Notice:
Due to the conversion of some ACS WFC or HRC observations into
WFPC2,
or NICMOS observations after the loss of ACS CCD science
capability
in January, there may be an occasional discrepancy between a
proposal's
listed (and correct) instrument usage and the abstract that
follows
it.
HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT # 4489
PERIOD
COVERED: UT November 14, 2007 (DOY 318)
OBSERVATIONS
SCHEDULED
ACS/SBC
WFPC2 11175
UV
Imaging to Determine the Location of Residual Star Formation in
Galaxies
Recently Arrived on the Red Sequence
We
have identified a sample of low-redshift {z = 0.04 - 0.10} galaxies
that
are candidates for recent arrival on the red sequence. They have
red
optical colors indicative of old stellar populations, but blue
UV-optical
colors that could indicate the presence of a small quantity
of
continuing or very recent star formation. However, their spectra lack
the
emission lines that characterize star-forming galaxies. We propose
to
use ACS/SBC to obtain high- resolution imaging of the UV flux in
these
galaxies, in order to determine the spatial distribution of the
last
episode of star formation. WFPC2 imaging will provide B, V, and I
photometry
to measure the main stellar light distribution of the galaxy
for
comparison with the UV imaging, as well as to measure color
gradients
and the distribution of interstellar dust. This detailed
morphological
information will allow us to investigate the hypothesis
that
these galaxies have recently stopped forming stars and to compare
the
observed distribution of the last star formation with predictions
for
several different mechanisms that may quench star formation in
galaxies.
WFPC2
10766
A
Deep X-ray Survey of the Small Magellanic Cloud
We
request deep observations of 2 representative fields in the Small
Magellanic
Cloud with Chandra and HST, with the primary goal of measuring
the
luminosity function and space density of X-ray binaries and other
sources
down to an unprecedented faint luminosity limit of 2x10E32
erg/s.
This will be the faintest XLF ever obtained for any galaxy,
including
our own. HST photometry to 24th magnitude in V and I filters
will
identify the sources and provide Fx/Fopt, which will be vital in
quantifying
the LMXB population and in measuring the properties of the
first
coronally active stars ever detected in an external galaxy.
NIC1/NIC2
11204
Imaging
Circumstellar Disks and Envelopes around Proto-Brown Dwarfs
Using
the Spitzer Space Telescope, we have discovered two young brown
dwarfs
with Class I spectral energy distributions {i.e., proto-brown
dwarfs}.
We propose to perform broad-band NICMOS imaging of these Class
I
brown dwarfs to spatially resolve their circumstellar disks and
envelopes.
If successful, these data would comprise the first
measurements
of this kind for brown dwarfs and would provide fundamental
constraints
on models for the formation of brown dwarfs.
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 DARKs. 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.
S/C
11163
Accreting
Pulsating White Dwarfs in Cataclysmic Variables
Recent
ground-based observations have increased the number of known
pulsating
white dwarfs in close binaries with active mass transfer
{cataclysmic
variables} from 5 to 11 systems. Our past Cycles 8 and 11
STIS
observations of the first 2 known, followed by our Cycle 13 SBC
observations
of the next 3 discovered, revealed the clear presence of
the
white dwarf and increased amplitude of the pulsations in the UV
compared
to the optical. The temperatures derived from the UV spectra
show
4 systems are much hotter than non- interacting pulsating white
dwarfs.
A larger sample is needed to sort out the nature of the
instability
strip in accreting pulsators i.e. whether effects of
composition
and rotation due to accretion result in a well-defined
instability
strip as a function of Teff.
WFPC2
11103
A
Snapshot Survey of The Most Massive Clusters of Galaxies
We
propose the continuation of our highly successful SNAPshot survey of
a
sample of 125 very X-ray luminous clusters in the redshift range
0.3-0.7.
As demonstrated by the 25 snapshots obtained so far in Cycle14
and
Cycle15 these systems frequently exhibit strong gravitational
lensing
as well as spectacular examples of violent galaxy interactions.
The
proposed observations will provide important constraints on the
cluster
mass distributions, the physical nature of galaxy-galaxy and
galaxy-gas
interactions in cluster cores, and a set of optically bright,
lensed
galaxies for further 8-10m spectroscopy. All of our primary
science
goals require only the detection and characterization of
high-surface-brightness
features and are thus achievable even at the
reduced
sensitivity of WFPC2. Because of their high redshift and thus
compact
angular scale our target clusters are less adversely affected by
the
smaller field of view of WFPC2 than more nearby systems.
Acknowledging
the broad community interest in this sample we waive our
data
rights for these observations. Due to a clerical error at STScI our
approved
Cycle15 SNAP program was barred from execution for 3 months and
only
6 observations have been performed to date - reinstating this SNAP
at
Cycle16 priority is of paramount importance to reach meaningful
statistics.
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:
(None)
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS
GSacq 06 06
FGS
REacq 08 08
OBAD
with Maneuver 28 28
SIGNIFICANT
EVENTS:
Flash
Report: Bay 8 Hot Season Plan Briefing
The
Bay 8 Hot Season Planning briefing was held November 13. This winter
there
are two beta peaks straddling earth’s perihelion passage. The
first
peak is in late November, and the second is in January. The
2007/2008
beta-peak environments will not be quite as severe as the one
in
the 2006/2007 season which occurred closer to perihelion. HST Project
agreed
not to impose hard attitude limits on operations near the beta
peaks.
Instead, STScI will review the Bay 8 incidence angles during time
periods
spanning the peaks and make scheduling adjustments as necessary.