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Daily Report #5116



 
 
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Old June 14th 10, 03:00 PM posted to sci.astro.hubble
Cooper, Joe
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Posts: 568
Default Daily Report #5116

HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #5116

PERIOD COVERED: 5am June 11 - 5am June 14, 2010 (DOY 162/09:00z-165/09:00z)

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

12299 - GSAcq(1,2,1) scheduled at 163/17:35:50z, the REAcqs(1,2,1)
scheduled at 163/18:55:04z, at 163/20:30:44z at 163/22:06:24z and at
163/23:42:04z all acquired fine lock backup on FGS 2 due to scan step
limit exceeded on FGS 1.

Observations possibly affected: COS 99 - 178, Proposal ID#11686.

12300 - REAcq(2,1,1) scheduled at 164/02:52:12z took two attempts to
achieve CT-DV.

Observations possibly affected: COS 179 Proposal ID#11698, WFC3
170-171 Proposal ID#11905, ACS 88 Proposal ID#11995.

12301 - REAcq(1,2,1) scheduled at 165/02:46:24 failed.

Observations affected: WFC3 3 - 5 Proposal ID#11588

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSAcq 21 21
FGS REAcq 32 31
OBAD with Maneuver 12 12

SIGNIFICANT EVENTS: (None)



OBSERVATIONS SCHEDULED:

COS/FUV 11997

FUV Internal/External Wavelength Scale Monitor

This program monitors the offsets between the wavelength scale set by
the internal wavecal versus that defined by absorption lines in
external targets. This is accomplished by observing two external
targets in the SMC: SK191 with G130M and G160M and Cl* NGC 330 ROB B37
with G140L (SK191 is too bright to be observed with G140L). The
cenwaves observed in this program are a subset of the ones used during
Cycle 17. Observing all cenwaves would require a considerably larger
number of orbits. Constraints on scheduling of each target are placed
so that each target is observed once every ~2-3 months. Observing the
two targets every month would also require a considerably larger
number of orbits.

ACS/WFC 11995

CCD Daily Monitor (Part 2)

This program comprises basic tests for measuring the read noise and
dark current of the ACS WFC and for tracking the growth of hot pixels.
The recorded frames are used to create bias and dark reference images
for science data reduction and calibration. This program will be
executed four days per week (Mon, Wed, Fri, Sun) for the duration of
Cycle 17. To facilitate scheduling, this program is split into three
proposals. This proposal covers 320 orbits (20 weeks) from 1 February
2010 to 20 June 2010.

WFC3/IR/S/C 11929

IR Dark Current Monitor

Analyses of ground test data showed that dark current signals are more
reliably removed from science data using darks taken with the same
exposure sequences as the science data, than with a single dark
current image scaled by desired exposure time. Therefore, dark current
images must be collected using all sample sequences that will be used
in science observations. These observations will be used to monitor
changes in the dark current of the WFC3-IR channel on a day-to-day
basis, and to build calibration dark current ramps for each of the
sample sequences to be used by Gos in Cycle 17. For each sample
sequence/array size combination, a median ramp will be created and
delivered to the calibration database system (CDBS).

WFC3/UVIS 11912

UVIS Internal Flats

This proposal will be used to assess the stability of the flat field
structure for the UVIS detector throughout the 15 months of Cycle 17.
The data will be used to generate on-orbit updates for the delta-flat
field reference files used in the WFC3 calibration pipeline, if
significant changes in the flat structure are seen.

WFC3/UVIS 11908

Cycle 17: UVIS Bowtie Monitor

Ground testing revealed an intermittent hysteresis type effect in the
UVIS detector (both CCDs) at the level of ~1%, lasting hours to days.
Initially found via an unexpected bowtie-shaped feature in flatfield
ratios, subsequent lab tests on similar e2v devices have since shown
that it is also present as simply an overall offset across the entire
CCD, i.e., a QE offset without any discernable pattern. These lab
tests have further revealed that overexposing the detector to count
levels several times full well fills the traps and effectively
neutralizes the bowtie. Each visit in this proposal acquires a set of
three 3x3 binned internal flatfields: the first unsaturated image will
be used to detect any bowtie, the second, highly exposed image will
neutralize the bowtie if it is present, and the final image will allow
for verification that the bowtie is gone.

