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 # 4369
PERIOD COVERED: UT May 23, 2007 (DOY 143)
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 10877
A Snapshot Survey of the Sites of Recent, Nearby
Supernovae
During the past few years, robotic {or nearly robotic}
searches for
supernovae {SNe}, most notably our Lick Observatory Supernova
Search
{LOSS}, have found hundreds of SNe, many of them in quite
nearby
galaxies {cz < 4000 km/s}. Most of the objects were
discovered before
maximum brightness, and have follow-up photometry and
spectroscopy; they
include some of the best-studied SNe to date. We propose
to conduct a
snapshot imaging survey of the sites of some of these
nearby objects, to
obtain late-time photometry that {through the shape of the
light and
color curves} will help reveal the origin of their
lingering energy. The
images will also provide high-resolution information on
the local
environments of SNe that are far superior to what we can
procure from
the ground. For example, we will obtain color-color and
color-magnitude
diagrams of stars in these SN sites, to determine the SN
progenitor
masses and constraints on the reddening. Recovery of the
SNe in the new
HST images will also allow us to actually pinpoint their
progenitor
stars in cases where pre- explosion images exist in the
HST archive.
This proposal is an extension of our successful Cycle 13
snapshot survey
with ACS. It is complementary to our Cycle 15 archival
proposal, which
is a continuation of our long-standing program to use
existing HST
images to glean information about SN environments.
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 10826
Galaxy Evolution During Half the Age of the Universe: ACS
imaging of
rich galaxy clusters
Detailed studies of nearby galaxies {z<0.05} show that
galaxies have
very complex histories of formation and evolution
involving mergers,
bursts of star formation, and morphological changes. Even
so, the global
properties of the galaxies {radii, luminosities, rotation
velocities,
velocity dispersions, and absorption line strengths}
follow a number of
very tight {empirical} scaling relations, e.g. the
Tully-Fisher relation
and the Fundamental Plane {FP}. We use the scaling
relations plus
quantative morphological measures for galaxy clusters up
to z=1 to
constrain models for galaxy evolution. Here we request 24
orbits to
obtain ACS imaging of the remaining three clusters in our
sample at
z~0.7-1.0. High resolution imaging of the clusters is
critical for our
study of star formation histories and structural evolution
in dense
environments since z<1. We have previously obtained
deep spectroscopic
observations of the clusters with Gemini. The data will
provide samples
large enough to establish the slope of the FP for each
cluster. With
multiple clusters at similar redshifts, we can probe
evolutionary
differences within a single epoch in order to decouple
changes due to
different environments. Our two other high-z clusters
exhibit different
chemical enrichment histories, which we argue are due to
the different
merging histories of these clusters.
NIC2 10858
NICMOS Imaging of the z ~ 2 Spitzer Spectroscopic Sample
of
Ultraluminous Infrared Galaxies
We propose to obtain NICMOS images of the first large
sample of high-z
ultra-luminous infrared galaxies {ULIRGs} whose redshifts
and physical
states have been determined with Spitzer mid-IR spectra.
The detection
of strong silicate absorption and/or PAH emission lines
suggest that the
these sources are a mixture of highly obscured starbursts,
AGNs and
composite systems at z=2. Although some of the spectra
show PAH emission
similar to local starburst ULIRGs, their bolometric
luminosities are
roughly an order of magnitude higher. One important
question is if major
mergers, which are the trigger for 95% of local ULIRGs,
also drive this
enormous energy output observed in our z=2 sample. The
NICMOS images
will allow us to {1} measure surface brightness profiles
of z~2 ULIRGs
and establish if major mergers could be common among our luminous
sources at these early epochs, {2} determine if starbursts
and AGNs
classified based on their mid-IR spetra would have
different
morphological signatures, thus different dynamic state;
{3} make
comparisons with the similar studies of ULIRGs at z ~ 0 -
1, thus infer
any evolutionary connections between high-z ULIRGs and the
formation of
normal, massive galaxies and quasars observed today.
FGS 11019
Monitoring FGS1r's Interferometric Response as a Function
of Spectral
Color
This proosal uses FGS1r in Transfer mode to observe
standard single
stars of a variety of spectral types to obtain point
source
interferograms for the Transfer mode calibration library.
In specific
cases, the calibration star will also be observed in POS
mode multiple
times with the F583W and F5ND elements to provide the data
to verify the
stabiligy of the cross filter calibration.
