Daily 3495

HUBBLE SPACE TELESCOPE

DAILY REPORT # 3495

PERIOD COVERED: DOYs 325-327

OBSERVATIONS SCHEDULED

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.

FGS 9970

The Best Brown Dwarf Yet?: FGS Astrometry of the Companion to the
Hyades Eclipsing Binary V471 Tau

The analysis of over 30 yr of 161 eclipse timings of the Hyades
eclipsing binary V471 Tauri shows the presence of a low mass tertiary
companion. A third body was found from periodic variations in the
observed arrival times of the eclipses - known as the ``light time''
effect. The light time effect occurs as the relative distance {and
light travel time} changes as the eclipsing binary moves around the
barycenter of the triple system. Our analysis yields an orbital period
of P_3=30.5+/-1.6 yr, e_3=0.31+/-0.04, a semi-major axis of
a_3=11.2+/-0.4 AU, and a tertiary mass M_3 sin i_3 =0.039+/- 0.004 Mo.
For orbital inclinations 35 degrees the mass of the third body would
be below the stable hydrogen burning limit of M~0.07 Mo and thus would
be a brown dwarf. We propose HST/FGS observations of V471 Tau over the
next 3 years {2 HST orbits/year} to determine its astrometric orbit.
These HST observations, when combined with Hipparcos astrometry and
the light time orbit, will unambiguously yield the orbital inclination
and the mass of the third body. The identification of a brown dwarf in
V471 Tau will provide the first direct dynamical mass determination of
a brown dwarf with a known age {tau{Hyades}=625 Myr}, chemical
composition, and distance. In a few years {near maximum elongation},
it should be feasible to obtain IR images and spectra of this object
that will provide crucial tests of brown dwarf models.

ACS/WFC 9902

The Evolution of the Host Galaxies of Radio-Quiet Quasars

Study of the host galaxies and environments of high redshift AGN is
proving a valuable probe of current theories of how galaxies form and
evolve. Results from our NICMOS imaging program have indicated that
the hosts of z ~ 2 -- 3 faint radio-quiet quasars {RQQ} have
luminosities only around local L*, making them similar to Lyman-break
field galaxies at the same redshifts, and to the low-z hosts RQQ
hosts. This is roughly consistent with theoretical predictions of
Kauffmann & Haehnelt {2000} for the hierarchical buildup of galaxy
hosts and their relation to their resident supermassive black holes.
The luminosity of the AGN in these RQQ is key to understanding this
relationship, however, and we are making a comprehensive archival HST
imaging study of the hosts of RQQs from low to high z at a range of
nuclear luminosities. At intermediate z, however, there are no studies
of the hosts of RQQs in the faint luminosity range that represents the
bulk of the quasar population. In the present proposal, we request
imaging at the same rest-wavelengths as our high-z sample of the hosts
of 10 similarly luminous RQQs at z ~ 0.9. These data will fill in an
important part of the parameter space defined by quasar luminosity and
redshift. Combined with existing HST data they will allow us to trace
the evolution of the hosts of RQQ and that of the relationship between
quasar luminosity and host galaxy luminosity.

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
0.7z1.9, 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.

STIS/CCD/MA1 9848

A SNAPSHOT Survey of Sharp-Lined Early B-Type Stars

Although spectrum synthesis studies of the UV spectra of sharp-lined
main sequence B stars provide us with some our best determinations of
the abundances of the Fe group and neutron capture elements and the
chemical evolution in our galaxy and the Magellanic Clouds, the HST
archive is virtually devoid of high resolution spectra of the bright
nearby B stars that have become to be regarded as abundance standards.
For example, there are NO observations of HR 1886, iota Her, and tau
Her, the sharpest-lined representatives {V sin i 5 km/s} of spectral
classes B1 V, B3 IV-V and B5 IV, and only a few tiny spectral
intervals of gamma Peg {B2 IV}. Information on the abundances of the
Fe group is important for computing opacities for stellar evolution
calculations and for determining astrophysical f-values. There are no
suitable galactic standards in the HST database to compare with recent
HST/STIS observations of B stars in the Magellanic Clouds and the
likely future observations of similar objects in M31 and other nearby
galaxies. To correct this deficiency, we propose SNAPSHOT observations
with the STIS E140M and E230M gratings of 33 of the best bright
abundance standards in nearby clusters and the galactic field. Using
this data we will determine the abundances of the Fe group and heavy
elements using the technique of spectrum synthesis with LTE and NLTE
treatments. We waive the proprietary period.

