explanation blue bibcodes open ADS page with paths to full text
Author name code: berger
ADS astronomy entries on 2022-09-14
author:"Berger, Thomas E." OR author:"Berger, Tom"
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Title: 4π Heliospheric Observing System - 4π-HeliOS: Exploring
the Heliosphere from the Solar Interior to the Solar Wind
Authors: Raouafi, Nour E.; Gibson, Sarah; Ho, George; Laming,
J. Martin; Georgoulis, Manolis K.; Szabo, Adam; Vourlidas, Angelos;
Mason, Glenn M.; Hoeksema, J. Todd; Velli, Marco; Berger, Thomas;
Hassler, Donald M.; Kinnison, James; Viall, Nicholeen; Case, Anthony;
Newmark, Jeffrey; Lepri, Susan; Krishna Jagarlamudi, Vamsee; Raouafi,
Nour; Bourouaine, Sofiane; Vievering, Juliana T.; Englander, Jacob A.;
Shannon, Jackson L.; Perez, Rafael M.; Chattopadhyay, Debarati; Mason,
James P.; Leary, Meagan L.; Santo, Andy; Casti, Marta; Upton, Lisa A.
2022cosp...44.1530R Altcode:
The 4$\pi$ Heliospheric Observing System (4$\pi$-HeliOS) is an
innovative mission concept study for the next Solar and Space
Physics Decadal Survey to fill long-standing knowledge gaps in
Heliophysics. A constellation of spacecraft will provide both remote
sensing and in situ observations of the Sun and heliosphere from a
full 4$\pi$-steradian field of view. The concept implements a holistic
observational philosophy that extends from the Sun's interior, to the
photosphere, through the corona, and into the solar wind simultaneously
with multiple spacecraft at multiple vantage points optimized for
continual global coverage over much of a solar cycle. The mission
constellation includes two spacecraft in the ecliptic and two flying as
high as $\sim$70$^\circ$ solar latitude. 4$\pi$-HeliOS will provide
new insights into the fundamental processes that shape the whole
heliosphere. The overarching goals of the 4$\pi$-HeliOS concept are
to understand the global structure and dynamics of the Sun's interior,
the generation of solar magnetic fields, the origin of the solar cycle,
the causes of solar activity, and the structure and dynamics of the
corona as it creates the heliosphere. The mission design study is
underway at the Johns Hopkins Applied Physics Laboratory Concurrent
Engineering Laboratory (ACE Lab), a premier mission design center,
fostering rapid and collaborative mission design evolutions.
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Title: Thermospheric Drag Sondes: on-demand probes of the lower
Thermosphere/Mesosphere system
Authors: Berger, Thomas; Pilinski, Marcin; Nock, Kerry; Sutton,
Eric; Bernstein, Research Valerie; Aaron, Kim; Warnecke, Mark;
Thayer, Jeffrey
2022cosp...44..804B Altcode:
The Thermospheric Drag Sonde (TDS) is a system concept designed to
provide multiple, affordable, and expendable thermosphere/mesosphere
probes in a compact format that can be stored on space stations,
like the International Space Station (ISS), and launched on
demand. The motivation for the concept is the lack of data on the
lower ionosphere/thermosphere/mesosphere (ITM) system (~100 - 300
km AMSL) and the difficulty in sustaining orbital platforms at these
very Low Earth Orbit (VLEO) altitudes for periods sufficient to sample
a wide variety of conditions in geospace. The TDS concept takes its
inspiration from upper atmospheric radiosondes that are launched on
demand on balloons to provide critical data for terrestrial weather
forecasting models. The recent loss of forty SpaceX Starlink satellites
due to unexpectedly large atmospheric drag increases at their staging
altitude of 210 km during a minor geomagnetic storm emphasizes the
need for improved forecasting and nowcasting information at VLEO
altitudes. Probe-on-demand systems such as the TDS would fill a key gap
in ITM science and data assimilation in forecasting models. A single
TDS consists of a compact storage format that deploys into large,
lightweight satellite equipped with one or more accelerometers to
directly measure drag effects, a dual-frequency GNSS receiver, a compact
radio link, and a passive de-orbit system that enables prompt re-entry
after deployment from the ISS. Utilizing innovative spherical profile
technology to simplify coefficient of drag calculations, TDS deployments
will obtain acceleration and GPS Precise Orbit Determination (POD)
data during descent and re-entry, providing neutral density profiles
for novel science investigations of the ITM system, forecast model data
assimilation, and nowcasting data to inform launch operations. The
concept is in development with a notional deployment to the ISS in
the 2026 timeframe.
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Title: Space Weather with Quantified Uncertainty (SWQU): Ensemble
Learning for Accurate and Reliable Uncertainty Quantification
Authors: Camporeale, Enrico; Bortnik, Jacob; Berger, Thomas; Guedes
dos Santos, Luiz Fernando; Hu, Andong
2022cosp...44..865C Altcode:
We give an overview of the NASA/NSF funded "Ensemble Learning for
Accurate and Reliable Uncertainty Quantification" SWQU project. The
objective of the project is to create the algorithmic prototype
that will combine a small number of high-fidelity (low error,
but computationally expensive) runs from physics-based models
with a large number of (possibly) less accurate but faster runs
from machine learning models. The goal is to obtain a more accurate
overall prediction than any individual model, and an estimation of the
associated uncertainties. We showcase application examples ranging from
geomagnetic index predictions to solar wind, radiation belt fluxes,
and ground based magnetic field forecasting. The core engine of the
probabilistic predictions is the Accurate and Reliable Uncertainty
Estimate (ACCRUE) model, that is briefly discussed. ACCRUE is able
to estimate uncertainties associated to deterministic predictions,
by solving a deep learning semi-supervised regression problem.
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Title: ESA's Human Interplanetary Exploration Radiation Risk
Assessment System (HIERRAS)
Authors: Heynderickx, Daniel; Berger, Thomas; Jiggens, Piers; Vainio,
Rami; Matthiä, Daniel; Lei, Fan; Raukunen, Osku; Sandberg, Ingmar;
Clucas, Simon; Truscott, Pete
2022cosp...44.2708H Altcode:
The Human Interplanetary Exploration Radiation Risk Assessment System
(HIERRAS, ESA Contract No 4000127129/19/NL/HK) is a chain of tools
for calculation of human radiological and equipment radiation effects
for future interplanetary missions within helio-radii 0.9-1.6 AU. The
system uses existing software tools and models rather than creating new
tools and focusses on seamless and intuitive interfaces between software
modules in order to minimise user intervention in the model chains. This
presentation will describe the overall HIERRAS system architecture and
the following components: \begin{itemize} \item Development of a Python
based application framework to collect user requests, execute model
runs and return the results to the users. Data are passed internally
as json structures which include a standardised set of descriptive
metadata. This HIERRAS framework uses the SPECTIRES Python software to
run environment and effects analysis models and tools locally as well
as through ESA's Network of Models (NoM) infrastructure. Information
on registered users and on run requests and results is maintained in
an SQL database. \item Development of a GUI to allow users to set up
model configurations, execute model runs and collect the results on a
series of web pages. The GUI communicates with the application framework
by exchanging json structures. Extensive background information and a
user manual are provided as well. \item Use of a response function type
approach to handle atmospheric transport and geometry shielding of the
primary radiation environment and derivation of radiation quantities
inside (and outside) space vehicles and habitats. \item HIERRAS uses the
Geant4 GRAS software to simulate 3D particle interactions with planetary
atmospheres and surfaces in addition to spacecraft structures, equipment
and astronauts. A GRAS pre-processor software tool (GRAPPA, abstract
submitted to Scientific Event F2.3) was developed to define position-
and epoch-dependent planetary surface geometries based on the Mars
Climate Database (MCD v5.3), LIP's SOILCOMPI dataset for Mars's surface
composition, and Lunar Prospector gamma-ray spectrometer data for the
Moon's surface composition. \item Re-processing and re-calibration
of the GOES HEPAD high energy proton flux time series. The data were
used to extend the SEPEM reference data with three energy channels
(up to 875 MeV). A new background identification and removal
algorithm was applied to the dataset. The SAPPHIRE SEP model was
updated accordingly. \item Definition of validation and verification
procedures using interplanetary mission datasets and outputs from the
ROSSINI3 study (ESA Contract No 4000125785/18/NL/GLC). \item Updates
to the Geant4 space applications and setting up of docker containers
for easy distribution, bypassing Geant4 installation. \end{itemize}
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Title: Poster Presentation and Discussion
Authors: Berger, Thomas
2022cosp...44.2707B Altcode:
Poster Presentation and Discussion
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Title: The Dosis 3D Project On-Board the International Space Sta-
Tion - Status and Science Overview of 10 Years of Measurements
(2012 - 2022)
Authors: Berger, Thomas
2022cosp...44.2691B Altcode:
The radiation environment encountered in space differs in nature from
that on Earth, consisting mostly of highly energetic ions from protons
up to iron, resulting in radiation levels far exceeding the ones present
on Earth for occupational radiation workers. Since the beginning of
the space era the radiation exposure during space missions has been
monitored with various passive and active radiation instruments. Also,
on-board the International Space Station (ISS) a number of area
monitoring devices provide data related to the spatial and temporal
variation of the radiation field in - and outside the ISS. The aim
of the DOSIS 3D (2012 - ongoing) experiment is the measurement of the
radiation environment within the European Columbus Laboratory of the
ISS. These measurements are, on the one hand, performed with passive
radiation detectors mounted at eleven locations within Columbus
for the determination of the spatial distribution of the radiation
field parameters and, on the other hand, with two active radiation
detectors (DOSTEL) mounted at a fixed position inside Columbus for
the determination of the temporal variation of the radiation field
parameters. The talk will give an overview of the current results of
the data evaluation performed for the passive and active radiation
detectors for DOSIS 3D in the years 2012 to 2022 and further focus on
the work in progress for data comparison with other passive and active
radiation detector systems measuring on-board the ISS. Acknowledgments:
The participation of the Technische Universität Wien, Atominstitut
(ATI), Vienna, Austria in the DOSIS-1 and -2 experiments was supported
by the Austrian Space Applications Programme (ASAP) under contract
no. 819643. The Polish contribution for the Institute of Nuclear
Physics (IFJ), Krakow, Poland was supported by the National Science
Center (project No DEC-2012/06/M/ST9/00423). EK greatly acknowledges
the possibility to participate in the project to DLR and to the ESA
PECS for the financial grant No. PECS4000108464. The participation
of the Nuclear Physics Institute of the Czech Academy of Sciences
has been supported by the grant of Czech Science Foundation (GACR)
No. 15-16622Y. The CAU, University of Kiel was supported by DLR under
grants 50WB0826, 50WB1026, 50WB1232, 50WB1533 and 50WB1817.
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Title: SEP Measurements on the Surface of Mars with the Radiation
Assessment Detector (RAD) aboard the Curiosity rover
Authors: Ehresmann, Bent; Berger, Thomas; Reitz, Guenther; Guo,
Jingnan; Zeitlin, Cary; Wimmer-Schweingruber, Robert; Matthiä,
Daniel; Hassler, Donald M.
2022cosp...44.1174E Altcode:
Exposure to space radiation remains one of the major risks for human
space exploration. Besides the ever-present Galactic Cosmic Radiation
(GCR), spontaneous Solar Energetic Particles (SEPs) emitted from
the Sun during Coronal Mass Ejections (CMEs) or solar flares, can
dominate planetary and interplanetary radiation fields and increase
the radiation dose by potentially orders of magnitudes. To better
understand SEP propagation throughout the heliosphere and their radial
and longitudinal dependencies, space weather monitoring at various
location throughout the heliosphere is required. On the surface of
Mars, the Radiation Assessment Detector (RAD) aboard NASA's Curiosity
rover has been analyzing the radiation environment in Gale crater since
2012. Besides characterizing the radiation dose, RAD is also capable
of measuring energy spectra and integral fluxes of charged and neutral
particles. For the example of charged particles, RAD can distinguish
between different ion species and for low-Z particles also between the
different isotopes. RAD's location on the surface of Mars allows for
unique space weather observations at 1.5 AU that are directly relevant
to understanding particle propagation through the inner heliosphere,
and the impact of space weather on future human explorers of the
Red Planet. RAD's detailed measurements of SEP events, and other
interesting observations, such as arrival times and duration of Forbush
Decreases, CMEs, or the occurrence of Co-Rotating Interaction Regions
(CIRs) provide valuable data for inter-comparison with measurements
from other instrument at Earth and throughout the heliosphere. To
contextualize the RAD SEP measurements, it is important to consider
that Mars possesses an, albeit thin, atmosphere that can filter out
lower-energy particles. Thus, protons need about 150 - 170 MeV to
propagate through the atmosphere, reach the surface, and be detected
by RAD. During the first nine years of its mission, RAD detected five
moderate SEP events on the surface of Mars. As the solar cycle is
now progressing towards the next solar maximum, strong SEP events are
more likely to occur. Consequently, RAD has measured the two strongest
events yet encountered, in the past four months. In this presentation,
we will provide an overview of 10 years of SEP event observations on
the surface of Mars with the RAD instrument. We will then focus on the
last two strongest SEP events: the October 28, 2021 event where dose
rates increased by a factor of 2.25; and the February 16, 2022 event
where dose rates increased by a factor of 3.5 during the event.
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Title: Development of the Internal Dosimetry Array for Gateway
Authors: Zabori, Balazs; Berger, Thomas; Hirn, Attila; Nagamatsu,
Aiko; Gutay, Gergely; Fetter, Viktor; Granja, Carlos; Boersma, Nadine
2022cosp...44.2698Z Altcode:
The Gateway space station, to be built in orbit around the Moon in
the mid-2020s, will not be protected by the Earth's magnetic field
or the atmosphere; hence, astronauts could be exposed to up to 700
times the radiation dose of an average human on Earth from space
radiation. The Internal Dosimeter Array (IDA) instrument suite is the
very first internal ESA experiment on board Gateway. The IDA payload
is accommodated inside the US HALO module within a Payload Bank and
it is composed of the following already existing and flight proven
instruments: - TRITEL 3D silicon detector telescope provided by Centre
for Energy Research (EK); - European Active Dosimeter (EAD) provided
by German Aerospace Center (DLR); - Medipix (MPX) detector provided by
Advacam s.r.o. (AVD); - PADLES and D-SPACE provided by Japanese Space
Agency (JAXA). IDA instruments provide, based on measurements of energy
deposition and particle track analysis, particle fluxes and fluences,
LET spectra, mean quality factors, absorbed dose and dose equivalent
rates, as well as intergrated absorbed dose and dose equivalent from the
charged particle component of space radiation. Besides charged particles
(electrons, protons, He ions and HZE particles), X-rays and gamma-rays
are also measured. The IDA instrument suite covers an overall LET range
up to 1470 keV/$\mu$m in water (including the full range of 0.1 -
150 keV/$\mu$m relevant relevant to radiation protection from space
radiation), and an absorbed dose rate range between nGy/h and a few
hundred mGy/h. IDA data acquisition will start soon after HALO launch
and will continue on a long term, including transit and on the final
halo-like orbit around the Moon. This final orbit will also pass through
the Van Allen radiation belts. Operations will be continuous even during
uncrewed periods. The scientific radiation data provided by IDA will
help the space dosimetry community to improve radiation physics models
for cancer and non-cancer (cardio-vascular system, central nervous
system) effects. These are of utmost importance in supporting crew risk
assessment for deep space exploration missions, not only in the frame
of the Artemis programme but for the future plans of human missions
to Mars. Radiation data provided by the Instruments will serve also as
inputs for studying radiation effects on electronics in deep space. The
present paper gives a brief descripton of the scientific instruments in
IDA and an overview of the system level concept of the IDA payload to
integrate all required instruments within a Gateway Payload Bank and
to provide a system interface between the instrumentation and Gateway
onboard system from electrical and software point of view.
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Title: Solar flare prediction with reduced false positives using a
hybrid CNN-ERT machine learning model
Authors: Berger, Thomas; Flyer, Natasha; Deshmukh, Varad; van der
Sande, Kiera
2022AAS...24043102B Altcode:
Solar flare prediction using modern machine learning models has been
an active field of research for the past several years. Due to the
impulsive, episodic, nature of solar flares, the datasets used to
train the models, whether from solar magnetic field or atmospheric
imaging instruments, are highly imbalanced: there are always many more
"non-flare" data than "flare" data for any given prediction window. This
dataset imbalance has two major impacts: one, it forces adaption of
training algorithms or model parameters that lead to unacceptably high
false-positive rates (FPR); and two, it skews the skill metrics used to
evaluate predictive performance of any model. <P />Here we demonstrate
a hybrid Convolutional Neural Network (CNN) and Extremely Randomized
Trees (ERT) model that is trained and tested on fully imbalanced
Solar Dynamics Observatory (SDO) Helioseismic and Magnetic Imager
(HMI) vector magnetic field data but which achieves a 48% reduction in
FPR relative to traditional single-architecture models for a 12-hour
forecasting window. The reduction in FPR is accompanied by only a
slight reduction in true positive rate (-12%), leading to a slight
decrease in the True Skill Score (TSS), but a large increase in the
Heidke Skill Score (HSS) and F1 score. The addition of the ERT stage
to the "deep learning" CNN model has the added advantage of enabling
ranking of magnetogram features used to achieve a high skill flare
prediction. We find that the probability of flaring provided by the
CNN model is the most predictive input, followed by the Schrijver
R-parameter, measures of magnetic field topological complexity, and
then the total unsigned vertical current and helicity. The resulting
model could be transitioned to operations to increase the short-term
forecasting skill of human-in-the-loop solar flare prediction systems
currently in use in space weather forecasting offices. <P />We also
demonstrate that the SDO Atmospheric Imaging Assembly (AIA) extreme
ultraviolet (EUV) images that are concurrent with the HMI magnetic
field data can be used to both replace the NOAA GOES X-ray flare catalog
as a source for supervised learning data labels, and as an additional
data source for increasing the skill of ML flare prediction models.
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Title: Decreasing False-alarm Rates in CNN-based Solar Flare
Prediction Using SDO/HMI Data
Authors: Deshmukh, Varad; Flyer, Natasha; van der Sande, Kiera;
Berger, Thomas
2022ApJS..260....9D Altcode: 2021arXiv211110704D
A hybrid two-stage machine-learning architecture that addresses the
problem of excessive false positives (false alarms) in solar flare
prediction systems is investigated. The first stage is a convolutional
neural network (CNN) model based on the VGG-16 architecture that
extracts features from a temporal stack of consecutive Solar Dynamics
Observatory Helioseismic and Magnetic Imager magnetogram images
to produce a flaring probability. The probability of flaring is
added to a feature vector derived from the magnetograms to train
an extremely randomized trees (ERT) model in the second stage to
produce a binary deterministic prediction (flare/no-flare) in a 12 hr
forecast window. To tune the hyperparameters of the architecture, a new
evaluation metric is introduced: the "scaled True Skill Statistic." It
specifically addresses the large discrepancy between the true positive
rate and the false positive rate in the highly unbalanced solar flare
event training data sets. Through hyperparameter tuning to maximize
this new metric, our two-stage architecture drastically reduces
false positives by ≍48% without significantly affecting the true
positives (reduction by ≍12%), when compared with predictions from
the first-stage CNN alone. This, in turn, improves various traditional
binary classification metrics sensitive to false positives, such as
the precision, F1, and the Heidke Skill Score. The end result is a
more robust 12 hr flare prediction system that could be combined with
current operational flare-forecasting methods. Additionally, using
the ERT-based feature-ranking mechanism, we show that the CNN output
probability is highly ranked in terms of flare prediction relevance.
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Title: Zodiacal exoplanets in time (ZEIT) XII: a directly imaged
planetary-mass companion to a young Taurus M dwarf star
Authors: Gaidos, E.; Hirano, T.; Kraus, A. L.; Kuzuhara, M.; Zhang,
Z.; Lee, R. A.; Salama, M.; Berger, T. A.; Grunblatt, S. K.; Ansdell,
M.; Liu, M. C.; Harakawa, H.; Hodapp, K. W.; Jacobson, S.; Konishi,
M.; Kotani, T.; Kudo, T.; Kurokawa, T.; Nishikawa, J.; Omiya, M.;
Serizawa, T.; Tamura, M.; Ueda, A.; Vievard, S.
2022MNRAS.512..583G Altcode: 2021arXiv211008655G; 2021MNRAS.tmp.2819G
We report the discovery of a resolved (0.9 arcsec) substellar companion
to a member of the 1-5 Myr Taurus star-forming region. The host star
(2M0437) is a single mid-M type (T<SUB>eff</SUB> ≍ 3100 K) dwarf with
a position, space motion, and colour-magnitude that support Taurus
membership, and possible affiliation with a ~2.5-Myr-old subgroup. A
comparison with stellar models suggests a 2-5 Myr age and a mass of
0.15-0.18M<SUB>⊙</SUB>. Although K2 detected quasi-periodic dimming
from close-in circumstellar dust, the star lacks detectable excess
infrared emission from a circumstellar disc and its H α emission is
not commensurate with accretion. Astrometry based on 3 yr of AO imaging
shows that the companion (2M0437b) is comoving, while photometry of
two other sources at larger separation indicates that they are likely
heavily reddened background stars. A comparison of the luminosity
of 2M0437b with models suggests a mass of 3-5 M<SUB>JUP</SUB>, well
below the deuterium burning limit, and an effective temperature of
1400-1500 K, characteristic of a late L spectral type. The H - K colour
is redder than the typical L dwarf, but comparable to other directly
detected young planets, e.g. those around HR 8799. The discovery of
a super-Jupiter around a very young, very low-mass star challenges
models of planet formation by either core accretion (which requires
time) or disc instability (which requires mass). We also detected a
second, comoving, widely separated (75 arcsec) object that appears to
be a heavily extincted star. This is certainly a fellow member of this
Taurus subgroup and statistically likely to be a bound companion.
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Title: Passive Radiometry of Subsurface Temperatures Using the Mars
2020 Rimfax Instrument
Authors: Siegler, M. A.; White, M. N.; Brovoll, S.; Hamran, S.;
Russell, P.; Mellon, M.; Berger, T.; Paige, D. A.; Hausrath, E.;
Martinez, G.; Rimfax; Mars 2020 Team
2022LPICo2678.1491S Altcode:
We are using a passive radiometry model of the Mars 2020 RIMFAX ground
penetrating radar instrument to constrain temperatures and properties
of the subsurface.
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Title: Dielectric Permittivity and Density of the Shallow Martian
Subsurface in Jezero Crater
Authors: Casademont, T. M.; Hamran, S. -E.; Amundsen, H. E. F.; Eide,
S.; Dypvik, H.; Berger, T.; Russell, P.
2022LPICo2678.1513C Altcode:
RIMFAX estimates of local radar wave propagation velocity by hyperbola
matching. With that, relative dielectric permittivity and bulk rock
density are derived.
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Title: Machine Learning Approaches to Solar-Flare Forecasting:
Is Complex Better?
Authors: Deshmukh, Varad; Baskar, Srinivas; Bradley, Elizabeth;
Berger, Thomas; Meiss, James D.
2022arXiv220208776D Altcode:
Recently, there has been growing interest in the use of machine-learning
methods for predicting solar flares. Initial efforts along these lines
employed comparatively simple models, correlating features extracted
from observations of sunspot active regions with known instances of
flaring. Typically, these models have used physics-inspired features
that have been carefully chosen by experts in order to capture the
salient features of such magnetic field structures. Over time, the
sophistication and complexity of the models involved has grown. However,
there has been little evolution in the choice of feature sets, nor
any systematic study of whether the additional model complexity is
truly useful. Our goal is to address these issues. To that end, we
compare the relative prediction performance of machine-learning-based,
flare-forecasting models with varying degrees of complexity. We also
revisit the feature set design, using topological data analysis to
extract shape-based features from magnetic field images of the active
regions. Using hyperparameter training for fair comparison of different
machine-learning models across different feature sets, we show that
simpler models with fewer free parameters \textit{generally perform
better than more-complicated models}, ie., powerful machinery does
not necessarily guarantee better prediction performance. Secondly, we
find that \textit{abstract, shape-based features contain just as much
useful information}, for the purposes of flare prediction, as the set of
hand-crafted features developed by the solar-physics community over the
years. Finally, we study the effects of dimensionality reduction, using
principal component analysis, to show that streamlined feature sets,
overall, perform just as well as the corresponding full-dimensional
versions.
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Title: Classification of Solar Flare Magnitudes Using SDO/AIA Movies
with 4D Convolutional Neural Networks
Authors: van der Sande, Kiera; Berger, Thomas; Flyer, Natasha;
Deshmukh, Varad
2021AGUFMNG45B0571V Altcode:
Currently, solar flares are labeled with a magnitude based on a
single global measurement of the sun -- the peak X-ray intensity
over the flaring event, as measured by the GOES satellite. Given
that solar flares are local events, human forecasters are then
tasked with labeling the active region on the sun associated with
the flare. This has potential for errors since it mandates using
at least two separate observational systems. Interest has been
growing in using imaging instruments to classify flare intensity and
location simultaneously. In addition, imaging instruments such as the
Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA),
which provides full-Sun images in ultraviolet and extreme ultraviolet
wavelengths, are increasingly used in machine learning (ML) solar flare
prediction models, as these images may reveal more features associated
with flaring than the photospheric magnetic field data that has been
mostly used to date. We demonstrate the use of AIA image cutouts
of solar active regions to characterize the peak X-ray magnitude of
solar flares via ML regression to the GOES measurements, offering an
alternative to using the GOES flare catalog for event location and data
labelling. We use a 4D Convolutional Neural Network (CNN) algorithm
trained on a temporal series of AIA images in various wavelengths,
with the corresponding outputs being the GOES flare magnitude for the
event. However, a challenge is that solar flare peak times and the
length of flaring vary as a function of wavelength, e.g., the flare
peak time in the SDO/AIA 171 Angstrom bandpass (as determined, e.g.,
by the maximum size of saturated pixels in the flare region) can be
as much as 40 minutes after the flare peak in the GOES data). We will
address this complication in constructing training databases for the
ML algorithm and present preliminary results of our regression modeling.
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Title: The SWx TREC Space Weather Data Portal: bringing data from
diverse sources to the community
Authors: Knuth, Jenny; Lucas, Greg; Pankratz, Christopher; Berger,
Thomas
2021AGUFMSM52A..08K Altcode:
An obstacle to understanding, viewing, and communicating space
weather is accessing relevant data. Users spend hours collecting
data from disparate sources and repositories. The learning curve for
finding relevant data is high, and only the most dedicated make the
leap. Datasets are viewed in separate repositories or downloaded and
visualized locally with a custom script. It takes specialized skills
to bring space weather data together for analysis. This results
in space weather often seeming cryptic, invisible, and difficult
to grasp. The University of Colorado at Boulders Space Weather
Technology, Research, and Education Center (SWx TREC), is working to
lower these barriers. SWx TRECs Space Weather Data Portal found at
https://lasp.colorado.edu/space-weather-portal, provides uniform access
to data housed in various remote repositories. In this presentation
I will show how the SWx Data Portal can address the needs of a broad
spectrum of end users: from space weather enthusiasts to educators,
scientists, and operational professionals. The SWx Data Portal enables
users to quickly view and download disparate data relevant to past
space weather events, all in one place. The selected data can be easily
compared, overplotted, curated, saved, downloaded, and shared. For
example, we will demonstrate how the SWx Data Portal can be used to
watch the unfolding of a space weather event from its initiation on
the Sun to its journey through space to its impacts on the Earth. The
relevant coronagraphs and solar images can be easily selected and
aligned in time with X-ray flux and particle data. The solar winds
speed, density, and temperature along with magnetic field direction and
strength can be traced alongside models of satellite drag, D-Region
Absorption, and geomagnetically induced currents. All of these data
products can be synced and viewed on one screen. Events can be saved,
shared, and submitted to the Data Portal's community Event Library. The
SWx Data Portal can help bridge the gap between scientists, forecasters,
and stakeholders by allowing graphical exploration of space weather
data and events. Such tools that connect disparate space weather data
will speed understanding and enable clearer communication to policy
makers and the public, ultimately protecting against space weathers
social and economic impacts.
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Title: University of Colorado SWx TREC Model Staging Platform:
Facilitating Model/Algorithm R2O and O2R Development within a Cloud
Computing Environment
Authors: Craft, James; Lucas, Greg; Pankratz, Christopher; Berger,
Thomas; Sutton, Eric
2021AGUFMSM52A..04C Altcode:
The Space Weather Technology, Research and Education Center (SWx TREC)
is an emerging national center of excellence in cross-disciplinary
research, technology, innovation, and education, intended to facilitate
evolving space weather research and forecasting needs. Within this
center, we are developing a Space Weather Model Staging Platform
(MSP) to facilitate the R2O and O2R pipelines. The MSP leverages
cloud computing to provide a managed computational environment for
independent science teams to deploy their processing software into
an operational-like system. Using cloud computing for the environment
enables traditional defined-cadence (daily, hourly) model runs to be
scheduled while also providing the ability to submit on-demand runs
during storm times with no additional bulk hardware purchases that
would otherwise sit idle most of the time. In this presentation, we
demonstrate the ways that the MSP is being utilized. First, in the R2O
pipeline, we have implemented code from the USGS to produce electric
field maps at a set cadence to demonstrate that the code can be run
in an operational mode. Second, in the O2R pipeline, we are taking
operational codes such as the Enlil Solar Wind Model and the NOAA Whole
Atmosphere Model (WAM), and enabling researchers to investigate new
data assimilation techniques that can supplement and enhance current
operational code capabilities. Finally, we demonstrate the use of cloud
resources to generate automatic flare forecasts from satellite images.
---------------------------------------------------------
Title: A New Interactive 3-Dimensional Data Viewer for the Enlil
Solar Wind Model
Authors: Pankratz, Christopher; Lucas, Greg; Knuth, Jenny; Odstrcil,
Dusan; Craft, James; Berger, Thomas
2021AGUFMSM53B..05P Altcode:
One of the critical models in space weather forecasting is the Enlil
solar wind prediction model that can inform space weather forecasters
the direction and speed of coronal mass ejections CMEs. The Enlil
code calculates the propagation of the solar wind throughout the 3D
heliosphere, but current visualization capabilities in the forecasting
offices are restricted to 2D planes intersecting Earth. This limits
forecasters to only be able to view CME properties that are traveling
directly in the plane of the Earth. Here, we present a new visualization
capability being developed to take advantage of the full Enlil 3D data
volume and interactively visualize the CME expansion out of the plane
of the Earth. This is designed to give forecasters and researchers the
full view of the heliosphere in a manner that can be tailored to these
different types of users. To accomplish this, we are deploying the Enlil
solar wind model into a scalable Cloud-based model staging platform
computing environment, which will allow the full 3D Enlil output to
reside in-situ with the visualization engine. We will discuss our
progress in deploying and running the Enlil model in the Cloud-based
testbed environment, the process of interacting with space weather
forecasters to design a new interactive 3D visualization tool that meets
their needs, and will demonstrate use of the visualization tool itself.
---------------------------------------------------------
Title: From 1973 to the 2020s, from SKYLAB to 3D vector magnetic
fields in prominences
Authors: Lacatus, Daniela; Judge, Philip; Gilbert, Holly; Paraschiv,
Alin; Berger, Thomas
2021AGUFMSH42B..05L Altcode:
Routine measurement of the vector magnetic fields threading prominences
would mark a significant advance in our ability to determine the
dynamics of the Sun's corona. Gilbert et al. (AGU abstract #849653)
have identified the near-UV (250-281 nm) as a prime region for
measurements of magnetic fields within the chromosphere and lower
transition region. Here, we perform an in depth analysis of the near
UV spectra of all prominences observed by the SKYLAB SO82B instrument
during 1973, for the first time. Using over 100 spectral lines we
process the photographic data from scratch, and solve for plasma
properties of several prominences. Given the known complexity of the
thermal and dynamical conditions within prominence plasma, we develop
a model to find mean electron temperatures, densities and mass columns
which capture each spectrums essential characteristics. Prominence
plasmas are optically thick in the cores of many spectral lines of Fe
II and Mg II present in this spectral region. The different optical
depths probe different surfaces along the line-of-sight, so that
near-UV spectro-polarimetry will uniquely determine vector magnetic
fields within the 3D volume of prominences. Therefore, we show that
this technique offers the best future method for answering critical
problems related to coronal dynamics, not only above active regions
as shown by Gilbert et al., but also in prominence plasmas.
---------------------------------------------------------
Title: New Insights into the Martian Radiation Environment gained
with the MSL/RAD Investigation
Authors: Ehresmann, Bent; Hassler, Don; Zeitlin, Cary;
Wimmer-Schweingruber, Robert; Loeffler, Sven; Guo, Jingnan;
Khaksarighiri, Salman; Matthiae, Daniel; Berger, Thomas; Reitz, Gunther
2021AGUFM.P24A..02E Altcode:
The Mars Science Laboratory / Radiation Assessment Detector (MSL/RAD)
has been conducting detailed measurements of the radiation environment
in Gale crater on Mars for more than 9 years. Understanding of this
radiation field, its composition, and its temporal evolution are vital
for the preparation of human exploration missions to Mars. Thereby,
protecting astronauts from the effects of space radiation remains
a critical step for the exploration of Mars. Long-term exposure to
radiation can lead to severe health effects and affects allowable
mission duration. Astronauts need to be protected from exposure to
both the long-term Galactic Cosmic Ray (GCR)-induced radiation, as
well as from short-term, but highly intense Solar Energetic Particles
(SEPs). Here, we provide new insights into the changes the Martian
radiation field has undergone since the beginning of the MSL mission
in mid-2012 (close to solar maximum of solar cycle 24) throughout
the deepest part of the solar minimum of cycle 24. We present how the
evolving solar cycle has affected dosimetric quantities, such as the
RAD-measured absorbed dose rate, Linear Energy Transfer (LET) spectrum,
and the biologically highly-important dose equivalent rate. From these
measurements, we make estimates of how much radiation astronauts would
be exposed to under different mission scenarios and timing. Furthermore,
we present new analysis of the natural radiation shielding effect of
Martian terrain, measured for the first-time in-situ by MSL/RAD. We find
that natural terrain, such as cliff sides or buttes, when high enough,
block out part of the incoming GCR radiation, leading to an overall
decrease in the measured dose rate. We present data from 5 occasions
where such a shielding effect was observed by MSL/RAD and analyze how
the angle of vertical obstruction of the natural terrain affects the
measured decrease in dose. These first-ever in-situ measurements of the
radiation shielding effect are crucial for the planning of radiation
shelters for future Mars explorers by providing insight into the angular
distribution of the radiation environment on the Martian surface. These
measurements are vital to validate radiation transport models used to
calculate the effectiveness of proposed radiation shelter designs.
---------------------------------------------------------
Title: Directionality of the Martian Surface Radiation and Derivation
of the Upward Albedo Radiation
Authors: Guo, Jingnan; Khaksarighiri, Salman; Wimmer-Schweingruber,
Robert F.; Hassler, Donald M.; Ehresmann, Bent; Zeitlin, Cary;
Löffler, Sven; Matthiä, Daniel; Berger, Thomas; Reitz, Günther;
Calef, Fred
2021GeoRL..4893912G Altcode:
Since 2012 August, the Radiation Assessment Detector (RAD) on
the Curiosity rover has been characterizing the Martian surface
radiation field which is essential in preparation for future crewed
Mars missions. RAD observed radiation dose is influenced by variable
topographical features as the rover traverses through the terrain. In
particular, while Curiosity was parked near a butte in the Murray
Buttes area, we find a decrease of the dose rate by (5 ± 1)% as
19% of the sky was obstructed, versus 10% in an average reference
period. Combining a zenith-angle-dependent radiation model and the
rover panoramic visibility map leads to a predicted reduction of the
downward dose by ∼12% due to the obstruction, larger than the observed
decrease. With the hypothesis that this difference is attributable to
albedo radiation coming from the butte, we estimate the (flat-terrain)
albedo radiation to be about 19% of the total surface dose.
---------------------------------------------------------
Title: Measuring the Magnetic Origins of Solar Flares, Coronal Mass
Ejections, and Space Weather
Authors: Judge, Philip; Rempel, Matthias; Ezzeddine, Rana; Kleint,
Lucia; Egeland, Ricky; Berdyugina, Svetlana V.; Berger, Thomas; Bryans,
Paul; Burkepile, Joan; Centeno, Rebecca; de Toma, Giuliana; Dikpati,
Mausumi; Fan, Yuhong; Gilbert, Holly; Lacatus, Daniela A.
2021ApJ...917...27J Altcode: 2021arXiv210607786J
We take a broad look at the problem of identifying the magnetic
solar causes of space weather. With the lackluster performance
of extrapolations based upon magnetic field measurements in the
photosphere, we identify a region in the near-UV (NUV) part of the
spectrum as optimal for studying the development of magnetic free energy
over active regions. Using data from SORCE, the Hubble Space Telescope,
and SKYLAB, along with 1D computations of the NUV spectrum and numerical
experiments based on the MURaM radiation-magnetohydrodynamic and
HanleRT radiative transfer codes, we address multiple challenges. These
challenges are best met through a combination of NUV lines of bright Mg
II, and lines of Fe II and Fe I (mostly within the 4s-4p transition
array) which form in the chromosphere up to 2 × 10<SUP>4</SUP>
K. Both Hanle and Zeeman effects can in principle be used to derive
vector magnetic fields. However, for any given spectral line the τ
= 1 surfaces are generally geometrically corrugated owing to fine
structure such as fibrils and spicules. By using multiple spectral
lines spanning different optical depths, magnetic fields across nearly
horizontal surfaces can be inferred in regions of low plasma β, from
which free energies, magnetic topology, and other quantities can be
derived. Based upon the recently reported successful sub-orbital space
measurements of magnetic fields with the CLASP2 instrument, we argue
that a modest space-borne telescope will be able to make significant
advances in the attempts to predict solar eruptions. Difficulties
associated with blended lines are shown to be minor in an Appendix.
---------------------------------------------------------
Title: VizieR Online Data Catalog: A list of ~330000 stars Kepler
missed (Wolniewicz+, 2021)
Authors: Wolniewicz, L. M.; Berger, T. A.; Huber, D.
2021yCat..51610231W Altcode:
In this paper we have analyzed the Kepler mission's target selection
function by using Gaia DR2 as the ground truth to characterize the
~500000 stars that Kepler could have observed, and compared this
population to the sample of ~200000 stars that were selected for
observations. <P />We started with a subset of 2.4million targets
within the KIC that are located in the Kepler field of view, which we
downloaded from the Mikulski Archive for Space Telescopes (MAST). As
a first step, we cross-matched the KIC with Gaia DR2 to obtain Gaia
information for each star in the KIC. To do this, we used the Centre
de Donnees astronomiques de Strasbourg (CDS) cross-match. <P />We
conducted a positional match with a matching radius of 5", because
the astrometric offsets between the KIC and Gaia have not been well
characterized. We removed duplicates by only selecting the Kepler
and Gaia ID associated with the most similar magnitudes in the Kepler
passband Kp and Gaia passband. We then extracted Gaia Re-normalized
unit weight error (RUWE) values for all sources. <P />(1 data file).
---------------------------------------------------------
Title: Solar Prominence Bubbles and Associated Plasma Instabilities:
IRIS and SDO/AIA Observations
Authors: Liu, W.; Berger, T.
2021AAS...23811311L Altcode:
Solar prominences are cool and dense plasma in the hot corona. The
so-called prominence bubbles are mysterious, dome-shaped, apparently
void structures residing in the lower portions of prominences. Such
bubbles are associated with various plasma instabilities, such as the
Rayleigh-Taylor (RT) and Kelvin-Helmholtz (KH) instabilities. The
former is manifested in plumes that are often produced at the top
boundary of a bubble and intrude upward into the dense prominence
material. The latter is found to be triggered by shear flows at
the bubble boundaries. We present recent observations of prominence
bubbles by IRIS and SDO/AIA, focusing on the diagnostic potential of
RT and KH instabilities on the physical conditions of the prominence
and its supporting magnetic field. We search for evidence of magnetic
flux emergence as the origin of prominence bubbles. We discuss their
role in mass ad magnetic flux transport in the solar atmosphere.
---------------------------------------------------------
Title: Rotation Distributions around the Kraft Break with TESS and
Kepler: The Influences of Mass, Metallicity, and Binarity
Authors: Avallone, E. A.; Tayar, J.; Van Saders, J.; Berger, T.;
Claytor, Z.
2021AAS...23831407A Altcode:
The year-long lightcurves observed in the southern continuous viewing
zone (SCVZ) of the Transiting Exoplanet Survey Satellite (TESS) and the
abundance of rotation periods measured with the Kepler Space Telescope
provide the ideal laboratory to understand stellar rotation across
the main sequence. Here, we find that while we can measure rotation
periods from lightcurves in the TESS SCVZ and use TESS lightcurves
to identify other classes of stellar variability (e.g. pulsations),
instrument systematics prevent the detection of rotation signals longer
than the TESS orbital period of 13.7 days. Due to this detection
limit, we combine more traditional methods of measuring rotation
from spectroscopic data with data from TESS and Kepler to conduct our
analysis. Using rotation periods derived from rotational velocities
measured by the APOGEE spectroscopic survey and radii inferred using
the Gaia mission, we find that we can trace rotation as a function of
evolutionary state and analyze the distribution of rotation periods
as a function of binarity around the Kraft Break. Additionally,
the distribution of detected stars in Kepler and TESS reveals key
differences between stellar populations probed by these two missions,
with TESS probing a significant population of young stars that were
not present in the Kepler sample.
---------------------------------------------------------
Title: Critical Science Plan for the Daniel K. Inouye Solar Telescope
(DKIST)
Authors: Rast, Mark P.; Bello González, Nazaret; Bellot Rubio,
Luis; Cao, Wenda; Cauzzi, Gianna; Deluca, Edward; de Pontieu, Bart;
Fletcher, Lyndsay; Gibson, Sarah E.; Judge, Philip G.; Katsukawa,
Yukio; Kazachenko, Maria D.; Khomenko, Elena; Landi, Enrico; Martínez
Pillet, Valentín; Petrie, Gordon J. D.; Qiu, Jiong; Rachmeler,
Laurel A.; Rempel, Matthias; Schmidt, Wolfgang; Scullion, Eamon; Sun,
Xudong; Welsch, Brian T.; Andretta, Vincenzo; Antolin, Patrick; Ayres,
Thomas R.; Balasubramaniam, K. S.; Ballai, Istvan; Berger, Thomas E.;
Bradshaw, Stephen J.; Campbell, Ryan J.; Carlsson, Mats; Casini,
Roberto; Centeno, Rebecca; Cranmer, Steven R.; Criscuoli, Serena;
Deforest, Craig; Deng, Yuanyong; Erdélyi, Robertus; Fedun, Viktor;
Fischer, Catherine E.; González Manrique, Sergio J.; Hahn, Michael;
Harra, Louise; Henriques, Vasco M. J.; Hurlburt, Neal E.; Jaeggli,
Sarah; Jafarzadeh, Shahin; Jain, Rekha; Jefferies, Stuart M.; Keys,
Peter H.; Kowalski, Adam F.; Kuckein, Christoph; Kuhn, Jeffrey R.;
Kuridze, David; Liu, Jiajia; Liu, Wei; Longcope, Dana; Mathioudakis,
Mihalis; McAteer, R. T. James; McIntosh, Scott W.; McKenzie, David
E.; Miralles, Mari Paz; Morton, Richard J.; Muglach, Karin; Nelson,
Chris J.; Panesar, Navdeep K.; Parenti, Susanna; Parnell, Clare E.;
Poduval, Bala; Reardon, Kevin P.; Reep, Jeffrey W.; Schad, Thomas A.;
Schmit, Donald; Sharma, Rahul; Socas-Navarro, Hector; Srivastava,
Abhishek K.; Sterling, Alphonse C.; Suematsu, Yoshinori; Tarr, Lucas
A.; Tiwari, Sanjiv; Tritschler, Alexandra; Verth, Gary; Vourlidas,
Angelos; Wang, Haimin; Wang, Yi-Ming; NSO and DKIST Project; DKIST
Instrument Scientists; DKIST Science Working Group; DKIST Critical
Science Plan Community
2021SoPh..296...70R Altcode: 2020arXiv200808203R
The National Science Foundation's Daniel K. Inouye Solar Telescope
(DKIST) will revolutionize our ability to measure, understand,
and model the basic physical processes that control the structure
and dynamics of the Sun and its atmosphere. The first-light DKIST
images, released publicly on 29 January 2020, only hint at the
extraordinary capabilities that will accompany full commissioning of
the five facility instruments. With this Critical Science Plan (CSP)
we attempt to anticipate some of what those capabilities will enable,
providing a snapshot of some of the scientific pursuits that the DKIST
hopes to engage as start-of-operations nears. The work builds on the
combined contributions of the DKIST Science Working Group (SWG) and
CSP Community members, who generously shared their experiences, plans,
knowledge, and dreams. Discussion is primarily focused on those issues
to which DKIST will uniquely contribute.
---------------------------------------------------------
Title: RIMFAX GPR on the MARS 2020 Investigation at Jezero Crater
Authors: Hamran, S. -E.; Paige, D. A.; Amundsen, H. E. F.; Berger, T.;
Brovoll, S.; Carter, L.; Damsgård, L.; Dypvik, H.; Eide, S.; Ghent,
R.; Kohler, J.; Mellon, M.; Nunes, D. C.; Plettemeier, D.; Russell, P.
2021LPI....52.1223H Altcode:
The Radar Imager for Mars' Subsurface Experiment (RIMFAX) is a Ground
Penetrating Radar on the Mars 2020 mission's Perseverance rover,
which is planned to land in Jezero Crater on February 18, 2021.
---------------------------------------------------------
Title: VizieR Online Data Catalog: 117 exoplanets in habitable zone
with Kepler DR25 (Bryson+, 2021)
Authors: Bryson, S.; Kunimoto, M.; Kopparapu, R. K.; Coughlin, J. L.;
Borucki, W. J.; Koch, D.; Aguirre, V. S.; Allen, C.; Barentsen, G.;
Batalha, N. M.; Berger, T.; Boss, A.; Buchhave, L. A.; Burke, C. J.;
Caldwell, D. A.; Campbell, J. R.; Catanzarite, J.; Chandrasekaran,
H.; Chaplin, W. J.; Christiansen, J. L.; Christensen-Dalsgaard,
J.; Ciardi, D. R.; Clarke, B. D.; Cochran, W. D.; Dotson, J. L.;
Doyle, L. R.; Duarte, E. S.; Dunham, E. W.; Dupree, A. K.; Endl, M.;
Fanson, J. L.; Ford, E. B.; Fujieh, M.; Gautier, T. N., III; Geary,
J. C.; Gilliland, R. L.; Girouard, F. R.; Gould, A.; Haas, M. R.;
Henze, C. E.; Holman, M. J.; Howard, A. W.; Howell, S. B.; Huber,
D.; Hunter, R. C.; Jenkins, J. M.; Kjeldsen, H.; Kolodziejczak, J.;
Larson, K.; Latham, D. W.; Li, J.; Mathur, S.; Meibom, S.; Middour,
C.; Morris, R. L.; Morton, T. D.; Mullally, F.; Mullally, S. E.;
Pletcher, D.; Prsa, A.; Quinn, S. N.; Quintana, E. V.; Ragozzine,
D.; Ramirez, S. V.; Sanderfer, D. T.; Sasselov, D.; Seader, S. E.;
Shabram, M.; Shporer, A.; Smith, J. C.; Steffen, J. H.; Still, M.;
Torres, G.; Troeltzsch, J.; Twicken, J. D.; Uddin, A. K.; van Cleve,
J. E.; Voss, J.; Weiss, L. M.; Welsh, W. F.; Wohler, B.; Zamudio, K. A.
2021yCat..51610036B Altcode:
We present the occurrence rates for rocky planets in the habitable
zones (HZs) of main-sequence dwarf stars based on the Kepler DR25
planet candidate catalog and Gaia-based stellar properties. We
provide the first analysis in terms of star-dependent instellation
flux, which allows us to track HZ planets. We define {eta}{Earth}
as the HZ occurrence of planets with radii between 0.5 and 1.5
R{Earth} orbiting stars with effective temperatures between 4800
and 6300K. We find that {eta}{Earth} for the conservative HZ is
between 0.37<SUB>-0.21</SUB><SUP>+0.48</SUP> (errors reflect 68%
credible intervals) and 0.60<SUB>-0.36</SUB><SUP>+0.90</SUP>
planets per star, while the optimistic HZ occurrence
is between 0.58<SUB>-0.33</SUB><SUP>+0.73</SUP> and
0.88<SUB>-0.51</SUB><SUP>+1.28</SUP> planets per star. These
bounds reflect two extreme assumptions about the extrapolation of
completeness beyond orbital periods where DR25 completeness data are
available. The large uncertainties are due to the small number of
detected small HZ planets. We find similar occurrence rates between
using Poisson likelihood Bayesian analysis and using Approximate
Bayesian Computation. Our results are corrected for catalog completeness
and reliability. Both completeness and the planet occurrence rate are
dependent on stellar effective temperature. We also present occurrence
rates for various stellar populations and planet size ranges. We
estimate with 95% confidence that, on average, the nearest HZ planet
around G and K dwarfs is ~6pc away and there are ~4 HZ rocky planets
around G and K dwarfs within 10pc of the Sun. <P />(1 data file).
---------------------------------------------------------
Title: The Stars Kepler Missed: Investigating the Biases Behind the
Kepler Target Selection Function
Authors: Wolniewicz, L. M.; Berger, T.; Huber, D.
2021AAS...23721104W Altcode:
The Kepler Mission revolutionized exoplanet science by obtaining highly
precise photometry of 170,000 stars over 4 years. A critical piece of
information needed to accurately exploit Kepler data is the Kepler
selection function, since nearly 200,000 targets had to be selected
for observation from a sample of over a million stars positioned over
the Kepler CCDs with minimal information of their evolutionary state,
stellar multiplicity, or proper motions. In this talk I will explain
how I use Gaia DR2 to reconstruct the Kepler selection function
and explore its biases with respect to evolutionary state, stellar
multiplicity, and proper motions. By comparing the stars positioned
on the Kepler CCDs that were not chosen for observation to those that
were, I will present the first evaluation of the biases of the Kepler
target selection function. I find that Kepler was complete for stars
brighter than K<SUB>p</SUB> = 14 magnitude, unbiased with respect to
proper motions, and that the selection function shows some bias against
stellar multiplicity, in the sense that stars without companions were
preferentially selected for observation.
---------------------------------------------------------
Title: Precise Demographics of Kepler Planets in the Gaia Era
Authors: Berger, T. A.; Huber, D.; Van Saders, J.; Gaidos, E.; Tayar,
J.; Weiss, L.; Kraus, A.
2021AAS...23731703B Altcode:
A major bottleneck for transiting exoplanet demographics has been
the lack of precise properties for most of the observed stars, as
the transit method measures exoplanet radii relative to their host's
radii. We live in a golden era of host star characterization because
of access to Gaia Data Release 2 (DR2) photometry, parallaxes, and
proper motions, large-scale spectroscopic surveys, and ground-based
photometric and spectroscopic follow-up. In this talk, I will present
a sharpened view of Kepler exoplanet demographics using Gaia DR2
parallaxes. First, I will present a comprehensive classification of
main sequence, subgiant, and giant stars in Kepler target sample. Using
revised planet radii and incident fluxes, I will identify the planet
radius gap, planets within the hot sub-Neptunian desert, the hot
Jupiter inflation trend, and present an updated census of habitable
zone planets. I will also present the Gaia-Kepler Stellar Properties
Catalog, the first homogeneous Kepler catalog to include stellar ages,
in addition to precise radii, masses, and mean stellar densities for
Kepler target stars. I will reveal the first observational evidence of
a stellar age dependence of the planet radius gap, where sub-Neptunes
become super-Earths on roughly Gyr timescales. In addition, I will show
that the planet radius valley exhibits a stellar mass dependence and
provide stringent constraints that will be required to discern between
the theories of core-powered mass-loss and photoevaporation. Finally,
I will reveal that most planets within the hot sub-Neptunian desert only
entered recently because of their host's evolution, identify Jupiters
with large radii at low incident fluxes, and demonstrate that planets in
single and multiple transiting systems share the same age distribution.
---------------------------------------------------------
Title: On Cooling Condensation Near Magnetic Null Points and the
Formation of Solar Coronal Rain and Prominences
Authors: Liu, Wei; Titov, Viacheslav; Downs, Cooper; Antolin, Patrick;
Luna, Manuel; Sun, Xudong; Berger, Thomas; Yu, Sijie; Yoffe, Luke
2021cosp...43E.975L Altcode:
The Sun's outer atmosphere, the corona, is million-degrees hot and
tenuous. Such hot plasma, under certain conditions, can enigmatically
undergo a radiative cooling instability and condense into material of
100 times cooler in the form of coronal rain or prominences. Where,
when, and how such cooling condensation takes place remain poorly
understood. Answers to these questions are not only important in their
own right, but also bear implications for the fundamental question
of coronal heating and the chromosphere-corona mass cycle. Magnetic
fields in the magnetized corona undoubtedly play a crucial role (e.g.,
by trapping the plasma), but where and how? We report recent imaging
and spectroscopic observations from SDO/AIA/HMI and IRIS that can
shed light on this puzzle. Through a systematic survey, we found that
a large fraction of quiet-Sun condensations preferentially occur at
the dips of coronal loops or funnels. Such dips are located at/near
magnetic topological features, such as null points and quasi-separatrix
layers (QSLs), which are regions characterized by high values of the
squashing factor. We also identified evidence of magnetic reconnection
at such locations, which can produce favorable conditions, e.g., density
enhancement by compression and/or mass trapping in plasmoids, that can
trigger run-away radiative cooling. We present proof-of-concept MHD
simulations that demonstrate the role of reconnection in transporting
cooled mass from overlying, long loops to underlying, short loops where
it slides down as coronal rain. We will discuss the significance and
broader implications of these results beyond the Sun.
---------------------------------------------------------
Title: The Dosis 3d Project On-Board the International Space Station -
Status and Science Overview of 8 Years of Measurements (2012 - 2020)
Authors: Berger, Thomas; Burmeister, Soenke
2021cosp...43E1878B Altcode:
The radiation environment encountered in space differs in nature from
that on Earth, consisting mostly of highly energetic ions from protons
up to iron, resulting in radiation levels far exceeding the ones present
on Earth for occupational radiation workers. Since the beginning of
the space era the radiation exposure during space missions has been
monitored with various passive and active radiation instruments. Also
on-board the International Space Station (ISS) a number of area
monitoring devices provide data related to the spatial and temporal
variation of the radiation field in - and outside the ISS. The aim
of the DOSIS 3D (2012 - ongoing) experiment is the measurement of the
radiation environment within the European Columbus Laboratory of the
ISS. These measurements are, on the one hand, performed with passive
radiation detectors mounted at eleven locations within Columbus
for the determination of the spatial distribution of the radiation
field parameters and, on the other hand, with two active radiation
detectors (DOSTEL) mounted at a fixed position inside Columbus for
the determination of the temporal variation of the radiation field
parameters. The talk will give an overview of the current results of
the data evaluation performed for the passive and active radiation
detectors for DOSIS 3D in the years 2012 to 2020 and further focus on
the work in progress for data comparison with other passive and active
radiation detector systems measuring on-board the ISS. Acknowledgments:
The participation of the Technische Universität Wien, Atominstitut
(ATI), Vienna, Austria in the DOSIS-1 and -2 experiments was supported
by the Austrian Space Applications Programme (ASAP) under contract
no. 819643. The Polish contribution for the Institute of Nuclear Physics
(IFJ), Krakow, Poland was supported by the National Science Center
(project No DEC-2012/06/M/ST9/00423). MTA EK greatly acknowledges
the possibility to participate in the project to DLR and to the ESA
PECS for the financial grant No. PECS4000108464. The participation
of the Nuclear Physics Institute of the Czech Academy of Sciences
has been supported by the grant of Czech Science Foundation (GACR)
No. 15-16622Y. The CAU, University of Kiel was supported by DLR under
grants 50WB0826, 50WB1026, 50WB1232, 50WB1533 and 50WB1817.
---------------------------------------------------------
Title: A New Interactive 3-Dimensional Data Viewer for the Enlil
Solar Wind Model
Authors: Pankratz, C. K.; Lucas, G.; Odstrcil, D.; Craft, J.; Knuth,
J.; Berger, T. E.
2020AGUFMSH0030017P Altcode:
One of the critical models in space weather forecasting is the Enlil
solar wind prediction model that can inform space weather forecasters
the direction and speed of coronal mass ejections CMEs. The Enlil
code calculates the propagation of the solar wind throughout the 3D
heliosphere, but current visualization capabilities in the forecasting
offices are restricted to 2D planes intersecting Earth. This limits
forecasters to only be able to view CME properties that are traveling
directly in the plane of the Earth. Here, we present a new visualization
capability being developed to take advantage of the full Enlil 3D
data volume and visualize the CME expansion out of the plane of
the Earth that is designed to give forecasters the full view of the
heliosphere. We will discuss our initial progress in deploying and
running the Enlil model in an on-demand mode in a Cloud-based Testbed
and will also describe the process of interacting with space weather
forecasters to design a tool that meets their needs.
---------------------------------------------------------
Title: Solar Prominence Bubbles and Associated Plasma Instabilities:
IRIS Observations and MHD Modeling
Authors: Liu, W.; Berger, T. E.; Fan, Y.
2020AGUFMSH0010014L Altcode:
Solar prominences are cool and dense plasma in the hot corona. The
so-called prominence bubbles are mysterious, dome-shaped, apparently
void structures residing in the lower portions of prominences. Such
bubbles are associated with various plasma instabilities, such as the
Rayleigh-Taylor (RT) and Kelvin-Helmholtz (KH) instabilities. The
former is manifested in plumes that are often produced at the top
boundary of a bubble and intrude upward into the dense prominence
material. The latter is found to be triggered by shear flows at the
bubble boundaries. We present recent observations of prominence
bubbles by IRIS, focusing on the diagnostic potential of RT and
KH instabilities on the physical conditions of the prominence and
its supporting magnetic field. We search for evidence of magnetic
flux emergence as the origin of prominence bubbles. We also present
preliminary 3D MHD simulations of the interaction of a bipole, as a
hypothetical bubble, emerging into an overlying prominence-carrying
flux-rope system. The simulations can provide further clues to the
origin and nature of prominence bubbles. We discuss their roll in mass
ad magnetic flux transport in the solar atmosphere.
---------------------------------------------------------
Title: A Cloud-based Testbed environment to help make models more
"useful"
Authors: Lucas, G.; Pankratz, C. K.; Craft, J.; Knuth, J.; Berger,
T. E.
2020AGUFMSA0040001L Altcode:
In the quote "All models are wrong, but some are useful", a key point
is that a model has to be made useful to the community in some way,
even if it may be "wrong". Here, we present a new Cloud-based Modeling
Testbed environment that is designed to help fill in the missing
"useful" piece when transitioning research models into operational
frameworks. We define the usefulness of the models by iteratively
engaging with the end-user, space weather forecasters and researchers,
during model development to assure that the end product meets the
needs of the community. We will present several specific examples of
research codes that we have transitioned to running in the Cloud and
made available to the public and how community and user feedback has
led to a better end product.
---------------------------------------------------------
Title: SWx TREC's Space Weather Data Portal: a launch pad for space
weather research
Authors: Knuth, J.; Lucas, G.; Pankratz, C. K.; Berger, T. E.; Clark,
R. D.; Skov, T. M.
2020AGUFMSM0030018K Altcode:
One obstacle to space weather research is the practical challenge
of accessing relevant data. Space weather data are housed in
disparate repositories, each with its own unique focus , be
it solar, magnetospheric, atmospheric , or earth-based. Much
of the effort spent acquiring data could instead be spent
on space weather research and education. <P />To address
this problem, the Space Weather Technology, Research, and
Education Center (SWx TREC), at the University of Colorado,
Boulder, in collaboration with the Laboratory for Atmospheric and
Space Physics (LASP), has developed the Space Weather Data Portal (<A
href="https://lasp.colorado.edu/space-weather-portal">https://lasp.colorado.edu/space-weather-portal</A>),
a tool built by and for the space weather community. <P />Through the
Data Portal, previously dispersed space weather data are in one unified
place, accessible to scientists, students, and curious individuals. The
focus is on the users and their ability to discover, display, compare,
overplot, and download relevant data. A user can filter for past
events then easily display and download data related to that event,
from the moment it occurs on the Sun, as it travels through space and
the atmosphere, to the impacts it has on the Earth. <P />Analysis
of space weather events via the Data Portal has proved useful for
forecaster training and online learning. The community-created <A
href="https://lasp.colorado.edu/space-weather-portal/event-library">Event
Library</A> is a short-cut to curated data collections that provide
narratives for context and serve as launch pads for further space
weather exploration.
---------------------------------------------------------
Title: Detecting spatiotemporal correlation in microflares for
improved solar eruption forecasting
Authors: Berger, T. E.; Deshmukh, V.; Flyer, N.; Poduval, B.
2020AGUFMSM047..04B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Shape-based Feature Engineering for Solar Flare Prediction
Authors: Deshmukh, Varad; Berger, Thomas; Meiss, James; Bradley,
Elizabeth
2020arXiv201214405D Altcode:
Solar flares are caused by magnetic eruptions in active regions
(ARs) on the surface of the sun. These events can have significant
impacts on human activity, many of which can be mitigated with enough
advance warning from good forecasts. To date, machine learning-based
flare-prediction methods have employed physics-based attributes of the
AR images as features; more recently, there has been some work that
uses features deduced automatically by deep learning methods (such as
convolutional neural networks). We describe a suite of novel shape-based
features extracted from magnetogram images of the Sun using the tools
of computational topology and computational geometry. We evaluate these
features in the context of a multi-layer perceptron (MLP) neural network
and compare their performance against the traditional physics-based
attributes. We show that these abstract shape-based features outperform
the features chosen by the human experts, and that a combination of
the two feature sets improves the forecasting capability even further.
---------------------------------------------------------
Title: Evidence for Top Quark Production in Nucleus-Nucleus Collisions
Authors: Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.;
Bergauer, T.; Dragicevic, M.; Erö, J.; Escalante Del Valle, A.;
Frühwirth, R.; Jeitler, M.; Krammer, N.; Lechner, L.; Liko, D.;
Madlener, T.; Mikulec, I.; Rad, N.; Schieck, J.; Schöfbeck, R.;
Spanring, M.; Templ, S.; Waltenberger, W.; Wulz, C. -E.; Zarucki,
M.; Chekhovsky, V.; Litomin, A.; Makarenko, V.; Suarez Gonzalez, J.;
Darwish, M. R.; De Wolf, E. A.; Di Croce, D.; Janssen, X.; Kello,
T.; Lelek, A.; Pieters, M.; Rejeb Sfar, H.; Van Haevermaet, H.; Van
Mechelen, P.; Van Putte, S.; Van Remortel, N.; Blekman, F.; Bols,
E. S.; Chhibra, S. S.; D'Hondt, J.; De Clercq, J.; Lontkovskyi, D.;
Lowette, S.; Marchesini, I.; Moortgat, S.; Python, Q.; Tavernier, S.;
Van Doninck, W.; Van Mulders, P.; Beghin, D.; Bilin, B.; Clerbaux, B.;
De Lentdecker, G.; Delannoy, H.; Dorney, B.; Favart, L.; Grebenyuk,
A.; Kalsi, A. K.; Makarenko, I.; Moureaux, L.; Pétré, L.; Popov,
A.; Postiau, N.; Starling, E.; Thomas, L.; Vander Velde, C.; Vanlaer,
P.; Vannerom, D.; Wezenbeek, L.; Cornelis, T.; Dobur, D.; Khvastunov,
I.; Niedziela, M.; Roskas, C.; Skovpen, K.; Tytgat, M.; Verbeke, W.;
Vermassen, B.; Vit, M.; Bruno, G.; Bury, F.; Caputo, C.; David, P.;
Delaere, C.; Delcourt, M.; Donertas, I. S.; Giammanco, A.; Lemaitre,
V.; Prisciandaro, J.; Saggio, A.; Taliercio, A.; Teklishyn, M.;
Vischia, P.; Wuyckens, S.; Zobec, J.; Alves, G. A.; Correia Silva,
G.; Hensel, C.; Moraes, A.; Aldá Júnior, W. L.; Belchior Batista
Das Chagas, E.; Carvalho, W.; Chinellato, J.; Coelho, E.; Da Costa,
E. M.; Da Silveira, G. G.; De Jesus Damiao, D.; Fonseca De Souza, S.;
Malbouisson, H.; Martins, J.; Matos Figueiredo, D.; Medina Jaime, M.;
Melo De Almeida, M.; Mora Herrera, C.; Mundim, L.; Nogima, H.; Rebello
Teles, P.; Sanchez Rosas, L. J.; Santoro, A.; Silva Do Amaral, S. M.;
Sznajder, A.; Thiel, M.; Tonelli Manganote, E. J.; Torres Da Silva
De Araujo, F.; Vilela Pereira, A.; Bernardes, C. A.; Calligaris,
L.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Lemos, D. S.;
Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Aleksandrov, A.;
Antchev, G.; Atanasov, I.; Hadjiiska, R.; Iaydjiev, P.; Misheva, M.;
Rodozov, M.; Shopova, M.; Sultanov, G.; Bonchev, M.; Dimitrov, A.;
Ivanov, T.; Litov, L.; Pavlov, B.; Petkov, P.; Petrov, A.; Fang, W.;
Guo, Q.; Wang, H.; Yuan, L.; Ahmad, M.; Hu, Z.; Wang, Y.; Chapon, E.;
Chen, G. M.; Chen, H. S.; Chen, M.; Jiang, C. H.; Leggat, D.; Liao,
H.; Liu, Z.; Sharma, R.; Spiezia, A.; Tao, J.; Wang, J.; Zhang, H.;
Zhang, S.; Zhao, J.; Agapitos, A.; Ban, Y.; Chen, C.; Chen, G.; Levin,
A.; Li, J.; Li, L.; Li, Q.; Lyu, X.; Mao, Y.; Qian, S. J.; Wang, D.;
Wang, Q.; Xiao, J.; You, Z.; Gao, X.; Xiao, M.; Avila, C.; Cabrera,
A.; Florez, C.; Fraga, J.; Sarkar, A.; Segura Delgado, M. A.; Mejia
Guisao, J.; Ramirez, F.; Ruiz Alvarez, J. D.; Salazar González,
C. A.; Vanegas Arbelaez, N.; Giljanovic, D.; Godinovic, N.; Lelas,
D.; Puljak, I.; Sculac, T.; Antunovic, Z.; Kovac, M.; Brigljevic, V.;
Ferencek, D.; Majumder, D.; Mesic, B.; Roguljic, M.; Starodumov, A.;
Susa, T.; Ather, M. W.; Attikis, A.; Erodotou, E.; Ioannou, A.; Kole,
G.; Kolosova, M.; Konstantinou, S.; Mavromanolakis, G.; Mousa, J.;
Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Saka, H.;
Tsiakkouri, D.; Finger, M.; Finger, M.; Kveton, A.; Tomsa, J.; Ayala,
E.; Carrera Jarrin, E.; Salama, E.; Lotfy, A.; Mahmoud, M. A.; Bhowmik,
S.; Carvalho Antunes De Oliveira, A.; Dewanjee, R. K.; Ehataht,
K.; Kadastik, M.; Raidal, M.; Veelken, C.; Eerola, P.; Forthomme,
L.; Kirschenmann, H.; Osterberg, K.; Voutilainen, M.; Brücken, E.;
Garcia, F.; Havukainen, J.; Karimäki, V.; Kim, M. S.; Kinnunen, R.;
Lampén, T.; Lassila-Perini, K.; Laurila, S.; Lehti, S.; Lindén, T.;
Siikonen, H.; Tuominen, E.; Tuominiemi, J.; Luukka, P.; Tuuva, T.;
Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Faure, J. L.;
Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault,
G.; Jarry, P.; Leloup, C.; Lenzi, B.; Locci, E.; Malcles, J.; Rander,
J.; Rosowsky, A.; Sahin, M. Ö.; Savoy-Navarro, A.; Titov, M.; Yu,
G. B.; Ahuja, S.; Amendola, C.; Beaudette, F.; Bonanomi, M.; Busson,
P.; Charlot, C.; Davignon, O.; Diab, B.; Falmagne, G.; Granier de
Cassagnac, R.; Kucher, I.; Lobanov, A.; Martin Perez, C.; Nguyen, M.;
Ochando, C.; Paganini, P.; Rembser, J.; Salerno, R.; Sauvan, J. B.;
Sirois, Y.; Zabi, A.; Zghiche, A.; Agram, J. -L.; Andrea, J.; Bloch,
D.; Bourgatte, G.; Brom, J. -M.; Chabert, E. C.; Collard, C.; Fontaine,
J. -C.; Gelé, D.; Goerlach, U.; Grimault, C.; Le Bihan, A. -C.; Van
Hove, P.; Asilar, E.; Beauceron, S.; Bernet, C.; Boudoul, G.; Camen,
C.; Carle, A.; Chanon, N.; Chierici, R.; Contardo, D.; Depasse, P.;
El Mamouni, H.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Jain,
Sa.; Laktineh, I. B.; Lattaud, H.; Lesauvage, A.; Lethuillier, M.;
Mirabito, L.; Torterotot, L.; Touquet, G.; Vander Donckt, M.; Viret,
S.; Khvedelidze, A.; Tsamalaidze, Z.; Feld, L.; Klein, K.; Lipinski,
M.; Meuser, D.; Pauls, A.; Preuten, M.; Rauch, M. P.; Schulz, J.;
Teroerde, M.; Eliseev, D.; Erdmann, M.; Fackeldey, P.; Fischer, B.;
Ghosh, S.; Hebbeker, T.; Hoepfner, K.; Keller, H.; Mastrolorenzo,
L.; Merschmeyer, M.; Meyer, A.; Millet, P.; Mocellin, G.; Mondal,
S.; Mukherjee, S.; Noll, D.; Novak, A.; Pook, T.; Pozdnyakov, A.;
Quast, T.; Radziej, M.; Rath, Y.; Reithler, H.; Roemer, J.; Schmidt,
A.; Schuler, S. C.; Sharma, A.; Wiedenbeck, S.; Zaleski, S.; Dziwok,
C.; Flügge, G.; Haj Ahmad, W.; Hlushchenko, O.; Kress, T.; Nowack,
A.; Pistone, C.; Pooth, O.; Roy, D.; Sert, H.; Stahl, A.; Ziemons,
T.; Aarup Petersen, H.; Aldaya Martin, M.; Asmuss, P.; Babounikau,
I.; Baxter, S.; Behnke, O.; Bermúdez Martínez, A.; Bin Anuar,
A. A.; Borras, K.; Botta, V.; Brunner, D.; Campbell, A.; Cardini,
A.; Connor, P.; Consuegra Rodríguez, S.; Danilov, V.; De Wit, A.;
Defranchis, M. M.; Didukh, L.; Domínguez Damiani, D.; Eckerlin, G.;
Eckstein, D.; Eichhorn, T.; Elwood, A.; Estevez Banos, L. I.; Gallo,
E.; Geiser, A.; Giraldi, A.; Grohsjean, A.; Guthoff, M.; Haranko, M.;
Harb, A.; Jafari, A.; Jomhari, N. Z.; Jung, H.; Kasem, A.; Kasemann,
M.; Kaveh, H.; Keaveney, J.; Kleinwort, C.; Knolle, J.; Krücker,
D.; Lange, W.; Lenz, T.; Lidrych, J.; Lipka, K.; Lohmann, W.; Mankel,
R.; Melzer-Pellmann, I. -A.; Metwally, J.; Meyer, A. B.; Meyer, M.;
Missiroli, M.; Mnich, J.; Mussgiller, A.; Myronenko, V.; Otarid, Y.;
Pérez Adán, D.; Pflitsch, S. K.; Pitzl, D.; Raspereza, A.; Saibel,
A.; Savitskyi, M.; Scheurer, V.; Schütze, P.; Schwanenberger,
C.; Shevchenko, R.; Singh, A.; Sosa Ricardo, R. E.; Tholen, H.;
Tonon, N.; Turkot, O.; Vagnerini, A.; Van De Klundert, M.; Walsh,
R.; Walter, D.; Wen, Y.; Wichmann, K.; Wissing, C.; Wuchterl, S.;
Zenaiev, O.; Zlebcik, R.; Aggleton, R.; Bein, S.; Benato, L.; Benecke,
A.; De Leo, K.; Dreyer, T.; Ebrahimi, A.; Feindt, F.; Fröhlich, A.;
Garbers, C.; Garutti, E.; Gonzalez, D.; Gunnellini, P.; Haller, J.;
Hinzmann, A.; Karavdina, A.; Kasieczka, G.; Klanner, R.; Kogler, R.;
Kurz, S.; Kutzner, V.; Lange, J.; Lange, T.; Malara, A.; Multhaup, J.;
Niemeyer, C. E. N.; Nigamova, A.; Pena Rodriguez, K. J.; Reimers, A.;
Rieger, O.; Schleper, P.; Schumann, S.; Schwandt, J.; Schwarz, D.;
Sonneveld, J.; Stadie, H.; Steinbrück, G.; Vormwald, B.; Zoi, I.;
Akbiyik, M.; Baselga, M.; Baur, S.; Bechtel, J.; Berger, T.; Butz,
E.; Caspart, R.; Chwalek, T.; De Boer, W.; Dierlamm, A.; El Morabit,
K.; Faltermann, N.; Flöh, K.; Giffels, M.; Gottmann, A.; Hartmann,
F.; Heidecker, C.; Husemann, U.; Iqbal, M. A.; Katkov, I.; Kudella,
S.; Maier, S.; Metzler, M.; Mitra, S.; Mozer, M. U.; Müller, D.;
Müller, Th.; Musich, M.; Quast, G.; Rabbertz, K.; Rauser, J.;
Savoiu, D.; Schäfer, D.; Schnepf, M.; Schröder, M.; Seith, D.;
Shvetsov, I.; Simonis, H. J.; Ulrich, R.; Wassmer, M.; Weber, M.;
Wöhrmann, C.; Wolf, R.; Wozniewski, S.; Anagnostou, G.; Asenov, P.;
Daskalakis, G.; Geralis, T.; Kyriakis, A.; Loukas, D.; Paspalaki,
G.; Stakia, A.; Diamantopoulou, M.; Karasavvas, D.; Karathanasis, G.;
Kontaxakis, P.; Koraka, C. K.; Manousakis-katsikakis, A.; Panagiotou,
A.; Papavergou, I.; Saoulidou, N.; Theofilatos, K.; Vellidis,
K.; Vourliotis, E.; Bakas, G.; Kousouris, K.; Papakrivopoulos,
I.; Tsipolitis, G.; Zacharopoulou, A.; Evangelou, I.; Foudas, C.;
Gianneios, P.; Katsoulis, P.; Kokkas, P.; Mallios, S.; Manitara, K.;
Manthos, N.; Papadopoulos, I.; Strologas, J.; Tsitsonis, D.; Bartók,
M.; Chudasama, R.; Csanad, M.; Gadallah, M. M. A.; Major, P.; Mandal,
K.; Mehta, A.; Pasztor, G.; Surányi, O.; Veres, G. I.; Bencze, G.;
Hajdu, C.; Horvath, D.; Sikler, F.; Veszpremi, V.; Vesztergombi,
G.; Beni, N.; Czellar, S.; Karancsi, J.; Molnar, J.; Szillasi, Z.;
Teyssier, D.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Csorgo, T.;
Lökös, S.; Nemes, F.; Novak, T.; Choudhury, S.; Komaragiri, J. R.;
Kumar, D.; Panwar, L.; Tiwari, P. C.; Bahinipati, S.; Dash, D.; Kar,
C.; Mal, P.; Mishra, T.; Muraleedharan Nair Bindhu, V. K.; Nayak,
A.; Sahoo, D. K.; Sur, N.; Swain, S. K.; Bansal, S.; Beri, S. B.;
Bhatnagar, V.; Chauhan, S.; Dhingra, N.; Gupta, R.; Kaur, A.; Kaur,
A.; Kaur, S.; Kumari, P.; Lohan, M.; Meena, M.; Sandeep, K.; Sharma,
S.; Singh, J. B.; Virdi, A. K.; Ahmed, A.; Bhardwaj, A.; Choudhary,
B. C.; Garg, R. B.; Gola, M.; Keshri, S.; Kumar, A.; Naimuddin, M.;
Priyanka, P.; Ranjan, K.; Shah, A.; Bharti, M.; Bhattacharya, R.;
Bhattacharya, S.; Bhowmik, D.; Dutta, S.; Ghosh, S.; Gomber, B.;
Maity, M.; Mondal, K.; Nandan, S.; Palit, P.; Purohit, A.; Rout,
P. K.; Saha, G.; Sarkar, S.; Sharan, M.; Singh, B.; Thakur, S.;
Behera, P. K.; Behera, S. C.; Kalbhor, P.; Muhammad, A.; Pradhan,
R.; Pujahari, P. R.; Sharma, A.; Sikdar, A. K.; Dutta, D.; Jha, V.;
Kumar, V.; Mishra, D. K.; Naskar, K.; Netrakanti, P. K.; Pant, L. M.;
Shukla, P.; Aziz, T.; Bhat, M. A.; Dugad, S.; Kumar Verma, R.; Sarkar,
U.; Banerjee, S.; Bhattacharya, S.; Chatterjee, S.; Das, P.; Guchait,
M.; Karmakar, S.; Kumar, S.; Majumder, G.; Mazumdar, K.; Mukherjee,
S.; Roy, D.; Sahoo, N.; Dube, S.; Kansal, B.; Kapoor, A.; Kothekar,
K.; Pandey, S.; Rane, A.; Rastogi, A.; Sharma, S.; Bakhshiansohi,
H.; Chenarani, S.; Etesami, S. M.; Khakzad, M.; Mohammadi Najafabadi,
M.; Naseri, M.; Felcini, M.; Grunewald, M.; Abbrescia, M.; Aly, R.;
Aruta, C.; Calabria, C.; Colaleo, A.; Creanza, D.; De Filippis, N.;
De Palma, M.; Di Florio, A.; Di Pilato, A.; Elmetenawee, W.; Fiore,
L.; Gelmi, A.; Iaselli, G.; Ince, M.; Lezki, S.; Maggi, G.; Maggi,
M.; Margjeka, I.; Merlin, J. A.; My, S.; Nuzzo, S.; Pompili, A.;
Pugliese, G.; Ranieri, A.; Selvaggi, G.; Silvestris, L.; Simone,
F. M.; Venditti, R.; Verwilligen, P.; Abbiendi, G.; Battilana, C.;
Bonacorsi, D.; Borgonovi, L.; Braibant-Giacomelli, S.; Campanini, R.;
Capiluppi, P.; Castro, A.; Cavallo, F. R.; Ciocca, C.; Cuffiani, M.;
Dallavalle, G. M.; Diotalevi, T.; Fabbri, F.; Fanfani, A.; Fontanesi,
E.; Giacomelli, P.; Grandi, C.; Guiducci, L.; Iemmi, F.; Lo Meo,
S.; Marcellini, S.; Masetti, G.; Navarria, F. L.; Perrotta, A.;
Primavera, F.; Rossi, A. M.; Rovelli, T.; Siroli, G. P.; Tosi, N.;
Albergo, S.; Costa, S.; Di Mattia, A.; Potenza, R.; Tricomi, A.; Tuve,
C.; Barbagli, G.; Cassese, A.; Ceccarelli, R.; Ciulli, V.; Civinini,
C.; D'Alessandro, R.; Fiori, F.; Focardi, E.; Latino, G.; Lenzi, P.;
Lizzo, M.; Meschini, M.; Paoletti, S.; Seidita, R.; Sguazzoni, G.;
Viliani, L.; Benussi, L.; Bianco, S.; Piccolo, D.; Bozzo, M.; Ferro,
F.; Mulargia, R.; Robutti, E.; Tosi, S.; Benaglia, A.; Beschi, A.;
Brivio, F.; Cetorelli, F.; Ciriolo, V.; De Guio, F.; Dinardo, M. E.;
Dini, P.; Gennai, S.; Ghezzi, A.; Govoni, P.; Guzzi, L.; Malberti,
M.; Malvezzi, S.; Menasce, D.; Monti, F.; Moroni, L.; Paganoni, M.;
Pedrini, D.; Ragazzi, S.; Tabarelli de Fatis, T.; Valsecchi, D.; Zuolo,
D.; Buontempo, S.; Cavallo, N.; De Iorio, A.; Fabozzi, F.; Fienga,
F.; Iorio, A. O. M.; Layer, L.; Lista, L.; Meola, S.; Paolucci,
P.; Rossi, B.; Sciacca, C.; Voevodina, E.; Azzi, P.; Bacchetta,
N.; Bisello, D.; Boletti, A.; Bragagnolo, A.; Carlin, R.; Checchia,
P.; De Castro Manzano, P.; Dorigo, T.; Dosselli, U.; Gasparini, F.;
Gasparini, U.; Hoh, S. Y.; Margoni, M.; Meneguzzo, A. T.; Presilla, M.;
Ronchese, P.; Rossin, R.; Simonetto, F.; Strong, G.; Tiko, A.; Tosi,
M.; Zanetti, M.; Zotto, P.; Zucchetta, A.; Zumerle, G.; Braghieri,
A.; Calzaferri, S.; Fiorina, D.; Montagna, P.; Ratti, S. P.; Re,
V.; Ressegotti, M.; Riccardi, C.; Salvini, P.; Vai, I.; Vitulo, P.;
Biasini, M.; Bilei, G. M.; Ciangottini, D.; Fanò, L.; Lariccia, P.;
Mantovani, G.; Mariani, V.; Menichelli, M.; Moscatelli, F.; Rossi, A.;
Santocchia, A.; Spiga, D.; Tedeschi, T.; Androsov, K.; Azzurri, P.;
Bagliesi, G.; Bertacchi, V.; Bianchini, L.; Boccali, T.; Castaldi, R.;
Ciocci, M. A.; Dell'Orso, R.; Di Domenico, M. R.; Donato, S.; Giannini,
L.; Giassi, A.; Grippo, M. T.; Ligabue, F.; Manca, E.; Mandorli, G.;
Messineo, A.; Palla, F.; Rizzi, A.; Rolandi, G.; Roy Chowdhury, S.;
Scribano, A.; Shafiei, N.; Spagnolo, P.; Tenchini, R.; Tonelli, G.;
Turini, N.; Venturi, A.; Verdini, P. G.; Cavallari, F.; Cipriani,
M.; Del Re, D.; Di Marco, E.; Diemoz, M.; Longo, E.; Meridiani, P.;
Organtini, G.; Pandolfi, F.; Paramatti, R.; Quaranta, C.; Rahatlou, S.;
Rovelli, C.; Santanastasio, F.; Soffi, L.; Tramontano, R.; Amapane,
N.; Arcidiacono, R.; Argiro, S.; Arneodo, M.; Bartosik, N.; Bellan,
R.; Bellora, A.; Biino, C.; Cappati, A.; Cartiglia, N.; Cometti, S.;
Costa, M.; Covarelli, R.; Demaria, N.; Kiani, B.; Legger, F.; Mariotti,
C.; Maselli, S.; Migliore, E.; Monaco, V.; Monteil, E.; Monteno, M.;
Obertino, M. M.; Ortona, G.; Pacher, L.; Pastrone, N.; Pelliccioni,
M.; Pinna Angioni, G. L.; Ruspa, M.; Salvatico, R.; Siviero, F.; Sola,
V.; Solano, A.; Soldi, D.; Staiano, A.; Trocino, D.; Belforte, S.;
Candelise, V.; Casarsa, M.; Cossutti, F.; Da Rold, A.; Della Ricca,
G.; Vazzoler, F.; Dogra, S.; Huh, C.; Kim, B.; Kim, D. H.; Kim, G. N.;
Lee, J.; Lee, S. W.; Moon, C. S.; Oh, Y. D.; Pak, S. I.; Sekmen, S.;
Yang, Y. C.; Kim, H.; Moon, D. H.; Francois, B.; Kim, T. J.; Park,
J.; Cho, S.; Choi, S.; Go, Y.; Ha, S.; Hong, B.; Lee, K.; Lee, K. S.;
Lim, J.; Park, J.; Park, S. K.; Roh, Y.; Yoo, J.; Goh, J.; Gurtu,
A.; Kim, H. S.; Kim, Y.; Almond, J.; Bhyun, J. H.; Choi, J.; Jeon,
S.; Kim, J.; Kim, J. S.; Ko, S.; Kwon, H.; Lee, H.; Lee, K.; Lee, S.;
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S. W.; Mengke, T.; Muthumuni, S.; Peltola, T.; Undleeb, S.; Volobouev,
I.; Wang, Z.; Whitbeck, A.; Appelt, E.; Greene, S.; Gurrola, A.;
Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.;
Romeo, F.; Sheldon, P.; Tuo, S.; Velkovska, J.; Verweij, M.; Ang, L.;
Arenton, M. W.; Cox, B.; Cummings, G.; Hakala, J.; Hirosky, R.; Joyce,
M.; Ledovskoy, A.; Neu, C.; Tannenwald, B.; Wang, Y.; Wolfe, E.; Xia,
F.; Karchin, P. E.; Poudyal, N.; Sturdy, J.; Thapa, P.; Black, K.;
Bose, T.; Buchanan, J.; Caillol, C.; Dasu, S.; De Bruyn, I.; Dodd, L.;
Galloni, C.; He, H.; Herndon, M.; Hervé, A.; Hussain, U.; Lanaro, A.;
Loeliger, A.; Loveless, R.; Madhusudanan Sreekala, J.; Mallampalli,
A.; Pinna, D.; Ruggles, T.; Savin, A.; Shang, V.; Sharma, V.; Smith,
W. H.; Teague, D.; Trembath-reichert, S.; Vetens, W.; CMS Collaboration
2020PhRvL.125v2001S Altcode:
Ultrarelativistic heavy ion collisions recreate in the laboratory
the thermodynamical conditions prevailing in the early universe up to
10<SUP>-6</SUP> sec , thereby allowing the study of the quark-gluon
plasma (QGP), a state of quantum chromodynamics (QCD) matter with
deconfined partons. The top quark, the heaviest elementary particle
known, is accessible in nucleus-nucleus collisions at the CERN
LHC, and constitutes a novel probe of the QGP. Here, we report the
first evidence for the production of top quarks in nucleus-nucleus
collisions, using lead-lead collision data at a nucleon-nucleon
center-of-mass energy of 5.02 TeV recorded by the CMS experiment. Two
methods are used to measure the cross section for top quark pair
production (σ<SUB>t t ¯</SUB> ) via the selection of charged
leptons (electrons or muons) and bottom quarks. One method relies
on the leptonic information alone, and the second one exploits,
in addition, the presence of bottom quarks. The measured cross
sections, σ<SUB>t t ¯</SUB>=2.5 4<SUB>-0.74</SUB><SUP>+0.84</SUP> and
2.03<SUB>-0.64</SUB><SUP>+0.71</SUP> μ b , respectively, are compatible
with expectations from scaled proton-proton data and QCD predictions.
---------------------------------------------------------
Title: Projected WIMP sensitivity of the XENONnT dark matter
experiment
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Althueser,
L.; Amaro, F. D.; Antochi, V. C.; Angelino, E.; Angevaare, J. R.;
Arneodo, F.; Barge, D.; Baudis, L.; Bauermeister, B.; Bellagamba, L.;
Benabderrahmane, M. L.; Berger, T.; Brown, A.; Brown, E.; Bruenner,
S.; Bruno, G.; Budnik, R.; Capelli, C.; Cardoso, J. M. R.; Cichon,
D.; Cimmino, B.; Clark, M.; Coderre, D.; Colijn, A. P.; Conrad,
J.; Cussonneau, J. P.; Decowski, M. P.; Depoian, A.; Di Gangi, P.;
Di Giovanni, A.; Di Stefano, R.; Diglio, S.; Elykov, A.; Eurin, G.;
Ferella, A. D.; Fulgione, W.; Gaemers, P.; Gaior, R.; Galloway, M.;
Gao, F.; Grandi, L.; Hasterok, C.; Hils, C.; Hiraide, K.; Hoetzsch,
L.; Howlett, J.; Iacovacci, M.; Itow, Y.; Joerg, F.; Kato, N.;
Kazama, S.; Kobayashi, M.; Koltman, G.; Kopec, A.; Landsman, H.;
Lang, R. F.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.;
Lombardi, F.; Long, J.; Lopes, J. A. M.; López Fune, E.; Macolino, C.;
Mahlstedt, J.; Mancuso, A.; Manenti, L.; Manfredini, A.; Marignetti,
F.; Marrodán Undagoitia, T.; Martens, K.; Masbou, J.; Masson, D.;
Mastroianni, S.; Messina, M.; Miuchi, K.; Mizukoshi, K.; Molinario,
A.; Morå, K.; Moriyama, S.; Mosbacher, Y.; Murra, M.; Naganoma,
J.; Ni, K.; Oberlack, U.; Odgers, K.; Palacio, J.; Pelssers, B.;
Peres, R.; Pienaar, J.; Pizzella, V.; Plante, G.; Qin, J.; Qiu,
H.; Ramírez García, D.; Reichard, S.; Rocchetti, A.; Rupp, N.;
dos Santos, J. M. F.; Sartorelli, G.; Šarčević, N.; Scheibelhut,
M.; Schreiner, J.; Schulte, D.; Schumann, M.; Scotto Lavina, L.;
Selvi, M.; Semeria, F.; Shagin, P.; Shockley, E.; Silva, M.; Simgen,
H.; Takeda, A.; Therreau, C.; Thers, D.; Toschi, F.; Trinchero, G.;
Tunnell, C.; Valerius, K.; Vargas, M.; Volta, G.; Wang, H.; Wei, Y.;
Weinheimer, C.; Weiss, M.; Wenz, D.; Wittweg, C.; Xu, Z.; Yamashita,
M.; Ye, J.; Zavattini, G.; Zhang, Y.; Zhu, T.; Zopounidis, J. P.
2020JCAP...11..031A Altcode: 2020arXiv200708796T
XENONnT is a dark matter direct detection experiment, utilizing
5.9 t of instrumented liquid xenon, located at the INFN Laboratori
Nazionali del Gran Sasso. In this work, we predict the experimental
background and project the sensitivity of XENONnT to the detection of
weakly interacting massive particles (WIMPs). The expected average
differential background rate in the energy region of interest,
corresponding to (1, 13) keV and (4, 50) keV for electronic and
nuclear recoils, amounts to 12.3 ± 0.6 (keV t y)<SUP>-1</SUP> and
(2.2± 0.5)× 10<SUP>-3</SUP> (keV t y)<SUP>-1</SUP>, respectively,
in a 4 t fiducial mass. We compute unified confidence intervals
using the profile construction method, in order to ensure proper
coverage. With the exposure goal of 20 t y, the expected sensitivity
to spin-independent WIMP-nucleon interactions reaches a cross-section
of 1.4×10<SUP>-48</SUP> cm<SUP>2</SUP> for a 50 GeV/c<SUP>2</SUP>
mass WIMP at 90% confidence level, more than one order of magnitude
beyond the current best limit, set by XENON1T . In addition,
we show that for a 50 GeV/c<SUP>2</SUP> WIMP with cross-sections
above 2.6×10<SUP>-48</SUP> cm<SUP>2</SUP> (5.0×10<SUP>-48</SUP>
cm<SUP>2</SUP>) the median XENONnT discovery significance exceeds 3σ
(5σ). The expected sensitivity to the spin-dependent WIMP coupling
to neutrons (protons) reaches 2.2×10<SUP>-43</SUP> cm<SUP>2</SUP>
(6.0×10<SUP>-42</SUP> cm<SUP>2</SUP>).
