Status Report

NASA Hubble Space Telescope Daily Report # 3398

By SpaceRef Editor
July 7, 2003
Filed under , ,





ACS 9472

A Snapshot Survey for Gravitational Lenses among z >= 4.0 Quasars

Over the last few years, the Sloan Digital Sky Survey has
revolutionized the study of high-redshift quasars by discovering over
200 objects with redshift greater than 4.0, more than doubling the
number known in this redshift interval. The sample includes eight of
the ten highest redshift quasars known. We propose a snapshot imaging
survey of a well-defined sample of 250 z > 4.0 quasars in order to
find objects which are gravitationally lensed. Lensing models
including magnification bias predict that at least 4% of quasars in a
flux-limited sample at z > 4 will be multiply lensed. Therefore this
survey should find of order 10 lensed quasars at high redshift; only
one gravitationally lensed quasar is currently known at z > 4. This
survey will provide by far the best sample to date of high-redshift
gravitational lenses. The observed fraction of lenses can put strong
constraints on cosmological models, in particular on the cosmological
constant Lambda. In addition, magnification bias can significantly
bias estimates of the luminosity function of quasars and the evolution
thereof; this work will constrain how important an effect this is, and
thereby give us a better understanding of the evolution of quasars and
black holes at early epochs, as well as constrain models for black
hole formation.

ACS 9468

ACS Grism Parallel Survey of Emission- line Galaxies at Redshift z .pl 7

We propose an ACS grism parallel survey to search for emission-line
galaxies toward 50 random lines of sight over the redshift interval 0
< 7. We request ACS parallel observations of duration more than one orbit at high galactic latitude to identify ~ 300 HAlpha emission-line galaxies at 0.5, ~ 720 O IILambda3727 emission-line galaxies at 1.68, and .pg 1000 Ly-alpha emission-line galaxies at 7 with total emission line flux 2* 10^-17 ergs s^-1 cm^-2 over 578 arcmin^2. We will obtain direct images with the F814W and F606W filters and dispersed images with the WFC/G800L grism at each position. The direct images will serve to provide a zeroth order model both for wavelength calibration of the extracted 1D spectra and for determining extraction apertures of the corresponding dispersed images. The primary scientific objectives are as follows: {1} We will establish a uniform sample of HAlpha and O II emission-line galaxies at z<1.7 in order to obtain accurate measurements of co-moving star formation rate density versus redshift over this redshift range. {2} We will study the spatial and statistical distribution of star formation rate intensity in individual galaxies using the spatially resolved emission-line morphology in the grism images. And {3} we will study high-redshift universe using Ly-alpha emitting galaxies identified at z .pl 7 in the survey. The data will be available to the community immediately as they are obtained.

ACS 9482

ACS Pure Parallel Lyman-Alpha Emission Survey {APPLES}

Ly-alpha line emission is an efficient tool for identifying young
galaxies at high redshift, because it is strong in galaxies with young
stars and little or no dust — properties expected in galaxies
undergoing their first burst of star- formation. Slitless spectroscopy
with the ACS Wide-Field Camera and G800L grism allows an unmatched
search efficiency for such objects over the uninterrupted range 4 <~ z <~ 7. We propose the ACS Pure Parallel Ly-alpha Emission Survey {``APPLES''}, to exploit this unique HST capability and so obtain the largest and most uniform sample of high redshift Ly-alpha emitters yet. Parallel observations will allow this survey to be conducted with minimal impact on HST resources, and we will place reduced images and extracted spectra in the public domain within three months of observation. We aim to find ~ 1000 Ly-alpha emitters, 5 times the biggest current sample of Ly-alpha emitters. This unprecedented sample will provide robust statistics on the populations and evolution of Ly-alpha emitters between redshifts 4--7; a robust measurement of the reionization redshift completely independent of the Gunn-Peterson trough; spatial clustering information for Ly-alpha emitters which would let us probe their bias function and hence halo mass as a function of redshift; many galaxies at redshift exceeding 6; and lower redshift serendipitous discoveries.

ACS 9463

Are OH/IR stars the youngest post-AGB stars? An ACS SNAPshot imaging

Essentially all well-characterized preplanetary nebulae {PPNs}–
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 propose an ACS/SNAPshot imaging survey of a large,
morphologically unbiased sample of these objects, selected using their
IRAS 12-to-25micron colors. Our ground-based imaging study of OH/IR
stars has revealed a few compact bipolar objects, supporting our
hypothesis. However since most objects remain unresolved, HST
observations are needed to determine how and when the bipolar geometry
asserts itself. 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 PPNs,
are common or rare phenomena.

