Daily # 4262

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4262

PERIOD COVERED: UT December 18, 2006 (DOY 352)

OBSERVATIONS SCHEDULED

ACS/HRC 10800

Kuiper Belt Binaries: Probes of Early Solar System Evolution

Binaries in the Kuiper Belt are a scientific windfall: in them we have
relatively fragile test particles which can be used as tracers of the
early dynamical evolution of the outer Solar System. We propose to
continue a Snapshot program using the ACS/HRC that has a demonstrated
discovery potential an order of magnitude higher than the HST
observations that have already discovered the majority of known
transneptunian binaries. With this continuation we seek to reach the
original goals of this project: to accumulate a sufficiently large
sample in each of the distinct populations collected in the Kuiper
Belt to be able to measure, with statistical significance, how the
fraction of binaries varies as a function of their particular
dynamical paths into the Kuiper Belt. Today's Kuiper Belt bears the
imprints of the final stages of giant-planet building and migration;
binaries may offer some of the best preserved evidence of that
long-ago era.

ACS/HRC 11041

ACS CCDs daily monitor

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. For cycle 15 the program will cover 18
months 12.1.06-05.31.08 and it has been divied into three different
proposal each covering six months. The three proposals are
11041-11042-11043.

ACS/HRC/WFPC2/NIC3 10842

A Cepheid Distance to the Coma Cluster

We propose to use the Advanced Camera for Surveys to search for
Cepheid variables in two spiral galaxies in the core of the Coma
cluster. A direct application of the canonical primary distance
indicator at 100 Mpc will measure the far-field Hubble constant free
of many of the systematic uncertainties which beset current
determinations relying on secondary indicators. Establishing the
far-field H_o with Cepheids will provide one of the strongest links in
the extragalactic distance scale and will directly calibrate the
fiducial fundamental plane of elliptical galaxies in Coma. With
ACS/HRC, S/N=5 to 10 or better can be reached for Cepheids with
periods of 40d to 70d at mean light in 5 orbits with the F606W filter
if H_o=72 km/s/Mpc. Efficient detection and phasing can be done with
twelve epochs optimally spaced for periods of 40-70d.

ACS/WFC 10886

The Sloan Lens ACS Survey: Towards 100 New Strong Lenses

As a continuation of the highly successful Sloan Lens ACS {SLACS}
Survey for new strong gravitational lenses, we propose one orbit of
ACS-WFC F814W imaging for each of 50 high- probability strong
galaxy-galaxy lens candidates. These observations will confirm new
lens systems and permit immediate and accurate photometry, shape
measurement, and mass modeling of the lens galaxies. The lenses
delivered by the SLACS Survey all show extended source structure,
furnishing more constraints on the projected lens potential than
lensed-quasar image positions. In addition, SLACS lenses have lens
galaxies that are much brighter than their lensed sources,
facilitating detailed photometric and dynamical observation of the
former. When confirmed lenses from this proposal are combined with
lenses discovered by SLACS in Cycles 13 and 14, we expect the final
SLACS lens sample to number 80--100: an approximate doubling of the
number of known galaxy-scale strong gravitational lenses and an
order-of-magnitude increase in the number of optical Einstein rings.
By virtue of its homogeneous selection and sheer size, the SLACS
sample will allow an unprecedented exploration of the mass structure
of the early-type galaxy population as a function of all other
observable quantities. This new sample will be a valuable resource to
the astronomical community by enabling qualitatively new strong
lensing science, and as such we will waive all but a short {3-month}
proprietary period on the observations.

FGS 11021

HST Pre-SM4 Focal Plane Alignment & ACS Absolute Scale

This proposal will determine and monitor the FGSs and SI positions and
orientations in V2,V3 space. Accuracy goals are 50 mas for position
and between 0.04 and 0.004 degrees for angle {depending on SI}. An
astrometric open cluster {M35} is observed using guidestars with
positions determined to ~ 20 mas. One or more astrometric targets are
placed in the available SIs' major channels as well as each FGS, and
POS TARGs step the target{s} over a significant fraction of the
detector. This proposal will serve to update the FGS and SI positions
and angles, which have trended, uncalibrated, since ~2002, at a rate
between 0.1 and 0.2 arcseconds or more per year. This will execute
before 22 December 2006. A single orbit visit will execute later but
before SM4/SMOV and will only include position/angle checks of any SI
trends and not contain the more costly FGS-FGS alignment, which will
need to be performed during SM4/SMOV. Finally, a special visit is
included in this proposal which will yield the absolute scale of
ACS/WFC with an accuracy of ~2x10-5 by observing a subset of M35
astrometric cluster members with relative positions known to 1 mas
and absolute separations known to ~2x10-5 {via FGS calibrations over
mission life}. This transfers the well-determined FGS absolute scale
knowledge onto ACS/WFC, with the goal of then impressing that
calibration onto an HST-JWST common field {e.g. LMC} in order to
support JWST calibration requirements.

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.

WFPC2 10748

WFPC2 CYCLE 14 Standard Darks

This dark calibration program obtains dark frames every week in order
to provide data for the ongoing calibration of the CCD dark current
rate, and to monitor and characterize the evolution of hot pixels.
Over an extended period these data will also provide a monitor of
radiation damage to the CCDs.

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:

10562 - REacq(2,3,3) failed to RGA control

REacq(2,3,3) scheduled at 352/16:21:21 failed due to scan step limit
exceeded on FGS 2 at 16:24:48. OBAD1 showed errors of V1=-40.59,
V2=-1307.41, V3=-26.53, RSS=1308.31. OBAD2 showed error of V1=-2.46,
V2=14.48, V3=-1.97, RSS=14.82.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 06 06
FGS REacq 08 07
OBAD with Maneuver 28 28

SIGNIFICANT EVENTS: (None)