Daily 3744

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 3744

PERIOD COVERED: DOYs 329-333

OBSERVATIONS SCHEDULED

ACS/HRC 9792

Uncovering the CV population in M15: a deep, time-resolved, far-UV
survey of the

We propose to carry out a deep, far-ultraviolet {FUV}, time-resolved
for faint cataclysmic variables {CVs} and other dynamically-formed
objects in the globular cluster {GC} M15. We will use the ACS/SBC to
carry out 6 epochs of FUV imaging of this cluster in a single filter,
and will use two additional visits to obtain images in other FUV and
NUV filters. Since crowding is not a problem in the FUV, this will
yield time-resolved FUV photometry of all blue objects in the cluster
core. Our CV census will be both deep enough to be essentially
complete and ``broad'' enough to involve all of the following CV
characteristics: {1} UV brightness; {2} blue FUV spectral shape; {3}
strong CIV and HeII emission; {4} short time-scale {$sim$ minutes}
variability {flickering, WD spin}; {6} intermediate time-scale {$sim$
hours} variability {orbital variations}; {7} long time-scale {$sim$
weeks} variability {dwarf nova eruptions}. We will thus find the CV
population in M15, if it exists. In addition, our survey will detect
numerous blue stragglers and hot white dwarfs, as well as any other
blue objects near the core. Finally, our photometry will yield
high-quality FUV light curves of the two low-mass x-ray binaries in
M15.

ACS/WFC/WFPC2 9392

The Ancient Stars of M32

The question of whether the dwarf elliptical galaxy M32 contains a
population of truly ancient stars has remained unsettled for decades.
We recently used HST/WFPC2 to identify for the first time a population
of RR Lyr stars in this galaxy. Since these stars are known only to be
present in stellar populations older than 8-10 Gyr, we contend that
M32 does possess an old stellar component and certainly cannot be
comprised of only intermediate-age {~ 5 Gyr} stars as has been
frequently suggested in the literature. Our earlier observations were
insufficient to determine even the most basic photometric properties
of these stars. Nor could we use the data to identify independent
evidence of the old population that could help constrain just what
fraction of the galaxy's stars are ancient. We propose new HST/ACS
observations to {a} get periods and luminosities of the previously
observed RR Lyr stars, {b} search for additional RR Lyr stars in a
significantly larger volume of M32, and {c} obtain ultra-deep 2-color
photometry to study the ancient main-sequence turnoff region of that
galaxy directly, {d} look for radial population gradients in M32, both
among the RR Lyr/Horizontal Branch and main- sequence populations, {e}
compare the M31/M32 old populations in terms of metallicity spread,
and {f} use the RR Lyr stars to precisely determine the relative and
possibly the absolute distances of M32 and M31's halo.

NIC1/NIC2/NIC3 8794

NICMOS Post-SAA calibration - CR Persistence Part 5

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 USEAFTER
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 DARKSs. 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.

NIC3 10383

NICMOS Cycle 13 Grism Re-Calibration

This cycle 13 proposal will quantify the repeatability of grism
observations with a star that has already been observed in cycle 12.
CYCLE 12 RESULTS AND CYCLE 13 FOLLOW UP: All cycle 12 data was
successfully acquired. One problem is that the repeatability as
measured by the comparison of the cycle 11 to the cycle 12
observations of P330E is only +/- 2%, as shown in Fig. 1 {attached to
the Phase 1 distribution}. We have extracted and corrected the cycle
12 data for intra-pixel and pixel gap sensitivity variations at each
of the 15 dither positions. The rms of these sets of 15 dithered
spectra, ie the scatter about the mean of an individual spectrum, is
typically 1- 2-percent, making the error in the mean 0.5-percent for
all the pixels in the central 90- percent of the wavelength
coverage.The goal and expectation is for repeatability to better than
1%. The somewhat poorer results may be attributed to flat field
differences between the Thompson dither strategy and that used in
9998; or perhaps, there is some synoptic change in the system
throughput. In order to distinguish these possibilities and hopefully
recover a repeatability of 1%, an observation of one of the cycle 12
standards must be repeated early in cycle 13, using the same dither
strategy as 9998. To minimize the measured amount of any synoptic
sensitivity change, the observations should be made before the end of
2004. The bulk of the cycle 12 observations were made in the 2004
January through 2004 July time frame, so that the ideal repeatability
target was observed early in 2004 and can be observed again this fall.
The bright Sloan standard BD+17d4708 is the ideal selection, having
been previously observed on 04Jan10. P330E would be a good choice,
except that it was previously observed too recently on 04Jun19 to
measure any sensitivity change back to 04 Jan; and the scheduling
would be rushed to get it before going into solar avoidance in
October.

