Hubble Space Telescope Daily Report #2865 – 4 May 2001

HUBBLE SPACE TELESCOPE

DAILY REPORT #2865

PERIOD COVERED: 0000Z (UTC) 05/03/01 – 0000Z (UTC) 05/04/01

Daily Status Report as of 124/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 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.

1.2 Completed Five Sets of STIS/CCD 9248 (Probing the Large Scale
Structure: Cosmic Shear Observations)

The Space Telescope Imaging Spectrograph (CCD) was used to measure
the distortion of light bundles from distant galaxies that probe the
statistical properties of the intervening inhomogeneous {dark} matter
distribution. Its tidal gravitational field distorts the observable image
shapes thereby causing a coherent ellipticity pattern {Cosmic Shear}. The
observations completed nominally.

1.3 Completed Four 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.

1.4 Completed Two Sets of STIS/CCD 8864 (CCD Dark Monitor-Part 2)

The Space Telescope Imaging Spectrograph (CCD) was used to monitor
the darks for the CCD. The proposal completed nominally.

1.5 Completed STIS/CCD 8607 (Completing the Local AGN Inventory: The
AGN Content of Composite Nuclei)

The Space Telescope Imaging Spectrograph (CCD) was used to increase
the knowledge of the local space density of AGNs which is of fundamental
importance to a number of astrophysical problems. A significant fraction
of nearby galaxies have nuclei whose spectra are intermediate between those
of LINERs and nuclear starbursts. These “transition objects” may be
composite systems that contain both a central AGN and circumnuclear star
formation. We will test this hypothesis by obtaining spatially-resolved
optical spectra of a well-defined sample of 15 nearby transition nuclei
selected from the extensive ground-based survey of Ho, Filippenko, and
Sargent. The observations completed with no reported problems.

1.6 Completed Six 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.

1.7 Completed WF/PC-2 8677 (Extragalactic Novae: the Maximum Magnitude
– Rate of Decline Relation in NGC 4472)

The WF/PC-2 was used to accomplish two goals: {1} to provide the
first homogeneous observational constraints on theoretical models for novae
outbursts; and {2} to assess the reliability of novae as standard candles
by using WFPC2 to collect well sampled light curves for 20-50 novae in the
supergiant elliptical galaxy NGC 4472, the brightest galaxy within 30
Mpc. Both the length of the observing window and the temporal sampling of
the observations are specifically designed to ensure that the novae peak
magnitudes and decline rates are measured accurately. These data will be
used to construct the first `Maximum Magnitude versus Rate of Decline’
{MMRD} relation for a galaxy beyond the Local Group. This relation is not
only a potentially powerful standard candle, but its shape and dispersion
are directly linked to physical parameters which govern the physics of
novae outbursts such as the white dwarf mass, temperature and mass
accretion rate. The proposal completed with no reported problems.

1.8 Completed STIS/CCD/MA1 8595 (Does the D/H Ratio Vary in Local
Interstellar Gas?)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
take measurements of the D/H ratio in the Local Interstellar Cloud {LIC}
that are consistent with 1.5 +/- 0.1 X 10^-5, while for other clouds within
~ 100 pc, the measurement uncertainties are larger. Two target white
dwarfs {WDs}, HZ 43 and GD 153, are chosen because EUVE data show low HI
column densities, thereby reducing the probabilities of multiple velocity
components and saturation of the DI line. The WDs have pure-H atmospheres,
so contamination of the interstellar lines by photospheric metal lines is
not an issue. The measurements completed with no reported problems.

1.9 Completed Four 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.

1.10 Completed STIS/CCD/MA2 8681 (Snapshot Survey of Variability of
Narrow and Broad Associated Absorption Lines in Quasars)

The Space telescope Imaging Spectrograph (CCD and MA2) was used to
investigate the variability in the strength of absorption lines in quasar
spectra which is definitive proof that we are observing material that is
physically associated with the quasars. This proposal will conduct a STIS
snapshot survey to provide second epoch observations of 37 quasars with
narrow associated or broad absorption lines {NALs and BALs}, previously
observed with the FOS. At high redshift several intrinsic NALs and about
two thirds of BALs are known to vary, often in accord with continuum
variability. The amplitudes increase and the timescales decrease with
decreasing quasar luminosity. The proposal completed nominally.

1.11 Completed Two Sets of STIS/CCD 8845 (Spectroscopic Flats C9)

The Space Telescope Imaging Spectrograph (CCD) was used to obtain
CCD flats in the spectroscopic mode. The observations completed with no
reported problems.

1.12 Completed Two Sets of STIS/CCD 8591 (The Smallest Nuclear Black Holes)

The Space Telescope Imaging Spectrograph (CCD) was used to observe
small nuclear black holes which are the last major unexplored part of BH
parameter space, searching for the smallest BHs that HST can possibly
find. The proposal completed with no reported anomalies.

1.13 Completed STIS/CCD 8865 (Bias Monitor-Part 2)

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 with no anomalous activity.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 8

Successful: 8

Scheduled Re-acquisitions: 9

Successful: 9

2.2 FHST Updates:

Scheduled: 10

Successful: 10

2.3 Operations Notes:

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of normal science observations and calibrations.