Status Report

NASA Hubble Space Telescope Daily Report # 3536

By SpaceRef Editor
January 23, 2004
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science




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.


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.


HH110: Collision between a Jet and a Cloud

We propose to study the shortlived event when a high-velocity
protostellar outflow collides with a dense molecular cloud core. It
has recently been realized that Herbig-Haro flows can attain gigantic
proportions, with flow lobes stretching over many parsecs. This
greatly increases the probability that an outflow rams into an
obstacle such as a molecular cloud core as it plows through the
interstellar medium. The HH 110 flow represents the rare case of an
outflow that has suffered a grazing collision with a cloud core.
Fortunately, the resulting shock is so bright that only a few orbits
are required for analysis. ACS imaging in Halpha in Cycles 12 and 14
will permit the study of detailed structure and kinematics of the flow
as it passes through the region of impact. This study has consequences
for our general understanding of the energy cycle and chemical
processing of the interstellar medium, turbulence in molecular clouds,
and the role of sequential star formation among low mass stars.


The role of dark matter and intracluster gas in galaxy formation and
cluster evolution

We propose a fully-sampled mosaic of 41 ACS images to survey galaxy
morphologies and measure weak lensing signals to the turn-around
radius in the X-ray luminous cluster, MS0451-03 {z=0.54}. The aim is
to isolate the physical processes which affect the evolution of
cluster galaxy morphologies in the context of well-defined dynamical
system. The study will be used in contrast to a successful campaign
undertaken in Cycle 9 on a optically-selected target. By comparing
morphologies with spectroscopic and Chandra X-ray data, we will
quantify the role of the intracluster medium and associated
substructures and establish the timescales and physical regions within
which the various environmental processes occur.

ACS/WFC 10057

ACS Ramp Filter Calibration

We request 3 orbits to observe a well-calibrated region in the Orion
Nebula with the primary goal of deriving monochromatic L-flats at
specific central wavelengths {lambda_c} for {a} WFC {inner+outer}
Halpha {FR716N, FR782N} and [OIII] {FR551N, FR601N} ramp filters. {b}
WFC middle ramp filters {FR388N, FR459M, FR505N, FR6546N, FR914M}.{c}
HRC middle ramp filters {FR388N, FR459M, FR505N, FR656N, FR914M}. As a
secondary goal, we will get an independent check of the wavelength
calibration which will be provided by the IDT team from the Cycle 11
program 9671. We request 1.5 CVZ orbits to observe two well-calibrated
standard star fields in 47 Tuc with the primary goal of deriving WFC
and HRC continuum L-flats for three middle {WFC1-MRAMP} filters:
FR656N, FR388N, and FR505N. These filters are selected as they are
frequently used to map the Halpha 6563 A, [OII] 3727A, and [OIII]
5007A lines and they include the least {FR388N} and most {FR505N}
uniform ramps, based on ground data {ISR ACS 02-01}. These 3 filters
should provide a good baseline for testing our approach and gauging
the range of non-uniformity in the continuum L-flats. For good spatial
sampling, the 2 fields are selected with stellar densities appropriate
to WFC and HRC. For good spectral sampling we will step in the central
wavelength in steps of 80 A, with 30s exposure at each lambda_c
providing good S/N for V=15-20 mag stars. We will use 2K subarrays to
reduce the frequency of buffer dumps.

ACS/WFC 12001

Emission-line Imaging of Young SNRs in the Magellanic Clouds

The fundamental processes of nucleosynthesis that take place deep
within the cores of massive stars are hidden from our scrutiny until
the stars explode as supernovae. Young supernova remnants {SNRs} allow
us to examine material from the cores of massive stars directly,
leading to observational tests of theories for stellar evolution,
nucleosynthesis, and the chemical enrichment of the ISM in galaxies.
We will image two young SNRs in the Magellanic Clouds {N132D in the
LMC and 1E0102.2-7219 in the SMC} using wide filters on the ACS Wide
Field Channel in order to capture the full velocity range of the
expanding debris field. These images will identify the brightest
ejecta knots for follow-up UV/optical spectroscopy and can be compared
to X-ray images to determine the locations of shock waves.

