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Daily Report #4949



 
 
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Old October 13th 09, 04:23 PM posted to sci.astro.hubble
Cooper, Joe
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Posts: 568
Default Daily Report #4949

HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #4949

PERIOD COVERED: 5am October 9 - 5am October 13, 2009 (DOY 282/09:00z-286/09:00z)

OBSERVATIONS SCHEDULED

NIC1/NIC2/NIC3 8795

NICMOS Post-SAA Calibration - CR Persistence Part 6

This is a new procedure proposed to alleviate the CR-persistence
problem of NICMOS. Dark frames will be obtained immediately upon
exiting the SAA contour 23, and every time a NICMOS exposure is
scheduled within 50 minutes of coming out of the SAA. The darks will
be obtained in parallel in all three NICMOS cameras. The post-SAA
darks will be non-standard reference files available to users with a
'Use After' date/time mark. The keyword 'UseAfter=date/time' will also
be added to the header of each post-SAA dark frame. The keyword must
be populated with the time, in addition to the date, because HST
crosses the SAA ~8 times per day, so each post-SAA dark will need to
have the appropriate time specified, for users to identify the ones
they need. Both the raw and processed images will be archived as
post-SAA darks. Generally we expect that all NICMOS
science/calibration observations started within 50 minutes of leaving
an SAA will need such MAPs to remove the CR persistence from the
science images. Each observation will need its own CRMAP, as different
SAA passages leave different imprints on the NICMOS detectors.

NIC1/NIC2/NIC3 11947

Extended Dark Monitoring

This program takes a series of darks to obtain darks (including
amplifier glow, dark current, and shading profiles) for all three
cameras in the read-out sequences used in Cycle 17. A set of 12 orbits
will be observed every two months for a total of 72 orbits for a 12
month Cycle 17. This is a continuation of Cycle 16 program 11330
scaled down by ~80%.

The first orbit (Visit A0) should be scheduled in the NICMOS SMOV
after the DC Transfer Test (11406) and at least 36h before the Filter
Wheel Test (11407). Data download using fast track.

The following 28 orbits (visit A1-N2) should be scheduled AFTER the
SMOV Proposal 11407 (Filter Wheel Test). This is done in order to
monitor the dark current following an adjustment of the NCS set-point.
These visits should be executed until the final temperature is reached
during SMOV.

WFC3/IR/S/C 11929

IR Dark Current Monitor

Analyses of ground test data showed that dark current signals are more
reliably removed from science data using darks taken with the same
exposure sequences as the science data, than with a single dark
current image scaled by desired exposure time. Therefore, dark current
images must be collected using all sample sequences that will be used
in science observations. These observations will be used to monitor
changes in the dark current of the WFC3-IR channel on a day-to-day
basis, and to build calibration dark current ramps for each of the
sample sequences to be used by GOs in Cycle 17. For each sample
sequence/array size combination, a median ramp will be created and
delivered to the calibration database system (CDBS).

WFC3/UVIS 11908

Cycle 17: UVIS Bowtie Monitor

Ground testing revealed an intermittent hysteresis type effect in the
UVIS detector (both CCDs) at the level of ~1%, lasting hours to days.
Initially found via an unexpected bowtie-shaped feature in flatfield
ratios, subsequent lab tests on similar e2v devices have since shown
that it is also present as simply an overall offset across the entire
CCD, i.e., a QE offset without any discernable pattern. These lab
tests have further revealed that overexposing the detector to count
levels several times full well fills the traps and effectively
neutralizes the bowtie. Each visit in this proposal acquires a set of
three 3x3 binned internal flatfields: the first unsaturated image will
be used to detect any bowtie, the second, highly exposed image will
neutralize the bowtie if it is present, and the final image will allow
for verification that the bowtie is gone.

WFC3/UVIS 11907

UVIS Cycle 17 Contamination Monitor

The UV throughput of WFC3 during Cycle 17 is monitored via weekly
standard star observations in a subset of key filters covering
200-600nm and F606W, F814W as controls on the red end. The data will
provide a measure of throughput levels as a function of time and
wavelength, allowing for detection of the presence of possible
contaminants.

