HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5156
PERIOD
COVERED: 5am August 9 - 5am August 10, 2010 (DOY 221/09:00z-222/09:00z)
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
10
10
FGS
REAcq
8
8
OBAD
with Maneuver
7
7
SIGNIFICANT
EVENTS: (None)
OBSERVATIONS
SCHEDULED
ACS/WFC
11996
CCD
Daily Monitor (Part 3)
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 308 orbits (19.25 weeks) from 21 June 2010 to 1 November
2010.
ACS/WFC3
11735
The
LSD Project: Dynamics, Merging and Stellar Populations of a Sample
of
Well-Studied LBGs at z~3
A
large observational effort with the ground-based ESO/VLT telescopes
allowed
us to obtain deep, spatially-resolved, near-IR spectra of
complete
sample of 11 Lyman-Break Galaxies at z~3.1. These observations
were
used to obtain, for the first time, the metallicity and the
dynamical
properties of a sample of objects that, albeit small, is
representative
of the total population of the LBGs. We propose to use
HST
to obtain high-resolution optical and near-IR images of this sample
of
LBGs in order to study the broad-band morphology and the stellar
light
distribution of these galaxies. These images, exploiting the
superior
spatial resolution of HST images and the low-background : 1-
will
allow a precise measure of the dynamical mass from the velocity
field
derived with spectroscopy; 2- will permit a comparison of the
distribution
of star formation (from the line emission) with the
underlying
stellar population, and, 3- will be used to check if the
complex
velocity field and the multiple line-emitting regions detected
in
most targets can be ascribed to on-going mergers. This accurate study
will
shed light on a number of unsolved problems still affecting the
knowledge
of the LBGs.
COS/FUV
11895
FUV
Detector Dark Monitor
Monitor
the FUV detector dark rate by taking long science exposures
without
illuminating 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.
COS/NUV
11894
NUV
Detector Dark Monitor
The
purpose of this proposal is to 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.
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.
COS/NUV
12052
COS
NUV Grating Efficiency Test
We
will perform two more grating efficiency tests to enable better
comparison
of results of grating efficiency tests done on the ground
with
external target spectroscopic sensitivity monitoring on orbit.
The
GETS contains 10 NUV exposures designed to get the same S/N of
various
emission lines throughout the NUV band. The sequence and
duration
of exposures in this NUV GET are the same as used by the IDT on
the
ground from 2004-2009 to monitor the relative efficiencies of the
NUV
gratings. The sequence starts with a 20-minute wait, to ensure that
the
lamp has cooled from any usage in a previous visit.
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.
STIS/CCD
11849
STIS
CCD Hot Pixel Annealing
This
purpose of this activity is to repair radiation induced hot pixel
damage
to the STIS CCD by warming the CCD to the ambient instrument
temperature
and annealing radiation-damaged pixels.
Radiation
damage creates hot pixels in the STIS CCD Detector. Many of
these
hot pixels can be repaired by warming the CCD from its normal
operating
temperature near -83 deg. C to the ambient instrument
temperature
(~ +5 deg. C) for several hours. The number of hot pixels
repaired
is a function of annealing temperature. The effectiveness of
the
CCD hot pixel annealing process is assessed by measuring the dark
current
behavior before and after annealing and by searching for any
window
contamination effects.
