Status Report

Hubble Space Telescope Daily Report #2975 – 12 Oct 2001

By SpaceRef Editor
October 12, 2001
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HUBBLE SPACE TELESCOPE

DAILY REPORT #2975

PERIOD COVERED: 0000Z (UTC) 10/11/01 – 0000Z (UTC) 10/12/01

Daily Status Report as of 285/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed WF/PC-2 9057 (Host Galaxies of Obscured QSOs Identified
by 2MASS)

The WF/PC-2 was used to perform a snapshot survey of red QSOs
discovered in The Two Micron All Sky Survey {2MASS} to investigate the
detailed properties of their host galaxies. This large, possibly dominant,
population of QSOs in the local universe has been previously overlooked
because reddening by {intrinsic} obscuration along our line of sight causes
their colors to be too red for identification by traditional “UV- excess”
techniques. Their near-IR colors are similar to PG- type {UV-excess} QSOs,
but it is far from certain whether they are indeed from the same parent
population or represent a completely new class of QSO. There were no
reported problems.

1.2 Completed STIS/CCD 9285 (POMS Test Proposal: STIS Non-scripted
Parallel Proposal Continuation III)

The Space Telescope Imaging Spectrograph (CCD) was used to make low
galactic latitude, non-scripted parallel observations as part of a POMS
test proposal. The observations were completed as planned, and no
anomalies were reported.

1.3 Completed STIS/CCD 8901 (Dark Monitor-Part 1)

The Space Telescope Imaging Spectrograph (CCD) was used to monitor
the darks. There was no anomalous activity.

1.4 Completed Three Sets of WF/PC-2 8936 (Cycle 10 Supplemental Darks
Pt1/3)

The WF/PC-2 was used to perform a dark calibration program that
obtains three dark frames every day to provide data for monitoring and
characterizing the evolution of hot pixels. The proposal completed with no
reported problems.

1.5 Completed STIS/CCD 8903 (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. There were no problems.

1.6 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.

1.7 Completed STIS/CCD/MA2 9051 (Identifying Damped Lyman-alpha
Galaxies at z~1)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
look for samped Lyman-alpha absorption systems that contain the bulk of the
neutral gas in the Universe in the redshift range z = 0.5 – 5, yet the
nature of the galaxies responsible for the absorption is not well
understood. Only recently have observers found more than a handful of
damped absorbers at redshifts z < 1.5. Using the FIRST Bright Quasar Survey {FBQS}, with over a 1000 quasars, the proposers have undertaken a survey to build a complete picture of he nature of the galaxies responsible for damped Lyman-alpha absorption systems at z~1 and to double the sample size at this redshift. No problems were encountered.

1.8 Completed Four Sets of WF/PC-2 8059 (POMS Test Proposal: Targeted
Parallel Archive Proposal)

The WF/PC-2 was used to observe the parallel opportunities
available in the neighborhood of bright galaxies are treated in a slightly
different way from the normal pure parallels. Local Group galaxies offer
the opportunity for a closer look at young stellar
populations. Narrow-band images in F656N can be used both to identify
young stars via their emission lines, and to map the gas distribution in
star-forming regions. The observations completed nominally.

1.9 Completed STIS/CCD 9176 (LMC Eclipsing Binaries with Cepheid
Components: The Key to the Extragalactic Distance Scale)

The Space Telescope Imaging Spectrograph (CCD) was used to
determine the distance to the LMC and to observe the Cepheid P-L that form
the backbone of the Cosmic Distance Scale and the determination of
H_degrees. Unfortunately, in spite of concerted efforts of many
investigators, the zero point of the Cepheid P-L law and the LMC distance
remain controversial and uncertain to ~10-15, using eclipsing binaries
{EBs} as “standard candles” to include two recently discovered LMC
eclipsing binaries {EBs} with Cepheid components. These observations of
these extraordinary systems hold the key to determining simultaneously the
Cepheid P-L zero point and the LMC distance, and to provide a direct test
of the Baade-Wesselink parallax method. There were no reported problems.