WFC3/UVIS 11905

WFC3 UVIS CCD Daily Monitor

The behavior of the WFC3 UVIS CCD will be monitored daily with a set
of full-frame, four-amp bias and dark frames. A smaller set of 2Kx4K
subarray biases are acquired at less frequent intervals throughout the
cycle to support subarray science observations. The internals from
this proposal, along with those from the anneal procedure (Proposal
11909), will be used to generate the necessary superbias and superdark
reference files for the calibration pipeline (CDBS).

COS/FUV 11895

FUV Detector Dark Monitor

The purpose of this proposal is to monitor the FUV detector dark rate
by taking long science exposures without illuminating the detector.
The detector dark rate and spatial distribution of counts will be
compared to pre-launch and SMOV data in order to verify the nominal
operation of the detector. Variations of count rate as a function of
orbital position will be analyzed to find dependence of dark rate on
proximity to the SAA. Dependence of dark rate as function of time will
also be tracked.

ACS/WFC3 11879

CCD Daily Monitor (Part 1)

This program comprises basic tests for measuring the read noise and
dark current of the ACS WFC and for tracking the growth of hot pixels.
The recorded frames are used to create bias and dark reference images
for science data reduction and calibration. This program will be
executed four days per week (Mon, Wed, Fri, Sun) for the duration of
Cycle 17. To facilitate scheduling, this program is split into three
proposals. This proposal covers 352 orbits (22 weeks) from 31 August
2009 to 31 January 2010.

STIS/CCD 11846

CCD Bias Monitor-Part 1

The purpose of this proposal is to monitor the bias in the 1x1, 1x2,
2x1, and 2x2 bin settings at gain=1, and 1x1 at gain = 4, to build up
high-S/N superbiases and track the evolution of hot columns.

STIS/CCD 11844

CCD Dark Monitor Part 1

The purpose of this proposal is to monitor the darks for the STIS CCD.

WFC3/IR 11838

Completing a Flux-limited Survey for X-ray Emission from Radio Jets

We will measure the changing flow speeds, magnetic fields, and energy
fluxes in well-resolved quasar jets found in our short-exposure
Chandra survey by combining new, deep Chandra data with radio and
optical imaging. We will image each jet with sufficient sensitivity to
estimate beaming factors and magnetic fields in several distinct
regions, and so map the variations in these parameters down the jets.
HST observations will help diagnose the role of synchrotron emission
in the overall SED, and may reveal condensations on scales less than
0.1 arcsec.

STIS/CCD 11806

Coordinated Observations of LCROSS Impacts

We propose to observe the LCROSS (Lunar Crater Observation and Sensing
Satellite) impacts. This program will use STIS and WFC3 to observe the
Moon in conjunction with NASA's LCROSS mission (assuming Servicing
Mission 4 occurs before the LCROSS impacts). The goal is to determine
whether or not water ice and/or vapor is present in the subsurface of
the Moon. We will address this issue by 1) observing the sunlit ejecta
plume created by the LCROSS impacts and 2) examine the Lunar exosphere
for the presence of OH and other volatile species.

WFC3/UVIS 11729

Photometric Metallicity Calibration with WFC3 Specialty Filters

The community has chosen to include several filters in the WFC3 filter
complement that have been designed to allow fairly precise estimates
of stellar metallicities, and many science programs are enabled by
this capability. Since these filters do not exactly match those used
for this purpose on the ground, however, the mapping of stellar colors
to stellar metallicities needs to be calibrated. We propose to achieve
this calibration through observations of five stellar clusters with
well known metallicities. We will calibrate several different filter
calibrations which will allow future users to determine what filter
combination best meets their science needs.

