Status Report

Hubble Space Telescope Daily Report #2905 2 July 2001

By SpaceRef Editor

July 2, 2001

Filed under Hubble Space Telescope, Space Telescope Science Institute, US

HUBBLE SPACE TELESCOPE

DAILY REPORT #2905

PERIOD COVERED: 0000Z (UTC) 06/29/01 – 0000Z (UTC) 07/02/01

Daily Status Report as of 183/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed Nine Sets of WF/PC-2 8828 (Cycle 9 Supplemental Darks pt3/3)

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 with no reported problems.

1.2 Completed Three Sets of WF/PC-2 8601 (A Snapshot Survey of Probable
Nearby Galaxies)

The WF/PC-2 was used to continue the very successful snapshot
survey in order to use the high spatial resolution of HST to determine
whether selected galaxies are nearby on the basis of resolution into stars,
and the magnitudes and colors of the brightest stars. There were no
reported problems.

1.3 Completed Two Sets of WF/PC-2 8581 (A Search For Low-Mass
Companions To Ultracool Dwarfs)

The WF/PC-2 was used to search for very low-mass {VLM} companions
to a complete sample of 120 late-M and L dwarfs, drawn mainly from the
2MASS and SDSS surveys. The primary goal is to determine the multiplicity
of M < 0.1 M_odot dwarfs. In particular, we aim to identify binary systems suitable for long-term astrometric monitoring and mass measurement, and systems with cool, sub-1000K companions. The proposal completed with no reported problems.

1.4 Completed WF/PC-2 8723 (A Snapshot Survey of Galactic Globular
Clusters)

The WF/PC-2 was used to observe the crowded centers of globular
clusters {GCs} that heretofore have produced intriguing discoveries of new
phenomena, most of which are not understood theoretically. The
observations completed with no reported problems.

1.5 Completed Five Sets of WF/PC-2 9044 (The Stellar Population of UGCA
292, An Extreme Low Metallicity Galaxy)

The WF/PC-2 was used to observe the third lowest metallicity galaxy
known, UGCA 292, that provides a unique opportunity to investigate the
evolutionary status of extremely metal–poor, gas–rich, star–forming
galaxies. UGCA 292 is sufficiently nearby, that it is possible to resolve
the stellar population with HST. These observations enable investigation
of the stellar population of this relatively unevolved galaxy and determine
if the low metallicity and high gas mass fraction are indicative of a newly
formed galaxy. The observations completed nominally.

1.6 Completed WF/PC-2 8632 (A UV Atlas of Nearby Galaxies)

The WF/PC-2 was used to perform a snapshot survey of local galaxies
at UV wavelengths with the F300W filter. The aim of the project is to
build a reference UV Atlas of normal galaxies, whose optical images are
well known, with the highest possible degree of information, covering all
the morphological types and luminosity classes. The proposal completed
normally.

1.7 Completed Two Sets of WF/PC-2 9133 (Imaging of Gravitational Lenses)

The WF/PC-2 was used to observe gravitational lenses that offer
unique opportunities to study cosmology, galactic structure, galaxy
evolution, quasar hosts and extinction. They are also the only sample of
galaxies selected on the basis of their mass rather than their luminosity
or surface brightness. While gravitational lenses can be discovered with
ground-based optical and radio observatories, converting them from
curiosities into scientific tools requires HST. There were no reported
anomalies.

1.8 Completed Two Sets of 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.

1.09 Completed Four Sets of WF/PC-2 9244 (POMS Test Proposal: WFII
Parallel Archive Proposal Continuation)

The WF/PC-2 was used to perform a generic target version of the
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 observations completed with no anomalous
activity.

1.10 Completed Two Sets of FGS/1 8731 (A High Angular Resolution Survey
of the Most Massive Stars in the SMC)

Fine Guidance Sensor #1 was used to conduct high angular resolution
observations of some of the SMC’s hottest and most luminous objects by
conducting a comprehensive survey of nearly every spectral type in the
upper portion of the HR diagram. Binary or multiple star systems will be
detected down to an unprecedented level, more than one order of magnitude
better than possible with WFPC2. The targets selected include a
representative list of normal Main Sequence O-stars and their evolved
descendents, namely supergiants, hypergiants, LBVs, and WRs, many of which
have been previously observed by HST’s spectrometers for purposes of
cosmological calibrations. The observations completed, and no problems
were reported.

1.11 Completed Three Sets of WF/PC-2 8683 (Imaging Of Brightest Cluster
Galaxies: The High End Of The Black Hole Mass Distribution)

The WF/PC-2 was used to make kinematic black hole detections in
galaxies to decide whether they indicate that the mass correlates with both
optical luminosity and radio power. The observation completed with no
reported problems.

