HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5037
PERIOD
COVERED: 5am February 19 - 5am February 22, 2010 (DOY 050/10:00z-053/10:00z)
OBSERVATIONS
SCHEDULED
WFC3/UV
12019
After
the Fall: Fading AGN in Post-starburst Galaxies
We
propose joint Chandra and HST observations of an extraordinary sample
of
12 massive post-starburst galaxies at z=0.4-0.8 that are in the
short-lived
evolution phase a few 100 Myr after the peak of
merger-driven
star formation and AGN activity. We will use the data to
measure
X-ray luminosities, black hole masses, and accretion rates; and
with
the accurate "clocks" provided by post-starburst stellar
populations,
we will directly test theoretical models that predict a
power-law
decay in the AGN light curve. We will also test whether star
formation
and black hole accretion shut down in lock-step, quantify
whether
the black holes transition to radiatively inefficient accretion
states,
and constrain the observational signatures of black hole
mergers.
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
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).
ACS/WFC3
11882
CCD
Hot Pixel Annealing
All
the data for this program is acquired using internal targets (lamps)
only,
so all of the exposures should be taken during Earth occultation
time
(but not during SAA passages). This program emulates the ACS
pre-flight
ground calibration and post launch SMOV testing (program
8948),
so that results from each epoch can be directly compared.
Extended
Pixel Edge Response (EPER) and First Pixel Response (FPR) data
will
be obtained over a range of signal levels for the Wide Field
Channel
(WFC). The High Resolution Channel (HRC) visits have been
removed
since it could not be repaired during SM4.
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.
COS/NUV/FUV
11741
Probing
Warm-Hot Intergalactic Gas at 0.5 < z < 1.3 with a Blind Survey
for
O VI, Ne VIII, Mg X, and Si XII Absorption Systems
Currently
we can only account for half of the baryons (or less) expected
to
be found in the nearby universe based on D/H and CMB observations.
This
"missing baryons problem" is one of the highest-priority challenges
in
observational extragalatic astronomy. Cosmological simulations
suggest
that the baryons are hidden in low-density, shock-heated
intergalactic
gas in the log T = 5 - 7 range, but intensive UV and X-ray
surveys
using O VI, O VII, and O VIII absorption lines have not yet
confirmed
this prediction. We propose to use COS to carry out a
sensitive
survey for Ne VIII and Mg X absorption in the spectra of nine
QSOs
at z(QSO) > 0.89. For the three highest-redshift QSOs, we will also
search
for Si XII. This survey will provide more robust constraints on
the
quantity of baryons in warm-hot intergalactic gas at 0.5 < z < 1.3,
and
the data will provide rich constraints on the metal enrichment,
physical
conditions, and nature of a wide variety of QSO absorbers in
addition
to the warm-hot systems. By comparing the results to other
surveys
at lower redshifts (with STIS, FUSE, and from the COS GTO
programs),
the project will also enable the first study of how these
absorbers
evolve with redshift at z < 1. By combining the program with
follow-up
galaxy redshift surveys, we will also push the study of
galaxy-absorber
relationships to higher redshifts, with an emphasis on
the
distribution of the WHIM with respect to the large-scale matter
distribution
of the universe.
WFC3/UVIS
11732
The
Temperature Profiles of Quasar Accretion Disks
We
can now routinely measure the size of quasar accretion disks using
gravitational
microlensing of lensed quasars. At optical wavelengths we
observe
a size and scaling with black hole mass roughly consistent with
thin
disk theory but the sizes are larger than expected from the
observed
optical fluxes. One solution would be to use a flatter
temperature
profile, which we can study by measuring the wavelength
dependence
of the disk size over the largest possible wavelength
baseline.
Thus, to understand the size discrepancy and to probe closer
to
the inner edge of the disk we need to extend our measurements to UV
wavelengths,
and this can only be done with HST. For example, in the UV
we
should see significant changes in the optical/UV size ratio with
black
hole mass. We propose monitoring 5 lenses spanning a broad range
of
black hole masses with well-sampled ground based light curves,
optical
disk size measurements and known GALEX UV fluxes during Cycles
17
and 18 to expand from our current sample of two lenses. We would
obtain
5 observations of each target in each Cycle, similar to our
successful
strategy for the first two targets.
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 (z>1). 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/IR
11696
Infrared
Survey of Star Formation Across Cosmic Time
We
propose to use the unique power of WFC3 slitless spectroscopy to
measure
the evolution of cosmic star formation from the end of the
reionization
epoch at z>6 to the close of the galaxy- building era at
z~0.3.Pure
parallel observations with the grisms have proven to be
efficient
for identifying line emission from galaxies across a broad
range
of redshifts. The G102 grism on WFC3 was designed to extend this
capability
to search for Ly-alpha emission from the first galaxies.
