Status Report

NASA Hubble Space Telescope Daily Report # 3425

By SpaceRef Editor
August 13, 2003
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GO 9428

SINS: The Supernova Intensive Study– Cycle 11

Supernovae create the chemical history of the Universe, energize the
interstellar gas, form the spine of the extragalactic distance scale,
and provide the only direct evidence for an accelerating universe.
SINS is a program to study supernovae, near and far. HST is the
perfect match in field and scale for spatially-resolved observations
of SN 1987A. There, a violent encounter between the fast-moving debris
and the stationary inner ring is well underway. Monitoring this
interaction will help solve the riddles of stellar evolution posed by
the enigmatic three-ring system of SN 1987A. Our UV observations of
Ly-Alpha emission reveal a remarkable reverse shock that provides a
unique laboratory for studying fast shocks and a powerful tool for
dissecting the structure of the vanished star. For more distant
events, we propose Target-of-Opportunity observations. In addition to
one bright new supernova in Cycle 11 discovered by any search at any
time, we propose to discover two supernovae for study in the
ultraviolet at times specified in advance, using the Lick Observatory
Supernova Search. SINS will study the historic SN 1987A, explore UV
emission from supernovae, and press late-time observations of
supernovae into uncharted territory of infrared catastrophes, light
echoes, and stellar remnants.

WFPC2 9595


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

STIS 9606

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.

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 9633

STIS parallel archive proposal – Nearby Galaxies – Imaging and

Using parallel opportunities with STIS which were not allocated by the
TAC, we propose to obtain deep STIS imagery with both the Clear
{50CCD} and Long-Pass {F28X50LP} filters in order to make
color-magnitude diagrams and luminosity functions for nearby galaxies.
For local group galaxies, we also include G750L slitless spectroscopy
to search for e.g., Carbon stars, late M giants and S-type stars. This
survey will be useful to study the star formation histories, chemical
evolution, and distances to these galaxies. These data will be placed
immediately into the Hubble Data Archive.

WFPC2 9634

POMS Test Proposal: WFII targeted parallel archive proposal

The parallel opportunities available with WFPC2 in the neighborhood of
bright galaxies are treated in a slightly different way from the
normal pure parallels. Local Group galaxies offer the opportunity for
a closer look at young stellar populations. Narrow-band images in
F656N can be used both to identify young stars via their emission
lines, and to map the gas distribution in star-forming regions. Thus,
the filter F656N is added to the four standard filters. Near more
distant galaxies, up to about 10 Mpc, we can map the population of
globular clusters; for this purpose, F300W is less useful, and only
F450W, F606W, and F814W will be used.

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.

STIS 9708

STIS Pure Parallel Imaging Program: Cycle 11

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

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.


The rarest of sightlines: probing the metallicity of a DLA with a
nearby Low Surface Brightness galaxy

We seek to measure the gas-phase metallicity, dust content, and gas
kinematics in the interstellar medium {ISM} of the Low Surface
Brightness {LSB} galaxy SBS 1543+593, by observing absorption lines in
the spectrum of the background QSO HS 1543+5921. The QSO shines
directly through the center of the LSB galaxy, producing a damped
Lyman-alpha {DLA} line. This is the lowest redshift DLA system known
outside of the local group. Specifically, we wish to use the G140M
grating of STIS to: a} determine the metallicity of the interstellar
gas in the LSB galaxy by accurately measuring the column densities of
neutral hydrogen and sulphur; and b} estimate the amount of dust
present from a precise measure of the nickel column density. The
grating settings chosen to accomplish these goals will also allow us
to: c} characterize the kinematics of cool gas in the disk and halo of
the LSB galaxy by observing the line profiles of strong low ionization
species {Si II, O I, C I, C II, etc.}; and d} search for absorption
from NV which may arise in any highly ionized component of the ISM due
to accretion of intragroup gas onto the galaxy.

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.

