Daily # 4275

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4275

PERIOD COVERED: UT January 09, 2007 (DOY 009)

OBSERVATIONS SCHEDULED

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.

NIC2, ACS/WFC 10802

SHOES-Supernovae, HO, for the Equation of State of Dark energy

The present uncertainty in the value of the Hubble constant {resulting
in an uncertainty in Omega_M} and the paucity of Type Ia supernovae at
redshifts exceeding 1 are now the leading obstacles to determining the
nature of dark energy. We propose a single, integrated set of
observations for Cycle 15 that will provide a 40% improvement in
constraints on dark energy. This program will observe known Cepheids
in six reliable hosts of Type Ia supernovae with NICMOS, reducing the
uncertainty in H_0 by a factor of two because of the smaller
dispersion along the instability strip, the diminished extinction, and
the weaker metallicity dependence in the infrared. In parallel with
ACS, at the same time the NICMOS observations are underway, we will
discover and follow a sample of Type Ia supernovae at z 1. Together,
these measurements, along with prior constraints from WMAP, will
provide a great improvement in HST's ability to distinguish between a
static, cosmological constant and dynamical dark energy. The Hubble
Space Telescope is the only instrument in the world that can make
these IR measurements of Cepheids beyond the Local Group, and it is
the only telescope in the world that can be used to find and follow
supernovae at z 1. Our program exploits both of these unique
capabilities of HST to learn more about one of the greatest mysteries
in science.

NIC3 10861

An ACS Treasury Survey of the Coma cluster of galaxies

We propose to use the unique spatial resolution of HST and ACS to
construct a Treasury imaging survey of the core and infall region of
the richest local cluster, Coma. We will observe samples of thousands
of galaxies down to magnitude B=27.3 with the aim of studying in
detail the dwarf galaxy population which, according to hierarchical
models of galaxy formation, are the earliest galaxies to form in the
universe. Our initial scientific objectives a 1} A study of the
structure of the dwarf galaxies, including scaling laws, nuclear
structure and morphology, to compare with hierarchical and
evolutionary models of their formation. 2} A study of the stellar
populations from colors and color gradients, and how the internal
chemical evolution of galaxies is affected by interaction with the
cluster gaseous and galaxy environment. 3} To determine the effect of
the cluster environment upon morphological features, disks, bulges and
bars, by comparing these structure in the Coma sample with field
galaxy samples. 4} Identification of dwarf galaxy samples for further
study with the new generation of multi-object and integral-field
spectrographs on 8-10 metre class telescopes such as Keck, Subaru,
Gemini, and GTC. This is the first such survey of a nearby rich
cluster. It will provide a key database for studies of galaxy
formation and evolution, and a very needed reference for comparison
with similar galaxy surveys both in lower density environments in the
nearby universe, and in high density environments at high redshifts.

NIC3 10874

Search for Extremely Faint z7 Galaxy Population with Cosmic Lenses

Deep UDF/NICMOS observations find a significant decrease in the number
of galaxy candidates between redshift z=6 and 7, but the sample at z7
is too small to draw conclusions. From our observations of 15 clusters
we have found a number of bright z-dropouts, aided by the lensing
amplification. We propose deep NICMOS observations of the best cases
of cluster centers where a rare combination of a significant lensing
effect and the richness in z-band dropouts in background may
dramatically increase the discovery rate. The NICMOS images will reach
an unprecendented depth of AB~27.8, or AB~30 in nonlensed intrinsic
magnitude, and may find many faint {~0.05L*} galaxies at z=7-10, at a
level that the UDF reaches for z~6 objects. We produce precision mass
distribution maps from weak-lensing models, which enable us to derive
the candidates' intrinsic magnitudes and their luminosity function.
The knowledge of such faint galaxy population at z7 will facilitate
the models of the IGM reionization and future JWST planning.

WFPC2 10915

ACS Nearby Galaxy Survey

Existing HST observations of nearby galaxies comprise a sparse and
highly non-uniform archive, making comprehensive comparative studies
among galaxies essentially impossible. We propose to secure HST's
lasting impact on the study of nearby galaxies by undertaking a
systematic, complete, and carefully crafted imaging survey of ALL
galaxies in the Local Universe outside the Local Group. The resulting
images will allow unprecedented measurements of: {1} the star
formation history {SFH} of a 100 Mpc^3 volume of the Universe with a
time resolution of Delta[log{t}]=0.25; {2} correlations between
spatially resolved SFHs and environment; {3} the structure and
properties of thick disks and stellar halos; and {4} the color
distributions, sizes, and specific frequencies of globular and disk
clusters as a function of galaxy mass and environment. To reach these
goals, we will use a combination of wide-field tiling and pointed deep
imaging to obtain uniform data on all 72 galaxies within a
volume-limited sample extending to ~3.5 Mpc, with an extension to the
M81 group. For each galaxy, the wide-field imaging will cover out to
~1.5 times the optical radius and will reach photometric depths of at
least 2 magnitudes below the tip of the red giant branch throughout
the limits of the survey volume. One additional deep pointing per
galaxy will reach SNR~10 for red clump stars, sufficient to recover
the ancient SFH from the color-magnitude diagram. This proposal will
produce photometric information for ~100 million stars {comparable to
the number in the SDSS survey} and uniform multi-color images of half
a square degree of sky. The resulting archive will establish the
fundamental optical database for nearby galaxies, in preparation for
the shift of high-resolution imaging to the near-infrared.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

10611 - GSacq(2,1,2) failed due to search radius limit exceeded

GSacq(2,1,2) scheduled at 009/22:45:10 failed at 22:48:38 due to
search radius limit exceeded on FGS 1. OBAD2 showed errors of
V1=-3.57, V2=-17.96, V3= -5.75 and RSS= 19.19. OBAD1 data is not
available due to LOS.

The Reacq(2,1,2) scheduled at 00:11:16 also failed due to search
radius limit exceeded on FGS 1. OBAd data was unavailable due to LOS.

REacq(2,1,2) scheduled at 01:50:22 failed due to search radius limit
exceeded on FGS 1. OBAD1 showed errors of V1=-72.51, V2=-1833.26,
V3=-38.72, RSS=1835.10. OBAD2 showed errors of V1=-3.92, V2=1.35,
V3=-9.51, RSS=10.38.

Upon acquisition of signal at 010/04:18:51, subsequent REacq(2,1,2)
scheduled at 010/03:28:35 had failed to RGA Hold (Gyro Control) due to
search radius limit exceeded on FGS 1. Pre-acquisition OBADs data not
available due to LOS.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 07 06
FGS REacq 08 05
OBAD with Maneuver 30 30

SIGNIFICANT EVENTS: (None)