Using
up to 250 orbits of pure parallel WFC3 spectroscopy, we will
observe
about 40 deep (4-5 orbit) fields with the combination of G102
and
G141, and about 20 shallow (2-3 orbit) fields with G141 alone.
Our
primary science goals at the highest redshifts are: (1) Detect Lya
in
~100 galaxies with z>5.6 and measure the evolution of the Lya
luminosity
function, independent of of cosmic variance; 2) Determine the
connection
between emission line selected and continuum-break selected
galaxies
at these high redshifts, and 3) Search for the proposed
signature
of neutral hydrogen absorption at re-ionization. At
intermediate
redshifts we will (4) Detect more than 1000 galaxies in
Halpha
at 0.5<z<1.8 to measure the evolution of the extinction-corrected
star
formation density across the peak epoch of star formation. This is
over
an order-of-magnitude improvement in the current statistics, from
the
NICMOS Parallel grism survey. (5) Trace ``cosmic downsizing" from
0.5<z<2.2;
and (6) Estimate the evolution in reddening and metallicty in
star-
forming galaxies and measure the evolution of the Seyfert
population.
For hundreds of spectra we will be able to measure one or
even
two line pair ratios -- in particular, the Balmer decrement and
[OII]/[OIII]
are sensitive to gas reddening and metallicity. As a bonus,
the
G102 grism offers the possibility of detecting Lya emission at
z=7-8.8.
To
identify single-line Lya emitters, we will exploit the wide
0.8--1.9um
wavelength coverage of the combined G102+G141 spectra. All
[OII]
and [OIII] interlopers detected in G102 will be reliably separated
from
true LAEs by the detection of at least one strong line in the G141
spectrum,
without the need for any ancillary data. We waive all
proprietary
rights to our data and will make high-level data products
available
through the ST/ECF.
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/UVIS/IR
11644
A
Dynamical-Compositional Survey of the Kuiper Belt: A New Window Into
the
Formation of the Outer Solar System
The
eight planets overwhelmingly dominate the solar system by mass, but
their
small numbers, coupled with their stochastic pasts, make it
impossible
to construct a unique formation history from the dynamical or
compositional
characteristics of them alone. In contrast, the huge
numbers
of small bodies scattered throughout and even beyond the
planets,
while insignificant by mass, provide an almost unlimited number
of
probes of the statistical conditions, history, and interactions in
the
solar system. To date, attempts to understand the formation and
evolution
of the Kuiper Belt have largely been dynamical simulations
where
a hypothesized starting condition is evolved under the
gravitational
influence of the early giant planets and an attempt is
made
to reproduce the current observed populations. With little
compositional
information known for the real Kuiper Belt, the test
particles
in the simulation are free to have any formation location and
history
as long as they end at the correct point. Allowing compositional
information
to guide and constrain the formation, thermal, and
collisional
histories of these objects would add an entire new dimension
to
our understanding of the evolution of the outer solar system. While
ground
based compositional studies have hit their flux limits already
with
only a few objects sampled, we propose to exploit the new
capabilities
of WFC3 to perform the first ever large-scale
dynamical-compositional
study of Kuiper Belt Objects (KBOs) and their
progeny
to study the chemical, dynamical, and collisional history of the
region
of the giant planets. The sensitivity of the WFC3 observations
will
allow us to go up to two magnitudes deeper than our ground based
studies,
allowing us the capability of optimally selecting a target list
for
a large survey rather than simply taking the few objects that can be
measured,
as we have had to do to date. We have carefully constructed a
sample
of 120 objects which provides both overall breadth, for a general
understanding
of these objects, plus a large enough number of objects in
the
individual dynamical subclass to allow detailed comparison between
and
within these groups. These objects will likely define the core
Kuiper
Belt compositional sample for years to come. While we have many
specific
results anticipated to come from this survey, as with any
project
where the field is rich, our current knowledge level is low, and
a
new instrument suddenly appears which can exploit vastly larger
segments
of the population, the potential for discovery -- both
anticipated
and not -- is extraordinary.
WFC3/UVIS
11629
Far-UV
Phase-Resolved Spectroscopy of PSR B0656+14
X-ray
observations of the brightest middle-aged pulsar PSR B0656+14 have
shown
a Wien tail of thermal emission from the neutron star surface in
soft
X-rays and magnetospheric emission at higher X-ray energies.
Optical/near-UV
observations of this pulsar have shown that its emission
is
predominantly magnetospheric in this range and indicated that the
Rayleigh-Jeans
thermal component could dominate in the far-UV. This
hypothesis
has been confirmed by our STIS/FUV observation, which,
however,
was too short to separate and study the thermal emission (only
2
of 8 allocated orbits were executed before the STIS failure). Using
the
superior sensitivity of COS/FUV, we will perform phase-resolved
spectroscopy
and wavelength-resolved timing of the pulsar radiation in
the
1105-1900 A band. The results of this observation, combined with the
optical-UV
and X-ray data, will allow us to firmly separate the thermal
and
magnetospheric components and infer the temperature and radius of
the
neutron star, which is important for understanding the thermal
evolution
of neutron stars and constraining the composition and equation
of
state of their superdense interiors.
