Notice: For the foreseeable future, the daily reports may
contain
apparent discrepancies between some proposal descriptions
and the listed
instrument usage. This is due to the conversion of
previously approved
ACS WFC or HRC observations into WFPC2, or NICMOS
observations
subsequent to the loss of ACS CCD science capability in
late January.
HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT # 4320
PERIOD COVERED: UT March 15, 2007 (DOY 074)
OBSERVATIONS SCHEDULED
ACS/SBC 11050
ACS UV contamination monitor
The observations consist of imaging and spectroscopy with
SBC of the
cluster NGC 6681 in order to monitor the temporal
evolution of the UV
sensitivity of the SBC.
FGS 10927
The Weight-Watcher Program for Subdwarfs
We propose to use HST/FGS1r to measure five subdwarf
spectroscopic
binaries to determine masses for the components. Their
metallicities,
[Fe/H], range from -0.5 to -2.5, and their projected
minimum separations
range from 9 to 24 mas. These binaries are resolvable with
HST/FGS1r but
not any ground-based technique. Currently, there are only
two subdwarf
systems having any mass measurements. The proposed work
will boost the
total number of subdwarf systems with masses from two to
seven, and
allow us to construct the first mass-luminosity relation
for
low-metallicity stars.
NIC1/NIC2/NIC3 8795
NICMOS Post-SAA calibration - CR Persistence Part 6
A new proceedure proposed to alleviate the CR-persistence
problem of
NICMOS. Dark frames will be obtained immediately upon
exiting the SAA
contour 23, and everytime 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.
NIC2 10802
SHOES-Supernovae, HO, for the Equation of State of Dark
energy
The present uncertainty in the value of the Hubble
constant {resulting
in an uncertainty in Omega_M} and the paucity of
redshifts exceeding 1 are now the leading obstacles to
determining the
nature of dark energy. We propose a single, integrated set
of
observations for Cycle 15 that will provide a 40%
improvement in
constraints on dark energy. This program will observe known
Cepheids in
six reliable hosts of
uncertainty in H_0 by a factor of two because of the
smaller dispersion
along the instability strip, the diminished extinction,
and the weaker
metallicity dependence in the infrared. In parallel with
ACS, at the
same time the NICMOS observations are underway, we will
discover and
follow a sample of
measurements, along with prior constraints from WMAP, will
provide a
great improvement in HST's ability to distinguish between
a static,
cosmological constant and dynamical dark energy. The
Hubble Space
Telescope is the only instrument in the world that can
make these IR
measurements of Cepheids beyond the Local Group, and it is
the only
telescope in the world that can be used to find and follow
supernovae at
z > 1. Our program exploits both of these unique
capabilities of HST to
learn more about one of the greatest mysteries in science.
NIC3 11080
Exploring the Scaling Laws of Star Formation
As a variety of surveys of the local and distant Universe
are
approaching a full census of galaxy populations, our
attention needs to
turn towards understanding and quantifying the physical
mechanisms that
trigger and regulate the large-scale star formation rates
{SFRs} in
galaxies.
NIC3 11098
Pinning down the redshift of the J-band dropout JD0910+46
The earliest galaxies in the Universe should have formed
at very high
redshifts, based both on models of hierarchical structure formation,
and
on observations of the microwave background polarization
by WMAP that
require significant ionization of the intergalactic medium
before z=10.
However, direct observation of sources at z>7 remains
highly challenging
due to their scarcity and faintness. We recently
identified a spatially
extended J-band dropout, JD0910+46, that is a promising
candidate for a
z>10 galaxy. Its spectral energy distribution is more
extreme than any
previously reported: It is undetected in our 2- orbit
J-band
observation, with a very red J-H color, yet is bluer in
H-K than
plausible lower redshift {z~3} model SEDs. These colors
are, however,
natural for a very high redshift star-burst galaxy in
which the
Lyman-alpha break has moved mostly or entirely through the
F110W band.
Here we propose deeper F110W and F187W observations to
better map the
spectral energy distribution of JD910+46, these have the
potential to
convincingly reject all low redshift solutions for the
origin of the
observed colours. We believe the importance of such a
discovery adds
urgency to the followup, and motivates this DD request.
Even in the
event that JD0910+46 lies at lower redshift understanding
the nature of
the object will be of great importance since it may lie in
a significant
overdensity of galaxies at z~4, and will be an important
tool for
identifying possible interlopers in samples of ultra
high-z galaxies.
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: (None)