Daily Report #4161

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4161

PERIOD COVERED: UT July 21,22,23, 2006 (DOY 202,203,204)

OBSERVATIONS SCHEDULED

NIC1/NIC2/NIC3 8794

NICMOS Post-SAA calibration - CR Persistence Part 5

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.

ACS/WFC 10775

An ACS Survey of Galactic Globular Clusters

We propose to conduct an ACS/WFC imaging survey of Galactic globular
clusters. We will construct the most extensive and deepest set of
photometry and astrometry to-date for these systems reaching a main
sequence mass of ~0.2 solar mass with S/N = 10. We will combine these
data with archival WFPC2 and STIS images to determine proper motions
for the stars in our fields. The resultant cleaned cluster CMDs will
allow us to study a variety of scientific questions. These include
[but are not limited to] 1} the determination of cluster ages and
distances 2} the construction of main sequence mass functions and the
issue of mass segregation 3} the internal motions and dynamical
evolution of globular clusters, and 4} absolute cluster motions,
orbits, and the Milky Way gravitational potential. We anticipate that
the unique resource provided by the proposed treasury archive will
play a central role in the field of globular cluster studies for
decades, with a stature comparable to that of the Hubble Deep Field
for high redshift studies.

ACS/HRC/WFC 10758

ACS CCDs daily monitor

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 programme will be
for the entire lifetime of ACS. Changes from cycle 13:- The default
gain for WFC is 2 e- /DN. As before bias frames will be collected for
both gain 1 and gain 2. Dark frames are acquired using the default
gain {2}. This program cover the period May, 31 2006- Oct, 1- 2006.
The first half of the program has a different proposal number: 10729.

WFPC2 10746

WFPC2 Cycle 14 CTE Monitor

Monitor CTE changes during Cycle 14. Test for chip-to-chip differences
in CTE

CAL/ACS 10735

SBC MAMA Recovery

This proposal is designed for the initial turn-on of the ACS MAMA
detector and to permit recovery after an anomalous shutdown. Anomalous
shutdowns can occur as a result of bright object violations which
trigger the Bright Scene Detection or Software Global Monitors.
Anomalous shutdowns can also occur as a result of MAMA hardware
problems. The Initial MAMA turn-on/recovery from anomalous shutdown
consists of three tests: a signal processing electronics check, high
voltage ramp-up to an intermediate voltage, and high voltage ramp-up
to the full operating voltage. During each of the two high voltage
ramp-ups, diagnostics are performed during a dark ACCUM. The turn-on
is followed by a MAMA Fold Analysis.

NIC3 10616

Gotcha! Using Swift GRBs to Pinpoint the Highest Redshift Galaxies

While there is convincing evidence that the Universe was re-ionized
between redshifts of 6.5 and 15, the role of galaxies in this process
is still not understood. Several star-forming galaxies at z~6 have
been identified in recent deep, narrow-field surveys, but the
expensive observations along with cosmic variance and contamination
make it difficult to assess their contribution to re-ionization.
Moreover, the detection of galaxies at z7 is exceedingly difficult
even with the Hubble UDF or cluster lensing. Significant progress can
be made using gamma-ray bursts {GRBs} localized with the
now-operational Swift satellite, which is capable of detecting bursts
out to z10. GRBs have the advantage of being an uncontaminated
signpost for star-formation, and their afterglows are sufficiently
bright even at z6 to allow photometric selection {via the Ly-alpha
drop out technique} with 2-5 meter telescopes. Using our approved TOO
programs at an extensive range of facilities {from 1-m robotic
telescopes to Keck/Magellan}, we can rapidly find afterglows at z6
and easily distinguish them from dusty low redshift bursts. This
approach is highly efficient compared to current techniques,
especially at z7. Here we request imaging with NICMOS {z6}, ACS
{z~6}, and Spitzer/IRAC to characterize the properties {SFR, age,
morphology} of up to five galaxies located in this manner, and begin
to address their role in re-ionization. These observations are
requested as 2 month TOOs, allowing flexibility of scheduling and at
the same time taking a unique and timely advantage of the exquisite
performance of three of NASA's premier missions.

