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 # 4491
PERIOD
COVERED: UT November 16, 17 & 18, 2007 (DOY 320,321,322)
OBSERVATIONS
SCHEDULED
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 DARKs. 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.
S/C
11320
NICMOS
Focus Monitoring Cycle 16
This
program is a version of the standard focus sweep used since cycle
7.
It has been modified to go deeper and uses more narrow filters for
improved
focus determination. A new source was added in Cycle 14 in
order
to accommodate 2-gyro mode: the open cluster NGC1850. This source
is
part of the current proposal. The old target, the open cluster
NGC3603,
will be used whenever available and the new target used to fill
the
periods when NGC3603 is not visible. Steps: a) Use refined target
field
positions as determined from cycle 7 calibrations b) Use
MULTIACCUM
sequences of sufficient dynamic range to account for defocus
c)
Do a 17-point focus sweep, +/- 8mm about the PAM mechanical zeropoint
for
each cameras 1 and 2, in 1.0mm steps. For NIC3 we step from -0.5mm
to
-9.5mm relative to mechanical zero, in steps of 1.0mm. d) Use PAM X/Y
tilt
and OTA offset slew compensations refined from previous focus
monitoring/optical
alignment activities
WFPC2
11312
The
Local Cluster Substructure Survey {LoCuSS}: Deep Strong Lensing
Observations
with WFPC2
LoCuSS
is a systematic and detailed investigation of the mass,
substructure,
and thermodynamics of 100 X-ray luminous galaxy clusters
at
0.15<z<0.3. The primary goal is to test our recent suggestion that
this
population is dominated by dynamically immature disturbed clusters,
and
that the observed mass-temperature relation suffers strong
structural
segregation. If confirmed, this would represent a paradigm
shift
in our observational understanding of clusters, that were hitherto
believed
to be dominated by mature, undisturbed systems. We propose to
complete
our successful Cycle 15 program {SNAP:10881} which prior to
premature
termination had delivered robust weak-lensing detections in 17
clusters,
and candidate strongly-lensed arcs in 11 of these 17. These
strong
and weak lensing signals will give an accurate measure of the
total
mass and structure of the dark matter distribution that we will
subsequently
compare with X-ray and Sunyaev Zeldovich Effect
observables.
The broader applications of our project include 1} the
calibration
of mass-temperature and mass-SZE scaling relations which
will
be critical for the calibration of proposed dark energy
experiments,
and 2} the low redshift baseline study of the demographics
of
massive clusters to aid interpretation of future high redshift {z>1}
cluster
samples. To complete the all-important high resolution imaging
component
of our survey, we request deep WFPC2 observations of 20
clusters
through the F606W filter, for which wide-field weak-lensing
data
are already available from our Subaru imaging program. The
combination
of deep WFPC2 and Subaru data for these 20 clusters will
enable
us to achieve the science program approved by the Cycle 15 TAC.
WFPC2
11233
Multiple
Generations of Stars in Massive Galactic Globular Clusters
This
is a follow-up to recent HST imaging of NGC 2808, which discovered
that
its main sequence is triple, with three well-separated parallel
branches
{Fig.~1}. Along with the double MS of Omega Centauri, this
challenges
the long-held paradigm that globular clusters are simple,
single
stellar populations. The cause of this main sequence multiplicity
in
both clusters is likely to be differences in helium abundance, which
could
play a fundamental role in the understanding of stellar
populations.
We propose to image seven more of the most massive globular
clusters,
to examine their main sequences for indications of splitting.
ACS/SBC
11215
New
Sightlines for the Study of Intergalactic Helium: Dozens of
High-Confidence,
UV-Bright Quasars from SDSS/GALEX
The
reionization of IGM helium is thought to have occurred at redshifts
of
z=3 to 4. Detailed study of HeII Lyman-alpha absorption toward a
handful
of QSOs at 2.7<z<3.3 demonstrated the high potential of such IGM
probes,
but the critically small sample size limits confidence in
cosmological
inferences. The requisite unobscured sightlines to high-z
are
extremely rare, but SDSS provides 5800, z>3.1 QSOs potentially
suitable
for HeII studies. We've cross-correlated SDSS quasars with
GALEX
UV sources to obtain dozens of new, high confidence, candidate
sightlines
{z=3.1-4.9} potentially useful for detailed HeII studies with
HST.
