Daily - 3879

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 3879

PERIOD COVERED: UT June 10-12, 2005 (DOY 161-163)

OBSERVATIONS SCHEDULED

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.

S/C 10706

SMS spanning anneal for Flight Software Update {ACS}

This is an anneal that will take the place of the regularly scheduled
anneal, and will span a calendar boundary. 1. Visit 1 must be
scheduled to start within 6 hours of an SMS boundary.

ACS/WFC 10698

ACS Imaging of Galaxy Cluster XMMUJ2235.3-2557 at z=1.4

We will obtain ACS I-band {F775W} and z-band {F850LP} observations of
the most distant X-ray luminous cluster {z=1.4} currently known. These
will complement forthcoming ACS z-band {F850LP} and NICMOS H-band
{F160W} imaging awarded in Cycle 14 GO programs {PIs Mullis and
Perlmutter} and existing ground-based data {VLT FORS2 R, z and VLT
ISAAC J, Ks}. These deep, multiband images will allow us to
characterize the galaxy populations in high-density environments at
the largest lookback times accessible to date.

FGS 10610

Astrometric Masses of Extrasolar Planets and Brown Dwarfs

We propose observations with HST/FGS to estimate the astrometric
elements {perturbation orbit semi-major axis and inclination} of
extra-solar planets orbiting six stars. These companions were
originally detected by radial velocity techniques. We have
demonstrated that FGS astrometry of even a short segment of reflex
motion, when combined with extensive radial velocity information, can
yield useful inclination information {McArthur et al. 2004}, allowing
us to determine companion masses. Extrasolar planet masses assist in
two ongoing research frontiers. First, they provide useful boundary
conditions for models of planetary formation and evolution of
planetary systems. Second, knowing that a star in fact has a plantary
mass companion, increases the value of that system to future
extrasolar planet observation missions such as SIM PlanetQuest, TPF,
and GAIA.

ACS/WFC 10493

A Survey for Supernovae in Massive High-Redshift Clusters

We propose to measure, to an unprecedented 30% accuracy, the SN-Ia
rate in a sample of massive z=0.5-0.9 galaxy clusters. The SN-Ia rate
is a poorly known observable, especially at high z, and in cluster
environments. The SN rate and its redshift dependence can serve as
powerful discrimiminants for a number of key issues in astrophysics
and cosmology. Our observations will: 1. Put clear constraints on the
characteristic SN-Ia "delay time, " the typical time between the
formation of a stellar population and the explosion of some of its
members as SNe-Ia. Such constraints can exclude entire categories of
SN-Ia progenitor models, since different models predict different
delays. 2. Help resolve the question of the dominant source of the
high metallicity in the intracluster medium {ICM} - SNe-Ia, or core-
collapse SNe from an early stellar population with a top-heavy IMF,
perhaps those population III stars responsible for the early
re-ionization of the Universe. Since clusters are excellent
laboratories for studying enrichment {they generally have a simple
star-formation history, and matter cannot leave their deep
potentials}, the results will be relevant for understanding metal
enrichment in general, and the possible role of first generation stars
in early Universal enrichment. 3. Reveal, via nuclear variability, the
AGN fraction in clusters at this redshift, to be compared with the
field AGN fraction. This will be valuable input for understanding
black-hole demographics, AGN evolution, and ICM energetics. 4.
Potentially discover intergalactic cluster SNe, which can trace the
stripped stellar population at high z.

NIC2 10428

The colours of QSO host galaxies at z=2 and the evolution of their
stellar masses

We propose to use NICMOS imaging to measure the rest-frame optical/UV
colours of a complete sample of 10 QSO host galaxies at redshifts
between z=1.5 and z=2. From our cycle 11 HST observations {the GEMS
project} we know that QSO host galaxies at redshifts of z~1 show blue
colors despite having early-type morphologies. This is in excellent
agreement with recent SDSS results on low-z AGN hosts, suggesting that
QSO-type activity in galaxies correlates strongly with the presence of
a young stellar population. Our proposed NICMOS observations will
allow us to test the validity of this hypothesis out to z~2, by
relating the observed QSO host colours to those of normal galaxies at
similar redshifts taken from GOODS. We have already established within
GEMS that the QSO hosts in our sample possess substantial UV
luminosities, most likely originating from young stars. Knowing
rest-frame colors, we can estimate stellar ages and stellar masses.
For the first time will it be possible to determine the evolution of
stellar masses in QSO host galaxies from z=2, the epoch of maximum QSO
activity, to the present. Our results will shed light on the relation
between nuclear activity and the star formation history of galaxies,
and how these processes may jointly drive the cosmic evolution of QSOs
and galaxies.

