Status Report

NASA Hubble Space Telescope Daily Report # 3418

By SpaceRef Editor
August 4, 2003
Filed under , ,

HUBBLE SPACE TELESCOPE

DAILY REPORT # 3418

PERIOD COVERED: DOYs 213-215

OBSERVATIONS SCHEDULED

ACS 9658

ACS Earth Flats

This program will obtain sequences of flat field images by observing the
bright
Earth. Several UV filters from the interim calibration program {9564}
require
additional exposures to obtain the required illumination. A few UV filters
from
this program will be repeated to monitor for changes in the flat fields and
to
verify the interim results. Since no streaks are observed in the UV, the
wavelength coverage is extended to longer wavelengths in order to explore
the
severity of streaks in the flats from clouds in the FOV. We have added
exposures
for the HRC in the visible filters to verify the results derived from the
L-flat
campaign and to explore the severity of streaks. We have also added
exposures on
WFC using the minimum exposure time and using filters which will not
saturate
the brightest WFC pixel by more than 10 times the full well.

ACS 9657

ACS Internal Flat Field Stability

The flat field stability and characterisation obtained during the ground
calibration and SMOV phases will be tested and verified through a sub-sample
of
the filter set. Only internal exposures with the calibration lamps will be
required.

ACS 9675

CCD Daily Monitor

This program consists of basic tests to monitor, the read noise, the
development
of hot pixels and test for any source of noise in ACS CCD detectors. This
programme will be executed once a day for the entire lifetime of ACS.

ACS 9984

Cosmic Shear With ACS Pure Parallels

Small distortions in the shapes of background galaxies by foreground mass
provide a powerful method of directly measuring the amount and distribution
of
dark matter. Several groups have recently detected this weak lensing by
large-scale structure, also called cosmic shear. The high resolution and
sensitivity of HST/ACS provide a unique opportunity to measure cosmic shear
accurately on small scales. Using 260 parallel orbits in Sloan textiti
{F775W}
we will measure for the first time: beginlistosetlength sep0cm
setlengthemsep0cm
setlength opsep0cm em the cosmic shear variance on scales <0.7 arcmin, em the skewness of the shear distribution, and em the magnification effect. endlist Our measurements will determine the amplitude of the mass power spectrum sigma_8Omega_m^0.5, with signal-to-noise {s/n} ~ 20, and the mass density Omega_m with s/n=4. They will be done at small angular scales where non-linear effects dominate the power spectrum, providing a test of the gravitational instability paradigm for structure formation. Measurements on these scales are not possible from the ground, because of the systematic effects induced by PSF smearing from seeing. Having many independent lines of sight reduces the uncertainty due to cosmic variance, making parallel observations ideal.

ACS 9831

Multiplicity among brown dwarfs in the Pleiades cluster

We have compiled a sample of 32 confirmed brown dwarfs in the Pleiades
cluster.
We propose to observe this sample with HST/ACS in SNAPSHOT mode in order to
search for very low mass multiple systems. Our goals are: 1} to determine
the
occurrence and frequency of binary systems among substellar objects, which
hold
important clues to the formation and evolution mechanism{s} of ultracool and
brown dwarfs, 2} to get an estimate of the Initial Mass Function {IMF} at
very
low masses, which is still unknown and very much needed to be corrected for
binarity, 3} to compare the distribution of multiple systems in young open
clusters and in the field.

ACS/HRC 9733

Direct imaging of the progenitors of massive, core-collapse supernovae

Modern supernovae searches in the nearby Universe are discovering large
numbers
of SNe which have massive star progenitors {Types II, Ib and Ic}. The
extensive
HST {and ground-based} image archives of galaxies within ~20Mpc enables
their
individual bright stellar content to be resolved. As massive, evolved stars
are
the most luminous single objects in a galaxy, the progenitors of
core-collapse
SNe should be directly detectable on pre-explosion images. Within the last
two
cycles we have set direct mass-limits on three type II-P supernovae using
HST
images, and already these can be used to constrain theoretical models of
pre-supernova stellar evolution which predict which stars cause which of the
supernovae types. We request time to continue this successful project, and
require ACS observations of future SNe which are discovered in galaxies
closer
than 20Mpc which have pre-explosion HST archive images available. These ToO
observations will allow the SNe to be precisely positioned on the
pre-explosion
frames with the required astrometric accuracy of around 0.05″, and allow
3-colour photometry of the surrounding stellar populations for reddening
estimations. The goal of this project is to directly identify the progenitor
stars of core-collapse supernovae. We will compare the progenitor detections
or
luminosity limits to our own stellar evolutionary tracks in order to
determine
masses or restrictive mass-limits for the progenitors.