---------------------------------------------------------
Title: Main-Sequence Reinflation of Hot Jupiters
Authors: Thorngren, D.; Lopez, E.; Fortney, J.; Berger, T.; Huber, D.
2020DPS....5221604T Altcode:
The unexpectedly large radii of hot Jupiters is an open question
in exoplanetary science for which a large number of explanations
have been proposed. We leverage the strong relationship between
hot Jupiter radii and incident fluxes to test these hypotheses by
examining whether planets inflate as their parent stars brighten
along the main sequence. To do this, we first study how the various
observable parameters of the system can be used to predict the planetary
radius. Next we show that stellar brightening is sufficient to cause
detectable reinflation. We then argue that the predictors of radius,
especially fractional age, flux, and ZAMS flux, point towards rapid
reinflation that keeps pace with stellar brightening. We also find
evidence for a delayed cooling effect in the first few gigayears of
a planet's life, though it is not sufficient alone to explain the
inflation phenomenon. Finally, we identify a negative relationship
between stellar metallicity and planet radius (corrected for mass and
flux), likely as a result of higher planetary metallicities.
---------------------------------------------------------
Title: Calibrating GONG Magnetograms with End-to-End Instrument
Simulation II: Theory of Calibration
Authors: Plowman, Joseph E.; Berger, Thomas E.
2020SoPh..295..142P Altcode: 2020arXiv200202490P
This is the second of three papers describing an `absolute'
calibration of the GONG magnetograph using an end-to-end simulation
of its measurement process. In the first paper, we described the
GONG instrument and our `end-to-end' simulation of its measurement
process. In this paper, we consider the theory of calibration,
and magnetograph comparison in general, identifying some of the
significant issues and pitfalls. The calibration of a magnetograph
is a function of whether or not it preserves flux, independent of
its spatial resolution. However, we find that the one-dimensional
comparison methods most often used for magnetograph calibration and
comparison will show dramatic differences between two magnetograms with
differing spatial resolution, even if they both preserve flux. Some of
the apparent disagreement between magnetograms found in the literature
are likely a result of these instrumental resolution differences rather
than any intrinsic calibration differences. To avoid them, spatial
resolution must be carefully matched prior to comparing magnetograms
or making calibration curves. In the third paper, we apply the lessons
learned here to absolute calibration of GONG using our `end-to-end'
measurement simulation.
---------------------------------------------------------
Title: Calibrating GONG Magnetograms with End-to-end Instrument
Simulation I: Background, the GONG Instrument, and End-to-end
Simulation
Authors: Plowman, Joseph E.; Berger, Thomas E.
2020SoPh..295..143P Altcode: 2020arXiv200202489P
This is the first of three papers describing an `absolute' calibration
of the GONG magnetograph using an end-to-end simulation of its
measurement process. The input to this simulation is a MURaM 3D
MHD photospheric simulation and the output is the corresponding
set of simulated data numbers which would be recorded by the GONG
detectors. These simulated data numbers are then used to produce
`synthetic magnetograms' which can be compared with the simulation
inputs. This paper describes the GONG instrument, the MURaM datacube,
our instrument simulator, and calculation of synthetic magnetograms,
setting the stage for the subsequent two papers. These will first lay
groundwork for calibration (and magnetogram comparison in general),
then apply them to calibration of GONG using the simulation results.
---------------------------------------------------------
Title: Calibrating GONG Magnetograms with End-to-End Instrument
Simulation III: Comparison, Calibration, and Results
Authors: Plowman, Joseph E.; Berger, Thomas E.
2020SoPh..295..144P Altcode: 2020arXiv200202486P
This is the last of three papers describing an `absolute' calibration of
the GONG magnetograph using and end-to-end simulation of its measurement
process. The simulation begins with a MURaM 3D MHD datacube and ends
with a `synthetic magnetogram' of the corresponding magnetic field
values as they would be observed by GONG. We determine a calibration
by comparing the synthetic magnetic field measurements with the MURaM
magnetic field values that produced them. The previous two papers
have described the GONG measurement process (both instrument and
data processing), our simulation of it, and the theory of magnetogram
comparison and calibration. In this paper, we address some final points
on calibration, combine all of this work into a set of calibration
curves, and consider the results. We also review the results of
the previous two papers for locality of reference. Our calibration
indicates that GONG magnetograms underestimate weak flux by a factor
of ∼2 near disk center, but that factor decreases to ∼1 as the
line-of-sight approaches the limb. A preliminary investigation of the
generalizability of these results suggests other instruments will
be affected in a similar way. We also find that some differences
in previous magnetograph comparisons are artifacts of instrumental
resolution which do not reflect an intrinsic calibration difference,
and the measurements are more similar than sometimes thought. These
results are directly applicable to question of solar wind prediction
model accuracies, particularly in the search for the cause of the
common discrepancy between predicted solar wind magnetic flux at 1 AU
and values measured in situ by current satellite missions.
---------------------------------------------------------
Title: Excess electronic recoil events in XENON1T
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Althueser,
L.; Amaro, F. D.; Antochi, V. C.; Angelino, E.; Angevaare, J. R.;
Arneodo, F.; Barge, D.; Baudis, L.; Bauermeister, B.; Bellagamba, L.;
Benabderrahmane, M. L.; Berger, T.; Brown, A.; Brown, E.; Bruenner,
S.; Bruno, G.; Budnik, R.; Capelli, C.; Cardoso, J. M. R.; Cichon,
D.; Cimmino, B.; Clark, M.; Coderre, D.; Colijn, A. P.; Conrad,
J.; Cussonneau, J. P.; Decowski, M. P.; Depoian, A.; di Gangi, P.;
di Giovanni, A.; di Stefano, R.; Diglio, S.; Elykov, A.; Eurin, G.;
Ferella, A. D.; Fulgione, W.; Gaemers, P.; Gaior, R.; Galloway, M.;
Gao, F.; Grandi, L.; Hasterok, C.; Hils, C.; Hiraide, K.; Hoetzsch,
L.; Howlett, J.; Iacovacci, M.; Itow, Y.; Joerg, F.; Kato, N.; Kazama,
S.; Kobayashi, M.; Koltman, G.; Kopec, A.; Landsman, H.; Lang, R. F.;
Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Long,
J.; Lopes, J. A. M.; López Fune, E.; Macolino, C.; Mahlstedt, J.;
Mancuso, A.; Manenti, L.; Manfredini, A.; Marignetti, F.; Marrodán
Undagoitia, T.; Martens, K.; Masbou, J.; Masson, D.; Mastroianni,
S.; Messina, M.; Miuchi, K.; Mizukoshi, K.; Molinario, A.; Morâ,
K.; Moriyama, S.; Mosbacher, Y.; Murra, M.; Naganoma, J.; Ni, K.;
Oberlack, U.; Odgers, K.; Palacio, J.; Pelssers, B.; Peres, R.;
Pienaar, J.; Pizzella, V.; Plante, G.; Qin, J.; Qiu, H.; Ramírez
García, D.; Reichard, S.; Rocchetti, A.; Rupp, N.; Dos Santos,
J. M. F.; Sartorelli, G.; Šarčević, N.; Scheibelhut, M.; Schreiner,
J.; Schulte, D.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Semeria,
F.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Takeda, A.;
Therreau, C.; Thers, D.; Toschi, F.; Trinchero, G.; Tunnell, C.;
Vargas, M.; Volta, G.; Wang, H.; Wei, Y.; Weinheimer, C.; Weiss, M.;
Wenz, D.; Wittweg, C.; Xu, Z.; Yamashita, M.; Ye, J.; Zavattini, G.;
Zhang, Y.; Zhu, T.; Zopounidis, J. P.; Xenon Collaboration, Mougeot, X.
2020PhRvD.102g2004A Altcode: 2020arXiv200609721A
We report results from searches for new physics with low-energy
electronic recoil data recorded with the XENON1T detector. With an
exposure of 0.65 tonne-years and an unprecedentedly low background
rate of 76 ±2<SUB>stat</SUB> events /(tonne ×year ×keV )
between 1 and 30 keV, the data enable one of the most sensitive
searches for solar axions, an enhanced neutrino magnetic moment
using solar neutrinos, and bosonic dark matter. An excess over known
backgrounds is observed at low energies and most prominent between
2 and 3 keV. The solar axion model has a 3.4 σ significance, and a
three-dimensional 90% confidence surface is reported for axion couplings
to electrons, photons, and nucleons. This surface is inscribed in
the cuboid defined by g<SUB>ae</SUB><3.8 ×10<SUP>-12</SUP>
, g<SUB>ae</SUB>g<SUB>an</SUB><SUP>eff</SUP><4.8
×10<SUP>-18</SUP> , and g<SUB>ae</SUB>g<SUB>a
γ</SUB><7.7 ×10<SUP>-22</SUP> GeV<SUP>-1</SUP> , and
excludes either g<SUB>ae</SUB>=0 or g<SUB>ae</SUB>g<SUB>a
γ</SUB>=g<SUB>ae</SUB>g<SUB>an</SUB><SUP>eff</SUP>=0 . The neutrino
magnetic moment signal is similarly favored over background at
3.2 σ , and a confidence interval of μ<SUB>ν</SUB>∈(1.4 ,2.9
)×10<SUP>-11</SUP> μ<SUB>B</SUB> (90% C.L.) is reported. Both
results are in strong tension with stellar constraints. The excess
can also be explained by β decays of tritium at 3.2 σ significance
with a corresponding tritium concentration in xenon of (6.2 ±2.0
)×10<SUP>-25</SUP> mol /mol . Such a trace amount can neither be
confirmed nor excluded with current knowledge of its production
and reduction mechanisms. The significances of the solar axion and
neutrino magnetic moment hypotheses are decreased to 2.0 σ and 0.9 σ
, respectively, if an unconstrained tritium component is included in
the fitting. With respect to bosonic dark matter, the excess favors
a monoenergetic peak at (2.3 ±0.2 ) keV (68% C.L.) with a 3.0 σ
global (4.0 σ local) significance over background. This analysis
sets the most restrictive direct constraints to date on pseudoscalar
and vector bosonic dark matter for most masses between 1 and 210 keV
/c<SUP>2</SUP> . We also consider the possibility that <SUP>37</SUP>Ar
may be present in the detector, yielding a 2.82 keV peak from electron
capture. Contrary to tritium, the <SUP>37</SUP>Ar concentration can
be tightly constrained and is found to be negligible.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Gaia-Kepler stellar properties
catalog. II. Planets (Berger+, 2020)
Authors: Berger, T. A.; Huber, D.; Gaidos, E.; van Saders, J. L.;
Weiss, L. M.
2020yCat..51600108B Altcode:
We computed the updated planet radii utilizing the planet-to-star radius
ratios provided in the KOI table from the NASA Exoplanet Archive and
the stellar radii computed in Paper I (Berger+, 2020, J/AJ/159/280). In
addition, we updated semimajor axes using the stellar masses in Paper
I and the orbital periods in Thompson+, 2018, J/ApJS/235/38. Finally,
we updated the incident fluxes for each planet by using the semimajor
axes and stellar luminosities from Paper I. <P />(1 data file).
---------------------------------------------------------
Title: VizieR Online Data Catalog: Stellar parameters for 13196
Kepler dwarfs (Angus+, 2020)
Authors: Angus, R.; Beane, A.; Price-Whelan, A. M.; Newton, E.;
Curtis, J. L.; Berger, T.; van Saders, J.; Kiman, R.; Foreman-Mackey,
D.; Lu, Y.; Anderson, L.; Faherty, J. K.
2020yCat..51600090A Altcode:
We used the publicly available Kepler-Gaia DR2 crossmatched catalog to
combine the McQuillan+ (2014, J/ApJS/211/24) catalog of stellar rotation
periods, measured from Kepler light curves, with the Gaia DR2 catalog of
parallaxes, proper motions, and apparent magnitudes. <P />(1 data file).
---------------------------------------------------------
Title: VizieR Online Data Catalog: Gaia-Kepler stellar properties
catalog.I. KIC stars (Berger+, 2020)
Authors: Berger, T. A.; Huber, D.; van Saders, J. L.; Gaidos, E.;
Tayar, J.; Kraus, A. L.
2020yCat..51590280B Altcode:
In this paper, we utilize Gaia DR2 parallaxes, homogeneous stellar g
and Ks photometry, and spectroscopic metallicities, where available, to
improve on previous analyses and present the most accurate, homogeneous,
and precise analysis of stars in the Kepler field. We re-derive stellar
Teff, logg, radii, masses, densities, luminosities, and ages for 186301
Kepler targets, and investigate the stellar properties of a number of
noteworthy Kepler exoplanet-hosting stars. <P />(2 data files).
---------------------------------------------------------
Title: Energy resolution and linearity of XENON1T in the MeV energy
range
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Althueser,
L.; Amaro, F. D.; Antochi, V. C.; Angelino, E.; Angevaare, J.;
Arneodo, F.; Barge, D.; Baudis, L.; Bauermeister, B.; Bellagamba,
L.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.;
Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Capelli, C.; Cardoso,
J. M. R.; Cichon, D.; Cimmino, B.; Clark, M.; Coderre, D.; Colijn,
A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; Depoian, A.;
Di Gangi, P.; Di Giovanni, A.; Di Stefano, R.; Diglio, S.; Elykov,
A.; Eurin, G.; Ferella, A. D.; Fulgione, W.; Gaemers, P.; Gaior, R.;
Rosso, A. Gallo; Galloway, M.; Gao, F.; Garbini, M.; Grandi, L.;
Hasterok, C.; Hils, C.; Hiraide, K.; Hoetzsch, L.; Hogenbirk, E.;
Howlett, J.; Iacovacci, M.; Itow, Y.; Joerg, F.; Kato, N.; Kazama,
S.; Kobayashi, M.; Koltman, G.; Kopec, A.; Landsman, H.; Lang, R. F.;
Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes,
J. A. M.; Fune, E. López; Macolino, C.; Mahlstedt, J.; Manenti, L.;
Manfredini, A.; Marignetti, F.; Undagoitia, T. Marrodán; Martens,
K.; Masbou, J.; Masson, D.; Mastroianni, S.; Messina, M.; Miuchi,
K.; Molinario, A.; Morâ, K.; Moriyama, S.; Mosbacher, Y.; Murra, M.;
Naganoma, J.; Ni, K.; Oberlack, U.; Odgers, K.; Palacio, J.; Pelssers,
B.; Peres, R.; Pienaar, J.; Pizzella, V.; Plante, G.; Qin, J.; Qiu,
H.; García, D. Ramírez; Reichard, S.; Rocchetti, A.; Rupp, N.;
dos Santos, J. M. F.; Sartorelli, G.; Šarčević, N.; Scheibelhut,
M.; Schindler, S.; Schreiner, J.; Schulte, D.; Schumann, M.; Lavina,
L. Scotto; Selvi, M.; Semeria, F.; Shagin, P.; Shockley, E.; Silva,
M.; Simgen, H.; Takeda, A.; Therreau, C.; Thers, D.; Toschi, F.;
Trinchero, G.; Tunnell, C.; Vargas, M.; Volta, G.; Wack, O.; Wang,
H.; Wei, Y.; Weinheimer, C.; Xu, M. Weiss; Wenz, D.; Wittweg, C.;
Wulf, J.; Xu, Z.; Yamashita, M.; Ye, J.; Zavattini, G.; Zhang, Y.;
Zhu, T.; Zopounidis, J. P.
2020EPJC...80..785A Altcode: 2020arXiv200303825A
Xenon dual-phase time projection chambers designed to search for
weakly interacting massive particles have so far shown a relative
energy resolution which degrades with energy above ∼ 200 keV due
to the saturation effects. This has limited their sensitivity in the
search for rare events like the neutrinoless double-beta decay of
13<SUP>6</SUP>Xe at its Q value, Q<SUB>β β</SUB>≃2.46 MeV . For
the XENON1T dual-phase time projection chamber, we demonstrate that
the relative energy resolution at 1 σ /μ is as low as (0.80 ±0.02 )
% in its one-ton fiducial mass, and for single-site interactions at
Q<SUB>β β</SUB>. We also present a new signal correction method to
rectify the saturation effects of the signal readout system, resulting
in more accurate position reconstruction and indirectly improving the
energy resolution. The very good result achieved in XENON1T opens
up new windows for the xenon dual-phase dark matter detectors to
simultaneously search for other rare events.
---------------------------------------------------------
Title: The Lunar Lander Neutron and Dosimetry (LND) Experiment on
Chang'E 4
Authors: Wimmer-Schweingruber, Robert F.; Yu, Jia; Böttcher, Stephan
I.; Zhang, Shenyi; Burmeister, Sönke; Lohf, Henning; Guo, Jingnan;
Xu, Zigong; Schuster, Björn; Seimetz, Lars; Freiherr vonÂ
Forstner, Johan L.; Ravanbakhsh, Ali; Knierim, Violetta; Kolbe,
Stefan; Woyciechowski, Hauke; Kulkarni, Shrinivasrao R.; Yuan,
Bin; Shen, Guohong; Wang, Chunqing; Chang, Zheng; Berger, Thomas;
Hellweg, Christine E.; Matthiä, Daniel; Hou, Donghui; Knappmann,
Alke; Büschel, Charlotte; Hou, Xufeng; Ren, Baoguo; Fu, Qiang
2020SSRv..216..104W Altcode: 2020arXiv200111028W
Chang'E 4 is the first mission to the far side of the Moon and consists
of a lander, a rover, and a relay spacecraft. Lander and rover were
launched at 18:23 UTC on December 7, 2018 and landed in the von
Kármán crater at 02:26 UTC on January 3, 2019. Here we describe the
Lunar Lander Neutron & Dosimetry experiment (LND) which is part
of the Chang'E 4 Lander scientific payload. Its chief scientific goal
is to obtain first active dosimetric measurements on the surface of
the Moon. LND also provides observations of fast neutrons which are a
result of the interaction of high-energy particle radiation with the
lunar regolith and of their thermalized counterpart, thermal neutrons,
which are a sensitive indicator of subsurface water content.
---------------------------------------------------------
Title: Long term variations of galactic cosmic radiation on board the
International Space Station, on the Moon and on the surface of Mars
Authors: Berger, Thomas; Matthiä, Daniel; Burmeister, Sönke; Zeitlin,
Cary; Rios, Ryan; Stoffle, Nicholas; Schwadron, Nathan A.; Spence,
Harlan E.; Hassler, Donald M.; Ehresmann, Bent; Wimmer-Schweingruber,
Robert F.
2020JSWSC..10...34B Altcode:
The radiation environment in free space and the related radiation
exposure is seen as one of the main health detriments for future
long-duration human exploration missions beyond Low Earth Orbit
(LEO). The steady flux of energetic particles in the galactic cosmic
radiation (GCR) produces a low dose-rate radiation exposure, which
is heavily influenced by several factors including the solar cycle,
the presence of an atmosphere, relevant magnetic fields (as on Earth)
and of course by the relevant spacecraft shielding. Investigations of
the GCR variations over the course of a solar cycle provide valuable
data for exploration mission planning and for the determination of the
radiation load received due to the GCR environment. Within the current
work these investigations have been performed applying three datasets
generated on board the International Space Station (ISS) with the
DOSTEL instruments in the frame of the DOSIS and DOSIS-3D projects,
with the CRaTER instrument in a Moon orbit and with the MSL-RAD
instrument on the way to and on the surface of Mars. To derive GCR
dose contributions on board the ISS two procedures have been developed
separating the contributions from GCR from passing's through the
South Atlantic Anomaly (SAA), as well as ways to extrapolate the GCR
dose measured on board the ISS to free space based on various ranges
of the McIlwain L-shell parameter. At the end we provide a dataset
spanning the timeframe for GCR measurements on the ISS (2009-2011 &
2012-2019), Moon (2009-2019) and Mars (2012-2019), thereby covering the
time span from the deep minimum of solar cycle 23, the ascending phase
and maximum of solar cycle 24, and the descending phase of cycle 24,
which is ongoing at the time of this writing.
---------------------------------------------------------
Title: Feasibility of Near-Real-Time GOLD Data Products
Authors: Codrescu, S. M.; Rowland, W. F.; Plummer, T. M.; Vanier,
B. A.; Berger, T. E.; Codrescu, M. V.
2020JGRA..12527819C Altcode:
A primary limitation for accurate specification and forecasting
of the thermosphere-ionosphere (TI) system is uncertainty in the
system forcing. This significantly impacts users who have operational
and real-time interests in the current and future state of the TI
system. Since Global-Scale Observations of the Limb and Disk (GOLD)
observations are expected to provide information about both the
current state and forcing of the TI system, GOLD products could
be an operational asset if they could be provided in near real
time. Production of GOLD data products requires knowledge of the
satellite pointing and location. The current scientific processing
implementation contains an operationally significant delay to await
definitive location and as-flown pointing. We present the results
of a demonstration low-latency processing system that assumes the
nominal satellite position and pointing to produce low-latency GOLD
data products. The resulting products are reasonably similar to the
scientific version but are available within minutes rather than hours.
---------------------------------------------------------
Title: Zodiacal exoplanets in time - X. The orbit and atmosphere of
the young 'neptune desert'-dwelling planet K2-100b
Authors: Gaidos, E.; Hirano, T.; Mann, A. W.; Owens, D. A.; Berger,
T. A.; France, K.; Vanderburg, A.; Harakawa, H.; Hodapp, K. W.;
Ishizuka, M.; Jacobson, S.; Konishi, M.; Kotani, T.; Kudo, T.;
Kurokawa, T.; Kuzuhara, M.; Nishikawa, J.; Omiya, M.; Serizawa, T.;
Tamura, M.; Ueda, A.
2020MNRAS.495..650G Altcode: 2020MNRAS.tmp..180G; 2020arXiv200312940G
We obtained high-resolution infrared spectroscopy and short-cadence
photometry of the 600-800 Myr Praesepe star K2-100 during transits
of its 1.67-d planet. This Neptune-size object, discovered by the
NASA K2 mission, is an interloper in the 'desert' of planets with
similar radii on short-period orbits. Our observations can be used
to understand its origin and evolution by constraining the orbital
eccentricity by transit fitting, measuring the spin-orbit obliquity by
the Rossiter-McLaughlin effect, and detecting any extended, escaping
the hydrogen-helium envelope with the 10 830 -Å line of neutral
helium in the 2s<SUP>3</SUP>S triplet state. Transit photometry with
1-min cadence was obtained by the K2 satellite during Campaign 18
and transit spectra were obtained with the IRD spectrograph on the
Subaru telescope. While the elevated activity of K2-100 prevented
us from detecting the Rossiter-McLaughlin effect, the new photometry
combined with revised stellar parameters allowed us to constrain the
eccentricity to e < 0.15/0.28 with 90/99 per cent confidence. We
modelled atmospheric escape as an isothermal, spherically symmetric
Parker wind, with photochemistry driven by ultraviolet radiation,
which we estimate by combining the observed spectrum of the active Sun
with calibrations from observations of K2-100 and similar young stars
in the nearby Hyades cluster. Our non-detection (<5.7 m Å) of a
transit-associated He I line limits mass-loss of a solar-composition
atmosphere through a T ≤ 10000 K wind to <0.3 M<SUB>⊕</SUB>
Gyr<SUP>-1</SUP>. Either K2-100b is an exceptional desert-dwelling
planet, or its mass-loss is occurring at a lower rate over a longer
interval, consistent with a core accretion-powered scenario for escape.
---------------------------------------------------------
Title: A Probabilistic Approach to Kepler Completeness and Reliability
for Exoplanet Occurrence Rates
Authors: Bryson, S.; Coughlin, J.; Batalha, N. M.; Berger, T.; Huber,
D.; Burke, C.; Dotson, J.; Mullally, S. E.
2020AJ....159..279B Altcode: 2019arXiv190603575B
Exoplanet catalogs produced by surveys suffer from a lack of
completeness (not every planet is detected) and less than perfect
reliability (not every planet in the catalog is a true planet),
particularly near the survey's detection limit. Exoplanet occurrence
rate studies based on such a catalog must be corrected for completeness
and reliability. The final Kepler data release, DR25, features a
uniformly vetted planet candidate catalog and data products that
facilitate corrections. We present a new probabilistic approach to the
characterization of Kepler completeness and reliability, making full use
of the Kepler DR25 products. We illustrate the impact of completeness
and reliability corrections with a Poisson-likelihood occurrence rate
method, using a recent stellar properties catalog that incorporates
Gaia stellar radii and essentially uniform treatment of the stellar
population. Correcting for reliability has a significant impact:
the exoplanet occurrence rate for orbital period and radius within
20% of Earth's around GK dwarf stars, corrected for reliability,
is ${0.015}_{-0.007}^{+0.011}$ , whereas not correcting results in
${0.034}_{-0.012}^{+0.018}$ —correcting for reliability reduces this
occurrence rate by more than a factor of two. We further show that using
Gaia-based versus DR25 stellar properties impacts the same occurrence
rate by a factor of two. We critically examine the the DR25 catalog and
the assumptions behind our occurrence rate method. We propose several
ways in which confidence in both the Kepler catalog and occurrence
rate calculations can be improved. This work provides an example of how
the community can use the DR25 completeness and reliability products.
---------------------------------------------------------
Title: Energetic particles measurements on the lunar far-side by
Lunar Lander Neutron and Dosimetry(LND) experiment
Authors: Xu, Zigong; Wimmer-Schweingruber, Robert F.; Guo, Jingnan;
Yu, Jia; Zhang, Shenyi; Berger, Thomas; Matthiae, Daniel; Burmeister,
Soenke; Boettcher, Stephan; Heber, Bernd
2020EGUGA..2221246X Altcode:
After Chang'E 4 successfully landed on the far side of the moon on Jan
3rd, 2019, the Lunar Lander Neutron and Dosimetry experiment has been
working for 13 lunar days from January, 2019 to January, 2020, sending
back the measurements of dose, linear energy transfer (LET) spectrum,
neutrons, and charged particles. Here, we show observations of charged
particles especially protons and Helium ions during quiet time. We
also present two solar energetic particle events registered by LND in
May 2019, which are also the first such measurements on the far-side
surface of the moon. The temporal variations of particle fluxes on the
far side of the moon detected by LND provide a new observation site
in space and can be helpful to improve our understanding of particle
propagation and transport in the heliosphere.
---------------------------------------------------------
Title: RIMFAX Ground Penetrating Radar Field Tests in the Western USA
Authors: Russell, P. S.; Nunes, D.; Hamran, S. -E.; Paige, D. A.;
Berger, T.; Amundsen, H. E. F.; Brovoll, S.; Carter, L. M.; Dypvik,
H.; Ghent, R.; Kohler, J.; Mellon, M. T.; Plettemeier, D.
2020LPI....51.3012R Altcode:
The RIMFAX GPR on Mars2020 was tested for performance and for insight
into Mars subsurfaces in several locations, lithologies, and structures
in the western US.
---------------------------------------------------------
Title: Leveraging the mathematics of shape for solar magnetic
eruption prediction
Authors: Deshmukh, Varad; Berger, Thomas E.; Bradley, Elizabeth;
Meiss, James D.
2020JSWSC..10...13D Altcode: 2020arXiv200305827D
Current operational forecasts of solar eruptions are made by human
experts using a combination of qualitative shape-based classification
systems and historical data about flaring frequencies. In the
past decade, there has been a great deal of interest in crafting
machine-learning (ML) flare-prediction methods to extract underlying
patterns from a training set - e.g. a set of solar magnetogram images,
each characterized by features derived from the magnetic field and
labeled as to whether it was an eruption precursor. These patterns,
captured by various methods (neural nets, support vector machines,
etc.), can then be used to classify new images. A major challenge with
any ML method is the featurization of the data: pre-processing the raw
images to extract higher-level properties, such as characteristics
of the magnetic field, that can streamline the training and use of
these methods. It is key to choose features that are informative,
from the standpoint of the task at hand. To date, the majority of
ML-based solar eruption methods have used physics-based magnetic and
electric field features such as the total unsigned magnetic flux, the
gradients of the fields, the vertical current density, etc. In this
paper, we extend the relevant feature set to include characteristics of
the magnetic field that are based purely on the geometry and topology
of 2D magnetogram images and show that this improves the prediction
accuracy of a neural-net based flare-prediction method.
---------------------------------------------------------
Title: Flying Through Uncertainty
Authors: Berger, T. E.; Holzinger, M. J.; Sutton, E. K.; Thayer, J. P.
2020SpWea..1802373B Altcode:
Space weather is the main source of uncertainty in the position of all
objects in low Earth orbit (LEO) below about 1,000 km. The main impact
is strong variation in the neutral density of the thermosphere as it
responds to radiative inputs from the Sun in the extreme ultraviolet
wavelength range, energetic particle precipitation in the high-latitude
auroral zones, and global-scale electrical currents generated during
geomagnetic storms. Waves and instabilities from the lower atmosphere
can also influence thermospheric density in complex ways. The variation
in neutral density leads to variable drag forces on satellites flying
through the thermosphere, which in turn causes orbital track changes. We
currently lack the ability to accurately model and predict the neutral
density changes in the thermosphere in response to space weather
inputs. Operational empirical models of thermospheric density are
inaccurate during space weather events, and mandate that LEO orbital
tracks carry large "error ellipsoids" around all objects to account
for positional uncertainty. This leads to many more "conjunction"
warnings than necessary as large error ellipsoids are frequently
calculated to intersect in orbit. As the LEO domain becomes more
crowded with the advent of commercial "megaconstellations" we face
a growing challenge to reduce orbital uncertainties by developing
whole atmosphere models to enable timely and accurate forecasts of
thermospheric conditions. We recommend that researchers, forecasters,
and policy makers coordinate to ensure that space weather research
and forecasting is tightly integrated into upcoming changes to the
operational Space Traffic Management system.
---------------------------------------------------------
Title: Radiation in Space: Relevance and Risk for Human Missions
Authors: Hellweg, Christine E.; Berger, Thomas; Matthiä, Daniel;
Baumstark-Khan, Christa
2020rsrr.book.....H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: University of Colorado Space Weather Technology, Research,
and Education Center (SWx TREC): An academic center of excellence
to accelerate research to operations and operations to research
transitions
Authors: Berger, T. E.; Thayer, J. P.; Baker, D. N.; Knipp, D. J.;
Pankratz, C. K.; Cranmer, S. R.; Sutton, E. K.; Baltzer, T.; Lucas,
G.; Craft, J.; Bosanac, N.; Smith, T. R.
2019AGUFMSA13A..06B Altcode:
The University of Colorado at Boulder Space Weather Technology Research
and Education Center (SWx TREC) is a University Chancellor's Grand
Challenge Initiative forming a campus-wide center for research, mission
and technology development, and educational initiatives in the space
weather enterprise. SWx TREC offers a unique open academic environment
with contributions not only from the departments of Astrophysics and
Planetary Sciences, Aerospace Engineering Sciences, and Atmospheric
and Oceanic Sciences, but from campus institutes such as the Laboratory
for Atmospheric and Space Physics (LASP) and the Cooperative Institute
for Research in Environmental Sciences (CIRES) as well. In addition,
SWx TREC serves as a "Front Range" space weather collaboration engine,
reaching out to local government (NOAA/SWPC, USAF/SpaceCommand)
and industry (Ball Aerospace, Lockheed Martin, Raytheon, Google)
elements, commercial space weather providers such as Astra LLC and Space
Environment Technologies (SET), and local FFRDCs such as the National
Solar Observatory (NSO), NCAR's High Altitude Observatory (HAO), the
Southwest Research Institute (SWRI), and Northwest Research Associates
(NWRA) to pursue opportunities to advance space weather forecasting
through innovative research. We discuss how SWx TREC is working with
these partners to develop new satellite drag models for Civil Space
Traffic Management (STM) applications, a Space Weather Data Portal to
ease multi-instrument data display and analysis, and a Space Weather
Testbed that will allow academic and commercial developers to test new
models and forecasting tools in a cloud-based prototyping facility
with student and professional forecaster engagement. SWx TREC is
also developing two innovative mission concepts to fill major gaps in
the current space weather observing system: the Solar Polar Observing
Constellation (SPOC) with Ball Aerospace, and the Operational Radiation
Belts (ORB) mission for the Air Force.
---------------------------------------------------------
Title: SWx TREC: An Emerging Community Resource for Integrative
Space Weather Data Access and Model/Algorithm R2O Promotion
Authors: Pankratz, C. K.; Baltzer, T.; Lucas, G.; Craft, J.; Knuth,
J.; Berger, T. E.; Sutton, E. K.; Baker, D. N.; Jaynes, A. N.
2019AGUFMSH33C3373P Altcode:
The Space Weather Technology, Research and Education Center (SWx TREC)
is an emerging national center of excellence in cross-disciplinary
research, technology, innovation, and education, intended to facilitate
evolving space weather research and forecasting needs. SWx TREC is
positioned to facilitate breakthrough research advances, innovative
missions, and data and computing technologies that directly support
the needs of the operational forecasting enterprise to ensure closure
of the Research to Operations (R2O) and Operations to Research (O2R)
loop. Improving our understanding and prediction of space weather
requires coupled Research and Operations. SWx-TREC is working
to provide new research models, applications and data for use in
operational environments, improving the Research-to-Operations (R2O)
pipeline. Advancement in the fundamental scientific understanding of
space weather processes is also vital, requiring that researchers have
convenient and effective access to a wide variety of data sets and
models from multiple sources. The space weather research community,
as with many scientific communities, must access data from dispersed
and often uncoordinated data repositories to acquire the data necessary
for the analysis and modeling efforts that advance our understanding
of solar influences and space physics in the Earth's environment. The
University of Colorado (CU) is a leading institution in both producing
data products and advancing the state of scientific understanding of
space weather processes, and is serving many of these needs, including
1) implementation of an interoperable data portal intended to more
effectively serve the needs of the Space Weather research community
and 2) implementing a community-accessible testbed environment to
support development, testing, transition, and use of new models and
algorithms. In this presentation, we will outline the motivating
factors for effective space weather data access and modeling support,
describe a new testbed environment for supporting model, algorithm,
and visualization testing/incubation needs, and demonstrate a new
Space Weather Data Portal, designed to meet the data management and
access needs of the disparate communities who require space weather
data and information.
---------------------------------------------------------
Title: Adding Lunar Observations to Multi-point Observations around
Earth to Determine the Structure Heliospheric Discontinuities
Authors: Wimmer-Schweingruber, R. F.; Yu, J.; Xu, Z.; Zhang, S.; Hou,
D.; Guo, J.; Freiherr von Forstner, J. L.; Lohf, H.; Boettcher, S. I.;
Burmeister, S.; Matthiae, D.; Berger, T.; Hellweg, C.
2019AGUFMSH41A..01W Altcode:
The Chinese Chang'E 4 spacecraft landed on the Moon on January 3,
2019. The Lunar Lander Neutrons and Dosimetry (LND) instrument aboard
the Chang'E 4 lander provides measurements of the radiation environment
on the Moon. Some of its data products are provided at a cadence of once
per minute. Combining such data with high time resolution data from
other spacecraft near Earth (i.e., ACE, DSCOVR, SOHO, and Wind at L1)
allows to determine the three-dimensional structure of discontinuities
in the solar wind when (instrumental) counting statistics are good
enough. <P />We will present first attempts at reconstructing the
inclination angles of large-scale heliospheric discontinuities using
data from ACE, Chang'E 4, DSCOVR, SOHO, and Wind. We assume a radially
flowing solar wind speed of constant speed in individual solar wind
streams and investigate the timing of discontinuities in count rates
of particle and solar-wind instruments on these spacecraft.
---------------------------------------------------------
Title: Energetic particles measurements on the lunar far side by
Lunar Lander Neutron and Dosimetry(LND) experiment
Authors: Xu, Z.; Wimmer-Schweingruber, R. F.; Guo, J.; Yu, J.; Zhang,
S.; Berger, T.; Matthiae, D.; Burmeister, S.; Boettcher, S. I.;
Heber, B.
2019AGUFMSH41D3340X Altcode:
After Chang'E 4 successfully landed on the far side of the moon on
Jan 3<SUP>rd</SUP>, 2019, the Lunar Lander Neutron and Dosimetry
experiment has been working for 7 lunar days from January to July,
sending back the measurements of dose, linear energy transfer (LET)
spectrum, neutrons and charged particles. Here, we show observations
of charged particles especially protons and Helium ions, including
long term variation and solar energetic events, which are also the
first such measurements on the surface of the moon. The long-term
variation is mainly caused by solar modulation of galactic cosmic rays
(GCR) and anomalous cosmic rays (ACR). Comparing the energy spectra
of protons and He4 with those detected by EPHIN in 2019 and during the
previous solar minimum in 1996, as well as the Crème and BO10 models,
we find that the protons detected by LND were from GCR and solar source,
while the He4 were mainly from the ACR. This is a consequence of LND's
energy coverage. We also derive the upward proton fluxes due to the
interaction of downward energetic particles with lunar regolith. We
will also present a solar energetic particle event registered by LND
in May, 2019. The temporal variations of particle fluxes on the far
side of the moon detected by LND provide a new observation site in
space and can be helpful to improve our understanding of particle
propagation and transport in the heliosphere.
---------------------------------------------------------
Title: The Solar Polar Observing Constellation (SPOC) Mission:
research and operational monitoring of space weather from polar
heliocentric orbits
Authors: Berger, T. E.; Bosanac, N.; Smith, T. R.; Duncan, N. A.;
Wu, G.; Turner, E.; Hurlburt, N.; Korendyke, C.
2019AGUFMSH43F3352B Altcode:
The Sun's polar regions remain largely unobserved and yet understanding
and monitoring of the magnetic field, convective flows, and coronal
outflow conditions in the solar polar regions are the keys to accurately
modeling and forecasting the solar cycle, solar wind conditions,
and CME arrival times at Earth. We describe the Solar Polar Observing
Constellation (SPOC), a mission to establish continuous high-resolution
imaging of solar magnetic field dynamics, high-latitude surface and
sub-surface convective flows, and coronal mass ejection tracking from
a low-eccentricity polar heliocentric orbit. SPOC will consist of two
identical spacecraft, each equipped with a Lockheed Martin Compact
Magnetic Imager (CMI, derived from the Solar Dynamics Observatory
(SDO) Helioseismic and Magnetic Imager), the Naval Research Laboratory
(NRL) Compact Coronagraph (CCOR), and in-situ solar wind and energetic
particle instruments. Falcon Heavy launch vehicles will place the
SPOC spacecraft into a Jupiter gravitational assist (JGA) heliocentric
orbit, achieving an 88-degree ecliptic inclination, with the spacecraft
passing over the solar poles within 4 years after launch. Ion engines
will subsequently reduce the eccentricity of the orbits to below 0.05
at approximately 0.9 AU within 6 years after launch. Orbital phasing
will place the spacecraft over alternate poles to enable continuous
monitoring of the polar regions with operational-level redundancy of
systems. The inclusion of CCOR will enable visualization and tracking
of coronal mass ejections from above (or below) the ecliptic for the
first time, greatly enhancing our ability to forecast CME arrival times
at Earth and other planets such as Mars. SPOC combines polar region
exploration, high-latitude helioseismology and magnetic imaging, and
operational space weather monitoring in a single mission. Along with
planned missions to the L1 and L5 Lagrangian points in the ecliptic,
SPOC will enable an approach to the long-sought goal of continuous
full-sphere measurements of the solar magnetic field, solar wind and CME
outflow, and energetic particle flux - a goal that cannot be achieved
with observations from the ecliptic plane alone.
---------------------------------------------------------
Title: Search for Light Dark Matter Interactions Enhanced by the
Migdal Effect or Bremsstrahlung in XENON1T
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Althueser,
L.; Amaro, F. D.; Antochi, V. C.; Angelino, E.; Arneodo, F.; Barge,
D.; Baudis, L.; Bauermeister, B.; Bellagamba, L.; Benabderrahmane,
M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.;
Bruno, G.; Budnik, R.; Capelli, C.; Cardoso, J. M. R.; Cichon, D.;
Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski,
M. P.; de Perio, P.; Depoian, A.; di Gangi, P.; di Giovanni, A.;
Diglio, S.; Elykov, A.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth,
A.; Fulgione, W.; Gaemers, P.; Gallo Rosso, A.; Galloway, M.; Gao, F.;
Garbini, M.; Grandi, L.; Greene, Z.; Hasterok, C.; Hils, C.; Hogenbirk,
E.; Howlett, J.; Iacovacci, M.; Itay, R.; Joerg, F.; Kazama, S.;
Kish, A.; Kobayashi, M.; Koltman, G.; Kopec, A.; Landsman, H.; Lang,
R. F.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi,
F.; Lopes, J. A. M.; López Fune, E.; Macolino, C.; Mahlstedt, J.;
Manenti, M.; Manfredini, A.; Marignetti, F.; Marrodán Undagoitia,
T.; Masbou, J.; Mastroianni, S.; Messina, M.; Micheneau, K.; Miller,
K.; Molinario, A.; Morâ, K.; Mosbacher, Y.; Murra, M.; Naganoma, J.;
Ni, K.; Oberlack, U.; Odgers, K.; Palacio, J.; Pelssers, B.; Peres,
R.; Pienaar, J.; Pizzella, V.; Plante, G.; Podviianiuk, R.; Qin, J.;
Qiu, H.; Ramírez García, D.; Reichard, S.; Riedel, B.; Rocchetti,
A.; Rupp, N.; Dos Santos, J. M. F.; Sartorelli, G.; Šarčević, N.;
Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schulte, D.; Schumann,
M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Shockley, E.; Silva,
M.; Simgen, H.; Therreau, C.; Thers, D.; Toschi, F.; Trinchero, G.;
Tunnell, C.; Upole, N.; Vargas, M.; Volta, G.; Wack, O.; Wang, H.;
Wei, Y.; Weinheimer, C.; Wenz, D.; Wittweg, C.; Wulf, J.; Ye, J.;
Zhang, Y.; Zhu, T.; Zopounidis, J. P.; Xenon Collaboration
2019PhRvL.123x1803A Altcode: 2019arXiv190712771A
Direct dark matter detection experiments based on a liquid xenon
target are leading the search for dark matter particles with masses
above ∼5 GeV /c<SUP>2</SUP>, but have limited sensitivity to lighter
masses because of the small momentum transfer in dark matter-nucleus
elastic scattering. However, there is an irreducible contribution from
inelastic processes accompanying the elastic scattering, which leads
to the excitation and ionization of the recoiling atom (the Migdal
effect) or the emission of a bremsstrahlung photon. In this Letter,
we report on a probe of low-mass dark matter with masses down to about
85 MeV /c<SUP>2</SUP> by looking for electronic recoils induced by
the Migdal effect and bremsstrahlung using data from the XENON1T
experiment. Besides the approach of detecting both scintillation
and ionization signals, we exploit an approach that uses ionization
signals only, which allows for a lower detection threshold. This
analysis significantly enhances the sensitivity of XENON1T to light
dark matter previously beyond its reach.
---------------------------------------------------------
Title: The University of Colorado Space Weather Technology, Research,
and Education Center's Space Weather Portal: A Tool for Easing Access
to and Understanding of Datasets to Characterize Space Weather Events
Authors: Baltzer, T.; Berger, T. E.; Knuth, J.; Lindholm, D. M.;
Wilson, A.; Pankratz, C. K.
2019AGUFMSH33C3371B Altcode:
In our work with researchers, we consistently hear that a significant
hurdle they encounter is obtaining datasets from disparate providers in
varying formats, needing to repeat processes to obtain new timeframes
for those datasets and that having an idea of what is available
(e.g. is there an instrument outage during the time of interest?) before
downloading it is often unavailable. This is particularly challenging
for space weather researchers attempting to characterize an
event from the moment of occurrence on the Sun to the impacts
it has on the Earth. <P />As part of the University of Colorado's
Space Weather Technology, Research and Education Center (SWx-TREC <A
href="https://www.colorado.edu/spaceweather/">https://www.colorado.edu/spaceweather/</A>),
the Laboratory for Atmospheric and Space
Physics (LASP) is developing a Space Weather Portal (<A
href="http://lasp.colorado.edu/space-weather-portal">http://lasp.colorado.edu/space-weather-portal</A>)
to provide unified access to disparate datasets to help close the
Research to Operations (R2O) and Operations to Research (O2R) gap. This
presentation will describe how this portal can be used to characterize
an historical event (2015 St. Patrick's day storm) from available
datasets, visualize them and download them for further use. It will
also describe the underlying middleware (LaTiS) that enables the portal.
---------------------------------------------------------
Title: Light Dark Matter Search with Ionization Signals in XENON1T
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Althueser,
L.; Amaro, F. D.; Antochi, V. C.; Angelino, E.; Arneodo, F.; Barge,
D.; Baudis, L.; Bauermeister, B.; Bellagamba, L.; Benabderrahmane,
M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.;
Bruno, G.; Budnik, R.; Capelli, C.; Cardoso, J. M. R.; Cichon, D.;
Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski,
M. P.; de Perio, P.; Depoian, A.; di Gangi, P.; di Giovanni, A.;
Diglio, S.; Elykov, A.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth,
A.; Fulgione, W.; Gaemers, P.; Gallo Rosso, A.; Galloway, M.; Gao,
F.; Garbini, M.; Grandi, L.; Greene, Z.; Hasterok, C.; Hils, C.;
Hogenbirk, E.; Howlett, J.; Iacovacci, M.; Itay, R.; Joerg, F.;
Kazama, S.; Kish, A.; Kobayashi, M.; Koltman, G.; Kopec, A.; Landsman,
H.; Lang, R. F.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner,
M.; Lombardi, F.; Lopes, J. A. M.; López Fune, E.; Macolino, C.;
Mahlstedt, J.; Manfredini, A.; Marignetti, F.; Marrodán Undagoitia,
T.; Masbou, J.; Mastroianni, S.; Messina, M.; Micheneau, K.; Miller,
K.; Molinario, A.; Morâ, K.; Mosbacher, Y.; Murra, M.; Naganoma, J.;
Ni, K.; Oberlack, U.; Odgers, K.; Palacio, J.; Pelssers, B.; Peres,
R.; Pienaar, J.; Pizzella, V.; Plante, G.; Podviianiuk, R.; Qin, J.;
Qiu, H.; Ramírez García, D.; Reichard, S.; Riedel, B.; Rocchetti,
A.; Rupp, N.; Dos Santos, J. M. F.; Sartorelli, G.; Šarčević, N.;
Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schulte, D.; Schumann,
M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Shockley, E.; Silva,
M.; Simgen, H.; Therreau, C.; Thers, D.; Toschi, F.; Trinchero, G.;
Tunnell, C.; Upole, N.; Vargas, M.; Volta, G.; Wack, O.; Wang, H.;
Wei, Y.; Weinheimer, C.; Wenz, D.; Wittweg, C.; Wulf, J.; Ye, J.;
Zhang, Y.; Zhu, T.; Zopounidis, J. P.; Xenon Collaboration
2019PhRvL.123y1801A Altcode: 2019arXiv190711485A
We report constraints on light dark matter (DM) models using ionization
signals in the XENON1T experiment. We mitigate backgrounds with strong
event selections, rather than requiring a scintillation signal, leaving
an effective exposure of (22 ±3 ) tonne day. Above ∼0.4 keV<SUB>e
e</SUB> , we observe <1 event/(tonne day keV<SUB>e e</SUB>) ,
which is more than 1000 times lower than in similar searches with
other detectors. Despite observing a higher rate at lower energies,
no DM or CEvNS detection may be claimed because we cannot model all of
our backgrounds. We thus exclude new regions in the parameter spaces
for DM-nucleus scattering for DM masses m<SUB>χ</SUB> within 3 - 6
GeV /c<SUP>2</SUP> , DM-electron scattering for m<SUB>χ</SUB>>30
MeV /c<SUP>2</SUP> , and absorption of dark photons and axionlike
particles for m<SUB>χ</SUB> within 0.186 - 1 keV /c<SUP>2</SUP> .
---------------------------------------------------------
Title: Cooling Condensation at Coronal Null Points and
Quasi-Separatrix Layers Involving Magnetic Reconnection
Authors: Liu, W.; Sun, X.; Yu, S.; Luna Bennasar, M.; Antolin, P.;
Titov, V. S.; Downs, C.; Berger, T. E.
2019AGUFMSH11C3394L Altcode:
The solar corona, Sun's outer atmosphere, is million-degrees hot and
tenuous. This hot plasma, under certain conditions, can enigmatically
undergo a radiative cooling instability and condense into material of
100 times cooler in the form of prominences or coronal rain. Where,
when, and how such cooling condensation takes place remain poorly
understood. Answers to these questions are not only of scientific
importance in their own right, but also bear implications for the
fundamental question of coronal heating and the chromosphere-corona
mass cycle. Magnetic fields in the magnetized corona undoubtedly play
a crucial role (e.g., by trapping the plasma), but where and how? We
report recent imaging and spectroscopic observations from SDO/AIA/HMI
and IRIS that can shed light on these puzzles. Through a systematic
survey, we found that a large fraction of quiet-Sun condensations
preferentially occur at the dips of coronal loops or funnels. Such dips
are located at/near magnetic topological features, such as null points
and quasi-separatrix layers (QSLs), which are regions characterized by
high values of the squashing factor. We also identified evidence of
magnetic reconnection at such locations, which can produce favorable
conditions, e.g., density enhancement by compression and/or mass
trapping in plasmoids, that can trigger run-away radiative cooling. We
present proof-of-concept MHD simulations that demonstrate the role of
reconnection in transporting cooled mass from overlying, long loops to
underlying, short loops where it slide down as coronal rain. We will
discuss the significance and broader implications of these results
beyond solar physics.
---------------------------------------------------------
Title: SWx TREC Testbed: Facilitating Model/Algorithm R2O and O2R
Development within a Cloud Computing Environment
Authors: Lucas, G.; Craft, J.; Pankratz, C. K.; Sutton, E. K.; Berger,
T. E.
2019AGUFMSH33C3372L Altcode:
The Space Weather Technology, Research and Education Center (SWx TREC)
is an emerging national center of excellence in cross-disciplinary
research, technology, innovation, and education, intended to facilitate
evolving space weather research and forecasting needs. Within this
center, we are developing a Space Weather Testbed environment to
facilitate the research to operations (R2O) and operations to research
(O2R) pipelines. The Testbed leverages cloud computing to provide
a managed computational environment for independent science teams to
deploy their processing software into an operational-like system. Using
cloud computing for the environment enables traditional defined-cadence
(daily, hourly) model runs to be scheduled while also providing the
ability to submit on-demand runs during storm times with no additional
bulk hardware purchases that would otherwise sit idle most of the
time. <P />In this poster, we will discuss the technologies that are
being used in producing the Space Weather Testbed and demonstrate two
ways that the testbed is currently being utilized. First, in the R2O
pipeline, we have implemented code from the USGS to produce electric
field maps at a set cadence to demonstrate that the code can be run
in an operational mode. Second, in the O2R pipeline, we are taking an
operational code, the NOAA Whole Atmosphere Model (WAM), and enabling
researchers to investigate new data assimilation techniques that can
supplement and enhance current operational code capabilities. The Space
Weather TREC Testbed is utilizing modern computer architectures and
software practices to facilitate researchers and forecasters bridge
the R2O and O2R gaps.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Revised radii of KIC stars &
planets using Gaia DR2 (Berger+, 2018)
Authors: Berger, T. A.; Huber, D.; Gaidos, E.; van Saders, J. L.
2019yCat..18660099B Altcode:
First, we crossmatched the positions of all stars from the Kepler
Stellar Properties Catalog (KSPC DR25; Mathur+ 2017, J/ApJS/229/30)
with the Gaia Data Release 2 (DR2, I/345) by utilizing the X-match
service of the Centre de Donnees astronomiques de Strasbourg (CDS). This
provided a table of Gaia DR2 source matches within 3" of each Keplers
tar. Excluding stars through a variety of cuts reduced our final sample
to 177911 Kepler stars. See section 2.1 for further details. <P />(2
data files).
---------------------------------------------------------
Title: Planetesimals around stars with TESS (PAST) - I. Transient
dimming of a binary solar analogue at the end of the planet
accretion era
Authors: Gaidos, E.; Jacobs, T.; LaCourse, D.; Vanderburg, A.;
Rappaport, S.; Berger, T.; Pearce, L.; Mann, A. W.; Weiss, L.; Fulton,
B.; Behmard, A.; Howard, A. W.; Ansdell, M.; Ricker, G. R.; Vanderspek,
R. K.; Latham, D. W.; Seager, S.; Winn, J. N.; Jenkins, J. M.
2019MNRAS.488.4465G Altcode: 2019arXiv190702476G; 2019MNRAS.tmp.1875G
We report detection of quasi-periodic (1.5-d) dimming of HD 240779, the
solar-mass primary in a 5 arcsec visual binary (also TIC 284730577),
by the Transiting Exoplanet Survey Satellite. This dimming, as has
been shown for other `dipper' stars, is likely due to occultation by
circumstellar dust. The barycentric space motion, lithium abundance,
rotation, and chromospheric emission of the stars in this system point
to an age of ≈125 Myr, and possible membership in the AB Doradus
moving group. As such it occupies an important but poorly explored
intermediate regime of stars with transient dimming between young
stellar objects in star-forming regions and main-sequence stars, and
between UX Orionis-type Ae/Be stars and M-type `dippers'. HD 240779, but
not its companion BD+10 714B, has Wide-field Infrared Survey Explorer
(WISE)-detected excess infrared emission at 12 and 22 μm indicative
of circumstellar dust. We propose that infrared emission is produced
by collisions of planetesimals during clearing of a residual disc at
the end of rocky planet formation, and that quasi-periodic dimming is
produced by the rapid disintegration of a ≳100 km planetesimal near
the silicate evaporation radius. Further studies of this and similar
systems will illuminate a poorly understood final phase of rocky planet
formation like that which produced the inner Solar system.
---------------------------------------------------------
Title: Phobos LIFE (Living Interplanetary Flight Experiment)
Authors: Betts, Bruce H.; Warmflash, David; Fraze, Raymond E.;
Friedman, Louis; Vorobyova, Elena; Lilburn, Timothy G.; Smith, Amy;
Rettberg, Petra; Jönsson, K. Ingemar; Ciftcioglu, Neva; Fox, George
E.; Svitek, Tomas; Kirschvinck, Joseph L.; Moeller, Ralf; Wassmann,
Marko; Berger, Thomas
2019AsBio..19.1177B Altcode:
The Planetary Society's Phobos Living Interplanetary Flight Experiment
(Phobos LIFE) flew in the sample return capsule of the Russian Federal
Space Agency's Phobos Grunt mission and was to have been a test of one
aspect of the hypothesis that life can move between nearby planets
within ejected rocks. Although the Phobos Grunt mission failed, we
present here the scientific and engineering design and motivation of the
Phobos LIFE experiment to assist with the scientific and engineering
design of similar future experiments. Phobos LIFE flew selected
organisms in a simulated meteoroid. The 34-month voyage would have
been the first such test to occur in the high-radiation environment
outside the protection of Earth's magnetosphere for more than a
few days. The patented Phobos LIFE "biomodule" is an 88 g cylinder
consisting of a titanium outer shell, several types of redundant seals,
and 31 individual Delrin sample containers. Phobos LIFE contained 10
different organisms, representing all three domains of life, and one
soil sample. The organisms are all very well characterized, most with
sequenced genomes. Most are extremophiles, and most have flown in low
Earth orbit. Upon return from space, the health and characteristics
of organisms were to have been compared with controls that remained
on Earth and have not yet been opened.
---------------------------------------------------------
Title: First Results from the Lunar Lander Neutron and Dosimetry
Experiment (LND) on China's Chang'E 4 mission to the far side of
the Moon
Authors: Wimmer-Schweingruber, Robert F.; Zhang, Shenyi; Yu, Jia;
Böttcher, Stephan I.; Burmeister, Sönke; Lohf, Henning; Guo, Jingnan;
Xu, Zigong; Berger, Thomas; Hellweg, Christine; Matthiä, Daniel
2019EPSC...13.1289W Altcode:
Chang'E 4 is the Chinese mission which landed on the far side of the
Moon at 02:26 UTC on January 3, 2019. It consists of a lander, a rover,
and an re- lay spacecraft. We will present first results from the Lunar
Lander Neutron and Dosimetry (LND) Experi- ment aboard Chang'E 4. LND
has obtained first active dosimetric measurements on the surface of
the Moon, both of the charged as well as neutral radiation com- ponent.
---------------------------------------------------------
Title: Measurements of radiation quality factor on Mars with the
Mars Science Laboratory Radiation Assessment Detector
Authors: Zeitlin, C.; Hassler, D. M.; Ehresmann, B.; Rafkin, S. C. R.;
Guo, J.; Wimmer-Schweingruber, R. F.; Berger, T.; Matthiä, D.
2019LSSR...22...89Z Altcode:
We report the first long-term measurements of the radiation quality
factor of energetic charged particles on the surface of Mars. The
Radiation Assessment Detector (RAD) aboard the Mars Science Laboratory
rover, also known as Curiosity, has been operating on Mars since
2012. RAD contains thin silicon detectors that record the ionization
energy loss of energetic charged particles. The particles are dominantly
galactic cosmic rays (GCRs) and the products of their interactions
in the Martian atmosphere, with occasional contributions from solar
energetic particles (SEPs). The quality factor on the surface of Mars
is influenced by two factors: variations in the shielding provided by
the atmosphere, and changes in the spectrum of the incident energetic
particle flux due to the 11-year solar cycle. The two cannot be easily
disentangled using the data alone, but insights can be gained from
calculations and Monte Carlo simulations.
---------------------------------------------------------
Title: Photochemistry on the Space Station—Antibody Resistance
to Space Conditions after Exposure Outside the International Space
Station
Authors: Coussot, Gaëlle; Le Postollec, Aurélie; Faye, Clément;
Baqué, Mickaël; Vandenabeele-Trambouze, Odile; Incerti, Sébastien;
Vigier, Flavie; Chaput, Didier; Cottin, Hervé; Przybyla, Bartos;
Berger, Thomas; Dobrijevic, Michel
2019AsBio..19.1053C Altcode:
Antibody-based analytical instruments are under development to detect
signatures of life on planetary bodies. Antibodies are molecular
recognition reagents able to detect their target at sub-nanomolar
concentrations, with high affinity and specificity. Studying antibody
binding performances under space conditions is mandatory to convince
space agencies of the adequacy of this promising tool for planetary
exploration. To complement previous ground-based experiments on
antibody resistance to simulated irradiation, we evaluate in this
paper the effects of antibody exposure to real space conditions during
the EXPOSE-R2 mission outside the International Space Station. The
absorbed dose of ionizing radiation recorded during the 588 days of
this mission (220 mGy) corresponded to the absorbed dose expected
during a mission to Mars. Moreover, samples faced, at the same time
as irradiation, thermal cycles, launch constraints, and long-term
storage. A model biochip was used in this study with antibodies in
freeze-dried form and under two formats: free or covalently grafted
to a solid surface. We found that antibody-binding performances were
not significantly affected by cosmic radiation, and more than 40% of
the exposed antibody, independent of its format, was still functional
during all this experiment. We conclude that antibody-based instruments
are well suited for in situ analysis on planetary bodies.
---------------------------------------------------------
Title: Photochemistry on the Space Station—Aptamer Resistance to
Space Conditions: Particles Exposure from Irradiation Facilities
and Real Exposure Outside the International Space Station
Authors: Coussot, Gaëlle; Le Postollec, Aurélie; Incerti, Sébastien;
Baqué, Mickaël; Faye, Clément; Vandenabeele-Trambouze, Odile;
Cottin, Hervé; Ravelet, Corinne; Peyrin, Eric; Fiore, Emmanuelle;
Vigier, Flavie; Caron, Jérôme; Chaput, Didier; Przybyla, Bartos;
Berger, Thomas; Dobrijevic, Michel
2019AsBio..19.1063C Altcode:
Some microarray-based instruments that use bioaffinity receptors
such as antibodies or aptamers are under development to detect
signatures of past or present life on planetary bodies. Studying the
resistance of such instruments against space constraints and cosmic
rays in particular is a prerequisite. We used several ground-based
facilities to study the resistance of aptamers to various types of
particles (protons, electrons, neutrons, and carbon ions) at different
energies and fluences. We also tested the resistance of aptamers
during the EXPOSE-R2 mission outside the International Space Station
(ISS). The accumulated dose measured after the 588 days of this mission
(220 mGy) corresponds to the accumulated dose that can be expected
during a mission to Mars. We found that the recognition ability of
fluorescently labeled aptamers was not significantly affected during
short-term exposure experiments taking into account only one type of
radiation at a time. However, we demonstrated that the same fluorescent
dye was significantly affected by temperature variations (-21°C to
+58°C) and storage throughout the entirety of the ISS experiment
(60% of signal loss). This induced a large variability of aptamer
signal in our analysis. However, we found that >50% of aptamers
were still functional after the whole EXPOSE-R2 mission. We conclude
that aptamer-based instruments are well suited for in situ analysis
on planetary bodies, but the detection step requires additional
investigations.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Radial velocities and transit
times for KOI 4 (Chontos+, 2019)
Authors: Chontos, A.; Huber, D.; Latham, D. W.; Bieryla, A.; van
Eylen, V.; Bedding, T. R.; Berger, T.; Buchhave, L. A.; Campante,
T. L.; Chaplin, W. J.; Colman, I. L.; Coughlin, J. L.; Davies, G.;
Hirano, T.; Howard, A. W.; Isaacson, H.
2019yCat..51570192C Altcode:
Following the asteroseismic reclassification of the host star, we
initiated an intensive radial velocity (RV) follow-up program using
the Tillinghast Reflector Echelle Spectrograph (TRES), a fiber-fed
echelle spectrograph spanning the spectral range of 3900-9100 Å
with a resolving power of R~44000. We obtained 23 spectra with TRES
between UT 2009 November 8 and 2017 September 13 using the medium 2.3"
fiber. The spectra were reduced and extracted as outlined in Buchhave
et al. (2010, J/ApJ/720/1118). The average exposure time of ~1800 s,
corresponding to a mean signal-to-noise ratio (S/N) per resolution
element of ~53 at the peak of the continuum near the Mg b triplet at
519 nm. We used the strongest S/N spectrum as a template to derive
relative RVs by cross-correlating the remaining spectra order-by-order
against the template, which is given a relative velocity of 0 km/s,
by definition. <P />(2 data files).
---------------------------------------------------------
Title: Coronal Condensation at Preferential Topological Locations:
The Birth of Solar Prominences and Coronal Rain
Authors: Liu, Wei; Sun, Xudong; Yu, Sijie; Antolin, Patrick; Titov,
Viacheslav; Downs, Cooper; Berger, Thomas
2019AAS...23412502L Altcode:
The million-degree hot and tenuous solar coronal plasma, under
certain conditions, can enigmatically undergo a radiative cooling
instability and condense into material of 100 times cooler in the form
of prominences or coronal rain. Where, when, and how such cooling
condensation takes place remain poorly understood. Answers to these
questions are not only of scientific importance in their own right,
but also bear implications for the fundamental question of coronal
heating and the chromosphere-corona mass cycle. Magnetic fields in the
magnetized corona undoubtedly play a crucial role (e.g., by trapping the
plasma), but where and how? We report recent imaging and spectroscopic
observations from SDO/AIA/HMI and IRIS that can shed light on these
puzzles. Through a systematic survey, we found that a large fraction
of quiet-Sun condensations preferentially occur at the dips of coronal
loops or funnels. Such dips are located at/near magnetic topological
features, such as null points and quasi-separatrix layers (QSLs), which
are regions characterized by high values of the squashing factor. We
also identified evidence of magnetic reconnection at such locations,
which can produce favorable conditions, e.g., density enhancement
by compression and/or mass trapping in plasmoids, that can trigger
run-away radiative cooling. We will discuss the significance and
broader implications of these novel observations.
---------------------------------------------------------
Title: Solar Polar Observing Constellation (SPOC): A New Age for
Solar Observations
Authors: Upton, Lisa; Berger, Thomas; Duncan, Nicole; Bosanac, Natasha
2019AAS...23410614U Altcode:
Current observing platforms can only measure the solar magnetic field
over a portion of the Earth-facing hemisphere, forcing us to rely on
solar rotation to build up fictional "synoptic maps" of the full-Sun
field over 27-days. The lack of magnetic field "boundary conditions"
over the full Sun represents a fundamental gap in our ability to
accurately model the solar coronal magnetic field and solar wind
acceleration. Views restricted to the ecliptic plane cannot capture
the Sun's polar regions. Observation of the poles from a high latitude
vantage point are needed to advance helioseismology and constrain
the Sun's polar fields and high latitude flows, which are crucial
to understanding the solar activity cycle. Furthermore, sustained
observation of the Sun's polar regions will enable helioseismology
investigations of the polar subsurface flows, allowing us to probe
deeper into the mechanisms of the solar cycle. <P />We propose a novel
constellation of small satellites called the Solar Polar Observing
Constellation (SPOC) that will obtain magnetic field and doppler
velocity measurements from a solar polar orbit, including nearly direct
overhead measurements of the poles. The SPOC constellation consists
of two identical satellites placed into 90-degree inclination
heliocentric orbits using Jupiter gravitational assist (JGA)
trajectories and ion electric propulsion to circularize the orbit
at about 0.9 AU. Instrumentation includes a compact helioseismic
magnetic imager, compact coronagraph, and in-situ solar wind plasma
measuring instruments. The SPOC mission follows the model of "hybrid
operational-research" missions developed by the CU Space Weather
Technology, Research, and Education (SWx-TREC) to enhance utility and
collaboration by developing critical operational data sources for space
weather forecasting that can also produce exploratory science data.
---------------------------------------------------------
Title: Deep Learning and Feature Engineering for Solar Flare
Prediction
Authors: Carande, Wendy Hawley; Berger, Tom; Cai, Justin; Craft,
James; Hartnett, Maxine; Jones, Andrew; Newman, William; Pankratz,
Chris; Woods, Tom
2019shin.confE.156C Altcode:
Space weather events can inflict chaos on our modern,
technologically-dependent world, such as degradation, and sometimes
even disruption, for our telecommunications, power grids, navigation
systems, and satellite operations. Therefore, improving the accuracy in
predicting such events is of the upmost importance. With this in mind,
we built a deep learning system capable of predicting M and X class
solar flares in a 24 hour time window, and we achieved a True Skill
Score of 0.9. The inputs to our deep learning algorithm are magnetograms
from the Solar Dynamics Observatory Helioseismic and Magnetic Imager
(SDO/HMI), and the output is a binary classification indicating whether
or not a solar flare will occur in the time window. The highest True
Skill Scores were attained with the convolutional neural networks
AlexNet and VGGNet. We are currently working to incorporate SDO Extreme
ultraviolet Variability (EVE) time series data into our existing deep
learning framework. As we add more data, we anticipate a richer model
with increased predictive power. Using examples and results from
our convolutional neural network and multilayer perceptron models,
we’ll present how we approached challenges and sought to fix them
and what methods we propose as we further develop our models. We’ll
also present the importance of feature engineering as it relates to
solar flare prediction, and the obstacles and rewards of creating our
own in-house features, including polarity inversion lines.
---------------------------------------------------------
Title: Calibrating GONG Magnetograms Using MURaM as Ground Truth
Authors: Plowman, Joseph; Petrie, Gordon; Berger, Tom
2019shin.confE.223P Altcode:
Results of a GONG calibration based on an end-to-end simulation of
its measurement process are presented. The calibration begins with a
MuRAM 3D MHD simulation, models solar radiative transfer of the GONG
nickel line, emulates the GONG measurement process, and inverts the
resulting synthetic GONG observations to produce magnetograms. The
theory of producing calibration curves from comparison of synthetic
magnetograms with the corresponding ground truth is then considered,
and the resulting calibration curves are shown. The implications of
these results for space weather applications are discussed, and they
also shed new light on the old question of the relative calibration
of magnetographs.
---------------------------------------------------------
Title: SWx TREC: An Open Space Weather (SWx) R2O Development and
Testbed Environment
Authors: Craft, James; Pankratz, Chris; Berger, Thomas; Thayer,
Jeffrey; Baltzer, Thomas; Baker, Daniel
2019EGUGA..2112073C Altcode:
The Chancellor of the University of Colorado recently awarded a Grand
Challenge grant to a group of departments and labs for the development
of the Space Weather Technology, Research and Education Center
(https://www.colorado.edu/spaceweather/). As part of this effort,
the Laboratory for Atmospheric and Space Physics (LASP) is developing
a Space Weather Testbed to provide a platform to explore research and
development models side-by-side with operational standards. The Space
Weather Testbed is being built using technologies employed by LASP
Data Systems for the Magnetospheric Multiscale Mission Science Data
Center and the Emirates Mars Mission Science Data Center. These data
centers provide a managed computational environment for independent
science teams to deploy their processing software into the operational
system. This poster will discuss the technologies that will be used in
producing the Space Weather Testbed and how the exploration between
Operations to Research (O2R) and Research to Operations (R2O) will
be supported.
---------------------------------------------------------
Title: Constraining the Spin-Dependent WIMP-Nucleon Cross Sections
with XENON1T
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Althueser,
L.; Amaro, F. D.; Anthony, M.; Antochi, V. C.; Arneodo, F.; Baudis, L.;
Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.;
Brown, A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik,
R.; Capelli, C.; Cardoso, J. M. R.; Cichon, D.; Coderre, D.; Colijn,
A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.;
di Gangi, P.; di Giovanni, A.; Diglio, S.; Elykov, A.; Eurin, G.;
Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.;
Galloway, M.; Gao, F.; Garbini, M.; Grandi, L.; Greene, Z.; Hasterok,
C.; Hogenbirk, E.; Howlett, J.; Iacovacci, M.; Itay, R.; Joerg, F.;
Kazama, S.; Kish, A.; Koltman, G.; Kopec, A.; Landsman, H.; Lang,
R. F.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi,
F.; Lopes, J. A. M.; López Fune, E.; Macolino, C.; Mahlstedt, J.;
Manfredini, A.; Marignetti, F.; Marrodán Undagoitia, T.; Masbou,
J.; Masson, D.; Mastroianni, S.; Messina, M.; Micheneau, K.; Miller,
K.; Molinario, A.; Morâ, K.; Mosbacher, Y.; Murra, M.; Naganoma, J.;
Ni, K.; Oberlack, U.; Odgers, K.; Pelssers, B.; Piastra, F.; Pienaar,
J.; Pizzella, V.; Plante, G.; Podviianiuk, R.; Priel, N.; Qiu, H.;
Ramírez García, D.; Reichard, S.; Riedel, B.; Rizzo, A.; Rocchetti,
A.; Rupp, N.; Dos Santos, J. M. F.; Sartorelli, G.; Šarčević, N.;
Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schulte, D.; Schumann,
M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Shockley, E.; Silva,
M.; Simgen, H.; Therreau, C.; Thers, D.; Toschi, F.; Trinchero, G.;
Tunnell, C.; Upole, N.; Vargas, M.; Wack, O.; Wang, H.; Wang, Z.;
Wei, Y.; Weinheimer, C.; Wenz, D.; Wittweg, C.; Wulf, J.; Xu, Z.;
Ye, J.; Zhang, Y.; Zhu, T.; Zopounidis, J. P.; Xenon Collaboration
2019PhRvL.122n1301A Altcode: 2019arXiv190203234A
We report the first experimental results on spin-dependent elastic
weakly interacting massive particle (WIMP) nucleon scattering from the
XENON1T dark matter search experiment. The analysis uses the full ton
year exposure of XENON1T to constrain the spin-dependent proton-only
and neutron-only cases. No significant signal excess is observed, and
a profile likelihood ratio analysis is used to set exclusion limits
on the WIMP-nucleon interactions. This includes the most stringent
constraint to date on the WIMP-neutron cross section, with a minimum of
6.3 ×10<SUP>-42</SUP> cm<SUP>2</SUP> at 30 GeV /c<SUP>2</SUP> and 90%
confidence level. The results are compared with those from collider
searches and used to exclude new parameter space in an isoscalar theory
with an axial-vector mediator.
---------------------------------------------------------
Title: The Lunar Lander Neutron and Dosimetry (LND) Experiment
on Chang'E4
Authors: Wimmer-Schweingruber, R. F.; Zhang, S.; Yu, J.; Hellweg,
C. E.; Guo, J.; Lohf, H.; Berger, T.; Böttcher, S. I.; Burmeister,
S.; Knappmann, A.; Knierim, V.; Schuster, B.; Seimetz, L.; Xu, Z.;
Shen, G.; Yuan, B.
2019LPI....50.2348W Altcode:
Chang'E4 was launched on December 8, 2018 and landed on January 3,
2019. We present first data from the Lunar Lander Neutron and Dosimetry
(LND) Experiment.
---------------------------------------------------------
Title: Limits of Life and the Habitability of Mars: The ESA Space
Experiment BIOMEX on the ISS
Authors: de Vera, Jean-Pierre; Alawi, Mashal; Backhaus, Theresa;
Baqué, Mickael; Billi, Daniela; Böttger, Ute; Berger, Thomas;
Bohmeier, Maria; Cockell, Charles; Demets, René; de la Torre Noetzel,
Rosa; Edwards, Howell; Elsaesser, Andreas; Fagliarone, Claudia;
Fiedler, Annelie; Foing, Bernard; Foucher, Frédéric; Fritz,
Jörg; Hanke, Franziska; Herzog, Thomas; Horneck, Gerda; Hübers,
Heinz-Wilhelm; Huwe, Björn; Joshi, Jasmin; Kozyrovska, Natalia;
Kruchten, Martha; Lasch, Peter; Lee, Natuschka; Leuko, Stefan; Leya,
Thomas; Lorek, Andreas; Martínez-Frías, Jesús; Meessen, Joachim;
Moritz, Sophie; Moeller, Ralf; Olsson-Francis, Karen; Onofri, Silvano;
Ott, Sieglinde; Pacelli, Claudia; Podolich, Olga; Rabbow, Elke; Reitz,
Günther; Rettberg, Petra; Reva, Oleg; Rothschild, Lynn; Garcia Sancho,
Leo; Schulze-Makuch, Dirk; Selbmann, Laura; Serrano, Paloma; Szewzyk,
Ulrich; Verseux, Cyprien; Wadsworth, Jennifer; Wagner, Dirk; Westall,
Frances; Wolter, David; Zucconi, Laura
2019AsBio..19..145D Altcode:
BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure
experiment housed within the exposure facility EXPOSE-R2 outside
the Zvezda module on the International Space Station (ISS). The
design of the multiuser facility supports—among others—the
BIOMEX investigations into the stability and level of degradation of
space-exposed biosignatures such as pigments, secondary metabolites,
and cell surfaces in contact with a terrestrial and Mars analog
mineral environment. In parallel, analysis on the viability of the
investigated organisms has provided relevant data for evaluation of the
habitability of Mars, for the limits of life, and for the likelihood
of an interplanetary transfer of life (theory of lithopanspermia). In
this project, lichens, archaea, bacteria, cyanobacteria, snow/permafrost
algae, meristematic black fungi, and bryophytes from alpine and polar
habitats were embedded, grown, and cultured on a mixture of martian and
lunar regolith analogs or other terrestrial minerals. The organisms and
regolith analogs and terrestrial mineral mixtures were then exposed to
space and to simulated Mars-like conditions by way of the EXPOSE-R2
facility. In this special issue, we present the first set of data
obtained in reference to our investigation into the habitability of
Mars and limits of life. This project was initiated and implemented
by the BIOMEX group, an international and interdisciplinary consortium
of 30 institutes in 12 countries on 3 continents. Preflight tests for
sample selection, results from ground-based simulation experiments,
and the space experiments themselves are presented and include a
complete overview of the scientific processes required for this space
experiment and postflight analysis. The presented BIOMEX concept could
be scaled up to future exposure experiments on the Moon and will serve
as a pretest in low Earth orbit.
---------------------------------------------------------
Title: First Results on the Scalar WIMP-Pion Coupling, Using the
XENON1T Experiment
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Althueser,
L.; Amaro, F. D.; Anthony, M.; Antochi, V. C.; Arneodo, F.; Baudis, L.;
Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.;
Brown, A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik,
R.; Capelli, C.; Cardoso, J. M. R.; Cichon, D.; Coderre, D.; Colijn,
A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.;
di Gangi, P.; di Giovanni, A.; Diglio, S.; Elykov, A.; Eurin, G.;
Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.;
Galloway, M.; Gao, F.; Garbini, M.; Grandi, L.; Greene, Z.; Hasterok,
C.; Hogenbirk, E.; Howlett, J.; Iacovacci, M.; Itay, R.; Joerg, F.;
Kaminsky, B.; Kazama, S.; Kish, A.; Koltman, G.; Kopec, A.; Landsman,
H.; Lang, R. F.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner,
M.; Lombardi, F.; Lopes, J. A. M.; López Fune, E.; Macolino, C.;
Mahlstedt, J.; Manfredini, A.; Marignetti, F.; Marrodán Undagoitia,
T.; Masbou, J.; Masson, D.; Mastroianni, S.; Messina, M.; Micheneau,
K.; Miller, K.; Molinario, A.; Morâ, K.; Murra, M.; Naganoma, J.;
Ni, K.; Oberlack, U.; Odgers, K.; Pelssers, B.; Piastra, F.; Pienaar,
J.; Pizzella, V.; Plante, G.; Podviianiuk, R.; Priel, N.; Qiu, H.;
Ramírez García, D.; Reichard, S.; Riedel, B.; Rizzo, A.; Rocchetti,
A.; Rupp, N.; Dos Santos, J. M. F.; Sartorelli, G.; Šarčević, N.;
Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schulte, D.; Schumann,
M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Shockley, E.; Silva,
M.; Simgen, H.; Therreau, C.; Thers, D.; Toschi, F.; Trinchero, G.;
Tunnell, C.; Upole, N.; Vargas, M.; Wack, O.; Wang, H.; Wang, Z.;
Wei, Y.; Weinheimer, C.; Wenz, D.; Wittweg, C.; Wulf, J.; Ye, J.;
Zhang, Y.; Zhu, T.; Zopounidis, J. P.; Hoferichter, M.; Klos, P.;
Menéndez, J.; Schwenk, A.; Xenon Collaboration
2019PhRvL.122g1301A Altcode: 2018arXiv181112482A
We present first results on the scalar coupling of weakly interacting
massive particles (WIMPs) to pions from 1 t yr of exposure with the
XENON1T experiment. This interaction is generated when the WIMP couples
to a virtual pion exchanged between the nucleons in a nucleus. In
contrast to most nonrelativistic operators, these pion-exchange
currents can be coherently enhanced by the total number of nucleons
and therefore may dominate in scenarios where spin-independent
WIMP-nucleon interactions are suppressed. Moreover, for natural values
of the couplings, they dominate over the spin-dependent channel due
to their coherence in the nucleus. Using the signal model of this
new WIMP-pion channel, no significant excess is found, leading to an
upper limit cross section of 6.4 ×10<SUP>-46</SUP> cm<SUP>2</SUP>
(90% confidence level) at 30 GeV /c<SUP>2</SUP> WIMP mass.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Lithium abundances of KOIs from
CKS spectra (Berger+, 2018)
Authors: Berger, T. A.; Howard, A. W.; Boesgaard, A. M.
2019yCat..18550115B Altcode:
One key follow-up survey of Kepler-discovered exoplanets is the
California Kepler Survey (CKS) (Petigura+ 2017, J/AJ/154/107),
which was proposed to measure precise stellar parameters (Teff, logg,
[Fe/H], vsini) by using local thermodynamic equilibrium (LTE) modeling
of Keck-HIRES spectra of ~1000 Kepler FGK stars. Most spectra have
signal-to-noise ratios (S/Ns) of ~45 per pixel, or ~90 per resolution
element at 6700Å, with a resolution R=55000 and wavelength coverage
from 3642-7990Å. S/N ranges from ~5 to ~200. <P />(3 data files).
---------------------------------------------------------
Title: Skynet Algorithm for Single-dish Radio
Mapping. I. Contaminant-cleaning, Mapping, and Photometering
Small-scale Structures
Authors: Martin, J. R.; Reichart, D. E.; Dutton, D. A.; Maples,
M. P.; Berger, T. A.; Ghigo, F. D.; Haislip, J. B.; Shaban, O. H.;
Trotter, A. S.; Barnes, L. M.; Paggen, M. L.; Gao, R. L.; Salemi,
C. P.; Langston, G. I.; Bussa, S.; Duncan, J. A.; White, S.; Heatherly,
S. A.; Karlik, J. B.; Johnson, E. M.; Reichart, J. E.; Foster, A. C.;
Kouprianov, V. V.; Mazlin, S.; Harvey, J.
2019ApJS..240...12M Altcode: 2018arXiv180806128M
We present a single-dish mapping algorithm with a number of advantages
over traditional techniques. (1) Our algorithm makes use of weighted
modeling, instead of weighted averaging, to interpolate between signal
measurements. This smooths the data, but without blurring the data
beyond instrumental resolution. Techniques that rely on weighted
averaging blur point sources sometimes by as much as 40%. (2)
Our algorithm makes use of local, instead of global, modeling to
separate astronomical signal from instrumental and/or environmental
signal drift along the telescope’s scans. Other techniques, such
as basket weaving, model this drift with simple functional forms
(linear, quadratic, etc.) across the entirety of scans, limiting their
ability to remove such contaminants. (3) Our algorithm makes use of
a similar, local modeling technique to separate astronomical signal
from radio-frequency interference (RFI), even if only continuum data
are available. (4) Unlike other techniques, our algorithm does not
require data to be collected on a rectangular grid or regridded before
processing. (5) Data from any number of observations, overlapping or
not, may be appended and processed together. (6) Any pixel density may
be selected for the final image. We present our algorithm and evaluate
it using both simulated and real data. We are integrating it into
the image-processing library of the Skynet Robotic Telescope Network,
which includes optical telescopes spanning four continents, and now
also Green Bank Observatory’s 20 m diameter radio telescope in West
Virginia. Skynet serves hundreds of professional users, and additionally
tens of thousands of students, of all ages. Default data products are
generated on the fly, but will soon be customizable after the fact.
---------------------------------------------------------
Title: Roadmap for Reliable Ensemble Forecasting of the Sun-Earth
System
Authors: Nita, Gelu; Angryk, Rafal; Aydin, Berkay; Banda, Juan;
Bastian, Tim; Berger, Tom; Bindi, Veronica; Boucheron, Laura; Cao,
Wenda; Christian, Eric; de Nolfo, Georgia; DeLuca, Edward; DeRosa,
Marc; Downs, Cooper; Fleishman, Gregory; Fuentes, Olac; Gary, Dale;
Hill, Frank; Hoeksema, Todd; Hu, Qiang; Ilie, Raluca; Ireland,
Jack; Kamalabadi, Farzad; Korreck, Kelly; Kosovichev, Alexander;
Lin, Jessica; Lugaz, Noe; Mannucci, Anthony; Mansour, Nagi; Martens,
Petrus; Mays, Leila; McAteer, James; McIntosh, Scott W.; Oria, Vincent;
Pan, David; Panesi, Marco; Pesnell, W. Dean; Pevtsov, Alexei; Pillet,
Valentin; Rachmeler, Laurel; Ridley, Aaron; Scherliess, Ludger; Toth,
Gabor; Velli, Marco; White, Stephen; Zhang, Jie; Zou, Shasha
2018arXiv181008728N Altcode:
The authors of this report met on 28-30 March 2018 at the New Jersey
Institute of Technology, Newark, New Jersey, for a 3-day workshop
that brought together a group of data providers, expert modelers, and
computer and data scientists, in the solar discipline. Their objective
was to identify challenges in the path towards building an effective
framework to achieve transformative advances in the understanding
and forecasting of the Sun-Earth system from the upper convection
zone of the Sun to the Earth's magnetosphere. The workshop aimed to
develop a research roadmap that targets the scientific challenge
of coupling observations and modeling with emerging data-science
research to extract knowledge from the large volumes of data (observed
and simulated) while stimulating computer science with new research
applications. The desire among the attendees was to promote future
trans-disciplinary collaborations and identify areas of convergence
across disciplines. The workshop combined a set of plenary sessions
featuring invited introductory talks and workshop progress reports,
interleaved with a set of breakout sessions focused on specific topics
of interest. Each breakout group generated short documents, listing
the challenges identified during their discussions in addition to
possible ways of attacking them collectively. These documents were
combined into this report-wherein a list of prioritized activities
have been collated, shared and endorsed.
---------------------------------------------------------
Title: Robust Chauvenet Outlier Rejection
Authors: Maples, M. P.; Reichart, D. E.; Konz, N. C.; Berger, T. A.;
Trotter, A. S.; Martin, J. R.; Dutton, D. A.; Paggen, M. L.; Joyner,
R. E.; Salemi, C. P.
2018ApJS..238....2M Altcode: 2018arXiv180705276M
Sigma clipping is commonly used in astronomy for outlier rejection,
but the number of standard deviations beyond which one should clip data
from a sample ultimately depends on the size of the sample. Chauvenet
rejection is one of the oldest, and simplest, ways to account for
this, but, like sigma clipping, it depends on the sample’s mean
and standard deviation, neither of which are robust quantities: both
are easily contaminated by the very outliers they are being used to
reject. Many, more robust measures of central tendency, and of sample
deviation, exist, but each has a trade-off with precision. Here we
demonstrate that outlier rejection can be both very robust and very
precise if decreasingly robust but increasingly precise techniques are
applied in sequence. To this end, we present a variation on Chauvenet
rejection that we call “robust” Chauvenet rejection (RCR),
which uses three decreasingly robust/increasingly precise measures
of central tendency and four decreasingly robust/increasingly precise
measures of sample deviation. We show this sequential approach to be
very effective for a wide variety of contaminant types, even when a
significant—even dominant—fraction of the sample is contaminated,
and especially when the contaminants are strong. Furthermore, we have
developed a bulk-rejection variant, to significantly decrease computing
times, and RCR can be applied both to weighted data and when fitting
parameterized models to data. We present aperture photometry in a
contaminated, crowded field as an example. RCR may be used by anyone
at <A href="https://skynet.unc.edu/rcr">https://skynet.unc.edu/rcr</A>,
and source code is available there as well.
---------------------------------------------------------
Title: Dark Matter Search Results from a One Ton-Year Exposure
of XENON1T
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.;
Althueser, L.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Baudis, L.;
Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.;
Brown, A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik,
R.; Capelli, C.; Cardoso, J. M. R.; Cichon, D.; Coderre, D.; Colijn,
A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.;
di Gangi, P.; di Giovanni, A.; Diglio, S.; Elykov, A.; Eurin, G.;
Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.;
Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Grandi, L.; Greene, Z.;
Qiu, H.; Hasterok, C.; Hogenbirk, E.; Howlett, J.; Itay, R.; Joerg, F.;
Kaminsky, B.; Kazama, S.; Kish, A.; Koltman, G.; Landsman, H.; Lang,
R. F.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.;
Lopes, J. A. M.; Mahlstedt, J.; Manfredini, A.; Marrodán Undagoitia,
T.; Masbou, J.; Masson, D.; Messina, M.; Micheneau, K.; Miller, K.;
Molinario, A.; Morâ, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack,
U.; Pelssers, B.; Piastra, F.; Pienaar, J.; Pizzella, V.; Plante,
G.; Podviianiuk, R.; Priel, N.; Ramírez García, D.; Rauch, L.;
Reichard, S.; Reuter, C.; Riedel, B.; Rizzo, A.; Rocchetti, A.; Rupp,
N.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler,
S.; Schreiner, J.; Schulte, D.; Schumann, M.; Scotto Lavina, L.;
Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Thers,
D.; Toschi, F.; Trinchero, G.; Tunnell, C.; Upole, N.; Vargas, M.;
Wack, O.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wittweg, C.;
Wulf, J.; Ye, J.; Zhang, Y.; Zhu, T.; Xenon Collaboration
2018PhRvL.121k1302A Altcode: 2018arXiv180512562A
We report on a search for weakly interacting massive particles (WIMPs)
using 278.8 days of data collected with the XENON1T experiment at
LNGS. XENON1T utilizes a liquid xenon time projection chamber with
a fiducial mass of (1.30 ±0.01 ) t o n , resulting in a 1.0 ton yr
exposure. The energy region of interest, [1.4 ,10.6 ] keV<SUB>ee</SUB>
([4.9 ,40.9 ] keV<SUB>nr</SUB> ), exhibits an ultralow electron recoil
background rate of [82<SUB>-3</SUB><SUP>+5</SUP>(syst ) ±3 (stat )
] events /(t o n yr keV<SUB>ee</SUB>) . No significant excess over
background is found, and a profile likelihood analysis parametrized
in spatial and energy dimensions excludes new parameter space for
the WIMP-nucleon spin-independent elastic scatter cross section
for WIMP masses above 6 GeV /c<SUP>2</SUP>, with a minimum of 4.1
×10<SUP>-47</SUP> cm<SUP>2</SUP> at 30 GeV /c<SUP>2</SUP> and a 90%
confidence level.
---------------------------------------------------------
Title: ESA Active Dosimeter a Technolgy Demonstration for ISS
and beyond
Authors: Straube, Ulrich; Berger, Thomas
2018cosp...42E3270S Altcode:
Human presence in space has increased significantly over the last
decade. Extended space flights supported by various international
crews that lasted half a year and longer became a reality. Challenges
to human health and well-being proofed to remain significant and
increasing with mission-length and workload. Ongoing strong efforts
did enable for such mission scenarios and shall do so for the future,
the human journey to deep space that is intended. Several of the risks
arising seem to have the potential to be mitigated and finally covered
sufficiently. Despite health risks from ionizing radiation during
extended exploratory deep space missions remain to be of significance
and may strongly limit human presence and mission goals beyond Low Earth
Orbit. The ESA Active Dosimeter [EAD] hardware enables for advanced
personal dosimetry capabilities in real time. The system consists of
several small portable Personal Active Dosimeters (MU = Mobile Unit's)
as well as a surface attached docking station, called "Personal Storage
Device (PSD)". The PSD provides data read-out data and advanced display
capabilities as well as data storage and telemetry. The PSD contains a
Tissue Equivalent Proportional Counter (TEPC) and an internal MU (iMU)
for advanced analysis of the complex radiation environment in the space
station and to ensure means of cross calibrations. The MU is applied
for personal dosimetry as well as used for area monitoring purposes
throughout the station. Verification of the system capabilities have
been successfully executed in flight on ISS. Further utilization has
been recommend by the ISS partner agencies. System developments and
testing, including operations during a future flight of NASA's Orion
program, is en-route. This presentation will give an overview of the
relevant data from the first year of operations on ISS.
