Daily Report #4481

Notice: Due to the conversion of some ACS WFC or HRC observations into
WFPC2, or NICMOS observations after the loss of ACS CCD science
capability in January, there may be an occasional discrepancy between
a proposal's listed (and correct) instrument usage and the abstract
that follows it.


HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT***** #4481

PERIOD COVERED: UT November 01, 2007 (DOY 305)

OBSERVATIONS SCHEDULED

FGS 11213

Distances to Eclipsing M Dwarf Binaries

We propose HST FGS observations to measure accurate distances of 5
nearby M dwarf eclipsing binary systems, from which model-independent
luminosities can be calculated. These objects have either poor or no
existing parallax measurements. FGS parallax determinations for these
systems, with their existing dynamic masses determined to better than
0.5%, would serve as model-independent anchor points for the low-mass
end of the mass-luminosity diagram.

NIC1/NIC2/NIC3 11330

NICMOS Cycle 16 Extended Dark

This takes a series of Darks in parallel to other instruments.

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 DARKs. 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.

S/C 11163

Accreting Pulsating White Dwarfs in Cataclysmic Variables

Recent ground-based observations have increased the number of known
pulsating white dwarfs in close binaries with active mass transfer
{cataclysmic variables} from 5 to 11 systems. Our past Cycles 8 and 11
STIS observations of the first 2 known, followed by our Cycle 13 SBC
observations of the next 3 discovered, revealed the clear presence of
the white dwarf and increased amplitude of the pulsations in the UV
compared to the optical. The temperatures derived from the UV spectra
show 4 systems are much hotter than non- interacting pulsating white
dwarfs. A larger sample is needed to sort out the nature of the
instability strip in accreting pulsators i.e. whether effects of
composition and rotation due to accretion result in a well-defined
instability strip as a function of Teff.

WFPC2 11027

Visible 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
4-14.

WFPC2 11029

WFPC2 CYCLE 15 Intflat Linearity Check and Filter Rotation Anomaly
Monitor

Intflat observations will be taken to provide a linearity check: the
linearity test consists of a series of intflats in F555W, in each gain
and each shutter. A combination of intflats, visflats, and earthflats
will be used to check the repeatability of filter wheel motions.
{Intflat sequences tied to decons, visits 1-18 in prop 10363, have
been moved to the cycle 15 decon proposal xxxx for easier scheduling.}
Note: long-exposure WFPC2 intflats must be scheduled during ACS
anneals to prevent stray light from the WFPC2 lamps from contaminating
long ACS external exposures.

WFPC2 11103

A Snapshot Survey of The Most Massive Clusters of Galaxies

We propose the continuation of our highly successful SNAPshot survey
of a sample of 125 very X-ray luminous clusters in the redshift range
0.3-0.7. As demonstrated by the 25 snapshots obtained so far in
Cycle14 and Cycle15 these systems frequently exhibit strong
gravitational lensing as well as spectacular examples of violent
galaxy interactions. The proposed observations will provide important
constraints on the cluster mass distributions, the physical nature of
galaxy-galaxy and galaxy-gas interactions in cluster cores, and a set
of optically bright, lensed galaxies for further 8-10m spectroscopy.
All of our primary science goals require only the detection and
characterization of high-surface-brightness features and are thus
achievable even at the reduced sensitivity of WFPC2. Because of their
high redshift and thus compact angular scale our target clusters are
less adversely affected by the smaller field of view of WFPC2 than
more nearby systems. Acknowledging the broad community interest in
this sample we waive our data rights for these observations. Due to a
clerical error at STScI our approved Cycle15 SNAP program was barred
from execution for 3 months and only 6 observations have been
performed to date - reinstating this SNAP at Cycle16 priority is of
paramount importance to reach meaningful statistics.

