Daily #3993

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 3993

PERIOD COVERED: UT November 21, 2005 (DOY 325)

OBSERVATIONS SCHEDULED

ACS/HRC 10396

Star Clusters, Stellar Populations, and the Evolution of the Small
Magellanic Cloud

As the closest star forming dwarf galaxy, the SMC is the preferred
location for detailed studies of this extremely common class of
objects. We therefore propose to use the capabilities of ACS, which
provide an improvement by an order of magnitude over what is possible
with ground- based optical imaging surveys that are limited by
confusion anddepth, to measure key stellar population parameters in
the SMC from VI color-magnitude diagrams. Our program focuses on
regions where crowding makes HST essential and includes 7 star
clusters and 7 field star locations. We will measure accurate ages of
the clusters, test stellar evolution models, gain fiducial stellar
sequences to use in fitting the field stars, check the form of the
IMF, and substantially extend the study of RR Lyrae variables in the
key NGC121 SMC globular cluster. The field pointings will allow us to
reconstruct the star formation history, look for enhanced star
formation that is expected when the SMC interacts with the LMC and/or
Milky Way, and compare its main sequence luminosity {and mass}
functions with those of the Milky Way, LMC, and UMi dwarf spheroidal.
This proposal is part of a coordinated HST and ground-based study of
the stellar history and star formation processes in the SMC.

ACS/HRC 10549

SAINTS - Supernova 1987A INTensive Survey

SAINTS is a program to observe SN 1987A, the brightest supernova in
384 years, as it morphs into the youngest supernova remnant at age 18.
HST is the unique and perfect tool for spatially- resolved
observations of the many physical components of SN 1987A. A violent
encounter is underway between the fastest-moving debris and the
circumstellar ring, exciting hotspots seen with HST that are suddenly
lighting up. The optical and X-ray flux from the ring are both rising
rapidly: HST and Chandra observations taken together are needed to
understand the physics of these shocked regions. In Cycle14, the
hotspots may fuse as the shock fully enters the ring. Photons from
these shocks may excite previously hidden gas outside the ring,
revealing the true extent of the mass loss that preceded the
explosion. The inner debris of the explosion itself, still excited by
radioactive isotopes produced in the explosion, is now well resolved
by ACS and seen to be aspherical, providing direct clues to the
mechanism of the explosion. Our search for a compact remnant is
beginning to eliminate some theoretical possibilities and we have the
opportunity in Cycle 14 to place much more stringent limits with
NICMOS. Many questions about SN 1987A remain unanswered. How did the
enigmatic three rings form in the late stages of Sanduleak -69 202?
Precisely what took place in the center during the core collapse and
bounce? Is a black hole or a neutron star left behind in the debris?
SAINTS has been a continuous program since HST was launched-- we
propose to extend this rich and deep data set for present use and
future reference to answer these central questions in the science of
supernovae.

ACS/HRC/WFC 10729

ACS CCDs daily monitor

This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise
in ACS CCD detectors. The files, biases and dark will be used to
create reference files for science calibration. This programme will be
for the entire lifetime of ACS. Changes from cycle 13:- The default
gain for WFC is 2 e-/DN. As before bias frames will be collected for
both gain 1 and gain 2. Dark frames are acquired using the default
gain {2}. This program cover the period Oct, 2 2005- May, 29-2006. The
second half of the program has a different proposal number: 10758.

ACS/WFC 10135

Unveiling the Progenitors and Physics of Cosmic Explosions

GRBs and XRFs are clearly highly asymmetric explosions and require a
long-lived power source {central engine}. In contrast, nearby
core-collapse events are essentially spherical explosions. However,
the failure of spherical neutrino driven collapses has led to the idea
that asymmetric energy release is essential for the explosion. The
recent finding of a Type Ic SN in GRB 030329, the association of the
low energy event GRB 980425 with SN 1998bw, the theoretical
development discussed above and the rise of collapsar models make it
timely to consider whether all these explosions contain engines. Given
the uncertainties in theoretical modeling it is clear that
observations are needed to guide models. A priori there is little
reason to expect connection between the ultra-relativistic jet that
powers the GRB and the explosive nucleosynthesis of the ~0.5 solar
masses of Nickel-56 that powers the accompanying supernova. We propose
a comprehensive program of ACS photometric searches {and measurements}
for SNe associated with GRBs and XRFs. In concert, we will undertake
ground- based spectroscopy to determine velocity widths, and measure
engine parameters from pan- chromatic afterglow observations. Our goal
is to produce a comprehensive database of engine and SN physical
parameters against which theoretical modeling will be guided.