ACS 9674

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 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 ideal.

ACS 9656

Stability of the ACS CCD: geometry, flat fielding, photometry

A moderately crowded stellar field, located ~6′ West of the centre of
the cluster 47 Tuc, is observed repeatedly {every three weeks with the
WFC, every other month with the HRC} in various filters, spending 1
orbit per epoch. Different filters will be used every time, so that
over the course of the year all filters will have been employed at
least twice. The most common filters will be checked more frequently.
The same field has been observed in the course of the SMOV phase and
the positions and magnitudes of the most prominent stars have been
accurately measured. Although the field is neither a proper
astrometric nor a proper photometric standard one, the positions and
magnitudes of the objects in it can be used to monitor any local and
large scale variations in the platescale and sensitivity of the
detectors. It should be noted that for the filters which have already
been used during the SMOV phase it will be sufficient to take one
single image, without CR-SPLIT, since the exposure time is always
short {20-30 sec} and there will be so many stars that the few of them
which are affected by cosmic rays can be discarded as outliers in the
photometry. For narrow and medium band filters not exercised on this
target in the SMOV phase, however, a baseline will have to be set.
This expenditure of time will apply to the current cycle only. At
variance with the approach used in SMOV, there is no need for large
telescope slews to place the same objects on opposite sides of the
detectors, thence allowing the programme to remain compact and
efficient. All exposure level parameters are set to their default
values, except for the amplifier gain of the WFC exposures in the
F606W band, which will be collected with the gain value of 2 for the
WFC for compatibility with the SMOV observations. The exposure time is
typically 30 seconds for the WFC, 60 sec for the HRC. No attempt will
be made to attain a predefined or the same orientation on the sky
amongst different epochs. Typically, for the WFC, five exposures will
be accommodated in one orbit. For the HRC, about 10 exposures can be
fitted within one orbit

ACS/HRC 9805

OGLE-TR-56b: The Most Interesting Transiting Planet

Our team has recently succeeded in confirming spectroscopically the
discovery of the first extrasolar giant planet found in a transit
search: OGLE-TR-56b. Its main parameters are: mass = 0.9 Jupiters,
size = 1.3 Jupiters. Thus, OGLE-TR-56b appears to be similar to HD
209458b, the only other known transiting giant planet. Unfortunately,
our planet radius determination is uncertain due to the very limited
precision of the ground-based photometry, and does not allow for a
meaningful comparison with theoretical model predictions. We propose
HST observations with the ACS-HRC of the main transit of OGLE-TR-56b,
which will improve the precision and the accuracy of the planet
parameters by close to a factor of 10. In addition, we propose a
timing experiment for the planet’s extremely close orbit {1.2-day
period, 0.023 AU from the star}, which will allow us to detect the
orbital decay and test convection theories.

ACS/WFC 9584

ACS Default {Archival} Pure Parallel Program II.

The Advanced Camera for Surveys (WFC) was used to test ACS pure

ACS/WFC 9682

The Physics of Relativistic Jets: Deep Chandra and HST Observations of
Two Newly Discovered Jets

We propose deep observations of two X-ray-bright jets newly discovered
in our A02 Survey, both with optical counterparts in our HST images.
The targets were selected because of their interesting physical
properties. Our goals are to obtain high-quality x-ray and optical
images to study the jet morphologies and determine the x-ray and
optical spectra. Both the morphologies and spectra will test the
origin of x-rays, whether they are from inverse Compton on microwave
background photons vs direct synchrotron emission, allowing us to
determine the jet physical parameters {Lorentz factors, particle
distributions, and beaming} at different locations in the jet. This
has important implications on the modes of energy transport and
dissipation in relativistic jets.


Gravitational Microlensing in the NGC 3314A-B Galaxy Pair

Determining the composition of the dark matter that dominates the
masses of galaxies is an important unsolved problem, and the results
of the MACHO Collaboration suggest that some of Milky Way’s dark
matter may be in the form of very old white dwarfs. However, some have
argued that the excess of microlensing events seen by MACHO are due to
a larger than expected microlensing rate for lens stars in the LMC
itself or its tidal debris. We propose to address this question by
detecting microlensing events in the line-of-sight galaxy pair NGC
3314 A & B. The large line-of-sight distance between these galaxies
gives an optical depth that is 3-4 orders of magnitude larger than if
the source stars and lenses were in the same galaxy, and the fact that
the background galaxy is a spiral ensures that there will be a
sufficient number of bright, non-variable source stars. Our proposed
observations should have the sensitivity to detect microlensing by
both ordinary stars and dark matter in NGC 3314A {the foreground
galaxy}. If there are dark matter microlensing events to be found,
they can be clearly distinguished from stellar microlensing events
because they will occur outside the visible disk of NGC 3314A. If
baryonic dark matter is detected in NGC 3314A, we will be able to map
its radial density variation.