ACS/HRC 10377

ACS Earth Flats

High signal sky flats will be obtained by observing the bright Earth
with the HRC and WFC. These observations will be used to verify the
accuracy of the flats currently used by the pipeline and will provide
a comparison with flats derived via other techniques: L- flats from
stellar observations, sky flats from stacked GO observations, and
internal flats using the calibration lamps. Weekly coronagraphic
monitoring is required to assess the changing position of the spots.

ACS/HRC/WFC 10367

ACS CCDs daily monitor- cycle 13 - part 1

This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise
in ACS CCD detectors. The files, biases and dark will be used to
create reference files for science calibration. This programme will be
for the entire lifetime of ACS.

ACS/WFC/NIC3 10339

PANS

Type Ia supernovae {SNe Ia} provide the only direct evidence for an
accelerating universe, an extraordinary result that needs the most
rigorous test. The case for cosmic acceleration rests on the
observation that SNe Ia at z = 0.5 are about 0.25 mag fainter than
they would be in a universe without acceleration. A powerful and
straightforward way to assess the reliability of the SN Ia measurement
and the conceptual framework of its interpretation is to look for
cosmic deceleration at z 1. This would be a clear signature of a
mixed dark-matter and dark-energy universe. Systematic errors in the
SNe Ia result attributed to grey dust or cosmic evolution of the SN Ia
peak luminosity would not show this change of sign. We have obtained a
toehold on this putative ``epoch of deceleration'' with SN 1997ff at z
= 1.7, and 3 more at z 1 from our Cycle 11 program, all found and
followed by HST. However, this is too important a test to rest on just
a few objects, anyone of which could be subject to a lensed
line-of-sight or misidentification. Here we propose to extend our
measurement with observations of twelve SNe Ia in the range 1.0 z
1.5 or 6 such SNe Ia and 1 ultradistant SN Ia at z = 2, that will be
discovered as a byproduct from proposed Treasury and DD programs.
These objects will provide a much firmer foundation for a conclusion
that touches on important questions of fundamental physics.

NIC3 10337

The COSMOS 2-Degree ACS Survey NICMOS Parallels

The COSMOS 2-Degree ACS Survey NICMOS Parallels. This program is a
companion to program 10092.

ACS/WFC 10325

Low Redshift Cluster Gravitational Lensing Survey

This proposal has two main scientific goals: to determine the dark
matter distribution of massive galaxy clusters, and to observe the
high redshift universe using these clusters as powerful cosmic
telescopes. Deep, g, r, i, z imaging of a sample of low-z {0.2-0.4}
clusters will yield a large sample of lensed background galaxies with
reliable photometric redshifts. By combining strong and weak lensing
constraints with the photometric redshift information it will be
possible to precisely measure the cluster dark matter distribution
with an unprecedented combination of high spatial resolution and area
coverage, avoiding many of the uncertainties which plague ground-based
studies and yielding definitive answers about the structure of massive
dark matter haloes. In addition, the cosmological parameters can be
constrained in a largely model independent way using the multiply
lensed objects due to the dependence of the Einsteining radius on the
distance to the source. We can also expect to detect several highly
magnified dropout galaxies behind the clusters in the redshift ranges
4-5 5-6 and 7-8, corresponding to a drop in the flux in the g, r, and
i bands relative to longer wavelength. We will obtain the best
information to date on the giant arcs already known in these clusters,
making possible detailed, pixel-by-pixel studies of their star
formation rate, dust distribution and structural components, including
spiral arms, out to a redshift of around z~2.5 in several passbands.

