HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5101
PERIOD
COVERED: 5am May 20 - 5am May 21, 2010 (DOY 140/09:00z-141/09:00z)
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
12285
- OBD Failed Quaternion @ 140/15:38:34z. GSAcq(1,0,1) at 140/15:52:06z
was successful.
COMPLETED
OPS REQUEST:
17543-3
- Dump OBAD tables after failed OBAD
COMPLETED
OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS
GSAcq
10
10
FGS
REAcq
6
6
OBAD
with Maneuver 6
5
SIGNIFICANT
EVENTS: (None)
OBSERVATIONS
SCHEDULED:
ACS/WFC
11591
Are
Low-Luminosity Galaxies Responsible for Cosmic Reionization?
Our
group has demonstrated that massive clusters, acting as powerful
cosmic
lenses, can constrain the abundance and properties of
low-luminosity
star-forming sources beyond z~6; such sources are thought
to
be responsible for ending cosmic reionization. The large
magnification
possible in the critical regions of well-constrained
clusters
brings sources into view that lie at or beyond the limits of
conventional
exposures such as the UDF. We have shown that the
combination
of HST and Spitzer is particularly effective in delivering
the
physical properties of these distant sources, constraining their
mass,
age and past star formation history. Indirectly, we therefore gain
a
valuable glimpse to yet earlier epochs. Recognizing the result (and
limitations)
of blank field surveys, we propose a systematic search
through
10
lensing
clusters with ACS/F814W and WFC3/[F110W+F160W] (in conjunction
with
existing deep IRAC data). Our goal is to measure with great
accuracy
the luminosity function at z~7 over a range of at least 3
magnitude,
based on the identification of about 50 lensed galaxies at
6.5<z<8.
Our survey will mitigate cosmic variance and extend the search
both
to lower luminosities and, by virtue of the WFC3/IRAC combination,
to
higher redshift. Thanks to the lensing amplification spectroscopic
follow-up
will be possible and make our findings the most robust prior
to
the era of JWST and the ELTs.
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
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.
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.
ACS/WFC/WFC3/IR/WFC3/UVI
11570
Narrowing
in on the Hubble Constant and Dark Energy
A
measurement of the Hubble constant to a precision of a few percent
would
be a powerful aid to the investigation of the nature of dark
energy
and a potent "end-to-end" test of the present cosmological model.
In
Cycle 15 we constructed a new, streamlined distance ladder utilizing
high-quality
type Ia supernova data and observations of Cepheids with
HST
in the near-IR to minimize the dominant sources of systematic
uncertainty
in past measurements of the Hubble constant and reduce its
total
uncertainty to a little under 5%. Here we propose to exploit this
new
route to reduce the remaining uncertainty by more than 30%,
translating
into an equal reduction in the uncertainty of the equation
of
state of dark energy. We propose three sets of observations to reach
this
goal: a mosaic of NGC 4258 with WFC3 in F160W to triple its sample
of
long period Cepheids, WFC3/F160W observations of the 6 ideal SN Ia
hosts
to triple their samples of Cepheids, and observations of NGC 5584
the
host of a new SN Ia, SN 2007af, to discover and measure its Cepheids
and
begin expanding the small set of SN Ia luminosity calibrations.
These
observations would provide the bulk of a coordinated program aimed
at
making the measurement of the Hubble constant one of the leading
constraints
on dark energy.
COS/FUV/COS/NUV
11742
Probing
HeII Reionization with GALEX-selected Quasar Sightlines and
HST/COS
We
propose spectroscopic observations with COS of eight z~3 QSOs that we
found
to be bright in the far ultraviolet. Our aim is to study
intergalactic
absorption caused by the onset of the He II Lyman forest.
Several
lines of evidence suggest that helium reionization occurred at
z~3.