WFC3/UVIS 11905

WFC3 UVIS CCD Daily Monitor

The behavior of the WFC3 UVIS CCD will be monitored daily with a set
of full-frame, four-amp bias and dark frames. A smaller set of 2Kx4K
subarray biases are acquired at less frequent intervals throughout the
cycle to support subarray science observations. The internals from
this proposal, along with those from the anneal procedure (Proposal
11909), will be used to generate the necessary superbias and superdark
reference files for the calibration pipeline (CDBS).

STIS/CC 11847

CCD Bias Monitor-Part 2

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

STIS/CC 11845

CCD Dark Monitor Part 2

Monitor the darks for the STIS CCD.

NIC1/NIC2 11818

NICMOS Confirmation of an Extrasolar pPanet Candidate Directly
Detected with ACS

With ACS/HRC coronagraphy, we have achieved the direct detection of a
planet candidate in F606W and F814W around a bright nearby star with a
debris belt. The planet candidate lies 18 astronomical units interior
to the dust belt and we detect counterclockwise orbital motion in
observations separated by 1.75 years. The candidate has mass no
greater than three Jupiter masses based on an analysis of its
luminosity and the dynamical argument that a significantly more
massive object would disrupt the dust belt. Using recent model
predictions for 100-300 Myr old planetary atmospheres, the planet
candidate has a temperature of ~400 K and a mass 1.6 - 3.4 M_J.
Variability at optical wavelengths suggests additional sources of
luminosity such as H-alpha emission or the episodic accretion of
cometary material. A key surprise is that the planet candidate is NOT
detected in Keck adaptive optics observations at 1.6 microns. Two
model atmospheres predict a flux a few times greater than our
detection limit, though the model predictions disagree with each other
by a factor of five due to theoretical uncertainty in the strength of
CH4 vibrational bands. These models predict the strongest emission
centered on the F110W passband of NICMOS such that the F814W - F110W
color will be red. Here we propose follow-up NICMOS observations to
verify that the emission observed in F814W is due to the emergent flux
from passive cooling of the planet, as opposed to other explanations,
such as reflected light from a Saturn analog with a circumplanetary
debris disk that would produce a bluer F814W - F110W color. Additional
deep images in and and out of the 1.14 micron water trough using NIC1
narrowband filters will test whether or not the emission is produced
from the passive cooling of a young massive planet.

COS/FUV/NUV 11733

WPVS 007: the little AGN that could

Outflows are important components of AGN, potentially removing angular
momentum, enriching the intergalactic medium, and potentially playing
a key role in the evolution of galaxies. Yet their astrophysics is
poorly understood. We propose an FUV observation of the
Seyfert-luminosity AGN WPVS 007 (M_V=-19.7, z=0.02882) using COS,
coordinated with a short Chandra observation. Observed to have a
miniBAL with maximum velocity v_max~1000 km/s in an 1996 HST
observation, it was discovered to have developed an additional BAL
flow by the time of the FUSE observation in 2003. The BAL flow has
maximum velocity of at least 6, 000 km/s, and the unambiguous presence
of PV indicates that it is very optically thick. In addition, it was
found to have normal X-ray flux during the ROSAT All Sky Survey, but
in subsequent observations from 1993 to 2003 it was observed to be
X-ray weak, suggesting that the X-rays were absorbed by the emerging
BAL.

Our proposed observations will contribute to our understanding of
outflows in three key areas. First, an observed relationship between
v_max and luminosity that is plausibly related to the acceleration
mechanism is violated in WPVS 007; thus WPVS 007 presents a challenge
to outflow models. Second, the observed evolution of the BAL flow may
be related to the small black hole mass and correspondingly compact
emission and absorption regions; thus, WPVS 007 offers the rare
opportunity to observe evolution of the outflow on human time scales.
Finally, while WPVS 007 has been observed to be X-ray weak since 1993,
a recent long Swift observation revealed the first detection of hard
X-ray emission. The proposed observations will reveal whether this
emergence of hard X-rays is accompanied by a decrease in the UV
absorption, and thus test the relationship between X-ray and UV
absorbers in BALQSOs.

