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#46328
Tue 13 Oct 2009 10:55:AM
|
Joined: Feb 2001
Posts: 381,903
Launch Director
|
OP
Launch Director
Joined: Feb 2001
Posts: 381,903 |
HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY REPORT #4949
PERIOD COVERED: 5am October 9 - 5am October 13, 2009 (DOY 282/09:00z-286/09:00z)
OBSERVATIONS SCHEDULED
NIC1/NIC2/NIC3 8795
NICMOS Post-SAA Calibration - CR Persistence Part 6
This is 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 'Use After' 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 darks. 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 11947
Extended Dark Monitoring
This program takes a series of darks to obtain darks (including
amplifier glow, dark current, and shading profiles) for all three
cameras in the read-out sequences used in Cycle 17. A set of 12 orbits
will be observed every two months for a total of 72 orbits for a 12
month Cycle 17. This is a continuation of Cycle 16 program 11330 scaled
down by ~80%.
The first orbit (Visit A0) should be scheduled in the NICMOS SMOV after
the DC Transfer Test (11406) and at least 36h before the Filter Wheel
Test (11407). Data download using fast track.
The following 28 orbits (visit A1-N2) should be scheduled AFTER the SMOV
Proposal 11407 (Filter Wheel Test). This is done in order to monitor the
dark current following an adjustment of the NCS set-point. These visits
should be executed until the final temperature is reached during SMOV.
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 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 11907
UVIS Cycle 17 Contamination Monitor
The UV throughput of WFC3 during Cycle 17 is monitored via weekly
standard star observations in a subset of key filters covering 200-600nm
and F606W, F814W as controls on the red end. The data will provide a
measure of throughput levels as a function of time and wavelength,
allowing for detection of the presence of possible contaminants.
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).
COS/FUV 11895
FUV Detector Dark Monitor
The purpose of this proposal is to monitor the FUV detector dark rate by
taking long science exposures without illuminating the detector. The
detector dark rate and spatial distribution of counts will be compared
to pre-launch and SMOV data in order to verify the nominal operation of
the detector. Variations of count rate as a function of orbital position
will be analyzed to find dependence of dark rate on proximity to the
SAA. Dependence of dark rate as function of time will also be tracked.
ACS/WFC3 11879
CCD Daily Monitor (Part 1)
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 352 orbits (22 weeks) from 31 August 2009 to 31 January
2010.
STIS/CCD 11846
CCD Bias Monitor-Part 1
The purpose of this proposal is to 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/CCD 11844
CCD Dark Monitor Part 1
The purpose of this proposal is to monitor the darks for the STIS CCD.
WFC3/IR 11838
Completing a Flux-limited Survey for X-ray Emission from Radio Jets
We will measure the changing flow speeds, magnetic fields, and energy
fluxes in well-resolved quasar jets found in our short-exposure Chandra
survey by combining new, deep Chandra data with radio and optical
imaging. We will image each jet with sufficient sensitivity to estimate
beaming factors and magnetic fields in several distinct regions, and so
map the variations in these parameters down the jets. HST observations
will help diagnose the role of synchrotron emission in the overall SED,
and may reveal condensations on scales less than 0.1 arcsec.
STIS/CCD 11806
Coordinated Observations of LCROSS Impacts
We propose to observe the LCROSS (Lunar Crater Observation and Sensing
Satellite) impacts. This program will use STIS and WFC3 to observe the
Moon in conjunction with NASA's LCROSS mission (assuming Servicing
Mission 4 occurs before the LCROSS impacts). The goal is to determine
whether or not water ice and/or vapor is present in the subsurface of
the Moon. We will address this issue by 1) observing the sunlit ejecta
plume created by the LCROSS impacts and 2) examine the Lunar exosphere
for the presence of OH and other volatile species.
