HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #4952
PERIOD
COVERED: 5am October 15 - 5am October 16, 2009 (DOY 288/09:00z-289/09:00z)
OBSERVATIONS
SCHEDULED
ACS/WFC
11840
Identifying
the Host Galaxies for Optically Dark Gamma-ray Bursts
We
propose to use the high spatial resolution of Chandra to obtain
precise
positions for a sample of Gamma-Ray Bursts (GRBs) with no
optical
afterglows, where the optical light is suppressed relative to
the
X-ray flux. These bursts are likely to be highly obscured and may
have
different environments from the optically bright GRBs. Our Chandra
observations
will (unlike Swift XRT positions) allow for the unique
identification
of a host galaxy. To locate these host galaxies we will
follow
up our Chandra positions with deep optical and IR observations
with
HST. The ultimate aim is to understand any differences between the
host
galaxies of optically dark and bright GRBs, and how these affect
the
use of GRBs as tracers of starformation and galaxy evolution at high
redshift.
ACS/WFC3
11599
Distances
of Planetary Nebulae from SNAPshots of Resolved Companions
Reliable
distances to individual planetary nebulae (PNe) in the Milky
Way
are needed to advance our understanding of their spatial
distribution,
birthrates, influence on galactic chemistry, and the
luminosities
and evolutionary states of their central stars (CSPN). Few
PNe
have good distances, however. One of the best ways to remedy this
problem
is to find resolved physical companions to the CSPN and measure
their
distances by photometric main-sequence fitting. We have previously
used
HST to identify and measure probable companions to 10 CSPN, based
on
angular separations and statistical arguments only. We now propose to
use
HST to re-observe 48 PNe from that program for which additional
companions
are possibly present. We then can use the added criterion of
common
proper motion to confirm our original candidate companions and
identify
new ones in cases that could not confidently be studied before.
We
will image the region around each CSPN in the V and I bands, and in
some
cases in the B band. Field stars that appear close to the CSPN by
chance
will be revealed by their relative proper motion during the 13+
years
since our original survey, leaving only genuine physical
companions
in our improved and enlarged sample. This study will increase
the
number of Galactic PNe with reliable distances by 50 percent and
improve
the distances to Pne with previously known companions.
ACS/WFC3
11670
The
Host Environments of Type Ia Supernovae in the SDSS Survey
The
Sloan Digital Sky Survey Supernova Survey has discovered nearly 500
type
Ia supernovae and created a large, unique, and uniform sample of
these
cosmological tools. As part of a comprehensive study of the
supernova
hosts, we propose to obtain Hubble ACS images of a large
fraction
of these galaxies. Integrated colors and spectra will be
measured
from the ground, but we require high-resolution HST imaging to
provide
accurate morphologies and color information at the site of the
explosion.
This information is essential in determining the systematic
effects
of population age on type Ia supernova luminosities and
improving
their reliability in measuring dark energy. Recent studies
suggest
two populations of type Ia supernovae: a class that explodes
promptly
after star-formation and one that is delayed by billions of
years.
Measuring the star-formation rate at the site of the supernova
from
colors in the HST images may be the best way to differentiate
between
these classes.
COS/NUV
11896
NUV
Spectroscopic Sensitivity Monitoring
The
purpose of this proposal is to monitor sensitivity of each NUV
grating
mode to detect any changes due to contamination or other causes.
NIC1/NIC2/NIC3
11947
Extended
Dark Monitoring
This
program takes a series of darks to obtain darks (including
amplifier
glow, dark current, and shading profiles) for all three
cameras
in the read-out sequences used in Cycle 17. A set of 12 orbits
will
be observed every two months for a total of 72 orbits for a 12
month
Cycle 17. This is a continuation of Cycle 16 program 11330 scaled
down
by ~80%.
The
first orbit (Visit A0) should be scheduled in the NICMOS SMOV after
the
DC Transfer Test (11406) and at least 36h before the Filter Wheel
Test
(11407). Data download using fast track.