WFC3/UVIS 11730

Continued Proper Motions of the Magellanic Clouds: Orbits, Internal
Kinematics, and Distance

In Cycles 11 and 13 we obtained two epochs of ACS/HRC data for fields
in the Magellanic Clouds centered on background quasars. We used these
data to determine the proper motions of the LMC and SMC to better than
5% and 15% respectively. The results had a number of unexpected
implications for the Milky Way-LMC-SMC system and received
considerable attention in the literature and in the press. The implied
three-dimensional velocities are larger than previously believed and
close to the escape velocity in a standard 10^12 solar mass Milky Way
dark halo. Our orbit calculations suggest the Clouds may not be bound
to the Milky Way or may just be on their first passage, both of which
are unexpected in view of traditional interpretations of the
Magellanic Stream. Alternatively, the Milky Way dark halo may be a
factor two more massive than previously believed, which would be
surprising in view of other observational constraints. Also, the
relative velocity between the LMC and SMC was larger than expected,
leaving open the possibility that the Clouds may not be bound to each
other. To further verify and refine our results we requested an
additional epoch data in Cycle 16 which is being executed with
WFPC2/PC due to the failure of ACS. A detailed analysis of one LMC
field shows that the field proper motion using all three epochs of
data is consistent within 1-sigma with the two- epoch data, thus
verifying that there are no major systematic effects in our previous
measurements. The random errors, however, are only smaller by a factor
of 1.4 because of the relatively large errors in the WFPC2 data. A
prediction for a fourth epoch with measurement errors similar to
epochs 1 and 2 shows that the uncertainties will improve by a factor
of 3. This will allow us to better address whether the Clouds are
indeed bound to each other and to the Milky Way. It will also allow us
to constrain the internal motions of various populations within the
Clouds, and to determine a distance to the LMC using rotational
parallax. Continuation of this highly successful program is therefore
likely to provide important additional insights. Execution in SNAPshot
mode guarantees maximally efficient use of HST resources.

COS/NUV/FUV 11720

Detailed Analysis of Carbon Atmosphere White Dwarfs

We propose to obtain UV spectra for the newly discovered white dwarf
stars with a carbon- dominated atmosphere. Model calculations show
that these stars emit most of their light in the UV part of the
electromagnetic spectrum and that an accurate determination of the
flux in this region is crucial for an accurate determination of the
atmospheric parameters. It will also provide a unique opportunity to
test the atomic data and broadening theory in stellar conditions never
met before. This will play a primordial role in our path to understand
the origin of these objects as well to obtain a better understanding
of the evolution of stars in general. The principal objective we hope
to achieve with these observations are 1) obtain accurate surface
gravity/mass for these stars, 2) constrain/determine the abundance of
other elements (O, He, Mg, Ne etc.), especially oxygen, 3) verify the
accuracy of the various theoretical atomic data used in the model
calculations, 4) understand the origin and evolution of carbon
atmosphere white dwarfs, in particular whether progenitor stars as
massive as 10.5 solar masses can produce white dwarfs, rather than
supernovae. We propose to observe 5 objects chosen carefully to cover
the range of observed properties among carbon atmosphere white dwarfs
(effective temperature, surface gravity, abundance of hydrogen/helium
and magnetic field).

WFC3/IR 11719

A Calibration Database for Stellar Models of Asymptotic Giant Branch
Stars

Studies of galaxy formation and evolution rely increasingly on the
interpretation and modeling of near-infrared observations. At these
wavelengths, the brightest stars are intermediate mass asymptotic
giant branch (AGB) stars. These stars can contribute nearly 50% of the
integrated luminosity at near infrared and even optical wavelengths,
particularly for the younger stellar populations characteristic of
high-redshift galaxies (z1). AGB stars are also significant sources
of dust and heavy elements. Accurate modeling of AGB stars is
therefore of the utmost importance.

