HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT # 4604
PERIOD
COVERED: 5am May 05 - 5am May 06, 2008 (DOY 126/0900z - 127/0900z)
OBSERVATIONS
SCHEDULED
NIC1
10487
A Search
for Debris Disks in the Coeval Beta Pictoris Moving Group
Resolved
observations of debris disks present us with the opportunity of
studying
planetary evolution in other solar systems. We propose to
search
for debris disks in the Beta Pictoris moving group {8-20 Myrs,
10-50
pc away} , which provides a coeval sample of multiple spectral
types,
and it has already produced two magnificent resolved debris
disks:
AU Mic and Beta Pic. Such coeval sample will provide us with a
snapshop
of the crucial time in disk evolution in which the disk makes
the
transition from optically thick to optically thin, and it will be
useful
to study the stellar mass dependence of the disk evolution.
NIC1
11136
Resolving
Ultracool Astrophysics with Brown Dwarf Binaries
We
propose to obtain resolved far-red and near-IR photometry of 13 brown
dwarf
binaries with HST/NICMOS in order to study one of the
long-standing
puzzles in ultracool astrophysics, namely the rapid change
in
spectra from L dwarfs to T dwarfs at nearly constant effective
temperature
(a.k.a. the "L/T transition''). While many nearby brown
dwarfs
have been studied, use of such samples is inevitably hindered by
the
unknown ages, masses, and metallicities of the field population.
Characterization
of resolved ultracool binaries is a promising avenue
for
addressing this problem, by providing coeval systems of the same
composition
with comparable masses and temperatures. Our proposed
HST/NICMOS
(0.9-1.6 micron) observations will be combined with longer
wavelength
ground-based photometry and spectroscopy from Keck laser
guide
star adaptive optics. The resulting multiband (0.9-2.5 micron)
dataset
will be a unique resource for measuring the evolution of
spectral
energy distributions across the L/T transition, to test
state-of-the-art
atmospheric models, and to determine the physical
process(es)
that dominate the L/T transition. Understanding the L/T
transition
is important not only for testing brown dwarf atmospheres,
but
also provides a key pathway for understanding the same physical
effects,
namely the formation and removal of clouds, in the atmospheres
of
the extrasolar planets.
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 i
mages.
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.
S/C
4974
TRTTEST
The
Transient Response Test is for the periodic performance monitoring
of
the FGS 2R servo A mechanism.
WFPC2
11113
Binaries
in the Kuiper Belt: Probes of Solar System Formation and
Evolution
The
discovery of binaries in the Kuiper Belt and related small body
populations
is powering a revolutionary step forward in the study of
this
remote region. Three quarters of the known binaries in the Kuiper
Belt
have been discovered with HST, most by our snapshot surveys. The
statistics
derived from this work are beginning to yield surprising and
unexpected
results. We have found a strong concentration of binaries
among
low-inclination Classicals, a possible size cutoff to binaries
among
the Centaurs, an apparent preference for nearly equal mass
binaries,
and a strong increase in the number of binaries at small
separations.
We propose to continue this successful program in Cycle 16;
we
expect to discover at least 13 new binary systems, targeted to
subgroups
where these discoveries can have the greatest impact.
WFPC2
11125
The
Dynamical Evolution of Globular Clusters
Globular
clusters evolve through dynamical interactions, with primordial
binaries
extending the time until core collapse by up to an order of
magnitude,
depending on the initial binary fraction. These dynamical
interactions
plus mass segregation causes the binary fraction to rise in
the
core but fall at larger radii. We hope to eventually test these
broad
predictions by comparing them to the binary properties for
globular
clusters at different states of evolution, defined by the ratio
of
their age to the dynamical relaxation time at the half-light radius.
The
most important unknown aspects in the modeling process are the
initial
conditions of binaries in the cluster. Here we propose to
determine
the initial binary fraction as a function of radius by
studying
three of the dynamically youngest globular clusters {NGC 5053,
NGC
5466, and NGC 5897}. The presence of binaries thickens the
Sequence
in a color-magnitude diagram, which can be detected with deep
multicolor
images.
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.
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of potential
non-nominal performance that will be investigated.)
HSTARS:
None
COMPLETED
OPS REQUEST:
18320-0
- TRTT #18 @ 126/16:55z
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
10
10
FGS
REacq
02
02
OBAD
with Maneuver
28
28
SIGNIFICANT
EVENTS:
The
18th run of the TRTT was successfully executed via Ops Request
18230.
The data will be analyzed and presented at the next guide star
working
group meeting to continue monitoring FGS2. The GSAcq at
126/18:25
immediately following the TRTT was successful.