Daily Report # 4368

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 # 4368

PERIOD COVERED: UT May 22, 2007 (DOY 142)

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}.

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.

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.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports of
potential non-nominal performance that will be investigated.)

HSTARS:

10826 - GSacq(2,3,2) failed due to search radius limit exceeded.

At 143/02:56:44 GSacq(2,3,2) scheduled at 143/02:51.21 failed due to search
radius limit exceeded on FGS 2. An ESB a05 was also received. OBAD1 showed
errors of V1=212.02, V2=2117.52, V3=481.67, RSS=2181.94. OBAD2 showed errors
of V1=12.95, V2=20.99, V3=18.46, and RSS=30.81.

COMPLETED OPS REQUEST: (None)

18087-0 - MSS/Gyro1 Converge & Remove Test#34 @142/1305z
18091-1 - PCS KF OOT Support,142/1308z
18088-1 - MSS/Gyro1 Initialization Test#13 for day142@142/1958z

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL

FGS GSacq 08 07
FGS REacq 03 03
OBAD with Maneuver 22 22

SIGNIFICANT EVENTS:

Evaluation of Universal Kalman Filter performance continued. Multiple text
segments were executed, all of them successfully. Details follow.

The KF was halted at 142/12:30. It was restarted at 142/12:33 with the MSS,
CSS and Gyro1 sensor inputs enabled. The initialization occurred during
orbit day in F2G. The Gyro1 sensor input was removed at 142/12:51 in orbit
day, in F2G, during a slow changing B-field and while the vehicle was
inertially fixed. All UKF parameters showed nominal operation. The test was
to monitor the removal of the Gyro1 sensor input from an MSS/CSS/Gyro1
converged filter (MC_G1_HNS, Test #34). The filter was halted again at
142/13:03 to remove the CSS input from the filter to restore the current
operational configuration of MSS only input. The filter was restarted at
142/13:05.

The filter was halted at 142/19:38. It was restarted at 142/19:42 with the
MSS and Gyro1 sensor inputs enabled. The initialization occurred during
orbit day during a T2G guiding interval and during a fast changing B-field
period while the vehicle was inertially fixed. All UKF parameters showed
nominal operation. The test was an MSS/Gyro1 Initialization test case with
the vehicle inertially fixed during a fast changing B-field (M_G1_INF, Test
#13). The filter was halted again at 142/19:56. reconfigured to use only MSS
input and restarted at 142/19:58.