Status Report

NASA Hubble Space Telescope Daily Report # 3538

By SpaceRef Editor
January 28, 2004
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science




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

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
0.7<z<1.9, which provides an excellent measure of current star
formation rate. We will also detect star-forming and active galaxies
in other redshift ranges using other emission lines. The grism
observations will produce by far the best available Halpha luminosity
functions over the crucial–but poorly observed–redshift range where
galaxies appear to have assembled most of their stellar mass. This key
process of galaxy evolution needs to be studied with IR data; we found
that observations at shorter wavelengths appear to have missed a large
fraction of the star-formation in galaxies, due to dust reddening. We
will also obtain deep F110W and F160W images, to examine the space
densities and morphologies of faint red galaxies. In addition to
carrying out the public parallels, we will make the fully reduced and
calibrated images and spectra available on-line, with some
ground-based data for the deepest parallel fields included.

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<z<0.8. We show that an
interesting constraint on the equation of state can be made with
supernovae observed at modest redshifts given the current knowledge of
the matter density. We will follow 10 Type Ia supernovae discovered
from the ground and passed to HST without disrupting its schedule. The
full data set will constrain the equation of state to 10% and strictly
limit the range of possible dark energy models. In keeping with the
ESSENCE policy, these observations will available to the community


A Search for the Missing Baryons in Nearby Cosmic Filaments

Most of the baryons in the local universe are "missing" in that they
are not in galaxies or in the previously detected gaseous phases.
These missing baryons are predicted to be in a warm-hot low density
phase, largely in the giant cosmic filaments that connect the denser
virialized clusters and groups of galaxies. Models show that the
highest covering fraction of such filaments occurs in superclusters
and observations of two AGNs behind known superclusters showed
multiple LyAlpha absorption systems at the supercluster redshift.
These results are impressive considering that these AGNs were not even
optimally located. Here we selected a several AGNs that lie close to
the expected central axis of supercluster filaments. These HST
observations will identify LyAlpha absorbing gas while a complementary
FUSE program will search for OVI gas in the same systems.

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.

NIC3 9846

The Origins of Sub-stellar Masses: Searching for the End of the IMF

Is there a preferred scale that defines the end of the IMF? We propose
to test this hypothesis by conducting a deep spectroscopic survey of
extremely low mass objects in the embedded young cluster associated
with NGC1333. At a distance of only 300pc, this cluster is one of the
nearest examples of a dense young cluster. We will be able to obtain
R=200 spectra and photometry for 40-60 cluster members with masses
between 5-40 Jupiter masses at an age of 1 Myr observed through
A{v}<10 mag. This will enable us to estimate temperatures and
luminosities for all sources detected in the survey. We will compare
their positions in an H-R diagram to PMS evolutionary tracks in order
to estimate their ages and masses. For a solar metallicity cloud at a
temperature of 10 K, the minimum mass for fragmentation is thought to
be 10 Jupiter masses. A statistically significant sample of objects
detected below this limit would challenge the role of hierarchical
fragmentation in limiting substellar masses. The proximity of this
cluster combined with the unique sensitivity, wavelength coverage, and
multi-object spectroscopic capability of NICMOS on HST make this
experiment possible.


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.


UV extinction by dust in unexplored LMC environments

The ensemble of results from studies of the UV extinction in the Milky
Way, Magellanic Clouds {MC}, M31 and M33, indicates a complex
dependence of the dust properties with environment, where starburst
activity and metallicity are relevant factors. Work in the LMC to
date, based on IUE data, has several drawbacks: a} only supergiants
could be used, b} they all have moderate extinction, c} the IUE S/N is
limited, d} the large IUE slit may include light from other sources,
such as scattered light from dust or faint companion stars, e} studies
are confined to few {extreme} environments. We propose to obtain UV
extinction curves more accurate than previous ones {from STIS spectra
of main sequence stars with higher reddening}, sampling four
environments in the LMC with different levels of star formation
activity, including the general field, hitherto unexplored. The
results will characterize the properties of dust in different
conditions, at the LMC metallicity, which is useful to interpret
integrated properties of distant galaxies, as well as GALEX upcoming
UV surveys. A complementary study is under way with FUSE in the far-UV
range. The combined results will provide insight on the properties of
small grains.