ACS/HRC 10272

A Snapshot Survey of the Sites of Recent, Nearby Supernovae

During the past few years, robotic {or nearly robotic} searches for
supernovae {SNe}, most notably our Lick Observatory Supernova Search
{LOSS}, have found hundreds of SNe, many of them in quite nearby
galaxies {cz 4000 km/s}. Most of the objects were discovered before
maximum brightness, and have follow-up photometry and spectroscopy;
they include some of the best-studied SNe to date. We propose to
conduct a snapshot imaging survey of the sites of some of these nearby
objects, to obtain late-time photometry that {through the shape of the
light and color curves} will help reveal the origin of their lingering
energy. The images will also provide high- resolution information on
the local environment of SNe that are far superior to what we can
procure from the ground. For example, we will obtain color-color and
color-magnitude diagrams of stars in these SN sites, to determine
their progenitor masses and constraints on the reddening. Recovery of
the SNe in the new HST images will also allow us to actually pinpoint
their progenitor stars in cases where pre-explosion images exist in
the HST archive. Use of ACS rather than WFPC2 will make our snapshot
survey even more valuable than our Cycle 9 survey. This Proposal is
complementary to our Cycle 13 archival proposal, in which we outline a
plan for using existing HST images to glean information about SN
environments.

ACS/HRC/WFC 10267

The Shadow Echoes of the Unique R Coronae Borealis Star, UW Cen

Understanding the R Coronae Borealis {RCB} stars is a key test for any
theory aiming to explain hydrogen deficiency in post-AGB stars. The
RCB stars are rare hydrogen- deficient carbon-rich supergiants that
undergo very spectacular declines in brightness of up to 8 magnitudes
at irregular intervals as dust forms near the star along the line of
sight. UW Cen is unique among the cool RCB stars in having a visible
circumstellar shell. The morphology of the nebula appears to change as
different parts are illuminated by light from the central star
modulated by shifting, thick dust clouds near its surface. The central
star acts like a "lighthouse, " shining through gaps between the
near-star dust clouds, and lighting up different portions of the outer
nebula. We propose a scientific program in which a small number of
observations using ACS/HRC will exploit UW Cen's unique circumstellar
shell to address two critical elements in understanding RCB stars:
determining an accurate distance to the star, and studying the
otherwise unobservable dust clouds forming near the star's surface. We
will model the images using Monte Carlo techniques to calculate the
radiative transfer through arbitrary distributions of dust viewed from
any angle.

ACS/HRC 10238

The nature of quasar host galaxies: combining ACS imaging and VLT
Integral Field Spectroscopy.

We propose to perform ACS/F606W imaging of a complete sample of 29
quasar host galaxies {0.08z0.34}. The spatial resolving power of the
ACS HRC, in combination with the acquisition of empirical PSFs and
advanced deconvolution techniques, will allow to study in detail
structures on scales of a few tens of parsecs, and to access the inner
regions of the host galaxies, even in the presence of bright nuclei.
We demonstrate that combining deep spectroscopy with high resolution
imaging in stable PSF conditions definitely constitutes the solution
to characterize the complex physical properties of quasar host
galaxies, from their outer regions to the inner 0.1 kpc, where most of
the information on the interplay between quasars and their hosts is
hidden. We propose to combine new ACS images with existing Integral
Field VLT Spectra. We will map the stellar and gas velocity fields in
2D, constrain the mass models, derive the radial host M/L ratios, map
and characterize the stellar populations and the ionization state of
the gas.

NIC/NIC3 10226

The NICMOS Grism Parallel Survey

We propose to continue managing the NICMOS pure parallel program.
Based on our experience, we are well prepared to make optimal use of
the parallel opportunities. The improved sensitivity and efficiency of
our observations will substantially increase the number of
line-emitting galaxies detected. As our previous work has
demonstrated, the most frequently detected line is Halpha at
0.7z1.9, which provides an excellent measure of current star
formation rate. We will also detect star-forming and active galaxies
in other redshift ranges using other emission lines. The grism
observations will produce by far the best available Halpha luminosity
functions over the crucial--but poorly observed--redshift range where
galaxies appear to have assembled most of their stellar mass. This key
process of galaxy evolution needs to be studied with IR data; we found
that observations at shorter wavelengths appear to have missed a large
fraction of the star-formation in galaxies, due to dust reddening. We
will also obtain deep F110W and F160W images, to examine the space
densities and morphologies of faint red galaxies. In addition to
carrying out the public parallels, we will make the fully reduced and
calibrated images and spectra available on-line, with some
ground-based data for the deepest parallel fields included.

