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Daily Report #5004



 
 
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Old January 4th 10, 08:44 PM posted to sci.astro.hubble
Bassford, Lynn[_2_]
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Posts: 91
Default Daily Report #5004

HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #5004

PERIOD COVERED: 5am December 31, 2009 - 5am January 4, 2010 (DOY 365/10:00z-004/10:00z)

OBSERVATIONS SCHEDULED

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/IR 11915

IR Internal Flat Fields

This program is the same as 11433 (SMOV) and depends on the completion
of the IR initial alignment (Program 11425). This version contains
three instances of 37 internal orbits: to be scheduled early, middle,
and near the end of Cycle 17, in order to use the entire 110-orbit
allocation.

In this test, we will study the stability and structure of the IR
channel flat field images through all filter elements in the WFC3-IR
channel. Flats will be monitored, i.e. to capture any temporal trends
in the flat fields and delta flats produced. High signal observations
will provide a map of the pixel-to-pixel flat field structure, as well
as identify the positions of any dust particles.

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).

WFC3/ACS 11888

ACS Internal Flat Fields

The stability of the CCD flat fields will be monitored using the
calibration lamps and a sub-sample of the filter set. High signal
observations will be used to assess the stability of the
pixel-to-pixel flat field structure and to monitor the position of the
dust motes.

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 11849

STIS CCD Hot Pixel Annealing

This purpose of this activity is to repair radiation induced hot pixel
damage to the STIS CCD by warming the CCD to the ambient instrument
temperature and annealing radiation-damaged pixels.

Radiation damage creates hot pixels in the STIS CCD Detector. Many of
these hot pixels can be repaired by warming the CCD from its normal
operating temperature near - 83 deg. C to the ambient instrument
temperature (~ +5 deg. C) for several hours. The number of hot pixels
repaired is a function of annealing temperature. The effectiveness of
the CCD hot pixel annealing process is assessed by measuring the dark
current behavior before and after annealing and by searching for any
window contamination effects.

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.

COS/NUV/FUV 11742

Probing HeII Reionization with GALEX-selected Quasar Sightlines and
HST/COS

We propose spectroscopic observations with COS of eight z~3 QSOs that
we found to be bright in the far ultraviolet. Our aim is to study
intergalactic absorption caused by the onset of the He II Lyman
forest. Several lines of evidence suggest that helium reionization
occurred at z~3. Understanding this process is critical for a complete
picture of the intergalactic medium and its evolution; it also gives
clues to hydrogen reionization at z6. The only direct means of
assessing He II reionization is through far- UV observations of the He
II Lyman alpha forest. Only 6 sightlines are known to date where this
is feasible, despite extensive surveys. Our program is designed to
double the number of available sightlines. To this effect, we
cross-correlated all known z2.73 quasars with UV source lists from
the GALEX satellite. The selected quasars were all significantly
detected in the far UV by GALEX, and their UV colors are similar to
those of already known quasars with transparent sightlines. Spectra
obtained with COS will allow us to compile the first comprehensive
sample of He II absorption spectra probing similar redshifts, enabling
a systematic investigation of the He II reionization epoch and the
spectral shape of the UV background.

WFC3/UVIS 11732

The Temperature Profiles of Quasar Accretion Disks

We can now routinely measure the size of quasar accretion disks using
gravitational microlensing of lensed quasars. At optical wavelengths
we observe a size and scaling with black hole mass roughly consistent
with thin disk theory but the sizes are larger than expected from the
observed optical fluxes. One solution would be to use a flatter
temperature profile, which we can study by measuring the wavelength
dependence of the disk size over the largest possible wavelength
baseline. Thus, to understand the size discrepancy and to probe closer
to the inner edge of the disk we need to extend our measurements to UV
wavelengths, and this can only be done with HST. For example, in the
UV we should see significant changes in the optical/UV size ratio with
black hole mass. We propose monitoring 5 lenses spanning a broad range
of black hole masses with well-sampled ground based light curves,
optical disk size measurements and known GALEX UV fluxes during Cycles
17 and 18 to expand from our current sample of two lenses. We would
obtain 5 observations of each target in each Cycle, similar to our
successful strategy for the first two targets.