---------------------------------------------------------
Title: Round Table Discussion - Part 1: The Future of Space Radiation
Research
Authors: Hellweg, Christine; Ottolenghi, Andrea; Sun, Yeqing; Berger,
Thomas
2018cosp...42E1428H Altcode:
Space radiation is the "Number One Health Risk" (Chancellor et
al., 2014) for long-term space missions beyond Low Earth Orbit
(LEO). During space missions, astronauts are chronically exposed
to galactic cosmic radiation (GCR) consisting of energetic protons,
helium and heavier nuclei up to iron. This chronic exposure increases
the risk for developing cancer and degenerative diseases (cataract
of the eye lens, and possibly also decrements of the central nervous
system (CNS) and other organ systems). The extents of these risks and
the underlying mechanisms have to be further elucidated. In addition
to the baseline exposure to GCR, Solar particle events (SPEs) bear
the risk of acute high dose exposure, and might even provoke the
acute radiation syndrome. Mitigation of the space radiation risks
necessitates a multidisciplinary approach, from understanding the
nature of the space radiation environment, the development of relevant
radiation dosimeter systems, having the relevant tools to model the
radiation environment, understanding the influence of shielding to
the biological effects of space radiation, and being able to develop
relevant countermeasures. The invited speakers of the cross discipline
talks of the session F2.5 will discuss the upcoming challenges in the
fields of space radiation physics, dosimetry, and modeling, biology
and countermeasure development.References:Chancellor JC, Scott GBI,1,
Sutton JP (2014) Space Radiation: The Number One Risk to Astronaut
Health beyond Low Earth Orbit. Life (Basel). 2014 Sep; 4(3): 491-510.
---------------------------------------------------------
Title: The september 2017 solar energetic particle event observed
by MSL/RAD on the surface of mars
Authors: Ehresmann, Bent; Berger, Thomas; Reitz, Guenther;
Burmeister, Soenke; Rafkin, Scot; Guo, Jingnan; Zeitlin, Cary;
Wimmer-Schweingruber, Robert; Matthiä, Daniel; Lohf, Henning;
Kristoffer Appel, Jan; Hassler, Donald M.
2018cosp...42E.966E Altcode:
The Radiation Assessment Detector (RAD) has been continuously monitoring
the Martian surface radiation environment in Gale crater as part of
NASA's Mars Science Laboratory (MSL) mission since August 2012. On
September 11 2017, RAD detected the strongest SEP event on the Martian
surface to date. This event lead to the highest radiation levels since
the beginning of the RAD operations in Gale crater. The SEPs associated
with this solar storm increased the surface radiation dose by a factor
of 3 over the course of a few hours, and the peak radiation dose was
more than 50% higher than the previous maximum measured in October
2013.Here, we give an overview of the heliospheric conditions during
the September 2017 solar storm, and present measurements of charged
particle spectra during and before the event. RAD saw significant
increases in the surface proton and helium fluxes, as well as in the
neutral particles (neutrons and gamma-rays) created by interactions
of the SEPs with the atmosphere and soil.
---------------------------------------------------------
Title: Scene-Setting talk: Solar Activity Forecasting in Practice
Authors: Berger, Thomas
2018shin.confE.159B Altcode:
We review the state-of-the-art in solar activity and resultant space
weather event forecasting as well as some of the challenges, both
Grand and mundane, as a scene-setting talk for Session 22
---------------------------------------------------------
Title: Three-dimensional Velocity Measurements in Solar Prominence
Bubbles and Combined Kelvin-Helmholtz/Rayleigh-Taylor Instability
Authors: Berger, Thomas; Hillier, Andrew; Liu, Wei
2018cosp...42E.293B Altcode:
We present measurements of flow velocities in solar prominences that
display so-called "prominence bubble" events. Prominence bubbles
are large-scale buoyant intrusions into prominences that rise from
below and penetrate into the overlying plasma. They are believed to
be due to magnetic flux emergence below prominences and can trigger
Rayleigh-Taylor and Kelvin-Helmholtz instability flows as they interact
with the overlying prominence. Prominence bubbles frequently result
in the formation of plumes that rise into, or entirely through, the
overlying prominence. This presents a mechanism for increasing magnetic
flux and helicity in the associated coronal magnetic flux tubes,
which are key for their eventual loss of equilibrium and eruptions
as coronal mass ejections (CMEs). In this presentation, Hinode/Solar
Optical Telescope (SOT) and Interface Region Imaging Spectrograph (IRIS)
observations are analyzed to infer three-dimensional flow vectors
in the "boundary layer" above several prominence bubble events. IRIS
Doppler velocity measurements indicate flow speeds of 50-100 km/sec
perpendicular to the sky plane, consistent with flow speeds inferred
from combined Kelvin-Helmholtz/Rayleigh-Taylor instability analysis
using typical quiescent prominence density and magnetic flux density
values. With these typical values, flow speeds and magnetic flux
densities within the bubbles can be inferred to be on the order of
100 km/sec and 10 Gauss, respectively. We discuss the implications of
these novel results, and in particular, the potential for strong shear
flows at the bubble boundary to trigger Kelvin-Helmholtz instability
waves that develop into large-scale Rayleigh-Taylor instability plumes.
---------------------------------------------------------
Title: Radiation measurements and dosimetry for deep-space exploration
Authors: Ehresmann, Bent; Berger, Thomas; Reitz, Guenther;
Burmeister, Soenke; Rafkin, Scot; Guo, Jingnan; Zeitlin, Cary;
Wimmer-Schweingruber, Robert; Matthiä, Daniel; Lohf, Henning;
Kristoffer Appel, Jan; Hassler, Donald M.
2018cosp...42E.965E Altcode:
Dosimetry and radiation monitoring are key factors for the planning of
future human exploration on deep-space missions outside of Low-Earth
Orbit (LEO), as radiation exposure poses one of the major health
risks for astronauts in deep space. The amount of radiation dose
astronauts would accumulate during typical mission scenarios and
durations can potentially exceed currently allowable exposure limits
within months.In space radiation monitoring the three main areas
of concern are: 1) high-energy and deeply-penetrating Galactic
Cosmic Rays (GCRs); 2) impulsive Solar Energetic Particle (SEP)
events with high flux intensities up to a few hundred MeVs; and 3)
secondary neutrons created by interactions of primary radiation with
spacecraft material or planetary atmospheres and soils. Furthermore,
in-situ radiation measurements provide invaluable input for radiation
transport models that are used to calculate expected radiation
exposures and shielding effectiveness, and subsequently potential
health risks for future deep-space mission scenarios.Here, we present
an overview of dosimetry in LEO, lunar orbit, and in deep space,
and place the findings from years of measurements in context of what
our current state of knowledge of space radiation implies for future
exploration missions. Because the planet Mars is a prime goal for future
exploration, we will focus in more detail on measurements conducted
on the Martian surface with the Radiation Assessment Detector (RAD)
as part of the Mars Science Laboratory (MSL) mission. Since Mars lacks
a global magnetic field and its atmosphere is very thin, the surface
is only weakly protected from impacts of GCRs and SEPs. This makes
understanding and assessing the Martian surface radiation environment
a key goal for future exploration. MSL/RAD has been characterizing in
detail the charged and neutral particle environment induced by GCRs,
as well as during short-term radiation enhancements from SEP events
arriving at Mars.We will discuss the capabilities of the existing
space dosimetry instrumentation, as well as highlight areas outside
the current scope where we need to improve our understanding of the
space radiation environment.
---------------------------------------------------------
Title: The Lunar Lander Neutron & Dosimetry (LND) Experiment
on Chang'E4
Authors: Wimmer-Schweingruber, Robert; Hellweg, Christine; Berger,
Thomas; Boettcher, Stephan; Burmeister, Soenke; Seimetz, Lars;
Schuster, Bjoern; Guo, Jingnan; Zhang, Shenyi; Lohf, Henning; Yu,
Jia; Knierim, Violetta; Shen, G.; Yuan, B.
2018cosp...42E3672W Altcode:
Chang'E4, the next Chinese mission to the Moon, is planned to launch
in December 2018 and to land on the far side of the Moon in the South
Pole Aitken Basin. The mission consists of a lander, a rover, and a
communication relay around the Earth-Moon L2 libration point. Here
we describe the Lunar Lander Neutron & Dosimetry experiment (LND)
on the lander. It consists of a stack of 10 segmented Si solid-state
detectors (SSDs) which forms a particle telescope to measure charged
particles (electrons 150-500 keV, protons 12-30 MeV, and heavier nuclei
15-30 MeV/nuc). A special geometrical arrangement allows observations
of fast neutrons (and g-rays) which are also important for dosimetry
and cosmic-ray exposure of lunar soils. Thermal neutrons are measured
using a very thin Gd conversion foil which is sandwiched between two
SSDs. Thermal neutrons are sensitive to subsurface water and important
to understand lunar surface mixing processes. Despite the aim of
landing humans on the Moon in the not too distant future, radiation
measurements in the vicinity of the Moon are remarkably scarce. Fairly
recent measurements in lunar orbit were provided by the Radiation Dose
Monitor (RADOM) on board Chandrayaan-1. The spacecraft reached its
operational 100 km circular orbit on November 12, 2008. Measurements
showed a dose rate of 0.23 mGy per day averaged over 3545 hours
of measurement time (20/11/2008 to 18/5/2009). Newer measurements
have been provided by the Cosmic Ray Telescope for the Effects of
Radiation (CRaTER) instrument on board the Lunar Reconnaissance Orbiter
(LRO). CRaTER measured a radiation exposure of about 0.22 _ 0.27 mGy
per day in its 50 km orbit. In comparison with these meager orbital
data, there is a real dearth of data on the lunar surface. The current
knowledge about the radiation environment on the surface of the Moon is
based exclusively on calculations using radiation transport models with
input parameters from models for the galactic cosmic ray spectra and for
solar particle events. This is highly questionable, especially since we
know that these models are fraught with uncertainties. Thus LND will
provide the first active dosimetry measurements on the surface of the
Moon.In this presentation we will discuss the science, implementation,
and status of LND on China's Chang'E4 mission.
---------------------------------------------------------
Title: Are "Solar Tornadoes" Really Rotating?
Authors: Liu, Wei; Chye Low, Boon; Okamoto, Joten; Berger, Thomas
2018cosp...42E2053L Altcode:
Solar "tornadoes" have been proposed to explain certain vertical
structures in prominences that exhibit apparent rotations. Yet, it
remains highly controversial whether such motions are real rotations
or transverse oscillations. We present a statistical study of IRIS
observations that reveal no clear evidence of systematic or coherent
rotations, which would otherwise result in opposite Doppler shifts,
i.e., blueshifts on the one side of the vertical structure and redshifts
on the other, which were not found in our sample of "tornadoes". In
addition, we find in one particular case observed by SDO/AIA that the
"tornado" disappeared upon the impact of an eruption that pushed
its mass away along a primarily horizontal trajectory (presumably
along magnetic field lines). This "tornado" shortly reformed with
the replenishment of material from the return flow of some of the
displaced mass back to its original location, at the dips of local
magnetic field lines, followed by back and forth transverse oscillations
around the dips. Such observations from both IRIS and AIA suggest that,
at least for the cases being analyzed here, the apparent oscillatory
motions of "tornadoes" are a result of longitudinal oscillations
(like a pendulum) of dense and heavy prominence material about the
local minimum of gravitational potential at the magnetic dips, an
interpretation proposed and supported by a number of authors.
---------------------------------------------------------
Title: Cool Material in the Hot Solar Corona and the
Chromosphere-Corona Mass Cycle
Authors: Liu, Wei; Vial, Jean-Claude; Antolin, Patrick; Sun, Xudong;
Berger, Thomas
2018cosp...42E2052L Altcode:
In the million-degree hot and tenuous solar corona, under favorable
conditions, some mass can undergo a radiative cooling instability and
condense into material of 100 times cooler in two distinct forms -
prominences and coronal rain. Being at similar temperatures, they
exhibit contrasting morphologies and behaviors: a quiescent prominence
usually consists of numerous long-lasting, filamentary downflow
threads, while coronal rain consists of transient mass blobs falling
at comparably higher speeds along well-defined, curved paths (e.g.,
guided by coronal loops). We report recent imaging and spectroscopic
observations from SDO/AIA and IRIS of a hybrid prominence-coronal
rain complex structure that suggest different magnetic environments
being responsible for such distinctions. We also present an ensemble
of observations of the so-called funnel prominences that reside near
the dips of magnetic funnels. Regardless of their morphological and
behavioral differences, a large fraction of prominence and coronal
rain material eventually falls back to the chromosphere and serves as
the return flow of the so-called chromosphere-corona mass cycle (the
other half of this cycle is the upward transport of heated mass from
the chromosphere to the corona). We estimate the downflow mass fluxes
in prominences and coronal rain, and compare them with the coronal
mass budget in this cycle and with the mass loss to the solar wind
and coronal mass ejections (CMEs). We will discuss the broad physical
implications of these observations for fundamental questions, such as
coronal heating and beyond.
---------------------------------------------------------
Title: Predicting Solar Eruptive Events Using Artificial Neural
Networks
Authors: Poduval, Bala; Berger, Tom
2018shin.confE.157P Altcode:
Solar eruptive events, such as coronal mass ejections (CMEs), are
the major sources of space weather events, causing disruptions and
damages to our technological infrastructure, and endangering humans in
space. Prediction of such eruptive events is highly challenging mainly
because of lack of a single physics-based model adequately representing
the complex solar dynamo and the magnetized, turbulent plasma. Methods
of artificial intelligence (AI) can develop algorithms to identify
patterns in long-stretches of data and make effective predictions with
reasonable accuracy. Making use of deep neural networks (DNNs), we
make an attempt to predict a few events in the SHARP catalog. Presented
here are the results and accuracies of our prediction.
---------------------------------------------------------
Title: Facilitating Advancements in Space Weather Data Availability
Through a Space Weather Testbed and Data Portal
Authors: Pankratz, Christopher; Baker, Daniel N.; Elkington, Scot;
Berger, Thomas; Jaynes, Allison; Craft, James; Baltzer, Thomas;
Sanchez, Fernando
2018cosp...42E2572P Altcode:
Society has grown reliant on complex and highly interconnected
technological systems, which makes us increasingly vulnerable to
the effects of space weather events. An extreme space weather event
today could conceivably impact many of the crucial systems we rely on,
including disrupting operating earth-orbiting satellites, potential
collapse of electrical grids, and impairing navigation, communication,
and remote sensing capabilities. Thus, it is imperative that the
scientific community address the question of just how severe events
might become and to ensure stakeholders have access to the essential
data needed for research and decision making. Stakeholders include
policy makers and public safety officials who need to be informed
by the facts on what might happen during extreme conditions. This
requires essentially extremely timely up-to-the-minute alerts,
warnings, and also forecasts of severe space weather events,
which in turn demands measurements, models, and associated data
products to be available via the most effective data discovery and
access methods possible. Similarly, advancement in the fundamental
scientific understanding of space weather processes is also vital,
requiring that researchers have convenient and effective access to a
wide variety of data sets and models from multiple sources. The space
weather research community, as with many scientific communities, must
access data from dispersed and often uncoordinated data repositories
to acquire the data necessary for the analysis and modeling efforts
that advance our understanding of solar influences and space physics on
the Earth's environment. The University of Colorado (CU) is a leading
institution in both producing data products and advancing the state of
scientific understanding of space weather processes, is well positioned
to address many of these issues. CU is inaugurating a dedicated Space
Weather Technology, Research, and Education Center (SWx TREC) that will
serve many of these needs, including implementation of an interoperable
data portal intended to more effectively serve the needs of the Space
Weather research community, as well as facilitating the advancement of
models into production/operational use. In this presentation, we will
outline the motivating factors for effective space weather data access
and present plans and methods for meeting model testing/incubation
needs, as well as the data management and access needs of the disparate
communities who require space weather data and information.
---------------------------------------------------------
Title: Towards Space Exploration of Moon, Mars & Neos: Radiation
Biological Basis
Authors: Hellweg, Christine; Baumstark-Khan, Christa; Berger, Thomas
2018cosp...42E1427H Altcode:
Radiation has emerged as the most critical issue to be resolved for
long-term missions both orbital and interplanetary. Astronauts are
constantly exposed to galactic cosmic radiation (GCR) of various
energies at a low dose rate. Primarily late tissue sequels like
genetic alterations, cancer and non-cancer effects, i.e. cataracts
and degenerative diseases of e.g. the central nervous system or
the cardiovascular system, are the potential risks. Cataracts were
observed to occur earlier and more often in astronauts exposed to higher
proportions of galactic ions (Cucinotta et al., 2001). Predictions of
cancer risk and acceptable radiation exposure in space are subject to
many uncertainties including the relative biological effectiveness
(RBE) of space radiation especially heavy ions, dose-rate effects
and possible interaction with microgravity and other spaceflight
environmental factors. The initial cellular response to radiation
exposure paves the way to late sequelae and starts with damage to the
DNA which complexity depends on the linear energy transfer (LET) of the
radiation. Repair of such complex DNA damage is more challenging and
requires more time than the repair of simple DNA double strand breaks
(DSB) which can be visualized by immunofluorescence staining of the
phosphorylated histone 2AX (γH2AX) and might explain the observed
prolonged cell cycle arrests induced by high-LET in comparison to
low-LET irradiation. Unrepaired or mis-repaired DNA DSB are proposed to
be responsible for cell death, mutations, chromosomal aberrations and
oncogenic cell transformation. Cell killing and mutation induction are
most efficient in an LET range of 90-200 keV/μm. Also the activation
of transcription factors such as Nuclear Factor κB (NF-κB) and gene
expression shaping the cellular radiation response depend on the LET
with a peak RBE between 90 and 300 keV/μm. Such LET-RBE relationships
were observed for cataract and cancer induction by heavy ions in
laboratory animals, with varying maximal efficiencies. Furthermore,
there is always the added risk of acute exposure to high proton fluxes
during a solar particle event (SPE), which can threaten immediate
survival of the astronauts in case of insufficient shielding by
eliciting the acute radiation syndrome. Its symptoms depend on absorbed
total radiation dose, type of radiation, the dose distribution in the
body and the individual radiation sensitivity. After the prodromal
stage with nausea and vomiting and a subsequent symptom-free phase,
depending on dose, the hematopoietic syndrome with suppression of
the acquired immune system and thrombocytopenia (0.7-4 Sv), the
gastrointestinal tract syndrome (5-12 Sv) or the central nervous
system syndrome (> 20 Sv) develop and they are accompanied by
exacerbated innate immune responses. Exposure to large SPE has to be
avoided by warning systems and stay inside a radiation shelter during
the event. Treatment options encompass e.g. the administration of
colony-stimulating factors (CSF), growth factors and blood transfusions
to overcome the hematopoietic syndrome and the administration of
antibiotics against secondary infections. A concerted action of
ground-based studies and space experiments is required to improve
the radiobiological basis of space radiation risk assessment and
countermeasure development.Reference:Cucinotta FA, Manuel FK, Jones J,
Iszard G, Murrey J, Djojonegro B and Wear M (2001) Space Radiation
and Cataracts in Astronauts. Rad Res 156, 460-466
---------------------------------------------------------
Title: The DOSIS 3D Project Onboard the International Space Station -
Analysis of the Solar Particle Event in September 2017
Authors: Burmeister, Soenke; Berger, Thomas; Matthiä, Daniel;
Bruedern, Maximilian
2018cosp...42E.473B Altcode:
Besides the effects of the microgravity environment, and the
psychological and psychosocial problems encountered in confined spaces,
radiation is the main health detriment for long duration human space
missions. The radiation environment encountered in space differs in
nature from that on earth, consisting mostly of high energetic ions
from protons up to iron, resulting in radiation levels far exceeding the
ones encountered on earth for occupational radiation workers. Accurate
knowledge of the physical characteristics of the space radiation field
in dependence on the solar activity, the orbital parameters and the
different shielding configurations of the International Space Station
ISS is therefore needed. As a follow up to the DOSIS experiment (2009
- 2011) DOSIS 3D measures since May 2012 the spatial and temporal
variations of the radiation field in Columbus. The active part the
DOSIS MAIN BOX thereby consist of two active radiation detectors
(Dosimetry Telescopes = DOSTELs) with a DDPU (DOSTEL Data and Power
Unit) is mounted in a Nomex pouch at a fixed location in the bottom area
of the European Physiology Module rack (EPM).The temporal variation in
dependence of ISS altitude and solar cycle has been measured with the
DOSTEL instruments since May 2012 covering thereby already 6 years of
continuous measurements in the frame of DOSIS 3D. Of special interest
was the first Solar Particle Event (SPE) (GLE 72) measured inside the
Space Station within the DOSIS 3D project in September 2017. This was
the first event measured since 2012 inside the ISS and in terms of
exploration missions extremely important, since it was also measured
in Moon orbit and at the surface of Mars. The presentation will focus
on the timeline of the event observed inside Columbus and provide data
for dose and relevant energy deposition spectra and also show first
comparisons with GEANT4 simulations. It will also provide comparison
with events observed with DOSTEL like instruments on space station MIR
(1997) and on ISS (2001).The CAU contributions to DOSIS and DOSIS 3D
are financially supported by BMWi under Grants 50WB0826, 50WB1026,
50WB1232 and 50WB1533.
---------------------------------------------------------
Title: The 2015 - Present Rise of the GCR as observed by RAD on Mars
Authors: Wimmer-Schweingruber, Robert; Berger, Thomas; Reitz, Guenther;
Burmeister, Soenke; Guo, Jingnan; Ehresmann, Bent; Zeitlin, Cary;
Matthiä, Daniel; Lohf, Henning; Hassler, Donald M.; von Forstner,
Johan Lauritz Freiherr; Khaksari, Salman; Thorben Lundt, Niklas
2018cosp...42E3670W Altcode:
The radiation exposure due to galactic cosmic rays has been rising
since early 2015 and is reaching some of the highest levels observed
in the space age. This observation is not limited to the near-Earth
space environment, but is also seen at Mars in measurements performed
by the highly capable Radiation Assessment Detector (RAD) on NASA's
Curiosity rover. We will discuss the increased radiation exposure
at Mars and elsewhere, put into the larger heliospheric context and
discuss implications for human exploration.
---------------------------------------------------------
Title: Space Radiation and Human Exploration on the Moon, Mars and
Neos - Dosimetry, Models and Challenges
Authors: Berger, Thomas; Hellweg, Christine; Uchihori, Yukio;
Matthiä, Daniel
2018cosp...42E.294B Altcode:
Space programs are shifting towards planetary exploration and,
in particular, towards missions by human beings to the Moon and to
Mars. Radiation is considered to be one of the major hazards for human
long-term missions beyond Low Earth Orbit (LEO). During transit to these
far away destinations and during relevant extravehicular activities
(EVA) on their surface, complete shielding of the highly energetic
particles is impracticable. The two sources of radiation that can
impact a mission outside the Earth's magnetic field are Solar Energetic
Particles (SEP) and Galactic Cosmic Rays (GCR). The main goal for
exploration missions is therefore the quantification and reduction of
space radiation health hazards, with the goal of maximizing the number
of days that may be spent in space. The research to be carried out
has to support all phases of exploration including mission planning,
component design, operation and post-flight studies. Having this in
mind this calls for novel and improved radiation detector assemblies as
well as extended calibrations, detector intercomparisons and analysis
algorithms. New measurements are a prerequisite for reliable risk
assessment, a crucial input for radiation source modelling, and are also
needed for real-time calibration of the detectors thereby allowing for a
detailed understanding of the radiation environment the astronauts are
going to live in. For exploration missions, radiation risk assessment
will predominately rely on simulation models. The reliability of these
models needs to be optimized through a series of tests against a wide
set of measurements at sites/conditions where instruments are available
or can be made available. More and more radiation details are needed
to correctly assess radiation risks, and this requires detailed model
outputs to be tested against proper measurements. In the last years
various radiation detector systems have been send either to the Moon
(circulating in Moon orbit) or are already on the surface of Mars,
providing thereby a tremendously needed data set for model validation
and benchmarking and input data to face the challenges ahead of us.
---------------------------------------------------------
Title: Space Weather - Technology, Research, and Education Center
(SWx-TREC)
Authors: Baker, Daniel N.; Thayer, Jeffrey; Berger, Thomas
2018cosp...42E.164B Altcode:
SWx-TREC is a new Center at the University of Colorado - Boulder
initiated under a grant intended to create a center of gravity
for the many units at CU working on space weather topics. TREC
will be in the College of Engineering and Applied Science and the
Laboratory for Atmospheric and Space Physics (LASP). It will be
able to work across the usual academic boundaries to better develop
and integrate space weather models, missions, and data that will
have a direct benefit to the operational forecasting offices. TREC
will also be the focal point for creating undergraduate, graduate,
and professional courses in space weather. TREC is currently making
strategic investments in research-to-operations (R2O) projects such
as an improved full-physics model of Low-Earth-Orbit satellite and
debris drag, as well as operations-to-research (O2R) projects including
improvements to solar magnetic field measurements and models that form
the basis of operational solar wind forecasting models. In addition,
TREC will host a "space weather data portal" and a forecast center
"test bed", enabling close interaction between operational forecasters
and researchers from around the nation and the world. In short,
TREC is a new academic research and technology center dedicated to
helping bridge the gap between space weather research and operations,
and to educating the space science workforce, from undergraduates to
industry professionals. TREC will work with national and international
operational forecast centers, industry, other academic groups,
and NSF and NASA centers such as the NASA/NSF CCMC, to develop and
transition new models and tools that improve space weather forecasting
and nowcasting. TREC will also be focusing significant effort on its
educational mission in alignment with CU's mission as a leading space
science university.
---------------------------------------------------------
Title: Implications of the September 2017 Solar Particle Event for
Human Exploration of Mars
Authors: Hassler, Donald M.; Berger, Thomas; Reitz, Guenther;
Burmeister, Soenke; Guo, Jingnan; Ehresmann, Bent; Zeitlin, Cary;
Wimmer-Schweingruber, Robert; Matthiä, Daniel
2018cosp...42E1393H Altcode:
Although the Sun is approaching solar minimum, a series of large solar
particle events (SPEs) occurred in September 2017 that impacted both
Earth and Mars. In particular, the event of 10 September 2017 was the
largest event that RAD has seen on the surface of Mars since it landed
in 2012. Due to the modulating effect of the Martian atmosphere, the
shape and intensity of these SEP spectra will differ significantly
between interplanetary space and the Martian surface. Understanding
how these SEP events influence the surface radiation field is crucial
to assessing associated health risks for potential human missions to
Mars. We will discuss in this talk the dosimetric quantities measured
by MSL RAD before, during and after the Sept. 10 event, and their
implications for potential human missions to Mars.MSL RAD is supported
by NASA (HEOMD) under JPL subcontract #1273039 to SwRI, and by DLR in
Germany under contract with Christian-Albrechts-Universitat (CAU).
---------------------------------------------------------
Title: Round Table Discussion - Part 2: The Future of Space Radiation
Research
Authors: Hellweg, Christine; Ottolenghi, Andrea; Sun, Yeqing; Berger,
Thomas
2018cosp...42E1429H Altcode:
Space radiation is the "Number One Health Risk" (Chancellor et
al., 2014) for long-term space missions beyond Low Earth Orbit
(LEO). During space missions, astronauts are chronically exposed
to galactic cosmic radiation (GCR) consisting of energetic protons,
helium and heavier nuclei up to iron. This chronic exposure increases
the risk for developing cancer and degenerative diseases (cataract
of the eye lens, and possibly also decrements of the central nervous
system (CNS) and other organ systems). The extents of these risks and
the underlying mechanisms have to be further elucidated. In addition
to the baseline exposure to GCR, Solar particle events (SPEs) bear
the risk of acute high dose exposure, and might even provoke the
acute radiation syndrome. Mitigation of the space radiation risks
necessitates a multidisciplinary approach, from understanding the
nature of the space radiation environment, the development of relevant
radiation dosimeter systems, having the relevant tools to model the
radiation environment, understanding the influence of shielding to
the biological effects of space radiation, and being able to develop
relevant countermeasures. The invited speakers of the cross discipline
talks of the session F2.5 will discuss the upcoming challenges in the
fields of space radiation physics, dosimetry, and modeling, biology
and countermeasure development.References:Chancellor JC, Scott GBI,1,
Sutton JP (2014) Space Radiation: The Number One Risk to Astronaut
Health beyond Low Earth Orbit. Life (Basel). 2014 Sep; 4(3): 491-510.
---------------------------------------------------------
Title: The DOSIS 3D Project Onboard the International Space Station -
Status and Science Overview of 6 years of measurements (2012 - 2018)
Authors: Berger, Thomas
2018cosp...42E.295B Altcode:
The radiation environment encountered in space differs in nature from
that on Earth, consisting mostly of highly energetic ions from protons
up to iron, resulting in radiation levels far exceeding the ones present
on Earth for occupational radiation workers. Since the beginning of
the space era the radiation exposure during space missions has been
monitored with various passive and active radiation instruments. Also
on-board the International Space Station (ISS) a number of area
monitoring devices provide data related to the spatial and temporal
variation of the radiation field in - and outside the ISS. The aim
of the DOSIS 3D (2012 - ongoing) experiment is the measurement of the
radiation environment within the European Columbus Laboratory of the
ISS. These measurements are, on the one hand, performed with passive
radiation detectors mounted at eleven locations within Columbus
for the determination of the spatial distribution of the radiation
field parameters and, on the other hand, with two active radiation
detectors (DOSTEL) mounted at a fixed position inside Columbus for
the determination of the temporal variation of the radiation field
parameters. The talk will give an overview of the current results of
the data evaluation performed for the passive and active radiation
detectors for DOSIS 3D in the years 2012 to 2018 and further focus on
the work in progress for data comparison with other passive and active
radiation detector systems measuring on-board the ISS. Acknowledgments:
The participation of the Technische Universität Wien, Atominstitut
(ATI), Vienna, Austria in the DOSIS-1 and -2 experiments was supported
by the Austrian Space Applications Programme (ASAP) under contract
no. 819643. The Polish contribution for the Institute of Nuclear Physics
(IFJ), Krakow, Poland was supported by the National Science Center
(project No DEC-2012/06/M/ST9/00423). MTA EK greatly acknowledges
the possibility to participate in the project to DLR and to the ESA
PECS for the financial grant No. PECS4000108464. The participation
of the Nuclear Physics Institute of the Czech Academy of Sciences
has been supported by the grant of Czech Science Foundation (GACR)
No. 15-16622Y. The CAU, University of Kiel was supported by DLR under
grants 50WB0826, 50WB1026, 50WB1232 and 50WB1533.
---------------------------------------------------------
Title: On the Nature of Funnel Prominences
Authors: Liu, Wei; Chye Low, Boon; Berger, Thomas
2018cosp...42E2054L Altcode:
It has been proposed that prominences are manifestations of a
magneto-thermal convection process that involves ever-present dynamic
descents of cool material threads and upflows of hot bubbles and plumes
(Berger et al. 2011 Nature). On global scales, prominences may play
an important role as the return flows of the chromosphere-corona
mass cycle. A critical step in this cycle is the condensation of
million-degree coronal plasma into T<10,000 K prominence material by
radiative cooling instability. Direct observational evidence has been
lacking for decades, a situation that has recently changed, especially
with the advent of the SDO mission. We present here SDO/AIA observations
of runaway cooling in coronal loops leading to condensation at magnetic
dips and formation of funnel-shaped prominences (e.g., Liu et al. 2012,
2014; Berger et al. 2012 ApJL). We find that a macroscopically quiescent
prominence is microscopically dynamic, involving the passage (through
condensation and drainage) of a significant mass of typically 10^{15}
gram/day (comparable to the mass of a typical CME). This picture
is further supported by the theoretical development on spontaneous
formation of current sheets and condensations (Low et al. 2012a, b,
ApJ). Such funnel prominences, usually small in size, can constitute
a new type of prominences. We suggest that similar processes could
produce elementary building blocks of large-scale quiescent prominences
in filament channels.
---------------------------------------------------------
Title: Energetic Particle Radiation Environment Observed by RAD on
the Surface of Mars During the September 2017 Event
Authors: Ehresmann, B.; Hassler, D. M.; Zeitlin, C.; Guo, J.;
Wimmer-Schweingruber, R. F.; Matthiä, D.; Lohf, H.; Burmeister, S.;
Rafkin, S. C. R.; Berger, T.; Reitz, G.
2018GeoRL..45.5305E Altcode:
The 10-12 September Solar Energetic Particle event produced the
strongest increase of the radiation environment measured by the
Radiation Assessment Detector on the surface of Mars since landing in
August 2012. We report the details of the measurements of the energetic
particle environment from Radiation Assessment Detector in Gale crater
during this event. The Solar Energetic Particle event increased the
low-energy proton flux (below 100 MeV) by a factor of 30, and the
higher-energy proton flux by a factor of 4, above preevent levels. The
<SUP>4</SUP>He flux (below 100 MeV/nuc) rose by factors up to 10,
and neutral particles by a factor of 2 above background. The increase
started on 10 September around 19:50 UTC, peak-level fluxes were reached
on the morning of 11 September and prevailed for about 10 hr before
decreasing toward background levels. The onset of a Forbush decrease
on 13 September decreased the proton flux below preevent intensities.
---------------------------------------------------------
Title: Analysis of the Radiation Hazard Observed by RAD on the
Surface of Mars During the September 2017 Solar Particle Event
Authors: Zeitlin, C.; Hassler, D. M.; Guo, J.; Ehresmann, B.;
Wimmer-Schweingruber, R. F.; Rafkin, S. C. R.; Freiherr von Forstner,
J. L.; Lohf, H.; Berger, T.; Matthiae, D.; Reitz, G.
2018GeoRL..45.5845Z Altcode:
We report dosimetric quantities measured by the Mars Science Laboratory
Radiation Assessment Detector (RAD) on the surface of Mars during the
10-12 September 2017 solar particle event. Despite 23 g/cm<SUP>2</SUP>
of CO<SUB>2</SUB> shielding provided by the atmosphere above RAD, dose
rates rose above background galactic cosmic ray levels by factors of 2
to 3 over the course of several hours and leveled off at sustained peak
rates for about 12 hr before declining over the following 36 hr. As
the solar particle event flux was gradually declining, a shock front
reached Mars and caused a sudden drop of about 15% in instantaneous dose
rates. No solar particles followed the shock arrival, and the magnetic
shielding of galactic cosmic rays by the shock reduced their intensity
to levels below those seen before the start of the event. This event
is the largest seen to date by RAD on Mars.
---------------------------------------------------------
Title: Signal yields of keV electronic recoils and their
discrimination from nuclear recoils in liquid xenon
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro,
F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister,
B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.;
Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.;
Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre,
D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.;
de Perio, P.; di Gangi, P.; di Giovanni, A.; Diglio, S.; Eurin, G.;
Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.;
Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Grandi,
L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Howlett, J.;
Itay, R.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman,
H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.;
Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Mahlstedt, J.; Manfredini,
A.; Maris, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.;
Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.;
Morâ, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha,
P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella,
V.; Piro, M. -C.; Plante, G.; Priel, N.; Ramírez García, D.; Rauch,
L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rupp, N.; Saldanha, R.; Dos
Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.;
Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin,
P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. V.; Stein, A.;
Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.; Wang,
H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wittweg, C.; Wulf, J.; Ye,
J.; Zhang, Y.; Zhu, T.; Xenon Collaboration
2018PhRvD..97i2007A Altcode: 2017arXiv170910149A
We report on the response of liquid xenon to low energy electronic
recoils below 15 keV from beta decays of tritium at drift fields of
92 V /cm , 154 V /cm and 366 V /cm using the XENON100 detector. A
data-to-simulation fitting method based on Markov Chain Monte Carlo
is used to extract the photon yields and recombination fluctuations
from the experimental data. The photon yields measured at the two
lower fields are in agreement with those from literature; additional
measurements at a higher field of 366 V /cm are presented. The
electronic and nuclear recoil discrimination as well as its dependence
on the drift field and photon detection efficiency are investigated
at these low energies. The results provide new measurements in the
energy region of interest for dark matter searches using liquid xenon.
---------------------------------------------------------
Title: The Lunar Lander Neutron and Dosimetry (LND) Experiment
on Chang'e4
Authors: Wimmer-Schweingruber, R. F.; Zhang, S.; Hellweg, C. E.; Yu,
J.; Guo, J.; Lohf, H.; Berger, T.; Böttcher, S. I.; Burmeister, S.;
Knappmann, A. C.; Knierim, V.; Schuster, B.; Seimetz, L.; Shen, G.;
Yuan, B.
2018LPI....49.1413W Altcode:
Chang'e4 is scheduled to launch to the far side of the Moon in December
2018. LND will measure the radiation environment in preparation of
human exploration.
---------------------------------------------------------
Title: Low-Energy Cosmic Rays: Radiation Environment Studies and
Astrophysics on the Deep Space Gateway
Authors: Losekamm, M. J.; Berger, T.
2018LPICo2063.3108L Altcode:
The Deep Space Gateway will be ideally located to investigate the cosmic
radiation that astronauts are subjected to in deep space and to help
shed light on one of the most intriguing astrophysical mysteries of
today: What is the universe made of?
---------------------------------------------------------
Title: Matroshka AstroRad Radiation Experiment (MARE) on the Deep
Space Gateway
Authors: Gaza, R.; Hussein, H.; Murrow, D.; Hopkins, J.; Waterman,
G.; Milstein, O.; Berger, T.; Przybyla, B.; Aeckerlein, J.; Marsalek,
K.; Matthiae, D.; Rutczynska, A.
2018LPICo2063.3042G Altcode:
The Matroshka AstroRad Radiation Experiment is a science payload on
Orion EM-1 flight. A research platform derived from MARE is proposed
for the Deep Space Gateway. Feedback is invited on desired Deep Space
Gateway design features to maximize its science potential.
---------------------------------------------------------
Title: Space Weather Research and Operational Observing from a
Cis-Lunar Deep Space Gateway
Authors: Berger, T. E.; Baker, D. N.; Woods, T. N.
2018LPICo2063.3147B Altcode:
We review the status of observational architectures for space weather
research and operational forecasting and suggest ways in which the
Deep Space Gateway may act as an ideal supplement to current and future
space weather observing platforms.
---------------------------------------------------------
Title: Alamos: An International Collaboration to Provide a Space
Based Environmental Monitoring Solution for the Deep Space Network
Authors: Kennedy, S. O.; Dunn, A.; Lecomte, J.; Buchheim, K.;
Johansson, E.; Berger, T.
2018LPICo2063.3069K Altcode:
This abstract proposes the advantages of an externally mounted
instrument in support of the human physiology, space biology, and human
health and performance key science area. Alamos provides Space-Based
Environmental Monitoring capabilities.
---------------------------------------------------------
Title: Results from Field Testing the RIMFAX GPR on Svalbard.
Authors: Hamran, S. E.; Amundsen, H. E. F.; Berger, T.; Carter, L. M.;
Dypvik, H.; Ghent, R. R.; Kohler, J.; Mellon, M. T.; Nunes, D. C.;
Paige, D. A.; Plettemeier, D.; Russell, P.
2017AGUFM.P23G..07H Altcode:
The Radar Imager for Mars' Subsurface Experiment - RIMFAX is a
Ground Penetrating Radar being developed for NASÁs MARS 2020 rover
mission. The principal goals of the RIMFAX investigation are to image
subsurface structures, provide context for sample sites, derive
information regarding subsurface composition, and search for ice
or brines. In meeting these goals, RIMFAX will provide a view of the
stratigraphic section and a window into the geological and environmental
history of Mars. To verify the design an Engineering Model (EM) of the
radar was tested in the field in the spring 2017. Different sounding
modes on the EM were tested in different types of subsurface geology on
Svalbard. Deep soundings were performed on polythermal glaciers down to
a couple of hundred meters. Shallow soundings were used to map a ground
water table in the firn area of a glacier. A combination of deep and
shallow soundings was used to image buried ice under a sedimentary layer
of a couple of meters. Subsurface sedimentary layers were imaged down
to more than 20 meters in sand stone permafrost. This presentation will
give an overview of the RIMFAX investigation, describe the development
of the radar system, and show results from field tests of the radar.
---------------------------------------------------------
Title: Search for bosonic super-WIMP interactions with the XENON100
experiment
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Althueser,
L.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.;
Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.;
Brown, A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik,
R.; Bütikofer, L.; Calvén, J.; Capelli, C.; Cardoso, J. M. R.;
Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau,
J. P.; Decowski, M. P.; de Perio, P.; di Gangi, P.; di Giovanni,
A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.;
Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.;
Geis, C.; Goetzke, L. W.; Greene, Z.; Grignon, C.; Hasterok, C.;
Hogenbirk, E.; Howlett, J.; Itay, R.; Kaminsky, B.; Kazama, S.;
Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.;
Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.;
Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodán Undagoitia,
T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.;
Micheneau, K.; Molinario, A.; Morâ, K.; Murra, M.; Naganoma, J.; Ni,
K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra,
F.; Pienaar, J.; Pizzella, V.; Piro, M. -C.; Plante, G.; Priel, N.;
Ramírez García, D.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo,
A.; Rupp, N.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut,
M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.;
Selvi, M.; Shagin, P.; Silva, M.; Simgen, H.; Sivers, M. V.; Stein,
A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.;
Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wittweg, C.; Wulf, J.;
Ye, J.; Zhang, Y.; Zhu, T.; Xenon Collaboration
2017PhRvD..96l2002A Altcode: 2017arXiv170902222X
We present results of searches for vector and pseudoscalar bosonic
super-weakly interacting massive particles (WIMPs), which are dark
matter candidates with masses at the keV-scale, with the XENON100
experiment. XENON100 is a dual-phase xenon time projection chamber
operated at the Laboratori Nazionali del Gran Sasso. A profile
likelihood analysis of data with an exposure of 224.6 live days ×34
kg showed no evidence for a signal above the expected background. We
thus obtain new and stringent upper limits in the (8 - 125 ) keV
/c<SUP>2</SUP> mass range, excluding couplings to electrons with
coupling constants of g<SUB>a e</SUB>>3 ×10<SUP>-13</SUP> for
pseudo-scalar and α<SUP>'</SUP>/α >2 ×10<SUP>-28</SUP> for vector
super-WIMPs, respectively. These limits are derived under the assumption
that super-WIMPs constitute all of the dark matter in our galaxy.
---------------------------------------------------------
Title: The XENON1T dark matter experiment
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro,
F. D.; Anthony, M.; Antunes, B.; Arneodo, F.; Balata, M.; Barrow,
P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger,
T.; Breskin, A.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.;
Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.;
Cervantes, M.; Chiarini, A.; Cichon, D.; Coderre, D.; Colijn, A. P.;
Conrad, J.; Corrieri, R.; Cussonneau, J. P.; Decowski, M. P.; de
Perio, P.; Gangi, P. Di; Giovanni, A. Di; Diglio, S.; Disdier, J. -M.;
Doets, M.; Duchovni, E.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth,
A.; Franco, D.; Front, D.; Fulgione, W.; Rosso, A. Gallo; Galloway,
M.; Gao, F.; Garbini, M.; Geis, C.; Giboni, K. -L.; Goetzke, L. W.;
Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.;
Huhmann, C.; Itay, R.; James, A.; Kaminsky, B.; Kazama, S.; Kessler,
G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.;
Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.;
Maier, R.; Manfredini, A.; Maris, I.; Undagoitia, T. Marrodán;
Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.;
Micheneau, K.; Molinario, A.; Morå, K.; Murra, M.; Naganoma, J.; Ni,
K.; Oberlack, U.; Orlandi, D.; Othegraven, R.; Pakarha, P.; Parlati,
S.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella,
V.; Piro, M. -C.; Plante, G.; Priel, N.; García, D. Ramírez; Rauch,
L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.;
Santos, J. M. F. dos; Saldanha, R.; Sartorelli, G.; Scheibelhut,
M.; Schindler, S.; Schreiner, J.; Schumann, M.; Lavina, L. Scotto;
Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers,
M. v.; Stern, M.; Stein, A.; Tatananni, D.; Tatananni, L.; Thers, D.;
Tiseni, A.; Trinchero, G.; Tunnell, C.; Upole, N.; Vargas, M.; Wack,
O.; Walet, R.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wittweg,
C.; Wulf, J.; Ye, J.; Zhang, Y.
2017EPJC...77..881A Altcode: 2017arXiv170807051X
The XENON1T experiment at the Laboratori Nazionali del Gran Sasso
(LNGS) is the first WIMP dark matter detector operating with a
liquid xenon target mass above the ton-scale. Out of its 3.2 t
liquid xenon inventory, 2.0 t constitute the active target of the
dual-phase time projection chamber. The scintillation and ionization
signals from particle interactions are detected with low-background
photomultipliers. This article describes the XENON1T instrument and
its subsystems as well as strategies to achieve an unprecedented
low background level. First results on the detector response and the
performance of the subsystems are also presented.
---------------------------------------------------------
Title: First Dark Matter Search Results from the XENON1T Experiment
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro,
F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister,
B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown,
A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.;
Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre,
D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.;
de Perio, P.; di Gangi, P.; di Giovanni, A.; Diglio, S.; Eurin, G.;
Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.;
Galloway, M.; Gao, F.; Garbini, M.; Gardner, R.; Geis, C.; Goetzke,
L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk,
E.; Howlett, J.; Itay, R.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish,
A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.;
Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Manfredini,
A.; Mariş, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.;
Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.;
Morâ, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha,
P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella,
V.; Piro, M. -C.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.;
Reuter, C.; Riedel, B.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Saldanha,
R.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler,
S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin,
P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. V.; Stein, A.;
Thapa, S.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas,
M.; Upole, N.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wulf,
J.; Ye, J.; Zhang, Y.; Zhu, T.; Xenon Collaboration
2017PhRvL.119r1301A Altcode: 2017arXiv170506655A
We report the first dark matter search results from XENON1T, a ∼2000
-kg -target-mass dual-phase (liquid-gas) xenon time projection chamber
in operation at the Laboratori Nazionali del Gran Sasso in Italy and the
first ton-scale detector of this kind. The blinded search used 34.2 live
days of data acquired between November 2016 and January 2017. Inside
the (1042 ±12 )-kg fiducial mass and in the [5 ,40 ] keV<SUB>nr</SUB>
energy range of interest for weakly interacting massive particle (WIMP)
dark matter searches, the electronic recoil background was (1.93 ±0.25
)×10<SUP>-4</SUP> events /(kg ×day ×keV<SUB>ee</SUB>) , the lowest
ever achieved in such a dark matter detector. A profile likelihood
analysis shows that the data are consistent with the background-only
hypothesis. We derive the most stringent exclusion limits on the
spin-independent WIMP-nucleon interaction cross section for WIMP masses
above 10 GeV /c<SUP>2</SUP> , with a minimum of 7.7 ×10<SUP>-47</SUP>
cm<SUP>2</SUP> for 35 -GeV /c<SUP>2</SUP> WIMPs at 90% C.L.
---------------------------------------------------------
Title: Quiescent Prominence Dynamics Observed with the Hinode
Solar Optical Telescope. II. Prominence Bubble Boundary Layer
Characteristics and the Onset of a Coupled Kelvin-Helmholtz
Rayleigh-Taylor Instability
Authors: Berger, Thomas; Hillier, Andrew; Liu, Wei
2017ApJ...850...60B Altcode: 2017arXiv170705265B
We analyze solar quiescent prominence bubble characteristics and
instability dynamics using Hinode/Solar Optical Telescope data. We
measure the bubble expansion rate, prominence downflows, and the
profile of the boundary layer brightness and thickness as a function
of time. The largest bubble analyzed rises into the prominence with a
speed of about 1.3 {km} {{{s}}}<SUP>-1</SUP> until it is destabilized by
a localized shear flow on the boundary. Boundary layer thickness grows
gradually as prominence downflows deposit plasma onto the bubble with
characteristic speeds of 20{--}35 {km} {{{s}}}<SUP>-1</SUP>. Lateral
downflows initiate from the thickened boundary layer with characteristic
speeds of 25{--}50 {km} {{{s}}}<SUP>-1</SUP>, “draining” the
layer of plasma. Strong shear flow across one bubble boundary leads
to an apparent coupled Kelvin-Helmholtz Rayleigh-Taylor (KH-RT)
instability. We measure shear flow speeds above the bubble of 10 {km}
{{{s}}}<SUP>-1</SUP> and infer interior bubble flow speeds on the order
of 100 {km} {{{s}}}<SUP>-1</SUP>. Comparing the measured growth rate
of the instability to analytic expressions, we infer a magnetic flux
density across the bubble boundary of ∼10<SUP>-3</SUP> T (10 Gauss)
at an angle of ∼ 70^\circ to the prominence plane. The results are
consistent with the hypothesis that prominence bubbles are caused by
magnetic flux that emerges below a prominence, setting up the conditions
for RT, or combined KH-RT, instability flows that transport flux,
helicity, and hot plasma upward into the overlying coronal magnetic
flux rope.
---------------------------------------------------------
Title: Search for magnetic inelastic dark matter with XENON100
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro,
F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister,
B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.;
Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.;
Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre,
D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.;
de Perio, P.; Di Gangi, P.; Di Giovanni, A.; Diglio, S.; Eurin, G.;
Fei, J.; Ferella, A. D.; Fieguth, A.; Franco, D.; Fulgione, W.; Gallo
Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke,
L. W.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Itay,
R.; Kaminsky, B.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.;
Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.;
Lombardi, F.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodán
Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani,
D.; Messina, M.; Micheneau, K.; Molinario, A.; Murra, M.; Naganoma,
J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.;
Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M. -C.; Plante, G.;
Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl,
S.; Rupp, N.; dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut,
M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.;
Selvi, M.; Shagin, P.; Silva, M.; Simgen, H.; Sivers, M. v.; Stein,
A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.;
Wang, H.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.
2017JCAP...10..039A Altcode: 2017arXiv170405804X
We present the first search for dark matter-induced delayed coincidence
signals in a dual-phase xenon time projection chamber, using the
224.6 live days of the XENON100 science run II. This very distinct
signature is predicted in the framework of magnetic inelastic dark
matter which has been proposed to reconcile the modulation signal
reported by the DAMA/LIBRA collaboration with the null results from
other direct detection experiments. No candidate event has been found in
the region of interest and upper limits on the WIMP's magnetic dipole
moment are derived. The scenarios proposed to explain the DAMA/LIBRA
modulation signal by magnetic inelastic dark matter interactions of
WIMPs with masses of 58.0 GeV/c<SUP>2</SUP> and 122.7 GeV/c<SUP>2</SUP>
are excluded at 3.3 σ and 9.3 σ, respectively.
---------------------------------------------------------
Title: Modelling the radiation on the Martian surface
Authors: Matthiä, D.; Berger, T.
2017EPSC...11..655M Altcode:
Radiation caused by galactic cosmic radiation can be harmful to
electronics and is of interest for future manned missions. A model
of the radiation exposure caused by galactic cosmic radiation on
the Martian surface is presented and the results are compared to
measurements by the Radiation Assessment (RAD) detector of the Mars
Science Laboratory (MSL).
---------------------------------------------------------
Title: Exploiting different active silicon detectors in the
International Space Station: ALTEA and DOSTEL galactic cosmic
radiation (GCR) measurements
Authors: Narici, Livo; Berger, Thomas; Burmeister, Sönke; Di Fino,
Luca; Rizzo, Alessandro; Matthiä, Daniel; Reitz, Günther
2017JSWSC...7A..18N Altcode:
The solar system exploration by humans requires to successfully deal
with the radiation exposition issue. The scientific aspect of this
issue is twofold: knowing the radiation environment the astronauts are
going to face and linking radiation exposure to health risks. Here we
focus on the first issue. It is generally agreed that the final tool
to describe the radiation environment in a space habitat will be a
model featuring the needed amount of details to perform a meaningful
risk assessment. The model should also take into account the shield
changes due to the movement of materials inside the habitat, which
in turn produce changes in the radiation environment. This model will
have to undergo a final validation with a radiation field of similar
complexity. The International Space Station (ISS) is a space habitat
that features a radiation environment inside which is similar to
what will be found in habitats in deep space, if we use measurements
acquired only during high latitude passages (where the effects of
the Earth magnetic field are reduced). Active detectors, providing
time information, that can easily select data from different orbital
sections, are the ones best fulfilling the requirements for these
kinds of measurements. The exploitation of the radiation measurements
performed in the ISS by all the available instruments is therefore
mandatory to provide the largest possible database to the scientific
community, to be merged with detailed Computer Aided Design (CAD)
models, in the quest for a full model validation. While some efforts in
comparing results from multiple active detectors have been attempted,
a thorough study of a procedure to merge data in a single data matrix
in order to provide the best validation set for radiation environment
models has never been attempted. The aim of this paper is to provide
such a procedure, to apply it to two of the most performing active
detector systems in the ISS: the Anomalous Long Term Effects in
Astronauts (ALTEA) instrument and the DOSimetry TELescope (DOSTEL)
detectors, applied in the frame of the DOSIS and DOSIS 3D project
onboard the ISS and to present combined results exploiting the features
of each of the two apparatuses.
---------------------------------------------------------
Title: The Fate of Cool Material in the Hot Corona: Solar Prominences
and Coronal Rain
Authors: Liu, Wei; Antolin, Patrick; Sun, Xudong; Vial, Jean-Claude;
Berger, Thomas
2017SPD....4810501L Altcode:
As an important chain of the chromosphere-corona mass cycle,
some of the million-degree hot coronal mass undergoes a radiative
cooling instability and condenses into material at chromospheric or
transition-region temperatures in two distinct forms - prominences
and coronal rain (some of which eventually falls back to the
chromosphere). A quiescent prominence usually consists of numerous
long-lasting, filamentary downflow threads, while coronal rain consists
of transient mass blobs falling at comparably higher speeds along
well-defined paths. It remains puzzling why such material of similar
temperatures exhibit contrasting morphologies and behaviors. We report
recent SDO/AIA and IRIS observations that suggest different magnetic
environments being responsible for such distinctions. Specifically,
in a hybrid prominence-coronal rain complex structure, we found that
the prominence material is formed and resides near magnetic null points
that favor the radiative cooling process and provide possibly a high
plasma-beta environment suitable for the existence of meandering
prominence threads. As the cool material descends, it turns into
coronal rain tied onto low-lying coronal loops in a likely low-beta
environment. Such structures resemble to certain extent the so-called
coronal spiders or cloud prominences, but the observations reported
here provide critical new insights. We will discuss the broad physical
implications of these observations for fundamental questions, such as
coronal heating and beyond (e.g., in astrophysical and/or laboratory
plasma environments).
---------------------------------------------------------
Title: Intrinsic backgrounds from Rn and Kr in the XENON100 experiment
Authors: XENON Collaboration; Aprile, E.; Aalbers, J.; Agostini, F.;
Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.;
Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.;
Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik,
R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.;
Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau,
J. P.; Decowski, M. P.; de Perio, P.; Di Gangi, P.; Di Giovanni, A.;
Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione,
W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.;
Goetzke, L. W.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.;
Itay, R.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman,
H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.;
Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Manfredini, A.; Maris,
I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson,
D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Morå, K.;
Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers,
B.; Persiani, R.; Piastra, F.; Pienaar, J.; Piro, M. -C.; Pizzella, V.;
Plante, G.; Priel, N.; Ramírez García, D.; Rauch, L.; Reichard, S.;
Reuter, C.; Rizzo, A.; Rupp, N.; dos Santos, J. M. F.; Sartorelli, G.;
Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto
Lavina, L.; Selvi, M.; Shagin, P.; Silva, M.; Simgen, H.; Sivers,
M. v.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.;
Vargas, M.; Wang, H.; Wang, Z.; Weber, M.; Wei, Y.; Weinheimer, C.;
Wulf, J.; Ye, J.; Zhang, Y.
2017arXiv170803617X Altcode:
In this paper, we describe the XENON100 data analyses used to assess
the target-intrinsic background sources radon ($^{222}$Rn), thoron
($^{220}$Rn) and krypton ($^{85}$Kr). We detail the event selections of
high-energy alpha particles and decay-specific delayed coincidences. We
derive distributions of the individual radionuclides inside the detector
and quantify their abundances during the main three science runs of
the experiment over a period of $\sim$ 4 years, from January 2010 to
January 2014. We compare our results to external measurements of radon
emanation and krypton concentrations where we find good agreement. We
report an observed reduction in concentrations of radon daughters
that we attribute to the plating-out of charged ions on the negatively
biased cathode.
---------------------------------------------------------
Title: The fading of Cassiopeia A, and improved models for the
absolute spectrum of primary radio calibration sources
Authors: Trotter, A. S.; Reichart, D. E.; Egger, R. E.; Stýblová,
J.; Paggen, M. L.; Martin, J. R.; Dutton, D. A.; Reichart, J. E.;
Kumar, N. D.; Maples, M. P.; Barlow, B. N.; Berger, T. A.; Foster,
A. C.; Frank, N. R.; Ghigo, F. D.; Haislip, J. B.; Heatherly, S. A.;
Kouprianov, V. V.; LaCluyzé, A. P.; Moffett, D. A.; Moore, J. P.;
Stanley, J. L.; White, S.
2017MNRAS.469.1299T Altcode: 2017arXiv170400002T
Based on 5 yr of observations with the 40-foot telescope at Green
Bank Observatory (GBO), Reichart & Stephens found that the radio
source Cassiopeia A had either faded more slowly between the mid-1970s
and late 1990s than Baars et al. had found it to be fading between the
late 1940s and mid-1970s, or that it had rebrightened and then resumed
fading sometime between the mid-1970s and mid-1990s, in the L band
(1.4 GHz). Here, we present 15 additional years of observations of
Cas A and Cyg A with the 40-foot in the L band, and three and a half
additional years of observations of Cas A, Cyg A, Tau A and Vir A
with GBO's recently refurbished 20-m telescope in the L and X (9 GHz)
bands. We also present a more sophisticated analysis of the 40-foot
data, and a reanalysis of the Baars et al. data, which reveals small,
but non-negligible differences. We find that overall, between the late
1950s and late 2010s, Cas A faded at an average rate of 0.670 ± 0.019
per cent yr<SUP>-1</SUP> in the L band, consistent with Reichart &
Stephens. However, we also find, at the 6.3σ credible level, that it
did not fade at a constant rate. Rather, Cas A faded at a faster rate
through at least the late 1960s, rebrightened (or at least faded at
a much slower rate), and then resumed fading at a similarly fast rate
by, at most, the late 1990s. Given these differences from the original
Baars et al. analysis, and given the importance of their fitted spectral
and temporal models for flux-density calibration in radio astronomy,
we update and improve on these models for all four of these radio
sources. In doing so, we additionally find that Tau A is fading at a
rate of 0.102^{+0.042}_{-0.043} per cent yr<SUP>-1</SUP> in the L band.
---------------------------------------------------------
Title: The radiation environment on the surface of Mars - Numerical
calculations of the galactic component with GEANT4/PLANETOCOSMICS
Authors: Matthiä, Daniel; Berger, Thomas
2017LSSR...14...57M Altcode:
Galactic cosmic radiation and secondary particles produced in the
interaction with the atmosphere lead to a complex radiation field on
the Martian surface. A workshop (;1st Mars Space Radiation Modeling
Workshop;) organized by the MSL-RAD science team was held in June 2016
in Boulder with the goal to compare models capable to predict this
radiation field with each other and measurements from the RAD instrument
onboard the curiosity rover taken between November 15, 2015 and
January 15, 2016. <P />In this work the results of PLANETOCOSMICS/GEANT4
contributed to the workshop are presented. Calculated secondary particle
spectra on the Martian surface are investigated and the radiation
field's directionality of the different particles in dependence on
the energy is discussed. Omnidirectional particle fluxes are used
in combination with fluence to dose conversion factors to calculate
absorbed dose rates and dose equivalent rates in a slab of tissue.
---------------------------------------------------------
Title: Effective field theory search for high-energy nuclear recoils
using the XENON100 dark matter detector
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro,
F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister,
B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.;
Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.;
Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre,
D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.;
de Perio, P.; di Gangi, P.; di Giovanni, A.; Diglio, S.; Eurin, G.;
Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.;
Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Greene,
Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Itay, R.; Kaminsky,
B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.;
Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.;
Lombardi, F.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodán
Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani,
D.; Messina, M.; Micheneau, K.; Molinario, A.; Morâ, K.; Murra,
M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.;
Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M. -C.;
Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo,
A.; Rosendahl, S.; Rupp, N.; Dos Santos, J. M. F.; Sartorelli, G.;
Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto
Lavina, L.; Selvi, M.; Shagin, P.; Silva, M.; Simgen, H.; Sivers,
M. V.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.;
Vargas, M.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wulf, J.;
Ye, J.; Zhang., Y.; Farmer, B.; Xenon Collaboration
2017PhRvD..96d2004A Altcode: 2017arXiv170502614A
We report on weakly interacting massive particles (WIMPs) search results
in the XENON100 detector using a nonrelativistic effective field theory
approach. The data from science run II (34 kg ×224.6 live days)
were reanalyzed, with an increased recoil energy interval compared
to previous analyses, ranging from (6.6 -240 ) keV<SUB>nr</SUB> . The
data are found to be compatible with the background-only hypothesis. We
present 90% confidence level exclusion limits on the coupling constants
of WIMP-nucleon effective operators using a binned profile likelihood
method. We also consider the case of inelastic WIMP scattering, where
incident WIMPs may up-scatter to a higher mass state, and set exclusion
limits on this model as well.
---------------------------------------------------------
Title: Prominence Bubble Shear Flows and the Coupled Kelvin-Helmholtz
— Rayleigh-Taylor Instability
Authors: Berger, Thomas; Hillier, Andrew
2017SPD....4820103B Altcode:
Prominence bubbles are large arched structures that rise from below
into quiescent prominences, often growing to heights on the order of
10 Mm before going unstable and generating plume upflows. While there
is general agreement that emerging flux below pre-existing prominences
causes the structures, there is lack of agreement on the nature of
the bubbles and the cause of the instability flows. One hypothesis is
that the bubbles contain coronal temperature plasma and rise into the
prominence above due to both magnetic and thermal buoyancy, eventually
breaking down via a magnetic Rayleigh-Taylor (RT) instability to
release hot plasma and magnetic flux and helicity into the overlying
coronal flux rope. Another posits that the bubbles are actually just
“arcades” in the prominence indicating a magnetic separator line
between the bipole and the prominence fields with the observed upflows
and downflows caused by reconnection along the separator. We analyze
Hinode/SOT, SDO/AIA, and IRIS observations of prominence bubbles,
focusing on characteristics of the bubble boundary layers that may
discriminate between the two hypotheses. We find speeds on the order
of 10 km/s in prominence plasma downflows and lateral shear flows
along the bubble boundary. Inflows to the boundary gradually increase
the thickness and brightness of the layer until plasma drains from
there, apparently around the dome-like bubble domain. In one case,
shear flow across the bubble boundary develops Kelvin-Helmholtz (KH)
vortices that we use to infer flow speeds in the low-density bubble
on the order of 100 km/sec. IRIS spectra indicate that plasma flows on
the bubble boundary at transition region temperatures achieve Doppler
speeds on the order of 50 km/s, consistent with this inference. Combined
magnetic KH-RT instability analysis leads to flux density estimates
of 10 G with a field angle of 30° to the prominence, consistent with
vector magnetic field measurements. In contrast, we find no evidence
of the impulsive brightening or bi-directional jets that are expected
from reconnection driven flows at bubble boundaries. We conclude that
observations to date are consistent with the hot bubble/Rayleigh-Taylor
instability hypothesis.
---------------------------------------------------------
Title: The radiation environment on the surface of Mars - Summary
of model calculations and comparison to RAD data
Authors: Matthiä, Daniel; Hassler, Donald M.; de Wet, Wouter;
Ehresmann, Bent; Firan, Ana; Flores-McLaughlin, John; Guo, Jingnan;
Heilbronn, Lawrence H.; Lee, Kerry; Ratliff, Hunter; Rios, Ryan R.;
Slaba, Tony C.; Smith, Michael; Stoffle, Nicholas N.; Townsend,
Lawrence W.; Berger, Thomas; Reitz, Günther; Wimmer-Schweingruber,
Robert F.; Zeitlin, Cary
2017LSSR...14...18M Altcode:
The radiation environment at the Martian surface is, apart from
occasional solar energetic particle events, dominated by galactic
cosmic radiation, secondary particles produced in their interaction
with the Martian atmosphere and albedo particles from the Martian
regolith. The highly energetic primary cosmic radiation consists
mainly of fully ionized nuclei creating a complex radiation field
at the Martian surface. This complex field, its formation and its
potential health risk posed to astronauts on future manned missions to
Mars can only be fully understood using a combination of measurements
and model calculations. In this work the outcome of a workshop held in
June 2016 in Boulder, CO, USA is presented: experimental results from
the Radiation Assessment Detector of the Mars Science Laboratory are
compared to model results from GEANT4, HETC-HEDS, HZETRN, MCNP6, and
PHITS. Charged and neutral particle spectra and dose rates measured
between 15 November 2015 and 15 January 2016 and model results
calculated for this time period are investigated.
---------------------------------------------------------
Title: Search for WIMP inelastic scattering off xenon nuclei with
XENON100
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro,
F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister,
B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.;
Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.;
Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre,
D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.;
de Perio, P.; di Gangi, P.; di Giovanni, A.; Diglio, S.; Eurin, G.;
Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.;
Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Greene,
Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Itay, R.; Kaminsky, B.;
Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch,
D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.;
Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodán Undagoitia,
T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.;
Micheneau, K.; Molinario, A.; Mora, K.; Murra, M.; Naganoma, J.; Ni,
K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra,
F.; Pienaar, J.; Pizzella, V.; Piro, M. -C.; Plante, G.; Priel, N.;
Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp,
N.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler,
S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin,
P.; Silva, M.; Simgen, H.; Sivers, M. V.; Stein, A.; Thers, D.; Tiseni,
A.; Trinchero, G.; Tunnell, C.; Vargas, M.; Wang, H.; Wang, Z.; Wei,
Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.; Xenon Collaboration
2017PhRvD..96b2008A Altcode: 2017arXiv170505830A
We present the first constraints on the spin-dependent, inelastic
scattering cross section of weakly interacting massive particles (WIMPs)
on nucleons from XENON100 data with an exposure of 7.64 ×10<SUP>3</SUP>
kg .days . XENON100 is a dual-phase xenon time projection chamber
with 62 kg of active mass, operated at the Laboratori Nazionali
del Gran Sasso (LNGS) in Italy and designed to search for nuclear
recoils from WIMP-nucleus interactions. Here we explore inelastic
scattering, where a transition to a low-lying excited nuclear state
of <mml:mmultiscripts>Xe 129 </mml:mmultiscripts>
is induced. The experimental signature is a nuclear recoil
observed together with the prompt deexcitation photon. We see no
evidence for such inelastic WIMP-<mml:mmultiscripts>Xe 129
</mml:mmultiscripts> interactions. A profile likelihood analysis
allows us to set a 90% C.L. upper limit on the inelastic, spin-dependent
WIMP-nucleon cross section of 3.3 ×10<SUP>-38</SUP> cm<SUP>2</SUP>
at 100 GeV /c<SUP>2</SUP> . This is the most constraining result to
date, and sets the pathway for an analysis of this interaction channel
in upcoming, larger dual-phase xenon detectors.
---------------------------------------------------------
Title: DOSIS & DOSIS 3D: radiation measurements with the DOSTEL
instruments onboard the Columbus Laboratory of the ISS in the years
2009-2016
Authors: Berger, Thomas; Burmeister, Sönke; Matthiä, Daniel;
Przybyla, Bartos; Reitz, Günther; Bilski, Pawel; Hajek, Michael;
Sihver, Lembit; Szabo, Julianna; Ambrozova, Iva; Vanhavere, Filip;
Gaza, Ramona; Semones, Edward; Yukihara, Eduardo G.; Benton, Eric R.;
Uchihori, Yukio; Kodaira, Satoshi; Kitamura, Hisashi; Boehme, Matthias
2017JSWSC...7A...8B Altcode:
The natural radiation environment in Low Earth Orbit (LEO) differs
significantly in composition and energy from that found on Earth. The
space radiation field consists of high energetic protons and heavier
ions from Galactic Cosmic Radiation (GCR), as well as of protons
and electrons trapped in the Earth's radiation belts (Van Allen
belts). Protons and some heavier particles ejected in occasional Solar
Particle Events (SPEs) might in addition contribute to the radiation
exposure in LEO. All sources of radiation are modulated by the solar
cycle. During solar maximum conditions SPEs occur more frequently with
higher particle intensities. Since the radiation exposure in LEO exceeds
exposure limits for radiation workers on Earth, the radiation exposure
in space has been recognized as a main health concern for humans in
space missions from the beginning of the space age on. Monitoring of
the radiation environment is therefore an inevitable task in human
spaceflight. Since mission profiles are always different and each
spacecraft provides different shielding distributions, modifying
the radiation environment measurements needs to be done for each
mission. The experiments "Dose Distribution within the ISS (DOSIS)"
(2009-2011) and "Dose Distribution within the ISS 3D (DOSIS 3D)"
(2012-onwards) onboard the Columbus Laboratory of the International
Space Station (ISS) use a detector suite consisting of two silicon
detector telescopes (DOSimetry TELescope = DOSTEL) and passive radiation
detector packages (PDP) and are designed for the determination of the
temporal and spatial variation of the radiation environment. With
the DOSTEL instruments' changes of the radiation composition and
the related exposure levels in dependence of the solar cycle, the
altitude of the ISS and the influence of attitude changes of the ISS
during Space Shuttle dockings inside the Columbus Laboratory have been
monitored. The absorbed doses measured at the end of May 2016 reached
up to 286 μGy/day with dose equivalent values of 647 μSv/day.
---------------------------------------------------------
Title: The Lunar Lander Neutron and Dosimetry (LND) Experiment
on Chang'e4
Authors: Wimmer-Schweingruber, R. F.; Zhang, S.; Hellweg, C. E.; Yu,
J.; Guo, J.; Lohf, H.; Berger, T.; Böttcher, S. I.; Burmeister, S.;
Jüngling, M.; Knappmann, A.; Knierim, V.; Schuster, B.; Seimetz,
L.; Shen, G.; Steinhagen, J.; Yuan, B.
2017LPI....48.1320W Altcode:
The Lunar Lander Neutron and Dosimetry (LND) experiment on China's
lunar mission Chang'e4 will measure the neutral and charged radiation
on the lunar surface.
---------------------------------------------------------
Title: STARLIFE - An International Campaign to Study the Role of
Galactic Cosmic Radiation in Astrobiological Model Systems
Authors: Moeller, Ralf; Raguse, Marina; Leuko, Stefan; Berger, Thomas;
Hellweg, Christine Elisabeth; Fujimori, Akira; Okayasu, Ryuichi;
Horneck, Gerda
2017AsBio..17..101M Altcode:
In-depth knowledge regarding the biological effects of the radiation
field in space is required for assessing the radiation risks in
space. To obtain this knowledge, a set of different astrobiological
model systems has been studied within the STARLIFE radiation campaign
during six irradiation campaigns (2013-2015). The STARLIFE group is
an international consortium with the aim to investigate the responses
of different astrobiological model systems to the different types of
ionizing radiation (X-rays, γ rays, heavy ions) representing major
parts of the galactic cosmic radiation spectrum. Low- and high-energy
charged particle radiation experiments have been conducted at the Heavy
Ion Medical Accelerator in Chiba (HIMAC) facility at the National
Institute of Radiological Sciences (NIRS) in Chiba, Japan. X-rays
or γ rays were used as reference radiation at the German Aerospace
Center (DLR, Cologne, Germany) or Beta-Gamma-Service GmbH (BGS, Wiehl,
Germany) to derive the biological efficiency of different radiation
qualities. All samples were exposed under identical conditions to the
same dose and qualities of ionizing radiation (i) allowing a direct
comparison between the tested specimens and (ii) providing information
on the impact of the space radiation environment on currently used
astrobiological model organisms.
---------------------------------------------------------
Title: Search for Electronic Recoil Event Rate Modulation with 4
Years of XENON100 Data
Authors: The XENON collaboration; Aprile, E.; Aalbers, J.; Agostini,
F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow,
P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger,
T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.;
Budnik, R.; Butikofer, L.; Calven, J.; Cardoso, J. M. R.; Cervantes,
M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau,
J. P.; Decowski, M. P.; de Perio, P.; Di Gangi, P.; Di Giovanni, A.;
Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Franco,
D.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini,
M.; Geis, C.; Goetzke, L. W.; Greene, Z.; Grignon, C.; Hasterok, C.;
Hogenbirk, E.; Itay, R.; Kaminsky, B.; Kessler, G.; Kish, A.; Landsman,
H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.;
Lindner, M.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodan
Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani,
D.; Messina, M.; Micheneau, K.; Miguez, B.; Molinario, A.; Murra,
M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.;
Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M. -C.;
Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo,
A.; Rosendahl, S.; Rupp, N.; dos Santos, J. M. F.; Sartorelli, G.;
Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto
Lavina, L.; Selvi, M.; Shagin, P.; Silva, M.; Simgen, H.; Sivers,
M. v.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.;
Wang, H.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.
2017arXiv170100769T Altcode:
We report on a search for electronic recoil event rate modulation
signatures in the XENON100 data accumulated over a period of 4 years,
from January 2010 to January 2014. A profile likelihood method, which
incorporates the stability of the XENON100 detector and the known
electronic recoil background model, is used to quantify the significance
of periodicity in the time distribution of events. There is a weak
modulation signature at a period of $431^{+16}_{-14}$ days in the low
energy region of $(2.0-5.8)$ keV in the single scatter event sample,
with a global significance of $1.9\,\sigma$, however no other more
significant modulation is observed. The expected annual modulation
of a dark matter signal is not compatible with this result. Single
scatter events in the low energy region are thus used to exclude the
DAMA/LIBRA annual modulation as being due to dark matter electron
interactions via axial vector coupling at $5.7\,\sigma$.
---------------------------------------------------------
Title: XENON100 dark matter results from a combination of 477
live days
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro,
F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister,
B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown,
E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.;
Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn,
A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio,
P.; di Gangi, P.; di Giovanni, A.; Diglio, S.; Duchovni, E.; Fei, J.;
Ferella, A. D.; Fieguth, A.; Franco, D.; Fulgione, W.; Gallo Rosso, A.;
Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Greene,
Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Itay, R.; Kaminsky,
B.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch,
D.; Levinson, L.; Le Calloch, M.; Levy, C.; Lin, Q.; Lindemann, S.;
Lindner, M.; Lopes, J. A. M.; Manfredini, A.; Marrodán Undagoitia,
T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Meng, Y.;
Messina, M.; Micheneau, K.; Miguez, B.; Molinario, A.; Murra, M.;
Naganoma, J.; Ni, K.; Oberlack, U.; Orrigo, S. E. A.; Pakarha, P.;
Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Piro, M. -C.;
Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo,
A.; Rosendahl, S.; Rupp, N.; Dos Santos, J. M. F.; Sartorelli, G.;
Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto
Lavina, L.; Selvi, M.; Shagin, P.; Silva, M.; Simgen, H.; Sivers,
M. V.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell,
C. D.; Wall, R.; Wang, H.; Weber, M.; Wei, Y.; Weinheimer, C.; Wulf,
J.; Zhang, Y.; Xenon Collaboration
2016PhRvD..94l2001A Altcode: 2016arXiv160906154X
We report on WIMP search results of the XENON100 experiment,
combining three runs summing up to 477 live days from January 2010 to
January 2014. Data from the first two runs were already published. A
blind analysis was applied to the last run recorded between April
2013 and January 2014 prior to combining the results. The ultralow
electromagnetic background of the experiment, ∼5 ×10<SUP>-3</SUP>
events /(keV<SUB>ee</SUB>×kg ×day ) ) before electronic recoil
rejection, together with the increased exposure of 48 kg ×yr ,
improves the sensitivity. A profile likelihood analysis using an energy
range of (6.6 - 43.3 ) keV<SUB>nr</SUB> sets a limit on the elastic,
spin-independent WIMP-nucleon scattering cross section for WIMP masses
above 8 GeV /c<SUP>2</SUP> , with a minimum of 1.1 ×10<SUP>-45</SUP>
cm<SUP>2</SUP> at 50 GeV /c<SUP>2</SUP> and 90% confidence level. We
also report updated constraints on the elastic, spin-dependent
WIMP-nucleon cross sections obtained with the same data. We set upper
limits on the WIMP-neutron (proton) cross section with a minimum of 2.0
×10<SUP>-40</SUP> cm<SUP>2</SUP> (52 ×10<SUP>-40</SUP> cm<SUP>2</SUP>
) at a WIMP mass of 50 GeV /c<SUP>2</SUP> , at 90% confidence level.
---------------------------------------------------------
Title: Probing the Physical Connection between Solar Prominences
and Coronal Rain
Authors: Liu, W.; Antolin, P.; Sun, X.; Vial, J. C.; Guo, L.; Gibson,
S. E.; Berger, T. E.; Okamoto, J.; De Pontieu, B.
2016AGUFMSH43C2587L Altcode:
Solar prominences and coronal rain are intimately related phenomena,
both involving cool material at chromospheric temperatures within the
hot corona and both playing important roles as part of the return flow
of the chromosphere-corona mass cycle. At the same time, they exhibit
distinct morphologies and dynamics not yet well understood. Quiescent
prominences consist of numerous long-lasting, filamentary downflow
threads, while coronal rain is more transient and falls comparably
faster along well-defined curved paths. We report here a novel, hybrid
prominence-coronal rain complex in an arcade-fan geometry observed
by SDO/AIA and IRIS, which provides new insights to the underlying
physics of such contrasting behaviors. We found that the supra-arcade
fan region hosts a prominence sheet consisting of meandering threads
with broad line widths. As the prominence material descends to the
arcade, it turns into coronal rain sliding down coronal loops with
line widths 2-3 times narrower. This contrast suggests that distinct
local plasma and magnetic conditions determine the fate of the cool
material, a scenario supported by our magnetic field extrapolations
from SDO/HMI. Specifically, the supra-arcade fan (similar to those
in solar flares) is likely situated in a current sheet, where the
magnetic field is weak and the plasma-beta could be close to unity, thus
favoring turbulent flows like those prominence threads. In contrast,
the underlying arcade has a stronger magnetic field and most likely a
low-beta environment, such that the material is guided along magnetic
field lines to appear as coronal rain. We will discuss the physical
implications of these observations beyond the phenomena of prominences
and coronal rain.
---------------------------------------------------------
Title: LND for Chang'E 4 Mission
Authors: Wimmer-Schweingruber, R. F.; Yu, J.; Hellweg, C.; Berger,
T.; Zhang, S.; Burmeister, S.; Seimetz, L.; Schuster, B.; Boettcher,
S. I.; Woyciechowski, H.; Guo, J.; Lohf, H.; Knierim, V.
2016AGUFMSM51A2465W Altcode:
The Lunar Lander Neutrons & Dosimetry experiment (LND) is part of
the payload of the next Chinese lunar mission, Chang'E 4, which is
planned to land on the far side of the Moon. The University of Kiel
in Germany is responsible for the design, development, and build of
LND. This instrument will be accommodated on the Chang'E 4 Lander and
has two major science objectives: dosimetry for human exploration of
the Moon and contribution to heliospheric science. To achieve the first
objective, LND is designed to determine the time series of dose rate
and of linear energy transfer (LET) spectra in the complex radiation
field of the lunar surface. For the second objective, LND is capable
to measure the particle fluxes and their temporal variations, which can
contribute to the understanding of particle propagation and transport in
the heliosphere. With a stack of 10 silicon solid-state detectors, LND
can measure fast neutrons in the energy rang from 2 - 20 MeV, protons
from 10 - 30 MeV, electrons from 60 - 500 keV, alpha particles from 10
- 20 MeV/n and heavy ions from 15 - 40 MeV/n. Using two Gd-sandwich
detectors, LND can in addition measure fluxes of thermal neutrons,
which are sensitive to subsurface water and important to understand
lunar surface mixing processes. Here we present the current development
status of LND including the test results of the engineering model,
together with plans for future activities.
---------------------------------------------------------
Title: Blending of Ground- and Space-Based Magnetograms: Application
to L1-L5 Solar Wind and Coronal Hole Predictions
Authors: Berger, T. E.; Pevtsov, A. A.; Martinez-Pillet, V.; Bertello,
L.; Petrie, G. J. D.; Arge, C. N.; Henney, C. J.; Biesecker, D. A.
2016AGUFMSH11C2241B Altcode:
We examine the effect of blending ground-based Global Oscillations
Network Group (GONG) line-of-sight solar magnetic flux maps
("magnetograms") with space-based magnetograms from the Solar Dynamics
Observatory (SDO) Helioseismic and Magnetic Imager (HMI) instrument on
solar wind and coronal hole model-based forecasts. The longitudinally
blended maps are used to "reforecast" solar wind conditions using the
Wang-Sheeley-Arge (WSA) solar wind model during historical periods
of coronal hole High Speed Streams (HSS) and Corotating Interaction
Regions (CIRs) and compared to Advanced Composition Explorer (ACE)
data at the L1 Lagrangian point. The same WSA runs are repeated using
GONG and HMI data alone to determine the effect of data blending. The
blended maps are also used to create Potential Field Source Surface
(PFSS) maps of open coronal field lines and compared with historical
coronal hole data from SDO Atmospheric Imaging Assembly (AIA)
images. The study addresses the feasibility of combining ground- and
space-based data from instruments with widely disparate and varying
spatiotemporal resolution and flux sensitivity levels for use as inputs
to solar wind and coronal hole forecasting models. The results are
relevant to mission studies considering blended data inputs from,
e.g., L5 Lagrangian point satellite instruments with ground-based
measurements on the Sun-Earth line, as well as to expected magnetogram
data from the Solar Orbiter Polarimetric and Helioseismic Imager (PHI)
instrument. This study complements others that examine the utility
of having multiple viewpoint (e.g. L1 and L5) magnetogram inputs to
solar wind models by exploring data blending from disparate instruments.
---------------------------------------------------------
Title: DARWIN: towards the ultimate dark matter detector
Authors: Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.;
Amsler, C.; Aprile, E.; Arazi, L.; Arneodo, F.; Barrow, P.; Baudis,
L.; Benabderrahmane, M. L.; Berger, T.; Beskers, B.; Breskin, A.;
Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik,
R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cichon, D.;
Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski,
M. P.; Diglio, S.; Drexlin, G.; Duchovni, E.; Erdal, E.; Eurin, G.;
Ferella, A.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.; Di Gangi,
P.; Di Giovanni, A.; Galloway, M.; Garbini, M.; Geis, C.; Glueck,
F.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hannen, V.;
Hogenbirk, E.; Howlett, J.; Hilk, D.; Hils, C.; James, A.; Kaminsky,
B.; Kazama, S.; Kilminster, B.; Kish, A.; Krauss, L. M.; Landsman,
H.; Lang, R. F.; Lin, Q.; Linde, F. L.; Lindemann, S.; Lindner,
M.; Lopes, J. A. M.; Marrodán Undagoitia, T.; Masbou, J.; Massoli,
F. V.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Morå,
K. D.; Morteau, E.; Murra, M.; Naganoma, J.; Newstead, J. L.; Ni, K.;
Oberlack, U.; Pakarha, P.; Pelssers, B.; de Perio, P.; Persiani, R.;
Piastra, F.; Piro, M. C.; Plante, G.; Rauch, L.; Reichard, S.; Rizzo,
A.; Rupp, N.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.;
Schindler, S.; Schumann, M.; Schreiner, J.; Scotto Lavina, L.; Selvi,
M.; Shagin, P.; Silva, M. C.; Simgen, H.; Sissol, P.; von Sivers,
M.; Thers, D.; Thurn, J.; Tiseni, A.; Trotta, R.; Tunnell, C. D.;
Valerius, K.; Vargas, M. A.; Wang, H.; Wei, Y.; Weinheimer, C.;
Wester, T.; Wulf, J.; Zhang, Y.; Zhu, T.; Zuber, K.
2016JCAP...11..017A Altcode: 2016arXiv160607001A
DARk matter WImp search with liquid xenoN (DARWIN) will be an experiment
for the direct detection of dark matter using a multi-ton liquid xenon
time projection chamber at its core. Its primary goal will be to explore
the experimentally accessible parameter space for Weakly Interacting
Massive Particles (WIMPs) in a wide mass-range, until neutrino
interactions with the target become an irreducible background. The
prompt scintillation light and the charge signals induced by particle
interactions in the xenon will be observed by VUV sensitive, ultra-low
background photosensors. Besides its excellent sensitivity to WIMPs
above a mass of 5 GeV/c<SUP>2</SUP>, such a detector with its large
mass, low-energy threshold and ultra-low background level will also be
sensitive to other rare interactions. It will search for solar axions,
galactic axion-like particles and the neutrinoless double-beta decay of
<SUP>136</SUP>Xe, as well as measure the low-energy solar neutrino flux
with < 1% precision, observe coherent neutrino-nucleus interactions,
and detect galactic supernovae. We present the concept of the DARWIN
detector and discuss its physics reach, the main sources of backgrounds
and the ongoing detector design and R&D efforts.
---------------------------------------------------------
Title: Low-mass dark matter search using ionization signals in
XENON100
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro,
F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister,
B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown,
E.; Bruenner, S.; Bruno, G.; Budnik, R.; Buss, A.; Bütikofer, L.;
Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn,
A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.;
di Gangi, P.; di Giovanni, A.; Duchovni, E.; Ferella, A. D.; Fieguth,
A.; Franco, D.; Fulgione, W.; Galloway, M.; Garbini, M.; Geis,
C.; Goetzke, L. W.; Greene, Z.; Grignon, C.; Gross, E.; Hasterok,
C.; Hogenbirk, E.; Itay, R.; Kaminsky, B.; Kessler, G.; Kish, A.;
Landsman, H.; Lang, R. F.; Levinson, L.; Le Calloch, M.; Levy, C.;
Linde, F.; Lindemann, S.; Lindner, M.; Lopes, J. A. M.; Lyashenko,
A.; Manfredini, A.; Marrodán Undagoitia, T.; Masbou, J.; Massoli,
F. V.; Masson, D.; Mayani, D.; Melgarejo Fernandez, A. J.; Meng, Y.;
Messina, M.; Micheneau, K.; Miguez, B.; Molinario, A.; Murra, M.;
Naganoma, J.; Oberlack, U.; Orrigo, S. E. A.; Pakarha, P.; Pelssers,
B.; Persiani, R.; Piastra, F.; Pienaar, J.; Plante, G.; Priel, N.;
Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp,
N.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler,
S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin,
P.; Simgen, H.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.;
Tunnell, C. D.; von Sivers, M.; Wall, R.; Wang, H.; Weber, M.; Wei,
Y.; Weinheimer, C.; Wulf, J.; Zhang, Y.; Xenon Collaboration
2016PhRvD..94i2001A Altcode: 2016arXiv160506262X
We perform a low-mass dark matter search using an exposure of 30 kg
×yr with the XENON100 detector. By dropping the requirement of a
scintillation signal and using only the ionization signal to determine
the interaction energy, we lowered the energy threshold for detection to
0.7 keV for nuclear recoils. No dark matter detection can be claimed
because a complete background model cannot be constructed without
a primary scintillation signal. Instead, we compute an upper limit
on the WIMP-nucleon scattering cross section under the assumption
that every event passing our selection criteria could be a signal
event. Using an energy interval from 0.7 keV to 9.1 keV, we derive a
limit on the spin-independent WIMP-nucleon cross section that excludes
WIMPs with a mass of 6 GeV /c<SUP>2</SUP> above 1.4 ×10<SUP>-41</SUP>
cm<SUP>2</SUP> at 90% confidence level.
---------------------------------------------------------
Title: DOSIS & DOSIS 3D: long-term dose monitoring onboard the
Columbus Laboratory of the International Space Station (ISS)
Authors: Berger, Thomas; Przybyla, Bartos; Matthiä, Daniel; Reitz,
Günther; Burmeister, Sönke; Labrenz, Johannes; Bilski, Pawel;
Horwacik, Tomasz; Twardak, Anna; Hajek, Michael; Fugger, Manfred;
Hofstätter, Christina; Sihver, Lembit; Palfalvi, Jozsef K.; Szabo,
Julianna; Stradi, Andrea; Ambrozova, Iva; Kubancak, Jan; Brabcova,
Katerina Pachnerova; Vanhavere, Filip; Cauwels, Vanessa; Van Hoey,
Olivier; Schoonjans, Werner; Parisi, Alessio; Gaza, Ramona; Semones,
Edward; Yukihara, Eduardo G.; Benton, Eric R.; Doull, Brandon A.;
Uchihori, Yukio; Kodaira, Satoshi; Kitamura, Hisashi; Boehme, Matthias
2016JSWSC...6A..39B Altcode:
The radiation environment encountered in space differs in nature from
that on Earth, consisting mostly of highly energetic ions from protons
up to iron, resulting in radiation levels far exceeding the ones present
on Earth for occupational radiation workers. Since the beginning of
the space era, the radiation exposure during space missions has been
monitored with various active and passive radiation instruments. Also
onboard the International Space Station (ISS), a number of area
monitoring devices provide data related to the spatial and temporal
variation of the radiation field in and outside the ISS. The aim of the
DOSIS (2009-2011) and the DOSIS 3D (2012-ongoing) experiments was and
is to measure the radiation environment within the European Columbus
Laboratory of the ISS. These measurements are, on the one hand,
performed with passive radiation detectors mounted at 11 locations
within Columbus for the determination of the spatial distribution
of the radiation field parameters and, on the other, with two active
radiation detectors mounted at a fixed position inside Columbus for
the determination of the temporal variation of the radiation field
parameters. Data measured with passive radiation detectors showed
that the absorbed dose values inside the Columbus Laboratory follow a
pattern, based on the local shielding configuration of the radiation
detectors, with minimum dose values observed in the year 2010 of 195-270
μGy/day and maximum values observed in the year 2012 with values
ranging from 260 to 360 μGy/day. The absorbed dose is modulated by
(a) the variation in solar activity and (b) the changes in ISS altitude.
---------------------------------------------------------
Title: The RIMFAX GPR Instrument Development for the Mars 2020
Rover Mission
Authors: Hamran, S. -E.; Amundsen, H. E. F.; Asak, L.; Berger, T.;
Brovoll, S.; Buskenes, J. I.; Carter, L.; Damsgård, L.; Diaz, C.;
Ghent, R.; Helleren, Ø.; Kohler, J.; Mellon, M.; Nunez, D.; Paige,
D.; Plettemeier, D.; Rowe, K.; Russell, P.; Sagsveen, B.; Ødegaard,
N.; Øyan, M. J.
2016LPICo1980.4031H Altcode:
The Radar Imager for Mars' subsurface eXperiment (RIMFAX) ground
penetrating radar (GPR) experiment for the Mars 2020 Rover will add
a new dimension to the rover's toolset by providing the capability to
image the shallow subsurface beneath the rover.