ACS/WFC 10207

Star Formation in Damped Lya Galaxies: Testing the Connection with the
Lyman Break Population

The principal challenge of damped Lya {DLA} research is to identify
and study the stellar components of these galaxies. Although two
decades of absorption-line research has yielded the HI gas content,
metallicity, velocity fields, molecular and dust content of these
galaxies only a handful have been studied in emission. Therefore, it
has been very difficult to compare the DLA galaxies with the
successful surveys of high z galaxies discovered in emission {e.g.
Lyman break galaxies; LBG}. This is particulary important given that
DLA systems are the probable precursors to galaxies like the Milky
Way. Because the DLA systems are identified toward bright background
quasars, deep observations at high spatial resolution with astable PSF
are essential and only HST provides the observing capability.
Recently, two major advances have greatly enhanced the prospects for
measuring emission from DLA host galaxies: {1} we have developed a new
spectroscopic technique for inferring the star formation rates {SFR}
of the DLA which enables one to pre-select the brightest candidates;
{2} the high spatial resolution and sensitivity of the ACS represents
a major improvement over previous capabilities. We will obtain deep
V-band images with the ACS of 5 high z DLA with the highest inferred
apparent optical magnitudes. The complete survey will offer a robust
statistical analysis of: {a} the extent and morphology of the DLA star
forming regions; {b} the likelihood that the DLA and LBG correspond to
the same population of protogalaxies; {c} a test of the protogalactic
clump models favored by CDM cosmology. We emphasize this program will
offer a major advance over all previous studies. Finally, we will
complement these HST observations with an extensive observing campaign
{IFU spectroscopy and deep IR imaging} on the Keck, VLT, and Magellan
telescopes to provide the most extensive dataset yet on the physical
properties of high z DLA.

ACS/HRC/NIC1/WFC 10190

The Star Formation History and Metallicity Evolution of M33: A
Comprehensive Study of Disk Evolution

We will obtain deep, panchromatic imaging photometry of stellar
populations in four fields ranging from 0.5 to 4 scale lengths across
the disk of the Local Group spiral M33. The observations are designed
to detect the oldest main-sequence turnoffs in three outer disk
fields, and to reach the crowding limit in the innermost field. We
will combine the photometry data with information we already have
in-hand on abundances from stars and H II regions in M33 to derive the
star formation history and metallicity evolution of the M33 disk. The
information from our four fields will allow us to obtain {1} the ages
of the oldest disk stars and the radial variation of their ages; {2}
the radial variation of the star formation history and its nature
{e.g., constant, declining, or bursting}; and {3} the metallicity
distribution in each field and the time evolution of the metallicity
gradient. Our team, an experienced mix of photometrists,
spectroscopists, and galaxy evolution theorists, will use the results
from this program to construct a comprehensive chemo- dynamical model
for the M33 disk. This detailed study of M33 will be a key in
developing an understanding of the formation and evolution of disks
that can be applied to studies of disks at both low and high redshift,
and will also yield a wealth of information on stellar populations,
chemical evolution, and star clusters that will be of great value to
future investigators.

ACS/WFC/NIC2 10189

PANS-Probing Acceleration Now with Supernovae

Type Ia supernovae {SNe Ia} provide the most direct evidence for an
accelerating Universe, a result widely attributed to dark energy.
Using HST in Cycle 11 we extended the Hubble diagram with 6 of the 7
highest-redshift SNe Ia known, all at z1.25, providing conclusive
evidence of an earlier epoch of cosmic deceleration. The full sample
of 16 new SNe Ia match the cosmic concordance model and are
inconsistent with a simple model of evolution or dust as alternatives
to dark energy. Understanding dark energy may be the biggest current
challenge to cosmology and particle physics. To understand the nature
of dark energy, we seek to measure its two most fundamental
properties: its evolution {i.e., dw/dz}, and its recent equation of
state {i.e., w{z=0}}. SNe Ia at z1, beyond the reach of the ground
but squarely within the reach of HST with ACS, are crucial to break
the degeneracy in the measurements of these two basic aspects of dark
energy. The SNe Ia we have discovered and measured with HST in Cycle
11, now double the precision of our knowledge of both properties. Here
we propose to quadruple the sample of SNe Ia at z1 in the next two
cycles, complementing on-going surveys from the ground at z1, and
again doubling the precision of dark energy constraints. Should the
current best fit model prove to be the correct one, the precision
expected from the current proposal will suffice to rule out a
cosmological constant at the 99% confidence level. Whatever the
result, these objects will provide the basis with which to extend our
empirical knowledge of this newly discovered and dominant component of
the Universe, and will remain one of the most significant legacies of
HST. In addition, our survey and follow-up data will greatly enhance
the value of the archival data within the target Treasury fields for
galaxy studies.

