HST Daily Report # 3275

HUBBLE SPACE TELESCOPE

DAILY REPORT # 3275

PERIOD COVERED: DOY 7

OBSERVATIONS SCHEDULED

NICMOS 8790

NICMOS Post-SAA calibration – CR Persistence Part 1.

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.

NICMOS/STIS CCD 9405

The Origin of Gamma-Ray Bursts

The rapid and accurate localization of gamma-ray bursts {GRBs} promised by a
working HETE-2 during the coming year may well revolutionize our ability to
study these enigmatic, highly luminous transients. We propose a program of
HST
and Chandra observations to capitalize on this extraordinary opportunity. We
will perform some of the most stringent tests yet of the standard model, in
which GRBs represent collimated relativistic outflows from collapsing
massive
stars. NICMOS imaging and STIS CCD spectroscopy will detect broad atomic
features of supernovae underlying GRB optical transients, at luminosities
more
than three times fainter than SN 1998bw. UV, optical, and X-ray spectroscopy
will be used to study the local ISM around the GRB. Chandra spectroscopy
will
investigate whether the GRB X-ray lines are from metals freshly ripped from
the
stellar core by the GRB. HST and CTIO infra-red imaging of the GRBs and
their
hosts will be used to determine whether `dark’ bursts are the product of
unusually strong local extinction; imaging studies may for the first time
locate
the hosts of `short’ GRBs. Our early polarimetry and late-time broadband
imaging
will further test physical models of the relativistic blast wave that
produces
the bright GRB afterglow, and will provide unique insight into the influence
of
the GRB environment on the afterglow.

ACS/WFC/HRC 9445

Gravitational Microlensing in the NGC 3314A-B Galaxy Pair.

The Advanced Camera for Surveys (WFC and HRC) was used to determine the
composition of the dark matter that dominates the masses of galaxies which
is an
important unsolved problem.

ACS 9453

The Age of the Andromeda Halo

With the advent of the ACS, we can cross a critical threshold in the study
of
galaxy formation: For the first time, we can resolve the old main sequence
stars
in the Andromeda halo, and thus directly determine the ages of the halo
stars in
a giant galaxy other than our own. As the nearest giant galaxy, Andromeda
offers
the best testing ground for understanding galaxy formation and evolution.
Resolution of its halo will tell us about its spread in age and metallicity,
thus providing a formation history. Via extensive simulations, we
demonstrate
that we can unambiguously characterize the halo population via a deep
F606W/F814W color-magnitude diagram reaching below the main sequence
turnoff.
The data will distinguish whether the halo formed quickly or through
protracted
infall and merging episodes, and would detect even a few percent trace of
intermediate age stars. Our field was carefully chosen to meet two criteria:
an
optimal stellar density ensuring adequate statistics while avoiding
overcrowding, and the inclusion of an Andromeda globular cluster matched to
the
peak halo metallicity. We also propose very brief observations in the same
two
bands of five Galactic globular clusters spanning a wide metallicity range,
thus
establishing population templates in the ACS photometric system that will be
used to calibrate and interpret the Andromeda data.

ACS 9480

Cosmic Shear With ACS Pure Parallels

Small distortions in the shapes of background galaxies by foreground mass
provide a powerful method of directly measuring the amount and distribution
of
dark matter. Several groups have recently detected this weak lensing by
large-scale structure, also called cosmic shear. The high resolution and
sensitivity of HST/ACS provide a unique opportunity to measure cosmic shear
accurately on small scales. Using 260 parallel orbits in Sloan textiti
{F775W}
we will measure for the first time: beginlistosetlength sep0cm
setlengthemsep0cm
setlength opsep0cm em the cosmic shear variance on scales <0.7 arcmin, em
the
skewness of the shear distribution, and em the magnification effect.
endlist Our
measurements will determine the amplitude of the mass power spectrum
sigma_8Omega_m^0.5, with signal-to-noise {s/n} ~ 20, and the mass density
Omega_m with s/n=4. They will be done at small angular scales where
non-linear
effects dominate the power spectrum, providing a test of the gravitational
instability paradigm for structure formation. Measurements on these scales
are
not possible from the ground, because of the systematic effects induced by
PSF
smearing from seeing. Having many independent lines of sight reduces the
uncertainty due to cosmic variance, making parallel observations ideal.