The Role of Groups in the Evolution of Galaxies at Intermediate Redshifts

Groups are the most common environment experienced by galaxies, yet
they remain the least studied. The tidal fields and dynamical friction
encountered by galaxies in groups probably holds the key to
understanding the role of environment in driving the evolution of
galaxies since z ~ 1. To study the evolution of galaxies in the group
environment, we propose the first unbiased HST study of groups at
moderate redshifts. Unlike previous HST group samples, that relied on
radio or X-ray properties, our kinematically selected sample is drawn
from a large redshift survey and is not biased towards unusually dense
groups. HST imaging is essential to determine the morphology of
galaxies in these systems and contrast this with the properties of
galaxies in denser and more evolved groups and rich clusters at these
epochs. HST data are also required to adequately compare the
properties of groups at intermediate redshifts with local group
samples derived from the 2df and Sloan surveys. We will combine the
HST images with deep ground-based observations to study how
morphologies and stellar populations of galaxies in groups have
evolved in time. These observations are key to understanding the
decline in the volume averaged star formation rate in the universe.

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

FGS 9879

An Astrometric Calibration of the Cepheid Period-Luminosity Relation

We propose to measure the parallaxes of 10 Galactic Cepheid variables.
There is no other instrument on or off the earth that can consistently
deliver HST FGS level of precision for critical parallaxes. When these
parallaxes {with 1-sigma precisions of 10% or better} are added to our
recent HST FGS parallax determination of delta Cep {Benedict et al
2002}, we anticipate determining the Period-Luminosity relation zero
point with a 0.03 mag precision. In addition to permitting the test of
assumptions that enter into other Cepheid distance determination
techniques, this calibration will reintroduce Galactic Cepheids as a
fundamental step in the extragalactic distance scale ladder. A
Period-Luminosity relation derived from solar metallicity Cepheids can
be applied directly to extragalactic solar metallicity Cepheids,
removing the need to bridge with the Large Magellanic Cloud and its
associated metallicity complications.

HST 9382

A Large Targeted Survey for z < 1.6 Damped Lyman Alpha Lines in SDSS QSO MgII-FeII Systems.

We have searched the first public release of SDSS QSO spectra for
low-z {z<1.65} metal absorption lines and found over 200 large rest equivalent width MgII-FeII systems. Previously, we empirically showed that such systems are good tracers of large neutral gas columns, with ~50% being classical damped Lyman alpha {DLA} systems {N_HI>=2*10^20
cm^-2}. Here we propose to follow up a well-defined subset of 79 of
them to search for DLAs with 0.47


Completing A Near-Infrared Search for Very Low Mass Companions to
Stars within 10 pc of the Sun

Most stars are fainter and less massive than the Sun. Nevertheless,
our knowledge of very low mass {VLM} red dwarfs and their brown dwarf
cousins is quite limited. Unknown are the true luminosity function
{LF}, multiplicity fraction, mass function, and mass-luminosity
relation for red and brown dwarfs, though they dominate the Galaxy in
both numbers and total mass. The best way to constrain these relations
is a search for faint companions to nearby stars. Such a search has
several advantages over field surveys, including greater sensitivity
to VLM objects and the availability of precise parallaxes from which
luminosities and masses can be derived. We propose to complete our
four-filter NICMOS snapshot search for companions to stars within 10
pc. With a 10 sigma detection limit of M_J ~ 20 at 10 pc, we can
detect companions between 10 and 100 AU that are at least 9 mag
fainter than the empirical end of the main sequence and at least 6.5
mag fainter than the brown dwarf Gl 229B. When completed, our search
will be the largest, most sensitive, volume-limited search for VLM
companions ever undertaken. Our four-filter search will permit
unambiguous identification of VLM-companion candidates for follow-up
observation. Together with IR speckle and deep imaging surveys, our
program will firmly establish the LF for VLM companions at separations
of 1-1000 AU and the multiplicity fraction of all stars within 10 pc.


