Hubble Space Telescope Status Report #2915 17 Jul 2001

HUBBLE SPACE TELESCOPE

DAILY REPORT #2915

PERIOD COVERED: 0000Z (UTC) 07/16/01 – 0000Z (UTC) 07/17/01

Daily Status Report as of 198/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed Four 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 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.

1.3 Completed STIS/CCD 9063 (Optical Counterparts of Isolated Neutron
Stars)

The Space Telescope Imaging Spectrograph (CCD) was used to test the
understanding of both quantum chromodynamics {QCD} and quantum
electrodynamics {QED}. Specifically, the measurement of radii of neutron
stars can test QCD at high density. This is being realized through
intensive X-ray observations of bright nearby neutron stars. However, the
natures of these important sources are not clear and to this end a simple
proper motion program is proposed as a means to obtain their ages and
potential association with star-forming regions. One of the sources is RX
J0720.4-3125 which has been argued to be an old magnetar — a highly
magnetized neutron star — and thanks to its high count rate is already a
choice object for X-ray missions. Magnetars, with their extreme magnetic
field strengths, are excellent laboratories for testing out some
expectation of QED. There were no reported problems.

1.4 Completed Three 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. As detailed in HSTAR 8274 and 2.1, the
acquisition for the final iteration of this proposal defaulted to fine lock
backup on one FGS only, possibly affecting ten observations. Otherwise,
the observations completed with no other anomalous activity.

1.5 Completed Three Sets of WF/PC-2 8935 (Cycle 10 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.

1.6 Completed Two 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.

1.7 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.

1.8 Completed WF/PC-2/STIS/CCD 8573 (Newborn Planets and Brown Dwarf
Companions in IC

The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were
used to search for young giant planets and brown dwarfs around ~100
low-mass stars and brown dwarfs in the nearby cluster IC 348. The
observations completed with no reported problems.

1.9 Completed WF/PC-2 8812 (Cycle 9 Internal Monitor)

The WF/PC-2 was used to obtain routine internal monitors for WFPC2
in order to monitor the health of the cameras. A variety of internal
exposures are obtained in order to provide a monitor of the integrity of
the CCD camera electronics in both bays {gain 7 and gain 15}, a test for
quantum efficiency in the CCDs, and a monitor for possible buildup of
contaminants on the CCD windows. There were no reported problems.

1.10 Completed Two Sets of WF/PC-2 9122 (The Physics of X-Ray/Optical Jets)

The WF/PC-2 was used to perform an important new probe of the
physics of large-scale radio jets that is possible with the discovery of
resolved X-ray/optical jets. The optical emission comes from high energy
electrons, which have short radiative lifetimes and so pinpoint particle
acceleration sites. Spectral energy distributions of knots in two jets
suggest the X-rays come from lower energy electrons inverse-Compton
scattering the {beamed} cosmic microwave background. This requires the jet
to be still relativistic on kiloparsec scales {out to ~1 Mpc for the
high-redshift jets.}. This model robustly constrains both the bulk
relativistic speed and the minimum electron energy in the jet, which
together determine the total jet power. To probe jet energetics and
physics generally, and to test the “Compton/CMB” interpretation
specifically, it is proposed to execute deep HST imaging of three
X-ray/optical jets {PKS 1127–145, PKS 0637–752, 3C 371} and one optical
jet {PKS 2201+044}, plus Chandra observations of the latter two. As
detailed in HSTAR 8274 and 2.1, the acquisition for the final iteration of
this proposal defaulted to fine lock backup on one FGS only, possibly
affecting three observations. Otherwise, the proposal completed with no
other reported problems.

1.11 Completed WF/PC-2/STIS/CCD 8559 (The Role of Dark Matter in
Cluster Formation and Galaxy Evolution)

The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were
used to observe the outer regions of massive clusters that represent
transitional areas of great cosmological importance where field galaxies
encounter the steep potential wells of dark matter and baryonic hot
gas. Little is known about either the dark matter profile at large radii
or the morphological properties of infalling galaxies at those redshifts
where strong evolution is observed in the cluster cores. The proposal
completed normally, with no reported problems.

1.12 Completed WF/PC-2 9251 (Cycle 10 Photometric Characterization)

The WF/PC-2 was used to provide a check of the zeropoints and
contamination rates in non-standard WF/PC-2 filters. No problems were
reported.

1.13 Completed Three Sets of WF/PC-2 9252 (Cycle 10 Clocks On Check)

The WF/PC-2 was used to perform closure calibration for clocks ‘on’
mode, which obtains dark frames in order to provide data to create a clocks
‘on’ super dark calibration reference file, to monitor and characterize the
evolution of hot pixels, and to obtain standard star observations for
photometric calibration. The proposal completed with no reported anomalous
activity.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 5

Successful: 5

Per HSTAR 8274, the acquisition at 198/025200Z failed to fine lock
on FGS-3 only when the scan step limit was exceeded on FGS-1. The
proposals described in 1.4 and 1.10 may have been affected.

Scheduled Re-acquisitions: 14

Successful: 14

2.2 FHST Updates:

Scheduled: 4

Successful: 4

2.3 Operations Notes:

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

The 486 engineering status buffer limits were adjusted once per ROP
DF-18A.

The ephemeris table was uplinked at 198/0154Z as directed by ROP
DF-07A.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of normal science observations and calibrations.