NIC1/NIC2/NIC3 8794
NICMOS Post-SAA calibration - CR Persistence Part 5
A new procedure proposed to alleviate the CR-persistence
problem of
NICMOS. Dark frames will be obtained immediately upon
exiting the SAA
contour 23, and every time a NICMOS exposure is scheduled
within 50
minutes of coming out of the SAA. The darks will be
obtained in parallel
in all three NICMOS Cameras. The POST-SAA darks will be
non- standard
reference files available to users with a USEAFTER
date/time mark. The
keyword 'USEAFTER=date/time' will also be added to the
header of each
POST-SAA DARK frame. The keyword must be populated with
the time, in
addition to the date, because HST crosses the SAA ~8 times
per day so
each POST-SAA DARK will need to have the appropriate time
specified, for
users to identify the ones they need. Both the raw and
processed images
will be archived as POST-SAA DARKSs. Generally we expect
that all NICMOS
science/calibration observations started within 50 minutes
of leaving an
SAA will need such maps to remove the CR persistence from
the science
images. Each observation will need its own CRMAP, as
different SAA
passages leave different imprints on the NICMOS detectors.
WFPC2 10888
Complexity in the Smallest Galaxies: Star Formation
History of the
Sculptor Dwarf Spheroidal
The Sculptor dwarf spheroidal galaxy {Scl dSph} is one of
the most
luminous of the Milky Way dSph satellites, suffers
virtually no
foreground confusion or reddening because of its high
galactic latitude,
and is nearby at 80 kpc from the Sun. It is of great
interest to
astronomy to understand the detailed histories of dSph
galaxies because
they may be survivors of the hierarchical merging process
that created
giant galaxies like our own. Despite this, the age
distribution of stars
in Scl dSph remains remarkably poorly constrained because
of a dearth of
high-quality color-magnitude diagrams {CMDs} of its
central regions. Scl
dSph is known to be complex on the basis of shallower
photometry, radial
velocity studies, and investigations of the metallicity;
however, the
age range of significant star-formation and the proportion
of stars
older and younger than 10 Gyr is still completely unknown.
The age of
the centrally concentrated, metal-rich population has
never been
measured. We propose to obtain deep optical images of the
core of Scl
dSph with WFPC2 in order to measure the temporal evolution
of its
star-formation rate over its entire lifetime. The ONLY way
to reliably
measure the variation in star-formation rate on Gyr
timescales at ages
of 10-13 Gyr is with photometry of a large number of stars
at and below
the oldest main-sequence turnoffs to magnitudes of {B,I} =
{25.1, 24.5}.
Because of the high stellar density and resulting image
crowding, it is
impossible to achieve the required level of photometric
precision except
with diffraction-limited imaging. These data will permit the
first
reliable measurement of the star-formation history of the
main body of
Scl dSph; limited inferences from WFPC2 data in an outer
field have been
made, but they were hindered not only by small number
statistics but by
the subsequent revelation of extremely strong population
gradients in
Scl dSph, such that the stars in the existing WFPC2 field
are not
representative of the galaxy as a whole. Our proposed
program will shed
strong new light on the formation processes of the
smallest galaxies.
Only by measuring the detailed early histories of galaxies
like Scl dSph
can we evaluate the impact of outside influences like
ram-pressure
stripping, tidal stirring, and photoionization feedback on
the evolution
of small galaxies.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS: (None from today)
10828 [May 15. 2007 (UT)] - Reacq(1,2,1) failed due to
Search Radius
Limit Exceeded @ 135/23:32:54z
During the PTAS data review it was noted that the
Reacq (1,2,1) at
135/23:32 had failed due to a Search Radius Limit
Exceeded Error. The
entire acquisition and guiding period were in a
ZOE. Previous
acquisition at 135/22:05 on the same stars had
succeeded and no problems
were seen with either star.
COMPLETED OPS REQUEST:
18089-0 - MSS Only Converged & Add Gyro1 Tests#21
& #25 for day 143
18092-0 - PCS KF OOT Support.
18054-0 - Preview KF Sun Vector Data via Telemetry Diags,
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS GSacq 08 08
FGS REacq 05 05
OBAD with Maneuver 26 26
SIGNIFICANT EVENTS:
Evaluation of Universal Kalman Filter performance
continued. Multiple
text segments were executed, all of them successfully.
Details follow.
Background Kalman Filter Operation:
The Gyro1 sensor input was added to the KF at 143/19:38 (OR
18089-0).
The filter was already converged with only the MSS sensor
input enabled.
The Gyro1 input was added during an M2G period, with the
vehicle
inertially fixed and during orbit day. All UKF parameters
showed nominal
operation. The test was to monitor the addition of the
Gyro1 sensor
input to an already converged filter (M_G1_RNF, Test #21).
The Gyro1
sensor input was left enabled to support the execution of
the subsequent
KF convergence test at 21:17.
The Gyro1 sensor input was removed from the KF at
143/21:17 (OR
18089-0). The filter was already converged with the MSS
and Gyro1 sensor
inputs enabled. The Gyro1 input was removed during an M2G
guiding
interval, with the vehicle inertially fixed and during
orbit day. All
UKF parmeters showed nominal operation. The test was to
monitor the
removal of the Gyro1 sensor input from the converged
filter (M_G1_HNF,
Test #25). The removal of the Gyro1 sensor input left the
KF in the
currently desired configuration with only the MSS sensor
input enabled.