Status Report

NASA Hubble Space Telescope Daily Report # 3466

By SpaceRef Editor
October 13, 2003
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HUBBLE SPACE TELESCOPE

DAILY REPORT # 3466

PERIOD COVERED: DOYs 283-285

OBSERVATIONS SCHEDULED

STIS/CCD 9981

The Ultra Deep Field – STIS parallels

We propose to obtain slitless spectroscopy of objects in the GEMS and
GOODS area around the UDF.

WFPC2 9980

The Ultra Deep Field – WFPC2 Parallels

The ACS Ultra Deep Field {UDF} is a survey carried out by using
Director’s Discretionary time. The main science drivers are galaxy
evolution and cosmology. The primary instrument is the Advanced Camera
for Surveys but WFPC2, NICMOS, and STIS will also be used in pure
parallel mode. The data will be made public. The UDF consists of a
single ultra-deep field {410 orbits in total} within the CDF-S GOODS
area. We request a modification of the default pure parallel programs.
Rather than duplicate the redder 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<z<1, allowing determination of the morphological
k-correction and the location of star formation within galaxies, using
a sample that is likely to be nearly complete with multi-wavelength
photometry and spectroscopic redshifts. The results can be used to
interpret observations of higher redshift galaxies by ACS.

NIC3 9979

The Ultra Deep Field – NICMOS Parallels

This is a plan to manage the NICMOS pure parallels of the ACS Ultra
Deep Survey. We will obtain a mix of F110W and F160W images along
sight-lines within the mosaiced ACS fields of the CDF-S GOODS and GEMS
surveys, with these sight-lines enabling an examination of the space
density and morphologies of the reddest galaxies.

ACS/CCD/WFC 9978

The Ultra Deep Field with ACS

The ACS Ultra Deep Field {UDF} is a survey carried out by using
Director’s Discretionary time. The main science driver are galaxy
evolution and cosmology. The primary instrument is the Advanced Camera
for Surveys but WFPC2 and NICMOS will also be used in parallel. The
data will be made public. The UDF consists of a single ultra-deep
field {410 orbits in total} within the CDF-S GOODS area. The survey
will use four filters: F435W {55 orbits}, F606W {55 orbits}, F775W
{150 orbits}, and F850LP {150 orbits}. The F435W {B} and F606W {V}
exposures will be one magnitude deeper than the equivalent HDF
filters. The F775W {I} exposure will be 1.5 magnitude deeper than the
equivalent HDF exposure. The depth in F775W and F850LP is optimized
for searching very red objects – like z=6 galaxies – at the detection
limit of the F850LP image. The pointing will be RA{J2000}=3 32 40.0
and Decl.{J2000}=-27 48 00. These coordinates may change slightly due
to guide star availability and implementation issues. We will attempt
to include in the field both a spectroscopically confirmed z=5.8
galaxy and a spectroscopically confirmed type Ia SN at z=1.3. The
pointing avoids the gaps with the lowest effective exposure on the
Chandra ACIS image of CDFS. This basic structure of the survey
represents a consensus recommendation of a Scientific Advisory
Committee to the STScI Director Steven Beckwith. A local Working Group
is looking in detail at the implementation of the survey.

FGS 9879

An Astrometric Calibration of the Cepheid Period-Luminosity Relation

We propose to measure the parallaxes of 10 Galactic Cepheid variables.
There is no other instrument on or off the earth that can consistently
deliver HST FGS level of precision for critical parallaxes. When these
parallaxes {with 1-sigma precisions of 10% or better} are added to our
recent HST FGS parallax determination of delta Cep {Benedict et al
2002}, we anticipate determining the Period-Luminosity relation zero
point with a 0.03 mag precision. In addition to permitting the test of
assumptions that enter into other Cepheid distance determination
techniques, this calibration will reintroduce Galactic Cepheids as a
fundamental step in the extragalactic distance scale ladder. A
Period-Luminosity relation derived from solar metallicity Cepheids can
be applied directly to extragalactic solar metallicity Cepheids,
removing the need to bridge with the Large Magellanic Cloud and its
associated metallicity complications.

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.

STIS/CCD/MA1 9858

A Search for the Missing Baryons in Nearby Cosmic Filaments

Most of the baryons in the local universe are "missing" in that they
are not in galaxies or in the previously detected gaseous phases.
These missing baryons are predicted to be in a warm-hot low density
phase, largely in the giant cosmic filaments that connect the denser
virialized clusters and groups of galaxies. Models show that the
highest covering fraction of such filaments occurs in superclusters
and observations of two AGNs behind known superclusters showed
multiple LyAlpha absorption systems at the supercluster redshift.
These results are impressive considering that these AGNs were not even
optimally located. Here we selected a several AGNs that lie close to
the expected central axis of supercluster filaments. These HST
observations will identify LyAlpha absorbing gas while a complementary
FUSE program will search for OVI gas in the same systems.

