HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5098
PERIOD
COVERED: 5am May 17 - 5am May 18, 2010 (DOY 137/09:00z-138/09:00z)
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
12283
- GSAcq(1,2,1) at 138/19:26:04z acquired fine lock backup on FGS 2 due to
scan step limit exceeded on FGS 1.
Observations possibly affected: STIS 22 to 23, proposal ID#11740.
REAcq(1,2,1) scheduled at 138/22:36:56z and at 139/00:12:48z
acquired
fine lock backup on FGS 2 with scan step limit exceeded on FGS 1.
Observations possibly affected: STIS 24-29 Proposal ID#11740; STIS
30
Proposal ID#11845; WFC3 80 and 84 Proposal ID#11914; WFC3 82
Proposal
ID#11908; WFC3 85 Proposal ID#11905; ACS 13-18 Proposal ID#11995.
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSAcq 10
10
FGS
REAcq 7
7
OBAD
with Maneuver 8
8
SIGNIFICANT
EVENTS: (None)
OBSERVATIONS
SCHEDULED:
ACS/WFC
11564
Optical
and Ultraviolet Photometry of Isolated Neutron Stars
We
propose ultraviolet and B-band observations of 5 nearby, thermally emitting
neutron stars. These
data
will measure the Rayleigh-Jeans tails of their spectra, providing a vital
complement to X-ray
spectroscopy
and helping to constrain atmospheric models, working toward the ultimate goal
of
unraveling
the physics of neutron stars. With these data we will have good-quality optical
and UV
data
for the full sample of these objects, allowing detailed comparisons between
them. Finally, the
data
should allow us to measure proper motions for one or two objects, and will
serve as the
reference
data for the remaining objects; such proper motions allow ages to be determined
for these
objects
by tracing them back to likely birth locations.
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.
ACS/WFC/WFC3/IR
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.
COS/FUV/COS/NUV
11598
How
Galaxies Acquire their Gas: A Map of Multiphase Accretion and Feedback in
Gaseous Galaxy Halos
We
propose to address two of the biggest open questions in galaxy formation - how
galaxies acquire
their
gas and how they return it to the IGM - with a concentrated COS survey of
diffuse multiphase
gas
in the halos of SDSS galaxies at z = 0.15 - 0.35. Our chief science goal is to
establish a basic
set
of observational facts about the physical state, metallicity, and kinematics of
halo gas,
including
the sky covering fraction of hot and cold material, the metallicity of infall
and outflow,
and
correlations with galaxy stellar mass, type, and color - all as a function of
impact parameter
from
10 - 150 kpc. Theory suggests that the bimodality of galaxy colors, the shape
of the luminosity
function,
and the mass-metallicity relation are all influenced at a fundamental level by
accretion
and
feedback, yet these gas processes are poorly understood and cannot be predicted
robustly from
first
principles. We lack even a basic observational assessment of the multiphase
gaseous content of
galaxy
halos on 100 kpc scales, and we do not know how these processes vary with
galaxy properties.
This
ignorance is presently one of the key impediments to understanding galaxy
formation in general.
We
propose to use the high-resolution gratings G130M and G160M on the Cosmic
Origins Spectrograph to
obtain
sensitive column density measurements of a comprehensive suite of multiphase
ions in the
spectra
of 43 z < 1 QSOs lying behind 43 galaxies selected from the Sloan Digital Sky
Survey. In
aggregate,
these sightlines will constitute a statistically sound map of the physical
state and
metallicity
of gaseous halos, and subsets of the data with cuts on galaxy mass, color, and
SFR will
seek
out predicted variations of gas properties with galaxy properties. Our
interpretation of these
data
will be aided by state-of-the-art hydrodynamic simulations of accretion and
feedback, in turn
providing
information to refine and test such models. We will also use Keck, MMT, and
Magellan (as
needed)
to obtain optical spectra of the QSOs to measure cold gas with Mg II, and
optical spectra of
the
galaxies to measure SFRs and to look for outflows. In addition to our other
science goals, these
observations
will help place the Milky Way's population of multiphase, accreting High
Velocity
Clouds
(HVCs) into a global context by identifying analogous structures around other
galaxies. Our
program
is designed to make optimal use of the unique capabilities of COS to address
our science
goals
and also generate a rich dataset of other absorption-line systems along a
significant total
pathlength
through the IGM (Delta z ~ 20).
COS/NUV
11894
NUV
Detector Dark Monitor
Measure
the NUV detector dark rate by taking long science exposures with no light on
the detector.
The
detector dark rate and spatial distribution of counts will be compared to
pre-launch and SMOV
data
in order to verify the nominal operation of the detector. Variations of count
rate as a
function
of orbital position will be analyzed to find dependence of dark rate on
proximity to the
SAA.
Dependence of dark rate as function of time will also be tracked.
STIS/CCD
11637
A
Closeup View of a Twin of SN 1987A Before Explosion
Last
year we reported the discovery of a ring nebula called SBW1 around a blue
supergiant star in
our
Galaxy. In almost every respect, it is a true "twin" of the
equatorial ring nebula around SN
1987A:
it has an identical physical radius of 0.2pc, a similar expansion speed and age,
it is
located
in a massive HII region, the central star is an early B supergiant with the
same luminosity
as
SN1987A's progenitor, and the ring's structure in our ground-based H-alpha
images looks almost
identical
to early HST images of SN1987A's ring. The detailed density structure of
SN1987A's ring on
scales
smaller than the limiting resolution of HST has become a pressing question,
because the
forward
shock of the supernova is now colliding with that ring, causing it to brighten
by 3 orders
of
magnitude and giving rise to a series of "hotspots" around the ring.