STIS/CCD
12228
Probing
for Exoplanets Hiding in Dusty Debris Disks: Inner (<10 AU) Disk
Imaging,
Characterization, and Exploration
We
propose new visible-light observations of a well-selected sample of
circumstellar
(CS) debris disks, all with HST pedigree, using STIS
PSF-subtracted
multi-roll coronagraphic imaging. Our new observations
will
probe the interior CS regions of these debris systems (with inner
working
distances of < approximately 8 AU for half the stars in this
sample),
corresponding to the giant planet and Kuiper belt regions
within
our own solar system. These new images will enable us to directly
inter-compare
the architectures of these exoplanetary debris systems in
the
context of our own Solar System. These observations will also permit
us,
for the first time, to characterize the material in these regions at
high
spatial resolution and to look for sub-structures within the disks
that
are the sign posts of planetary formation and evolution; in
particular,
asymmetries and non-uniform debris structures signal the
presence
of co-orbiting perturbing planets. Additionally, all of our
objects
have been observed previously at longer wavelengths (but much
lower
spatial resolution and imaging efficacy) with NICMOS, but with an
inner
working angle comparable to STIS multi-roll coronagraphy. The
combination
of new optical and existing near-IR imaging will strongly
constrain
the dust properties, thus enabling an assessment of grain
processing
and planetesimal populations. These results will directly
inform
upon the posited planet formation mechanisms that occur after the
~
10 My epoch of gas depletion, at a time in our solar system when giant
planets
were migrating and the terrestrial planets were forming, and
directly
test theoretical models of these processes. The outer reaches
(only)
of most of these systems were previously observed with a much
larger
(~ 6x on average), spatially limiting, effective inner working
angle
of the ACS coronagraph. The previous ACS images are therefore
completely
inadequate to address our science goals of imaging the inner
structures
of these CS disks. Our proposed investigation, enabled ONLY
with
HST STIS visible-light coronagraphy, will uniquely probe into the
interior
regions of these systems for the first time with spatial
resolution
comparable to ACS and with augmenting NICMOS near-IR disk
photometry
in hand.
WFC3/ACS/IR
11563
Galaxies
at z~7-10 in the Reionization Epoch: Luminosity Functions to
<0.2L*
from Deep IR Imaging of the HUDF and HUDF05 Fields
The
first generations of galaxies were assembled around redshifts
z~7-10+,
just 500-800 Myr after recombination, in the heart of the
reionization
of the universe. We know very little about galaxies in this
period.
Despite great effort with HST and other telescopes, less than
~15
galaxies have been reliably detected so far at z>7, contrasting with
the
~1000 galaxies detected to date at z~6, just 200-400 Myr later, near
the
end of the reionization epoch. WFC3 IR can dramatically change this
situation,
enabling derivation of the galaxy luminosity function and its
shape
at z~7-8 to well below L*, measurement of the UV luminosity
density
at z~7-8 and z~8-9, and estimates of the contribution of
galaxies
to reionization at these epochs, as well as characterization of
their
properties (sizes, structure, colors). A quantitative leap in our
understanding
of early galaxies, and the timescales of their buildup,
requires
a total sample of ~100 galaxies at z~7-8 to ~29 AB mag. We can
achieve
this with 192 WFC3 IR orbits on three disjoint fields
(minimizing
cosmic variance): the HUDF and the two nearby deep fields of
the
HUDF05. Our program uses three WFC3 IR filters, and leverages over
600
orbits of existing ACS data, to identify, with low contamination, a
large
sample of over 100 objects at z~7-8, a very useful sample of ~23
at
z~8-9, and limits at z~10. By careful placement of the WFC3 IR and
parallel
ACS pointings, we also enhance the optical ACS imaging on the
HUDF
and a HUDF05 field. We stress (1) the need to go deep, which is
paramount
to define L*, the shape, and the slope alpha of the luminosity
function
(LF) at these high redshifts; and (2) the far superior
performance
of our strategy, compared with the use of strong lensing
clusters,
in detecting significant samples of faint z~7-8 galaxies to
derive
their luminosity function and UV ionizing flux. Our recent z~7.4
NICMOS
results show that wide-area IR surveys, even of GOODS-like depth,
simply
do not reach faint enough at z~7-9 to meet the LF and UV flux
objectives.
In the spirit of the HDF and the HUDF, we will waive any
proprietary
period, and will also deliver the reduced data to STScI. The
proposed
data will provide a Legacy resource of great value for a wide
range
of archival science investigations of galaxies at redshifts z~2-9.
The
data are likely to remain the deepest IR/optical images until JWST
is
launched, and will provide sources for spectroscopic follow up by
JWST,
ALMA and EVLA.