ACS/WFC 9765

The Dusty ISM Substructure in Nearby Spiral Galaxies

We propose an ACS V&I imaging snapshot survey of all nearby edge-on spiral
galaxies in order to measure the small scale structures in their dust
extinction
down to the 10pc scale. Dust and molecular gas are thightly coupled and
therefore HST high resolution reddening maps can reveal information about
the
cold ISM phase on a scale inaccessible from the groundby any other means. We
have recently discovered a sudden change in dust lane properties using
ground-based data; all galaxies with rotation speeds in access of 120km/s
show
dust lanes, but none of the slower rotators does. This transition may be
caused
by a sudden change in the state of the multiphase ISM, and HST resolution
imaging is needed to fully quantify this effect. Analysis will consist of
full
radiative transfer modeling of dust extinction with realistic, fractal like
substructure and power spectrum analysis of the structure from the global
to the
10pc scale. By observing a sample of galaxies with a range in structural
parameters we can quantify how the cold ISM structure changes as function of
radius, rotation speed, local surface density, et cetera. This information
is
duly needed with SIRTF soon providing a wealth of information on dust
absorption, but lacking the resolution to determine the small scale
distribution
of the dust.

ACS/WFC 9902

The Evolution of the Host Galaxies of Radio-Quiet Quasars

Study of the host galaxies and environments of high redshift AGN is proving
a
valuable probe of current theories of how galaxies form and evolve. Results
from
our NICMOS imaging program have indicated that the hosts of z ~ 2 — 3 faint
radio-quiet quasars {RQQ} have luminosities only around local L*, making
them
similar to Lyman-break field galaxies at the same redshifts, and to the
low-z
hosts RQQ hosts. This is roughly consistent with theoretical predictions of
Kauffmann & Haehnelt {2000} for the hierarchical buildup of galaxy hosts and
their relation to their resident supermassive black holes. The luminosity
of the
AGN in these RQQ is key to understanding this relationship, however, and we
are
making a comprehensive archival HST imaging study of the hosts of RQQs from
low
to high z at a range of nuclear luminosities. At intermediate z, however,
there
are no studies of the hosts of RQQs in the faint luminosity range that
represents the bulk of the quasar population. In the present proposal, we
request imaging at the same rest-wavelengths as our high-z sample of the
hosts
of 10 similarly luminous RQQs at z ~ 0.9. These data will fill in an
important
part of the parameter space defined by quasar luminosity and redshift.
Combined
with existing HST data they will allow us to trace the evolution of the
hosts of
RQQ and that of the relationship between quasar luminosity and host galaxy
luminosity.

ACS/WFPC2 9481

Pure Parallel Near-UV Observations with WFPC2 within High-Latitude ACS
Survey
Fields

In anticipation of the allocation of ACS high-latitude imaging survey{s}, we
request a modification of the default pure parallel program for those WFPC2
parallels that fall within the ACS survey field. Rather than duplicate the
red
bands which will be done much better with ACS, we propose to observe in the
near-ultraviolet F300W filter. These data will enable study of the
rest-frame
ultraviolet morphology of galaxies at 0

FGS 9971

FGS Astrometry of a Star Hosting an Extrasolar Planet: The Mass of Upsilon
Andromedae d

We propose observations with HST/FGS to determine the astrometric elements
{perturbation orbit semimajor axis and inclination} produced by the
outermost
extra-solar planet orbiting the F8V star Upsilon Andromedae. These
observations
will permit us to determine the actual mass of the planet by providing the
presently unknown sin i factor intrinsic to the radial velocity method which
discovered this object. An inclination, i = 30degrees, within the range of
one
very low precision determination using reanalyzed HIPPARCOS intermediate
data
products, would produce the observed radial velocity amplitude, K = 66 ms
with a
companion mass of ~8 M_Jupiter. Such a mass would induce in Upsilon
Andromedae a
perturbation semi-major axis, Alpha = 0arcs0012, easily within the reach of
HST/FGS fringe tracking astrometry. The proposed observations will yield a
planetary mass, rather than, as previous investigations have done, only
suggest
a planetary mass companion.