NIC2 10418

Morphologies and Color Gradients of Galaxies with the Oldest Stellar
Populations at High Redshifts

We have isolated a sample of 9 luminous {~2L*} galaxies with the very
oldest stellar populations at their respective redshifts. The galaxies
have been found in radio- source fields chosen to be at the key
redshifts z~1.5 and z~2.5, which allow the cleanest separation of old
stellar populations from highly reddened starbursts with colors
derived from standard filter combinations. Ground-based observations
in excellent seeing and with adaptive optics of 3 of these galaxies
indicate that all 3 are dominated by well relaxed disks of old stars,
suggesting that the first large stellar systems to form in the
universe were disks in which star formation proceeded extremely
rapidly and efficiently. In order to test this conjecture, we are
requesting NICMOS2 exposures of our sample to obtain high S/N imaging
in the F160W filter to determine detailed morphologies of the old
stellar population, coupled with either NICMOS2 F110W or ACS F814W
exposures {depending on redshift} to determine color gradients and/or
other systematic color variations that might provide clues to
formation processes.

ACS/WFC/WFPC2 10402

The Formation and Evolution of Spirals: An ACS and WFPC2 Imaging
Survey of Nearby Galaxies

Over 50% of galaxies in the local universe are spirals. Yet the star
formation histories and evolution of this crucial population remain
poorly understood. We propose to combine archival data with new
ACS/WFC and WFPC2 observations of 11 galaxies, to tackle a
comprehensive investigation of nearby spirals covering the entire
spiral sequence. The new observations will fill a serious deficiency
in HST's legacy, and maximize the scientific return of existing HST
data. The filter combination of UBVI, and Halpha is ideal for studying
stellar populations, dust properties, and the ISM. Our immediate
scientific objectives a {i} to use the resolved cluster
populations, both young massive clusters and ancient globular clusters
as a chronometer, to understand how spirals assembled as a function of
time; {ii} study the rapid disruption properties of young clusters;
and {iii} understand dust distributions in spirals from pc to kpc
scales. Each of these goals provides an important step towards
charting the evolution of galaxies, and an essential baseline for
interpreting the galaxy populations being surveyed in both the early
and present universe. The resolution of our survey, which exploits the
excellent imaging capabilities of HST's two optical cameras, will
enable us to understand the record of star cluster, and galaxy
formation in a level of detail which is not possible for more distant
systems. Finally, the proposed observations will provide a key to
interpret an extensive, multiwavelength archive of space- and ground-
based data at lower spatial resolution {SPITZER, CHANDRA, GALEX,
NICMOS P alpha and H band imaging} for local spirals.

ACS/HRC/WFC 10399

Accurate and Robust Calibration of the Extragalactic Distance Scale
with the Maser Galaxy NGC4258 II

The extragalactic distance scale {EDS} is defined by a comparison of
Cepheid Period-Luminosity {PL} relations for nearby galaxies and the
LMC, whose uncertain distance is thereby the SOLE anchor. Studies of
masers orbiting the central black hole in NGC4258 have provided the
most accurate extragalactic distance ever {7.2+/-0.5 Mpc}, and new
radio data and analysis techniques will reduce the uncertainty to
3.5% {0.07 mag} by 2005. Since this distance is well determined and
based on geometric arguments, NGC4258 can provide a much needed new
anchor for the EDS. Ultimately, the combination of an independent
measurement of H0 and measurements of CMB fluctuations {e.g., WMAP}
can be used to directly constrain cosmological parameters including
the equation of state of dark energy. In our Cycle 12 proposal, we
defined a program spanning two cycles. The Cycle 12 portion was
accepted. We have acquired WFC images and are constructing well
sampled PL relations in 3 colors {BVI}. The purpose of the Cycle 13
observations is to address systematic sources of error and is crucial
for the success of the entire program. To disentangle the effects of
reddening and metallicity, and to characterize the effects of
blending, we require 50 orbits to obtain H-band photometry
{NICMOS/NIC2} and high resolution images {ACS/HRC}.

ACS/HRC/WFC 10389

ACS CCDs daily monitor - Cycle 13 - Part 2

This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise
in ACS CCD detectors. The files, biases and dark will be used to
create reference files for science calibration. This program will be
for the entire lifetime of ACS.

NIC1/NIC2/NIC3 10380

Cycle 13 NICMOS dark current, shading profile, and read noise
monitoring program

The purpose of this proposal is to monitor the dark current, read
noise, and shading profile for all three NICMOS detectors throughout
the duration of Cycle 13. This proposal is an essentially unchanged
continuation of PID 9993 which cover the duration of Cycle 12.

