Daily Rpt #4121

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT #4121

PERIOD COVERED: UT May 24, 2006 (DOY 144)

OBSERVATIONS SCHEDULED

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 10588

The Host Galaxies of Post-Starburst Quasars

We propose to use ACS to conduct a snapshot imaging survey of
post-starburst quasars now being discovered in signficant numbers by
the Sloan Digital Sky Survey. Post-starburst quasars are broad-lined
AGN that also possess Balmer jumps and high-n Balmer absorption lines
indicative of luminous stellar populations on order of 100 Myr old.
These objects, representing a few percent of the z 0.5 quasar
population, may be an evolutionary stage in the transition of
ultraluminous infrared galaxies into normal quasars, or a type of
galaxy interaction that triggers both star formation and nuclear
activity. These sources may also illustrate how black hole mass/bulge
mass correlations arise. Ground-based imaging of individual
poststarburst quasars has revealed merger remnants, binary systems,
and single point sources. Our ACS snapshots will enable us to
determine morphologies and binary structure on sub-arcsecond scales
{surely present in the sample}, as well as basic host galaxy
properties. We will be looking for relationships among morphology,
particularly separation of double nuclei, the starburst age, the
quasar black hole mass and accretion rate, that will lead to an
understanding of the triggering activity and mutual evolution. This
project will bring quantitative data and statistics to the previously
fuzzy and anecdotal topic of the "AGN-starburst connection" and help
test the idea that post-starburst quasars are an early evolutionary
stage of normal quasars.

ACS/WFC 10775

An ACS Survey of Galactic Globular Clusters

We propose to conduct an ACS/WFC imaging survey of Galactic globular
clusters. We will construct the most extensive and deepest set of
photometry and astrometry to-date for these systems reaching a main
sequence mass of ~0.2 solar mass with S/N = 10. We will combine these
data with archival WFPC2 and STIS images to determine proper motions
for the stars in our fields. The resultant cleaned cluster CMDs will
allow us to study a variety of scientific questions. These include
[but are not limited to] 1} the determination of cluster ages and
distances 2} the construction of main sequence mass functions and the
issue of mass segregation 3} the internal motions and dynamical
evolution of globular clusters, and 4} absolute cluster motions,
orbits, and the Milky Way gravitational potential. We anticipate that
the unique resource provided by the proposed treasury archive will
play a central role in the field of globular cluster studies for
decades, with a stature comparable to that of the Hubble Deep Field
for high redshift studies.

FGS 10611

Precise Distances to Nearby Planetary Nebulae

We propose to carry out astrometry with the FGS to obtain accurate and
precise distances to four nearby planetary nebulae. In 1992, Cahn et
al. noted that ``The distances to Galactic planetary nebulae remain a
serious, if not THE most serious, problem in the field, despite
decades of study.'' Twelve years later, the same statement still
applies. Because the distances to planetary nebulae are so uncertain,
our understanding of their masses, luminosities, scale height, birth
rate, and evolutionary state is severely limited. To help remedy this
problem, HST astrometry can guarantee parallaxes with half the error
of any other available approach. These data, when combined with
parallax measurements from the USNO, will improve distance
measurements by more than a factor of two, producing more accurate
distances with uncertainties that are of the order of ~6%. Lastly,
most planetary nebula distance scales in the literature are
statistical. They require several anchor points of known distance in
order to calibrate their zero point. Our program will provide "gold
standard" anchor points by the end of 2006, a decade before any
anticipated results from future space astrometry missions.

NIC3/ACS/WFC 10504

Characterizing the Sources Responsible for Cosmic Reionization

Our group has demonstrated the role that massive clusters, acting as
powerful cosmic lenses, can play in constraining the abundance and
properties of low-luminosity star-forming sources beyond z~6; such
sources are thought to be responsible for ending cosmic reionization.
The large magnification possible in the critical regions of
well-constrained clusters brings sources into view that lie at or
beyond the limits of conventional exposures such as the UDF, as well
as those in imaging surveys being undertaken with IRAC onboard
Spitzer. We have shown that the combination of HST and Spitzer is
particularly effective in delivering the physical properties of these
distant sources, constraining their mass, age and past star formation
history. Indirectly, we therefore gain a valuable glimpse to yet
earlier epochs. Recognizing the result {and limitations} of the UDF
exposure, we propose a systematic search through 6 lensing clusters
with ACS and NICMOS for further z~6-7 sources in conjunction with
existing deep IRAC data. Our survey will mitigate cosmic variance and
extend the search both to lower luminosities and, by virtue of the
NICMOS/IRAC combination, to higher redshift. The goal is to count and
characterize representative sources at z~6-10 and to delineate the
redshift range of activity for the planning of future observations.