ACS/WFC 9788

A Narrow-band Snapshot Survey of Nearby Galaxies

We propose to use ACS/WFC to conduct the first comprehensive HST
narrow-band {H-alpha + [N II]} imaging survey of the central regions
of nearby bulge-dominated disk {S0 to Sbc} galaxies. This survey will
cover, at high angular resolution extending over a large field, an
unprecedented number of galaxies representing many different
environments. It will have important applications for many
astrophysical problems of current interest, and it will be an
invaluable addition to the HST legacy. The observations will be
conducted in snapshot mode, drawing targets from a complete sample of
145 galaxies selected from the Palomar spectroscopic survey of nearby
galaxies. Our group will use the data for two primary applications.
First, we will search for nuclear emission-line disks suitable for
future kinematic measurements with STIS, in order to better constrain
the recently discovered relations between black hole mass and bulge
properties. Preliminary imaging of the type proposed here must be
done, sooner or later, if we are to make progress in this exciting new
field. Second, we will investigate a number of issues related to
extragalactic star formation. Specifically, we will systematically
characterize the properties of H II regions and super star clusters on
all galactic scales, from circumnuclear regions to the large-scale

ACS/HRC 9853

A Search for Young Binary Brown Dwarfs: Constraining Formation
Scenarios and Masses Through Multiplicity

We propose to use the Advanced Camera for Surveys / High Resolution
Camera to conduct a direct imaging multiplicity survey of 34 young
brown dwarfs in the nearest regions of recent star formation, the T
association Taurus-Auriga and the OB association Upper Scorpius. The
determined multiplicity fraction, the separation distribution, and the
mass ratio distribution will offer stringent observational constraints
on proposed brown dwarf formation scenarios. Moreover, the small
semi-major axes of known field and open cluster brown dwarf binaries
suggest the exciting possibility of our identifying several very close
binaries {< 15 AU}. Continued monitoring of these systems would yield,
on a decade timescale, the first dynamical mass estimates of T Tauri
brown dwarfs. With masses intermediate between those of stars and
planets, brown dwarfs offer our best hope of relating the reasonably
well understood processes of star formation to the less well
understood processes of planet formation.


Where is the Local Hot Gas?

We wish to sample the absorption characteristics of 3 lines-of-sight
in the local interstellar medium to establish the physical location of
the production sites of the highly ionized absorption lines of CIV,
SiIV and NV. Such lines are formed at gas temperatures of ~ 100, 000K
and all have been widely observed throughout the Galaxy. However,
evidence for the formation of any of these high ions within the hot
gas of the Local Bubble {LB} remains inconclusive, supporting the
similar lack of detections of the OVI ion {T ~ 300, 000K} within 100pc
recently reported by the FUSE satellite. Using our recently gained
information on the contours of the neutral boundary to the LB, we have
selected 3 pairs of stars located just within, and just beyond the LB
boundary. We shall test whether high ionization ions are formed either
{a} beyond the LB boundary in more distant interstellar bubbles of hot
gas, {b} at the conductive interface of the LB neutral boundary, or
{c} at possible conductive interfaces between hot gas within the LB
and the diffuse clouds embedded within it. Hopefully, these
observations will enable theorists to better model the {anomalous}
ionization state, pressure and chemical abundance of the local
interstellar gas and will assist in the interpretation of data soon to
be gained from the NASA CHIPS mission.

ACS/WFC 9891

A snapshot survey of rich stellar clusters in the Large and Small
Magellanic Clouds

Rich stellar clusters are vital to a wide variety of astrophysical
research, from stellar evolution studies to the formation and
evolution of galaxies. In this context, it is important to understand
how rich star clusters form and evolve. The cluster systems in the LMC
and SMC are particularly important in achieving this, because they are
the only systems which contain clusters at all stages of evolution
while being close enough to be studied as fully resolved stellar
populations – although in general this requires the capabilities of
HST. We have recently investigated the structural evolution of LMC and
SMC clusters using archival WFPC2 data, and demonstrated a dramatic
trend in the sizes of these clusters with age. We have shown that this
trend likely represents genuine structural evolution in these
clusters, although it is not clear whether we are observing a
dynamical process or the signature of changing formation conditions.
This result has implications for all astronomical research involving
massive stellar clusters. To develop this work further requires the
extension of our two samples, so that they are statistically
quantifiable. This will allow a number of key questions regarding the
structural evolution trend to be answered. We propose a two-colour
ACS/WFC SNAP survey of rich Magellanic Cloud clusters to achieve this
aim. The unique resolution and sensitivity of ACS/WFC is required for
success, because of the crowded nature of the targets. The SNAP data
will have a large number of additional applications, both to globular
cluster and Magellanic Cloud research.

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


Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.) None



                          SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq              9                          9
FGS REacq              5                          5
FHST Update            11                        11


Configured CCS "G" String to Prime Ops for CCS Release 4.0.3 checkout
@ 224:10:47Z, configured CCS "B" String to Prime Ops for CCS Release
4.0.3 checkout @ 224/23:29Z.

SpaceRef staff editor.