Notice: For the foreseeable future, the daily reports may
contain
apparent discrepancies between some proposal descriptions
and the listed
instrument usage. This is due to the conversion of
previously approved
ACS WFC or HRC observations into WFPC2, or NICMOS
observations
subsequent to the loss of ACS CCD science capability in
late January.
HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT # 4362
PERIOD COVERED: UT May 14, 2007 (DOY 134)
OBSERVATIONS SCHEDULED
WFPC2 10800
Kuiper Belt Binaries: Probes of Early Solar System
Evolution
Binaries in the Kuiper Belt are a scientific windfall: in
them we have
relatively fragile test particles which can be used as
tracers of the
early dynamical evolution of the outer Solar System. We
propose to
continue a Snapshot program using the ACS/HRC that has a
demonstrated
discovery potential an order of magnitude higher than the
HST
observations that have already discovered the majority of
known
transneptunian binaries. With this continuation we seek to
reach the
original goals of this project: to accumulate a
sufficiently large
sample in each of the distinct populations collected in
the Kuiper Belt
to be able to measure, with statistical significance, how
the fraction
of binaries varies as a function of their particular
dynamical paths
into the Kuiper Belt. Today's Kuiper Belt bears the
imprints of the
final stages of giant-planet building and migration;
binaries may offer
some of the best preserved evidence of that long-ago era.
WFPC2 10832
Solving the microlensing puzzle: An HST high-resolution
imaging approach
We propose to use the HST Advanced Camera for Surveys High
Resolution
Channel to obtain high resolution imaging data for 10
bona-fide LMC
microlensing events seen in the original MACHO survey. The
purpose of
this survey will be to assess whether or not the lens and
source stars
have separated enough to be resolved since the original
microlensing
event took place - about a decade has passed since the
original MACHO
survey and the HST WFPC2 follow-up observations of the
microlensing
events. If the components of the lensing event are
resolved, we will
determine the apparent magnitude and color of both the
lens and the
source stars. These data, in combination with Spitzer/IRAC
data and
Magellan near-IR JHK data, will be used to ascertain the
basic
properties of the lens stars. With the majority of the
microlensing
events in the original MACHO survey observed at the
highest spatial
resolution currently possible, we will be able to draw
important
conclusions as to what fraction of these events have
lenses which belong
to some population of dwarf stars in the disk and what
fraction must be
due to lenses in the halo or beyond. These data will
greatly increase
our understanding of the structure of the Galaxy by
characterizing the
stellar population responsible for the gravitational
microlensing.
ACS/SBC 10862
Comprehensive Auroral Imaging of Jupiter and Saturn during
the
International Heliophysical Year
A comprehensive set of observations of the auroral
emissions from
Jupiter and Saturn is proposed for the International
Heliophysical Year
in 2007, a unique period of especially concentrated
measurements of
space physics phenomena throughout the solar system. We
propose to
determine the physical relationship of the various auroral
processes at
Jupiter and Saturn with conditions in the solar wind at
each planet.
This can be accomplished with campaigns of observations,
with a sampling
interval not to exceed one day, covering at least one
solar rotation.
The solar wind plasma density approaching Jupiter will be
measured by
the New Horizons spacecraft, and a separate campaign near
opposition in
May 2007 will determine the effect of large-scale
variations in the
interplanetary magnetic field {IMF} on the Jovian aurora
by
extrapolation from near-Earth solar wind measurements. A
similar Saturn
campaign near opposition in Jan. 2007 will combine
extrapolated solar
wind data with measurements from a wide range of locations
within the
Saturn magnetosphere by Cassini. In the course of making
these
observations, it will be possible to fully map the auroral
footprints of
Io and the other satellites to determine both the local
magnetic field
geometry and the controlling factors in the
electromagnetic interaction
of each satellite with the corotating magnetic field and
plasma density.
