HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT #4756
PERIOD COVERED: 5am December 12 - 5am December 15, 2008
(DOY
347/1000z-350/1000z)
OBSERVATIONS SCHEDULED
WFPC2 11962
A New Supernova in the Antennae; Narrowing in on the
Hubble Constant and
Dark Energy
A measurement of the Hubble constant to a precision of a
few percent
would be a powerful aid to the investigation of the nature
of dark
energy and a potent "end-to-end" test of the
present cosmological model.
In Cycle 15 we constructed a new, streamlined distance
ladder utilizing
high-quality type Ia supernova data and observations of
Cepheids with
HST in the near-IR to minimize the dominant sources of
systematic
uncertainty in past measurements of the Hubble constant
and reduce its
total uncertainty to a little under 5%. Here we propose to
exploit this
new route with a rare opportunity to begin reducing the
remaining
uncertainty. SN 2007sr in the Antennae (NGC 4038/9) is the
rare SN Ia
which is suitable for increasing the precision of small
calibration
sample of
Cepheids are within range of observing with WFPC2 (and
NICMOS, should it
return to life). But we need to act fast as the window of
long
visibility and fixed orient runs from mid-early December
2008 to early
March 2009. We request 34 orbits with WFPC2 to find the
Cepheids in the
SN host. We also request 16 orbits to observe the Cepheids
we find with
Camera 2, F160W if NICMOS becomes available by April 2009
. (If NICMOS
does not return we would forgo these observations and ask
the TTRB to
let us make them with our own WFC3-IR allocation, though
we much prefer
the smaller pixel size of NIC2).
FGS 11943
Binaries at the Extremes of the H-R Diagram
We propose to use HST/Fine Guidance Sensor 1r to survey
for binaries
among some of the most massive, least massive, and oldest
stars in our
part of the Galaxy. FGS allows us to spatially resolve
binary systems
that are too faint for ground-based, speckle or optical
long baseline
interferometry, and too close to resolve with AO. We
propose a
SNAP-style program of single orbit FGS TRANS mode
observations of very
massive stars in the cluster NGC 3603, luminous blue variables,
nearby
low mass main sequence stars, cool subdwarf stars, and
white dwarfs.
These observations will help us to (1) identify systems
suitable for
followup studies for mass determination, (2) study the
role of binaries
in stellar birth and in advanced evolutionary states, (3)
explore the
fundamental properties of stars near the main
sequence-brown dwarf
boundary, (4) understand the role of binaries for X-ray
bright systems,
(5) find binaries among ancient and nearby subdwarf stars,
and (6) help
calibrate the white dwarf mass - radius relation.
FGS 11942
Increasing the Accuracy of HST Astrometry with FGS1R
We propose to observe six exoplanetary system host stars
and two
planetary nebulae central stars with FGS1r. All objects
have been
previously observed under proposals GO-09233, -09969,
-10989, and
-11210. These observations will significantly extend the
time baseline,
permitting improvements in the determination of proper
motion. This
systematic motion must be removed to get at the perturbation
of
interest, either due to exoplanetary companions or the
orbital motion of
the Earth (parallax). In most cases the perturbation
orbits will also
improve. We improve either companion mass or PN parallax.
For one
target, GJ 876, theoretical dynamical modelers have
proposed an
inclination closer to 50 degrees, while FGS3 measurements
indicated an
inclination closer to 84 degrees. These new data, once
combined with our
older FGS3 data, will permit an independent remeasurement
of the
inclination of the outermost companion, and a
re-evaluation of widely
used dynamical algorithms.
FGS 11870
Calibrating FGS1R's Optical Field Angle Distortion (OFAD),
Second Epoch
This proposal gathers the data needed to calibrate the
optical field
angle distortions in FGS1r to the level of accuracy
required for
astrometry science. Selected stars from the galactic
cluster M35 are
repeatedly observed in POSITION mode by FGS1r with F583W
filter at a
variety of spacecraft pointings and telescope roll angles.
Ideally the
observations are to occur at a time when this ecliptic
star field is
near the anti-sun direction so that HST's roll angle is
unconstrained.
Unfortunately this is not possible under two gyro
operations. Therefore,
the observations in this proposal are somewhat very
constrained in roll.
However, this test should suffice as an adequate update to
the original
FGS1r OFAD that executed in December 2000. For each visit,
the desired
telescope pointing is specified by POS TARG and ORIENT
special
requirements.
WFPC2 11289
SL2S: The Strong Lensing Legacy Survey
Recent systematic surveys of strong galaxy-galaxy lenses
{CLASS, SLACS,
GOODS, etc.} are producing spectacular results for galaxy
masses roughly
below a transition mass M~10^13 Mo. The observed lens
properties and
their evolution up to z~0.2, consistent with numerical
simulations, can
be described by isothermal elliptical potentials. In
contrast, modeling
of giant arcs in X-ray luminous clusters {halo masses M
>~10^13 Mo}
favors NFW mass profiles, suggesting that dark matter
halos are not
significantly affected by baryon cooling. Until recently,
lensing
surveys were neither deep nor extended enough to probe the
intermediate
mass density regime, which is fundamental for
understanding the assembly
of structures. The CFHT Legacy Survey now covers 125
square degrees, and
thus offers a large reservoir of strong lenses probing a
large range of
mass densities up to z~1. We have extracted a list of 150
strong lenses
using the most recent CFHTLS data release via automated
procedures.
