HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5082
PERIOD
COVERED: 5am April 23 - 5am April 26, 2010 (DOY 113/09:00z-116/09:00z)
OBSERVATIONS
SCHEDULED
WFC3/UV
12094
WFC3/UVIS
Image Skew
This
proposal will provide an independent check of the skew in the ACS
astrometric
catalog of Omega Cen stars, using exposures taken in a
45-deg
range of telescope roll. The roll sequence will also provide a
test
for orbital variation of skew and field angle dependent PSF
variations.
The astrometric catalog of Omega Cen, improved for a skew,
will
be used to derive the geometric distorion to all UVIS filters,
which
has preliminarily been determined from F606W images and an
astrometric
catalog of 47 Tuc.
WFC3/IR
12051
Cross
Calibration of NICMOS and WFC3 in the Low-Count-Rate Regime
NICMOS
has played a key role in probing the deep near infrared regime
for
a decade. It has been the only instrument available to observe faint
objects
in the near infrared that are not observable from the ground.
However,
the calibration of NICMOS has turned out to be difficult in the
low-count-rate
regime. The NICMOS calibration team has extrapolated a
power-law
to describe the apparent non-linearity in the NICMOS detectors
from
measurements at ~50-5000 ADU/s to flux counts around 0.1-1 ADU/s.
Precise
measurements of faint objects (such as SNe Ia at high redshift)
require
us to reduce the uncertainties from this extrapolation. Here we
propose
to determine the absolute zeropoint for faint objects by
cross-calibrating
the WFC3 and NICMOS detectors in observations of early
type
galaxies at redshifts z>1.
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
11936
IR
Grism Flux Calibration
This
program will determine image displacement, spectral trace and flux
calibration
for the IR G102 and G141 grisms as a function of spatial
position
within the field of view. The HST flux standard GD71 will be
observed
in a 9-point pattern in the IR field of view, which will
provide
the necessary image displacement, spectral trace, and throughput
measurements.
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).
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.
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/ACS/IR
11731
Studying
Cepheid Systematics in M81: H-Band Observations
The
local value of the Hubble Constant remains one of the most important
constraints
in cosmology, but improving on the 10% accuracy of the HST
Key
Project is challenging. No improvements will be convincing until the
metallicity
dependence is well constrained and blending effects are
fully
understood. M81 and its dwarf companion Holmberg IX are superb
laboratories
for studying Cepheid systematics because they contain large
numbers
of bright Cepheids with a good spread in metallicity lying at a
common,
relatively close distance. We have identified 180 12<P< 70 day
Cepheids
in these two galaxies using the Large Binocular Telescope
(compared
to 30 in total by the KP), and will expand the sample further
in
2008-2009. We will use 10 orbits with WFC3/IR to obtain H-band images
of
100 Cepheids in M81 to add to the ACS/BVI calibrations we will obtain
from
archival data and 1 orbit with WFC3/UVIS to add B-band data for
Holmberg
IX. Four band BVIH photometry will allow us to flux calibrate,
estimate
extinction, measure metallicity effects and then check the
results
in detail. We can also examine blending effects on WFC3/IR data
in
a relatively nearby galaxy before it is applied to more distant
galaxies.
Our M81 sample is three times larger than the next best
sample,
that of NGC4258, and suffers less from blending because M81 is
at
half the distance, so it is an excellent laboratory for studying
Cepheid
systematics even if it lacks as precise a geometric distance as
NGC4258.
COS/NUV/FUV
11727
UV
Spectroscopy of Local Lyman Break Galaxy Analogs: New Clues to Galaxy
Formation
in the Early Universe
Much
of our information about galaxy evolution and the interaction
between
galaxies and the IGM at high-z has been provided by the Lyman
Break
Galaxies (LBGs). However, it is difficult to investigate these
faint
and distant objects in detail. To address this, we have used the
GALEX
All-Sky Imaging Survey and the SDSS to identify for the first time
a
rare population of low- redshift galaxies with properties remarkably
similar
to the high-redshift LBGs. These local "Lyman Break Analogs"
(LBAs)
resemble LBGs in terms of morphology, size, UV luminosity, star
formation
rate, UV surface brightness, stellar mass, velocity
dispersion,
metallicity, and dust content. We are assembling a wide
range
of data on these objects with the goal of using them as local
laboratories
for better understanding the relevant astrophysical
processes
in LBGs. These data include HST imaging (95 orbits in Cy15 and
16),
Spitzer photometry and spectroscopy, Chandra and XMM X-ray imaging
and
spectroscopy, and near-IR integral field spectroscopy (VLT, Keck,
and
Gemini). In this proposal we are requesting the most important
missing
puzzle piece: far-UV spectra with a signal-to-noise and spectral
resolution
significantly better than available for typical LBGs. We will
use
these spectra to study the LBA's galactic winds, probe the processes
that
regulate the escape of Ly-a and Lyman continuum radiation,
determine
chemical abundances for the stars and gas, and constrain the
form
of the high-end of the Initial Mass Function. Adding these new COS
data
will give us vital information about these extraordinary sites of
star
formation in the local universe. In so-doing it will also shed new
light
on the processes that led to the formation of stars, the building
of
galaxies, and the enrichment and heating of the IGM in the early
universe.