WFC3/UVIS 11714

Snapshot Survey for Planetary Nebulae in Local Group Globular Clusters

Planetary nebulae (PNe) in globular clusters (GCs) raise a number of
interesting issues related to stellar and galactic evolution. The
number of PNe known in Milky Way GCs, four, is surprisingly low if one
assumes that all stars pass through a PN stage. However, it is likely
that the remnants of stars now evolving in galactic GCs leave the AGB
so slowly that any ejected nebula dissipates long before the star
becomes hot enough to ionize it. Thus there should not be ANY PNe in
Milky Way GCs--but there are four! It has been suggested that these
PNe are the result of mergers of binary stars within GCs, i.e., that
they are descendants of blue stragglers. The frequency of occurrence
of PNe in external galaxies poses more questions, because it shows a
range of almost an order of magnitude.

I propose a SNAPshot survey aimed at discovering PNe in the GC systems
of Local Group galaxies outside the Milky Way. These clusters, some of
which may be much younger than their counterparts in our galaxy, might
contain many more PNe than those of our own galaxy. I will use the
standard technique of emission-line and continuum imaging, which
easily discloses PNe. This proposal continues a WFPC2 program started
in Cycle 16, but with the more powerful WFC3. As a by-product, the
survey will also produce color-magnitude diagrams for numerous
clusters for the first time, reaching down to the horizontal branch.

FGS 11704

The Ages of Globular Clusters and the Population II Distance Scale

Globular clusters are the oldest objects in the universe whose age can
be accurately determined. The dominant error in globular cluster age
determinations is the uncertain Population II distance scale. We
propose to use FGS 1R to obtain parallaxes with an accuracy of 0.2
milliarcsecond for 9 main sequence stars with [Fe/H] -1.5. This will
determine the absolute magnitude of these stars with accuracies of
0.04 to 0.06mag. This data will be used to determine the distance to
24 metal-poor globular clusters using main sequence fitting. These
distances (with errors of 0.05 mag) will be used to determine the ages
of globular clusters using the luminosity of the subgiant branch as an
age indicator. This will yield absolute ages with an accuracy of 5%,
about a factor of two improvement over current estimates. Coupled with
existing parallaxes for more metal-rich stars, we will be able to
accurately determine the age for globular clusters over a wide range
of metallicities in order to study the early formation history of the
Milky Way and provide an independent estimate of the age of the
universe.

The Hipparcos database contains only 1 star with [Fe/H] -1.4 and an
absolute magnitude error less than 0.18 mag which is suitable for use
in main sequence fitting. Previous attempts at main sequence fitting
to metal-poor globular clusters have had to rely on theoretical
calibrations of the color of the main sequence. Our HST parallax
program will remove this source of possible systematic error and yield
distances to metal-poor globular clusters which are significantly more
accurate than possible with the current parallax data. The HST
parallax data will have errors which are 10 times smaller than the
current parallax data. Using the HST parallaxes, we will obtain main
sequence fitting distances to 11 globular clusters which contain over
500 RR Lyrae stars. This will allow us to calibrate the absolute
magnitude of RR Lyrae stars, a commonly used Population II distance
indicator.

WFC3/UV/ACS/WFC 11688

Exploring the Bottom End of the White Dwarf Cooling Sequence in the
Open Cluster NGC6819

The recent discovery by our group of an unexpectedly bright end of the
white-dwarf (WD) luminosity function (LF) of the metal-rich, old open
cluster NGC 6791 casts serious doubts on our understanding of the
physical process which rules the formation and the cooling of WDs. It
is clear at this point that the theory badly needs more observations.
Here we propose WFC3/UVIS and ACS/WFC HST observations reaching the
bottom end of the WD LF, for the first time in a solar-metallicity,
2.5-Gyr-old, populous open cluster: NGC 6819.