ACS/WFC 10587

Measuring the Mass Dependence of Early-Type Galaxy Structure

We propose two-color ACS-WFC Snapshot observations of a sample of 118
candidate early- type gravitational lens galaxies. Our lens-candidate
sample is selected to yield {in combination with earlier results} an
approximately uniform final distribution of 40 early-type strong
lenses across a wide range of masses, with velocity dispersions {a
dynamical proxy for mass} ranging from 125 to 300 km/s. The proposed
program will deliver the first significant sample of low-mass
gravitational lenses. All of our candidates have known lens and source
redshifts from Sloan Digital Sky Survey data, and all are bright
enough to permit detailed photometric and stellar- dynamical
observation. We will constrain the luminous and dark-matter mass
profiles of confirmed lenses using lensed-image geometry and
lens-galaxy structural/photometric measurements from HST imaging in
combination with dynamical measurements from spatially resolved
ground-based follow-up spectroscopy. Hence we will determine, in
unprecedented detail, the dependence of early-type galaxy mass
structure and mass-to-light ratio upon galaxy mass. These results will
allow us to directly test theoretical predictions for halo
concentration and star-formation efficiency as a function of mass and
for the existence of a cuspy inner dark- matter component, and will
illuminate the structural explanation behind the fundamental plane of
early-type galaxies. The lens-candidate selection and confirmation
strategy that we propose has been proven successful for high-mass
galaxies by our Cycle 13 Snapshot program {10174}. The program that we
propose here will produce a complementary and unprecedented lens
sample spanning a wide range of lens-galaxy masses.

NIC1/NIC2 10410

Anisotropy and obscuration in the near-nuclear regions of powerful
radio galaxies

Despite the success of the orientation-based unified schemes for
powerful radio sources, we are still far from understanding the
distribution of obscuring material in the near-nuclear regions of such
sources, and how this distribution evolves with radio power. Following
on from our highly successful Cycle 7 pilot observations of Cygnus A,
we propose a near-IR polarimetric survey of a complete sample of
powerful radio galaxies in order map the near-nuclear illumination
cones, and investigate the distribution of obscuring material on a 0.1
to 1kpc scale. In particular, the observations will allow us to test
the "receding torus model'' which predicts that the opening angles of
the illumination cones are smaller in low redshift/low power radio
galaxies than in their high redshift/high power counterparts.We will
also investigate whether AGN- and jet-driven outflows have a
substantial effect on distribution of obscuring material by "hollowing
out'' the quasar illumination cones in the more powerful sources.
Finally, by using our polarization maps to search for signs of
intrinsic anisotropy in the near-IR continuum within the cones, we
will investigate the geometry of the near-IR continuum emitting
regions close to the quasar nuclei. These observations are not only
crucial for our understanding of radio source unification, but also
provide key information about the effects of AGN-induced outflows on
the ISM of the host galaxies.

NICMOS 8791

NICMOS Post-SAA calibration - CR Persistence Part 2

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 10748

WFPC2 CYCLE 14 Standard Darks

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:
17592-0 - Genslew for proposal 10539 - slot 14 @ 325/1952z
17593-0 - Genslew for proposal 10539 - slot 13 @ 325/1954z
17594-0 - Genslew for proposal 10539 - slot 12 @ 325/1955z

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 04 04
FGS REacq 12 12
OBAD with Maneuver 20 20

SIGNIFICANT EVENTS: (None)