Hubble Space Telescope Daily Report #2836 26 Mar 2001

HUBBLE SPACE TELESCOPE

DAILY REPORT #2836

PERIOD COVERED: 0000Z (UTC) 03/23/01 – 0000Z (UTC) 03/26/01

Daily Status Report as of 085/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed Five 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.

1.2 Completed WF/PC-2 8599 (A Census of Nuclear Star Clusters in
Late-Type Spiral Galaxies)

The WF/PC-2 was used to conduct an I-band snapshot survey of a
well-defined sample of nearby, face-on spiral galaxies of type Scd or
later. The proposal completed nominally.

1.3 Completed Eighteen 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}. As
described in 2.1 and HSTAR 8132, the acquisition/re-acquisitions for the
eleventh iteration of this proposal defaulted to fine lock back-up on one
FGS only. Otherwise, the observations completed nominally.

1.4 Completed WF/PC-2 8604 (Stellar Populations Across the Small
Magellanic Cloud (SMC) : History and Structure)

The WF/PC-2 was used to investigate the structure and evolutionary
history of the SMC by obtaining a series of 50 three-color snapshots of
selected SMC regions. With this polling of SMC field star properties, we
will produce color-magnitude diagrams in the U, V and I bands which will
reach V~23.5 in regions too crowded to be observed accurately from the
ground. The observations completed nominally.

1.5 Completed WF/PC-2 8598 (Snapshot Survey of Extended OIIl Lambda
5007Angstrom Emission in Seyfert Galaxies)

The WF/PC-2 was used for a snapshot survey of narrow band OIII
Lambda 5007Angstrom images for a well defined sample of 88 Seyfert galaxies
{29 Seyfert 1s and 59 Seyfert 2s}, 18 of which already have data in the
archive, selected from a mostly isotropic property, the 60Mum flux. These
data will be used: 1} to determine the origin of the misalignment between
the accretion disk axis and the host galaxy plane axis, which can be due to
mergers with other galaxies, or by the self induced radiation warping; 2}
to compare the size and shape of the Narrow Line Regions (NLR) of Seyfert
1s and Seyfert 2s, and to study the frequency of conically shaped NLR in
Seyfert galaxies, which are usually unresolved from ground-based
observations; and 3} estimate the importance of shocks to the ionization of
the NLR. The observations completed with no reported problems.

1.6 Completed Three Sets of 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.

1.7 Completed STIS/CCD/MA2 8623 (HST, Chandra, and FUSE Studies of
Interstellar Material toward HD 24534 {aka X Persei})

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
make high-resolution UV spectroscopic observations of the reddened star HD
24534 {aka X Persei} in order to: {1} establish accurate gas-phase column
densities for elements other than carbon and oxygen {for which high-
quality data already exist}, for the purpose of deriving {in conjunction
with FUSE and Chandra observations} absolute depletions of several key
elements; and {2} further pursue molecular abundances toward this star, to
supplement HST/GHRS data obtained earlier which showed that this line of
sight supports a rich chemistry. The observations completed nominally.

1.8 Completed Fifteen 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 described in 2.1 and HSTAR 8132, the
acquisition/re-acquisitions for the ninth iteration of this proposal
defaulted to fine lock back-up on one FGS only. Otherwise, the
observations completed with no other anomalous activity.

1.9 Completed WF/PC-2 8648 (SINS: The Supernova Intensive Study– Cycle 9)

The WF/PC-2) was used to observe supernovae which explode to create
the chemical history of the Universe and energize the interstellar
gas. The proposal completed with no reported problems.

1.10 Completed Seven 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. As described in 2.1 and HSTAR
8132, the acquisition/re-acquisitions for the seventh iteration of this
proposal defaulted to fine lock back-up on one FGS only. Otherwise, there
were no other reported problems.

1.11 Completed STIS/CCD/MA1 8606 (Determining the Nature of the
Variable Absorption in AGN: Monitoring NGC 3783 with HST And Chandra)

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
investigate Seyfert 1 galaxies, many of which show intrinsic UV absorption
lines, characterized by high moderate widths, significant outflow
velocities, and variability on time scales as small as days. Seyferts with
UV absorption also show variable X-ray “warm absorbers”, characterized by
O VII and O VIII absorption edges, which suggests a common
origin. Variability monitoring is the key to understanding the absorbers,
by providing their radial locations, densities, and evolution in
ionization, column density, velocity, and coverage of the inner active
nucleus. The proposal completed with no problems.

