Daily # 4200

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4200

PERIOD COVERED: UT September X15,16,17, 2006 (DOY 258,259,260)

OBSERVATIONS SCHEDULED

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.

WFPC2 10915

ACS Nearby Galaxy Survey

Existing HST observations of nearby galaxies comprise a sparse and
highly non-uniform archive, making comprehensive comparative studies
among galaxies essentially impossible. We propose to secure HST's
lasting impact on the study of nearby galaxies by undertaking a
systematic, complete, and carefully crafted imaging survey of ALL
galaxies in the Local Universe outside the Local Group. The resulting
images will allow unprecedented measurements of: {1} the star
formation history {SFH} of a 100 Mpc^3 volume of the Universe with a
time resolution of Delta[log{t}]=0.25; {2} correlations between
spatially resolved SFHs and environment; {3} the structure and
properties of thick disks and stellar halos; and {4} the color
distributions, sizes, and specific frequencies of globular and disk
clusters as a function of galaxy mass and environment. To reach these
goals, we will use a combination of wide-field tiling and pointed deep
imaging to obtain uniform data on all 72 galaxies within a
volume-limited sample extending to ~3.5 Mpc, with an extension to the
M81 group. For each galaxy, the wide-field imaging will cover out to
~1.5 times the optical radius and will reach photometric depths of at
least 2 magnitudes below the tip of the red giant branch throughout
the limits of the survey volume. One additional deep pointing per
galaxy will reach SNR~10 for red clump stars, sufficient to recover
the ancient SFH from the color-magnitude diagram. This proposal will
produce photometric information for ~100 million stars {comparable to
the number in the SDSS survey} and uniform multi-color images of half
a square degree of sky. The resulting archive will establish the
fundamental optical database for nearby galaxies, in preparation for
the shift of high-resolution imaging to the near-infrared.

ACS/HRC 10909

Exploring the diversity of cosmic explosions: The supernovae of
gamma-ray bursts

While the connection between gamma-ray bursts {GRBs} and supernovae
{SNe} is now clearly established, there is a large variety of
observational properties among these SNe and the physical parameters
of these explosions are poorly known. As part of a comprehensive
program, we propose to use HST in order to obtain basic information
about the supernovae associated with gamma-ray bursts. HST offers the
means to cleanly separate the light curves of the GRB afterglow from
the supernova, and to remove the contamination from the host galaxy,
opening a clear route to the fundamental parameters of the SN. From
these observations, we will determine the absolute magnitude at
maximum, the shape of the spectral energy distribution, and any change
over time of the energy distribution. We will also measure the rate of
decay of the exponential tail. Merged with the ground-based data that
we will obtain for each event, we will be able to compare our data set
to models and constrain the energy of the explosion, the mass of the
ejecta and the mass of Nickel synthesized during the explosion. These
results will shed light on the apparent variety of supernovae
associated with gamma-ray bursts and X-ray flashes, and on the
relation between these SNe and other, more common varieties of core-
collapse explosions.

NIC1 10889

The Nature of the Halos and Thick Disks of Spiral Galaxies

We propose to resolve the extra-planar stellar populations of the
thick disks and halos of seven nearby, massive, edge-on galaxies using
ACS, NICMOS, and WFPC2 in parallel. These observations will provide
accurate star counts and color-magnitude diagrams 1.5 magnitudes below
the tip of the Red Giant Branch sampled along the two principal axes
and one intermediate axis of each galaxy. We will measure the
metallicity distribution functions and stellar density profiles from
star counts down to very low average surface brightnesses, equivalent
to ~32 V- mag per square arcsec. These observations will provide the
definitive HST study of extra-planar stellar populations of spiral
galaxies. Our targets cover a range in galaxy mass, luminosity, and
morphology and as function of these galaxy properties we will provide:
- The first systematic study of the radial and isophotal shapes of the
diffuse stellar halos of spiral galaxies - The most detailed
comparative study to date of thick disk morphologies and stellar
populations - A comprehensive analysis of halo and thick disk
metallicity distributions as a function of galaxy type and position
within the galaxy. - A sensitive search for tidal streams - The first
opportunity to directly relate globular cluster systems to their field
stellar population We will use these fossil records of the galaxy
assembly process preserved in the old stellar populations to test halo
and thick disk formation models within the hierarchical galaxy
formation scheme. We will test LambdaCDM predictions on sub-galactic
scales, where it is difficult to test using CMB and galaxy redshift
surveys, and where it faces its most serious difficulties.

