HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT #
4162
PERIOD COVERED: UT July 24, 2006 (DOY 205)
OBSERVATIONS SCHEDULED
ACS/HRC 10800
Kuiper Belt Binaries: Probes of Early Solar System Evolution
Binaries in the Kuiper Belt are a scientific windfall: in them we
have
relatively fragile test particles which can be used as tracers of
the
early dynamical evolution of the outer Solar System. We propose to
continue a Snapshot program using the ACS/HRC that has a
demonstrated
discovery potential an order of magnitude higher than the HST
observations that have already discovered the majority of known
transneptunian binaries. With this continuation we seek to reach the
original goals of this project: to accumulate a sufficiently large
sample in each of the distinct populations collected in the Kuiper
Belt
to be able to measure, with statistical significance, how the
fraction
of binaries varies as a function of their particular dynamical paths
into the Kuiper Belt. Today's Kuiper Belt bears the imprints of the
final stages of giant-planet building and migration; binaries may
offer
some of the best preserved evidence of that long-ago era.
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 10258
Tracing the Emergence of the Hubble Sequence Among the Most Luminous
and
Massive Galaxies
There is mounting evidence that the redshift range 1 < z < 2 was
an
important era when massive galaxies assembled their stellar content
and
assumed their present--day morphologies. Despite extensive HST
imaging
surveys, however, there is very little data in the optical rest
frame
{i.e., observed near--infrared} on the morphologies of the most
luminous
galaxies at these redshifts. We propose to image a carefully
selected
set of 20 of the most luminous, K--band selected GOODS galaxies at 1.3
<
z < 2, using NICMOS camera 2. This offers diffraction--limited,
critically sampled imaging at 1.6 microns to ensure the best angular
resolution for comparison to ACS. The galaxies are chosen to span a
simple 4--fold parameter space of morphological and spectral type,
in
order to provide the most information about the variety of massive
galaxy properties in this redshift range. We will investigate the
emergence of large scale--length disks, stable spiral structure,
mature
bulges with red stellar populations, central bar structures, the
incidence of disturbed morphology, the existence {or lack thereof}
of
blue ellipticals, and other questions that concern the evolution and
maturation of the brightest, largest, and most massive ordinary
galaxies
in this critical redshift range.
ACS/WFC/NIC2 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.
NIC1 10889
The Nature of the Halos and Thick Disks of Spiral Galaxies
We propose to resolve the extra-planar stellar populations of the
thick
disks and halos of seven nearby, massive, edge-on galaxies using
ACS,
NICMOS, and WFPC2 in parallel. These observations will provide
accurate
star counts and color-magnitude diagrams 1.5 magnitudes below the tip
of
the Red Giant Branch sampled along the two principal axes and one
intermediate axis of each galaxy. We will measure the metallicity
distribution functions and stellar density profiles from star counts
down to very low average surface brightnesses, equivalent to ~32
V-mag
per square arcsec. These observations will provide the definitive
HST
study of extra-planar stellar populations of spiral galaxies. Our
targets cover a range in galaxy mass, luminosity, and morphology and
as
function of these galaxy properties we will provide: - The first
systematic study of the radial and isophotal shapes of the diffuse
stellar halos of spiral galaxies - The most detailed comparative
study
to date of thick disk morphologies and stellar populations - A
comprehensive analysis of halo and thick disk metallicity
distributions
as a function of galaxy type and position within the galaxy. - A
sensitive search for tidal streams - The first opportunity to
directly
relate globular cluster systems to their field stellar population We
will use these fossil records of the galaxy assembly process
preserved
in the old stellar populations to test halo and thick disk formation
models within the hierarchical galaxy formation scheme. We will test
LambdaCDM predictions on sub-galactic scales, where it is difficult
to
test using CMB and galaxy redshift surveys, and where it faces its
most
serious difficulties.
NIC1/NIC2/NIC3 8794
NICMOS Post-SAA calibration - CR Persistence Part 5
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.
