Daily Report #4237

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4237

PERIOD COVERED: UT November 08, 2006 (DOY 312)

OBSERVATIONS SCHEDULED

ACS/HRC 10556

Neutral Gas at Redshift z=0.5

Damped Lyman-alpha systems {DLAs} are used to track the bulk of the
neutral hydrogen gas in the Universe. Prior to HST UV spectroscopy,
they could only be studied from the ground at redshifts z1.65.
However, HST has now permitted us to discover 41 DLAs at z1.65 in our
previous surveys. Follow up studies of these systems are providing a
wealth of information about the evolution of the neutral gas phase
component of the Universe. But one problem is that these 41
low-redshift systems are spread over a wide range of redshifts
spanning nearly 70% of the age of the Universe. Consequently, past
surveys for low-redshift DLAs have not been able to offer very good
precision in any small redshift regime. Here we propose an ACS-HRC-
PR200L spectroscopic survey in the redshift interval z=[0.37, 0.7]
which we estimate will permit us to discover another 41 DLAs. This
will not only allow us to double the number of low-redshift DLAs, but
it will also provide a relatively high-precision regime in the
low-redshift Universe that can be used to anchor evolutionary studies.
Fortunately DLAs have high absorption equivalent width, so
ACS-HRC-PR200L has high-enough resolution to perform this proposed
MgII-selected DLA survey.

ACS/HRC 10738

Earth Flats

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 in the pipeline and to monitor any changes. Weekly
coronagraphic monitoring is required to assess the changing position
of the spots.

ACS/HRC 10833

Host Galaxies of Reverberation Mapped AGNs

We propose to obtain unsaturated high-resolution images of 17
reverberation-mapped active galactic nuclei in order to remove the
point-like nuclear light from each image, thus yielding a
"nucleus-free" image of the host galaxy. This will allow investigation
of host galaxy properties: our particular interest is determination of
the host-galaxy starlight contribution to the reverberation-mapping
observations. This is necessary {1} for accurate determination of the
relationship between the AGN nuclear continuum flux and the size of
the broad Balmer-line emitting regions of AGNs, which is important in
estimating black hole masses for large samples of QSOs, and {2} for
accurate determination of the bolometric luminosity of the AGN proper.
Through observations in Cycles 12 and 14, we have obtained or will
obtain images of 18 of the 35 objects in the reverberation-mapping
compilation of Peterson et al. {2004}. These observations revealed
that the host-galaxy contribution, even in the higher-luminosity AGNs,
is higher than expected and that all of the reverberation-mapped AGNs
will have to be observed, not just the lower-luminosity sources; each
source is different, and each source is important. Therefore we
request time to observe the 17 remaining reverberation-mapped AGNs.

ACS/HRC 10883

Light Echoes for Type Ia Supernovae

We propose a SNAPshot survey of light echoes from highly extinct SNIa.
The major science goal is to determine whether the dust causing the
reddening of SNIa is of circumstellar origin or interstellar origin.
We plan to observe about 25 SNIa. These observations are relevant for
the studies of SNIa progenitor systems and for extinction corrections
for supernova cosmology.

ACS/HRC/WFC 10733

CCD Hot Pixel Annealing

Hot pixel annealing will continue to be performed once every 4 weeks.
The CCD TECs will be turned off and heaters will be activated to bring
the detector temperatures to about +20C. This state will be held for
approximately 6 hours, after which the heaters are turned off, the
TECs turned on, and the CCDs returned to normal operating condition.
To assess the effectiveness of the annealing, a bias and four dark
images will be taken before and after the annealing procedure for both
WFC and HRC. The HRC darks are taken in parallel with the WFC darks.
The charge transfer efficiency {CTE} of the ACS CCD detectors declines
as damage due to on-orbit radiation exposure accumulates. This
degradation has been closely monitored at regular intervals, because
it is likely to determine the useful lifetime of the CCDs. We combine
the annealling activity with the charge transfer efficiency monitoring
and also merge into the routine dark image collection. To this end,
the CTE monitoring exposures have been moved into this proposal . All
the data for this program is acquired using internal targets {lamps}
only, so all of the exposures should be taken during Earth occultation
time {but not during SAA passages}. This program emulates the ACS
pre-flight ground calibration and post-launch SMOV testing {program
8948}, so that results from each epoch can be directly compared.
Extended Pixel Edge Response {EPER} and First Pixel Response {FPR}
data will be obtained over a range of signal levels for both the Wide
Field Channel {WFC}, and the High Resolution Channel {HRC}.

ACS/HRC/WFC 10758

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. Changes from cycle 13:- The default
gain for WFC is 2 e-/DN. As before bias frames will be collected for
both gain 1 and gain 2. Dark frames are acquired using the default
gain {2}. This program cover the period May, 31 2006- Oct, 1-2006. The
first half of the program has a different proposal number: 10729.

