HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5097
PERIOD
COVERED: 5am May 14 - 5am May 17, 2010 (DOY 134/09:00z-137/09:00z)
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
(None)
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSAcq
19
19
FGS
REAcq
19
19
OBAD
with Maneuver 18
18
SIGNIFICANT
EVENTS: (None)
OBSERVATIONS
SCHEDULED:
WFC3/IR/S/C
12089
Persistence
- Part 2
The
IR detectors on WFC3, like other IR detectors, trap charge when
exposed
to sources near or above the full well of the detector diodes.
This
charge leaks out, producing detectable afterglow images for periods
which
can last for several hours, depending on the amount of over
exposure.
These visits, which consist of tungsten lamp exposures of
varying
durations followed by darks, are intended to provide a better
calibration
of persistence over the full area of the IR detector of
WFC3.
WFC3/UV/IR
12021
An
Irradiated Disk in an Ultraluminous X-Ray Source
Whether
ultraluminous X-ray sources (ULXs) contain stellar-mass or
intermediate-mass
black holes (IMBHs) is an important, but as yet
unresolved,
astrophysical question. We have discovered variable optical
emission
from the ULX NGC 5408 X-1 that we interpret as reprocessed
emission
in an irradiated disk. We propose simultaneous observations
with
Chandra and HST to test this interpretation and place constraints
on
the geometry of the accretion disk. The observations should provide a
means
to discriminate between stellar-mass versus intermediate-mass
black
holes.
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).
WFC3/UVIS
11903
UVIS
Photometric Zero Points
This
proposal obtains the photometric zero points in 53 of the 62
UVIS/WFC3
filters: the 18 broad-band filters, 8 medium-band filters, 16
narrow-band
filters, and 11 of the 20 quad filters (those being used in
cycle
17). The observations will be primary obtained by observing the
hot
DA white dwarf standards GD153 and G191-B2B. A redder secondary
standard,
P330E, will be observed in a subset of the filters to provide
color
corrections. Repeat observations in 16 of the most widely used
cycle
17 filters will be obtained once per month for the first three
months,
and then once every second month for the duration of cycle 17,
alternating
and depending on target availability. These observations
will
enable monitoring of the stability of the photometric system.
Photometric
transformation equations will be calculated by comparing the
photometry
of stars in two globular clusters, 47 Tuc and NGC 2419, to
previous
measurements with other telescopes/instruments.
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.
FGS
11789
An
Astrometric Calibration of Population II Distance Indicators
In
2002, HST produced a highly precise parallax for RR Lyrae. That
measurement
resulted in an absolute magnitude, M(V)= 0.61+/-0.11, a
useful
result, judged by the over ten refereed citations each year
since.
It is, however, unsatisfactory to have the direct,
parallax-based,
distance scale of Population II variables based on a
single
star. We propose, therefore, to obtain the parallaxes of four
additional
RR Lyrae stars and two Population II Cepheids, or W Vir
stars.
The Population II Cepheids lie with the RR Lyrae stars on a
common
K-band Period-Luminosity relation. Using these parallaxes to
inform
that relationship, we anticipate a zero point error of 0.04
magnitude.
This result should greatly strengthen confidence in the
Population
II distance scale and increase our understanding of RR Lyrae
star
and Pop. II Cepheid astrophysics.
FGS
11788
The
Architecture of Exoplanetary Systems
Are
all planetary systems coplanar? Concordance cosmogony makes that
prediction.
It is, however, a prediction of extrasolar planetary system
architecture
as yet untested by direct observation for main sequence
stars
other than the Sun. To provide such a test, we propose to carry
out
FGS astrometric studies on four stars hosting seven companions. Our
understanding
of the planet formation process will grow as we match not
only
system architecture, but formed planet mass and true distance from
the
primary with host star characteristics for a wide variety of host
stars
and exoplanet masses.
We
propose that a series of FGS astrometric observations with
demonstrated
1 millisecond of arc per-observation precision can
establish
the degree of coplanarity and component true masses for four
extrasolar
systems: HD 202206 (brown dwarf+planet); HD 128311
(planet+planet),
HD 160691 = mu Arae (planet+planet), and HD 222404AB =
gamma
Cephei (planet+star). In each case the companion is identified as
such
by assuming that the minimum mass is the actual mass. For the last
target,
a known stellar binary system, the companion orbit is stable
only
if coplanar with the AB binary orbit.