HST/WFC3 images of SBW1 will
provide
a snapshot of an SN1987A-like ring before the supernova explodes, and will
provide a
detailed
view of the important density inhomogeneities in the ring with a physical
spatial
resolution
10 times better than HST images of SN1987A (because SBW1 is 10 times closer to
us). STIS
spectra
will allow us to directly measure the radial density structure of the ring.
Both the overall
radial
density profile and the detailed structures of the clumps that give rise to the
"hotspots"
are
critical factors in modeling the rapid evolution of SN1987A, and our proposed
study of SBW1 will
provide
extremely valuable input for those models.
STIS/CCD
11740
A
Complete Optical and NIR Atmospheric Transmission Spectrum of the Exoplanet
HD189733b
The
hot Jupiter HD189733b offers the best exoplanet in which to perform atmospheric
studies through
transit
spectroscopy. Here we propose STIS and Nicmos spectra to help construct a full exoplanetary
transit
transmission spectrum that extends over the entire optical and near-infrared
range. Such a
spectrum
will link existing observed atmospheric features such as haze, water, and
methane,
providing
a coherent understanding of all these reported features. With a spectrum
covering many
observed
absorption features, the absolute pressure scale and abundances can be
determined linking
observed
features to the actual atmospheric properties of the exoplanet.
STIS/CCD
11845
CCD
Dark Monitor Part 2
Monitor
the darks for the STIS CCD.
STIS/CCD
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/CCD/STIS/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/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
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 possiblity 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
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/WFC3/UVI
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 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/UVI
11657
The
population of compact planetary nebulae in the Galactic Disk
We
propose to secure narrow- and broad-band images of compact planetary nebulae
(PNe) in the
Galactic
Disk to study the missing link of the early phases of post-AGB evolution.
Ejected AGB
envelopes
become PNe when the gas is ionized. PNe expand, and, when large enough, can be
studied in
detail
from the ground. In the interim, only the HST capabilities can resolve their
size,
morphology,
and central stars. Our proposed observations will be the basis for a systematic
study of
the
onset of morphology. Dust properties of the proposed targets will be available
through approved
Spitzer/IRS
spectra, and so will the abundances of the alpha-elements. We will be able thus
to
explore
the interconnection of morphology, dust grains, stellar evolution, and
populations. The
target
selection is suitable to explore the nebular and stellar properties across the
Galactic Disk,
and
to set constraints on the Galactic evolutionary models through the analysis of
metallicity and
population
gradients.
WFC3/UVI
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<BR>and
dark frames. A smaller set of 2Kx4K subarray biases are acquired at less frequent
intervals<BR>throughout
the cycle to support subarray science observations. The internals from this
proposal,<BR>along
with those from the anneal procedure (11909), will be used to generate the
necessary
superbias<BR>and superdark reference files for the calibration pipeline
(CDBS).
WFC3/UVI
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/UVI
11914
UVIS
Earth Flats
This
program is an experimental path finder for Cycle 18 calibration.
Visible-wavelength flat fields
will
be obtained by observing the dark side of the Earth during periods of full moon
illumination.
The
observations will consist of full-frame streaked WFC3 UVIS imagery: per 22-min
total exposure
time
in a single "dark-sky" orbit, we anticipate collecting 7000 e/pix in
F606W or 4500 e/pix in
F814W.
To achieve Poisson S/N > 100 per pixel, we requires at least 2 orbits of
F606W and 3 orbits
of
F814W.
For
UVIS narrowband filters, exposures of 1 sec typically do not saturate on the
sunlit Earth, so
we
will take sunlit Earth flats for three of the more-commonly used narrowband
filters in Cycle 17
plus
the also-popular long-wavelength quad filters, for which we get four filters at
once.
Why
not use the Sunlit Earth for the wideband visible-light filters? It is too
bright in the
visible
for WFC3 UVIS minimum exposure time of 0.5 sec. Similarly, for NICMOS the
sunlit-Earth is
too
bright which saturates the detector too quickly and/or induces abnormal
behaviors such as
super-shading
(Gilmore 1998, NIC 098-011). In the narrowband visible and broadband near-UV
its not
too
bright (predictions in Cox et al. 1987 "Standard Astronomical Sources for
HST: 6. Spatially Flat
Fields."
and observations in ACS Program 10050).
Other
possibilities? Cox et al.'s Section II.D addresses many other possible sources
for flat
fields,
rejecting them for a variety of reasons. A remaining possibility would be the
totally
eclipsed
moon. Such eclipses provide approximately 2 hours (1 HST orbit) of opportunity
per year, so
they
are too rare to be generically useful. An advantage of the moon over the Earth
is that the moon
subtends
less than 0.25 square degree, whereas the Earth subtends a steradian or more,
so scattered
light
and light potentially leaking around the shutter presents additional problems
for the Earth.
Also,
we're unsure if HST can point 180 deg from the Sun.