Status Report

NASA Hubble Space Telescope Daily Report # 3459

By SpaceRef Editor
October 2, 2003
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ACS 9984

Cosmic Shear With ACS Pure Parallels

Small distortions in the shapes of background galaxies by foreground
mass provide a powerful method of directly measuring the amount and
distribution of dark matter. Several groups have recently detected
this weak lensing by large-scale structure, also called cosmic shear.
The high resolution and sensitivity of HST/ACS provide a unique
opportunity to measure cosmic shear accurately on small scales. Using
260 parallel orbits in Sloan textiti {F775W} we will measure for the
first time: beginlistosetlength sep0cm setlengthemsep0cm setlength
opsep0cm em the cosmic shear variance on scales <0.7 arcmin, em the
skewness of the shear distribution, and em the magnification effect.
endlist Our measurements will determine the amplitude of the mass
power spectrum sigma_8Omega_m^0.5, with signal-to-noise {s/n} ~ 20,
and the mass density Omega_m with s/n=4. They will be done at small
angular scales where non-linear effects dominate the power spectrum,
providing a test of the gravitational instability paradigm for
structure formation. Measurements on these scales are not possible
from the ground, because of the systematic effects induced by PSF
smearing from seeing. Having many independent lines of sight reduces
the uncertainty due to cosmic variance, making parallel observations

ACS/HRC 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/HRC 9987

Coronagraphic search for disks around nearby stars

We will use the coronagraphic and imaging modes of the High Resolution
camera to study of the role of circumstellar disks in planetary system
formation over timescales of ~1-1000 Myr. Our targets comprise pre
Main-Sequence {MS} and MS stars, selected by infrared excess, and
targets selected from SIRTF surveys. Some targets, like Beta Pictoris
have debris disks that have been detected at optical or near-IR
wavelengths, while others have disks inferred from mid-IR or ISO
observations. We will obtain multicolor images of each target’s
circumstellar environment for the purpose of {1} detecting and
characterizing disk morphologies over all scales {including warps and
regions of enhanced or depleted density}, and {2} seeking evidence of
embedded planets. Direct and occulted images will be recorded for
studying the disks within 2 arcseconds of these targets; the
coronagraph will be used to image the outer regions of the disks.
Together with existing infrared observations, we will provide
constraints on the sizes, distribution, and composition of dust


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.


The Grism-ACS Program for Extragalactic Science {GRAPES}

We propose an ACS grism spectroscopic survey with a wide component and
an ultradeep single ACS field. The wide component covers the
well-imaged GOODS Chandra Deep Field south and the deepest field will
be the Ultra Deep field to be observed in cycles 11 and 12. The Grism
ACS Program for Extra-galactic Science {GRAPES} will: {1} Probe the
reionization epoch by robustly determining the luminosity function of
Lyman-alpha emitters, Lyman break galaxies and low luminosity AGNs at
z~6, and thus the sources of ionizing photons at the end of the "dark
ages". A similar census of ionizing photon sources at z=4-6 needed to
maintain the ionized state of the IGM will also be achieved. {2} Study
galaxy formation and evolution by finding galaxies in a contiguous
redshift range between z=4-7 and evolution of black holes through a
census of low-luminosity AGNs. {3} Study star-formation and galaxy
assembly at its peak at z=1-2 by identifying star-forming galaxies by
their emission lines, old galaxies by the 4000 AA break and any
combination of new and old populations showing both lines and breaks.
{4} Allow the deepest unbiased spectroscopy yet, for identification of
objects to I=27. {5} Enhance the value of multiwavelength data in the
UDF and GOODS field to the astronomical community.