COS/NUV/FUV
11728
The
Impact of Starbursts on the Gaseous Halos of Galaxies
Perhaps
the most important (yet uncertain) aspects of galaxy evolution
are
the processes by which galaxies accrete gas and by which the
resulting
star formation and black hole growth affects this accreting
gas.
It is believed that both the form of the accretion and the nature
of
the feedback change as a function of the galaxy mass. At low mass the
gas
comes in cold and the feedback is provided by massive stars. At high
mass,
the gas comes in hot, and the feedback is from an AGN. The
changeover
occurs near the mass where the galaxy population transitions
from
star-forming galaxies to red and dead ones. The population of red
and
dead galaxies is building with cosmic time, and it is believed that
feedback
plays an important role in this process: shutting down star
formation
by heating and/or expelling the reservoir of cold halo gas. To
investigate
these ideas, we propose to use COS far-UV spectra of
background
QSOs to measure the properties of the halo gas in a sample of
galaxies
near the transition mass that have undergone starbursts within
the
past 100 Myr to 1 Gyr. The galactic wind associated with the
starburst
is predicted to have affected the properties of the gaseous
halo.
To test this, we will compare the properties of the halos of the
post-starburst
galaxies to those of a control sample of galaxies matched
in
mass and QSO impact parameter. Do the halos of the post-starburst
galaxies
show a higher incidence rate of Ly-Alpha and metal
absorption-lines?
Are the kinematics of the halo gas more disturbed in
the
post-starbursts? Has the wind affected the ionization state and/or
the
metallicity of the halo? These data will provide fresh new insights
into
the role of feedback from massive stars on the evolution of
galaxies,
and may also offer clues about the properties of the QSO metal
absorption-line
systems at high-redshift .
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).
COS/NUV
11705
Physical
Properties of Quasar Outflows: From BALs to Mini-BALs
Accretion
disk outflows are important components of quasar environments.
They
might play a major role in facilitating accretion, regulating star
formation
in the host galaxies and distributing metals to the
surrounding
gas. They reveal themselves most conspicuously via broad
absorption
lines (BALs), but they appear even more frequently in other
guises
such as the weaker and narrower "mini-BALs." How are these
diverse
outflow features related? Are mini-BALs really just "mini"
versions
of the BALs, or do they represent a fundamentally different
type
of outflow, with different degrees of ionization, column densities,
mass
loss rates, physical origins, etc.?
We
propose HST-COS spectroscopy to make the first quantitative
assessment
of the outflow physical conditions across the full range of
weak/narrow
mini-BALs to strong/broad BALs. Our strategy is to measure
key
diagnostic lines (SVI, OVI, CIII, SIV, PV, etc.) at 930A - 1130A
(rest-
frame) in a sample of 7 outflow quasars with known mini-BALs
through
weak BALs. We will then 1) combine the COS data with
ground-based
spectra of the same quasars to include more lines (CIV,
SiIV)
at longer wavelengths, and 2) include in our analysis a nearly
identical
UV/optical dataset obtained previously for a sample of quasars
with
strong BALs. Our study of this combined dataset will be an
essential
next step toward a more global understanding of quasar
outflows.
WFC3/UVIS/IR
11700
Bright
Galaxies at z>7.5 with a WFC3 Pure Parallel Survey
The
epoch of reionization represents a special moment in the history of
the
Universe as it is during this era that the first galaxies and star
clusters
are formed. Reionization also profoundly affects the
environment
where subsequent generations of galaxies evolve. Our
overarching
goal is to test the hypothesis that galaxies are responsible
for
reionizing neutral hydrogen. To do so we propose to carry out a pure
parallel
WFC3 survey to constrain the bright end of the redshift z>7.5
galaxy
luminosity function on a total area of 176 arcmin^2 of sky.