WFC3/IR 11719

A Calibration Database for Stellar Models of Asymptotic Giant Branch
Stars

Studies of galaxy formation and evolution rely increasingly on the
interpretation and modeling of near-infrared observations. At these
wavelengths, the brightest stars are intermediate mass asymptotic
giant branch (AGB) stars. These stars can contribute nearly 50% of the
integrated luminosity at near infrared and even optical wavelengths,
particularly for the younger stellar populations characteristic of
high-redshift galaxies (z1). AGB stars are also significant sources
of dust and heavy elements. Accurate modeling of AGB stars is
therefore of the utmost importance.

The primary limitation facing current models is the lack of useful
calibration data. Current models are tuned to match the properties of
the AGB population in the Magellanic Clouds, and thus have only been
calibrated in a very narrow range of sub- solar metallicities.
Preliminary observations already suggest that the models are
overestimating AGB lifetimes by factors of 2-3 at lower metallicities.
At higher (solar) metallicities, there are no appropriate observations
for calibrating the models.

We propose a WFC3/IR SNAP survey of nearby galaxies to create a large
database of AGB populations spanning the full range of metallicities
and star formation histories. Because of their intrinsically red
colors and dusty circumstellar envelopes, tracking the numbers and
bolometric fluxes of AGB stars requires the NIR observations we
propose here. The resulting observations of nearby galaxies with deep
ACS imaging offer the opportunity to obtain large (100-1000's)
complete samples of AGB stars at a single distance, in systems with
well-constrained star formation histories and metallicities.

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 11706

The Parallax of the Planet Host Star XO-3

We will use HST+FGS to measure the parallax of the transiting planet
host star XO 3. The resulting accurate distance measurement will
provide the most accurate radius determination to date for this
massive extrasolar planet (XO-3B), allowing us to critically test
current giant extrasolar planet structure models. These observations
will also constrain the amount of heating that may be produced inside
XO-3B by tides raised on the planet as it moves through its 3.2
d-eccentric (e ~ 0.22) orbit.

STIS/CCD 11703

The Nature of the Black Hole in a NGC 4472 Globular Cluster and the
Origin of Its Broad [OIII] Emission

We propose to use STIS to obtain optical spectroscopy at high spatial
resolution of the black hole-hosting globular cluster RZ2109 in the
Virgo elliptical NGC 4472. This is motivated by our very recent
discovery broad [OIII] 4959, 5007 emission with a width of several
thousand km/s in this globular cluster. The STIS spectroscopy will
enable us to determine if the very broad [OIII] emission is due to
material driven at high velocity from the central accreting black hole
across the globular cluster, or if the velocity widths are due to
gravitational motions very close to the central black hole. In the
former case, the [OIII] emission should extend over a few-tenths of an
arcsecond and be spatially resolved by HST and STIS, while in the
latter case, the emission lines will be unresolved. Distinguishing
between these two possibilities will allow us to - 1) determine
whether the black hole is of intermediate mass or a stellar mass, and
thereby whether the black hole mass - sigma relation extends to
globular cluster masses, 2) test models of black hole formation and
evolution in dense stellar systems, and 3) address the nature of
accretion in the high luminosity black-hole X-ray source, and
constrain the feedback processes from luminous black holes into their
surrounding medium in dense stellar systems.

WFC3/UVIS/IR 11700

Bright Galaxies at z7.5 with a WFC3 Pure Parallel Survey

The epoch of reionization represents a special moment in the history
ofthe Universe as it is during this era that the first galaxies and
star clusters are formed. Reionization also profoundly affects the
environment where subsequent generations of galaxies evolve. Our
overarching goal is to test the hypothesis that galaxies are
responsible for reionizing neutral hydrogen. To do so we propose to
carry out a pure parallel WFC3 survey to constrain the bright end of
the redshift z7.5 galaxy luminosity function on a total area of 176
arcmin^2 of sky. Extrapolating the evolution of the luminosity
function from z~6, we expect to detect about 20 Lyman Break Galaxies
brighter than M_* at z~8 significantly improving the current sample of
only a few galaxies known at these redshifts. Finding significantly
fewer objects than predicted on the basis of extrapolation from z=6
would set strong limits to the brightness of M_*, highlighting a fast
evolution of the luminosity function with the possible implication
that galaxies alone cannot reionize the Universe. Our observations
will find the best candidates for spectroscopic confirmation, that is
bright z7.5 objects, which would be missed by small area deeper
surveys. The random pointing nature of the program is ideal to beat
cosmic variance, especially severe for luminous massive galaxies,
which are strongly clustered. In fact our survey geometry of 38
independent fields will constrain the luminosity function like a
contiguous single field survey with two times more area at the same
depth. Lyman Break Galaxies at z7.5 down to m_AB=26.85 (5 sigma) in
F125W will be selected as F098M dropouts, using three to five orbits
visits that include a total of four filters (F606W, F098M, F125W,
F160W) optimized to remove low-redshift interlopers and cool stars.
Our data will be highly complementary to a deep field search for
high-z galaxies aimed at probing the faint end of the luminosity
function, allowing us to disentangle the degeneracy between faint end
slope and M_* in a Schechter function fit of the luminosity function.
We waive proprietary rights for the data. In addition, we commit to
release the coordinates and properties of our z7.5 candidates within
one month from the acquisition of each field.