The
following 28 orbits (visit A1-N2) should be scheduled AFTER the SMOV
Proposal
11407 (Filter Wheel Test). This is done in order to monitor the
dark
current following an adjustment of the NCS set-point. These visits
should
be executed until the final temperature is reached during SMOV.
NIC1/NIC2/NIC3
8795
NICMOS
Post-SAA Calibration - CR Persistence Part 6
This
is a new procedure proposed to alleviate the CR-persistence problem
of
NICMOS. Dark frames will be obtained immediately upon exiting the SAA
contour
23, and every time a NICMOS exposure is scheduled within 50
minutes
of coming out of the SAA. The darks will be obtained in parallel
in
all three NICMOS cameras. The post-SAA darks will be non-standard
reference
files available to users with a 'Use After' date/time mark.
The
keyword 'UseAfter=date/time' will also be added to the header of
each
post-SAA dark frame. The keyword must be populated with the time,
in
addition to the date, because HST crosses the SAA ~8 times per day,
so
each post-SAA dark will need to have the appropriate time specified,
for
users to identify the ones they need. Both the raw and processed
images
will be archived as post-SAA darks. Generally we expect that all
NICMOS
science/calibration observations started within 50 minutes of
leaving
an SAA will need such MAPs to remove the CR persistence from the
science
images. Each observation will need its own CRMAP, as different
SAA
passages leave different imprints on the NICMOS detectors.
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.
STIS/CCD
11844
CCD
Dark Monitor Part 1
The
purpose of this proposal is to monitor the darks for the STIS CCD.
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.
WFC3/IR
11618
WFC3
Observations of VeLLOs and the Youngest Star Forming Environments
The
Cores-to-Disks Spitzer Legacy team has discovered a number of
extremely
low luminosity sources embedded deep within nearby (< 300 pc)
cores
previously thought to be starless. With substellar masses, these
low
luminosity sources represent either the youngest low-mass protostars
yet
detected or the first embedded brown dwarfs. In either case, they
represent
a new observed class of sources referred to as VeLLOs (Very
Low
Luminosity Objects). We propose WFC3 F160W observations of a small
sample
of these sources, to be combined with deep ground-based
observations
at Ks, to address a broad set of issues concerning VeLLOs
and
the environments within which they are forming. First, the
morphology
of their outflow cavities will be traced, yielding estimates
of
the inclinations and opening angles of the cavities and the
evolutionary
stages of the VeLLOs. Second, our observations will reveal
background
stars seen through the densest regions of cores harboring
these
VeLLOs. The color-excesses of the background stars will yield the
highest
angular resolution extinction maps necessary to directly probe
the
inner density structure of these cores, found very soon after the
onset
of collapse, which would constrain the initial conditions of
collapse
within these isolated environments. In addition, we will
construct
similar maps of the dense pre-protostellar core L694-2 and the
protostellar
core B335. These maps will provide a snapshot of the
evolution
of the inner density structure of a core prior to low-mass
star
formation and soon thereafter, for comparison with the inner
density
structure of cores that have formed VeLLOs. Finally, these
extinction
maps will enable us to determine the core "centers", or
positions
of peak column densities. Comparison of these centers with the
positions
of the VeLLOs may yield insight regarding potential
differences
between the formation of low-mass stars and brown dwarfs.
WFC3/UV
11627
Resolving
the Puzzling Nature of the Ultra-compact Binary V407 Vul
Recently,
three variable stars have been identified as likely accreting
binary
systems with ultra-short orbital periods of 10 minutes or less.
This
makes them the closest binaries known as well as strong sources of
gravitational
wave emission. These objects have thus been identified as
crucial
calibration sources for the LISA mission. V407 Vul diplays a 9.5
minute
period at optical and X-ray wavelengths. Several different binary
geometries
have been proposed to explain this variable star with all but
one
scenario identifying the 9.5 minute period with the binary orbital
period.