---------------------------------------------------------
Title: Joint SDO and IRIS Observations of a Novel, Hybrid
Prominence-Coronal Rain Complex
Authors: Liu, Wei; Antolin, Patrick; Sun, Xudong; Gao, Lijia; Vial,
Jean-Claude; Gibson, Sarah; Okamoto, Takenori; Berger, Thomas;
Uitenbroek, Han; De Pontieu, Bart
2016usc..confE..99L Altcode:
Solar prominences and coronal rain are intimately related phenomena,
both involving cool material at chromospheric temperatures within the
hot corona and both playing important roles as part of the return flow
of the chromosphere-corona mass cycle. At the same time, they exhibit
distinct morphologies and dynamics not yet well understood. Quiescent
prominences consist of numerous long-lasting, filamentary downflow
threads, while coronal rain is more transient and falls comparably
faster along well-defined curved paths. We report here a novel, hybrid
prominence-coronal rain complex in an arcade-fan geometry observed
by SDO/AIA and IRIS, which provides new insights to the underlying
physics of such contrasting behaviors. We found that the supra-arcade
fan region hosts a prominence sheet consisting of meandering threads
with broad line widths. As the prominence material descends to the
arcade, it turns into coronal rain sliding down coronal loops with
line widths 2-3 times narrower. This contrast suggests that distinct
local plasma and magnetic conditions determine the fate of the cool
material, a scenario supported by our magnetic field extrapolations
from SDO/HMI. Specifically, the supra-arcade fan (similar to those
in solar flares; e.g., McKenzie 2013) is likely situated in a current
sheet, where the magnetic field is weak and the plasma-beta could be
close to unity, thus favoring turbulent flows like those prominence
threads. In contrast, the underlying arcade has a stronger magnetic
field and most likely a low-beta environment, such that the material
is guided along magnetic field lines to appear as coronal rain. We
will discuss the physical implications of these observations beyond
prominence and coronal rain.
---------------------------------------------------------
Title: Transitioning GONG data processing to NOAA SWPC operations
Authors: Reinard, Alysha; Berger, Thomas; Marble, Andrew; Hill, Frank
2016shin.confE..26R Altcode:
The NOAA Space Weather Prediction Center (SWPC) is the nation's official
source of space weather watches, warnings, and alerts, providing 24x7
forecasting and support to critical infrastructure operators around
the world. Observations of the conditions on the Sun are crucial for
determining when and if a warning is needed. The Global Oscillation
Network Group (GONG) operated by the National Solar Observatory (NSO)
consists of six ground stations, allowing continuous observations of the
Sun. Of particular interest for space weather purposes are the H-alpha
images and magnetograms. H-alpha data is used to identify filaments and
their eruptions, to assess active region evolution and plage extent,
and to help localize flare locations. Magnetograms are used to identify
neutral lines, examine potential shearing areas and characterize the
magnetic structure of active regions. GONG magnetograms also provide
the initial condition for models of solar wind expansion such as
the WSA-Enlil model. GONG helioseismology products, in particular
far-side imaging, are being examined for operational use in the near
future. <P />NSO has operated GONG as a science facility since 1995
and has provided processed space weather data products to NOAA via
public internet connections for the past several years. In 2014 the
White House Office of Management and Budget (OMB) requested that NOAA
transition the GONG network to an operational space weather asset
in order to ensure the continued flow of critical magnetogram data
for solar wind models. NSO will continue to operate and manage the
instruments and sites, but the H-alpha images and 10 minute averaged
magnetogram data will be sent directly to SWPC for processing and use
in space weather modeling. SWPC will make these data available to NSO
and the public via the new NOAA Integrated Dissemination Program (IDP)
network. We discuss the progress and details of this change.
---------------------------------------------------------
Title: Towards Space Exploration of Moon, Mars Neos: Radiation
Biological Basis
Authors: Hellweg, Christine; Baumstark-Khan, Christa; Berger, Thomas;
Reitz, Guenther
2016cosp...41E.825H Altcode:
Radiation has emerged as the most critical issue to be resolved for
long-term missions both orbital and interplanetary. Astronauts are
constantly exposed to galactic cosmic radiation (GCR) of various
energies with a low dose rate. Primarily late tissue sequels like
genetic alterations, cancer and non-cancer effects, i.e. cataracts
and degenerative diseases of e.g. the central nervous system or
the cardiovascular system, are the potential risks. Cataracts were
observed to occur earlier and more often in astronauts exposed to higher
proportions of galactic ions (Cucinotta et al., 2001). Predictions of
cancer risk and acceptable radiation exposure in space are subject to
many uncertainties including the relative biological effectiveness
(RBE) of space radiation especially heavy ions, dose-rate effects
and possible interaction with microgravity and other spaceflight
environmental factors. The initial cellular response to radiation
exposure paves the way to late sequelae and starts with damage to the
DNA which complexity depends on the linear energy transfer (LET) of the
radiation. Repair of such complex DNA damage is more challenging and
requires more time than the repair of simple DNA double strand breaks
(DSB) which can be visualized by immunofluorescence staining of the
phosphorylated histone 2AX (γH2AX) and might explain the observed
prolonged cell cycle arrests induced by high-LET in comparison to
low-LET irradiation. Unrepaired or mis-repaired DNA DSB are proposed to
be responsible for cell death, mutations, chromosomal aberrations and
oncogenic cell transformation. Cell killing and mutation induction are
most efficient in an LET range of 90-200 keV/µm. Also the activation
of transcription factors such as Nuclear Factor κB (NF-κB) and gene
expression shaping the cellular radiation response depend on the LET
with a peak RBE between 90 and 300 keV/µm. Such LET-RBE relationships
were observed for cataract and cancer induction by heavy ions in
laboratory animals, with varying maximal efficiencies. Furthermore,
there is always the added risk of acute exposure to high proton fluxes
during a solar particle event (SPE), which can threaten immediate
survival of the astronauts in case of insufficient shielding by
eliciting the acute radiation syndrome. Its symptoms depend on absorbed
total radiation dose, type of radiation, the dose distribution in the
body and the individual radiation sensitivity. After the prodromal stage
with nausea and vomiting and a subsequent symptom-free phase, depending
on dose, the hematopoietic syndrome with suppression of the acquired
immune system and thrombocytopenia (0.7-4 Sv), the gastrointestinal
tract syndrome (5-12 Sv) or the central nervous system syndrome (>
20 Sv) develop and they are accompanied by exacerbated innate immune
responses. Exposure to large SPE has to be avoided by warning systems
and stay inside a radiation shelter during the event. Treatment options
encompass e.g. the administration of colony-stimulating factors (CSF),
growth factors and blood transfusions to overcome the hematopoietic
syndrome and the administration of antibiotics against secondary
infections. A concerted action of ground-based studies and space
experiments is required to improve the radiobiological basis of space
radiation risk assessment and countermeasure development. References:
Cucinotta FA, Manuel FK, Jones J, Iszard G, Murrey J, Djojonegro B
and Wear M (2001) Space Radiation and Cataracts in Astronauts. Rad
Res 156, 460-466
---------------------------------------------------------
Title: Operational Space Weather Activities in the US
Authors: Berger, Thomas; Singer, Howard; Onsager, Terrance; Viereck,
Rodney; Murtagh, William; Rutledge, Robert
2016cosp...41E.180B Altcode:
We review the current activities in the civil operational space
weather forecasting enterprise of the United States. The NOAA/Space
Weather Prediction Center is the nation's official source of space
weather watches, warnings, and alerts, working with partners in the
Air Force as well as international operational forecast services to
provide predictions, data, and products on a large variety of space
weather phenomena and impacts. In October 2015, the White House Office
of Science and Technology Policy released the National Space Weather
Strategy (NSWS) and associated Space Weather Action Plan (SWAP) that
define how the nation will better forecast, mitigate, and respond to
an extreme space weather event. The SWAP defines actions involving
multiple federal agencies and mandates coordination and collaboration
with academia, the private sector, and international bodies to,
among other things, develop and sustain an operational space weather
observing system; develop and deploy new models of space weather
impacts to critical infrastructure systems; define new mechanisms for
the transition of research models to operations and to ensure that the
research community is supported for, and has access to, operational
model upgrade paths; and to enhance fundamental understanding of
space weather through support of research models and observations. The
SWAP will guide significant aspects of space weather operational and
research activities for the next decade, with opportunities to revisit
the strategy in the coming years through the auspices of the National
Science and Technology Council.
---------------------------------------------------------
Title: Data and Models Needed to Support Civil Aviation
Authors: Onsager, Terrance; Biesecker, D. A.; Berger, Thomas;
Rutledge, Robert
2016cosp...41E1469O Altcode:
The effective utilization of existing data and models is an important
element in advancing the goals of the COSPAR/ILWS space weather
roadmap. This is recommended to be done through innovative approaches
to data utilization, including data driving, data assimilation, and
ensemble modeling. This presentation will focus on observations and
models needed to support space weather services for civil aviation and
commercial space transportation. The service needs for aviation will be
discussed, and an overview will be given of some of the existing data
and models that can provide these services. Efforts underway to define
the requirements for real-time data and to assess current modeling
capabilities will be described. Recommendations will be offered for
internationally coordinated activities that could identify priorities
and further the roadmap goals.
---------------------------------------------------------
Title: Experience Transitioning Models and Data at the NOAA Space
Weather Prediction Center
Authors: Berger, Thomas
2016cosp...41E.181B Altcode:
The NOAA Space Weather Prediction Center has a long history of
transitioning research data and models into operations and with the
validation activities required. The first stage in this process involves
demonstrating that the capability has sufficient value to customers to
justify the cost needed to transition it and to run it continuously
and reliably in operations. Once the overall value is demonstrated,
a substantial effort is then required to develop the operational
software from the research codes. The next stage is to implement
and test the software and product generation on the operational
computers. Finally, effort must be devoted to establishing long-term
measures of performance, maintaining the software, and working with
forecasters, customers, and researchers to improve over time the
operational capabilities. This multi-stage process of identifying,
transitioning, and improving operational space weather capabilities
will be discussed using recent examples. Plans for future activities
will also be described.
---------------------------------------------------------
Title: Transitioning GONG data processing to NOAA SWPC operations
Authors: Reinard, Alysha; Marble, Andrew R.; Berger, Thomas
2016SPD....47.0205R Altcode:
The NOAA Space Weather Prediction Center (SWPC) is the nation's official
source of space weather watches, warnings, and alerts, providing 24x7
forecasting and support to critical infrastructure operators around
the world. Observations of the conditions on the Sun are crucial for
determining when and if a warning is needed. The Global Oscillation
Network Group (GONG) operated by the National Solar Observatory (NSO)
consists of six ground stations, allowing continuous observations of the
Sun. Of particular interest for space weather purposes are the H-alpha
images and magnetograms. The H-alpha data are used to identify filaments
and their eruptions, to assess active region evolution and plage extent,
and to help localize flare locations. The magnetograms are used to
identify neutral lines, to examine potential shearing areas and to
characterize the magnetic structure of active regions. GONG magnetograms
also provide the initial condition for models of solar wind expansion
through the heliosphere such as the WSA-Enlil model. Although beyond
the scope of current space weather applications, GONG helioseismology
products can be used to assess active region emergence on the far
side of the Sun and to indicate the flaring potential of a front-side
active region. These products are being examined as future tools in
flare prediction.NSO has operated GONG as a science facility since 1995
and has provided processed space weather data products to NOAA via for
the past several years. In 2014 the White House Office of Management
and Budget (OMB) requested that NOAA transition the GONG network to an
operational space weather asset in order to ensure the continued flow of
critical data for solar wind models. NSO will continue to operate and
manage the instruments and sites, but the H-alpha images and 10 minute
averaged magnetogram data will be sent directly to SWPC for processing
and use in space weather modeling. SWPC will make these data available
to NSO and the public via the new NOAA Integrated Dissemination Program
(IDP) network. We discuss the progress and details of this change.
---------------------------------------------------------
Title: Physics reach of the XENON1T dark matter experiment.
Authors: Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro,
F. D.; Anthony, M.; Arazi, L.; Arneodo, F.; Balan, C.; Barrow, P.;
Baudis, L.; Bauermeister, B.; Berger, T.; Breur, P.; Breskin, A.;
Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer,
L.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn,
A. P.; Conrad, J.; Contreras, H.; Cussonneau, J. P.; Decowski, M. P.;
de Perio, P.; Di Gangi, P.; Di Giovanni, A.; Duchovni, E.; Fattori,
S.; Ferella, A. D.; Fieguth, A.; Franco, D.; Fulgione, W.; Galloway,
M.; Garbini, M.; Geis, C.; Goetzke, L. W.; Greene, Z.; Grignon, C.;
Gross, E.; Hampel, W.; Hasterok, C.; Itay, R.; Kaether, F.; Kaminsky,
B.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch,
D.; Levinson, L.; Le Calloch, M.; Levy, C.; Lindemann, S.; Lindner,
M.; Lopes, J. A. M.; Lyashenko, A.; Macmullin, S.; Manfredini, A.;
Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Mayani, D.;
Melgarejo Fernandez, A. J.; Meng, Y.; Messina, M.; Micheneau, K.;
Miguez, B.; Molinario, A.; Murra, M.; Naganoma, J.; Oberlack, U.;
Orrigo, S. E. A.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra,
F.; Pienaar, J.; Plante, G.; Priel, N.; Rauch, L.; Reichard,
S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; dos Santos,
J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner,
J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Simgen,
H.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.;
von Sivers, M.; Wall, R.; Wang, H.; Weber, M.; Wei, Y.; Weinheimer,
C.; Wulf, J.; Zhang, Y.
2016JCAP...04..027A Altcode: 2015arXiv151207501T
The XENON1T experiment is currently in the commissioning phase at
the Laboratori Nazionali del Gran Sasso, Italy. In this article we
study the experiment's expected sensitivity to the spin-independent
WIMP-nucleon interaction cross section, based on Monte Carlo predictions
of the electronic and nuclear recoil backgrounds. <P />The total
electronic recoil background in 1 tonne fiducial volume and (1, 12)
keV electronic recoil equivalent energy region, before applying any
selection to discriminate between electronic and nuclear recoils,
is (1.80 ± 0.15) · 10<SUP>-4</SUP> (kg·day·keV)<SUP>-1</SUP>,
mainly due to the decay of <SUP>222</SUP>Rn daughters inside the xenon
target. The nuclear recoil background in the corresponding nuclear
recoil equivalent energy region (4, 50) keV, is composed of (0.6
± 0.1) (t·y)<SUP>-1</SUP> from radiogenic neutrons, (1.8 ± 0.3)
· 10<SUP>-2</SUP> (t·y)<SUP>-1</SUP> from coherent scattering of
neutrinos, and less than 0.01 (t·y)<SUP>-1</SUP> from muon-induced
neutrons. The sensitivity of XENON1T is calculated with the Profile
Likelihood Ratio method, after converting the deposited energy of
electronic and nuclear recoils into the scintillation and ionization
signals seen in the detector. We take into account the systematic
uncertainties on the photon and electron emission model, and on the
estimation of the backgrounds, treated as nuisance parameters. The
main contribution comes from the relative scintillation efficiency
Script L<SUB>eff</SUB>, which affects both the signal from WIMPs
and the nuclear recoil backgrounds. After a 2 y measurement in 1 t
fiducial volume, the sensitivity reaches a minimum cross section
of 1.6 · 10<SUP>-47</SUP> cm<SUP>2</SUP> at m<SUB>χ</SUB> = 50
GeV/c<SUP>2</SUP>.
---------------------------------------------------------
Title: The Martian surface radiation environment - a comparison of
models and MSL/RAD measurements
Authors: Matthiä, Daniel; Ehresmann, Bent; Lohf, Henning; Köhler,
Jan; Zeitlin, Cary; Appel, Jan; Sato, Tatsuhiko; Slaba, Tony; Martin,
Cesar; Berger, Thomas; Boehm, Eckart; Boettcher, Stephan; Brinza,
David E.; Burmeister, Soenke; Guo, Jingnan; Hassler, Donald M.;
Posner, Arik; Rafkin, Scot C. R.; Reitz, Günther; Wilson, John W.;
Wimmer-Schweingruber, Robert F.
2016JSWSC...6A..13M Altcode:
Context: The Radiation Assessment Detector (RAD) on the Mars Science
Laboratory (MSL) has been measuring the radiation environment on the
surface of Mars since August 6th 2012. MSL-RAD is the first instrument
to provide detailed information about charged and neutral particle
spectra and dose rates on the Martian surface, and one of the primary
objectives of the RAD investigation is to help improve and validate
current radiation transport models. Aims: Applying different numerical
transport models with boundary conditions derived from the MSL-RAD
environment the goal of this work was to both provide predictions for
the particle spectra and the radiation exposure on the Martian surface
complementing the RAD sensitive range and, at the same time, validate
the results with the experimental data, where applicable. Such validated
models can be used to predict dose rates for future manned missions as
well as for performing shield optimization studies. Methods: Several
particle transport models (GEANT4, PHITS, HZETRN/OLTARIS) were used to
predict the particle flux and the corresponding radiation environment
caused by galactic cosmic radiation on Mars. From the calculated
particle spectra the dose rates on the surface are estimated. Results:
Calculations of particle spectra and dose rates induced by galactic
cosmic radiation on the Martian surface are presented. Although good
agreement is found in many cases for the different transport codes,
GEANT4, PHITS, and HZETRN/OLTARIS, some models still show large,
sometimes order of magnitude discrepancies in certain particle
spectra. We have found that RAD data is helping to make better choices
of input parameters and physical models. Elements of these validated
models can be applied to more detailed studies on how the radiation
environment is influenced by solar modulation, Martian atmosphere
and soil, and changes due to the Martian seasonal pressure cycle. By
extending the range of the calculated particle spectra with respect
to the experimental data additional information about the radiation
environment is gained, and the contribution of different particle
species to the dose is estimated.
---------------------------------------------------------
Title: Matroshka DOSTEL measurements onboard the International Space
Station (ISS)
Authors: Labrenz, Johannes; Burmeister, Soenke; Berger, Thomas; Heber,
Bernd; Reitz, Guenther
2015JSWSC...5A..38L Altcode:
This paper presents the absorbed dose and dose equivalent rate
measurements achieved with the DOSimetry TElescope (DOSTEL) during
the two Matroshka (MTR) experiment campaigns in 2004/2005 (MTR-1)
and 2007/2008 (MTR-2B). The comparison between the inside (MTR-2B)
and outside (MTR-1) mission has shown that the shielding thickness
provided by the International Space Station (ISS) spacecraft hull has
a minor effect on the radiation exposure caused by Galactic Cosmic
Rays (GCR). The exposure varies with the solar modulation of the GCR,
too. Particles from Earth's radiation belts are effectively shielded
by the spacecraft hull, and thus the contribution to the radiation
exposure is lower for the inside measurement during MTR-2B. While
the MTR-DOSTEL absorbed dose rate shows a good agreement with passive
detectors of the MTR experiment for the MTR-2B mission phase, the MTR-1
absorbed dose rates from MTR-DOSTEL measurements are much lower than
those obtained by a nearby passive detector. Observed discrepancies
between the MTR-DOSTEL measurements and the passive detectors located
nearby could be explained by the additional exposure to an enhanced
flux of electrons trapped between L-parameter 2.5 and 3.5 caused by
solar storms in July 2004.
---------------------------------------------------------
Title: Transitioning GONG data processing to NOAA SWPC operations
Authors: Reinard, A.; Marble, A.; Hill, F.; Berger, T. E.
2015AGUFMSH21B2394R Altcode:
The NOAA Space Weather Prediction Center (SWPC) is the nation's official
source of space weather watches, warnings, and alerts, providing 24x7
forecasting and support to critical infrastructure operators around
the world. Observations of the conditions on the Sun are crucial for
determining when and if a warning is needed. The Global Oscillation
Network Group (GONG) operated by the National Solar Observatory (NSO)
consists of six ground stations, allowing continuous observations of the
Sun. Of particular interest for space weather purposes are the H-alpha
images and magnetograms. The H-alpha data are used to identify filaments
and their eruptions, to assess active region evolution and plage extent,
and to help localize flare locations. The magnetograms are used to
identify neutral lines, to examine potential shearing areas and to
characterize the magnetic structure of active regions. GONG magnetograms
also provide the initial condition for models of solar wind expansion
through the heliosphere such as the WSA-Enlil model. Although beyond
the scope of current space weather applications, GONG helioseismology
products can be used to assess active region emergence on the far
side of the Sun and to indicate the flaring potential of a front-side
active region. These products are being examined as future tools in
flare prediction. NSO has operated GONG as a science facility since
1995 and has provided processed space weather data products to NOAA
via public internet connections for the past several years. In 2014
the White House Office of Management and Budget (OMB) requested that
NOAA transition the GONG network to an operational space weather asset
in order to ensure the continued flow of critical magnetogram data
for solar wind models. NSO will continue to operate and manage the
instruments and sites, but the H-alpha images and 10 minute averaged
magnetogram data will be sent directly to SWPC for processing and use
in space weather modeling. SWPC will make these data available to NSO
and the public via the new NOAA Integrated Dissemination Program (IDP)
network. We discuss the progress and details of this change.
---------------------------------------------------------
Title: Fifty Years of Space Weather Forecasting from Boulder
Authors: Berger, T. E.
2015AGUFMSM13F..01B Altcode:
The first official space weather forecast was issued by the Space
Disturbances Laboratory in Boulder, Colorado, in 1965, ushering in
an era of operational prediction that continues to this day. Today,
the National Oceanic and Atmospheric Administration (NOAA) charters
the Space Weather Prediction Center (SWPC) as one of the nine National
Centers for Environmental Prediction (NCEP) to provide the nation's
official watches, warnings, and alerts of space weather phenomena. SWPC
is now integral to national and international efforts to predict space
weather events, from the common and mild, to the rare and extreme,
that can impact critical technological infrastructure. In 2012, the
Strategic National Risk Assessment included extreme space weather
events as low-to-medium probability phenomena that could, unlike
any other meteorogical phenomena, have an impact on the government's
ability to function. Recognizing this, the White House chartered the
Office of Science and Technology Policy (OSTP) to produce the first
comprehensive national strategy for the prediction, mitigation, and
response to an extreme space weather event. The implementation of the
National Strategy is ongoing with NOAA, its partners, and stakeholders
concentrating on the goal of improving our ability to observe, model,
and predict the onset and severity of space weather events. In addition,
work continues with the research community to improve our understanding
of the physical mechanisms - on the Sun, in the heliosphere, and in
the Earth's magnetic field and upper atmosphere - of space weather
as well as the effects on critical infrastructure such as electrical
power transmission systems. In fifty years, people will hopefully
look back at the history of operational space weather prediction and
credit our efforts today with solidifying the necessary developments
in observational systems, full-physics models of the entire Sun-Earth
system, and tools for predicting the impacts to infrastructure to
protect against any and all forms of space weather.
---------------------------------------------------------
Title: The Future of Operational Space Weather Observations
Authors: Berger, T. E.
2015AGUFMSH12A..03B Altcode:
We review the current state of operational space weather observations,
the requirements for new or evolved space weather forecasting
capablities, and the relevant sections of the new National strategy
for space weather developed by the Space Weather Operations, Research,
and Mitigation (SWORM) Task Force chartered by the Office of Science
and Technology Policy of the White House. Based on this foundation,
we discuss future space missions such as the NOAA space weather
mission to the L1 Lagrangian point planned for the 2021 time frame
and its synergy with an L5 mission planned for the same period;
the space weather capabilities of the upcoming GOES-R mission, as
well as GOES-Next possiblities; and the upcoming COSMIC-2 mission for
ionospheric observations. We also discuss the needs for ground-based
operational networks to supply mission critical and/or backup space
weather observations including the NSF GONG solar optical observing
network, the USAF SEON solar radio observing network, the USGS real-time
magnetometer network, the USCG CORS network of GPS receivers, and
the possibility of operationalizing the world-wide network of neutron
monitors for real-time alerts of ground-level radiation events.
---------------------------------------------------------
Title: Space experiment "Cellular Responses to Radiation in Space
(CELLRAD)": Hardware and biological system tests
Authors: Hellweg, Christine E.; Dilruba, Shahana; Adrian, Astrid;
Feles, Sebastian; Schmitz, Claudia; Berger, Thomas; Przybyla,
Bartos; Briganti, Luca; Franz, Markus; Segerer, Jürgen; Spitta,
Luis F.; Henschenmacher, Bernd; Konda, Bikash; Diegeler, Sebastian;
Baumstark-Khan, Christa; Panitz, Corinna; Reitz, Günther
2015LSSR....7...73H Altcode:
One factor contributing to the high uncertainty in radiation risk
assessment for long-term space missions is the insufficient knowledge
about possible interactions of radiation with other spaceflight
environmental factors. Such factors, e.g. microgravity, have to
be considered as possibly additive or even synergistic factors in
cancerogenesis. Regarding the effects of microgravity on signal
transduction, it cannot be excluded that microgravity alters the
cellular response to cosmic radiation, which comprises a complex network
of signaling pathways. <P />The purpose of the experiment ;Cellular
Responses to Radiation in Space; (CELLRAD, formerly CERASP) is to
study the effects of combined exposure to microgravity, radiation and
general space flight conditions on mammalian cells, in particular Human
Embryonic Kidney (HEK) cells that are stably transfected with different
plasmids allowing monitoring of proliferation and the Nuclear Factor
κB (NF-κB) pathway by means of fluorescent proteins. <P />The cells
will be seeded on ground in multiwell plate units (MPUs), transported
to the ISS, and irradiated by an artificial radiation source after an
adaptation period at 0 × g and 1 × g. After different incubation
periods, the cells will be fixed by pumping a formaldehyde solution
into the MPUs. Ground control samples will be treated in the same
way. For implementation of CELLRAD in the Biolab on the International
Space Station (ISS), tests of the hardware and the biological systems
were performed. The sequence of different steps in MPU fabrication
(cutting, drilling, cleaning, growth surface coating, and sterilization)
was optimized in order to reach full biocompatibility. Different
coatings of the foil used as growth surface revealed that coating
with 0.1 mg/ml poly-D-lysine supports cell attachment better than
collagen type I. The tests of prototype hardware (Science Model)
proved its full functionality for automated medium change, irradiation
and fixation of cells. Exposure of HEK cells to the β-rays emitted
by the radiation source dose-dependently decreased cell growth and
increased NF-κB activation. The signal of the fluorescent proteins
after formaldehyde fixation was stable for at least six months after
fixation, allowing storage of the MPUs after fixation for several months
before the transport back to Earth and evaluation of the fluorescence
intensity. In conclusion, these tests show the feasibility of CELLRAD
on the ISS with the currently available transport mechanisms.
---------------------------------------------------------
Title: First High-resolution Spectroscopic Observations of an Erupting
Prominence Within a Coronal Mass Ejection by the Interface Region
Imaging Spectrograph (IRIS)
Authors: Liu, Wei; De Pontieu, Bart; Vial, Jean-Claude; Title, Alan
M.; Carlsson, Mats; Uitenbroek, Han; Okamoto, Takenori J.; Berger,
Thomas E.; Antolin, Patrick
2015ApJ...803...85L Altcode: 2015arXiv150204738L
Spectroscopic observations of prominence eruptions associated with
coronal mass ejections (CMEs), although relatively rare, can provide
valuable plasma and three-dimensional geometry diagnostics. We report
the first observations by the Interface Region Imaging Spectrograph
mission of a spectacular fast CME/prominence eruption associated with
an equivalent X1.6 flare on 2014 May 9. The maximum plane-of-sky and
Doppler velocities of the eruption are 1200 and 460 km s<SUP>-1</SUP>,
respectively. There are two eruption components separated by ∼200
km s<SUP>-1</SUP> in Doppler velocity: a primary, bright component
and a secondary, faint component, suggesting a hollow, rather than
solid, cone-shaped distribution of material. The eruption involves
a left-handed helical structure undergoing counterclockwise (viewed
top-down) unwinding motion. There is a temporal evolution from upward
eruption to downward fallback with less-than-free-fall speeds and
decreasing nonthermal line widths. We find a wide range of Mg ii k/h
line intensity ratios (less than ∼2 expected for optically-thin
thermal emission): the lowest ever reported median value of 1.17
found in the fallback material, a comparably high value of 1.63 in
nearby coronal rain, and intermediate values of 1.53 and 1.41 in
the two eruption components. The fallback material exhibits a strong
(\gt 5σ ) linear correlation between the k/h ratio and the Doppler
velocity as well as the line intensity. We demonstrate that Doppler
dimming of scattered chromospheric emission by the erupted material
can potentially explain such characteristics.
---------------------------------------------------------
Title: Characteristics of Operational Space Weather Forecasting:
Observations and Models
Authors: Berger, Thomas; Viereck, Rodney; Singer, Howard; Onsager,
Terry; Biesecker, Doug; Rutledge, Robert; Hill, Steven; Akmaev,
Rashid; Milward, George; Fuller-Rowell, Tim
2015TESS....111204B Altcode:
In contrast to research observations, models and ground support
systems, operational systems are characterized by real-time data
streams and run schedules, with redundant backup systems for most
elements of the system. We review the characteristics of operational
space weather forecasting, concentrating on the key aspects of ground-
and space-based observations that feed models of the coupled Sun-Earth
system at the NOAA/Space Weather Prediction Center (SWPC). Building
on the infrastructure of the National Weather Service, SWPC is working
toward a fully operational system based on the GOES weather satellite
system (constant real-time operation with back-up satellites),
the newly launched DSCOVR satellite at L1 (constant real-time data
network with AFSCN backup), and operational models of the heliosphere,
magnetosphere, and ionosphere/thermosphere/mesophere systems run on the
Weather and Climate Operational Super-computing System (WCOSS), one of
the worlds largest and fastest operational computer systems that will
be upgraded to a dual 2.5 Pflop system in 2016. We review plans for
further operational space weather observing platforms being developed
in the context of the Space Weather Operations Research and Mitigation
(SWORM) task force in the Office of Science and Technology Policy
(OSTP) at the White House. We also review the current operational
model developments at SWPC, concentrating on the differences between
the research codes and the modified real-time versions that must run
with zero fault tolerance on the WCOSS systems. Understanding the
characteristics and needs of the operational forecasting community
is key to producing research into the coupled Sun-Earth system with
maximal societal benefit.
---------------------------------------------------------
Title: Constitutive expression of tdTomato protein as a cytotoxicity
and proliferation marker for space radiation biology
Authors: Chishti, Arif A.; Hellweg, Christine E.; Berger, Thomas;
Baumstark-Khan, Christa; Feles, Sebastian; Kätzel, Thorben; Reitz,
Günther
2015LSSR....4...35C Altcode:
The radiation risk assessment for long-term space missions requires
knowledge on the biological effectiveness of different space radiation
components, e.g. heavy ions, on the interaction of radiation and
other space environmental factors such as microgravity, and on the
physical and biological dose distribution in the human body. Space
experiments and ground-based experiments at heavy ion accelerators
require fast and reliable test systems with an easy readout for
different endpoints. In order to determine the effect of different
radiation qualities on cellular proliferation and the biological
depth dose distribution after heavy ion exposure, a stable human
cell line expressing a novel fluorescent protein was established
and characterized. tdTomato, a red fluorescent protein of the new
generation with fast maturation and high fluorescence intensity,
was selected as reporter of cell proliferation. Human embryonic kidney
(HEK/293) cells were stably transfected with a plasmid encoding tdTomato
under the control of the constitutively active cytomegalovirus (CMV)
promoter (ptdTomato-N1). The stably transfected cell line was named
HEK-ptdTomato-N1 8. This cytotoxicity biosensor was tested by ionizing
radiation (X-rays and accelerated heavy ions) exposure. As biological
endpoints, the proliferation kinetics and the cell density reached 100 h
after irradiation reflected by constitutive expression of the tdTomato
were investigated. Both were reduced dose-dependently after radiation
exposure. Finally, the cell line was used for biological weighting of
heavy ions of different linear energy transfer (LET) as space-relevant
radiation quality. The relative biological effectiveness of accelerated
heavy ions in reducing cellular proliferation peaked at an LET of 91
keV/μm. The results of this study demonstrate that the HEK-ptdTomato-N1
reporter cell line can be used as a fast and reliable biosensor system
for detection of cytotoxic damage caused by ionizing radiation.
---------------------------------------------------------
Title: Photochemical studies in low Earth orbit for organic
compounds related to small bodies, Titan and Mars. Current and
future facilities.
Authors: Cottin, H.; Saiagh, K.; Nguyen, D.; Grand, N.; Bénilan, Y.;
Cloix, M.; Coll, P.; Gazaux, M. -C.; Fray, N.; Khalaf, D.; Raulin,
F.; Stalort, F.; Carrasco, N.; Szopa, C.; Chaput, D.; Bertrand, M.;
Westall, F.; Mattioda, A.; Quinn, R.; Ricco, A.; Santos, O.; Baratta,
G. A.; Strazzulla, G.; Palumbo, M. E.; Le Postollec, A.; Dobrijevic,
M.; Coussot, G.; Vigier, F.; Vandenabeele-Trambouze, O.; Incerti,
S.; Berger, T.
2015BSRSL..84...60C Altcode:
The study of the evolution of organic matter subjected to space
conditions, and more specifically to solar photons in the vacuum
ultraviolet range (120-200 nm) has been undertaken in low Earth Orbit
since the 90's, and implemented on various space platforms. The
most recent exposure facilities are BIOPAN outside the Russian
automatic capsules FOTON, and EXPOSE-E & -R (1&2) outside
the International Space Station. They allow the photolysis of many
different samples simultaneously, and provide us with valuable data
about the formation and evolution of organic matter in the Solar System
(meteorites, comets, Titan's atmosphere, the Martian surface...) and
in the Interstellar Medium. They have been used by European teams in
the recent past(ORGANIC on BIOPAN V-FOTON M2 and UVolution on BIOPAN
VI-FOTON M3, PROCESS on EXPOSE-E, AMINO and ORGANICS on EXPOSE-R),
and a new EXPOSE set is currently exposed outside the ISS (PSS
on EXPOSE-R2). These existing tools are very valuable; however,
they have significant limitations that limit their capabilities and
scientific return. One of the most critical issues for current studies
is the lack of any in-situ analysis of the evolution of the samples
as a function of time. Only two measurements are available for the
experiment: one before and one after the exposure. A significant step
forward has been achieved with the O/OREOS NASA nanosatellite and the
OREOcube ESA project with onboard UV-visible measurements. However, for
organic samples, following the evolution of the samples would be more
informative and provide greater insight with infrared measurements,
which display specific patterns characteristic of major organic
functionalities in the mid-infrared range (4000-1000 cm-1).
---------------------------------------------------------
Title: GRB 150212A: Skynet DSO14/GORT observations.
Authors: Trotter, A.; Reichart, D.; Lacluyze, A.; Haislip, J.; Smith,
A.; Caton, D.; Hawkins, L.; McLin, K.; Cominsky, L.; Aji, A.; Berger,
T.; Dow, A.; Foster, A.; Frank, N.; Ivarsen, K.; Maples, M.; Moore,
J.; Nysewander, M.; Salemi, C.; Crain, J. A.
2015GCN.17458....1T Altcode: 2015GCN..17458...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 150314A: Skynet Yerkes-41 Observations of the Optical
Afterglow.
Authors: Trotter, A.; Reichart, D.; Lacluyze, A.; Haislip, J.;
Hoette, V.; Cudworth, K.; Harper, D.; Kron, R.; Linder, T.; Russell,
R.; Struble, E.; Aji, A.; Berger, T.; Dow, A.; Foster, A.; Frank,
N.; Ivarsen, K.; Maples, M.; Moore, J.; Nysewander, M.; Salemi, C.;
Crain, J. A.
2015GCN.17577....1T Altcode: 2015GCN..17577...1T
No abstract at ADS
---------------------------------------------------------
Title: Mars methane detection and variability at Gale crater
Authors: Webster, Christopher R.; Mahaffy, Paul R.; Atreya, Sushil K.;
Flesch, Gregory J.; Mischna, Michael A.; Meslin, Pierre-Yves; Farley,
Kenneth A.; Conrad, Pamela G.; Christensen, Lance E.; Pavlov, Alexander
A.; Martín-Torres, Javier; Zorzano, María-Paz; McConnochie, Timothy
H.; Owen, Tobias; Eigenbrode, Jennifer L.; Glavin, Daniel P.; Steele,
Andrew; Malespin, Charles A.; Archer, P. Douglas; Sutter, Brad; Coll,
Patrice; Freissinet, Caroline; McKay, Christopher P.; Moores, John E.;
Schwenzer, Susanne P.; Bridges, John C.; Navarro-Gonzalez, Rafael;
Gellert, Ralf; Lemmon, Mark T.; MSL Science Team; Abbey, William;
Achilles, Cherie; Agard, Christophe; Alexandre Alves Verdasca, José;
Anderson, Dana; Anderson, Robert C.; Anderson, Ryan B.; Appel, Jan
Kristoffer; Archer, Paul Douglas; Arevalo, Ricardo; Armiens-Aparicio,
Carlos; Arvidson, Raymond; Atlaskin, Evgeny; Atreya, Andrew Sushil;
Azeez, Aubrey Sherif; Baker, Burt; Baker, Michael; Balic-Zunic,
Tonci; Baratoux, David; Baroukh, Julien; Barraclough, Bruce; Battalio,
Michael; Beach, Michael; Bean, Keri; Beck, Pierre; Becker, Richard;
Beegle, Luther; Behar, Alberto; Belgacem, Inès; Bell, James F., III;
Bender, Steven; Benna, Mehdi; Bentz, Jennifer; Berger, Jeffrey; Berger,
Thomas; Berlanga, Genesis; Berman, Daniel; Bish, David; Blacksberg,
Jordana; Blake, David F.; José Blanco, Juan; Blaney, Ávalos Diana;
Blank, Jennifer; Blau, Hannah; Bleacher, Lora; Boehm, Eckart; Bonnet,
Jean-Yves; Botta, Oliver; Böttcher, Stephan; Boucher, Thomas; Bower,
Hannah; Boyd, Nick; Boynton, William; Braswell, Shaneen; Breves,
Elly; Bridges, John C.; Bridges, Nathan; Brinckerhoff, William;
Brinza, David; Bristow, Thomas; Brunet, Claude; Brunner, Anna;
Brunner, Will; Buch, Arnaud; Bullock, Mark; Burmeister, Sönke;
Burton, John; Buz, Jennifer; Cabane, Michel; Calef, Fred; Cameron,
James; Campbell, John L.; Cantor, Bruce; Caplinger, Michael; Clifton,
Carey, Jr.; Caride Rodríguez, Javier; Carmosino, Marco; Carrasco
Blázquez, Isaías; Cavanagh, Patrick; Charpentier, Antoine; Chipera,
Steve; Choi, David; Christensen, Lance; Clark, Benton; Clegg, Sam;
Cleghorn, Timothy; Cloutis, Ed; Cody, George; Coll, Patrice; Coman,
Ecaterina I.; Conrad, Pamela; Coscia, David; Cousin, Agnès; Cremers,
David; Crisp, Joy A.; Cropper, Kevin; Cros, Alain; Cucinotta, Francis;
d'Uston, Claude; Davis, Scott; Day, Mackenzie; Daydou, Yves; DeFlores,
Lauren; Dehouck, Erwin; Delapp, Dorothea; DeMarines, Julia; Dequaire,
Tristan; Des Marais, David; Desrousseaux, Roch; Dietrich, William;
Dingler, Robert; Domagal-Goldman, Shawn; Donny, Christophe; Downs,
Robert; Drake, Darrell; Dromart, Gilles; Dupont, Audrey; Duston,
Brian; Dworkin, Jason P.; Dyar, M. Darby; Edgar, Lauren; Edgett,
Kenneth; Edwards, Christopher S.; Edwards, Laurence; Edwards, Peter;
Ehlmann, Bethany; Ehresmann, Bent; Eigenbrode, Jennifer; Elliott,
Beverley; Elliott, Harvey; Ewing, Ryan; Fabre, Cécile; Fairén,
Alberto; Fairén, Alberto; Farley, Kenneth; Farmer, Jack; Fassett,
Caleb; Favot, Laurent; Fay, Donald; Fedosov, Fedor; Feldman, Jason;
Fendrich, Kim; Fischer, Erik; Fisk, Martin; Fitzgibbon, Mike; Flesch,
Gregory; Floyd, Melissa; Flückiger, Lorenzo; Forni, Olivier; Fox,
Valerie; Fraeman, Abigail; Francis, Raymond; François, Pascaline;
Franz, Heather; Freissinet, Caroline; French, Katherine Louise;
Frydenvang, Jens; Garvin, James; Gasnault, Olivier; Geffroy, Claude;
Gellert, Ralf; Genzer, Maria; Getty, Stephanie; Glavin, Daniel;
Godber, Austin; Goesmann, Fred; Goetz, Walter; Golovin, Dmitry; Gómez
Gómez, Felipe; Gómez-Elvira, Javier; Gondet, Brigitte; Gordon,
Suzanne; Gorevan, Stephen; Graham, Heather; Grant, John; Grinspoon,
David; Grotzinger, John; Guillemot, Philippe; Guo, Jingnan; Gupta,
Sanjeev; Guzewich, Scott; Haberle, Robert; Halleaux, Douglas; Hallet,
Bernard; Hamilton, Victoria; Hand, Kevin; Hardgrove, Craig; Hardy,
Keian; Harker, David; Harpold, Daniel; Harri, Ari-Matti; Harshman,
Karl; Hassler, Donald; Haukka, Harri; Hayes, Alexander; Herkenhoff,
Kenneth; Herrera, Paul; Hettrich, Sebastian; Heydari, Ezat; Hipkin,
Victoria; Hoehler, Tori; Hollingsworth, Jeff; Hudgins, Judy; Huntress,
Wesley; Hurowitz, Joel; Hviid, Stubbe; Iagnemma, Karl; Indyk, Stephen;
Israël, Guy; Jackson, Ryan Steele; Jacob, Samantha; Jakosky, Bruce;
Jean-Rigaud, Laurent; Jensen, Elsa; Kløvgaard Jensen, Jaqueline;
Johnson, Jeffrey R.; Johnson, Micah; Johnstone, Stephen; Jones,
Andrea; Jones, John H.; Joseph, Jonathan; Joulin, Mélissa; Jun,
Insoo; Kah, Linda C.; Kahanpää, Henrik; Kahre, Melinda; Kaplan,
Hannah; Karpushkina, Natalya; Kashyap, Srishti; Kauhanen, Janne;
Keely, Leslie; Kelley, Simon; Kempe, Fabian; Kemppinen, Osku; Kennedy,
Megan R.; Keymeulen, Didier; Kharytonov, Alexander; Kim, Myung-Hee;
Kinch, Kjartan; King, Penelope; Kirk, Randolph; Kirkland, Laurel;
Kloos, Jacob; Kocurek, Gary; Koefoed, Asmus; Köhler, Jan; Kortmann,
Onno; Kotrc, Benjamin; Kozyrev, Alexander; Krau, Johannes; Krezoski,
ß. Gillian; Kronyak, Rachel; Krysak, Daniel; Kuzmin, Ruslan; Lacour,
Jean-Luc; Lafaille, Vivian; Langevin, Yves; Lanza, Nina; Lapôtre,
Mathieu; Larif, Marie-France; Lasue, Jérémie; Le Deit, Laetitia;
Le Mouélic, Stéphane; Lee, Ella Mae; Lee, Qiu-Mei; Lee, Rebekka;
Lees, David; Lefavor, Matthew; Lemmon, Mark; Lepinette, Alain;
Lepore, Malvitte Kate; Leshin, Laurie; Léveillé, Richard; Lewin,
Éric; Lewis, Kevin; Li, Shuai; Lichtenberg, Kimberly; Lipkaman,
Leslie; Lisov, Denis; Little, Cynthia; Litvak, Maxim; Liu, Lu; Lohf,
Henning; Lorigny, Eric; Lugmair, Günter; Lundberg, Angela; Lyness,
Eric; Madsen, Morten Bo; Magee, Angela; Mahaffy, Paul; Maki, Justin;
Mäkinen, Teemu; Malakhov, Alexey; Malespin, Charles; Malin, Michael;
Mangold, Nicolas; Manhes, Gerard; Manning, Heidi; Marchand, Geneviève;
Marín Jiménez, Mercedes; Martín García, César; Martin, David
K.; Martin, Mildred; Martin, Peter; Martínez Martínez, Germán;
Martínez-Frías, Jesús; Martín-Sauceda, Jaime; Martín-Soler,
Martín Javier; Martín-Torres, F. Javier; Mason, Emily; Matthews,
Tristan; Matthiä, Daniel; Mauchien, Patrick; Maurice, Sylvestre;
McAdam, Amy; McBride, Marie; McCartney, Elaina; McConnochie, Timothy;
McCullough, Emily; McEwan, Ian; McKay, Christopher; McLain, Hannah;
McLennan, Scott; McNair, Sean; Melikechi, Noureddine; Mendaza de
Cal, Teresa; Merikallio, Sini; Merritt, Sean; Meslin, Pierre-Yves;
Meyer, Michael; Mezzacappa, Alissa; Milkovich, Sarah; Millan, Maëva;
Miller, Hayden; Miller, Kristen; Milliken, Ralph; Ming, Douglas;
Minitti, Michelle; Mischna, Michael; Mitchell, Julie; Mitrofanov,
Igor; Moersch, Jeffrey; Mokrousov, Maxim; Molina, Antonio; Moore,
Jurado Casey; Moores, John E.; Mora-Sotomayor, Luis; Moreno, Gines;
Morookian, John Michael; Morris, Richard V.; Morrison, Shaunna;
Mousset, Valérie; Mrigakshi, Alankrita; Mueller-Mellin, Reinhold;
Muller, Jan-Peter; Muñoz Caro, Guillermo; Nachon, Marion; Nastan,
Abbey; Navarro López, Sara; Navarro González, Rafael; Nealson,
Kenneth; Nefian, Ara; Nelson, Tony; Newcombe, Megan; Newman, Claire;
Newsom, Horton; Nikiforov, Sergey; Nikitczuk, Matthew; Niles, Paul;
Nixon, Brian; Noblet, Audrey; Noe, Eldar; Nolan, Dobrea Thomas;
Oehler, Dorothy; Ollila, Ann; Olson, Timothy; Orthen, Tobias;
Owen, Tobias; Ozanne, Marie; de Pablo Hernández, Miguel Ángel;
Pagel, Hannah; Paillet, Alexis; Pallier, Etienne; Palucis, Marisa;
Parker, Timothy; Parot, Yann; Parra, Alex; Patel, Kiran; Paton, Mark;
Paulsen, Gale; Pavlov, Alexander; Pavri, Betina; Peinado-González,
Verónica; Pepin, Robert; Peret, Laurent; Pérez, René; Perrett,
Glynis; Peterson, Joseph; Pilorget, Cedric; Pinet, Patrick; Pinnick,
Veronica; Pla-García, Jorge; Plante, Ianik; Poitrasson, Franck;
Polkko, Jouni; Popa, Radu; Posiolova, Liliya; Posner, Arik; Pradler,
Irina; Prats, Benito; Prokhorov, Vasily; Raaen, Eric; Radziemski, Leon;
Rafkin, Scot; Ramos, Miguel; Rampe, Elizabeth; Rapin, William; Raulin,
François; Ravine, Michael; Reitz, Günther; Ren, Jun; Rennó, Nilton;
Rice, Melissa; Richardson, Mark; Ritter, Birgit; Rivera-Hernández,
Frances; Robert, François; Robertson, Kevin; Rodriguez Manfredi,
José Antonio; José Romeral-Planelló, Julio; Rowland, Scott; Rubin,
David; Saccoccio, Muriel; Said, David; Salamon, Andrew; Sanin, Anton;
Sans Fuentes, Sara Alejandra; Saper, Lee; Sarrazin, Philippe; Sautter,
Violaine; Savijärvi, Hannu; Schieber, Juergen; Schmidt, Mariek;
Schmidt, Walter; Scholes, Daniel; Schoppers, Marcel; Schröder,
Susanne; Schwenzer, Susanne P.; Sciascia Borlina, Cauê; Scodary,
Anthony; Sebastián Martínez, Eduardo; Sengstacken, Aaron; Shechet,
Jennifer Griffes; Shterts, Ruslan; Siebach, Kirsten; Siili, Tero;
Simmonds, John J.; Sirven, Jean-Baptiste; Slavney, Susan; Sletten,
Ronald; Smith, Michael D.; Sobron Sanchez, Pablo; Spanovich, Nicole;
Spray, John; Spring, Justin; Squyres, Steven; Stack, Katie; Stalport,
Fabien; Starr, Richard; Stein, Andrew Steele Thomas; Stern, Jennifer;
Stewart, Noel; Stewart, Wayne; Stipp, Svane Susan Louise; Stoiber,
Kevin; Stolper, Edward; Sucharski, Robert; Sullivan, Robert; Summons,
Roger; Sumner, Dawn Y.; Sun, Vivian; Supulver, Kimberley; Sutter, Brad;
Szopa, Cyril; Tan, Florence; Tate, Christopher; Teinturier, Samuel;
ten Kate, Inge Loes; Thomas, Alicia; Thomas, Peter; Thompson, Lucy;
Thuillier, Franck; Thulliez, Emmanual; Tokar, Robert; Toplis, Michael;
de la Torre Juárez, Manuel; Torres Redondo, Josefina; Trainer,
Melissa; Treiman, Allan; Tretyakov, Vladislav; Ullán-Nieto, Aurora;
Urqui-O'Callaghan, Roser; Valentín-Serrano, Patricia; Van Beek,
Jason; Van Beek, Tessa; VanBommel, Scott; Vaniman, David; Varenikov,
Alexey; Vasavada, Ashwin R.; Vasconcelos, Paulo; de Vicente-Retortillo
Rubalcaba, Álvaro; Vicenzi, Edward; Vostrukhin, Andrey; Voytek,
Mary; Wadhwa, Meenakshi; Ward, Jennifer; Watkins, Jessica; Webster,
Christopher R.; Weigle, Gerald; Wellington, Danika; Westall, Frances;
Wiens, Roger; Wilhelm, Mary Beth; Williams, Amy; Williams, Joshua;
Williams, Rebecca; Williams, Richard B.; Williford, Kenneth; Wilson,
Michael A.; Wilson, Sharon A.; Wimmer-Schweingruber, Robert; Wolff,
Michael; Wong, Michael; Wray, James; Yana, Charles; Yen, Albert;
Yingst, Aileen; Zeitlin, Cary; Zimdar, Robert; Zorzano Mier, María-Paz
2015Sci...347..415W Altcode:
Reports of plumes or patches of methane in the martian atmosphere
that vary over monthly time scales have defied explanation to
date. From in situ measurements made over a 20-month period by the
tunable laser spectrometer of the Sample Analysis at Mars instrument
suite on Curiosity at Gale crater, we report detection of background
levels of atmospheric methane of mean value 0.69 ± 0.25 parts per
billion by volume (ppbv) at the 95% confidence interval (CI). This
abundance is lower than model estimates of ultraviolet degradation
of accreted interplanetary dust particles or carbonaceous chondrite
material. Additionally, in four sequential measurements spanning a
60-sol period (where 1 sol is a martian day), we observed elevated
levels of methane of 7.2 ± 2.1 ppbv (95% CI), implying that Mars is
episodically producing methane from an additional unknown source.
---------------------------------------------------------
Title: GRB 150318A: Skynet PROMPT-CTIO Observations.
Authors: Trotter, A.; Reichart, D.; Haislip, J.; Aji, A.; Beauchemin,
R.; Berger, T.; Dow, A.; Foster, A.; Frank, N.; Hinckle, M.; Ivarsen,
K.; Lacluyze, A.; Maples, M.; Moore, J.; Nysewander, M.; Salemi, C.;
Zbinden, L.; Crain, J. A.
2015GCN.17605....1T Altcode: 2015GCN..17605...1T
No abstract at ADS
---------------------------------------------------------
Title: Cosmic radiation exposure of biological test systems during
the EXPOSE-R mission
Authors: Berger, Thomas; Hajek, Michael; Bilski, Pawel
2015IJAsB..14...27B Altcode:
In the frame of the EXPOSE-R mission outside the Russian Zvezda Module
of the International Space Station (ISS) passive thermoluminescence
dosimeters were applied to measure the radiation exposure of biological
samples. The detectors were located beneath the sample carriers to
determine the dose levels for maximum shielding. The dose measured
beneath the sample carriers varied between 317 +/- 10 and 230 +/-
2 mGy, which amount to an average dose rate of 381 +/- 12 and 276 +/-
2 μGy d<SUP>-1</SUP>. These values are close to those assessed for the
interior of the ISS and reflect the high shielding of the biological
experiments within the EXPOSE-R facility. As a consequence of the
high shielding (several g cm<SUP>-2</SUP>), the biological samples
were predominantly exposed to galactic cosmic heavy ions and trapped
protons in the Earth's radiation belts, whereas the trapped electrons
did not reach the samples.
---------------------------------------------------------
Title: Estimating the temporal cutoff-rigidity variations and their
implication on manned space missions
Authors: Herbst, K.; Labrenz, J.; Kopp, A.; Heber, B.; Burmeister,
S.; Berger, T.
2014AGUFMSM31A4156H Altcode:
Using the PLANETOCOSMICS code the vertical cutoff rigidity or
equivalently the minimum energy a particle must have in order to reach a
given location on Earth is calculated. The program allows investigations
that depend on the Earth's magnetic field strength and geometry as a
function of time. Today it is well known that the magnetic field is the
subject of temporal variations on long as well as short time-scales
which reflects itself, e.g., in the global vertical cutoff-rigidity
distribution at 20 km altitude (see Herbst et al., 2013). Focusing
on the changes during the era of manned space missions (1961-2014)
we extend our analysis of the vertical cutoff rigidity variations to
about 450 km i.e. to the International Space Station (ISS) orbit. The
outcome of this analysis will be compared to measurements of the
DOSimetry TELescope (DOSTEL), an instrument that has been operational
for several time periods onboard the ISS, allowing to determine the
response function of the instrument. Using the Force-Field parameter
derived from neutron monitors (see Usoskin et al., 2011) we will
present maps of DOSTEL measurements for more than 50 years that are
caused by galactic cosmic ray variations along hypothetical ISS orbits.
---------------------------------------------------------
Title: First High-resolution Spectroscopic Observations by IRIS
of a Fast, Helical Prominence Eruption Associated with a Coronal
Mass Ejection
Authors: Liu, W.; De Pontieu, B.; Okamoto, T. J.; Vial, J. C.; Title,
A. M.; Antolin, P.; Berger, T. E.; Uitenbroek, H.
2014AGUFMSH11D..04L Altcode:
High-resolution spectroscopic observations of prominence eruptions and
associated coronal mass ejections (CMEs) are rare but can provide
valuable plasma and energy diagnostics. New opportunities have
recently become available with the advent of the Interface Region
Imaging Spectrograph (IRIS) mission equipped with high resolution of
0.33-0.4 arcsec in space and 1 km/s in velocity, together with the
Hinode Solar Optical Telescope of 0.2 arcsec spatial resolution. We
report the first result of joint IRIS-Hinode observations of a
spectacular prominence eruption occurring on 2014-May-09. IRIS
detected a maximum redshift of 450 km/s, which, combined with the
plane-of-sky speed of 800 km/s, gives a large velocity vector of 920
km/s at 30 degrees from the sky plane. This direction agrees with the
source location at 30 degrees behind the limb observed by STEREO-A
and indicates a nearly vertical ejection. We found two branches of
redshifts separated by 200 km/s appearing in all strong lines at
chromospheric to transition-region temperatures, including Mg II k/h,
C II, and Si IV, suggesting a hollow, rather than solid, cone in the
velocity space of the ejected material. Opposite blue- and redshifts
on the two sides of the prominence exhibit corkscrew variations both
in space and time, suggestive of unwinding rotations of a left-handed
helical flux rope. Some erupted material returns as nearly streamline
flows, exhibiting distinctly narrow line widths (~10 km/s), about
50% of those of the nearby coronal rain at the apexes of coronal
loops, where the rain material is initially formed out of cooling
condensation. We estimate the mass and kinetic energy of the ejected
and returning material and compare them with those of the associated
CME. We will discuss the implications of these observations for CME
initiation mechanisms.
---------------------------------------------------------
Title: The Daniel K. Inouye Solar Telescope: A Project Update.
Authors: Rimmele, T.; Berger, T.; McMullin, J.; Warner, M.; Casinsi,
R.; Kuhn, J.; Lin, H.; Woeger, F.; Schmidt, W.; Tritschler, A.;
Inouye, Daniel K.; Solar Telescope Team
2014amos.confE..43R Altcode:
The Advanced Technology Solar Telescope will be the largest solar
facility ever built. Designed and developed to meet the needs of
critical high resolution and high sensitivity spectral and polarimetric
observations of the sun, this facility will support key experiments
for the study of solar magnetism and its influence on the solar wind,
flares, coronal mass ejections and solar irradiance variability. The
4-meter diameter facility will operate over a broad wavelength range
(0.35 to 28 microns), using state-of-the-art adaptive optics systems to
provide diffraction limited imaging and the ability to resolve features
approximately 20 km on the Sun. Five first light instruments will be
available at the start of operations. Key subsystems have been designed
and fabrication is well underway, including the site construction,
which began in December 2012. We provide an update on the development
of the facilities both on site at the Haleakala Observatories in Maui
and the development of components around the world. We present the
overall construction and integration schedule leading to the start of
operations in mid-2019 and touch on operations aspects.
---------------------------------------------------------
Title: Construction status of the Daniel K. Inouye Solar Telescope
Authors: McMullin, Joseph P.; Rimmele, Thomas R.; Martínez Pillet,
Valentin; Berger, Thomas E.; Casini, Roberto; Craig, Simon C.; Elmore,
David F.; Goodrich, Bret D.; Hegwer, Steve L.; Hubbard, Robert P.;
Johansson, Erik M.; Kuhn, Jeffrey R.; Lin, Haosheng; McVeigh, William;
Schmidt, Wolfgang; Shimko, Steve; Tritschler, Alexandra; Warner,
Mark; Wöger, Friedrich
2014SPIE.9145E..25M Altcode:
The Daniel K. Inouye Solar Telescope (DKIST, renamed in December 2013
from the Advanced Technology Solar Telescope) will be the largest
solar facility built when it begins operations in 2019. Designed
and developed to meet the needs of critical high resolution and high
sensitivity spectral and polarimetric observations of the Sun, the
observatory will enable key research for the study of solar magnetism
and its influence on the solar wind, flares, coronal mass ejections
and solar irradiance variations. The 4-meter class facility will
operate over a broad wavelength range (0.38 to 28 microns, initially
0.38 to 5 microns), using a state-of-the-art adaptive optics system to
provide diffraction-limited imaging and the ability to resolve features
approximately 25 km on the Sun. Five first-light instruments will be
available at the start of operations: Visible Broadband Imager (VBI;
National Solar Observatory), Visible SpectroPolarimeter (ViSP; NCAR High
Altitude Observatory), Visible Tunable Filter (VTF; Kiepenheuer Institut
für Sonnenphysik), Diffraction Limited Near InfraRed SpectroPolarimeter
(DL-NIRSP; University of Hawai'i, Institute for Astronomy) and the
Cryogenic Near InfraRed SpectroPolarimeter (Cryo-NIRSP; University of
Hawai'i, Institute for Astronomy). As of mid-2014, the key subsystems
have been designed and fabrication is well underway, including the
site construction, which began in December 2012. We provide an update
on the development of the facilities both on site at the Haleakalā
Observatories on Maui and the development of components around the
world. We present the overall construction and integration schedule
leading to the handover to operations in mid 2019. In addition, we
outline the evolving challenges being met by the project, spanning the
full spectrum of issues covering technical, fiscal, and geographical,
that are specific to this project, though with clear counterparts to
other large astronomical construction projects.
---------------------------------------------------------
Title: The Interface Region Imaging Spectrograph (IRIS)
Authors: De Pontieu, B.; Title, A. M.; Lemen, J. R.; Kushner, G. D.;
Akin, D. J.; Allard, B.; Berger, T.; Boerner, P.; Cheung, M.; Chou,
C.; Drake, J. F.; Duncan, D. W.; Freeland, S.; Heyman, G. F.; Hoffman,
C.; Hurlburt, N. E.; Lindgren, R. W.; Mathur, D.; Rehse, R.; Sabolish,
D.; Seguin, R.; Schrijver, C. J.; Tarbell, T. D.; Wülser, J. -P.;
Wolfson, C. J.; Yanari, C.; Mudge, J.; Nguyen-Phuc, N.; Timmons,
R.; van Bezooijen, R.; Weingrod, I.; Brookner, R.; Butcher, G.;
Dougherty, B.; Eder, J.; Knagenhjelm, V.; Larsen, S.; Mansir, D.;
Phan, L.; Boyle, P.; Cheimets, P. N.; DeLuca, E. E.; Golub, L.;
Gates, R.; Hertz, E.; McKillop, S.; Park, S.; Perry, T.; Podgorski,
W. A.; Reeves, K.; Saar, S.; Testa, P.; Tian, H.; Weber, M.; Dunn, C.;
Eccles, S.; Jaeggli, S. A.; Kankelborg, C. C.; Mashburn, K.; Pust, N.;
Springer, L.; Carvalho, R.; Kleint, L.; Marmie, J.; Mazmanian, E.;
Pereira, T. M. D.; Sawyer, S.; Strong, J.; Worden, S. P.; Carlsson,
M.; Hansteen, V. H.; Leenaarts, J.; Wiesmann, M.; Aloise, J.; Chu,
K. -C.; Bush, R. I.; Scherrer, P. H.; Brekke, P.; Martinez-Sykora,
J.; Lites, B. W.; McIntosh, S. W.; Uitenbroek, H.; Okamoto, T. J.;
Gummin, M. A.; Auker, G.; Jerram, P.; Pool, P.; Waltham, N.
2014SoPh..289.2733D Altcode: 2014arXiv1401.2491D; 2014SoPh..tmp...25D
The Interface Region Imaging Spectrograph (IRIS) small explorer
spacecraft provides simultaneous spectra and images of the photosphere,
chromosphere, transition region, and corona with 0.33 - 0.4 arcsec
spatial resolution, two-second temporal resolution, and 1 km
s<SUP>−1</SUP> velocity resolution over a field-of-view of up to
175 arcsec × 175 arcsec. IRIS was launched into a Sun-synchronous
orbit on 27 June 2013 using a Pegasus-XL rocket and consists of a
19-cm UV telescope that feeds a slit-based dual-bandpass imaging
spectrograph. IRIS obtains spectra in passbands from 1332 - 1358 Å,
1389 - 1407 Å, and 2783 - 2834 Å, including bright spectral lines
formed in the chromosphere (Mg II h 2803 Å and Mg II k 2796 Å) and
transition region (C II 1334/1335 Å and Si IV 1394/1403 Å). Slit-jaw
images in four different passbands (C II 1330, Si IV 1400, Mg II k
2796, and Mg II wing 2830 Å) can be taken simultaneously with spectral
rasters that sample regions up to 130 arcsec × 175 arcsec at a variety
of spatial samplings (from 0.33 arcsec and up). IRIS is sensitive to
emission from plasma at temperatures between 5000 K and 10 MK and will
advance our understanding of the flow of mass and energy through an
interface region, formed by the chromosphere and transition region,
between the photosphere and corona. This highly structured and dynamic
region not only acts as the conduit of all mass and energy feeding
into the corona and solar wind, it also requires an order of magnitude
more energy to heat than the corona and solar wind combined. The
IRIS investigation includes a strong numerical modeling component
based on advanced radiative-MHD codes to facilitate interpretation of
observations of this complex region. Approximately eight Gbytes of data
(after compression) are acquired by IRIS each day and made available
for unrestricted use within a few days of the observation.
---------------------------------------------------------
Title: The Rayleigh-Taylor Instability and the role of Prominences
in the Chromosphere-Corona Mass Cycle
Authors: Berger, Thomas; Liu, Wei; Hillier, Andrew; Scullion, Eamon;
Low, Boon Chye
2014AAS...22421201B Altcode:
We review recent results in the study of so-called "prominence
bubbles", a buoyant instability discovered in quiescent solar
prominences by the Hinode/SOT instrument in 2007. Analysis of the
plasma flows along the boundary of the bubbles indicates that shear
flows leading to Kelvin-Helmholtz instability waves can develop into
the seed perturbations triggering the Rayleigh-Taylor instability. The
non-linear phase of the RT instability leads to the formation of large
turbulent plumes that transport the bubble plasma (and presumably
magnetic flux) into the overlying coronal flux rope. We propose that
the upward turbulent transport of hot bubble plasma and the downflows
of cooler chromospheric plasma in the prominence are related aspects
of a large-scale "chromosphere-corona mass cycle" in which hot plasma
and magnetic flux and helicity from the chromosphere are transported
upwards while the cooler prominence plasma downflows, which decouple
from the magnetic field they are originally frozen-into, represent
the condensation return flows of the cycle. This cycling enables a
mechanism by which magnetic flux and helicity build up in the coronal
flux rope while mass drains out of the flux rope, eventually triggering
a "loss of confinement" eruption in the form of a CME.
---------------------------------------------------------
Title: Evidence of Magnetic Reconnection Involving Partially Ionized
Coronal Rain near Null Points Observed by SDO/AIA and IRIS
Authors: Liu, Wei; Antolin, Patrick; Sun, Xudong; Berger, Thomas E.
2014shin.confE..50L Altcode:
Coronal rain is cool, partially ionized material formed in the hot,
fully ionized corona. We report a newly discovered class of coronal
rain formed near cusp-shaped portions of coronal loops, indicative
of topological null points. We present evidence of cross-field flows
associated with magnetic reconnection near such null points from
SDO/AIA and IRIS observations, investigate the responsible magnetic
environment, and infer clues to where and when catastrophic cooling
take place to produce coronal rain. We also discuss the implications
of such a cooling process for the enigmatic coronal heating mechanisms
(e.g., Antolin et al. 2010) and compare transient coronal rain and
persistent prominence downflows.
---------------------------------------------------------
Title: IRIS Observations of Coronal Rain and Prominences: Return
Flows of the Chromosphere-Corona Mass Cycle
Authors: Liu, Wei; Berger, Thomas; Antolin, Patrick; Schrijver, Karel
2014AAS...22431303L Altcode:
It has recently been recognized that a mass cycle (e.g., Berger
et al. 2011; McIntosh et al. 2012) between the hot, tenuous solar
corona and the cool, dense chromosphere underneath it plays an
important role in the mass budget and dynamic evolution of the solar
atmosphere. Although the corona ultimately loses mass through the solar
wind and coronal mass ejections, a fraction of its mass returns to the
chromosphere in coronal rain, downflows of prominences, and other as-yet
unidentified processes. We present here analysis of joint observations
of IRIS, SDO/AIA, and Hinode/SOT of such phenomena. By utilizing the
wide temperature coverage (logT: 4 - 7) provided by these instruments
combined, we track the coronal cooling sequence (e.g., Schrijver 2001;
Liu et al. 2012; Berger et al. 2012) leading to the formation of such
material at transition region or chromospheric temperatures (logT: 4 -
5) in the million-degree corona. We compare the cooling times with those
expected from the radiative cooling instability. We also measure the
kinematics and densities of such downflows and infer their mass fluxes,
which are compared to the upward mass fluxes into the corona, e.g.,
those associated with spicules and flux emergence. Special attention is
paid to coronal rain formed near cusp-shaped portions of coronal loops,
funnel-shaped prominences at dips of coronal loops, and their respective
magnetic environments. With the information about where and when such
catastrophic cooling events take place, we discuss the implications for
the enigmatic coronal heating mechanisms (e.g., Antolin et al. 2010).
---------------------------------------------------------
Title: Dose and dose equivalent and related risk during a cruise
to Mars
Authors: Reitz, Günther; Matthiae, Daniel; Berger, Thomas; Zeitlin,
Cary; Hassler, Don; Rafkin, Scott; Ehresmann, Bent; Cucinotta, Francis;
Wimmer-Schweingruber, Robert; Boehm, Eckart; Burmeister, Soenke; Guo,
Jingnan; Koehler, jan; Martin, Cesar; Boettcher, Stephan; Brinza,
David; Posner, Arik
2014EGUGA..1616162R Altcode:
The radiation exposure in space can be estimated with numerical
simulations applying different models for the galactic cosmic
rays (GCR) irradiating a defined shielding geometry or by in
situ measurements. A comparison of commonly used GCR models,
Badhwar-O'Neill2010, Burger-Usoskin, CREME2009/CREME96, and the recently
released Badhwar-O'Neill 2011 with the newly developed DLR model show
considerable differences in particle fluences. The differences arising
in the calculated radiation exposure by applying these models were
quantified in terms of absorbed dose and dose equivalent rates using
the GEANT4 Monte-Carlo framework for different shielding thicknesses and
the cumulative shielding distribution of the MSL transfer vehicle. The
calculations are compared with actual measurement of the Radiation
Assessment detector (RAD) of the Mars Science Lab (MSL) on its cruise
towards Mars and on the surface of Mars. From the dose equivalents
measured and calculated estimates of the upper and lower limits for
the risks for a human flight to Mars assuming the radiation environment
experienced by MSL-RAD are given using the NASA risk model.
---------------------------------------------------------
Title: GRB 141026A: Skynet PROMPT-CTIO/Yerkes-41 Observations.
Authors: Trotter, A.; Haislip, J.; Reichart, D.; Hoette, V.; Cudworth,
K.; Harper, D.; Kron, R.; Linder, T.; Russell, R.; Struble, E.;
Aji, A.; Beauchemin, R.; Berger, T.; Dow, A.; Foster, A.; Frank,
N.; Hinckle, M.; Ivarsen, K.; Lacluyze, A.; Maples, M.; Moore, J.;
Nysewander, M.; Salemi, C.; Zbinden, L.; Crain, J. A.
2014GCN.16967....1T Altcode: 2014GCN..16967...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 140215A: continued skynet PROMPT observations of the
optical afterglow.
Authors: Lacluyze, A.; Haislip, J.; Reichart, D.; Trotter, A.;
Poshyachinda, S.; Rujopakarn, W.; Foster, A.; Frank, N.; Ivarsen,
K.; Moore, J.; Nysewander, M.; Beauchemin, R.; Berger, T.; Carroll,
M.; Cromartie, H. T.; Egger, R.; Hinckle, M.; Ireland, A.; Maples,
M.; Scott, L.; Crain, J. A.
2014GCN.15858....1L Altcode: 2014GCN..15858...1L
No abstract at ADS
---------------------------------------------------------
Title: Mars' Surface Radiation Environment Measured with the Mars
Science Laboratory's Curiosity Rover
Authors: Hassler, Donald M.; Zeitlin, Cary; Wimmer-Schweingruber,
Robert F.; Ehresmann, Bent; Rafkin, Scot; Eigenbrode, Jennifer L.;
Brinza, David E.; Weigle, Gerald; Böttcher, Stephan; Böhm, Eckart;
Burmeister, Soenke; Guo, Jingnan; Köhler, Jan; Martin, Cesar; Reitz,
Guenther; Cucinotta, Francis A.; Kim, Myung-Hee; Grinspoon, David;
Bullock, Mark A.; Posner, Arik; Gómez-Elvira, Javier; Vasavada,
Ashwin; Grotzinger, John P.; MSL Science Team; Kemppinen, Osku;
Cremers, David; Bell, James F.; Edgar, Lauren; Farmer, Jack; Godber,
Austin; Wadhwa, Meenakshi; Wellington, Danika; McEwan, Ian; Newman,
Claire; Richardson, Mark; Charpentier, Antoine; Peret, Laurent;
King, Penelope; Blank, Jennifer; Schmidt, Mariek; Li, Shuai;
Milliken, Ralph; Robertson, Kevin; Sun, Vivian; Baker, Michael;
Edwards, Christopher; Ehlmann, Bethany; Farley, Kenneth; Griffes,
Jennifer; Miller, Hayden; Newcombe, Megan; Pilorget, Cedric; Rice,
Melissa; Siebach, Kirsten; Stack, Katie; Stolper, Edward; Brunet,
Claude; Hipkin, Victoria; Léveillé, Richard; Marchand, Geneviève;
Sánchez, Pablo Sobrón; Favot, Laurent; Cody, George; Steele, Andrew;
Flückiger, Lorenzo; Lees, David; Nefian, Ara; Martin, Mildred;
Gailhanou, Marc; Westall, Frances; Israël, Guy; Agard, Christophe;
Baroukh, Julien; Donny, Christophe; Gaboriaud, Alain; Guillemot,
Philippe; Lafaille, Vivian; Lorigny, Eric; Paillet, Alexis; Pérez,
René; Saccoccio, Muriel; Yana, Charles; Armiens-Aparicio, Carlos;
Rodríguez, Javier Caride; Blázquez, Isaías Carrasco; Gómez, Felipe
Gómez; Hettrich, Sebastian; Malvitte, Alain Lepinette; Jiménez,
Mercedes Marín; Martínez-Frías, Jesús; Martín-Soler, Javier;
Martín-Torres, F. Javier; Jurado, Antonio Molina; Mora-Sotomayor,
Luis; Caro, Guillermo Muñoz; López, Sara Navarro; Peinado-González,
Verónica; Pla-García, Jorge; Manfredi, José Antonio Rodriguez;
Romeral-Planelló, Julio José; Fuentes, Sara Alejandra Sans; Martinez,
Eduardo Sebastian; Redondo, Josefina Torres; Urqui-O'Callaghan, Roser;
Mier, María-Paz Zorzano; Chipera, Steve; Lacour, Jean-Luc; Mauchien,
Patrick; Sirven, Jean-Baptiste; Manning, Heidi; Fairén, Alberto;
Hayes, Alexander; Joseph, Jonathan; Squyres, Steven; Sullivan, Robert;
Thomas, Peter; Dupont, Audrey; Lundberg, Angela; Melikechi, Noureddine;
Mezzacappa, Alissa; Berger, Thomas; Matthia, Daniel; Prats, Benito;
Atlaskin, Evgeny; Genzer, Maria; Harri, Ari-Matti; Haukka, Harri;
Kahanpää, Henrik; Kauhanen, Janne; Kemppinen, Osku; Paton, Mark;
Polkko, Jouni; Schmidt, Walter; Siili, Tero; Fabre, Cécile; Wray,
James; Wilhelm, Mary Beth; Poitrasson, Franck; Patel, Kiran; Gorevan,
Stephen; Indyk, Stephen; Paulsen, Gale; Gupta, Sanjeev; Bish, David;
Schieber, Juergen; Gondet, Brigitte; Langevin, Yves; Geffroy, Claude;
Baratoux, David; Berger, Gilles; Cros, Alain; d'Uston, Claude; Forni,
Olivier; Gasnault, Olivier; Lasue, Jérémie; Lee, Qiu-Mei; Maurice,
Sylvestre; Meslin, Pierre-Yves; Pallier, Etienne; Parot, Yann; Pinet,
Patrick; Schröder, Susanne; Toplis, Mike; Lewin, Éric; Brunner,
Will; Heydari, Ezat; Achilles, Cherie; Oehler, Dorothy; Sutter, Brad;
Cabane, Michel; Coscia, David; Israël, Guy; Szopa, Cyril; Dromart,
Gilles; Robert, François; Sautter, Violaine; Le Mouélic, Stéphane;
Mangold, Nicolas; Nachon, Marion; Buch, Arnaud; Stalport, Fabien;
Coll, Patrice; François, Pascaline; Raulin, François; Teinturier,
Samuel; Cameron, James; Clegg, Sam; Cousin, Agnès; DeLapp, Dorothea;
Dingler, Robert; Jackson, Ryan Steele; Johnstone, Stephen; Lanza,
Nina; Little, Cynthia; Nelson, Tony; Wiens, Roger C.; Williams,
Richard B.; Jones, Andrea; Kirkland, Laurel; Treiman, Allan; Baker,
Burt; Cantor, Bruce; Caplinger, Michael; Davis, Scott; Duston, Brian;
Edgett, Kenneth; Fay, Donald; Hardgrove, Craig; Harker, David; Herrera,
Paul; Jensen, Elsa; Kennedy, Megan R.; Krezoski, Gillian; Krysak,
Daniel; Lipkaman, Leslie; Malin, Michael; McCartney, Elaina; McNair,
Sean; Nixon, Brian; Posiolova, Liliya; Ravine, Michael; Salamon,
Andrew; Saper, Lee; Stoiber, Kevin; Supulver, Kimberley; Van Beek,
Jason; Van Beek, Tessa; Zimdar, Robert; French, Katherine Louise;
Iagnemma, Karl; Miller, Kristen; Summons, Roger; Goesmann, Fred;
Goetz, Walter; Hviid, Stubbe; Johnson, Micah; Lefavor, Matthew;
Lyness, Eric; Breves, Elly; Dyar, M. Darby; Fassett, Caleb; Blake,
David F.; Bristow, Thomas; DesMarais, David; Edwards, Laurence;
Haberle, Robert; Hoehler, Tori; Hollingsworth, Jeff; Kahre, Melinda;
Keely, Leslie; McKay, Christopher; Wilhelm, Mary Beth; Bleacher, Lora;
Brinckerhoff, William; Choi, David; Conrad, Pamela; Dworkin, Jason P.;
Floyd, Melissa; Freissinet, Caroline; Garvin, James; Glavin, Daniel;
Harpold, Daniel; Jones, Andrea; Mahaffy, Paul; Martin, David K.;
McAdam, Amy; Pavlov, Alexander; Raaen, Eric; Smith, Michael D.; Stern,
Jennifer; Tan, Florence; Trainer, Melissa; Meyer, Michael; Voytek,
Mary; Anderson, Robert C.; Aubrey, Andrew; Beegle, Luther W.; Behar,
Alberto; Blaney, Diana; Calef, Fred; Christensen, Lance; Crisp, Joy A.;
DeFlores, Lauren; Ehlmann, Bethany; Feldman, Jason; Feldman, Sabrina;
Flesch, Gregory; Hurowitz, Joel; Jun, Insoo; Keymeulen, Didier; Maki,
Justin; Mischna, Michael; Morookian, John Michael; Parker, Timothy;
Pavri, Betina; Schoppers, Marcel; Sengstacken, Aaron; Simmonds, John
J.; Spanovich, Nicole; Juarez, Manuel de la Torre; Webster, Christopher
R.; Yen, Albert; Archer, Paul Douglas; Jones, John H.; Ming, Douglas;
Morris, Richard V.; Niles, Paul; Rampe, Elizabeth; Nolan, Thomas;
Fisk, Martin; Radziemski, Leon; Barraclough, Bruce; Bender, Steve;
Berman, Daniel; Dobrea, Eldar Noe; Tokar, Robert; Vaniman, David;
Williams, Rebecca M. E.; Yingst, Aileen; Lewis, Kevin; Leshin, Laurie;
Cleghorn, Timothy; Huntress, Wesley; Manhès, Gérard; Hudgins, Judy;
Olson, Timothy; Stewart, Noel; Sarrazin, Philippe; Grant, John;
Vicenzi, Edward; Wilson, Sharon A.; Hamilton, Victoria; Peterson,
Joseph; Fedosov, Fedor; Golovin, Dmitry; Karpushkina, Natalya;
Kozyrev, Alexander; Litvak, Maxim; Malakhov, Alexey; Mitrofanov,
Igor; Mokrousov, Maxim; Nikiforov, Sergey; Prokhorov, Vasily; Sanin,
Anton; Tretyakov, Vladislav; Varenikov, Alexey; Vostrukhin, Andrey;
Kuzmin, Ruslan; Clark, Benton; Wolff, Michael; McLennan, Scott;
Botta, Oliver; Drake, Darrell; Bean, Keri; Lemmon, Mark; Schwenzer,
Susanne P.; Anderson, Ryan B.; Herkenhoff, Kenneth; Lee, Ella Mae;
Sucharski, Robert; Hernández, Miguel Ángel de Pablo; Ávalos, Juan
José Blanco; Ramos, Miguel; Malespin, Charles; Plante, Ianik; Muller,
Jan-Peter; Navarro-González, Rafael; Ewing, Ryan; Boynton, William;
Downs, Robert; Fitzgibbon, Mike; Harshman, Karl; Morrison, Shaunna;
Dietrich, William; Kortmann, Onno; Palucis, Marisa; Sumner, Dawn Y.;
Williams, Amy; Lugmair, Günter; Wilson, Michael A.; Rubin, David;
Jakosky, Bruce; Balic-Zunic, Tonci; Frydenvang, Jens; Jensen, Jaqueline
Kløvgaard; Kinch, Kjartan; Koefoed, Asmus; Madsen, Morten Bo; Stipp,
Susan Louise Svane; Boyd, Nick; Campbell, John L.; Gellert, Ralf;
Perrett, Glynis; Pradler, Irina; VanBommel, Scott; Jacob, Samantha;
Owen, Tobias; Rowland, Scott; Atlaskin, Evgeny; Savijärvi, Hannu;
García, César Martín; Mueller-Mellin, Reinhold; Bridges, John C.;
McConnochie, Timothy; Benna, Mehdi; Franz, Heather; Bower, Hannah;
Brunner, Anna; Blau, Hannah; Boucher, Thomas; Carmosino, Marco;
Atreya, Sushil; Elliott, Harvey; Halleaux, Douglas; Rennó, Nilton;
Wong, Michael; Pepin, Robert; Elliott, Beverley; Spray, John; Thompson,
Lucy; Gordon, Suzanne; Newsom, Horton; Ollila, Ann; Williams, Joshua;
Vasconcelos, Paulo; Bentz, Jennifer; Nealson, Kenneth; Popa, Radu;
Kah, Linda C.; Moersch, Jeffrey; Tate, Christopher; Day, Mackenzie;
Kocurek, Gary; Hallet, Bernard; Sletten, Ronald; Francis, Raymond;
McCullough, Emily; Cloutis, Ed; ten Kate, Inge Loes; Kuzmin, Ruslan;
Arvidson, Raymond; Fraeman, Abigail; Scholes, Daniel; Slavney, Susan;
Stein, Thomas; Ward, Jennifer; Berger, Jeffrey; Moores, John E.
2014Sci...343D.386H Altcode:
The Radiation Assessment Detector (RAD) on the Mars Science Laboratory's
Curiosity rover began making detailed measurements of the cosmic ray
and energetic particle radiation environment on the surface of Mars
on 7 August 2012. We report and discuss measurements of the absorbed
dose and dose equivalent from galactic cosmic rays and solar energetic
particles on the martian surface for ~300 days of observations during
the current solar maximum. These measurements provide insight into
the radiation hazards associated with a human mission to the surface
of Mars and provide an anchor point with which to model the subsurface
radiation environment, with implications for microbial survival times
of any possible extant or past life, as well as for the preservation
of potential organic biosignatures of the ancient martian environment.
---------------------------------------------------------
Title: Introduction to session F2.3 “Space Radiation
Dosimetry—Measurements and Models, Detector Development and
Groundbased Characterisation”
Authors: Berger, Thomas
2014cosp...40E.293B Altcode:
Introduction to the session F2.3 "Space Radiation Dosimetry"
---------------------------------------------------------
Title: Prominence Science with ATST Instrumentation
Authors: Rimmele, Thomas; Berger, Thomas; Casini, Roberto; Elmore,
David; Kuhn, Jeff; Lin, Haosheng; Schmidt, Wolfgang; Wöger, Friedrich
2014IAUS..300..362R Altcode:
The 4m Advance Technology Solar Telescope (ATST) is under construction
on Maui, HI. With its unprecedented resolution and photon collecting
power ATST will be an ideal tool for studying prominences and filaments
and their role in producing Coronal Mass Ejections that drive Space
Weather. The ATST facility will provide a set of first light instruments
that enable imaging and spectroscopy of the dynamic filament and
prominence structure at 8 times the resolution of Hinode. Polarimeters
allow high precision chromospheric and coronal magnetometry at visible
and infrared (IR) wavelengths. This paper summarizes the capabilities
of the ATST first-light instrumentation with focus on prominence and
filament science.
---------------------------------------------------------
Title: European Crew Personal Active Dosimeter (EuCPAD), a novel
dosimetry system utilizing operational and scientific synergies for
the benefit of humans in space
Authors: Straube, Ulrich; Berger, Thomas
2014cosp...40E3215S Altcode:
A significant expansion of Human presence in space can be recognized
over the last decade. Not only the frequency of human space mission
did rise, but also time in space, mission duration with extended
flights lasting half a year or more are becoming "standard". Despite
the challenges to human health and well-being are still significant, or
may even increase with mission length and work density. Also radiation
exposure in space remains one of the inevitable and dominating
factors relevant to crew- health, -safety and therefore mission
success. The radiation environment that the space crews are exposed to
differs significantly as compared to earth. Exposure in flight exceed
doses that are usually received by terrestrial radiation workers on
ground. Expanding "medical" demands are not a solely characteristics
of current and current and upcoming mission scenarios. Likewise the
margins for what is understood as "efficient utilization" for the fully
operational science platform ISS, are immense. Understanding, accepting
and approaching these challenges ESA-HSO did choose a particular pass
of implementation for one of their current developments. Exploiting
synergies of research, science and medical operational aspects, the
"European Crew Personal Active Dosimeter for Astronauts (EuCPAD)"
development exactly addresses these circumstances. It becomes novel
part of ESA Radiation Protection Initiative for astronauts. The
EuCPAD project aims at the development and manufacturing of an active
(powered) dosimeter system to measure astronaut's exposures, support
risk assessment dose management by providing a differentiated data
set. Final goal is the verification of the system capabilities for
medical monitoring at highest standards. The EuCPAD consists of several
small portable Personal Active Dosimeters (MU = Mobile Unitas) and a
rack mounted docking station “Personal Storage Device (PSD)” for
MU storage, data read out and telemetry. The PSD furthermore contains a
Tissue Equivalent Proportional Counter (TEPC) and an internal MU(iMU) to
enable complex environmental measurements and cross calibrations. This
presentation will give an introduction to the dosimetry system and
of the current status. The EuCPAD project is carried out under ESA
Contract No. 4200023059/09/NL/CP,
---------------------------------------------------------
Title: 10Be Production in the Atmosphere by Galactic Cosmic Rays
Authors: Matthiä, Daniel; Herbst, Klaudia; Heber, Bernd; Berger,
Thomas; Reitz, Günther
2014crh..book..333M Altcode:
No abstract at ADS
---------------------------------------------------------
Title: GRB 141221A: Skynet PROMPT-CTIO observations of the optical
afterglow.
Authors: Trotter, A.; Haislip, J.; Reichart, D.; Aji, A.; Beauchemin,
R.; Berger, T.; Dow, A.; Foster, A.; Frank, N.; Hinckle, M.; Ivarsen,
K.; Lacluyze, A.; Maples, M.; Moore, J.; Nysewander, M.; Salemi, C.;
Zbinden, L.; Crain, J. A.
2014GCN.17210....1T Altcode: 2014GCN..17210...1T
No abstract at ADS
---------------------------------------------------------
Title: Dose Measurements on the BION-M1 satellite applying passive
detector packages
Authors: Stradi, Andrea; Berger, Thomas; Kodaira, Satoshi; Kubancak,
Jan; Palfalvi, Jozsef K.; Ambrozova, Iva; Tolochek, Raisa; Shurshakov,
Vyacheslav; Szabo, Julianna
2014cosp...40E3214S Altcode:
A passive detector package was developed in the past years in the
Centre for Energy Research, Hungarian Academy of Science to detect
cosmic ray particles, to determine their flux and dose. It consists
of thermoluminescent detectors (TLD) and plastic solid state nuclear
track detectors (SSNTD). In the frame of a scientific co-operation
between the Institute for Biomedical Problems (IBMP) fourteen packages
were flow within the new BION-M1 satellite program together with
biological samples and detector packages from other participants. Two
packages were located outside and the rest ones inside the recoverable
capsule. Comparing to the previous BION and similar FOTON experiments,
(all together 17 successful ones), this flight was a “champion”
with the highest altitude (575 km), orbital inclination (64.9°)
and flight duration (30 days). The external exposure provided a unique
possibility to study not only the elevated level of cosmic rays but also
the behavior of the detector packages in extreme circumstances as low
temperature and pressure. The paper will summarize the construction
of the detector packages, the calibration and evaluation processes,
as well as, the linear energy transfer (LET) spectra, the absorbed dose
and the mean quality factor. These quantities will be compared taking
into consideration their location inside and outside the capsule and
to the results of other participants. Also some comparison of results
to the previous BION and FOTON flights and contemporary measurements
on the ISS will be presented.
---------------------------------------------------------
Title: GRB 140301A: skynet R-COP observations.
Authors: Trotter, A.; Haislip, J.; Lacluyze, A.; Reichart, D.;
Verveer, A.; Spuck, T.; Foster, A.; Frank, N.; Ivarsen, K.; Moore, J.;
Nysewander, M.; Beauchemin, R.; Berger, T.; Carroll, M.; Cromartie,
H. T.; Egger, R.; Hinckle, M.; Ireland, A.; Maples, M.; Scott, L.;
Crain, J. A.
2014GCN.15897....1T Altcode: 2014GCN..15897...1T
No abstract at ADS
---------------------------------------------------------
Title: Future Diagnostic Capabilities: The 4-meter Daniel K. Inouye
Solar Telescope
Authors: Berger, Thomas; Reardon, Kevin; Elmore, David; Woeger,
Friedrich; Tritschler, Alexandra; Rimmele, Thomas
2014cosp...40E.294B Altcode:
We discuss the observational capabilities of the Daniel K. Inouye
Solar Telescope (DKSIT), formerly known as the Advanced Technology
Solar Telescope (ATST), currently under construction on Haleakala
Mountain on the island of Maui, Hawaii, with first light anticipated
in mid-2019. The DKIST will be a 4-meter aperture Gregorian telescope
with advanced environmental control and adaptive optics capable of
producing diffraction-limited resolution in visible light of 0.03"
or about 20 km in the solar photosphere. The first light instrument
suite will include the Visible Broadband Imager (VBI), an interference
filter-based instrument capable of 30 Hz imaging of photospheric and
chromospheric magnetic structures in the 380 to 800 nm wavelength
range. All VBI images will be reconstructed in near-real-time using
the KISIP speckle reconstruction algorithm adapted to the DKIST
optical and AO configuration. The Visible Spectropolarimeter (ViSP)
instrument being fabricated by the High Altitude Observatory (HAO) will
enable high-precision slit-spectropolarimetery in any three spectral
regions from 380 to 900 nm. The ViSP instrument will be the highest
precision spectropolarimeter ever produced with a spatial resolution
of approximately 40 km at 600 nm and temporal resolution of 10s to
achieve 1e-03 polarimetric precision. The Visible Tunable Filter (VTF)
instrument under fabrication at the Kiepenheuer Institute for Solar
Physics (KIS) is a triple-etalon Fabry-Perot imaging spectropolarimeter
instrument capable of diffraction limited measurements of the Fe I
630.2 nm and Ca II 854.2 nm spectral lines for Doppler and magnetic
measurements in the photosphere and chromosphere, respectively. The
VTF will also enable the highest spatial and temporal resolution
observations yet achieved in the H-alpha line for detailed studies of
chromospheric dynamics in response to photospheric magnetic drivers. The
Diffraction-Limited Near-IR Spectropolarimeter (DL-NiRSP) and the
Cryogenic Near-IR Spectropolarimeter (Cryo-NiRSP) instruments, both
under fabrication at the University of Hawaii, will enable polarimetric
and spectroscopic investigations in the largely unexplored infra-red
spectral region. The DL-NiRSP will span 900 nm to 2.5 microns in
wavelength and include a novel fiber-optic "Integral Field Unit"
(IFU) for true imaging spectropolarimetry in three simultaneous
spectral regions over a variable field of view. This instrument
will enable revolutionary measurements of prominence magnetic fields
and will also, in the wider field mode, enable coronal polarimetric
studies. The Cryo-NiRSP instrument spans the 1--5 micron wavelength
range and will make near-diffraction limited 0.3" resolution slit-scan
measurements of the coronal magnetic field out to 1.3 solar radii
with temporal resolution measured in minutes. The DKIST facility
will undergo extensive polarimetric calibration to ensure that the
ultimate goal of 5e-04 polarimetic precision is obtainable under the
best conditions. All of the data from the DKIST will be transmitted
to the central DKIST data center in Boulder, Colorado where automated
reduction and calibration pipelines will rapidly provide the community
with calibrated data products for use in science investigations. The
DKIST will also be operated in a "Service Mode" access model in which
investigators will not be required to travel to the telescope to
accomplish their science observations.
