HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5147
PERIOD
COVERED: 5am July 27 - 5am July 28, 2010 (DOY 208/09:00z-209/09:00z)
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
12342
- REAcq(2,1,1) at 209/06:54:02z resulted in a "scan step limit
exceeded"
error in FGS2 on the first attempt. The REAcq went on to succeed
on the
second attempt.
Observations possibly affected WFC 73-75, Proposal ID#11700; COS
45,
Proposal ID#11598
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS
GSAcq 7
7
FGS
REAcq
8
8
OBAD
with Maneuver 4
4
SIGNIFICANT
EVENTS: (None)
OBSERVATIONS
SCHEDULED:
COS/NUV/FUV
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.
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/S/C/FUV
12082
Extending
COS/G130M Coverage Down to 905A With Two New Central
Wavelengths.
These
exploratory observations will provide sensitivity, wavelength
range,
and resolution measurements for two new COS FUV G130M central
wavelength
settings. These new settings will extend COS/G130M coverage
down
to 905? in two new bandpasses; 1021-1171? (BLUE) and 905-1055?
(Ultra-BLUE).
The modes are chosen to provide continuous coverage from
905?
to the existing coverage in the G130M/1291? setting with
approximately
30? of overlap in each mode for cross-calibration
purposes.
No focus adjustments will be made for these settings, as this
is
deemed an unnecessary risk to COS.
These
new modes have the potential to provide greater than FUSE
sensitivity
at moderate (3, 000-5, 000) resolution.
Three
WD targets are defined;
1)
GD50 (GSC-04717-00588; a well observed standard WD) 2) WD0320-539
(GSC-08493-00891,
one of the targets used in exploring the G140L
sensitivity),
3) REJ0503-289 (WD-5001-289 = GSC-04717-00588, a hot EUVE
bright
WD)
But
only target 2) is used at this time.
In
the observations section, G130M/1291A is a placeholder for the BLUE
and
Super-BLUE settings.
STIS/CC
11845
CCD
Dark Monitor Part 2
Monitor
the darks for the STIS CCD.
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.
WFC3/IR
11933
IR
Rate Dependent Non-linearity
The
NICMOS non-linearity known as the Bohlin Effect has revealed that
the
apparent flux of a source observed by NICMOS is not a simple, linear
function
of count rate. The effect has been characterized by
observations
of star clusters observed with and without additional
background
from the internal lamps. As WFC3 lacks internal lamps which
can
be used to add background, we will rely on the bright Earth limb to
provide
additional background. We will observe a star cluster, 47 Tuc,
repeatedly
throughout a complete HST orbit which has been chosen to put
the
closest approach to the bright Earth to be 13.5 degrees, the closest
approach
allowed while retaining FGS guiding. Another set will be done
with
the BE limb closest approach of 15.5 degrees. The observations will
be
done with the two most commonly used filters, F110W and F160W and at
two
different bright Earth limb angles to test the linearity of the
non-linearity.
We have also included an orbit on NGC 1850 to repeat the
NICMOS
field for which the linearity of the field has been established.
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/UV/ACS/WFC/IR
12055
A
Panchromatic Hubble Andromeda Treasury - I
We
propose to image the north east quadrant of M31 to deep limits in the
UV,
optical, and near-IR. HST imaging should resolve the galaxy into
more
than 100 million stars, all with common distances and foreground
extinctions.
UV through NIR stellar photometry (F275W, F336W with
WFC3/UVIS,
F475W and F814W with ACS/WFC, and F110W and F160W with
WFC3/NIR)
will provide effective temperatures for a wide range of
spectral
types, while simultaneously mapping M31's extinction. Our
central
science drivers are to: understand high-mass variations in the
stellar
IMF as a function of SFR intensity and metallicity; capture the
spatially-resolved
star formation history of M31; study a vast sample of
stellar
clusters with a range of ages and metallicities. These are
central
to understanding stellar evolution and clustered star formation;
constraining
ISM energetics; and understanding the counterparts and
environments
of transient objects (novae, SNe, variable stars, x-ray
sources,
etc.). As its legacy, this survey adds M31 to the Milky Way and
Magellanic
Clouds as a fundamental calibrator of stellar evolution and
star-formation
processes for understanding the stellar populations of
distant
galaxies. Effective exposure times are 977s in F275W, 1368s in
F336W,
4040s in F475W, 4042s in F814W, 699s in F110W, and 1796s in
F160W,
including short exposures to avoid saturation of bright sources.
These
depths will produce photon-limited images in the UV. Images will
be
crowding-limited in the optical and NIR, but will reach below the red
clump
at all radii. The images will reach the Nyquist sampling limit in
F160W,
F475W, and F814W.
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
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.