1.12 Completed Two Sets of WF/PC-2 8698 (Identification of the Galaxy’s
Missing Mass)

The WF/PC-2 was used to observe the nature of dark matter that is
one of the key astrophysical questions of the day. The existence of dark
matter and its dynamical dominance in the outer parts of our Galaxy and
spiral galaxies with flat rotation curves is well established. The MACHO
project has identified ~half of the Milky Way’s dark matter with stellar
objects of ~0.5 M_sun, probably white dwarfs. But the location of the
microlensing in the halo is disputed. Several have detected two candidate
halo white dwarfs of L/L_sun ~ 10^-5 in the Hubble Deep Field with 25 +/- 5
mas/year proper motions. The observations completed with no reported problems.

1.13 Completed Two Sets of FGS/1R 8618 (Parallaxes of Magnetic CVs)

The FGSs were used to gather data for the calculation of
trigonometric parallaxes of cataclysmic variable {CVs} which are needed to
obtain reliable information on luminosities, accretion rates, and on radii
and masses of the stellar components. They are also needed to derive the
space density, an important ingredient for theories of CV evolution. The
observations completed with no reported problems.

1.14 Completed WF/PC-2 8591 (The Smallest Nuclear Black Holes)

The WF/PC-2 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.

1.15 Completed WF/PC-2 8583 (Imaging Snapshots of Asteroids)

The WF/PC-2 was used to obtain images of the fifty largest main
belt asteroids that have favorable apparitions during cycle 9. The images
will be searched for companion bodies, as well as mineralogical variegation
on the resolved main bodies. There were no reported problems.

1.16 Completed Six 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.

1.17 Completed WF/PC-2 8720 (Masses and Multiplicity of Nearby Free-
floating Methane and L Dwarfs)

The WF/PC-2 was used to observe 50 very-low-mass objects in the
solar neighborhood with spectral types of L0 and later {including several
dwarfs with Methane absorption bands in their atmospheres}. These objects
will be observed in two filter bands with the aim to identify close
companions, measure their colors, and to obtain first epoch data of the
newly discovered binaries. The observations completed nominally.

1.18 Completed WF/PC-2 8824 (Decontaminations and Associated
Observations Pt. 3/4)

The WF/PC-2 was used for the monthly WFPC2 decons. Also included
are instrument monitors tied to decons: photometric stability check, focus
monitor, pre- and post-decon internals {bias, intflats, kspots, & darks},
UV throughput check, VISFLAT sweep, and internal UV flat check. There were
no reported problems.

1.19 Completed STIS/CCD/MA2 8714 (The ^12C/^13C Abundance Ratio in NGC
3242)

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
carry out high quality spectroscopic observations of ^12C and ^13C in the
ionized gas of the planetary nebula {PN} NGC 3242 by using the C iii
multiplet near <~m 1908 Angstrom. NGC 3242 is the only PN with a measured abundance of ^3He, an isotope of cosmological interest. The observed ^3He abundance is in agreement with the predictions of standard stellar evolution models for a ~ 1 M_odot star. However, low-mass stars cannot produce ^3He at the level indicated by NGC 3242 and by standard models otherwise the resulting ^3He abundance in the Galaxy would be a factor ~ 20--100 higher than observed in the local ISM, in H ii regions, and in meteorites. T he only solution to this problem appears to rely on a non-standard mixing process that preferentially destroys ^3He during the RGB/AGB phases. The observations completed without incident.

1.20 Completed STIS/CCD 8226 (Discerning the Origins of Blue
Stragglers: Masses and Rotation Rates)

The Space Telescope Imaging Spectrograph (CCD) was used to study
the blue stragglers in globular cluster NGC-5272-OF. Conventional wisdom
holds that the masses of Blue Straggler Stars in globular clusters are
significantly larger than the turnoff mass. A wavelength calibration
observation was also taken. As described in 2.1 and HSTAR 8132, the
acquisition/re-acquisitions for this proposal defaulted to fine lock
back-up on one FGS only. Otherwise, the observations were executed as
scheduled, and no further anomalies were noted.