---------------------------------------------------------
Title: GRB 140518A: Skynet GORT Detections of the Optical Afterglow.
Authors: Trotter, A.; Lacluyze, A.; Haislip, J.; Reichart, D.; McLin,
K.; Cominsky, L.; Cromartie, H. T.; Foster, A.; Frank, N.; Ivarsen,
K.; Maples, M.; Moore, J.; Nysewander, M.; Beauchemin, R.; Berger, T.;
Dow, A.; Hinckle, M.; Patterson, A.; Pegues, H.; Pozo, J.; Waddell,
D.; Crain, J. A.
2014GCN.16304....1T Altcode: 2014GCN..16304...1T
No abstract at ADS
---------------------------------------------------------
Title: Solar Prominence Fine Structure and Dynamics
Authors: Berger, Thomas
2014IAUS..300...15B Altcode:
We review recent observational and theoretical results on the fine
structure and dynamics of solar prominences, beginning with an
overview of prominence classifications, the proposal of possible new
“funnel prominence” classification, and a discussion of the recent
“solar tornado” findings. We then focus on quiescent prominences
to review formation, down-flow dynamics, and the “prominence
bubble” phenomena. We show new observations of the prominence bubble
Rayleigh-Taylor instability triggered by a Kelvin-Helmholtz shear flow
instability occurring along the bubble boundary. Finally we review
recent studies on plasma composition of bubbles, emphasizing that
differential emission measure (DEM) analysis offers a more quantitative
analysis than photometric comparisons. In conclusion, we discuss the
relation of prominences to coronal magnetic flux ropes, proposing that
prominences can be understood as partially ionized condensations of
plasma forming the return flow of a general magneto-thermal convection
in the corona.
---------------------------------------------------------
Title: Development of a New Radiation Sensor for Satellite Missions
Authors: Ritter, Birgit; Berger, Thomas; Reitz, Guenther; Hauslage,
Jens; Marsalek, Karel; Aeckerlein, Joachim; M, Hartmut
2014cosp...40E2748R Altcode:
The RAMIS (RAdiation Measurements In Space) experiment aims to measure
cosmic radiation with energy deposition ranging from minimal ionizing
protons up to relativistic iron nuclei. The radiation detector
principle uses two silicon detectors, each with an active area of
0.5cm² that are arranged in a telescope configuration. The experiment
will fly in 2016 on the first mission of the newly developed DLR
(German Aerospace Center) Compact Satellite, which intends to provide
an easy accessible platform for scientific research within DLR as well
as for international partners and their experiments. As the satellite
will orbit Earth at an altitude of about 600 km on a polar orbit,
valuable insights are gained not only in the galactic cosmic ray (GCR)
component of the radiation field and in solar energetic particles (SEPs)
in case of solar events. Also the trapped radiation in the horns of
the electron belts around Earth can be studied in detail. Particle
fluxes will be monitored and energy deposition spectra recorded from
which linear energy transfer spectra will be generated. These spectra
give an estimate for the quality of the radiation field. The RAMIS
experiment consists of two modules, i.e. two small silicon detector
telescopes, with one module being located outside on top of the
satellite, while the other one is placed inside next to the primary
payload of the satellite, the Eu:CROPIS experiment. Eu:CROPIS is a
combined self-sustained biological life support system under Moon
and Mars gravity, which uses Euglena as oxygen suppliers, biofilter
for wastewater treatment and detoxification, and urine as primary
fertilizer. In addition to its scientific output RAMIS will provide
dosimetric monitoring for Eu:CROPIS and serve as a radiation exposure
information system for the satellite bus. Furthermore the obtained
data can be used for benchmarking and improvement of radiation belt
models as well as of shielding models by combining the results of both
modules. The RAMIS experiment, the prototype performance and first
test measurements of the detector system will be presented.
---------------------------------------------------------
Title: Long term dose monitoring onboard the European Columbus module
of the International Space Station (ISS) in the frame of the DOSIS
and DOSIS 3D project
Authors: Berger, Thomas
2014cosp...40E.292B Altcode:
The radiation environment encountered in space differs in nature from
that on earth, consisting mostly of high energetic ions from protons up
to iron, resulting in radiation levels far exceeding the ones present
on earth for occupational radiation workers. Accurate knowledge of the
physical characteristics of the space radiation field in dependence
on the solar activity, the orbital parameters and the different
shielding configurations of the International Space Station (ISS) is
therefore needed. For the investigation of the spatial and temporal
distribution of the radiation field inside the European Columbus module
the experiment “Dose Distribution Inside the ISS” (DOSIS), under
the project and science lead of the German Aerospace Center (DLR), was
launched on July 15th 2009 with STS-127 to the ISS. The DOSIS experiment
consists of a combination of “Passive Detector Packages” (PDP)
distributed at eleven locations inside Columbus for the measurement of
the spatial variation of the radiation field and two active Dosimetry
Telescopes (DOSTELs) with a Data and Power Unit (DDPU) in a dedicated
nomex pouch mounted at a fixed location beneath the European Physiology
Module rack (EPM) for the measurement of the temporal variation of
the radiation field parameters. The DOSIS experiment suite measured
during the lowest solar minimum conditions in the space age from July
2009 to June 2011. In July 2011 the active hardware was transferred to
ground for refurbishment and preparation for the follow up DOSIS 3D
experiment. The hardware for DOSIS 3D was launched with Soyuz 30S to
the ISS on May 15th 2012. The PDPs are replaced with each even number
Soyuz flight starting with Soyuz 30S. Data from the active detectors
is transferred to ground via the EPM rack which is activated once
a month for this action. The presentation will give an overview of
the DOSIS and DOSIS 3D experiment and focus on the results from the
passive radiation detectors from the DOSIS 3D experiment (2012 - 2014)
in comparison to the data of the DOSIS experiment (2009 - 2011). The
Polish contribution was supported by the National Science Centre (No
DEC-2012/06/M/ST9/00423). The CAU contributions to DOSIS and DOSIS
3D are financially supported by BMWi under Grants 50WB0826, 50WB1026
and 50WB1232.
---------------------------------------------------------
Title: GRB 141221A: Continued Skynet PROMPT-CTIO observations.
Authors: Trotter, A.; Haislip, J.; Reichart, D.; Aji, A.; Beauchemin,
R.; Berger, T.; Dow, A.; Foster, A.; Frank, N.; Hinckle, M.; Ivarsen,
K.; Lacluyze, A.; Maples, M.; Moore, J.; Nysewander, M.; Salemi, C.;
Zbinden, L.; Crain, J. A.
2014GCN.17221....1T Altcode: 2014GCN..17221...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 141031A: Skynet PROMPT-CTIO Observations.
Authors: Trotter, A.; Haislip, J.; Reichart, D.; Aji, A.; Beauchemin,
R.; Berger, T.; Dow, A.; Foster, A.; Frank, N.; Hinckle, M.; Ivarsen,
K.; Lacluyze, A.; Maples, M.; Moore, J.; Nysewander, M.; Salemi, C.;
Zbinden, L.; Crain, J. A.
2014GCN.17004....1T Altcode: 2014GCN..17004...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB140215A: skynet PROMPT optical observations.
Authors: Lacluyze, A.; Haislip, J.; Reichart, D.; Trotter, A.; Foster,
A.; Frank, N.; Ivarsen, K.; Moore, J.; Nysewander, M.; Beauchemin,
R.; Berger, T.; Carroll, M.; Cromartie, H. T.; Egger, R.; Hinckle,
M.; Ireland, A.; Maples, M.; Scott, L.; Crain, J. A.
2014GCN.15840....1L Altcode: 2014GCN..15840...1L
No abstract at ADS
---------------------------------------------------------
Title: Correction: MAXI J1421-613: skynet PROMPT/R-COP observations.
Authors: Trotter, A.; Reichart, D.; Verveer, A.; Spuck, T.; Lacluyze,
A.; Haislip, J.; Foster, A.; Frank, N.; Ivarsen, K.; Moore, J.;
Nysewander, M.; Beauchemin, R.; Berger, T.; Carroll, M.; Cromartie,
H. T.; Egger, R.; Hinckle, M.; Ireland, A.; Maples, M.; Scott, L.;
Crain, J. A.; Baumgartner, W. H.
2014GCN.15755....1T Altcode: 2014GCN..15755...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 141022A: Skynet PROMPT-CTIO Observations.
Authors: Trotter, A.; Haislip, J.; Reichart, D.; Aji, A.; Beauchemin,
R.; Berger, T.; Dow, A.; Foster, A.; Frank, N.; Hinckle, M.; Ivarsen,
K.; Lacluyze, A.; Maples, M.; Moore, J.; Nysewander, M.; Salemi, C.;
Zbinden, L.; Crain, J. A.
2014GCN.17023....1T Altcode: 2014GCN..17023...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 140213A: continued skynet R-COP/PROMPT detections of a
rebrightening optical afterglow.
Authors: Trotter, A.; Haislip, J.; Reichart, D.; Lacluyze, A.;
Verveer, A.; Spuck, T.; Foster, A.; Frank, N.; Ivarsen, K.; Moore, J.;
Nysewander, M.; Beauchemin, R.; Berger, T.; Carroll, M.; Cromartie,
H. T.; Egger, R.; Hinckle, M.; Ireland, A.; Maples, M.; Scott, L.;
Crain, J. A.
2014GCN.15859....1T Altcode: 2014GCN..15859...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 141212A: Skynet R-COP Observations.
Authors: Trotter, A.; Haislip, J.; Reichart, D.; Verveer, A.; Spuck,
T.; Aji, A.; Beauchemin, R.; Berger, T.; Dow, A.; Foster, A.; Frank,
N.; Hinckle, M.; Ivarsen, K.; Lacluyze, A.; Maples, M.; Moore, J.;
Nysewander, M.; Salemi, C.; Zbinden, L.; Crain, J. A.
2014GCN.17161....1T Altcode: 2014GCN..17161...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 141017A: Skynet PROMPT-CTIO/SSO Observations.
Authors: Trotter, A.; Haislip, J.; Reichart, D.; Aji, A.; Beauchemin,
R.; Berger, T.; Dow, A.; Foster, A.; Frank, N.; Hinckle, M.; Ivarsen,
K.; Lacluyze, A.; Maples, M.; Moore, J.; Nysewander, M.; Salemi, C.;
Zbinden, L.; Crain, J. A.
2014GCN.17028....1T Altcode: 2014GCN..17028...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 140118A/MAXI J1421-613: skynet PROMPT/R-COP observations.
Authors: Trotter, A.; Reichart, D.; Verveer, A.; Spuck, T.; Lacluyze,
A.; Haislip, J.; Foster, A.; Frank, N.; Ivarsen, K.; Moore, J.;
Nysewander, M.; Beauchemin, R.; Berger, T.; Carroll, M.; Cromartie,
H. T.; Egger, R.; Hinckle, M.; Ireland, A.; Maples, M.; Scott, L.;
Crain, J. A.
2014GCN.15753....1T Altcode: 2014GCN..15753...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 140213A: continued skynet R-COP/PROMPT observations of
the optical afterglow.
Authors: Trotter, A.; Haislip, J.; Reichart, D.; Lacluyze, A.;
Verveer, A.; Spuck, T.; Foster, A.; Frank, N.; Ivarsen, K.; Moore, J.;
Nysewander, M.; Beauchemin, R.; Berger, T.; Carroll, M.; Cromartie,
H. T.; Egger, R.; Hinckle, M.; Ireland, A.; Maples, M.; Scott, L.;
Crain, J. A.
2014GCN.15862....1T Altcode: 2014GCN..15862...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 140213A: skynet R-COP detection of optical afterglow.
Authors: Trotter, A.; Haislip, J.; Reichart, D.; Lacluyze, A.;
Verveer, A.; Spuck, T.; Foster, A.; Frank, N.; Ivarsen, K.; Moore, J.;
Nysewander, M.; Beauchemin, R.; Berger, T.; Carroll, M.; Cromartie,
H. T.; Egger, R.; Hinckle, M.; Ireland, A.; Maples, M.; Scott, L.;
Crain, J. A.
2014GCN.15828....1T Altcode: 2014GCN..15828...1T
No abstract at ADS
---------------------------------------------------------
Title: Long term dose monitoring onboard the European Columbus module
of the international space station (ISS) in the frame of DOSIS and
DOSIS 3D project - results from the active instruments
Authors: Burmeister, Soenke; Berger, Thomas; Reitz, Guenther; Boehme,
Matthias; Haumann, Lutz; Labrenz, Johannes
2014cosp...40E.434B Altcode:
Besides the effects of the microgravity environment, and the
psychological and psychosocial problems encountered in confined
spaces, radiation is the main health detriment for long duration
human space missions. The radiation environment encountered in
space differs in nature from that on earth, consisting mostly of
high energetic ions from protons up to iron, resulting in radiation
levels far exceeding the ones encountered on earth for occupational
radiation workers. Accurate knowledge of the physical characteristics
of the space radiation field in dependence on the solar activity,
the orbital parameters and the different shielding configurations
of the International Space Station ISS is therefore needed. For the
investigation of the spatial and temporal distribution of the radiation
field inside the European COLUMBUS module the experiment DOSIS (Dose
Distribution Inside the ISS) under the lead of DLR has been launched
on July 15 (th) 2009 with STS-127 to the ISS. The experimental package
was transferred from the Space Shuttle into COLUMBUS on July 18 (th)
. It consists of a combination of passive detector packages (PDP)
distributed at 11 locations inside the European Columbus Laboratory and
two active radiation detectors (Dosimetry Telescopes = DOSTELs) with
a DDPU (DOSTEL Data and Power Unit) in a Nomex pouch (DOSIS MAIN BOX)
mounted at a fixed location beneath the European Physiology Module rack
(EPM) inside COLUMBUS. The active components of the DOSIS experiment
were operational from July 18 (th) 2009 to June 16 (th) 2011. After
refurbishment the hardware has been reactivated on May 15 (th) 2012
as active part of the DOSIS 3D experiment and provides continuous data
since this activation. The presentation will focus on the latest results
from the two DOSTEL instruments as absorbed dose, dose equivalent
and the related LET spectra gathered within the DOSIS (2009 - 2011)
and DOSIS 3D (2012 - 2014) experiment. The CAU contributions to DOSIS
and DOSIS 3D are financially supported by BMWi under Grants 50WB0826,
50WB1026 and 50WB1232
---------------------------------------------------------
Title: Coronal Condensation in Funnel Prominences as Return Flows
of the Chromosphere-Corona Mass Cycle
Authors: Liu, Wei; Berger, Thomas E.; Low, B. C.
2014IAUS..300..441L Altcode:
We present SDO/AIA observations of a potentially novel type of
prominence, called “funnel prominence”, that forms out of coronal
condensation at magnetic dips. <P />They can drain a large amount
of mass (up to ~10<SUP>15</SUP> g day<SUP>-1</SUP>) and may play an
important role as return flows of the chromosphere-corona mass cycle.
---------------------------------------------------------
Title: Preparation of the Biochip experiment on the EXPOSE-R2 mission
outside the International Space Station
Authors: Vigier, F.; Le Postollec, A.; Coussot, G.; Chaput, D.;
Cottin, H.; Berger, T.; Incerti, S.; Triqueneaux, S.; Dobrijevic,
M.; Vandenabeele-Trambouze, O.
2013AdSpR..52.2168V Altcode:
Biochips might be suited for planetary exploration. Indeed, they
present great potential for the search for biomarkers - molecules that
are the sign of past or present life in space - thanks to their size
(miniaturized devices) and sensitivity. Their detection principle is
based on the recognition of a target molecule by affinity receptors
fixed on a solid surface. Consequently, one of the main concerns when
developing such a system is the behavior of the biological receptors
in a space environment. In this paper, we describe the preparation
of an experiment planned to be part of the EXPOSE-R2 mission, which
will be conducted on the EXPOSE-R facility, outside the International
Space Station (ISS), in order to study the resistance of biochip
models to space constraints (especially cosmic radiation and thermal
cycling). This experiment overcomes the limits of ground tests which
do not reproduce exactly the space parameters. Indeed, contrary to
ground experiments where constraints are applied individually and in a
limited time, the biochip models on the ISS will be exposed to cumulated
constraints during several months. Finally, this ISS experiment is a
necessary step towards planetary exploration as it will help assessing
whether a biochip can be used for future exploration missions.
---------------------------------------------------------
Title: Estimation of Galactic Cosmic Ray exposure inside and outside
the Earth's magnetosphere during the recent solar minimum between
solar cycles 23 and 24
Authors: Mrigakshi, Alankrita Isha; Matthiä, Daniel; Berger, Thomas;
Reitz, Günther; Wimmer-Schweingruber, Robert F.
2013AdSpR..52..979M Altcode:
The evidently low solar activity observed between solar cycles 23
and 24 during the years 2008-2010 led to a substantial increase in
the Galactic Cosmic Ray (GCR) intensity in comparison with preceding
solar minima. As the GCRs consist of highly-ionizing charged particles
having the potential to cause biological damage, they are a subject of
concern for manned missions to space. With the enhanced particle fluxes
observed between 2008 and 2010, it is reasonable to assume that the
radiation exposure from GCR must have also increased to unusually high
levels. In this paper, the GCR exposure outside and inside the Earth's
magnetosphere is numerically calculated for time periods starting from
1970 to the end of 2011 in order to investigate the increase in dose
levels during the years 2008-2010 in comparison with the last three
solar minima. The dose rates were calculated in a water sphere, used
as a surrogate for the human body, either unshielded or surrounded by
aluminium shielding of 0.3, 10 or 40 g/cm<SUP>2</SUP>. By performing
such a long-term analysis, it was estimated that the GCR exposure
during the recent solar minimum was indeed the largest in comparison
with previous minima and that the increase was more pronounced for
locations outside the magnetosphere.
---------------------------------------------------------
Title: Organ shielding and doses in Low-Earth orbit calculated for
spherical and anthropomorphic phantoms
Authors: Matthiä, Daniel; Berger, Thomas; Reitz, Günther
2013AdSpR..52..528M Altcode:
Humans in space are exposed to elevated levels of radiation compared
to ground. Different sources contribute to the total exposure with
galactic cosmic rays being the most important component. The application
of numerical and anthropomorphic phantoms in simulations allows the
estimation of dose rates from galactic cosmic rays in individual
organs and whole body quantities such as the effective dose. The
male and female reference phantoms defined by the International
Commission on Radiological Protection and the hermaphrodite numerical
RANDO phantom are voxel implementations of anthropomorphic phantoms
and contain all organs relevant for radiation risk assessment. These
anthropomorphic phantoms together with a spherical water phantom were
used in this work to translate the mean shielding of organs in the
different anthropomorphic voxel phantoms into positions in the spherical
phantom. This relation allows using a water sphere as surrogate for the
anthropomorphic phantoms in both simulations and measurements. Moreover,
using spherical phantoms in the calculation of radiation exposure
offers great advantages over anthropomorphic phantoms in terms of
computational time. In this work, the mean shielding of organs in the
different voxel phantoms exposed to isotropic irradiation is presented
as well as the corresponding depth in a water sphere. Dose rates
for Low-Earth orbit from galactic cosmic rays during solar minimum
conditions were calculated using the different phantoms and are
compared to the results for a spherical water phantom in combination
with the mean organ shielding. For the spherical water phantom the
impact of different aluminium shielding between 1 g/cm<SUP>2</SUP>
and 100 g/cm<SUP>2</SUP> was calculated. The dose equivalent rates
were used to estimate the effective dose rate.
---------------------------------------------------------
Title: The Advanced Technology Solar Telescope Construction Status
Report
Authors: McMullin, Joseph P.; Rimmele, T. R.; Warner, M.; Berger,
T.; Keil, S. L.
2013SPD....4440001M Altcode:
The Advanced Technology Solar Telescope (ATST) will provide observing
capabilities in the visible through infrared wavelengths with
unprecedented resolution and sensitivity. Designed to study solar
magnetism that controls the solar wind, flares, CMEs and variability in
the Sun's output, the ATST will be capable of detecting and spatially
resolving the fundamental astrophysical processes at their intrinsic
scales throughout the solar atmosphere. The 4-m class facility is
currently under construction in Maui, HI on the Haleakala Observatories
site with a scheduled completion of July 2019. Since the start of
site construction in December of 2012, significant progress has been
made toward the development of the observatory buildings (excavation,
foundations, working towards the steel erection). In addition, off-site,
the major subsystems of the telescope have been contracted, designs are
complete and fabrication is underway. We review the science drivers,
design details, technical challenges, and provide a construction status
update on the subsystems and their integration.
---------------------------------------------------------
Title: The ATST Instrumentation suite: capabilities, synergies,
and science goals
Authors: Berger, Thomas; ATST Science Team
2013SPD....4440002B Altcode:
The ATST will have a full complement of first generation instrumentation
to cover observations of the solar atmosphere from the photosphere to
the corona: the Visible Broadband Imager (VBI) will be an interference
filter imager providing the highest spatial and temporal resolution
image sequences for ATST, spanning from the deep photosphere through
the chromosphere, and perhaps providing coronal imaging as well;
the Visible Spectropolarimeter (ViSP) will be an advanced slit
spectropolarimeter enabling simultaneous multi-line spectropolarimetry
from 380 to 900 nm; the Visible Tunable Filter (VTF) will be a dual
tunable Fabry-Perot system enabling rapid cadence spectral imaging and
spectropolarimetry in the 520 to 870 nm range; the Diffraction-limited
Near-IR Spectropolarimeter (DL-NiRSP) will be an advanced fiber-optic
image plane spectropolarimeter offering simultaneous imaging and
full-profile spectropolarimetry from 900 to 2500 nm; and the Cryogenic
Near-IR Spectropolarimeter (Cryo-NiRSP) will provide coronal slit
spectropolarimetry from 1--5 microns. We will review the science
capabilities of these first generation instruments as well as their
synergistic use in multi-instrument observing programs to achieve
novel science investigations.
---------------------------------------------------------
Title: Funnel Prominences as Return Flows of the Chromosphere-Corona
Mass Cycle: SDO/AIA Observations of Coronal Condensation
Authors: Liu, Wei; Berger, T.; Low, B. C.
2013SPD....44...42L Altcode:
It has recently been proposed that prominences play an important role
as return flows of the chromosphere-corona mass cycle, in which hot
plasma is transported upward in forms of spicules and prominence bubbles
(likely due to flux emergence), while cool plasma drains downward in
forms of vertical prominence threads (Berger et al. 2011 Nature). A
critical step in this cycle is the condensation of the million-degree
coronal plasma into T<10,000 K prominence material by a radiative
cooling instability (i.e., thermal non-equilibrium), as numerically
simulated (Karpen & Antiochos 2008; Xia et al. 2012) and first
evidenced in recent SDO/AIA observations (Liu et al. 2012; Berger et
al. 2012 ApJL). Such a runaway cooling process occurs in coronal loops
of various sizes and generally leads to condensation at magnetic dips
and formation of funnel-shaped prominences. A moderate-sized prominence
can drain a significant mass of typically 10^15 gram/day, which is
comparable to the mass of a CME or a fraction of the entire corona. Here
we present a survey of funnel prominences that appear to be common
in AIA observations at various locations and times. We find longer
cooling times in longer/taller coronal loops whose densities are lower,
consistent with the expected quadratic dependence on density of the
optically-thin radiative loss. We propose that such funnel prominences,
usually small in size, can constitute a new type of prominences, and
similar processes can produce elementary building blocks of large-scale
quiescent prominences in filament channels. This picture is supported
by the recent theoretical development on spontaneous formation of
current sheets and condensations manifested as prominence threads
(Low et al. 2012a, b, ApJ).Abstract (2,250 Maximum Characters): It
has recently been proposed that prominences play an important role
as return flows of the chromosphere-corona mass cycle, in which hot
plasma is transported upward in forms of spicules and prominence bubbles
(likely due to flux emergence), while cool plasma drains downward in
forms of vertical prominence threads (Berger et al. 2011 Nature). A
critical step in this cycle is the condensation of the million-degree
coronal plasma into T<10,000 K prominence material by a radiative
cooling instability (i.e., thermal non-equilibrium), as numerically
simulated (Karpen & Antiochos 2008; Xia et al. 2012) and first
evidenced in recent SDO/AIA observations (Liu et al. 2012; Berger et
al. 2012 ApJL). Such a runaway cooling process occurs in coronal loops
of various sizes and generally leads to condensation at magnetic dips
and formation of funnel-shaped prominences. A moderate-sized prominence
can drain a significant mass of typically 10^15 gram/day, which is
comparable to the mass of a CME or a fraction of the entire corona. Here
we present a survey of funnel prominences that appear to be common
in AIA observations at various locations and times. We find longer
cooling times in longer/taller coronal loops whose densities are lower,
consistent with the expected quadratic dependence on density of the
optically-thin radiative loss. We propose that such funnel prominences,
usually small in size, can constitute a new type of prominences, and
similar processes can produce elementary building blocks of large-scale
quiescent prominences in filament channels. This picture is supported
by the recent theoretical development on spontaneous formation of
current sheets and condensations manifested as prominence threads
(Low et al. 2012a, b, ApJ).
---------------------------------------------------------
Title: <SUP>10</SUP>Be Production in the Atmosphere by Galactic
Cosmic Rays
Authors: Matthiä, Daniel; Herbst, Klaudia; Heber, Bernd; Berger,
Thomas; Reitz, Günther
2013SSRv..176..333M Altcode: 2011SSRv..tmp..290M
Galactic cosmic ray nuclei and energetic protons produced in solar
flares and accelerated by coronal mass ejections are the main sources
of high-energy particles of extraterrestrial origin in near-Earth space
and inside the Earth's atmosphere. The intensity of galactic cosmic
rays inside the heliosphere is strongly influenced by the modulation of
the interstellar source particles on their way through interplanetary
space. Among others, this modulation depends on the activity of the Sun,
and the resulting intensity of the energetic particles in the atmosphere
is an indicator of the solar activity. Therefore, rare isotopes
found in historical archives and produced by spallation reactions
of primary and secondary hadrons of cosmic origin in the atmosphere,
so-called cosmogenic nuclides, can be used to reconstruct the solar
activity in the past. The production rate of <SUP>10</SUP>Be, one of
the cosmogenic nuclides most adequate to study the solar activity,
is presented showing its variations with geographic latitude and
altitude and the dependence on different production cross-sections
present in literature. In addition, estimates for altitude integrated
production rates of <SUP>10</SUP>Be at different locations since the
early nineteen sixties are shown.
---------------------------------------------------------
Title: The Advanced Technology Solar Telescope: Science Drivers and
Construction Status
Authors: Rimmele, Thomas; Berger, Thomas; McMullin, Joseph; Keil,
Stephen; Goode, Phil; Knoelker, Michael; Kuhn, Jeff; Rosner, Robert;
Casini, Roberto; Lin, Haosheng; Woeger, Friedrich; von der Luehe,
Oskar; Tritschler, Alexandra; Atst Team
2013EGUGA..15.6305R Altcode:
The 4-meter Advance Technology Solar Telescope (ATST) currently
under construction on the 3000 meter peak of Haleakala on Maui,
Hawaii will be the world's most powerful solar telescope and the
leading ground-based resource for studying solar magnetism. The
solar atmosphere is permeated by a 'magnetic carpet' that constantly
reweaves itself to control solar irradiance and its effects on Earth's
climate, the solar wind, and space weather phenomena such as flares and
coronal mass ejections. Precise measurement of solar magnetic fields
requires a large-aperture solar telescope capable of resolving a few
tens of kilometers on the solar surface. With its 4 meter aperture,
the ATST will for the first time resolve magnetic structure at the
intrinsic scales of plasma convection and turbulence. The ATST's
ability to perform accurate and precise spectroscopic and polarimetric
measurements of magnetic fields in all layers of the solar atmosphere,
including accurate mapping of the elusive coronal magnetic fields,
will be transformative in advancing our understanding of the magnetic
solar atmosphere. The ATST will utilize the Sun as an important astro-
and plasma-physics "laboratory" demonstrating key aspects of omnipresent
cosmic magnetic fields. The ATST construction effort is led by the US
National Solar Observatory. State-of-the-art instrumentation will be
constructed by US and international partner institutions. The technical
challenges the ATST is facing are numerous and include the design of the
off-axis main telescope, the development of a high order adaptive optics
system that delivers a corrected beam to the instrument laboratory,
effective handling of the solar heat load on optical and structural
elements, and minimizing scattered light to enable observations
of the faint corona. The ATST project has transitioned from design
and development to its construction phase. The project has awarded
design and fabrication contracts for major telescope subsystems. Site
construction has commenced following the successful conclusion of
the site permitting process. Science goals and construction status of
telescope and instrument systems will be discussed.
---------------------------------------------------------
Title: Comparison of solar horizontal velocity fields from SDO/HMI
and Hinode data
Authors: Roudier, Th.; Rieutord, M.; Prat, V.; Malherbe, J. M.; Renon,
N.; Frank, Z.; Švanda, M.; Berger, T.; Burston, R.; Gizon, L.
2013A&A...552A.113R Altcode: 2013arXiv1303.4271R
Context. The measurement of the Sun's surface motions with a high
spatial and temporal resolution is still a challenge. <BR /> Aims:
We wish to validate horizontal velocity measurements all over the
visible disk of the Sun from Solar Dynamics Observatory/ Helioseismic
and Magnetic Imager (SDO/HMI) data. <BR /> Methods: Horizontal velocity
fields are measured by following the proper motions of solar granules
using a newly developed version of the coherent structure tracking
(CST) code. The comparison of the surface flows measured at high
spatial resolution (Hinode, 0.1 arcsec) and low resolution (SDO/HMI,
0.5 arcsec) allows us to determine corrections to be applied to
the horizontal velocity measured from HMI white light data. <BR />
Results: We derive horizontal velocity maps with spatial and temporal
resolutions of respectively 2.5 Mm and 30 min. From the two components
of the horizontal velocity v<SUB>x</SUB> and v<SUB>y</SUB> measured
in the sky plane and the simultaneous line of sight component from
SDO/HMI dopplergrams v<SUB>D</SUB>, we derive the spherical velocity
components (v<SUB>r</SUB>, v<SUB>θ</SUB>, v<SUB>ϕ</SUB>). The
azimuthal component v<SUB>ϕ</SUB> gives the solar differential rotation
with a high precision (± 0.037 km s<SUP>-1</SUP>) from a temporal
sequence of only three hours. <BR /> Conclusions: By following the
proper motions of the solar granules, we can revisit the dynamics of
the solar surface at high spatial and temporal resolutions from hours
to months and years with the SDO data.
---------------------------------------------------------
Title: Simulations of the Dynamics of the Magnetic Rayleigh-Taylor
Instability in Solar Prominences
Authors: Hillier, A.; Berger, T.; Shibata, K.; Isobe, H.
2013ASPC..474..147H Altcode:
The magnetic Rayleigh-Taylor instability plays an important role in the
mass and magnetic flux transport in many astrophysical bodies. Solar
prominences also display this instability and recent observations using
the Solar Optical Telescope onboard the Hinode satellite have revealed
these dynamics in amazing detail. The observations show rising plumes,
approximately 1 Mm in width, that propagate through the dense prominence
material from low-density bubbles, i.e. the situation expected when the
magnetic Rayleigh-Taylor instability occurs. To study this phenomenon,
we performed 3D simulations of the magnetic Rayleigh-Taylor instability
in the Kippenhahn-Schlüter prominence model. The plumes formed in
these simulations are filamentary structures that are aligned with
the magnetic field created as 3D modes of the magnetic Rayleigh-Taylor
instability. The plumes rise, developing large structures from smaller
structures through an inverse cascade process driven by nonlinear
interaction. The results suggest that the plumes observed in the
prominence may be used to study the conditions inside the prominence.
---------------------------------------------------------
Title: How Galactic Cosmic Ray models affect the estimation of
radiation exposure in space
Authors: Mrigakshi, Alankrita Isha; Matthiä, Daniel; Berger, Thomas;
Reitz, Günther; Wimmer-Schweingruber, Robert F.
2013AdSpR..51..825M Altcode:
The radiation environment in space is a major concern for human
spaceflight because of the adverse effects of high levels of radiation
on astronauts' health. Therefore, it is essential to perform radiation
risk assessments already during the concept studies of a manned
mission. Galactic Cosmic Rays (GCR) have been identified to be one of
the primary sources of radiation exposure in space.This work presents
an evaluation of the radiation exposure caused by GCR between 1970
and 2011 in near-Earth interplanetary space and at the orbit of the
International Space Station (ISS) by making numerical simulations
with the Monte-Carlo framework GEANT4. Commonly used GCR models -
CREME96, CREME2009 and Badhwar-O'Neill2010 are used to describe the
GCR spectra and the differences arising from the application of these
different models in terms of absorbed dose and dose equivalent rates
are investigated. Additionally, the depth distribution of the dose
quantities and the relative contribution of particles with different
energies to the total exposure during solar maximum and minimum
conditions are studied.The differences in the spectra, described by
the models, result in considerable differences in the estimation of
the radiation exposure.
---------------------------------------------------------
Title: A ready-to-use galactic cosmic ray model
Authors: Matthiä, Daniel; Berger, Thomas; Mrigakshi, Alankrita I.;
Reitz, Günther
2013AdSpR..51..329M Altcode:
Galactic cosmic ray nuclei close to Earth are of great importance
in different fields of research. By studying their intensity in
near-Earth interplanetary space and modeling their modulation in the
heliosphere it is possible to gain knowledge both about the structure
of the heliosphere and the transport processes within. Additionally,
secondary phenomena like cloud formation, ionization processes in
the atmosphere, cosmogenic nuclide production and radiation exposure
in space and at aviation altitudes are related to the intensity of
the galactic cosmic rays and their modulation in the heliosphere. In
order to improve the knowledge about these processes and underlying
mechanisms it is often beneficial to perform numerical simulations. A
necessary prerequisite for such simulations is a model describing the
galactic cosmic ray intensities for all particle types and energies of
importance. Several of these models exist in the literature. However,
many of these do not provide essential characteristics like the
description of heavier nuclei or it is difficult to associate them to
recent or actual solar modulation conditions. In this work a model
is presented which describes the galactic cosmic ray spectra of
nuclei based on a single parameter. The values of this parameter for
different solar modulation conditions are derived from measurements
of the Advanced Composition Explorer (ACE) spacecraft and Oulu neutron
monitor count rates. Comparing the galactic cosmic ray spectra predicted
by the model to a comprehensive set of experimental data from literature
shows very good agreement.
---------------------------------------------------------
Title: GRB 130605A: continued Skynet/PROMPT observations.
Authors: Trotter, A.; Lacluyze, A.; Reichart, D.; Haislip, J.; Berger,
T.; Carroll, M.; Cromartie, H. T.; Egger, R.; Foster, A.; Foster, C.;
Frank, N.; Ivarsen, K.; James, D.; Maples, M.; Moore, J.; Nysewander,
M.; Speckhard, E.; Taylor, P.; Crain, J. A.
2013GCN.14778....1T Altcode: 2013GCN..14778...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130514A: Skynet/PROMPT/DSO detections.
Authors: Trotter, A.; Reichart, D.; Haislip, J.; Lacluyze, A.; Smith,
A.; Caton, D.; Hawkins, L.; Berger, T.; Cromartie, H. T.; Egger, R.;
Foster, A.; Frank, N.; Ivarsen, K.; Maples, M.; Moore, J.; Nysewander,
M.; Speckhard, E.; Crain, J. A.
2013GCN.14648....1T Altcode: 2013GCN..14648...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130912A: skynet DSO-14/Yerkes-41/PROMPT-CTIO observations.
Authors: Trotter, A.; Reichart, D.; Haislip, J.; Lacluyze, A.; Smith,
A. B.; Caton, D.; Hawkins, L.; Hoette, V.; Cudworth, K.; Harper, D.;
Kron, R.; Linder, T.; Russell, R.; Struble, E.; Berger, T.; Cromartie,
H. T.; Egger, R.; Foster, A.; Frank, N.; Ivarsen, K.; Maples, M.;
Moore, J.; Nysewander, M.; Crain, J. A.
2013GCN.15218....1T Altcode: 2013GCN..15218...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 131117A: skynet PROMPT optical detection of an afterglow.
Authors: Trotter, A.; Reichart, D.; Haislip, J.; Frank, N.; Lacluyze,
A.; Moore, J.; Berger, T.; Cromartie, H. T.; Egger, R.; Foster, A.;
Ivarsen, K.; Maples, M.; Nysewander, M.; Crain, J. A.
2013GCN.15491....1T Altcode: 2013GCN..15491...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130831A: continued Skynet/PROMPT-SSO, PROMPT-CTIO and
Yerkes-41 detections.
Authors: Trotter, A.; Haislip, J.; Reichart, D.; Lacluyze, A.;
Moore, J.; Frank, N.; Hoette, V.; Harper, D.; Kron, R.; Cudworth,
K.; Struble, E.; Russell, R.; Berger, T.; Cromartie, H. T.; Egger,
R.; Foster, A.; Ivarsen, K.; Maples, M.; Nysewander, M.; Crain, J. A.
2013GCN.15164....1T Altcode: 2013GCN..15164...1T
No abstract at ADS
---------------------------------------------------------
Title: On MATROSHKA / DOSTEL Data Interpretation
Authors: Labrenz, Johannes; Berger, Thomas; Burmeister, Soenke; Heber,
Bernd; Reitz, Guenther
2013ICRC...33.2302L Altcode:
MATROSHKA (MTR) is an ESA experiment facility under the science and
project lead of DLR Cologne. The radiation exposure inside a human
phantom is measured by active and passive radiation detectors. The
DOSimetry TELescope (DOSTEL), built at CAU Kiel in cooperation with
DLR Cologne, is a particle telescope consisting of two Si-semiconductor
detectors. Count rates as well as energy deposition spectra are measured
by this instrument. The DOSTEL was operating during the first MATROSHKA
mission phase (MTR-1) where the phantom was mounted outside the Zvezda
module (Service Module SM) of the ISS from Feb. 2004 to Aug. 2005. The
DOSTEL count rate measurements showed the expected dependence on
the geomagnetic vertical cutoff rigidity (Rc). In this work a time
correction method for the DOSTEL data using this Rc dependence will
be presented.
---------------------------------------------------------
Title: GRB 130521A: Skynet/PROMPT observations.
Authors: James, D.; Foster, C.; Taylor, P.; Carroll, M.; Trotter,
A.; Reichart, D.; Lacluyze, A.; Haislip, J.; Berger, T.; Cromartie,
H. T.; Egger, R.; Foster, A.; Frank, N.; Ivarsen, K.; Maples, M.;
Moore, J.; Nysewander, M.; Speckhard, E.; Crain, J. A.
2013GCN.14697....1J Altcode: 2013GCN..14697...1J
No abstract at ADS
---------------------------------------------------------
Title: GRB 130615A: continued Skynet/PROMPT observations.
Authors: Frank, N.; Trotter, A.; Haislip, J.; Reichart, D.; Lacluyze,
A.; Berger, T.; Carroll, M.; Cromartie, H. T.; Egger, R.; Foster, A.;
Foster, C.; Ivarsen, K.; James, D.; Maples, M.; Moore, J.; Nysewander,
M.; Speckhard, E.; Taylor, P.; Crain, J. A.
2013GCN.14909....1F Altcode: 2013GCN..14909...1F
No abstract at ADS
---------------------------------------------------------
Title: The Calibration of the Flight Radiation Environment Detector
(FRED)
Authors: Möller, T.; Berger, T.; Böttcher, S.; Burmeister,
S.; Ehresmann, B.; Heber, B.; Labrenz, J.; Panitzsch, L.;
Wimmer-Schweingruber, R. F.
2013ICRC...33.1977M Altcode:
The mixed radiation field in the Earth's atmosphere is caused by the
interaction of cosmic and trapped radiation with the atmosphere. A
plethora of secondary particles is created which, together with
the primary radiation, creates this complex natural mixed radiation
field. Apart from charged particles (predominantly protons, electrons,
muons, pions, and alpha particles)), it also contains neutral
particles, i.e., neutrons and gamma rays, which are generally difficult
to measure. The Flight Radiation Environment Detector (FRED) was
designed to measure quantitatively the contributions of the charged and
neutral components. It consists of four segmented silicon solid-state
detectors which form a particle telescope and also form an efficient
anti-coincidence to separate the neutral radiation. Thus FRED is also
designed to measure the respective dose rate from charged and neutral
particles. Here we present the general design of FRED and the results
of a calibration campaign at the Heavy Ion Medical Accelerator in Chiba
(HIMAC) facility at the National Institute of Radiological Sciences
(NIRS), Japan.
---------------------------------------------------------
Title: GRB 130907A: skynet DSO-14/Yerkes-41/GORT confirmation of a
fading afterglow.
Authors: Trotter, A.; Reichart, D.; Haislip, J.; Lacluyze, A.; McLin,
K.; Cominsky, L.; Smith, A. B.; Caton, D.; Hawkins, L.; Hoette, V.;
Cudworth, K.; Harper, D.; Kron, R.; Linder, T.; Russell, R.; Struble,
E.; Berger, T.; Cromartie, H. T.; Egger, R.; Foster, A.; Frank, N.;
Ivarsen, K.; Maples, M.; Moore, J.; Nysewander, M.; Crain, J. A.
2013GCN.15193....1T Altcode: 2013GCN..15193...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130420A: continued Skynet/GORT Observations/Detections.
Authors: Trotter, A.; Frank, N.; Lacluyze, A.; Reichart, D.; McLin,
K.; Cominsky, L.; Berger, T.; Cromartie, H. T.; Egger, R.; Foster,
A.; Haislip, J.; Ivarsen, K.; Maples, M.; Moore, J.; Nysewander, M.;
Speckhard, E.; Crain, J. A.
2013GCN.14445....1T Altcode: 2013GCN..14445...1T
No abstract at ADS
---------------------------------------------------------
Title: Skynet/GORT observations of GRB130420A.
Authors: Trotter, A.; Frank, N.; Lacluyze, A.; Reichart, D.; McLin,
K.; Cominsky, L.; Berger, T.; Crain, J. A.; Cromartie, H. T.; Egger,
R.; Foster, A.; Haislip, J.; Ivarsen, K.; Maples, M.; Moore, J.;
Nysewander, M.; Speckhard, E.
2013GCN.14427....1T Altcode: 2013GCN..14427...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130612A: Skynet/PROMPT detection of the optical afterglow.
Authors: Trotter, A.; Hailslip, J.; Reichart, D.; Lacluyze, A.;
Berger, T.; Carroll, M.; Cromartie, H. T.; Egger, R.; Foster, A.;
Foster, C.; Frank, N.; Ivarsen, K.; James, D.; Maples, M.; Moore,
J.; Nysewander, M.; Speckhard, E.; Taylor, P.; Crain, J. A.
2013GCN.14877....1T Altcode: 2013GCN..14877...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130427A: skynet detections of a possible supernova.
Authors: Trotter, A.; Reichart, D.; Haislip, J.; Lacluyze, A.;
McLin, K.; Cominsky, L.; Smith, A.; Caton, D.; Hawkins, L.; Holmes,
B.; Linder, T.; Berger, T.; Cromartie, H. T.; Egger, R.; Foster,
A.; Frank, N.; Ivarsen, K.; Maples, M.; Moore, J.; Nysewander, M.;
Speckhard, E.; Crain, J. A.
2013GCN.14662....1T Altcode: 2013GCN..14662...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130427A: ten nights of Skynet/PROMPT/GORT observations.
Authors: Trotter, A.; Reichart, D.; Haislip, J.; Lacluyze, A.; McLin,
K.; Cominsky, L.; Berger, T.; Cromartie, H. T.; Egger, R.; Foster,
A.; Frank, N.; Ivarsen, K.; Maples, M.; Moore, J.; Nysewander, M.;
Speckhard, E.; Crain, J. A.
2013GCN.14608....1T Altcode: 2013GCN..14608...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130427A: Skynet/PROMPT observations.
Authors: Trotter, A.; Reichart, D.; Haislip, J.; Lacluyze, A.; Berger,
T.; Cromartie, H. T.; Egger, R.; Foster, A.; Frank, N.; Ivarsen, K.;
Maples, M.; Moore, J.; Nysewander, M.; Speckhard, E.; Crain, J. A.
2013GCN.14497....1T Altcode: 2013GCN..14497...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130606A: continued Skynet/PROMPT observations.
Authors: Trotter, A.; Lacluyze, A.; Reichart, D.; Haislip, J.; Berger,
T.; Carroll, M.; Cromartie, H. T.; Egger, R.; Foster, A.; Foster, C.;
Frank, N.; Ivarsen, K.; James, D.; Maples, M.; Moore, J.; Nysewander,
M.; Speckhard, E.; Taylor, P.; Crain, J. A.
2013GCN.14826....1T Altcode: 2013GCN..14826...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130615A: Skynet/PROMPT observations.
Authors: Frank, N.; Trotter, A.; Haislip, J.; Reichart, D.; Lacluyze,
A.; Berger, T.; Carroll, M.; Cromartie, H. T.; Egger, R.; Foster, A.;
Foster, C.; Ivarsen, K.; James, D.; Maples, M.; Moore, J.; Nysewander,
M.; Speckhard, E.; Taylor, P.; Crain, J. A.
2013GCN.14901....1F Altcode: 2013GCN..14901...1F
No abstract at ADS
---------------------------------------------------------
Title: GRB 130521A: Skynet/PROMPT detection of an extremely red
afterglow.
Authors: James, D.; Foster, C.; Taylor, P.; Carroll, M.; Trotter,
A.; Reichart, D.; Lacluyze, A.; Haislip, J.; Berger, T.; Cromartie,
H. T.; Egger, R.; Foster, A.; Frank, N.; Ivarsen, K.; Maples, M.;
Moore, J.; Nysewander, M.; Speckhard, E.; Crain, J. A.
2013GCN.14713....1J Altcode: 2013GCN..14713...1J
No abstract at ADS
---------------------------------------------------------
Title: GRB 130610A: Skynet/PROMPT detection of the optical afterglow.
Authors: Trotter, A.; Haislip, J.; Lacluyze, A.; Reichart, D.; Berger,
T.; Carroll, M.; Cromartie, H. T.; Egger, R.; Foster, A.; Frank,
N.; Ivarsen, K.; James, D.; Maples, M.; Moore, J.; Nysewander, M.;
Speckhard, E.; Taylor, P.; Crain, J. A.
2013GCN.14844....1T Altcode: 2013GCN..14844...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130919A: skynet PROMPT-CTIO optical upper limits.
Authors: Trotter, A.; Reichart, D.; Haislip, J.; Lacluyze, A.; Moore,
J.; Frank, N.; Ivarsen, K.; Nysewander, M.; Foster, A.; Berger, T.;
Cromartie, H. T.; Egger, R.; Maples, M.; Crain, J. A.
2013GCN.15235....1T Altcode: 2013GCN..15235...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130907A: skynet DSO-14/Yerkes-41 detections of a possible
afterglow.
Authors: Trotter, A.; Haislip, J.; Lacluyze, A.; Moore, J.; Frank, N.;
Reichart, D.; Smith, A.; Caton, D.; Hawkins, L.; Hoette, V.; Harper,
D.; Kron, R.; Cudworth, K.; Struble, E.; Russell, R.; Linder, T.;
Berger, T.; Cromartie, H. T.; Egger, R.; Foster, A.; Ivarsen, K.;
Maples, M.; Nysewander, M.; Crain, J. A.
2013GCN.15191....1T Altcode: 2013GCN..15191...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 131024A: skynet R-COP optical observations.
Authors: Trotter, A.; Haislip, J.; Reichart, D.; Verveer, A.; Spuck,
T.; Lacluyze, A.; Frank, N.; Moore, J.; Berger, T.; Cromartie,
H. T.; Egger, R.; Foster, A.; Ivarsen, K.; Maples, M.; Nysewander,
M.; Speckhard, E.; Crain, J. A.
2013GCN.15369....1T Altcode: 2013GCN..15369...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130606A: Skynet/PROMPT detection of the optical afterglow.
Authors: Trotter, A.; Lacluyze, A.; Reichart, D.; Haislip, J.; Berger,
T.; Carroll, M.; Cromartie, H. T.; Egger, R.; Foster, A.; Foster, C.;
Frank, N.; Ivarsen, K.; James, D.; Maples, M.; Moore, J.; Nysewander,
M.; Speckhard, E.; Taylor, P.; Crain, J. A.
2013GCN.14815....1T Altcode: 2013GCN..14815...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 131004A: skynet PROMPT/DSO-14 upper limits.
Authors: Frank, N.; Trotter, A.; Reichart, D.; Haislip, J.; Lacluyze,
A.; Smith, A.; Caton, D.; Hawkins, L.; Berger, T.; Cromartie, H. T.;
Egger, R.; Foster, A.; Ivarsen, K.; Maples, M.; Moore, J.; Nysewander,
M.; Speckhard, E.; Crain, J. A.
2013GCN.15317....1F Altcode: 2013GCN..15317...1F
No abstract at ADS
---------------------------------------------------------
Title: GRB 130719A: Skynet/PROMPT observations.
Authors: Trotter, A.; Reichart, D.; Lacluyze, A.; Haislip, J.; Berger,
T.; Carroll, M.; Cromartie, H. T.; Egger, R.; Foster, A.; Foster, C.;
Frank, N.; Ivarsen, K.; James, D.; Maples, M.; Moore, J.; Nysewander,
M.; Speckhard, E.; Taylor, P.; Crain, J. A.
2013GCN.15030....1T Altcode: 2013GCN..15030...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130605A: Skynet/PROMPT detection of a fading afterglow.
Authors: Trotter, A.; Lacluyze, A.; Reichart, D.; Haislip, J.; Berger,
T.; Carroll, M.; Cromartie, H. T.; Egger, R.; Foster, A.; Foster, C.;
Frank, N.; Ivarsen, K.; James, D.; Maples, M.; Moore, J.; Nysewander,
M.; Speckhard, E.; Taylor, P.; Crain, J. A.
2013GCN.14776....1T Altcode: 2013GCN..14776...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130831A: Skynet/PROMPT-SSO detections.
Authors: Trotter, A.; Haislip, J.; Lacluyze, A.; Moore, J.; Frank,
N.; Reichart, D.; Berger, T.; Cromartie, H. T.; Egger, R.; Foster,
A.; Ivarsen, K.; Maples, M.; Nysewander, M.; Crain, J. A.
2013GCN.15148....1T Altcode: 2013GCN..15148...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130427A: continued Skynet/PROMPT observations.
Authors: Trotter, A.; Reichart, D.; Haislip, J.; Lacluyze, A.; Berger,
T.; Cromartie, H. T.; Egger, R.; Foster, A.; Frank, N.; Ivarsen, K.;
Maples, M.; Moore, J.; Nysewander, M.; Speckhard, E.; Crain, J. A.
2013GCN.14510....1T Altcode: 2013GCN..14510...1T
No abstract at ADS
---------------------------------------------------------
Title: GRB 130612A: continued Skynet/PROMPT/GORT/DSO observations.
Authors: Carroll, M.; Trotter, A.; Hailslip, J.; Reichart, D.;
Lacluyze, A.; McLin, K.; Cominsky, L.; Smith, A.; Caton, D.; Hawkins,
L.; Berger, T.; Cromartie, H. T.; Egger, R.; Foster, A.; Foster, C.;
Frank, N.; Ivarsen, K.; James, D.; Maples, M.; Moore, J.; Nysewander,
M.; Speckhard, E.; Taylor, P.; Crain, J. A.
2013GCN.14914....1C Altcode: 2013GCN..14914...1C
No abstract at ADS
---------------------------------------------------------
Title: GRB 130722A: Skynet/GORT observations.
Authors: Trotter, A.; Reichart, D.; McLin, K.; Cominsky, L.; Berger,
T.; Carroll, M.; Cromartie, H. T.; Egger, R.; Foster, A.; Foster, C.;
Frank, N.; Haislip, J.; Ivarsen, K.; James, D.; Lacluyze, A.; Maples,
M.; Moore, J.; Nysewander, M.; Speckhard, E.; Taylor, P.; Crain, J. A.
2013GCN.15017....1T Altcode: 2013GCN..15017...1T
No abstract at ADS
---------------------------------------------------------
Title: The Prominence/Coronal Cavity System: A Unified View of
Magnetic Structures in the Solar Corona
Authors: Berger, T.
2012ASPC..463..147B Altcode:
Hinode/SOT and SDO/AIA movies have given us new insights into the
dynamic connections between prominences and coronal cavities. The
observations suggest that prominences and coronal cavities are
elements of a single large-scale structure in the solar corona:
a helical magnetic flux rope. We discuss supporting observational
evidence such as the relationship between the so-called “prominence
bubbles” discovered by Hinode/SOT and coronal cavities, as well as
spiral flows in the central regions of coronal cavities observed by
AIA. We hypothesize that coronal cavity flux ropes support a form
of magneto-thermal convection in which hot plasma and magnetic
flux are transported upward into the coronal cavity flux rope
with subsequent radiative cooling and condensation forming the
partially ionized prominence return flows seen in visible light
observations. Understanding the mass, magnetic flux, and helicity
transport of this complex system will lead to better understanding of
quiet Sun coronal mass ejections (CMEs).
---------------------------------------------------------
Title: Radiation exposure in the moon environment
Authors: Reitz, Guenther; Berger, Thomas; Matthiae, Daniel
2012P&SS...74...78R Altcode:
During a stay on the moon humans are exposed to elevated radiation
levels due to the lack of substantial atmospheric and magnetic shielding
compared to the Earth's surface. The absence of magnetic and atmospheric
shielding allows cosmic rays of all energies to impinge on the lunar
surface. Beside the continuous exposure to galactic cosmic rays
(GCR), which increases the risk of cancer mortality, exposure through
particles emitted in sudden nonpredictable solar particle events (SPE)
may occur. SPEs show an enormous variability in particle flux and energy
spectra and have the potential to expose space crew to life threatening
doses. On Earth, the contribution to the annual terrestrial dose of
natural ionizing radiation of 2.4 mSv by cosmic radiation is about
1/6, whereas the annual exposure caused by GCR on the lunar surface
is roughly 380 mSv (solar minimum) and 110 mSv (solar maximum). The
analysis of worst case scenarios has indicated that SPE may lead to an
exposure of about 1 Sv. The only efficient measure to reduce radiation
exposure is the provision of radiation shelters. Measurements on the
lunar surface performed during the Apollo missions cover only a small
energy band for thermal neutrons and are not sufficient to estimate
the exposure. Very recently some data were added by the Radiation Dose
Monitoring (RADOM) instrument operated during the Indian Chandrayaan
Mission and the Cosmic Ray Telescope (CRaTER) instrument of the NASA LRO
(Lunar Reconnaisance Orbiter) mission. These measurements need to be
complemented by surface measurements. Models and simulations that exist
describe the approximate radiation exposure in space and on the lunar
surface. The knowledge on the radiation exposure at the lunar surface
is exclusively based on calculations applying radiation transport codes
in combination with environmental models. Own calculations are presented
using Monte-Carlo simulations to calculate the radiation environment on
the moon and organ doses on the surface of the moon for an astronaut in
an EVA suit and are compared with measurements. Since it is necessary to
verify/validate such calculations with measurement on the lunar surface,
a description is given of a radiation detector for future detailed
surface measurements. This device is proposed for the ESA Lunar Lander
Mission and is capable to characterize the radiation field concerning
particle fluencies, dose rates and energy transfer spectra for ionizing
particles and to measure the dose contribution of secondary neutrons.
---------------------------------------------------------
Title: The Mobile Dosimetric Telescope - A Small Size Active
Personal Dosimeter for Application at High Altitudes and Onboard
the International Space Station
Authors: Ritter, B.; Marsalek, K.; Berger, T.; Burmeister, S.; Reitz,
G.; Heber, B.
2012AGUFMSM23B2308R Altcode:
The radiation environment at cruising altitudes, as well as in Low Earth
Orbit - like on the International Space Station - differs significantly
from the natural radiation environment on Earth. Especially in Low Earth
Orbit it poses one of the main health risks for long duration human
missions. Therefore, it is essential to monitor the properties of the
radiation field in such environments. The Mobile Dosimetric Telescope
MDT, is a small size battery driven personal dosimeter based on silicon
detector technology that has been developed to observe absorbed dose and
dose rate in real time. Two silicon diodes are arranged in a telescope
configuration, which allows the measurement of the ionizing constituents
of the radiation field and partially the neutral contribution to the
dose. The absorbed dose is obtained by considering every particle in
either of the detectors. Particles traversing both diodes are detected
as coincidence events that enable to derive linear energy transfer (LET)
spectra. From these the quality factor of the field is determined,
which is necessary for the estimation of the dose equivalent. The
detection range of the device covers energy depositions from minimal
ionizing particles up to relativistic heavy ions. Calibrations of the
detector system have been performed with various radioactive sources and
with heavy ions at the Heavy Ion Medical Accelerator (HIMAC) facility
at the National Institute for Radiological Sciences (NIRS) in Chiba,
Japan. Additionally, the MDT has been successfully tested onboard
aircraft. The results of these measurements are in good agreement with
those from other radiation detectors. The presentation will focus on
data taken during long haul flights in the northern hemisphere.
---------------------------------------------------------
Title: 2nd ATST-EAST Workshop in Solar Physics: Magnetic Fields from
the Photosphere to the Corona
Authors: Rimmele, T. R.; Tritschler, A.; Wöger, F.; Collados Vera,
M.; Socas-Navarro, H.; Schlichenmaier, R.; Carlsson, M.; Berger, T.;
Cadavid, A.; Gilbert, P. R.; Goode, P. R.; Knölker, M.
2012ASPC..463.....R Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Assessment of Galactic Cosmic Ray Models and Implications on
the Estimation of Radiation Exposure in Space
Authors: Mrigakshi, A. I.; Matthiä, D.; Berger, T.; Reitz, G.;
Wimmer-Schweingruber, R. F.
2012AGUFMSM23B2309M Altcode:
Astronauts are subjected to elevated levels of high-energy
ionizing radiation in space which poses a substantial risk to their
health. Therefore, the assessment of the radiation exposure for long
duration manned spaceflight is essential. This is done by measuring
dose using various detector techniques and by performing numerical
simulations utilizing radiation transport codes which allow to predict
radiation exposure for future missions and for conditions where
measurements are not feasible or available. A necessary prerequisite
for an accurate estimation of the exposure using the latter approach
is a reliable description of the radiation spectra. Accordingly,
in order to estimate the exposure from the Galactic Cosmic Rays
(GCRs), which are one of the major sources of radiation exposure in
space, GCR models are required. This work presents an evaluation
of GCR models for dosimetry purposes and the effect of applying
these models on the estimation of GCR exposure in space outside
and inside the Earth's magnetosphere. To achieve this, widely used
GCR models - Badhwar-O'Neill2010, Burger-Usoskin, CREME2009 and
CREME96, were evaluated by comparing model spectra for light and
heavy nuclei with measurements from various high-altitude balloon
and space missions over several decades. Additionally a new model,
based on the GCR-ISO model, developed at the German Aerospace Centre
(DLR) was also investigated. The differences arising in the radiation
exposure by applying these models are quantified in terms of absorbed
dose and dose equivalent rates that were estimated numerically using
the GEANT4 Monte-Carlo framework. During certain epochs in the last
decade, there are large discrepancies between the model and the measured
spectra. All models exhibit weaknesses in describing the increased GCR
flux that was observed in 2009-2010. The differences in the spectra,
described by the models, result in considerable differences in the
estimated dose quantities.
---------------------------------------------------------
Title: Supporting Mars exploration: BIOMEX in Low Earth Orbit and
further astrobiological studies on the Moon using Raman and PanCam
technology
Authors: de Vera, Jean-Pierre; Boettger, Ute; Noetzel, Rosa de
la Torre; Sánchez, Francisco J.; Grunow, Dana; Schmitz, Nicole;
Lange, Caroline; Hübers, Heinz-Wilhelm; Billi, Daniela; Baqué,
Mickael; Rettberg, Petra; Rabbow, Elke; Reitz, Günther; Berger,
Thomas; Möller, Ralf; Bohmeier, Maria; Horneck, Gerda; Westall,
Frances; Jänchen, Jochen; Fritz, Jörg; Meyer, Cornelia; Onofri,
Silvano; Selbmann, Laura; Zucconi, Laura; Kozyrovska, Natalia; Leya,
Thomas; Foing, Bernard; Demets, René; Cockell, Charles S.; Bryce,
Casey; Wagner, Dirk; Serrano, Paloma; Edwards, Howell G. M.; Joshi,
Jasmin; Huwe, Björn; Ehrenfreund, Pascale; Elsaesser, Andreas; Ott,
Sieglinde; Meessen, Joachim; Feyh, Nina; Szewzyk, Ulrich; Jaumann,
Ralf; Spohn, Tilman
2012P&SS...74..103D Altcode:
The Low Earth Orbit (LEO) experiment Biology and Mars Experiment
(BIOMEX) is an interdisciplinary and international space research
project selected by ESA. The experiment will be accommodated on the
space exposure facility EXPOSE-R2 on the International Space Station
(ISS) and is foreseen to be launched in 2013. The prime objective of
BIOMEX is to measure to what extent biomolecules, such as pigments
and cellular components, are resistant to and able to maintain
their stability under space and Mars-like conditions. The results of
BIOMEX will be relevant for space proven biosignature definition and
for building a biosignature data base (e.g. the proposed creation
of an international Raman library). The library will be highly
relevant for future space missions such as the search for life on
Mars. The secondary scientific objective is to analyze to what extent
terrestrial extremophiles are able to survive in space and to determine
which interactions between biological samples and selected minerals
(including terrestrial, Moon- and Mars analogs) can be observed under
space and Mars-like conditions. In this context, the Moon will be an
additional platform for performing similar experiments with negligible
magnetic shielding and higher solar and galactic irradiation compared to
LEO. Using the Moon as an additional astrobiological exposure platform
to complement ongoing astrobiological LEO investigations could thus
enhance the chances of detecting organic traces of life on Mars. We
present a lunar lander mission with two related objectives: a lunar
lander equipped with Raman and PanCam instruments which can analyze the
lunar surface and survey an astrobiological exposure platform. This dual
use of testing mission technology together with geo- and astrobiological
analyses will significantly increase the science return, and support
the human preparation objectives. It will provide knowledge about
the Moon's surface itself and, in addition, monitor the stability
of life-markers, such as cells, cell components and pigments, in an
extraterrestrial environment with much closer radiation properties to
the surface of Mars. The combination of a Raman data base of these
data together with data from LEO and space simulation experiments,
will lead to further progress on the analysis and interpretation of
data that we will obtain from future Moon and Mars exploration missions.
---------------------------------------------------------
Title: Science with Large Solar Telescopes: Addressing Key Science
Questions with New Observing Modes
Authors: Berger, T.
2012IAUSS...6E.201B Altcode:
We review the capabilities of existing and future large solar telescopes
with an emphasis on the key science questions that these instruments
must address. Large solar telescopes coming online now, as well as
the 4-meter ATST coming online in 2018 are tasked with extending high
resolution and polarimetric investigations from the lower atmospheric
regions into the higher regions and connecting the dynamics between
the two. The overall goal is to understand the interaction of flows and
magnetic fields in the convection zone down to O(10) km scales and the
magnetohydrodynamic transport, storage, and release of energy in the
upper atmosphere leading to coronal heating and eruptive events. The
ATST in particular will have unique opportunities to address this goal
with new observations of the infrared atmosphere at very high spatial
resolution and with coronagraphic capabilities. We discuss some of
the multi-instrument ATST observing programs that will investigate
such topics as small-scale magnetoconvection and energetic events in
the lower atmosphere and energy release in filament eruptions.
---------------------------------------------------------
Title: SDO/AIA Detection of Solar Prominence Formation within a
Coronal Cavity
Authors: Berger, Thomas E.; Liu, Wei; Low, B. C.
2012ApJ...758L..37B Altcode: 2012arXiv1208.3431B
We report the first analyses of SDO/AIA observations of the formation of
a quiescent polar crown prominence in a coronal cavity. The He II 304 Å
(log T <SUB>max </SUB> ~ 4.8 K) data show both the gradual disappearance
of the prominence due to vertical drainage and lateral transport of
plasma followed by the formation of a new prominence 12 hr later. The
formation is preceded by the appearance of a bright emission "cloud"
in the central region of the coronal cavity. The peak brightness of
the cloud progressively shifts in time from the Fe XIV 211 Å channel,
through the Fe XII 193 Å channel, to the Fe IX 171 Å channel (log T
<SUB>max </SUB> ~ 6.2, 6.1, 5.8 K, respectively) while simultaneously
decreasing in altitude. Filter ratio analysis estimates the initial
temperature of the cloud to be approximately log T ~ 6.25 K with
evidence of cooling over time. The subsequent growth of the prominence
is accompanied by darkening of the cavity in the 211 Å channel. The
observations imply prominence formation via in situ condensation of hot
plasma from the coronal cavity, in support of our previously proposed
process of magnetothermal convection in coronal magnetic flux ropes.
---------------------------------------------------------
Title: Numerical Simulations of the Magnetic Rayleigh-Taylor
Instability in the Kippenhahn-Schlüter Prominence
Model. II. Reconnection-triggered Downflows
Authors: Hillier, Andrew; Isobe, Hiroaki; Shibata, Kazunari; Berger,
Thomas
2012ApJ...756..110H Altcode: 2011arXiv1106.2613H
The launch of the Hinode satellite has allowed high-resolution
observations of supersonic bright downflows in quiescent prominences,
known as prominence knots. We present observations in the Ca
II H spectral line using the Solar Optical Telescope on board
the Hinode satellite of a descending plasma knot of size ~900
km. The knot initially undergoes ballistic motion before undergoing
impulsive accelerations at the same time as experiencing increases
in intensity. We also present a subset of our three-dimensional
magnetohydrodynamic simulations, performed to investigate the
nonlinear stability of the Kippenhahn-Shlüter prominence model
to the magnetic Rayleigh-Taylor instability in which interchange
reconnection occurs. The interchange reconnection in the model
breaks the force balance along the field lines which initiates the
downflows. The downflows propagate with a downward fluid velocity
of ~15 km s<SUP>-1</SUP> and a characteristic size of ~700 km. We
conclude that the observed plasma blob and the simulated downflow are
driven by the breaking of the force balance along the magnetic field
as a result of a change in magnetic topology caused by reconnection
of the magnetic field.
---------------------------------------------------------
Title: The interface region imaging spectrograph for the IRIS Small
Explorer mission
Authors: Wülser, Jean-Pierre; Title, Alan M.; Lemen, James R.; De
Pontieu, Bart; Kankelborg, Charles C.; Tarbell, Theodore D.; Berger,
Thomas E.; Golub, Leon; Kushner, Gary D.; Chou, Catherine Y.; Weingrod,
Isaac; Holmes, Buck; Mudge, Jason; Podgorski, William A.
2012SPIE.8443E..08W Altcode:
The Interface Region Imaging Spectrograph (IRIS) is a NASA SMall
EXplorer mission scheduled for launch in January 2013. The primary goal
of IRIS is to understand how the solar atmosphere is energized. The
IRIS investigation combines advanced numerical modeling with a high
resolution UV imaging spectrograph. IRIS will obtain UV spectra
and images with high resolution in space (0.4 arcsec) and time (1s)
focused on the chromosphere and transition region of the Sun, a complex
interface region between the photosphere and corona. The IRIS instrument
uses a Cassegrain telescope to feed a dual spectrograph and slit-jaw
imager that operate in the 133-141 nm and 278-283 nm ranges. This paper
describes the instrument with emphasis on the imaging spectrograph,
and presents an initial performance assessment from ground test results.
---------------------------------------------------------
Title: The Hydromagnetic Interior of a Solar Quiescent
Prominence. II. Magnetic Discontinuities and Cross-field Mass
Transport
Authors: Low, B. C.; Liu, W.; Berger, T.; Casini, R.
2012ApJ...757...21L Altcode:
This second paper of the series investigates the transverse response
of a magnetic field to the independent relaxation of its flux tubes
of fluid seeking hydrostatic and energy balance, under the frozen-in
condition and suppression of cross-field thermal conduction. The
temperature, density, and pressure naturally develop discontinuities
across the magnetic flux surfaces separating the tubes, requiring the
finite pressure jumps to be compensated by magnetic-pressure jumps in
cross-field force balance. The tangentially discontinuous fields are
due to discrete currents in these surfaces, δ-function singularities
in the current density that are fully admissible under the rigorous
frozen-in condition but must dissipate resistively if the electrical
conductivity is high but finite. The magnetic field and fluid must
thus endlessly evolve by this spontaneous formation and resistive
dissipation of discrete currents taking place intermittently in
spacetime, even in a low-β environment. This is a multi-dimensional
effect in which the field plays a central role suppressed in the
one-dimensional (1D) slab model of the first paper. The study begins
with an order-of-magnitude demonstration that of the weak resistive
and cross-field thermal diffusivities in the corona, the latter is
significantly weaker for small β. This case for spontaneous discrete
currents, as an important example of the general theory of Parker, is
illustrated with an analysis of singularity formation in three families
of two-dimensional generalizations of the 1D slab model. The physical
picture emerging completes the hypothesis formulated in Paper I that
this intermittent process is the origin of the dynamic interiors of
a class of quiescent prominences revealed by recent Hinode/SOT and
SDO/AIA high-resolution observations.
---------------------------------------------------------
Title: Quiescent Prominence Dynamics: An Update on Hinode/SOT
Discoveries
Authors: Berger, T.
2012ASPC..454...79B Altcode:
Hinode/SOT has revealed two new flow systems in quiescent prominences:
large-scale (order 10 Mm) “bubbles” or “arches” that
“inflate” below prominences to create dark cavities in the
prominence, and small-scale (order 1 Mm) dark plumes that rise
with constant velocity to heights of 10-20 Mm above their origin
at the base of prominences. Both flow systems are highly dynamic
with ascent speeds ranging from 1-30 km s<SUP>-1</SUP> and evidence
in the small-scale plumes of Kelvin-Helmholtz instabilities and
turbulent mixing. Neither flow system has been observed in active
region prominences. Multi-instrument analysis of one typical cavity
shows the column density to be at least a factor of 5 less than the
overlying prominence plasma. We discuss the developing understanding
of these flow systems in the context of a single formation mechanism:
buoyancy instabilities in an emerging flux rope that interacts with
the overlying prominence. Measurements of plume and bubble sizes and
occurrence frequencies, combined with the column density finding,
implies that these flows are a significant source of mass and magnetic
flux for quiescent prominences and coronal cavities, respectively.
---------------------------------------------------------
Title: Plasma Instabilities in Quiescent Prominences
Authors: Ryutova, M.; Berger, T.; Frank, Z.; Title, A.; Tarbell, T.
2012ASPC..454..143R Altcode:
We study dynamics of quiescent prominences using several data sets
taken with the SOT on Hinode. We find a number of processes occurring
at different stages of the prominence evolution that are common for
all the chosen cases, and having universal character, can be related
to a fundamental plasma instabilities. We combine the observational
evidence and theory to identify these instabilities. Here we discuss
only two examples: (1) Coronal cavity formation under a prominence
body and its evolution associated with screw pinch instability, and
(2) Development of a regular series of plumes and spikes typical to
the Rayleigh-Taylor instability modified by solenoidal magnetic field.
---------------------------------------------------------
Title: Simulations of Buoyant Plumes in Solar Prominences
Authors: Hurlburt, N.; Berger, T.
2012ASPC..454..137H Altcode: 2012arXiv1201.4352H
Observations of solar prominences reveal a complex, dynamic flow
field within them. The flow field within quiescent prominences
is characterized by long "threads" and dark "bubbles" that fall
and rise (respectively) in a thin sheet. The flow field in active
prominences display more helical motions that travel along the axis
of the prominence. We explore the possible dynamics of both of these
with the aid of 2.5D MHD simulations. Our model, compressible plasma
possesses density and temperature gradients and resides in magnetic
field configurations that mimc those of a solar prominence. We present
results of various configurations and discuss the nonlinear behavior
of the resulting dynamics.
---------------------------------------------------------
Title: The Hydromagnetic Interior of a Solar Quiescent
Prominence. I. Coupling between Force Balance and Steady Energy
Transport
Authors: Low, B. C.; Berger, T.; Casini, R.; Liu, W.
2012ApJ...755...34L Altcode: 2012arXiv1203.1056L
This series of papers investigates the dynamic interiors of quiescent
prominences revealed by recent Hinode and SDO/AIA high-resolution
observations. This first paper is a study of the static equilibrium
of the Kippenhahn-Schlüter diffuse plasma slab, suspended vertically
in a bowed magnetic field, under the frozen-in condition and subject
to a theoretical thermal balance among an optically thin radiation,
heating, and field-aligned thermal conduction. The everywhere-analytical
solutions to this nonlinear problem are an extremely restricted subset
of the physically admissible states of the system. For most values
of the total mass frozen into a given bowed field, force balance
and steady energy transport cannot both be met without a finite
fraction of the total mass having collapsed into a cold sheet of zero
thickness, within which the frozen-in condition must break down. An
exact, resistive hydromagnetic extension of the Kippenhahn-Schlüter
slab is also presented, resolving the mass-sheet singularity into
a finite-thickness layer of steadily falling dense fluid. Our
hydromagnetic result suggests that the narrow, vertical prominence
H<SUB>α</SUB> threads may be falling across magnetic fields, with
optically thick cores much denser and ionized to much lower degrees than
conventionally considered. This implication is discussed in relation
to (1) the recent SDO/AIA observations of quiescent prominences that
are massive and yet draining mass everywhere in their interiors, (2)
the canonical range of 5-60 G determined from spectral polarimetric
observations of prominence magnetic fields over the years, and (3)
the need for a more realistic multi-fluid treatment.
---------------------------------------------------------
Title: Assessment of galactic cosmic ray models
Authors: Mrigakshi, Alankrita Isha; Matthiä, Daniel; Berger, Thomas;
Reitz, Günther; Wimmer-Schweingruber, Robert F.
2012JGRA..117.8109M Altcode: 2012JGRA..11708109M
Among several factors involved in the development of a manned
space mission concept, the astronauts' health is a major concern
that needs to be considered carefully. Galactic cosmic rays (GCRs),
which mainly consist of high-energetic nuclei ranging from hydrogen to
iron and beyond, pose a major radiation health risk in long-term space
missions. It is therefore required to assess the radiation exposure of
astronauts in order to estimate their radiation risks. This can be done
either by performing direct measurements or by making computer based
simulations from which the dose can be derived. A necessary prerequisite
for an accurate estimation of the exposure using simulations is a
reliable description of the GCR spectra. The aim of this work is to
compare GCR models and to test their applicability for the exposure
assessment of astronauts. To achieve this, commonly used models capable
of describing both light and heavy GCR particle spectra were evaluated
by investigating the model spectra for various particles over several
decades. The updated Badhwar-O'Neill model published in the year
2010, CREME2009 which uses the International Standard model for GCR,
CREME96 and the Burger-Usoskin model were examined. Hydrogen, helium,
oxygen and iron nuclei spectra calculated by the different models are
compared with measurements from various high-altitude balloon and
space-borne experiments. During certain epochs in the last decade,
there are large discrepancies between the GCR energy spectra described
by the models and the measurements. All the models exhibit weaknesses
in describing the increased GCR flux that was observed in 2009-2010.
---------------------------------------------------------
Title: The Power Spectrum of the Solar Surface Flows from Hinode
Data and First Observations with MOF/CALAS Pic-du-Midi
Authors: Roudier, T.; Rieutord, M.; Rincon, F.; Malherbe, J. -M.;
Brito, D.; Berger, T.; Frank, Z.; Parés, L.; Bourrec, E.; Beigbeder,
F.
2012ASPC..454...47R Altcode:
Many features of solar surface turbulence, like the supergranulation,
are still poorly understood.We use long time series of images taken by
the Solar Optical Telescope on board the Hinode satellite to determine
the velocity fields. The dynamics in the subgranulation range can
be investigated with unprecedented precision thanks to the absence
of seeing effects and the use of the MTF of SOT for correcting the
spectra. The first MOF/CALAS/Pic-du-Midi results are also shown.
---------------------------------------------------------
Title: Simulations of MATROSHKA experiment outside the ISS using PHITS
Authors: Puchalska, M.; Sihver, L.; Sato, T.; Berger, T.; Reitz, G.
2012AdSpR..50..489P Altcode:
The radiation environment at the altitude of the International Space
Station (ISS) is substantially different than anything typically
encountered on Earth in both the character of the radiation field and
the significantly higher dose rates. Concerns about the biological
effects on humans of this highly complex natural radiation field are
increasing due to higher amount of astronauts performing long-duration
missions onboard the ISS and especially if looking into planned future
manned missions to Mars. In order to begin the process of predicting the
dose levels seen by the organs of an astronaut, being the prerequisite
for radiation risk calculations, it is necessary to understand the
character of the radiation environment both in- and outside of the
ISS as well as the relevant contributions from the radiation field
to the organ doses. In this paper the three-dimensional Monte Carlo
Particle and Heavy Ion Transport code System (PHITS) and a voxel-based
numerical human model NUNDO (Numerical RANDO) were used to estimate
the radiation load of human organs during a long term activity outside
the ISS. The baseline measured data was generated with the MATROSHKA-1
(MTR-1) experiment taking place from February 2004 up to October 2005
outside the Russian Zvezda module of the ISS, thereby simulating a
long term extravehicular activity (EVA) of an astronaut. The organ
absorbed dose values calculated by PHITS for the inner organs are in
a good agreement with the experimental data. However, a rather large
disagreement was observed for the most outer organs. This disagreement
appears to be due to the strong dependence that the thickness of the
applied carbon fiber container, acting as the EVA suit of the astronaut,
has on the effects caused by the trapped electron (TE) component. The
organ dose equivalent values for the deeper organs are a factor of two
lower than the experimental data. The detailed reason behind this is
still under investigation.
---------------------------------------------------------
Title: The DOSIS and DOSIS 3D Experiments onboard the International
Space Station - Results from the Active DOSTEL Instruments
Authors: Burmeister, Soenke; Berger, Thomas; Reitz, Guenther; Beaujean,
Rudolf; Boehme, Matthias; Haumann, Lutz; Labrenz, Johannes; Kortmann,
Onno
2012cosp...39..261B Altcode: 2012cosp.meet..261B
Besides the effects of the microgravity environment, and the
psychological and psychosocial problems experienced in confined spaces,
radiation is the main health detriment for long duration human space
missions. The radiation environment encountered in space differs in
nature from that on earth, consisting mostly of high energetic ions
from protons up to iron, resulting in radiation levels far exceeding
the ones present on earth for occupational radiation workers. Accurate
knowledge of the physical characteristics of the space radiation
field in dependence on the solar activity, the orbital parameters
and the different shielding configurations of the International Space
Station ISS is therefore needed. For the investigation of the spatial
and temporal distribution of the radiation field inside the European
COLUMBUS module the experiment DOSIS (Dose Distribution Inside the
ISS) under the lead of DLR was launched on July 15th 2009 with STS-127
to the ISS. The experimental package was transferred from the Space
Shuttle into COLUMBUS on July 18th. It consists of a combination of
passive detector packages (PDP) distributed at 11 locations inside
the European Columbus Laboratory and two active radiation detectors
(DOSTELs) with a DDPU (DOSTEL Data and Power Unit) in a nomex pouch
(DOSIS MAIN BOX) mounted at a fixed location beneath the European
Physiology Module rack (EPM) inside COLUMBUS. The DOSTELs measured
during the lowest solar minimum conditions in the space age from
July 18th 2009 to June 16th 2011. In July 2011 the active hardware
was transferred to ground for refurbishment and preparation for the
DOSIS-3D experiment. The hardware will be launched with the Soyuz 30S
flight to the ISS on May 15th 2012 and activated approximately ten
days later. Data will be transferred from the DOSTEL units to ground
via the EPM rack which is activated approximately every four weeks for
this action. First Results for the active DOSIS-3D measurements such
as count rate profiles, dose rates and LET spectra will be presented
in comparison to the data of the DOSIS experiment as well as the DOSMAP
experiment which has been performed during solar maximum in 2001.
---------------------------------------------------------
Title: Presentation of the Biochip experiment on the EXPOSE-R2
facility aboard the International Space Station
Authors: Vigier, Flavie; Cottin, Hervé; Dobrijevic, Michel; Berger,
Thomas; Coussot, Gaelle; Incerti, Sebastien; Vandenabeele-Trambouze,
Odile; Le Postollec, Aurelie; Chaput, Didier
2012cosp...39.2091V Altcode: 2012cosp.meet.2091V
No abstract at ADS
---------------------------------------------------------
Title: Biological Weighting of Depth Dose Distribution in a Heavy
Ion Exposed Phantom Head
Authors: Hellweg, Christine; Baumstark-Khan, Christa; Schmitz,
Claudia; Berger, Thomas; Reitz, Guenther; Chishti, Arif Ali; Koerner,
Dipl. -(FH). Christine; Feles, Sebastian; La Tessa, Chiara; Lau,
Patrick
2012cosp...39..745H Altcode: 2012cosp.meet..745H
No abstract at ADS
---------------------------------------------------------
Title: Intercomparison of luminescence detectors for space radiation
dosimetry within Proton-ICCHIBAN experiments
Authors: Uchihori, Yukio; Ploc, Ondrej; Yasuda, Nakahiro; Berger,
Thomas; Hajek, Michael; Kodaira, Satoshi; Benton, Eric; Ambrozova,
Iva; Kitamura, Hisashi
2012cosp...39.2025U Altcode: 2012cosp.meet.2025U
Luminescence detectors for space radiation dosimetry are frequently
used to estimate personal and environmental doses in the International
Space Station and other space vehicles. Detector responses for cosmic
rays and their secondaries were investigated for a long time and it is
well-known that luminescence detectors have dependencies of response
on LET (Linear Energy Transfer). Some of luminescence detectors show
over-response to gamma rays (used for routine calibration) and others
have similar responses to gamma rays. But, because of lack of sufficient
and reliable calibration data in the low LET region (about 1 keV/μm),
it is the responses of these detectors at LET is poorly known. Protons
make up the dominant portion of the fluence from space radiation, so
the LET region corresponding to energetic protons must be characterized
very well. For that purpose, calibration and intercomparison experiments
were performed using relatively low energy (30 to 80 MeV) proton beams
at the National Institute of Radiological Sciences, Chiba, Japan. In
this paper, the results of these intercomparison experiments, including
high energy protons and light ions, are reported and illustrate the
response of luminescence detectors in the low LET region. This research
will help improve our understanding of space dosimeters and reliable
dose measurement for astronauts and cosmonauts in low earth orbit.
---------------------------------------------------------
Title: The Mobile Dosimetric Telescope (MDT) - Development of a small
size active personal dosimeter for application at high altitudes
and onboard the International Space Station
Authors: Ritter, Birgit; Berger, Thomas; Reitz, Guenther; Burmeister,
Soenke; Heber, Bernd; Marsalek, Karel
2012cosp...39.1615R Altcode: 2012cosp.meet.1615R
The radiation environment in space poses one of the main health risks
for long duration human missions as it differs significantly from the
natural radiation environment on Earth. Therefore, it is essential to
monitor the properties of the radiation field in such environments. The
aim of this work is to develop a small size battery driven personal
dosimeter, based on silicon detector technology. Two silicon detectors
are arranged in a telescope configuration, which allows the measurement
of the ionizing constituents of the field and partially of the neutral
contribution to the dose. The absorbed dose is obtained by measuring
every particle in either of the detectors. Additionally, particles
traversing both diodes are detected as coincidences. From these
measurements linear energy transfer (LET) spectra will be generated
from which the quality factor of the field will be determined. Quality
factor times absorbed dose in the detector gives the dose equivalent -
a central quantity in radiation protection. Calibrations of the detector
system have been and will further be performed with various radioactive
sources, and with heavy ions at the Heavy Ion Medical Accelerator
(HIMAC) facility at NIRS in Chiba, Japan.
---------------------------------------------------------
Title: MATROSHKA - Results from the exposure inside the Japanese
KIBO Module - and comparison with previous missions
Authors: Berger, Thomas
2012cosp...39..147B Altcode: 2012cosp.meet..147B
No abstract at ADS
---------------------------------------------------------
Title: Altitude Dependence of the Dose Rate From Ground up to the
Stratosphere.
Authors: Möller, Thomas; Berger, Thomas; Ehresmann, Bent; Burmeister,
Soenke; Labrenz, Johannes; Heber, Bernd; Wimmer-Schweingruber, Robert;
Panitzsch, Lauri
2012cosp...39.1266M Altcode: 2012cosp.meet.1266M
No abstract at ADS
---------------------------------------------------------
Title: Assessment of Galactic Cosmic Ray Models
Authors: Isha Mrigakshi, Alankrita; Matthiä, Daniel; Berger, Thomas;
Reitz, Guenther; Wimmer-Schweingruber, Robert
2012cosp...39.1285I Altcode: 2012cosp.meet.1285I
No abstract at ADS
---------------------------------------------------------
Title: Simulations of the radiation exposure outside and inside the
Earth's magnetosphere
Authors: Isha Mrigakshi, Alankrita; Matthiä, Daniel; Berger, Thomas;
Reitz, Guenther; Wimmer-Schweingruber, Robert
2012cosp...39.1286I Altcode: 2012cosp.meet.1286I
No abstract at ADS
---------------------------------------------------------
Title: Acoustic Events in the Solar Atmosphere from Hinode/SOT
NFI Observations
Authors: Malherbe, J. -M.; Roudier, T.; Rieutord, M.; Berger, T.;
Franck, Z.
2012SoPh..278..241M Altcode: 2012arXiv1207.1170M
We investigate the properties of acoustic events (AEs), defined as
spatially concentrated and short duration energy flux, in the quiet
Sun, using observations of a 2D field of view (FOV) with high spatial
and temporal resolution provided by the Solar Optical Telescope (SOT)
onboard Hinode. Line profiles of Fe I 557.6 nm were recorded by the
Narrow-band Filter Imager (NFI) on a 82″×82″ FOV during 75 min with
a time step of 28.75 s and 0.08″ pixel size. Vertical velocities were
computed at three atmospheric levels (80, 130, and 180 km) using the
bisector technique, allowing the determination of energy flux to be
made in the range 3 - 10 mHz using two complementary methods (Hilbert
transform and Fourier power spectrum). Horizontal velocities were
computed using local correlation tracking (LCT) of continuum intensities
providing divergences. We found that the net energy flux is upward. In
the range 3 - 10 mHz, a full FOV space and time averaged flux of 2700 W
m<SUP>−2</SUP> (lower layer 80 - 130 km) and 2000 W m<SUP>−2</SUP>
(upper layer 130 - 180 km) is concentrated in less than 1 % of the
solar surface in the form of narrow (0.3″) AE. Their total duration
(including rise and decay) is of the order of 10<SUP>3</SUP> s. Inside
each AE, the mean flux is 1.6×10<SUP>5</SUP> W m<SUP>−2</SUP>
(lower layer) and 1.2×10<SUP>5</SUP> W m<SUP>−2</SUP> (upper). Each
event carries an average energy (flux integrated over space and time)
of 2.5×10<SUP>19</SUP> J (lower layer) to 1.9×10<SUP>19</SUP> J
(upper). More than 10<SUP>6</SUP> events could exist permanently on
the Sun, with a birth and decay rate of 3500 s<SUP>−1</SUP>. Most
events occur in intergranular lanes, downward velocity regions, and
areas of converging motions.
---------------------------------------------------------
Title: Simulations of the Magnetic Rayleigh-Taylor Instability in
the Kippenhahn-Schlüter Prominence Model
Authors: Hillier, A.; Berger, T.; Shibata, K.; Isobe, H.
2012ASPC..456..157H Altcode:
The launch of the Hinode satellite, with the Solar Optical Telescope,
allowed for high resolution, high time cadence observations of
prominences to be performed in the seeing free environment of
space. The most striking discovery from these observations is of
plumes, approximately 1 Mm in width, that propagate through the
prominence material. The plumes initiate from underdense bubbles that
form beneath prominences, rise at constant speeds of approximately 20
km s<SUP>-1</SUP> and are formed in the conditions required for the
magnetic Rayleigh-Taylor instability to occur. To study this phenomenon,
we performed 3D simulations of the magnetic Rayleigh-Taylor instability
in the Kippenhahn-Schlüter prominence model. The plumes formed in
these simulations are filamentary structures that are aligned with
the magnetic field created as 3D modes of the magnetic Rayleigh-Taylor
instability. The plumes rise, developing large structures from smaller
structures through an inverse cascade process driven by nonlinear
interaction. The results suggest that the plumes observed in the
prominence may be used to study the conditions inside the prominence.
---------------------------------------------------------
Title: The Rayleigh-taylor Instability In The Solar Corona: Prominence
Coronal-cavity Interactions And The Evolution To Eruptive States
Authors: Berger, Thomas
2012AAS...22050801B Altcode:
We review the discovery and analysis of the Rayleigh-Taylor
instability in quiescent solar prominences by the Hinode/SOT and
SDO/AIA instruments. The instability is apparently caused by the
emergence of magnetic flux near the polarity inversion line below the
prominences. The emerging flux is rapidly heated to coronal temperatures
of 1 MK or higher and the resulting large temperature gradient with
the cool overlying prominence plasma leads to a "magneto-thermal"
convective instability that develops into a classic Rayleigh-Taylor
system of plumes and downflows. The significance of the discovery
is that it offers a mechanism by which magnetic flux and helicity are
periodically injected into the coronal cavity flux ropes overlying solar
prominences. The increasing flux and helicity in the cavity develop
a quasi-steady evolution eventually terminating in the eruption of
a slow coronal mass ejection (Fan & Gibson 2007; Zhang, Flyer,
& Low 2006). We suggest further investigations using SDO/AIA,
ground-based observatories, and the upcoming IRIS mission to verify
and extend the SOT and AIA findings.