NICMOS 8790

NICMOS Post-SAA calibration - CR Persistence Part 1.

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.

WFPC2 10628

Determining the Lifetime of Planetary Nebula Knots from Observations
of the Core of the Helix Nebula.

Knots within the Planetary Nebulae {PN} are ubiquitous components and
form at the interface of the expanding ionized zone and the
surrounding dusty and molecule-rich neutral layers. About half of the
total mass ejected by the precursor star becomes trappped in the
Knots, which will join the Interstellar Medium {ISM} within a few tens
of thousands of years. If they survive, they may be the source of the
micro-structures that appear to be common in the ISM, a result that
would be important in understanding the exchange of matter between
stars and the ISM. We propose observations that will characterize the
Knots over a wider ionization range and ages than has been done
before, which should yield the best model for the Knots and therefore
the best prediction of their fates. Knots are not seen within a well
defined distance from the central star. We don't know if this is
because they are being destroyed by photoevaporation {since the inner
Knots would be the youngest}, an important factor in our modeling.
However, the inner core of the Helix Nebula has not been imaged in the
HeII emission that dominates the region. We propose eight orbits of
observations that will search the inner core of the Helix for
undetected knots using the WFPC2 HeII F469N filter and the ACS-WFC
F502N filter that isolates [OIII] emission. Our WFPC2 pointing will
also allow imaging the best studied knot in HeII, giving us the best
possible data for that Knot. These combined results will be modeled
with the new Hydro- Cloudy code, allowing us to determine if they will
survive the PN stage and become components of the ISM. At no
additional cost of observing time we will be able to derive a
calibration of the WFPC2 F469N filter, to make unprecedented quality
parallel images in molecular hydrogen, and to extended the coverage of
high resolution emission-line images of the Helix Nebula.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

#10276- REacq(1,2,1) failed to RGA Control @ 145/03:09:05z

The Target REacq(1,2,1) scheduled at 145/03:09:05 - 03:17:10 failed to
RGA Hold due to search radius limit exceeded on FGS-1. A 486 ESB "a05"
(FGS Coarse Track failed-Search Radius Limit exceeded) was received at
145/03:15:01. Prior GSAcq using same star id was successful.
Pre-acquisition OBAD/MAP had (RSS) value of 8.29 arcseconds. There
were no FHST OBAD (with maneuver) scheduled prior to REacq. Subsequent
OBAD/MAP at 145/03:17:23 had (RSS) value of 71.33 arcseconds. REacq
did not attempt due to enough error. Per PCS SE approval a Real-time
OBAD Correction using COP 3.55 (OPS REQUEST 1777-1) was executed at
145/04:24:19. Subsequent REacq at 145/04:44:59 was successful.

#10277- FGS-3 Bit Flip in SAA Level 2 @ 145/00:06:57z

At 145/00:06:57 during SAA-2 passage, FGS-3 experienced a bit-flip
which caused QF3SRLEX and QSRCHRXC to flag. The FGSs are known to be
susceptible in the SAA, and upset parameters have been experienced in
the past with no impact to FGSs. The guide star acquisition at
145/07:59:34 using FGS-3 cleared the flags and proceeded normally. The
spacecraft was in RGA Hold when the anomaly occurred.

COMPLETED OPS REQUEST:
#17777- Real-Time OBAD @ 145/04:24:19z

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 5 5
FGS REacq 10 9 (HSTAR
10276)
OBAD with Maneuver 20 20


SIGNIFICANT EVENTS:

Battery 5 Capacity Test Flash Report #2

The 2006 Battery 5 capacity test results are 55.8Ah at 5A and 51.8Ah
at 9A.