WFC3/UVIS 11729
Photometric Metallicity Calibration with WFC3 Specialty Filters
The community has chosen to include several filters in the WFC3 filter
complement that have been designed to allow fairly precise estimates of
stellar metallicities, and many science programs are enabled by this
capability. Since these filters do not exactly match those used for this
purpose on the ground, however, the mapping of stellar colors to stellar
metallicities needs to be calibrated. We propose to achieve this
calibration through observations of five stellar clusters with well
known metallicities. We will calibrate several different filter
calibrations which will allow future users to determine what filter
combination best meets their science needs.
WFC3/UVIS 11714
Snapshot Survey for Planetary Nebulae in Local Group Globular Clusters
Planetary nebulae (PNe) in globular clusters (GCs) raise a number of
interesting issues related to stellar and galactic evolution. The number
of PNe known in Milky Way GCs, four, is surprisingly low if one assumes
that all stars pass through a PN stage. However, it is likely that the
remnants of stars now evolving in galactic GCs leave the AGB so slowly
that any ejected nebula dissipates long before the star becomes hot
enough to ionize it. Thus there should not be ANY PNe in Milky Way
GCs--but there are four! It has been suggested that these PNe are the
result of mergers of binary stars within GCs, i.e., that they are
descendants of blue stragglers. The frequency of occurrence of PNe in
external galaxies poses more questions, because it shows a range of
almost an order of magnitude.
I propose a SNAPshot survey aimed at discovering PNe in the GC systems
of Local Group galaxies outside the Milky Way. These clusters, some of
which may be much younger than their counterparts in our galaxy, might
contain many more PNe than those of our own galaxy. I will use the
standard technique of emission-line and continuum imaging, which easily
discloses PNe. This proposal continues a WFPC2 program started in Cycle
16, but with the more powerful WFC3. As a by-product, the survey will
also produce color-magnitude diagrams for numerous clusters for the
first time, reaching down to the horizontal branch.
FGS 11704
The Ages of Globular Clusters and the Population II Distance Scale
Globular clusters are the oldest objects in the universe whose age can
be accurately determined. The dominant error in globular cluster age
determinations is the uncertain Population II distance scale. We propose
to use FGS 1R to obtain parallaxes with an accuracy of 0.2
milliarcsecond for 9 main sequence stars with [Fe/H] < -1.5. This will
determine the absolute magnitude of these stars with accuracies of 0.04
to 0.06mag. This data will be used to determine the distance to 24
metal-poor globular clusters using main sequence fitting. These
distances (with errors of 0.05 mag) will be used to determine the ages
of globular clusters using the luminosity of the subgiant branch as an
age indicator. This will yield absolute ages with an accuracy of 5%,
about a factor of two improvement over current estimates. Coupled with
existing parallaxes for more metal-rich stars, we will be able to
accurately determine the age for globular clusters over a wide range of
metallicities in order to study the early formation history of the Milky
Way and provide an independent estimate of the age of the universe.
The Hipparcos database contains only 1 star with [Fe/H] < -1.4 and an
absolute magnitude error less than 0.18 mag which is suitable for use in
main sequence fitting. Previous attempts at main sequence fitting to
metal-poor globular clusters have had to rely on theoretical
calibrations of the color of the main sequence. Our HST parallax program
will remove this source of possible systematic error and yield distances
to metal-poor globular clusters which are significantly more accurate
than possible with the current parallax data. The HST parallax data will
have errors which are 10 times smaller than the current parallax data.
Using the HST parallaxes, we will obtain main sequence fitting distances
to 11 globular clusters which contain over 500 RR Lyrae stars. This will
allow us to calibrate the absolute magnitude of RR Lyrae stars, a
commonly used Population II distance indicator.
WFC3/UV/ACS/WFC 11688
Exploring the Bottom End of the White Dwarf Cooling Sequence in the Open
Cluster NGC6819
The recent discovery by our group of an unexpectedly bright end of the
white-dwarf (WD) luminosity function (LF) of the metal-rich, old open
cluster NGC 6791 casts serious doubts on our understanding of the
physical process which rules the formation and the cooling of WDs. It is
clear at this point that the theory badly needs more observations. Here
we propose WFC3/UVIS and ACS/WFC HST observations reaching the bottom
end of the WD LF, for the first time in a solar-metallicity,
2.5-Gyr-old, populous open cluster: NGC 6819.
