Status Report

Hubble Space Telescope Daily Report #2818 28 Feb 2001

By SpaceRef Editor

February 28, 2001

Filed under Space Telescope Science Institute, US

HUBBLE SPACE TELESCOPE

DAILY REPORT #2818

PERIOD COVERED: 0000Z (UTC) 02/27/01 – 0000Z (UTC) 02/28/01

Daily Status Report as of 059/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed Three Sets of WF/PC-2 8827 (Cycle 9 Supplemental Darks pt2/3)

The WF/PC-2 was used to obtain three dark frames every day to
provide data for monitoring and characterizing the evolution of hot
pixels. The proposal completed nominally.

1.2 Completed Two Sets of STIS/CCD 8837 (CCD Dark Monitor-Part 1)

The Space Telescope Imaging Spectrograph (CCD) was used to monitor
the darks. The proposal completed with no reported problems.

1.3 Completed WF/PC-2/STIS/CCD 8690 (The Central Region of NGC4696:
Manifestation of the Physics of Mergers?)

The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were
used to observe massive, dominant ellipticals with attendant emission-line
gas, dust and hot, heavy X–ray emitting coronae which lie at the very
centers of galaxy clusters. The physics of these complex, high pressure
regions remains controversial: Are cooling flows responsible? Do mergers
dominate, with massive accretion events triggering an array of
phenomena? Is the AGN crucial? A major impetus to understanding the
physics of these regions will come with Chandra. NGC4696 in the Centaurus
galaxy cluster is archetypal. WFPC2 images have shown a dramatic
bifurcation between gas and dust. T he nucleus itself is seen to be a
compact triple, with two blue components straddling a third red one. We
propose to obtain STIS long- slit spectra along a line-emission filament
and along a dust filament. The proposal completed with no reported problems.

1.4 Completed STIS/CCD/MA2 8673 (The Properties of Ly-Alpha Absorbers
at Redshifts Between 0.9HST)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used
obtain new Echelle resolution spectra of three bright quasars which, when
combined with archived and scheduled observations, will be used to
characterize the properties of Ly-Alpha absorbers in the redshift range
0.9

1.5 Completed Three Sets of WF/PC-2 8805 (POMS Test Proposal: WFII
Parallel Archive Proposal Continuation)

The WF/PC-2 was used to perform a 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 Parallels Working Group. The proposal completed with no reported
problems.

1.6 Completed Four Sets of WF/PC-2 8816 (Cycle 9 UV Earthflats)

The WF/PC-2 was used to obtain sequences of Earth streak flats to
improve the quality of pipeline flat fields for the WFPC2 UV filter set and
in order to monitor flat field stability. There were no reported problems.

1.7 Completed Two Sets of WF/PC-2 8811 (Cycle 9 Standard Darks)

The WF/PC-2 was used to obtain 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. The proposal completed with no reported problems.

1.8 Completed STIS/CCD 8624 (Imaging and Spectroscopy of Dusty
Circumstellar Disks)

The Space Telescope Imaging Spectrograph (CCD) was used to further
understanding of the properties and evolution of dusty disks in the
circumstellar environments of young stars which is a key element in
furthering our concepts of the formation mechanisms of extra-solar
planetary systems. The proposal completed with no reported problems.

1.9 Completed Eight Sets of STIS/CCD 8562 (Probing the Large Scale
Structure: Cosmic Shear Observations)

The Space Telescope Imaging Spectrograph (CCD) was used to probe
the distortion of light bundles from distant galaxies, looking at the
statistical properties of the intervening inhomogeneous {dark} matter
distribution. The proposal completed nominally.

1.10 Completed WF/PC-2 8604 (Stellar Populations Across the Small
Magellanic Cloud (SMC) : History and Structure)

The WF/PC-2 was used to investigate the structure and evolutionary
history of the SMC by obtaining a series of 50 three-color snapshots of
selected SMC regions. With this polling of SMC field star properties, we
will produce color-magnitude diagrams in the U, V and I bands which will
reach V~23.5 in regions too crowded to be observed accurately from the
ground. The observations completed nominally.

1.11 Completed WF/PC-2 8720 (Masses and Multiplicity of Nearby Free-
floating Methane and L Dwarfs)

The WF/PC-2 was used to observe 50 very-low-mass objects in the
solar neighborhood with spectral types of L0 and later {including several
dwarfs with Methane absorption bands in their atmospheres}. These objects
will be observed in two filter bands with the aim to identify close
companions, measure their colors, and to obtain first epoch data of the
newly discovered binaries. The observations completed nominally.

1.12 Completed STIS/CCD 8838 (Bias Monitor – Part 1)

The Space Telescope Imaging Spectrograph (CCD) was used to 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. The proposal completed nominally.

1.13 Completed WF/PC-2 8598 (Snapshot Survey of Extended OIIl Lambda
5007Angstrom Emission in Seyfert Galaxies)

The WF/PC-2 was used for a snapshot survey of narrow band OIII
Lambda 5007Angstrom images for a well defined sample of 88 Seyfert galaxies
{29 Seyfert 1s and 59 Seyfert 2s}, 18 of which already have data in the
archive, selected from a mostly isotropic property, the 60Mum flux. These
data will be used: 1} to determine the origin of the misalignment between
the accretion disk axis and the host galaxy plane axis, which can be due to
mergers with other galaxies, or by the self induced radiation warping; 2}
to compare the size and shape of the Narrow Line Regions (NLR) of Seyfert
1s and Seyfert 2s, and to study the frequency of conically shaped NLR in
Seyfert galaxies, which are usually unresolved from ground-based
observations; and 3} estimate the importance of shocks to the ionization of
the NLR. The observations completed with no reported problems.

1.14 Completed Two Sets of WF/PC-2 8705 (External Shear in the
Time-Delay Lens RX J0911+05)

The WF/PC-2 was used to map the mass distribution in the vicinity
of the multiple QSO system RX J0911+05 using weak gravitational
lensing. This object has emerged as one of the most promising candidates
for a cosmological determination of the Hubble constant using time delay
measurements. There is evidence that a high-redshift cluster of galaxies
acts as the source of a very large external shear, affecting the lens
potential. Deep WFPC2 images will allow direct measurement of this shear
from the distortions of faint background galaxies. The proposal completed
with no reported problems.

1.15 Completed STIS/CCD/MA2 8652 (Evolution of the Extinction Curve)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
examine the extinction curve that has been determined precisely in only a
few galaxies: the Milky Way {MW}, the Large and Small Magellanic clouds
{LMC and SMC}. It has also been determined towards several starburst
galaxies, but its significance then depends on the precise star-gas-dust
geometry. There is no general agreement on a model to explain its
characteristics; laboratory experiments fail to reproduce the famous
2175Angstrom feature under the conditions of the popular silicate-graphite
model. The MW, LMC and SMC extinction curves are generally used to bracket
extinction curves in other galaxies. Extinction by dust influences the
determination of the Hubble constant from cepheids, of Omega_mathrm M and
Lambda using Type Ia Supernovae or gravitational lenses, of the
cosmological density of gas and star formation history and the origin the
Cosmic Infrared Background. The proposal completed with no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 7

Successful: 7

Scheduled Re-acquisitions: 8

Successful: 8

2.2 FHST Updates:

Scheduled:
13

Successful: 13

2.3 Operations Notes:

Operations personnel supported GSFC Internal Simulation #5 (EVA-4)
yesterday from 8:00 a.m. until approximately 7:30 p.m.

The SSR EDAC error counter was cleared twice per ROP SR-1A.