ACS/WFC 10886

The Sloan Lens ACS Survey: Towards 100 New Strong Lenses

As a continuation of the highly successful Sloan Lens ACS {SLACS}
Survey for new strong gravitational lenses, we propose one orbit of
ACS-WFC F814W imaging for each of 50 high- probability strong
galaxy-galaxy lens candidates. These observations will confirm new
lens systems and permit immediate and accurate photometry, shape
measurement, and mass modeling of the lens galaxies. The lenses
delivered by the SLACS Survey all show extended source structure,
furnishing more constraints on the projected lens potential than
lensed-quasar image positions. In addition, SLACS lenses have lens
galaxies that are much brighter than their lensed sources,
facilitating detailed photometric and dynamical observation of the
former. When confirmed lenses from this proposal are combined with
lenses discovered by SLACS in Cycles 13 and 14, we expect the final
SLACS lens sample to number 80--100: an approximate doubling of the
number of known galaxy-scale strong gravitational lenses and an
order-of-magnitude increase in the number of optical Einstein rings.
By virtue of its homogeneous selection and sheer size, the SLACS
sample will allow an unprecedented exploration of the mass structure
of the early-type galaxy population as a function of all other
observable quantities. This new sample will be a valuable resource to
the astronomical community by enabling qualitatively new strong
lensing science, and as such we will waive all but a short {3-month}
proprietary period on the observations.

ACS/WFC 10882

Emission Line Snapshots of 3CR Radio Galaxies

Radio galaxies are an important class of extragalactic objects: they
are one of the most energetic astrophysical phenomena and they provide
an exceptional probe of the evolving Universe, lying typically in high
density regions but well-represented across a wide redshift range. In
earlier Cycles we carried out extensive HST observations of the 3CR
sources in order to acquire a complete and quantitative inventory of
the structure, contents and evolution of these important objects. We
discovered new optical jets, dust lanes, and revealed point-like
nuclei whose properties support AGN unified schemes. Here, we propose
to obtain ACS emission line images at low and high excitation of 3CR
sources with z0.3, both low- and classical high- power radio
galaxies, as a major enhancement to an already superb dataset. We aim
to probe fundamental relationships between warm optical line-emitting
gas, radio source structure {jets and lobes} and X-ray coronal halos.
We will combine our existing UV images with new emission- line images
to establish quantitative star formation characteristics and their
relation to dust and merging, and with emission-line excitation maps,
test theories on ionization beam patterns and luminosities from active
nuclei. We will seek jet induced star formation and knowing optical
emission-line physics, investigate quantitative jet physics. The
nuclear emission line properties of the galaxies will themselves be
established and used as ingredients in continuing tests of unified AGN
theories. The resulting database will be an incredibly valuable
resource to the astronomical community for years to come.

ACS/WFC 10880

The host galaxies of QSO2s: AGN feeding and evolution at high
luminosities

Now that the presence of supermassive black holes in the nuclei of
galaxies is a well established fact, other questions related to the
AGN phenomena still have to be answered. Problems of particular
interest are how the AGN gets fed, how the black hole evolves and how
the evolution of the black hole is related to the evolution of the
galaxy bulge. Here we propose to address some of these issues using
ACS/WFC + F775W snapshot images of 73 QSO2s with redshifts in the
range 0.3z0.4. These observations will be combined with similar
archival data of QSO1s and ground based data of Seyfert and normal
galaxies. First, we will intestigate whether interactions are the most
important feeding mechanism in high luminosity AGNs. This will be done
in a quantitative way, comparing the asymmetry indices of QSO2 hosts
with those of lower luminosity AGNs and normal galaxies. Second, we
will do a detailed study of the morphology of the host galaxies of
both QSO types, to determine if they are similar, or if there is an
evolutionary trend from QSO2s to QSO1s. The results from this project
will represent an important step in the understanding of AGN
evolution, and may also introduce a substantial modification to the
Unified Model.

