Daily #4079

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT #4079

PERIOD COVERED: UT March 27, 2006 (DOY 086)

OBSERVATIONS SCHEDULED

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/SBC 10507

High resolution imaging of Jupiter's diffuse auroral emissions inside
and outside the main oval during solar

The analysis of HST-STIS FUV images has greatly and quickly advanced
our knowledge of the magnetospheric mechanisms producing the auroral
emissions on the giant planets. However, these studies were limited to
the brightest emissions and very little has been said about the
fainter emissions, mainly because of the lower S/N. We propose to
image the faint auroral emissions on Jupiter which could not be
observed with STIS. We will take full advantage of ACS/SBC's higher
sensitivity to observe the diffuse auroral FUV emissions appearing
poleward and directly equatorward of Jupiter's main auroral oval in
the northern hemisphere. This proposal has the potential to reveal new
magnetosphere-ionosphere coupling mechanisms especially those
involving solar wind interactions with a giant planet.

ACS/WFC 10582

Probing The Galaxy-wide Globular Cluster - Low Mass X-ray Binary
Connection in Early-type Galaxies

The combination of high-resolution imaging from Hubble {HST} and
Chandra {CXO} has completely revolutionized our understanding of
extragalactic low-mass X-ray binaries {LMXBs} and globular clusters
{GCs}; however, studies have been limited by short X-ray exposures and
relatively small fields. NGC 4697 amd NGC 4365 are relatively simple
elliptical galaxies in the X- ray that will have deep CXO
observations. We propose ACS observations in six flanking fields per
galaxy to provide a study of the GC-LMXB connection in normal
early-type galaxies with unprecedented depth, spatial resolution and
areal coverage. Combined with existing central field observations, we
will detect ~900 and ~2700 GCs GCs in most of NGC 4697 and all of NGC
4365. These two galaxies will have the greatest number of detected
GC-LMXBs to date {~70 & 120}. We will measure the fraction of LMXBs
found in GCs, and the fraction of GCs which contain LMXBs, as a
function of X-ray luminosity, galactocentric distance, color, GC
half-light radius, and local GC specific frequency. We will test
existing models of GC formation/evolution and LMXB
formation/evolution. Using the radial profile of optical light, GCs,
and LMXBS, we will determine the percentage of field LMXBs which may
have originated in GCs.

ACS/WFC/WFC 10776

HST/ACS Mosaic of M82

A six-pointing ACS WFC mosaic of the galaxy M82 will be obtained in
four filters, B, V, I and H- alpha. Four orbits per pointing will
allow high-quality S/N images of the entire galaxy.

ACS/WFC/WFPC2 10584

The link between X-ray source and stellar populations in M81

We propose to perform a deep v~26-27.0 HST-ACS survey of the nearby
{3.6 Mpc} spiral galaxy M~81 in order to study the nature of its X-ray
source populations detected with Chandra. For the first time in a
galaxy other than the Milky-Way or the Magelanic Clouds, we will
classify X-ray sources as High-Mass and Low-Mass X-ray binaries
{HMXBs, LMXBs} and investigate how these populations depend on their
galactic environment. The classification will be performed {a} by
finding and classifying unique optical counterparts for the X-ray
sources and {b} studying the stellar populations in their vicinity.
Both tasks require the 0.1'' resolution of HST-ACS which matches well
the positional accuracy of Chandra. Finally we will use these results
together with X-ray binary evolution synthesis models in order to
constrain X-ray binary {XRB} evolution channels. These data will also
be a great resource for studies of the star-formation and star-
cluster populations in one of the prototypical spiral galaxies.

NIC2 10527

Imaging Scattered Light from Debris Disks Discovered by the Spitzer
Space Telescope Around 20 Sun-like Stars

We propose to use the high contrast capability of the NICMOS
coronagraph to image a sample of newly discovered circumstellar disks
associated with sun-like stars. These systems were identified by their
strong thermal infrared emission with the Spitzer Space Telescope as
part of the Spitzer Legacy Science program titled, "The Formation and
Evolution of Planetary Systems {FEPS}." Modelling of the thermal
excess emission in the form of spectral energy distributions alone
cannot distinguish between narrowly confined high opacity disks and
broadly distributed, low opacity disks. However, our proposed NICMOS
observations can, by imaging the light scattered from this material.
Even non- detections will place severe constraints on the disk
geometry, ruling out models with high optical depth. Unlike previous
disk imaging programs, our program contains a well defined sample of
solar mass stars covering a range of ages from ~10Myrs to a few Gyrs,
allowing us to study the evolution of disks from primordial to debris
for the first time. These results will greatly improve our
understanding of debris disks around Sun- like stars at stellar ages
nearly 10x older than any previous investigation. Thus we will have
fit a crucial piece into the puzzle concerning the formation and
evolution of our own solar system.

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.

WFPC2 10751

WFPC2 CYCLE 14 Intflat Linearity Check and Filter Rotation Anomaly
Monitor

Intflat observations will be taken to provide a linearity check: the
linearity test consists of a series of intflats in F555W, in each gain
and each shutter. A combination of intflats, visflats, and earthflats
will be used to check the repeatability of filter wheel motions.
{Intflat sequences tied to decons, visits 1-18 in prop 10363, have
been moved to the cycle 14 decon proposal 10744 for easier
scheduling.} Note: long-exposure WFPC2 intflats must be scheduled
during ACS anneals to prevent stray light from the WFPC2 lamps from
contaminating long ACS external exposures.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

10183 - GSacq(2,1,2) failed due to search radius limit exceeded
@087/0250Z During LOS the GSacq(2,1,2) scheduled at 087/02:50:14
failed due to search radius limit exceeded on FGS 1. The map at
02:57:09 showed errors of V1= 0.45, V2= 5.24, V3= 7.82, RSS= 9.43.

10184 - REacq(2,1,2) failed due to search radius limit exceeded
@087/0532z During LOS the REacq(2,1,2) scheduled at 087/05:31:31
failed due to search radius limit exceeded on FGS 2. ESB message a05 -
FGS Coarse Track failed - Search Radius Limit exceeded was received.
The map at 06:08:22 showed errors of V1=0.09, V2=-1204.19, V3=-42.57,
RSS=1204.94.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 14 13 087/0250z
(HSTAR#10183)
FGS REacq 02 01 087/0532z
(HSTAR#10184)
OBAD with Maneuver 28 28

SIGNIFICANT EVENTS: (None)