Status Report

HST Daily Report # 3306

By SpaceRef Editor
February 26, 2003
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HUBBLE SPACE TELESCOPE

DAILY REPORT # 3306

PERIOD COVERED: DOY 55

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.

ACS 9352

The Deceleration Test from Treasury Type Ia Supernovae at Redshifts 1.2 to
1.6

Type Ia supernovae {SNe Ia} provide the only direct evidence for an
accelerating
universe, an extraordinary result that needs a rigorous test. The case for
cosmic acceleration rests on the observation that SNe Ia at z ~ 0.5 are ~
0.25
mag fainter than they would be in a universe without acceleration. A
powerful
and straightforward way to assess the reliability of the SN Ia measurement
and
the conceptual framework of its interpretation is to look for cosmic
deceleration at z >= 1. This would be a clear signature of a mixed
dark-matter
and dark-energy universe. Systematic errors in the SN Ia result attributed
to
grey dust or cosmic evolution of the SN Ia peak luminosity would not show
this
change of sign. We have demonstrated proof of this concept with a single SN
Ia,
SN 1997ff at z = 1.7, found and followed by HST. The results suggest an
early
epoch of deceleration, but this is too important a conclusion to rest on
just
one object. Here we propose to use HST for observations of six SNe Ia in the
range 1.2 <= z <= 1.6, that will be discovered as a byproduct from proposed Treasury programs for high-latitude ACS surveys. Six objects will provide a much firmer foundation for a conclusion that touches on important questions of fundamental physics.

NICMOS 9386

Infrared Photometry of a Statistically Significant Sample of KBOs

While the discovery rate of Kuiper Belt objects is accelerating, the
physical
study of this new region of the solar system has been slowed by a lack of
basic
astrophysical data. Photometric observations of the majority of the more
than
400 known KBOs and Centaurs are rudimentary and incomplete, particularly in
the
infrared. The multicolor optical-infrared photometry that exists for a small
subset of KBOs often shows significant discrepancies between observations by
different observers. Their intrinsic faintness puts them at the practical
limits
of ground-based systems. In July 2001 we began what will be the largest
uniform
sample of optical photometry of KBOs with a WFPC2 SNAPSHOT program that will
perform accurate photometry at V, R, and I on a sample of up to 150 targets.
We
seek to greatly enhance the value of this survey by obtaining J and H
photometry
on the same sample using NICMOS. Combined optical and infrared broad band
photometry is a far more powerful tool for physical studies than is either
alone. Our sample includes objects that will be observed at thermal infrared
wavelengths by SIRTF and will be used with those data to derive the first
accurate diameters, albedos, and surface properties for a large sample of
KBOs.

ACS 9401

The ACS Virgo Cluster Survey

We propose the most comprehensive imaging survey to date of low-redshift,
early-type galaxies. Our goal is to exploit the exceptional imaging
capabilities
of the ACS by acquiring deep images — in the SDSS g^ and z^ bandpasses
— for
163 E, S0, dE, dE, N and dS0 galaxies in Virgo, the nearest rich cluster.
This
extraordinary dataset would likely constitute one of the principal legacies
of
HST, and would have widespread applications for many diverse areas of
astrophysics. Our immediate scientific objectives are threefold: {1} measure
metallicities, ages and radii for the many thousands of globular clusters
{GCs}
in these galaxies, and use this information to derive the protogalactic mass
spectrum of each galaxy; {2} measure the central luminosity and color
profile of
each galaxy, and use this information to carry out a completely independent
test
of the merging hierarchy inferred from the GCs, with the aid of N-body codes
that simulate the merger of galaxies containing massive black holes; and {3}
calibrate the z^ -band SBF method, measure Virgo’s 3-D structure, and carry
out
the definitive study of the GC luminosity function’s precision as a standard
candle. Our proposed Virgo Cluster Survey will yield a database of
unprecedented
depth, precision and uniformity, and will enable us to study the record of
galaxy and cluster formation in a level of detail which will never be
possible
with more distant systems.