ACS/WFC 9821

The Second Parameter Effect in Metal-Rich Globular Clusters: A
Snapshot Study of NGC 6388

While it has long been known that at least one parameter besides the
metallicity, [Fe/H], determines the horizontal branch {HB} morphology
of Galactic globular clusters {GCs}, our ignorance as to the nature of
this second parameter {or parameters} has been a major stumbling block
in understanding the formation history and age of the GC system. The
hot HB populations recently discovered by HST in the metal-rich GCs
NGC 6388 and NGC 6441 provide a unique opportunity for unraveling this
second-parameter effect. Many different theories have been proposed to
explain the pronounced upward slope of the HBs in these GCs, including
stellar rotation, metallicity spread, and a dwarf galaxy origin. We
propose to test these theories by obtaining B, V, I time-series
photometry of the RR Lyrae variables in the core of NGC 6388 in order
to determine whether, as predicted, the pulsation periods are
unusually long due to a high HB luminosity. If confirmed, this would
argue against age or mass loss as the second parameter in NGC 6388
and, more generally, would have implications for the use of RR Lyrae
stars as standard candles for determining GC distances and ages. Light
curves will also be obtained for the crowded Population II Cepheids
near the core of NGC 6388, the most metal-rich GC, along with NGC
6441, known to contain such stars. We waive proprietary rights to any
data obtained.

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.

FGS 9971

FGS Astrometry of a Star Hosting an Extrasolar Planet: The Mass of
Upsilon Andromedae d

We propose observations with HST/FGS to determine the astrometric
elements {perturbation orbit semimajor axis and inclination} produced
by the outermost extra-solar planet orbiting the F8V star Upsilon
Andromedae. These observations will permit us to determine the actual
mass of the planet by providing the presently unknown sin i factor
intrinsic to the radial velocity method which discovered this object.
An inclination, i = 30degrees, within the range of one very low
precision determination using reanalyzed HIPPARCOS intermediate data
products, would produce the observed radial velocity amplitude, K = 66
ms with a companion mass of ~8 M_Jupiter. Such a mass would induce in
Upsilon Andromedae a perturbation semi-major axis, Alpha = 0arcs0012,
easily within the reach of HST/FGS fringe tracking astrometry. The
proposed observations will yield a planetary mass, rather than, as
previous investigations have done, only suggest a planetary mass

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.

NIC1/NIC2/NIC3 8792

NICMOS Post-SAA calibration – CR Persistence Part 3

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.

NIC3 9824

NIC3 SNAPs of nearby galaxies imaged in the mid-UV: the remarkable
cool stellar population in late-type galaxies.

We propose a NIC3 H-band {F160W} SNAPshot survey of 48 nearby mid- to
late-type galaxies covering all inclinations. In Cycle 9 and 10, we
imaged ~100 galaxies in the mid-UV {F300W/F255W} and I-band {F814W}
with WFPC2, and obtained UBVR CCD surface photometry from the ground.
Early-mid-type galaxies show the usual small radial color-gradients,
where disks become somewhat bluer at larger radii. But, remarkably,
the majority of {lower luminosity, smaller and rounder} late-type
galaxies shows the opposite trend and becomes redder outwards in all
filters. While young UV/blue-bright stellar populations dominate their
inner morphology, most late-type galaxies must have a significant halo
or thick disk of older stars. Combining our proposed NIC3 H-band with
existing WFPC2 images will span the wavelength range 0.29-1.6 micron
at resolutions of 0.04-0.16" {FWHM}. This Panchromatic Nearby Galaxy
Atlas will be applicable to a wide range of problems, and will be made
public immediately. Our NIC3/F160W science goals are to: {1} Establish
the nature of the old outer stellar population. All target galaxies
have z<0.005, allowing us to resolve any luminous, cool supergiant
population. NIC3 is essential to make a pixel-to-pixel color-magnitude
study of the nature, distribution and uniformity of the outer stellar
populations, which will constrain dwarf galaxy formation theories. {2}
Determine galaxy structure at 5-20 pc resolution, tracing the old
stellar population and mass distribution compared to the star-forming
regions seen in the mid-UV. A range of inclinations is needed to
distinguish between old thick disks or halos in late-type galaxies.
{3} Make a multi-wavelength pixel-to-pixel decomposition to help
delineate the effects of dust, age, and metallicity. Since we must
cover a range of inclinations, NIC3 H-band is essential to map the
effects from dust, and see how these may affect the studies of {1} and

NIC3 9979

The Ultra Deep Field – NICMOS Parallels

This is a plan to manage the NICMOS pure parallels of the ACS Ultra
Deep Survey. We will obtain a mix of F110W and F160W images along
sight-lines within the mosaiced ACS fields of the CDF-S GOODS and GEMS
surveys, with these sight-lines enabling an examination of the space
density and morphologies of the reddest galaxies.

