HST Daily Report # 3267
HUBBLE SPACE TELESCOPE
DAILY REPORT # 3267
PERIOD COVERED: DOY 352
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.
ACS/WFC/HRC 9075
Cosmological Parameters from Type Ia Supernovae at High Redshift.
The Advanced Camera for Surveys (WFC and HRC) was used to obtain a Hubble
diagram of Type Ia supernovae {SNe Ia} that will be of long lasting value as
a
record of the expansion history of the universe.
NICMOS/STIS CCD 9405
The Origin of Gamma-Ray Bursts
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 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 9454
The Nature of the UV Continuum in LINERs: A Variability Test
LINERs may be the most common AGNs, and the signposts of accretion onto the
massive black holes present in most galaxies. However, the LINER spectrum is
the
result of UV excitation, and, in at least some LINERs, a nuclear cluster of
hot
stars, rather than an AGN, dominates the energetics in the UV. Thus, it is
still
unknown if the UV continuum, or the optical emission lines it excites, have
anything to do with an AGN. The demographics and accretion physics of
low-luminosity AGNs hinge on this question. We propose to search for
variability
in a sample of 17 LINERs with compact UV nuclei. Variability can reveal an
AGN
component in the UV continuum, even when its light is not dominant. We will
test
systematically the handful of non-definitive reports of UV variability, and
potentially quantify the AGN contribution to the UV emission. Variability in
all
or most objects will be strong evidence that LINERs mark dormant AGNs in
most
galaxies. Alternatively, a general null detection of variability will
suggest
that, even in LINERs with additional AGN signatures, the UV continuum is
stellar
in origin. Contemporaneous monitoring with the VLA/VLBA of 11 objects which
have
radio cores {five of which we already know are radio-variable} will reveal
the
relations between UV and radio variations. The UV-variable objects will be
targeted for future, better-sampled, monitoring.
ACS 9463
Are OH/IR stars the youngest post-AGB stars? An ACS SNAPshot imaging survey
Essentially all well-characterized preplanetary nebulae {PPNs}– objects in
transition between the AGB and planetary nebula evolutionary phases – are
bipolar, whereas the mass-loss envelopes of AGB stars are strikingly
spherical.
In order to understand the processes leading to bipolar mass-ejection, we
need
to know at what stage of stellar evolution does bipolarity in the mass-loss
first manifest itself? We have recently hypothesized that most OH/IR stars
{evolved mass- losing stars with OH maser emission} are very young PPNe. We
propose an ACS/SNAPshot imaging survey of a large, morphologically unbiased
sample of these objects, selected using their IRAS 12-to-25micron colors.
Our
ground-based imaging study of OH/IR stars has revealed a few compact bipolar
objects, supporting our hypothesis. However since most objects remain
unresolved, HST observations are needed to determine how and when the
bipolar
geometry asserts itself. Our complementary program of interferometric
mapping of
the OH maser emission in our sources is yielding kinematic information with
spatial resolution comparable to that in the HST images. The HST/radio data
will
provide crucial input for theories of post-AGB stellar evolution. In
addition,
these data will also indicate whether the multiple concentric rings,
“searchlight beams”, and truncated equatorial disks recently discovered
with
HST in a few PPNs, are common or rare phenomena.
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.
ACS/WFPC2 9488
Cosmic Shear – with ACS Pure Parallel Observations
The ACS, with greater sensitivity and sky coverage, will extend our ability
to
measure the weak gravitational lensing of galaxy images caused by the large
scale distribution of dark matter. We propose to use the ACS in pure
parallel
{non- proprietary} mode, following the guidelines of the ACS Default Pure
Parallel Program. Using the HST Medium Deep Survey WFPC2 database we have
measured cosmic shear at arc-min angular scales. The MDS image parameters,
in
particular the galaxy orientations and axis ratios, are such that any
residual
corrections due to errors in the PSF or jitter are much smaller than the
measured signal. This situation is in stark contrast with ground-based
observations. We have also developed a statistical analysis procedure to
derive
unbiased estimates of cosmic shear from a large number of fields, each of
which
has a very small number of galaxies. We have therefore set the stage for
measurements with the ACS at fainter apparent magnitudes and smaller, 10
arc-second scales corresponding to larger cosmological distances. We will
adapt
existing MDS WFPC2 maximum likelihood galaxy image analysis algorithms to
work
with the ACS. The analysis would also yield an online database similar to
that
in archive.stsci.edu/mds/
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.
CAL/WF2 9597
Intflat Sweep, Visflat Sweep, and Filter Anomaly Check
No abstract available.
STIS 9605
CCD Dark Monitor-Part 1
Monitor the darks for the STIS CCD
STIS 9607
CCD Bias Monitor – Part 1
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.
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 9640
Flats Stability
This calibration proposal is the Cycle 11 NICMOS monthly monitor A series of
camera 1, 2, & 3 flat fields will be obtained to monitor the health of the
cameras.
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.
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.
STIS 9692
STIS Pure Parallel Imaging Program: Cycle 10
This is the default archival pure parallel program for STIS during cycle 10.
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.
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 13 13
FGS REacq 2 2
FHST Update 22 22
LOSS of LOCK
SIGNIFICANT EVENTS:
Decrease (0.05 ?K) in NCS PID Control Set Point scheduled for 353/12:47Z (OR
16887-1). Prime
(dewar NOT active) and Alternate (neon, ACTIVE) control points will be set
to 77.15 ?K and
72.35 ?K, respectively.