An ACS/WFC H-alpha Survey of the Orion Nebula

We propose to survey nearly 500 square arcminutes of the Orion Nebula
in H-alpha using the ACS/WFC, increasing the sky coverage by an order
of magnitude over the sum of all previous HST observations. This
survey will, for the first time, sample the majority of young stars
and circumstellar environments in the extended Trapezium cluster of 2,
000 low-mass stars. Our primary goal is to determine the survival rate
and statistical properties of protoplanetary disks in the type of
radiation field and dynamical environment in which most stars are
born. The survey will be used to search for new silhouette disks,
bright proplyds, microjets, large-scale outflows, and to characterize
the properties of these objects as a function of location in the
nebula. We will determine accurate proper motions in regions where
previous HST data exist. However, 90% of our fields will be observed
with HST for the first time. This survey will provide the first
complete census of pre-main sequence objects and outflows in an HII
region and will constrain the extent of hazards to planet formation in
such environments. The images will also provide a legacy for future
stellar and nebular variability studies and proper motion measurements
by providing a first epoch data base.

NIC2 9801

Are OH/IR Stars the Youngest post-AGB stars? A NICMOS Imaging Survey

Essentially all well-characterized preplanetary nebulae {PPNe}–
objects in transition between the AGB and planetary nebula
evolutionary phases – are bipolar, whereas the mass-loss envelopes of
AGB stars are strikingly spherical. In order to understand the
processes leading to bipolar mass-ejection, we need to know at what
stage of stellar evolution does bipolarity in the mass-loss first
manifest itself. We have recently hypothesized that most OH/IR stars
{evolved mass- losing stars with OH maser emission} are very young
PPNe. We are conducting a multiwavelength survey program of imaging
and spectroscopic observations of such objects, using a large,
morphologically unbiased sample selected using IRAS 12-to-25 micron
colors. Our ongoing HST/SNAP imaging survey of the optically bright
half of this sample with WFPC2 and ACS is highly successful: 19/32
objects observed are extended with bipolar/multipolar shapes
{remaining objects are unresolved}. Slightly more than 50% of our
sample are optically too faint or undetected but have strong near-IR
counterparts — we therefore propose a NICMOS SNAPshot imaging survey
of these optically-faint OH/IR stars. These observations are crucial
for determining how and when the bipolar geometry asserts itself. The
results from our NICMOS survey {together with the WFPC2/ACS survey}
will allow us to draw general conclusions about the onset of bipolar
mass-ejection during late stellar evolution. Our complementary program
of interferometric mapping of the OH maser emission in our sources is
yielding kinematic information with spatial resolution comparable to
that in the HST images. The HST/radio data will provide crucial input
for theories of post-AGB stellar evolution. In addition, these data
will also indicate whether the multiple concentric rings, "searchlight
beams”, and truncated equatorial disks recently discovered with HST
in a few PPNe, are common or rare phenomena.

STIS/MA1 9790

Separating Activity and Accretion in T Tauri Stars

Due to their unique evolutionary state, the naked {non-accreting} T
Tauri stars {NTTS} are the only real proxies for what the underlying
magnetically active star of a classical TTS {CTTS} system looks like.
Comparative analysis then allows us to separate stellar properties
from accretion properties in CTTS. In addition, the late-type NTTS are
excellent candidates for studying rotation-activity relationships in
fully convective stars and probing the properties of turbulent
dynamos. With the limited data currently available, NTTS appear to be
very magnetically active stars with higher than expected H-alpha/X-ray
flux ratios but lower transition region fluxes relative to other
active stars. However, the data are very incomplete. We will use
HST-STIS observations of transition region line fluxes on 11 fully
convective NTTS to establish the level and structure of dynamo
generated emission in these young stars. In principal, these far
ultraviolet emission lines are sensitive diagnostics of mass accretion
onto CTTS, since accretion shocks on the stellar surface should
produce substantial emission measure at 10^5 – 10^6 K. However, it is
imperative that we first understand the emissions from NTTS before we
can use these lines to study accretion onto CTTS.

