Status Report

NASA Hubble Space Telescope Daily Report # 3647

By SpaceRef Editor
July 6, 2004
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science




S/C/NIC1/NIC3 9994

NICMOS Focus Stability

The purpose of this activity is to determine if the best focus
determined in SMOV is stable. This program will execute in
approximately one month intervals starting about 1 month after the
last execution of proposal 8980.


Boron in stars of same O and Li, but different Be: testing cosmic-ray
vs. neutrino spallation

We propose to further investigate the origin of the light elements Li,
Be, and B, by observing B in a group of galactic stars found to have
similar O abundances but to differ significantly in their Be content.
Contrary to Li, which is produced in the Big Bang and its abundance in
halo stars constrains primordial nucleosynthesis and the baryonic
density, Be and B are produced later by cosmic ray spallation as the
galactic halo forms. Knowledge of their evolution is now being used
along with that of [O/H] {and [Fe/H]} as a powerful discriminant
between different models of the chemical and dynamical evolution of
the galaxy. Light element abundances can be used to test these
theories only if they have not been altered by destruction in stars.
Recently we have identified a small number of stars characterized by
the same O abundance but large differences in their Be content, which
cannot be accounted for by stellar depletion {since their Li is
undepleted}. As neutrino-spallation contributes only to the production
of isotope 11 of B, and not to Be, Be and B abundanes in the same
stars will allow us to see if B scales with Be {evidence for a CR
spallation origin} or with O {evidence for contribution from neutrino


A test of the foreground proximity effect at z=1.2

The diffuse UV background flux J is a crucial component for
cosmological evolution models, though few determinations have been
made. The proximity effect, the thinning out of the Lyman alpha forest
near a sight- line’s background quasar and explained at least partly
by the enhanced ionization from the quasar, is a key method to measure
J. A foreground proximity effect {FPE} should exist from quasars close
on the sky but at different z; it can constrain J and test the
enhanced ionization model. Galaxy clustering around the quasar may
modify the effect, but knowing the galaxy density around the Lya
forest should allow for corrections. We propose to measure the FPE at
z=1.2, which is advantageous because 1} the diffuse UV flux is lower,
and thus contrast with the UV flux of neighboring quasars is higher,
and 2} galaxies are easier to identify at z=1.2. We have good
knowledge of the physical volume we wish to study through surveys for
quasars, MgII absorbers and galaxies, to constrain the
redshift-dependent galaxy density along the line of sight. We will
analyze the results based on pixel opacities, which is more sensitive
to fluctuations in J than traditional line counting, and will compare
our results with cosmological simulations to derive estimates of the
UV background in the context of available physical models.

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.


AALs in Quasars: Diagnostics of the Environment

Associated absorption lines {AALs} in quasar spectra carry a wealth of
information on the gas-phase kinematics, ionization states, column
densities, outflow masses, and elemental abundances near the quasars.
Most of the existing UV spectra have low spectral resolution, which
hampers efforts to accurately determine these properties at low
redshifts. We propose medium-resolution FUV and NUV STIS spectroscopy,
more than an order of magnitude improvement in spectral resolution
over previous studies, to observe a sample of AAL quasars at redshifts
and luminosities intermediate between the nearby Seyferts and the
bright, high-z quasars. Our aim is to determine basic physical
parameters for the absorbers, measure the abundances, search for AAL
variability, and constrain the location of the absorbers relative to
the central quasars. A unique aspect of our z~0.2 sample is the
ability to get both UV and X-ray diagnostics, thus allowing us to
perform a joint analysis of our STIS data with X-ray observations to
further constrain the full range of ionizations and column densities
of the UV/X-ray absorbing gas.

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.


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.