COS/FUV 11687

SNAPing Coronal Iron

This is a Snapshot Survey to explore two forbidden lines of highly
ionized iron in late-type coronal sources. Fe XII 1349 (T~ 2 MK) and
Fe XXI 1354 (T~ 10 MK) -- well known to Solar Physics -- have been
detected in about a dozen cool stars, mainly with HST/STIS. The UV
coronal forbidden lines are important because they can be observed
with velocity resolution of better than 15 km/s, whereas even the
state-of-the-art X-ray spectrometers on Chandra can manage only 300
km/s in the kilovolt band where lines of highly ionized iron more
commonly are found. The kinematic properties of hot coronal plasmas,
which are of great interest to theorists and modelers, thus only are
accessible in the UV at present. The bad news is that the UV coronal
forbidden lines are faint, and were captured only in very deep
observations with STIS. The good news is that 3rd-generation Cosmic
Origins Spectrograph, slated for installation in HST by SM4, in a mere
25 minute exposure with its G130M mode can duplicate the sensitivity
of a landmark 25-orbit STIS E140M observation of AD Leo, easily the
deepest such exposure of a late-type star so far. Our goal is to build
up understanding of the properties of Fe XII and Fe XXI in additional
objects beyond the current limited sample: how the lineshapes depend
on activity, whether large scale velocity shifts can be detected, and
whether the dynamical content of the lines can be inverted to map the
spatial morphology of the stellar corona (as in "Doppler Imaging'').
In other words, we want to bring to bear in the coronal venue all the
powerful tricks of spectroscopic remote sensing, well in advance of
the time that this will be possible exploiting the corona's native
X-ray radiation. The 1290-1430 band captured by side A of G130M also
contains a wide range of key plasma diagnostics that form at
temperatures from below 10, 000 K (neutral lines of CNO), to above
200, 000 K (semi-permitted O V 1371), including the important bright
multiplets of C II at 1335 and Si IV at 1400; yielding a diagnostic
gold mine for the subcoronal atmosphere. Because of the broad value of
the SNAP spectra, beyond the coronal iron project, we waive the normal
proprietary rights.

WFC3/UV/IR 11664

The WFC3 Galactic Bulge Treasury Program: Populations, Formation
History, and Planets

Exploiting the full power of the Wide Field Camera 3 (WFC3), we
propose deep panchromatic imaging of four fields in the Galactic
bulge. These data will enable a sensitive dissection of its stellar
populations, using a new set of reddening-free photometric indices we
have constructed from broad-band filters across UV, optical, and
near-IR wavelengths. These indices will provide accurate temperatures
and metallicities for hundreds of thousands of individual bulge stars.
Proper motions of these stars derived from multi-epoch observations
will allow separation of pure bulge samples from foreground disk
contamination. Our catalogs of proper motions and panchromatic
photometry will support a wide range of bulge studies.

Using these photometric and astrometric tools, we will reconstruct the
detailed star-formation history as a function of position within the
bulge, and thus differentiate between rapid- and extended-formation
scenarios. We will also measure the dependence of the stellar mass
function on metallicity, revealing how the characteristic mass of star
formation varies with chemistry. Our sample of bulge stars with
accurate metallicities will include 12 candidate hosts of extrasolar
planets. Planet frequency is correlated with metallicity in the solar
neighborhood; our measurements will extend this knowledge to a remote
environment with a very distinct chemistry.

Our proposal also includes observations of six well-studied globular
and open star clusters; these observations will serve to calibrate our
photometric indices, provide empirical population templates, and
transform the theoretical isochrone libraries into the WFC3 filter
system. Besides enabling our own program, these products will provide
powerful new tools for a host of other stellar-population
investigations with HST/WFC3. We will deliver all of the products from
this Treasury Program to the community in a timely fashion.

WFC3/UVIS 11657

The Population of Compact Planetary Nebulae in the Galactic Disk

We propose to secure narrow- and broad-band images of compact
planetary nebulae (PNe) in the Galactic Disk to study the missing link
of the early phases of post-AGB evolution. Ejected AGB envelopes
become PNe when the gas is ionized. PNe expand, and, when large
enough, can be studied in detail from the ground. In the interim, only
the HST capabilities can resolve their size, morphology, and central
stars. Our proposed observations will be the basis for a systematic
study of the onset of morphology. Dust properties of the proposed
targets will be available through approved Spitzer/IRS spectra, and so
will the abundances of the alpha- elements. We will be able thus to
explore the interconnection of morphology, dust grains, stellar
evolution, and populations. The target selection is suitable to
explore the nebular and stellar properties across the galactic disk,
and to set constraints on the galactic evolutionary models through the
analysis of metallicity and population gradients.