Extrapolating
the evolution of the luminosity function from z~6, we
expect
to detect about 20 Lyman Break Galaxies brighter than M_* at z~8
significantly
improving the current sample of only a few galaxies known
at
these redshifts. Finding significantly fewer objects than predicted
on
the basis of extrapolation from z=6 would set strong limits to the
brightness
of M_*, highlighting a fast evolution of the luminosity
function
with the possible implication that galaxies alone cannot
reionize
the Universe. Our observations will find the best candidates
for
spectroscopic confirmation, that is bright z>7.5 objects, which
would
be missed by small area deeper surveys. The random pointing nature
of
the program is ideal to beat cosmic variance, especially severe for
luminous
massive galaxies, which are strongly clustered. In fact our
survey
geometry of 38 independent fields will constrain the luminosity
function
like a contiguous single field survey with two times more area
at
the same depth. Lyman Break Galaxies at z>7.5 down to m_AB=26.85 (5
sigma)
in F125W will be selected as F098M dropouts, using three to five
orbits
visits that include a total of four filters (F606W, F098M, F125W,
F160W)
optimized to remove low-redshift interlopers and cool stars. Our
data
will be highly complementary to a deep field search for high- z
galaxies
aimed at probing the faint end of the luminosity function,
allowing
us to disentangle the degeneracy between faint end slope and
M_*
in a Schechter function fit of the luminosity function. We waive
proprietary
rights for the data. In addition, we commit to release the
coordinates
and properties of our z>7.5 candidates within one month from
the
acquisition of each field.
COS/FUV
11699
On
the Evolutionary Status of Extremely Hot Helium Stars - are the O(He)
Stars
Successors of the R CrB Stars?
We
propose UV spectroscopy of the four unique post-AGB stars of spectral
type
O(He) in order to understand the origin of their peculiar surface
abundances.
These stars are the only known amongst the hottest post-AGB
stars
(effective temperatures > 100, 000 K) whose atmospheres are
composed
of almost pure helium. This chemistry markedly differs from
that
of the hydrogen-deficient post-AGB evolutionary sequence with
objects
which have carbon dominated atmospheres (PG1159 stars and
Wolf-Rayet
central stars).
While
PG1159 and Wolf-Rayet stars are the result of a late helium-shell
flash,
this scenario cannot explain the O(He) stars. Instead, they are
possibly
double-degenerate mergers. We speculate that the four O(He)
stars
represent evolved RCrB stars, which also have helium-dominated
atmospheres.
We aim to determine the C, N, O, and Si abundances
precisely,
in order to proof this evolutionary link.
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.
WFC3/IR
11666
Chilly
Pairs: A Search for the Latest-type Brown Dwarf Binaries and the
Prototype
Y Dwarf
We
propose to use HST/NICMOS to image a sample of 27 of the nearest (<
20
pc) and lowest luminosity T-type brown dwarfs in order to identify
and
characterize new very low mass binary systems. Only 3 late-type T
dwarf
binaries have been found to date, despite that fact that these
systems
are critical benchmarks for evolutionary and atmospheric models
at
the lowest masses. They are also the most likely systems to harbor Y
dwarf
companions, an as yet unpopulated putative class of very cold (T <
600
K) brown dwarfs. Our proposed program will more than double the
number
of T5-T9 dwarfs imaged at high resolution, with an anticipated
yield
of ~5 new binaries with initial characterization of component
spectral
types. We will be able to probe separations sufficient to
identify
systems suitable for astrometric orbit and dynamical mass
measurements.
We also expect one of our discoveries to contain the first
Y-type
brown dwarf. Our proposed program complements and augments
ongoing
ground-based adaptive optics surveys and provides pathway
science
for JWST.
WFC3/IR/ACS/WFC
11663
Formation
and Evolution of Massive Galaxies in the Richest Environments
at
1.5 < z < 2.0
We
propose to image seven 1.5<z<2 clusters and groups from the IRAC
Shallow
Cluster Survey with WFC3 and ACS in order to study the formation
and
evolution of massive galaxies in the richest environments in the
Universe
in this important redshift range. We will measure the evolution
of
the sizes and morphologies of massive cluster galaxies, as a function
of
redshift, richness, radius and local density. In combination with
allocated
Keck spectroscopy, we will directly measure the dry merger
fraction
in these clusters, as well as the evolution of Brightest
Cluster
Galaxies (BCGs) over this redshift range where clear model
predictions
can be confronted. Finally we will measure both the epoch of
formation
of the stellar populations and the assembly history of that
stellar
mass, the two key parameters in the modern galaxy formation
paradigm.
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.
