HST Daily Report #3349
HUBBLE SPACE TELESCOPE
DAILY REPORT #3349
PERIOD COVERED: DOY 114
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.
NICMOS 9402
A NICMOS Study of Merging Nuclei in the Toomre Sequence: Finding Order
Amid Chaos
gas clouds and glaring star formation activity. The dynamically
important centers of mass can only be
uncovered by imaging at NIR wavelengths and with the high spatial
resolution of HST. We propose a
near-infrared imaging program to inspect the physical processes of
merging at spatial scales of ~100
pc. The Toomre Sequence provides the best sample of merging galaxies for
such a study, because it has
been studied extensively from the ground, and the global properties are
well understood. Our previous
Cycle 9 WFPC2 images of the nuclei have revealed a wealth of information
on star forming activity and
dust, but based on those data alone it is impossible to determine the
locations of the current centers
of mass. Determining the mass centers and stellar density profiles is
important for understanding both
the kinematics and the dynamical evolution of the nuclei, and the
formation of nuclear density cusps
in galaxies. We propose J, H and K band imaging of the nuclei in early
and intermediate stage mergers
in the Toomre Sequence. Because of the much reduced effect of dust
extinction, the near-infrared images
are also optimally suited to searches for nuclear rings and bars around
the nuclei.
Combined with our ongoing Cycle 9 program, these data will provide a
detailed view of the structure and
evolution of a sequence of merger nuclei.
STIS 9437
Quantitative Constraints for Massive Star Evolution Models with Rotation
Rotation is now recognized as an important physical component in
understanding massive stars. Theory
suggests that rotation affects the lifetimes, chemical yields, stellar
evolution tracks, and the
supernova and compact remnant properties {Heger & Langer 2000, Maeder &
Meynet 2000}. In a Cycle 7
program, we proved that rotational mixing occurs in massive main
sequence stars {Venn et al. 2001}. In
this proposal, we want to quantitatively test model predictions and
constrain the theory for a better
understanding of massive star evolution. We are requesting HST STIS
observations of the BIII 2066
Angstrom resonance line of seven massive stars in three young clusters
carefully selected from IUE
analyses. These stars show traces of boron depletion, but without
nitrogen enrichment; rotation is the
only theory able to explain this abundance pattern. These new abundances
will allow us to test rotating
model predictions: that mixing strength increases with stellar age,
mass, and rotation rate. They will
also help to quantitatively constrain the rotational mixing
efficiencies in massive stars. One very
high S/N spectrum of a moderately boron-depleted star is also requested.
We wish to measure its 11B/10B
ratio, which is predicted to change as boron is depleted in the
rotating models. This ratio will
further confirm rotational effects and observationally constrain the
10B{p, Alpha} thermonuclear
reaction rate, which is presently highly uncertain.
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/NIC 9452
Characterizing the Star Formation History of a Highly Magnified z=5.6
Lyman Alpha Source
We have located a remarkably faint pair of compact images arising from a
z=5.6 Lyman Alpha emitting
source, magnified 33-fold by the lensing foreground cluster Abell 2218.
Keck spectra verify the lensing
hypothesis but fail to locate any UV stellar continuum to interesting
limits, suggesting the object is
a 10^6 M_sun source viewed close to its epoch of formation. We argue
the source could be
representative of an abundant population of low mass systems forming
their first stars at z>5, this
example becoming visible only by virtue of the strong gravitational
magnification. We seek HST imaging
to provide much tighter constraints on the nature and distribution of
starlight in this intriguing
source. ACS will be used to investigate the spatial extent of UV
continuum light on <100 pc scales also
providing the
equivalent width of the Lyman Alpha emission. NIC will be used to
measure the slope of the rest- frame
continuum in order to break age and mass degeneracies caused by the
unknown amount of dust extinction.
HST uniquely provides the resolution and sensitivity to gather detailed
information on a remarkable
source which may be representative of a population seen in future
surveys with NGST.
ACS 9480
Cosmic Shear With ACS Pure Parallels
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.
WFPC2 9594
WFPC2 CYCLE 11 SUPPLEMENTAL DARKS pt2/3
This dark calibration program obtains 3 dark frames every day to provide
data for monitoring and
characterizing the evolution of hot pixels
WFPC2/ACS 9601
WFPC2-ACS Photometric Cross-Calibration
This proposal is aimed at providing photometric zeropoint
cross-calibration between the commonly used
WFPC2 photometric filter sets and those that will be used for ACS
programs. The proposal includes
observations of globular clusters spanning a wide range in metallicity,
including NGC 2419 and 47 Tuc.
In addition, we will obtain WFPC2 observations of the primary ACS
standard star. This program will
produce a valuable tie-in between the WFPC2, ACS and Sloan filter
photometric systems.
STIS 9606
CCD Dark Monitor-Part 2
Monitor the darks for the STIS CCD.
STIS 9608
CCD Bias Monitor – Part 2
Monitor the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1,
and 1×1 at gain = 4, to build up
high-S/N superbiases and track the evolution of hot columns.
ACS 9650
CCD Hot Pixel Annealing
Hot pixel annealing will be performed once every 4 weeks. The CCD TECs
will be turned off and heaters
will be activated to bring the WFC detector temperature to about +10C.
The HRC temperature will reach
about 30C.This state will be held for approximately 24 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
this procedure, a bias and two dark images will be taken before and
after the annealing procedure for
both WFC and HRC.
ACS 9674
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.
STIS 9708
STIS Pure Parallel Imaging Program: Cycle 11
This is the default archival pure parallel program for STIS during cycle
11.
WFPC2 9709
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 paralell images of random areas of the sky, following the
recommendations of the 2002
Parallels Working Group.
WFPC2 9710
POMS Test Proposal: WFII backup parallel archive proposal
This is a POMS test proposal designed to simulate scientific plans.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies:
(The following are preliminary reports of potential non-nominal
performance that will be investigated.)
HSTARs:
8999 GSACQ(2,3,2) results in FL backup, Scan Step Limit Exceeded on FGS
3 @114/2249z
COMPLETED OPS REQs:
None
OPS NOTES EXECUTED:
SCHEDULED SUCCESSFUL FAILURE
TIMES
FGS GSacq 6
6
FGS REacq 5
5
FHST Update 15
15
LOSS of LOCK
SIGNIFICANT EVENTS: None