WFC3/IR 11696

Infrared Survey of Star Formation Across Cosmic Time

We propose to use the unique power of WFC3 slitless spectroscopy to
measure the evolution of cosmic star formation from the end of the
reionization epoch at z6 to the close of the galaxy-building era at
z~0.3.Pure parallel observations with the grisms have proven to be
efficient for identifying line emission from galaxies across a broad
range of redshifts. The G102 grism on WFC3 was designed to extend this
capability to search for Ly-alpha emission from the first galaxies.
Using up to 250 orbits of pure parallel WFC3 spectroscopy, we will
observe about 40 deep (4-5 orbit) fields with the combination of G102
and G141, and about 20 shallow (2-3 orbit) fields with G141 alone.

Our primary science goals at the highest redshifts a (1) Detect Lya
in ~100 galaxies with z5.6 and measure the evolution of the Lya
luminosity function, independent of of cosmic variance; 2) Determine
the connection between emission line selected and continuum-break
selected galaxies at these high redshifts, and 3) Search for the
proposed signature of neutral hydrogen absorption at re-ionization. At
intermediate redshifts we will (4) Detect more than 1000 galaxies in
Halpha at 0.5z1.8 to measure the evolution of the
extinction-corrected star formation density across the peak epoch of
star formation. This is over an order-of-magnitude improvement in the
current statistics, from the NICMOS Parallel grism survey. (5) Trace
``cosmic downsizing" from 0.5z2.2; and (6) Estimate the evolution in
reddening and metallicty in star-forming galaxies and measure the
evolution of the Seyfert population. For hundreds of spectra we will
be able to measure one or even two line pair ratios -- in particular,
the Balmer decrement and [OII]/[OIII] are sensitive to gas reddening
and metallicity. As a bonus, the G102 grism offers the possibility of
detecting Lya emission at z=7-8.8.

To identify single-line Lya emitters, we will exploit the wide
0.8--1.9um wavelength coverage of the combined G102+G141 spectra. All
[OII] and [OIII] interlopers detected in G102 will be reliably
separated from true LAEs by the detection of at least one strong line
in the G141 spectrum, without the need for any ancillary data. We
waive all proprietary rights to our data and will make high-level data
products available through the ST/ECF.

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/IR 11644

A Dynamical-Compositional Survey of the Kuiper Belt: A New Window Into
the Formation of the Outer Solar System

The eight planets overwhelmingly dominate the solar system by mass,
but their small numbers, coupled with their stochastic pasts, make it
impossible to construct a unique formation history from the dynamical
or compositional characteristics of them alone. In contrast, the huge
numbers of small bodies scattered throughout and even beyond the
planets, while insignificant by mass, provide an almost unlimited
number of probes of the statistical conditions, history, and
interactions in the solar system. To date, attempts to understand the
formation and evolution of the Kuiper Belt have largely been dynamical
simulations where a hypothesized starting condition is evolved under
the gravitational influence of the early giant planets and an attempt
is made to reproduce the current observed populations. With little
compositional information known for the real Kuiper Belt, the test
particles in the simulation are free to have any formation location
and history as long as they end at the correct point. Allowing
compositional information to guide and constrain the formation,
thermal, and collisional histories of these objects would add an
entire new dimension to our understanding of the evolution of the
outer solar system. While ground based compositional studies have hit
their flux limits already with only a few objects sampled, we propose
to exploit the new capabilities of WFC3 to perform the first ever
large-scale dynamical-compositional study of Kuiper Belt Objects
(KBOs) and their progeny to study the chemical, dynamical, and
collisional history of the region of the giant planets. The
sensitivity of the WFC3 observations will allow us to go up to two
magnitudes deeper than our ground based studies, allowing us the
capability of optimally selecting a target list for a large survey
rather than simply taking the few objects that can be measured, as we
have had to do to date. We have carefully constructed a sample of 120
objects which provides both overall breadth, for a general
understanding of these objects, plus a large enough number of objects
in the individual dynamical subclass to allow detailed comparison
between and within these groups. These objects will likely define the
core Kuiper Belt compositional sample for years to come. While we have
many specific results anticipated to come from this survey, as with
any project where the field is rich, our current knowledge level is
low, and a new instrument suddenly appears which can exploit vastly
larger segments of the population, the potential for discovery -- both
anticipated and not -- is extraordinary.