---------------------------------------------------------
Title: Some Dynamic Analysis of the Photosphere from Hinode/SOT and
SDO/HMI Observations
Authors: Roudier, T.; Malherbe, J.; Rieutord, M.; Berger, T.; Frank,
Z.; Prat, V.; Renon, N.; Gizon, L.; Svanda, M.
2012ASPC..456...65R Altcode:
We first present the important role played by the families of granule
(or Tree of Fragmenting granules) in the formation of the photospheric
network. Then, we describe the occurence and characteristics of
acoustic events (AE), defined as spatially concentrated energy flux,
in the quiet Sun. Finally, we present how horizontal velocities obtained
from SDO/HMI data are calibrated by using Hinode/SOT observations.
---------------------------------------------------------
Title: Emergence of Twisted Flux in Prominence Observations
Authors: Okamoto, T. J.; Tsuneta, S.; Berger, T. E.; Lites, B. W.
2012ASPC..455..123O Altcode:
The emergence of twisted flux is a key process for supply of magnetic
flux into the corona as well as solar dynamic activities such as sunspot
formation and trigger of coronal mass ejections. In particular, there
are numerous discussions about the role and necessity of twisted flux
emergence for origin of prominences. However, the difficulty to measure
vector magnetic fields has not allowed us to investigate the detailed
relationship between emerging twisted flux and prominence. Hinode has
changed the situation. The Spectro-Polarimeter aboard Hinode has high
sensitivity to weaker magnetic fields of fine structures, and provides
opportunities to detect weak horizontal magnetic fields. As a result,
we have obtained signatures of twisted flux emergence associated with
prominences: The observational features are "broadening and narrowing
of a region dominated by horizontal magnetic field" and "rotating
direction of horizontal field" on the photosphere. Moreover, the data
show the interaction between the emerging twisted flux and granules,
and that the flux rope has high intrinsic strength 650 G, while the
flux density is as low as 100 G. Theoretical research with numerical
simulation on the basis of these results is active. In addition, we
investigate activities of a coronal cavity overlying a prominence on
the limb, and suggest the existence of twisted flux rope to explain the
activities of prominence and the coronal cavity comprehensively. Here
we introduce both these observational and theoretical results, and
discuss the details about emerging twisted flux.
---------------------------------------------------------
Title: SDO/AIA Observations of Sustained Coronal Condensation in
Prominences as Return Flows of the Chromosphere-Corona Mass Cycle
Authors: Liu, Wei; Berger, T.; Low, B. C.
2012AAS...22020708L Altcode:
It has recently been proposed that prominences are manifestations
of a magneto-thermal convection process that involves ever-present
dynamic descents of cool material threads and upflows of hot bubbles
(Berger et al. 2011 Nature). On global scales, prominences may play
an important role as the return flows of the chromosphere-corona
mass cycle, in which hot mass is originally transported upward
through spicules. A critical step in this cycle is the condensation of
million-degree coronal plasma into T<10,000 K prominence material by
radiative cooling instability. However, direct observation of coronal
condensation has been difficult in the past, a situation recently
changed. We present here the first example observed with SDO/AIA,
in which hours of gradual cooling through multiple EUV channels (from
2 MK to 80,000 K) in large-scale loops leads to eventual condensation
at magnetic dips, where we find evidence of magnetic reconnection and
subsequent outflows. A moderate-size prominence of 10^14 gram is then
formed. Its mass is not static but maintained by a continual supply
through condensation at a high rate of 10^10 gram/s against a comparable
drainage through numerous vertical threads at less than free-fall
speeds. Most of the total condensation of 10^15 gram, comparable
to a CME mass and an order of magnitude more than the instantaneous
mass of the prominence itself, is drained in merely one day. These
new observations show that a macroscopically quiescent prominence is
microscopically dynamic (Liu, Berger, Low 2012 ApJL), involving the
passage of a significant mass that bears important implications for
the chromosphere-corona mass cycle. This interpretation is further
supported by the recent theoretical development on spontaneous formation
of current sheets and cool condensations (Low, Berger, Casini, &
Liu, 2012 submitted to ApJ).
---------------------------------------------------------
Title: Cosmic Radiation Exposure of Biological Test Systems During
the EXPOSE-E Mission
Authors: Berger, Thomas; Hajek, Michael; Bilski, Pawel; Körner,
Christine; Vanhavere, Filip; Reitz, Günther
2012AsBio..12..387B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Quasi full-disk maps of solar horizontal velocities using
SDO/HMI data
Authors: Roudier, Th.; Rieutord, M.; Malherbe, J. M.; Renon, N.;
Berger, T.; Frank, Z.; Prat, V.; Gizon, L.; Švanda, M.
2012A&A...540A..88R Altcode: 2012arXiv1203.0514R
<BR /> Aims: For the first time, the motion of granules (solar plasma
on the surface on scales larger than 2.5 Mm) has been followed over
the entire visible surface of the Sun, using SDO/HMI white-light
data. <BR /> Methods: Horizontal velocity fields are derived from image
correlation tracking using a new version of the coherent structure
tracking algorithm. The spatial and temporal resolutions of the
horizontal velocity map are 2.5 Mm and 30 min, respectively. <BR
/> Results: From this reconstruction, using the multi-resolution
analysis, one can obtain to the velocity field at different scales
with its derivatives such as the horizontal divergence or the vertical
component of the vorticity. The intrinsic error on the velocity is
~0.25 km s<SUP>-1</SUP> for a time sequence of 30 min and a mesh size
of 2.5 Mm. This is acceptable compared to the granule velocities, which
range between 0.3 km s<SUP>-1</SUP> and 1.8 km s<SUP>-1</SUP>. A high
correlation between velocities computed from Hinode and SDO/HMI has
been found (85%). From the data we derive the power spectrum of the
supergranulation horizontal velocity field, the solar differential
rotation, and the meridional velocity.
---------------------------------------------------------
Title: The Hydromagnetic Nature of Quiescent Prominences
Authors: Low, B. C.; Berger, T.; Casini, R.; Liu, W.
2012decs.confE..84L Altcode:
High-resolution observations of quiescent prominences with Hinode
and SDO have revealed within their interiors the ever-¬present
descent at less than free-fall speeds of cool, vertical dense
filaments interspersed among upward, narrow streams at comparable
speeds of heated, low-density plasma. We address the physical nature
of this dynamical state. Despite the high magnetic Reynolds numbers
characterizing this hydromagnetic environment, magnetic reconnection
takes place via spontaneous formation and dissipation of current sheets
by the coupled effects of highly-anisotropic thermal conduction,
gravity, optically-thin radiation, heating, and high electrical
conductivity. In this interesting new version of the theory of Parker
(1994, Spontaneous current sheets in magnetic fields, Cambridge U
Press), pervasive reconnections produce a perennial local descent of
dense condensations under gravity along newly reconnected magnetic field
lines and a concurrent turbulent rise of buoyant pockets of heated
magnetized plasma through the large-scale magnetic structure. This
mechanism may explain the massive downward drainage through a quiescent
prominence observed recently (Liu et al. 2012 ApJ 745, L21) and, in
the broader context, relate the quiescent prominence to the surrounding
chromosphere/corona as a novel, large-scale, magneto-thermal convective
phenomenon (Berger et al. 2011, Nature 472, 197).
---------------------------------------------------------
Title: SDO/AIA Observations of Sustained Coronal Condensation and Mass
Drainage in Prominences as Return Flows of the Chromosphere-Corona
Mass Cycle
Authors: Liu, Wei; Berger, Thomas; Low, B. C.
2012decs.confE..90L Altcode:
It has recently been proposed that prominences are manifestations
of a magneto-thermal convection process that involves ever-present
dynamic descents of cool material threads and upflows of hot bubbles
(Berger et al. 2011 Nature). On global scales, prominences may play
an important role as the return flows of the chromosphere-corona mass
cycle, in which hot mass is originally transported upward through
spicules. A critical step in this cycle is the condensation of
million-degree coronal plasma into T<10,000 K prominence material
by radiative cooling instability. However, direct observation of
coronal condensation has been difficult in the past, a situation
recently changed with the launch of the Hinode/SOT and SDO/AIA. We
present here the first example observed with SDO/AIA, in which hours of
gradual cooling through multiple EUV channels (from 2 MK to 80,000 K)
in large-scale loops leads to eventual condensation at magnetic dips,
forming a moderate-size prominence of 10^14 gram. The prominence
mass is not static but maintained by a continual supply through
condensation at a high rate of 10^10 gram/s against a comparable
drainage through numerous vertical threads at less than free-fall
speeds. Most of the total condensation of 10^15 gram, comparable
to a CME mass and an order of magnitude more than the instantaneous
mass of the prominence itself, is drained in merely one day. These
new observations show that a macroscopically quiescent prominence
is microscopically dynamic, involving the passage of a significant
mass that bears important implications for the chromosphere-corona
mass cycle. This interpretation is further supported by the recent
theoretical development on spontaneous formation of current sheets
and cool condensations (Low, Berger, Casini, & Liu, this meeting).
---------------------------------------------------------
Title: The Prominence/Coronal Cavity Connection: using Hinode, AIA,
and IRIS to explore the source of quiet-Sun CMEs
Authors: Berger, Thomas
2012decs.confE..29B Altcode:
The Hinode and SDO/AIA missions have revolutionized our view of
prominences and coronal cavities. Hinode/SOT observations have
established that quiescent prominences are extremely dynamic structures
with constant filamentary downflows, rising magnetic "bubbles"
that lead to Rayleigh-Taylor instability flows, and various MHD wave
modes. SDO/AIA has shown that coronal cavities have helical magnetic
topology and that quiescent prominences and coronal cavities should
be viewed as elements of a single magnetic system: magnetic flux ropes
in the corona, by far the largest coherent magnetic structures on the
Sun and the source of all quiet-Sun CMEs. In this talk we review the
Hinode/SOT and SDO/AIA observations of prominences and coronal cavities
to demonstrate the unification of these previously disparate topics. We
conclude with a look at possible measurements using IRIS to further
our understanding of this complex chromospheric/coronal magnetic system.
---------------------------------------------------------
Title: First SDO/AIA Observation of Solar Prominence Formation
Following an Eruption: Magnetic Dips and Sustained Condensation
and Drainage
Authors: Liu, Wei; Berger, Thomas E.; Low, B. C.
2012ApJ...745L..21L Altcode:
Imaging solar coronal condensation forming prominences was difficult
in the past, a situation recently changed by Hinode and the Solar
Dynamics Observatory (SDO). We present the first example observed with
the SDO/Atmospheric Imaging Assembly, in which material gradually cools
through multiple EUV channels in a transequatorial loop system that
confines an earlier eruption. Nine hours later, this leads to eventual
condensation at the dips of these loops, forming a moderate-size
prominence of ~10<SUP>14</SUP> g, to be compared to the characteristic
10<SUP>15</SUP> g mass of a coronal mass ejection (CME). The prominence
mass is not static but maintained by condensation at a high estimated
rate of 10<SUP>10</SUP> g s<SUP>-1</SUP> against a comparable, sustained
drainage through numerous vertical downflow threads, such that 96% of
the total condensation (~10<SUP>15</SUP> g) is drained in approximately
one day. The mass condensation and drainage rates temporally correlate
with the total prominence mass. The downflow velocity has a narrow
Gaussian distribution with a mean of 30 km s<SUP>-1</SUP>, while the
downward acceleration distribution has an exponential drop with a
mean of ~1/6 g <SUB>⊙</SUB>, indicating a significant canceling of
gravity, possibly by the Lorentz force. Our observations show that
a macroscopically quiescent prominence is microscopically dynamic,
involving the passage of a significant mass through it, maintained
by a continual mass supply against a comparable mass drainage, which
bears important implications for CME initiation mechanisms in which
mass unloading is important.
---------------------------------------------------------
Title: Numerical Simulations of the Magnetic Rayleigh-Taylor
Instability in the Kippenhahn-Schlüter Prominence Model. I. Formation
of Upflows
Authors: Hillier, Andrew; Berger, Thomas; Isobe, Hiroaki; Shibata,
Kazunari
2012ApJ...746..120H Altcode:
The launch of the Hinode satellite led to the discovery of rising
plumes, dark in chromospheric lines, that propagate from large
(~10 Mm) bubbles that form at the base of quiescent prominences. The
plumes move through a height of approximately 10 Mm while developing
highly turbulent profiles. The magnetic Rayleigh-Taylor instability
was hypothesized to be the mechanism that drives these flows. In this
study, using three-dimensional (3D) MHD simulations, we investigate the
nonlinear stability of the Kippenhahn-Schlüter prominence model for the
interchange mode of the magnetic Rayleigh-Taylor instability. The model
simulates the rise of a buoyant tube inside the quiescent prominence
model, where the interchange of magnetic field lines becomes possible
at the boundary between the buoyant tube and the prominence. Hillier
et al. presented the initial results of this study, where upflows of
constant velocity (maximum found 6 km s<SUP>-1</SUP>) and a maximum
plume width ≈1.5 Mm which propagate through a height of approximately
6 Mm were found. Nonlinear interaction between plumes was found to be
important for determining the plume dynamics. In this paper, using
the results of ideal MHD simulations, we determine how the initial
parameters for the model and buoyant tube affect the evolution of
instability. We find that the 3D mode of the magnetic Rayleigh-Taylor
instability grows, creating upflows aligned with the magnetic field
of constant velocity (maximum found 7.3 km s<SUP>-1</SUP>). The width
of the upflows is dependent on the initial conditions, with a range
of 0.5-4 Mm which propagate through heights of 3-6 Mm. These results
are in general agreement with the observations of the rising plumes.
---------------------------------------------------------
Title: Simulations of the magnetic Rayleigh-Taylor instability in
a quiescent prominence model to study the dark upflows observed
in prominences
Authors: Hillier, A. S.; Berger, T. E.; Shibata, K.; Isobe, H.
2011AGUFMSH33A2033H Altcode:
Observations of quiescent prominences by the Solar Optical Telescope
(SOT) on board the Hinode satellite show plumes of hot, underdense
material rising through the prominence. These plumes form at the
boundary between the prominence and low density bubbles, approximately
10 Mm in size, that appear beneath the prominence, and then rise
through the prominence material at speeds of approximately 20 km/s and
widths of approximately 1.5 Mm. The plume profile ranges from highly
turbulent to smooth, suggesting that the prominence conditions, as well
as those of the bubble, are important in determining the dynamics. To
investigate this phenomenon, we perform simulations of the magnetic
Rayleigh-Taylor instability in a local prominence model. The instability
creates rising plumes of hot, underdense material that propagate through
the prominence material at a velocity of approximately 6-7 km/s and
widths of approximately 1.5 Mm, in rough agreement with the Hinode
observations. Nonlinear effects, in which the interaction between
plumes drives an inverse cascade process creating large plumes from
smaller plumes, are found to be important. Increasing the magnetic
field strength creates smoother plume structures. The addition of a
strong guide field, which is suggested in some prominence models, does
not hinder plume formation but does change the dynamic scaling. The
Rayleigh-Taylor instability drives an upward flow of magnetic energy
and a downward flow of mass. The results from the simulations well
match the characteristics of the observed plumes, suggesting that
the magnetic Rayleigh-Taylor instability could be important in
determining prominence structure as well as changing the magnetic
energy distribution in overlying coronal cavities which ultimately
erupt as coronal mass ejections.
---------------------------------------------------------
Title: Quiescent Prominences, Coronal Cavities, and Coronal Mass
Ejections: a unified systems viewpoint
Authors: Berger, T. E.
2011AGUFMSH33A2034B Altcode:
We review the observed relationships between polar crown quiescent
prominences, coronal cavities, and polar crown CMEs with the goal of
understanding these phenomena as aspects of a single magnetic system. We
propose that the fundamental structure is a helical magnetic flux
rope suspended in the corona. Coronal cavities are the (view-angle
dependent) markers of the density depletion in the core of the flux
rope. Quiescent prominences are plasma flow systems in the current
sheet region below the flux rope. The recently discovered coronal
prominence bubbles that propagate via a Rayleigh-Taylor instability
through the prominence region are injections of new magnetic flux and
helicity into the coronal flux rope. Flux ropes erupt as slow coronal
mass ejections when the magnetic energy density exceeds that of the
overlying "arcade" fields, essentially forming a "magnetic bubble"
that "floats" away from the Sun. We emphasize that this system and
its mechanism of eruption may not be applicable to the much stronger
magnetic fields in active region prominence formations.
---------------------------------------------------------
Title: Numerical Simulations of the Magnetic Rayleigh-Taylor
Instability in the Kippenhahn-Schlüter Prominence Model
Authors: Hillier, Andrew; Isobe, Hiroaki; Shibata, Kazunari; Berger,
Thomas
2011ApJ...736L...1H Altcode: 2011arXiv1107.4882A
The launch of the Hinode satellite has allowed unprecedented
high-resolution, stable images of solar quiescent prominences to
be taken over extended periods of time. These new images led to the
discovery of dark upflows that propagated from the base of prominences,
developing highly turbulent profiles. As yet, how these flows are driven
is not fully understood. To study the physics behind these phenomena,
we use three-dimensional magnetohydrodynamic simulations to investigate
the nonlinear stability of the Kippenhahn-Shlüter prominence model
to the magnetic Rayleigh-Taylor instability. The model simulates the
rise of a buoyant tube inside a quiescent prominence, where the upper
boundary between the tube and prominence model is perturbed to excite
the interchange of magnetic field lines. We found upflows of constant
velocity (maximum found 6 km s<SUP>-1</SUP>) and a maximum plume
width ≈1500 km which propagate through a height of approximately 6
Mm in the no guide field case. The case with the strong guide field
(initially B<SUB>y</SUB> = 2B<SUB>x</SUB> ) results in a large plume
that rises through the prominence model at ~5 km s<SUP>-1</SUP> with
width ~900 km (resulting in width of 2400 km when viewed along the
axis of the prominence), reaching a height of ~3.1 Mm. In both cases,
nonlinear processes were important for determining plume dynamics.
---------------------------------------------------------
Title: Flares Producing Well-organized Post-flare Arcades (Slinkies)
Have Early Precursors
Authors: Ryutova, M. P.; Frank, Z.; Hagenaar, H.; Berger, T.
2011ApJ...733..125R Altcode:
Exploding loop systems producing X-ray flares often, but not always,
bifurcate into a long-living, well-organized system of multi-threaded
loop arcades resembling solenoidal slinkies. The physical conditions
that cause or prevent this process are not known. To address this
problem, we examined most of the major (X-class) flares that occurred
during the last decade and found that the flares that bifurcate into
long-living slinky arcades have different signatures than those that
do not "produce" such structures. The most striking difference is that,
in all cases of slinky formation, GOES high energy proton flux becomes
significantly enhanced 10-24 hr before the flare occurs. No such effect
was found prior to the "non-slinky" flares. This fact may be associated
with the difference between energy production by a given active region
and the amount of energy required to bring the entire system into
the form of well-organized, self-similar loop arcades. As an example
illustrating the process of post-flare slinky formation, we present
observations taken with the Hinode satellite, in several wavelengths,
showing a time sequence of pre-flare and flare activity, followed by
the formation of dynamically stable, well-organized structures. One
of the important features revealed is that post-flare coronal slinky
formation is preceded by scale invariant structure formation in the
underlying chromosphere/transition region. We suggest that the observed
regularities can be understood within the framework of self-organized
critical dynamics characterized by scale invariant structure formation
with critical parameters largely determined by energy saturation
level. The observed regularities per se may serve as a long-term
precursor of strong flares and may help to study predictability of
system behavior.
---------------------------------------------------------
Title: SDO/AIA Observations of Coronal Condensation Leading to
Prominence Formation
Authors: Liu, Wei; Berger, T.; Low, B. C.; Casini, R.
2011SPD....42.2119L Altcode: 2011BAAS..43S.2119L
Coronal condensation takes place when million degree coronal plasma
undergoes radiative cooling instability. Direct observation of coronal
condensation in prominences has been difficult in the past, but with the
launch of the Hinode/SOT and SDO/AIA instruments, numerous observations
of plasma condensing "out of nowhere" high up in quiescent prominences
have been captured. We present here one such event seen with SDO/AIA. On
25-Nov-2010, a prominence above the southwest limb is swept away by
a nearby eruption, and for next a few hours there is no visible 304
A material in the local corona. Then, a portion of the coronal loops
at the same location progressively sags and forms a local dip, where
the first sign of new, cool material appears, 7.5 hours after the
eruption. This is a clear indication of coronal condensation, and the
gradual sag of the loops is likely a result of increasing weight of
the condensed material that has been accumulated at the dip. Similar
condensation occurs nearby at a larger rate and leads to the formation
of a moderate-size prominence. The estimated prominence mass increases
linearly for about 7 hours at a rate of 2.6e10 grams/sec and reaches
approximately 6e14 grams. Simultaneously, the prominence drains through
vertical flows of approximately 32 km/s, bringing the mass back to the
chromosphere. We estimate the mass drain rate to be 2.7e10 grams/sec,
which, together with the estimated mass accumulation rate, implies a
coronal condensation rate of approximately 5.3e10 grams/sec. This study
can provide critical information about the coupling between condensation
energetics and MHD, prominence mass cycles, and coronal mass ejections
initiated by loss of anchoring prominence mass (e.g., Low 2001).
---------------------------------------------------------
Title: Filament and Prominence Research with the Advanced Technology
Solar Telescope
Authors: Berger, Thomas
2011SPD....42.0802B Altcode: 2011BAAS..43S.0802B
Recent advances in our understanding of solar filaments on the disk
and prominences off the limb have come primarily from the Hinode/Solar
Optical Telescope (SOT) and the Solar Dynamics Observatory/Atmospheric
Imaging Assembly (AIA). These moderate spatial and temporal resolution
instruments offer the huge advantage of seeing-free, low-scattering,
observations from space. However they are limited in their abilities
to provide spectral and/or polarimetric information. In contrast,
the ATST will provide extremely high spatial and temporal resolution
images of both filaments and prominences in a wide variety of spectral
lines and polarimetric modes. We review recent SOT and AIA research
as well as the current science questions regarding the formation and
dynamics of filaments and prominences and their role in active and
quiet-region coronal mass ejections. We then discuss key measurements
that the ATST is expected to make and how these measurements will
significantly advance our understanding of these enigmatic markers of
magnetic energy storage in the solar corona.
---------------------------------------------------------
Title: A Droplet Model of Quiescent Prominence Downflows
Authors: Haerendel, G.; Berger, T.
2011ApJ...731...82H Altcode:
Observations of quiescent prominences with the Solar Optical
Telescope on the Hinode satellite have revealed the ubiquitous
existence of downflows forming coherent thin and highly structured
vertically oriented threads with velocities between 10 and 20 km
s<SUP>-1</SUP>. Their widths range between 300 and 500 km. They are
often initiated at the top of the visible prominence, but sometimes also
at intermediate level. We propose that the downflows are made of plasma
packets that squeeze themselves through the dominantly horizontal field
under the action of gravity. Their origin is assumed to be hot plasma
supplied from either inside or the immediate vicinity of the prominence
and condensing at its top. Under compression and further cooling,
the matter overflows to the flanks of the prominence dragging its
magnetic field with it. Under the increasing action of gravity, vertical
structures are forming which eventually disconnect from the field of
the inflow channel thus forming finite plasma packets. This process is
reminiscent of water flowing over a mountain ridge and breaking up into
a multitude of droplets. Like water droplets being subject to air drag,
the falling plasma droplets experience a drag force by the horizontal
prominence field and assume a steady vertical velocity. This happens via
the excitation of Alfvén waves. Lateral confinement by the prominence
field determines their spatial extent. The small scales of the droplets
and the directional balance of their internal tangled magnetic fields
can explain the absence of appreciable vertical components in magnetic
field measurements. On the basis of the observed width and vertical
speed of the downflows and by adopting a prominence field of about 8 G,
we derive central density and temperature of the droplets, which turn
out to be quite consistent with known prominence characteristics. In
the formulation of the drag force a dimensionless "magnetic drag
coefficient" has been introduced with a value well below unity.
---------------------------------------------------------
Title: Magneto-thermal convection in solar prominences
Authors: Berger, Thomas; Testa, Paola; Hillier, Andrew; Boerner, Paul;
Low, Boon Chye; Shibata, Kazunari; Schrijver, Carolus; Tarbell, Ted;
Title, Alan
2011Natur.472..197B Altcode:
Coronal cavities are large low-density regions formed by
hemispheric-scale magnetic flux ropes suspended in the Sun's outer
atmosphere. They evolve over time, eventually erupting as the dark
cores of coronal mass ejections. Although coronal mass ejections are
common and can significantly affect planetary magnetospheres, the
mechanisms by which cavities evolve to an eruptive state remain poorly
understood. Recent optical observations of high-latitude `polar crown'
prominences within coronal cavities reveal dark, low-density `bubbles'
that undergo Rayleigh-Taylor instabilities to form dark plumes rising
into overlying coronal cavities. These observations offered a possible
mechanism for coronal cavity evolution, although the nature of the
bubbles, particularly their buoyancy, was hitherto unclear. Here we
report simultaneous optical and extreme-ultraviolet observations of
polar crown prominences that show that these bubbles contain plasma at
temperatures in the range (2.5-12)×10<SUP>5</SUP> kelvin, which is
25-120 times hotter than the overlying prominence. This identifies a
source of the buoyancy, and suggests that the coronal cavity-prominence
system supports a novel form of magneto-thermal convection in the solar
atmosphere, challenging current hydromagnetic concepts of prominences
and their relation to coronal cavities.
---------------------------------------------------------
Title: Chromospheric Jet and Growing "Loop" Observed by Hinode: New
Evidence of Fan-spine Magnetic Topology Resulting from Flux Emergence
Authors: Liu, Wei; Berger, Thomas E.; Title, Alan M.; Tarbell,
Theodore D.; Low, B. C.
2011ApJ...728..103L Altcode: 2010arXiv1012.1897L
We present observations of a chromospheric jet and growing "loop" system
that show new evidence of a fan-spine topology resulting from magnetic
flux emergence. This event, occurring in an equatorial coronal hole on
2007 February 9, was observed by the Hinode Solar Optical Telescope in
the Ca II H line in unprecedented detail. The predecessor of the jet is
a bundle of fine material threads that extend above the chromosphere and
appear to rotate about the bundle axis at ~50 km s<SUP>-1</SUP> (period
lsim200 s). These rotations or transverse oscillations propagate upward
at velocities up to 786 km s<SUP>-1</SUP>. The bundle first slowly and
then rapidly swings up, with the transition occurring at the onset of an
A4.9 flare. A loop expands simultaneously in these two phases (velocity:
16-135 km s<SUP>-1</SUP>). Near the peak of the flare, the loop appears
to rupture; simultaneous upward ejecta and mass downflows faster than
free-fall appear in one of the loop legs. The material bundle then
swings back in a whip-like manner and develops into a collimated jet,
which is orientated along the inferred open-field lines with transverse
oscillations continuing at slower rates. Some material falls back along
smooth streamlines, showing no more oscillations. At low altitudes, the
streamlines bifurcate at presumably a magnetic null point and bypass
an inferred dome, depicting an inverted-Y geometry. These streamlines
closely match in space the late Ca II H loop and X-ray flare loop. These
observations are consistent with the model that flux emergence in an
open-field region leads to magnetic reconnection, forming a jet and
fan-spine topology. We propose that the material bundle and collimated
jet represent the outer spine in quasi-static and eruptive stages,
respectively, and the growing loop is a two-dimensional projection of
the three-dimensional fan surface.
---------------------------------------------------------
Title: MHD simulations of quiescent prominence upflows in the
Kippenhahn-Schlüter prominence model
Authors: Hillier, A. S.; Isobe, H.; Shibata, K.; Berger, T. E.
2011ASInC...2..331H Altcode:
Images from the Hinode satellite have led to the discovery of dark
upflows that propagate from the base of prominences, developing highly
turbulent profiles. The magnetic Rayleigh-Taylor instability has been
hypothesized as the mechanism to create these plumes. To study the
physics behind this phenomenon we use 3D magnetohydrodynamic simulations
to investigate the nonlinear stability of the Kippenhahn-Shlüter
prominence model to the magnetic Rayleigh-Taylor instability. The model
simulates the rise of a buoyant tube inside a quiescent prominence,
where the upper boundary between the tube and prominence model is
perturbed to excite the interchange of magnetic field lines. We
find upflows of constant velocity (maximum found 6 km s^{-1}) and a
maximum plume width ≈ 1500 km which propagate through a height of
approximately 6 Mm, in general agreement with the Hinode observations.
---------------------------------------------------------
Title: Greenhouse effect in quiescent prominences
Authors: Ryutova, M.; Berger, T. E.; Title, A. M.
2010AGUFMSH51A1664R Altcode:
Quiescent prominences, by definition, are huge “clouds” of cool,
dense plasma overlying rarefied hot corona and supported by a complex
magnetic field anchored in the photosphere along the magnetic polarity
inversion line. One of the most prominent features in their dynamics
is formation, growth and collapse of bubble/cavities filled by coronal
plasma and emerging, often repeatedly, under a prominence body. As
such, prominence/corona interface itself is subject of fundamental
plasma instabilities, which include development of a regular series
of plumes and spikes typical to the Rayleigh-Taylor instability, the
Kelvin-Helmholtz instability, often followed by a sudden collimated mass
upflow, which, in nonlinear stage having an explosive character may
be responsible for CMEs. These were only recently studied in detail
with high cadence, high resolution data obtained from the Hinode
satellite. Even more surprises are brought by the SDO/AIA instrument
showing the Sun's atmosphere in 12 visible and EUV wavelengths. AIA
multi-wavelength images in a temperature range from 10<SUP>5</SUP>
~K to 2 × 10<SUP>6</SUP> ~K combined with the Hinode/SOT data show
that plasma inside the prominence cavity, being as expected, at
coronal temperatures, in fact exceeds the temperature of the ambient
corona. We suggest that an energetically open highly dynamic processes
releasing energy at the prominence/cavity interface accompanied by the
“radiative exchange”, may cause additional increase of temperature
and/or density inside cavity. Given pervasive character of prominences,
future studies will allow us to perform quantitative and statistical
analysis, and reveal relations between the size of cavity, its
temperature, and magnetic properties.
---------------------------------------------------------
Title: Coordinated observations of solar prominences with Hinode/SOT
and SDO/AIA
Authors: Berger, T. E.; Tarbell, T. D.; Schrijver, C. J.; Title,
A. M.; Boerner, P.; Shine, R. A.
2010AGUFMSH21C..04B Altcode:
We show the first detailed study of a solar quiescent prominence
using simultaneous observations from the Hinode/SOT and SDO/AIA
instruments. The prominence studied is a polar crown prominence
located at the base of a large coronal cavity on the NW solar limb on
22-June-2010. Hinode observed the prominence for 2.75 hours running
the HOP 73 prominence observation program to acquire Ca II H-line
filtergrams and H-alpha doppler observations at a 20-second cadence. SOT
observations in Ca II H-line and H-alpha spectral lines reveal the
common dynamics of filamentary downflows and large-scale oscillations
of the prominence body. In addition a dark cavity is observed to
rise into the prominence and stagnate before going unstable to form
Rayleigh-Taylor plume upflows. AIA observations in the 304, 171, 193,
and 211 channels with 14 second cadence reveal that both the cavity
and the plume upflows are bright in these hotter passbands. Filter
ratio measurements as well as preliminary EM estimates imply that
the cavity and plume plasma temperature is at least 10^6 K. Plasma at
this temperature has never been detected or theorized in a confined
configuration in the lower chromosphere below a prominence. Assuming
an electron number density of 3e09 cm-3, the balance between thermal
pressure in the cavity and magnetic pressure in the overlying prominence
implies a magnetic flux density of order 10 gauss, in line with earlier
measurements of prominence magnetic fields. However the cavity likely
contains a significant magnetic energy density of its own implying that
the prominence magnetic fields may need to be significantly higher to
balance the cavity buoyancy. The existence of 10^6 K plasma confined
below a quiescent prominence and the subsequent onset of buoyancy
instabilities present new challenges to theories of prominence and
coronal cavity formation and suggest new avenues for supply of mass
and magnetic flux to the associated coronal cavity systems that make
up the bulk of CMEs. Hinode/SOT Ca II H-line image overlain on SDO/AIA
304A image of a quiescent solar prominence.
---------------------------------------------------------
Title: Space Based Observations of Coronal Cavities in Conjunction
with the Total Solar Eclipse of July 2010
Authors: Kucera, T. A.; Berger, T. E.; Boerner, P.; Dietzel, M.;
Druckmuller, M.; Gibson, S. E.; Habbal, S. R.; Morgan, H.; Reeves,
K. K.; Schmit, D. J.; Seaton, D. B.
2010AGUFMSH51A1666K Altcode:
In conjunction with the total solar eclipse on July 11, 2010 we
coordinated a campaign between ground and space based observations. Our
specific goal was to augment the ground based measurement of coronal
prominence cavity temperatures made using iron lines in the IR (Habbal
et al. 2010 ApJ 719 1362) with measurements performed by space based
instruments. Included in the campaign were Hinode/EIS, XRT and SOT,
PROBA2/SWAP, SDO/AIA, SOHO/CDS and STEREO/SECCHI/EUVI, in addition
to the ground based IR measurements. We plan to use a combination of
line ratio and forward modeling techniques to investigate the density
and temperature structure of the cavities at that time.
---------------------------------------------------------
Title: A rising cool column associated with formation of prominence
and coronal cavity
Authors: Okamoto, T. J.; Tsuneta, S.; Berger, T. E.
2010AGUFMSH51A1665O Altcode:
A prominence consists of relatively cool chromospheric plasma found
above the solar limb at coronal heights where the temperature and
density are typically two order of magnitude higher and lower,
respectively. Prominences are frequently associated with larger
coronal structures known as coronal cavities. There are numerous
observational studies on prominences with multi-wavelength and
with high-spatial resolution and also on the relationship between
cavities and coronal mass ejections, while less analyses on activities
inside coronal cavities. Continuous observations were performed of a
quiescent prominence with the Hinode satellite on 2006 December 23
and 24. In the Ca II H-line channel of the Solar Optical Telescope
we observed a peculiar slowly-rising column of cool material from the
lower atmosphere. The apparent ascent speed of the column is 2 km/s,
while the fine structures of the column exhibit much faster motion
of up to 20 km/s. The column eventually becomes a faint low-lying
prominence. An overlying coronal cavity associated with the appearance
of the column seen in the X-ray and EUV moves upward at 5 km/s. We
discuss the relationship between these episodes and suggest that
they are due to the emergence of a helical flux rope that undergoes
reconnection with lower coronal fields, possibly carrying material into
the coronal cavity. Under the assumption of the emerging flux scenario,
the lower velocity of 2 km/s and the higher one of 20 km/s in the column
are attributed to the rising motion of the emerging flux and to the
outflow driven by magnetic reconnection between the emerging flux and
the pre-existing coronal field, respectively. Our presentation gives a
coherent explanation of the enigmatic phenomenon of the rising column
with the emergence of the helical rope and its effect on the corona.
---------------------------------------------------------
Title: Observation of Plasma Instabilities in Quiescent Prominences
Authors: Ryutova, M.; Berger, T.; Frank, Z.; Tarbell, T.; Title, A.
2010SoPh..267...75R Altcode: 2010SoPh..tmp..170R
We study dynamics of quiescent prominences using several data sets taken
with the Solar Optical Telescope (SOT) on Hinode. We find a number of
processes occurring at different stages of prominence evolution that
are common for all of our chosen cases and, having universal character,
can be related to fundamental plasma instabilities. We combine the
observational evidence and theory to identify these instabilities. Here
we discuss three examples: i) prominence cavity formation and its
evolution, associated with a screw-pinch instability; ii) development
of a regular series of plumes and spikes typical to the Rayleigh -
Taylor (RT) instability; and iii) the appearance of growing ripples at
the prominence/corona interface, often followed by a sudden collimated
mass upflow, attributed to the Kelvin - Helmholtz (KH) instability. The
conditions for transition from a linear (rippling mode) to nonlinear
stage of the KH instability, known to have an explosive character,
are specified. Given excellent Hinode data, all three aspects of
prominence dynamics allow quantitative analysis.
---------------------------------------------------------
Title: PHITS simulations of the Matroshka experiment
Authors: Gustafsson, K.; Sihver, L.; Mancusi, D.; Sato, T.; Reitz,
G.; Berger, T.
2010AdSpR..46.1266G Altcode:
The radiation environment in space is very different from the one
encountered on Earth. In addition to the sparsely ionizing radiation,
there are particles of different Z with energies ranging from keV up
to hundreds of GeV which can cause severe damage to both electronics
and humans. It is therefore important to understand the interactions
of these highly ionizing particles with different materials such as
the hull of space vehicles, human organs and electronics. We have used
the Particle and Heavy-Ion Transport code System (PHITS), which is
a three-dimensional Monte Carlo code able to calculate interactions
and transport of particles and heavy ions with energies up to 100
GeV/nucleon in most matter. PHITS is developed and maintained by
a collaboration between RIST (Research Organization for Information
Science & Technology), JAEA (Japan Atomic Energy Agency), KEK (High
Energy Accelerator Research Organization), Japan and Chalmers University
of Technology, Sweden. For the purpose of examining the applicability
of PHITS to the shielding design we have simulated the ESA facility
Matroshka (MTR) designed and lead by the German Aerospace Center
(DLR). Preliminary results are presented and discussed in this paper.
---------------------------------------------------------
Title: HAMLET- Human Model MATROSHKA for Radiation Exposure
Determination of Astronauts
Authors: Reitz, G.; Berger, T.
2010OLEB...40..601R Altcode:
The exploration of space as seen in specific projects from the European
Space Agency (ESA) for example, the search for life on Mars (ExoMars),
acts as groundwork for human long duration space missions. One of
the main constraints for long duration human missions, besides the
psychological factors and the impact of microgravity on the human
physiological system, is radiation. The radiation load on astronauts and
cosmonauts in space (as for the ISS) is a factor of 100 higher than the
natural radiation on earth. This radiation load will further increase
should humans travel to Mars. In preparation for long duration space
missions it is important to evaluate the impact of space radiation
in order to secure the safety of the astronauts and minimize their
radiation risks. To determine the radiation risk on humans one has
to measure the radiation doses to radiosensitive organs within the
human body. One way to approach this is the European Space Agencys
(ESA) facility MATROSHKA (MTR) under the scientific and project lead
of DLR. It is dedicated to determine the radiation load on astronauts
within and outside the International Space Station (ISS), and was
launched in January 2004. MTR is currently in its fourth experimental
phase. MTR, which mimics a human head and torso, is an anthropomorphic
phantom containing over 6,000 radiation detectors to determine the
depth dose and organ dose distribution in the body. It is the largest
international research initiative ever performed in the field of space
dosimetry and combines the expertise of leading research institutions
around the world. It consequently generates a huge pool of data of
potentially immense value for research. Aiming at optimal scientific
exploitation, the collaborative project HAMLET is bringing together a
European expert committee, consisting exclusively of members of the MTR
consortium, to process and compile the data acquired individually by
the participating laboratories. Based on experimental input as well
as on radiation transport calculations, a three-dimensional model
for the distribution of radiation dose in an astronauts body will
be built up. The results will describe the exposure conditions both
for extra-vehicular activities (MTR-1, 20042005) and inside the ISS
(MTR-2A/B/KIBO, 200620010). The scientific achievements contribute
essentially to radiation risk estimations for future interplanetary
space exploration by humans, putting them on a solid experimental and
theoretical basis. Maximum public outreach is assured by making the
carefully processed data and related reports directly available to the
scientific community and the public via a web-based database. The HAMLET
project is funded by the European Commission under the EUs Seventh
Framework Programme (FP7) under Project Nr: 218817 and coordinated by
the German Aerospace Center (DLR) http://www-fp7-hamlet.eu
---------------------------------------------------------
Title: A Rising Cool Column as a Signature of Helical Flux Emergence
and Formation of Prominence and Coronal Cavity
Authors: Okamoto, Takenori J.; Tsuneta, Saku; Berger, Thomas E.
2010ApJ...719..583O Altcode: 2010arXiv1006.4633O
Continuous observations were performed of a quiescent prominence
with the Solar Optical Telescope on board the Hinode satellite
on 2006 December 23 and 24. A peculiar slowly rising column of
~10<SUP>4</SUP> K plasma develops from the lower atmosphere during
the observations. The apparent ascent speed of the column is 2 km
s<SUP>-1</SUP>, while the fine structures of the column exhibit much
faster motion of up to 20 km s<SUP>-1</SUP>. The column eventually
becomes a faint low-lying prominence. An overlying coronal cavity
associated with the appearance of the column seen in the X-ray and
EUV moves upward at ~5 km s<SUP>-1</SUP>. We discuss the relationship
between these episodes and suggest that they are due to the emergence
of a helical flux rope that undergoes reconnection with lower coronal
fields, possibly carrying material into the coronal cavity. Under
the assumption of the emerging flux scenario, the lower velocity of 2
km s<SUP>-1</SUP> and the higher one of 20 km s<SUP>-1</SUP> in the
column are attributed to the rising motion of the emerging flux and
to the outflow driven by magnetic reconnection between the emerging
flux and the pre-existing coronal field, respectively. The present
paper gives a coherent explanation of the enigmatic phenomenon of the
rising column with the emergence of the helical rope and its effect
on the corona. We discuss the implications that the emergence of such
a helical rope has on the dynamo process in the convection zone.
---------------------------------------------------------
Title: High Survival of Rock Inhabiting Photosynthetic Organisms in
a Simulated Interplanetary Transfer
Authors: de la Torre, R.; Sancho, L. G.; Horneck, G.; Rettberg, P.;
Berger, T.; Ascaso, C.; de los Rios, A.; Wierzchos, J.; de Vera, J. P.;
Ott, S.; Cockell, C.; Olsson, K.; Frias, J. M.; Demets, R.; Onofri, S.
2010OLEB...40..539D Altcode:
Interplanetary transfer of rock inhabiting life by means of meteorites
is a step supported by the hypothesis of lithopanspermia, which argues
that impact-expelled rocks from a planets surface serve as vehicles
for spreading living material from one planet of the solar system to
another. To test the survival of prokaryotic- and eukaryotic symbiotic
organisms in relation to lithopanspermia, three experiments have been
performed in space, the first two on a short mission, on board of Biopan
of the Foton satellite, and the third one in a long-term mission on
the EXPOSE facility of the International Space Station ISS. The first
experiment, called LICHENS (May 2005), has demonstrated for the first
time the high survival capacity of eukaryotic symbiotic organisms
in space (bipolar epilithic lichen species Rhizocarpon geographicum
and Xanthoria elegans during 16 days in BIOPAN-5). In the following
experiment Lithopanspermia (Biopan-6, FOTON-M3 satellite, 14.09.07)
we have pursued a more ambitious aim, to demonstrate- and intercompare
the survival capacity, not only of these eukaryotic symbiotic organisms,
this time also that of prokaryotic symbiotic organisms. For this test,
we have selected the previously tested species R. geographicum and
X. elegansbut this time prepared with- and without cortex and lichenic
substances, their reproductive structures, endoevaporitic microbial
communities, epilithic microbial communities with cyanobacterial
akinetes of Anabaena, and a vagrant lichen species, Aspicilia
fruticulosa. Exposure to different UV-conditions of a low Earth orbit
(LEO, 300 km) were performed: solar extraterrestrial UV-radiation, Mars
simulated UVclimate, UV-B radiation and PAR, space vacuum at 106mB,
microgravity and temperatures between23C and +16C. After flight, the
first analysis with chlorophyll a- fluorescence confirmed a high and
fast recovery of the biological activity of A. fruticulosa and of the
epilithic lichen with cortex and with lichenic substances, comparable
to the high survival rates observed in the experiment Lichens (de la
Torre et al. 2007; Sancho et al., 2007); a high germination capacity
of the ascospores and the survival of the resting state cells of
Anabaena were also observed, as also a certain level of survival of the
endoevaporitic microorganisms from the halite rock (the Atacama Desert)
(LIFE/DEAD assay and fluorescent microscopy). These experiments have
demonstrated that organisms adapted to tolerate extreme conditions on
our planet, like epilitihic lichens and resting state phototrophic
organisms of microbial communities, could resist an interplanetary
travel through space. The third experiment, LIFE (LIchensand Fungi
Experiment), was a long term experiment (February 2008-August 2009)
where desiccated lichens, fungi and cryptoendolithic communities
were exposed to environmental space- and Mars simulated conditions
on the EXPOSE facility of the ISS. The results will contribute to the
likelihood of Lithopanspermia, demonstrating the limits for life.
---------------------------------------------------------
Title: Survival of lichens and bacteria exposed to outer space
conditions - Results of the Lithopanspermia experiments
Authors: de la Torre, Rosa; Sancho, Leopoldo G.; Horneck, Gerda; Ríos,
Asunción de los; Wierzchos, Jacek; Olsson-Francis, Karen; Cockell,
Charles S.; Rettberg, Petra; Berger, Thomas; de Vera, Jean-Pierre
P.; Ott, Sieglinde; Frías, Jesus Martinez; Melendi, Pablo Gonzalez;
Lucas, Maria Mercedes; Reina, Manuel; Pintado, Ana; Demets, René
2010Icar..208..735D Altcode:
In the space experiments Lithopanspermia, experimental support
was provided to the likelihood of the lithopanspermia concept
that considers a viable transport of microorganisms between the
terrestrial planets by means of meteorites. The rock colonising lichens
Rhizocarpon geographicum and Xanthoria elegans, the vagrant lichen
Aspicilia fruticulosa, and endolithic and endoevaporitic communities
of cyanobacteria and bacteria with their natural rock substrate were
exposed to space for 10 days onboard the Biopan facility of the European
Space Agency (ESA). Biopan was closed during launch and re-entry. In
addition, in the Stone facility, one sample of R. geographicum on its
natural granitic substrate was attached at the outer surface of the
re-entry capsule close to the stagnation point, only protected by a
thin cover of glass textolite. Post-flight analysis, which included
determination of the photosynthetic activity, LIVE/DEAD staining,
and germination capacity of the ascospores, demonstrated that all
three lichen were quite resistant to outer space conditions, which
include the full spectrum of solar extraterrestrial electromagnetic
radiation or selected wavelength ranges. This high resistance of
the lichens to space appears to be due to their symbiotic nature and
protection by their upper pigmented layer, the cortex. In contrast,
the rock- or halite-inhabiting bacteria were severely damaged by the
same exposure. After atmospheric re-entry, the granite of the Stone
sample was transformed into a glassy, nearly homogenous material,
with several friction striae. None of the lichen cells survived
this re-entry process. The data suggest that lichens are suitable
candidates for testing the concept of lithopanspermia, because they
are extremely resistant to the harsh environment of outer space. The
more critical event is the atmospheric re-entry after being captured
by a planet. Experiments simulating the re-entry process of a
microbe-carrying meteoroid did not show any survivors.
---------------------------------------------------------
Title: Emergence of Helical Flux and the Formation of an Active
Region Filament Channel
Authors: Lites, B. W.; Kubo, M.; Berger, T.; Frank, Z.; Shine, R.;
Tarbell, T.; Title, A.; Okamoto, T. J.; Otsuji, K.
2010ApJ...718..474L Altcode:
We present comprehensive observations of the formation and evolution
of a filament channel within NOAA Active Region (AR) 10978 from
Hinode/Solar Optical Telescope and TRACE. We employ sequences
of Hinode spectro-polarimeter maps of the AR, accompanying Hinode
Narrowband Filter Instrument magnetograms in the Na I D1 line, Hinode
Broadband Filter Instrument filtergrams in the Ca II H line and G-band,
Hinode X-ray telescope X-ray images, and TRACE Fe IX 171 Å image
sequences. The development of the channel resembles qualitatively
that presented by Okamoto et al. in that many indicators point to
the emergence of a pre-existing sub-surface magnetic flux rope. The
consolidation of the filament channel into a coherent structure takes
place rapidly during the course of a few hours, and the filament form
then gradually shrinks in width over the following two days. Particular
to this filament channel is the observation of a segment along its
length of horizontal, weak (500 G) flux that, unlike the rest of the
filament channel, is not immediately flanked by strong vertical plage
fields of opposite polarity on each side of the filament. Because this
isolated horizontal field is observed in photospheric lines, we infer
that it is unlikely that the channel formed as a result of reconnection
in the corona, but the low values of inferred magnetic fill fraction
along the entire length of the filament channel suggest that the bulk
of the field resides somewhat above the low photosphere. Correlation
tracking of granulation in the G band presents no evidence for either
systematic flows toward the channel or systematic shear flows along
it. The absence of these flows, along with other indications of these
data from multiple sources, reinforces (but does not conclusively
demonstrate) the picture of an emerging flux rope as the origin of
this AR filament channel.
---------------------------------------------------------
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
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<SUP>-1</SUP>, 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<SUP>-1</SUP>. 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 km<SUP>2</SUP> s<SUP>-1</SUP> reaching
maximum projected areas from 2 to 15 Mm<SUP>2</SUP>. 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: Astrobiological Aspects of the Mutagenesis of Cosmic Radiation
on Bacterial Spores
Authors: Moeller, Ralf; Reitz, Günther; Berger, Thomas; Okayasu,
Ryuichi; Nicholson, Wayne L.; Horneck, Gerda
2010AsBio..10..509M Altcode:
Based on their unique resistance to various space parameters, Bacillus
endospores are one of the model systems used for astrobiological
studies. In this study, spores of B. subtilis were used to study
the effects of galactic cosmic radiation (GCR) on spore survival and
induced mutagenesis. In interplanetary space, outside Earth's protective
magnetic field, spore-containing rocks would be exposed to bombardment
by high-energy charged particle radiation from galactic sources and
from the Sun, which consists of photons (X-rays, γ rays), protons,
electrons, and heavy, high-energy charged (HZE) particles. B. subtilis
spores were irradiated with X-rays and accelerated heavy ions (helium,
carbon, silicon and iron) in the linear energy transfer (LET) range of
2-200 keV/μm. Spore survival and the rate of the induced mutations
to rifampicin resistance (Rif<SUP>R</SUP>) depended on the LET of
the applied species of ions and radiation, whereas the exposure
to high-energy charged particles, for example, iron ions, led to
a low level of spore survival and increased frequency of mutation
to Rif<SUP>R</SUP> compared to low-energy charged particles and
X-rays. Twenty-one Rif<SUP>R</SUP> mutant spores were isolated from
X-ray and heavy ion-irradiated samples. Nucleotide sequencing located
the Rif<SUP>R</SUP> mutations in the rpoB gene encoding the β-subunit
of RNA polymerase. Most mutations were primarily found in Cluster I
and were predicted to result in amino acid changes at residues Q469L,
A478V, and H482P/Y. Four previously undescribed alleles in B. subtilis
rpoB were isolated: L467P, R484P, and A488P in Cluster I and H507R in
the spacer between Clusters I and II. The spectrum of Rif<SUP>R</SUP>
mutations arising from spores exposed to components of GCR is distinctly
different from those of spores exposed to simulated space vacuum and
martian conditions.
---------------------------------------------------------
Title: Direct Imaging of an Emerging Flux Rope and a Resulting
Chromospheric Jet Observed by Hinode
Authors: Liu, Wei; Berger, T.; Title, A. M.; Tarbell, T. D.; DeRosa, M.
2010AAS...21640307L Altcode: 2010BAAS...41R.878L
Magnetic flux emergence has been traditionally observed on the disk by
identifying changes in magnetograms. Observations near the limb offer
an alternative perspective and allow direct imaging of emerging flux
ropes. We present Hinode/SOT Ca II H observations of such an event in
an equatorial coronal hole on 2007 February 9. The precursor of the
event was a bundle of fine material threads that extended at an oblique
angle above the chromosphere and appeared to rotate about a common
axis. This bundle first slowly and then rapidly swung up, accompanied
by a loop that appeared at the base of the bundle and expanded at
comparable rates. During the first (slow rise) stage, the apex of the
loop ascended at 16 km/s, a velocity similar to that of H-alpha arch
filaments (e.g., Chou & Zirin) and of emerging flux ropes expanding
into the corona as found in MHD simulations (e.g., Fan & Gibson;
Martinez-Sykora). The second stage started at the onset of a GOES A5
flare and the loop expansion accelerated, reaching a velocity of 130
km/s when the loop appeared to rupture near the peak of the flare. The
material bundle then swung back in a whiplike manner and developed into
a collimated jet, exhibiting oscillatory transverse motions across its
axis, as expected from unwinding twists. Some jet material fell back
along smooth streamlines, which bypass an unseen dome and presumably
a null point in the low corona, depicting an inverted-Y shape. Some
of these observations resemble the model (e.g., Uchida & Shibata)
of the emergence of a twisted flux rope into an open field region that
leads to reconnection and formation of a jet. Some observations are,
however, not predicted in previous models and we will discuss their
implications.
---------------------------------------------------------
Title: Quasistable radiation belt in the slot region
Authors: Labrenz, Johannes; Burmeister, Sönke; Berger, Thomas; Reitz,
Günther; Heber, Bernd; Beaujean, Rudolf
2010EGUGA..1210920L Altcode:
MATROSHKA is an ESA experiment under leadership of DLR Cologne. The
radiation exposure inside a human phantom is measured by active
and passive detectors. The DOSimetry TELescope (DOSTEL) was built
at CAU Kiel in cooperation with DLR Cologne; it consists of two
Si-semiconductor detectors forming a telescope. Count rates as well
as energy deposit spectra are measured by this instrument. MATROSHKA
is on board ISS since January 2004. The active instruments were
operating during the first mission phase (MTR1) where the phantom
was mounted outside the ISS from February 2004 to august 2005. In
2008 the active instruments were operating again in another mission
phase (MTR2b). During (MTR2b) MATROSHKA was mounted inside the Service
Module of the ISS. The DOSTEL measurements shows the expected transits
through the inner radiation belt (SAA) over the South Atlantic and
transits through the outer radiation belt at the highest geomagnetic
latitudes. In Sept. and Oct. 2004 an additional radiation belt in the
so called slot region appeared. In this work the measurements of this
quasi stable slot region belt will be presented and compared to results
of other experiments.
---------------------------------------------------------
Title: Inside the Meteorite — Bacterial Spore Survival After
Exposure to Galactic Cosmic Radiation
Authors: Moeller, R.; Berger, T.; Matthiä, D.; Okayasu, R.; Kato,
T.; Kitamura, H.; Reitz, G.
2010LPICo1538.5218M Altcode:
Based on their unique resistance to various space parameters, bacterial
spores are one of the model systems used for astrobiological studies. In
our research, we studied the response of Bacillus subtilis spores to
the exposure of galactic cosmic radiation.
---------------------------------------------------------
Title: On the power spectrum of solar surface flows
Authors: Rieutord, M.; Roudier, T.; Rincon, F.; Malherbe, J. -M.;
Meunier, N.; Berger, T.; Frank, Z.
2010A&A...512A...4R Altcode: 2009arXiv0911.3319R
Context. The surface of the Sun provides us with a unique and
very detailed view of turbulent stellar convection. Studying its
dynamics can therefore help us make significant progress in stellar
convection modelling. Many features of solar surface turbulence like
the supergranulation are still poorly understood. <BR /> Aims: The aim
of this work is to give new observational constraints on these flows
by determining the horizontal scale dependence of the velocity and
intensity fields, as represented by their power spectra, and to offer
some theoretical guidelines to interpret these spectra. <BR /> Methods:
We use long time-series of images taken by the Solar Optical Telescope
(SOT) on board the Hinode satellite; we reconstruct both horizontal
(by granule tracking) and vertical (by Doppler effect) velocity
fields in a field-of-view of ~ 75 × 75 Mm<SUP>2</SUP>. The dynamics
in the subgranulation range can be investigated with unprecedented
precision thanks to the absence of seeing effects and the use of the
modulation transfer function of SOT for correcting the spectra. <BR />
Results: At small subgranulation scales down to 0.4 Mm the spectral
density of kinetic energy associated with vertical motions exhibits
a k<SUP>-10/3</SUP>-like power law, while the intensity fluctuation
spectrum follows either a k<SUP>-17/3</SUP> or a k<SUP>-3</SUP>-like
power law at the two continuum levels investigated (525 and 450
nm respectively). We discuss the possible physical origin of these
scalings and interpret the combined presence of k<SUP>-17/3</SUP> and
k<SUP>-10/3</SUP> power laws for the intensity and vertical velocity
as a signature of buoyancy-driven turbulent dynamics in a strongly
thermally diffusive regime. In the mesogranulation range and up to a
scale of 25 Mm, we find that the amplitude of the vertical velocity
field decreases like λ<SUP>-3/2</SUP> with the horizontal scale
λ. This behaviour corresponds to a k<SUP>2</SUP> spectral power
law. Still in the 2.5-10 Mm mesoscale range, we find that intensity
fluctuations in the blue continuum also follow a k<SUP>2</SUP>
power law. In passing we show that granule tracking cannot sample
scales below 2.5 Mm. We finally further confirm the presence of a
significant supergranulation energy peak at 30 Mm in the horizontal
velocity power spectrum and show that the emergence of a pore erases
this spectral peak. We tentatively estimate the scale height of the
vertical velocity field in the supergranulation range and find 1 Mm;
this value suggests that supergranulation flows are shallow.
---------------------------------------------------------
Title: Relative nuclear abundances in ISS with Altcriss experiment
Authors: Casolino, Marco; Picozza, Piergiorgio; Narici, Livio;
Pugliese, Mariagabriella; Durante, Marco; di Fino, Luca; Zaconte,
Veronica; Nagamatsu, Aiko; Berger, Thomas; Benghin, Victor; Sihver,
Lembit; Lobascio, Cesare
2010cosp...38.3199C Altcode: 2010cosp.meet.3199C
The Altcriss project aims to perform a long term survey of the radiation
environment on board the International Space Station. Measurements
were performed with active and passive devices in different locations
and orientations of the Russian segment of the station. The goal
is to perform a detailed evaluation of the differences in particle
fluence and nuclear composition due to different shielding material
and attitude of the station. The Sileye-3/Alteino detector is used to
identify nuclei up to Iron in the energy range above ' 60 MeV/n. Several
passive dosimeters (TLDs, CR39) are also placed in the same location of
Sileye-3 detector. Polyethylene shielding is periodically interposed
in front of the detectors to evaluate the effectiveness of shielding
on the nuclear component of the cosmic radiation. In this work we will
discuss results obtained with active and passive detectors in various
location of the station during expedition 12 to 16.
---------------------------------------------------------
Title: Dosimetry of charged and neutral particles onboard a
stratospheric balloon
Authors: Dönsdorf, Esther Miriam; Burmeister, Soenke; Heber, Bernd;
Benton, Eric; Berger, Thomas
2010cosp...38.3225D Altcode: 2010cosp.meet.3225D
The interaction of the primary galactic cosmic rays with constituents
of the atmosphere leads to a complex secondary radiation field at
high altitudes. Of special interest for aviation and thereby also for
radiation protection is the height up to 30 km where the radiation
field consists of charged and neutral particles. For the determination
of the dose rates up to this altitude in the Earth's atmosphere a
stratopheric balloon flight will be performed in central Oklahoma
which has a cutoff rigidity of about 4 GV. Onboard there will be two
different active radiation detector systems to measure the dose of
charged and neutral particles in the stratosphere. The first one is a
silicon telescope which consists of two 2 cm2 silicon PIN-photodiodes
used as semiconductor detectors. This instrument will mainly be used
to measure the charged component of the radiation field due to the
fact that the silicon detectors have a rather low efficiency for the
detection of neutrons and gammas with energies higher than 60 keV. The
second instrument is a so called phoswich detector. It is composed of
two dissimilar scintillators optically coupled to each other and to a
common photomultiplier tube. For this experimental setup a combination
of a fast plastic scintillator BC412 and a slow inorganic scintillator
CsI(Na) is used. The pulses from the two scintillators will be separated
by applying pulse shape analysis. These two different scintillator
materials have been chosen because BC412 is hydrogen rich and thus
the cross section for fast neutrons is relatively high and CsI(Na)
has a high cross section for gamma radiation. The objective of the
phoswich detector is to distinguish between gammas and neutrons but
it is also possible to measure charged particles with this setup. The
aim of the balloon flight is to determine the dose measured with these
two different instruments and in particular to differentiate between
the dose induced by charged particles and by the different neutral
components of the secondary radiation field at high altitudes. A
description of the concept and the assembly of the two instruments as
well as first calibration results will be presented.
---------------------------------------------------------
Title: MHD simulations of upflows in the Kippenhahn-Schlueter
prominence model
Authors: Hillier, Andrew; Shibata, Kazunari; Isobe, Hiroaki; Berger,
Thomas
2010cosp...38.2914H Altcode: 2010cosp.meet.2914H
The launch of SOT on the Hinode satellite, with it's previously
unprecedented high resolution, high cadence images of solar prominences,
led to the discovery of small scale, highly dynamic flows in quiescent
prominences. Berger et al. (2008) reported dark upflows that propagated
from the base of the prominence through a height of approximately 10
Mm before ballooning into the familiar mushroom shape often associated
with the Rayleigh-Taylor instability. Whether such phenomena can be
driven by instabilities and, if so, how the instability evolve is yet
to be fully investigated. In this study, we use the Kippenhahn-Schlueter
(K-S) prominence model as the base for 3D numerical MHD simulations. The
K-S prominence model is linearly stable for ideal MHD perturbationss,
but can be made unstable through nonlinear perturbations, which we
impose through inserting a low density (high temperature) tube through
the centre of the prominence. Our simulations follow the linear and
nonlinear evolution of upflows propagating from the hot tube through the
K-S prominence model. We excited Rayleigh-Taylor like modes inside the
K-S model with a wave along the contact discontinuity created between
the hot tube and the K-S prominence, and solved the pertur-bations
of this system. For such a complex setting, the linear evolution of
the instability has 0.7 not been studied, and we found the growth
rate to be ∼ ( ρ+ -ρ- - 0.05)k 0.22 . The most ρ+ +ρ- unstable
wavelength was ∼ 100 km which, through the inverse cascade process,
created upflows of ∼ 300 km. The rising plumes obtained a constant
rise velocity in the nonlinear stage due to the creation of adverse
magnetic and gas pressure gradients at the top of the plume.
---------------------------------------------------------
Title: Determination of nuclear tracks parameters on sequentially
etched PADC detectors
Authors: Horwacik, Tomasz; Bilski, Pawel; Koerner, Christine; Facius,
Rainer; Berger, Thomas; Nowak, Tomasz; Reitz, Guenther; Olko, Pawel
2010cosp...38.3227H Altcode: 2010cosp.meet.3227H
Polyallyl Diglycol Carbonate (PADC) detectors find many applications in
radiation protection. One of them is the cosmic radiation dosimetry,
where PADC detectors measure the linear energy transfer (LET) spectra
of charged particles (from protons to heavy ions), supplementing TLD
detectors in the role of passive dosemeter. Calibration exposures
to ions of known LET are required to establish a relation between
parameters of track observed on the detector and LET of particle
creating this track. PADC TASTRAK nuclear track detectors were exposed
to 12 C and 56 Fe ions of LET in H2 O between 10 and 544 keV/µm. The
exposures took place at the Heavy Ion Medical Accelerator (HIMAC)
in Chiba, Japan in the frame of the HIMAC research project "Space
Radiation Dosimetry-Ground Based Verification of the MATROSHKA Facility"
(20P-240). Detectors were etched in water solution of NaOH with three
different temperatures and for various etching times to observe the
appearance of etched tracks, the evolution of their parameters and
the stability of the etching process. The applied etching times (and
the solution's concentrations and temperatures) were: 48, 72, 96,
120 hours (6.25 N NaOH, 50 O C), 20, 40, 60, 80 hours (6.25 N NaOH,
60 O C) and 8, 12, 16, 20 hours (7N NaOH, 70 O C). The analysis of the
detectors involved planimetric (2D) measurements of tracks' entrance
ellipses and mechanical measurements of bulk layer thickness. Further
track parameters, like angle of incidence, track length and etch rate
ratio were then calculated. For certain tracks, results of planimetric
measurements and calculations were also compared with results of optical
track profile (3D) measurements, where not only the track's entrance
ellipse but also the location of the track's tip could be directly
measured. All these measurements have been performed with the 2D/3D
measurement system at DLR. The collected data allow to create sets of
V(LET in H2 O) calibration curves suitable for short, intermediate
and long etching time and will be use during analysis of detectors
exposed on the International Space Station during DOSIS and MATROSHKA
experiments. The help and support of Yukio Uchihori and Hisashi Kitamura
during the irradiations at HIMAC is highly appreciated. This work
was supported by the Polish Ministry of Science and Higher Education,
grants: No N N505 261535 and No. DWM/N118/ESA/2008.
---------------------------------------------------------
Title: A droplet model for downflows in hedgerow prominences
Authors: Haerendel, Gerhard; Berger, Thomas
2010cosp...38.2915H Altcode: 2010cosp.meet.2915H
Observations of hedgerow prominences with the Solar Optical Telescope of
the Hinode mission have revealed the ubiquitous existence of downflows
forming coherent thin and highly structured near-vertical threads
with velocities between 10 and 20 km/s. Their widths range between
300 and 500 km. They are often initiated at the top of the visible
prominence, but sometimes also at intermediate level. We propose that
the downflows are made of plasma packets that squeeze themselves through
the dominantly horizontal field under the action of gravity. Their
origin is assumed to be hot plasma either supplied from outside along
the arcade field overarching the prominence and condensing at its top,
or along the spine field of the prominence itself. Under compression
and further cooling, the matter sinks into the prominence dragging
its magnetic field with it, but eventually disconnecting it from the
arcade field thus forming finite packets. The horizontal prominence
field exerts a drag force on the downward moving packets like air on a
falling droplet. Balancing the gravitational and drag forces yields an
upper limit on their length of the order of 1000 km. Lateral pressure
balance limits their width to about 500 km. Pushing themselves at high
speed through the horizontal field, the plasma "droplets" excite a
multitude of incoherent Alfvén waves. Nonlinear interactions of these
waves fill the prominence with a spectrum of oscillatory and propagating
wave modes. Absorption of part of that wave energy, whose ultimate
source is gravitational energy, and radiative cooling constitute the
energy balance of the falling matter and determine the mean fall speed (
14 km/s). The small scales of the "droplets" and thus of their frozen-in
magnetic fields explain the absence of vertical components in magnetic
field measurements. The above estimates of the droplet characteristics
rest on prominence parameters with mean density of 2.5x1012 cm-3,
temperature of 7500 K, and horizontal fields of order 8 G.
---------------------------------------------------------
Title: MATSIM -The Development and Validation of a Numerical Voxel
Model based on the MATROSHKA Phantom
Authors: Beck, Peter; Rollet, Sofia; Berger, Thomas; Bergmann,
Robert; Hajek, Michael; Latocha, Marcin; Vana, Norbert; Zechner,
Andrea; Reitz, Guenther
2010cosp...38.3204B Altcode: 2010cosp.meet.3204B
The AIT Austrian Institute of Technology coordinates the project MATSIM
(MATROSHKA Simulation) in collaboration with the Vienna University of
Technology and the German Aerospace Center. The aim of the project
is to develop a voxel-based model of the MATROSHKA anthro-pomorphic
torso used at the International Space Station (ISS) as foundation
to perform Monte Carlo high-energy particle transport simulations
for different irradiation conditions. Funded by the Austrian Space
Applications Programme (ASAP), MATSIM is a co-investigation with the
European Space Agency (ESA) ELIPS project MATROSHKA, an international
collaboration of more than 18 research institutes and space agencies
from all over the world, under the science and project lead of the
German Aerospace Center. The MATROSHKA facility is designed to determine
the radiation exposure of an astronaut onboard ISS and especially
during an ex-travehicular activity. The numerical model developed in
the frame of MATSIM is validated by reference measurements. In this
report we give on overview of the model development and compare photon
and neutron irradiations of the detector-equipped phantom torso with
Monte Carlo simulations using FLUKA. Exposure to Co-60 photons was
realized in the standard ir-radiation laboratory at Seibersdorf, while
investigations with neutrons were performed at the thermal column
of the Vienna TRIGA Mark-II reactor. The phantom was loaded with
passive thermoluminescence dosimeters. In addition, first results of
the calculated dose distribution within the torso are presented for
a simulated exposure in low-Earth orbit.
---------------------------------------------------------
Title: The DOSIS -Experiment onboard the Columbus Laboratory of the
International Space Station -First Mission Results from the Active
DOSTEL Instruments
Authors: Burmeister, Soenke; Berger, Thomas; Beaujean, Rudolf;
Boehme, Matthias; Haumann, Lutz; Kortmann, Onno; Labrenz, Johannes;
Reitz, Guenther
2010cosp...38.3195B Altcode: 2010cosp.meet.3195B
Besides the effects of the microgravity environment, and the
psychological and psychosocial problems encountered in confined
spaces, radiation is the main health detriment for long dura-tion
human space missions. The radiation environment encountered in
space differs in nature from that on earth, consisting mostly of
high energetic ions from protons up to iron, resulting in radiation
levels far exceeding the ones encountered on earth for occupational
radiation workers. Accurate knowledge of the physical characteristics
of the space radiation field in dependence on the solar activity,
the orbital parameters and the different shielding configurations
of the International Space Station ISS is therefore needed. For the
investigation of the spatial and temporal distribution of the radiation
field inside the European COLUMBUS module the DLR experiment DOSIS
(Dose Distribution Inside the ISS) was launched on July 15th 2009
with STS-127 to the ISS. The experimental package was transferred from
the Space Shuttle into COLUMBUS on July 18th. It consists in a first
part of a combination of passive detector packages (PDP) distributed
at 11 locations inside the European Columbus Laboratory. The second
part are two active radiation detectors (DOSTELs) with a DDPU (DOSIS
Data and Power Unit) in a nomex pouch (DOSIS MAIN BOX) mounted at a
fixed location beneath the European Physiology Module (EPM) inside
COLUMBUS. After the successful installation the active part has been
activated on the 18th July 2009. Each of the DOSTEL units consists of
two 6.93 cm PIPS silicon detectors forming a telescope with an opening
angle of 120. The two DOSTELs are mounted with their telescope axis
perpendicular to each other to investigate anisotropies of the radiation
field inside the COLUMBUS module especially during the passes through
the South Atlantic Anomaly (SAA) and during Solar Particle Events
(SPEs). The data from the DOSTEL units are transferred to ground
via the EPM rack which is activated approximately every four weeks
for this action. The first data downlink was performed on July 31st
2009. First Results for the DOSTEL measurements such as count rate
profiles, dose rates and LET spectra will be presented in comparison
to the data obtained by other experiments.
---------------------------------------------------------
Title: Depth dose distribution study within a phantom torso after
irradiation with a simulated Solar Particle Event at NSRL
Authors: Berger, Thomas; Matthiä, Daniel; Koerner, Christine; George,
Kerry; Rhone, Jordan; Cucinotta, Francis A.; Reitz, Guenther
2010cosp...38.3205B Altcode: 2010cosp.meet.3205B
The adequate knowledge of the radiation environment and the doses
incurred during a space mission is essential for estimating an
astronaut's health risk. The space radiation environment is complex and
variable, and exposures inside the spacecraft and the astronaut's body
are com-pounded by the interactions of the primary particles with the
atoms of the structural materials and with the body itself. Astronauts'
radiation exposures are measured by means of personal dosimetry,
but there remains substantial uncertainty associated with the
computational extrap-olation of skin dose to organ dose, which can
lead to over-or under-estimation of the health risk. Comparisons
of models to data showed that the astronaut's Effective dose (E)
can be pre-dicted to within about a +10In the research experiment
"Depth dose distribution study within a phantom torso" at the NASA
Space Radiation Laboratory (NSRL) at BNL, Brookhaven, USA the large
1972 SPE spectrum was simulated using seven different proton energies
from 50 up to 450 MeV. A phantom torso constructed of natural bones and
realistic distributions of human tissue equivalent materials, which is
comparable to the torso of the MATROSHKA phantom currently on the ISS,
was equipped with a comprehensive set of thermoluminescence detectors
and human cells. The detectors are applied to assess the depth dose
distribution and radiation transport codes (e.g. GEANT4) are used to
assess the radiation field and interactions of the radiation field
with the phantom torso. Lymphocyte cells are strategically embedded at
selected locations at the skin and internal organs and are processed
after irradiation to assess the effects of shielding on the yield of
chromosome damage. The first focus of the pre-sented experiment is to
correlate biological results with physical dosimetry measurements in the
phantom torso. Further on the results of the passive dosimetry using the
anthropomorphic phantoms represent the best tool to generate reliable to
benchmark computational radiation transport models in a radiation field
of interest. The presentation will give first results of the physical
dose distribution, the comparison with GEANT4 computer simulations,
based on a Voxel model of the phantom, and a comparison with the data
from the chromosome aberration study. The help and support of Adam
Russek and Michael Sivertz of the NASA Space Radiation Laboratory
(NSRL), Brookhaven, USA during the setup and the irradiation of the
phantom are highly appreciated. The Voxel model describing the human
phantom used for the GEANT4 simulations was kindly provided by Monika
Puchalska (CHALMERS, Gothenburg, Sweden).
---------------------------------------------------------
Title: Simulation of the radiation exposure in space during a large
solar energetic particle event with GEANT4
Authors: Matthiä, Daniel; Berger, Thomas; Puchalska, Monika; Reitz,
Guenther
2010cosp...38.3226M Altcode: 2010cosp.meet.3226M
The radiation field in space is complex due to the various contributing
sources and astronauts at the International Space Station (ISS) in
low Earth orbit or beyond are exposed to significantly increased
doses compared to on ground or in the lower atmosphere. The main
sources of the increased radiation level are Galactic Cosmic Ray
(GCR) particles, mainly fully charged ions from hydrogen to iron with
energies up to hundreds of GeV per nucleon and more, trapped protons
from the radiation belts with energies up to several hundreds of MeV,
and solar energetic particles up to several GeV released in large
eruptions on the sun related to solar x-ray flares and coronal mass
ejections. While the intensities of Galactic Cosmic Rays and trapped
protons are relatively stable and changing slowly over the solar cycle,
solar energetic particle events last for several hours up to days and
are characterized by strong increases in the particle intensity. The
radiation exposure during a large particle event can be very harmful to
astronauts especially during extra vehicular activities and outside the
protective magnetic field of the Earth. The MATROSHKA human phantom
was and is used on the International Space Station to measure the
radiation exposure in and outside ISS in order to evaluate the radiation
risk in low Earth orbit. A voxel-based description of the MATROSHKA
phantom (NUNDO-Numerical RANDO Model) was used in the present work to
numerically estimate the radiation exposure of the human body and the
individual organs during a large solar particle event. The transport
of primary protons following an exponential energy distribution was
simulated in order to calculate the energy deposition and organ doses in
the MATROSHKA phantom during such an event taking into account different
amounts of shielding provided by a surrounding aluminum shell. The
primary particle energy distribution used in this work follows the
description of the spectrum of the solar energetic particle event in
August 1972 in the energy range from 45 MeV to 1 GeV. The transport
calculations of the energetic particles through the shielding and the
phantom model were performed using the Monte-Carlo code GEANT4.
---------------------------------------------------------
Title: HAMLET -Human Model MATROSHKA for Radiation Exposure
Determination of Astronauts -Current status and results
Authors: Reitz, Guenther; Berger, Thomas; Bilski, Pawel; Burmeister,
Soenke; Labrenz, Johannes; Hager, Luke; Palfalvi, Jozsef K.; Hajek,
Michael; Puchalska, Monika; Sihver, Lembit
2010cosp...38.3202R Altcode: 2010cosp.meet.3202R
The exploration of space as seen in specific projects from the European
Space Agency (ESA) acts as groundwork for human long duration space
missions. One of the main constraints for long duration human missions
is radiation. The radiation load on astronauts and cosmonauts in space
(as for the ISS) is a factor of 100 higher than the natural radiation
on Earth and will further increase should humans travel to Mars. In
preparation for long duration space missions it is important to
evaluate the impact of space radiation in order to secure the safety
of the astronauts and minimize their radiation risks. To determine
the radiation risk on humans one has to measure the radiation doses
to radiosensitive organs within the human body. One way to approach
this is the ESA facility MATROSHKA (MTR), under the scientific and
project lead of DLR. It is dedicated to determining the radiation
load on astronauts within and outside the International Space Station
(ISS), and was launched in January 2004. MTR is currently preparing for
its fourth experimental phase inside the Japanese Experimental Module
(JEM) in summer 2010. MTR, which mimics a human head and torso, is an
anthropomorphic phantom containing over 6000 radiation detectors to
determine the depth dose and organ dose distribution in the body. It
is the largest international research initiative ever performed in the
field of space dosimetry and combines the expertise of leading research
institutions around the world, thereby generating a huge pool of data
of potentially immense value for research. Aiming at optimal scientific
exploitation, the FP7 project HAMLET aims to process and compile the
data acquired individually by the participating laboratories of the
MATROSHKA experiment. Based on experimental input from the MATROSHKA
experiment phases as well as on radiation transport calculations,
a three-dimensional model for the distribution of radiation dose in
an astronaut's body will be built up. The scientific achievements
contribute essentially to radiation risk estimations for future
interplanetary space exploration by humans, putting them on a solid
experimental and theoretical basis. The talk will give an overview
of the current status of the MATROSHKA data evaluation and results
and comparisons of the first three MTR experimental phases (MTR-1,
2A and 2B). The HAMLET project is funded by the European Commission
under the EUs Seventh Frame-work Programme (FP7) under Project
Nr: 218817 and coordinated by the German Aerospace Center (DLR)
http://www-fp7-hamlet.eu
---------------------------------------------------------
Title: Hinode/SOT Measurements of Flows and Waves in Solar Prominences
Authors: Berger, Thomas; Okamoto, Takenori; Schmieder, Brigitte
2010cosp...38.2913B Altcode: 2010cosp.meet.2913B
We review Hinode Solar Optical Telescope (SOT) measurements of flows
and waves in quies-cent and active solar prominences. In quiescent
prominences, Hinode/SOT observations have revealed a new mode of
buoyant transport in the form of dark upflows that originate at
the chromospheric base of the prominence. The upflows can take the
form of large-scale (10 Mm) "bubbles" that rise through the entire
prominence into the overlying coronal cavity, or they can take the form
of numerous small-scale (1 Mm) plumes that generate from an apparent
Rayleigh-Taylor instability on the boundary between the prominence and
the impinging buoy-ant flow system. The episodic flows directly inject
mass, magnetic flux, and helicity into the overlying coronal cavity,
moving the system towards destabilization and eruption in the form of
CMEs. Hinode/SOT quiescent prominence observations have also verified
the existence of ubiquitous downflow streams and vortex flows confirming
that prominences are far from magne-tostatic conditions. Tracking and
doppler measurements of prominence downflows find speeds of 5-15 km s-1
and imply that the trajectories are not strictly vertical. Active region
promi-nence studies find counter-streaming flows along horizontal
magnetic field lines with velocities of 20-30 km s-1 ; upflows,
downflow streams, and rotational flows have not been observed in
these systems. Active Region prominence field lines exhibit transverse
oscillations indicative of Alfv`n waves with periods of several minutes,
amplitudes of 1 Mm, and wavelengths of 250 Mm or more. These properties
are consistent with magnetic field strengths of 50 gauss or more at
typical prominence density conditions and carry enough energy to heat
the surrounding prominence/corona transition region (PCTR).
---------------------------------------------------------
Title: Space activities and radiation protection of crew members
Authors: Straube, Ulrich; Berger, Thomas; Reitz, Guenther; Facius,
Rainer; Reiter, Thomas; Kehl, Marcel; Damann, M. D. Volker; Tognini,
Michel
2010cosp...38.3193S Altcode: 2010cosp.meet.3193S
Personnel working as crew in space-based activities e.g. professional
astronauts and cosmo-nauts but also -to a certain extend-space flight
participants ("space tourists"), demand health and safety considerations
that have to include radiation protection measures. The radiation
environment that a crew is exposed to during a space flight, differs
significantly to that found on earth including commercial aviation,
mainly due to the presence of heavy charged particles with great
potential for biological damage. The exposure exceeds those routinely
received by terrestrial radiation workers. A sequence of activities
has to be conducted targeting to mitigate adverse effects of space
radiation. Considerable information is available and applied through the
joint efforts of the Space Agencies that are involved in the operations
of the International Space Station, ISS. This presentation will give
an introduction to the current measures for ra-diation monitoring and
protection of astronauts of the European Space Agency (ESA). It will
include information: on the radiation protection guidelines that shall
ensure the proper imple-mentation and execution of radiation protection
measures, the operational hardware used for radiation monitoring and
personal dosimetry on ISS, as well as information about operational
procedures that are applied.
---------------------------------------------------------
Title: HAMLET -Matroshka IIA and IIB experiments aboard the ISS:
comparison of organ doses
Authors: Kato, Zoltan; Reitz, Guenther; Berger, Thomas; Bilski,
Pawel; Hajek, Michael; Sihver, Lembit; Palfalvi, Jozsef K.; Hager,
Luke; Burmeister, Soenke
2010cosp...38.3219K Altcode: 2010cosp.meet.3219K
The Matroshka experiments and the related FP7 HAMLET project aimed to
study the dose burden of the cosmic rays in the organs of the crew
working inside and outside the ISS. Two of the experiments will be
discussed. They were performed in two different locations inside
the ISS: during the Matroshka 2A (in 2006) the phantom was stored
in the Russian Docking Module (Pirs), while during the Matroshka 2B
(in 2007-08) it was inside the Russian Service Module (Zvezda). Both
experiments were performed in the decreasing phase of the solar
cycle. Solid state nuclear track detectors (SSNTD) were applied to
investigate the dose contribution of the high LET radiation above
∼10 keV/µm. Two configurations of SSNTDs stacks were constructed:
one for the exposure in the so called organ dose boxes (in the lung
and kidney), another one for the skin dose measurements, embedded
in the nomex poncho of the Phantom. In addition a reference package
was placed outside the phantom. After exposure the detectors were
transferred to the Earth for data evaluation. Short and long etching
procedures were applied to distinguish the high and low LET particles,
respectively. The particle tracks were evaluated by a semi automated
image analyzer. Addi-tionally manual track parameter measurements
were performed on very long tracks. As the result of measurements the
LET spectra were deduced. Based on these spectra, the absorbed dose,
the dose equivalent and the mean quality factor were calculated. The
configuration of the stacks, the methods of the calibration and
evaluation and finally the results will be presented and compared. The
multiple etching and the combined evaluation method allowed to
determine the fraction of the dose originated from HZE particles
(Z>2 and range > major axis). Further on, data eval-uation
was performed to separate the secondary particles (target fragments)
from the primary particles. Although the number of high LET particles
above a ∼80 keV/µm was found to be higher during the Matroshka 2B
experiment than in the previous phase it was not possible to attribute
this observation to the lower Sun activity in 2008, since the locations
inside the ISS were different. The HAMLET project is funded by the
European Commission under the EUs Seventh Frame-work Programme (FP7)
under Project Nr: 218817 and coordinated by the German Aerospace Center
(DLR) http://www-fp7-hamlet.eu
---------------------------------------------------------
Title: Dosimetry and Vibration measurements in BIOLAB and EMCS
(Dos-ViBE)
Authors: Ideström, Johan Olof; Hendrik Anken, Ralf; Reitz, Guenther;
Berger, Thomas; Hauslage, Jens; Schuber, Marianne; Fossum, Knut R.;
Vanhavere, Filip
2010cosp...38.3217I Altcode: 2010cosp.meet.3217I
Space irradiation and vibrations in even small dosages can impact
biological experiments and have not yet been measured in the biological
payloads of the Columbus module at the Interna-tional Space Station
(ISS). Installing active dosimeters and accelerometers in the Experiment
Containers (EC) of Biolab and the European Modular Cultivation System
(EMCS), to sur-vey in-situ the radiation and vibrations in these
facilities, should be performed to serve as a reference of the space
conditions to future experiments. To monitor the radiation field,
the space radiation should be measured with an active dosime-ter
inside the Multi-User-Facilities, as close to the actual shielding
conditions of the biological experiments as possible. To measure the
full spectrum of vibration frequencies, several instru-ments with
different measurement ranges and sensitivity should be combined. The
radiation and vibrations should be measured simultaneously in Biolab
and EMCS to compare their radiation shielding and sensitivities to
vibrations from the ISS. The radiation could also be measured with
passive dosimeters. On the one hand this would be a back-up to the
active dosimeter and on the other hand it would provide additional
data since the passive dosimeters can give additional information
on the radiation LET spectrum. As a response to ESA's Announcement
of Opportunity (ILSRA-2009), a joint experiment in Biolab and EMCS,
entitled Dos-ViBE, was proposed by the co-authors. The objectives and
experimental flow of Dos-ViBE are outlined in this presentation.
---------------------------------------------------------
Title: Bacterial spore survival after exposure to HZE particle
bombardment -implication for the lithopanspermia hypothesis.
Authors: Moeller, Ralf; Berger, Thomas; Matthiä, Daniel; Okayasu,
Ryuichi; Kitamura, H.; Reitz, Guenther
2010cosp...38.3313M Altcode: 2010cosp.meet.3313M
Based on their unique resistance to various space parameters,
bacterial spores (mainly spores of Bacillus subtilis) are one of
the model systems used for astrobiological studies. More re-cently,
spores of B. subtilis have been applied for experimental research on
the likelihood of interplanetary transfer of life. Since its first
postulation by Arrhenius in 1903, the pansper-mia hypothesis has been
revisited many-times, e.g. after the discovery of several lunar and
Martian meteorites on Earth [1,2]. These information provided intriguing
evidence that rocks may naturally be transferred between the terrestrial
planets. The scenario of panspermia, now termed "lithopanspermia"
involves three basic hypothetical steps: (i) the escape process,
i.e. removal to space of biological material, which has survived being
lifted from the surface to high altitudes; (ii) interim state in space,
i.e., survival of the biological material over time scales comparable
with interplanetary or interstellar passage; (iii) the entry process,
i.e. nondestruc-tive deposition of the biological material on another
planet [2]. In our research, spores of B. subtilis were used to
study the effects of galactic cosmic radiation on spore survival and
induced mutations. On an interplanetary journey, outside a protective
magnetic field, spore-containing rocks would be exposed to bombardment
by high-energy charged particle radiation from galac-tic sources and
from the sun. Air-dried spore layers on three different host materials
(i.e., non-porous igneous rocks (gabbro), quartz, and spacecraft analog
material (aluminum)) were irradiated with accelerated heavy ions (Helium
and Iron) with a LET (linear energy transfer) ˆ of 2 and 200 keV/Am,
at the Heavy Ion Medical Accelerator (HIMAC) at the National In-stitute
of Radiological Sciences, (NIRS), Chiba, Japan in the frame of the HIMAC
research project 20B463 "Characterization of heavy ion-induced damage
in Bacillus subtilis spores and their global transcriptional response
during spore germination" (Moeller et al., 2008 [3]). To simulate the
interplanetary journey of a meteorite, stacks of spore-samples on gabbro
slides in different depths were exposed. Spore survival and the rate of
the induced mutations (i.e., sporulation-deficiency (Spo-)) depended
on the LET of the applied species of ions as well as on the location
(and depth) of the irradiated spores in the artificial meteorite. The
exposure to high LET iron ions led to a low level of spore survival
and increased frequency of mutation to Spo-compared to low-energy
charged particles compared to the low LET helium ions. In order to
obtain insights on the role of DNA repair by nonhomologous end joining
(NHEJ), homologous recombination (HR) and apurinic/apyrimidinic (AP)
endonucleases in B. subtilis spore resistance to high-energy charged
particles has been studied in parallel. Spores deficient in NHEJ and
AP endonucleases were significantly more sensitive to HZE particle
bombardment than were the HR-mutant and wild-type spores, indicating
that NHEJ and AP endonucleases provide DNA break repair pathways
during spore germination. ((References: [1] Arrhenius, S. 1903. Die
Verbreitung des Lebens im Weltenraum. Umschau 7:481-485.; [2] Nicholson,
W. L. 2009. Ancient micronauts: interplanetary transport of microbes
by cosmic impacts. Trends Mi-crobiol. 17:243-250.; [3] Moeller, R.,
P. Setlow, G. Horneck, T. Berger, G. Reitz, P. Rettberg, A. J. Doherty,
R. Okayasu, and W. L. Nicholson. 2008. Roles of the major, small,
acid-soluble spore proteins and spore-specific and universal DNA
repair mechanisms in resistance of Bacillus subtilis spores to
ionizing radiation from X-rays and high-energy charged-particle
bombardment. J. Bacteriol. 190:1134-1140.))
---------------------------------------------------------
Title: Preparation and Current Situation of Proton-ICCHIBAN-2
Experiment
Authors: Uchihori, Yukio; Yasuda, Nakahiro; Kitamura, H.; Kodaira,
S.; Benton, Eric; Hajek, Michael; Berger, Thomas; Jadrnickova, Iva;
Ploc, Ondrej
2010cosp...38.3208U Altcode: 2010cosp.meet.3208U
The ICCHIBAN (Inter Comparison for Cosmicrays with Heavy Ion Beams at
NIRS) working group has organized and performed various ICCHIBAN runs
for active and passive radiation detectors at HIMAC, NIRS, Japan, Loma
Linda and Brookhaven, USA and CERN, Switzer-land since the start of the
ICCHIBAN project in the year 2002. One of the main focus points of this
project is to understand the response of the applied detector systems
(either active or passive) for personal and area dosimetry in space
environment to a simulated sub-set of the space radiation environment,
focusing on the heavy ion response. This is of special importance
for the further intercomparison of space radiation data gathered by
various international in-stitutes and universities for space radiation
experiments as MATROSHKA, DOSIS, DOBIES, BRADOS, MATROSHKA-R etc. The
ICCHIBAN experiments have created a big database of response data,
especially for all the different passive radiation detectors and
detector materials (Thermoluminescence (TLD) and Optical Luminescence
(OSL)) over the last 7 years, resulting in a better understanding
of how and why we still have differences in the measurement results
from common space experiments -as the Space ICCHIBAN 2 experiment. One
of the reasons why for the differences in the TLD/OSL results is the
lack of intercomparison and response data for low LET particles up to
around 10 keV/m, especially protons. Due to the fact, that the main
contribution to absorbed dose in low earth orbit is due to protons,
the ICCHIBAN working group has started the set-up of a Proton ICCHIBAN
intercomparison experiment at NIRS. The Proton ICCHIBAN run has
been performed at the cyclotron at NIRS, Chiba in February 2010. 15
institutes from 12 countries sent or brought their dosimeters and
exposed them to 40 and 70 MeV proton beams with the same doses and
exposure conditions. In this paper, the experiment procedures and
current situation of the intercomparision experiments will be shown.
