Status Report

NASA Hubble Space Telescope Daily Report # 3435

By SpaceRef Editor
August 28, 2003
Filed under , ,





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 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 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

ACS/HRC 9422

Masses of AGB stars

There are few AGB stars with known masses. We have undertaken a
program to measure spectroscopic orbits for about 50 binary systems
containing M giants and typically white dwarfs. These are all single
lined systems so the spectroscopic orbit of the M giant results in a
mass function, m_2^3sin^3i / {m_1 + m_2}^2, for the secondary. Under
special conditions, it is possible to undertake a simple observation
that allows a solution for the masses. By measuring the angular
separation at the epoch of greatest elongation of a zero eccentricity,
eclipsing system {i.e. a system with a known inclination} m_1+m_2 can
be determined, hence allowing the masses to be solved. Parallaxes
indicate that there are two systems that can be resolved using
HST/ACS. We propose to carry out this observation.

ACS/HRC 9823

Rings of Uranus: Dynamics, Particle Properties and Shepherding Moons

We propose to image the rings and small inner satellites of Uranus
using the High Resolution Channel of the ACS. The revolutionary
capabilities of the ACS will allow us to address a variety of
important questions relating to ring properties and ring-moon
interactions. Observations at a range of wavelengths and phase angles
will reveal the opposition surges of these rings and moons, providing
information on color and surface structure. Measurements of the ring
in front of the planet will provide complementary information on
optical depth; any variations of optical depth with wavelength will
reveal the rings’ poorly-constrained population of embedded dust. The
rings of Uranus are closing rapidly as the planet approaches equinox
in 2007, an event that takes place only every 42 years. Using this
opportunity, our observations will be repeated at different solar and
terrestrial tilt angles; this sequence of images will be particularly
valuable for constraining the physical thickness and packing density
of the rings. We will place particular emphasis on the rotational
variations of the Epsilon Ring, whose radial width {and therefore its
packing density} varies by a factor of five. In addition, a set of
deep exposures targeted just off the planet will enable us to detect
any 4-5 km moons embedded within the ring system. Dynamicists invoke
numerous such moons to "shepherd" the many sharp ring boundaries, so
this will serve as a definitive test of the theory.


The Morphological, Photometric, and Spectroscopic Properties of
Intermediate Redshift Cluster Galaxies:

New and fundamental constraints on the evolutionary state of high
redshift clusters will be made by obtaining deep, multiband images
{SDSS r, i, z} over the central 1.5 Mpc regions of seven distant
clusters in the range 0.76 < z < 1.27. The ACS data will allow us to
{1} definitively establish the morphological composition and star
formation rates as functions of clustercentric radius, local density,
x-ray luminosity {obtained from accompanying Chandra, and XMM data},
{2} explore the relationship between substructure, kinematics, and
morphology, {3} strongly constrain the galaxy merger frequency and the
origins of elliptical and S0 galaxies, {4} measure the mass
distribution independently from the light {via gravitational lensing}
enabling comparisons with kinematically derived masses, and {5} study
the evolution of the structure of the brightest cluster members. The
clusters selected for this program already have extensive
spectroscopic observations and NIR imaging is either in hand or
underway from approved ground based programs. To date, the lower part
of this redshift range has only been marginally studied with HST. Our
sample includes the two most distant, spectroscopically confirmed
superclusters and will significantly increase the baseline over which
evolutionary effects can be studied. The data will also be used to
identify very high-z galaxies via their unique spectral properties.

ACS/WFPC2 9488

Cosmic Shear – with ACS Pure Parallel Observations

The ACS, with greater sensitivity and sky coverage, will extend our
ability to measure the weak gravitational lensing of galaxy images
caused by the large scale distribution of dark matter. We propose to
use the ACS in pure parallel {non- proprietary} mode, following the
guidelines of the ACS Default Pure Parallel Program. Using the HST
Medium Deep Survey WFPC2 database we have measured cosmic shear at
arc-min angular scales. The MDS image parameters, in particular the
galaxy orientations and axis ratios, are such that any residual
corrections due to errors in the PSF or jitter are much smaller than
the measured signal. This situation is in stark contrast with
ground-based observations. We have also developed a statistical
analysis procedure to derive unbiased estimates of cosmic shear from a
large number of fields, each of which has a very small number of
galaxies. We have therefore set the stage for measurements with the
ACS at fainter apparent magnitudes and smaller, 10 arc-second scales
corresponding to larger cosmological distances. We will adapt existing
MDS WFPC2 maximum likelihood galaxy image analysis algorithms to work
with the ACS. The analysis would also yield an online database similar
to that in

