HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5094
PERIOD
COVERED: 5am May 11 - 5am May 12, 2010 (DOY 131/09:00z-132/09:00z)
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
9
9
FGS
REAcq
8
8
OBAD
with Maneuver 7
7
SIGNIFICANT
EVENTS: (None)
OBSERVATIONS
SCHEDULED
ACS/WFC3
11882
CCD
Hot Pixel Annealing
This
program continues the monthly anneal that has taken place every
four
weeks for the last three cycles. We now obtain WFC biases and darks
before
and after the anneal in the same sequence as is done for the ACS
daily
monitor (now done 4 times per week). So the anneal observation
supplements
the monitor observation sets during the appropriate week.
Extended
Pixel Edge Response (EPER) and First Pixel Response (FPR) data
will
be obtained over a range of signal levels for the Wide Field
Channel
(WFC). This program emulates the ACS pre-flight ground
calibration
and post-launch SMOV testing (program 8948), so that results
from
each epoch can be directly compared. The High Resolution Channel
(HRC)
visits have been removed since it could not be repaired during
SM4.
This
program also assesses the read noise, bias structure, and amplifier
cross-talk
of ACS/WFC using the GAIN=1.4 A/D conversion setting. This
investigation
serves as a precursor to a more comprehensive study of WFC
performance
using GAIN=1.4.
STIS/CC
11654
UV
Studies of a Core Collapse Supernova
Observations
of the UV spectrum of core collapse SNe hold unique
information
about nucleosynthesis, the mass loss history, shock physics
and
dust formation in the explosion on massive stars. This proposal aims
at
a detailed study of a bright core collapse SN, discovered by any of
the
many ongoing surveys, either a Type IIP, IIn or Ibc supernova. We
will
address the role of circumstellar interaction and mass loss through
CNO
lines in the UV, the nature of dust formation from UV line profiles
and
use the UV continuum as a diagnostic of non-thermal emission from
the
shock. The overall goal of our team is to achieve a better
understanding
of these objects by combining HST data with complementary
ground-based
observations. We have used HST to obtain UV spectra from
the
explosion to the nebular phase. Over the past decade, we have
conducted
studies of nearby SNe with HST, and we have published an
extensive
series of papers. When Nature provides a bright candidate, HST
should
be ready to respond.
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
11712
Calibration
of Surface Brightness Fluctuations for WFC3/IR
We
aim to characterize galaxy surface brightness fluctuations (SBF), and
calibrate
the SBF distance method, in the F110W and F160W filters of the
Wide
Field Camera 3 IR channel. Because of the very high throughput of
F110W
and the good match of F160W to the standard H band, we anticipate
that
both of these filters will be popular choices for galaxy
observations
with WFC3/IR. The SBF signal is typically an order of
magnitude
brighter in the near-IR than in the optical, and the
characteristics
(sensitivity, FOV, cosmetics) of the WFC3/IR channel
will
be enormously more efficient for SBF measurements than previously
available
near-IR cameras. As a result, our proposed SBF calibration
will
allow accurate distance derivation whenever an early-type or
bulge-dominated
galaxy is observed out to a distance of 150 Mpc or more
(i.e.,
out to the Hubble flow) in the calibrated passbands. For
individual
galaxy observations, an accurate distance is useful for
establishing
absolute luminosities, black hole masses, linear sizes,
etc.
Eventually, once a large number of galaxies have been observed
across
the sky with WFC3/IR, this SBF calibration will enable accurate
mapping
of the total mass density distribution in the local universe
using
the data available in the HST archive. The proposed observations
will
have additional important scientific value; in particular, we
highlight
their usefulness for understanding the nature of multimodal
globular
cluster color distributions in giant elliptical galaxies.
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/IR/S/C
12089
Persistence
- Part 2
The
IR detectors on WFC3, like other IR detectors, trap charge when
exposed
to sources near or above the full well of the detector diodes.
This
charge leaks out, producing detectable afterglow images for periods
which
can last for several hours, depending on the amount of over
exposure.
These visits, which consist of tungsten lamp exposures of
varying
durations followed by darks, are intended to provide a better
calibration
of persistence over the full area of the IR detector of
WFC3.
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
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/UVIS
11697
Proper
Motion Survey of Classical and SDSS Local Group Dwarf Galaxies
Using
the superior resolution of HST, we propose to continue our proper
motion
survey of Galactic dwarf galaxies. The target galaxies include
one
classical dwarf, Leo II, and six that were recently identified in
the
Sloan Digital Sky Survey data: Bootes I, Canes Venatici I, Canes
Venatici
II, Coma Berenices, Leo IV, and Ursa Major II. We will observe
a
total of 16 fields, each centered on a spectroscopically-confirmed
QSO.
Using QSOs as standards of rest in measuring absolute proper
motions
has proven to be the most accurate and most efficient method.
HST
is our only option to quickly determine the space motions of the
SDSS
dwarfs because suitable ground-based imaging is only a few years
old
and such data need several decades to produce a proper motion. The
two
most distant galaxies in our sample will require time baselines of
four
years to achieve our goal of a 30-50 km/s uncertainty in the
tangential
velocity; given this and the finite lifetime of HST, it is
imperative
that first-epoch observations be taken in this cycle. The
SDSS
dwarfs have dramatically lower surface brightnesses and
luminosities
than the classical dwarfs. Proper motions are crucial for
determining
orbits of the galaxies and knowing the orbits will allow us
to
test theories for the formation and evolution of these galaxies and,
more
generally, for the formation of the Local Group.
WFC3/UVIS
11730
Continued
Proper Motions of the Magellanic Clouds: Orbits, Internal
Kinematics,
and Distance
In
Cycles 11 and 13 we obtained two epochs of ACS/HRC data for fields in
the
Magellanic Clouds centered on background quasars. We used these data
to
determine the proper motions of the LMC and SMC to better than 5% and
15%
respectively. The results had a number of unexpected implications
for
the Milky Way-LMC-SMC system and received considerable attention in
the
literature and in the press. The implied three-dimensional
velocities
are larger than previously believed and close to the escape
velocity
in a standard 10^12 solar mass Milky Way dark halo. Our orbit
calculations
suggest the Clouds may not be bound to the Milky Way or may
just
be on their first passage, both of which are unexpected in view of
traditional
interpretations of the Magellanic Stream. Alternatively, the
Milky
Way dark halo may be a factor two more massive than previously
believed,
which would be surprising in view of other observational
constraints.
Also, the relative velocity between the LMC and SMC was
larger
than expected, leaving open the possibility that the Clouds may
not
be bound to each other. To further verify and refine our results we
requested
an additional epoch data in Cycle 16 which is being executed
with
WFPC2/PC due to the failure of ACS. A detailed analysis of one LMC
field
shows that the field proper motion using all three epochs of data
is
consistent within 1-sigma with the two- epoch data, thus verifying
that
there are no major systematic effects in our previous measurements.
The
random errors, however, are only smaller by a factor of 1.4 because
of
the relatively large errors in the WFPC2 data. A prediction for a
fourth
epoch with measurement errors similar to epochs 1 and 2 shows
that
the uncertainties will improve by a factor of 3. This will allow us
to
better address whether the Clouds are indeed bound to each other and
to
the Milky Way. It will also allow us to constrain the internal
motions
of various populations within the Clouds, and to determine a
distance
to the LMC using rotational parallax. Continuation of this
highly
successful program is therefore likely to provide important
additional
insights. Execution in SNAPshot mode guarantees maximally
efficient
use of HST resources.
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).