ACS/WFC/NIC2 10496

Decelerating and Dustfree: Efficient Dark Energy Studies with
Supernovae and Clusters

We propose a novel HST approach to obtain a dramatically more useful
"dust free" Type Ia supernovae {SNe Ia} data set than available with
the previous GOODS searches. Moreover, this approach provides a
strikingly more efficient search-and-follow-up that is primarily pre-
scheduled. The resulting dark energy measurements do not share the
major systematic uncertainty at these redshifts, that of the
extinction correction with a prior. By targeting massive galaxy
clusters at z 1 we obtain a five-times higher efficiency in
detection of Type Ia supernovae in ellipticals, providing a
well-understood host galaxy environment. These same deep cluster
images then also yield fundamental calibrations required for future
weak lensing and Sunyaev-Zel'dovich measurements of dark energy, as
well as an entire program of cluster studies. The data will make
possible a factor of two improvement on supernova constraints on dark
energy time variation, and much larger improvement in systematic
uncertainty. They will provide both a cluster data set and a SN Ia
data set that will be a long standing scientific resource.

FGS 10927

The Weight-Watcher Program for Subdwarfs

We propose to use HST/FGS1r to measure five subdwarf spectroscopic
binaries to determine masses for the components. Their metallicities,
[Fe/H], range from -0.5 to -2.5, and their projected minimum
separations range from 9 to 24 mas. These binaries are resolvable with
HST/FGS1r but not any ground-based technique. Currently, there are
only two subdwarf systems having any mass measurements. The proposed
work will boost the total number of subdwarf systems with masses from
two to seven, and allow us to construct the first mass-luminosity
relation for low- metallicity stars.

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 10847

Coronagraphic Polarimetry of HST-Resolved Debris Disks

We propose to take full advantage of the recently commissioned
coronagraphic polarimetry modes of ACS and NICMOS to obtain imaging
polarimetry of circumstellar debris disks that were imaged previously
by the HST coronagraphs, but without the polarizers. It is well
established that stars form in gas-rich protostellar disks, and that
the planets of our solar system formed from a circum-solar disk.
However, the connection between the circumstellar disks that we
observe around other stars and the processes of planet formation is
still very uncertain. Mid-IR spectral studies have suggested that disk
grains are growing in the environments of young stellar objects during
the putative planet-formation epoch. Furthermore, structures revealed
in well resolved images of circumstellar disks suggest gravitational
influences on the disks from co-orbital bodies of planetary mass.
Unfortunately, existing imaging data provides only rudimentary
information about the disk grains and their environments. Our proposed
observations, which can be obtained only with HST, will enable us to
quantitatively determine the sizes of the grains and optical depths as
functions of their location within the disks {i.e., detailed
tomography}. Armed with these well-determine physical and geometrical
systemic parameters, we will develop a set of self-consistent models
of disk structures to investigate possible interactions between unseen
planets and the disks from which they formed. Our results will also
calibrate models of the thermal emission from these disks, that will
in turn enable us to infer the properties of other debris disks that
cannot be spatially resolved with current or planned instruments and
telescopes.

NIC2 10856

Delayed Negative Feedback in the Super Star Clusters of SBS0335-052E

The critical unanswered question in calculations of galaxy formation
and evolution is the degree of feedback from the formation of the
first massive stars on subsequent evolution. Even the sign of the term
is uncertain. Super Star Clusters give one very dramatic answer by
forming several thousand O stars in a volume with a radius of only a
few parsecs. How can that many massive stars form in such a small
volume without immediate dissipation of all gas by the intense
ionizing radiation from the stars? SBS0335-052E has done this, not
once but at least 6 times in a region of approximately 500 parsecs in
size. It has also managed to do this with the third lowest metallicity
of any known galaxy. The record lowest metallicity is held by its
companion SBS0335- 052W. These observations are designed to test one
answer to this enigma; that all of the ionizing photons are absorbed
within a few hundred AU of the stars that emit them. This delays the
negative feedback from photoionization and allows the formation of
other stars in the immediate neighborhood who are oblivious to the
massive stars nearby. This scenario predicts that both molecular and
ionized gas exist within the radius of the super star clusters and
that their emission should be spatially coincident. We propose to test
this hypothesis with high spatial resolution NICMOS camera 2 images in
the hydrogen Pa alpha and molecular hydrogen {1-0} S{1} emission
lines. Spatial coincidence of the emission regions will confirm that
gas within the cluster is shielded from ionizing and dissociating
photons and is capable of forming new stars within this tiny region in
spite of the presence of thousands of massive stars. The current burst
of star formation was probably triggered by interaction with the giant
spiral galaxy NGC 1376. This proposal contains parallel observations
of this galaxy with the ACS WFC. Due to the intense interest in
SBS0335-052 we waive all proprietary rights. The observations will
then immediately compliment observations by the Great Observatories,
Spitzer and ground base observatories .

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: (None)

COMPLETED OPS REQUEST:
#17951-1 T2G Init Ram Installation @ 313/00:40z

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 09 09
FGS REacq 05 05
OBAD with Maneuver 28 28

SIGNIFICANT EVENTS:

Flash Report - FSW T2gInit RAM Installation:

FSW T2gInit Patch was successfully installed in HST486 RAM. The
T2gInit loads were completed at 312/15:22:50z and the T2gInit Patch
was activated at 312/16:13:31z. After software activation, PCS SE
monitored attitude control mode transitions and all executed
successfully. DMS, FSW, and Systems Management also monitored
telemetry during this period and everything was nominal. The post
installation RAM memory dump was good @ 313/00:40z (7:40pm).