ACS/WFC 9744

HST Imaging of Gravitational Lenses

Gravitational lenses offer unique opportunities to study cosmology,
dark matter, galactic structure, galaxy evolution and quasar host
galaxies. They are also the only sample of galaxies selected based on
their mass rather than their luminosity or surface brightness. While
gravitational lenses can be discovered with ground-based optical and
radio observations, converting them into astrophysical tools requires
HST. HST has demonstrated that it is the only telescope that can in
each case precisely locate the lens galaxy, measure its luminosity,
color and structure, and search for lensed images of the source host
galaxy given the typical image separations of ~1”. We will obtain
ACS/WFC V and I images and NICMOS H images of 21 new lenses never
observed by HST and NICMOS H images of 16 lenses never observed by HST
in the IR. As in previous cycles, we request that the data be made
public immediately.

NIC2 9726

A NICMOS search for obscured supernovae in starburst galaxies

Recent near-IR monitoring campaigns were successful in detecting
obscured supernovae {SNe} in starburst galaxies. The inferred SN rate
is much higher than that obtained in previous optical campaigns, but
it is still significantly lower than expected by the high level star
formation of these systems. One possible explanation for the shortage
of SNe is that most of them occur in the nuclear region, where the
limited angular resolution of groundbased observations prevents their
detection. We propose NICMOS SNAP observations of a sample of
starburst galaxies already observed once by NICMOS, with the goal of
exploiting its sensitivity and angular resolution to detect nuclear
obscured SNe which might have been missed by groundbased surveys.
These observation will allow to assess the real SN rate in starbust
galaxies and deliver a sample of SN occurring in the extreme
environment of galactic nuclei. We expect to detect more than 55 SNe
{if the whole sample is observed}. If the number of SNe detected in
the program is much lower than expected it would prompt for a revision
of our understanding of the relation between the star formation rate
and the SN rate.

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 parallel images of random
areas of the sky, following the recommendations of the 2002 Parallels
Working Group.

STIS 9383

Probing the Grains Responsible for Extinction Using Small Magellanic
Cloud Sightlines

Small Magellanic Cloud sightlines have the greatest potential to
relate specific interstellar extinction features to distinct grain
properties. The reasons for this are 1} prominent extinction features
such as the 2175 Angstrom bump and the far-ultraviolet rise vary among
SMC targets and 2} grain types may be very different from those in the
Galaxy. Specifically, Welty et al. {2001} recently identified an SMC
sightline that contains dust, but no silicate grains. Silicates are a
dominant source of extinction in all dust models; the SMC may be the
only location where the importance of silicates can be verified or
disproved. We propose to explore the relationship between grain types
and extinction toward 2 SMC stars with very different extinction
curves; AzV 18 lacks a 2175 Angstrom bump and has a strong far-UV rise
while the extinction curve towards the SMC star AzV 456 has a
prominent 2175 Angstrom bump and a much weaker far-UV rise. We will
compare the interstellar abundances of atoms that are prevalent in
silicates {Si, Mg, Fe} toward these 2 stars and use the results to
constrain dust extinction models. These SMC observations, which can
only be obtained with STIS, are the only direct way to probe the
connection between grain types/environments and extinction. The
results from this study will be useful for modeling and understanding
all regions that contain dust {AGN, circumstellar disks, star
formation regions, etc.}.

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.

WFPC2 10082

POMS Test Proposal: WFII backup parallel archive proposal

This is a POMS test proposal designed to simulate scientific plans

WFPC2 10069

WFPC2 CYCLE 12 Supplemental Darks, Part 1/3

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

ACS/HRC 10050

ACS Earth Flats

High signal sky flats will be obtained by observing the bright Earth
with the HRC and WFC. These observations will be used to verify the
accuracy of the flats currently used by the pipeline and will provide
a comparison with flats derived via other techniques: L-flats from
stellar observations, sky flats from stacked GO observations, and
internal flats using the calibration lamps. Weekly coronographic
monitoring is required to assess the changing position of the spots.

ACS/WFC 10046

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 detector
temperatures to about +20C. This state will be held for approximately
12 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 after the annealing procedure for both WFC and HRC. The HRC
darks are taken in parallel with the WFC darks.

ACS/HRC/WFC 10042

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/CCD 10019

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/CCD 10017

CCD Dark Monitor-Part 1

Monitor the darks for the STIS CCD.

STIS/CCD 10000

STIS Pure Parallel Imaging Program: Cycle 12

This is the default archival pure parallel program for STIS during cycle 12.

FLIGHT OPERATIONS SUMMARY:

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

COMPLETED OPS REQs:
17054-1 Reconfigure for MSS magnetic field TLM @ 284/0512z

OPS NOTES EXECUTED:
1155-0 Batery#1 Capacity Test Ground Limit Values @284/1417z (closed)

                              SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq                  21                        21
FGS REacq                  22                        22
FHST Update                32                        32
LOSS of LOCK

SIGNIFICANT EVENTS:

Successfully completed OR 17054-2, Reconfigure for MSS Magnetic Field
Telemetry @ 284/05:12Z. MSS measured data from MSS 1 and MSS 2 need
to be placed into TMDIAG slots to allow for a 20 Hz sample rate.
Each data set is required to be telemetered for a time duration of 30
– 35 minutes in PN Format.

SpaceRef staff editor.