Also in the course of making these observations, the
auroral emission
properties will be compared with the properties of the
near-IR
ionospheric emissions {from ground-based observations} and
non thermal
radio emissions, from ground-based observations for
Jupiter?s decametric
radiation and Cassini plasma wave measurements of the
Saturn Kilometric
Radiation {SKR}.
WFPC2 10880
The host galaxies of QSO2s: AGN feeding and evolution at
high
luminosities
Now that the presence of supermassive black holes in the
nuclei of
galaxies is a well established fact, other questions
related to the AGN
phenomena still have to be answered. Problems of
particular interest are
how the AGN gets fed, how the black hole evolves and how
the evolution
of the black hole is related to the evolution of the
galaxy bulge. Here
we propose to address some of these issues using ACS/WFC +
F775W
snapshot images of 73 QSO2s with redshifts in the range
0.3<z<0.4. These
observations will be combined with similar archival data
of QSO1s and
ground based data of Seyfert and normal galaxies. First,
we will
intestigate whether interactions are the most important
feeding
mechanism in high luminosity AGNs. This will be done in a
quantitative
way, comparing the asymmetry indices of QSO2 hosts with
those of lower
luminosity AGNs and normal galaxies. Second, we will do a
detailed study
of the morphology of the host galaxies of both QSO types,
to determine
if they are similar, or if there is an evolutionary trend
from QSO2s to
QSO1s. The results from this project will represent an
important step in
the understanding of AGN evolution, and may also introduce
a substantial
modification to the Unified Model.
WFPC2 11024
WFPC2 CYCLE 15 INTERNAL MONITOR
This calibration proposal is the Cycle 15 routine internal
monitor for
WFPC2, to be run weekly to monitor the health of the
cameras. A variety
of internal exposures are obtained in order to provide a
monitor of the
integrity of the CCD camera electronics in both bays {both
gain 7 and
gain 15 -- to test stability of gains and bias levels}, a
test for
quantum efficiency in the CCDs, and a monitor for possible
buildup of
contaminants on the CCD windows. These also provide raw
data for
generating annual super-bias reference files for the
calibration
pipeline.
WFPC2 10889
The Nature of the Halos and Thick Disks of Spiral Galaxies
We propose to resolve the extra-planar stellar populations
of the thick
disks and halos of seven nearby, massive, edge-on galaxies
using ACS,
NICMOS, and WFPC2 in parallel. These observations will
provide accurate
star counts and color-magnitude diagrams 1.5 magnitudes below
the tip of
the Red Giant Branch sampled along the two principal axes
and one
intermediate axis of each galaxy. We will measure the
metallicity
distribution functions and stellar density profiles from
star counts
down to very low average surface brightnesses, equivalent
to ~32 V-mag
per square arcsec. These observations will provide the
definitive HST
study of extra-planar stellar populations of spiral
galaxies. Our
targets cover a range in galaxy mass, luminosity, and
morphology and as
function of these galaxy properties we will provide: - The
first
systematic study of the radial and isophotal shapes of the
diffuse
stellar halos of spiral galaxies - The most detailed
comparative study
to date of thick disk morphologies and stellar populations
- A
comprehensive analysis of halo and thick disk metallicity
distributions
as a function of galaxy type and position within the
galaxy. - A
sensitive search for tidal streams - The first opportunity
to directly
relate globular cluster systems to their field stellar
population We
will use these fossil records of the galaxy assembly
process preserved
in the old stellar populations to test halo and thick disk
formation
models within the hierarchical galaxy formation scheme. We
will test
LambdaCDM predictions on sub-galactic scales, where it is
difficult to
test using CMB and galaxy redshift surveys, and where it
faces its most
serious difficulties.
WFPC2 10799
Photometric Mapping of Vesta's Southern Hemisphere
We propose to image asteroid 4 Vesta throughout one
complete rotation
during its opposition and close approach to Earth in May
of 2007 in four
filters for the purposes of improving knowledge of its
spin pole, size,
shape, albedo and composition across its surface. We will
conduct a
satellite search. Multi-filter imaging will extend the
range of
photometric mapping into the southern hemisphere where a
large basin
exists, and will extend compositional mapping further into
the southern
hemisphere than previous observations. The results will
improve our
understanding of protoplanetary processes and support
scientific
planning for NASA's Dawn mission to orbit Vesta 2011.