WFPC2 10608

Probing the star formation law in the extreme outer limits of M83, a
prototypical XUV-disk galaxy

The Galaxy Evolution Explorer {GALEX} has discovered a new sub-class
of spiral galaxy, which we refer to as extended UV-disk {XUV-disk}
galaxies. They are distinguished by conspicuous UV-bright star
clusters located at galactocentric radii extending to many times the
optical {R25} extent, and appear to represent a population of spiral
galaxies still actively building, or augmenting, their stellar disk.
However, XUV-disks pose a mystery in the form of a relative lack of
HII regions {traced by H-alpha emission} associated with outer disk,
UV-bright stellar clusters. M83 is an XUV-disk prototype and the focus
of this proposal. It has an H-alpha surface brightness profile
characterized by a steep decline at the radius beyond which the
gaseous disk is thought to become dynamically stable {against collapse
and ensuing star formation}, but GALEX UV profiles show no "edge" at
this location. Our HST study of M83 aims to resolve this puzzling
discrepancy, confirmed in several XUV-disks, by searching for
Lyman-continuum producing O stars that are either absent or present
without nebulosity. HST provides the only means of resolving
individual massive stars in the FUV band at M83's distance. Without
HST, we lose the critical ability to photometrically classify O and B
stars. Our multiwavelength observations will also constrain the
history of star formation in the outer disk over Gyr timescales by
characterizing the evolved stellar population, both using resolved
giants and color analysis of the diffuse background.

ACS/WFC 10597

Resolving the Connection Between Globular Clusters and Low-Mass X-ray
Binaries

Because of their high central densities, globular clusters {GCs} are
efficient producers of low-mass X-ray binaries {LMXBs}. To shed light
on the detailed formation mechanism of LXMBs in GCs, we propose to
measure accurate structural parameters for hundreds of GCs in NGC
5128: the only giant elliptical galaxy within 5 Mpc of the Milky Way.
We will carry out the first complete survey of GCs in the inner region
of NGC 5128, measure GC structural parameters of unprecedented
acccuracy, and derive GC luminosity profiles in the cluster cores.
These measurement will allow us to determine precisely which GC
structural properties control the presence of an X-ray source and thus
probe the details of the LXMB formation process in GCs. We will
additionally use the measured structural parameters to perform the
most comprehensive study of the fundamental plane of GCs in early-type
galaxies, a fundamental set of correlations which holds key
information on GC formation and evolution.

ACS/WFC 10592

An ACS Survey of a Complete Sample of Luminous Infrared Galaxies in the
Local Universe

At luminosities above 10^11.4 L_sun, the space density of far-infrared
selected galaxies exceeds that of optically selected galaxies. These
`luminous infrared galaxies' {LIRGs} are primarily interacting or
merging disk galaxies undergoing enhanced star formation and Active
Galactic Nuclei {AGN} activity, possibly triggered as the objects
transform into massive S0 and elliptical merger remnants. We propose
ACS/WFC imaging of a complete sample of 88 L_IR 10^11.4 L_sun
luminous infrared galaxies in the IRAS Revised Bright Galaxy Sample
{RBGS: i.e., 60 micron flux density 5.24 Jy}. This sample is ideal
not only in its completeness and sample size, but also in the
proximity and brightness of the galaxies. The superb sensitivity,
resolution, and field of view of ACS/WFC on HST enables a unique
opportunity to study the detailed structure of galaxies that sample
all stages of the merger process. Imaging will be done with the F439W
and F814W filters {B and I-band} to examine as a function of both
luminosity and merger state {i} the evidence at optical wavelengths of
star formation and AGN activity and the manner in which instabilities
{bars and bridges} in the galaxies may funnel material to these active
regions, {ii} the relationship between star formation and AGN
activity, and {iii} the structural properties {AGN, bulge, and disk
components} and fundamental parameters {effective radius and surface
brightness} of LIRGs and their similarity with putative evolutionary
byproducts {elliptical, S0 and classical AGN host galaxies}. This HST
survey will also bridge the wavelength gap between a Spitzer imaging
survey {covering seven bands in the 3.6-160 micron range} and a GALEX
UV imaging survey of these galaxies, but will resolve complexes of
star clusters and multiple nuclei at resolutions well beyond the
capabilities of either Spitzer or GALEX. The combined datasets will
result in the most comprehensive multiwavelength study of interacting
and merging galaxies to date.

