Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.stsci.edu/ftp/observing/status_reports/old_reports_01/hst_status_06_11_01 Дата изменения: Mon Jun 11 15:25:27 2001 Дата индексирования: Sun Dec 23 10:20:51 2007 Кодировка: Поисковые слова: comet

HUBBLE SPACE TELESCOPE

DAILY REPORT #2890

PERIOD COVERED: 0000Z (UTC) 06/08/01 - 0000Z (UTC) 06/11/01

Daily Status Report as of 162/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed WF/PC-2 8699 (The Origin of Short-Period Comets)

The WF/PC-2 was used to detect and characterize cometary nuclei in
order to determine the basic physical properties of a large fraction of the
population of short-period comets. By acquiring statistically significant
data, we can study the origin of this family of comets and test the
hypothesis that they are collisional fragments from the Kuiper Belt
Objects. The observations completed with no reported problems.

1.2 Completed Six 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 Eight Sets of 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.

1.4 Completed WF/PC-2 9170 (The Post-CE Status of the Massive WD Binary
LB11146)

The WF/PC-2 was used to perform analyses of the spectrum of LB11146
that was discovered to be a binary system composed of magnetic/nonmagnetic
white dwarfs each having a mass estimated to be ~0.9 M_solar, making it the
only known double degenerate system with a combined mass exceeding the
Chandrasekhar limit. No errors were reported.

1.5 Completed 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.

1.6 Completed Six Sets of WF/PC-2 8811 (Cycle 9 Standard Darks)

The WF/PC-2 was used to obtain dark frames every week in order to
provide data for the ongoing calibration of the CCD dark current rate, and
to monitor and characterize the evolution of hot pixels. Over an extended
period these data will also provide a monitor of radiation damage to the
CCDs. The proposal completed with no reported problems.

1.7 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.

1.8 Completed Five 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.

1.9 Completed Three Sets of WF/PC-2 9073 (Ultraluminous X-Ray Sources
and Intermediate Mass Black Holes)

The WF/PC-2 was used to observe ultraluminous X-ray sources {ULX}
that are second only to AGNs in point-source luminosity yet they have no
known optical counterparts. These extraordinary X-ray objects, which
radiate at the Eddington luminosity of a 30-100 solar mass object, are
non-nuclear sources in normal disk galaxies. One explanation is that they
are binary systems where the accreting black hole has a mass of 30-100
solar masses, although this challenges stellar evolutionary models, which
do not predict remnants larger than about 10 solar masses. Another
possibility is that ULXs are intermediate mass black holes acting as
micro-quasars in galaxy disks and representing the link between stellar
black holes {4-10 solar masses} and supermassive black holes {10^6-10^10
solar masses}. The observations completed with no reported problems.

1.10 Completed WF/PC-2 8641 (Testing the Accelerating Universe)

The WF/PC-2 was used to observe Type Ia supernovae which provide
evidence for an accelerating universe: an extraordinary result that needs
to be rigorously tested. The observations completed with no reported problems.

1.11 Completed Three Sets of WF/PC-2 8816 (Cycle 9 UV Earthflats)

The WF/PC-2 was used to obtain sequences of Earth streak flats to
improve the quality of pipeline flat fields for the WFPC2 UV filter set and
in order to monitor flat field stability. There were no reported problems.

1.12 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.

1.13 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.

1.14 Completed Two 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.

1.15 Completed Three Sets of 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.

1.16 Completed WF/PC-2 8550 (Heritage Observations of NGC 6782)

The WF/PC-2 was used to make observations of galaxy NGC 6782,
augmenting archival data to produce a full-color Hubble Heritage image for
public outreach. The observations completed nominally.

1.17 Completed 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.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:
Scheduled Acquisitions: 29
Successful: 29

Scheduled Re-acquisitions: 20
Successful: 20

2.2 FHST Updates:
Scheduled: 52
Successful: 52

2.3 Operations Notes:

The STIS instrument remains in safe mode.

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

The CCS 485 engineering status buffer limits were adjusted on five
occasions per ROP DF-18A.

A new HST 486 SMAC20 SI C&DH safing sequence, which utilizes STIS
on side 2, was successfully uplinked at 159/1408Z per an operations request.

The EPS limits set was returned to normal ranges after the high sun
time has passed. This was done at 159/1832Z.

At 159/1832Z, the CCC 5 Voltage/Temperature Level 5 to Level 4 was
raised, as was the Trickle Charge Initiation parameter (from 2 to
3). Trickle charge initiation occurred nominally at 159/190623Z.

At 159/1833Z, the pressure-based battery capacity equations were
updated.

Per ROP NS-3, the NSSC-1 status buffer was dumped at 160/0024Z.

A TTR was written for a required re-transmit at 161/1322Z during an
NSSC-1 uplink. Later, at 161/1324Z, the SI C&DH error counter was reset as
directed by ROP NS-5.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of normal science observations and calibrations.

/CAW