NICMOS Observations of the Galactic Center: Environment of a Black Hole

Intensive observation of the Galactic Center in recent years has shown
conclusively that the Milky Way is home to a 2.5*10^6Msun black hole.
Infrared observations of the stellar population have revealed a
bright, young stellar cluster nearly coincident with the Center. We
still do not know how the black hole influences its surroundings
beyond the stellar dynamics very close to the hole. We do not even
know whether the Milky Way has a core similar that seen in massive
bulges or has a mass distribution that follows a power-law right into
the center. We propose to use NICMOS to measure the central surface
brightness profile of the galaxy, and to measure proper motions over
the critical volume where the transition from black hole-dominated
gravitational field to stellar mass- dominated gravitational field
occurs. The data collected to investigate these issues will also shed
light on the main sequence associated with the young stellar cluster
and whether it formed in situ or elsewhere in the galaxy.


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.


The NICMOS Parallel Observing Program

We propose to manage the default set of pure parallels with NICMOS.
Our experience with both our GO NICMOS parallel program and the public
parallel NICMOS programs in cycle 7 prepared us to make optimal use of
the parallel opportunities. The NICMOS G141 grism remains the most
powerful survey tool for HAlpha emission-line galaxies at
cosmologically interesting redshifts. It is particularly well suited
to addressing two key uncertainties regarding the global history of
star formation: the peak rate of star formation in the relatively
unexplored but critical 1<= z <= 2 epoch, and the amount of star formation missing from UV continuum-based estimates due to high extinction. Our proposed deep G141 exposures will increase the sample of known HAlpha emission- line objects at z ~ 1.3 by roughly an order of magnitude. We will also obtain a mix of F110W and F160W images along random sight-lines to examine the space density and morphologies of the reddest galaxies. The nature of the extremely red galaxies remains unclear and our program of imaging and grism spectroscopy provides unique information regarding both the incidence of obscured star bursts and the build up of stellar mass at intermediate redshifts. In addition to carrying out the parallel program we will populate a public database with calibrated spectra and images, and provide limited ground- based optical and near-IR data for the deepest parallel fields.


A SNAPSHOT Survey of the Hot Interstellar Medium

We propose to obtain SNAPSHOT STIS echelle observations of key tracers
of hot interstellar gas {CIV, NV and SiIV} for selected FUSE Team OVI
survey targets with known UV fluxes. By taking advantage of the
SNAPSHOT observing mode we will efficiently obtain a large number of
spectra suitable for the study of the highly ionized hot component of
the interstellar medium {ISM}. Our goals are to explore the physical
conditions in and distribution of such gas, as well as to explore the
nature of the interfaces between the hot ISM and the other
interstellar gas phases. Using inter–comparisons of the various ionic
ratios for CIV, NV, OVI and SiIV, we will be able to discriminate
between the various models for the production of the highly ionized
gas in the Galactic ISM. The survey will also enable detailed studies
of regions already known to contain hot gas through X-ray emission
measurements {e.g., SNRs and radio loops}. The proposed SNAPSHOT
observations will extend our previous Cycle 9 survey {which was
compromised by the STIS side 1 failure}, and should roughly double the
number of stars for which high quality STIS observations of the
important hot gas tracers are available, enabling us to derive a truly
global view of the hot ISM.

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 9606

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.

STIS 9447

Characterizing the Atmosphere of an Extrasolar Planet

HD 209458 b is the first extrasolar planet known to transit the disk
of its parent star. Precise measurement of both the photometric
transit curve and the radial velocity orbit has allowed for an
accurate estimation of the mass, radius, average density, and surface
gravity. Numerous theoretical investigations of the planetary
atmospheres have been presented in the literature, but no data capable
of addressing these has yet been published. We propose to use the
method of transmission spectroscopy to constrain greatly models of the
planetary atmosphere. We will use STIS to disperse the stellar flux
over a large number of detector pixels. The photometric signal is
produced by summing the counts over a desired band. For each of twelve
bands spanning the UV to the near-IR, we will obtain sufficient
precision to detect variations in the transit depth greater than 5 X
10^-5. We have already made a detection of the sodium absorption
signature in the planetary atmosphere. With these new data, we will be
able to detect, if present, absorption due to Rayleigh scattering,
water bands, and/or strong alkali metal lines. These observations will
allow us to determine the broad characteristics of the planetary
atmosphere. For example, we will be able to distinguish between models
with a high cloud deck, and those with no clouds but reduced chemical