ACS/HRC 10182

Towards a Comprehensive Understanding of Type Ia Supernovae: The
Necessity of UV Observations

Type Ia supernovae {SNe Ia} are very important to many diverse areas
of astrophysics, from the chemical evolution of galaxies to
observational cosmology which led to the discovery of dark energy and
the accelerating Universe. However, the utility of SNe Ia as
cosmological probes depends on the degree of our understanding of SN
Ia physics, and various systematic effects such as cosmic chemical
evolution. At present, the progenitors of SNe Ia and the exact
explosion mechanisms are still poorly understood, as are evolutionary
effects on SN Ia peak luminosities. Since early-time UV spectra and
light curves of nearby SNe Ia can directly address these questions, we
propose an approach consisting of two observational components: {1}
Detailed studies of two very bright, young, nearby SNe Ia with HST UV
spectroscopy at 13 epochs within the first 1.5 months after discovery;
and {2} studies of correlations with luminosity for five somewhat more
distant Hubble-flow SNe Ia, for which relative luminosities can be
determined with precision, using 8 epochs of HST UV spectroscopy
and/or broad-band imaging. The HST data, along with extensive
ground-based optical to near-IR observations, will be analyzed with
state-of-the-art models to probe SN Ia explosion physics and constrain
the nature of the progenitors. The results will form the basis for the
next phase of precision cosmology measurements using SNe Ia, allowing
us to more fully capitalize on the substantial past {and future}
investments of time made with HST in observations of high-redshift SNe
Ia.

NIC2 10177

Solar Systems In Formation: A NICMOS Coronagraphic Survey of
Protoplanetary and Debris Disks

Until recently, despite decades of concerted effort applied to
understanding the formation processes that gave birth to our solar
system, the detailed morphology of circumstellar material that must
eventually form planets has been virtually impossible to discern. The
advent of high contrast, coronagraphic imaging as implemented with the
instruments aboard HST has dramatically enhanced our understanding of
natal planetary system formation. Even so, only a handful of evolved
disks {~ 1 Myr and older} have been imaged and spatially resolved in
light scattered from their constituent grains. To elucidate the
physical processes and properties in potentially planet-forming
circumstellar disks, and to understand the nature and evolution of
their grains, a larger spatially resolved and photometrically reliable
sample of such systems must be observed. Thus, we propose a highly
sensitive circumstellar disk imaging survey of a well-defined and
carefully selected sample of YSOs {1-10 Myr T Tau and HAeBe stars} and
{ app 10 Myr} main sequence stars, to probe the posited epoch of
planetary system formation, and to provide this critically needed
imagery. Our resolved images will shed light on the spatial
distributions of the dust in these thermally emissive disks. In
combination with their long wavelength SEDs the physical properties of
the grains will be discerned, or constrained by our photometrically
accurate surface brightness sensitivity limits for faint disks which
elude detection. Our sample builds on the success of the exploratory
GTO 7233 program, using two-roll per orbit PSF-subtracted NICMOS
coronagraphy to provide the highest detection sensitivity to the
smallest disks around bright stars which can be imaged with HST. Our
sample will discriminate between proposed evolutionary scenarios while
providing a legacy of cataloged morphologies for interpreting mid- and
far-IR SEDs that the recently launched Spitzer Space Telescope will
deliver.