NICMOS 9485

Completing A Near-Infrared Search for Very Low Mass Companions to Stars
within
10 pc of the Sun

Most stars are fainter and less massive than the Sun. Nevertheless, our
knowledge of very low mass {VLM} red dwarfs and their brown dwarf cousins is
quite limited. Unknown are the true luminosity function {LF}, multiplicity
fraction, mass function, and mass-luminosity relation for red and brown
dwarfs,
though they dominate the Galaxy in both numbers and total mass. The best way
to
constrain these relations is a search for faint companions to nearby stars.
Such
a search has several advantages over field surveys, including greater
sensitivity to VLM objects and the availability of precise parallaxes from
which
luminosities and masses can be derived. We propose to complete our
four-filter
NICMOS snapshot search for companions to stars within 10 pc. With a 10 sigma
detection limit of M_J ~ 20 at 10 pc, we can detect companions between 10
and
100 AU that are at least 9 mag fainter than the empirical end of the main
sequence and at least 6.5 mag fainter than the brown dwarf Gl 229B. When
completed, our search will be the largest, most sensitive, volume-limited
search
for VLM companions ever undertaken. Our four-filter search will permit
unambiguous identification of VLM-companion candidates for follow-up
observation. Together with IR speckle and deep imaging surveys, our program
will
firmly establish the LF for VLM companions at separations of 1-1000 AU and
the
multiplicity fraction of all stars within 10 pc.

WFPC2 9593

WFPC2 CYCLE 11 SUPPLEMENTAL DARKS pt1/3

This dark calibration program obtains 3 dark frames every day to provide
data
for monitoring and characterizing the evolution of hot pixels.

WFPC2 9596

WFPC2 CYCLE 11 INTERNAL MONITOR

This calibration proposal is the Cycle 11 routine internal monitor for
WFPC2, to
be run weekly to monitor the health of the cameras. A variety of internal
exposures are obtained in order to provide a monitor of the integrity of
the CCD
camera electronics in both bays {gain 7 and gain 15}, a test for quantum
efficiency in the CCDs, and a monitor for possible buildup of contaminants
on
the CCD windows.

WFPC2 9598

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 4-10.

WFPC2 9599

WFPC2 Cycle 11 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 8-10.

STIS 9605

CCD Dark Monitor-Part 1

STIS 9607

CCD Bias Monitor – Part 1

high-S/N superbiases and track the evolution of hot columns.

STIS 9615

Cycle 11 MAMA Dark Monitor

the primary means of checking on health of the MAMA detectors systems
through
frequent monitoring of the background count rate. The purpose is to look for
evidence of change in dark indicative of detector problem developing.

STIS 9633

STIS parallel archive proposal – Nearby Galaxies – Imaging and Spectroscopy

Using parallel opportunities with STIS which were not allocated by the TAC,
we
propose to obtain deep STIS imagery with both the Clear {50CCD} and
Long-Pass
{F28X50LP} filters in order to make color-magnitude diagrams and luminosity
functions for nearby galaxies. For local group galaxies, we also include
G750L
slitless spectroscopy to search for e.g., Carbon stars, late M giants and
S-type
stars. This survey will be useful to study the star formation histories,
chemical evolution, and distances to these galaxies. These data will be
placed
immediately into the Hubble Data Archive.

NICMOS 9637

NICMOS Focus Stability

The purpose of this activity is to determine if the best focus determined in
SMOV is stable. This program will execute in approximately one month
intervals
starting about 1 month after the last execution of proposal 8980.

ACS 9647

CCD Daily Monitor Part I

This program consists of basic tests to monitor, the read noise, the
development
of hot pixels and test for any source of noise in ACS CCD detectors. This
programme will be executed once a day for the entire lifetime of ACS.

NICMOS 9702

NICMOS Parallel Thermal Background

NICMOS Camera 2 pure parallel exposures in the F222M and F237M filters to
establish the stability of the HST+NCS+Instrument thermal emission. This
data
will be compared against the already available Camera 3 measurements in
F222M
which show an increased thermal background.

STIS 9706

STIS Pure Parallel Imaging Program: Cycle 10

This is the default archival pure parallel program for STIS during cycle 10.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports of
potential non-nominal performance that will be investigated.) None

COMPLETED OPS REQs: None

OPS NOTES EXECUTED: None

                          SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq              10                       10
FGS REacq              6                          6
FHST Update            22                        22
LOSS of LOCK

SIGNIFICANT EVENTS:

HST Venus Observation Ops Acceptance Test scheduled 008/11:00Z-009/05:00Z
with
GDOC, HITT, SE, and VEST using CCS "B" String with CCS Release 4.0.1 and PRD
O06100TQ1. The purpose of this testing is to validate Venus Observation
Macro
installation and removal procedures in an operational scenario using a test
unique SMS to validate the proper fail-over to software sunpoint rather than
inertial hold.