The primary limitation facing current models is the lack of useful
calibration data. Current models are tuned to match the properties of
the AGB population in the Magellanic Clouds, and thus have only been
calibrated in a very narrow range of sub-solar metallicities.
Preliminary observations already suggest that the models are
overestimating AGB lifetimes by factors of 2-3 at lower metallicities.
At higher (solar) metallicities, there are no appropriate observations
for calibrating the models.

We propose a WFC3/IR SNAP survey of nearby galaxies to create a large
database of AGB populations spanning the full range of metallicities
and star formation histories. Because of their intrinsically red
colors and dusty circumstellar envelopes, tracking the numbers and
bolometric fluxes of AGB stars requires the NIR observations we
propose here. The resulting observations of nearby galaxies with deep
ACS imaging offer the opportunity to obtain large (100-1000's)
complete samples of AGB stars at a single distance, in systems with
well-constrained star formation histories and metallicities.

WFC3/UVIS/IR 11702

Search for Very High-z Galaxies with WFC3 Pure Parallel

WFC3 will provide an unprecedented probe to the early universe beyond
the current redshift frontier. Here we propose a pure parallel program
using this new instrument to search for Lyman-break galaxies at
6.5z8.8 and to probe the epoch of reionization, a hallmark event in
the history of the early universe. We request 200 orbits, spreading
over 30 ~ 50 high Galactic latitude visits (|b|20deg) that last for 4
orbits and longer, resulting a total survey area of about 140~230
square arcminute. Based on our understanding of the new HST parallel
observation scheduling process, we believe that the total number of
long-duration pure parallel visits in Cycle 17 should be sufficient to
accommodate our program. We waive all proprietary rights to our data,
and will also make the enhanced data products public in a timely
manner.

(1) We will use both the UVIS and the IR channels, and do not need to
seek optical data from elsewhere.

(2) Our program will likely triple the size of the probable candidate
samples at z~7 and z~8, and will complement other targeted programs
aiming at the similar redshift range.

(3) Being a pure parallel program, our survey will only make very
limited demand on the scarce HST resources. More importantly, as the
pure parallel pointings will be at random sight-lines, our program
will be least affected by the bias due to the large scale structure
("cosmic variance").

(4) We aim at the most luminous LBG population, and will address the
bright-end of the luminosity function at z~8 and z~7. We will
constrain the value of L* in particular, which is critical for
understanding the star formation process and the stellar mass assembly
history in the first few hundred million years of the universe.

(5) The candidates from our survey, most of which will be the
brightest ones that any surveys would be able to find, will have the
best chance to be spectroscopically confirmed at the current 8--10m
telescopes.

(6) We will also find a large number of extremely red, old galaxies at
intermediate redshifts, and the fine spatial resolution offered by the
WFC3 will enable us constrain their formation history based on the
study of their morphology, and hence shed light on their connection to
the very early galaxies in the universe.

COS/NUV/FUV 11698

The Structure and Dynamics of Virgo's Multi-Phase Intracluster Medium

The dynamical flows of the intracluster medium (ICM) are largely
unknown. We propose to map the spatial and kinematic distribution of
the warm ICM of the nearby Virgo cluster using the Cosmic Origins
Spectrograph. 15 sightlines at a range of impact parameters within the
virial radius of the cluster (0.2 - 1.7 Mpc) will be probed for
Lyman-alpha absorption and the data compared to blind HI, dust and
x-ray surveys to create a multi-phase map of the cluster's ICM.
Absorption line sightlines are commonly 40-100 kpc from a galaxy,
allowing the flow of baryons between galaxies and the ICM to be
assessed. The velocity distribution of the absorbers will be directly
compared to simulations and used to constrain the turbulent motions of
the ICM. This proposal will result in the first map of a cluster's
warm ICM and provide important tests for our theoretical understanding
of cluster formation and the treatment of gas cooling in cosmological
simulations.