ACS/WFC 10325

Low Redshift Cluster Gravitational Lensing Survey

This proposal has two main scientific goals: to determine the dark
matter distribution of massive galaxy clusters, and to observe the
high redshift universe using these clusters as powerful cosmic
telescopes. Deep, g, r, i, z imaging of a sample of low-z {0.2-0.4}
clusters will yield a large sample of lensed background galaxies with
reliable photometric redshifts. By combining strong and weak lensing
constraints with the photometric redshift information it will be
possible to precisely measure the cluster dark matter distribution
with an unprecedented combination of high spatial resolution and area
coverage, avoiding many of the uncertainties which plague ground-based
studies and yielding definitive answers about the structure of massive
dark matter haloes. In addition, the cosmological parameters can be
constrained in a largely model independent way using the multiply
lensed objects due to the dependence of the Einsteinng ring radius on
the distance to the source. We can also expect to detect several
highly magnified dropout galaxies behind the clusters in the redshift
ranges 4-5 5-6 and 7-8, corresponding to a drop in the flux in the g,
r, and i bands relative to longer wavelength. We will obtain the best
information to date on the giant arcs already known in these clusters,
making possible detailed, pixel-by-pixel studies of their star
formation rate, dust distribution and structural components, including
spiral arms, out to a redshift of around z~2.5 in several passbands.

ACS/HRC 10198

Probing the Dynamics of the Galactic Bar through the Kinematics of
Microlensed

The observed optical depths to microlensing of stars in the Galactic
bulge are difficult to reconcile with our present understanding of
Galactic dynamics. The main source of uncertainty in those comparisons
is now shifting from microlensing measurements to the dynamical models
of the Galactic bar. We propose to constrain the Galactic bar models
with proper motion observations of Bulge stars that underwent
microlensing by determining both the kinematic identity of the
microlensed sources and the importance of streaming motions. The
lensed stars are typically farther than randomly selected stars.
Therefore, our proper motion determinations for 36 targeted MACHO
events will provide valuable constraints on the dynamics of bulge
stars as a function of distance. The first epoch data for our proposed
events is already available in the HST archive so the project can be
completed within a single HST cycle. The exceptional spatial
resolution of HST is essential for completion of the project.
Constraints on the total mass in the bulge will ultimately lead to the
determination of the amount of dark matter in inner Galaxy.

FGS 10197

The Astrophysical Parameters of Very Metal-Poor Halo Binaries

Little is currently known concerning the mass-luminosity relation
{MLR} of Population II stars. In Cycle 10, we began an initial study
with FGS1 to resolve a sample of known spectroscopic binaries
preselected as high-velocity and/or low metallicity objects. This has
resulted in significant new information about the astrophysical
parameters of metal-poor stars, but was limited mainly to intermediate
metallicities, not to true Population II stars. A new sample of
metal-poor spectroscopic binaries identified by Latham and his
collaborators {e.g. Latham et al 2002} contains three new very
metal-poor objects resolvable with FGS. We propose to observe these
binaries and obtain additional observations of two very important
resolved targets from our initial sample. As with that program, we
will couple the already-known spectroscopic orbits with astrometric
information which only FGS can deliver at present. To ensure that the
most will be gained from these data, we also request observations of
three metal-poor single stars to be used as calibration objects. In
combination with results from our previous program, these observations
can be expected to resolve the question of the location of the
Population II main sequence and give valuable insight into the
accuracy of isochrone fitting for determination of globular clusters
ages. Due to the combination of target magnitudes and expected
separations, no object in this sample can be resolved without the
unique capabilities of FGS.

ACS/HRC 10182

Towards a Comprehensive Understanding of Type Ia Supernovae: The
Necessity of UV Observations

Type Ia supernovae {SNe Ia} are very important to many diverse areas
of astrophysics, from the chemical evolution of galaxies to
observational cosmology which led to the discovery of dark energy and
the accelerating Universe. However, the utility of SNe Ia as
cosmological probes depends on the degree of our understanding of SN
Ia physics, and various systematic effects such as cosmic chemical
evolution. At present, the progenitors of SNe Ia and the exact
explosion mechanisms are still poorly understood, as are evolutionary
effects on SN Ia peak luminosities. Since early-time UV spectra and
light curves of nearby SNe Ia can directly address these questions, we
propose an approach consisting of two observational components: {1}
Detailed studies of two very bright, young, nearby SNe Ia with HST UV
spectroscopy at 13 epochs within the first 1.5 months after discovery;
and {2} studies of correlations with luminosity for five somewhat more
distant Hubble-flow SNe Ia, for which relative luminosities can be
determined with precision, using 8 epochs of HST UV spectroscopy
and/or broad-band imaging. The HST data, along with extensive
ground-based optical to near-IR observations, will be analyzed with
state-of-the-art models to probe SN Ia explosion physics and constrain
the nature of the progenitors. The results will form the basis for the
next phase of precision cosmology measurements using SNe Ia, allowing
us to more fully capitalize on the substantial past {and future}
investments of time made with HST in observations of high-redshift SNe
Ia.