Our time-resolved spectroscopy and photometry from the ground
revealed
that the optical light is dominated by a stationary G9 star
which
would be inconsistent with the mass donor star of a compact
binary.
We propose ACS/HRC imaging in order to confirm the tentative
0.03"
mis-alignment we have picked up between this G9 star and the
underlying
variable. Confirmation of a spatial separation between the
variable
and this field star would conclusively rule out that the G star
is
part of a low-inclination binary and thus verify it as a LISA source.
In
addition, we propose UV imaging that will allow us to determine the
NUV
luminosity of the variable star and thereby reliably infer the
distance
and the nature (and thus the gravitational wave signal) of the
ultra-compact
binary, as either mass transfer or magnetic interaction
powers
the X-ray source. Only HST imaging can provide rigorous proof for
an
ultra-compact binary interpretation for V407 Vul and thus validate it
as
LISA verification source
WFC3/UV
11906
WFC3
UVIS CCD Gain
The
absolute gain of each quadrant of the WFC3 UVIS detector will be
measured
for the nominal detector readout configuration and at the
on-orbit
operating temperature.
WFC3/UV/IR
11664
The
WFC3 Galactic Bulge Treasury Program: Populations, Formation
History,
and Planets
Exploiting
the full power of the Wide Field Camera 3 (WFC3), we propose
deep
panchromatic imaging of four fields in the Galactic bulge. These
data
will enable a sensitive dissection of its stellar populations,
using
a new set of reddening-free photometric indices we have
constructed
from broad-band filters across UV, optical, and near-IR
wavelengths.
These indices will provide accurate temperatures and
metallicities
for hundreds of thousands of individual bulge stars.
Proper
motions of these stars derived from multi-epoch observations will
allow
separation of pure bulge samples from foreground disk
contamination.
Our catalogs of proper motions and panchromatic
photometry
will support a wide range of bulge studies.
Using
these photometric and astrometric tools, we will reconstruct the
detailed
star-formation history as a function of position within the
bulge,
and thus differentiate between rapid- and extended-formation
scenarios.
We will also measure the dependence of the stellar mass
function
on metallicity, revealing how the characteristic mass of star
formation
varies with chemistry. Our sample of bulge stars with accurate
metallicities
will include 12 candidate hosts of extrasolar planets.
Planet
frequency is correlated with metallicity in the solar
neighborhood;
our measurements will extend this knowledge to a remote
environment
with a very distinct chemistry.
Our
proposal also includes observations of six well-studied globular and
open
star clusters; these observations will serve to calibrate our
photometric
indices, provide empirical population templates, and
transform
the theoretical isochrone libraries into the WFC3 filter
system.
Besides enabling our own program, these products will provide
powerful
new tools for a host of other stellar-population investigations
with
HST/WFC3. We will deliver all of the products from this Treasury
Program
to the community in a timely fashion.
WFC3/UVIS
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/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/IR
11909
UVIS
Hot Pixel Anneal
The
on-orbit radiation environment of WFC3 will continually generate new
hot
pixels. This proposal performs the procedure required for repairing
those
hot pixels in the UVIS CCDs. During an anneal, the two-stage
thermo-electric
cooler (TEC) is turned off and the four-stage TEC is
used
as a heater to bring the UVIS CCDs up to ~20 deg. C. As a result of
the
CCD warmup, a majority of the hot pixels will be fixed; previous
instruments
such as WFPC2 and ACS have seen repair rates of about 80%.
Internal
UVIS exposures are taken before and after each anneal, to allow
an
assessment of the procedure's effectiveness in WFC3, provide a check
of
bias, global dark current, and hot pixel levels, as well as support
hysteresis
(bowtie) monitoring and CDBS reference file generation. One
IR
dark is taken after each anneal, to provide a check of the IR
detector.
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
8
8
FGS
REAcq
9
9
OBAD
with Maneuver
7
7
SIGNIFICANT
EVENTS: (None)