ACS/WFC 9860

ESSENCE: Measuring the Dark Energy Equation of State

The accelerating universe appears to be dominated by a dark energy
with a significant negative pressure. The ratio of the pressure to
density of this mysterious energy {its equation of state} is an
observable which can differentiate between the proliferating candidate
theories. We propose to estimate the dark energy equation of state by
observing Type Ia supernovae at redshifts near z=0.7 with HST in
concert with the on-going ESSENCE NOAO Survey program that is
discovering and studying supernovae between 0.3

NIC/NIC3 9865

The NICMOS Parallel Observing Program

We propose to continue managing the NICMOS pure parallel program.
Based on our experience, we are well prepared to make optimal use of
the parallel opportunities. The improved sensitivity and efficiency of
our observations will substantially increase the number of
line-emitting galaxies detected. As our previous work has
demonstrated, the most frequently detected line is Halpha at


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 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.

STIS/CCD 10017

CCD Dark Monitor-Part 1

Monitor the darks for the STIS CCD.

STIS/CCD 10019

CCD Bias Monitor – Part 1

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/CCD 10085

STIS Pure Parallel Imaging Program: Cycle 12

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

STIS/MA1 10083

HST UV Images of Saturn’s Aurora Coordinated with Cassini Solar Wind

A key measurement goal of the Cassini mission to Saturn is to obtain
simultaneous solar wind and auroral imaging measurements in a campaign
scheduled for Jan. 2004. Cassini will measure the solar wind
approaching Saturn continuously from 9 Jan. – 6 Feb., but not closer
to Saturn due to competing spacecraft orientation constraints. The
only system capable of imaging Saturn’s aurora in early 2004 will be
HST. In this community DD proposal we request the minimum HST time
needed to support the Cassini mission during the solar wind campaign
with UV images of Saturn’s aurora. Saturn’s magnetosphere is
intermediate between the “closed” Jovian case with large internal
sources of plasma and the Earth’s magnetosphere which is open to solar
wind interactions. Saturn’s aurora has been shown to exhibit large
temporal variations in brightness and morphology from Voyager and HST
observations. Changes of auroral emitted power exceeding one order of
magnitude, dawn brightenings, and latitudinal motions of the main oval
have all been observed. Lacking knowledge of solar wind conditions
near Saturn, it has not been possible to determine its role in
Saturn’s auroral processes, nor the mechanisms controlling the auroral
precipitation. During Cassini’s upcoming approach to Saturn there will
be a unique opportunity to answer these questions. We propose to image
one complete rotation of Saturn to determine the corotational and
longitudinal dependences of the auroral activity. We will then image
the active sector of Saturn once every two days for a total coverage
of 26 days during the Cassini campaign to measure the upstream solar
wind parameters. This is the minimum coverage needed to ensure
observations of the aurora under solar wind pressure variations of
more than a factor of two, based on the solar wind pressure variations
measured by Voyager 2 near Saturn on the declining phase of solar
activity. The team of proposers has carried out a similar coordinated
observing campaign of Jupiter during the Cassini flyby, resulting in a
set of papers and HST images on the cover of Nature on 28 February

WFPC2 10069

WFPC2 CYCLE 12 Supplemental Darks, Part 1/3

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

WFPC2 10082

POMS Test Proposal: WFII backup parallel archive proposal

This is a POMS test proposal designed to simulate scientific plans

WFPC2 10084

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.


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

HSTAR 9293: GS Acquisition (2,1,2) @ 021/13:39:51Z resulted in FL
backup using FGS 2 due to SSLE (QF2SSLEX) on FGS 2. Under

HSTAR 9294: On review of SA012O PTAS TC processing log, OTA SE
confirmed the GS Reacquisition (2,1,2) @ 013/17:08:15Z took two
attempts to achieve FL data valid on FGS 2. The second attempt was
successful, so no science impact should have occurred. The GS
Acquisition @ 013/13:55:35Z and other two GS Reacquisition @
013/15:32:15Z and 013/18:44:14Z were successful on their first
attempts. During the anomalous attempt, the FGS 2 STOP flag was
raised without any other flags, suggesting the FGS walked off the star
during the FL walk down. Under investigation.

HSTAR 9295: GS Acquisition (1,2,2) @ 022/07:15:59Z resulted in FL
backup using FGS 1. Prior FHST FM Updates @ 022/06:53:59Z and
06:56/44Z showed good attitude error vector. FHST Map @ 022/07:52:50Z
showed error values of 1.705, -2.881 and 9.260 arcsec. Under



                             SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq                 10                        10
FGS REacq                 3                           3
FHST Update               17                         17


SpaceRef staff editor.