Status Report

Hubble Space Telescope Daily Report #2882 – 30 May 2001

By SpaceRef Editor

May 30, 2001

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

HUBBLE SPACE TELESCOPE

DAILY REPORT #2882

PERIOD COVERED: 0000Z (UTC) 05/29/01 – 0000Z (UTC) 05/30/01

Daily Status Report as of 150/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed WF/PC-2 8702 (The Most Elusive Nuclei of LMC Planetary
Nebulae)

The WF/PC-2 was used to carry out a SNAPSHOT survey of the faintest
nuclei of planetary nebulae {PNe} in the LMC. This program will be a
crucial follow-on to a Cycle 8 SNAPSHOT of LMC Pne. In this case the plan
is to observe the faintest or most obscured nuclei to determine their
evolutionary state to an accuracy not possible in the Galaxy. These
faintest central stars are predicted to be among the most massive nuclei,
and owing to the typically advanced age of the surrounding nebulae, are the
most sensitive discriminants for validating the post-AGB evolution time
scales predicted by theory. The observations completed with no reported
problems.

1.2 Completed Three 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.

1.3 Completed Two 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.

1.4 Completed WF/PC-2 8599 (A Census of Nuclear Star Clusters in
Late-Type Spiral Galaxies)

The WF/PC-2 was used to conduct an I-band snapshot survey of a
well-defined sample of nearby, face-on spiral galaxies of type Scd or
later. The proposal completed nominally.

1.5 Completed Two 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.

1.6 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.

1.7 Completed WF/PC-2 8600 (Dwarf Elliptical Galaxy Snapshot Survey III)

The WF/PC-2 was used to extend our V and I snapshot survey of
nearby dwarf elliptical {dE} galaxies to include a sample of 30 bright dE
with significant globular cluster {GC} populations. There were no reported
problems.

1.8 Completed WF/PC-2 8592 (Pixel Microlensing of M87)

The WF/PC-2 was used to undertake a pixel microlensing study of M87
in order to: 1} probe the lower end of the M87 IMF via star-star lensing,
2} possibly obtain the first evidence of Massive Compact Objects (MACHOs)
in the halo of a galaxy other than our own, and 3} search for intracluster
MACHOs. The proposal completed nominally.

1.9 Completed WF/PC-2 8682 (A Snapshot Study of 0bservational Cosmology)

The WF/PC-2 was used to examine the observational constraints on
the cosmic star formation history that is currently among the most active
fields in observational cosmology. The most widely used tracer of the
co-moving volume-averaged star formation rate {SFR} is the UV luminosity
density, which early results found to peak at z~1- 2. The apparent
identification of the primary epoch of metal production and star formation
in the Universe led to intense theoretical and observational
interest. Nevertheless, and remarkably for such a fundamental observation,
little is known about the history of star formation in the Universe beyond
its global average. There were no reported anomalies.

1.10 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.

1.11 Completed WF/PC-2 9132 (Resolving the Puzzling Dark Mass
Concentration in Abell 1942)

The WF/PC-2 was used to make observations that will significantly
improve the precision and localized position of a puzzling
signal. Independent lensing analyses of two optical datasets reveal a
striking mass concentration south of the cluster center with no obvious
visible source counterpart. Placed at the redshift of the cluster the
implied mass would be M{0.5h^-1mboxMpc} >= 1* 10^14M_odot. The absence of
an obvious excess of faint sources in suitably deep infrared images makes
it highly unlikely that such a strong lensing signal can be caused by a
projected background cluster of galaxies. No anomalous activity was reported.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 8

Successful: 8

Scheduled Re-acquisitions: 8

Successful: 8

2.2 FHST Updates:

Scheduled: 20

Successful: 20

2.3 Operations Notes:

The STIS instrument remains in safe mode.

Using ROP SR-1A, the SSR EDAC error counter was cleared twice.