WFC3/ACS/UVIS 11613

GHOSTS: Stellar Outskirts of Massive Spiral Galaxies

We propose to continue our highly successful GHOSTS HST survey of the
resolved stellar populations of nearby, massive disk galaxies using
SNAPs. These observations provide star counts and color-magnitude
diagrams 2-3 magnitudes below the tip of the Red Giant Branch of the
outer disk and halo of each galaxy. We will measure the metallicity
distribution functions and stellar density profiles from star counts
down to very low average surface brightnesses, equivalent to ~32 V-mag
per square arcsec.

This proposal will substantially improve our unique sampling of galaxy
outskirts. Our targets cover a range in galaxy mass, luminosity,
inclination, and morphology. As a function of these galaxy properties,
this survey provides: - the most extensive, systematic measurement of
radial light profiles and axial ratios of the diffuse stellar halos
and outer disks of spiral galaxies; - a comprehensive analysis of halo
metallicity distributions as function of galaxy type and position
within the galaxy; - an unprecedented study of the stellar metallicity
and age distribution in the outer disk regions where the disk
truncations occur; - the first comparative study of globular clusters
and their field stellar populations.

We will use these fossil records of the galaxy assembly process to
test halo formation models within the hierarchical galaxy formation
scheme.

ACS/WFC3 11599

Distances of Planetary Nebulae from SNAPshots of Resolved Companions

Reliable distances to individual planetary nebulae (PNe) in the Milky
Way are needed to advance our understanding of their spatial
distribution, birthrates, influence on galactic chemistry, and the
luminosities and evolutionary states of their central stars (CSPN).
Few PNe have good distances, however. One of the best ways to remedy
this problem is to find resolved physical companions to the CSPN and
measure their distances by photometric main-sequence fitting. We have
previously used HST to identify and measure probable companions to 10
CSPN, based on angular separations and statistical arguments only. We
now propose to use HST to re-observe 48 PNe from that program for
which additional companions are possibly present. We then can use the
added criterion of common proper motion to confirm our original
candidate companions and identify new ones in cases that could not
confidently be studied before. We will image the region around each
CSPN in the V and I bands, and in some cases in the B band. Field
stars that appear close to the CSPN by chance will be revealed by
their relative proper motion during the 13+ years since our original
survey, leaving only genuine physical companions in our improved and
enlarged sample. This study will increase the number of Galactic PNe
with reliable distances by 50 percent and improve the distances to PNe
with previously known companions.

WFC3/UVIS 11565

A Search for Astrometric Companions to Very Low-Mass, Population II
Stars

We propose to carry out a Snapshot search for astrometric companions
in a subsample of very low-mass, halo subdwarfs identified within 120
parsecs of the Sun. These ultra-cool M subdwarfs are local
representatives of the lowest-mass H burning objects from the Galactic
Population II. The expected 3-4 astrometric doubles that will be
discovered will be invaluable in that they will be the first systems
from which gravitational masses of metal-poor stars at the bottom of
the main sequence can be directly measured.

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/FUV 11541

COS-GTO: Cool, Warm, and Hot Gas in the Cosmic Web and in Galaxy Halos

COS G130M and G160M 20, 000 resolution observations will be obtained
for 17 QSOs to study cool, warm and hot gas in the cosmic web and in
galaxy halos. 5 QSOs with z from 0.177 to 0.574 and sum z = 1.68 will
be observed with S/N = 40-50 per resolution element. 12 QSOs with z =
0.286 to 0.669 and sum z = 5.57 will be observed with S/N = 30-40. The
observations will allow a wide range of IGM studies including
determining the frequency of occurrence of the different types of
absorption systems detected, along with studies of the physical
conditions and elemental abundances in the different systems. Special
emphasis will be given to a study of the properties of highly ionized
IGM as traced by O VI, O V, O IV, N V, and C IV. The high S/N of the
observations will allow a search for broad Lyman alpha absorption and
weak metal line absorption that can be crucial for the evaluation of
physical conditions and elemental abundances. Supporting ground based
observations will allow studies of the association of the absorbers
with galaxy structures along the 17 lines of sight. The overall goal
of the program will be to obtain the information that will allow an
assessment of the baryonic content of the IGM as revealed by UV and
EUV absorption lines seen in the spectra of QSOs.