We propose brief, 2-orbit reconnaissance ACS SBC prism exposures
toward
each of the best dozen new quasars, to definitively verify UV
flux
down to HeII. Our combined SDSS/GALEX selection insures a high
confirmation
rate, as the quasars are already known to be UV bright in
GALEX.
Our program will provide a statistical sample of HeII sightlines
extending
to high redshift, enabling future long exposure follow-up
spectra
with the SBC prism, or superb quality COS or STIS spectra after
SM4.
Stacks of our prism spectra will also directly yield ensemble
information.
Ultimately, the new sightlines will enable confident
measures
of the spectrum and evolution of the ionizing background, the
evolution
of HeII opacity, the epoch of helium reionization, and the
density
of IGM baryons.
FGS
11211
An
Astrometric Calibration of Population II Distance Indicators
In
2002 HST produced a highly precise parallax for RR Lyrae. That
measurement
resulted in an absolute magnitude, M{V}= 0.61+/-0.11, a
useful
result, judged by the over ten refereed citations each year
since.
It is, however, unsatisfactory to have the direct,
parallax-based,
distance scale of Population II variables based on a
single
star. We propose, therefore, to obtain the parallaxes of four
additional
RR Lyrae stars and two Population II Cepheids, or
stars.
The Population II Cepheids lie with the RR Lyrae stars on a
common
K-band Period-Luminosity relation. Using these parallaxes to
inform
that relationship, we anticipate a zero-point error of 0.04
magnitude.
This result should greatly strengthen confidence in the
Population
II distance scale and increase our understanding of RR Lyrae
star
and Pop II Cepheid astrophysics.
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!
NIC3
11191
NICMOS
Imaging of a z>4 High-Redshift Ultraluminous Submillimeter Source
We
propose 16 orbits of deep NICMOS 1.6 um imaging of GOODS850-5, a
unique
z>4 candidate SCUBA source that is bright in the submillimeter
{submm}
but extremely faint at all other wavelengths. GOODS850-5 is a 11
mJy
850 um source discovered in our GOODS- N SCUBA survey. It does not
have
a radio counterpart and its accurate location was recently
determined
with the SMA interferometer. It is not detected by the
GOODS-N
HST ACS imaging and is just above the detection limit of the
ultradeep
Spitzer imaging at 3.6-24 um. Its faint radio flux and its
Spitzer
color suggest a redshift of z>4, and potentially even z>6. It
has
an incredible star formation rate of ~1000 solar mass per year, and
it
can quickly grow into a >10^11 solar mass massive galaxy. Radio faint
submm
sources like GOODS850-5 may be a new population of high-redshift
massive
galaxies that are not picked up by any of the previous optical,
near-IR,
and radio surveys, and therefore it is crucial to obtain the
redshift
of GOODS850-5. However, because of its extreme optical
faintness,
the only way to constrain its redshift is photometric
redshift
with the existing Spitzer photometry and the proposed NICMOS
1.6
um photometry. NICMOS is the only instrument that can provide
information
about its redshift and morphology among all space- based and
ground-based
instruments at all wavelengths. The proposed observation
will
provide unique insight on galaxy evolution and mass assembly at
high
redshift.
WFPC2
11178
Probing
Solar System History with Orbits, Masses, and Colors of
Transneptunian
Binaries
The
recent discovery of numerous transneptunian binaries {TNBs} opens a
window
into dynamical conditions in the protoplanetary disk where they
formed
as well as the history of subsequent events which sculpted the
outer
Solar System and emplaced them onto their present day heliocentric
orbits.
To date, at least 47 TNBs have been discovered, but only about a
dozen
have had their mutual orbits and separate colors determined,
frustrating
their use to investigate numerous important scientific
questions.
The current shortage of data especially cripples scientific
investigations
requiring statistical comparisons among the ensemble
characteristics.
We propose to obtain sufficient astrometry and
photometry
of 23 TNBs to compute their mutual orbits and system masses
and
to determine separate primary and secondary colors, roughly tripling
the
sample for which this information is known, as well as extending it
to
include systems of two near-equal size bodies. To make the most
efficient
possible use of HST, we will use a
optimally
schedule our observations.