FGS 9883

Parallaxes of Extreme Halo Subgiants: Calibrating Globular Cluster
Distances and
the Ages of the Oldest Stars

The ages of the oldest stars are a key constraint on the evolution of our
Galaxy, the history of star formation, and cosmological models. These ages
are
usually determined from globular clusters. However, it is alternatively
possible
to determine ages of extreme Population II subgiants in the solar
neighborhood
based on trigonometric parallaxes, without any recourse to clusters. This
approach completely avoids the vexing issues of cluster distances,
reddenings,
and chemical compositions. There are 3 known nearby, extremely
metal-deficient
Pop II subgiants with Hipparcos parallax errors of 6-11% which are
available for
such age determinations. At present, based on the latest isochrones, the
derived
ages of these stars {HD 84937, HD 132475, and HD 140283} are all close to 14
Gyr, uncomfortably close to or higher than current estimates of the age of
the
universe. However, the errors in the Hipparcos parallaxes imply
uncertainties of
at least 2 Gyr in the ages of the 3 stars. We propose to measure parallaxes
of
these three Pop II subgiants using HST’s Fine Guidance Sensor 1R. We expect
to
reduce the Hipparcos parallax error bars by factors of 5-6, providing the
most
stringent test yet of current theoretical stellar models of Pop II stars and
pushing the age uncertainties to below 0.5 Gyr. These data will also provide
a
major new constraint on the distance scale of globular clusters, with wide
implications for stellar evolution and the calibration of Pop II standard
candles.

HST 9382

A Large Targeted Survey for z < 1.6 Damped Lyman Alpha Lines in SDSS QSO MgII-FeII Systems.

We have searched the first public release of SDSS QSO spectra for low-z
{z<1.65} metal absorption lines and found over 200 large rest equivalent width MgII-FeII systems. Previously, we empirically showed that such systems are good tracers of large neutral gas columns, with ~50% being classical damped Lyman alpha {DLA} systems {N_HI>=2*10^20 cm^-2}. Here we propose to follow up a well-defined
subset of 79 of them to search for DLAs with 0.47

NICMOS 9640

Flats Stability

This calibration proposal is the Cycle 11 NICMOS monthly monitor A series of
camera 1, 2, & 3 flat fields will be obtained to monitor the health of the
cameras.

NICMOS 8791

NICMOS Post-SAA calibration – CR Persistence Part 2

A new procedure proposed to alleviate the CR-persistence problem of NICMOS.
Dark
frames will be obtained immediately upon exiting the SAA contour 23, and
every
time a NICMOS exposure is scheduled within 50 minutes of coming out of the
SAA.
The darks will be obtained in parallel in all three NICMOS Cameras. The
POST-SAA
darks will be non-standard reference files available to users with a
USEAFTER
date/time mark. The keyword ‘USEAFTER=date/time’ will also be added to the
header of each POST-SAA DARK frame. The keyword must be populated with the
time,
in addition to the date, because HST crosses the SAA ~8 times per day so
each
POST-SAA DARK will need to have the appropriate time specified, for users to
identify the ones they need. Both the raw and processed images will be
archived
as POST-SAA DARKSs. Generally we expect that all NICMOS science/calibration
observations started within 50 minutes of leaving an SAA will need such maps
to
remove the CR persistence from the science images. Each observation will
need
its own CRMAP, as different SAA passages leave different imprints on the
NICMOS
detectors.

STIS 9608

CCD Bias Monitor – Part 2

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.

STIS 9606

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.