ACS 9831

Multiplicity among brown dwarfs in the Pleiades cluster

We have compiled a sample of 32 confirmed brown dwarfs in the Pleiades
cluster. We propose to observe this sample with HST/ACS in SNAPSHOT
mode in order to search for very low mass multiple systems. Our goals
a 1} to determine the occurrence and frequency of binary systems
among substellar objects, which hold important clues to the formation
and evolution mechanism{s} of ultracool and brown dwarfs, 2} to get an
estimate of the Initial Mass Function {IMF} at very low masses, which
is still unknown and very much needed to be corrected for binarity, 3}
to compare the distribution of multiple systems in young open clusters
and in the field.

NIC3/ACS/HRC/WFC 9803

Deep NICMOS Images of the UDF

The ACS Ultra Deep Field {UDF} images will greatly enhance the rich
suite of deep multi-wavelength images in the Chandra Deep Field South
{CDF--S}. We propose to complete the image set with deep near-IR
NICMOS images at 1.1 and 1.6 microns over a significant fraction of
the UDF, providing a critical link between the HST ACS and SIRTF
observations. The timely addition of the near-IR images ensures that
investigators will have images that span the spectrum from X-ray to
far IR. In recognition of the value of the near IR images this
proposal is submitted as a Treasury proposal with no proprietary
period. The proposal team will deliver science quality images,
mosaiced images covering 4.9 sq arc min, and a photometric catalog
complete to an AB mag of 28.2 in both the F110W and F160W filters. The
program also delivers a parallel extremely deep ACS field, 8' away,
that reaches to within 0.6 mag of the UDF in the same filters as the
UDF. The scientific program of the proposal team focuses on the star
formation history of the universe, evolved galaxies at high redshift,
galaxies at the epoch of reionization, and the redshift evolution of
AGNs and ULIRGs. The HDF-N is currently the only field with
spatially-coincident deep HST imaging in both the optical and near-IR.
The small size of the HDF-N means that large scale structure is the
dominant error in the results from the HDF-N. Providing observations
in a field that is spatially uncorrelated is critically important. The
UDF/CDF-S fulfills that goal. The depth of the UDF ACS imaging, and
the wealth of Great Observatory and ground based observations in the
CDF-S, make these NICMOS observations uniquely valuable. An
extraordinarily rich array of science opportunities await the
community from the NICMOS UDF data.

ACS/HRC/WFC 9796

Observations of Intermediate Mass Black Hole Candidate Ultra-Luminous
X-ray Sources

Ultra-luminous X-ray {ULX} sources are off-nuclear point sources in
nearby normal galaxies. Variability observed on the timescale of days,
weeks, and years signals that ULXS are accreting sources, likely
harboring black holes. However, the observed X-ray luminosity of these
systems far exceeds the Eddington limit for a 10 Msun black hole; some
ULXs may be intermediate mass black holes. The identification and
study of optical counterparts with HST will be central to better
understanding these objects. We propose to obtain deep U-B-V-I
exposures of 4 extremely bright ULXs in nearby spirals: NGC 1313 X-1
and X-2, M81 X-9 {Holmberg II X-1}, and M74 X-1. Each has a 0.5''
Chandra position, and X-ray luminosity and spectral characteristics
consistent with expectations for intermediate mass black holes. We
will use the colors we obtain, the magnitudes we measure, and any
source variability {also, correlated optical-X-ray variability from
simultaneous Chandra snapshots} to constrain the nature of the donor
stars and the black holes {10 Msun or 100-1000 Msun}, and the
formation and evolution scenarios for each system.

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-diaram 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/HRC/WFC 9773

Ram Pressure Stripping in the Virgo Spiral NGC 4522

We propose to image in BVI with HST ACS/WFC the highly inclined Virgo
cluster spiral galaxy NGC 4522, which is perhaps the nearest and
clearest case of a galaxy whose interstellar medium {ISM} is being
actively stripped by the pressure of the intracluster medium {ICM}.
High resolution HST B-I mages of dust in the ISM will show important
details of the interaction, such as what happens to giant molecular
clouds in the interaction, how rapidly and cleanly disks are stripped,
and whether star formation is triggered by ICM pressure. We will
identify extraplanar star clusters which formed in the stripped gas,
and from their ages and spatial distribution constrain the stripping
history of NGC 4522. Only with the spatial resolution of HST can we
map dust features down to the few pc scale of GMCs, and clearly
identify stars clusters. In-depth study of this galaxy should provide
new insight into the physical processes which occur in ICM-ISM
interactions, and give us greater understanding of galaxy evolution in
clusters of all types and at all redshifts.