WFC3/IR 11694

Mapping the Lnteraction Between High-Redshift Galaxies and the
Lntergalactic Environment

With the commissioning of the high-throughput large-area camera
WFC3/IR, it is possible for the first time to undertake an efficient
survey of the rest-frame optical morphologies of galaxies at the peak
epoch of star formation in the universe. We therefore propose deep
WFC3/IR imaging of over 320 spectroscopically confirmed galaxies
between redshift 1.6 z 3.4 in well-studied fields which lie along
the line of sight to bright background QSOs. The spectra of these
bright QSOs probe the IGM in the vicinity of each of the foreground
galaxies along the line of sight, providing detailed information on
the physical state of the gas at large galactocentric radii. In
combination with our densely sampled UV/IR spectroscopy, stellar
population models, and kinematic data in these fields, WFC3/IR imaging
data will permit us to construct a comprehensive picture of the
structure, dynamics, and star formation properties of a large
population of galaxies in the early universe and their effect upon
their cosmological environment.

COS/FUV 11686

The Cosmological Impact of AGN Outflows: Measuring Absolute Abundances
and Kinetic Luminosities

AGN outflows are increasingly invoked as a major contributor to the
formation and evolution of supermassive black holes, their host
galaxies, the surrounding IGM, and cluster cooling flows. Our HST/COS
proposal will determine reliable absolute chemical abundances in six
AGN outflows, which influences several of the processes mentioned
above. To date there is only one such determination, done by our team
on Mrk 279 using 16 HST/STIS orbits and 100 ksec of FUSE time. The
advent of COS and its high sensitivity allows us to choose among
fainter objects at redshifts high enough to preclude the need for
FUSE. This will allow us to determine the absolute abundances for six
AGN (all fainter than Mrk 279) using only 40 HST COS orbits. This will
put abundances studies in AGN on a firm footing, an elusive goal for
the past four decades. In addition, prior FUSE observations of four of
these targets indicate that it is probable that the COS observations
will detect troughs from excited levels of C III. These will allow us
to measure the distances of the outflows and thereby determine their
kinetic luminosity, a major goal in AGN feedback research.
11686( 7) - 25-Sep-2009 13:44:14 - [ 2]

We will use our state of the art column density extraction methods and
velocity-dependent photoionization models to determine the abundances
and kinetic luminosity. Previous AGN outflow projects suffered from
the constraints of deciding what science we could do using ONE of the
handful of bright targets that were observable. With COS we can choose
the best sample for our experiment. As an added bonus, most of the
spectral range of our targets has not been observed previously,
greatly increasing the discovery phase space.

WFC3/ACS/IR 11677

Is 47 Tuc Young? Measuring its White Dwarf Cooling Age and Completing
a Hubble Legacy

With this proposal we will firmly establish the age of 47 Tuc from its
cooling white dwarfs. 47 Tuc is the nearest and least reddened of the
metal-rich disk globular clusters. It is also the template used for
studying the giant branches of nearby resolved galaxies. In addition,
the age sensitive magnitude spread between the main sequence turnoff
and horizontal branch is identical for 47 Tuc, two bulge globular
clusters and the bulge field population. A precise relative age
constraint for 47 Tuc, compared to the halo clusters M4 and NGC 6397,
both of which we recently dated via white dwarf cooling, would
therefore constrain when the bulge formed relative to the old halo
globular clusters. Of particular interest is that with the higher
quality ACS data on NGC 6397, we are now capable with the technique of
white dwarf cooling of determining ages to an accuracy of +/-0.4 Gyrs
at the 95% confidence level. Ages derived from the cluster turnoff are
not currently capable of reaching this precision. The important role
that 47 Tuc plays in galaxy formation studies, and as the metal-rich
template for the globular clusters, makes the case for a white dwarf
cooling age for this metal-rich cluster compelling.