ACS/WFC 10588

The Host Galaxies of Post-Starburst Quasars

We propose to use ACS to conduct a snapshot imaging survey of
post-starburst quasars now being discovered in signficant numbers by
the Sloan Digital Sky Survey. Post- starburst quasars are broad-lined
AGN that also possess Balmer jumps and high-n Balmer absorption lines
indicative of luminous stellar populations on order of 100 Myr old.
These objects, representing a few percent of the z 0.5 quasar
population, may be an evolutionary stage in the transition of
ultraluminous infrared galaxies into normal quasars, or a type of
galaxy interaction that triggers both star formation and nuclear
activity. These sources may also illustrate how black hole mass/bulge
mass correlations arise. Ground- based imaging of individual
poststarburst quasars has revealed merger remnants, binary systems,
and single point sources. Our ACS snapshots will enable us to
determine morphologies and binary structure on sub-arcsecond scales
{surely present in the sample}, as well as basic host galaxy
properties. We will be looking for relationships among morphology,
particularly separation of double nuclei, the starburst age, the
quasar black hole mass and accretion rate, that will lead to an
understanding of the triggering activity and mutual evolution. This
project will bring quantitative data and statistics to the previously
fuzzy and anecdotal topic of the "AGN-starburst connection" and help
test the idea that post-starburst quasars are an early evolutionary
stage of normal quasars.

ACS/HRC 10556

Neutral Gas at Redshift z=0.5

Damped Lyman-alpha systems {DLAs} are used to track the bulk of the
neutral hydrogen gas in the Universe. Prior to HST UV spectroscopy,
they could only be studied from the ground at redshifts z1.65.
However, HST has now permitted us to discover 41 DLAs at z1.65 in our
previous surveys. Followup studies of these systems are providing a
wealth of information about the evolution of the neutral gas phase
component of the Universe. But one problem is that these 41
low-redshift systems are spread over a wide range of redshifts
spanning nearly 70% of the age of the Universe. Consequently, past
surveys for low-redshift DLAs have not been able to offer very good
precision in any small redshift regime. Here we propose an
ACS-HRC-PR200L spectroscopic survey in the redshift interval z=[0.37,
0.7] which we estimate will permit us to discover another 41 DLAs.
This will not only allow us to double the number of low-redshift DLAs,
but it will also provide a relatively high-precision regime in the
low-redshift Universe that can be used to anchor evolutionary studies.
Fortunately DLAs have high absorption equivalent width, so ACS-
HRC-PR200L has high-enough resoultion to perform this proposed
MgII-selected DLA survey.

