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 # 4407
PERIOD COVERED: UT July 18, 2007 (DOY 199)
OBSERVATIONS SCHEDULED
ACS/SBC 10907
New Sightlines for the Study of Intergalactic Helium: A
Dozen
High-Confidence, UV-Bright Quasars from SDSS/GALEX
The reionization of intergalactic helium is thought to
have occurred
between redshifts of about 3 and 4. Detailed study of HeII
Lyman-alpha
absorption toward a handful quasars at 2.7<z<3.3
demonstrates the great
potential of such probes of the IGM, but the current
critically-small
sample limits confidence in resulting cosmological
inferences. The
requisite unobscured quasar sightlines to high-redshift
are extremely
rare, especially due to severe absorption in random
intervening
Lyman-limit systems, but SDSS provides thousands of
z>3.1 quasars
potentially suitable for HeII studies. We have
cross-correlated SDSS
quasars with GALEX UV sources to obtain a dozen new, very
high-confidence, candidate quasars/sightlines {z=3.1 to
4.1} potentially
useful for detailed HeII studies even with current HST
instruments. We
propose brief, 2-orbit per target, reconnaissance spectral
exposures
with the ACS SBC prism to definitively verify UV flux down
to the HeII
break. Our combined SDSS/GALEX selection insures a very
high- yield of
confirmations, as the quasars are already known to be
UV-bright from
broadband GALEX images. The additional sightlines,
extending to very
high-redshift, will directly enable ensemble spectral
stacks, as well as
long exposure follow-up spectra, at high S/N with the
ACS/SBC
ultraviolet prisms {or perhaps STIS or
measure the spectrum and evolution of the ionizing background
radiation,
the evolution of HeII opacity, and the density of
intergalactic baryons.
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.
NIC1/NIC3 10924
Constraints on the Assembly and Dynamical Masses of z~2
Galaxies
We propose deep NICMOS/NIC2 F160W imaging of seven
star-forming galaxies
at z~2. These galaxies comprise an entirely unique sample,
with not only
redshifts measured from optical and near-IR spectra, but
also
SINFONI/VLT near-IR integral field spectroscopic
measurements providing
kinematic maps of H-alpha emission out to radii of >=10
kpc. We aim to
determine the dynamical masses and evolutionary states of
these systems,
as part of the larger goal of understanding how mass is
assembled in
distant galaxies. In order to interpret our novel H-alpha
integral field
maps in terms of mass, we require detailed knowledge of
the structural
parameters of our target objects at rest-frame optical
wavelengths and
on ~1 kpc scales. We want to establish if the mass is
distributed in a
disk, bulge, or merging sub-units, and if we can detect
tidal features
associated with a merger. F160W imaging with NICMOS/NIC2
provides the
perfect combination of sensitivity and resolution to
address these
questions, and arrive at the fundamental quantity: the
dynamical mass.
NIC2 10849
Imaging Scattered Light from Debris Disks Discovered by
the Spitzer
Space Telescope around 21 Sun-like Stars
We propose to use the high-contrast capability of the
NICMOS coronagraph
to image a sample of newly discovered circumstellar disks
associated
with Sun-like stars. These systems were identified by
their strong
thermal infrared {IR} emission with the Spitzer Space
Telescope as part
of the Spitzer Legacy Science program titled "The
Formation and
Evolution of Planetary Systems" {FEPS, P.I.:
M.Meyer}. Modeling of the
thermal excess emission from the spectral energy
distributions alone
cannot distinguish between narrowly confined high-opacity
disks and
broadly distributed, low-opacity disks. By resolving light
scattered by
the circumstellar material, our proposed NICMOS
observations can break
this degeneracy, thus revealing the conditions under which
planet
formation processes are occurring or have occurred. For
three of our
IR-excess stars that have known radial-velocity planets,
resolved
imaging of the circumstellar debris disks may further
offer an
unprecedented view of planet-disk interactions in an
extrasolar
planetary system. Even non-detections of the light
scattered by the
circumstellar material will place strong constraints on
the disk
geometries, ruling out disk models with high optical
depth. Unlike
previous disk imaging programs, our program contains a well-defined
sample of ~1 solar mass stars covering a range of ages
from 3 Myr to 3
Gyr, thus allowing us to study the evolution of disks from
primordial to
debris for the first time. The results from our program
will greatly
improve our understanding of the architecture of debris
disks around
Sun-like stars, and will create a morphological context
for the
existence of our own solar system. This proposal is for a
continuation
of an approved Cycle 14 program {GO/10527, P.I.: D.
Hines}.
NIC3 11082
NICMOS Imaging of GOODS: Probing the Evolution of the
Earliest Massive
Galaxies, Galaxies Beyond Reionization, and the High
Redshift Obscured
Universe
Deep near-infrared imaging provides the only avenue
towards
understanding a host of astrophysical problems, including:
finding
galaxies and AGN at z > 7, the evolution of the most
massive galaxies,
the triggering of star formation in dusty galaxies, and
revealing
properties of obscured AGN. As such, we propose to observe
60 selected
areas of the GOODS North and South fields with NICMOS
Camera 3 in the
F160W band pointed at known massive M > 10^11 M_0
galaxies at z > 2
discovered through deep Spitzer imaging. The depth we will
reach {26.5
AB at 5 sigma} in H_160 allows us to study the internal
properties of
these galaxies, including their sizes and morphologies,
and to
understand how scaling relations such as the Kormendy
relationship
evolved. Although NIC3 is out of focus and under sampled,
it is currently
our best opportunity to study these galaxies, while also
sampling enough
area to perform a general NIR survey 1/3 the size of an
ACS GOODS field.
These data will be a significant resource, invaluable for
many other
science goals, including discovering high redshift
galaxies at z > 7,
the evolution of galaxies onto the Hubble sequence, as
well as examining
obscured AGN and dusty star formation at z > 1.5. The
GOODS fields are
the natural location for HST to perform a deep NICMOS
imaging program,
as extensive data from space and ground based
observatories such as
Chandra, GALEX, Spitzer, NOAO, Keck, Subaru, VLT, JCMT,
and the VLA are
currently available for these regions. Deep
high-resolution
near-infrared observations are the one missing ingredient
to this
survey, filling in an important gap to create the deepest,
largest, and
most uniform data set for studying the faint and distant
universe. The
importance of these images will increase with time as new
facilities
come on line, most notably WFC3 and ALMA, and for the
planning of future
JWST observations.
WFPC2 11022
WFPC2 Cycle 15 Decontaminations and Associated
Observations
This proposal is for the WFPC2 decons. Also included are
instrument
monitors tied to decons: photometric stability check,
focus monitor,
pre- and post-decon internals {bias, intflats, kspots,
& darks}, UV
throughput check, VISFLAT sweep, and internal UV flat
check. 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)
SCHEDULED
SUCCESSFUL
FGS
GSacq
05
05
FGS REacq
10
10
OBAD with Maneuver
30
30
COMPLETED OPS NOTES: (None)
SIGNIFICANT EVENTS: (None)