COS/FUV 11687
SNAPing Coronal Iron
This is a Snapshot Survey to explore two forbidden lines of highly
ionized iron in late-type coronal sources. Fe XII 1349 (T~ 2 MK) and Fe
XXI 1354 (T~ 10 MK) -- well known to Solar Physics -- have been detected
in about a dozen cool stars, mainly with HST/STIS. The UV coronal
forbidden lines are important because they can be observed with velocity
resolution of better than 15 km/s, whereas even the state-of-the-art
X-ray spectrometers on Chandra can manage only 300 km/s in the kilovolt
band where lines of highly ionized iron more commonly are found. The
kinematic properties of hot coronal plasmas, which are of great interest
to theorists and modelers, thus only are accessible in the UV at
present. The bad news is that the UV coronal forbidden lines are faint,
and were captured only in very deep observations with STIS. The good
news is that 3rd-generation Cosmic Origins Spectrograph, slated for
installation in HST by SM4, in a mere 25 minute exposure with its G130M
mode can duplicate the sensitivity of a landmark 25-orbit STIS E140M
observation of AD Leo, easily the deepest such exposure of a late-type
star so far. Our goal is to build up understanding of the properties of
Fe XII and Fe XXI in additional objects beyond the current limited
sample: how the lineshapes depend on activity, whether large scale
velocity shifts can be detected, and whether the dynamical content of
the lines can be inverted to map the spatial morphology of the stellar
corona (as in "Doppler Imaging''). In other words, we want to bring to
bear in the coronal venue all the powerful tricks of spectroscopic
remote sensing, well in advance of the time that this will be possible
exploiting the corona's native X-ray radiation. The 1290-1430 band
captured by side A of G130M also contains a wide range of key plasma
diagnostics that form at temperatures from below 10, 000 K (neutral
lines of CNO), to above 200, 000 K (semi-permitted O V 1371), including
the important bright multiplets of C II at 1335 and Si IV at 1400;
yielding a diagnostic gold mine for the subcoronal atmosphere. Because
of the broad value of the SNAP spectra, beyond the coronal iron project,
we waive the normal proprietary rights.
WFC3/UV/IR 11664
The WFC3 Galactic Bulge Treasury Program: Populations, Formation
History, and Planets
Exploiting the full power of the Wide Field Camera 3 (WFC3), we propose
deep panchromatic imaging of four fields in the Galactic bulge. These
data will enable a sensitive dissection of its stellar populations,
using a new set of reddening-free photometric indices we have
constructed from broad-band filters across UV, optical, and near-IR
wavelengths. These indices will provide accurate temperatures and
metallicities for hundreds of thousands of individual bulge stars.
Proper motions of these stars derived from multi-epoch observations will
allow separation of pure bulge samples from foreground disk
contamination. Our catalogs of proper motions and panchromatic
photometry will support a wide range of bulge studies.
Using these photometric and astrometric tools, we will reconstruct the
detailed star-formation history as a function of position within the
bulge, and thus differentiate between rapid- and extended-formation
scenarios. We will also measure the dependence of the stellar mass
function on metallicity, revealing how the characteristic mass of star
formation varies with chemistry. Our sample of bulge stars with accurate
metallicities will include 12 candidate hosts of extrasolar planets.
Planet frequency is correlated with metallicity in the solar
neighborhood; our measurements will extend this knowledge to a remote
environment with a very distinct chemistry.
Our proposal also includes observations of six well-studied globular and
open star clusters; these observations will serve to calibrate our
photometric indices, provide empirical population templates, and
transform the theoretical isochrone libraries into the WFC3 filter
system. Besides enabling our own program, these products will provide
powerful new tools for a host of other stellar-population investigations
with HST/WFC3. We will deliver all of the products from this Treasury
Program to the community in a timely fashion.