STIS 9973

Intensive Coverage of the Eta Carinae Event in 2003

For a variety of reasons, HST can provide a very special and unique
data set when Eta Car experiences its next spectroscopic event in
mid-2003. Explaining the phenomenon is only part of the motivation.
This star and its ejecta have unique characteristics that make them
important for several branches of astrophysics; and when a
spectroscopic event occurs, it’s like varying the parameters in an
experiment {or rather, set of experiments}. The 2003 event may be the
only chance in the forseeable future to obtain such a data set,
especially with HST. Eta Carinae has extreme parameters; it is
mysterious in surprisingly basic ways; and HST/STIS can gather useful
data on it at a terrific rate. As we explain below, the proposed data
set will be valuable in several independent ways: It will help solve a
specific set of current problems, it will constitute a large and
unique archival data base for both stellar and nebular astrophysics,
and it will be well-suited for educational uses.

STIS 9415

Is the Compact HVC Toward Ton S210 Remnant Debris from the Formation
of the Local Group?

There is a fortuitous coincidence in the positions of the quasar Ton
S210 and a compact ionH1 high velocity cloud on the sky that makes it
possible to test the hypothesis that such clouds are extragalactic
entities located in the Local Group. The HVC toward Ton S210 has H I
21 cm emission properties similar to those of isolated compact HVCs
suspected of being Local Group clouds. It has recently been detected
in O VI absorption by FUSE, which suggests that either there is hot
gas associated with the collapse of the cloud or that the HVC is
interacting with a hot, tenuous Galactic halo or Local Group medium.
We propose to observe the HVC in absorption against the smooth
ultraviolet continuum of Ton S210 with HST/STIS. To answer the
question posed in the proposal title, we will combine the STIS
observation with extant FUSE and H I 21 cm data to determine the
metallicity, elemental abundances, and ionization properties of the
HVC. To date, such information has been difficult to obtain for all
but a few HVCs, and this is the first time such an opportunity has
been available for a compact HVC. The results of this study will bear
directly upon the issues of the locations of compact HVCs, the
ionization conditions of HVCs detected in O VI absorption, and the
possible influence HVCs might have on the chemical evolution of

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 9708

STIS Pure Parallel Imaging Program: Cycle 11

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

STIS 9507

STIS/UV snapshot survey of bright AGN

We propose a UV spectroscopic snapshot survey of bright AGN,
quadrupling the number of Seyferts UV spectra and adding dozens of new
quasars, aimed at the following goals: beginenumerate em Finding the
relationship between the intrinsic luminosity of the AGN and the
maximum velocity {and width} of the outflow emanating from it, and
determining the frequency of outflows in low-z AGN as a function of
luminosity. em Surveying IGM absorption line systems in numerous new
sight-lines. em Identifying promising targets for observations with
the future highly sensitive Cosmic Origin Spectrograph. endenumerate A
35-minute snapshot with exposures in either the G140L or G230L will
yield spectra with a minimum S/N > 15 per resolution element at all
wavelengths for all our potential targets. This will allow us to be
sensitive to absorption lines to a limiting equivalent width of 0.3
Angstrom at the 3 Sigma level. In order to facilitate rapid
observational followup, we waive the data proprietary period entirely.


The Galactic Warm Ionized Medium: the First Direct Measures of its
Ionization and Abundances

The warm ionized medium {WIM} is the dominant gaseous component of the
Galactic halo and represents an important sink of the radiative and
kinetic energy output of stars and supernovae, though the source of
its ionization remains unknown. We will use stis spectroscopy of the
post-AGB stars ROB 162 and ZNG 1 in the globular clusters NGC 6397 and
Messier 5 to measure directly the abundances and ionization states of
several key metals in the Galactic WIM. These sight lines are unique:
because the two clusters also contain pulsars with published radio
dispersion measurements, these are the only sight lines for which we
can derive the column densities of both HI, em and ionH2, as well as
the columns of multiple ionization stages of the important metals S,
P, and Fe. We will use the proposed stis observations with existing
use data to derive the total gas-phase abundances of S, P, and Fe for
the material along these sight lines with no ionization uncertainties.
We will directly measure the ionization fractions of S and P in the
WIM. We will also infer the dust content of the WIM. Our study of the
ionization state and dust content of the WIM will provide the best yet
constraints for models of this gas. Our work will also provide the
best constraint for the fundamental “cosmic” reference abundance
{averaged over these sight lines} of the undepleted elements S and P.