1.21 Completed WF/PC-2 8567 (Confirming the Parallax of the Neutron
Star RX J185635-3754)

The WF/PC-2 was used to perform observations of the isolated
neutron star RX J185635-3754 that has previously revealed a motion of 0.8
arcsec in 2.5 years. This is a combination of the annual parallax and the
proper motion. There were no reported problems.

1.22 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.

1.23 Completed STIS/CCD/MA1 8662 (A Snapshot Survey of the Hot
Interstellar Medium)

The Space Telescope Imaging Spectrograph (CCD And MA1) was used to
obtain snapshot STIS echelle observations of key tracers of hot
interstellar gas {C IV, N IV, and Si IV} for selected FUSE Team O VI survey
targets with known UV fluxes. By taking advantage of the snapshot
observing mode we will efficiently obtain a large number of spectra
suitable for the study of the highly ionized hot component of the
interstellar medium {ISM}. Our goals are to explore the physical
conditions in and distribution of such gas, as well as to explore the
nature of the interfaces between the hot ISM and the other interstellar gas
phases. The observations completed with no reported problems.

1.24 Completed STIS/CCD 8666 (Outflows from the Disk Fueling the
Massive Black Hole in M87)

The Space Telescope Imaging Spectrograph (CCD) was used to observe
the disk in M87 that is a prototype for gas orbiting a massive central
object. Although the disk is rotating, its morphology and kinematics are
far from simple. A deep Halpha+N II HST image shows a trailing, three arm
spiral superposed on the underlying disk, and an extended system of
filaments. The NW filaments appear to connect directly to the
disk. Ground-based and HST observations suggest that some of the filaments
originate in a bi-directional wind emanating from the disk. Such a wind
can carry away angular momentum, enabling gas to flow through the resolved
disk into the accretion disk around the black hole. We propose high
spatial resolution spectroscopy aimed at achieving the following scientific
goals: 1} Determine if winds are carrying angular momentum away from the
disk, thereby enabling inflow and fueling of the massive black hole, 2}
Estimation of the rate of mass loss and angular momentum loss from the
disk, and 3} Use changes in the velocities and line strengths at the
positions of the spiral- like features in the disk to determine if these
are shocks where gas is flowing through a density wave. The CCD exposure
timeout described in 2.3 and HSTAR 8133 occurred during this proposal. Any
possible effect on sceince is not currently known. The proposal completed
with no other reported problems.

1.25 Completed WF/PC-2 8883 (POMS Test Proposal: WFII Backup Parallel
Archive Proposal II)

The WF/PC-2 was used to complete a POMS test proposal designed to
simulate scientific plans. There were no reported problems.

1.26 Completed Two Sets of WF/PC-2 8818 (Cycle 9 Photometric
Characterization)

The WF/PC-2 was used to check the zeropoints and contamination
rates in non-standard WF/PC-2 filters. There were no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:

Scheduled Acquisitions: 21

Successful: 21

Scheduled Re-acquisitions: 23

Successful: 23

Per HSTAR 8132, the acquisition at 083/142134Z failed to fine lock
back-up on FGS-3 only. Thsi had been expected since the same stars had
been used in the acquisition detailed in HSTAR 8129. The two following
re-acquisitions, at 083/155927Z and at 083/173549Z has similar fates. The
proposals described in 1.3, 1.8, 1.10 and 1.20 may have been affected.

2.2 FHST Updates:

Scheduled: 58

Successful: 58

2.3 Operations Notes:

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

One three occasions the engineering status buffer limits were
adjusted per ROP DF-18A.

The NSSC-1 status buffer was dumped and reset at 083/0451A as
directed by ROP NS-3.

HSTAR 8133 tells of a STIS 688 status buffer message being received
at 084/162048Z, indicating that a CCD exposure had timed out. This
occurred during the proposal detailed in 1.24. Using ROP NS-12, the STIS
flight software error counter was reset at 084/1842Z.

Using ROP RD-7A, ESTR-2 was reconditioned at 085/0401Z.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of normal science observations and calibrations.