Daily # 4191

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4191

PERIOD COVERED: UT September 01,02,03,04, 2006 (DOY 244,245,246,247)

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.

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration - CR Persistence Part 4

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.

FGS 10989

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/HRC 10870

The Ring Plane Crossings of Uranus in 2007

The rings of Uranus turn edge-on to Earth in May and August 2007. In
between, we will have a rare opportunity to see the unlit face of the
rings. With the nine optically thick rings essentialy invisible, we
will observe features and phenomena that are normally lost in their
glare. We will use this opportunity to search thoroughly for the
embedded "shepherd" moons long believed to confine the edges of the
rings, setting a mass limit roughly 10 times smaller than that of the
smallest shepherd currently known, Cordelia. We will measure the
vertical thicknesses of the rings and study the faint dust belts only
known to exist from a single Voyager image. We will also study the
colors of the newly-discovered faint, outer rings; recent evidence
suggests that one ring is red and the other blue, implying that each
ring is dominated by a different set of physical processes. We will
employ near-edge-on photometry from 2006 and 2007 to derive the
particle filling factor within the rings, to observe how ring epsilon
responds to the "traffic jam" as particles pass through its narrowest
point, and to test the latest models for preserving eccentricities and
apse alignment within the rings. Moreover, this data set will allow us
to continue monitoring the motions of the inner moons, which have been
found to show possibly chaotic orbital variations; by nearly doubling
the time span of the existing ACS astrometry, the details of the
variations will become much clearer.

NIC2 10847

Coronagraphic Polarimetry of HST-Resolved Debris Disks

We propose to take full advantage of the recently commissioned
coronagraphic polarimetry modes of ACS and NICMOS to obtain imaging
polarimetry of circumstellar debris disks that were imaged previously
by the HST coronagraphs, but without the polarizers. It is well
established that stars form in gas-rich protostellar disks, and that
the planets of our solar system formed from a circum-solar disk.
However, the connection between the circumstellar disks that we
observe around other stars and the processes of planet formation is
still very uncertain. Mid-IR spectral studies have suggested that disk
grains are growing in the environments of young stellar objects during
the putative planet-formation epoch. Furthermore, structures revealed
in well resolved images of circumstellar disks suggest gravitational
influences on the disks from co-orbital bodies of planetary mass.
Unfortunately, existing imaging data provides only rudimentary
information abou the disk grains and their environments. Our proposed
observations, which can be obtained only with HST, will enable us to
quantitatively determine the sizes of the grains and optical depths as
functions of their location within the disks {i.e., detailed
tomography}. Armed with these well-determine physical and geometrical
systemic parameters, we will develop a set of self-consistent models
of disk structures to investigate possible interactions between unseen
planets and the disks from which they formed. Our results will also
calibrate models of the thermal emission from these disks, that will
in turn enable us to infer the properties of other debris disks that
cannot be spatially resolved with current or planned instruments and
telescopes.

ACS/WFC 10846

The Halo Structure of RCS2-2327.4-0204

We propose ACS, NICMOS, and Chandra observations of the central region
of the extraordinary and newly discovered galaxy cluster:
RCS2-2327.4-0204 at z=0.700. This cluster shows 3 or more arcs in
ground-based imaging, with an Einstein radius of 49". Such a large
Einstein radius {3-4 times larger than seen in most clusters} has been
seen in precisely one other cluster in the universe - namely Abell
1689 at z=0.18. From our proposed data we expect to see ~70 lensed
source images, from ~20 image families. We will use both strong and
weak lensing constraints from these data to construct the central mass
profile of the cluster, which, when combined with ground based data
extending to a half degree FOV, will allow us to measure critically
important dark matter halo parameters {such as concentration}. The
target cluster is selected from a large ongoing survey with a
well-defined search volume, which allows us to compare our results to
expectations from simulations. We will also compare the lensing
derived mass profiles to the x- ray equivalent measures; this will
illuminate whether the dominant baryonic component is in equilibrium
with the potential. The area of high magnification behind this cluster
is an order of magnitude larger than typical lensing clusters observed
previously by HST; this order of magnitude increase in area directly
translates into a 10 times better chance for finding very high
redshift galaxies. Many of the highest redshift galaxies found to date
have been found behind massive lensing clusters observed by HST, and
we expect to add to that sample dramatically.

ACS/WFC 10824

Measuring the Shape and Orientation of the Galactic Dark-Matter Halo
using Hypervelocity Stars

We propose to obtain high-resolution images of five hypervelocity
stars in the Galactic halo in order to establish the first-epoch
astrometric frame for them, as a part of a long-term program to
measure precise proper motions. The origin of these recently
discovered stars, all with positive radial velocities above 540 km/s,
is consistent only with being ejected from the deep potential well of
the massive black hole at the Galactic center. The deviations of their
space motions from purely radial trajectories probe the departures
from spherical symmetry of the Galactic potential, mainly due to the
triaxiality of the dark-matter halo. Reconstructing the full
three-dimensional space motion of the hypervelocity stars, through
astrometric proper motions, provides a unique opportunity to measure
the shape and orientation of the dark halo. The hypervelocity stars
allow measurement of the potential up to 75 kpc from the center,
independently of and at larger distances than are afforded by tidal
streams of satellite galaxies such as the Sagittarius dSph galaxy.
HVS3 may be associated with the LMC, rather then the Galactic center,
and would therefore present a case for a supermassive black hole at
the center of the LMC. We request one orbit with ACS/WFC for each of
the five hypervelocity stars to establish their current positions
relative to background galaxies. We will request a repeated
observation of these stars in Cycle 17, which will conclusively
measure the astrometric proper motions.

