Daily #4085

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT #4085

PERIOD COVERED: UT April 04, 2006 (DOY 094)

OBSERVATIONS SCHEDULED

ACS/HRC 10474

Shooting Stars: Looking for Direct Evidence of Massive Central Black
Holes in Globular Clusters

We propose to make observations that directly test the proposition
that globular clusters contain massive black holes. Our targets are
the bulge globular clusters NGC 6388 and NGC 6441. These are probably
among the most massive in the galaxy, but are understudied compared to
more familiar objects such as M15. Our analysis suggests that these
two clusters are the most likely to show unambiguous evidence for a
central massive black hole if such things exist in globular clusters.
The observations proposed will give us the first thorough kinematic
and photometric studies of these two clusters. The combination of the
two epochs will give us proper motions good to of order 6 km/s. In
addition, they will provide us with the first good, deep,
color-magnitude diagrams for these clusters. These diagrams will be
used to investigate the make up of the stellar population in the
clusters, to more firmly establish their distances, ages, and
metallicities, and to search for a binary sequence.

ACS/WFC 10496

Decelerating and Dustfree: Efficient Dark Energy Studies with
Supernovae and Clusters

We propose a novel HST approach to obtain a dramatically more useful
"dust free" Type Ia supernovae {SNe Ia} dataset than available with
the previous GOODS searches. Moreover, this approach provides a
strikingly more efficient search-and-follow-up that is primarily pre-
scheduled. The resulting dark energy measurements do not share the
major systematic uncertainty at these redshifts, that of the
extinction correction with a prior. By targeting massive galaxy
clusters at z 1 we obtain a five-times higher efficiency in
detection of Type Ia supernovae in ellipticals, providing a
well-understood host galaxy environment. These same deep cluster
images then also yield fundamental calibrations required for future
weak lensing and Sunyaev-Zel'dovich measurements of dark energy, as
well as an entire program of cluster studies. The data will make
possible a factor of two improvement on supernova constraints on dark
energy time variation, and much larger improvement in systematic
uncertainty. They will provide both a cluster dataset and a SN Ia
dataset that will be a longstanding scientific resource.

ACS/WFC 10573

Globular Clusters in the Direction of the Inner Galaxy

The age, chemical and kinematic distributions of stellar populations
provide powerful constraints on models of the formation and evolution
of the Milky Way. The globular clusters constitute an especially
useful case because the stars within individual clusters are coeval
and spatially distinct. But a serious limitation in the study of many
globular clusters -- especially those located near the Galactic Center
-- has been the existence of large absolute and differential
extinction by foreground dust. We propose to use the ACS to map the
differential extinction and remove their effects in a large sample of
globular clusters located in the direction of the inner Galaxy using a
technique refined recently by von Braun and Mateo {2001}. These
observations and their analyses will let us produce high quality
color-magnitude diagrams of these poorly studied clusters that will
allow us to determine these clusters' relative ages, distances and
chemistry and to address important questions about the formation and
the evolution of the inner Galaxy. Our aim for these ACS observations
is to obtain data for the most crowded clusters in the inner Galaxy
where the excellent spatial resolution of the ACS is most necessary.

ACS/WFC 10592

An ACS Survey of a Complete Sample of Luminous Infrared Galaxies in
the Local Universe

At luminosities above 10^11.4 L_sun, the space density of far-infrared
selected galaxies exceeds that of optically selected galaxies. These
`luminous infrared galaxies' {LIRGs} are primarily interacting or
merging disk galaxies undergoing enhanced star formation and Active
Galactic Nuclei {AGN} activity, possibly triggered as the objects
transform into massive S0 and elliptical merger remnants. We propose
ACS/WFC imaging of a complete sample of 88 L_IR 10^11.4 L_sun
luminous infrared galaxies in the IRAS Revised Bright Galaxy Sample
{RBGS: i.e., 60 micron flux density 5.24 Jy}. This sample is ideal
not only in its completeness and sample size, but also in the
proximity and brightness of the galaxies. The superb sensitivity,
resolution, and field of view of ACS/WFC on HST enables a unique
opportunity to study the detailed structure of galaxies that sample
all stages of the merger process. Imaging will be done with the F439W
and F814W filters {B and I-band} to examine as a function of both
luminosity and merger state {i} the evidence at optical wavelengths of
star formation and AGN activity and the manner in which instabilities
{bars and bridges} in the galaxies may funnel material to these active
regions, {ii} the relationship between star formation and AGN
activity, and {iii} the structural properties {AGN, bulge, and disk
components} and fundamental parameters {effective radius and surface
brightness} of LIRGs and their similarity with putative evolutionary
byproducts {elliptical, S0 and classical AGN host galaxies}. This HST
survey will also bridge the wavelength gap between a Spitzer imaging
survey {covering seven bands in the 3.6-160 micron range} and a GALEX
UV imaging survey of these galaxies, but will resolve complexes of
star clusters and multiple nuclei at resolutions well beyond the
capabilities of either Spitzer or GALEX. The combined datasets will
result in the most comprehensive multiwavelength study of interacting
and merging galaxies to date.