ACS 9440

The Composition of Io’s Pele Plume

We propose to determine the composition of Io’s largest volcanic plume,
Pele,
with unprecedented accuracy. This will give us new constraints on the
temperatures, pressures, and magma composition of this volcano, and thus an
improved window into Io’s interior. We will use the proven Jupiter transit
spectroscopy technique, which resulted in the discovery of S_2 gas in the
Pele
plume, but will use exposures that are 4 times longer than in the discovery
observations. This will allow us to accurately measure plume SO_2
abundances,
seen only with low S/N in the discovery observations, and possibly SO, in
addition to S_2, and gives the chance to discover other, currently unknown,
plume components. We will also use ACS to obtain UV and visible images of
the
Pele plume in reflected light prior to Jupiter transit, to constrain the
dust
abundance and particle size in the plume. This will allow refined estimates
of
plume dust/gas ratios and resurfacing rates. We will repeat the observations
four times to build up S/N to even higher levels, and to look for time
variability in both dust and gas abundance and chemistry.

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.

ACS/WFPC2 9481

Pure Parallel Near-UV Observations with WFPC2 within High-Latitude ACS
Survey
Fields

In anticipation of the allocation of ACS high-latitude imaging survey{s}, we
request a modification of the default pure parallel program for those WFPC2
parallels that fall within the ACS survey field. Rather than duplicate the
red
bands which will be done much better with ACS, we propose to observe in the
near-ultraviolet F300W filter. These data will enable study of the
rest-frame
ultraviolet morphology of galaxies at 0

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.

ACS/WFPC2 9488

Cosmic Shear – with ACS Pure Parallel Observations

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/

ACS 9500

The Evolution of Galaxy Structure from 10, 000 Galaxies with 0.1HST Proposal
9500

We propose to determine the evolution of galaxy structure over the last half
of
cosmic history from galaxy images in the redshift range 0.1100 AGNs identified in the
field,
we will investigate whether the population of host galaxies evolved in the
last
10^10 years.

WFPC2 9592

WFPC2 CYCLE 11 Standard Darks

This dark calibration program obtains dark frames every week in order to
provide
data for the ongoing calibration of the CCD dark current rate, and to
monitor
and characterize the evolution of hot pixels. Over an extended period these
data
will also provide a monitor of radiation damage to the CCDs.

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 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.

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 9615

Cycle 11 MAMA Dark Monitor

This test performs the routine monitoring of the MAMA detector dark noise.
This
proposal will provide 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.

ACS 9658

ACS Earth Flats

This program will obtain sequences of flat field images by observing the
bright
Earth. Several UV filters from the interim calibration program {9564}
require
additional exposures to obtain the required illumination. A few UV filters
from
this program will be repeated to monitor for changes in the flat fields and
to
verify the interim results. Since no streaks are observed in the UV, the
wavelength coverage is extended to longer wavelengths in order to explore
the
severity of streaks in the flats from clouds in the FOV. We have added
exposures
for the HRC in the visible filters to verify the results derived from the
L-flat
campaign and to explore the severity of streaks. We have also added
exposures on
WFC using the minimum exposure time and using filters which will not
saturate
the brightest WFC pixel by more than 10 times the full well.

WFPC2/PC1 9663

Focus Monitoring

The HST focus is monitored using WFPC2/PC1. In principle ACS/HRC should
provide
superior capability for monitoring the HST focus. Since most of the HST
science
will shift to ACS in Cycle 11 trending observations are continued with this
program to establish the focus of WFPC2/PC1 {and hence HST} and ACS/HRC
{and WFC
to a lessor degree} using exposures over full orbits that are taken in
parallel.
With parallel exposures breathing cancels out for the relative camera
offset.

ACS 9673

CCD Daily Monitor

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

STIS 9685

Multiwavelength Observations of Jupiter’s Auroral Hot Spot

Joint Chandra HRC-I and HST STIS observations in Dec 2000 found that the
northern auroral x-ray emission comes from a localized hot spot located
poleward
of the main auroral oval, magnetically connected to regions in the outer
magnetosphere beyond 30 Jupiter radii. In addition, the x-ray hot spot
pulsates
with a quasi-period of about 45 minutes. The hot spot occurs in a region
where
both anomalous infrared emissions and bright, transient far-ultraviolet
{FUV}
flares have been observed. These results are inconsistent with excitation by
energetic heavy ions precipitating from the region of the Io plasma torus.
Our
simultaneous HST STIS and CHANDRA ACIS-S observations of Jupiter seek to
understand the source mechanisms and energetics of the jovian x-ray aurora.
We
will also seek near-simultaneous ground infrared observations with the IRTF.

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               08                        08
FGS REacq               07                        07
FHST Update             20               19         @56/09:07:48z The
second of 2 updates failed, no HSTAR required
LOSS of LOCK

SIGNIFICANT EVENTS: None

SpaceRef staff editor.