COS/NUV/FUV 11522

COS-GTO: Star Formation/Lyman-Alpha

A sample of 20 star-forming galaxies will be observed with COS G130M.
The galaxies were selected from the Kitt Peak International
Spectroscopic Survey (KISSR) data release and cover a broad range of
luminosity, oxygen abundance, and reddening. The goal of the program
is to characterize the Lyman-alpha properties and establish
correlations with fundamental galaxy properties. Each galaxy will be
observed for one orbit.

WFC3/ACS/UVIS 11360

Star Formation in Nearby Galaxies

Star formation is a fundamental astrophysical process; it controls
phenomena ranging from the evolution of galaxies and nucleosynthesis
to the origins of planetary systems and abodes for life. The WFC3,
optimized at both UV and IR wavelengths and equipped with an extensive
array of narrow-band filters, brings unique capabilities to this area
of study. The WFC3 Scientific Oversight Committee (SOC) proposes an
integrated program on star formation in the nearby universe which will
fully exploit these new abilities. Our targets range from the
well-resolved R136 in 30 Dor in the LMC (the nearest super star
cluster) and M82 (the nearest starbursting galaxy) to about half a
dozen other nearby galaxies that sample a wide range of star-formation
rates and environments. Our program consists of broad band
multiwavelength imaging over the entire range from the UV to the
near-IR, aimed at studying the ages and metallicities of stellar
populations, revealing young stars that are still hidden by dust at
optical wavelengths, and showing the integrated properties of star
clusters. Narrow-band imaging of the same environments will allow us
to measure star-formation rates, gas pressure, chemical abundances,
extinction, and shock morphologies. The primary scientific issues to
be addressed a (1) What triggers star formation? (2) How do the
properties of star-forming regions vary among different types of
galaxies and environments of different gas densities and compositions?
(3) How do these different environments affect the history of star
formation? (4) Is the stellar initial mass function universal or
determined by local conditions?

WFC3/ACS/IR 11235

HST NICMOS Survey of the Nuclear Regions of Luminous Infrared Galaxies
in the Local Universe

At luminosities above 10^11.4 L_sun, the space density of far-infrared
selected galaxies exceeds that of optically selected galaxies. These
`luminous infrared galaxies' (LIRGs) are primarily interacting or
merging disk galaxies undergoing enhanced star formation and Active
Galactic Nuclei (AGN) activity, possibly triggered as the objects
transform into massive S0 and elliptical merger remnants. We propose
NICMOS NIC2 imaging of the nuclear regions of a complete sample of 88
L_IR 10^11.4 L_sun luminous infrared galaxies in the IRAS Revised
Bright Galaxy Sample (RBGS: i.e., 60 micron flux density 5.24 Jy).
This sample is ideal not only in its completeness and sample size, but
also in the proximity and brightness of the galaxies. The superb
sensitivity and resolution of NICMOS NIC2 on HST enables a unique
opportunity to study the detailed structure of the nuclear regions,
where dust obscuration may mask star clusters, AGN, and additional
nuclei from optical view, with a resolution significantly higher than
possible with Spitzer IRAC. This survey thus provides a crucial
component to our study of the dynamics and evolution of IR galaxies
presently underway with Wide-Field, HST ACS/WFC3, and Spitzer IRAC
observations of these 88 galaxies. Imaging will be done with the F160W
filter (H-band) to examine as a function of both luminosity and merger
stage: (i) the luminosity and distribution of embedded star clusters,
(ii) the presence of optically obscured AGN and nuclei, (iii) the
correlation between the distribution of 1.6 micron emission and the
mid-IR emission as detected by Spitzer IRAC, (iv) the evidence of bars
or bridges that may funnel fuel into the nuclear region, and (v) the
ages of star clusters for which photometry is available via ACS/WFC3
observations. The NICMOS data, combined with the HST ACS, Spitzer, and
GALEX observations of this sample, will result in the most
comprehensive study of merging and interacting galaxies to date.

