy of 10(27)
erg. The total energy supplied by transient brightenings and flares,
assuming that the power-law continues to lower energy, is estimated
to be at most a factor of 5 smaller than the heating rate required for
the active-region corona. We need weaker events with an occurrence rate
much higher than the extrapolated power-law to explain the heating of
the active-region corona with transient brightenings.
Title: Temperature Structure of Active Regions Deduced from the
Helium-Like Sulphur Lines
Authors: Watanabe, Tetsuya; Haka, Hirohisa; Shimizu, Toshifumi; Hiei,
Eijiro; Bentley, Robert D.; Lang, James; Phillips, Kenneth J. H.; David
Pike, C.; Fludra, Andrzej; Bromage, Barbara J. I.; Mariska, John T.
Bibcode: 1995SoPh..157..169W
Altcode:
Solar active-region temperatures have been determined from the full-Sun
spectra of helium-like sulphur (SXV) observed by the Bragg Crystal
Spectrometer on board theYohkoh satellite. The average temperature
deduced from SXV is demonstrated to vary with the solar activity level:
A temperature of 2.5 × 106 K is derived from the spectra
taken during low solar activity, similar to the general corona, while
4 × 106 K is obtained during a higher activity phase. For
the latter, the high-temperature tail of the differential emission
measure of active regions is found most likely due to the superposition
of numerous flare-like events (micro/nano-flares).
Title: Transient Brightenings in Active Regions Observed by the
Yohkoh Soft X-Ray Telescope
Authors: Shimizu, T.
Bibcode: 1995SPD....26..712S
Altcode: 1995BAAS...27..968S
No abstract at ADS
Title: Magnetic Shear and Enhanced Coronal Heating in Active Regions
Authors: Falconer, D.; Moore, R. L.; Porter, J.; Shimizu, T.;
Shearer, K.
Bibcode: 1995SPD....26..913F
Altcode: 1995BAAS...27..976F
No abstract at ADS
Title: Explosion mechanism of collapse-driven supernovae
Authors: Sato, K.; Shimizu, T.; Yamada, S.
Bibcode: 1995NuPhA.588..345S
Altcode:
No abstract at ADS