Understanding this process is critical for a complete picture of
the
intergalactic medium and its evolution; it also gives clues to
hydrogen
reionization at z>6. The only direct means of assessing He II
reionization
is through far-UV observations of the He II Lyman alpha
forest.
Only 6 sightlines are known to date where this is feasible,
despite
extensive surveys. Our programme is designed to double the
number
of available sightlines. To this effect, we cross-correlated all
known
z>2.73 quasars with UV source lists from the GALEX satellite. The
selected
quasars were all significantly detected in the far UV by GALEX,
and
their UV colors are similar to those of already known quasars with
transparent
sightlines. Spectra obtained with COS will allow us to
compile
the first comprehensive sample of He II absorption spectra
probing
similar redshifts, enabling a systematic investigation of the He
II
reionization epoch and the spectral shape of the UV background.
S/C/WFC3/IR
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).
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/MA2
11857
STIS
Cycle 17 MAMA Dark Monitor
This
proposal monitors the behavior of the dark current in each of the
MAMA
detectors.
The
basic monitor takes two 1380s ACCUM darks each week with each
detector.
However, starting Oct 5, pairs are only included for weeks
that
the LRP has external MAMA observations planned. The weekly pairs of
exposures
for each detector are linked so that they are taken at
opposite
ends of the same SAA free interval. This pairing of exposures
will
make it easier to separate long and short term temporal variability
from
temperature dependent changes.
For
both detectors, additional blocks of exposures are taken once every
six
months. These are groups of five 1314 s FUV-MAMA TIME-TAG darks or
five
3x315 s NUV ACCUM darks distributed over a single SAA free
interval.
This will give more information on the brightness of the FUV
MAMA
dark current as a function of the amount of time that the HV has
been
on, and for the NUV MAMA will give a better measure of the short
term
temperature dependence.
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
11915
IR
Internal Flat Fields
This
program is the same as 11433 (SMOV) and depends on the completion
of
the IR initial alignment (program 11425). This version contains three
instances
of 37 internal orbits; to be scheduled early, middle, and near
the
end of Cycle 17, in order to use the entire 110-orbit allocation.
In
this test, we will study the stability and structure of the IR
channel
flat field images through all filter elements in the WFC3-IR
channel.
Flats will be monitored, i.e. to capture any temporal trends in
the
flat fields, and delta flats produced. High signal observations will
provide
a map of the pixel-to-pixel flat field structure, as well as
identify
the positions of any dust particles.
WFC3/IR/WFC3/UVI
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/UVI
11360
Star
Formation in Nearby Galaxies
Star
formation is a fundamental astrophysical process; it controls
phenomena
ranging from the evolution of galaxies and nucleosynthesis to
the
origins of planetary systems and abodes for life. The WFC3,
optimized
at both UV and IR wavelengths and equipped with an extensive
array
of narrow-band filters, brings unique capabilities to this area of
study.
The WFC3 Scientific Oversight Committee (SOC) proposes an
integrated
program on star formation in the nearby universe which will
fully
exploit these new abilities. Our targets range from the
well-resolved
R136 in 30 Dor in the LMC (the nearest super star cluster)
and
M82 (the nearest starbursting galaxy) to about half a dozen other
nearby
galaxies that sample a wide range of star-formation rates and
environments.
Our program consists of broad-band multiwavelength imaging
over
the entire range from the UV to the near-IR, aimed at studying the
ages
and metallicities of stellar populations, revealing young stars
that
are still hidden by dust at optical wavelengths, and showing the
integrated
properties of star clusters. Narrow-band imaging of the same
environments
will allow us to measure star-formation rates, gas
pressure,
chemical abundances, extinction, and shock morphologies. The
primary
scientific issues to be addressed are: (1) What triggers star
formation?
(2) How do the properties of star-forming regions vary among
different
types of galaxies and environments of different gas densities
and
compositions? (3) How do these different environments affect the
history
of star formation? (4) Is the stellar initial mass function
universal
or determined by local conditions?
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.