ACS/WFC 9789

The Distance to the Pleiades

Despite its fundamental importance to stellar astrophysics, the
distance to the Pleiades open cluster remains in great dispute.
Main-sequence fitting results in a distance of 132.3 +/- 1.9 pc, while
the Hipparcos average parallax for Pleaides member stars gives a
distance of 116.4 +/- 2.9 pc. If the Hipparcos distance is to be
believed, our current understanding of stellar astrophysics is
dramatically incomplete. On the other hand, it has been proposed that
the Hipparcos parallax measurement to the Pleiades suffers systematic
uncertainties which result in the discrepancy with the main-sequence
fitting technique. The question will remain open until an independent
distance measurement to the Pleiades cluster is performed. We will use
ACS imaging to determine the parallax to the Pleiades to an accuracy
of about 1.5%. This will resolve the current controversy over the
distance to the cluster once and for all.

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.


Search for Core-disrupting Wide-Angle Winds

We propose to obtain observations with STIS/FUV-MAMA of H$_2$
fluorescent lines along the cavity surrounding the star T Tau N. Since
H$_2$ fluorescent lines are direct tracers of shock-excitation in
low-mass star-forming regions, the high resolution achievable with
STIS will allow us to delineate the region of interaction between the
wind and the cloud, and to investigate the geometry of the outflow at
unprecedentedly close distances to its source, < 100 AU. Our
observations will allow us to confirm, map out, and provide
quantitative estimates of the off-axis {wide-angle} flow for the first
time. Understanding the geometry of the wind is crucial because {1} it
determines whether outflows can disrupt their natal cores, and {2} it
tests theories of jet production and collimation.


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.

ACS/HRC 9782

Measuring Black Hole Masses in Double Peaked Broad Lined AGNs

To date there have been few black hole {BH} mass estimates for
luminous broad line AGN, including those derived from reverberation
mapping. In this context, objects with "double-peaked" broad lines are
particularly important because the line emission is believed to arise
in a relativistically rotating accretion disk. If this model is
correct, then the BH mass can be determined directly from periodic
variations in the line-profile shape. In two cases {Arp 102B and NGC
1097} such variations have been claimed. The goal of this proposal is
to confront the relativistic disk model for the double-peaked Balmer
lines with independent limits on the central masses for 5 of the
nearest and brightest "double-peaked emitters" {NGC 1097, Arp 102B,
Pictor A, 3C390.3, 3C332}, determined by using STIS long-slit
spectroscopy to map the velocity field of circum-nuclear ionized gas.
These observations will critically test the idea that the line
emission in these objects comes from an accretion disk and thus
provide unique insights into the physical processes operating in both
the BLR and the "central engine".

ACS/HRC 9748

Ceres: High-Resolution Mapping and Determination of Physical

We propose a modest, 6-orbit HST ACS/HRC program to fully map the
asteroid 1 Ceres for the first time. These high signal-to-noise, high
resolution maps will be obtained in three ACS filter bandpasses from
the visible to the UV. The goals of our program are to advance
knowledge about Ceres dramatically, to resolve certain longstanding
issues regarding Ceres, and to support planning for the Dawn Discovery
mission’s planned orbital tour of Ceres. The specific scientific
objectives of this proposed Cycle 12 effort are: {1} To achieve dense
rotational phase coverage with multi-spectral imaging over the
complete rotation period of Ceres to map its surface; {2} To resolve
surface features and investigate the nature of the Piazzi feature
detected by HST/FOC in 1995; {3} To track surface features in order to
unambigously determine Ceres’ pole position; {4} To measure the
three-dimensional shape of Ceres better than any existing shape model
in order to significantly refine density measurements; and {5} To map
Ceres’ color variegation and photometric parameters in order to
identify possible surface units for the first time. These goals
require high resolution visible and ultraviolet imaging, which can
only be obtained with HST. As we demonstrate in this proposal, the
January, 2004 opposition of Ceres is the best in the next 6 years for
both data quality and planning of the Dawn mission.

