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 # 4329
PERIOD COVERED: UT March 28, 2007 (DOY 087)
OBSERVATIONS SCHEDULED
ACS/SBC 11011
Dissecting An Accretion Disk
We will use 5 epochs of CXO and HST imaging to determine
the X-ray and
UV size of the accretion disk of the lensed quasar
RXJ1131--1231 using
microlensing. Based on preliminary data, we find that the
X-ray source
is roughly 1/10 the size of the accretion disk in the
rest-frame B-band.
The new observations will significantly reduce the
uncertainties in this
estimate, provide a comparison between the size of the
X-ray source and
the size of the accretion disk in the rest frame
ultraviolet, and have
the signal-to-noise ratio necessary to begin examining the
size of the
hard and soft-band X-ray emission regions separately. The
results will
quantitatively test accretion disk theory and X-ray
emission mechanisms.
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 10612
Binary Stars in Cyg OB2: Relics of Massive Star Formation
in a
Super-Star Cluster
We propose to make a high angular resolution SNAP survey
of the massive
stars in the nearby, super-star cluster Cyg OB2. We will
use FGS1r TRANS
mode observations to search for astrometric companions in
the separation
range of 0.01 to 1.00 arcsec and in the magnitude
difference range
smaller than 4 magnitudes. The observations will test the
idea that the
formation of very massive stars involves mergers and the
presence of
nearby companions. Discovery of companions to massive
stars in this
relatively nearby complex will provide guidance in the
interpretation of
apparently supermassive stars in distant locations. The
search for
companions will also be important for verification of
fundamental
parameters derived from spectroscopy, adjustments to main
sequence
fitting and distance estimations, determining third light
contributions
of eclipsing binaries, identifying wide colliding wind
binaries,
studying the relationship between orbital and spin angular
momentum, and
discovering binaries amenable to future mass
determinations. The massive
star environment in Cyg OB2 may be similar to the kinds
found in the
earliest epoch of star formation, so that a study of the
role of
binaries in Cyg OB2 will help us understand the formation
processes of
the first stars in the Universe.
NIC1/NIC2/NIC3 8795
NICMOS Post-SAA calibration - CR Persistence Part 6
A new proceedure proposed to alleviate the CR-persistence
problem of
NICMOS. Dark frames will be obtained immediately upon
exiting the SAA
contour 23, and everytime 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 i
mages. Each observation will need its own CRMAP, as
different SAA
passages leave different imprints on the NICMOS detectors.
NIC3 11080
Exploring the Scaling Laws of Star Formation
As a variety of surveys of the local and distant Universe
are
approaching a full census of galaxy populations, our
attention needs to
turn towards understanding and quantifying the physical
mechanisms that
trigger and regulate the large-scale star formation rates
{SFRs} in
galaxies.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS:
10758 - GSAcq (2,3,3) failed due to STOP flag on FGS 2
GSAcq (2,3,3) scheduled from 087/21:24:29-21:31:50 failed due to STOP
flags "QF2STOPF & QSTOP".
OBAD #1 RSS: 1232.49 a-s
OBAD #2 RSS: 6.50 a-s
OBAD MAP RSS: 284.51 a-s
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
09
08
FGS
REacq
02
02
OBAD with Maneuver
22
22
SIGNIFICANT EVENTS: (None)