WFPC2 11124

The Origin of QSO Absorption Lines from QSOs

We propose using WFPC2 to image the fields of 10 redshift z ~ 0.7
foreground {FG} QSOs which lie within ~29-151 kpc of the sightlines to
high-z background {BG} QSOs. A surprisingly high fraction of the BG
QSO spectra show strong MgII {2796,2803} absorption lines at precisely
the same redshifts as the FG QSOs. The high resolution capabilities of
WFPC2 are needed to understand the origin of these absorption systems,
in two ways. First, we wish to explore the FG QSO environment as close
as possible to the position of the BG QSO, to search for interloping
group or cluster galaxies which might be responsible for the
absorption, or irregularly shaped post-merger debris between the FG
and BG QSO which may indicate the presence of large amount of
disrupted gas along a sightline. Similarly, high resolution images are
needed to search for signs of tidal interactions between any galaxies
which might be found close to the FG QSO. Such features might provide
evidence of young merging events causing the start of QSO duty cycles
and producing outflows from the central AGN. Such winds may be
responsible for the observed absorption lines. Second, we seek to
measure the intrinsic parameters of the FG QSO host galaxy, such as
luminosity and morphology, to correlate with the properties of the
MgII absorption lines. We wish to observe each field through the F814W
filter, close to the rest-frame B-band of the FG QSO. These blue data
can reveal enhanced star formation regions close to the nucleus of the
host galaxy, which may be indicative of galaxy mergers with the FG QSO
host. The FG QSO environment offers quite a different set of phenomena
which might be responsible for MgII absorption, providing an important
comparison to studies of MgII absorption from regular field galaxies.

WFPC2 11167

A Unique High Resolution Window to Two Strongly Lensed Lyman Break
Galaxies

On rare occasions, the otherwise very faint Lyman Break Galaxies
{LBGs} are magnified by gravitational lensing to provide exceptional
targets for detailed spectroscopic and imaging studies. We propose HST
WFPC2 and NICMOS imaging of two strongly lensed Lyman Break Galaxies
{LBGs} that were recently discovered by members of our team. These two
LBGs -- the "8 O'Clock Arc" and the "SDSS J1206+5142 Arc" -- are
currently the brightest known LBGs, roughly 3 times brighter than the
former record-holder, MS1512-cB58 {a.k.a. "cB58"}. The z=2.73 "8
O'Clock Arc" extends ~10 arcsec in length and is magnified by a factor
of 12. The z=2.00 "SDSS J1206+5142 Arc" also extends ~10 arcsec in
length and is magnified by a factor of 30. Due to their brightness and
magnification, these two strongly lensed LBGs offer an unprecedented
opportunity for the very detailed investigation of two individual
galaxies at high redshift. We are currently pursuing a vigorous
ground-based campaign to obtain multi-wavelength {UV, optical, NIR,
radio} observations of these two LBGs, but our campaign currently
lacks a means of obtaining high-resolution optical/NIR imaging -- a
lack that currently only HST can address. Our prime objective for this
proposal is to obtain high resolution HST images of these two systems
with two-orbit WFPC2 images in the BVI bands and two-orbit NICMOS/NIC2
images in the J and H bands. These data will allow us to construct
detailed lensing models, probe the mass and light profiles of the
lenses and their environments, and constrain the star formation
histories and rest-frame UV/optical spectral energy distributions of
the LBGs.

WFPC2 11312

The Local Cluster Substructure Survey {LoCuSS}: Deep Strong Lensing
Observations with WFPC2

LoCuSS is a systematic and detailed investigation of the mass,
substructure, and thermodynamics of 100 X-ray luminous galaxy clusters
at 0.15z0.3. The primary goal is to test our recent suggestion that
this population is dominated by dynamically immature disturbed
clusters, and that the observed mass-temperature relation suffers
strong structural segregation. If confirmed, this would represent a
paradigm shift in our observational understanding of clusters, that
were hitherto believed to be dominated by mature, undisturbed systems.
We propose to complete our successful Cycle 15 program {SNAP:10881}
which prior to premature termination had delivered robust weak-lensing
detections in 17 clusters, and candidate strongly-lensed arcs in 11 of
these 17. These strong and weak lensing signals will give an accurate
measure of the total mass and structure of the dark matter
distribution that we will subsequently compare with X-ray and Sunyaev
Zeldovich Effect observables. The broader applications of our project
include 1} the calibration of mass-temperature and mass-SZE scaling
relations which will be critical for the calibration of proposed dark
energy experiments, and 2} the low redshift baseline study of the
demographics of massive clusters to aid interpretation of future high
redshift {z1} cluster samples. To complete the all-important high
resolution imaging component of our survey, we request deep WFPC2
observations of 20 clusters through the F606W filter, for which
wide-field weak-lensing data are already available from our Subaru
imaging program. The combination of deep WFPC2 and Subaru data for
these 20 clusters will enable us to achieve the science program
approved by the Cycle 15 TAC.

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: (None)

COMPLETED OPS NOTES: (None)

*********************** SCHEDULED***** SUCCESSFUL

FGS GSacq*************** 06**************** 06
FGS REacq*************** 09**************** 09
OBAD with Maneuver* **** 30**************** 30

SIGNIFICANT EVENTS: (None)