NIC2, ACS/WFC 10802

SHOES-Supernovae, HO, for the Equation of State of Dark energy

The present uncertainty in the value of the Hubble constant {resulting
in an uncertainty in Omega_M} and the paucity of Type Ia supernovae at
redshifts exceeding 1 are now the leading obstacles to determining the
nature of dark energy. We propose a single, integrated set of
observations for Cycle 15 that will provide a 40% improvement in
constraints on dark energy. This program will observe known Cepheids
in six reliable hosts of Type Ia supernovae with NICMOS, reducing the
uncertainty in H_0 by a factor of two because of the smaller
dispersion along the instability strip, the diminished extinction, and
the weaker metallicity dependence in the infrared. In parallel with
ACS, at the same time the NICMOS observations are underway, we will
discover and follow a sample of Type Ia supernovae at z 1. Together,
these measurements, along with prior constraints from WMAP, will
provide a great improvement in HST's ability to distinguish between a
static, cosmological constant and dynamical dark energy. The Hubble
Space Telescope is the only instrument in the world that can make
these IR measurements of Cepheids beyond the Local Group, and it is
the only telescope in the world that can be used to find and follow
supernovae at z 1. Our program exploits both of these unique
capabilities of HST to learn more about one of the greatest mysteries
in science.

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 10748

WFPC2 CYCLE 14 Standard Darks

This dark calibration program obtains dark frames every week in order
to provide data for the ongoing calibration of the CCD dark current
rate, and to monitor and characterize the evolution of hot pixels.
Over an extended period these data will also provide a monitor of
radiation damage to the CCDs.

ACS/SBC 10743

Improved Wavelength Calibration of the SBC Prisms

Two QSOs at redshifts z=0.234 and z=0.313 will be observed in order to
provide additional sampling points for the SBC prism wavelength
calibration, using Ly alpha redshifted to 1500 AA and 1600 AA.
Combined with the existing {Cycle 13} data, the wavelength scale will
be sampled at 100 AA intervals between 1300 AA and 1700 AA.

ACS/HRC 10741

Continuum L-Flats for Ramp Filters

This program will obtain data to be used for creation of continuum
L-flats for ACS ramp filters.

ACS/WFC 10730

External CTE Monitor

Monitor CTE in Cycle 14 for WFC and HRC

ACS/WFC/NIC3 10632

Searching for galaxies at z6.5 in the Hubble Ultra Deep Field

We propose to obtain deep ACS {F606W, F775W, F850LP} imaging in the
area of the original Hubble Ultra Deep Field NICMOS parallel fields
and - through simultaneous parallel observations - deep NICMOS {F110W,
F160W} imaging of the ACS UDF area. Matching the extreme imaging depth
in the optical and near-IR bands will result in seven fields with
sufficiently sensitive multiband data to detect the expected typical
galaxies at z=7 and 8. Presently no such a field exist. Our combined
optical and near-IR ultradeep fields will be in three areas separated
by about 20 comoving Mpc at z=7. This will allow us to give a first
assessment of the degree of cosmic variance. If reionization is a
process extending over a large redshift interval and the luminosity
function doesn't evolve strongly beyond z=6, these data will allow us
to identify of the order of a dozen galaxies at 6.5z8.5 - using the
Lyman break technique - and to place a first constrain on the
luminosity function at z6.5. Conversely, finding fewer objects would
be an indication that the bulk of reionization is done by galaxies at
z=6. By spending 204 orbits of prime HST time we will capitalize on
the investment of 544 prime orbits already made on the Hubble Ultra
Deep Field {UDF}. We have verified that the program as proposed is
schedulable and that it will remain so even if forced to execute in
the 2-gyro mode. The data will be non-proprietary and the reduced
images will be made public within 2 months from the completion of the
observations.

