Daily Report #4599

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4599

PERIOD COVERED: UT April 28, 2008 (DOY 119)

OBSERVATIONS SCHEDULED

SIGNIFICANT EVENTS: (None)

FGS 11212

Filling the Period Gap for Massive Binaries

The current census of binaries among the massive O-type stars is seriously
incomplete for systems in the period range from years to millennia because
the radial velocity variations are too small and the angular separations too
close for easy detection. Here we propose to discover binaries in this
observational gap through a Faint Guidance Sensor SNAP survey of relatively
bright targets listed in the Galactic O Star Catalog. Our primary goal is to
determine the binary frequency among those in the cluster/association,
field, and runaway groups. The results will help us assess the role of
binaries in massive star formation and in the processes that lead to the
ejection of massive stars from their natal clusters. The program will also
lead to the identification of new, close binaries that will be targets of
long term spectroscopic and high angular resolution observations to
determine their masses and distances. The results will also be important for
the interpretation of the spectra of suspected and newly identified binary
and multiple systems.

FGS 11214

HST/FGS Astrometric Search for Young Planets Around Beta Pic and AU Mic

Beta Pic and AU Mic are two nearby Vega-type debris disk stars. Both of
these disk systems have been spatially resolved in exquisite detail,
predominantly via the ACS coronagraph and WFPC-2 cameras onboard HST. These
images exhibit a wealth of morphological features which provide compelling
indirect evidence that these systems likely harbor short-period planetary
body{ies}. We propose to use the superlative astrometric capabilities of
HST/FGS to directly detect these planets, hence provide the first direct
planet detection in a Vega-type system whose disk has been imaged at high
spatial resolution.

NIC1/NIC2/NIC3 8795

NICMOS Post-SAA calibration - CR Persistence Part 6

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.

NIC3 11120

A Paschen-Alpha Study of Massive Stars and the ISM in the Galactic Center

The Galactic center (GC) is a unique site for a detailed study of a
multitude of complex astrophysical phenomena, which may be common to nuclear
regions of many galaxies. Observable at resolutions unapproachable in other
galaxies, the GC provides an unparalleled opportunity to improve our
understanding of the interrelationships of massive stars, young stellar
clusters, warm and hot ionized gases, molecular clouds, large scale magnetic
fields, and black holes. We propose the first large-scale hydrogen Paschen
alpha line survey of the GC using NICMOS on the Hubble Space Telescope. This
survey will lead to a high resolution and high sensitivity map of the
Paschen alpha line emission in addition to a map of foreground extinction,
made by comparing Paschen alpha to radio emission. This survey of the inner
75 pc of the Galaxy will provide an unprecedented and complete search for
sites of massive star formation. In particular, we will be able to (1)
uncover the distribution of young massive stars in this region, (2) locate
the surfaces of adjacent molecular clouds, (3) determine important physical
parameters of the ionized gas, (4) identify compact and ultra-compact HII
regions throughout the GC. When combined with existing Chandra and Spitzer
surveys as well as a wealth of other multi-wavelength observations, the
results will allow us to address such questions as where and how massive
stars form, how stellar clusters are disrupted, how massive stars shape and
heat the surrounding medium, and how various phases of this medium are
interspersed.

WFPC2 11022

WFPC2 Cycle 15 Decontaminations and Associated Observations

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

WFPC2 11130

AGNs with Intermediate-mass Black Holes: Testing the Black Hole-Bulge
Paradigm, Part II

The recent progress in the study of central black holes in galactic nuclei
has led to a general consensus that supermassive {10^6-10^9 solar mass}
black holes are closely connected with the formation and evolutionary
history of large galaxies, especially their bulge component. Two outstanding
issues, however, remain unresolved. Can central black holes form in the
absence of a bulge? And does the mass function of central black holes extend
below 10^6 solar masses? Intermediate-mass black holes {10^6 solar masses},
if they exist, may offer important clues to the nature of the seeds of
supermassive black holes. Using the SDSS, our group has successfully
uncovered a new population of AGNs with intermediate-mass black holes that
reside in low-luminosity galaxies. However, very little is known about the
detailed morphologies or structural parameters of the host galaxies
themselves, including the crucial question of whether they have bulges or
not. Surprisingly, the majority of the targets of our Cycle 14 pilot program
have structural properties similar to dwarf elliptical galaxies. The
statistics from this initial study, however, are really too sparse to reach
definitive conclusions on this important new class of black holes. We wish
to extend this study to a larger sample, by using the Snapshot mode to
obtain WFPC2 F814W images from a parent sample of 175 AGNs with
intermediate- mass black holes selected from our final SDSS search. We are
particularly keen to determine whether the hosts contain bulges, and if so,
how the fundamental plane properties of the host depend on the mass of their
central black holes. We will also investigate the environment of this unique
class of AGNs.