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/UV/IR
11717
Unraveling
the Mysterious Origin of GRB 070125
We
propose a modest (2 WFC3 orbits) HST program to ascertain the origin
of
the mysterious gamma-ray burst GRB 070125. With a duration of 60 s
and
a high local (i.e. parsec scale) circum-burst density, GRB 070125
resembles
a canonical (i.e. massive-star progenitor) long-duration
event.
However, we have strong evidence that GRB 070125 exploded in the
halo
of its host galaxy, far away from the bulk of massive star
formation.
The UV detection of a compact, star-forming cluster would
confirm
our original hypothesis that GRB 070125 exploded in a tidal tail
formed
by galaxy interactions (analogous to the Tadpole and Antenna
galaxies)
at z = 1.54. Alternatively, the absence of ongoing star
formation
and the presence of an old stellar population would require a
novel
explosion process unassociated with massive stars. While the
former
would open a new path to study star formation and galaxy
interactions
at high redshift, the latter would require a re-thinking of
one
of the fundamental tenets of GRB astronomy: the 1:1 mapping between
duration
and progenitor system.
ACS/WFC
11715
The
Luminous Galactic Cepheid RS Puppis: A Geometric Distance from its
Nested
Light Echoes
RS
Puppis is one of the most luminous Cepheids in the Milky Way (P =
41.4
days) and an analog of the bright Cepheids used to measure
extragalactic
distances. An accurate distance would help anchor the
zero-point
of the bright end of the period-luminosity relation, but at a
distance
of about 2 kpc it is too far away for a trigonometric parallax
with
existing instrumentation.
RS
Pup is unique in being surrounded by a reflection nebula, whose
brightness
varies as pulses of light from the Cepheid propagate
outwards.
Members of our team have used ground-based imaging of the
nebula
to derive phase lags in the light variations of individual
features
in the nebula, and have inferred a seemingly very precise
geometric
distance to the star. However, there is an unavoidable
ambiguity
involving the cycle counts, which was resolved by assuming
that
the features lie in the plane of the sky. If this assumption is
incorrect,
a large systematic error would be introduced into the
distance
measurement.
We
show that polarimetric imaging using the high spatial resolution of
ACS/WFC
and its ability to image close to the star can resolve this
ambiguity
and yield a reliable geometric distance to RS Pup. We will
also
obtain a wide-field multicolor image of the nebula, in order to
study
its morphology and the mass-loss history of the Cepheid.
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.
WFC3/UVIS/IR
11702
Search
for Very High-z Galaxies with WFC3 Pure Parallel
WFC3
will provide an unprecedented probe to the early universe beyond
the
current redshift frontier. Here we propose a pure parallel program
using
this new instrument to search for Lyman-break galaxies at
6.5<z<8.8
and to probe the epoch of reionization, a hallmark event in
the
history of the early universe. We request 200 orbits, spreading over
30
~ 50 high Galactic latitude visits (|b|>20deg) that last for 4 orbits
and
longer, resulting a total survey area of about 140~230 square
arcminute.
Based on our understanding of the new HST parallel
observation
scheduling process, we believe that the total number of
long-duration
pure parallel visits in Cycle 17 should be sufficient to
accommodate
our program. We waive all proprietary rights to our data,
and
will also make the enhanced data products public in a timely manner.
(1)
We will use both the UVIS and the IR channels, and do not need to
seek
optical data from elsewhere.
(2)
Our program will likely triple the size of the probable candidate
samples
at z~7 and z~8, and will complement other targeted programs
aiming
at the similar redshift range.
(3)
Being a pure parallel program, our survey will only make very
limited
demand on the scarce HST resources. More importantly, as the
pure
parallel pointings will be at random sight-lines, our program will
be
least affected by the bias due to the large scale structure ("cosmic
variance").
