Hubble Space Telescope Daily Report #2955 – 13 Sep 2001

HUBBLE SPACE TELESCOPE

DAILY REPORT #2955

PERIOD COVERED: 0000Z (UTC) 09/11/01 – 0000Z (UTC) 09/13/01

Daily Status Report as of 256/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 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.

1.2 Completed Eight Sets of WF/PC-2 8941 (Cycle 10 UV Earthflats)

The WF/PC-2 was used to monitor flat field stability by obtaining
sequences of earth streak flats to improve the quality of pipeline flat
fields for the WFPC2 UV filter set. The proposal had no problems.

1.3 Completed Six 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.

1.4 Completed STIS/CCD/MA1 9304 (Ultraviolet Spectroscopy of the
Unexpected Outburst of WZ Sagittae)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
observe the extreme dwarf nova WZ Sge that unexpectedly went into outburst
on July 23, 2001, ten years earlier than anticipated. This event offers
the chance to obtain high-quality, time-resolved far-UV spectra, as the
outburst continues through its peak into decline. The observations
completed with no reported problems.

1.5 Completed Three Sets of STIS/CCD 8901 (Dark Monitor-Part 1)

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

1.6 Completed Five Sets of STIS/CCD 9088 (Next Generation Spectral
Library of Stars)

The Space Telescope Imaging Spectrograph (CCD) was used to produce
a “Next Generation” Spectral Library of 600 stars for use in modeling the
integrated light of galaxies and clusters by using the low dispersion UV
and optical gratings of STIS. The library will be roughly equally divided
among four metallicities, very low {Fe/H < -1.5}, low {-1.5 < Fe/H < -0.5}, near-solar {-0.5 < Fe/H < 0.1}, and super-solar {Fe/H > 0.1}, well-sampling
the entire HR-diagram in each bin. Such a library will surpass all extant
compilations and have lasting archival value, well into the Next Generation
Space Telescope era. No problems occurred.

1.7 Completed Seventeen 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.

1.8 Completed Two Sets of 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.

1.9 Completed Two Sets of FGS/1 9171 (High Speed Photometry of the
Transiting Planet HD 209458b)

Fine Guidance Sensor #1 was used to observe HD 209458b, the only
extrasolar giant planet {EGP} detected that has an orbit inclined enough
toward the Sun for the transits to be detected. Differential photometry
with respect to comparison stars showed a transit depth of 1.5 a transit
time of 3.2 hours. Transit ingress and egress are ~25 minutes in duration
suggesting the planet transits along a short chord instead of the full
stellar disk. It is proposed to observe the transit ingress {1-orbit} and
egress {1-orbit} with a FGS used as a high- speed photometer. The proposal
completed with no reported problems.

1.10 Completed Four Sets of 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.

1.11 Completed Two Sets of WF/PC-2 9060 (Photometry of a Statistically
Significant Sample of Kuiper Belt Objects)

The WF/PC-2 was used to propel the physical study of KBOs forward
by performing accurate photometry at V, R, and I on a sample of up to 150
KBOs. The sample is made up of objects that will be observed at thermal
infrared wavelengths by SIRTF and will be used with those data to derive
the first accurate diameters and albedos for a large sample of KBOs. The
observations completed nominally.

1.12 Completed STIS/CCD/MA1 8622 (The Interstellar Isotopic Ratio of
Boron toward Omicron Persei and Nearby Sight Lines)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
determine the isotopic ratio 11B/10B for diffuse interstellar material
along lines of sight to o Persei, 40 Persei, Zeta Persei, and X Persei that
pass close to the star- forming region IC 348. The proposal completed
nominally.

1.13 Completed Two Sets of STIS/MA1/MA2 8843 (Cycle 9 MAMA Dark
Measurements)

The Space Telescope Imaging Spectrograph (MA1 and MA2) was used to
perform the routine monitoring of the MAMA detector dark noise. The
proposal completed nominally.

1.14 Completed Two Sets of WF/PC-2 9042 (An Archive To Detect The
Progenitors Of Massive, Core-Collapse Supernovae)

The WF/PC-2 was used to search for supernovae which have massive
star progenitors. The already extensive HST archive and high-resolution
ground-based images of galaxies within ~20 Mpc enables us to resolve and
quantify their individual bright stellar content. As massive, evolved
stars are the most luminous single objects in a galaxy, the progenitors of
core-collapse supernovae should be directly detectable on pre-explosion
images. One Type II progenitor has been observed this year, and the
investigators have proposed a short, companion WFPC2 proposal to confirm
this candidate and identify a second. The observations completed nominally.