WFPC2 11178

Probing Solar System History with Orbits, Masses, and Colors of
Transneptunian Binaries

The recent discovery of numerous transneptunian binaries {TNBs} opens a
window into dynamical conditions in the protoplanetary disk where they
formed as well as the history of subsequent events which sculpted the outer
Solar System and emplaced them onto their present day heliocentric orbits.
To date, at least 47 TNBs have been discovered, but only about a dozen have
had their mutual orbits and separate colors determined, frustrating their
use to investigate numerous important scientific questions. The current
shortage of data especially cripples scientific investigations requiring
statistical comparisons among the ensemble characteristics. We propose to
obtain sufficient astrometry and photometry of 23 TNBs to compute their
mutual orbits and system masses and to determine separate primary and
secondary colors, roughly tripling the sample for which this information is
known, as well as extending it to include systems of two near-equal size
bodies. To make the most efficient possible use of HST, we will use a Monte
Carlo technique to optimally schedule our observations.

WFPC2 11202

The Structure of Early-type Galaxies: 0.1-100 Effective Radii

The structure, formation and evolution of early-type galaxies is still
largely an open problem in cosmology: how does the Universe evolve from
large linear scales dominated by dark matter to the highly non-linear scales
of galaxies, where baryons and dark matter both play important, interacting,
roles? To understand the complex physical processes involved in their
formation scenario, and why they have the tight scaling relations that we
observe today {e.g. the Fundamental Plane}, it is critically important not
only to understand their stellar structure, but also their dark-matter
distribution from the smallest to the largest scales. Over the last three
years the SLACS collaboration has developed a toolbox to tackle these issues
in a unique and encompassing way by combining new non-parametric strong
lensing techniques, stellar dynamics, and most recently weak gravitational
lensing, with high-quality Hubble Space Telescope imaging and VLT/Keck
spectroscopic data of early-type lens systems. This allows us to break
degeneracies that are inherent to each of these techniques separately and
probe the mass structure of early-type galaxies from 0.1 to 100 effective
radii. The large dynamic range to which lensing is sensitive allows us both
to probe the clumpy substructure of these galaxies, as well as their
low-density outer haloes. These methods have convincingly been demonstrated,
by our team, using smaller pilot-samples of SLACS lens systems with HST
data. In this proposal, we request observing time with WFPC2 and NICMOS to
observe 53 strong lens systems from SLACS, to obtain complete multi-color
imaging for each system. This would bring the total number of SLACS lens
systems to 87 with completed HST imaging and effectively doubles the known
number of galaxy-scale strong lenses. The deep HST images enable us to fully
exploit our new techniques, beat down low-number statistics, and probe the
structure and evolution of early-type galaxies, not only with a uniform
data-set an order of magnitude larger than what is available now, but also
with a fully coherent and self-consistent methodological approach!

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

11282 - GSAcq(1,2,1) Loss of Lock while guiding

Following a successful GSAcq (1,2,1), scheduled at 120/07:18:21, a Loss of
Lock occurred while guiding under FGS 1 and 2 at 120/07:38:40. (QF1STOPF)
stop flag indication set on FGS-1. P4TAKDAT (Take Data Flag) went down at
that time, causing ACS 779 Status Buffer Messages ("Fold Mechanism Move Was
Blocked") to occur at 120/07:38:40, 120/07:50:13, 120/08:01:46. The
spacecraft entered T2G mode. The TERM EXP was not scheduled until
120/08:15:52.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL FAILURE TIMES

FGS GSacq 10 10
FGS REacq 04 04
OBAD with Maneuver 28 28
LOSS of LOCK 120/07:38:40z

SIGNIFICANT EVENTS: (None)