NIC2 10176

Coronagraphic Survey for Giant Planets Around Nearby Young Stars

A systematic imaging search for extra-solar Jovian planets is now
possible thanks to recent progress in identifying "young stars near
Earth". For most of the proposed young {~ 30 Myrs} and nearby {~ 60
pc} targets, we can detect a few Jupiter-mass planets as close as a
few tens of AUs from the primary stars. This represents the first time
that potential analogs of our solar system - that is planetary systems
with giant planets having semi-major axes comparable to those of the
four giant planets of the Solar System - come within the grasp of
existing instrumentation. Our proposed targets have not been observed
for planets with the Hubble Space Telescope previously. Considering
the very successful earlier NICMOS observations of low mass brown
dwarfs and planetary disks among members of the TW Hydrae Association,
a fair fraction of our targets should also turn out to posses low mass
brown dwarfs, giant planets, or dusty planetary disks because our
targets are similar to {or even better than} the TW Hydrae stars in
terms of youth and proximity to Earth. Should HST time be awarded and
planetary mass candidates be found, proper motion follow-up of
candidate planets will be done with ground-based AOs.

ACS/WFC 10174

Dark-matter halos and evolution of high-z early-type galaxies

Gravitational lensing and stellar dynamics provide two complementary
methods to determine the mass distribution and evolution of luminous
and dark-matter in early-type {E/S0} galaxies. The combined study of
stellar dynamics and gravitational lensing allows one to break
degeneracies inherent to each method separately, providing a clean
probe of the internal structure of massive galaxies. Since most lens
galaxies are at redshifts z=0.1-1.0, they also provide the required
look-back time to study their structural and stellar-population
evolution. We recently analyzed 5 E/S0 lens galaxies between z=0.5 and
1.0, combining exquisite Hubble Space Telescope imaging data with
kinematic data from ground-based Keck spectroscopy, placing the first
precise constraints on the dark- matter mass fraction and its inner
slope beyond the local Universe. To expand the sample to ~30 systems
-- required to study potential trends and evolution in the E/S0 mass
profiles -- we propose to target the 49 E/S0 lens-galaxy candidates
discovered by Bolton et al. {2004} from the Sloan Digital Sky Survey
{SDSS}. With the average lens rate being 40% and some systems having a
lensing probability close to unity, we expect to discover ~20 strong
gravitational lenses from the sample. This will triple the current
sample of 9 E/S0 systems, with data in hand. With the sample of 30
systems, we will be able to determine the average slope of the
dark-matter and total mass profile of E/S0 galaxies to 10% and 4%
accuracy, respectively. If present, we can simultaneously detect 10%
evolution in the total mass slope with 95% confidence. This will
provide unprecedented constraints on E/S0 galaxies beyond the local
Universe and allow a stringent test of their formation scenarios and
the standard cosmological model.

NIC2 10173

Infrared Snapshots of 3CR Radio Galaxies

Radio galaxies are an important class of extragalactic objects: they
are one of the most energetic astrophysical phenomena and they provide
an exceptional probe of the evolving Universe, lying typically in high
density regions but well-represented across a wide redshift range. In
earlier Cycles we carried out extensive HST observations of the 3CR
sources in order to acquire a complete and quantitative inventory of
the structure, contents and evolution of these important objects.
Amongst the results, we discovered new optical jets, dust lanes,
face-on disks with optical jets, and revealed point-like nuclei whose
properties support FR-I/BL Lac unified schemes. Here, we propose to
obtain NICMOS infrared images of 3CR sources with z0.3 as a major
enhancement to an already superb dataset. We aim to deshroud dusty
galaxies, study the underlying host galaxy free from the distorting
effects of dust, locate hidden regions of star formation and establish
the physical characteristics of the dust itself. We will measure
frequency and spectral energy distributions of point-like nuclei,
expected to be stronger and more prevalent in the IR, seek spectral
turnovers in known synchrotron jets and find new jets. We will
strongly test unified AGN schemes and merge these data with existing
X-ray to radio observations. The resulting database will be an
incredibly valuable resource to the astronomical community for years
to come.

WFPC2 10170

Atmospheric Variability on Uranus and Neptune

We propose Snapshot observations of Uranus and Neptune to monitor
changes in their atmospheres on time scales of weeks, months, and
years. Uranus is rapidly approaching equinox in 2007, with another 4
degrees of latitude becoming visible every year. Recent HST
observations during this epoch {including 6818: Hammel, Lockwood, and
Rages; 7885: Hammel, Karkoschka, and Marley; 8680: Hammel, Rages,
Lockwood, and Marley; and 8634: Rages, Hammel, Lockwood, Marley, and
McKay} have revealed strongly wavelength-dependent latitudinal
structure and the presence of numerous visible-wavelength cloud
features in the northern hemisphere. Long-term ground-based
observations {Lockwood and Thompson 1999} show seasonal brightness
changes whose origins are not well understood. Recent near-IR images
of Neptune obtained using adaptive optics on the Keck Telescope
together with images from our Cycle 9 Snapshot program {8634} show a
general increase in activity at south temperate latitudes as well as
the possible development of another Great Dark Spot. Further Snapshot
observations of these two dynamic planets will elucidate the nature of
long-term changes in their zonal atmospheric bands and clarify the
processes of formation, evolution, and dissipation of discrete albedo
features.