WFPC2 10903
Resolving the LMC Microlensing Puzzle: Where are the
Lensing Objects?
We are requesting 12 HST orbits to continue to investigate
the nature of
the population that gives rise to the microlensing seen
towards the LMC.
This proposal builds on the cycle 14 HST program {10583}
and will
complement the study with 12 yet-to-be discovered
microlensing
candidates from Fall 2006. Our SuperMacho project is an
ongoing ground-
based survey on the CTIO 4m that has demonstrated the
ability to detect
LMC microlensing events via frame subtraction. The
combination of high
angular resolution and photometric accuracy with HST will
allow us to 1}
confrim that the detected flux excursions arise from LMC
stars, rather
than background supernovae or AGN, and 2} obtain reliable
baseline flux
measurements for the objects in their unlensed state. This
latter
measurement in important in determining the microlensing
optical depth
towards the LMC.
WFPC2 11023
WFPC2 CYCLE 15 Standard Darks - part 1
This dark calibration program obtains dark frames every
week in order to
provide data for the ongoing calibration of the CCD dark
current rate,
and to monitor and characterize the evolution of hot
pixels. Over an
extended period these data will also provide a monitor of
radiation
damage to the CCDs.
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:
18081-0 - PCS KF OOT Support
18078-0 - MSS Only KF Converged & Add Gyro2, Test #38
for day 134
18082-0 - PCS KF OOT Support
18079-0 - MSS/CSS Initialization Test #6 for day 134
18054-0 - Preview KF Sun Vector Data via Telemetry Diags,
18080-0 - MSS/CSS/Gyro1 Initialization Test #16 for day
134
COMPLETED OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS GSacq
10
10
FGS REacq
02
02
OBAD with Maneuver
24
24
SIGNIFICANT EVENTS:
Evaluation of Universal Kalman Filter performance
continued. Multiple
text segments were executed, all of them successfully.
Details follow.
Background Kalman Filter Operation Flash Report for day
134
The Gyro2 sensor input was added to the KF at 134/12:55.
The input was
added during a vehicle slew, an M2G guiding interval and a
slow changing
B-field. The filter was already converged with only MSS
sensor input.
All UKF parameters showed nominal operation. The test was
an MSS
converged test case with Gyro2 sensor input added during a
vehicle slew
and a slow changing B-field (M_G2_RVS, Test #38). The
Gyro2 sensor input
was removed at 13:41 to restore the current configuration
of MSS only
input.
The KF was halted at 134/14:38. It was restarted at
134/14:40 with the
MSS and CSS sensor inputs enabled. The initialization
occurred during
orbit day, during a vehicle slew and during a slow
changing B-field. All
UKF parameters showed nominal operation. The test was an
MSS/CSS
Initialization test case during a slow changing B-field and
during a
vehicle slew (M_C_IVS, Test #6). The filter remained in
this
configuration up to the next test period below.
The KF was halted at 134/16:17. It was restarted at
134/16:24 with the MSS, CSS and Gyro1 sensor inputs
enabled. The
initialization occurred during orbit day, during a slow
changing B-field
and during a vehicle maneuver. All UKF parameters showed
nominal
operation. The test was an MSS/CSS/Gyro1 Initialization
test case during
a slow changing B-field and during a vehicle maneuver
(MC_G1_IVS, Test
#16). The filter was halted and reconfigured to use only
MSS sensor
input at 134/16:43.
This completes the KF convergence testing for this week.
It is necessary
to allow the orbit to process to place the fast and slow
changing
B-field periods during operational working hours. The KF
has been placed
into the MSS only sensor input to provide data for one of
the long-term
(~1 week) test cases.