STIS 9615

Cycle 11 MAMA Dark Monitor

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

STIS/CCD 10000

STIS Pure Parallel Imaging Program: Cycle 12

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

STIS/CCD 10017

CCD Dark Monitor-Part 1

Monitor the darks for the STIS CCD.

STIS/CCD 10019

CCD Bias Monitor – Part 1

Monitor the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1,
and 1×1 at gain = 4, to build up high-S/N superbiases and track the
evolution of hot columns.

STIS/CCD 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.

WFPC2 10073

Earth Flats

This proposal monitors flatfield stability. This proposal obtains
sequences of Earth streak flats to construct high quality flat fields
for the WFPC2 filter set. These flat fields will allow mapping of the
OTA illumination pattern and will be used in conjunction with previous
internal and external flats to generate new pipeline superflats. These
Earth flats will complement the Earth flat data obtained during cycles

WFPC2 9595


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

WFPC2 9709

POMS Test Proposal: WFII parallel archive proposal

This is the generic target version of the WFPC2 Archival Pure Parallel
program. The program will be used to take parallel images of random
areas of the sky, following the recommendations of the 2002 Parallels
Working Group.

WFPC2 9712

Pure Parallel Near-UV Observations with WFPC2 within High-Latitude ACS
Survey Fields

In anticipation of the allocation of ACS high-latitude imaging
survey{s}, we request a modification of the default pure parallel
program for those WFPC2 parallels that fall within the ACS survey
field. Rather than duplicate the red bands which will be done much
better with ACS, we propose to observe in the near-ultraviolet F300W
filter. These data will enable study of the rest-frame ultraviolet
morphology of galaxies at 0<z<1. We will determine the morphological
k-correction, and the location of star formation within galaxies,
using a sample that is likely to be nearly complete with
multi-wavelength photometry and spectroscopic redshifts. The results
can be used to interpret observations of higher redshift galaxies by

WFPC2 9980

The Ultra Deep Field – WFPC2 Parallels

The ACS Ultra Deep Field {UDF} is a survey carried out by using
Director’s Discretionary time. The main science drivers are galaxy
evolution and cosmology. The primary instrument is the Advanced Camera
for Surveys but WFPC2, NICMOS, and STIS will also be used in pure
parallel mode. The data will be made public. The UDF consists of a
single ultra-deep field {410 orbits in total} within the CDF-S GOODS
area. We request a modification of the default pure parallel programs.
Rather than duplicate the redder bands which will be done much better
with ACS, we propose to observe in the near-ultraviolet F300W filter.
These data will enable study of the rest-frame ultraviolet morphology
of galaxies at 0<z<1, allowing determination of the morphological
k-correction and the location of star formation within galaxies, using
a sample that is likely to be nearly complete with multi-wavelength
photometry and spectroscopic redshifts. The results can be used to
interpret observations of higher redshift galaxies by ACS.


Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.) None

17045 – FSW 2.4A EEPROM Installation @ 274/1936z


                            SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq                 7                         7
FGS REacq                 8                         8  
FHST Update               9                         9


Successfully completed installation of FSW 2.4a EEPROM @ 274/19:36:11Z
(OR 17045 with attached script IP-43). The FSW 2.4a EEPROM load was
completed @ 274/17:39:15Z, a baseline EEPROM dump was completed @
274/19:21:00Z and verified by FSW personnel.

Successfully completed update of Battery Coefficients on all CCS
operational strings @ 274/12:24Z, based on Battery 1 information from
the Battery Capacity Test on Day 259. See GSCA 711 for details.

SpaceRef staff editor.