NIC2 10169

Star Formation in Luminous Infrared Galaxies: giant HII Regions and
Super Star Clusters

Luminous Infrared Galaxies {LIRGs, LIR = 10^11-10^12Lsol} and
Ultraluminous Infrared Galaxies {LIR10^12Lsol} account for
approximately 75% of all the galaxies detected in the mid-infrared in
the redshift range z=0-1.5. In the local universe it is found that
LIRGs are predominantly powered by intense star formation {SF}.
However, the physical conditions and processes governing such dramatic
activity over scales of tens to a few hundred parsecs are poorly
known. In the last decade HST has been playing a significant role,
mainly with the discovery of super star clusters {SSCs}, and more
recently, giant HII regions. Based on observations of a few LIRGs, we
found that these giant HII regions and associated SSCs appear to be
more common in LIRGs than in normal galaxies, and may dominate the
star formation activity in LIRGs. A larger sample is required to
address fundamental questions. We propose an HST/NICMOS targeted
campaign of a volume limited sample {v5200km/s} of 24 LIRGs. This
proposal will probe the role of giant HII regions in the overall
energetics of the current star formation, their relation to SSCs, and
the dependence of star formation properties on other parameters of
LIRGs. Such detailed knowledge of the SF properties of LIRGs in the
local universe is essential for understanding galaxies at high
redshift.

ACS/WFC 10154

Morphology of z ~ 7-10 galaxies viewed through gravitational
telescopes

The aim of these observations is to obtain deep z/ACS and H/NICMOS
images in the core of two lensing clusters, A1835 and AC114, where a
few z ~ 7-10 galaxy candidates have been selected from our ultra-deep
JHK imaging program with Isaac/VLT. Spectroscopic observations have
allowed to confirm 2 of these candidates thanks to the detection of
faint emission lines identified as Lyman alpha at z=7.2 and 10. Our
HST project is focused on two main goals: {1} the morphological
confirmation of galaxy candidates lying near critical lines, and {2}
the determination of the physical scales involved in star-forming
regions at z ~ 7-10. These goals should have important implications on
our present knowledge of the galaxy formation process in the early
Universe.

ACS/WFC 10135

Unveiling the Progenitors and Physics of Cosmic Explosions

GRBs and XRFs are clearly highly asymmetric explosions and require a
long-lived power source {central engine}. In contrast, nearby
core-collapse events are essentially spherical explosions. However,
the failure of spherical neutrino driven collapses has led to the idea
that asymmetric energy release is essential for the explosion. The
recent finding of a Type Ic SN in GRB 030329, the association of the
low energy event GRB 980425 with SN 1998bw, the theoretical
development discussed above and the rise of collapsar models make it
timely to consider whether all these explosions contain engines. Given
the uncertainties in theoretical modeling it is clear that
observations are needed to guide models. A priori there is little
reason to expect connection between the ultra- relativistic jet that
powers the GRB and the explosive nucleosynthesis of the ~0.5 solar
masses of Nickel-56 that powers the accompanying supernova. We propose
a comprehensive program of ACS photometric searches {and measurements}
for SNe associated with GRBs and XRFs. In concert, we will undertake
ground-based spectroscopy to determine velocity widths, and measure
engine parameters from pan- chromatic afterglow observations. Our goal
is to produce a comprehensive database of engine and SN physical
parameters against which theoretical modeling will be guided.