ACS/HRC/WFC 9770

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

Detailed studies of nearby galaxies {z0.05} 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/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 {V17.5}. We will also
measure two control clusters, one being an "old" family, and the other
a collection of background asteroids that do not have a family
association, and further compare with our determined value for the
frequency of large main-belt binaries {2%}. We request visits to 180
targets, using ACS/HRC.

ACS/WFC 9744

HST Imaging of Gravitational Lenses

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

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 0z1. 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
ACS.

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.

STIS/ACS/NICMOS 9430

The Role of Jets in Shaping Planetary Nebulae

Recent CO observations of several planetary nebulae {PN} suggest that
collimated outflows may play a crucial role in the early shaping of
these objects. The idea that jets may be the primary driver of the
early development of some PN represents a major shift in thinking
about the evolution of these objects. In the past, the role of jets
has been considered secondary to the interacting winds scenario, the
standard model of PN formation. We propose to use the unique
capabilities of HST to access the importance of collimated outflows in
the development of the young PN PK166-06D1 {AFGL 618}. We have chosen
PK166-06D1 for this study because it is in the early stages of PN
formation - the time during which jets would have the greatest impact
on PN development. We propose to use STIS, ACS, and NICMOS to
characterize the collimated outflows present in PK166- 06D1. The goals
of this study a 1} to characterize the interaction of the jets with
the surrounding AGB shell by determining the physical conditions in
the outflows and the interaction regions, 2} to determine the
structure of the surrounding AGB shell using deep optical imaging, 3}
to investigate the origin of the collimated outflows by examining the
central regions of the nebula. We require both the stability and high
spatial resolution capabilities of HST for this project because we
will be investigating the detailed structure of compact regions {
1"}.

NICMOS 8790

NICMOS Post-SAA calibration - CR Persistence Part 1.

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.

WFPC2 10082

POMS Test Proposal: WFII backup parallel archive proposal

This is a POMS test proposal designed to simulate scientific plans

WFPC2 10075

WFPC2 CYCLE 12 Intflat and Viflat Sweeps and Filter Rotation Anomaly
Monitor

Using intflat observations, this WFPC2 proposal is designed to monitor
the pixel-to-pixel flatfield response and provide a linearity check.
The intflat sequences, to be done once during the year, are similar to
those from the Cycle 11 program 9597. The images will provide a backup
database in the event of complete failure of the visflat lamp as well
as allow monitoring of the gain ratios. The sweep is a complete set of
internal flats, cycling through both shutter blades and both gains.
The linearity test consists of a series of intflats in F555W, in each
gain and each shutter. As in Cycle 11, we plan to continue to take
extra visflat, intflat, and earthflat exposures to test the
repeatability of filter wheel motions.

WFPC2 10069

WFPC2 CYCLE 12 Supplemental Darks, Part 1/3

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

ACS/HRC/WFC 10042

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.

STIS/CCD 10019

CCD Bias Monitor - Part 1

Monitor the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1,
and 1x1 at gain = 4, to build up high-S/N superbiases and track the
evolution of hot columns.

STIS/CCD 10017

CCD Dark Monitor-Part 1

Monitor the darks for the STIS CCD.

STIS/CCD 10000

STIS Pure Parallel Imaging Program: Cycle 12

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

FLIGHT OPERATIONS SUMMARY:

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

HSTAR 9217: FHST Update failure and GS Acquisition (2,0,2) failed to
Gyro control due to SRLE on FGS 2 @ 326/04:06:14Z. Prior GS
Acquisition failure and Full Maneuver Updates (U2,3FM) failures @
326/03:32:39Z and 326/03:35:24Z both due to FHST 1. FHST Map @
326/04:53Z showed errors of 51.203, - 64.262, - 60.102. FHST Roll
Delay U1,3RD @ 326/05:11:17Z failed due to FHST 1. Subsequent FHST
Full Maneuver Updates @ 326/06:20:23Z and 326/06:23:08Z were
successful with first update producing results of 21.644, 113.034,
49.638 after Type 2 slew. GS Acquisition @ 326/06:52:22Z was
successful. Under investigation.

COMPLETED OPS REQs: None

OPS NOTES EXECUTED: None

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 15 15
FGS REacq 16 16
FHST Update 30 30
LOSS of LOCK

SIGNIFICANT EVENTS: None