WFC3/IR 11189

Probing the Early Universe with GRBs

Cosmology is beginning to constrain the nature of the earliest stars
and galaxies to form in the Universe, but direct observation of
galaxies at z6 remains highly challenging due to their scarcity,
intrinsically small size, and high luminosity distance. GRB
afterglows, thanks to their extreme luminosities, offer the
possibility of circumventing these normal constraints by providing
redshifts and spectral information which couldn't be obtained through
direct observation of the host galaxies themselves. In addition, the
association of GRBs with massive stars means that they are an
indicator of star formation, and that their hosts are likely
responsible for a large proportion of the ionizing radiation during
that era. Our collaboration is conducting a campaign to rapidly
identify and study candidate very high redshift bursts, bringing to
bear a network of 2, 4 and 8m telescopes with near-IR instrumentation.
Swift has proven capable of detecting faint, distant GRBs, and
reporting accurate positions for many bursts in near real-time. Here
we propose to continue our HST program of targeting GRBs at z~6 and
above. HST is crucial to this endeavor, allowing us (a) to
characterize the basic properties, such as luminosity and color, and
in some cases morphologies, of the hosts, which is essential to
understanding these primordial galaxies and their relationship to
other galaxy populations; and (b) to monitor the late time afterglows
and hence compare them to lower-z bursts and test the use of GRBs as
standard candles.

NIC3/WFC3/IR 11149

Characterizing the Stellar Populations in Lyman-Alpha Emitters and
Lyman Break Galaxies at 5.7z7 in the Subaru Deep Field

The epoch of reionization marks a major phase transition of the
Universe, during which the intergalactic space became transparent to
UV photons. Determining when this occurred and the physical processes
involved represents the latest frontier in observational cosmology.
Over the last few years, searches have intensified to identify the
population of high-redshift (z6) galaxies that might be responsible
for this process, but the progress is hampered partly by the
difficulty of obtaining physical information (stellar mass, age, star
formation rate/history) for individual sources. This is because the
number of z6 galaxies that have both secure spectroscopic redshifts
and high-quality infrared photometry (especially with Spitzer/IRAC) is
still fairly small. Considering that only several photometric points
are available per source, and that many model SEDs are highly
degenerate, it is crucial to obtain as many observational constraints
as possible for each source to ensure the validity of SED modeling. To
better understand the physical properties of high-redshift galaxies,
we propose here to conduct HST/NICMOS (72 orbits) and Spitzer/IRAC
(102 hours) imaging of spectroscopically confirmed, bright (z26 mag
(AB)) Ly-alpha emitters (LAEs) and Lyman-break galaxies (LBGs) at
5.7z7 selected from the Subaru Deep Field. Spectroscopic redshifts
remove one critical free parameter from SED modeling while bright
source magnitudes ensure high-quality photometric data. By making
accurate determinations of stellar masses, ages, and star-formation
histories, we will specifically address the following major questions:
(1) Do LAEs and LBGs represent physically different galaxy populations
at z6 as suggested recently? (2) Is Ly-alpha emission systematically
suppressed at z6 with respect to continuum emission? (i.e., are we
reaching the epoch of incomplete reionization?), and (3) Do we see any
sign of abnormally young stellar population in any of the z6
galaxies?

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

#12148 GSAcq(1,2,1) @2010/002/11:45:50z failed due to search radius
limit exceeded on FGS1.

Observations affected: WFC3 #200-201 Proposal #11644, WFC3 #202
Proposal #11929

#12150 GSAcq(1,2,1) @2010/003/07:21:19z and REAcqs @003/08:58:27z,
003/10:34:21z, 003/12:10:15z and 003/13:46:09z result in fine lock
backup on FGS1.

Observations possibly affected: COS #111-114 Proposal #11742, WFC3
#223-227 Proposal #11696, STIS #46-47 Proposal #11849, STIS #48
Proposal #11844

#12152 GSAcq(1,2,1) @2010/003/15:22:27z and REAcqs @003/16:57:25z,
003/18:33:23z and 003/20:09:21z resulted in fine lock backup (1,0,1)

Observations possibly affected: COS #115-130 Proposal #11541, STIS #49
Proposal #11844, STIS #50-52 Proposal #11846, WFC3 #228-231 Proposal
#11541

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSAcq 29 28
FGS REAcq 35 35
OBAD with Maneuver 25 25

SIGNIFICANT EVENTS: (None)
 




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