1.12 Completed WF/PC-2 8597 (The Fueling of Active Nuclei: Why are
Active Galaxies Active?)

The WF/PC-2 was used to investigate the accretion onto massive
black holes that are believed to be the energy source for AGN. However,
evidence for black holes in quiescent galaxies has also been reported. Why
are these galaxies inactive? One possibility is that active galaxies are
better at providing fuel to the nuclear region than quiescent
galaxies. Other possible fueling mechanisms such as “bars-within-bars”
or nuclear spirals cannot be investigated from the ground because they are
relatively small features in the ISM. The observations were completed as
planned.

1.13 Completed Three Sets of WF/PC-2 9086 (Investigating the Formation
History of Spiral Galaxy Halos)

The WF/PC-2 was used to make observations in order to constrain the
origin of spiral galaxy halos by studying stellar populations near the tip
of the red giant branch. This will be the first systematic study of this
population in external galaxies and will quadruple the sample of normal
spiral galaxies for which the halo metallicity distribution function is
measured. This larger sample will permit study of the relationship between
the bulge, disk, and halo components and between halos and globular
systems. Such correlations will in turn provide indications as to whether
the halo, bulge, and globular cluster systems built up nearly
simultaneously in the early universe or were accreted over time through
different kinds of merging events. The loss-of-lock described in 2.1 and
HSTAR 8253 occurred during the first iteration of this proposal, near the
end of the four-hour duration of the proposal. Otherwise, the proposal
completed nominally with no further reported problems.

1.14 Completed Three Sets of WF/PC-2 8820 (Wavelength Stability of
Narrow Band and Linear Ramp Filters)

The WF/PC-2 was used to verify the mapping of wavelength as a
function of CCD position on linear ramp filters and to check for changes in
central wavelengths of the narrow band filters. The proposal completed
nominally.

1.15 Completed Four Sets of FGS/1 9034 (The Masses and Luminosities of
Population II Stars)

Fine Guidance Sensor #1 was used to observe the mass-luminosity
relation {MLR} of Population II stars of which very little is currently
known. With the advent of the Hipparcos Catalogue, improved distances to
many spectroscopic binaries known to be Pop II systems are now
available. After surveying the literature and making reasonable estimates
of the secondary masses, we find 13 systems whose minimum separation should
be larger than the resolution limit of FGS #1. The observations completed
nominally.

1.16 Completed FGS/1R 8618 (Parallaxes of Magnetic CVs)

The FGSs were used to gather data for the calculation of
trigonometric parallaxes of cataclysmic variable {CVs} which are needed to
obtain reliable information on luminosities, accretion rates, and on radii
and masses of the stellar components. They are also needed to derive the
space density, an important ingredient for theories of CV evolution. The
observations completed with no reported problems.

1.17 Completed WF/PC-2 9257 (Cycle 10 Super-PSF)

The WF/PC-2 was used to obtain deep images of the WFPC2 Point
Spread Function (PSF) in several broadband filters in order to investigate
the 2-dimensional structure in the PSF wings and characterize the change in
structure with varying focus and target color. There were no reported
problems.

1.18 Completed Two Sets of WF/PC-2 8583 (Imaging Snapshots of Asteroids)

The WF/PC-2 was used to obtain images of the fifty largest main
belt asteroids that have favorable apparitions during cycle 9. The images
will be searched for companion bodies, as well as mineralogical variegation
on the resolved main bodies. There were no reported problems.

1.19 Completed WF/PC-2 8177 (Investigating Type Ia Supernovae and an
Accelerating Universe)

The WF/PC-2 was used to obtain rest frame U and B photometry for
four z~ 0.85 Supernova (SN) Ia. These observations will be coupled to
ground-based rest frame V photometry and spectra. These data, combined
with previous samples, will extend the D_L vs. z diagram for SN Ia to
z~0.85, and allow us to discriminate the redshift dependence of supernova
magnitudes in an accelerating Universe from that expected to result from
systematic effects such as age of the stellar population, chemical
evolution, a drift in the properties of dust, and weak gravitational
lensing. The proposal completed with no reported problems.

1.20 Completed WF/PC-2 8829 (Observatory Focus Monitor)

The WF/PC-2 was used to analyze the HST focus which drifts slowly
and shows evidence of undergoing slips of a few microns at random
times. The rate of the WFPC2 monitoring program is insufficient to track
and/or understand OTA behavior in order to request timely and appropriate
secondary mirror corrections. This 14-orbit program obtains a large amount
of high signal to noise focus data and will be sufficient to more
accurately define the HST focus. There were no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 32

Successful: 32

There was a loss-of-lock at 180/202046Z during the proposal
detailed in 1.13. Lock was recovered via new #44 commanding. HSTAR 8253
was written.

Per HSTAR 8255, another loss-of-lock occurred at
183/040652Z. There were no executing proposals at that time.

Scheduled Re-acquisitions: 16

Successful: 16

2.2 FHST Updates:

Scheduled: 69

Successful: 68

Per HSTAR 8254, the full maneuver update scheduled for 180/230100Z
failed due to FGS-2. The subsequent acquisition was successful.