Reverberation Mapping of the Least Luminous Seyfert 1 Galaxy NGC 4395

We propose to make a short UV and optical reverberation mapping
monitoring of NGC~4395, by far the least luminous Seyfert 1 galaxy
known {M_B~ -10}, where the Broad Line Region {BLR} is most likely
between a fraction of a light hour to a few light hours across. This
program will: 1. extend by a factor of ~100 the range of R_BLR probed
by RM, 2. allow to test models for AGN continuum emission and BLR
structure at very low L and M_BH. 3. provide significantly more
reliable estimates of its M_BH than currently available, 4. allow to
probe the M_BH-sigma_* relation in AGN at very low M_BH, which cannot
be probed by other methods. Existing archival FOS observations
indicate significant {up to 30-40%} line and continuum variations
within one orbit, suggesting that the proposed RM is likely to
succeed. The unusually small R_BLR in NGC 4395 implies that RM can be
performed here at only a fraction of the cost required in typical AGN.

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 9777

The environment of QSOs at the reionization epoch

Our goal is to elucidate the role of QSOs and galaxies at the tail end
of reionization by identifying z~6 galaxies near SDSS z>6 QSOs through
their red i-z colors. A similar technique was used by the SDSS to
identify the QSOs themselves. Based on our understanding of the growth
of structure in the Universe and on observations at z ~= 4, we expect
z~6 QSOs to be associated to the high peaks in the matter density
distribution. Therefore, they should be surrounded by an excess of
objects – as compared to random fields – unless the ionizing radiation
from the QSOs themselves is inhibiting star formation. We will
concentrate on 5 QSOs discovered by the SDSS at z>~6 and spend 7
orbits with ACS on each of the QSO fields {2.5 in F775W – i – and 4.5
in F850LP – z}, for a total of 35 orbits. The exposures are optimized
for the detection of objects with i-z> 2. The reference properties of
the field population will be provided by GOODS which is reaching the
same depth. The proposed observations will be capable of revealing the
dominant effect between galaxy suppression by the QSO ionizing flux
and number density excess due to clustering. We will test whether the
balance between suppression and enhancement evolves with redshift. We
will also be able to estimate for these fields the ionizing continuum
contribution by galaxies and compare it with that of the QSOs. If
galaxies are found to be comparably important to QSOs in these
selected fields, the idea that hydrogen reionization is primarily due
to stellar radiation would be significantly strengthened.


Young Massive Clusters in Spiral Galaxies and the Connection with Open

We propose to carry out a census of star clusters in the disks of the
nearby spiral galaxies NGC 45, NGC 1313, NGC 4395, NGC 5236 and NGC
7793. Using ACS, we will identify much fainter and older star clusters
than possible in previous ground-based surveys, or even in HST imaging
of more distant galaxies. For the first time, we will directly explore
the connection between young "massive” {or "super”} star clusters
{YMCs} and lower-mass "open” clusters in different star forming
environments. We will test the universality of the luminosity- and
mass functions of stellar clusters and establish whether the presence
of YMCs is a result of a top-heavy cluster luminosity function, or
follows from generally richer cluster systems. Our target galaxies
span a range of morphological properties, surface brightness and star
formation rate. Some of them are known from ground-based studies to
host large numbers of YMCs while others have more modest cluster
populations. However, previous ground-based data were restricted to
luminous clusters younger than about 500 Myr. Here we will extend the
search to clusters formed throughout the entire lifetime of each
galaxy and reach clusters with properties typical of the Milky Way
open clusters. This will allow us to close the gap between studies of
extragalactic and Galactic disk clusters.


Galaxy Evolution During Half the Age of the Universe: ACS imaging of
rich galaxy clusters