WFC3/UVIS 11657
The Population of Compact Planetary Nebulae in the Galactic Disk
We propose to secure narrow- and broad-band images of compact planetary
nebulae (PNe) in the Galactic Disk to study the missing link of the
early phases of post-AGB evolution. Ejected AGB envelopes become PNe
when the gas is ionized. PNe expand, and, when large enough, can be
studied in detail from the ground. In the interim, only the HST
capabilities can resolve their size, morphology, and central stars. Our
proposed observations will be the basis for a systematic study of the
onset of morphology. Dust properties of the proposed targets will be
available through approved Spitzer/IRS spectra, and so will the
abundances of the alpha- elements. We will be able thus to explore the
interconnection of morphology, dust grains, stellar evolution, and
populations. The target selection is suitable to explore the nebular and
stellar properties across the galactic disk, and to set constraints on
the galactic evolutionary models through the analysis of metallicity and
population gradients.
WFC3/UVIS 11594
A WFC3 Grism Survey for Lyman Limit Absorption at z=2
We propose to conduct a spectroscopic survey of Lyman limit absorbers at
redshifts 1.8 < z < 2.5, using WFC3 and the G280 grism. This proposal
intends to complete an approved Cycle 15 SNAP program (10878), which was
cut short due to the ACS failure. We have selected 64 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 16.0 <
log(NHI) < 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 16.0 < log(NHI) < 17.5 cm^-2. Third, we
will identify those sightlines which could provide a measurement of the
primordial D/H ratio. By carrying out this survey, we can also help
place meaningful constraints on two key quantities of cosmological
relevance. First, we will estimate the amount of metals in the LLS using
the f(N), and ground based observations of metal line transitions.
Second, by determining f(N) of the PLLS, we can constrain the amplitude
of the ionizing UV background at z~2 to a greater precision. This survey
is ideal for a snapshot observing program, because the on-object
integration times are all well below 30 minutes, and follow-up
observations from the ground require minimal telescope time due to the
QSO sample being bright.
COS/FUV 11592
Testing the Origin(s) of the Highly Ionized High-Velocity Clouds: A
Survey of Galactic Halo Stars at z>3 kpc
Cosmological simulation predicts that highly ionized gas plays an
important role in the formation and evolution of galaxies and their
interplay with the intergalactic medium. The NASA HST and FUSE missions
have revealed high-velocity CIV and OVI absorption along extragalactic
sightlines through the Galactic halo. These highly ionized high-velocity
clouds (HVCs) could cover 85% of the sky and have a detection rate
higher than the HI HVCs. Two competing, equally exciting, theories may
explain the origin of these highly ionized HVCs: 1) the "Galactic"
theory, where the HVCs are the result of feedback processes and trace
the disk-halo mass exchange, perhaps including the accretion of matter
condensing from an extended corona; 2) the "Local Group" theory, where
they are part of the local warm-hot intergalactic medium, representing
some of the missing baryonic matter of the Universe. Only direct
distance determinations can discriminate between these models. Our group
has found that some of these highly ionized HVCs have a Galactic origin,
based on STIS observations of one star at z<5.3 kpc. We propose an HST
FUV spectral survey to search for and characterize the high velocity NV,
CIV, and SiIV interstellar absorption toward 24 stars at much larger
distances than any previous searches (4<d<21 kpc, 3<|z|<13 kpc). COS
will provide atomic to highly ionized species (e.g., OI, CII, CIV, SiIV)
that can be observed at sufficient resolution (R~22, 000) to not only
detect these highly ionized HVCs but also to model their properties and
understand their physics and origins. This survey is only possible
because of the high sensitivity of COS in the FUV spectral range.
ACS/WFC3 11586
Exceptional Galactic Halo Globular Clusters and the Second Parameter
We propose to obtain deep ACS-WFC images of six globular clusters (five
of which have no previous HST photometry) that reside in the Galactic
halo, where the second parameter effect is most pronounced. These
globular clusters are among the least studied in the Galaxy and yet,
from the perspective of the second parameter phenomenon, the most
intriguing.
With the best available CMDs only reaching the vicinity of the main
sequence turn off at present, the unique sensitivity and resolution of
ACS-WFC will yield ages of unprecedented precision for these clusters.