WFC3/UVIS 11594

A WFC3 Grism Survey for Lyman Limit Absorption at z=2

We propose to conduct a spectroscopic survey of Lyman limit absorbers
at redshifts 1.8 z 2.5, using WFC3 and the G280 grism. This
proposal intends to complete an approved Cycle 15 SNAP program
(10878), which was cut short due to the ACS failure. We have selected
64 quasars at 2.3 z 2.6 from the Sloan Digital Sky Survey
Spectroscopic Quasar Sample, for which no BAL signature is found at
the QSO redshift and no strong metal absorption lines are present at z
2.3 along the lines of sight. The survey has three main

observational goals. First, we will determine the redshift frequency
dn/dz of the LLS over the column density range 16.0 log(NHI) 20.3
cm^-2. Second, we will measure the column density frequency
distribution f(N) for the partial Lyman limit systems (PLLS) over the
column density range 16.0 log(NHI) 17.5 cm^-2. Third, we will
identify those sightlines which could provide a measurement of the
primordial D/H ratio. By carrying out this survey, we can also help
place meaningful constraints on two key quantities of cosmological
relevance. First, we will estimate the amount of metals in the LLS
using the f(N), and ground based observations of metal line
transitions. Second, by determining f(N) of the PLLS, we can constrain
the amplitude of the ionizing UV background at z~2 to a greater
precision. This survey is ideal for a snapshot observing program,
because the on-object integration times are all well below 30 minutes,
and follow-up observations from the ground require minimal telescope
time due to the QSO sample being bright.

COS/FUV 11592

Testing the Origin(s) of the Highly Ionized High-Velocity Clouds: A
Survey of Galactic Halo Stars at z3 kpc

Cosmological simulation predicts that highly ionized gas plays an
important role in the formation and evolution of galaxies and their
interplay with the intergalactic medium. The NASA HST and FUSE
missions have revealed high-velocity CIV and OVI absorption along
extragalactic sightlines through the Galactic halo. These highly
ionized high-velocity clouds (HVCs) could cover 85% of the sky and
have a detection rate higher than the HI HVCs. Two competing, equally
exciting, theories may explain the origin of these highly ionized
HVCs: 1) the "Galactic" theory, where the HVCs are the result of
feedback processes and trace the disk-halo mass exchange, perhaps
including the accretion of matter condensing from an extended corona;
2) the "Local Group" theory, where they are part of the local warm-hot
intergalactic medium, representing some of the missing baryonic matter
of the Universe. Only direct distance determinations can discriminate
between these models. Our group has found that some of these highly
ionized HVCs have a Galactic origin, based on STIS observations of one
star at z5.3 kpc. We propose an HST FUV spectral survey to search for
and characterize the high velocity NV, CIV, and SiIV interstellar
absorption toward 24 stars at much larger distances than any previous
searches (4d21 kpc, 3|z|13 kpc). COS will provide atomic to highly
ionized species (e.g., OI, CII, CIV, SiIV) that can be observed at
sufficient resolution (R~22, 000) to not only detect these highly
ionized HVCs but also to model their properties and understand their
physics and origins. This survey is only possible because of the high
sensitivity of COS in the FUV spectral range.

ACS/WFC3 11586

Exceptional Galactic Halo Globular Clusters and the Second Parameter

We propose to obtain deep ACS-WFC images of six globular clusters
(five of which have no previous HST photometry) that reside in the
Galactic halo, where the second parameter effect is most pronounced.
These globular clusters are among the least studied in the Galaxy and
yet, from the perspective of the second parameter phenomenon, the most
intriguing.