NIC2 9834

Finding Planets in the Stellar Graveyard: A Faint Companion Search of
White Dwarfs with NICMOS

We propose to do a deep search for substellar objects in orbit around
white dwarfs with the newly refurbished NICMOS camera as part of the
PI’s doctoral thesis work. Direct imaging of planets around main
sequence stars is difficult due to the large contrast ratio, a problem
which is much less severe for companions to white dwarfs. White dwarfs
are not usually considered in planet searches but recent theoretical
work and observations are motivating new searches for planetary
systems and dust disks around DAZ white dwarfs. We propose to conduct
the search with the NIC2 coronagraph to find resolved companions and
do photometry to search for unresolved companions through Near-IR
excesses. We estimate that the survey will be sensitive to brown
dwarfs, high mass jovian planets, and dust disks. By probing a wide
range of orbital separations and companion masses, this survey will
help to answer questions about the brown dwarf desert, common envelope
evolution, and planet formation. HST and NICMOS provide a unique
capability to do this search, as no ground based observatory with AO
can adequately search for faint companions as close and with such high

NIC2 9875

The Fundamental Plane of Massive Gas-Rich Mergers

We propose deep NICMOS H-band imaging of a carefully selected sample
of 33 luminous, late-stage galactic mergers. This program is part of a
comprehensive investigation of the most luminous mergers in the nearby
universe, the ultraluminous infrared galaxies {ULIGs}. The
high-resolution HST images will complement an extensive set of
ground-based data that include long-slit NIR spectra from a recently
approved Large VLT Programme. This unique dataset will allow us to
derive with unprecedented precision structural -and- kinematic
parameters for a large unbiased sample of objects spanning the entire
ULIG luminosity function. These data will refine the fundamental plane
of massive gas-rich mergers and enable us to answer the following
questions: {1} Do ultraluminous mergers form elliptical galaxies, and
in particular, giant ellipticals? {2} Do ULIGs evolve into optically
bright QSOs? The results from this detailed study of massive mergers
in the local universe will be relevant to understanding galaxy
formation and evolution at earlier epochs, and in particular, the
dusty sub-mm population that accounts for more than half of the star
formation at z > 1.


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 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 9615

Cycle 11 MAMA Dark Monitor

This test performs the routine monitoring of the MAMA detector dark
noise. This proposal will provide the primary means of checking on
health of the MAMA detectors systems through frequent monitoring of
the background count rate. The purpose is to look for evidence of
change in dark indicative of detector problem developing.

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 10000

STIS Pure Parallel Imaging Program: Cycle 12

This is the default archival pure parallel program for STIS during
cycle 12.

STIS/MA2 9804

Experimental Proof of the Neutrino Process in SN from Boron Isotope

The light elements Li, Be, and B are formed in the Big Bang {Li} and
by Cosmic Ray {CR} spallation. But the abundance of 11B has never been
satisfactorily explained: 11B/10B in the solar system is 4.0, CR
spallation predicts 2.5. There needs to be another source of 11B.
Woosely et al. {1990} predict the large flux of neutrinos in Type II
supernovae will synthesize elements, including converting 12C to 11B.
This "neutrino process" has never been experimentally verified. A
"smoking gun" would be to find a metal poor star whose elements came
primarily from Type II SN and whose B is pure 11B — only the neutrino
process could produce that. In a previous cycle we obtained STIS
measurements of a metal poor star and were able to clearly show that
11B/10B <= 4. We now ask for additional observations of higher S/N,
which can distinguish if 11B/10B = 4, or if the mix is pure 11B. In
either case we will end up with a precise measure of how much 11B in
old stars is NOT produced by CRs, and likely due to SN, and can place
a new constraint on the temperature and density of SN models in the
region where neutrino-induced nucleosynthesis is thought to take
place. Although this test could be made in a single star, we ask to
observe two, to increase the confidence in what is a subtle isotopic
measurement. We propose to observe the brightest two suitable metal
poor stars. One is in the CVZ.

