Daily # 4222

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4222

PERIOD COVERED: UT October 18, 2006 (DOY 291)

OBSERVATIONS SCHEDULED

ACS/HRC 10867

SAINTS - Supernova 1987A INTensive Survey

SAINTS is a program to observe SN 1987A, the brightest supernova in
383 years, as it morphs into the youngest supernova remnant at age 19.
HST is a unique tool for spatially-resolved observations of the many
physical components of SN 1987A. A violent encounter is now underway
between the fastest-moving debris and the circumstellar ring: the
collision excites "hotspots" that light up suddenly. The optical,
infrared and X-ray fluxes are rising rapidly and vary significantly on
6-month time scales: regularly-spaced HST, SPITZER, and CHANDRA
observations are needed to understand the physics of these shocked
regions. In Cycle 15, the many separate hotspots may begin to fuse as
the shock fully enters the circumstellar ring. Photons from these
shocks may excite previously invisible gas outside the ring, revealing
the true extent of the mass loss that preceded the explosion of
Sanduleak -69 202. The inner debris of the explosion itself, still
excited by radioactive isotopes produced in the explosion, is now
resolved by ACS and seen to be aspherical, providing direct evidence
on the asymmetry of the explosion. Many questions about SN 1987A
remain unanswered despite our diligent efforts at observation and
analysis since the launch of HST. How did the enigmatic three rings
form? Precisely what took place in the core during the core collapse
and bounce? Is a black hole or a neutron star left behind in the
debris? The rich and deep data set from SAINTS will be a resource for
current use and for future reference to help answer these central
questions of supernova science.

ACS/HRC/WFC 10758

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 May, 31 2006- Oct, 1-2006. The
first half of the program has a different proposal number: 10729.

ACS/WFC 10595

A Reference Database for Accurate Ages and Metallicities of Globular
Clusters in the Magellanic Clouds

We propose to finalize the compilation of a comprehensive database of
high-quality ages and metallicities of Simple Stellar Populations
{SSPs} in the Milky Way and the Magellanic Clouds. We will acquire new
ACS imagery for 8 young and intermediate-age globular clusters in the
Magellanic Clouds to create high-quality color-magnitude diagrams
{CMDs} to enable accurate measurements of their ages and
metallicities. In concert with a similar analysis of CMD data already
available in the HST archive for 8 more such GCs, the resulting
database will provide a well-sampled coverage of the full range of
ages and metallicities known among globular clusters {0.5 = Age {Gyr}
= 13.5 and -2.3 = [Fe/H] = +0.1, respectively}. This database will
form the crucial basis for our ongoing, comprehensive multi-wavelength
program to: {1} establish empirical relations among SSP colors {from
the UV [GALEX] through the mid-IR [Spitzer]}, line strengths, ages and
metallicities, and {2} provide a stringent test of the systemic
accuracy of age and metallicity determinations using state-of-the-art
population synthesis models.

ACS/WFC 10816

The Formation History of Andromeda's Extended Metal-Poor Halo

We propose deep ACS imaging in the outer spheroid of the Andromeda
galaxy, in order to measure the star formation history of its true
halo. For the past 20 years, nearly all studies of the Andromeda
"halo" were focused on the spheroid within 30 kpc of the galaxy's
center, a region now known to host significant substructure and
populations with high metallicity and intermediate ages. However, two
groups have recently discovered an extended metal-poor halo beyond 30
kpc; this population is distinct in its surface-brightness profile,
abundance distribution, and kinematics. In earlier cycles, we obtained
deep images of the inner spheroid {11 kpc on the minor axis}, outer
disk {25 kpc on the major axis}, and giant tidal stream, yielding the
complete star formation history in each field. We now propose deep ACS
imaging of 4 fields bracketing this 30 kpc transition point in the
spheroid, so that the inner spheroid and the extended halo populations
can be disentangled, enabling a reconstruction of the star formation
history in the halo. A wide age distribution in the halo, as found in
the inner spheroid, would imply the halo was assembled through ongoing
accretion of satellite galaxies, while a uniformly old population
would be a strong indication that the halo was formed during the early
rapid collapse of the Andromeda proto-galaxy.

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration - CR Persistence Part 4

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 10744

WFPC2 Cycle 14 Decontaminations and Associated Observations

This proposal is for the WFPC2 decontamination. Also included are
instrument monitors tied to decontamination: photometric stability
check, focus monitor, pre- and post-decontamination internals {bias,
intflats, kspots, & darks}, UV throughput check, VISFLAT sweep, and
internal UV flat check.

WFPC2 10915

ACS Nearby Galaxy Survey

Existing HST observations of nearby galaxies comprise a sparse and
highly non-uniform archive, making comprehensive comparative studies
among galaxies essentially impossible. We propose to secure HST's
lasting impact on the study of nearby galaxies by undertaking a
systematic, complete, and carefully crafted imaging survey of ALL
galaxies in the Local Universe outside the Local Group. The resulting
images will allow unprecedented measurements of: {1} the star
formation history {SFH} of a 100 Mpc^3 volume of the Universe with a
time resolution of Delta[log{t}]=0.25; {2} correlations between
spatially resolved SFHs and environment; {3} the structure and
properties of thick disks and stellar halos; and {4} the color
distributions, sizes, and specific frequencies of globular and disk
clusters as a function of galaxy mass and environment. To reach these
goals, we will use a combination of wide-field tiling and pointed deep
imaging to obtain uniform data on all 72 galaxies within a
volume-limited sample extending to ~3.5 Mpc, with an extension to the
M81 group. For each galaxy, the wide-field imaging will cover out to
~1.5 times the optical radius and will reach photometric depths of at
least 2 magnitudes below the tip of the red giant branch throughout
the limits of the survey volume. One additional deep pointing per
galaxy will reach SNR~10 for red clump stars, sufficient to recover
the ancient SFH from the color-magnitude diagram. This proposal will
produce photometric information for ~100 million stars {comparable to
the number in the SDSS survey} and uniform multi-color images of half
a square degree of sky. The resulting archive will establish the
fundamental optical database for nearby galaxies, in preparation for
the shift of high-resolution imaging to the near-infrared.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

10471 - GSAcq (2,1,1) failed to RGA control due to Search Radius Limit
Exceeded on FGS 2

At 291/10:36:11 GSAcq (2,1,1) failed to RGA control due to Search
Radius Limit Exceeded on FGS 2. At 291/10:10:14 received ESB 1902
(OBAD Failed ID) on OBAD #1, the recorded values were V1= -229531.80,
V2= -174409.81, V3= -277475.18, RSS= 400120.10. Forward link was not
available prior to start of OBAD #2. OBAD #2 = V1 -53.72, V2 2400.62,
V3 -275.43, RSS 2416.97. OBAD MAP = V1 -46.12, V2 -58.97, V3 -14.89,
RSS 76.33

10472 - GSACQ(2,1,2) failed, Search Radius Limit Exceeded on FGS 2

REACQ(2,1,1) at 292/03:15:39 failed due to Search Radius Limit
Exceeded on FGS 2 at 03:20:21. Five status buffer 1805 messages (T2G
MOVING TARGET DETECTED) and one A05 message (FGS Coarse Track failed-
search Radius Limit exceeded) were received. OBAD data prior to REACQ
was not immediately available. Primary GSACQ(2,1,1) at 01:42:08 and
REACQ(2,1,1) at 04:51:28 were successful.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 09 08
FGS REacq 05 03
OBAD with Maneuver 28 28

SIGNIFICANT EVENTS: (None)