Detailed studies of nearby galaxies {z<0.05} have shown that galaxies
have very complex histories of formation and evolution involving
mergers, bursts of star formation, and morphological changes. Even so,
the global properties of the galaxies {radii, luminosities, rotation
velocities, velocity dispersions, and absorption line strengths}
follow a number of very tight {empirical} scaling relations, e.g. the
Tully-Fisher relation and the Fundamental Plane. These relations place
constraints on models for galaxy evolution. The results for nearby
galaxies rely on high signal-to-noise spectroscopy and multi-color
photometry. With the Gemini Telescopes and the Hubble Space Telescope
{HST} it is possible to carry out similar detailed studies of galaxies
at much larger redshifts, up to z~1.0, equivalent to half the age of
the Universe. We have started a project using the scaling relations
and aimed at studying the galaxy evolution over the last half of the
age of the Universe. The project is based on a large database of
spectroscopy and photometry of galaxies in 15 X-ray selected clusters
of galaxies with redshifts between 0.15 and 1.0. Spectroscopic
observations are being obtained using both Gemini Telescopes; we have
observed 6 clusters so far, covering from z=0.18 to z=0.83. We propose
to use HST/ACS to image the clusters and determine the morphologies
and measure the sizes of the galaxies. At this time we ask for 26
orbits to image four of the clusters in our sample.

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 tightly 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.


Integrated Absorption- and Emission-Line Analysis of Nebulae

Serious discrepancies have arisen in CNONe abundance determinations
for galactic nebulae in the past ten years depending upon which type
of emission lines are used in the analysis: forbidden vs. permitted
lines. The cause of the discrepancies, which can exceed an order of
magnitude for some PNe, has been studied intensively but is still
unknown. Emission line abundances cannot be considered reliable until
the nature of these contradictory results is understood. We have
developed a technique for integrating absorption lines into emission
analyses for diffuse nebulae that provides an independent check on the
validity of emission-line analyses. It requires high resolution
observations of UV resonance absorption produced by the nebular gas in
imbedded or background stars together with optical spectra of the
nebulae. We propose to obtain UV spectra of four PNe central stars
with STIS that will provide data necessary to exploit the new
technique of integrated abundance determination that combines both
emission and absorption lines.


Tracing the History of Cosmic Expansion to z~2 with Type Ia Supernovae

Type Ia supernovae {SNe Ia} provide the only direct evidence for an
accelerating universe, an extraordinary result that needs the most
rigorous test. The case for cosmic acceleration rests on the
observation that SNe Ia at z = 0.5 are about 0.25 mag fainter than
they would be in a universe without acceleration. A powerful and
straightforward way to assess the reliability of the SN Ia measurement
and the conceptual framework of its interpretation is to look for
cosmic deceleration at z > 1. This would be a clear signature of a
mixed dark-matter and dark-energy universe. Systematic errors in the
SNe Ia result attributed to grey dust or cosmic evolution of the SN Ia
peak luminosity would not show this change of sign. We have obtained a
toehold on this putative “epoch of deceleration” with SN 1997ff at z
= 1.7, and 3 more at z > 1 from our Cycle 11 program, all found and
followed by HST. However, this is too important a test to rest on just
a few objects, anyone of which could be subject to a lensed
line-of-sight or misidentification. Here we propose to extend our
measurement with observations of twelve SNe Ia in the range 1.0 < z <
1.5 or 6 such SNe Ia and 1 ultradistant SN Ia at z = 2, that will be
discovered as a byproduct from proposed Treasury and DD programs.
These objects will provide a much firmer foundation for a conclusion
that touches on important questions of fundamental physics.

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration – CR Persistence Part 4

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.

S/C 10336

2-Gyro Reacquisition Test

This proposal will test the software that will be used to perform
target reacquisition when HST only has two working gyroscopes.