Following our first SNAPSHOT proposal in cycle 15, we
propose to
continue the Hubble follow-up targeting a larger list of
130 lensing
candidates. These are intermediate mass range candidates
{between
galaxies and clusters} that are selected in the redshift
range of 0.2-1
with no a priori X-ray selection. The HST resolution is
necessary for
confirming the lensing candidates, accurate modeling of
the lenses, and
probing the total mass concentration in galaxy groups up
to z~1 with the
largest unbiased sample available to date.
FGS 11213
Distances to Eclipsing M Dwarf Binaries
We propose HST FGS observations to measure accurate
distances of 5
nearby M dwarf eclipsing binary systems, from which
model-independent
luminosities can be calculated. These objects have either
poor or no
existing parallax measurements. FGS parallax
determinations for these
systems, with their existing dynamic masses determined to
better than
0.5%, would serve as model-independent anchor points for
the low-mass
end of the mass-luminosity diagram.
WFPC2 11130
AGNs with Intermediate-mass Black Holes: Testing the Black
Hole-Bulge
Paradigm, Part II
The recent progress in the study of central black holes in
galactic
nuclei has led to a general consensus that supermassive
{10^6-10^9 solar
mass} black holes are closely connected with the formation
and
evolutionary history of large galaxies, especially their
bulge
component. Two outstanding issues, however, remain
unresolved. Can
central black holes form in the absence of a bulge? And
does the mass
function of central black holes extend below 10^6 solar
masses?
Intermediate-mass black holes {<10^6 solar masses}, if
they exist, may
offer important clues to the nature of the seeds of
supermassive black
holes. Using the SDSS, our group has successfully
uncovered a new
population of AGNs with intermediate-mass black holes that
reside in
low-luminosity galaxies. However, very little is known
about the
detailed morphologies or structural parameters of the host
galaxies
themselves, including the crucial question of whether they
have bulges
or not. Surprisingly, the majority of the targets of our
Cycle 14 pilot
program have structural properties similar to dwarf
elliptical galaxies.
The statistics from this initial study, however, are
really too sparse
to reach definitive conclusions on this important new
class of black
holes. We wish to extend this study to a larger sample, by
using the
Snapshot mode to obtain WFPC2 F814W images from a parent
sample of 175
AGNs with intermediate- mass black holes selected from our
final SDSS
search. We are particularly keen to determine whether the
hosts contain
bulges, and if so, how the fundamental plane properties of
the host
depend on the mass of their central black holes. We will
also
investigate the environment of this unique class of AGNs.
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.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS:
11604 - GSAcq(2,3,2) failed due to QF2STOPF flag on FGS-2
At
347/08:40:36 GSAcq (2,3,2) scheduled from 08:36:52 - 08:44:10 failed
due to QF2STOPF flag on FGS-2.
Observation affected: Astrometry Proposal ID 11943
11605 - GSACQ(2,3,2) failed, Search Radius Limit exceeded
on FGS 2
GSACQ(2,3,2) at 347/13:21:26 failed to RGA control with Search Radius
Limit exceeded on FGS 2 at 13:28:01.
Observations affected: Astrometry, proposal ID 11943.
11607 - GSAcq(2,3,3) failed to RGA Hold (Gyro Control)
Upon acquisition of signal at 349/13:45:16, the GSAcq(2,3,3) scheduled
at
349/13:19:23 - 13:27:28 had failed to RGA Hold due to (QF2STOPF) stop
indication flag set on FGS-2.
Observation affected: Astrometry, Proposal ID 11942.
11608 - GSAcq(2,3,3) failed to RGA Hold (Gyro Control)
Upon acquisition of signal at 349/15:22:15, the GSAcq(2,3,3) scheduled
at
349/14:55:16 - 15:03:21 had failed to RGA Hold due to (QF2STOPF) stop
indication flag set on FGS-2.
Observations affected: Astrometry, Proposal ID 11942.
11609 - GSAcq(2,3,3) failed to RGA Hold (Gyro Control)
GSAcq(2,3,3) scheduled at 349/18:07:02 - 18:15:07 failed to RGA Hold due
to
(QF2STOPF) stop flag indication on FGS-2.
Observations affected: Astrometry, Proposal ID 11942.
11610 - GSAcq(2,3,3) failed to RGA Hold (Gyro Control)
GSAcq(2,3,3) scheduled at 349/19:42:55 - 19:51:00 failed to RGA Hold due
to
(QF2STOPF) stop flag indication on FGS-2.
Observations affected: Astrometry, Proposal ID 11942.
11611 - GSAcq(2,3,3) failed to RGA Hold (Gyro Control)
GSAcq(2,3,3) scheduled at 349/21:18:49 - 21:26:54 failed to RGA Hold due
to
(QF2STOPF) stop flag indication on FGS-2.
Observations affected: Astrometry, Proposal ID 11942.
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS GSacq
29
22
FGS REacq
06
06
OBAD with Maneuver
70
68
SIGNIFICANT EVENTS: (None)