(4)
We aim at the most luminous LBG population, and will address the
bright-end
of the luminosity function at z~8 and z~7. We will constrain
the
value of L* in particular, which is critical for understanding the
star
formation process and the stellar mass assembly history in the
first
few hundred million years of the universe.
(5)
The candidates from our survey, most of which will be the brightest
ones
that any surveys would be able to find, will have the best chance
to
be spectroscopically confirmed at the current 8--10m telescopes.
(6)
We will also find a large number of extremely red, old galaxies at
intermediate
redshifts, and the fine spatial resolution offered by the
WFC3
will enable us constrain their formation history based on the study
of
their morphology, and hence shed light on their connection to the
very
early galaxies in the universe.
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/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/UV
11602
High-resolution
imaging of three new UV-bright lensed arcs
We
have identified and spectroscopically confirmed three new strongly
lensed,
UV-bright star-forming galaxies at z ~ 2 that are similar to the
well-studied
gravitationally lensed Lyman Break Galaxy (LBG)
MS1512-cB58,
and are of comparable brightness to the ''8 O'Clock Arc''
(Allam
et al. 2007) and ''Clone'' systems (Lin et al. 2008). The 8
O'Clock
Arc and Clone have already been awarded 20 orbits for deep WFPC2
and
NICMOS imaging in five bands (HST cycle 16, Program 11167, PI:
Allam).
Adding these three recently discovered objects thus completes a
unique
set of the brightest known strongly lensed galaxies at z ~ 2,
with
magnitudes of r~20-21, and they provide a new window into the
detailed
study of the properties of high redshift galaxies. We propose
21
orbits for deep WFC3 imaging in five bands (F475W, F606W, F814W,
F110W,
and F160W) in order to construct detailed lensing models, to
probe
the mass and light profiles of the lensing galaxies and their
environments,
and to constrain the spectral energy distributions, star
formation
histories, and morphologies of the lensed galaxies.
WFC3/ACS/IR
11600
Star
Formation, Extinction, and Metallicity at 0.7<z<1.5: H-Alpha Fluxes
and
Sizes from a Grism Survey of GOODS-N
The
global star formation rate (SFR) is ~10x higher at z=1 than today.
This
could be due to drastically elevated SFR in some fraction of
galaxies,
such as mergers with central bursts, or a higher SFR across
the
board. Either means that the conditions in z=1 star forming galaxies
could
be quite different from local objects. The next step beyond
measuring
the global SFR is to determine the dependence of SFR,
obscuration,
metallicity, and size of the star-forming region on galaxy
mass
and redshift. However, SFR indicators at z=1 typically apply local
calibrations
for UV, [O II] and far-IR, and do not agree with each other
on
a galaxy-by-galaxy basis. Extinction, metallicity, and dust
properties
cause uncontrolled offsets in SFR calibrations. The great
missing
link is Balmer H-alpha, the most sensitive probe of SFR. We
propose
a slitless WFC3/G141 IR grism survey of GOODS-N, at 2
orbits/pointing.
It will detect Ha+[N II] emission from 0.7<z<1.5, to
L(Ha)
= 1.7 x 10^41 erg/sec at z=1, measuring H-alpha fluxes and sizes
for
> 600 galaxies, and a small number of higher-redshift emitters. This
will
produce: an emission-line redshift survey unbiased by magnitude and
color
selection; star formation rates as a function of galaxy
properties,
e.g. stellar mass and morphology/mergers measured by ACS;
comparisons
of SFRs from H-alpha to UV and far-IR indicators;
calibrations
of line ratios of H-alpha to important nebular lines such
as
[O II] and H-beta, measuring variations in metallicity and extinction
and
their effect on SFR estimates; and the first measurement of scale
lengths
of the H-alpha emitting, star- forming region in a large sample
of
z~1 sources.
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/UV
11556
Investigations
of the Pluto System
We
propose a set of high SNR observations of the Pluto system that will
provide
improved lightcurves, orbits, and photometric properties of Nix
and
Hydra. The key photometric result for Nix and Hydra will be a vastly
improved
lightcurve shape and rotation period to test if the objects are
in
synchronous rotation or not. A second goal of this program will be to
retrieve
a new epoch of albedo map for the surface of Pluto. These
observations
will also improve masses and in some case densities for the
bodies
in the Pluto system.
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
33
33
FGS
REAcq
27
27
OBAD
with Maneuver 20 20
SIGNIFICANT
EVENTS: (None)