Hubble Space Telescope Daily Report #2881 – 29 May 2001

HUBBLE SPACE TELESCOPE

DAILY REPORT #2881

PERIOD COVERED: 0000Z (UTC) 05/25/01 – 0000Z (UTC) 05/29/01

Daily Status Report as of 149/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

1.1 Completed Eight 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 WF/PC-2 8585 (Cosmological Parameters from Type Ia
Supernovae at High Redshift)

The WF/PC-2 was used to measure the cosmological parameters, Omega,
Lambda, and thus the curvature, Omega_k, using Type Ia supernovae {SNe Ia}
as calibrated standard candles. There were no reported problems.

1.3 Completed 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.

1.4 Completed Four 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.

1.5 Completed WF/PC-2 8677 (Extragalactic Novae: the Maximum Magnitude
– Rate of Decline Relation in NGC 4472)

The WF/PC-2 was used to accomplish two goals: {1} to provide the
first homogeneous observational constraints on theoretical models for novae
outbursts; and {2} to assess the reliability of novae as standard candles
by using WFPC2 to collect well sampled light curves for 20-50 novae in the
supergiant elliptical galaxy NGC 4472, the brightest galaxy within 30
Mpc. Both the length of the observing window and the temporal sampling of
the observations are specifically designed to ensure that the novae peak
magnitudes and decline rates are measured accurately. These data will be
used to construct the first `Maximum Magnitude versus Rate of Decline’
{MMRD} relation for a galaxy beyond the Local Group. This relation is not
only a potentially powerful standard candle, but its shape and dispersion
are directly linked to physical parameters which govern the physics of
novae outbursts such as the white dwarf mass, temperature and mass
accretion rate. The proposal completed with no reported problems.

1.6 Completed WF/PC-2 8707 (A Study of Star Formation in Galactic
Resonance Rings)

The WF/PC-2 was used to observe rings of star formation which are a
common phenomenon of early-type spiral galaxies. Most rings form by gas
cloud collisions near resonances, under the continuous action of gravity
torques from a bar perturbation, while a small number form in response to a
mild tidal interaction with a nearby companion. In either case, a
resonance is a very special place in any galaxy where star formation can be
enhanced and may proceed either as a starburst or continuously over a long
time period. Resonance rings are natural dynamical laboratories for star
cluster formation and evolution. The observation completed normally with
no reported problems.

1.7 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.

1.8 Completed Eight Sets of 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.

1.9 Completed WF/PC-2 9106 (The Biggest Black Holes)

The WF/PC-2 was used to perform searches for supermassive black
holes in galaxy centers that have led to the discoveries that {1} most or
all hot galaxies contain massive dark objects at their centers, presumably
black holes; and {2} there is a tight correlation between the black-hole
mass and the luminosity-weighted velocity dispersion of the hot component
of the galaxy. This remarkable relationship suggests a strong link between
black-hole formation, AGN activity, and galaxy formation, and once it is
understood this link should advance our understanding of all three
processes. There were no reported problems.

1.10 Completed Two Sets of WF/PC-2 8602 (A Snapshot Survey of the Sites
of Recent, Nearby Supernovae)

The WF/PC-2 was used to conduct a snapshot survey in V and I of the
sites of the nearby SNe, which have precisely known positions, to obtain
high-resolution information on their local environment. The proposal
completed with no reported problems.

1.11 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.

1.12 Completed Three Sets of WF/PC-2 8579 (A Search for the Martian
Dust Belts)

The WF/PC-2 was used to Mars that has been long believed should be
encircled by two faint rings of dust, one originating from each of its
moons Phobos and Deimos. Similar dust rings have recently been associated
with all the inner small moons of Jupiter. Earth will pass through Mars’
equatorial plane within weeks of its opposition, providing a unique
opportunity to detect these rings via direct imaging. The proposal
completed nominally.

1.13 Completed WF/PC-2 9163 (Kinematics Of Emission-Line Gas Disks In
Radio-Quiet Galaxies)

The WF/PC-2 was used to measure central black hole {BH} masses from
the rotation rate of the emission-line gas, and to determine the nature and
structure of the gas disks. Three galaxies with no radio jets and with
Halpha+[NII] emission have been identified, which have dust disks similar
to those commonly seen in our sample of radio-loud active galaxies. All
observations completed nominally.

1.14 Completed WF/PC-2 9092 (V605 Aql: Sakurai’s Older Brother)

The WF/PC-2 was used to observe post-AGB stars that can undergo a
final episode of helium shell burning after the star has ejected a
planetary nebula and has started on the white dwarf track. Starting in
1996 Sakurai’s star has been observed to undergo a final helium shell
flash. The same series of events occurred in V605 Aql 91 years ago. These
stars both ejected a shell of gas first seen as a pseudo-photosphere and
then as a thick dust envelope. The shells are expanding at about 100 km
s-1 and in the case of V605 Aql the shell now appears about 1"
across. This proposal will image this shell. The proposal completed with
no anomalous activity.

1.15 Completed WF/PC-2 8718 (Understanding the Anomalous Hot Stellar
Population in Galactic Globular Clusters)

The WF/PC-2 was used to image in mid- {F255W} and near-UV {F336W}
the globular cluster NGC5986. During the HST survey, it was found that
this object has a horizontal branch with an anomalously extended blue
tailand puzzling gaps along it. There were no reported problems.

1.16 Completed WF/PC-2 9103 (Resolving New Examples of Edge-on Young
Stellar Object Disks)

The WF/PC-2 was used to perform edge-on, optically thick
circumstellar disks observations have been previously imaged by the Hubble
Space Telescope in association with several nearby young stars. In these
systems, the central star is occulted from direct view, large PSF artifacts
are absent, and the disk reflected light is clearly seen. It is for these
objects in nearby star-forming regions that HST has provided the best,
highest resolution {7-10 AU} views to date of disks which may form
planetary systems like our own. Comparison of edge-on disk images with
scattered light models has allowed key structural parameters such as the
disk outer radius, vertical scale height, radial density profile, total
mass, and dust grain properties to be determined. No problems were
reported.