ACS/HRC 9747

An Imaging Survey of the Statistical Frequency of Binaries Among
Exceptionally-Young Dynamical Families in the Main Asteroid Belt

We propose an ambitious SNAPSHOT program to determine the frequency of
binaries among two very young asteroid families in the Main Belt, with
potentially profound implications. These families {of C- and S-type}
have recently been discovered {Nesvorny et al. 2002, Nature 417, 720},
through dynamical modeling, to have been formed at 5.8 MY and 8.3 MY
ago in catastrophic impact events. This is the first time such
precise and young ages have been assigned to a family. Main-belt
binaries are almost certainly produced by collisions, and we would
expect a young family to have a significantly higher frequency of
binaries than the background, because they may not yet have been
destroyed by impact or longer-term gravitational instabilities. In
fact, one of the prime observables from such an event should be the
propensity for satellites. This is the best way that new numerical
models for binary production by collisions {motivated largely by our
ground-based discoveries of satellites among larger asteroids}, can be
validated and calibrated. HST is the only facility that can be used to
search for binaries among such faint objects {V>17.5}. We will also
measure two control clusters, one being an "old" family, and the other
a collection of background asteroids that do not have a family
association, and further compare with our determined value for the
frequency of large main-belt binaries {2%}. We request visits to 180
targets, using ACS/HRC.

ACS/WFC 9744

HST Imaging of Gravitational Lenses

Gravitational lenses offer unique opportunities to study cosmology,
dark matter, galactic structure, galaxy evolution and quasar host
galaxies. They are also the only sample of galaxies selected based on
their mass rather than their luminosity or surface brightness. While
gravitational lenses can be discovered with ground-based optical and
radio observations, converting them into astrophysical tools requires
HST. HST has demonstrated that it is the only telescope that can in
each case precisely locate the lens galaxy, measure its luminosity,
color and structure, and search for lensed images of the source host
galaxy given the typical image separations of ~1”. We will obtain
ACS/WFC V and I images and NICMOS H images of 21 new lenses never
observed by HST and NICMOS H images of 16 lenses never observed by HST
in the IR. As in previous cycles, we request that the data be made
public immediately.

NIC2 9741

The Exciting Wavelength of Extended Red Emission

We propose to determine the wavelength of the photons which excite
Extended Red Emission {ERE} by mapping the small scale structure of
ERE and molecular hydrogen {H_2} in the reflection nebulae NGC 2023
and 7023. Both of these nebulae display sharp narrow ERE-filaments
within photodissociation regions {PDR} which also show infrared H_2
fluorescence. In these opically thick filaments, different wavelength
photons penetrate to different depths. By comparing the widths of
these filaments in ERE and H_2 we will determine the exciting
wavelength of ERE. This is possible because the combined opacity of
dust and H_2 to the exciting radiation {lambda < 1100 A} of H_2
fluorescence is known, and the comparison of the thickness of the ERE
and H_2 filaments will allow a determination of the dust opacity at
the wavelength at which ERE is being excited. This is a sensitive test
to distinguish between different materials which have been proposed as
the carrier of ERE {e.g., carbon or silicon nanoparticles, polycyclic
aromatic hydrocarbon molecules, hydrogenated amorphous carbon, etc.},
because the photoluminescense excitation spectra of these different
materials differ by large amounts. Identifying the material which
produces ERE is important as recent work on ERE in the diffuse
interstellar medium has shown that the material which produces ERE
comprises a significant component of dust grains.

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.


ACS Imaging and STIS Spectroscopy of Binary Brown Dwarfs

We have compiled a sample of 9 spatially resolved binary brown dwarfs
{18 objects}, and now propose ACS imaging and STIS spectroscopic
follow-up observations. While theoretical models on the interplay of
chemical and physical processes governing brown dwarf atmospheres have
reached a high level of sophistication, interpretation of
observational data remains difficult. As brown dwarfs never stabilize
themselves on the hydrogen main sequence, there is always an ambiguity
between the temperature or luminosity of any brown dwarf and its mass
or age. The individual components of brown dwarf binaries, however,
are expected to be coeval and have the same underlying chemical
composition. This provides crucial constraints on any model, thus
greatly reducing the number of the free parameters. The aim is to
obtain photometric and spectroscopic data to probe the physical and
chemical properties of the brown dwarf atmospheres, as well as second
epoch astrometric data to characterize th e orbital motion. The study
will provide important feedback on theoretical model atmospheres and
evolutionary tracks for brown dwarfs. As such, it will be an important
step towards a better understanding of objects with spectral
properties intermediate between those of giant planets and late-type


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/CCD 10085

STIS Pure Parallel Imaging Program: Cycle 12

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

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.