ACS/WFC/HRC 10536

What Are Stalled Preplanetary Nebulae? An ACS SNAPshot Survey

Essentially all planetary nebulae {PNs} are aspherical, whereas the
mass-loss envelopes of AGB stars are strikingly spherical. Our
previous SNAPshot surveys of a morphologically unbiased sample of
pre-planetary nebulae {PPNs} -- objects in transition between the AGB
and PN evolutionary phases -- show that roughly half our observed
targets are resolved, with bipolar or multipolar morphologies.
Spectroscopic observations of our sample confirm that these objects
have not yet evolved into planetary nebulae. Thus, the transformation
from spherical to aspherical geometries has already fully developed by
the time these dying stars have become PPNs. Although our current
studies have yielded exciting results, they are limited in two
important ways -- {1} the number of well-resolved objects is still
small {18}, and the variety of morphologies observed relatively
multitudinous, hence no clear trends can yet be established between
morphology and other source properties {e.g., near-IR, far-IR colors,
stellar spectral type, envelope mass}, and {2} the current samples are
strongly biased towards small PPNs, as inferred from their low 60-to-
25 micron flux ratios [R{60/25}1]. However, the prototype of objects
with R{60/25}1, the Frosty Leo Nebula, has a puzzlingly large
post-AGB age {almost 10^4 yr} and a fairly cool central star, very
different from the expectations of single-star stellar evolutionary
models. A proposed, but still speculative, hypothesis for such objects
is that the slow evolution of the central star is due to backflow of
material onto the mass-losing star, retarding its evolution towards
the PN phase. This hypothesis has significant consequences for both
stellar and nebular evolution. We therefore propose a survey of PPNs
with R{60/25}1 which is heavily weighted towards the discovery of
such "stalled PPNs". Supporting kinematic observations using long-slit
optical spectroscopy {with the Keck}, millimeter and radio
interferometric observations {with OVRO, VLA & VLBA} are being
undertaken. The results from this survey {together with our previous
work} will allow us to draw general conclusions about the complex
mass-outflow processes affecting late stellar evolution, and will
provide crucial input for theories of post-AGB stellar evolution. Our
survey will produce an archival legacy of long-standing value for
future studies of dying stars.

WFPC2 10534

Active Atmospheres 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; 8680: Hammel, Rages, Lockwood, and Marley; 8634: Rages, Hammel,
Lockwood, Marley, and McKay; and 10170: Rages, Hammel, Lockwood, and
Marley} 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 Telesccope
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.

NIC2 10527

Imaging Scattered Light from Debris Disks Discovered by the Spitzer
Space Telescope Around 20 Sun-like Stars

We propose to use the high contrast capability of the NICMOS
coronagraph to image a sample of newly discovered circumstellar disks
associated with sun-like stars. These systems were identified by their
strong thermal infrared emission with the Spitzer Space Telescope as
part of the Spitzer Legacy Science program titled, "The Formation and
Evolution of Planetary Systems {FEPS}." Modelling of the thermal
excess emission in the form of spectral energy distributions alone
cannot distinguish between narrowly confined high opacity disks and
broadly distributed, low opacity disks. However, our proposed NICMOS
observations can, by imaging the light scattered from this material.
Even non- detections will place severe constraints on the disk
geometry, ruling out models with high optical depth. Unlike previous
disk imaging programs, our program contains a well defined sample of
solar mass stars covering a range of ages from ~10Myrs to a few Gyrs,
allowing us to study the evolution of disks from primordial to debris
for the first time. These results will greatly improve our
understanding of debris disks around Sun-like stars at stellar ages
nearly 10x older than any previous investigation. Thus we will have
fit a crucial piece into the puzzle concerning the formation and
evolution of our own solar system.

ACS/HRC/WFC 10514

Kuiper Belt Binaries: Probes of Early Solar System Evolution

Binaries in the Kuiper Belt are a scientific windfall: in them we have
relatively fragile test particles which can be used as tracers of the
early dynamical evolution of the outer Solar System. We propose a
Snapshot program using the ACS/HRC that has a potential discovery
efficiency an order of magnitude higher than the HST observations that
have already discovered the majority of known transneptunian binaries.
By more than doubling the number of observed objects in dynamically
hot and cold subpopulations we will be able to answer, with
statistical significance, the question of whether these groups differ
in the abundance of binaries as a result of their particular dynamical
paths into the Kuiper Belt. Today's Kuiper Belt bears the imprints of
the final stages of giant-planet building and migration; binaries may
offer some of the best preserved evidence of that long-ago era.

ACS/HRC 10512

Search for Binaries Among Faint Jupiter Trojan Asteroids

We propose an ambitious SNAPSHOT program to survey faint Jupiter
Trojan asteroids for binary companions. We target 150 objects, with
the expectation of acquiring data on about 50%. These objects span
Vmag = 17.5-19.5, a range inaccessible with ground-based adaptive
optics. We now have a significant sample from our survey of brighter
Trojans to suggest that the binary fraction is similar to that which
we find among brighter main-belt asteroids, roughly 2%. However, our
observations suggest a higher binary fraction for smaller main-belt
asteroids, probably the result of a different formation mechanism
{evident also from the physical characteristics of the binaries}.
Because the collision environment among the Trojans is similar to that
of the Main Belt, while the composition is likely to be very
different, sampling the binary fraction among the fainter Trojans
should help us understand the collisional and binary formation
mechanisms at work in various populations, including the Kuiper Belt,
and help us evaluate theories for the origin of the Trojans.
Calibration of and constraints on models of binary production and
collisional evolution can only be done using these large-scale,
real-life physical systems that we are beginning now to find and
utilize.