STIS/CCD
11606
Dynamical
Hypermassive Black Hole Masses
We
will use STIS spectra to derive the masses of 5 hypermassive black
holes
(HMBHs). From the observed scaling relations defined by less
massive
spheroids, these objects are expected to reside at the nuclei of
host
galaxies with stellar velocity dispersions greater than 320 km/s.
These
5 targets have confirmed regular gas distributions on the scales
of
the black hole sphere of influence. It is essential that the sphere
of
influence is resolved for accurate determinations of black hole mass
(0.1").
These scales cannot be effectively observed from the ground.
Only
two HMBHs have had their masses modeled so far; it is impossible to
draw
any general conclusions about the connections between HMBH mass and
their
massive host galaxies. With these 5 targets we will determine
whether
these HMBHs deviate from the scaling relations defined by less
massive
spheroids. A larger sample will allow us to firmly anchor the
high
mass end of the correlation between black hole mass and stellar
velocity
dispersion, and other scaling relations. Therefore we are also
conducting
a SNAPshot program with which we expect to detect a further
24
HMBH candidates for STIS observation in future cycles. At the
completion
of this project we will have populated the high mass end of
the
scaling relations with the sample sizes enjoyed by less massive
spheroids.
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.
WFC3/ACS/IR
11584
Resolving
the Smallest Galaxies with ACS
An
order of magnitude more dwarf galaxies are expected to inhabit the
Local
Group, based on currently accepted galaxy formation models, than
have
been observed. This discrepancy has been noted in environments
ranging
from the field to rich clusters, with evidence emerging that
lower
density regions contain fewer dwarfs per giant than higher density
regions,
in further contrast to model predictions. However, there is no
complete
census of the faintest dwarf galaxies in any environment. The
discovery
of the smallest and faintest dwarfs is hampered by the
limitations
in detecting such compact or low surface brightness
galaxies,
and this is compounded by the great difficulty in determining
accurate
distances to, or ascertaining group membership for, such faint
objects.
The M81 group provides a powerful means for establishing
membership
for faint galaxies in a low density region. With a distance
modulus
of 27.8, the tip of the red giant branch (TRGB) appears at I ~
24,
just within the reach of ground based surveys. We have completed a
65
square degree survey in the region around M81 with the CFHT/MegaCam.
Half
of our survey was completed before Cycle 16 and we were awarded
time
with WFPC2 to observe 15 new candidate dwarf galaxy group members
in
F606W and F814W bands in order to construct color-magnitude diagrams
from
which to measure accurate TRGB distances and determine star
formation
and metallicity histories. The data obtained show that 8 - 9
of
these objects are galaxies at the same distance as M81. In completing
our
survey, we have discovered an additional 8 candidate galaxies we
propose
to image with ACS in order to measure TRGB distances and
establish
membership. We also wish to re-observe our smallest candidate
group
member and a tidal dwarf candidate with deeper observations made
possible
with ACS. Once membership has been established for this second
set
of candidates, we will have a complete census of the dwarf galaxy
population
in the M8 group to M_r ~ -10, allowing us to obtain a firm
measurement
of the luminosity function faint-end slope, and, combined
with
previous HST data, to provide a complete inventory of the age and
abundance
properties for the collapsed core of the M81 group.
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.
WFC3/ACS/IR
11563
Galaxies
at z~7-10 in the Reionization Epoch: Luminosity Functions to
<0.2L*
from Deep IR Imaging of the HUDF and HUDF05 Fields
The
first generations of galaxies were assembled around redshifts
z~7-10+,
just 500-800 Myr after recombination, in the heart of the
reionization
of the universe. We know very little about galaxies in this
period.