Several recent analyses have suggested that 47 Tuc is more than 2 Gyrs
younger than the Galactic halo. Others have suggested an age similar
to that of the most metal poor globular clusters. The current
situation is clearly uncertain and obviously a new approach to age
dating this important cluster is required.

With the observations of 47 Tuc, this project will complete a legacy
for HST. It will be the third globular cluster observed for white
dwarf cooling; the three covering almost the full metallicity range of
the cluster system. Unless JWST has its proposed bluer filters (700
and 900 nm) this science will not be possible perhaps for decades
until a large optical telescope is again in space. Ages for globular
clusters from the main sequence turnoff are less precise than those
from white dwarf cooling making the science with the current proposal
truly urgent.

ACS/WFC3 11669

The Origins of Short Gamma-Ray Bursts

During the past decade extraordinary progress has been made in
determining the origin of long- duration gamma-ray bursts. It has been
conclusively shown that these objects derive from the deaths of
massive stars. Nonetheless, the origin of their observational cousins,
short-duration gamma-ray bursts (SGRBs) remains a mystery. While SGRBs
are widely thought to result from the inspiral of compact binaries,
this is a conjecture. SGRBs have been found in elliptical galaxies,
Abell Clusters, star-forming dwarfs and even an edge-on spiral.
Whether they primarily result from an old population, a young
population, or rapid evolution of binaries in globular clusters
remains open.

Here we propose to employ two related sets of observations which may
dramatically advance our understanding of short bursts. The first is a
variant of a technique that we pioneered and used to great effect in
elucidating the origins of long-duration bursts. We will examine a
statistical sample of hosts and measure the degree to which SGRB
locations trace the red or blue light of their hosts, and thus old or
young stellar populations. This will allow us to study the
demographics of the SGRB population in a manner largely free of the
distance dependent selection effects which have so far bedeviled this
field. In the second line of attack we will use two targets of
opportunity to obtain extremely precise positions of up to two nearby
bursts -- one on a star-forming galaxy and the other on a elliptical.
Observation of the star-formation galaxy could link at least some
bursts directly to a young population; however, a discovery in later
images of a globular cluster at the site of the explosion in an
elliptical would provide revolutionary evidence that SGRBs are formed
from compact binaries.

WFC3/UV 11635

In Search of SNIb/Ic Wolf-Rayet Progenitors and Comparison with Red
Supergiants (SNII Progenitors) in the Giant ScI Spiral M101

We propose to test two of the clearest predictions of the theory of
evolution of massive-star evolution: 1) The formation of Wolf-Rayet
stars depends strongly on these stars' metallicity (Z), with
relatively fewer WR stars forming at lower Z, and 2) Wolf-Rayet stars
die as Type Ib or Ic supernovae. To carry out these tests we propose a
deep, narrowband imaging survey of the massive star populations in the
ScI spiral galaxy M101. Just as important, we will test the hypothesis
that Superclusters like 30 Doradus are always richly populated with WR
stars, and by implication that these complexes are responsible for the
spectral signatures of starburst galaxies.

Our previous HST survey of the HII regions in the ScIII galaxy NGC
2403 suggested that the distribution of WR stars and RSG is a
sensitive diagnostic of the recent star-forming history of these large
complexes: young cores of O and WR stars are surrounded by older halos
containing RSG. Theory predicts that this must change with
metallicity; relatively fewer WR stars form at lower Z. A key goal of
our proposal is to directly test this paradigm in a single galaxy,
M101 being the ideal target. The abundance gradient across M101 (a
factor of 20) suggests that relatively many more WR will be found in
the inner parts of this galaxy than in the outer "suburbs". Second, we
note that WR stars are predicted to end their lives as core-collapse
or pair-instability supernovae. The WR population in M101 may be
abundant enough for one to erupt as a Type Ib or Ic supernova within a
generation. The clear a priori identification of a WR progenitor would
be a major legacy of HST. Third, we will also determine if
"superclusters", heavily populated by WR stars, are common in M101. It
is widely claimed that such Superclusters produce the integrated
spectral signatures of Starburst galaxies. We will be able to directly
measure the numbers and emission-line luminosities of thousands of
Wolf Rayet stars located in hundreds of M101 Superclusters, and
correlate those numbers against the Supercluster sizes and
luminosities. It is likely (but far from certain) that Supercluster
sizes and emission-line luminosities are driven by their Wolf-Rayet
star content. Our sample will be the largest and best-ever
Supercluster/Wolf Rayet sample, an excellent local proxy for
characterizing starburst galaxies' Superclusters.

