HST Daily Report # 3338
DAILY REPORT # 3338
PERIOD COVERED: DOY 99
OBSERVATIONS SCHEDULED NICMOS 8791
NICMOS Post-SAA calibration – CR Persistence Part 2
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 9033
Measuring the mass distribution in the most distant, very X-ray luminous
galaxy
cluster known
distribution in the massive, distant galaxy cluster ClJ1226.9+3332, recently
discovered by us. At z=0.888 this exceptional system is more X-ray luminous
and
more distant than both MS1054.4-0321 and ClJ0152.7-1357, the previous record
holders, thus providing yet greater leverage for cosmological studies of
cluster
evolution. ClJ1226.9+3332 differs markedly from all other currently known
distant clusters in that it exhibits little substructure and may even host a
cooling flow, suggesting that it could be the first cluster to be discovered
at
high redshift that is virialized. We propose joint HST and Chandra
observations
to investigate the dynamical state of this extreme object. This project will
1}
take advantage of HST’s superb resolution at optical wavelengths to
accurately
map the mass distribution within 1.9 h^{-1} 50 Mpc via strong and weak
gravitational lensing, and 2} use Chandra’s unprecedented resolution in the
X-ray waveband to obtain independent constraints on the gas and dark matter
distribution in the cluster core, including the suspected cooling flow
region.
As a bonus, the proposed WFPC2 observations will allow us to test the
results by
van Dokkum et al. {1998, 1999} on the properties of cluster galaxies
{specifically merger rate and morphologies} at z~0.8 from their HST study of
MS1054.4-0321.
STIS/MA2 9096
Objective-Prism Spectroscopy of Massive Young Clusters.
obtaining STIS NUV-MAMA objective-prism spectroscopy in the 1300-3600
Angstrom
range of three nearby extragalactic regions with a total of ~ 10 MYCs since
most
of the present knowledge of the UV spectral properties of massive young
clusters
{MYCs} is based on IUE data with marginal spatial resolution. Slitless
techniques are seldom attempted on crowded clusters due to the overlap among
different sources. It is planned to overcome that problem by observing with
two
different roll angles, using comparison UV and optical images from the HST
archive.
ACS 9363
Ultra Low Surface Brightness Galaxies
Extremely low surface brightness galaxies have been detected in the Virgo
cluster, which are 2 magnitudes fainter than any previously known in that
cluster or even in the Local Group. ACS images of three of these should
resolve
stars at the giant branch tip, and allow us to determine distances, mean
metal
abundance of the stars, and rough ages. Confirmation of the nature of these
galaxies will provide evidence that dark matter halos are pervasive in the
universe, extending to galaxies with stellar densities 6 times lower than
currently known. These resolved stars would be the most distant yet observed
accurately by HST.
STIS/MA2 9465
The Cosmic Carbon Budget
Gaseous carbon drives the chemistry of, and is an important coolant in
interstellar clouds. In solid form, carbon is the second most abundant
element
in interstellar dust, the key element contributing to interstellar
extinction,
and the dominant heat source in some interstellar clouds. Given the
fundamental
importance of this element to interstellar cloud physics, it is surprising
that
only 8 measurements of gas- phase carbon abundances exist for neutral
clouds; 7
are in diffuse clouds where the least amount of chemistry and dust
incorporation
are expected. The single measurement in a translucent cloud suggests a C
abundance that differs from the diffuse clouds, but the measurement
uncertainties make this difference statistically insignificant. We,
therefore,
have no information about carbon’s behavior in translucent clouds, regions
dense
enough for chemistry and dust growth to be important but low enough
extinction
so that UV spectroscopy is possible {unlike for molecular clouds}. We
propose to
measure total gas-phase C abundances in 6 translucent clouds with our
principal
scientific goals being to 1} accurately determine the fraction of carbon in
the
gas and dust phases in environments bridging the gap between diffuse and
molecular clouds 2} determine the relative depletions of C and O in neutral
clouds with known O-depletion enhancements and 3} explore how the
interstellar
gas-phase C/H is related to extinction variations.
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 9484
The NICMOS Parallel Observing Program
We propose to manage the default set of pure parallels with NICMOS. Our
experience with both our GO NICMOS parallel program and the public parallel
NICMOS programs in cycle 7 prepared us to make optimal use of the parallel
opportunities. The NICMOS G141 grism remains the most powerful survey tool
for
HAlpha emission-line galaxies at cosmologically interesting redshifts. It is
particularly well suited to addressing two key uncertainties regarding the
global history of star formation: the peak rate of star formation in the
relatively unexplored but critical 1<= z <= 2 epoch, and the amount of star
formation missing from UV continuum-based estimates due to high extinction.
Our
proposed deep G141 exposures will increase the sample of known HAlpha
emission-
line objects at z ~ 1.3 by roughly an order of magnitude. We will also
obtain a
mix of F110W and F160W images along random sight-lines to examine the space
density and morphologies of the reddest galaxies. The nature of the
extremely
red galaxies remains unclear and our program of imaging and grism
spectroscopy
provides unique information regarding both the incidence of obscured star
bursts
and the build up of stellar mass at intermediate redshifts. In addition to
carrying
out the parallel program we will populate a public database with calibrated
spectra and images, and provide limited ground- based optical and near-IR
data
for the deepest parallel fields.
WFPC2 9594
WFPC2 CYCLE 11 SUPPLEMENTAL DARKS pt2/3
characterizing the evolution of hot pixels
STIS 9606
CCD Dark Monitor-Part 2
STIS 9608
CCD Bias Monitor – Part 2
high-S/N superbiases and track the evolution of hot columns.
ACS 9673
CCD Daily Monitor
for any source of noise in ACS CCD detectors. This programme will be
executed
once a day for the entire lifetime of ACS
WFPC2 9676
POMS Test Proposal: WFII parallel archive proposal
This is the generic target version of the WFPC2 Archival Pure Parallel
program.
The program will be used to take parallel images of random areas of the sky,
following the recommendations of the 2002 Parallels Working Group.
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.
WFPC2 9710
POMS Test Proposal: WFII backup parallel archive proposal
This is a POMS test proposal designed to simulate scientific plans.
Significant Spacecraft Anomalies: (The following are preliminary reports of
potential non-nominal performance that will be investigated.) None
Executed Ops Note 1095: Consolidated PCS Limit Modifications @ 099/20:30Z.
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 04 04
FGS REacq 11 11
FHST Update 08 08
LOSS of LOCK
SIGNIFICANT EVENTS:
Successfully completed TDRS J Level 6 Testing @ 099/17:58Z. See OR 16921-2.
Dumped HST486 Table 1 @ 099/17:55:27Z (ROP DF-1A).
FOT real-time spacecraft operations continue from the GSFC MOR, pending
study of
SIMOR commercial power loss event. HST-FSB3 Server remains inoperative.