NIC2 10847
Coronagraphic Polarimetry of HST-Resolved Debris Disks
We propose to take full advantage of the recently commissioned
coronagraphic polarimetry modes of ACS and NICMOS to obtain imaging
polarimetry of circumstellar debris disks that were imaged previously
by
the HST coronagraphs, but without the polarizers. It is well
established
that stars form in gas-rich protostellar disks, and that the planets
of
our solar system formed from a circum-solar disk. However, the
connection between the circumstellar disks that we observe around
other
stars and the processes of planet formation is still very uncertain.
Mid-IR spectral studies have suggested that disk grains are growing
in
the environments of young stellar objects during the putative
planet-
formation epoch. Furthermore, structures revealed in well resolved
images of circumstellar disks suggest gravitational influences on
the
disks from co-orbital bodies of planetary mass. Unfortunately,
existing
imaging data provides only rudimentary information abou the disk
grains
and their environments. Our proposed observations, which can be
obtained
only with HST, will enable us to quantitatively determine the sizes
of
the grains and optical depths as functions of their location within
the
disks {i.e., detailed tomography}. Armed with these well-determine
physical and geometrical systemic parameters, we will develop a set
of
self-consistent models of disk structures to investigate possible
interactions between unseen planets and the disks from which they
formed. Our results will also calibrate models of the thermal
emission
from these disks, that will in turn enable us to infer the properties
of
other debris disks that cannot be spatially resolved with current or
planned instruments and telescopes.
WFPC2 10608
Probing the star formation law in the extreme outer limits of M83, a
prototypical XUV-disk galaxy The Galaxy Evolution Explorer {GALEX}
has
discovered a new sub-class of spiral galaxy, which we refer to as
extended UV-disk {XUV-disk} galaxies. They are distinguished by
conspicuous UV-bright star clusters located at galactocentric radii
extending to many times the optical {R25} extent, and appear to
represent a population of spiral galaxies still actively building,
or
augmenting, their stellar disk. However, XUV-disks pose a mystery in
the
form of a relative lack of HII regions {traced by H-alpha emission}
associated with outer disk, UV-bright stellar clusters. M83 is an
XUV-disk prototype and the focus of this proposal. It has an H-alpha
surface brightness profile characterized by a steep decline at the
radius beyond which the gaseous disk is thought to become
dynamically
stable {against collapse and ensuing star formation}, but GALEX UV
profiles show no "edge" at this location. Our HST study of M83
aims to
resolve this puzzling discrepancy, confirmed in several XUV-disks,
by
searching for Lyman-continuum producing O stars that are either
absent
or present without nebulosity. HST provides the only means of
resolving
individual massive stars in the FUV band at M83's distance. Without
HST,
we lose the critical ability to photometrically classify O and B
stars.
Our multiwavelength observations will also constrain the history of
star
formation in the outer disk over Gyr timescales by characterizing
the
evolved stellar population, both using resolved giants and color
analysis of the diffuse background.
WFPC2 10748
WFPC2 CYCLE 14 Standard Darks
This dark calibration program obtains dark frames every week in order
to
provide data for the ongoing calibration of the CCD dark current
rate,
and to monitor and characterize the evolution of hot pixels. Over an
extended period these data will also provide a monitor of radiation
damage to the CCDs.
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:
#17863-0 Place +CC SPA Back On-Line @ 205/18:54z
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS
GSacq
08
08
FGS
REacq
08
08
OBAD with Maneuver
26
26
SIGNIFICANT EVENTS:
Flash Report: +CC SPA Back on-line
With
suntime decreasing, battery temperatures are now at acceptable
levels and
therefore the +CC SPA was placed back on-line at 205/1853 GMT
in both
hardware and in FSW. The +CC SPA will now be included in HSTÂ’s
nominal
charging scheme.
-Lynn
Lynn F. Bassford
CHAMP HST Missions Operations Manager
Lockheed Martin Technical Operations
GSFC PH#: 301-286-2876
"The Hubble Space Telescope is the Babe Ruth of astronomical
observatories, the Muhammad Ali of cosmic photography
"
- Robert Roy Britt, space.com 7-14-4
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