STIS/CC
11626
Searching
for the Upper Mass Limit in NGC 3603, the Nearest Giant H II
Region
What
is the mass of the highest mass star? 100Mo? 150Mo? 200Mo? Or
higher?
Theory gives us little guidance as to what physics sets the
upper
mass limit, presuming one exists. Is it due to limitations in the
highest
masses that can coalesce? Or is it due to stability issues in
such
a behemoth? Observationally, the upper mass limit is poorly
constrained
at present, with the strongest evidence coming from the
K-band
luminosity function of the Arches cluster near the Galactic
Center.
Here we propose to investigate this question by determining the
Initial
Mass Function of NGC 3603, the nearest giant H II region. This
cluster
is known to contain a wealth of O3 and hydrogen-rich
Wolf-Rayets,
the most luminous and massive of stars. By constructing an
accurate
H-R diagram for the cluster, we will construct a present day
mass
function using newly computed high mass evolutionary tracks, and
convert
this to an initial mass function using the inferred ages. This
will
allow us to see whether or not there is a true deficit of high mass
stars,
evidence of an upper mass cutoff. At the same time we are likely
to
establish good masses for the highest mass stars ever determined. We
have
laid the groundwork for this project using the Magellan 6.5-m
telescope
and the excellent seeing found on Las Campanas, plus analysis
of
archival ACS/HRS frames, but we now need to obtain spectra of the
stars
unobservable from the ground. This can only be done with HST and a
reburbished
STIS.
WFC3/UV
11605
Obtaining
the Missing Links in the Test of Very Low Mass Evolutionary
Models
with HST
We
are proposing for spatially resolved ACS+HRC observations of 11 very
low
mass binaries spanning late-M, L and T spectral types in order to
obtain
precise effective temperature measurements for each component.
All
of our targets are part of a program in which we are measuring
dynamical
masses of very low-mass binaries to an unprecedented precision
of
10% (or better). However, without precise temperature measurements,
the
full scientific value of these mass measurements cannot be realized.
Together,
mass and temperature measurements will allow us to distinguish
between
brown dwarf evolutionary models that make different assumptions
about
the interior and atmospheric structure of these ultra-cool
objects.
While dynamical masses can be obtained from the ground in the
near-IR,
obtaining precise temperatures require access to optical data
which,
for these sub-arcsecond binaries, can only be obtained from space
with
Hubble.
WFC3/ACS/IR
11597
Spectroscopy
of IR-Selected Galaxy Clusters at 1 < z < 1.5
We
propose to obtain WFC3 G141 and G102 slitless spectroscopy of galaxy
clusters
at 1 < z < 1.5 that were selected from the IRAC survey of the
Bootes
NDWFS field. Our IRAC survey contains the largest sample of
spectroscopically
confirmed clusters at z > 1. The WFC3 grism data will
measure
H-alpha to determine SFR, and fit models to the low resolution
continua
to determine stellar population histories for the brighter
cluster
members, and redshifts for the red galaxies too faint for
ground-based
optical spectroscopy.
WFC3/UVIS
11595
Turning
Out the Light: A WFC3 Program to Image z>2 Damped Lyman Alpha
Systems
We
propose to directly image the star-forming regions of z>2 damped Lya
systems
(DLAs) using the WFC3/UVIS camera on the Hubble Space Telescope.
In
contrast to all previous attempts to detect the galaxies giving rise
to
high redshift DLAs, we will use a novel technique that completely
removes
the glare of the background quasar. Specifically, we will target
quasar
sightlines with multiple DLAs and use the higher redshift DLA as
a
``blocking filter'' (via Lyman limit absorption) to eliminate all FUV
emission
from the quasar. This will allow us to carry out a deep search
for
FUV emission from the lower redshift DLA, shortward of the Lyman
limit
of the higher redshift absorber. The unique filter set and high
spatial
resolution afforded by WFC3/UVIS will then enable us to directly
image
the lower redshift DLA and thus estimate its size, star- formation
rate
and impact parameter from the QSO sightline. We propose to observe
a
sample of 20 sightlines, selected primarily from the SDSS database,
requiring
a total of 40 HST orbits. The observations will allow us to
determine
the first FUV luminosity function of high redshift DLA
galaxies
and to correlate the DLA galaxy properties with the ISM
characteristics
inferred from standard absorption-line analysis to
significantly
improve our understanding of the general DLA population.
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/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.
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).