ACS/HRC 10272

A Snapshot Survey of the Sites of Recent, Nearby Supernovae

During the past few years, robotic {or nearly robotic} searches for
supernovae {SNe}, most notably our Lick Observatory Supernova Search
{LOSS}, have found hundreds of SNe, many of them in quite nearby
galaxies {cz < 4000 km/s}. Most of the objects were discovered before
maximum brightness, and have follow-up photometry and spectroscopy;
they include some of the best-studied SNe to date. We propose to
conduct a snapshot imaging survey of the sites of some of these nearby
objects, to obtain late-time photometry that {through the shape of the
light and color curves} will help reveal the origin of their lingering
energy. The images will also provide high-resolution information on
the local environment of SNe that are far superior to what we can
procure from the ground. For example, we will obtain color-color and
color-magnitude diagrams of stars in these SN sites, to determine
their progenitor masses and constraints on the reddening. Recovery of
the SNe in the new HST images will also allow us to actually pinpoint
their progenitor stars in cases where pre-explosion images exist in
the HST archive. Use of ACS rather than WFPC2 will make our snapshot
survey even more valuable than our Cycle 9 survey. This Proposal is
complementary to our Cycle 13 archival proposal, in which we outline a
plan for using existing HST images to glean information about SN

ACS/WFC 10260

The Most Massive Star Clusters: Supermassive Globular Clusters or
Dwarf Galaxy Nuclei?

Evidence is mounting that the most massive globular clusters, such as
Omega Centauri and M31-G1, may be related to the recently discovered
"Ultra-Compact Dwarfs" and the dense nuclei of dE, N galaxies.
However, no systematic imaging investigation of these supermassive
globular clusters — at the level of Omega Cen and beyond — has been
done, and we do not know what fraction of them might bear the
signatures {such as large effective radii or tidal tails} of having
originated as dE nuclei. We propose to use the ACS/WFC to obtain deep
images of 18 such clusters in NGC 5128 and M31, the two nearest rich
globular cluster systems. These globulars are the richest star
clusters that can be found in nature, the biggest of them reaching
10^7 Solar masses, and they are likely to represent the results of
star formation under the densest and most extreme conditions known.
Using the profiles of the clusters including their faint outer
envelopes, we will carry out state-of-the-art dynamical modelling of
their structures, and look for any clear evidence which would indicate
that they are associated with stripped satellites. This study will
build on our previous work with STIS and WFPC2 imaging designed to
study the ‘Fundamental Plane’ of globular clusters. When our new work
is combined with Archival WFPC2, STIS, and ACS material, we will also
be able to construct the definitive mapping of the Fundamental Plane
of globular clusters at its uppermost mass range, and confirm whether
or not the UCD and dE, N objects occupy a different structural
parameter space.

NIC/NIC3 10226

The NICMOS Grism Parallel Survey

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.

NIC2 10176

Coronagraphic Survey for Giant Planets Around Nearby Young Stars

A systematic imaging search for extra-solar Jovian planets is now
possible thanks to recent progress in identifying "young stars near
Earth". For most of the proposed young {<~ 30 Myrs} and nearby {<~ 60
pc} targets, we can detect a few Jupiter-mass planets as close as a
few tens of AUs from the primary stars. This represents the first time
that potential analogs of our solar system – that is planetary systems
with giant planets having semi-major axes comparable to those of the
four giant planets of the Solar System – come within the grasp of
existing instrumentation. Our proposed targets have not been observed
for planets with the Hubble Space Telescope previously. Considering
the very successful earlier NICMOS observations of low mass brown
dwarfs and planetary disks among members of the TW Hydrae Association,
a fair fraction of our targets should also turn out to posses low mass
brown dwarfs, giant planets, or dusty planetary disks because our
targets are similar to {or even better than} the TW Hydrae stars in
terms of youth and proximity to Earth. Should HST time be awarded and
planetary mass candidates be found, proper motion follow-up of
candidate planets will be done with ground-based AOs.


The Evolution and Assembly of Galactic Disks: Integrated studies of
mass, stars and gas in the Extended Groth Strip