STIS 9437

Quantitative Constraints for Massive Star Evolution Models with Rotation

Rotation is now recognized as an important physical component in
understanding
massive stars. Theory suggests that rotation affects the lifetimes, chemical
yields, stellar evolution tracks, and the supernova and compact remnant
properties {Heger & Langer 2000, Maeder & Meynet 2000}. In a Cycle 7
program, we
proved that rotational mixing occurs in massive main sequence stars {Venn
et al.
2001}. In this proposal, we want to quantitatively test model predictions
and
constrain the theory for a better understanding of massive star evolution.
We
are requesting HST STIS observations of the BIII 2066 Angstrom resonance
line of
seven massive stars in three young clusters carefully selected from IUE
analyses. These stars show traces of boron depletion, but without nitrogen
enrichment; rotation is the only theory able to explain this abundance
pattern.
These new abundances will allow us to test rotating model predictions: that
mixing strength increases with stellar age, mass, and rotation rate. They
will
also help to quantitatively constrain the rotational mixing efficiencies in
massive stars. One very high S/N spectrum of a moderately boron-depleted
star is
also requested. We wish to measure its 11B/10B ratio, which is predicted to
change as boron is depleted in the rotating models. This ratio will further
confirm rotational effects and observationally constrain the 10B{p, Alpha}
thermonuclear reaction rate, which is presently highly uncertain.

STIS 9613

STIS CCD Spectroscopic Flats C11

Obtain CCD flats on the STIS CCD in spectroscopic mode.

STIS 9708

STIS Pure Parallel Imaging Program: Cycle 11

This is the default archival pure parallel program for STIS during cycle 11.

STIS 9783

The Ages of Nuclear Star Clusters in Early-type Spiral Galaxies

We propose to obtain STIS G430L spectra of the previously identified nuclear
star cluster in a sample of 16 spiral galaxies of early to intermediate
Hubble
type. HST’s spatial resolution is required to separate the nuclear cluster
from
the underlying galaxy bulge. Analysis of the spectra with population
synthesis
methods will reveal the cluster ages. We will use the age distribution to
constrain the duty cycle of nuclear cluster formation. Comparison of the
results
to those for a larger sample of nuclear clusters in late-type, bulgeless
galaxies will allow us to investigate possible differences between the
formation
mechanisms of nuclear clusters in early and late Hubble types. Such
differences
might be expected because galaxy bulges show a dichotomy: in late Hubble
types,
the surface brightness profiles are best described by an exponential, while
they
follow a de Vaucouleurs law in earlier types. Although the reason for this
dichotomy is still unknown, it is plausible that galaxy bulges have
different
formation mechanisms at the two ends of the Hubble sequence. We know that
{1}
nuclear cluster formation is linked to the funneling of gas towards the
nucleus
via gravitational torques from stellar bars, {2} a nuclear mass
concentration
can make bars unstable, and {3} unstable bars can form bulges. Therefore,
the
age distribution of nuclear star clusters contains important clues to the
evolution of galaxy centers and promises new insight into the origin of the
Hubble sequence.

STIS 9786

The Next Generation Spectral Library

We propose to continue the Cycle 10 snapshot program to produce a Next
Generation Spectral Library of 600 stars for use in modeling the integrated
light of galaxies and clusters. This program is using the low dispersion UV
and
optical gratings of STIS. The library will be roughly equally divided among
four
metallicities, very low {[Fe/H] lt -1.5}, low {[Fe/H] -1.5 to -0.5},
near-solar
{[Fe/H] -0.3 to 0.1}, and super-solar {[Fe/H] gt 0.2}, 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.
Because of the universal utility and community-broad nature of this venture,
we
waive the entire proprietary period.