ACS/HRC 10539

Coronagraphic Imaging of Bright New Spitzer Debris Disks

Fifteen percent of bright main sequence stars possess dusty
circumstellar debris disks revealed by far-infrared photometry. These
disks are signposts of planetary systems: collisions among larger,
unseen parent bodies maintain the observed dust population against
losses to radiation pressure and P-R drag. Images of debris disks at
optical, infrared, and millimeter wavelengths have shown central
holes, rings, radial gaps, warps, and azimuthal asymmetries which
indicate the presence of planetary mass perturbers. Such images
provide unique insights into the structure and dynamics of
exoplanetary systems. Relatively few debris disks have been spatially
resolved. Only nine have ever been resolved at any wavelength, and at
wavelengths 10 microns {where subarcsec resolution is available},
only seven: beta Pictoris, HR 4796, HD 141569, AU Mic, HD 107146, HD
92945, and Fomalhaut. Imaging of many other debris disk targets has
been attempted with various HST cameras/coronagraphs and adaptive
optics, but without success. The key property which renders a debris
disk observable in scattered light is its dust optical depth. The
seven disks imaged so far all have a dust excess luminosity ~ 0.01%
that of the central star; no disks with smaller optical depths have
been detected. Most main sequence stars known to meet this requirement
have already been observed, so future progress in debris disk imaging
depends on discovering additional stars with large infrared excess.
The Spitzer Space Telescope offers the best opportunity in 20 years to
identify new examples of high optical depth debris disk systems. We
propose ACS coronagraphic imaging of nine bright, new debris disks
uncovered during the first year of the Spitzer mission. Our goal is to
obtain the first resolved images of these disks at ~3 AU resolution,
define the disk sizes and orientations, and uncover disk substructures
indicative of planetary perturbations. The results should double the
number of debris disks observed at 0.06" resolution, and open a wider
window into the structure of planetary systems.

ACS/WFC 10503

The Star Formation Histories of Early Type Dwarf Galaxies in Low
Density Environments: Clues from the Sculptor Group

We seek HST ACS/WFC time to conduct a detailed study of the stellar
populations of 5 early-type {dE, dE/dIrr} dwarf galaxies in the nearby
{~1.5 to 4 Mpc} Sculptor group. Four of these systems have been
recently found to contain modest amounts of HI, and existing
ground-based and HST snapshot data point to the potential presence of
small populations of young {blue} stars in at least three of these
systems. Consequently, they resemble the Local Group 'transition'
objects Phoenix and LGS3. The relative number of such transition
systems is thus substantially larger in the low density environment of
the Scl group than for the Local Group. Detailed stellar populations
studies will allow estimation of the star formation histories, via
stellar population modelling of the color-magnitude diagrams, of the
target dwarfs, which in turn will connect to gas consumption and
retention rates. For the two nearer dwarfs we aim to reach below the
horizontal branch {a first for any system beyond the Local Group}
equivalent to a main sequence turnoff age of ~1 Gyr. The observations
of these two systems will also allow detection of RR Lyrae variables
and thus direct confirmation of the presence of old populations. For
the other three dwarfs will we cover the first 2.5 mags of the red
giant branch, equivalent to the main sequence termination for a ~300
Myr population. The results will have implications for theories of
galaxy formation and evolution, particularly with regard to the
evolutionary relation between low luminosity dEs and dwarf irregulars.

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.

ACS/SBC 10259

Planetary nebulae in the SMC: a study of stellar evolution and
populations in an extremely low- metallicity environment

The final phase of the evolution of low- and intermediate-mass stars,
the planetary nebula {PN} ejection, is thought to largely contribute
to the carbon and nitrogen enrichment in galaxies, in particular in
old stellar populations. Stellar generations forming from a carbon-
and nitrogen- enriched medium are a necessary condition for planetary
and life formation. It is essential to understand how stars go through
the process of shedding their chemically-enriched shells, and to test
the predictions of stellar evolution theory on the relationship
between stellar mass and elemental enrichment. Magellanic Cloud PNs
are ideal probes for this study. Their abundances can be directly
related to the mass of the central stars and to that of the stellar
progenitor, without the great {distance and reddening} uncertainties
that affect Galactic PNs. The UV lines are essential for calculating
the abundances of the element related to stellar evolution {C, N, O}
and to progenitor populations {e.g., Ne}. We propose to acquire UV
spectroscopy of the SMC PNs whose morphology and central star
properties has been previously determined by us with HST. We will
derive the {C, N, O} abundance-to-mass relation, and determine the
extent to which the mass of the progenitors of asymmetric PNs exceed
that of symmetric PNs. We will also test the PN luminosity function,
and probe cosmic recycling, in a very low-metallicity environment.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

10416 - FHST OBAD Failure

At acquisition of signal 244/20:00:01 OBAD2 scheduled at 244/19:27:22
using trackers 1 and 2 failed. 486 ESB message 1901
"OBAD_TOO_FEW_STARS" was received at 244/19:30:12. Subsequent guide
star acquisition was successful.

10418 - FHST OBAD Map Failure, Too Few Stars

OBAD without maneuver (map) scheduled at 247/19:37:25 using trackers 1
and 2 failed. ESB message 1901 "OBAD_TOO_FEW_STARS" was received at
19:40:11. GOBSTAT ("OBAD Status')= 255 (AttDtErr) QT2GMST
("T2gStar_MapState") = "MapCompl"

10419 - GSACQ(2,3,3) failed

Upon acquisition of signal at 248.00:56:45, HST was in gyro control
with QF2STOPF, QF3STOPF and QSTOP flags set. GSACQ(2,3,3) at
248/00:18:43 failed to RGA control.


COMPLETED OPS REQUEST:
17543-2 - Dump OBAD tables after failed OBAD
17543-2 - Dump OBAD tables after failed OBAD

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 31 30
FGS REacq 23 23
OBAD with Maneuver 108 107