This project is a 126-orbit imaging survey in F606W/F814W ACS to
measure the evolution of galaxy disks from redshift z = 1.4 to the
present. By combining HST imaging with existing observations in the
Extended Groth Strip, we can for the first time simultaneously
determine the mass in dark matter that underlies disks, the mass in
stars within those disks, and the rate of formation of new stars from
gas in the disks, for samples of >1, 000 objects. ACS observations are
critical for this work, both for reliable identifications of disks and
for determining their sizes and inclinations. Combining these data
with the kinematics measured from high-resolution Keck DEIMOS spectra
will give dynamical masses that include dark matter. Stellar masses
can be measured separately using ground-based BRIK and Spitzer IRAC
GTO data, while cross-calibrated star formation rates will come from
DEEP2 spectra, GALEX, and Spitzer/MIPS. The field chosen is the only
one where all multiwavelength data needed will be available in the
near term. These data will show how the fundamental properties of
disks {luminosity, rotation speed, scale length} and their scaling
relations have evolved since z~1, and also will measure the build-up
of stellar disks directly, providing fundamental tests of disk
formation and evolution. In addition to the above study of disk
galaxies, the data will also be used to measure the evolution of
red-sequence galaxies and their associated stellar populations. ACS
images will yield the number of red-sequence galaxies versus time,
together with their total associated stellar mass. ACS images are
crucial to classify red-sequence galaxies into normal E/S0s versus
peculiar types and to measure radii, which will complete the suite of
fundamental structural parameters needed to study evolution. We will
measure the zeropoints of major scaling laws {Fundamental Plane,
radius versus sigma}, as well as evolution in characteristic
quantities such as L*, v*, and r*. Stellar population ages will be
estimated from high-resolution Keck DEIMOS spectra and compared to SED
evolution measured from GALEX, HST, Spitzer, and ground-based colors.
Important for both disk and red-galaxy programs are parallel exposures
to be taken with both NIC3 {J and H} and WFPC2 {B}. These are arranged
so that ACS, WFPC2, and NIC3 all overlap where possible , providing a
rich data set of galaxies imaged with all three HST cameras from B to
H. These data will be used to measure restframe visible morphologies
and UV star-formation rates for galaxies near the edge of the survey,
to discover and count EROs below the Keck spectroscopic limit of R =
24, and to provide an improved database of photometric redshifts for
galaxies in the overlap regions.

ACS/HRC 10130

Systemic Proper Motions of the Magellanic Clouds from Astrometry with
ACS: II. Second Epoch Images

We request second epoch observations with ACS of Magellanic Cloud
fields centered on the 40 quasars in the LMC and SMC for which we have
first epoch Cycle 11 data. The new data will determine the systemic
proper motion of the Clouds. An extensive astrometric analysis of the
first epoch data shows that follow-up observations with a two year
baseline will allow us to measure the proper motion of the clouds to
within 0.022 mas/year in each of the two orthogonal directions
{assuming that we can image 25 quasars, i.e., with a realistic
Snapshot Program completion rate}. The best weighted combination of
all previous measurements has a seven times larger error than what we
expect. We will determine the proper motion of the clouds with 2%
accuracy. When combined with HI data for the Magellanic Stream this
will constrain both the mass distribution in the Galactic Halo and
theoretical models for the origin of the Magellanic Stream. Previous
measurements are too crude for such constraints. Our data will provide
by far the most accurate proper motion measurement for any Milky Way

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 10071

WFPC2 CYCLE 12 Supplemental Darks Part 3/3

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/HRC 10050

ACS Earth Flats

High signal sky flats will be obtained by observing the bright Earth
with the HRC and WFC. These observations will be used to verify the
accuracy of the flats currently used by the pipeline and will provide
a comparison with flats derived via other techniques: L-flats from
stellar observations, sky flats from stacked GO observations, and
internal flats using the calibration lamps. Weekly coronagraphic
monitoring is required to assess the changing position of the spots.

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 10020

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/CCD 10018

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.