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 10082

POMS Test Proposal: WFII backup parallel archive proposal

This is a POMS test proposal designed to simulate scientific plans

WFPC2 10072


This calibration proposal is the Cycle 12 routine internal monitor for
WFPC2, to be run weekly 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.

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 10068

WFPC2 CYCLE 12 Standard Darks

This dark calibration program obtains 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.


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/WFC 10054

ACS photometric Stability

A set of four spectrophotometric standard stars {GD71, G191B2B, GD153,
and HZ43} is observed once with ACS’s WFC and HRC through all filters,
except the ramp filters, to assess the sensitivity of the instrument
and measure accurate photometric zero points. The stars are placed at
the centre of the aperture, and two images are taken through each
filter. This programme is based on proposals 9020 and 9654 designed
for SMOV and Cycle 11, and also on programme 9563 from the interim
period. No RAMP filters are calibrated here. The exposure times have
been calculated to reach, on average, SNR~350 in the central pixel for
broad band filters.

STIS/MA1 10034

Cycle 12 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/CCD 10022

STIS CCD Hot Pixel Annealing Cycle 12

The effectiveness of the CCD hot pixel annealing process is assessed
by measuring the dark current behavior before and after annealing and
by searching for any window contamination effects. In addition CTE
performance is examined by looking for traps in a low signal level
flat. Follows on from proposal 9612.

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 10017

CCD Dark Monitor-Part 1

Monitor the darks for the STIS CCD.

ACS/WFC 10006

Black Hole X-ray Novae in M31

During A01-3 we found 22 Black Hole X-ray Novae {BHXN} in M31 using
Chandra, and with HST {WFPC2} found two optical counterparts. Our
results suggest either a surprisingly high ratio of BH to NS binaries,
or a surprisingly high duty cycle for BHXN. We propose to continue
this program, with the goals of understanding the relative number of
BH vs. NS X-ray binaries in the M31 bulge, and determining the orbital
period distribution and duty cycles of these BHXN. Continued
observations can determine the duty cycle. The new ACS will allow us
to go 2 mags deeper than the WFPC2, and could triple the number of
optical counterparts and therefore orbital period estimates. M31 is
the only galaxy near enough to allow this extragalactic survey for


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

HSTAR 9297: GS Acquisition (2,1,2) @ 024/10:31:48Z resulted in FL
backup using FGS 2. No flags were observed but FL was acquired only
on FGS 2. Prior FHST RD Update @ 024/10:06:19Z showed good attitude
error vector. FHST Map @ 024/11:00:16Z showed error values of -6.736,
-1.002 and -28.766 arcsec. Under investigation.

HSTAR 9298: GS Acquisition (3,2,3) @ 026/02:16:32Z resulted in FL
backup (2,0,2) due to SSLE on FGS 2. Following GS Reacquisition @
026/03:53:01Z also resulted in FL backup on FGS 2. Prior FHST RD
Update @ 026/02:02:35Z, during LOS, showed good attitude error vector.
FHST Map @ 026/02:54:46Z showed error values of 3.317, -5.223, and
-6.108 arcsec.Under investigation.


1189-0 – Change Limits MAMA2 Threshold Voltage @ 025/0111z
1190-0 – Return Thermal Limits to Database Values @ 023/1645z

                           SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq               43                       43
FGS REacq               14                       14
FHST Update             83                       83


EPS Charge Optimization (removal of -D and +BB SPAs) scheduled, first
opportunity 027/15:50Z – 16:40Z, second opportunity 028/14:08Z –

HST Command Timing test scheduled 027/12:00Z – 22:00Z with GDOC, SOC,
HITT, and CCS using CCS "D" String with CCS Release and PRD
O06300ST. The purpose of this testing is to check the command timing
for CCS Release with historical, baselined numbers.

SpaceRef staff editor.