Despite great effort with HST and other telescopes, less than
~15
galaxies have been reliably detected so far at z>7, contrasting with
the
~1000 galaxies detected to date at z~6, just 200-400 Myr later, near
the
end of the reionization epoch. WFC3 IR can dramatically change this
situation,
enabling derivation of the galaxy luminosity function and its
shape
at z~7-8 to well below L*, measurement of the UV luminosity
density
at z~7-8 and z~8-9, and estimates of the contribution of
galaxies
to reionization at these epochs, as well as characterization of
their
properties (sizes, structure, colors). A quantitative leap in our
understanding
of early galaxies, and the timescales of their buildup,
requires
a total sample of ~100 galaxies at z~7-8 to ~29 AB mag. We can
achieve
this with 192 WFC3 IR orbits on three disjoint fields
(minimizing
cosmic variance): the HUDF and the two nearby deep fields of
the
HUDF05. Our program uses three WFC3 IR filters, and leverages over
600
orbits of existing ACS data, to identify, with low contamination, a
large
sample of over 100 objects at z~7-8, a very useful sample of ~23
at
z~8-9, and limits at z~10. By careful placement of the WFC3 IR and
parallel
ACS pointings, we also enhance the optical ACS imaging on the
HUDF
and a HUDF05 field. We stress (1) the need to go deep, which is
paramount
to define L*, the shape, and the slope alpha of the luminosity
function
(LF) at these high redshifts; and (2) the far superior
performance
of our strategy, compared with the use of strong lensing
clusters,
in detecting significant samples of faint z~7-8 galaxies to
derive
their luminosity function and UV ionizing flux. Our recent z~7.4
NICMOS
results show that wide-area IR surveys, even of GOODS-like depth,
simply
do not reach faint enough at z~7-9 to meet the LF and UV flux
objectives.
In the spirit of the HDF and the HUDF, we will waive any
proprietary
period, and will also deliver the reduced data to STScI. The
proposed
data will provide a Legacy resource of great value for a wide
range
of archival science investigations of galaxies at redshifts z~2-9.
The
data are likely to remain the deepest IR/optical images until JWST
is
launched, and will provide sources for spectroscopic followup by
JWST,
ALMA and EVLA.
COS/NUV
11561
An
Intensive COS Spectroscopic Study of the Planetary Debris Disks
Around
two Warm White Dwarfs
It
is very likely that the gas giants in our Solar system will survive
the
evolution of the Sun into a white dwarf, and the same is thought to
be
generally true for Jovian planets around solar-like stars if their
initial
orbits are wider than ~3AU. Despite this prediction, no
unambiguous
detection of a planet around a white dwarf has been
announced
so far. However, over the past few years, about a dozen white
dwarfs
have been identified which host metal-rich debris disks that are
thought
to stem from the tidal disruption of asteroids. In most cases
the
debris disks are observed in the form of an infrared flux excess,
and
offer relatively little diagnostic potential for the study of their
structure.
We have discovered three warm (T~20000K) white dwarfs with
metal-rich
debris disks in a gaseous phase which display strong
double-peaked
CaII emission lines in the I-band and weak Fe 5169A
emission.
The line profiles can be modeled in terms of Keplerian disks
with
an extension of ~1Rsun around the white dwarfs. Photospheric MgII
4481A
absorption demonstrates that the white dwarfs are accreting from
the
debris disks. Besides these spectral features, the optical
wavelength
range is devoid of other useful metal transitions. Here, we
propose
an intensive spectroscopic ultraviolet study of these systems,
which
will provide (a) ~1000 photospheric absorption lines of 15
chemical
elements, allowing an accurate abundance study of the material
accreted
from the debris disks, and (b) ~2 dozen additional emission
lines
of Mg, Cr, Ti, and Fe that will provide detailed insight into the
dynamical,
thermal, and density structure of these exo-planetary debris
disks.
WFC3/UVI/IR
11557
The
Nature of Low-Ionization BAL QSOs
The
rare subclass of optically-selected QSOs known as low-ionization
broad
absorption line (LoBAL) QSOs show signs of high-velocity gas
outflows
and reddened continua indicative of dust obscuration. Recent
studies
show that galaxies hosting LoBAL QSOs tend to be ultraluminous
infrared
systems that are undergoing mergers, and that have dominant
young
(< 100 Myr) stellar populations. Such studies support the idea
that
LoBAL QSOs represent a short- lived phase early in the life of
QSOs,
when powerful AGN-driven winds are blowing away the dust and gas
surrounding
the QSO. If so, understanding LoBALs would be critical in
the
study of phenomena regulating black hole and galaxy evolution, such
as
AGN feedback and the early stages of nuclear accretion. These
results,
however, come from very small samples that may have serious
selection
biases. We are therefore taking a more aggressive approach by
conducting
a systematic multiwavelength study of a volume limited sample
of
LoBAL QSOs at 0.5 < z < 0.6 drawn from SDSS. We propose to image
their
host galaxies in two bands using WFC3/UVIS and WFC3/IR to study
the
morphologies for signs of recent tidal interactions and to map their
interaction
and star forming histories. We will thus determine whether
LoBAL
QSOs are truly exclusively found in young merging systems that are
likely
to be in the early stages of nuclear accretion.
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.
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:
18814-0
- Null Genslew for proposal 12077 - slot 7 @ 050/1152z
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSAcq
19
19
FGS
REAcq
27
27
OBAD
with Maneuver 16
16
SIGNIFICANT
EVENTS: (None)