These data will provide us with new insight into the stellar populations
present in the outer Galactic halo and the nature of the second
parameter. The second parameter plays a critical role in our
understanding of the formation and evolution of the Galaxy and the
proposed observations will shed new light on this problem and these
exceptional clusters.
WFC3/UVI 11580
Watching Young Planetary Nebulae Grow: The Movie
The development of magneto-hydro gas dynamical models is the key to the
understanding of both the physics (processes) and astronomy (initial
conditions) of astrophysical nebulae of all sorts. The models are
reaching their highest degree of accuracy when applied to and compared
against pre Planetary Nebulae (pPNe) thanks to the simplicity, relative
lack of extinction, and the detail of the imaging and kinematic data
that have bcome available for these objects. The primary barrier to
progress is inadequate kinematic data of pPNe against which the
predictions models can be tested. Unlike PNe, pPNe do not emit emission
lines for detailed Doppler measurements. Therefore it is essential to
find another way to monitor the morphological evolution.
Only HST can uncover the dynamics of the growth patterns by subtracting
multi-epoch images spanning a decade or more. We have selected four pPNe
with highly collimated outflows in different evolutionary stages for
which high-quality first epoch images were obtained from 1996 to 2002.
All of them display regularly shaped thin rims, sharp edges, and
symmetric pairs of knots or bowshocks that are ideal for our purposes.
We will closely mimic many of the earlier exposures using ACS and to
monitor changes in structures. The morphology and its evolution will be
compared to 3-D MHD models with adaptive grids in order to build a far
clearer picture of the nuclear geometry which shaped the outflows and
constrained their propagation to the present. We shall also obtain R, J,
and H images for use with a 3-D dust radiative transfer code LELUYA to
model the dust distribution deep into the nuclear zones.
NIC2/WFC3/IR 11548
Infrared Imaging of Protostars in the Orion A Cloud: The Role of
Environment in Star Formation
We propose NICMOS and WFC3/IR observations of a sample of 252 protostars
identified in the Orion A cloud with the Spitzer Space Telescope. These
observations will image the scattered light escaping the protostellar
envelopes, providing information on the shapes of outflow cavities, the
inclinations of the protostars, and the overall morphologies of the
envelopes. In addition, we ask for Spitzer time to obtain 55-95 micron
spectra of 75 of the protostars. Combining these new data with existing
3.6 to 70 micron photometry and forthcoming 5-40 micron spectra measured
with the Spitzer Space Telescope, we will determine the physical
properties of the protostars such as envelope density, luminosity,
infall rate, and outflow cavity opening angle. By examining how these
properties vary with stellar density (i.e. clusters vs. groups vs.
isolation) and the properties of the surrounding molecular cloud; we can
directly measure how the surrounding environment influences protostellar
evolution, and consequently, the formation of stars and planetary
systems. Ultimately, this data will guide the development of a theory of
protostellar evolution.
COS/NUV/FUV/WFC3/UVI 11534 S/IR COS-GTO: Atmosphere of a Transiting
Planet
COS observations of a transiting planet at different orbital locations
will be useful in identifying the chemical content, size, temperature,
and flows in the atmosphere of a transiting planet.
NIC 11408
NICMOS Focus and PAM Grid Tilt Tests
The purpose of this proposal is determine the PAM settings corresponding
to best focus for NIC1 and NIC2. A test will aslo be done on NIC3 in
order to establish that the nominal PAM position of -9.5mm relative to
mechanical zero results in an acceptable focus.
The program consists of: Visit 01: Focus sweep using NIC1 Visit 02:
Focus sweep using NIC2 Visit 03: Focus sweep using NIC3 Visit 04: Uplink
of revised PAM settings (if needed) Visit 05: PAM X/Y grid tilt for NIC1
Visit 06: PAM X/Y grid tilt for NIC2 Visit 07: PAM X/Y grid tilt for
NIC3 Visit 08: Uplink of revised PAM X/Y parameters (if needed)
The focus sweeps are based on the normal focus monitoring proposal
11320. The tilt grid measurements are based on proposal 8977 (NIC1) and
9645 (NIC2 and NIC3).
