HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT # 4263
PERIOD COVERED: UT December 19, 2006 (DOY 3353)
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/WFC 10809
The nature of "dry" mergers in the nearby Universe
Recent studies have shown that "dry" mergers of red,
bulge-dominated
galaxies at low redshift play an important role in shaping today's
most
massive ellipticals. These mergers have been identified in extremely
deep ground-based images of red sequence galaxies at z ~ 0.1. The
ground-based images reach surface brightness limits of AB ~ 29, but
lack
the resolution to study the morphologies of the galaxies inside the
effective radius. Here we propose to obtain ACS images of a
representative sample of 40 of these red sequence galaxies: 15
ongoing
dry mergers, 15 remnants, and 10 undisturbed objects. We will
measure
the isophote shapes and ellipticities of the galaxies, their dust
content, morphological fine structure {shells and ripples}, AGN
content,
and their location on the Fundamental Plane. By comparing galaxies
in
different stages of the merging process we can constrain the amount
of
gas associated with these red mergers, the effect of active nuclei,
and
track structural changes. As two galaxies can be observed in a
single
orbit 20 orbits are requested to observe the 40 galaxies.
ACS/WFC 10886
The Sloan Lens ACS Survey: Towards 100 New Strong Lenses
As a continuation of the highly successful Sloan Lens ACS {SLACS}
Survey
for new strong gravitational lenses, we propose one orbit of ACS-WFC
F814W imaging for each of 50 high- probability strong galaxy-galaxy
lens
candidates. These observations will confirm new lens systems and
permit
immediate and accurate photometry, shape measurement, and mass
modeling
of the lens galaxies. The lenses delivered by the SLACS Survey all
show
extended source structure, furnishing more constraints on the
projected
lens potential than lensed-quasar image positions. In addition,
SLACS
lenses have lens galaxies that are much brighter than their lensed
sources, facilitating detailed photometric and dynamical observation
of
the former. When confirmed lenses from this proposal are combined
with
lenses discovered by SLACS in Cycles 13 and 14, we expect the final
SLACS lens sample to number 80--100: an approximate doubling of the
number of known galaxy-scale strong gravitational lenses and an
order-of-magnitude increase in the number of optical Einstein rings.
By
virtue of its homogeneous selection and sheer size, the SLACS sample
will allow an unprecedented exploration of the mass structure of the
early-type galaxy population as a function of all other observable
quantities. This new sample will be a valuable resource to the
astronomical community by enabling qualitatively new strong lensing
science, and as such we will waive all but a short {3-month}
proprietary
period on the observations.
ACS/WFC/WFPC2 10890
Morphologies of the Most Extreme High-Redshift Mid-IR-Luminous
Galaxies
The formative phase of the most massive galaxies may be extremely
luminous, characterized by intense star- and AGN-formation. Till
now,
few such galaxies have been unambiguously identified at high
redshift,
restricting us to the study of low-redshift ultraluminous infrared
galaxies as possible analogs. We have recently discovered a sample
of
objects which may indeed represent this early phase in galaxy
formation,
and are undertaking an extensive multiwavelength study of this
population. These objects are bright at mid-IR wavelengths
{F[24um]>0.8mJy}, but deep ground based imaging suggests extremely
faint
{and in some cases extended} optical counterparts {R~24-27}. Deep
K-band
images show barely resolved galaxies. Mid-infrared spectroscopy with
Spitzer/IRS reveals that they have redshifts z ~ 2-2.5, suggesting
bolometric luminosities ~10^{13-14}Lsun! We propose to obtain deep
ACS
F814W and NIC2 F160W images of these sources and their environs in
order
to determine kpc-scale morphologies and surface photometry for these
galaxies. The proposed observations will help us determine whether
these
extreme objects are merging systems, massive obscured starbursts
{with
obscuration on kpc scales!} or very reddened {locally obscured} AGN
hosted by intrinsically low-luminosity galaxies.
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.
NIC2, ACS/WFC 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 Type Ia supernovae
at
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 Type Ia supernovae with NICMOS, reducing the
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 Type Ia supernovae at z > 1. Together, these
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 10792
Quasars at Redshift z=6 and Early Star Formation History
We propose to observe four high-redshift quasars {z=6} in the NIR in
order to estimate relative Fe/Mg abundances and the central black
hole
mass. The results of this study will critically constrain models of
joint quasar and galaxy formation, early star formation, and the
growth
of supermassive black holes. Different time scales and yields for
alpha-elements {like O or Mg} and for iron result into an iron
enrichment delay of ~0.3 to 0.6 Gyr. Hence, despite the well-known
complexity of the FeII emission line spectrum, the ratio iron/alpha
-
element is a potentially useful cosmological clock. The central
black
hole mass will be estimated based on a recently revised back hole mass
-
luminosity relationship. The time delay of the iron enrichment and
the
time required to form a supermassive black hole {logM>8 Msol, tau
~0.5Gyr} as evidenced by quasar activity will be used to date the
beginning of the first intense star formation, marking the formation
of
the first massive galaxies that host luminous quasars, and to
constrain
the epoch when supermassive black holes start to grow by
accretion.
WFPC2 10745
WFPC2 CYCLE 14 INTERNAL MONITOR
This calibration proposal is the Cycle 14 routine internal monitor
for
WFPC2, to be run weekly to monitor the health of the cameras. A
variety
of internal exposures are obtained in order to provide a monitor of
the
integrity of the CCD camera electronics in both bays {both gain 7
and
gain 15 -- to test stability of gains and bias levels}, a test for
quantum efficiency in the CCDs, and a monitor for possible buildup
of
contaminants on the CCD windows. These also provide raw data for
generating annual super-bias reference files for the calibration
pipeline.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary
reports
of potential non-nominal performance that will be investigated.)
HSTARS:
10563 - GSAcq(1,3,1) failed to RGA Hold (Gyro Control)
The
GSAcq(1,3,1) scheduled at 354/00:22:40 - 00:30:45 failed to RGA Hold
due
to (QF1SRLEX) search radius limit exceeded on FGS-1. Pre-acquisition
OBADs showed (RSS) attitude correction values of 3802.35 and 7.23
arcseconds. Post-acquisition OBAD/MAP had 3-axis (RSS) error value
of
1.97 arcseconds.
REACQ(1,3,1) at 02:00:06 and 03:13:13 also failed.
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS
GSacq
12
11
FGS
REacq
03
01
OBAD with Maneuver
28
28
SIGNIFICANT EVENTS:
Flash Report - HST dynamic inertia & aero torque changes -
The sequence of configuration changes exercising HST dynamic inertia
and
aerodynamic torque compensations is complete, and the on-going
operational configuration with both compensations enabled has been
established. Both compensations are performing as expected.
-Lynn
Lynn F. Bassford
CHAMP HST Missions Operations Manager
Lockheed Martin Mission Services (LMMS)
GSFC PH#: 301-286-2876
"The Hubble Space Telescope is the astronomical observatory and
key to unlocking the most cosmic mysteries of the past, present and
future." - 7/26/6