With the best available CMDs only reaching the vicinity of the main
sequence turn off at present, the unique sensitivity and resolution of
ACS-WFC will yield ages of unprecedented precision for these clusters.
These data will provide us with new insight into the stellar
populations present in the outer Galactic halo and the nature of the
second parameter. The second parameter plays a critical role in our
understanding of the formation and evolution of the Galaxy and the
proposed observations will shed new light on this problem and these
exceptional clusters.

WFC3/UVI 11580

Watching Young Planetary Nebulae Grow: The Movie

The development of magneto-hydro gas dynamical models is the key to
the understanding of both the physics (processes) and astronomy
(initial conditions) of astrophysical nebulae of all sorts. The models
are reaching their highest degree of accuracy when applied to and
compared against pre Planetary Nebulae (pPNe) thanks to the
simplicity, relative lack of extinction, and the detail of the imaging
and kinematic data that have bcome available for these objects. The
primary barrier to progress is inadequate kinematic data of pPNe
against which the predictions models can be tested. Unlike PNe, pPNe
do not emit emission lines for detailed Doppler measurements.
Therefore it is essential to find another way to monitor the
morphological evolution.

Only HST can uncover the dynamics of the growth patterns by
subtracting multi-epoch images spanning a decade or more. We have
selected four pPNe with highly collimated outflows in different
evolutionary stages for which high-quality first epoch images were
obtained from 1996 to 2002. All of them display regularly shaped thin
rims, sharp edges, and symmetric pairs of knots or bowshocks that are
ideal for our purposes. We will closely mimic many of the earlier
exposures using ACS and to monitor changes in structures. The
morphology and its evolution will be compared to 3-D MHD models with
adaptive grids in order to build a far clearer picture of the nuclear
geometry which shaped the outflows and constrained their propagation
to the present. We shall also obtain R, J, and H images for use with a
3-D dust radiative transfer code LELUYA to model the dust distribution
deep into the nuclear zones.

NIC2/WFC3/IR 11548

Infrared Imaging of Protostars in the Orion A Cloud: The Role of
Environment in Star Formation

We propose NICMOS and WFC3/IR observations of a sample of 252
protostars identified in the Orion A cloud with the Spitzer Space
Telescope. These observations will image the scattered light escaping
the protostellar envelopes, providing information on the shapes of
outflow cavities, the inclinations of the protostars, and the overall
morphologies of the envelopes. In addition, we ask for Spitzer time to
obtain 55-95 micron spectra of 75 of the protostars. Combining these
new data with existing 3.6 to 70 micron photometry and forthcoming
5-40 micron spectra measured with the Spitzer Space Telescope, we will
determine the physical properties of the protostars such as envelope
density, luminosity, infall rate, and outflow cavity opening angle. By
examining how these properties vary with stellar density (i.e.
clusters vs. groups vs. isolation) and the properties of the
surrounding molecular cloud; we can directly measure how the
surrounding environment influences protostellar evolution, and
consequently, the formation of stars and planetary systems.
Ultimately, this data will guide the development of a theory of
protostellar evolution.

COS/NUV/FUV/WFC3/UVI 11534 S/IR COS-GTO: Atmosphere of a Transiting
Planet

COS observations of a transiting planet at different orbital locations
will be useful in identifying the chemical content, size, temperature,
and flows in the atmosphere of a transiting planet.

NIC 11408

NICMOS Focus and PAM Grid Tilt Tests

The purpose of this proposal is determine the PAM settings
corresponding to best focus for NIC1 and NIC2. A test will aslo be
done on NIC3 in order to establish that the nominal PAM position of
-9.5mm relative to mechanical zero results in an acceptable focus.

The program consists of: Visit 01: Focus sweep using NIC1 Visit 02:
Focus sweep using NIC2 Visit 03: Focus sweep using NIC3 Visit 04:
Uplink of revised PAM settings (if needed) Visit 05: PAM X/Y grid tilt
for NIC1 Visit 06: PAM X/Y grid tilt for NIC2 Visit 07: PAM X/Y grid
tilt for NIC3 Visit 08: Uplink of revised PAM X/Y parameters (if
needed)

The focus sweeps are based on the normal focus monitoring proposal
11320. The tilt grid measurements are based on proposal 8977 (NIC1)
and 9645 (NIC2 and NIC3).