S/C 10718

The Exosphere of a Newly Discovered Transiting Planet

We propose to use HST to directly detect the atmosphere and extended
envelope {exosphere} of a recently discovered planet that transits the
relatively bright star HD 149026. Absorption of background stellar
Lyman-alpha emission is an extremely sensitive exospheric diagnostic
that only HST can measure. If the HD 149026 planet is evaporating,
then hydrogen in the exosphere should fill or overfill the Roche lobe,
which has a size 4 times the diameter of Jupiter. If we do not detect
a decrease in Lyman-alpha flux during several transits, then the
hydrogen exosphere does not fill the Roche lobe of the planet and
significant evaporation is unlikely. This would be a surprise, given
that Vidal-Madjar et al. {2003} detected the exosphere of the planet
that transits HD 209458, and the models of Lecavelier des Etangs et
al. {2004} predict an order of magnitude more evaporation for the
planet around HD 149026, due to its lower mass and smaller orbital
distance. The newly discovered planet has 3 times the mean density and
at least 3 times the core mass of the planet that transits HD 209458,
which is consistent with significant exospheric evaporation in the
past. We will also use ACS/PR200L observations to measure stellar limb
darkening in the NUV, to detect Mg in the lower atmosphere of the
planet, and to search for evidence of a moon or planetary rings.

WFPC2 10745

WFPC2 CYCLE 14 INTERNAL MONITOR

This calibration proposal is the Cycle 14 routine internal monitor for
WFPC2, to be run weekly to monitor the health of the cameras. A
variety of internal exposures are obtained in order to provide a
monitor of the integrity of the CCD camera electronics in both bays
{both gain 7 and gain 15 -- to test stability of gains and bias
levels}, a test for quantum efficiency in the CCDs, and a monitor for
possible buildup of contaminants on the CCD windows. These also
provide raw data for generating annual super-bias reference files for
the calibration pipeline.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

10197 - GSAcq (1,2,1) failed due to search radius limit exceeded on
FGS- @ 094/12:01:30z

GSAcq (1,2,1) scheduled at 094/11:56:22-12:03:11 failed due to search
radius limit exceeded on FGS-1. At 094/11:59:01 received ESB
"1805"(x3)(Moving target detected) and later received ESB "a05"
(Exceeded SRL). OBAD #1: V1 -321.53, V2 -1306.23, V3 -569.31, RSS
1460.73. OBAD #2: V1 5.41, V2 -6.58, V3 -3.56, RSS 9.23 OBAD MAP: V1
-0.67, V2 75.62, V3 -0.27, RSS 75.63

10199 - GSAcq(2,1,2) requires two attempts to achieve CT-DV @
089/21:51:32z

GSAcq(2,1,2) scheduled for 2006/089 21:51:32 required two attempts to
achieve CT-DV on FGS2. The acquisition was successful.

COMPLETED OPS REQUEST:
17689-0 - Battery 6 Capacity Test Script & Battery Pressure Limit
COP (Step thru 17)
17693-0 - Genslew for proposal 10695 - slot 7 @ 094/18:53z
17694-0 - Genslew for proposal 10695 - slot 8 @ 094/18:55z


COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 12 11 Hstar # 10197
FGS REacq 03 03
OBAD with Maneuver 30 30


SIGNIFICANT EVENTS:

Commanding for the Battery 6 Capacity Test started as scheduled at DOY
094/1155 GMT (4/4 at 7:55 am) with setting the Battery Pressure Test
for a 5-battery system. Battery 6 was taken off-line and battery
discharge was begun at 1353 GMT (4/4 at 9:53 am).

Battery 6 switched from the High-rate to Low-rate discharge resistor
at approximately 095/0011 GMT (4/4 at 08:11 pm).

Following completion of the discharge, which is expected to occur
around 096/1600 GMT (4/06 at 12:00 noon), Battery 6 will be placed
back on-line in hardware during orbit night. On the orbit night pass
following battery back to section switch, the Elevated VTFE Macro will
be executed. On 097/1200 GMT (4/07 at 8:00 am), Battery 6 is scheduled
to be placed back on-line in FSW.

As of 095/0045 GMT (4/4 at 08:41 pm local), the battery 6 discharge
continues nominally.