STIS/CCD/MA2 9967

Cepheid Masses: U Aql {Cycle 12 continuation of 9146}

Quantitative understanding of classical Cepheids provides confidence in
their
use as primary extragalactic distance indicators, as well as in the
understanding of the evolution of more massive stars and more evolved
stars. HST
UV spectroscopy provides a unique opportunity to contribute to the dramatic
improvement in the precision of fundamental stellar parameters by
determining
the mass of the binary Cepheid U Aql, a high-priority Cepheid mass. In this
project, the orbital velocity amplitude of the hot main sequence companion
is to
be measured from STIS echelle spectra and combined with the orbital velocity
amplitude of the Cepheid from the ground-based orbit and the mass of the
main
sequence companion to provide the Cepheid mass. The sensitivity of the STIS
spectrograph makes possible a higher dispersion observation over a wider
wavelength region than the previous GHRS medium resolution spectra. We
expect
the radial velocities measured from the STIS spectra to reduce the
uncertainty
{s.d.} in the mass of U Aql from 13% {in the previous GHRS result} to < 5%.

WFPC2 9591

Cycle 11 WFPC2 CTE Characterization

Monitor CTE changes during Cycle 11; test whether 2X2 binning affects CTE
{may
be relevant for ACS}; and perform a high S/N long-vs-short test in an
uncrowded
field.

WFPC2 9710

POMS Test Proposal: WFII backup parallel archive proposal

This is a POMS test proposal designed to simulate scientific plans.

WFPC2 9709

POMS Test Proposal: WFII parallel archive proposal

This is the generic target version of the WFPC2 Archival Pure Parallel
program.
The program will be used to take parallel images of random areas of the sky,
following the recommendations of the 2002 Parallels Working Group.

WFPC2 9595

WFPC2 CYCLE 11 SUPPLEMENTAL DARKS pt3/3

This dark calibration program obtains 3 dark frames every day to provide
data
for monitoring and characterizing the evolution of hot pixels.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports of
potential non-nominal performance that will be investigated.)

HSTAR 9102: NICMOS Cooling System Safed and generated four Status Buffer
entries
beginning @ 214/06:38:43Z. EXEC 908 P=200, T=61035.
EXEC 1121 P=23614, T=61051.
EXEC 919 Pa-10000, T=61103. NCS Comp Slip Sensor
broke limit @ 214/06:39:14Z,
reaching a peak value of 39.16 for one sample and
then settling to an average
values of 18.31. Vehicle was in SAA Level 1 at time
of anomaly.
Under investigation.

HSTAR 9103: GS Acquisition @ 216/00:58:02Z resulted in FL backup on FGS 2
due SSLE on
FGS 3 @ 216/01:01:49Z. Under investigation.

COMPLETED OPS REQs:

  • 17010-0 Battery 5 Capacity Test @ 213/1949z
  • 17014-1 Recover from Cold SA Test Failure, Part 1 @ 213/1812z
  • 17015-0 Recover from Cold SA Test Failure, Part 2 @ 213/1930z
  • 17016-0 8051 History and Min/Max Buffer Dumps @ 214/1302z
  • 17017-0 Turn On NCS CPL Startup Heater @ 214/1132z
  • 17018-0 Power On PCE @ 214/1949z
  • 17019-0 Safe NICMOS due to NCC safing @ 214/21:56:43z

OPS NOTES EXECUTED:
0910-2 SI Console response to MCE Resets after FSW 4.8 is activated @ 213/2216z

  • 1143-0 Set-up TMDIAGs to Monitor OCA Tlm @ 213/1752z
  • 1144-0 SOC Ground Lim Mod Post Batt 4 Capacity Test (DOY 2003/213) @ 213/1753z
  • 0924-0 HSTAR Documentation for Guide Star Acq Failure/Loss of Lock @ 216/0101z
  • 0916-0 Tabulation of Slew Attitude Error (Miss-distance) @ 216/0144z
  • 0900-1 COMMAND PROBLEM @ 214/08:04:29z

                        SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq            23                        23
FGS REacq            26                        26
FHST Update          53                        53
LOSS of LOCK

SIGNIFICANT EVENTS:

NICMOS Cooling System Safed see HSTAR 9102.

On attempt to return Battery 5 to the FSW 6-Battery System @ 213/14:24:52Z,
the Cold SA
Protection test failed and EPS processing went to Hardware Charge Control
(HWCC).
EPS/FSW verified the test failed because the battery was put back in the
FSW 6-Battery
System before all VTFE bits were zeroed. Completed remaining steps in
Battery 5
Capacity Test @ 213/19:49Z (OR 17010).

SpaceRef staff editor.