Daily 3851

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT******* #3851

PERIOD COVERED: DOY 122

OBSERVATIONS SCHEDULED

ACS/HRC 10198

Probing the Dynamics of the Galactic Bar through the Kinematics of
Microlensed Stars

The observed optical depths to microlensing of stars in the Galactic
bulge are difficult to reconcile with our present understanding of
Galactic dynamics. The main source of uncertainty in those comparisons
is now shifting from microlensing measurements to the dynamical models
of the Galactic bar. We propose to constrain the Galactic bar models
with proper motion observations of Bulge stars that underwent
microlensing by determining both the kinematic identity of the
microlensed sources and the importance of streaming motions. The
lensed stars are typically farther than randomly selected stars.
Therefore, our proper motion determinations for 36 targeted MACHO
events will provide valuable constraints on the dynamics of bulge
stars as a function of distance. The first epoch data for our proposed
events is already available in the HST archive so the project can be
completed within a single HST cycle. The exceptional spatial
resolution of HST is essential for completion of the project.
Constraints on the total mass in the bulge will ultimately lead to the
determination of the amount of dark matter in inner Galaxy.

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 10389

ACS CCDs daily monitor - Cycle 13 - Part 2

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 10361

Earth Flats

This proposal monitors flatfield stability. This proposal obtains
sequences of Earth streak flats to construct high quality flat fields
for the WFPC2 filter set. These flat fields will allow mapping of the
OTA illumination pattern and will be used in conjunction with previous
internal and external flats to generate new pipeline superflats. These
Earth flats will complement the Earth flat data obtained during cycles
4-12.

ACS/WFC/HRS 10371

ACS CCD Flash Calibration

This activity provides a set of CCD FLASH exposure reference images
for each current level/shutter-side/detector combination, for the pair
of FLASH LEDs on the instrument side currently in use. It also tests
the short-term repeatability at the shortest FLASH exposure times that
are expected to be used {1.0 sec}.

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/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.

FGS 10197

The Astrophysical Parameters of Very Metal-Poor Halo Binaries

Little is currently known concerning the mass-luminosity relation
{MLR} of Population II stars. In Cycle 10, we began an initial study
with FGS1 to resolve a sample of known spectroscopic binaries
preselected as high-velocity and/or low metallicity objects. This has
resulted in significant new information about the astrophysical
parameters of metal-poor stars, but was limited mainly to intermediate
metallicities, not to true Population II stars. A new sample of
metal-poor spectroscopic binaries identified by Latham and his
collaborators {e.g. Latham et al 2002} contains three new very
metal-poor objects resolvable with FGS. We propose to observe these
binaries and obtain additional observations of two very important
resolved targets from our initial sample. As with that program, we
will couple the already-known spectroscopic orbits with astrometric
information which only FGS can deliver at present. To ensure that the
most will be gained from these data, we also request observations of
three metal-poor single stars to be used as calibration objects. In
combination with results from our previous program, these observations
can be expected to resolve the question of the location of the
Population II main sequence and give valuable insight into the
accuracy of isochrone fitting for determination of globular clusters
ages. Due to the combination of target magnitudes and expected
separations, no object in this sample can be resolved without the
unique capabilities of FGS.

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration - CR Persistence Part 4

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.

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.

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.

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.

WFPC2 10132

UV Confirmation of New Quasar Sightlines Suitable for the Study of
Intergalactic Helium

The reionization of intergalactic helium is thought to have occurred
between redshifts of about 3 and 4. The study of HeII Lyman-alpha
absorption towards a half- dozen quasars at 2.7z3.5 demonstrates the
great potential of such probes of the IGM, but the current
critically-small sample limits confidence in resulting cosmological
inferences. The requisite unobscured quasar sightlines to
high-redshift are extremely rare, especially due to severe absorption
in random intervening Lyman-limit systems, but SDSS provides hundreds
of bright, new quasars at such redshifts potentially suitable for HeII
studies. Our cycle 13 SNAP program proposes to verify the UV
detectability of 40 new, bright, z2.9 SDSS quasars, but with special
emphasis on extending helium studies to the highest redshift
sightlines. Our proposed approach has already proven successful, and
additional sightlines will enable follow-up spectal observations to
measure the spectrum and evolution of the ionizing background
radiation, the density of intergalactic baryons, and the epoch of
reionization of the IGM.

WFPC2 10356

WFPC2 Cycle 13 Decontaminations and Associated Observations

This proposal is for the monthly WFPC2 decons. Also included are
instrument monitors tied to decons: photometric stability check, focus
monitor, pre- and post- decon internals {bias, intflats, kspots, &
darks}, UV throughput check, VISFLAT sweep, and internal UV flat
check.

WFPC2 10362

WFPC2 Cycle 13 UV Earth Flats

Monitor flat field stability. This proposal obtains sequences of earth
streak flats to improve the quality of pipeline flat fields for the
WFPC2 UV filter set. These Earth flats will complement the UV earth
flat data obtained during cycles 8-12.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

9793 -* GSacq(1,2,2) Results in Fine Lock Backup GSacq(2,0,2) @
122/15:37:54z GSACQ(1,2,2) scheduled for 122/15:37:54 - 15:45:05
resulted in Fine Lock on FGS 2 only due to scan step limit exceeded on
FGS 1. The previous Updated scheduled at 15:06, 15:09 both passed with
small attitude error. The following map scheduled for 16:03:11 showed
attitude errors of: -3.161, -6.965 and -5.453 arcsec.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES:
1333-0 - Change JERRCNT Limit @ 122/15:21z


************************ SCHEDULED**** SUCCESSFUL*** FAILURE TIMES
FGS Gsacq************** 13******************** 13
FGS
Reacq*************** 05******************** 05
FHST Update************ 21********************* 21
LOSS of LOCK


SIGNIFICANT EVENTS: (None)