Status Report

NASA Hubble Space Telescope Daily Report #3635

By SpaceRef Editor
June 21, 2004
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science




ACS/HRC 9703

Coronagraphic Search for Planets around Nearby Stars

We will use the HRC coronagraph to search for planets, disks, and
exo-zodiacal dust around nearby stars. We have selected the following
stars: alpha Cen A and B, tau Ceti, and epsilon Eridani. The
observations of each star will be taken at two or more epochs. The
observations will be broken into a sequence of short exposures and
taken at different roll angles to compensate for "telescope breathing"
during the orbit. As a further precaution, the observations will be
scheduled after the closest possible nearby pointing in order to
minimize thermal changes in the OTA during the first orbit of
observations. After matching phases, the PSFs from one star will be
subtracted from the other star.


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.

ACS/SBC 10047

ACS UV Contamination Monitor

A standard star field {NGC6681} is observed every three months,
alternating between after and before annealing operations, through all
the ACS broad band UV filters. NGC6681 hosts several UV spectro –
photometric standard stars for which accurate spectra have been {and
will continue to be} measured with STIS. Two SBC dark current
exposures taken as the last exposure of each SBC sequence. Also, to
minimize SBS turn-on/turn-off cycles and in order to check the lab
flats for the SBC detector, internal observations using the deuterium
lamp with F125LP are being taken inflight, following the UV monitor
observations. The internal flats have been taken ~monthly since SMOV,
and the degradation of the lamp has been monitored. The total exposure
time to date is ~15 hours giving a total of 8600 counts/pixel. The
goal is 10, 000 counts/pixel such that the resulting pipeline flat has
uncertainties of ~1% due to poisson counting statistics. Thus,
approximately 3 additional hours of observation are required.

ACS/WFC 9722

Life in the fast lane: The dark-matter distribution in the most
massive galaxy clusters in the Universe at z>0.5

We propose two-filter ACS observations of a complete sample of 12 very
X-ray luminous galaxy clusters at 0.5<z<0.7 as a cornerstone of a
comprehensive multi-wavelength study of the properties of the most
massive clusters in the universe. Our sample includes the famous
systems Cl0016+16 and MS0451-03; all other clusters are new
discoveries from the MACS survey. Being the counterparts of the
best-studied systems at lower and higher redshift and comprising ALL
massive clusters at 0.5<z<0.7 observable from Mauna Kea this sample
will become the ultimate reference for cluster studies at z>0.5. HST’s
unique capabilities will allow us to: 1} measure accurately the
clusters’ dark matter distribution on scales from tens to more than
500/h_50 kpc from observations of strong and weak gravitational
lensing, 2} use galaxy-galaxy lensing to measure the shape, extent,
and mass content of the dark-matter halos of both cluster and field
galaxies, and 3} study the color morphology of mergers and the star
formation history of galaxies in a high-density environment. The
proposed observations are complemented by Chandra observations of all
our targets {all 12 awarded, 11 executed to date} which provide
independent constraints on the dark matter and gas distribution in the
cluster cores, as well a by extensive groundbased observations of weak
lensing on yet larger scales, galaxy dynamics, and the SZ effect.

NIC/NIC3 9865

The NICMOS Parallel Observing Program

We propose to continue managing the NICMOS pure parallel program.
Based on our experience, we are well prepared to make optimal use of
the parallel opportunities. The improved sensitivity and efficiency of
our observations will substantially increase the number of
line-emitting galaxies detected. As our previous work has
demonstrated, the most frequently detected line is Halpha at
0.7<z<1.9, which provides an excellent measure of current star
formation rate. We will also detect star-forming and active galaxies
in other redshift ranges using other emission lines. The grism
observations will produce by far the best available Halpha luminosity
functions over the crucial–but poorly observed–redshift range where
galaxies appear to have assembled most of their stellar mass. This key
process of galaxy evolution needs to be studied with IR data; we found
that observations at shorter wavelengths appear to have missed a large
fraction of the star-formation in galaxies, due to dust reddening. We
will also obtain deep F110W and F160W images, to examine the space
densities and morphologies of faint red galaxies. In addition to
carrying out the public parallels, we will make the fully reduced and
calibrated images and spectra available on-line, with some
ground-based data for the deepest parallel fields included.

NIC1/NIC2/NIC3 8792

NICMOS Post-SAA calibration – CR Persistence Part 3

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.

NIC2 9856

A near-IR imaging survey of submm galaxies with spectroscopic

Submillimeter {submm} surveys with SCUBA have identified a population
of obscured star-forming and active galaxies at high redshift. Our
recent spectroscopic campaigns with the Keck-10m telescope have
uncovered redshifts for 37 SCUBA galaxies. The wide redshift range of
the radio identified submm population {z=1-4} implies that many
varieties of sources driven by different physical processes may be
selected in a submm survey. We propose to use HST-NICMOS, ACS to
obtain 2-filter images of a sample of 15 SCUBA galaxies with redshifts
spanning z=0.8-3.5. Our goal is to understand what physical process
{major mergers?} drive their strong evolution and great luminosities,
and what the implications are for galaxy evolution models.

STIS/CCD 10018

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.

STIS/CCD 10020

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.


Probing the High Redshift Universe with Quasar Emission Lines

The quasar epoch is believed to be associated with the birth of the
most massive galaxies, a time marked by rapid star formation and
evolution. Quasar emission lines can reveal the chemical evolution and
physical state of gas in the very center of these galaxies. Analysis
of the observed line strengths, using tools that have recently become
available, implies that the chemical composition of the emitting gas
correlates with quasar luminosity in a way that is suggestive of the
known galactic mass/luminosity/metallicity correlations. The emission
lines can also reveal the form of the ionizing radiation field emitted
by the central object. Understanding the evolution of the central
powerhouse is important for black hole accretion physics and because
its spectrum is likely to dominate the ionization of the IGM. There
are many high-ionization permitted emission lines in the region below
1000A rest wavelength that can provide important new constraints on
these measurements. Thus, there is a critical need for spectra over
the full rest-wavelength range ~ 600A through the UV. Through a pilot
Cycle 10 archival study, we have identified the QSO HE 1122-1648 as an
optimal object for such a study. This QSO has a sufficiently high
redshift {z = 2.4} so that we can see down to very short rest
wavelengths {463A} in observed-wavelength regions where STIS has high
sensitivity, and lies on a line of sight with an unusually low density
of intervening Ly-alpha absorber clouds. A high-quality spectrum of
this object will have implications for the ionization of the IGM and
will leverage the unique UV capabilities of HST to complement the
galaxy formation studies that NGST will do at higher redshift.

WFPC2 10071

WFPC2 CYCLE 12 Supplemental Darks Part 3/3

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


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



                        SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq            7                             7
FGS REacq            6                             6
FHST Update         13                          13


Successfully completed first group of Intensity data collections per
Ops Request 17198. Sections A through D (of consolidated script) have
been executed thus far.

FHST Rate Control and FHST Intensity data collections continued. See
Ops Request 17198 and 17199-1 for details.

Set-up and execution of HST CCS Release CT verification test
scheduled 169/11:00Z – 19:00Z with GDOC, HITT, and SOC using CCS "H"
String with CCS Release xxx (intentionally removed) and PRD xx. The
purpose of this testing is to verify GSCA 793 Upgrade to PF-13 Spare.

SpaceRef staff editor.