ACS/HRC 10133

HST / Chandra Monitoring of a Dramatic Flare in the M87 Jet

As the nearest galaxy with an optical jet, M87 affords an unparalleled
opportunity to study extragalactic jet phenomena at the highest
resolution. During 2002, HST and Chandra monitoring of the M87 jet
detected a dramatic flare in knot HST-1 located ~1" from the nucleus.
As of late 2003 its brightness has increased twenty-fold in the
optical band, and continues to increase sharply; the X-rays show a
similarly dramatic outburst. In both bands HST-1 now greatly exceeds
the nucleus in brightness. To our knowledge this is the first
incidence of an optical or X-ray outburst from a jet region which is
spatially distinct from the core source; this presents an
unprecedented opportunity to study the processes responsible for
non-thermal variability and the X-ray emission. We propose seven
epochs of HST/STIS monitoring during Cycle 13, as well as seven epochs
of Chandra/ACIS observation {5ksec each}. We also include a brief
HRC/ACS observations that will be used to gather spectral information
and map the magnetic field structure. This monitoring is continued
into Cycles 14 and 15. The results of this investigation are of key
importance not only for understanding the nature of the X-ray emission
of the M87 jet, but also for understanding flares in blazar jets,
which are highly variable, but where we have never before been able to
resolve the flaring region in the optical or X-rays. These
observations will allow us to test synchrotron emission models for the
X-ray outburst, constrain particle acceleration and loss timescales,
and study the jet dynamics associated with this flaring component.
Revisions 6 Oct 2004: We are replacing STIS visits 1-7 with ACS/HRC
observations in new visits 31- 37.

FGS 10106

An Astrometric Calibration of the Cepheid Period-Luminosity Relation

We propose to measure the parallaxes of 10 Galactic Cepheid variables.
When these parallaxes {with 1-sigma precisions of 10% or better} are
added to our recent HST FGS parallax determination of delta Cep
{Benedict et al 2002}, we anticipate determining the Period-Luminosity
relation zero point with a 0.03 mag precision. In addition to
permitting the test of assumptions that enter into other Cepheid
distance determination techniques, this calibration will reintroduce
Galactic Cepheids as a fundamental step in the extragalactic distance
scale ladder. A Period-Luminosity relation derived from solar
metallicity Cepheids can be applied directly to extragalactic solar
metallicity Cepheids, removing the need to bridge with the Large
Magellanic Cloud and its associated metallicity complications.

ACS/WFC/WFPC2 10092

The COSMOS 2-Degree ACS Survey

We will undertake a 2 square degree imaging survey {Cosmic Evolution
Survey -- COSMOS} with ACS in the I {F814W} band of the VIMOS
equatorial field. This wide field survey is essential to understand
the interplay between Large Scale Structure {LSS} evolution and the
formation of galaxies, dark matter and AGNs and is the one region of
parameter space completely unexplored at present by HST. The
equatorial field was selected for its accessibility to all
ground-based telescopes and low IR background and because it will
eventually contain ~100, 000 galaxy spectra from the VLT-VIMOS
instrument. The imaging will detect over 2 million objects with I 27
mag {AB, 10 sigma}, over 35, 000 Lyman Break Galaxies {LBGs} and
extremely red galaxies out to z ~ 5. COSMOS is the only HST project
specifically designed to probe the formation and evolution of
structures ranging from galaxies up to Coma-size clusters in the epoch
of peak galaxy, AGN, star and cluster formation {z ~0.5 to 3}. The
size of the largest structures necessitate the 2 degree field. Our
team is committed to the assembly of several public ancillary datasets
including the optical spectra, deep XMM and VLA imaging, ground-based
optical/IR imaging, UV imaging from GALEX and IR data from SIRTF.
Combining the full-spectrum multiwavelength imaging and spectroscopic
coverage with ACS sub-kpc resolution, COSMOS will be Hubble's ultimate
legacy for understanding the evolution of both the visible and dark
universe.

FLIGHT OPERATIONS SUMMARY:

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

HSTAR 9612-U2,3FM Update Failure. U2,3FM scheduled for 322/06:32:39
resulted in error box results failure indicating "2 FAILED". One 486
status buffer 901 message was observed. Subsequent GSACQ(2,1,2)
passed. Under investigation.

COMPLETED OPS REQs: None

OPS NOTES EXECUTED: None


SCHEDULED SUCCESSFUL FAILURE TIMES
FGS Gsacq 40 40
FGS Reacq 22 22
FHST
Update 68 67 322/06:32:39
(HSTAR 9612)
LOSS of LOCK


SIGNIFICANT EVENTS: None