---------------------------------------------------------
Title: The DOSIS -Experiment onboard the Columbus Laboratory of the
International Space Station -Overview and first mission results
Authors: Reitz, Guenther; Berger, Thomas; Kürner, Christine;
Burmeister, Sünke; Hajek, Michael; Bilski, Pawel; Horwacik, Tomasz;
Vanhavere, Filip; Spurny, Frantisek; Jadrnickova, Iva; Pálfalvi,
József K.; O'Sullivan, Denis; Yasuda, Nakahiro; Uchihori, Yukio;
Kitamura, Hisashi; Kodaira, Satoshi; Yukihara, Eduardo; Benton,
Eric; Zapp, Neal; Gaza, Ramona; Zhou, Dazhuang; Semones, Edward;
Roed, Yvonne; Boehme, Matthias; Haumann, Lutz
2010cosp...38.3194R Altcode: 2010cosp.meet.3194R
Besides the effects of the microgravity environment, and the
psychological and psychosocial problems encountered in confined spaces,
radiation is the main health detriment for long dura-tion human space
missions. The radiation environment encountered in space differs in
nature from that on earth, consisting mostly of high energetic ions
from protons up to iron, resulting in radiation levels far exceeding the
ones encountered on earth for occupational radiation workers. Accurate
knowledge of the physical characteristics of the space radiation field
in dependence on the solar activity, the orbital parameters and the
different shielding configurations of the International Space Station
ISS is therefore needed. The DOSIS (Dose Distribution inside the ISS)
experiment, under the project and science lead of DLR, aims for the
spatial and tempo-ral measurement of the radiation field parameters
inside the European Columbus laboratory onboard the International Space
Station. This goal is achieved by applying a combination of passive
(Thermo-and Optical luminescence detectors and Nuclear track etch
detectors) and active (silicon telescope) radiation detectors. The
passive radiation detectors -so called pas-sive detector packages
(PDP) are mounted at eleven positions within the Columbus laboratory
-aiming for a spatial dose distribution measurement of the absorbed
dose, the linear energy transfer spectra and the dose equivalent with
an average exposure time of six months. Two active silicon telescopes
-so called Dosimetry Telescopes (DOSTEL 1 and DOSTEL 2) together with
a Data and Power Unit (DDPU) are mounted within the DOSIS Main Box
at a fixed loca-tion beneath the European Physiology Module (EPM)
rack. The DOSTEL 1 and DOSTEL 2 detectors are positioned at a 90
angle to each other for a precise measurement of the temporal and
spatial variation of the radiation field, especially during crossing
of the South Atlantic Anomaly (SAA). The DOSIS hardware was launched
with the Space Shuttle Endeavour to the International Space Station
on 15 July 2009 and installed by European Astronaut Frank de Winne
on 18 July 2009. The first PDP set was downloaded after an exposure
time of 124 days in November 2009 and a second PDP set was installed
in November 2009. The active part of the instrument suit is working
since July 2009. The presentation will give an overview about the
DOSIS experiment as well as first results from the passive and active
radiation detector measurements. The Austrian activities within this
experiment were supported by the Austrian Space Appli-cations Programme
(ASAP) of the Federal Ministry for Transport, Innovation and Technology
under contract no. 819643. The Polish contribution to this work was
supported by the Min-istry of Science and Higher Education, grant
No. DWM/N118/ESA/2008. The Hungarian contribution was supported by
the ESA PECS grant No. C98066.
---------------------------------------------------------
Title: Simulations of MATROSHKA experiments at ISS using PHITS
Authors: Puchalska, Monika; Sihver, L.; Sato, T.; Berger, T.; Reitz, G.
2010cosp...38.3203P Altcode: 2010cosp.meet.3203P
Concerns about the biological effects of space radiation are increasing
rapidly due to the per-spective of long-duration manned missions,
both in relation to the International Space Station (ISS) and to
manned interplanetary missions to Moon and Mars in the future. As a
prepara-tion for these long duration space missions it is important
to ensure an excellent capability to evaluate the impact of space
radiation on human health in order to secure the safety of the
astronauts/cosmonauts and minimize their risks. It is therefore
necessary to measure the radi-ation load on the personnel both inside
and outside the space vehicles and certify that organ and tissue
equivalent doses can be simulated as accurate as possible. In this
paper we will present simulations using the three-dimensional Monte
Carlo Particle and Heavy Ion Transport code System (PHITS) of long
term dose measurements performed with the ESA supported ex-periment
MATROSHKA (MTR), which is an anthropomorphic phantom containing over
6000 radiation detectors, mimicking a human head and torso. The MTR
experiment, led by the German Aerospace Center (DLR), was launched in
January 2004 and has measured the ab-sorbed dose from space radiation
both inside and outside the ISS. In this paper preliminary comparisons
of measured and calculated dose and organ doses in the MTR located
outside the ISS will be presented. The results confirm previous
calculations and measurements which indicate that PHITS is a suitable
tool for estimations of dose received from cosmic radiation and when
performing shielding design studies of spacecraft. Acknowledgement:
The research leading to these results has received funding from the
Euro-pean Commission in the frame of the FP7 HAMLET project (Project
218817).
---------------------------------------------------------
Title: Response of the Chromosphere to Penumbral Dynamics: Bow Shocks
and Microjets
Authors: Ryutova, M.; Berger, T.; Frank, Z.; Title, A.
2009ASPC..415..373R Altcode:
We have analyzed the data sets obtained with the SOT instrument
on Hinode during the disc passage of AR 10923 (November 10--20,
2006). Along with a limited number of jet-like features (Katsukawa
2007), we found other kinds of bright chromospheric transients
abundantly pervading the entire penumbra and drifting as a whole in
a direction perpendicular to their long axes. Quantitative analysis
based on our recent penumbral model (Ryutova et al. 2008a) shows that
they have all the signatures of bow shocks produced in the overlying
chromosphere by post-reconnection penumbral filaments.
---------------------------------------------------------
Title: Supergranulation, Network Formation, and TFGs Evolution from
Hinode Observations
Authors: Roudier, T.; Rincon, F.; Rieutord, M.; Brito, D.; Beigbeder,
F.; Parès, L.; Malherbe, J. -M.; Meunier, N.; Berger, T.; Frank, Z.
2009ASPC..415..203R Altcode:
In this paper, we analyse a a 48h high-resolution time sequence of the
quiet Sun photosphere obtained with the Solar Optical Telescope onboard
Hinode. Using floating corks advected by velocity fields inferred from
photometry measurements, we show that long-living Trees of Fragmenting
Granules play a crucial role in the advection of small-scale magnetic
fields and in the build-up of the magnetic network.
---------------------------------------------------------
Title: Hinode/SOT Observations of Quiescent Prominence Dynamics
Authors: Berger, T.
2009ASPC..415..109B Altcode:
Hinode/SOT observations of quiescent, or “Quiet Sun,” prominences
(QSPs) have confirmed and extended several dynamic characteristics
known from previous ground-based observations: filamentary downflow
streams, large-scale vortex flows, long-period body oscillations, and
counter-streaming flows have been seen in most QSPs to date. Beyond
these known characteristics, we have discovered completely new dynamics
in QSPs, primary among which are large-scale (up to 50 Mm diameter)
“bubbles” that inflate below prominences, as well as dark turbulent
plume upflows that intermittently traverse them to heights of 15 Mm
or more above the chromospheric spicules. Here we briefly review the
prominence dynamics seen in the SOT dataset and provide quantitative
measures of some of their characteristics. In general we conclude
that there is no such thing as a static prominence---all quiescent
prominences are in constant motion, primarily in downflow streams
along apparently vertical streamlines. The constant draining motion
implies that there is no need for “suspension against gravity” of
the prominence gas. Fully 3-D dynamic models that take into account
non-steady prominence mass transport are required to advance our
understanding of these enigmatic objects.
---------------------------------------------------------
Title: ON THE DOWNFLOWS IN HEDGEROW PROMINENCES
Authors: Berger, T. E.; Haerendel, G.
2009AGUFMSH44A..07B Altcode:
We analyze the downflows in quiescent prominences with respect to
width, vertical velocity and acceleration, using sequences of images
from the Solar Optical Telescope (SOT) of the Hinode mission. SOT
sequences in both 656.3 nm H-alpha and 396.8 nm Ca II H-line bandpasses
show that the downflows have typical widths of 300 km, lengths up
to 15 Mm, and speeds on the order of 10--20 km/s. Most downflows
initiate near the top of the visible-light prominence in the form
of bright knots and show an initial acceleration before achieving
relatively constant speeds. Downflows typically end either in the
chromosphere below the prominence or on large arches that sometimes
form lower boundaries to the prominences. In some cases, downflows
are strongly deflected by arches indicating a large gradient in the
magnetic field at those locations. The vertical coherence of most of
the threads over much of the prominence height suggests a continuous
stream of plasma. The frozen-field condition implies the presence of
vertical magnetic field dragged by the downflow with balanced up and
down polarity. This explains the absence of vertical components in
magnetic field measurements. The large-scale horizontal field plays
an important role in the dynamics of the downflow, in two ways. It
compresses the thread plasma and field and presents an obstacle
to the downflow. The energy gained by falling in the gravitational
field is in part expended in stretching the vertical field, in part
in pushing the horizontal field out of the way and in part by covering
the radiative losses of the compressed plasma. With total densities of
the order of nearly 10^12 cm-3 and horizontal fields of order 10 G,
energy and force balance yield vertical velocities of about 10 km/s
and temperatures of 7000-8000 K. The threads are nourished by plasma
inflow from outside the prominence along largely horizontal fields
and sudden onset of gravitational instability.
---------------------------------------------------------
Title: Formation and Dynamics of Multi-thread Arcades of Coronal Loops
Authors: Ryutova, M.; Frank, Z.; Berger, T.
2009ASPC..415..291R Altcode:
Coronal structures having various forms and dynamics, often bifurcate
into a long living, well organized multi-thread loop arcades. To
describe this process we use the model of energetically open system,
consisting of current carrying magnetic loops that interconnect a high
β energy production region with a low β dissipation region through
the resistive stresses. The model includes feedback managed by the
transition region. Such a system may be driven into various dynamic
forms including spontaneous process of self-organization.
---------------------------------------------------------
Title: Observations of Large-Scale Dynamic Bubbles in Prominences
Authors: de Toma, G.; Casini, R.; Berger, T. E.; Low, B. C.; de Wijn,
A. G.; Burkepile, J. T.; Balasubramaniam, K. S.
2009ASPC..415..163D Altcode:
Solar prominences are very dynamic objects, showing continuous motions
down to their smallest resolvable spatial and temporal scales. However,
as macroscopic magnetic structures, they are remarkably stable during
their quiescent phase. We present recent ground-based and Hinode
observations of large-scale bubble-like, dynamic sub-structures that
form within and rise through quiescent prominences without disrupting
them. We investigate the similarities and differences of the Hinode
and ground-based observations and discuss their implications for models
of prominences.
---------------------------------------------------------
Title: Sunspot Penumbrae: Formation and Fine Structure
Authors: Ryutova, M.; Berger, T.; Title, A.
2009ASPC..415..361R Altcode:
Sub-arcsecond observations revealing the fine sub-structure of
penumbral filaments and new properties of their dynamics, provide both
the basis and constraints for novel models of the penumbra. Even more
severe conditions are imposed on models by new data obtained with the
SOT instrument on Hinode, showing e.g. direct connection between the
dynamic changes in penumbra and appearance of bright transients in
the overlying chromosphere. We propose the mechanism that not only
explains the observed properties of individual filaments, but is part
of the physical process that determines formation of penumbra and its
impact on the overlying atmosphere.
---------------------------------------------------------
Title: An Intriguing Chromospheric Jet Observed by Hinode: Fine
Structure Kinematics and Evidence of Unwinding Twists
Authors: Liu, Wei; Berger, Thomas E.; Title, Alan M.; Tarbell,
Theodore D.
2009ApJ...707L..37L Altcode: 2009arXiv0910.5186L
We report a chromospheric jet lasting for more than 1 hr observed by
the Hinode Solar Optical Telescope in unprecedented detail. The ejection
occurred in three episodes separated by 12-14 minutes, with the amount
and velocity of material decreasing with time. The upward velocities
range from 438 to 33 km\nolimits s\nolimits ^{-1}, while the downward
velocities of the material falling back have smaller values (mean:
-56 km\nolimits s\nolimits ^{-1}) and a narrower distribution (standard
deviation: 14 km\nolimits s\nolimits ^{-1}). The average acceleration
inferred from parabolic spacetime tracks is 141 m\nolimits s^{-2}, a
fraction of the solar gravitational acceleration. The jet consists of
fine threads (0farcs5-2” wide), which exhibit coherent, oscillatory
transverse motions perpendicular to the jet axis and about a common
equilibrium position. These motions propagate upward along the jet,
with the maximum phase speed of 744 ± 11 km\nolimits s\nolimits ^{-1}
at the leading front of the jet. The transverse oscillation velocities
range from 151 to 26 km\nolimits s\nolimits ^{-1}, amplitudes from
6.0 to 1.9 Mm\nolimits, and periods from 250 to 536 s\nolimits. The
oscillations slow down with time and cease when the material starts to
fall back. The falling material travels along almost straight lines in
the original direction of ascent, showing no transverse motions. These
observations are consistent with the scenario that the jet involves
untwisting helical threads, which rotate about the axis of a single
large cylinder and shed magnetic helicity into the upper atmosphere.
---------------------------------------------------------
Title: Service-Mode Observations for Ground-Based Solar Physics
Authors: Reardon, K. P.; Rimmele, T.; Tritschler, A.; Cauzzi, G.;
Wöger, F.; Uitenbroek, H.; Tsuneta, S.; Berger, T.
2009ASPC..415..332R Altcode: 2009arXiv0909.1522R
There are significant advantages in combining Hinode observations
with ground-based instruments that can observe additional spectral
diagnostics at higher data rates and with greater flexibility. However,
ground-based observations, because of the random effects of weather
and seeing as well as the complexities data analysis due to changing
instrumental configurations, have traditionally been less efficient
than satellite observations in producing useful datasets. Future large
ground-based telescopes will need to find new ways to optimize both
their operational efficiency and scientific output. <P />We have begun
experimenting with service-mode or queue-mode observations at the Dunn
Solar Telescope using the Interferometric Bidimensional Spectrometer
(IBIS) as part of joint Hinode campaigns. We describe our experiences
and the advantag es of such an observing mode for solar physics.
---------------------------------------------------------
Title: Helical Shape and Twisting Motion as Intrinsic Properties of
Penumbral Filaments
Authors: Shine, R. A.; Ryutova, M.; Berger, T. E.; Title, A. M.;
Tarbell, T. D.; Ichimoto, K.
2009AGUFMSH23B1541S Altcode:
A wealth of high resolution data obtained with advanced ground based
telescopes and the SOT instrument on HINODE have led to new findings
in the properties of penumbral filaments and controversies in their
interpretation. Here we address one such issue, namely the question of
whether the apparent twist of filaments is real or is just a viewing
effect. We show that the helical shape and twisting motions of penumbral
filaments follow from first principles and represent an integral part of
penumbra formation and dynamics. As such, these properties link together
other observed features of filaments including their magnetic and
thermal substructure and their impact on the overlying atmosphere. At
all stages of penumbral dynamics, qualitative agreement of theory and
observations is supported by quantitative analysis as well.
---------------------------------------------------------
Title: High Resolution Observations of Solar Quiescent Prominences
with the Hinode Solar Optical Telescope: an Open Challenge to 21st
Century Ground-based Solar Telescopes (Invited)
Authors: Berger, T. E.
2009AGUFMSH53B..06B Altcode:
The Solar Optical Telescope (SOT) on the Japanese Hinode satellite is a
0.5-meter diameter Gregorian solar telescope in a 600 km Sun-synchronous
orbit. The telescope achieves diffraction-limited imaging with no
atmospheric seeing in a wavelength range from 380 nm to 660 nm. Using
both the Broadband Filter Imager (BFI) Ca II H-line channel at 389.6
nm and the tunable Narrowband Filter Imager (NFI) H-alpha channel at
656.3 nm we have observed many quiescent solar prominences since the
satellite launch in September 2006. The excellent optical quality
and low scattering of the SOT telescope combined with the lack of
atmospheric scattering and seeing enables us to capture multi-hour
diffraction-limited movies of quiescent prominences above the limb
that achieve 200 km spatial resolution and 15--30 second temporal
resolution. These SOT observations have led to the discovery of new
flows in the solar outer atmosphere in the form of buoyant small-scale
(2--6 Mm) plumes and large-scale (10--50 Mm) "bubbles" or arches that
originate below quiescent prominences and rise with speeds of 10--30
km/sec to heights of 10--30+ Mm above the solar limb. In this talk
we review the kinematic properties of these new flows in combination
with the long-observed filamentary downflows to show that quisecent
prominences are not magnetostatic structures "suspended against
gravity" but are rather entirely dynamic structures in which mass is
continually drained in the downflows while being resupplied largely by
condensation from the coronal cavity above and episodic buoyant flows
from below. The Hinode/SOT instrument has definitively shown the value
of flying high-resolution visible-light solar telescopes in space by
acheiving in its first six months what had been a long-standing goal of
ground-based solar prominence research for the past 50 years. However
many key quiescent prominence characteristics cannot be measured by the
limited instrumentation on the Hinode satellite. Primary among these
is vector magnetic field in prominences at high spatial and temporal
resolution and the thermodynamic and magnetic characteristics of the
new plume and bubble flows. It is hoped that the new generation of
adaptive-optics ground-based telescopes such as the 1.6-m NST can
make progress in these areas while we await the next solar space
telescope missions.
---------------------------------------------------------
Title: Role of the Resistive and Thermal Instabilities in Dynamics
of Quiescent Prominences
Authors: Frank, Z.; Ryutova, M.; Berger, T. E.; Title, A. M.; Tarbell,
T. D.
2009AGUFMSH41B1653F Altcode:
We present the observations taken with the SOT instrument on Hinode in
G-band and Ca H lines. High cadence data compiled in movies show clear
evidence for several fundamental plasma instabilities. We combine
the observational evidence and theoretical estimates to identify
these instabilities. The following can be given as examples. (1)
An analogue of the Kelvin-Helmholtz instability develops at the
prominence/corona interface that manifests itself in growing ripples
during a linear growth phase and may be followed by a nonlinear stage
taking the form of an explosive instability corresponding to a CME
ejection. This instability also includes the regime of "smoke ring"
formation. (2) The appearence of "bubbles and spikes" typical to
the Rayleigh-Taylor instability are observed. Their evolution and
growth rates are found to be modified by both poloidal and toroidal
components of magnetic field. (3) A resistive interchange instability,
associated with an "unfavorable" magnetic field curvature relative to
the density/temperature gradients, may be responsible for a hot barb
formation, its evolution and collapse.
---------------------------------------------------------
Title: Fine Structures and Kinematics of an Intriguing Chromospheric
Jet Observed by Hinode Solar Optical Telescope
Authors: Liu, W.; Berger, T. E.; Title, A. M.; Tarbell, T. D.
2009AGUFMSH51A1266L Altcode:
Transient, small-scale ejections of plasma from the lower atmosphere
are common manifestations of solar activity. Hinode, with its superior
resolutions, has spurred renewed interest in solar jets since its
launch. Here we report a chromospheric jet lasting for more than 1
hr on 2007 February 9 observed by the Hinode Solar Optical Telescope
(SOT) in unprecedented detail. SOT Ca II H passband observations
at high resolution of 0.2 arcsecond and cadence of 8 s allowed us to
investigate the fine structures and kinematics of the jet. The ejection
occurred in three episodes, rather than continuously, with the amount
and velocity of material decreasing with time. The upward velocities
along the jet range from ~440 to ~30 km/s, while the downward velocities
of the material falling back have much smaller values (mean: -60 km/s)
and a narrower distribution. Some tracks in the space-time plot clearly
show parabolic shapes and the inferred acceleration is a fraction of
the solar gravitational acceleration. The jet consists of fine threads
(0.5-2 arcsecond wide), which exhibit coherent, oscillatory transverse
motions perpendicular to the jet axis and about a common equilibrium
position. These motions propagate upward, with the maximum phase speed
of ~740 km/s found at the leading front of the jet. The transverse
oscillation velocities range from 150 to 30 km/s, amplitudes from 6 to 2
Mm, and periods from 250 to 550 s. The oscillations slow down with time
and cease when the material starts to fall back. The falling material
travels along almost straight lines in the original direction of ascent,
showing no transverse motions. These observations are consistent with
the models suggested by Shibata & Uchida (1985) and Canfield et
al. (1996). In this scenario, the jet involves untwisting helical
threads, which rotate about the axis of a single large cylinder and
shed magnetic helicity into the upper atmosphere. Implications of this
event in the context of multiwavelength data in H-alpha, EUV, and X-rays
will be discussed. A chromospheric jet observed by Hinode SOT in the
Ca II H passband (T=1-2×10 4 K). Note the helical-like fine threads.
---------------------------------------------------------
Title: Origin of Filamentary Structures and Flows in Quiescent
Prominences
Authors: Ryutova, M.; Berger, T. E.; Tarbell, T. D.; Frank, Z.; Title,
A. M.
2009AGUFMSH23B1540R Altcode:
The paradox of fine vertical structure has usually referred to an
apparent contradiction met when comparing vertical fine structures
of quiescent prominences observed on the limb with the necessary
horizontal magnetic field along their long axis. In addition to this
fundamental problem, the very formation of fine vertical structures
has been a long standing puzzle. Here we address these problems and
show that considering the global structure of a prominence as a large
scale skewed formation with toroidal and poloidal fields removes the
paradox and allows derivation of dynamic stability criteria. This also
includes the mechanism of the fine structure formation and peculiarities
of downward mass motions. Theoretical estimates of key parameters
are compared with the observations taken with the SOT instrument
on Hinode. We find results of comparison very encouraging. For the
approximate 3D reconstruction of the general shape of prominences,
the STEREO A and B images have been used.
---------------------------------------------------------
Title: The Experiment LIFE-SPORES under Development for the
Phobos-Grunt Mission
Authors: Rettberg, P.; Rabbow, E.; Moller, R.; Wamann, M.; Berger,
T.; Horneck, G.; Reitz, G.; Sychev, V.; Betts, B.; Warmflash, D.
2009OLEB...39...83R Altcode:
The Russian space agency will launch a sample return mission nicknamed
Phobos-Grunt to the Martian moon Phobos. According to plans, the
spacecraft will land on Phobos, collect soil and rock samples from
its surface, and then return back to Earth. The spacecraft will
release a capsule containing all the samples gathered on Phobos,
to land on Earth. Attached to the capsule for the entire 34 months
of the journey will be a small cylinder containing a collection
of terrestrial microorganisms. In its flight, the cylinder will
be, in effect, a simulated space rock, subject to the same extreme
conditions as a Martian meteorite traveling to Earth. It is the Living
Interplanetary Flight Experiment (LIFE) experiment of The Planetary
Society (http://www.planetary.org/programs/projects/life/). The
panspermia theory hypothesises that living organisms could be
transported through the solar system and then take hold on other
planets. In one component of the LIFE experiment called LIFE-SPORES,
the ability of spores from the bacterium Bacillus subtilis to survive
an interplanetary travel from Earth to Mars moon Phobos and back will
be tested. In addition to the well-characterized and already sequenced
wildtype strain Bacillus subtilis 168 a newly developed strain, MW01,
whose cells are about 3 to 4 times more UV and ionising radiation
resistant than 168, will be used as test object. For dosimetry of
ionsing radiation during the mission TLDs (thermoluminescence detectors)
will be used and analyzed post-flight. Both bacterial strains are now
part of an ongoing experiment on the ISS, ADAPT, on EXPOSE-E mounted
on the Eutef platform of Columbus which will be exposed to the space
conditions in LEO for about 18 months.
---------------------------------------------------------
Title: Temporal and spatial evolution of the solar energetic particle
event on 20 January 2005 and resulting radiation doses in aviation
Authors: Matthiä, D.; Heber, B.; Reitz, G.; Meier, M.; Sihver, L.;
Berger, T.; Herbst, K.
2009JGRA..114.8104M Altcode: 2009JGRA..11408104M
The solar energetic particle event on 20 January 2005 was one of the
largest ground level events ever observed. Neutron monitor stations in
the Antarctic recorded count rate increases of several thousand percent
caused by secondary energetic particles, and it took more than 36 h to
return to background level. Such huge increases in high energetic solar
cosmic radiation on the ground are obviously accompanied by considerable
changes in the radiation environment at aviation altitudes. Measurements
of 28 neutron monitor stations were used in this work to numerically
approximate the primary solar proton spectra during the first 12 h of
the event by minimizing the differences between measurements and the
results of Monte-Carlo calculated count rate increases. The primary
spectrum of solar energetic protons was approximated by a power law
in rigidity and a linear angular distribution. The incoming direction
of the solar energetic particles was determined and compared to the
interplanetary magnetic field direction during the event. The effects
on the radiation exposure at altitudes of about 12 km during that time
were estimated to range from none at low latitudes up to almost 2 mSv/h
for a very short time in the Antarctic region and about 0.1 mSv/h at
high latitudes on the Northern Hemisphere. After 12 h, dose rates were
still increased by 50% at latitudes above 60° whereas no increases
at all occurred at latitudes below 40° during the whole event.
---------------------------------------------------------
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.
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.
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: First Results from a Novel Magnetograph (SHAZAM)
Authors: DeForest, Craig; Rimmele, T.; Berger, T.; Peterson, J.
2009SPD....40.3301D Altcode:
The magnetic energy flux through the Sun's surface is dominated by small
features at all currently observable spatial scales; hence there is a
strong need to improve the spatial resolution of magnetic measurements,
which are increasingly photon starved as telescopes improve. The Solar
High-speed Zeeman Magnetograph (SHAZAM) is a line-of-sight magnetograph
based on the principle of spectral stereoscopy. It is designed to
acquire magnetograms quickly enough to beat image fluctuations due
to both solar evolution and terrestrial seeing, even on scales under
100 km on the Sun. It is over 100x more photon efficient than existing
quantitative magnetographs such as SOHO/MDI. We present first results
from an observing run at the National Solar Observatory's Dunn Solar
Telescope in May 2009, hopefully including near-diffraction-limited,
time resolved magnetogram sequences with better than 150km resolution
on the surface of the Sun.
---------------------------------------------------------
Title: Prominence Bubbles and Plumes: Thermo-magnetic Buoyancy in
Coronal Cavity Systems
Authors: Berger, Thomas; Hurlburt, N.
2009SPD....40.1007B Altcode:
The Hinode/Solar Optical Telescope continues to produce high spatial
and temporal resolution images of solar prominences in both the
Ca II 396.8 nm H-line and the H-alpha 656.3 nm line. Time series
of these images show that many quiescent prominences produce large
scale (50 Mm) dark "bubbles" that "inflate" into, and sometimes burst
through, the prominence material. In addition, small-scale (2--5 Mm)
dark plumes are seen rising into many quiescent prominences. We show
typical examples of both phenomena and argue that they originate from
the same mechanism: concentrated and heated magnetic flux that rises
due to thermal and magnetic buoyancy to equilibrium heights in the
prominence/coronal-cavity system. More generally, these bubbles and
upflows offer a source of both magnetic flux and mass to the overlying
coronal cavity, supporting B.C. Low's theory of CME initiation via
steadily increasing magnetic buoyancy breaking through the overlying
helmut streamer tension forces. Quiescent prominences are thus seen
as the lowermost parts of the larger coronal cavity system, revealing
through thermal effects both the cooled downflowing "drainage" from
the cavity and the heated upflowing magnetic "plasmoids" supplying the
cavity. We compare SOT movies to new 3D compressible MHD simulations
that reproduce the dark turbulent plume dynamics to establish the
magnetic and thermal character of these buoyancy-driven flows into
the corona.
---------------------------------------------------------
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.
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: Simulations Of Buoyant Plumes In Solar Prominences
Authors: Hurlburt, Neal E.; Berger, T.
2009SPD....40.1009H Altcode:
Recent observations of solar prominences have revealed a complex,
dynamic flow field within them. The flow field within quiescent
prominences is characterized by long “threads” and dark “bubbles”
that fall and rise (respectively) in a thin sheet. The flow field
in active prominences display more helical motions that travel
along the axis of the prominence. We explore the possible dynamics
of both of these with the aid of 2.5D MHD simulations. Our model,
compressible plasma possesses density and temperature gradients and
resides in magnetic field configurations that mimc those of a solar
prominence. The system is the subjected to to localized heating to
trigger a variety of modes and instabilities.
---------------------------------------------------------
Title: Mesoscale dynamics on the Sun's surface from HINODE
observations
Authors: Roudier, Th.; Rieutord, M.; Brito, D.; Rincon, F.; Malherbe,
J. M.; Meunier, N.; Berger, T.; Frank, Z.
2009A&A...495..945R Altcode: 2009arXiv0902.2299R
Context: <BR />Aims: The interactions of velocity scales on the Sun's
surface, from granulation to supergranulation are still not understood,
nor are their interaction with magnetic fields. We thus aim at giving
a better description of dynamics in the mesoscale range which lies
between the two scales mentioned above. <BR />Methods: We analyse a
48 h high-resolution time sequence of the quiet Sun photosphere at
the disk center obtained with the Solar Optical Telescope onboard
Hinode. The observations, which have a field of view of 100´´ ×
100´´, typically contain four supergranules. We monitor in detail the
motion and evolution of granules as well as those of the radial magnetic
field. <BR />Results: This analysis allows us to better characterize
Trees of Fragmenting Granules issued from repeated fragmentation of
granules, especially their lifetime statistics. Using floating corks
advected by measured velocity fields, we show their crucial role
in the advection of the magnetic field and in the build up of the
network. Finally, thanks to the long duration of the time series, we
estimate that the turbulent diffusion coefficient induced by horizontal
motion is approximately 430 km<SUP>2</SUP> s<SUP>-1</SUP>. <BR
/>Conclusions: These results demonstrate that the long living families
contribute to the formation of the magnetic network and suggest that
supergranulation could be an emergent length scale building up as small
magnetic elements are advected and concentrated by TFG flows. Our
estimate for the magnetic diffusion associated with this horizontal
motion might provide a useful input for mean-field dynamo models.
---------------------------------------------------------
Title: The Solar Chromosphere: Old Challenges, New Frontiers
Authors: Ayres, T.; Uitenbroek, H.; Cauzzi, G.; Reardon, K.; Berger,
T.; Schrijver, C.; de Pontieu, B.; Judge, P.; McIntosh, S.; White,
S.; Solanki, S.
2009astro2010S...9A Altcode:
No abstract at ADS
---------------------------------------------------------
Title: On the Penumbral Jetlike Features and Chromospheric Bow Shocks
Authors: Ryutova, M.; Berger, T.; Frank, Z.; Title, A.
2008ApJ...686.1404R Altcode:
We present observations of sunspot penumbrae obtained during the disk
passage of AR 10923 (2006 November 10-20) with the SOT instrument on
Hinode in 4305 Å G band and Ca II λ3968 H line. Along with recently
discovered jetlike features (Katsukawa et al. 2007), we find other
kinds of bright elongated transients abundantly pervading the entire
penumbra and drifting as a whole in a direction almost perpendicular
to their long axes. Their measured velocities strongly depend
on their orientation with respect to the line of sight and range
from simeq1 to simeq20 km s<SUP>-1</SUP>. We present quantitative
analysis of these features and interpret them relative to our recent
penumbral model (Ryutova et al. 2008) to show that they are produced
by shocks resulting from a slingshot effect associated with the ongoing
reconnection processes in neighboring penumbral filaments. Due to sharp
stratification of the low atmosphere, postreconnection flux tubes moving
upward quickly accelerate. At transonic velocities a bow (detached)
shock is formed in front of the flux tube, as usually occurs in cases
of blunt bodies moving with supersonic velocities. Observed parameters
of transients are in good agreement with calculated parameters of
bow shocks. On some, much more rare occasions compared to "drifting"
bow-shock-type transients, there appear compact bright transients
moving in the radial direction, along their long axis, and having
velocities of 20-50 km s<SUP>-1</SUP>. We relate these features to a
category of true microjets.
---------------------------------------------------------
Title: Hinode, TRACE, SOHO, and Ground-based Observations of a
Quiescent Prominence
Authors: Heinzel, P.; Schmieder, B.; Fárník, F.; Schwartz, P.;
Labrosse, N.; Kotrč, P.; Anzer, U.; Molodij, G.; Berlicki, A.;
DeLuca, E. E.; Golub, L.; Watanabe, T.; Berger, T.
2008ApJ...686.1383H Altcode:
A quiescent prominence was observed by several instruments on
2007 April 25. The temporal evolution was recorded in Hα by the
Hinode SOT, in X-rays by the Hinode XRT, and in the 195 Å channel by
TRACE. Moreover, ground-based observatories (GBOs) provided calibrated
Hα intensities. Simultaneous extreme-UV (EUV) data were also taken by
the Hinode EIS and SOHO SUMER and CDS instruments. Here we have selected
the SOT Hα image taken at 13:19 UT, which nicely shows the prominence
fine structure. We compare this image with cotemporaneous ones taken
by the XRT and TRACE and show the intensity variations along several
cuts parallel to the solar limb. EIS spectra were obtained about half
an hour later. Dark prominence structure clearly seen in the TRACE and
EIS 195 Å images is due to the prominence absorption in H I, He I,
and He II resonance continua plus the coronal emissivity blocking due
to the prominence void (cavity). The void clearly visible in the XRT
images is entirely due to X-ray emissivity blocking. We use TRACE, EIS,
and XRT data to estimate the amount of absorption and blocking. The
Hα integrated intensities independently provide us with an estimate of
the Hα opacity, which is related to the opacity of resonance continua
as follows from the non-LTE radiative-transfer modeling. However,
spatial averaging of the Hα and EUV data have quite different natures,
which must be taken into account when evaluating the true opacities. We
demonstrate this important effect here for the first time. Finally,
based on this multiwavelength analysis, we discuss the determination
of the column densities and the ionization degree of hydrogen in
the prominence.
---------------------------------------------------------
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.
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.
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: Hinode Observations of Magnetic Elements in Internetwork Areas
Authors: de Wijn, A. G.; Lites, B. W.; Berger, T. E.; Frank, Z. A.;
Tarbell, T. D.; Ishikawa, R.
2008ApJ...684.1469D Altcode: 2008arXiv0806.0345D
We use sequences of images and magnetograms from Hinode to
study magnetic elements in internetwork parts of the quiet solar
photosphere. Visual inspection shows the existence of many long-lived
(several hours) structures that interact frequently and may migrate
over distances of ~7 Mm over a period of a few hours. About a fifth
of the elements have an associated bright point in G-band or Ca
II H intensity. We apply a hysteresis-based algorithm to identify
elements. The algorithm is able to track elements for about 10 minutes
on average. Elements intermittently drop below the detection limit,
although the associated flux apparently persists and often reappears
some time later. We infer proper motions of elements from their
successive positions and find that they obey a Gaussian distribution
with an rms of 1.57 +/- 0.08 km s<SUP>-1</SUP>. The apparent flows
indicate a bias of about 0.2 km s<SUP>-1</SUP> toward the network
boundary. Elements of negative polarity show a higher bias than elements
of positive polarity, perhaps as a result of the dominant positive
polarity of the network in the field of view or because of increased
mobility due to their smaller size. A preference for motions in X is
likely explained by higher supergranular flow in that direction. We
search for emerging bipoles by grouping elements of opposite polarity
that appear close together in space and time. We find no evidence
supporting Joy's law at arcsecond scales.
---------------------------------------------------------
Title: The Small-Scale Field Measured With Hinode/SOT and Feature
Tracking: Where is the mixed- polarity flux?
Authors: Deforest, C. E.; Lamb, D. A.; Berger, T.; Hagenaar, H.;
Parnell, C.; Welsch, B.
2008AGUSMSP51D..01D Altcode:
We report on the results of the first feature tracking study of
the solar magnetic field with Hinode/SOT. We processed a SOT Na-D
line-of-sight magnetogram sequence with five different magnetic
tracking codes. The SOT data allow us to probe the evolving magnetic
field on the granular scale for hours at a time, something that was
not possible with either ground-based observations (which are limited
to short periods of good seeing) or prior space-based observations
(which are limited to arcsecond spatial scales). We find that the field
is much less mixed than previously supposed: while Hinode resolves
small-scale structure within features that, to SOHO/MDI, would
appear as monolithic flux concentrations, this substructure has but
a single sign. Furthermore, the average distance between identifiable
flux concentrations of opposite sign remains nearly unchanged at the
higher resolution, a result that is quite surprising in light of the
common picture of a sea of strong mixed-polarity flux concentrations
dotting the inter-granular lanes. We discuss possible mechanisms for
this surprising result, and implications for the small-scale dynamo.
---------------------------------------------------------
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.
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.
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: Evershed Flows as an Integral Part of Penumbral Formation
and its Fine Structure
Authors: Ryutova, M.; Berger, T.; Lites, B.; Title, A.; Frank, Z.
2008AGUSMSP41B..07R Altcode:
Observations of Evershed flows with the Solar Optical Telescope (SOT)
on Hinode (Ichimito, Shine, Lites, et al. 2008, PASJ, 59, S593) showed
that penumbral flows have small scale structures and much more complex
properties than those of a simple outflow of material with unique
direction and appearence. We address this problem and show that the
flow properties are directly connected to the observed properties of
penumbral filaments and are an integral part of penumbral development
during sunspot formation. In our recent model (Ryutova, Berger, &
Title, 2008, ApJ, 676, April), based on the observations that sunspot
has a filamentary structure and consists of a dense conglomerate of
non-collinear interlaced flux tubes, the penumbra is formed due to
an on-going reconnection processes that leads to branching out of the
peripheral flux tubes from the "trunk". As flux tubes have different
parameters, branching occurs at different heights and with different
inclinations, thus forming an "uncombed" penumbra. Each elemental act
of reconnection generates an inevitable twist in the post-reconnection
filaments that acquire a screw pinch configuration. This explains
the remarkable dynamic stability of penumbral filaments and their
observed properties, such as presence of dark cores, wrapping and
spinning of filaments around each other, bright footpoints, etc. Here
we show that propagation of twist along current carrying helical flux
tubes is accompanied by plasma flows that may have diverse properties
depending on the location of interacting flux tubes, their inclination
and pitch. We apply the model to observations taken with the SOT
instrument, which includes spectro-polarimetric data, and perform
quantitative analysis.
---------------------------------------------------------
Title: Quiescent Prominence Structure and Dynamics: a new View From
the Hinode/SOT
Authors: Berger, T.; Okamoto, J.; Slater, G.; Magara, T.; Tarbell,
T.; Tsuneta, S.; Hurlburt, N.
2008AGUSMSP53A..01B Altcode:
To date the Hinode/Solar Optical Telescope (SOT) has produced over a
dozen sub-arcsecond, multi-hour movies of quiescent solar prominences
in both the Ca II 396.8~nm H-line and the H-alpha 656.3~nm line. These
datasets have revealed new details of the structure and dynamics of
quiescent prominences including a new form of mass transport in the
form of buoyant plume upflows from the chromosphere. We review the
SOT prominence datasets to show that quiescent prominences appear in
two major morphological categories: "vertically" and "horizontally"
structured. The vertically structured prominences all show ubiquitous
downflows in 400--700~km wide "streams" with velocities of approximately
10~km~s-1. Most of the vertically structured prominences also show
episodic upflows in the form of dark turbulent plumes with typical
velocities of 20~km~s-1. Large-scale oscillations are frequently
seen in vertical prominences with periods on the order of 10 min and
upward propagation speeds of approximately 10~km~s-1. In addition,
"bubble" events in which large voids 10--30~Mm across inflate and
then burst are seen in some of the vertical prominences. In contrast,
the horizontally structured quiescent prominences exhibit only limited
flows along the horizontal filaments. We speculate on the origin of
the distinction between the vertically and horizontally structured
prominences, taking into account viewing angle and the underlying
photospheric magnetic flux density. We also discuss the nature of the
mysterious dark plumes and bubble expansions and their implications
for prominence mass balance in light of recent models of prominence
magnetic structure that find vertical flows along some field lines.
---------------------------------------------------------
Title: Magnetic Fields in the Photosphere: Professor Parker's
Contributions to our Understanding of Surface Activity on the Sun
Authors: Berger, T.
2008AGUSMSP33A..02B Altcode:
Magnetic fields in the photosphere of the Sun span sizes from large
sunspot active regions on the order of 50 Mm down to the smallest
observable magnetic elements 100 km or less in diameter. The generation
of these fields in the convection zone and their subsequent interactions
with photospheric flowfields are responsible for the majority of
observed solar variability over a large range of time and wavelength
scales. Professor Parker's research has encompassed this range and
shed light on the origins of large scale active regions, the structure
and dynamics of sunspots, and the implications of the highly dynamic
interactions of magnetic elements with the convective flowfield. We
review the contributions of Prof. Parker to these topics in the light of
recent observations from both ground-based and space-based telescopes
and point out issues of continuing controversy that require further
theoretical and observational exploration.
---------------------------------------------------------
Title: On the Fine Structure and Formation of Sunspot Penumbrae
Authors: Ryutova, M.; Berger, T.; Title, A.
2008ApJ...676.1356R Altcode:
Recent high-resolution observations with the 1 m Swedish Solar Telescope
(SST) on La Palma reveal the fine substructure of penumbral filaments
and new properties of their dynamics. These findings provide both the
basis and constraints for novel models of the penumbra. We present new
observations of a large isolated sunspot near Sun center obtained with
the SST in 2006. Our data, taken simultaneously in the 4305 Å G-band
and 4364 Å continuum bandpasses and compiled in high-cadence movies,
confirm the previous results and reveal new features of penumbral
filament dynamics. We find that individual filaments are cylindrical
helices with the apparent properties of vortex tubes exhibiting flow
patterns similar to kinked flux tubes. Measured pitch/radius ratios
of helical filaments indicate their dynamic stability. We propose a
mechanism that explains the fine structure of penumbral filaments,
their observed dynamics, and their formation process in association
with sunspot properties. The mechanism assumes that the umbra itself
is a dense conglomerate of twisted, interlaced flux tubes with
peripheral filaments branching out from the "trunk" at different
heights due to ongoing reconnection processes and arcing downward to
the photosphere. The twist of individual filaments, and the resulting
distribution of magnetic fields and temperature, is due to the onset
of the well-known screw pinch instability, the parameters of which
can be measured from our data.
---------------------------------------------------------
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
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<SUP>-1</SUP> and the
intensification of the field strength to 2 kG. These observations
agree very well with the theoretical predictions.
---------------------------------------------------------
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
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<SUP>-1</SUP>,
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<SUP>-1</SUP>
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.
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 Altcriss project on board the International Space Station
Authors: Casolino, M.; Minori, M.; Picozza, P.; Fuglesang, C.; Galper,
A.; Popov, A.; Benghin, V.; Petrov, V. M.; Nagamatsu, A.; Berger, T.;
Reitz, G.; Durante, M.; Pugliese, M.; Roca, V.; Sihver, L.; Cucinotta,
F.; Semones, E.; Shavers, M.; Guarnieri, V.; Lobascio, C.; Castagnolo,
D.; Fortezza, R.
2008ICRC....1..489C Altcode: 2008ICRC...30a.489C
The Altcriss project aims perform long term measurement of the
radiation environment in different points of the International Space
Station. To achieve this goal, it employs an active silicon detector,
Sileye-3/Alteino, to monitor nuclei up to Iron in the energy range above
40 MeV/n. Both long term modulation of galactic cosmic rays going toward
solar minimum and solar particles events will be observed. A number
of different dosimeters are being employed to measure the dose and
compare it with the silicon detector data. Another aim of the project
is to monitor the effectiveness of shielding materials in orbit: a set
of polyethylene tiles is placed in the detector acceptance window and
particle flux and composition is compared with measurements in the
same locations without shielding. Dosimeters are thus placed behind
the shielding material and in an unshielded location to cross-correlate
this information. The observation campaign begun in December 2005 and
is running continuously ever since. Active and passive data have been
retreived at the end of expedition 13, 14 and Astrolab mission. In
this work we will describe the experiment and the preliminary results.
---------------------------------------------------------
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.
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 B<SUP>T</SUP><SUB>app</SUB> = 55 Mx cm <SUP>-2</SUP>, as
compared to the corresponding average vertical apparent flux density of
| B<SUP>L</SUP><SUB>app</SUB>| = 11 Mx cm <SUP>-2</SUP>. 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 |
B<SUP>L</SUP><SUB>app</SUB>| and B<SUP>T</SUP><SUB>app</SUB>, 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: Depth dose distributions measured with thermoluminescence
detectors inside the anthropomorphic torso of the MATROSHKA experiment
inside and outside the ISS
Authors: Berger, Thomas; Reitz, Guenther; Hajek, Michael; Bergmann,
Robert; Bilski, Pawel; Puchalska, Msc. Monika
2008cosp...37..257B Altcode: 2008cosp.meet..257B
The ESA MATROSHKA (MTR) facility was realized through the German
Aerospace Center, DLR, Cologne, as main contractor, aiming for the
determination of skin and organ doses within a simulated human upper
torso. MTR simulates, by applying an anthropomorphic upper torso, as
exact as possible an astronaut performing either an extravehicular
activity (EVA) (MTR Phase 1) or an astronaut working inside the
International Space Station (MTR Phase 2A). It consists of a human
phantom, a Base Structure and a Carbon fibre container - simulating
the astronaut‘s space suit. The phantom itself is made up of 33
slices composed of natural bones, embedded in tissue equivalent
plastic of different density for tissue and lung. The Phantom slices
are equipped with channels and cut-outs to allow the accommodation of
active and passive dosemeters, temperature and pressure sensors. Over
4800 passive detectors (thermoluminescence detectors (TLDs) and plastic
nuclear track detectors) constitute the radiation experiments which are
beside inside the phantom also located on top the head of the phantom,
in front of the belly and around the body as part of a Poncho and a
Hood. In its 1st exposure phase (MTR 1: 2004 - 2005) MTR measured the
depth dose distribution of an astronaut performing an EVA - mounted
outside the Zvezda Module. In its 2nd exposure phase the phantom
was positioned inside the ISS to monitor the radiation environment
and measure the depth dose distribution in dependence on the inside
shielding configurations. The majority of the TLDs provided for the
determination of the depth dose distribution was provided by IFJ-PAN,
ATI and DLR. Data of "combined" depth dose distribution of the three
different groups will be shown for the MTR-1 exposure (outside the
ISS) and the MTR-2A (inside the ISS). The discussion will focus on the
difference in depth dose as well as skin dose distribution based on the
different shielding thickness provided by the two experimental phases.
---------------------------------------------------------
Title: Vertical plasma motions in prominence sheets observed by Hinode
Authors: Panasenco, Olga; Velli, Marco; Berger, Thomas
2008cosp...37.2337P Altcode: 2008cosp.meet.2337P
We analyze the approximately vertical motions inside prominence plasma
observed by Hinode on 25 April 2007 in Hα line and 30 November 2006 in
CaH line. Well-established observational facts are that all filaments
(prominences on the limb) are composed of fine threads of similar
dimensions, rooted in the photosphere and presumably tracing magnetic
field lines, and that continuous counter-streaming motions occur
along threads. We take into account the geometry of the prominence
sheet and the viewing angle to reduce possible projection effect and
more correctly interpret the nature of observational downward flows
of denser and cooler plasma as well as the upward flow of hotter
plasma which appears dark in the Hα and CaH spectral lines. The dark
upflows exhibit turbulent flow properties such as vortex formation and
shedding that are consistent with the properties of thermal starting
plumes. Sometimes an illusion of dark upward motion is generated by
rarefactions in the plasma sheet caused by the cooler denser downward
flows. On both dates, we suspect there is probably more filament mass
in the prominence that is visible in either the Hα or CaH lines. The
source of the downward moving plasma may be located either higher
above the visible upper edge of the prominence or on the far end of
the prominence spine. The bright downward motions of the more cool
and dense plasma may be partly due to the counter-streaming motion
along the magnetic fields lines, or it may be due to the presence of
rayleigh-taylor type or ballooning/interchange instabilities in the
upper regions of the prominence, which are then stabilized lower down
where the magnetic field is stronger and the plasma beta lower.
---------------------------------------------------------
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.
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 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.
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: 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.
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: On the Chromospheric Micro-jets Associated with the Penumbral
Filaments
Authors: Ryutova, M.; Berger, T.; Tarbell, T.; Frank, Z.; Title, A.
2007AGUFMSH22A0843R Altcode:
We present observations of sunspot penumbrae obtained during the disk
passage of AR 10923 (November 10--20, 2006) with the Solar Optical
Telescope (SOT) on the Hinode satellite. Co-aligned multi-hour movies
taken simultaneously in several wavelengths show fine-scale dynamics
at the sub-arcsecond level. The dynamics include helical flows along
penumbral filaments, branching of filaments, and penumbral "micro-jets"
recently described by Katsukawa et al. (AAS 210, 94.13). We present
quantitative analyzes of the penumbral jets and interpret them relative
to our recent model of penumbral filaments (Ryutova, Berger and Title,
2007, in "Collective phenomena in macroscopic systems", Ed. G. Bertin,
et al., World Scientific) to show that the jets are the result of
magnetic reconnection of the helical field lines in neighboring
non-collinear filaments.
---------------------------------------------------------
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.
2007Sci...318.1577O Altcode: 2008arXiv0801.1958O
Solar prominences are cool 10<SUP>4</SUP> kelvin plasma clouds
supported in the surrounding 10<SUP>6</SUP> 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: 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.
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: 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
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<SUP>-2</SUP> (assuming the horizontal field structures are
spatially resolved), in contrast to the average apparent vertical flux
density of 11Mxcm<SUP>-2</SUP>. 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: Penumbral Dynamics and its Manifestation in the Overlying
Chromosphere
Authors: Ryutova, Margarita; Berger, Thomas; Tarbell, Theodor; Frank,
Zoe; Title, Alan
2007APS..DPPYP8056R Altcode:
Mature sunspots are usually surrounded by penumbra - a dense
conglomerate of a random interlaced flux tubes with varying
inclinations. High resolution observations show a fine sub-structure
of penumbral filaments and new regularities in their dynamics. These
regularities fit well our recent model of penumbra based on cascading
reconnection events occurring in the system of non-collinear flux
tubes. Each act of reconnection generates twist in the reconnected
filaments and facilitates the onset of a screw pinch instability,
consistent with the observations showing that individual filaments
are cylindrical helices with a pitch/radius ratio providing their
stability. In addition, the post-reconnection products produce a
sling-shot effect that generates oblique shocks and leads to appearence
of a lateral jets. Here we report high resolution (120-180 km) high
cadence (15-30 sec) observations taken with the Solar Optical Telescope
(SOT) on the Hinode satellite. Co-aligned multi-hour movies taken
simultaneously in several wavelengths show detailed behavior of penumbra
filaments and their effect on the overlying chromosphere. We confirm
the ubiquitous nature of penumbral micro-jets recently discovered by
SOT instrument (Katsukawa et al. 2007, AAS 210, 94.13), and present
quantitative analysis of chromospheric jets based on our recent model
of penumbra.
---------------------------------------------------------
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.
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: 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
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: Hinode Observations of the Onset Stage of a Solar Filament
Eruption
Authors: Sterling, Alphonse C.; Moore, Ronald L.; Berger, Thomas
E.; Bobra, Monica; Davis, John M.; Jibben, Patricia; Kano, Ryohei;
Lundquist, Loraine L.; Myers, D.; Narukage, Noriyuki; Sakao, Taro;
Shibasaki, Kiyoto; Shine, Richard A.; Tarbell, Theodore D.; Weber, Mark
2007PASJ...59S.823S Altcode:
We used Hinode X-Ray Telescope (XRT) and Solar Optical Telescope (SOT)
filtergraph (FG) Stokes-V magnetogram observations, to study the
early onset of a solar eruption that includes an erupting filament
that we observe in TRACE EUV images. The filament undergoes a slow
rise for at least 20min prior to its fast eruption and strong soft
X-ray (SXR) flaring; such slow rises have been previously reported,
and the new Hinode data elucidate the physical processes occurring
during this period. XRT images show that during the slow-rise phase,
an SXR sigmoid forms from apparent reconnection low in the sheared core
field traced by the filament, and there is a low-level intensity peak
in both EUV and SXRs during the slow rise. MDI and SOT FG Stokes-V
magnetograms show that the pre-eruption filament is along a neutral
line between opposing-polarity enhanced network cells, and the SOT
magnetograms show that these opposing fields are flowing together
and canceling for at least six hours prior to eruption. From the MDI
data we measured the canceling network fields to be ∼ 40G, and we
estimated that ∼ 10<SUP>19</SUP> Mx of flux canceled during the
five hours prior to eruption; this is only ∼ 5% of the total flux
spanned by the eruption and flare, but apparently its tether-cutting
cancellation was enough to destabilize the sigmoid field holding the
filament and resulted in that field's eruption.
---------------------------------------------------------
Title: What are 'Faculae'?
Authors: Berger, T. E.; Title, A. M.; Tarbell, T.; Rouppe van der
Voort, L.; Löfdahl, M. G.; Scharmer, G. B.
2007ASPC..369..103B Altcode:
We present very high resolution filtergram and magnetogram observations
of solar faculae taken at the Swedish 1-meter Solar Telescope (SST)
on La Palma. Three datasets with average line-of-sight angles of 16,
34, and 53 degrees are analyzed. The average radial extent of faculae is
at least 400~km. In addition we find that contrast versus magnetic flux
density is nearly constant for faculae at a given disk position. These
facts and the high resolution images and movies reveal that faculae are
not the interiors of small flux tubes - they are granules seen through
the transparency caused by groups of magnetic elements or micropores
“in front of” the granules. Previous results which show a strong
dependency of facular contrast on magnetic flux density were caused
by bin-averaging of lower resolution data leading to a mixture of
the signal from bright facular walls and the associated intergranular
lanes and micropores. The findings are relevant to studies of total
solar irradiance (TSI) that use facular contrast as a function of disk
position and magnetic field in order to model the increase in TSI with
increasing sunspot activity.
---------------------------------------------------------
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.
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: Contrast Analysis of Solar Faculae and Magnetic Bright Points
Authors: Berger, T. E.; Rouppe van der Voort, L.; Löfdahl, M.
2007ApJ...661.1272B Altcode:
The morphology and contrast of small-scale solar magnetic elements at
four disk positions is analyzed. The data were obtained at the Swedish
1 m Solar Telescope (SST) over 3 yr (2003-2005). Two of the data sets
have disk positions near disk center (average μ=cosθ>0.8) and show
numerous “magnetic bright points” (MBPs), and two are sufficiently
limbward to show prominent “faculae” (average μ<=0.6). The
filtergrams are obtained in the 430.5 nm G band and 436.4 nm
“continuum” bandpasses; the magnetograms are Fe I 630.25 nm Stokes
V images taken with the Solar Optical Universal Polarimeter (SOUP)
tunable filter. In all images we achieve nearly diffraction-limited
resolution (~100 km in the G band). Analysis shows that MBPs and faculae
are distinct radiative signatures of the magnetic field: MBPs have a
constant or slightly decreasing contrast with increasing magnetogram
signal, while facular contrast increases linearly with magnetogram
signal. Faculae are much larger than MBPs, with an average radial
width of 400 km. The observations support recent modeling showing that
faculae are granules seen through the opacity reduction provided by
magnetic elements (or groups thereof), while MBPs are caused by lateral
radiation leakage scattering from deeper layers of the magnetic element.
---------------------------------------------------------
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.
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. <P
/>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: 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
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. <P />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.
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. <P />This work was supported by
NASA under the Hinode/SOT contract NNM07AA01C.
---------------------------------------------------------
Title: Hinode Observations of Umbral Dots
Authors: Hurlburt, Neal E.; Berger, T.; Ichimoto, K.; SOT Team
2007AAS...210.9409H Altcode: 2007BAAS...39..218H
We analyze observations of sunspot umbra taken by the Solar Optical
Telescope (SOT) on Hinode to ascertain the properties of umbral
dots. The observations consist of coordinated, multi-wavelength
observing sequences spanning several hours for each spot
considered. Typically these multi-wavelength observations include
longitudinal magnetograms in 6302, and filtergrams in Calcium II H,
G-band and blue continuum. We report on the spatial and temporal
properties of the umbral dots and their relation to the umbral field
and overlying chromosphere. <P />This work was supported in part by
NASA in part under the Hinode/SOT contract NNM07AA01C.
---------------------------------------------------------
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
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. <P />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: 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.
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: An Hα Surge Provoked by Moving Magnetic Features near an
Emerging Flux Region
Authors: Brooks, D. H.; Kurokawa, H.; Berger, T. E.
2007ApJ...656.1197B Altcode:
We present a detailed study of Hα surges from cotemporal
high-resolution multiwavelength images of NOAA AR 8227 obtained by
the 50 cm Swedish Vacuum Solar Telescope (formerly situated on La
Palma, Spain) and TRACE. We find that two kinds of collisions between
opposite polarity magnetic flux produce the surges. First, one edge of
an emerging flux region (EFR) collides with the preexisting magnetic
field and causes continual surge activities, which have already been
named EFR surges by previous authors. Secondly, moving magnetic features
(MMFs), which emerge near the sunspot penumbra, pass through the ambient
plasma and eventually collide with the opposite polarity magnetic
field of the EFR. During their passage from the sunspot penumbra to
the EFR, the MMFs constantly interacted with other magnetic elements
and had a close relationship and showed similar flow patterns to Ca
II K bright points. These brightenings were located at the leading
edges of the MMFs. Cancellation of opposite polarity magnetic flux
at the surge footpoint is observed, accompanied by chromospheric and
coronal brightenings. We explain the evolutionary and morphological
characteristics of the multiwavelength features associated with the Hα
surges in both cases by the extension of previous 2D schematic models of
reconnection in surges. Furthermore, by measuring the expansion velocity
and photospheric magnetic field around the surge footpoint, we estimate
a dimensionless reconnection rate of 0.04 (ratio of inflow velocity to
Alfvén velocity). This is sufficient to produce a significant surge
that heats the chromospheric plasma to coronal temperatures.
---------------------------------------------------------
Title: The Altcriss project on board the International Space Station
Authors: Casolino, M.; Altamura, F.; Minori, M.; Picozza, P.;
Fuglesang, C.; Galper, A.; Popov, A.; Benghin, V.; Petrov, V. M.;
Nagamatsu, A.; Berger, T.; Reitz, G.; Durante, M.; Pugliese, M.; Roca,
V.; Sihver, L.; Cucinotta, F.; Semones, E.; Shavers, M.; Guarnieri,
V.; Lobascio, C.; Castagnolo, D.; Fortezza, R.
2007AdSpR..40.1746C Altcode: 2007arXiv0708.2586C
The Altcriss project aims to perform a long term survey of the radiation
environment on board the International Space Station. Measurements are
being performed with active and passive devices in different locations
and orientations of the Russian segment of the station. The goal is to
perform a detailed evaluation of the differences in particle fluence and
nuclear composition due to different shielding material and attitude of
the station. The Sileye-3/Alteino detector is used to identify nuclei
up to Iron in the energy range above ≃60 MeV/ n. Several passive
dosimeters (TLDs, CR39) are also placed in the same location of Sileye-3
detector. Polyethylene shielding is periodically interposed in front of
the detectors to evaluate the effectiveness of shielding on the nuclear
component of the cosmic radiation. The project was submitted to ESA in
reply to the AO in the Life and Physical Science of 2004 and data taking
began in December 2005. Dosimeters and data cards are rotated every 6
months: up to now three launches of dosimeters and data cards have been
performed and have been returned with the end of expedition 12 and 13.
---------------------------------------------------------
Title: Continuum Contrast as a function of Magnetic Flux Density
and Disk Position: Results from a full Solar Cycle of SOHO/MDI data
Authors: Soto, K.; Basri, G.; Ramos-Stierle, F.; Lewis, T.; Reiners,
A.; Berger, T.
2006AGUFMSH11A0373S Altcode:
The key to understanding total solar irradiance variability is
to understand the mechanisms by continuum contrast is effected
by the distribution of magnetic flux across the surface of the
Sun. The Michelson Doppler Imager (MDI) instrument on the Solar and
Heliospheric Observatory (SOHO) satellite has measured full-disk
Stokes-V magnetograms along with cotemporal continuum images
throughout Solar Cycle 23. We present the results of an examination
of the relationship between corrected MDI continuum images with their
cotemporal corrected MDI magnetograms. By separating the series of
images into bins of Magnetic Flux Density (MFD) and limb angle,
we perform a non-linear least squares fit to the data to produce
a 3rd-order polynomial function of continuum contrast vs. MFD and
disk position. Using the obtained function we can accurately predict
continuum contrast at any given disk position as a function of MFD
measured in a given magnetogram. The resulting predictions can be used
to make simulated continuum images suitable for bolometric correction
and input into total irradiance models. This research was partially
supported by LWS TR&T Grant NNG05GK46G
---------------------------------------------------------
Title: Sunspot Contrast Measurements from MDI Full-Disk Images:
Variations with Disk Position and Solar Cycle Phase
Authors: Lewis, T.; Soto, K.; Basri, G.; Ramos-Stierle, F.; Reiners,
A.; Berger, T.
2006AGUFMSH11A0374L Altcode:
We report measurements of sunspot umbral and penumbral contrast as
a function of Magnetic Flux Density (MFD), disk position, and time
over Solar Cycle 23 from full-disk magnetogram and continuum images
of the SOHO/MDI instrument. Using a technique of image segmentation
which utilizes region labeling of entire MDI intensity images in
order to segment prospective sunspots and then the application of
radial derivatives from the centers of the spots we successfully
identify the umbral-penumbral interface of large sunspots in the MDI
database. The extracted penumbral and umbral pixels of these images
are binned according to MFD and disk position to study the behavior
of sunspot contrast. We report measurements of sunspot umbral and
penumbral contrast as a function of Magnetic Flux Density (MFD), disk
position, and time over Solar Cycle 23 from full- disk magnetogram
and continuum images of the SOHO/MDI instrument. This research was
partially supported by LWS TR&T Grant NNG05 GK48G.
---------------------------------------------------------
Title: Correction of MDI Full-Disk Magnetograms for Limb Angle
Effects by the Assumption of Average Magnetic Uniformity
Authors: Ramos-Stierle, F.; Soto, K.; Basri, G.; Lewis, T.; Reiners,
A.; Berger, T.
2006AGUFMSH11A0375R Altcode:
Analysis of magnetic fields on the sun is crucial to understanding
the generation of solar active regions, plage, and the supergranular
network and their contributions to Total Solar Irradiance (TSI)
variation. The Michelson Doppler Imager (MDI) instrument on the Solar
and Heliospheric Observatory (SOHO) satellite has measured full-disk
Stokes-V magnetograms along with cotemporal continuum images throughout
Solar Cycle 23. These pairs of images can be used to study continuum
irradiance changes correlated to magnetogram signal over the entire
disk and over most of Cycle 23. However the MDI magnetogram signal
must be corrected for line-of-sight angle variations. Typically a 1/mu
correction factor (where mu is the cosine of the line-of-sight angle
to the surface normal) is applied across the entire disk. However
near-limb measurements where mu approaches zero are siginificantly
over-corrected by a simple 1/mu factor. We demonstrate a newly
developed geometric correction function for MDI magnetograms based on
the assumption that the distribution of Magnetic Flux Density (MFD)
in the active latitudes should exhibit the same behavior no matter
what angle it is viewed from. We examine a series of 106 magnetograms
in the time period from 01-January-2001 to 30-April-2001. This method
was successful in correcting MDI magnetograms to reasonable MFD in the
limbs, with a minimal number of overcorrected points in the extreme
limb, an improvement upon the typical approach of 1/mu. The resulting
distributions of MFD were more uniform over 50 bins of mu and can be
more successfully used to study continuum irradiance variations as a
function of MFD across the entire disk. This research was partially
supported by LWS TR&T Grant NNG05GK46G.
---------------------------------------------------------
Title: The visible-light broad-band imager for ATST: preliminary
design
Authors: Uitenbroek, Han; Tritschler, Alexandra; An, Hyun Kyoung;
Berger, Thomas
2006SPIE.6269E..61U Altcode: 2006SPIE.6269E.193U
This poster outlines the conceptual design of the Visible-light
Broad-band Imager (VBI) instrument for the Advanced Technology Solar
Telescope (ATST) as it follows from scientific requirements. The VBI
is scheduled to be the first-light instrument of the ATST, highlighting
the telescope's high spatial resolution capabilities.
---------------------------------------------------------
Title: Horizontal and Vertical Flow Structure in Emerging Flux Regions
Authors: Kozu, Hiromichi; Kitai, Reizaburo; Brooks, David H.; Kurokawa,
Hiroki; Yoshimura, Keiji; Berger, Thomas E.
2006PASJ...58..407K Altcode:
In order to obtain an overall view of the flow structure of convective
gas in emerging flux regions (EFRs), we studied three EFRs in two
solar active regions, NOAA 8218 and NOAA 10774. Using the Local
Correlation Tracking method, we found several horizontally divergent
flow structures, which were stable over a period of 1 hour, in 2
EFRs in NOAA 8218. The horizontal flow velocities and the sizes
of the structures were around 500m s<SUP>-1</SUP> and about 4Mm
in radius, respectively. We analyzed another dataset of NOAA 10774
using spectroscopic methods and found temporarily stable up-ward gas
flows in the central part of the EFR. The line-of-sight velocities
were around 150m s<SUP>-1</SUP> and the size of the flow patch was
2 to 5Mm in radius. These results support our previous findings that
convective-cell-like flow appears in the central part of an EFR. We
estimated from these results that the depth of the flow cell in EFRs
is about 600km, and the turn-over time of the cell is about 2 hours.
---------------------------------------------------------
Title: BRADOS Dose determination in the Russian Segment of the
International Space Station
Authors: Hajek, M.; Berger, T.; Fugger, M.; Fuerstner, M.; Vana, N.;
Akatov, Y.; Shurshakov, V.; Arkhangelsky, V.
2006AdSpR..37.1664H Altcode:
In the frame of the joint experiment BRADOS-1, absorbed dose and average
linear energy transfer were assessed by means of <SUP>7</SUP>LiF:Mg,Ti
(TLD-700) thermoluminescence detectors for different panels onboard
the Russian Segment of the International Space Station in the timeframe
between February and October 2001 (248 days). A technique is presented
to correct the measured absorbed dose values for thermoluminescent
efficiency in the radiation climate onboard the spacecraft. Average
linear energy transfer is determined from the high-temperature
thermoluminescence emission in the TLD-700 glowcurve and used as a
parameter in the thermoluminescent-efficiency correction. Depending
on the shielding distribution, the efficiency-corrected absorbed dose
varies between 168(2) μGy/d in panel No. 318 (core block ceiling) and
249(4) μGy/d in panel No. 443 (starboard-side commander cabin). The
experimental data are compared with model calculations using detailed
shielding distributions and orbit parameters as input.
---------------------------------------------------------
Title: Comparison of various techniques for the exact determination
of absorbed dose in heavy ion fields using passive detectors
Authors: Berger, T.; Reitz, G.; Hajek, M.; Vana, N.
2006AdSpR..37.1716B Altcode:
Passive thermoluminescent detectors (TLDs) are commonly applied for the
determination of absorbed dose in routine radiation protection. The
usage of TLDs in heavy ion fields, e.g., in space dosimetry or for
treatment planing in radiotherapy, requires the detailed knowledge of
the efficiency of these detectors to the ion under study in dependence
on the LET of the ion. This is due to the fact, that the detection
efficiency of TLDs changes with increasing LET. If the changing
efficiency of the TL-material is not taken into account, this would
lead to a deviation of the measured absorbed dose. In the framework
of the ICCHIBAN project - which was started as an intercomparison
of passive and active detector systems used for dose determination
in space - "BLIND" exposures were carried out. No information about
dose and ion species was given to the investigators. Three different
methods were used for the efficiency correction of TLDs after the
BLIND exposures. The first method used the different LET efficiency
of the TL-materials LiF:Mg, Ti and LiF:Mg, Cu, P to determine the LET
and from this LET the efficiency of the LiF:Mg, Ti dosemeters. The
second method used the high temperature emissions in LiF:Mg, Ti for
the efficiency correction. The third method used a combination of TLDs
and CR-39 track etch detectors to determine the total absorbed dose
during the BLIND exposures. The paper will discuss the three methods,
and focus on their applicability to precise dose determination and
recalculation in space dosimetry.
---------------------------------------------------------
Title: Status of NSRL-ICCHIBAN, ICCHIBAN-7 and -8 and future ICCHIBAN
experiments
Authors: Uchihori, Y.; Benton, E. R.; Yasuda, N.; Kitamura, H.; Hajek,
M.; Berger, T.; Zeitlin, C.; Miller, J.
2006cosp...36.3567U Altcode: 2006cosp.meet.3567U
The ICCHIBAN InterComparison for Cosmic-rays with Heavy Ion Beams At
NIRS project is an international collaboration established in order
to intercompare detector response and intercalibrate space radiation
instruments used for astronaut and cosmonaut dosimetry Over the past
four years 20 laboratories in 12 nations have participated in eight
ICCHIBAN experiments at the NIRS HIMAC in Japan and two ICCHIBAN
experiments at accelerator facilities in the USA Results from the
ICCHIBAN experiments have improved the calibration of space flight
radiation instruments have proved useful in resolving discrepancies
between measurements made by different instruments during space flight
and have aided in analyzing and interpreting data obtained by both
active and passive detectors exposed in low-Earth orbit We present
here the current status of the ICCHIBAN project including the status
of the ICCHIBAN-7 and ICCHIBAN-8 experiments carried out at HIMAC in
Sept 2005 together with plans for future ICCHIBAN experiments
---------------------------------------------------------
Title: The MATROSHKA Facility - History and science overview
Authors: Reitz, G.; Berger, T.
2006cosp...36.2259R Altcode: 2006cosp.meet.2259R
The ESA MATROSHKA facility was realized through the German Aerospace
Center DLR Cologne as main contractor On the 29th of January 2004
the facility was launched with a Russian PROGRESS vehicle to the
International Space Station It was installed outside the Russian
segment Zvezda on the 26th February 2004 and remained there until
August 2005 and simulates as exact as possible an astronaut during an
extravehicular activity EVA The MATROSHKA facility basically consists
of a human phantom a Base Structure and a Container The container as
well as the phantom is mounted to the base structure which serves as
a footprint for the human phantom The container is a Carbon Fiber
structure and forms with the Base Structure a closed volume that
contains a dry oxygen atmosphere and protects the phantom against e g
space vacuum space debris solar UV and material off-gassing It acts also
as a simulation of the space suit The phantom body is made of commercial
phantom parts well introduced in the field of radiotherapy It consists
of 33 slices composed of natural bones embedded in tissue equivalent
plastic of different density for tissue and lung The Phantom slices
are equipped with channels and cut-outs to allow the accommodation
of active and passive dosemeters temperature and pressure sensors The
radiation experiments accommodated in the facility are performed under
leadership of DLR in a cooperation of more than 15 research institutes
from all over the world The MATROSHKA experiments represent therefore
the currently biggest international
---------------------------------------------------------
Title: Dose distribution in a human phantom onboard aircraft
Authors: Berger, T.; Meier, M.; Reitz, G.; Schridde, M.
2006cosp...36.2257B Altcode: 2006cosp.meet.2257B
The exposure of aircrew personnel to cosmic radiation has been
considered as occupational exposure in the European Union since the
European Council Directive 96 29 EURATOM became effective on May
13 1996 In Germany the corresponding safety standards for aircrew
which include dose assessment among other things are regulated by the
German Radiation Protection Ordinance which implemented the European
law and was amended in 2001 The radiation exposure of most German
aircrew is calculated by the DLR Institute of Aerospace Medicine in
Cologne applying the calculation program EPCARD in the framework of the
aircrew dose determination system CALVADOS underline CAL culated and
underline V erified underline A viation underline DOS imetry Beside the
operational dose calculations DLR performs measuring flights applying
active e g TEPC DOSTEL etc and passive TLDs bubble detectors radiation
detectors to verify the calculation codes Within these activities the
project BODO underline BO dy underline DO simetry comprised a long term
exposure of a RANDO copyright anthropomorphic phantom to measure for the
first time the skin and the depth dose distribution inside a simulated
human torso at aviation altitudes The torso was flown for three months
from mid of July to mid of October 2004 onboard a Lufthansa Cargo
aircraft This torso made up of 27 polyurethane slices with different
densities -- simulating tissue and organs -- was equipped with passive
thermoluminescence detectors TLDs of different types namely TLD 600
6 LiF Mg
---------------------------------------------------------
Title: Performance of novel polymer shields aboard the ESA Biopan-5
mission
Authors: Hajek, M.; Berger, T.; Fugger, M.; Vana, N.
2006cosp...36.2292H Altcode: 2006cosp.meet.2292H
Radiation exposure of astronaut crew has been identified as a key
issue in human spaceflight The reduction of dose by appropriate
shielding measures is thus donated an essential role for the future
development of space exploration particularly with regard to long-term
interplanetary missions Optimization of shielding strategies and
design may involve polymeric materials with enhanced hydrogen content
specifically developed to attenuate high charge-and-energy HZE particles
such as those encountered in galactic cosmic rays GCR The projectile
energy loss is proportional to rho cdot Z A and reaches a maximum for
hydrogen targets Light elements are also expected to minimize target
fragmentation particularly the production of secondary neutrons The
LETVAR experiment flow aboard the European Space Agency ESA Biopan-5
mission as part of a 27 kg payload attached to the external surface of
the Foton-M2 descent capsule was dedicated to studying the shielding
performance of three different polymers in reference to aluminium when
exposed to the unshielded space environment in low-earth orbit LEO
The mission was launched successfully on May 31 2005 from the Baikonur
Cosmodrome Kazakhstan and spent 15 6 days at an orbital altitude between
262 and 304 km inclined by 63 r to the equatorial plane After recovery
absorbed dose and average linear energy transfer LET were determined
in front and behind the material slabs To support data interpretation
material samples equivalent to those flown in space were exposed---to
the extent possible
---------------------------------------------------------
Title: Inclination of magnetic fields and flows in sunspot penumbrae
Authors: Langhans, K.; Scharmer, G. B.; Kiselman, D.; Löfdahl, M. G.;
Berger, T. E.
2005A&A...436.1087L Altcode:
An observational study of the inclination of magnetic fields and
flows in sunspot penumbrae at a spatial resolution of 0.2 arcsec is
presented. The analysis is based on longitudinal magnetograms and
Dopplergrams obtained with the Swedish 1-m Solar Telescope on La Palma
using the Lockheed Solar Optical Universal Polarimeter birefringent
filter. Data from two sunspots observed at several heliocentric
angles between 12 ° and 39 ° were analyzed. We find that the
magnetic field at the level of the formation of the Fe i-line wing
(630.25 nm) is in the form of coherent structures that extend radially
over nearly the entire penumbra giving the impression of vertical
sheet-like structures. The inclination of the field varies up to
45 ° over azimuthal distances close to the resolution limit of the
magnetograms. Dark penumbral cores, and their extensions into the outer
penumbra, are prominent features associated with the more horizontal
component of the magnetic field. The inclination of this dark penumbral
component - designated B - increases outwards from approximately 40 °
in the inner penumbra such that the field lines are nearly horizontal
or even return to the solar surface already in the middle penumbra. The
bright component of filaments - designated A - is associated with the
more vertical component of the magnetic field and has an inclination
with respect to the normal of about 35 ° in the inner penumbra,
increasing to about 60 ° towards the outer boundary. The magnetogram
signal is lower in the dark component B regions than in the bright
component A regions of the penumbral filaments. The measured rapid
azimuthal variation of the magnetogram signal is interpreted as being
caused by combined fluctuations of inclination and magnetic field
strength. The Dopplergrams show that the velocity field associated with
penumbral component B is roughly aligned with the magnetic field while
component A flows are more horizontal than the magnetic field. The
observations give general support to fluted and uncombed models of
the penumbra. The long-lived nature of the dark-cored filaments makes
it difficult to interpret these as evidence for convective exchange
of flux tubes. Our observations are in broad agreement with the two
component model of Bellot Rubi et al. (2003), but do not rule out the
embedded flux tube model of Solanki & Montavon (1993).
---------------------------------------------------------
Title: Magnetic Topology and Wave Propagation in the Solar Atmosphere
Authors: Lawrence, J. K.; Cadavid, A. C.; McIntosh, S. W.; Berger,
T. E.
2005AGUSMSH13C..01L Altcode:
We analyze a 9 hr sequence of simultaneous, high resolution, 21 s
cadence SVST G-band and K-line solar filtergrams plus magnetograms
of lower cadence and resolution. The data include both network and
internetwork areas (Berger and Title 2001, Cadavid, et al. 2003,
Lawrence, et al. 2003). Time series of the G-band and K-line data are
compared after filtering by a Morlet wavelet transform of period 2.5
min. On the average, the K-line signal is delayed by several seconds
after the G-band signal Δ T = 8.6 ± 0.1 s for weak (|BZ| < 50 G)
magnetic field in internetwork but Δ T = 7.2 ± 0.1 s for weak field
in an area including network. The internetwork has no strong fields,
but in network (|BZ| > 80 G) the mean delay time drops to Δ T =
3.4 ± 0.3 s. This is consistent with results by McIntosh, Fleck and
Tarbell (2004) using TRACE 1600Å and 1700Å UV image series. Our
principal result is that the time delay is greater in the internetwork
than in the network by 1.4 ± 0.1 s, even for the same local magnetic
field strength. This suggests that the difference must be an effect
of the field topology. Spatial maps of time delays, in comparison
to maps of such topological quantities as the height in the solar
atmosphere at which the plasma β = 1, offer additional details of the
relationship between wave propagation and the magnetic fields in the
solar atmosphere. This work was supported in part by grants NSF-ATM
9987305 and NASA-NAG5-10880. The SVST is operated by the Swedish
Royal Academy of Sciences at the Spanish Observatorio del Roque de
los Muchachos of the Instituto de Astrofisica de Canarias. Berger,
T.E. and Title, A.M. 2001, ApJ, 553, 449. Cadavid, A.C., et al. 2003,
ApJ, 586, 1409. Lawrence, J.K., et al. 2003, ApJ, 597, 1178. McIntosh,
S.W., Fleck, B. and Tarbell, T.D. 2004, ApJ, 609, L95.
---------------------------------------------------------
Title: High resolution magnetogram measurements of solar faculae
Authors: Berger, T. E.; Rouppe van der Voort, L.; Lofdahl, M. G.
2005AGUSMSP31A..02B Altcode:
We present new images of magnetic elements near the solar limb
("faculae") along with magnetogram measurements and contrast
profiles. Imaging magnetogram observations were made of AR 10377 at μ
= cosθ = 0.6 on 06-June-2003 using the Swedish 1-m Solar Telescope;
the data are the highest spatial resolution magnetogram measurements of
faculae to date. Contrary to previous lower resolution measurements,
we find no correlation between facular contrast and magnetic flux
density at a given disk position. Increasing magnetic flux density
in a region implies an increasing prevalence of micropores. Previous
observations which lacked sufficient spatial resolution to discern
dark micropore "floors" from bright facular walls find a strong
non-linear dependence of facular contrast on magnetic flux density,
with decreasing contrast beyond a certain flux density. We show instead
that the observed contrast of bright facular walls is independent of
magnetic flux density when properly segmented from dark micropores. The
observations are useful for examining the detailed structure of faculae
including the dark lanes found on the disk-center side of many faculae
(explained by several recent 3D MHD numerical simulations). The average
radial profile for 678 faculae segmented from the dataset is very
nearly gaussian with a FWHM radial extent of 265 km and an extended
tail on the limbward side, as predicted by current MHD simulations.
---------------------------------------------------------
Title: First-Light Instrumentation for the Advanced Technology
Solar Telescope
Authors: Rimmele, T.; Balasubramaniam, K.; Berger, T.; Elmore, D.;
Gary, A.; Keller, C.; Kuhn, J.; Lin, H.; Mickey, D.; Pevtsov, A.;
Robinson, B.; Sigwarth, M.; Soccas-Navarro, H.
2005AGUSMSP34A..03R Altcode:
The 4m Advanced Technology Solar Telescope (ATST) is the next
generation ground based solar telescope. In this paper we provide
an overview of the ATST post-focus instrumentation. The majority of
ATST instrumentation is located in an instrument Coude lab facility,
where a rotating platform provides image de-rotation. A high order
adaptive optics system delivers a corrected beam to the Coude lab
facility. Alternatively, instruments can be mounted at the Nasmyth
focus. For example, instruments for observing the faint corona
preferably will be mounted at Nasmyth where maximum throughput
is achieved. In addition, the Nasmyth focus has minimum telescope
polarization and minimum stray light. We give an overview of the
initial set of first generation instruments: the Visible-Light
Broadband Imager (VLBI), the Visible Spectro-Polarimeter (ViSP),
the Near-IR Spectro-Polarimeter (NIRSP), which includes a coronal
module, and the Visible Tunable Filter. We also discuss the unique and
efficient approach to the ATST instrumentation, which builds on the use
of common components such as detector systems, polarimetry packages
and various opto-mechanical components. For example, the science
requirement for polarimetric sensitivity (10-5 relative to intensity)
and accuracy (5'10-4 relative to intensity) place strong constraints
on the polarization analysis and calibration units. Consequently,
these systems are provided at the facility level, rather than making
it part of the requirement for each instrument.
---------------------------------------------------------
Title: Solar Magnetic Flux as a Function of Disk Position over the
Solar Cycle
Authors: Berger, T.
2005AGUSMSP41B..07B Altcode:
A novel analysis of a SOHO/MDI full-disk magnetogram time series
from March 1996 to November 2004 is presented. Each of the 26,052
magnetograms in the series are segmented into sectors of constant
μ = cos θ, each sector having a width of Δμ = 0.05. Within each
sector, a histogram of signed magnetic flux density, corrected for
the line-of-sight angle θ, is compiled. For each magnetogram we thus
obtain a distribution of signed magnetic flux density as a function
of μ. Summing the signed flux in each μ bin gives the total signed
flux as a function of μ. Plotting these totals for each μ-sector
as a function of time over the course of Solar Cycle 22 reveals that
cycle minimum and maximum are differentiated only by the magnitude of
the flux distributions. In other words, in contrast to analogous plots
of flux versus heliocentric latitude, there is no discernible pattern,
or "Butterfly Diagram", of flux seen on the solar disk from Earth. The
finding is relevant to investigations of total solar irradiance (TSI)
since it is known that the primary cause of the ~ 0.1% TSI variation
over the solar cycle is the distribution of non-sunspot magnetic flux
at smaller μ-values (so-called "faculae").
---------------------------------------------------------
Title: Solar magnetic elements at 0.1 arcsec resolution. II. Dynamical
evolution
Authors: Rouppe van der Voort, L. H. M.; Hansteen, V. H.; Carlsson,
M.; Fossum, A.; Marthinussen, E.; van Noort, M. J.; Berger, T. E.
2005A&A...435..327R Altcode:
Small magnetic structures can be seen in G-band filtergrams as isolated
bright points, strings of bright points and dark micro-pores. At a
resolution of 0.1 arcsec, new forms of magnetic structures are found
in strong field areas: elongated “ribbons” and more circular
“flowers”. In this paper we study the temporal evolution of
these small scale magnetic structures. In strong-field regions the
time-evolution is more that of a magnetic fluid than that of collections
of flux-tubes that keep their identity. We find that the granular flow
concentrates the magnetic field into flux sheets that are visible as
thin bright features in the filtergrams. Weak upflows are found in
the flux sheets and downflows in the immediate surroundings. The flux
sheets often become unstable to a fluting instability and the edges
buckle. The sheets tend to break up into strings of bright points,
still with weak upflows in the magnetic elements and zero velocity or
downflows between them. Where there are larger flux concentrations
we find ribbons, flowers and micro-pores. There is a continuous
transition between these forms and they evolve from one form to
another. The appearance is mostly determined by the horizontal size
- larger structures are dark (micro-pores), narrower structures are
ribbon shaped and the flowers are the smallest in extent. All these
structures have darker inner parts and a bright edge. The plasma is
found to be at rest in the ribbons, with small concentrations of weak
upflow sites. Narrow sheets with downdrafts are found right at the
edges of the magnetic field concentrations.
---------------------------------------------------------
Title: Thin Threads of Solar Filaments
Authors: Lin, Yong; Engvold, OddbjØrn; der Voort, Luc Rouppe van;
Wiik, Jun Elin; Berger, Thomas E.
2005SoPh..226..239L Altcode:
High-resolution images obtained in Hα with the new Swedish Solar
Telescope at La Palma, Spain, have been used for studies of fine-scale
threads in solar filaments. The widths of the thin threads are ≤0.3
arcsec. The fact that the width of the thinnest threads is comparable
to the diffraction limit of the telescope of about 0.14 arcsec,
at the wavelength of Hα, suggests that even thinner threads may
exist. Assuming that the threads represent thin magnetic strings,
we conclude that only a small fraction of these are filled with
observable absorbing plasma, at a given time. The absorbing plasma
is continuously flowing along the thread structures at velocities
15± 10 kms<SUP>−1</SUP>, which suggests that the flows must be
field-aligned. In one case where a bundle of thin threads appears
to be rooted in the nearby photosphere, we find that the individual
threads connects with intergranular, dark lanes in the photosphere. We
do not find signs of typical network fields at the `roots' of the fine
threads, as normally evidenced by bright points in associated G-band
images. It is suggested that filament threads are rooted in relatively
weak magnetic fields.
---------------------------------------------------------
Title: Solar magnetic elements at 0.1 arcsec resolution. General
appearance and magnetic structure
Authors: Berger, T. E.; Rouppe van der Voort, L. H. M.; Löfdahl,
M. G.; Carlsson, M.; Fossum, A.; Hansteen, V. H.; Marthinussen, E.;
Title, A.; Scharmer, G.
2004A&A...428..613B Altcode:
New observations of solar magnetic elements in a remnant active region
plage near disk center are presented. The observations were obtained at
the recently commissioned Swedish 1-m Solar Telescope on La Palma. We
examine a single 430.5 nm G-band filtergram that resolves ∼70 km
(0.1 arcsec) structures and find new forms of magnetic structures
in this particular region. A cotemporal Ca II H-line image is used
to examine the low-chromosphere of network elements. A cotemporal Fe
I 630.25 nm magnetogram that resolves structures as small as 120 km
(0.18 arcsec) FWHM with a flux sensitivity of approximately 130 Mx
cm<SUP>-2</SUP> quantifies the magnetic structure of the region. A
Ni I 676.8 nm Dopplergram establishes relative velocity patterns
associated with the network features with an accuracy of about 300 m
s<SUP>-1</SUP>. We find that magnetic flux in this region as seen in
both the magnetogram and the G-band image is typically structured into
larger, amorphous, “ribbons” which are not resolved into individual
flux tubes. The measured magnetic flux density in the ribbon structures
ranges from 300 to 1500 Mx cm<SUP>-2</SUP>, the higher values occurring
at localized concentrations embedded within the ribbons. The Dopplergram
indicates relative downflows associated with all magnetic elements
with some indication that higher downflows occur adjacent to the peak
magnetic flux location. The mean absolute magnetic flux density of the
remnant plage network is about 130 Mx cm<SUP>-2</SUP>; in the lowest
flux regions of the field-of-view, the mean absolute flux density is
approximately 60 Mx cm<SUP>-2</SUP>. Within these quiet regions we do
not find evidence of pervasive kilo-gauss strength magnetic elements
as seen in recent high resolution internetwork studies. In general,
the observations confirm recent 3-dimensional numerical simulations
which show that the magnetic field in high-density regions such as
plage is concentrated in complex structures that are not generally
composed of discrete magnetic flux tubes. <P />Appendices are only
available in electronic form at http://www.edpsciences.org
---------------------------------------------------------
Title: Recent Progress in High-Resolution Observations
Authors: Berger, T. E.; Title, A. M.
2004ASPC..325...95B Altcode:
We review recent optical observations of the solar photosphere and
chromosphere with an emphasis on those observations that attain
spatial resolution values below 0.25 arcsec. Results from the Dutch
Open Telescope (DOT) on La Palma, the Dunn Solar Telescope (DST)
on Sacramento Peak, and the Vacuum Tower Telescope (VTT) on Tenerife
are reviewed. Particular emphasis is placed on results from the newly
commissioned Swedish 1-meter Solar Telescope (SST) on La Palma following
our successful campaigns at this instrument in 2002 and 2003. The SST
with adaptive optics can now achieve 0.0 arcsec resolution imaging
of the Sun in multiple simultaneous wavelengths. Scientific findings
on the structure of sunspot penumbrae and lightbridges, small-scale
magnetic elements, and faculae at the limb are reviewed. The Lockheed
Solar Optical Universal Polarimeter (SOUP) birefringent tunable filter
at the SST produced 0.16 arcsec resolution magnetograms in the summer
of 2003 that have shed new light on the structure and dynamics of
small-scale magnetic fields in the solar photosphere.
---------------------------------------------------------
Title: Instrumentation for the Advanced Technology Solar Telescope
Authors: Rimmele, Thomas R.; Hubbard, Robert P.; Balasubramaniam,
K. S.; Berger, Tom; Elmore, David; Gary, G. Allen; Jennings, Don;
Keller, Christoph; Kuhn, Jeff; Lin, Haosheng; Mickey, Don; Moretto,
Gilberto; Socas-Navarro, Hector; Stenflo, Jan O.; Wang, Haimin
2004SPIE.5492..944R Altcode:
The 4-m aperture Advanced Technology Solar Telescope (ATST) is the
next generation ground based solar telescope. In this paper we provide
an overview of the ATST post-focus instrumentation. The majority of
ATST instrumentation is located in an instrument Coude lab facility,
where a rotating platform provides image de-rotation. A high order
adaptive optics system delivers a corrected beam to the Coude lab
facility. Alternatively, instruments can be mounted at Nasmyth or
a small Gregorian area. For example, instruments for observing the
faint corona preferably will be mounted at Nasmyth focus where maximum
throughput is achieved. In addition, the Nasmyth focus has minimum
telescope polarization and minimum stray light. We describe the set of
first generation instruments, which include a Visible-Light Broadband
Imager (VLBI), Visible and Near-Infrared (NIR) Spectropolarimeters,
Visible and NIR Tunable Filters, a Thermal-Infrared Polarimeter &
Spectrometer and a UV-Polarimeter. We also discuss unique and efficient
approaches to the ATST instrumentation, which builds on the use of
common components such as detector systems, polarimetry packages and
various opto-mechanical components.
---------------------------------------------------------
Title: Three-Dimensional Structure of the Active Region Photosphere
as Revealed by High Angular Resolution
Authors: Lites, B. W.; Scharmer, G. B.; Berger, T. E.; Title, A. M.
2004SoPh..221...65L Altcode:
Blue continuum images of active regions at ∼ 60° from the center
of the solar disk obtained with the new Swedish 1-m Solar Telescope
reveal heretofore unreported structure of the magnetized solar
atmosphere. Perhaps the most striking aspect of these images is
that, at an angular resolution of 0.12″, they show clearly the
three-dimensional structure of the photosphere. In particular,
the Wilson depression of the dark floors of pores is readily
apparent. Conversely, the segmented structure of light bridges running
through sunspots and pores reveal that light bridges are raised
above the dark surroundings. The geometry of light bridges permits
estimates of the height of their central (slightly darker) ridge:
typically in the range 200-450 km. These images also clearly show
that facular brightenings outside of sunspots and pores occur on the
disk-center side of those granules just limbward of intergranular lanes
that presumably harbor the associated plage magnetic flux. In many cases
the brightening extends 0.5″ or more over those granules. Furthermore,
a very thin, darker lane is often found just centerward of the facular
brightening. We speculate that this feature is the signature of cool
down flows that surround flux tubes in dynamical models. These newly
recognized observational aspects of photospheric magnetic fields
should provide valuable constraints for MHD models of the magnetized
photosphere, and examination of those models as viewed from oblique
angles is encouraged.