WFC3/ACS/IR 11359

Panchromatic WFC3 Survey of Galaxies at Intermediate z: Early Release
Science Program for Wide Field Camera 3

The unique panchromatic capabilities of WFC3 will be used to survey
the structure and evolution of galaxies at the peak of the galaxy
assembly epoch. Deep ultraviolet and near-IR imaging and slitless
spectroscopy of existing deep multi-color ACS fields will be used to
gauge star-formation and the growth of stellar mass as a function of
morphology, structure and surrounding density in the critical epoch 1
z 4. Images in the F225W, F275W, and F336W filters will identify
galaxies at z 1.5 from their UV continuum breaks, and provide
star-formation indicators tied directly to both local and z 3
populations. Deep near-IR (F125W and F160W) images will probe the
stellar mass function well below 10^9 Msun for mass-complete samples.
Lastly, the WFC3 slitless UV and near-IR grisms will be used to
measure redshifts and star-formation rates from H-alpha and rest-frame
UV continuum slope. This WFC3 ERS program will survey one 4 x 2 mosaic
for a total area of 50 square arcminutes to 5-sigma depths of m_AB =
27 in most filters from the mid-UV through the near-IR.

This multicolor high spatial resolution data set will allow the user
to gauge the growth of galaxies through star-formation and merging.
High precision photometric and low-resolution spectroscopic redshifts
will allow accurate determinations of the faint-end of the luminosity
and mass functions, and will shed light on merging and tidal
disruption of stellar and gaseous disks. The WFC3 images will also
allow detailed studies of the internal structure of galaxies, and the
distribution of young and old stellar populations. This program will
demonstrate the unique power of WFC3 by applying its many diverse
modes and full panchromatic capability to a forefront problem in
astrophysics.

ACS/WFC3 11343

Identifying the Host Galaxies for Optically Dark Gamma-Ray Bursts

We propose to use the high spatial resolution capabilities of Chandra
to obtain precise positions for a sample of Gamma-ray bursts (GRBs)
with no optical afterglows, where the optical light is suppressed
relative to the X-ray flux. These bursts are likely to be highly
obscured and may have different environments from the optically bright
GRBs. Our Chandra observations will (unlike Swift-XRT positions) allow
for the unique identification of a host galaxy. To locate these host
galaxies we will follow up our Chandra positions with deep optical and
IR observations with HST. The ultimate aim is to understand any
differences between the host galaxies of optically dark and bright
GRBs, and how these affect the use of GRBs as tracers of star
formation and galaxy evolution at high redshift.

WFC3/IR 11202

The Structure of Early-type Galaxies: 0.1-100 Effective Radii

The structure, formation and evolution of early-type galaxies is still
largely an open problem in cosmology: how does the Universe evolve
from large linear scales dominated by dark matter to the highly
non-linear scales of galaxies, where baryons and dark matter both play
important, interacting, roles? To understand the complex physical
processes involved in their formation scenario, and why they have the
tight scaling relations that we observe today (e.g. the Fundamental
Plane), it is critically important not only to understand their
stellar structure, but also their dark-matter distribution from the
smallest to the largest scales. Over the last three years the SLACS
collaboration has developed a toolbox to tackle these issues in a
unique and encompassing way by combining new non-parametric strong
lensing techniques, stellar dynamics, and most recently weak
gravitational lensing, with high-quality Hubble Space Telescope
imaging and VLT/Keck spectroscopic data of early-type lens systems.
This allows us to break degeneracies that are inherent to each of
these techniques separately and probe the mass structure of early-type
galaxies from 0.1 to 100 effective radii. The large dynamic range to
which lensing is sensitive allows us both to probe the clumpy
substructure of these galaxies, as well as their low-density outer
haloes. These methods have convincingly been demonstrated, by our
team, using smaller pilot-samples of SLACS lens systems with HST data.
In this proposal, we request observing time with WFC3 and NICMOS to
observe 53 strong lens systems from SLACS, to obtain complete
multi-color imaging for each system. This would bring the total number
of SLACS lens systems to 87 with completed HST imaging and effectively
doubles the known number of galaxy-scale strong lenses. The deep HST
images enable us to fully exploit our new techniques, beat down
low-number statistics, and probe the structure and evolution of early-
type galaxies, not only with a uniform data-set an order of magnitude
larger than what is available now, but also with a fully-coherent and
self-consistent methodological approach!