1.10 Completed WF/PC-2 9249 (POMS Test Proposal: WFII Backup Parallel
Archive Proposal II)

The WF/PC-2 was used to execute a POMS test proposal designed to
simulate scientific plans. The proposal completed with no reported problems.

1.11 Completed Two Sets of STIS/MA1/MA2 9120 (Planetary Nebulae In The
LMC: A Study On Stellar Evolution And Populations)

The Space Telescope Imaging Spectrograph (MA1 and MA2) was used to
investigate the final phase of the evolution of low- and intermediate-mass
stars, the Planetary Nebula {PN} ejection that is thought to provide the
main source of carbon and nitrogen enrichment in galaxies. The
observations completed nominally with no reported problems.

1.12 Completed STIS/MA1/MA2 8920 (Cycle 10 MAMA Dark Measurements)

The Space Telescope Imaging Spectrograph (MA1 and MA2) was used to
perform the routine monitoring of the MAMA detector dark noise, and is the
primary means of checking on health of the MAMA detectors systems through
frequent monitoring of the background count rate. The proposal completed
with no reported anomalous activity.

1.13 Completed STIS/CCD 9177 (Tidal Disruption of Stars by Massive
Black Holes in Galaxy Nuclei: After the Flare)

The Space Telescope Imaging Spectrograph (CCD) was used to observe
supermassive black hole that will rip apart a star that strays within its
tidal radius, causing an Eddington-limited UV/X-ray flare for several
months as the orbiting debris accretes. While such events are predicted to
occur at most once in 10^4 yr per galaxy, an experiment was performed in
1990-91 which sampled hundreds of thousands of galaxies in the ideal
wavelength band. Three galaxies had unusual X-ray flares, but no evidence
for nuclear activity in ground-based spectra. To establish beyond a
reasonable doubt that these were tidal disruption events, it is proposed to
make a sensitive search for permanent Seyfert activity, the only possible
alternative to the disruption hypothesis. Nuclear optical spectra obtained
through a narrow slit will reject most of the starlight and place limits on
AGN-like emission line activity below those of the weakest
Seyferts. Masses of black holes could be studied by monitoring the
outburst light curves and the spectra of the tidal debris. The proposal
completed with no reported problems.

1.14 Completed STIS/CCD 9143 (Spectrophotometry of Nearby Seyfert 2
Nuclei: Can We Eliminate the Seyfert 2 Class?)

The Space Telescope Imaging Spectrograph (CCD) was used to
investigate Seyfert 2s that are distinguished by the absence of the broad
emission lines characteristic of Seyfert 1s and more luminous QSOs. Are
Seyfert 2s fundamentally different from Seyfert 1s and their brighter
cousins? Or is the broad emission line region in Seyfert 2s simply
suppressed by obscuring material as postulated by the unification
model? If the latter model is correct, the weak broad emission lines in
the Seyfert 2s may simply be overwhelmed by starlight from the
circumnuclear region, particularly in the case of recent star
formation. It is proposed to determine if all Seyfert 2s have {weak} broad
emission line regions by obtaining long-slit STIS spectroscopy for a
well-defined sample of 20 Seyfert 2s {3 archival, 17 new}. The
observations completed with no anomalous activity.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 6

Successful: 6

Scheduled Re-acquisitions: 9

Successful: 9

2.2 FHST Updates:

Scheduled: 10

Successful: 10

2.3 Operations Notes:

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

SSR engineering record was commanded three times as directed by ROP
SR-4.

ROP SR-8 was used to commanded autonomous engineering record at
284/1951Z and at 284/2120Z.

SSA transmitter #1 was commanded on and off for the interval
284/2201Z to 284/2235Z; transmitter #2, 285/0404Z to 285/0433Z. In each
case, ROP IC-2 was utilized.

At 285/0003, per ROP NS-5, the NSSC-1 status buffer was dumped and
reset.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of normal science observations and calibrations.

SpaceRef staff editor.