---------------------------------------------------------
Title: Observations of solar magnetic elements with 0.1" resolution
Authors: Berger, T. E.; Rouppe van der Voort, L. H. M.; Lofdahl,
M. G.; Carlsson, M.; Fossum, A.; Hansteen, V. H.; Marthinussen, E.;
Title, A. M.; Scharmer, G.
2004AAS...204.2005B Altcode: 2004BAAS...36..686B
New observations of solar magnetic elements in a remnant active region
plage near disk center are presented. The observations were taken with
the Swedish 1-meter Solar Telescope on La Palma. We examine a single
430.5 nm G-band filtergram that resolves ∼70 km (0.”1) structures
and find new forms of magnetic structures in this particular region. A
simultaneous Ca II H-line image is used to examine the low-chromosphere
of network elements. A simultaneous Fe I 630.25 nm magnetogram
that resolves structures as small as 120 km (0.”18) FWHM with a
flux sensitivity of approximately 130 Mx cm<SUP>-2</SUP> quantifies
the magnetic structure of the region. A Ni I 676.8 nm Dopplergram
establishes relative velocity patterns associated with the network
features with an accuracy of about 300 m s<SUP>-1</SUP>. Magnetic flux
in this region as seen in both the magnetogram and the G-band image
is typically structured into larger, amorphous, “ribbons” with a
wide range of flux density values, rather than isolated kilogauss
flux tubes. We also present filtergrams and magnetograms of magnetic
elements at the solar limb showing that solar faculae are resolved
into bright granular walls that appear to project 350 to 500 km above
the photosphere.
---------------------------------------------------------
Title: Austrian dose measurements onboard space station MIR and the
International Space Station - overview and comparison
Authors: Berger, T.; Hajek, M.; Summerer, L.; Vana, N.; Akatov, Y.;
Shurshakov, V.; Arkhangelsky, V.
2004AdSpR..34.1414B Altcode:
The Atominstitute of the Austrian Universities has conducted various
space research missions in the last 12 years in cooperation with
the Institute for Biomedical Problems in Moscow. They dealt with the
exact determination of the radiation hazards for cosmonauts and the
development of precise measurement devices. Special emphasis will be
laid on the last experiment on space station MIR the goal of which
was the determination of the depth distribution of absorbed dose and
dose equivalent in a water filled Phantom. The first results from
dose measurements onboard the International Space Station (ISS) will
also be discussed. The spherical Phantom with a diameter of 35 cm was
developed at the Institute for Biomedical Problems and had 4 channels
where dosemeters can be exposed in different depths. The exposure period
covered the timeframe from May 1997 to February 1999. Thermoluminescent
dosemeters (TLDs) were exposed inside the Phantom, either parallel or
perpendicular to the hull of the spacecraft. For the evaluation of
the linear energy transfer (LET), the high temperature ratio (HTR)
method was applied. Based on this method a mean quality factor and,
subsequently, the dose equivalent is calculated according to the
Q(LET <SUB>∞</SUB>) relationship proposed in ICRP 26. An increased
contribution of neutrons could be detected inside the Phantom. However
the total dose equivalent did not increase over the depth of the
Phantom. As the first Austrian measurements on the ISS dosemeter
packages were exposed for 248 days, starting in February 2001 at
six different locations onboard the ISS. The Austrian dosemeter sets
for this first exposure on the ISS contained five different kinds of
passive thermoluminescent dosemeters. First results showed a position
dependent absorbed dose rate at the ISS.
---------------------------------------------------------
Title: Comparison of various techniques for the exact determination
of absorbed dose in heavy ion fields using passive detectors
Authors: Berger, T.; Reitz, G.; Hajek, M.; Vana, N.
2004cosp...35.4425B Altcode: 2004cosp.meet.4425B
Passive thermoluminescent detectors (TLDs) are commonly applied for the
determination of absorbed dose in routine radiation protection. The
usage of TLDs in heavy ion fields, e.g. for treatment planing in
radiotherapy or in space dosimetry, requires the detailed knowledge of
the efficiency of these detectors to the ion under study in dependence
on the LET of the ion. This is due to the fact, that the detection
efficiency of TLDs changes with increasing LET. This would lead - if
the changing efficiency of the TL- material is not taken into account -
to a measured deviation of the absorbed dose. In the framework of the
ICCHIBAN project - which was started as an intercomparison of passive
and active detector systems used for dose determination in space -
"Blind" exposures were carried out. No information about dose and
ion species was given for the investigators. Three different methods
were used for the efficiency correction of TLDs after the BLIND
exposures. The first method used the different LET efficiency of the
TL-materials LiF: Mg, Ti and LiF:Mg, Cu,P to determine the LET and
based on this value the efficiency of the LiF: Mg, Ti dosemeters. The
second method used the high temperature emissions in LiF: Mg, Ti for
the efficiency correction. The third method applied used a combination
of TLDs and CR-39 track etch detectors to determine the total absorbed
dose during the BLIND exposures. The paper will discuss the threee
methods, and focus on the applicability for the usage of these methods
for dose determination and recalculation in space dosimetry.
---------------------------------------------------------
Title: BRADOS - Dose determination in the Russian segment of the
International Space Station
Authors: Hajek, M.; Berger, T.; Fürstner, M.; Fugger, M.; Vana, N.;
Akatov, Y.; Shurshakov, V.; Arkhangelsky, V.
2004cosp...35.1950H Altcode: 2004cosp.meet.1950H
Absorbed dose and dose-average linear energy transfer (LET) were
assessed by means of LiF: Mg, Ti thermoluminescence (TL) detectors
at different locations onboard the Russian segment (RS) of the
International Space Station (ISS) in the timeframe between February
and November 2001, i.e. for 248 days. Based on calibrations of the
employed detectors in a variety of heavy-ion beams, mainly at the
Heavy Ion Medical Accelerator (HIMAC) in Chiba, Japan, the measured
absorbed dose values could be corrected for the TL dose registration
efficiency in the radiation climate onboard the ISS. Various strategies
for efficiency correction are discussed. For the specific case the
efficiency correction accounted for a reduction by nearly 20 % in
dose, implying that without proper consideration of the TL efficiency
behaviour the absorbed dose inside the ISS would be overestimated. The
dose-average LET was derived from TLD-700 measurements evaluated
according to the well-established high-temperature ratio (HTR) method
which analyzes the TL emission in the temperature range between 248 and
310 C. According to the shielding distribution, the efficiency-corrected
absorbed dose was found to vary between 155 μ Gy/d for panel N 457
(RS-ISS toilet) and 230 μ Gy/d for panel N 443 (RS-ISS starboard
cabin). The determined LET indicated a modification of the spectral
composition of the onboard radiation field for the different exposure
locations. Arrangement of TLD-600 and TLD-700 in pair allowed also some
information about the neutron component to be drawn. Experimentally
determined absorbed dose values are compared with model calculations by
means of a self-developed code, using as input data detailed shielding
distributions and proton fluxes from AP-8 and JPL algorithms.
---------------------------------------------------------
Title: A study of the causal relationship between the emergence of
a twisted magnetic flux rope and a small Hα two-ribbon flare
Authors: Brooks, D. H.; Kurokawa, H.; Yoshimura, K.; Kozu, H.; Berger,
T. E.
2003A&A...411..273B Altcode:
We present results from an analysis of a small two-ribbon flare which
occurred above emerging flux in solar active region NOAA 8218 on 1998,
May 13th and which was observed by the Swedish Vacuum Solar Telescope
(SVST) on the island of La Palma, Spain. The relatively simple magnetic
morphology and small size of the flare together with the high quality
of the SVST observations allow us to examine the essential properties
of flares in emerging flux regions in greater detail than before. <P
/>In this paper we compare and contrast the flaring emerging flux region
simultaneously with a non-flaring emerging flux region within the same
field of view. Unusual magnetic footpoint motions are observed in the
flaring region, coincident with the Hα kernels, which result in a
high level of shearing of the magnetic neutral line between opposite
polarities. The Hα images show dark filament structures which form an
inverted S-like shape immediately prior to the flare and then separate
after the energy release disrupts the magnetic field. We interpret
the motions and structures as strong evidence for the emergence of a
twisted magnetic flux rope which developed a sheared configuration with
the overlying magnetic field. In contrast the companion region shows
separating footpoints, with apparent arch-like filament connections in
the Hα images, consistent with the expected appearance of emerging
flux. The observations imply that the attachment of the inverted
S-shaped structure may be an observational consequence of the magnetic
reconnection or untwisting of the field which triggered the flare. We
also find some evidence that the increase in magnetic flux is faster
in the flaring region. <P />Finally, we propose a simple schematic
model of the emergence of a twisted magnetic flux rope and attached
branch which can account for the observed footpoint motions and Hα
structures of the flaring region. Such a model can, in principle,
induce partial magnetic reconnection in the overlying coronal field
and we found some evidence of coronal loop footpoint brightenings
which support our conclusions. Our high resolution study supports the
results of previous authors that even a small twisted structure in an
emerging flux tube can be important for flare production.
---------------------------------------------------------
Title: Influence of Photospheric Magnetic Fields and Dynamics on
Chromospheric K-Line Emission
Authors: Lawrence, J. K.; Cadavid, A. C.; Miccolis, D.; Berger, T. E.;
Ruzmaikin, A.
2003ApJ...597.1178L Altcode:
We analyze a 9 hr sequence of simultaneous, high-resolution,
high-cadence G-band and K-line solar filtergrams plus magnetograms
of lower cadence and resolution. Images include both network
and internetwork. The magnetic and filtergram intensities, their
fluctuations, and relative phases change with progressive strengthening
of local magnetic field. At increased flux levels, sudden photospheric
downflows create long-lived magnetic elements. For weak magnetic fields
the K-line and G-band intensities include an oscillatory component
with period 4 minutes. For stronger fields, the K-line period shifts
to 5 minutes, while the G-band fluctuations fade due to dissociation
of their source, the CH radical. These K-line and G-band fluctuations,
whose periods are longer than the acoustic cutoff, are coherent and
in phase. They also are coherent with fluctuations of the magnetic
field. Weak-field magnetic fluctuations lead the intensity fluctuations
by a phase shift of 90°. Strong-field magnetic fluctuations trail the
intensities by 100°. These are interpreted as standing waves in the
photosphere and low chromosphere. Another class of G-band fluctuations,
with periods shorter than the acoustic cutoff, is associated both
with stronger magnetic fields and with enhanced K-line emission with
fluctuations longer than the cutoff period. This suggests waves excited
by rapid photospheric perturbations and propagating up along magnetic
flux tubes.
---------------------------------------------------------
Title: Future Capabilities for Solar/Stellar Observations
Authors: Carpenter, K.; Hassler, D.; Berger, T.; Bastian, T.;
Pallavicini, R.; Balachandran, S.
2003csss...12..359C Altcode:
This session outlines the potential instrumental capabilities for the
observation of cool stars and the Sun. The individual contributions
cover space-based solar missions (Hassler), ground-based solar
optical/IR instruments (Berger), solar-stellar radio capabilities
(Bastian), space-based stellar missions (Carpenter), ground-based
optical (Pallavicini) and infrared facilities (Balachandran) for
stellar observations.
---------------------------------------------------------
Title: The Observation of Sunspot Light-Bridge Structure and Dynamics
Authors: Berger, T. E.; Berdyugina, S. V.
2003ApJ...589L.117B Altcode:
We present very high resolution multiwavelength images of a sunspot
light bridge in NOAA Active Region 10132 taken at the Swedish 1
m Solar Telescope on La Palma on 2002 September 25. The adaptive
optics-corrected images resolve 100 km scale bright grains on either
side of an approximately 380 km dark lane in the center of the
bridge. Movies of the data show the grains in a steady unidirectional
flow with an average speed of 900 m s<SUP>-1</SUP> along the entire
length of the bridge. Overturning motions are seen in the larger grains,
suggesting a convective origin for these structures. Simultaneous 160
nm ultraviolet images from the Transition Region and Coronal Explorer
(TRACE) satellite show a constant brightness enhancement over the light
bridge, implying a steady chromospheric heat source. TRACE 160 nm movies
do not resolve the unidirectional flow; instead, they suggest that a
horizontal oscillatory motion exists in the chromosphere of the light
bridge. A C2.0 flare at 16:00 UT, one ribbon of which occurs directly
along the light bridge, indicates a high level of magnetic stress
and impulsive dissipation associated with the observed light-bridge
dynamics.
---------------------------------------------------------
Title: Influence of Photospheric Magnetism and Dynamics on
Chromospheric K-line Emission
Authors: Lawrence, J. K.; Cadavid, A. C.; Miccolis, D.; Berger, T. E.;
Ruzmaikin, A.
2003SPD....34.0704L Altcode: 2003BAAS...35..820L
We analyze a unique 9 hr sequence of near simultaneous, high resolution
and high cadence G-band and K-line SVST solar filtergrams together
with magnetograms of lower cadence and resolution. We focus on a
region of the solar surface that includes both internetwork and
network. We examine how the (temperature minimum/chromospheric)
CaII K-line and (photospheric) G-band intensities, their temporal
fluctuations and their coherence and phase relations, with each other
and with magnetic fluctuations, change as we progress from weak magnetic
fields (internetwork) to intermediate and strong fields (network). <P
/>As the background level of flux is increased, sudden photospheric
downflow events can create long-lived, compact (i.e. network) magnetic
elements. For weak magnetic fields the K-line and G-band intensity
signals show an oscillatory component with period centered on 4 min. As
we pass to strong fields, the K-line signal shifts to a 5 min period
while the G-band signal fades, presumably due to dissociation of the
CH radical. The K-line and G-band signals are coherent and nearly
in-phase. They are both coherent with fluctuations of the magnetic
field. For weak field the magnetic signal leads the intensity signals by
90<SUP>o</SUP> in phase. For intermediate and strong fields the magnetic
signal trails the intensities by 110<SUP>o</SUP>. We interpret this as
a transition from acoustic standing waves with weak, passive magnetic
field to a slow mode trapped magnetoacoustic wave. For intermediate
magnetic field we find, in addition to the coherent waves, that G-band
fluctuations at frequencies above the acoustic cutoff (period <
3.5 min) are associated with magnetic fields and with K-line emission
at periods > 3.5 min. This suggests the presence of flux tube
waves excited by rapid photospheric perturbations. <P />This work
was supported by grants NSF-ATM 9987305 and NASA-NAG5-10880. The SVST
is operated by the Swedish Royal Academy of Sciences at the Spanish
Observatorio del Roque de los Muchachos of the Instituto de Astrofisica
de Canarias.
---------------------------------------------------------
Title: Observations of magnetoconvection in Sunspots with 100 km
resolution
Authors: Berger, T. E.; Löfdahl, M. G.; Scharmer, G.; Title, A. M.
2003SPD....34.1108B Altcode: 2003BAAS...35..828B
We present new observations from the Swedish 1-meter Solar Telescope
(SST) on La Palma with ∼0.1 arcsecond ( ∼100 km) resolution:
the highest resolution yet achieved in solar observations. We focus
on sunspot and active region magnetoconvective phenomena using G-band
4305 Å, 4877 Å continuum, 7507 Å TiO bandhead, and Ca II 3968 Å
H-line filtergram movies. The G-band data are post-processed using
Joint Phase Diverse Speckle wavefront restoration to create a full
diffraction limited time series. Sunspot light-bridges are shown to
have dark lanes less than 300 km in width that are coherent along
the entire length of the bridge. Similarly, we find elongated dark
“canals” in plage regions, particularly near pores, that appear to be
highly modified intergranular downflow lanes. The canals are less than
200 km in width and are much more coherent than intergranular lanes
in non-magnetic regions, often retaining their basic structure for
more than one granular turn-over time. Both the light-bridge central
lane and the canals appear to be the result of highly constrained
flow structure in strong magnetic field regions -- an aspect of solar
magnetoconvection that has not previously been observed. This reseach
was supported by funding from the Royal Swedish Academy of Sciences,
a SOHO Guest Investigator subcontract to California State University
Northridge, and the NASA TRACE contract NAS5-38099 at Lockheed Martin.
---------------------------------------------------------
Title: Photospheric Sources of Chromospheric Dynamics in the
Internetwork
Authors: Cadavid, A. C.; Lawrence, J. K.; Berger, T. E.; Ruzmaikin, A.
2003SPD....34.0703C Altcode: 2003BAAS...35..820C
We analyze a unique 9 hr sequence of near simultaneous, high
resolution and high cadence G-band and K-line solar filtergrams
together with magnetograms of lower cadence and resolution, taken
with the SVST. We investigate an internetwork region characterized
by magnetic fields with strength < 150 Gauss and focus on the
phenomena surrounding discrete photospheric darkening “events”
in G-band intensities. 72 % of the darkenings are followed after 2
min by K-line brightenings. In the remaining cases the darkenings are
instead preceded by K-line brightenings 2 min earlier. In both cases
the preceding and following G-band minima are each associated with
transient magnetic enhancements, and thus, presumably, photospheric
inflows followed by outflows. The magnetic field appears to have no
role in coupling the photospheric phenomena to the chromosphere, and
acts as a passive tracer of horizontal photospheric flows that converge
on the photospheric darkening events and then rebound. The timing and
coupling of the photospheric darkenings and chromospheric brightenings
appear to be regulated by a pre-existing 4 min oscillation of the
solar atmosphere. Other oscillations with periods in the range 1-8
min also are present, and in general the wave power is doubled at the
time of an event. At short periods temporal structure is resolved. Our
results favor an acoustic source for enhanced amplitudes of K-line
intensity oscillations.
---------------------------------------------------------
Title: Weak-Field Magnetogram Calibration using Advanced Stokes
Polarimeter Flux Density Maps - II. SOHO/MDI Full-Disk Mode
Calibration
Authors: Berger, T. E.; Lites, B. W.
2003SoPh..213..213B Altcode:
Cotemporal Ni i 676.8 nm full-disk magnetograms from the Michelson
Doppler Interferometer (MDI) instrument on SOHO and the Advanced Stokes
Polarimeter (ASP) are quantitatively compared using observations
of active region AR 8218, a large negative polarity sunspot group
observed at S20 W22 on 13 May 1998. MDI produces flux density estimates
based on a polarized line center-of-gravity algorithm using moderate
spectral resolution filtergrams with approximately 4 arc sec angular
resolution. The magnetograms are formed by an on-board image processor
and sent to the ground where they are calibrated using an empirical
model to produce flux density maps. The ASP uses high spectral
resolution Stokes polarimetric observations to produce very high
precision vector magnetic field maps at angular resolution values on
the order of 1 arc sec in good seeing. We use ASP inversion results to
create a reference ASP `longitudinal magnetic flux density map' with
which to calibrate the MDI full-disk magnetograms. The magnetograms from
each instrument are scaled to a common reference frame and co-aligned
with an accuracy of about 1.6 arc sec. Regions of invalid data,
poor field-of-view overlap, and sunspots are masked out in order to
calibrate MDI predominately on the relatively vertical `weak-field'
plage magnetic elements. Pixel-to-pixel statistical comparisons are
used to determine an MDI magnetogram linear calibration relative to
reference ASP flux density values. We find that the current Level-1.5
MDI full-disk calibration gives flux density values lower on average
by a factor of 0.64±0.013 compared to the ASP reference in active
region plage. In sunspot regions (penumbra and umbra) the factor
is 0.69±0.007.
---------------------------------------------------------
Title: Photospheric Sources and Brightening of the Internetwork
Chromosphere
Authors: Cadavid, A. C.; Lawrence, J. K.; Berger, T. E.; Ruzmaikin, A.
2003ApJ...586.1409C Altcode:
We analyze a unique 9 hr sequence of near-simultaneous, high-resolution
and high-cadence G-band and K-line solar filtergrams, together with
magnetograms of lower cadence and resolution. Our focus is on the
phenomena surrounding discrete photospheric darkening “events” in
internetwork G-band intensities. 72% of the darkenings are followed
after 2 minutes by K-line brightenings. In the remaining cases,
the darkenings are instead preceded by K-line brightenings 2 minutes
earlier. Equivalent results are found when reference is shifted to
K-line brightening events, although these two sets overlap by no more
than 15%. The timing and coupling of the photospheric darkenings and
chromospheric brightenings appear to be regulated by a preexisting 4
minute oscillation of the solar atmosphere. Other oscillations with
periods in the range 1-8 minutes also are present, and in general
the wave power is doubled at the time of an event. Our results
favor an acoustic source for enhanced amplitudes of K-line intensity
oscillations. The magnetic field acts as a passive tracer of horizontal
photospheric flows that converge on the photospheric darkening events
and then rebound.
---------------------------------------------------------
Title: Intensity tracers of the magnetic field: pitfalls and
opportunities
Authors: Lites, B. W.; Berger, T. E.
2002ESASP.505...57L Altcode: 2002solm.conf...57L; 2002IAUCo.188...57L
Magnetic fields are the main source of structuring of the solar
atmosphere. Stokes I images at various wavelengths reflect this
structure at the monochromatic heights of formation of the intensity. In
the photosphere intensity tracers identify the location and evolution
of kiloGauss flux tubes. In the chromosphere and above Stokes I images
may be used to identify the direction of the magnetic lines of force,
and may be used to establish the connectivity of the field inferred from
photospheric vector magnetograms. In some circumstances the intensity
diagnostics of the field may be misleading. Some of these "pitfalls"
are discussed.
---------------------------------------------------------
Title: Weak-Field Magnetogram Calibration using Advanced Stokes
Polarimeter Flux-Density Maps - I. Solar Optical Universal Polarimeter
Calibration
Authors: Berger, T. E.; Lites, B. W.
2002SoPh..208..181B Altcode:
Cotemporal Fe i 630.2 nm magnetograms from the Solar Optical Universal
Polarimeter (SOUP) filter and the Advanced Stokes Polarimeter (ASP) are
quantitatively compared using observations of active region AR 8218,
a large negative polarity sunspot group observed at S20 W22 on 13 May
1998. The SOUP instrument produces Stokes V/I `filter magnetograms'
with wide field of view and spatial resolution below 0.5 arc sec
in good seeing, but low spectral resolution. In contrast, the ASP
uses high spectral resolution to produce very high-precision vector
magnetic field maps at spatial resolution values on the order of 1
arc sec in good seeing. We use ASP inversion results to create an ASP
`longitudinal magnetic flux-density map' with which to calibrate the
less precise SOUP magnetograms. The magnetograms from each instrument
are co-aligned with an accuracy of about 1 arc sec. Regions of invalid
data, poor field-of-view overlap, and sunspots are masked out in order
to calibrate SOUP predominately on the relatively vertical `weak-field'
plage magnetic elements. Pixel-to-pixel statistical comparisons are
used to determine the SOUP magnetogram linear calibration constant
relative to ASP flux-density values. We compare three distinct
methods of scaling the ASP and SOUP data to a common reference
frame in order to explore filling factor effects. The recommended
SOUP calibration constant is 17 000 ± 550 Mx cm<SUP>−2</SUP> per
polarization percent in plage regions. We find a distinct polarity
asymmetry in SOUP response relative to the ASP, apparently due to a
spatial resolution effect in the ASP data: the smaller, less numerous,
minority polarity structures in the plage region are preferentially
blended with the majority polarity structures. The blending occurs to
a lesser degree in the high-resolution SOUP magnetogram thus leading
to an apparent increase in SOUP sensitivity to the minority polarity
structures relative to the ASP. One implication of this effect is
that in mixed polarity regions on the Sun, lower spatial resolution
magnetograms may significantly underestimate minority polarity flux
levels, thus leading to apparent flux imbalances in the data.
---------------------------------------------------------
Title: Observation and Modelling of Micropore Formation in Active
Network Regions
Authors: Berger, T. E.; Löfdahl, M. G.; Bercik, D. J.
2002AAS...200.9101B Altcode: 2002BAAS...34Q.953B
We present phase-diversity corrected G-band 4305 Å and 4364 Å
continuum image time series showing the formation of a micropore in
a small active region near disk center. The data were acquired at
the Swedish Vacuum Solar Telescope on La Palma in June of 1997 and
post-processed using the Phase Diverse Speckle (PDS) algorithm to
produce diffraction limited images throughout the majority of both
time series. The micropore dataset comprises a 29x29 Mm field of view
and spans 5.1 hours with a 38 second cadence. The micropore forms in
a strong sink area that can be seen to “collect" many G-band bright
points over the first 2 hours of the observation. During this time
there is an occasional darkening at the sink point that may be the
first unstable phase of the micropore formation. Once a stable dark
pore forms in the flowfield, it grows to a maximum diameter of 1.2 Mm
in approximately 1.9 hours. The pore persists for another 35 minutes
before apparently being broken up by the intergranular flowfield. The
total “lifetime" of the stable pore phase is 2.5 hours. A separate
nearby micropore of 1.5 Mm maximum diameter exists for the entire 5.2
hour data span. We show G-band and continuum movies of the micropore
formation, correlation tracking flowfield analyses, G-band bright
point tracking results, and area versus time plots for the micropore
formation lifetime. The observational data are compared with fully
compressible 3D MHD numerical simulations which show the development
of a similar micropore structure within the computational domain. This
research was supported by NASA SR&T grant NASW-98008, The Royal
Swedish Academy of Sciences, NSF and NASA funding at Michigan State
University, and Lockheed Martin IRAD funding.
---------------------------------------------------------
Title: Mesogranulation from Principal Component Analysis of SVST
Photospheric Continuum Images
Authors: Bell, E.; Cadavid, A. C.; Lawrence, J. K.; Berger, T. E.
2002AAS...200.3805B Altcode: 2002BAAS...34Q.699B
We analyze a sequence of 279 images of the photosphere made with the
Swedish Vacuum Solar Telescope on 1997 June 11. The sequence spans 3
hr with cadence 38 s. The images were taken in continuum near 4364
Å, and underwent phase diversity reconstruction. Resolution is ~
0.2 Mm and field of view 32 X 32 Mm. We carried out a principal
component analysis on sequences of 15 images spaced 6 min apart and
covering 1.5 hr. The 15 X 15 correlation matrix of each such set
of images was diagonalized, giving 15 eigenimages which are linear
combinations of the original 15. The eigenimage corresponding to the
largest eigenvalue is the linear combination that best resembles the
original set as a whole; those with smaller and smaller eigenvalues
resemble the overall set less and less well. Fourier spectra of the
eigenimages were calculated separately for several sequences and
then averaged together to reduce uncertainties. Fourier analysis
of the leading eigenimage reveals structure at two scales: one for
λ =1/ν ~ 1.5 Mm corresponding to granulation and another for λ ~
4.5 Mm. Because of their scale and because the time span of the sets
lies between the lifetimes of granules and mesogranules, we interpret
the latter as mesogranules. The subsequent eigenimages do not show the
larger structure, but show the granular peak at successively smaller
scales. This indicates a spatio-temporal scaling of the granulation
with shorter lifetimes for smaller features. For comparison purposes,
simulated granulation images (Cattaneo, Lenz and Weiss 2001) were
similarly analyzed and give similar results. Work supported in part
by grants NSF-ATM-9987305, NASA-NAG5-10880 and the NASA CSUN/JPL PAIR
Program. F. Cattaneo, D. Lenz and N. Weiss 2001, ApJ, 563, L91.
---------------------------------------------------------
Title: High Resolution Spatio-Temporal Study of Photospheric and
Chromospheric Energetics
Authors: Cadavid, A. C.; Lawrence, J. K.; Berger, T. E.
2002AAS...200.3809C Altcode: 2002BAAS...34..700C
We study the photosphere/chromosphere energetic connection using a
nine hour sequence of SVST images obtained May 30, 1998. The data
consist of co-spatial, nearly simultaneous filtergrams of G-band
(4305 Å ), Ca II K (3934 Å ), two (6563 Å) Hα channels offset by
0.35 Å and 0.7 Å , and Fe I (6302 Å) magnetograms. The cadence of
the G-band and Ca K observations is ~ 30 s; that of the other images
is ~ 2 min. The pixel scale is 0.06 Mm and field of view 48 X 48 Mm
on the Sun. The filtergram resolution is > 0.2 Mm; that of the
magnetograms > 0.3 Mm with single magnetogram sensitivity <
150 G. We have co-registered the images to 1 or 2 pixel accuracy. The
number distribution of Ca brightenings and of localized changes in
magnetic field strength, measured in standard deviations (σ ) from
the image means, present three different characteristic regimes;
that of the magnetic “free energy” (a derived measure based on
the local variance of magnetic field) presents two. Ca brightenings
below 3σ show a weak but significant correlation with local magnetic
field and free energy. At 3σ the strength of the correlation abruptly
increases. Above 5σ no correlation is apparent, but large magnetic
field values appear. Using a mask to remove the network areas, the
weakest brightenings (<1.5 σ ) show anti-correlation with the
magnetic field. For 1.5 σ to 4.5 σ there is no correlation. For
selected network examples we follow the time evolution in all observed
lines. We find cases in which an increase and then relaxation in the
magnetic free energy just precedes a local rise in Ca emission followed
by a drop to a lower background level than initially. Work supported
in part by NSF-ATM-9987305 and NASA-NAG5-10880.
---------------------------------------------------------
Title: Observations of the Structure of small scale photospheric
fields
Authors: Lawrence, J.; Cadavid, A.; Ruzmaikin, A.; Berger, T.
2002ocnd.confE..26L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Small-scale solar magnetic dynamics
Authors: Berger, Thomas
2002ocnd.confE...2B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Austrian radiation dose measurements onboard space station
mir and the international space station iss - overview and comparison
Authors: Berger, T.; Hajek, M.; Summerer, L.; Vana, N.; Akatov, Y.;
Shurshakov, V.; Arkhangelsky, V.
2002cosp...34E2588B Altcode: 2002cosp.meetE2588B
The Atominstitut of the Austrian Universities has conducted various
space research missions in the last 12 years in cooperation with
the Institute for Biomedical Problems in Moscow. They dealt with the
exact determination of the radiation hazards for cosmonauts and the
development o precise measurement devices.f Special emphasis will be
laid on the last experiment on space station MIR the goal of which
was the determination of the depth distribution of absorbed dose and
dose equivalent in a water filled phantom. The first results from
dose measurements onboard the International Space Station will also
be discussed.. The phantom with a diameter of 35 cm was developed
at the Institute for Biomedical Problems and had 4 channels where
dosemeters can be exposed in different depths. The exp osure period
covered the timeframe from May 1997 to February 1999. Thermoluminescent
dosemeters (TLDs) were exposed inside the phantom, either parallel
or perpendicular to the hull of the spacecraft. For the evaluation of
the linear energy transfer (LET), the High Temperature Ratio (HTR) -
method was applied. Based on this method a mean quality factor and,
subsequently, the dose equivalent is calculated according to the
Q(LET ) relationship proposed in ICRP 26. An increased contribution
of neutrons could be detected inside the phantom. However the total
dose equivalent did not increase over the depth of the phantom. As the
first Austrian measurements on the ISS dosemeter packages were exposed
for 248 days, starting in February 2001 at six different locations
onboard the ISS. The Austrian dosemeter sets for this first exposure
on the ISS contained 5 different kinds of passive thermoluminescent
dosemeters. First results showed a position dependent absorbed dose
rate and LET at the ISS. Dose rates ranged from 180 to 280 μGy/d. The
differences in dose measurements onboard the 2 space stations will
be discussed.
---------------------------------------------------------
Title: Precision spectro-polarimeter for high-resolution observations
of solar magnetic fields
Authors: Lites, Bruce W.; Elmore, David F.; Streander, Kim V.; Akin,
David L.; Berger, Tom; Duncan, Dexter W.; Edwards, Chris G.; Francis,
Barbara; Hoffmann, Chris; Katz, Noah; Levay, Michael; Mathur, Dnyanesh;
Rosenberg, William A.; Sleight, Ericka; Tarbell, Theodore D.; Title,
Alan M.; Torgerson, Darrel
2001SPIE.4498...73L Altcode:
As a Japanese National space mission with international collaboration,
Solar-B (2005 launch) will carry a spectro- polarimeter (SP)
to be operated in visible light to obtain the first high angular
resolution, precision measurements of solar vector magnetic fields
from space. The SP is part of the Focal Plane Package (FPP) fed by a
diffraction-limited 50-cm optical telescope. The SP will be operated
exclusively at the photospheric 630 nm Fe I lines. It features a
rotating, low-order crystalline quartz retarder for polarization
modulation and a reflecting Littrow spectrograph design that is
shortened by using diffraction from the 12micrometers wide slit to
fill the grating. Polarization analysis is accomplished by a modified
Savart plate beam splitter. A custom CCD detector with two active
areas, one for each beam from the beam splitter, allows continuous
high duty-cycle sampling of polarization. The spectrograph slit will
sample a 0.16 x 164 arcsec<SUP>2</SUP> rectangle of the solar image,
which may be scanned across the slit by up to +/- 160 arcsec in order
to build up vector magnetic field maps of the solar photosphere. Along
with simultaneous, co-spatial imaging and polarimetry with the filter
imagers of the FPP, the SP will provide a precise view of active and
quiet solar magnetic fields that control the structure, dynamics,
and energetics of the upper solar atmosphere.
---------------------------------------------------------
Title: Two dual-wavelength sequences of high-resolution solar
photospheric images captured over several hours and restored by use
of phase diversity
Authors: Löfdahl, M. G.; Berger, T. E.; Seldin, J. H.
2001A&A...377.1128L Altcode:
The collection, seeing compensation, and temporal filtering of two
high-resolution time-sequences of solar photospheric images are
described. 44arcsecx80 arcsec image sequences of co-spatial and
co-temporal 430.5 nm G band and 436.4 nm continuum filtergrams,
were obtained with the 47.5 cm Swedish Vacuum Solar Telescope. One
data set covers 5 hours of photospheric evolution; the other covers
8 hours. The field-of-view contains both an enhanced network region,
a large pore, and in the longer sequence, a pore forming event. The
mean time between frames is <40 s. With a few exceptions, the G
band frames are partitioned phase-diverse speckle (PPDS) restorations
of three realizations of the atmospheric turbulence acquired rapidly in
sequence. Due to strict simultaneity and closely spaced wavelengths, the
G band wavefronts, compensated for fixed aberration differences, could
also be used for deconvolving the corresponding continuum data. For
some of the data, collected during periods of particularly bad seeing,
restorations made with a related method, joint phase-diverse speckle,
were substituted for the PPDS restorations.
---------------------------------------------------------
Title: Spatiotemporal Scaling of Solar Surface Flows
Authors: Lawrence, J. K.; Cadavid, A. C.; Ruzmaikin, A.; Berger, T. E.
2001PhRvL..86.5894L Altcode: 2001astro.ph..1224L
The sun provides an excellent natural laboratory for nonlinear
phenomena. We use motions of magnetic bright points on the solar
surface, at the smallest scales yet observed, to study the small scale
dynamics of the photospheric plasma. The paths of the bright points
are analyzed within a continuous time random walk framework. Their
spatial and temporal scaling suggests that the observed motions are
the walks of imperfectly correlated tracers on a turbulent fluid flow
in the lanes between granular convection cells.
---------------------------------------------------------
Title: On the Relation of G-Band Bright Points to the Photospheric
Magnetic Field
Authors: Berger, T. E.; Title, A. M.
2001ApJ...553..449B Altcode:
Cotemporal observations in the 4305 Å G-band and Ca II λ3933 K-line,
Fe I 6302 Å magnetograms, and 6563 Å Hα images are used to study the
relation of G-band bright points (GBPs) to magnetic elements in the
photosphere. Angular resolution of 0.2" and 0.3" is achieved in the
best G-band and magnetogram images, respectively. Single magnetogram
sensitivity of 120-150 gauss (Φ<SUB>min</SUB>~10<SUP>16</SUP> Mx)
is achieved. Small-scale GBPs appear both in intergranular lanes
and on the edges of certain bright, rapidly expanding granules. The
latter class of GBPs are nonmagnetic (at the flux limit) and are
a source of confusion in magnetic element studies. The large-scale
pattern of GBPs and magnetic flux in plage are highly correlated;
GBPs occur preferentially on the periphery of extended plage regions,
which are primarily demarcated by dark or neutral-contrast regions
(e.g., pores or unresolved structures). On subarcsecond scales, GBPs
are cospatial (to within an average of 0.24") and comorphous with
magnetic elements in intergranular lanes; larger flux concentrations
appear more diffuse than the associated GBP groupings. The average peak
flux density of GBPs in the data set is ~160 gauss. No significant
trend in GBP flux density as a function of either contrast or size
is found. Rings of magnetic elements on 5" scales remain very stable
for periods on the order of hours. GBPs trace the temporal evolution
of magnetic elements closely: there is no indication of a lead or lag
(to within the 30-90 s precision of our data) in the appearance of GBPs
relative to the appearance of magnetic elements. Pore formation via
the accumulation of magnetic elements at a flow-field sink is seen in
the data set. Magnetic elements and granules are continually advected
into pores by the photospheric flow field.
---------------------------------------------------------
Title: Intercomparison of SOUP, ASP, LPSP, and MDI magnetograms
Authors: Berger, T.; Lites, B.; Martinez-Pillet, V.; Tarbell, T.;
Title, A.
2001AGUSM..SP51B12B Altcode:
We compare simultaneous magnetograms of a solar active region taken by
the Advanced Stokes Polarimeter (ASP) and the Solar Optical Universal
Polimeter (SOUP) in 1998. In addition we compare magnetograms taken by
the La Palma Stokes Polarimeter (LPSP), the Michelson Doppler Imager
(MDI) on SOHO, and the SOUP instrument in 2000. The SOUP instrument on
the Swedish Vacuum Solar Telescope (SVST) attains the highest spatial
resolution but has the least understood calibration; the ASP on the Dunn
Solar Telescope (DST) at Sacramento Peak attains the highest magnetic
field precision. The goal of the program is to better quantify the
SOUP magnetograms and thereby study magnetic element dynamics in the
photosphere with higher precision.
---------------------------------------------------------
Title: High Resolution Observations and Modeling of Small-Scale
Solar Magnetic Elements
Authors: Berger, Thomas E.
2001STIN...0132415B Altcode:
This research contract investigating the radiative transfer and
dynamic physics of the smallest observable magnetic structures in the
solar photosphere. Due to the lack of a high-resolution visible light
satellite instrument for solar studies, all data were acquired using
ground-based instrumentation. The primary goal of the investigation was
to understand the formation and evolution of "G-band bright points" in
relation to the associated magnetic elements. G-band bright points are
small (on the order of 100 kin or less in diameter) bright signatures
associated with magnetic flux elements in the photosphere. They are seen
in the A2A-X2 4308 A molecular bandhead of the CH radical ill the solar
spectrum and offer the highest spatial resolution and highest contrast
"tracers" of small magnetic structure on the Sun.
---------------------------------------------------------
Title: Local-area helioseismology by SOT on-board Solar-B
Authors: Sekii, T.; Shibahashi, H.; Kosovichev, A. G.; Duvall, T. L.,
Jr.; Berger, T. E.; Bush, R.; Scherrer, P. H.
2001ESASP.464..327S Altcode: 2001soho...10..327S
Solar-B satellite, a successor to Yohkoh, will be launched
in 2005. Placed in a sun-synchronous orbit, it will carry out
multi-wavelength observation in optical, EUV and X-ray ranges. One of
the instruments on Solar-B, Solar Optical Telescope (SOT), a Japan/US
collaboration, aims at measuring the magnetic field and the Doppler
velocity field in the solar photosphere. Although it is not specifically
designed for helioseismic observations, the high-resolution Dopplergram
produced by SOT is potentially a very powerful tool for detailed
seismic investigation of subsurface magnetic and thermal structures
and associated mass flows. If successful, these measurements will be
an important contribution to the main goal of the Solar-B project:
understanding the origin and dynamics of the basic magnetic structures
and their effects on the solar corona. We discuss the prospect and
challenges of local-area helioseismology by SOT.
---------------------------------------------------------
Title: In-flight performance of the Very high Angular resolution
ULtraviolet Telescope sounding rocket payload
Authors: Korendyke, Clarence M.; Vourlidas, A.; Cook, John W.; Dere,
Kenneth P.; Feldman, R.; Howard, Russell A.; Lilley, D. N.; Morrill,
Jeff S.; Moses, J. Daniel; Moulton, Norman E.; Moye, Robert W.;
Roberts, D. E.; Shepler, E. L.; Smith, J. K.; Socker, Dennis G.;
Spears, T. R.; Waymire, R. S.; Brown, Wayne E.; Tarbell, Theodore D.;
Berger, Tom; Handy, Brian N.
2000SPIE.4139..340K Altcode:
The Very high Angular Resolution ULtraviolet Telescope experiment was
successfully launched on May 7, 1999 on a Black Brant sounding rocket
vehicle from White Sands Missile Range. The instrument consists of a
30 cm UV diffraction limited telescope followed by a double grating
spectroheliograph tuned to isolate the solar Lyman (alpha) emission
line. During the flight, the instrument successfully obtained a series
of images of the upper chromosphere with a limiting resolution of
approximately 0.33 arc-seconds. The resulting observations are the
highest resolution images of the solar atmosphere obtained from space
to date. The flight demonstrated that subarc-second ultraviolet images
of the solar atmosphere are achievable with a high quality, moderate
aperture space telescope and associated optics. Herein, we describe
the payload and its in- flight performance.
---------------------------------------------------------
Title: On the Nature of the “Moss” Observed by TRACE
Authors: Martens, P. C. H.; Kankelborg, C. C.; Berger, T. E.
2000ApJ...537..471M Altcode:
“Moss” is the name given to low-lying (~3000 km), hot (~1 MK) solar
coronal plasma that has been observed recently by the Transition
Region and Coronal Explorer (TRACE). This paper investigates two
hypotheses regarding the nature of the moss: (1) emission from small,
million degree loops; (2) emission from the legs of 3-10 million
degree loops. We update the coronal radiative loss curve, using the
most recent results for coronal abundances, and use an analytical loop
model to find that the first hypothesis requires a filling factor close
to unity to reproduce the observed emission measure, while the second
hypothesis results in a filling factor of about 0.1, in agreement
with other independent multiwavelength analyses of moss. We find that
the vertical extent and the height of the moss layer above the limb
are also very well reproduced with the second hypothesis. We further
show that the observed brightness of the moss scales linearly with
the loop pressure and filling factor, independent of the loop length,
and we derive a general expression for the conversion factor.
---------------------------------------------------------
Title: The Solar-B Focal Plane Package
Authors: Berger, T. E.; Title, A. M.; Tarbell, T. D.; Lites, B. W.;
Elmore, D. F.
2000SPD....31.0292B Altcode: 2000BAAS...32..827B
Solar-B is a Japanese national space science mission of the Institute
of Space and Astronautical Sciences (ISAS) with participation from
US and UK research groups. The satellite consists of a 50-cm optical
telescope and Focal Plane Package (FPP) designed for high resolution
photospheric and chromospheric imaging and spectro-polarimetry as
well as two coronal instruments: the X-Ray Telescope (XRT) and the
Extreme-ultraviolet Imaging Spectrometer (EIS). Solar-B will be
launched into a Sun-synchronous orbit in August of 2004. A team of
Lockheed Martin Solar and Astrophysics Laboratory (LMSAL), High Altitude
Observatory, and ISAS personnel are designing the FPP instrument. It
consists of a narrow-band tunable birefringent filter system,
a wide band interference filter system, and a spectro-polarimeter
system for very high sensitivity Stokes polarimetry, all of which
will be fabricated at LMSAL. We describe the main science goals of
the FPP as well as the current instrument design and performance
characteristics. This work is supported by NASA contract NAS8-00014
(Solar-B FPP).
---------------------------------------------------------
Title: The Solar Photosphere
Authors: Berger, Tom
2000astu.confE...4B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Dynamics of Transition Region `Moss' at high time resolution
Authors: De Pontieu, B.; Berger, T. E.; Schrijver, C. J.; Title, A. M.
1999SoPh..190..419D Altcode:
Recent observations of solar active regions made with the Transition
Region and Coronal Explorer (TRACE) have revealed finely textured,
low-lying extreme ultraviolet (EUV) emission, called the moss. It
appears as a bright, dynamic pattern with dark inclusions, structured
on spatial scales of 1 to 3 Mm. The moss has been interpreted as the
upper transition region above active region plage and below relatively
hot loops. Here we study the temporal variability of the morphology of
the moss using a 2-hr time sequence of high-cadence TRACE 171 Å images
and G-band, Ca ii K-line and Hα filtergrams from the Swedish Vacuum
Solar Telescope (SVST, La Palma) on 1 June 1999. The data provide a
unique view of the connections between the photosphere, chromosphere,
transition region and corona in an active region. We find that the
moss is dynamic on time scales of 10-30 s due to intrinsic changes
in brightness, obscuration by chromospheric jets and motion caused
by physical interaction with these jets. The temporal variations of
the bright moss elements occur on shorter time scales than those of
the Ca ii K-line bright points. The bright moss elements generally do
not occur directly above the G-band or Ca ii K-line bright points in
the photosphere or lower chromosphere. This suggests that the upper
transition region emission often occurs at the interface of neighboring
flux tubes. The temporal variability of the moss brightness on 30
s time scales may suggest that the energy source of these intensity
changes occurs relatively locally (height <10 000 km).
---------------------------------------------------------
Title: What is Moss?
Authors: Berger, T. E.; De Pontieu, B.; Fletcher, L.; Schrijver,
C. J.; Tarbell, T. D.; Title, A. M.
1999SoPh..190..409B Altcode:
TRACE observations of active regions show a peculiar extreme ultraviolet
(EUV) emission over certain plage areas. Termed `moss' for its spongy,
low-lying, appearance, observations and modeling imply that the
phenomenon is caused by thermal conduction from 3-5 MKcoronal loops
overlying the plage: moss is the upper transition region emission of
hot coronal loops. The spongy appearance is due to the presence of
chromospheric jets or `spicules' interspersed with the EUV emission
elements. High cadence TRACE observations show that the moss EUV
elements interact with the chromospheric jets on 10 s time scales. The
location of EUV emission in the moss does not correlate well to the
locations of underlying magnetic elements in the chromosphere and
photosphere, implying a complex magnetic topology for coronal loop
footpoint regions. We summarize here the key observations leading to
these conclusions and discuss new implications for understanding the
structuring of the outer solar atmosphere.
---------------------------------------------------------
Title: High-resolution Imaging of the Solar Chromosphere/Corona
Transition Region
Authors: Berger, T. E.; De Pontieu, B.; Schrijver, C. J.; Title, A. M.
1999ApJ...519L..97B Altcode:
The properties of a previously unresolved extreme-ultraviolet (EUV)
emission in solar active regions are examined using coordinated data
sets from the Transition Region and Coronal Explorer (TRACE) satellite,
the Michelson Doppler Imager on the Solar and Heliospheric Observatory
satellite, the Soft X-Ray Telescope (SXT) on the Yohkoh satellite, and
the ground-based Swedish Vacuum Solar Telescope (SVST) on La Palma. The
emission appears most prominently in TRACE Fe IX/Fe X 171 Å images
as a bright dynamic network surrounding dark inclusions on scales of
2-3 Mm, confined to layers approximately 1-3 Mm thick with base heights
approximately 2-4 Mm above the photosphere. It is seen only above plage
regions that underlie (3-5)×10<SUP>6</SUP> K coronal loops visible
in SXT images. The bright EUV elements emit at temperatures of about
10<SUP>6</SUP> K. Fine-scale motions and brightness variations of the
emission occur on timescales of 1 minute or less. The dark inclusions
correspond to jets of chromospheric plasma seen in simultaneous SVST
filtergrams in the wings of Hα. The combined characteristics imply
that we are at least partially resolving the structure and dynamics
of the conductively heated upper transition region between the solar
chromosphere and corona.
---------------------------------------------------------
Title: A new view of the solar outer atmosphere by the Transition
Region and Coronal Explorer
Authors: Schrijver, C. J.; Title, A. M.; Berger, T. E.; Fletcher, L.;
Hurlburt, N. E.; Nightingale, R. W.; Shine, R. A.; Tarbell, T. D.;
Wolfson, J.; Golub, L.; Bookbinder, J. A.; DeLuca, E. E.; McMullen,
R. A.; Warren, H. P.; Kankelborg, C. C.; Handy, B. N.; De Pontieu, B.
1999SoPh..187..261S Altcode:
The Transition Region and Coronal Explorer (TRACE) - described in the
companion paper by Handy et al. (1999) - provides an unprecedented
view of the solar outer atmosphere. In this overview, we discuss the
initial impressions gained from, and interpretations of, the first
million images taken with TRACE. We address, among other topics,
the fine structure of the corona, the larger-scale thermal trends,
the evolution of the corona over quiet and active regions, the high
incidence of chromospheric material dynamically embedded in the coronal
environment, the dynamics and structure of the conductively dominated
transition region between chromosphere and corona, loop oscillations
and flows, and sunspot coronal loops. With TRACE we observe a corona
that is extremely dynamic and full of flows and wave phenomena, in
which loops evolve rapidly in temperature, with associated changes in
density. This dynamic nature points to a high degree of spatio-temporal
variability even under conditions that traditionally have been referred
to as quiescent. This variability requires that coronal heating can
turn on and off on a time scale of minutes or less along field-line
bundles with cross sections at or below the instrumental resolution
of 700 km. Loops seen at 171 Å (∼1 MK) appear to meander through
the coronal volume, but it is unclear whether this is caused by the
evolution of the field or by the weaving of the heating through the
coronal volume, shifting around for periods of up to a few tens of
minutes and lighting up subsequent field lines. We discuss evidence
that the heating occurs predominantly within the first 10 to 20 Mm
from the loop footpoints. This causes the inner parts of active-region
coronae to have a higher average temperature than the outer domains.
---------------------------------------------------------
Title: Dynamics of the Solar Chromosphere. II. Ca II H<SUB>2V</SUB>
and K<SUB>2V</SUB> Grains versus Internetwork Fields
Authors: Lites, B. W.; Rutten, R. J.; Berger, T. E.
1999ApJ...517.1013L Altcode:
We use the Advanced Stokes Polarimeter at the NSO/Sacramento Peak
Vacuum Tower Telescope to search for spatio-temporal correlations
between enhanced magnetic fields in the quiet solar internetwork
photosphere and the occurrence of Ca II H<SUB>2V</SUB> grains in the
overlying chromosphere. We address the question of whether the shocks
that produce the latter are caused by magnetism-related processes,
or whether they are of purely hydrodynamic nature. The observations
presented here are the first in which sensitive Stokes polarimetry is
combined synchronously with high-resolution Ca II H spectrometry. We pay
particular attention to the nature and significance of weak polarization
signals from the internetwork domain, obtaining a robust estimate of
our magnetographic noise level at an apparent flux density of only
3 Mx cm<SUP>-2</SUP>. For the quiet Sun internetwork area analyzed
here, we find no direct correlation between the presence of magnetic
features with apparent flux density above this limit and the occurrence
of H<SUB>2V</SUB> brightenings. This result contradicts the one-to-one
correspondence claimed by Sivaraman & Livingston. We also find no
correspondence between H<SUB>2V</SUB> grains and the horizontal-field
internetwork features discovered by Lites et al.
---------------------------------------------------------
Title: Dynamics of Transition Region Moss
Authors: Berger, T. E.; de Pontieu, B.; Schrijver, C. J.; Title, A. M.
1999AAS...194.7901B Altcode: 1999BAAS...31..963B
We examine the dynamics of solar transition region "moss", the 10(6)
K EUV emission at the footpoint regions of 2--3 MK active region coronal
loops. Comparisons of TRACE 171 Angstroms movies with SVST (La Palma) Ca
II K-line, Hα , and G-band movies are made. Local Correlation Tracking
(LCT) flowmapping techniques are used to establish the photospheric
flowfield in plage regions with and without associated moss. The
relation of moss emission to chromospheric spicules or fibrils is
examined in detail using Hα movies and dopplergrams. In addition,
several microflare events occuring in plage regions are analyzed using
TRACE and SVST movies. This research was supported by NASA contract
NAS5-38099 (TRACE) and NASA SR&T grant NASW-98008.
---------------------------------------------------------
Title: The Solar-B Solar Optical Telescope Focal Plane Package
Authors: Levay, M.; Berger, T.; Rosenberg, W.; Tarbell, T.; Title,
A.; Bogdan, T.; Elmore, D.; Lites, B.
1999AAS...194.7610L Altcode: 1999BAAS...31R.957L
The primary goal of the Solar-B mission is to understand the physical
processes responsible for dynamics and heating of the outer solar
atmosphere. The Focal Plane Package (FPP) instrument for the 50-cm Solar
Optical Telescope provides precise measurements of the vector magnetic
field, vertical and horizontal flows, and thermal conditions in the
photosphere and low chromosphere with spatial resolution as high as
0.16 arcsec and a field-of-view as large as 320 x 160 arcsec. The FPP
can measure continuously and at high cadence to follow the evolution
of solar features. The FPP consists of broad ( 8 Angstroms) and narrow
( 100 m Angstroms) filters and a spectro-polarimeter that provides
precise polarimetry with high spectral resolution ( 25 m Angstroms). A
correlation tracker and tip-tilt mirror ensure that all focal planes
are stable to better than 0.01 arcsec. A major design consideration
of the FPP is cooperative science operations with the other Solar-B
instruments. Solar-B is a Japanese mission with US and UK partners;
S. Tsuneta is the PI of the Solar Optical Telescope and A. Title the
US PI of the FPP. It is scheduled to launch in Japanese FY 2004.
---------------------------------------------------------
Title: Dynamics and Plasma Diagnostics of Transition Region “Moss”
using SOHO/CDS, TRACE and SVST (La Palma)
Authors: de Pontieu, B.; Berger, T. E.; Fletcher, L.; Schrijver,
C. J.; Title, A. M.
1999AAS...194.7804D Altcode: 1999BAAS...31..961D
Recent observations of solar active regions with the Transition
Region And Coronal Explorer (TRACE) have revealed finely textured,
low-lying extreme ultraviolet (EUV) emission, called the “moss”,
appearing as a bright dynamic pattern with dark inclusions. The moss
has been interpreted as the upper transition region by Berger et al.,
(1999). In this poster we study the physical conditions in the moss
plasma, as well as its dynamics and connections to photosphere and
chromosphere. Using simultaneous SOHO Coronal Diagnostic Spectrometer
(CDS) and TRACE observations of Active Region (AR) 8227 on 30-May-1998
we determine the physical parameters of the moss material. We find T_e =
0.6-1.5 10(6) K and n_e = 2-5 10(9) cm(-3) at a temperature of 1.3 10(6)
K. The pressure in the moss plasma is higher than that in coronal loops
observed in the TRACE Fe IX/X 171 Angstroms passband, and moss emission
is associated with high temperature loops, observed by SXT and by CDS
in lines of T_max > 2.5 10(6) K. The volume filling factor of the
moss plasma is of the order 0.1 and the path along which the emission
originates is of the order 1,000 km long. We examine the dynamics of
the moss plasma, by making comparisons of TRACE 171 Angstroms movies
with SVST (La Palma) Ca II K-line, Hα , and G-band movies. Local
Correlation Tracking (LCT) flowmapping techniques are used to establish
the photospheric flowfield in plage regions with and without associated
moss. The relation of moss emission to chromospheric spicules or fibrils
is examined in detail using Hα movies and dopplergrams. In addition,
several miniflare events occuring in plage regions are analyzed using
TRACE and SVST movies. This research was supported by NASA contract
NAS5-38099 (TRACE) and NASA SR&T grant NASW-98008.
---------------------------------------------------------
Title: Coordinated Observations of Transition Region Dynamics using
TRACE and the SVST
Authors: Berger, T.; de Pontieu, B.; Schrijver, C.; Title, A.;
Scharmer, G.
1999ASPC..183..365B Altcode: 1999hrsp.conf..365B
No abstract at ADS
---------------------------------------------------------
Title: Dynamics of the Quiet Solar Chromosphere
Authors: Rutten, R. J.; Lites, B. W.; Berger, T. E.; Shine, R. A.
1999ASPC..158..249R Altcode: 1999ssa..conf..249R
No abstract at ADS
---------------------------------------------------------
Title: Measurements of Solar Magnetic Element Dispersal
Authors: Berger, Thomas E.; Löfdahl, Mats G.; Shine, Richard A.;
Title, Alan M.
1998ApJ...506..439B Altcode:
The dispersal of magnetic elements in the solar photospheric flow
field is studied by tracking individual “magnetic bright points”
(MBPs) identified in a G-band 4305 Å filtergram time series obtained
at the 50 cm Swedish Vacuum Solar Telescope on La Palma, Spain. The time
series spans approximately 70 minutes with a field of view of 29" × 29"
near disk center. All images in the time series are restored to near
the telescope diffraction limit (~0.2" in the G band) using partitioned
phase diverse speckle techniques. Regions of enhanced magnetic network
and quiet Sun are examined. In the network region, automated tracking
of individual MBPs reveals approximately Gaussian diffusion, with
indications for slightly “superdiffusive” dispersal. The inferred
Gaussian diffusion coefficient is 60.4 +/- 10.9 km<SUP>2</SUP>
s<SUP>-1</SUP>. In the quiet-Sun region, local correlation tracking
velocity measurements show the dispersal of artificial tracers to be
non-Gaussian over most of our data set with indications of an asymptotic
approach to a 285 km<SUP>2</SUP> s<SUP>-1</SUP> Gaussian diffusion.
---------------------------------------------------------
Title: Measurements of Solar Magnetic Element Motion from
High-Resolution Filtergrams
Authors: Berger, Thomas E.; Löfdahl, Mats G.; Shine, Richard S.;
Title, Alan M.
1998ApJ...495..973B Altcode:
Solar photospheric flowfield properties on sub-0.5" scales are
measured using local correlation tracking (LCT) and object tracking of
magnetic bright points (MBPs: photospheric bright points associated
with magnetic elements). The dataset is a 70 minute time series
of cospatial and cotemporal G-band 4305 Å and wideband 4686 Å
filtergrams obtained with the 50 cm Swedish Vacuum Solar Telescope on
the island of La Palma, Spain. We examine a 29" × 70" field of view
(FOV) near disk center and compare a 29" × 29" magnetic network
subfield and a 27" × 27" apparently nonmagnetic “quiet-Sun”
subfield. The mean time between frames is 23.75 s. Each frame is
created by partitioned phase-diverse speckle restoration of three
image pairs acquired rapidly in sequence. Angular resolution is ~0.4"
or less in all frames of the restored data set. <P />From LCT on a 0.4"
grid with 0.83" FWHM apodization, we find the flow speeds to be Rayleigh
distributed with a mode of 550 m s<SUP>-1</SUP> and an average of 950
m s<SUP>-1</SUP> in the network FOV; in the quiet FOV the modal speed
is 700 m s<SUP>-1</SUP> with a mean of 1100 m s<SUP>-1</SUP>. Within
the network FOV, a “magnetic region” defined by the loci of tracked
MBPs exhibit even greater alteration: rms contrast of the region is
8% higher in the G band compared to areas outside, LCT speeds are
reduced by a factor of 1.6, and the convective flow structures are
smaller and much more chaotic. Mesogranulation is entirely absent in
the magnetic region. The modal and mean speeds of 534 tracked MBPs
are 300 m s<SUP>-1</SUP> and 1470 m s<SUP>-1</SUP>, respectively. MBPs
split and merge with mean times of 320 and 404 s respectively. The mean
lifetime of MBPs in the data set is 9.33 minutes although approximately
5% of the objects can be tracked for the entire 70 minute duration of
the time series.
---------------------------------------------------------
Title: On the Dynamics of Magnetic Flux Concentrations in Quiet
Photospheric Network.
Authors: Sakai, J. I.; Ryutova, M.; Schrijver, K.; Shine, R.; Tarbell,
T.; Berger, T.; Title, A.; Hagenaar, H.
1997SPD....28.0260S Altcode: 1997BAAS...29..904S
Magnetic flux concentrations in the quiet photospheric network show
a complex dynamics which includes merging of colliding fluxes, the
"total" or partial cancellation of neighboring fluxes, fragmentation
and others. We propose a mechanism to explain the observed phenomena
based on the idea that magnetic flux concentrations in the photospheric
network are essentially non-collinear. We show that non-collinearity
of colliding fluxes leads to the whole new class of effects which are
observed; for example, the apparent cancellation of opposite polarity
fluxes turns into the formation of horizontal magnetic fluxes (which
later may appear as a new weaker bipoles) and is accompanied by the
shock formation and mini-flares. In the case of shock formation
the reconnection area becomes a source of the acoustic emission;
mini-flares may be seen as bright points. The energetics of these
processes strongly depends on geometry of "collision" and physical
parameters of colliding fluxes. For example, if colliding fluxes have
comparable and "small" cross sections, the reconnection results in
complete reorganization of their magnetic fields; if merging fluxes
are large enough or considerably different, magnetic flux may be
only partially reconnected and partially survived. Reconnection of
non-collinear equal polarity fluxes leads to the "scattering" processes
which include the fragmentation into several smaller fluxes if initially
colliding concentrations carried different amount of magnetic flux. We
give the example of numerical simulation for the case of merging and
fragmentation process occurring during the collision of collinear
"strong" and "weak" magnetic flux concentrations. The calculation
results shown to be consistent with observational data from both
the SOHO/MDI instrument and the Swedish Vacuum Solar Telescope on
La Palma. This research is supported by NASA contract NAG5-3077 at
Stanford University and the MDI contract PR 9162 at Lockheed.
---------------------------------------------------------
Title: Phase-Diversity Restoration of two Simultaneous 70-minute
Photospheric Sequences.
Authors: Lofdahl, M. G.; Berger, T. E.; Shine, R. A.; Title, A. M.
1997SPD....28.0218L Altcode: 1997BAAS...29..896L
Seeing effects have been corrected in two cospatial and cotemporal
70-minute sequences of images collected in the G-band 4305 Angstroms and
wideband 4686 Angstroms. The data were obtained with the 50 cm Swedish
Vacuum Solar Telescope on the island of La Palma, Spain. The 29arcsecx
70arcsec field-of-view (FOV) near disk center contains both an enhanced
network region and an (apparently) non-magnetic “quiet” region of
granulation. The mean time between restored frames is 23.5 s. Each of
the 180 images is created with Phase-Diverse Speckle (PDS) imaging,
using two different focus positions sampled at the best three snapshots
of the atmospheric turbulence (seeing) during a 20-second selection
window. Wavefronts are estimated for each focused--defocused image
pair and a restored frame is produced from all six images. The average
resolution in the restored sequence is about 0farcs4 (corresponding to
spatial frequencies up to half the diffraction limit of the telescope),
which is good enough to allow detection of ~ 0farcs2 bright points. The
data is used for statistical measurements of magnetic element speed,
interaction frequency, and lifetime (see accompanying poster by
T. E. Berger et al). We show destretched and space-time filtered
movies of both the G-band and continuum images, as well as raw data
to demonstrate the effect of the restoration process. This work was
supported by NASA contracts NAS5-30386 at Stanford and NAS8-39747 and
Independent Research Funds at Lockheed-Martin. MGL was supported by
the Swedish Science Research Council.
---------------------------------------------------------
Title: Comparison of Granulation Correlation Tracking (CT) and
Feature Tracking (FT) Results from SOHO/MDI and the Swedish Vacuum
Solar Telescope on La Palma
Authors: Shine, R.; Strous, L.; Simon, G.; Berger, T.; Hurlburt, N.;
Tarbell, T.; Title, A.; Scharmer, G.
1997SPD....28.0262S Altcode: 1997BAAS...29Q.904S
We have computed photospheric velocity flow maps from simultaneous
observations taken with MDI and at the Swedish Vacuum Solar Tower
(SVST) on La Palma on August 15, 1996. Both sets consist of a series
of photospheric images, and flow maps are computed by following the
local motions of granules. The MDI data have the important advantages
of very stable images and longer continuous coverage of the same area
of the solar surface. This longer coverage is necessary to study the
evolution of mesogranules, supergranules, and to detect possible low
amplitude motions on scales larger than supergranules. However, the
high resolution mode of MDI is limited by the small telescope size to
about 1.2 arc seconds angular resolution and uses a 0.6 arc second pixel
size. This is adequate to show granulation but has the rms constrast
significantly reduced to about 2%. Early efforts adapting techniques
that were successful with higher resolution ground based images gave
poor results and although new methods have now been developed, there
are still some problems with accuracy. On the other hand, the SVST
images have much higher angular resolution (as good as 0.2 arc second)
but suffer from variable atmospheric distortion. They also have a much
smaller field of view. By detailed comparison of the two data sets
and by using CT and FT techniques to track the motions, we hope to
understand the sources of any differences between them and to develop
credible correction parameters to the MDI data sets if necessary. This
work was supported by NASA Grant NAG5-3077 at Stanford and Lockheed
Martin, by AFOSR and the Fellows Program of AF Phillips Lab at NSO/SP,
and by the Swedish Royal Academy of Sciences.
---------------------------------------------------------
Title: Measurements of Magnetic Element Dynamics in the Network
Authors: Berger, T. E.; Lofdahl, M. G.; Shine, R. A.; Title, A. M.
1997SPD....28.0219B Altcode: 1997BAAS...29..896B
Statistical measurements of magnetic element speed, interaction
frequency, and lifetime in an enhanced network region at disk center
are presented. The primary dataset is a 70 min time series of G-band
4305 Angstroms filtergrams taken at the 50 cm Swedish Vacuum Solar
Telescope (SVST) on the island of La Palma, Spain. A second time
series of 4686 Angstroms wide-band continuum filtergrams, cospatial
and simultaneous to within several milliseconds with the G-band
images, is also studied. The field-of-view is near Sun center and
includes a region of enhanced network activity with many G-band bright
points. Both time series are corrected for seeing to very near the
telescope diffraction limit by the technique of Phase Diverse Speckle
(PDS) restoration (see accompanying poster by M. G. Lofdahl et al). We
show destretched and space-time filtered movies of both the G-band and
continuum images in two fields-of-view: a region of quiet granulation
and the region of enhanced network activity. Within the network, local
correlation tracking measurements on a 0\farcs4 grid show the RMS
speed to be 778 m s(-1) ; outside the network the RMS speed is 1168 m
s(-1) . Corkflow simulations show that normal convective flow patterns
(granulation and mesogranulation) are absent in the network. Magnetic
elements move with modal and mean speeds of 100 m s(-1) and 815 m s(-1)
, respectively. The mean interaction frequency (time between either
merging or splitting) is 220 s. The mean lifetime of tracked magnetic
elements in the network is 9.33 min although 5% of the elements are
tracked for the entire 70 min of the times series. This work was
supported by NASA contracts NAS5-30386 at Stanford and NAS8-39747 and
Independent Research Funds at Lockheed-Martin. MGL was supported by
the Swedish Science Research Council.
---------------------------------------------------------
Title: Observation and Analysis of Small-Scale Solar Magnetic
Structure
Authors: Berger, Thomas Edward
1997PhDT........14B Altcode:
Properties of small-scale magnetic structures in the photosphere
are analyzed in multi-spectral time-series image sets obtained at
the 50 cm Swedish Solar Vacuum Telescope (SVST) on the island of La
Palma, Spain. Several of the images are among the highest resolution
images of the solar photosphere yet obtained. Sub-arcsecond-scale
magnetic 'elements' are identified, segmented, and tracked using
bright points found in very high spatial resolution G-band 4305 A
filtergrams. Simultaneous images including Ca II K-line filtergrams,
Fe I 6302 A magnetograms, and 4686 A broadband continuum filtergrams
allow cross-wavelength comparison of properties. Angular resolution
of the filtergrams is typically 0.25 <SUP>”</SUP> and temporal
resolution is in the range of 20-100 sec; magnetogram resolution
approaches 0.3<SUP>”</SUP> in some images and is generally below
0.5<SUP>”</SUP>. To above an 84% statistical confidence level, G-band
bright points occur exclusively at sites of kilogauss, sub-arcsecond,
magnetic flux concentrations in the photosphere; magnetic flux
concentration is a necessary but not sufficient condition for the
occurrence of G-band bright points. The measured distribution of
magnetic element diameters in active region network is log-normal
with a modal value of 220 km (0.3<SUP>”</SUP>). The smallest elements
observed are 120 km (0.17<SUP>”</SUP>) in diameter; the largest are
about 600 km (0.7<SUP>”</SUP>) in diameter. The average contrast with
respect to quiet Sun of magnetic elements in the G-band is 30%: 2-3
times higher than the average continuum contrast. Magnetic element
contrast does not vary with size within the size range of G-band
bright point measurements. Average contrast increases with limbward
heliocentric angle to a peak of about 80% at μ = /cosθ = 0.3; there
is evidence of a decrease with further increase in angle. Magnetic
elements undergo a continual fragmentation/merging evolution driven
by the granular convective flowfield of the photosphere; morphological
time scales are on the order of 100 seconds. Velocities of individual
elements range from 1-5 km s<SUP>-1</SUP> with an RMS value of 2.4
km s<SUP>-1</SUP>. The range of motion is typically on granular and
mesogranular scales (1000-2500 km) with an average value of 2100
km. Individual fragments from clusters have a characteristic lifetime
on the order of the granulation correlation time (6-8 minutes). The
lifetime of clusters associated with persistent sinks in the granular
flowfield is on the order of hours. Classical statistical analysis of
displacement versus time yields a diffusion coefficient for network
magnetic elements of 224.8± 0.2 km s<SUP>-1</SUP>. In general, the
results are inconsistent with the idea of small-scale magnetic flux
in the photosphere being contained in stable, isolated, 'flux tubes'
and emphasize the need for better understanding of the formation and
the thermal (and∨ non-thermal) heating of magnetic regions in the
photosphere.
---------------------------------------------------------
Title: On the dynamics of magnetic flux concentrations in quiet
photospheric network.
Authors: Sakai, J. I.; Ryutova, M.; Schrijver, K.; Shine, R. A.;
Tarbell, T. D.; Berger, T. E.; Title, A. M.; Hagenaar, H. J.
1997BAAS...29T.904S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Double-Gaussian Models of Bright Points or Why Bright Points
Are Usually Dark
Authors: Title, A. M.; Berger, T. E.
1996ApJ...463..797T Altcode:
We have modeled the structure of small bright features, "bright points"
seen in an outstanding CH filter (0-band) image. In our model, bright
points consist of a Gaussian bright core centered in a Gaussian dark
surround. The basis for this approach is the observation that nearly
all of the bright points in the image exist within intergranular lanes,
vertices between granules, or local brightness depressions. Using
reasonable estimates for the size and depth of vertices and lanes, the
model predicts that bright points clearly detectable in images with
0".2 resolution will seldom be detectable in images with resolutions
beyond 0".4. This occurs because the transfer function of the telescope
and atmosphere averages the bright points with their comparably sized
dark surroundings to near zero contrast when blurred beyond 0".4. These
results explain the great rarity of images that clearly show bright
points. Furthermore, the image shows many bright points with core
diameters equal to that of the FWHM of a point-spread function of a
perfect telescope. If the intensity profiles of these bright points
were Gaussian on a flat background, then their intrinsic brightness
would have to be unrealistically high and they would not disappear
on images blurred beyond 0".4, but would simply gradually expand in
size and drop in contrast as the blur increased. Because the bright
points are sites of magnetic fields, our model helps to explain lower
resolution disk center observations that show magnetic fields occur in
regions that are dark relative to the mean continuum level. The modeling
also suggests that bright points with diameters of 0".1 or less would
be undetectable in the current generation of 0.5 m high-resolution
solar telescopes, under any seeing conditions.
---------------------------------------------------------
Title: Observation and Analysis of Small-scale Solar Magnetic
Structure
Authors: Berger, T.
1996AAS...188.3312B Altcode: 1996BAAS...28..869B
Solar magnetic flux elements on spatial scales below 350 km (0\arcsec.5)
are analyzed using G-Band 4305 Angstroms, Ca II K-line, and 4686
Angstroms continuum filtegrams as well as Fe I 6302 Angstroms and
5250 Angstroms magnetograms acquired nearly simultaneously at the
Swedish Solar Vacuum Telescope on La Palma. Spatial resolution is below
0\arcsec.3 in the majority of images. Phase-diversity image restoration
is applied to yield a 180 frame (78 minute) image set in which nearly
every frame exhibits 0\arcsec.2 spatial resolution. Image processing
algorithms are developed which successfully segment the magnetic
elements from the surrounding granulation for analysis. The FWHM of
magnetic elements demarcated by G-band bright points in disk-center
plage is log-normally distributed with a modal value of 220 km and
an average value of 250 km. Average disk center contrast of magnetic
elements in the G-band is 31% with maximum values frequently exceeding
70% relative to the quiet-Sun average. Simulataneous 4686 Angstroms
continuum contrast is 2 to 3 times lower. The average G-band contrast
of magnetic elements shows no size dependency over a range of 150---600
km in diameter. G-band bright points occur without exception on sites
of isolated magnetic flux concentrations or peninsular concentrations
extending from larger concentrations of flux; isolated magnetic
flux concentrations are found without associated G-band bright
points. Magnetic elements demarcated by G-band bright points occupy
no more than 1---2% of plage and active network regions by area at
any one time. Magnetic elements move in the intergranular flowfield
at speeds from 0.5 to 5 km sec(-1) . The RMS speed is 2.4 km sec(-1)
over an average range of 2100 km (3\arcsec). Continual fragmentation
and merging of magnetic elements is the normal evolutionary mode
for small-scale magnetic elements. The time scale for the dynamics
is approximately 6--8 minutes, but significant morphological changes
occur on time scales as short as 100 seconds. Analysis of the tracks
of individual elements yields a diffusion coefficient of 224.8+/-0.2
{km}(2{sec}(-1)) . Indications of anomolous diffusivity consistent with
diffusion on a fractal geometry are found. This research was supported
by the SOI-MDI NASA contract NAG5-3077 at Stanford University and NASA
contract NAS8-39747 and independent research funds at Lockheed-Martin.
---------------------------------------------------------
Title: On the Dynamics of Small-Scale Solar Magnetic Elements
Authors: Berger, T. E.; Title, A. M.
1996ApJ...463..365B Altcode:
We report on the dynamics of the small-scale solar magnetic field, based
on analysis of very high resolution images of the solar photosphere
obtained at the Swedish Vacuum Solar Telescope. The data sets are
movies from 1 to 4 hr in length, taken in several wavelength bands
with a typical time between frames of 20 5. The primary method of
tracking small-scale magnetic elements is with very high contrast
images of photospheric bright points, taken through a 12 Å bandpass
filter centered at 4305 Å in the Fraunhofer "G band." Previous studies
have established that such bright points are unambiguously associated
with sites of small-scale magnetic flux in the photosphere, although
the details of the mechanism responsible for the brightening of the
flux elements remain uncertain. The G band bright points move in the
intergranular lanes at speeds from 0.5 to 5 km s<SUP>-1</SUP>. The
motions appear to be constrained to the intergranular lanes and are
primarily driven by the evolution of the local granular convection flow
field. Continual fragmentation and merging of flux is the fundamental
evolutionary mode of small-scale magnetic structures in the solar
photosphere. Rotation and folding of chains or groups of bright points
are also observed. The timescale for magnetic flux evolution in active
region plage is on the order of the correlation time of granulation
(typically 6-8 minutes), but significant morphological changes can occur
on timescales as short as 100 5. Smaller fragments are occasionally
seen to fade beyond observable contrast. The concept of a stable,
isolated subarcsecond magnetic "flux tube" in the solar photosphere
is inconsistent with the observations presented here.
---------------------------------------------------------
Title: Motion and Evolution of Solar Magnetic Elements
Authors: Berger, T. E.; Schrijver, C. J.; Shine, R. S.; Tarbell,
T. D.; Title, A. M.; Scharmer, G.
1995AAS...18710104B Altcode: 1995BAAS...27.1426B
The dynamics of sub-arcsecond solar magnetic flux tubes are analyzed
based on very-high resolution movies of photospheric bright points
obtained in 1994 at the 50-cm Swedish Solar Vacuum Telescope (SVST)
on the island of La Palma, Spain. The bright points are imaged using
a 12 Angstroms bandpass interference filter centered at 4305 Angstroms
in the “G Band” molecular bandhead of the CH molecule. The image sets
typically consist of up to 4 hours of consecutive images taken at a 10
to 20 second cadence. Spatial resolution throughout the movies averages
less than 0\arcsec.5 and many frames in the sets exhibit resolution
down to 0\arcsec.25. Magnetic flux elements in the photosphere are
shown to move continually along the intergranular lanes at speeds
of up to 5 km/sec and ranges up to several thousand km. Evolution of
individual magnetic elements is dominated by the local evolution of
surrounding granules. Fragmentation and merging is the fundamental
mode of evolution of the majority of magnetic elements seen in our
data. Rotation and folding of chains or groups of elements is also
frequently observed. The time scale for the fragmentation/merging
evolution of the elements is on the order of the lifetime of granulation
(6--8 minutes), but significant morphological changes are seen to
occur on time scales as short as 100 seconds. The concept of a stable,
isolated, sub-arcsecond magnetic flux element in the solar photosphere
is inconsistent with the observations presented here.
---------------------------------------------------------
Title: New Observations of Subarcsecond Photospheric Bright Points
Authors: Berger, T. E.; Schrijver, C. J.; Shine, R. A.; Tarbell,
T. D.; Title, A. M.; Scharmer, G.
1995ApJ...454..531B Altcode:
We have used an interference filter centered at 4305 Å within the
bandhead of the CH radical (the "G band") and real-time image selection
at the Swedish Vacuum Solar Telescope on La Palma to produce very
high contrast images of subarcsecond photospheric bright points at all
locations on the solar disk. During the 6 day period of 1993 September
15-20 we observed active region NOAA 7581 from its appearance on the
East limb to a near disk-center position on September 20. A total of
1804 bright points were selected for analysis from the disk center image
using feature extraction image processing techniques. The measured FWHM
distribution of the bright points in the image is subnormal with a modal
value of 220 km (0".30) and an average value of 250 km (0".35). The
smallest measured bright point diameter is 120 km (0".17) and the
largest is 600 km (0".69). Approximately 60% of the measured bright
points are circular (eccentricity ∼1.0), the average eccentricity
is 1.5, and the maximum eccentricity corresponding to filigree in
the image is 6.5. The peak contrast of the measured bright points is
normally distributed. The contrast distribution variance is much greater
than the measurement accuracy, indicating a large spread in intrinsic
bright-point contrast. When referenced to an averaged "quiet-Sun area 1n
the image, the modal contrast is 29% and the maximum value is 75%; when
referenced to an average intergranular lane brightness in the image,
the distribution has a modal value of 61 % and a maximum of 119%. The
bin-averaged contrast of G-band bright points is constant across the
entire measured size range. The measured area of the bright points,
corrected for population and selection effects, covers about 1.8% of
the total image area. Large pores and micropores occupy an additional
2% of the image area, implying a total area fraction of magnetic
proxy features in the image of 3.8%. We discuss the implications of
this area fraction measurement in the context of previously published
measurements which show that typical active region plage has a magnetic
filling factor on the order of 10% or greater. The results suggest that
in the active region analyzed here, less than 50% of the small-scale
magnetic flux tubes are demarcated by visible proxies such as bright
points or pores.
---------------------------------------------------------
Title: Frame Selection Techniques for Solar Movies
Authors: Shine, R. A.; Tarbell, T.; Title, A.; Scharmer, G.; Simon,
G.; Brandt, P.; Berger, T.
1995SPD....26..506S Altcode: 1995BAAS...27..957S
No abstract at ADS
---------------------------------------------------------
Title: Properties of Sub-Arcsecond Facular Bright Points
Authors: Berger, T.; Schrijver, C.; Shine, R.; Tarbell, T.; Title,
A.; Scharmer, G.
1995SPD....26..505B Altcode: 1995BAAS...27..957B
No abstract at ADS
---------------------------------------------------------
Title: On the Relation Between Facular Bright Points and the
Magnetic Field
Authors: Berger, Thomas; Shine, Richard; Tarbell, Theodore; Title,
Alan; Scharmer, Goran
1994AAS...185.8607B Altcode: 1994BAAS...26.1465B
Multi-spectral images of magnetic structures in the solar photosphere
are presented. The images were obtained in the summers of 1993 and
1994 at the Swedish Solar Telescope on La Palma using the tunable
birefringent Solar Optical Universal Polarimeter (SOUP filter), a 10
Angstroms wide interference filter tuned to 4304 Angstroms in the band
head of the CH radical (the Fraunhofer G-band), and a 3 Angstroms wide
interference filter centered on the Ca II--K absorption line. Three
large format CCD cameras with shuttered exposures on the order of
10 msec and frame rates of up to 7 frames per second were used to
create time series of both quiet and active region evolution. The
full field--of--view is 60times 80 arcseconds (44times 58 Mm). With
the best seeing, structures as small as 0.22 arcseconds (160 km) in
diameter are clearly resolved. Post--processing of the images results
in rigid coalignment of the image sets to an accuracy comparable to the
spatial resolution. Facular bright points with mean diameters of 0.35
arcseconds (250 km) and elongated filaments with lengths on the order
of arcseconds (10(3) km) are imaged with contrast values of up to 60
% by the G--band filter. Overlay of these images on contemporal Fe I
6302 Angstroms magnetograms and Ca II K images reveals that the bright
points occur, without exception, on sites of magnetic flux through the
photosphere. However, instances of concentrated and diffuse magnetic
flux and Ca II K emission without associated bright points are common,
leading to the conclusion that the presence of magnetic flux is a
necessary but not sufficient condition for the occurence of resolvable
facular bright points. Comparison of the G--band and continuum images
shows a complex relation between structures in the two bandwidths:
bright points exceeding 350 km in extent correspond to distinct
bright structures in the continuum; smaller bright points show no
clear relation to continuum structures. Size and contrast statistical
cross--comparisons compiled from measurements of over two-thousand
bright point structures are presented. Preliminary analysis of the time
evolution of bright points in the G--band reveals that the dominant mode
of bright point evolution is fission of larger structures into smaller
ones and fusion of small structures into conglomerate structures. The
characteristic time scale for the fission/fusion process is on the
order of minutes.
---------------------------------------------------------
Title: Stanford MAMA detector characterization facility
Authors: Timothy, J. Gethyn; Bergamini, Paolo; Berger, Thomas E.;
Bumala, Robert W.; Liu, Sharon; Martinez, Ted; Slater, David C.
1993SPIE.2006...59T Altcode:
We have designed and fabricated a high-vacuum facility for the detailed
characterization of the Multi-Anode Microchannel Array (MAMA) detector
systems at Extreme Ultraviolet and Far Ultraviolet wavelengths between
about 300 angstroms and 3000 angstroms. The first task for this facility
is the characterization of the MAMA detectors for the European Space
Agency/NASA Solar and Heliosphere Observatory (SOHO) mission. This
paper describes the different configurations of the characterization
facility and outlines the SOHO MAMA characterization procedures.
---------------------------------------------------------
Title: Performance characteristics of the MAMA detectors for the
SUMER instrument on the SOHO Mission
Authors: Timothy, J. Gethyn; Bergamini, Paolo; Berger, Thomas E.;
Bumala, Robert W.; Slater, David C.
1993SPIE.2006...69T Altcode:
We have initiated the characterizations of the Multi-Anode Microchannel
Array (MAMA) detector systems for the European Space Agency/NASA Solar
and Heliospheric Observatory (SOHO) mission. In this paper we briefly
review the configurations of the SOHO MAMA detectors and describe
their expected performance characteristics based on the results of
characterizations of the curved-channel microchannel plates and of the
initial characterization of the first engineering model detector system
for the Solar Ultraviolet Measurements of Emitted Radiation instrument.
---------------------------------------------------------
Title: Spectroscopic characterization of the EUV toroidal grating
for the HiRES rocket
Authors: Naletto, Giampiero; Perin, Marco; Tondello, Giuseppe;
Villoresi, Paolo; Contarini, Gabriella; Timothy, J. Gethyn; Bergamini,
Paolo; Berger, Thomas E.
1993SPIE.2006...22N Altcode:
The evaluation of the performances of a toroidal grating for the
high-resolution EUV spectroheliometer (HiRES) has been realized. This is
a holographically ruled grating operating in a normal incidence Rowland
configuration at the 510 - 630 angstroms spectral range. An analysis
of the grating resolution performances has been realized by means of a
scintillator- intensifier-CCD detector showing very good results. Also
a measurement of the grating diffraction efficiency has been performed,
showing on the contrary a value lower than the predicted one.
---------------------------------------------------------
Title: The High Resolution Extreme-Ultraviolet Spectroheliometer
(HiRES) Experiment: Capabilities and Observing Goals
Authors: Berger, T. E.; Timothy, J. G.; Walker, A. B. C., Jr.; Jain,
S. K.; Saxena, A. K.; Bhattacharyya, J. C.; Huber, M. C. E.; Tondello,
G.; Naletto, G.
1993BAAS...25.1209B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: HiRES: High Resolution Extreme Ultraviolet Spectroheliometer.
Authors: Berger, T.; Bergamini, P.; Kirby, H.; Timothy, J. G.; Walker,
A. B. C.; Bhattacharyya, J. C.; Jain, S. K.; Saxena, A. K.; Huber,
M. C. E.; Naletto, G.; Tondello, G.
1993uxrs.conf..289B Altcode: 1993uxsa.conf..289B
The HiRES sounding rocket payload is designed to obtain very high
spatial, spectral, and temporal resolution images of the solar
chromospheric and coronal plasmas in the extreme ultraviolet (EUV)
wavelength range from 500 to 650 Å. The instrument consists of a 450
mm f/15 Gregorian telescope feeding a 1-m normal incidence stigmatic
spectrometer. The stigmatic spectrometer utilizes a toroidal diffraction
grating formed by a unique elastic substrate deformation technique
in order to achieve simultaneous spatial and spectral focusing at
two points on the detector plane. Spatial resolution on the order
of 0.4 arcsecond across a 3×3 arcmin<SUP>2</SUP> field of view is
obtained. Temporal resolution of the order of milliseconds is achieved
by the use of an advanced imaging Multi-Anode Microchannel Array
(MAMA) detector. A hydrogen-alpha 6562.8 Å camera and a 0.25-m EUV
solar irradiance spectrometer are also included in the payload.
---------------------------------------------------------
Title: An imaging extreme ultraviolet spectrometer.
Authors: Bergamini, P.; Berger, T. E.; Giaretta, G.; Huber, M. C. E.;
Naletto, G.; Timothy, J. G.; Tondello, G.
1993uxrs.conf..285B Altcode: 1993uxsa.conf..285B
A laboratory extreme ultraviolet (EUV) imaging spectrometer has
been fabricated and tested. This instrument is used to test and to
characterize toroidal gratings like those which will be employed in
the high-resolution spectroheliometer (HiRES) configured for flight
on a sounding rocket. The imaging spectrometer will be used also for
characterization and calibration of Multi Anode Microchannel Array
(MAMA) detectors foreseen on the ESA/NASA Solar Heliospheric Observatory
(SOHO) satellite. The spectrometer employs a concave toroidal grating
illuminated at normal incidence in a 1 meter Rowland circle mounting:
high efficiency is achieved because the grating is the only reflecting
surface. The grating is able to produce stigmatic images over
a wavelength range of about 100 Å or 200 Å centered respectively
around 600 Å or 1200 Å. The results of the initial imaging tests
and the measurements carried out are presented and discussed.
---------------------------------------------------------
Title: Interferometric methods for assessment of toroidal diffraction
grating performance
Authors: Baker, Phillip; Bergamini, Paolo; Berger, Tom; Timothy, J. G.
1993SPIE.1742..453B Altcode:
The measurement of the shape and optical performance of toroidal
mirrors has always presented a challenge to the manufacturer and user of
these types of optical elements. This report presents a technique for
evaluating the complex shape and optical performance of long radius
toroidal mirrors that are to be used in the EUV. The measurement
techniques will be discussed and examples given. Interferometric
analysis will be presented. Performance spot diagrams and MTF analysis
will be discussed. Manufacturing techniques will be evaluated with
respect to the application of more definitive measurement technology.
---------------------------------------------------------
Title: Design and test of a High-Resolution EUV Spectroheliometer
Authors: Berger, Thomas E.; Timothy, J. G.; Walker, Arthur B. C., Jr.;
Kirby, Helen; Morgan, Jeffrey S.; Jain, Surendra K.; Saxena, Ajay K.;
Bhattacharyya, Jagadish C.; Huber, Martin C. E.; Tondello, Giuseppe
1992SPIE.1546..446B Altcode: 1992SPIE.2011..446B
The HiRES High-Resolution EUV Spectroheliometer is a sounding rocket
instrument yielding very high spatial, spectral, and temporal resolution
images of the solar outer atmosphere, on the basis of a 45-cm Gregorian
telescope feeding a normal-incidence stigmatic EUV spectrometer with
imaging multianode microchannel-array detector system, as well as an
IR spectrometer with imaging CCD detector system. Attention is given
to the expected performance of this system, including the effects of
vibrational misalignments due to the sounding rocket flight environment.
---------------------------------------------------------
Title: HiRES: a high-resolution stigmatic extreme ultraviolet
spectroheliometer for sudies of the fine-scale structure of the
solar chromosphere, transition region, and corona.
Authors: Timothy, J. G.; Berger, Thomas E.; Morgan, Jeffrey S.;
Walker, Arthur B. C., Jr.; Jain, Surendra K.; Saxena, Ajay K.;
Bhattacharyya, Jagadish C.; Huber, Martin C. E.; Tondello, Giuseppe;
Naletto, Giampiero
1991OptEn..30.1142T Altcode:
The authors describe the design of a high-resolution stigmatic
extreme-ultraviolet spectroheliometer, which consists of a 45 cm
Gregory telescope coupled to a spectrometer employing a single toroidal
diffraction grating in a normal-incidence Rowland circle mounting and
an imaging pulse-counting multianode microchannel array (MAMA) detector
system. The spectroheliometer will produce spatially resolved spectra
of the chromosphere, transition region, and corona with an angular
resolution of 0.4″or better, a spectral resolution λ/Δλ of about
10<SUP>4</SUP> in first order, and a temporal resolution of the order
of seconds. Because of the geometric fidelity of the MAMA detector
system, the spectroheliometer will be able to determine Doppler shifts
to a resolution of at least 2 mÅ at wavelengths near 600Å (≡1.0
km s<SUP>-1</SUP>), depending on the level of the accumulated signal.
---------------------------------------------------------
Title: High-resolution stigmatic EUV spectroheliometer for studies
of the fine scale structure of the solar chromosphere, transition
region, and corona
Authors: Timothy, J. Gethyn; Berger, Thomas E.; Morgan, Jeffrey S.;
Walker, Arthur B.; Bhattacharyya, Jagadish C.; Jain, Surendra K.;
Saxena, Ajay K.; Huber, Martin C.; Tondello, Giuseppe; Naletto,
Giampiero
1991SPIE.1343..350T Altcode:
No abstract at ADS
