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 # 4457
PERIOD
COVERED: UT September 27, 2007 (DOY 270)
OBSERVATIONS
SCHEDULED
WFPC2
10909
Exploring
the diversity of cosmic explosions: The supernovae of
gamma-ray
bursts
While
the connection between gamma-ray bursts {GRBs} and supernovae
{SNe}
is now clearly established, there is a large variety of
observational
properties among these SNe and the physical parameters of
these
explosions are poorly known. As part of a comprehensive program,
we
propose to use HST in order to obtain basic information about the
supernovae
associated with gamma-ray bursts. HST offers the means to
cleanly
separate the light curves of the GRB afterglow from the
supernova,
and to remove the contamination from the host galaxy, opening
a
clear route to the fundamental parameters of the SN. From these
observations,
we will determine the absolute magnitude at maximum, the
shape
of the spectral energy distribution, and any change over time of
the
energy distribution. We will also measure the rate of decay of the
exponential
tail. Merged with the ground-based data that we will obtain
for
each event, we will be able to compare our data set to models and
constrain
the energy of the explosion, the mass of the ejecta and the
mass
of Nickel synthesized during the explosion. These results will shed
light
on the apparent variety of supernovae associated with gamma-ray
bursts
and X-ray flashes, and on the relation between these SNe and
other,
more common varieties of core-collapse explosions.
FGS
10930
Mass
and Radius of a Near-Chandrasekhar-limit magnetic white dwarf
REJ0317-853
is a unique object. According to our analyses it is the most
massive
white dwarf ever found, with a mass of 1.35 solar masses,
approaching
the Chandrasekhar limit. With a period of just 725 seconds
it
is the most rapidly rotating isolated white dwarf ever found.
Moreover,
RE J0317-853 is the hottest magnetic white dwarf discovered so
far
and has a strong magnetic field varying from about 180 to more than
700
MG over the stellar surface. Due to its strong polarization and high
mass
it has been used to test gravitational theories predicting
gravitational
birefringence. However, the existing mass and radius
determination
is indirect and still uncertain and would greatly profit
from
a high-precision parallax determination with the HST FGS.
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.
WFPC2
11033
Full
Moon Earth Flats Closeout
Flat
field exposures will be obtained by observing the moonlit Earth
with
the broadband WFPC2 filters F606W and F814W, which saturate in the
minimum
exposure time on the sunlit Earth. These observations will be
used
to improve the flats currently in the pipeline and are part of the
WFPC2
closeout operations. Because CTE effects are large for star flats
and
small for full field illumination, Earth flats are the superior
technique.
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
03
03
FGS
REacq
11
11
OBAD
with Maneuver
28
28
SIGNIFICANT
EVENTS: (None)