WFC3/IR
11671
Kinematic
Reconstruction of the Origin and IMF of the Massive Young
Clusters
at the Galactic Center
We
propose to exploit the wide field capabilities of Wide Field Camera 3
to
study star formation at the Galactic center. By studying young stars
located
in the most physically extreme region of our Galaxy, we can test
star
formation theories, which suggest that such environments should
favor
high mass stars and, in extreme cases, should suppress star
formation
entirely. Specifically, we will measure the proper motions and
photometry
of stars over the full extent of the three massive young
clusters
that have been identified at the Galactic Center (Arches,
Quintuplet,
and the Young Nuclear Star Cluster). These observations are
a
factor of ?2000 more efficient than what can be done with ground-based
adaptive
optics. Our goals are two-fold. First, we hope to establish the
initial
sites of star formation in order to obtain an accurate estimate
of
the conditions that led to the stellar populations within these
clusters.
Answering this question for the Young Nuclear Star Cluster is
particularly
important as it establishes whether or not star formation
can
indeed proceed within 0.1 pc of our Galaxy's supermassive black
hole.
Second, we will measure the IMF in the Arches and Quintuplet,
where
dynamical evolution is less severe, using proper motions to
determine
membership and to reveal the tidal radius. Probing how the
properties
of the emergent stellar populations within our Galaxy may be
affected
by the physical environment in which they arise is an important
first
step to understanding how they might vary as a function of cosmic
time
and thereby affect our models of galaxy formation and evolution.
WFC3/IR
11926
IR
Zero Points
We
will measure and monitor the zeropoints through the IR filters using
observations
of the white dwarf standard stars, GD153, GD71 and GD191B2B
and
the solar analog standard star, P330E. Data will be taken monthly
during
Cycle 17. Observations of the star cluster, NGC 104, are made
twice
to check color transformations. We expect an accuracy of 2% in the
wide
filter zeropoints relative to the HST photometric system, and 5% in
the
medium- and narrow-band filters.
WFC3/UVIS
11630
Monitoring
Active Atmospheres on Uranus and Neptune
We
propose Snapshot observations of Uranus and Neptune to monitor
changes
in their atmospheres on time scales of weeks and months, as we
have
been doing for the past seven years. Previous Hubble Space
Telescope
observations (including previous Snapshot programs 8634,
10170,
10534, and 11156), together with near-IR images obtained using
adaptive
optics on the Keck Telescope, reveal both planets to be dynamic
worlds
which change on time scales ranging from hours to (terrestrial)
years.
Uranus equinox occurred in December 2007, and the northern
hemisphere
is becoming fully visible for the first time since the early
1960s.
HST observations during the past several years (Hammel et al.
2005,
Icarus 175, 284 and references therein) have revealed strongly
wavelength-dependent
latitudinal structure, the presence of numerous
visible-wavelength
cloud features in the northern hemisphere, at least
one
very long- lived discrete cloud in the southern hemisphere, and in
2006
the first clearly defined dark spot seen on Uranus. Long term
ground-based
observations (Lockwood and Jerzekiewicz, 2006, Icarus 180,
442;
Hammel and Lockwood 2007, Icarus 186, 291) reveal seasonal
brightness
changes that seem to demand the appearance of a bright
northern
polar cap within the next few years. Recent HST and Keck
observations
of Neptune (Sromovsky et al. 2003, Icarus 163, 256 and
references
therein) show a general increase in activity at south
temperate
latitudes until 2004, when Neptune returned to a rather
Voyager-like
appearance with discrete bright spots rather than active
latitude
bands. Further Snapshot observations of these two dynamic
planets
will elucidate the nature of long-term changes in their zonal
atmospheric
bands and clarify the processes of formation, evolution, and
dissipation
of discrete albedo features.
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
11912
UVIS
Internal Flats
This
proposal will be used to assess the stability of the flat field
structure
for the UVIS detector throughout the 15 months of Cycle 17.
The
data will be used to generate on-orbit updates for the delta-flat
field
reference files used in the WFC3 calibration pipeline, if
significant
changes in the flat structure are seen.