WFC3/ACS/IR 11359
Panchromatic WFC3 Survey of Galaxies at Intermediate z: Early Release
Science Program for Wide Field Camera 3
The unique panchromatic capabilities of WFC3 will be used to survey the
structure and evolution of galaxies at the peak of the galaxy assembly
epoch. Deep ultraviolet and near-IR imaging and slitless spectroscopy of
existing deep multi-color ACS fields will be used to gauge
star-formation and the growth of stellar mass as a function of
morphology, structure and surrounding density in the critical epoch 1 <
z < 4. Images in the F225W, F275W, and F336W filters will identify
galaxies at z < 1.5 from their UV continuum breaks, and provide
star-formation indicators tied directly to both local and z > 3
populations. Deep near-IR (F125W and F160W) images will probe the
stellar mass function well below 10^9 Msun for mass-complete samples.
Lastly, the WFC3 slitless UV and near-IR grisms will be used to measure
redshifts and star-formation rates from H-alpha and rest-frame UV
continuum slope. This WFC3 ERS program will survey one 4 x 2 mosaic for
a total area of 50 square arcminutes to 5-sigma depths of m_AB = 27 in
most filters from the mid-UV through the near-IR.
This multicolor high spatial resolution data set will allow the user to
gauge the growth of galaxies through star-formation and merging. High
precision photometric and low-resolution spectroscopic redshifts will
allow accurate determinations of the faint-end of the luminosity and
mass functions, and will shed light on merging and tidal disruption of
stellar and gaseous disks. The WFC3 images will also allow detailed
studies of the internal structure of galaxies, and the distribution of
young and old stellar populations. This program will demonstrate the
unique power of WFC3 by applying its many diverse modes and full
panchromatic capability to a forefront problem in astrophysics.
ACS/WFC3 11343
Identifying the Host Galaxies for Optically Dark Gamma-Ray Bursts
We propose to use the high spatial resolution capabilities of Chandra to
obtain precise positions for a sample of Gamma-ray bursts (GRBs) with no
optical afterglows, where the optical light is suppressed relative to
the X-ray flux. These bursts are likely to be highly obscured and may
have different environments from the optically bright GRBs. Our Chandra
observations will (unlike Swift-XRT positions) allow for the unique
identification of a host galaxy. To locate these host galaxies we will
follow up our Chandra positions with deep optical and IR observations
with HST. The ultimate aim is to understand any differences between the
host galaxies of optically dark and bright GRBs, and how these affect
the use of GRBs as tracers of star formation and galaxy evolution at
high redshift.
WFC3/IR 11202
The Structure of Early-type Galaxies: 0.1-100 Effective Radii
The structure, formation and evolution of early-type galaxies is still
largely an open problem in cosmology: how does the Universe evolve from
large linear scales dominated by dark matter to the highly non-linear
scales of galaxies, where baryons and dark matter both play important,
interacting, roles? To understand the complex physical processes
involved in their formation scenario, and why they have the tight
scaling relations that we observe today (e.g. the Fundamental Plane), it
is critically important not only to understand their stellar structure,
but also their dark-matter distribution from the smallest to the largest
scales. Over the last three years the SLACS collaboration has developed
a toolbox to tackle these issues in a unique and encompassing way by
combining new non-parametric strong lensing techniques, stellar
dynamics, and most recently weak gravitational lensing, with
high-quality Hubble Space Telescope imaging and VLT/Keck spectroscopic
data of early-type lens systems. This allows us to break degeneracies
that are inherent to each of these techniques separately and probe the
mass structure of early-type galaxies from 0.1 to 100 effective radii.
The large dynamic range to which lensing is sensitive allows us both to
probe the clumpy substructure of these galaxies, as well as their
low-density outer haloes. These methods have convincingly been
demonstrated, by our team, using smaller pilot-samples of SLACS lens
systems with HST data. In this proposal, we request observing time with
WFC3 and NICMOS to observe 53 strong lens systems from SLACS, to obtain
complete multi-color imaging for each system. This would bring the total
number of SLACS lens systems to 87 with completed HST imaging and
effectively doubles the known number of galaxy-scale strong lenses. The
deep HST images enable us to fully exploit our new techniques, beat down
low-number statistics, and probe the structure and evolution of early-
type galaxies, not only with a uniform data-set an order of magnitude
larger than what is available now, but also with a fully-coherent and
self-consistent methodological approach!