ACS/HRC 10878

An ACS Prism Snapshot Survey for z~2 Lyman Limit Systems

We propose to conduct a spectroscopic survey of Lyman limit absorbers
at redshifts 1.7 z 2.2, using ACS/HRC and the PR200L prism. We
have selected 100 quasars at 2.3 z 2.6 from the Sloan Digital Sky
Survey Spectroscopic Quasar sample, for which no BAL signature is
found at the QSO redshift and no strong metal absorption lines are
present at z 2.3 along the lines of sight. The survey has three main
observational goals. First, we will determine the redshift frequency
dN/dz of the LLS over the column density range 16.3 log N_HI 20.3
cm^-2. Second, we will measure the column density frequency
distribution f{N} for the partial Lyman limit systems {PLLS} over the
column density range 16.3 log N_HI 17.5 cm^-2. Third, we will
identify new sightlines for measurements of the primordial D/H ratio.
With this survey, we will also constrain two key quantities of
cosmological relevance: First, the measurements of dN/dz for optically
thick LLS and f{N} for the PLLS are critical to estimating the
attenuation of extragalactic ionizing sources {e.g. QSOs}. Currently,
uncertainties in dN/dz and f{N} are the greatest sources of
uncertainty for inferring the shape and intensity of the UV background
radiation field. Second, we will estimate the amount of metals in the
LLS using the f{N} and ground based observations of metal line
transitions. It is possible that a significant fraction of the
"missing metals" at z~2 are associated with these highly ionized
absorbers. Third, analysis of the LLS lends to investigations of the
interface between galaxies {i.e. the damped Lyman alpha systems} and
the intergalactic medium {i.e. the Lyman alpha forest}. This survey is
ideal for a snapshot observing program, because the on-object
integration times are less than 10 minutes, and the targets cover the
majority of the northern sky.

NIC2 10852

Coronagraphic Polarimetry with NICMOS: Dust grain evolution in T Tauri
stars

The formation of planetary systems is intimately linked to the dust
population in circumstellar disks, thus understanding dust grain
evolution is essential to advancing our understanding of how planets
form. By combining {1} the coronagraphic polarimetry capabilities of
NICMOS, {2} powerful 3-D radiative transfer codes, and {3}
observations of objects known to span the Class II-III stellar
evolutionary phases, we will gain crucial insight into dust grain
growth. By observing objects representative of a known evolutionary
sequence of YSOs, we will be able to investigate how the dust
population evolves in size and distribution during the crucial
transition from a star+disk system to a system containing
planetesimals. When combine with our previous study on dust grain
evolution in the Class I-II phase, the proposed study will help to
establish the fundamental time scales for the depletion of ISM-like
grains: the first step in understanding the transformation from small
submicron sized dust grains, to large millimeter sized grains, and
untimely to planetary bodies.