NIC3/ACS/WFC 10504

Characterizing the Sources Responsible for Cosmic Reionization

Our group has demonstrated the role that massive clusters, acting as
powerful cosmic lenses, can play in constraining the abundance and
properties of low-luminosity star- forming sources beyond z~6; such
sources are thought to be responsible for ending cosmic reionization.
The large magnification possible in the critical regions of well-
constrained clusters brings sources into view that lie at or beyond
the limits of conventional exposures such as the UDF, as well as those
in imaging surveys being undertaken with IRAC onboard Spitzer. We have
shown that the combination of HST and Spitzer is particularly
effective in delivering the physical properties of these distant
sources, constraining their mass, age and past star formation history.
Indirectly, we therefore gain a valuable glimpse to yet earlier
epochs. Recognizing the result {and limitations} of the UDF exposure,
we propose a systematic search through 6 lensing clusters with ACS and
NICMOS for further z~6-7 sources in conjunction with existing deep
IRAC data. Our survey will mitigate cosmic variance and extend the
search both to lower luminosities and, by virtue of the NICMOS/IRAC
combination, to higher redshift. The goal is to count and characterize
representative sources at z~6-10 and to delineate the redshift range
of activity for the planning of future observations.

ACS/WFC/NIC2 10496

Decelerating and Dustfree: Efficient Dark Energy Studies with
Supernovae and Clusters

We propose a novel HST approach to obtain a dramatically more useful
"dust free" Type Ia supernovae {SNe Ia} dataset than available with
the previous GOODS searches. Moreover, this approach provides a
strikingly more efficient search-and-follow-up that is primarily
pre-scheduled. The resulting dark energy measurements do not share the
major systematic uncertainty at these redshifts, that of the
extinction correction with a prior. By targeting massive galaxy
clusters at z 1 we obtain a five-times higher efficiency in
detection of Type Ia supernovae in ellipticals, providing a
well-understood host galaxy environment. These same deep cluster
images then also yield fundamental calibrations required for future
weak lensing and Sunyaev-Zel'dovich measurements of dark energy, as
well as an entire program of cluster studies. The data will make
possible a factor of two improvement on supernova constraints on dark
energy time variation, and much larger improvement in systematic
uncertainty. They will provide both a cluster dataset and a SN Ia
dataset that will be a longstanding scientific resource.


FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

#10368 REacq(2,3,3) failed to RGA control. @ 203/20:13:36z

The REacq(2,3,3) scheduled at 203/20:10:18 failed due to scan step
limit exceeded on FGS 2. The OBAD2 at 20:05:14 showed errors of V1=
8.38, V2= -4.70, V3= -1.22, and RSS= 9.68. The Map at 20:28:52 showed
errors of V1=5.75,V2=0.16,V3=1.95, and RSS=6.07. Observation affected:
ACS 3

#10370 REacq(2,3,2) resulted in fine lock backup (2,0,2) @ 204/15:23:04z

REacq(2,3,2) scheduled at 204/15:19:40 resulted in fine lock backup
(2,0,2) due to receiving stop flag QF2STOPF on FGS 3 at 15:23:04.
OBAD2 showed errors of V1=15.52, V2=7.93, V3=10.74,and RSS=20.49. The
map at 15:27:06 showed errors of V1=1.27, V2=-9.92, V3=-2.77, and
RSS=10.38. Observations affected: ACS 32-34

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES:
#1510-0 Adjust ACS Error Count @ 204/00:38z

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 24 24
FGS REacq 19 18 203/20:10:18z (HSTAR #10368)
OBAD with Maneuver 80 80

SIGNIFICANT EVENTS: (None)