WFC3/ACS/IR 11142
Revealing the Physical Nature of Infrared Luminous Galaxies at 0.3<z<2.7
Using HST and Spitzer
We aim to determine physical properties of IR luminous galaxies at
0.3<z<2.7 by requesting coordinated HST/NIC2 and MIPS 70um observations
of a unique, 24um flux-limited sample with complete Spitzer mid-IR
spectroscopy. The 150 sources investigated in this program have S(24um)
> 0.8mJy and their mid-IR spectra have already provided the majority
targets with spectroscopic redshifts (0.3<z<2.7). The proposed
150~orbits of NIC2 and 66~hours of MIPS 70um will provide the physical
measurements of the light distribution at the rest-frame ~8000A and
better estimates of the bolometric luminosity. Combining these
parameters together with the rich suite of spectral diagnostics from the
mid-IR spectra, we will (1) measure how common mergers are among LIRGs
and ULIRGs at 0.3<z<2.7, and establish if major mergers are the drivers
of z>1 ULIRGs, as in the local Universe, (2) study the co-evolution of
star formation and blackhole accretion by investigating the relations
between the fraction of starburst/AGN measured from mid-IR spectra vs.
HST morphologies, L(bol) and z, and (3) obtain the current best
estimates of the far-IR emission, thus L(bol) for this sample, and
establish if the relative contribution of mid-to-far IR dust emission is
correlated with morphology (resolved vs. unresolved).
NIC2 10897
Coronagraphic imaging of the submillimeter debris disk of a 200Myr old
M-dwarf
A recent sub-millimeter survey has unambiguously discovered a new debris
disk around the M0.5 dwarf GJ842.2 which is 200 Myr old. Reanalysis of
the IRAS data has shown that there is also a 25 micron excess toward
this star indicating warm dust close to the star. It is also only the
second debris disk found among M-dwarfs that constitute 70 % of the
stars in the Galaxy. Collisional and Poynting-Roberston timescale
arguments indicate that the cold grains detected in the sub-mm are
``primordial'', i.e. original grains from the protoplanetary phase. The
disk around GJ842.2 is thus unique in terms of the presence of dust at
such a late stage of evolution and presents two conundrums: why did it
retain so much primordial dust at large distances, and why does it
continue to produce dust close to the star? We propose to conduct high
contrast NICMOS coronagraphic imaging of GJ842.2 to determine the
spatial distribution of the small reflecting grains and test the various
scenarios which might explain the IRAS and sub-mm data e.g.resonant
trapping of dust by planets or ``sandblasting'' by interstellar medium
grains working more aggressively on a low-luminosity star than on an
A-type star like Beta Pic. Also, we would search for an evolutionary
sequence between GJ842.2 and the only other M-dwarf with a disk resolved
by HST, the 10 Myr old AU Mic system.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports
of potential non-nominal performance that will be investigated.)
HSTARS:
12040 - GSAcq(1,2,1) scheduled at 283/03:37:59 - 03:45:30 failed to RGA
Hold (gyro control) due to search radius limit exceeded on FGS-2
Observations affected: STIS 89 Proposal ID# 10897.
12041 - GSAcq(1,2,1) scheduled at 286/02:05:19 - 02:12:50 and
REAcq(1,2,1) scheduled at 286/03:28:54 both resulted in fine lock backup
(1,0,1) using FGS-1.
Observations possibly affected: STIS 10, Proposal ID# 11846 and
WFC3 36-37, Proposal ID# 11202.
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS GSAcq 40 39
FGS REAcq 21 21
OBAD with Maneuver 34 34
SIGNIFICANT EVENTS: (None)
David Cottle
UBB Owner & Administrator
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