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 10829

Secular Evolution at the End of the Hubble Sequence

The bulgeless disk galaxies at the end of the Hubble Sequence evolve
at a glacial pace relative to their more violent, earlier-type
cousins. The causes of their internal, or secular evolution are
important because secular evolution represents the future fate of all
galaxies in our accelerating Universe and is a key ingredient to
understanding galaxy evolution in lower-density environments at
present. The rate of secular evolution is largely determined by the
stability of the cold ISM against collapse, star formation, and the
buildup of a central bulge. Key diagnostics of the ISM's stability are
the presence of compact molecular clouds and narrow dust lanes.
Surprisingly, edge-on, pure disk galaxies with circular velocities
below 120 km/s do not appear to contain such dust lanes. We propose to
obtain ACS/WFC F606W images of a well-selected sample of extremely
late-type disk galaxies to measure the characteristic scale size of
the cold ISM and determine if they possess the unstable, cold ISM
necessary to drive secular evolution. Our sample has been carefully
constructed to include disk galaxies above and below the critical
circular velocity of 120 km/s where the dust properties of edge-on
disks change so remarkably. We will then use surface brightness
profiles to search for nuclear star clusters and pseudobulges, which
are early indicators that secular evolution is at work, as well as
measure the pitch angle of the dust lanes as a function of radius to
estimate the central mass concentrations.

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.

NIC1 10725

Photometric Stability

This NICMOS calibration proposal carries out photometric monitoring
observations during Cycle 14. The format of the program is similar to
that of the Cycle 12 program 9995 and Cycle 13 program 10381, but a
few modifications were made. Provisions had to be made to adopt to 2-
gyro mode {G191B2B was added as extra target to provide target
visibility through most of the year}. Where before 4 or 7 dithers were
made in a filter before we moved to the next filter, now we observe
all filters at one position before moving to the next dither position.
While the previous method was chosen to minimize the effect of
persistence, we now realize that persistence is connected to charge
trapping and by moving through the filter such that the count rate
increases, we reach equilibrium more quickly between charge being
trapped and released. We have also increased exposure times where
possible to reduce the charge trapping non-linearity effects.

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 10508

Orbits, Masses, and Densities of Three Transneptunian Binaries

The subset of transneptunian objects {TNOs} having natural satellites
offers unique opportunities for physical studies of these distant
relics from the outer parts of the protoplanetary nebula. HST/ACS is
ideally suited to determining orbits of TNO satellites, resulting in
the system masses. In conjunction with thermal emission observations
by Spitzer, which provides sizes, we can determine the densities of
TNOs. Densities offer a powerful window into their bulk compositions
and interior structures.

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/WFC 10494

Imaging the mass structure of distant lens galaxies

The surface brightness distribution of extended gravitationally lensed
arcs and Einstein rings contains super-resolved information about the
lensed object, and, more excitingly, about the smooth and clumpy mass
distribution of the lens galaxies. The source and lens information can
non-parametrically be separated, resulting in a direct
"gravitational-mass image" of the inner mass-distribution of
cosmologically-distant galaxies {Koopmans 2005}. With this goal in
mind, we propose deep HST ACS-F555W/F814W and NICMOS-F160W imaging of
15 gravitational-lens systems with spatially resolved lensed sources,
selected from the 17 new lens systems discovered by the Sloan Lens ACS
Survey {Bolton et al. 2004}. Each system has been selected from the
SDSS and confirmed in a time-efficient HST-ACS snapshot program
{cycle-13}; they show highly-magnified arcs or Einstein rings, lensed
by a massive early-type lens galaxy. High- fidelity multi-color HST
images are required {not delivered by the 420-sec snapshot images} to
isolate these lensed images {properly cleaned, dithered and
extinction-corrected} from the lens galaxy surface brightness
distribution, and apply our "gravitational-mass imaging" technique.
The sample of galaxy mass distributions - determined through this
method from the arcs and Einstein ring HST images - will be studied
to: {i} measure the smooth mass distribution of the lens galaxies
{Dark and luminous mass are separated using the HST images and the
stellar M/L values derived from a joint stellar-dynamical analysis of
each system}; {ii} quantify statistically and individually the
incidence of mass-substructure {with or without obvious luminous
counter- parts such as dwarf galaxies}. Since dark-matter substructure
should be considerably more prevalent at higher redshift, both results
provide a direct test of this prediction of the CDM hierarchical
structure-formation model.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS: (None)

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 28 28
FGS REacq 14 14
OBAD with Maneuver 82 82

SIGNIFICANT EVENTS: (None)