WFPC2 10170

Atmospheric Variability on Uranus and Neptune

We propose Snapshot observations of Uranus and Neptune to monitor
changes in their atmospheres on time scales of weeks, months, and
years. Uranus is rapidly approaching equinox in 2007, with another 4
degrees of latitude becoming visible every year. Recent HST
observations during this epoch {including 6818: Hammel, Lockwood, and
Rages; 7885: Hammel, Karkoschka, and Marley; 8680: Hammel, Rages,
Lockwood, and Marley; and 8634: Rages, Hammel, Lockwood, Marley, and
McKay} have revealed strongly wavelength-dependent latitudinal
structure and the presence of numerous visible-wavelength cloud
features in the northern hemisphere. Long-term ground-based
observations {Lockwood and Thompson 1999} show seasonal brightness
changes whose origins are not well understood. Recent near-IR images
of Neptune obtained using adaptive optics on the Keck Telescope
together with images from our Cycle 9 Snapshot program {8634} show a
general increase in activity at south temperate latitudes as well as
the possible development of another Great Dark Spot. Further Snapshot
observations of these two dynamic planets will elucidate the nature of
long-term changes in their zonal atmospheric bands and clarify the
processes of formation, evolution, and dissipation of discrete albedo
features.

ACS/WFC 10135

Unveiling the Progenitors and Physics of Cosmic Explosions

GRBs and XRFs are clearly highly asymmetric explosions and require a
long-lived power source {central engine}. In contrast, nearby
core-collapse events are essentially spherical explosions. However,
the failure of spherical neutrino driven collapses has led to the idea
that asymmetric energy release is essential for the explosion. The
recent finding of a Type Ic SN in GRB 030329, the association of the
low energy event GRB 980425 with SN 1998bw, the theoretical
development discussed above and the rise of collapsar models make it
timely to consider whether all these explosions contain engines. Given
the uncertainties in theoretical modeling it is clear that
observations are needed to guide models. A priori there is little
reason to expect connection between the ultra-relativistic jet that
powers the GRB and the explosive nucleosynthesis of the ~0.5 solar
masses of Nickel-56 that powers the accompanying supernova. We propose
a comprehensive program of ACS photometric searches {and measurements}
for SNe associated with GRBs and XRFs. In concert, we will undertake
ground-based spectroscopy to determine velocity widths, and measure
engine parameters from pan-chromatic afterglow observations. Our goal
is to produce a comprehensive database of engine and SN physical
parameters against which theoretical modeling will be guided.

ACS/WFC 10119

Solving the Mystery of the Short-Hard Gamma-Ray Bursts

Seven years after the afterglow detections that revolutionized studies
of the long- soft gamma-ray bursts, not even one afterglow of a
short-hard GRB has been seen, and the nature of these events has
become one of the most important problems in GRB research. The
forthcoming Swift satellite will report few-arcsecond localizations
for short-hard bursts in minutes, however, enabling prompt, deep
optical afterglow searches for the first time. Discovery and
observation of the first short-hard optical afterglows will answer
most of the critical questions about these events: What are their
distances and energies? Do they occur in distant galaxies, and if so,
in which regions of those galaxies? Are they the result of collimated
or quasi-spherical explosions? In combination with an extensive
rapid-response ground-based campaign, we propose to make the critical
high-sensitivity HST TOO observations that will allow us to answer
these questions. If theorists are correct in attributing the
short-hard bursts to binary neutron star coalescence events, then the
short-hard bursts are signposts to the primary targeted source
population for ground- based gravitational-wave detectors, and
short-hard burst studies will have a vital role to play in guiding
their observations.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

9842 - GSACQ(1,3,1) Failed to RGA Control, Search Radius Limit
Exceeded on FGS 1 & 3 @ 161/1713z

COMPLETED OPS REQUEST:
17447-0 - Real Time Map @ 161/1834z

COMPLETED OPS NOTES:
1342-0 - Adjust ACS Error Count (closed) @ 163/2312z
1352-0 - 486/NSSC-1 FSW CFG (MODE SWITCH) @ 163/2321z

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS Gsacq 22 21 161/1713z
FGS Reacq 21 19 161/1848z
and 161/2024z
FHST Update 43 43
LOSS of LOCK

SIGNIFICANT EVENTS:

ACS successfully transitioned to Operate mode and activated its new
FSW (CS 4.01) Sunday evening (163/23:30). ACS first images using the
new FSW are scheduled for 164/02:18.