WFC3/ACS/UVIS 11613

GHOSTS: Stellar Outskirts of Massive Spiral Galaxies

We propose to continue our highly successful GHOSTS HST survey of the
resolved stellar populations of nearby, massive disk galaxies using
SNAPs. These observations provide star counts and color-magnitude
diagrams 2-3 magnitudes below the tip of the Red Giant Branch of the
outer disk and halo 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.

This proposal will substantially improve our unique sampling of galaxy
outskirts. Our targets cover a range in galaxy mass, luminosity,
inclination, and morphology. As a function of these galaxy properties,
this survey provides: - the most extensive, systematic measurement of
radial light profiles and axial ratios of the diffuse stellar halos
and outer disks of spiral galaxies; - a comprehensive analysis of halo
metallicity distributions as function of galaxy type and position
within the galaxy; - an unprecedented study of the stellar metallicity
and age distribution in the outer disk regions where the disk
truncations occur; - the first comparative study of globular clusters
and their field stellar populations.

We will use these fossil records of the galaxy assembly process to
test halo formation models within the hierarchical galaxy formation
scheme.

WFC3/ACS/UVIS 11603

A Comprehensive Study of Dust Formation in Type II Supernovae with
HST, Spitzer, and Gemini

The recent discovery of three extremely bright Type II SNe, (2007it,
2007oc, 2007od) gives us a unique opportunity to combine observations
with HST, Spitzer, and Gemini to study the little understood dust
formation process in Type II Sne. Priority 1 Spitzer Cycle 5 and band
1 Gemini 2008A time has already been approved for this project. Since
late-time Type II Sne are faint and tend to be in crowded fields, we
need the high sensitivity and high spatial resolution of ACS and
NICMOS/NIC2 for these observations. This project is motivated by the
recent detection of large amounts of dust in high redshift galaxies.
The dust in these high-z galaxies must come from young, massive stars
so Type II Sne could be potential sources. The mechanism and the
efficiency of dust condensation in Type II SN ejecta are not well
understood, largely due to the lack of observational data. We plan to
produce a unique dataset, combining spectroscopy and imaging in the
visible, near- and mid-IR covering the key phase, 400-700 days after
maximum when dust is known to form in the SN ejecta. Therefore, we are
proposing for coordinated HST/NOAO observations (HST ACS, NICMOS/NIC2
& Gemini/GMOS and TReCS) which will be combined with our Spitzer Cycle
5 data to study these new bright Sne. The results of this program will
place strong constraints on the formation of dust seen in young high
redshift (z5) galaxies.


WFC3/UVIS 11588

Galaxy-Scale Strong Lenses from the CFHTLS Survey

We aim to investigate the origin and evolution of early-type galaxies
using gravitational lensing, modeling the mass profiles of objects
over a wide range of redshifts. The low redshift (z = 0.2) sample is
already in place following the successful HST SLACS survey; we now
propose to build up and analyze a sample of comparable size (~50
systems) at high redshift (0.4 z 0.9) using HST WFC3 Snapshot
observations of lens systems identified by the SL2S collaboration in
the CFHT legacy survey.