WFC3/ACS/IR 11142

Revealing the Physical Nature of Infrared Luminous Galaxies at
0.3z2.7 Using HST and Spitzer

We aim to determine physical properties of IR luminous galaxies at
0.3z2.7 by requesting coordinated HST/NIC2 and MIPS 70um
observations of a unique, 24um flux-limited sample with complete
Spitzer mid-IR spectroscopy. The 150 sources investigated in this
program have S(24um) 0.8mJy and their mid-IR spectra have already
provided the majority targets with spectroscopic redshifts
(0.3z2.7). The proposed 150~orbits of NIC2 and 66~hours of MIPS 70um
will provide the physical measurements of the light distribution at
the rest-frame ~8000A and better estimates of the bolometric
luminosity. Combining these parameters together with the rich suite of
spectral diagnostics from the mid-IR spectra, we will (1) measure how
common mergers are among LIRGs and ULIRGs at 0.3z2.7, and establish
if major mergers are the drivers of z1 ULIRGs, as in the local
Universe, (2) study the co-evolution of star formation and blackhole
accretion by investigating the relations between the fraction of
starburst/AGN measured from mid-IR spectra vs. HST morphologies,
L(bol) and z, and (3) obtain the current best estimates of the far-IR
emission, thus L(bol) for this sample, and establish if the relative
contribution of mid-to-far IR dust emission is correlated with
morphology (resolved vs. unresolved).

NIC2 10897

Coronagraphic imaging of the submillimeter debris disk of a 200Myr old
M-dwarf

A recent sub-millimeter survey has unambiguously discovered a new
debris disk around the M0.5 dwarf GJ842.2 which is 200 Myr old.
Reanalysis of the IRAS data has shown that there is also a 25 micron
excess toward this star indicating warm dust close to the star. It is
also only the second debris disk found among M-dwarfs that constitute
70 % of the stars in the Galaxy. Collisional and Poynting-Roberston
timescale arguments indicate that the cold grains detected in the
sub-mm are ``primordial'', i.e. original grains from the
protoplanetary phase. The disk around GJ842.2 is thus unique in terms
of the presence of dust at such a late stage of evolution and presents
two conundrums: why did it retain so much primordial dust at large
distances, and why does it continue to produce dust close to the star?
We propose to conduct high contrast NICMOS coronagraphic imaging of
GJ842.2 to determine the spatial distribution of the small reflecting
grains and test the various scenarios which might explain the IRAS and
sub-mm data e.g.resonant trapping of dust by planets or
``sandblasting'' by interstellar medium grains working more
aggressively on a low-luminosity star than on an A-type star like Beta
Pic. Also, we would search for an evolutionary sequence between
GJ842.2 and the only other M-dwarf with a disk resolved by HST, the 10
Myr old AU Mic system.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.)

HSTARS:

12040 - GSAcq(1,2,1) scheduled at 283/03:37:59 - 03:45:30 failed to
RGA Hold (gyro control) due to search radius limit exceeded on FGS-2

Observations affected: STIS 89 Proposal ID# 10897.

12041 - GSAcq(1,2,1) scheduled at 286/02:05:19 - 02:12:50 and
REAcq(1,2,1) scheduled at 286/03:28:54 both resulted in fine lock
backup (1,0,1) using FGS-1.

Observations possibly affected: STIS 10, Proposal ID# 11846 and WFC3
36-37, Proposal ID# 11202.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSAcq 40 39
FGS REAcq 21 21
OBAD with Maneuver 34 34

SIGNIFICANT EVENTS: (None)


 




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