HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT #4728
PERIOD COVERED: 5am October 30 - 5am October 31, 2008 (DOY
304/0900z-305/0900z)
OBSERVATIONS SCHEDULED
ACS/SBC 11158
HST Imaging of UV Emission in Quiescent Early-type
Galaxies
We have constructed a sample of early type galaxies at
z~0.1 that have
blue UV-optical colors, yet also show no signs of optical
emission, or
extended blue light. We have cross-correlated the SDSS
catalog and the
Galaxy Evolution Explorer Medium Imaging Survey to select
a sample of
galaxies where this UV emission is strongest. The origin
of the UV
rising flux in these galaxies continues to be debated, and
the
possibility that some fraction of these galaxies may be
experiencing low
levels of star formation cannot be excluded. There is also
a possibility
that low level AGN activity {as evidenced by a point
source} is
responsible We propose to image the UV emission using the
HST/SBC and to
explore the morphology of the UV emission relative to the
optical light.
WEPC2 11196
An Ultraviolet Survey 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 starbursts and creating/fueling
central AGN. We
propose far {ACS/SBC/F140LP} and near {WFPC2/PC/F218W} UV
imaging of a
sample of 27 galaxies drawn from the complete IRAS Revised
Bright Galaxy
Sample {RBGS} LIRGs sample and known, from our Cycle 14 B
and I-band ACS
imaging observations, to have significant numbers of
bright {23 < B < 21
mag} star clusters in the central 30 arcsec. The HST UV
data will be
combined with previously obtained HST, Spitzer, and GALEX
images to {i}
calculate the ages of the clusters as function of merger
stage, {ii}
measure the amount of UV light in massive star clusters
relative to
diffuse regions of star formation, {iii} assess the
feasibility of using
the UV slope to predict the far-IR luminosity {and thus
the star
formation rate} both among and within IR-luminous
galaxies, and {iv}
provide a much needed catalog of rest- frame UV
morphologies for
comparison with rest-frame UV images of high-z LIRGs and
Lyman Break
Galaxies. These observations will achieve the resolution
required to
perform both detailed photometry of compact structures and
spatial
correlations between UV and redder wavelengths for a
physical
interpretation our IRX-Beta results. The HST UV data,
combined with the
HST ACS, Spitzer, Chandra, and GALEX observations of this
sample, will
result in the most comprehensive study of luminous
starburst galaxies to
date.
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 11289
SL2S: The Strong Lensing Legacy Survey
Recent systematic surveys of strong galaxy-galaxy lenses
{CLASS, SLACS,
GOODS, etc.} are producing spectacular results for galaxy
masses roughly
below a transition mass M~10^13 Mo. The observed lens
properties and
their evolution up to z~0.2, consistent with numerical
simulations, can
be described by isothermal elliptical potentials. In
contrast, modeling
of giant arcs in X-ray luminous clusters {halo masses M
>~10^13 Mo}
favors NFW mass profiles, suggesting that dark matter
halos are not
significantly affected by baryon cooling. Until recently,
lensing
surveys were neither deep nor extended enough to probe the
intermediate
mass density regime, which is fundamental for
understanding the assembly
of structures. The CFHT Legacy Survey now covers 125
square degrees, and
thus offers a large reservoir of strong lenses probing a
large range of
mass densities up to z~1. We have extracted a list of 150
strong lenses
using the most recent CFHTLS data release via automated
procedures.
Following our first SNAPSHOT proposal in cycle 15, we
propose to
continue the Hubble follow-up targeting a larger list of
130 lensing
candidates. These are intermediate mass range candidates
{between
galaxies and clusters} that are selected in the redshift
range of 0.2-1
with no a priori X-ray selection. The HST resolution is
necessary for
confirming the lensing candidates, accurate modeling of
the lenses, and
probing the total mass concentration in galaxy groups up
to z~1 with the
largest unbiased sample available to date.
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: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
12
12
FGS
REacq 02
02
OBAD with Maneuver
28
28
SIGNIFICANT EVENTS: (None)