STIS/CCD/MA2 11568

A SNAPSHOT Survey of the Local Interstellar Medium: New NUV
Observations of Stars with Archived FUV Observations

We propose to obtain high-resolution STIS E230H SNAP observations of
MgII and FeII interstellar absorption lines toward stars within 100
parsecs that already have moderate or high-resolution far-UV (FUV),
900-1700 A, observations available in the MAST Archive. Fundamental
properties, such as temperature, turbulence, ionization, abundances,
and depletions of gas in the local interstellar medium (LISM) can be
measured by coupling such observations. Due to the wide spectral range
of STIS, observations to study nearby stars also contain important
data about the LISM embedded within their spectra. However, unlocking
this information from the intrinsically broad and often saturated FUV
absorption lines of low-mass ions, (DI, CII, NI, OI), requires first
understanding the kinematic structure of the gas along the line of
sight. This can be achieved with high resolution spectra of high-mass
ions, (FeII, MgII), which have narrow absorption lines, and can
resolve each individual velocity component (interstellar cloud). By
obtaining short (~10 minute) E230H observations of FeII and MgII, for
stars that already have moderate or high- resolution FUV spectra, we
can increase the sample of LISM measurements, and thereby expand our
knowledge of the physical properties of the gas in our galactic
neighborhood. STIS is the only instrument capable of obtaining the
required high resolution data now or in the foreseeable future.

STIS/CCD 11567

Boron Abundances in Rapidly Rotating Early-B Stars

Models of rotation in early-B stars predict that rotationally driven
mixing should deplete surface boron abundances during the
main-sequence lifetime of many stars. However, recent work has shown
that many boron depleted stars are intrinsically slow rotators for
which models predict no depletion should have occurred, while
observations of nitrogen in some more rapidly rotating stars show less
mixing than the models predict. Boron can provide unique information
on the earliest stages of mixing in B stars, but previous surveys have
been biased towards narrow- lined stars because of the difficulty in
measuring boron abundances in rapidly rotating stars. The two targets
observed as part of our Cycle 13 SNAP program 10175, just before STIS
failed, demonstrate that it is possible to make useful boron abundance
measurements for early-B stars with Vsin(i) above 100 km/s. We propose
to extend that survey to a large enough sample of stars to allow
statistically significant tests of models of rotational mixing in
early-B stars.

WFC3/UVIS 11565

A Search for Astrometric Companions to Very Low-Mass, Population II
Stars

We propose to carry out a Snapshot search for astrometric companions
in a subsample of very low-mass, halo subdwarfs identified within 120
parsecs of the Sun. These ultra-cool M subdwarfs are local
representatives of the lowest-mass H burning objects from the Galactic
Population II. The expected 3-4 astrometric doubles that will be
discovered will be invaluable in that they will be the first systems
from which gravitational masses of metal-poor stars at the bottom of
the main sequence can be directly measured.

WFC3/UV 11556

Investigations of the Pluto System

We propose a set of high SNR observations of the Pluto system that
will provide improved lightcurves, orbits, and photometric properties
of Nix and Hydra. The key photometric result for Nix and Hydra will be
a vastly improved lightcurve shape and rotation period to test if the
objects are in synchronous rotation or not. A second goal of this
program will be to retrieve a new epoch of albedo map for the surface
of Pluto. These observations will also improve masses and in some case
densities for the bodies in the Pluto system.

NIC 11495

The first direct detection of an extrasolar planetary stratosphere?

We request NICMOS grism spectroscopy to observe the transit of
WASP-3b. This newly discovered planet is the hottest nearby planet
discovered so far. The atmosphere is predicted to be so hot that TiO
and VO remain in the gas phase, creating a hot, strongly absorbing
stratosphere. This molecular absorption will cause a 6% enhancement in
the transit depth at 0.8 microns, compared to that at 1.3 microns.
NICMOS/G096 and NICMOS/G141 observations will therefore provide a
straightforward test of the hot stratosphere hypothesis. The HST
observations will provide a precisely determined radius measurement.
This is required to drive advances in theories of planetary formation,
evolution, and atmospheric physics and chemistry. The atmospheric TiO
and VO absorption is predicted to cause an anomalously high IR
brightness temperature for the planet. We need HST's direct test of
the hot stratosphere hypothesis promptly to enable appropriate
cold-Spitzer observations to be planned and interpreted. Spitzer is
likely to exhaust its cryogens before these observations could be
scheduled via the cycle 17 GO process.

 




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