1.15 Completed STIS/MA2 8710 (Timing And Proper Motion Measurement Of
The Proposed Optical Counterpart Of The Nearby Pulsar PSR1929+10)

The Space Telescope Imaging Spectrograph (MA2) was used to observe
PSR1929+10, an old, nearby isolated neutron star detected as an X-ray
pulsar. Optical observations of neutron stars include both young and
middle-aged objects for which different emission models {e.g.
magnetospheric and thermal} have been proposed. However, the general
picture is far from being clear. A firm optical identification of
PSR1929+10 would thus be crucial to understand the long term evolution of
the optical luminosity of pulsars and to investigate possible turnovers in
the emission physics. No anomalous activity occurred.

1.16 Completed STIS/CCS/MA2 9048 (Boron Constraints on Slow Mixing in
Low Mass Stars)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
observe the atomic and nuclear characteristics of the light elements Li, Be
and B, that make their photospheric abundances ideal tracers of internal
physical processes in stars. Both Li and Be have been heavily utilized to
this end since their diminished abundances are a direct result of the
extent of internal slow mixing between surface and interior layers, as has
been shown with ground-based data. Boron provides a fresh and special
probe because it survives to greater depths inside stars than does Li or
Be, and can thus uniquely reveal the depth of mixing. It is proposed to
observe B in stars with very large depletions of Li and Be, i.e. stars
which have been the most seriously affected by mixing. No problems occurred.

1.17 Completed FGS/1 9168 (The Distances to AM CVn Stars)

Fine Guidance Sensor (FGS) #1 was used to determine the parallaxes
and proper motions of the five brightest of the seven known AM CVn
systems. AM CVn systems are binaries where mass is transferred from a
completely hydrogen-deficient, degenerate mass donor to a white dwarf
primary through a helium accretion disk. A better understanding of these
systems is crucial for a number of reasons: (1) to study the late stages of
binary evolution, (2) to study the effect of chemical composition on the
physics of accretion discs, (3) to estimate their contribution to the
Supernovae Ia rate, and (4) to estimate their contribution to the
gravitational radiation background. All observations completed with no
reported problems.

1.18 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.

1.19 Completed STIS/CCD 9123 (Synchrotron Self-Compton Emission from
the Radio Hot Spots of Cygnus A)

The Space Telescope Imaging Spectrograph (CCD) was used to observe
radio galaxy Cygnus A recently studied in X-rays with Chandra. Four of the
radio hot spots were detected with similar morphologies to the radio
maps. The X-ray emission is almost certainly synchrotron self-Compton
emission from the radio synchrotron emitting electrons. The predictions of
this model are in excellent agreement with the Chandra spectra and also
imply a magnetic field strength close to equipartition. It is proposed to
image the predicted SSC emission from the hot spots in the optical with
goals a} to confirm the optical fluxes predicted by the SSC model, and b}
to use the radio synchrotron and optical SSC brightness distributions at
~eq 0.1 arc sec resolution to determine the internal structures of the
magnetic fields and relativistic particles within the two brighter hot
spots. The proposal completed with no reported problems.

1.20 Completed STIS/CCD/MA2 9040 (Baryons In Intermediate Redshift {Z >
1} OVI Absorbers)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
search for intervening OVI absorption systems in two further extremely UV
bright intermediate redshift QSOs {HS 0747 + 4259, z = 1.9, V = 15.6; HS
0818+2554, z = 1.5, V = 15.4} using the STIS E230M Echelle mode. The
scientific aim is to measure the baryonic fraction in the warm-hot
intergalactic medium at redshifts 1 <=q z <=q 1.8. Present existing data on HE 0515-4414 taken also with STIS E230M seem to indicate that the baryonic fraction at z = 1.5 is lower by a factor of ~ 15 than the high value found by Tripp et al. {2000} for z < 0.3. Our results need to be confirmed by more lines of sight, and we plan to test hierarchical structure formation models which predict a rapid evolution between z = 1.5 and z = 0. The observations completed as planned with no reported anomalous activity.

1.21 Completed STIS/CCD/MA2 8915 (Echelle Sensitivity)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
observe the flux standard G191B2B, obtaining echelle spectra in all primary
and intermediate wavelength settings. There was no reported anomalous
activity.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 19

Successful: 19

Scheduled Re-acquisitions: 11

Successful: 11

2.2 FHST Updates:

Scheduled: 43

Successful: 43

2.3 Operations Notes:

Operations personnel performed their normal work while operating
from the SIMOR at the Science Institute in Baltimore. Most other HST
personnel were not present due to closing of GSFC for the national emergency

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

The engineering status buffer limits were cleared at 256/0239Z per
ROP DF-18A.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of normal science observations and calibrations.