WFPC2 10065

Mars at Closest Approach

We will take highest-quality HST images of Mars at it’s closest
approach in ca 50,000 years.

WFPC2 9595


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

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 9710

POMS Test Proposal: WFII backup parallel archive proposal

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

WFPC2 9740

CIII] Imagery of Planetary Nebulae and HII Regions — A Snap Program

We propose to undertake a SNAP program of WFPC2 imagery of several
planetary nebulae and extragalactic HII regions with the F185W filter
to study the spatial variation of the CIII] 1909 Angstrom emission
lines across the nebulae. Much of our current knowledge of carbon
abundances in planetary nebulae and HII regions are based on UV
spectroscopic observations of this line yet there have not been any
studies of its spatial variations in nebulae compared to several of
the prominent optical lines {e.g. [OIII] 5007 Angstroms}. Such
observations, coupled with photoionization modeling of the nebulae,
will enable us to assess the utility of using the CIII] line in
abundance calculations of C/O and C/H in nebulae and possibly permit
improved empirical emission-line diagnostic techniques for ionization
corrections to get the elemental carbon abundances from C++/O++
observations based on CIII]/[OIII] 1909/5007. We also plan to study
the spatial variation of the CIII] 1909 Angstrom collisionally excited
lines against the CII 4267 Angstrom permitted line in many of the
nebulae using previous and planned ground-based longslit echelle
spectroscopy coupled with the HST WFPC2 F185W imagery.


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

HSTAR 9129: FHST Full Maneuver (U1,3FM) Update @ 239/09:29:59Z and
09:32:44Z using FHST 2 and 3 (optimal pair 1,3) failed with Error Box
indicating "3 FAILED" for mnemonics QEBSTFG0, QEBSTFG1, and QEBSTFG2.
Subsequent GS Acquisition (3,1,3) @ 239/09:35:29Z with Primary FGS
Search Radius = 55 arcsec was successful. Under investigation.



                         SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq             11                       11
FGS REacq             04                        04
FHST Update           19                        19


Mars Opposition DD Visit (10066501) expedited data delivery ahead of
schedule @ 238/23:12:24Z – 23:32Z.

Command Timing Test scheduled 239/11:00Z – 21:00Z with GDOC SOC HITT,
and CCS using CCS "C" String with Release 4.0.3 and PRD S07200. The
purpose of this testing is to run command timing testing with CCS
Release 4.0.3 on the "C" String for Servicing Mission testing.

CCS Release 4.0.3 "C" String Exception testing 238/12:00Z – 16:25Z.
Part 1 of the test CCS responded to erroneous logins, as expected.
Command attempts without privileges failed. The FTP of a file from
Backbone to Core was successful. Part 2 CCS handled command typos
correctly. SM/PART, Command Queue, as well as CCSLite and Countdown
Clock functionality were all verified. Part 3 CCS handled forma
changes, CRC errors, Minor Frame gaps and FEP mode changes correctly.
All activities were conducted in the Servicing Mission mode.

Completed HSTSIM/CCSPSS Verification testing 237/16:15Z – 18:36Z using
CCS "C" String with CCS Release 4.0.3. All objectives were met. Wrote
TSAR 2591 regarding telemetry Format D and a difference greater than
two minutes in SCT and UTC times. Upon further investigation Format
D/E is derived from Ground Receipt Time (GRT), we did not set the GRT
to ± 30 seconds at the beginning of the test. This action will be
discussed at the next test meeting. A minor problem regarding safing
loads on the "C" String inhibited us from safing the NSSC-1 but were
able to obtain the objective of getting to Format D. Also received a
count failure with our HST486 load which is previously documented in
CR 6917.

Completed CCS Ops/SM Account Verification Test using CCS "C" String
with Release 4.0.3 and PRD S07200. Test was successful, except for:
Typo in IPCONFIG directive was not caught by CCS. TSAR 2588 written
previously on this issue. While in JSC mode, received a "JSC timeout
or validation failure enter /SEND or /CLEAR" error message. The JSC
time out has been previously documented in CCS CR 8229/TSAR 2530,
however, tried the /CLEAR and /SEND. Neither action had any effect on
the error and had to partial re-cycle CCS command. TSAR 2590 written
to document this issue.

SpaceRef staff editor.