1.17 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.

1.18 Completed WF/PC-2 9107 (The Fundamental Plane for Nuclear Black
Holes)

The WF/PC-2 was used to conduct more in-depth searches for
supermassive black holes in galaxy centers. Previous work has led to the
discoveries that {1} most or all hot galaxies contain massive dark objects
at their centers, presumably black holes; {2} there is a remarkably tight
correlation between the black-hole mass and the luminosity-weighted
velocity dispersion of the hot component of the galaxy. T his mbh-Sigma
relation has a scatter which is <0.3 dex in mbh and consistent with
zero. This relationship suggests a strong link between black-hole
formation, AGN activity, and galaxy formation, and once it is understood
this link should advance our understanding of all three processes. The
goal of this proposal is to investigate the scatter in the mbh-Sigma
relation and the role of possible second parameters, by examining a sample
of galaxies at fixed velocity dispersion Sigma=200+/- 20 kms. This
approach decouples the effects of a second parameter from uncertainties in
the shape of the mbh-Sigma relation, and minimizes spurious correlations
because all of the galaxies will be studied using the same well-tested
observational and modeling techniques. No anomalous activity occurred.

1.19 Completed WF/PC-2 8634 (Atmospheric Variability on Uranus and
Neptune)

The WF/PC-2 was used to obtain snapshot observations of Uranus and
Neptune to monitor changes in their atmospheres on time scales of months to
years. Uranus is rapidly approaching equinox in 2007, with another 4
degrees of latitude in the northern hemisphere becoming visible every
year. Recent HST images during this unique epoch have revealed: {i}
strongly wavelength-dependent latitudinal structure, {ii} the presence of
numerous visible-wavelength cloud features in the northern hemisphere, and,
{iii} in the near-IR, discrete features northward of 25degrees N that have
the highest contrast ever seen for a Uranian cloud. Long-term ground-
based observations show seasonal brightness changes whose origins are not
well understood. Recent IR images of Neptune obtained using adaptive
optics on the Keck Telescope indicate that a new "Bright Companion" type of
feature has recently appeared in the southern hemisphere. Snapshot
observations of these two dynamic planets can supply context in which to
discern the nature of long-term changes in their latitudinal atmospheric
bands and to track the appearance, movement, and disappearance of discrete
albedo features. There were no reported problems.

1.20 Completed Seven Sets of 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.

1.21 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.

1.22 Completed Three Sets of 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.

1.23 Completed WF/PC-2 8829 (Observatory Focus Monitor)

The WF/PC-2 was used to analyze the HST focus which drifts slowly
and shows evidence of undergoing slips of a few microns at random
times. The rate of the WFPC2 monitoring program is insufficient to track
and/or understand OTA behavior in order to request timely and appropriate
secondary mirror corrections. This 14-orbit program obtains a large amount
of high signal to noise focus data, sometimes in two Science Instruments at
once, and will be sufficient to more accurately define the HST
focus. There were no reported problems.

1.24 Completed 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.

1.25 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.

1.26 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.

1.27 Completed WF/PC-2 9138 (Host Galaxies of Gravitationally Lensed
Quasars)

The WF/PC-2 was used to perform imaging studies of quasar host
galaxies at high redshift that are biased toward detecting luminous
hosts. Gravitational lensing combined with optical and near-IR imaging
enhances their detectivity and has nearly doubled the number of known hosts
at z>1. Lens studies have successfully imaged hosts with lower
luminosities at farther distances beneath a larger fraction of quasars than
imaging of non- lensed quasars. We propose deep WFPC2 follow-up imaging of
five lensed systems in the F555W and F814W filters, which offer unique
opportunities for detailed studies of faint, high-redshift, quasar
hosts. The proposal completed as planned.

1.28 Completed WF/PC-2 8600 (Dwarf Elliptical Galaxy Snapshot Survey
III)

The WF/PC-2 was used to extend our V and I snapshot survey of
nearby dwarf elliptical {dE} galaxies to include a sample of 30 bright dE
with significant globular cluster {GC} populations. There were no reported
problems.

1.29 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.

2.0 FLIGHT OPERATIONS SUMMARY:

2.1 Guide Star Acquisitions:
Scheduled Acquisitions: 50
Successful: 50

Scheduled Re-acquisitions: 16
Successful: 16

2.2 FHST Updates:
Scheduled: 88
Successful: 87

Per HSTAR 8234, the roll delay update scheduled for 146/113800Z
failed due to tracker #3. The subsequent acquisition was successful.

2.3 Operations Notes:

The STIS instrument remains in safe.

Using ROP SR-01A, the SSR EDAC error counter was cleared eight
times.

On two occasions, the CCS engineering status buffer limits were
adjusted per ROP DF-18A.

As directed by an operations request, the EPS limits were modified
due to the high Sun time for the period day 143 to day 158. This was
accomplished at 146/0057Z.

Per HSTAR 8233, the parameter EFG1_3T flagged out-of-limits low
with a value of 17.9479 degC. The limit is 18.00 degC.

A TTR was written for a required re-transmit at 147/1245Z during a
NSSC-1 load. Later, using ROP NS-5, NSSC-1 errors were reset.

At 148/083945Z, operations personnel noted that QF1STOPF and
QF1SSLEX had flagged out-of-limits while HST was guiding on FGS-3
only. This was indicates a possible FGS-1 "bit flip" during a ZOE.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

Continuation of normal science observations and calibrations.