Hubble Space Telescope Daily Report #2895 – 18 June 2001

HUBBLE SPACE TELESCOPE

DAILY REPORT #2895

PERIOD COVERED: 0000Z (UTC) 06/15/01 – 0000Z (UTC) 06/18/01

Daily Status Report as of 169/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed Seven 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 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.

1.3 Completed Three Sets of WF/PC-2 9085 (Measuring The Masses Of
High-Z Quasar Host Galaxies)

The WF/PC-2 was used to investigate the close link between
black-hole mass and spheroid mass in both quiescent and active galaxies in
the local universe. Consequently black-hole and spheroid formation/growth
are now viewed as intimately related processes, and establishing the mass
of quasar host galaxies as a function of redshift is now seen as a key
measurement in observational cosmology. From the Cycle 7 NICMOS program,
the best estimate to date of the mass evolution of the hosts of both
radio-quiet and radio-loud quasars out to z ~eq 2 has been derived. Under
the assumption of passive stellar-population evolution our results are
consistent with the black-hole/spheroid population being unchanged out to z
~eq 2. However, the crucial assumption of passive evolution needs to be
tested. All observations competed nominally.

1.4 Completed 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.

1.5 Completed 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.

1.6 Completed WF/PC-2 9115 (The Evolution of Extreme Gas Rich Galaxies)

The WF/PC-2 was used to observe a recently discovered sample of the
closest known low surface brightness, very gas-rich dwarf galaxies outside
of the Local Group. These galaxies represent an extreme star formation
environment, where the fuel for star formation appears plentiful, the local
environment {the Centaurus A group of galaxies} provides opportunities for
tidally-induced star formation, and yet star formation appears to be
surpressed {by two orders of magnitude} compared to other `typical’
galaxies. The goal is to understand the star formation history in this
puzzling environment of low stellar density and high gas content. By
resolving the underlying stellar component, the observer will obtain
critical information on the mean metallicity and star formation history of
these galaxies.

1.7 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.

1.8 Completed 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.

1.9 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.

1.10 Completed WF/PC-2 9043 (Cepheid Distances to Early-type Galaxies)

The WF/PC-2 was used to continue observations in the HST Key
Project on the Extragalactic Distance Scale and the HST project on the
“Calibration of Nearby Type Ia Supernovae” that have greatly improved our
knowledge of the Hubble Constant by providing a solid zero point for the
Tully- Fisher {TF} relation and Type Ia Supernovae {SNIa}. However, severe
inconsistencies remain for distance estimators to early-type galaxies such
as surface brightness fluctuations {SBF}, the planetary nebula luminosity
function {PNLF}, the fundamental plane {FP}, and the globular cluster
luminosity function {GCLF}. As a result, the distance to the Virgo cluster
core remains uncertain by as much as 20 determination is directly affected
by a lingering 0.1 mag {5 uncertainty in the photometric calibration of the
WFPC2. Resolving these issues is essential not only to firm up the
extragalactic distance scale, but also to understand the mass and velocity
structure of the local universe. SBF in particular is emerging as the
method of choice for mapping local velocity fields to 10, 000 kms because
it offers an order of magnitude less Malmquist bias than TF, and SNIa are
too rare to study large scale flows effectively. This project will tighten
the photometric calibration of the WFPC2, and provide a solid Cepheid
calibration for SBF and PNLF. The observations completed nominally.

1.11 Completed WF/PC-2 9157 (Fundamental Properties Of L-Type Dwarfs In
Binaries)

The WF/PC-2 was used to characterize the physical properties of
eight L-dwarfs in four binary systems. The goal is to obtain astrometric,
photometric and spectroscopic measurements of each component that will
yield basic information on their atmospheric and dynamical properties. The
proposal completed nominally.

1.12 Completed Five Sets of WF/PC-2 8824 (Decontaminations and
Associated Observations Pt. 3/4)

The WF/PC-2 was used for the monthly WFPC2 decons. Also included
are instrument monitors tied to decons: photometric stability check, focus
monitor, pre- and post-decon internals {bias, intflats, kspots, & darks},
UV throughput check, VISFLAT sweep, and internal UV flat check. There were
no reported problems.

1.13 Completed Four 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.

1.14 Completed WF/PC-2 9045 (The Relationship Between Radio Luminosity
and Radio-Loud AGN Host Galaxy Properties)

The WF/PC-2 was used to determine the relationship between the
properties of the host galaxies of radio-loud AGN and their radio
luminosities. Previous studies in this area with the HST have concentrated
on the 3C sample which shows a tight correlation between luminosity and
redshift, such that evolutionary effects cannot be distinguished from those
depending upon radio luminosity. Our sample of 46 radio galaxies at z ~
0.5 comes from four complete, low-frequency-selected samples of radio
sources with differing flux limits. Thus the total sample spans an
unprecedented three orders of magnitude in radio luminosity at a fixed
redshift interval. The proposal completed with no reported problems.

1.15 Completed Three 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.

1.16 Completed Two Sets of WF/PC-2 8815 (Cycle 9 Earth Flats)

The WF/PC-2 was used to monitor flatfield stability. This proposal
obtains sequences of Earth streak flats to construct high quality flat
fields for the WF/PC-2 filter set. These flat fields will allow mapping of
the OTA illumination pattern and will be used in conjunction with previous
internal and external flats to generate new pipeline superflats. The
proposal completed nominally.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 27

Successful: 27

Scheduled Re-acquisitions: 15

Successful: 15

2.2 FHST Updates:

Scheduled: 65

Successful: 64

The update at 169 0831Z failed.

2.3 Operations Notes:

The Space Telescope Imaging Spectrograph remains in safe mode.

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

Using ROP DF-18A, the engineering status buffer limits were
adjusted on eight occasions.

Operations personnel managed the WF/PC-2 ground system limits for
the period 168/0119Z to 168/1340Z during a period of decontamination.

A TTR was written when there was a required re-transmit during a
486 load at 169/0745Z.

When problems arose on CCS string “A” (see HSTAR 8246), real-time
operations transferred to CCS string “G” at 169/0500Z. Later, at
169/0906Z, real-time operations returned to “A” string.

The NSSC-1 status buffer was dumped and reset at 169/0854Z as
directed by ROP NS-3.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of normal science observations and calibrations.