Towards a global understanding of accretion physics –, Clues from an UV
spectroscopic survey of cataclysmic variables

Accretion inflows and outflows are fundamental phenomena in a wide
variety of astrophysical environments, such as Young Stellar Objects,
galactic binaries, and AGN. Observationally, cataclysmic variables
{CVs} are particularly well suited for the study of accretion
processes. We propose to carry out a STIS UV spectroscopic snapshot
survey of CVs that fully exploits the diagnostic potential of these
objects for our understanding of accretion physics. This survey will
provide an homogenous database of accretion disc and wind outflow
spectra covering a wide range of mass transfer rates and binary
inclinations. We will analyze these spectra with state-of-the-art
accretion disc model spectra {SYNDISK}, testing our current knowledge
of the accretion disc structure, and, thereby, providing new insight
into the so far not well understood process of viscous dissipation. We
will use our parameterized wind model PYTHON for the analysis of the
radiation driven accretion disc wind spectra, assessing the
fundamental question whether the mass loss rate correlates with the
disc luminosity. In addition, our survey data will identify a number
of systems in which the white dwarf significantly contributes to the
UV flux, permitting an analysis of the impact of mass accretion on the
evolution of these compact stars. This survey will at least double, if
not triple, the number of high-quality accretion disc / wind outflow /
accreting white dwarf spectra, and we waive our proprietary rights to
permit a timely use of this database.


Wind Accretion and State Transitions in the Black Hole Binary Cyg X-1

The black hole binary, Cyg X-1, is generally observed in one of two
long duration X-ray states: a low flux, hard spectrum state {most
common} and a high flux, soft spectrum state {rare}. Models predict
that the high/soft state corresponds to a high mass transfer phase in
the binary, and since the X-ray source is fueled by accretion from the
stellar wind of the supergiant companion, the simple expectation is
that the high/soft state results from an increased wind mass loss
rate. Alternatively, a decrease in the wind mass loss rate could
result in a more ionized and slower wind in the vicinity of the black
hole, which would then be more easily accreted by the black hole. The
best test of these hypotheses is to observe the UV P Cygni lines of
the supergiant that are formed in its wind outflow. We recently used
HST/STIS to obtain the first ever high resolution UV spectra of the
system while it resided in the unusual high/soft state. Cyg X-1 has
now returned to the low/hard state, and here we propose to revisit Cyg
X-1 and complete our investigation of the wind – X-ray state
connection. The study will determine {1} the mass loss rate and the
dynamical {density and velocity} structure of the wind of the
supergiant star in both X-ray states, and {2} how the X-ray source
ionizes the wind. These spectra will be useful for other
investigations and will form an important resource for the entire
research community.

WFPC2 9710

POMS Test Proposal: WFII backup parallel archive proposal

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

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 9816

Proper motion kinematics in Galactic bulge/bar fields

With this proposal we continue a succesful programme to measure proper
motions in fields in the galactic bulge. We are able to reach
accuracies of ca 10km/s in transverse motion at a distance of 8kpc,
for thousands of stars per WFPC2 field. In combination with VLT
spectroscopic radial velocities and metallicity indices, we will be
able to construct a full dynamical and stellar-population model for
our Bulge. Previous fields in this programme were on the minor axis;
the fields proposed here {using first epoch observations from
1995-1998 from the archive} lie in the first quadrant, on the near
side of the Galactic bar. We also wish to establish first-epoch
observations in the 4th quadrant, where no suitable data exist so far.

WFPC2 9595


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


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

HSTAR 9073: GS Acquisition (3,1,3) @ 184/15:06:57Z resulted in FL
backup on FGS 1 due tU2,3RD update @
184/14:47:45Z showed attitude/vehicle er 0.234,
6.135, -5.815. FHST Map @ 184/15:39:56Z showed errors of
6.259, 0.851, 6.336. Under investigation.

16996-1 Battery 4 Capacity Test @ 184/1228z

1115-0 CCC IPCONFIG Connections @ 184/1626z
1128-1 Adjust ACS Error Count Limit @ 184/1920z
0924-0 HSTAR Documentation for Guide Star Acq Failure/Loss of Lock @
1124-0 Perform Observation Re-Dumps on the Partial Obs. Level @
186/2310z, 186/2311z
0900-1 COMMAND PROBLEM @ 186/0943z
1115-0 CCC IPCONFIG Connections @ 188/0242z
0916-0 Tabulation of Slew Attitude Error (Miss-distance) @ 188/0116z

FGS GSacq 29 29
FGS REacq 32 32
FHST Update 69 69

Successfully returned Battery 4 to the FSW 6-battery system @ 184/12:18Z
(OR 16996-1).

SpaceRef staff editor.