NIC3 10014

Spectrophotometry of FAINT IR STANDARDS

We propose to establish new IR faint standards in the 15-17 mag range.
Appropriate spectral types for faint IR standards are solar analogs
and hotter WDs. Many M type and cooler stars are variable, so that
long term monitoring is required before committing HST time to such
cool stars. A few G type and WD faint stars will provide a set of
faint IR standards with minimal sky and color coverage. Existing HST
images of any candidates can provide verification that there are no
contaminating stars above the 1% level within 2-3arcsec. However, the
ACS calibration field in 47 Tuc is too crowded for linking to ground
based observations. If the other candidates are selected from SDSS or
other ground based data, then the NICMOS and STIS acquisition images
can provide this verification, as well as correction factors for
arbitrary photometric size apertures. The SNAP team is providing the
northern faint stars using unreleased SDSS data. In addition, the
extreme coolest types such as L and T stars have proven essential to
sorting out the long wavelength QE of ACS; both the ACS and eventually
WFC3 calibrations could be improved with knowledge of L and T SEDs in
the region beyond 0.95 microns. In addition to the primary purpose of
ACS QE vs. wavelength and broad band F814W and F850LP calibrations,
these three stars in C.} below are at the flux level required for WFC3
grism calibration. The brighter M, L, and T standard stars will each
require a NICMOS orbit, while each faint standard requires two NICMOS
orbits and one STIS orbit for complete wavelength coverage. The STIS
spectra of the M and L stars are done as ACS calibrations in cycles 12
and 11, respectively. An additional faint WD has already been proposed
for 2 NICMOS and 4 STIS orbits in their cycle 12 programs already. See
Table 1 for a summary of the 18 orbit allocation for this program
10014. Bright stars in the V=0-6 mag range would be useful for direct
comparisons to NIST calibrated lamps. This comparison would offer the
opportunity to compare two fundamentally different realms of physics:
pure hydrogen stellar models and laboratory black body physics.
Unfortunately, the NICMOS bright limit is V=~8 for a solar analog and
a 1s exposure without defocussing the OTA. The primary Sloan standard
BD+17d4708 at V=9.9 is safely fainter than this NICMOS limit.


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

HSTAR 9461: FHST Roll Delay Update (U2,3RD) @ 184/13:14:22Z failed
with Error Box results indicating tracker "2FAILED" for mnemonics
QEBSTFG0, QEBSTFG1, and QEBSTFG2. Prior FHST Map @ 184/12:57:30Z
showed 3-axis (RSS) value ~ 9.00 arcsec. Subsequent GS Acquisition
(2,1,1) @ 184/13:45:28Z was successful. Under investigation.

HSTAR 9462: GS Acquisition (3,2,2) @ 184/15:04:40Z, during ZOE,
resulted in FL backup using FGS 3 at AOS without FGS indicating flags.
FGS Modes and flag bit changes could not be determined at this time
pending future ETR dump. Prior FHST FM Updates @ 184/14:49:04Z and
14:51:49Z showed good attitude error correction. Subsequent GS
Reacquisition (3,2,2) @ 184/16:40:49Z resulted in FL backup. Under

HSTAR 9463: FHST Roll Delay Update (U2,3RD) @ 184/22:53:51Z failed
with Error Box results indicating "2FAILED" for mnemonics QEBSTFG0,
QEBSTFG1, and QEBSTFG2. Subsequent GS Acquisition (2,1,1) @
184/23:10:42Z was successful. Under investigation.

HSTAR 9466: FHST Full Maneuver Updates failed (Optimal FHST Pair
1,3), during ZOE @ 186/177:15:14Z and 186/17:53:59Z. Error Box
results indicating "3FAILED" for mnemonics QEBSTFG0, QEBSTFG1, and
QEBSTFG2 at AOS. Subsequent GS Acquisition (2,1,1) @ 186/17:56:44Z
was successful. Extract of engineering telemetry following ETR dump
showed BOTH of the Full Maneuver Updates failed. Under investigation.

HSTAR 9467: FHST Full Maneuver Update (U1,2FM) @ 187/04:35:12Z failed
with Error Box results indicating "2FAILED" for mnemonics QEBSTFG0,
QEBSTFG1, and QEBSTFG2 @ 187/04:35:46Z. Second FHST FM Update @
187/04:40:12Z was successful, as was GS Acquisition (3,2,2) @
187/05:14:44Z. Under investigation.

HSTAR 9468: GS Acquisition (3,2,2) @ 187/07:25:00Z failed to FL
backup on FGS 3. Upon AOS, HST was operating in FL backup on FGS 3
only. Further information after engineering recorder dump. No FGS
flags were set at AOS. Extracted engineering data showed SSLE @
187/07:05:19Z, GS Reacquisition (3,2,2) @ 187/08:38:28Z also failed to
FL backup on FGS 3.

HSTAR 9469: GS Acquisition (3,2,2) @ 187/11:51:10Z resulted in FL
backup, guiding on FGS 3 due to SSLE on FGS 2. FHST Map @ 187/12:30Z
showed vehicle axis errors of 4.756, -4.453, and 3.257 arcsec. GS
Reacquisition (3,2,2) @ 187/13:36:11Z also failed to FL backup.
Under investigation.

17201-0 Battery 5 Capacity Test @ 184/1440z
17207-0 Set up ACS memory monitor @ 184/1612z

1248-0 RTCS 26 Inhibited in SMS 187 @ 187/0047z
1249-0 Verify ACS FW2 Fourier Correction Alogrithm Update @ 187/0047z
0916-0 Tabulation of Slew Attitude Error (Miss-distance) @ 187/0138z

                          SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq              35                           35
FGS REacq              24                           24
Update           55                           50 

184/13:14:22z, 184/22:53:51z


Battery 5 discharge at the high rate continued until 181/20:17Z where
the Battery 5 Voltage dropped to 26.63 Volts and the FSW ACR
autonomously switched to the low rate, as planned. The measure
capacity was 54.5 Ah. Based on discharge through the 5.1 Ohm resistor.
When Battery 5 was last tested in July 2003, the capacity was measured
to be 61.2 Ah. The discharge continued until Battery 5 dropped below 5
Volts @ 183/14:30Z. The battery was placed back on charge with one SPA
online for one orbit and OCA disabled. The other two SPAs were
autonomously brought online the second orbit. OCA was enabled @
183/23:54Z. Battery 5 returned to FSW 6-battery system @ 184/14:29Z.

An update to the NCS Temperature setpoint was last routinely reset on
Day 100 to its current seasonal setting. The seasonal setpoint setting
was lowered by 0.05 degrees @ 187/00:10Z, executed entirely from the

Setup ACS Memory Monitor to capture SMS commanding to update a
constant term in the ACS Filter Wheel 2 Resolver Fourier Correction
algorithm and the mechanism raw resolver counts @ 184/16:12Z (OR
17207). Updated the constant term in the ACS Filter Wheel 2 Resolver
Fourier Correction algorithm (EDAC RAM) @ 187/00:31Z; executed
entirely from the SMS. This change was done to correct a bias
subsequently observed in the resolver readings and should prevent the
reoccurrence of Filter Wheel positioning errors, see HSTAR 9455.
Update also added to the Boot-to-Operate reconfiguration instruction.

Repeated the Two-Gyro Target Reacquisition test @ 187/03:29Z, special
command Proposal 10336, executed entirely from the SMS.

Gyro Scale Factor was modified for this calendar; modified value is:
rga_scale_error = 1.4"/degree.

SSA Transmitter 1 was placed back in service starting SMS 187.

PCS and SAC rescheduled a routine update to the RGA Scale
Factor/Alignment Table and Bias Offset Calibration. These changes
involve relatively minor corrections to the Gyro Scale Factor and High
Mode Bias Offset tables. Two uplink opportunities are identified:
188/16:02:11Z – 188/16:27:42Z and 188/19:34:22Z – 20:17:00Z. Vehicle
will be RGA Hold during the uplink, with the FGSs in default. As
before there is a concurrent ACS observation during the identified
window, but this internal CCD monitoring Proposal 10061 "CCD Daily
Monitor" should remain unaffected by these activities.

SpaceRef staff editor.