NIC2
11155
Dust
Grain Evolution in Herbig Ae Stars: NICMOS Coronagraphic Imaging
and
Polarimetry
We
propose to take advantage of the sensitive coronagraphic capabilities
of
NICMOS to obtain multiwavelength coronagraphic imaging and
polarimetry
of primordial dust disks around young intermediate-mass
stars
{Herbig Ae stars}, in order to advance our understanding of how
dust
grains are assembled into larger bodies. Because the polarization
of
scattered light is strongly dependent on scattering particle size and
composition,
coronagraphic imaging polarimetry with NICMOS provides a
uniquely
powerful tool for measuring grain properties in spatially
resolved
circumstellar disks. It is widely believed that planets form
via
the gradual accretion of planetesimals in gas-rich, dusty
circumstellar
disks, but the connection between this suspected process
and
the circumstellar disks that we can now observe around other stars
remains
very uncertain. Our proposed observations, together with
powerful
3-D radiative transfer codes, will enable us to quantitatively
determine
dust grain properties as a function of location within disks,
and
thus to test whether dust grains around young stars are in fact
growing
in size during the putative planet-formation epoch. HST imaging
polarimetry
of Herbig Ae stars will complement and extend existing
polarimetric
studies of disks around lower-mass T Tauri stars and debris
disks
around older main-sequence stars. When combined with these
previous
studies, the proposed research will help us establish the
influence
of stellar mass on the growth of dust grains into larger
planetesimals,
and ultimately to planets. Our results will also let us
calibrate
models of the thermal emission from these disks, a critical
need
for validating the properties of more distant disks inferred on the
basis
of spectral information alone.
NIC2
11143
NICMOS
imaging of submillimeter galaxies with CO and PAH redshifts
We
propose to obtain F110W and F160W imaging of 10 z~2.4 submillimeter
galaxies
{SMGs} whose optical redshifts have been confirmed by the
detection
of millimeter CO and/or mid-infrared PAH emission. With the
4000A
break falling within/between the two imaging filters, we will be
able
to study these sources' spatially resolved stellar populations
{modulo
extinction} in the rest-frame optical. SMGs' large luminosities
appear
to be due largely to merger-triggered starbursts; high-resolution
NICMOS
imaging will help us understand the stellar masses, mass ratios,
and
other properties of the merger progenitors, valuable information in
the
effort to model the mass assembly history of the universe.
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.
ACS/SBC
11116
Exploring
the Early FUV History of Cool Stars: Transition Regions at 30
Myr
Stellar
magnetic activity derives from the so-called "dynamo," a
hydromagnetic
interplay between overturning plasma motions and
differential
rotation in stars cool enough to support significant
surface
convection zones. The magnetic fields resulting from dynamo
action
are in turn are responsible for a wide range of high-energy
emissions,
including the spectacular outbursts called flares. Dynamo
powered
magnetic activity is not confined solely to stars, but also must
occur,
for example, in accretion disks of all descriptions, and in some
planets.
A great deal is known about magnetic activity in middle-aged G
dwarfs
like our Sun, thanks to its proximity. Less is known, however,
about
the much younger stars, newly emerged from the T-Tauri stage. Yet,
it
is during this phase that they reach the peak of their magnetic
activity,
and subsidiary influences, such as the impact of ionizing
radiation
and strong coronal winds on developing solar systems, also are
maximum.
One of the key missing ingredients in our current understanding
are
measurements of FUV emissions of such stars, to complement the
extensive
collections of coronal {1-10 MK} X-ray measurements,
particularly
from recent ROSAT, Chandra and XMM-Newton surveys. We
propose
to conduct sensitive ACS/SBC prism ultraviolet spectroscopy of
selected
fields in two young {30 Myr} Galactic clusters--IC 2391 and IC
2602--to
inventory the key C IV emission index {~0.1 MK} over a much
larger
and more diverse sample of coeval objects than has been possible
hitherto.
A key question is whether the FUV emissions also suffer the
"saturation"
and "super-saturation" at short rotation periods seen in
coronal
X-rays, or whether they continue to rise in the fastest rotating
stars.
The saturation behavior of the different temperature regimes
holds
important clues to the organization of the surface active regions
on
these very young stars, and should allow us to distinguish among
several
competing models.
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.
ACS/SBC
10872
Lyman
Continuum Emission in Galaxies at z=1.2
Lyman
continuum photons produced in massive starbursts may have played a
dominant
role in the reionization of the Universe. Starbursts are
important
contributors to the ionizing metagalactic background at lower
redshifts
as well. However, their contribution to the background depends
upon
the fraction of ionizing radiation that escapes from the intrinsic
opacity
of galaxies below the Lyman limit. Current surveys suggest
escape
fractions of a few percent, up to 10%, with very few detections
{as
opposed to upper limits} having been reported. No detections have
been
reported in the epochs between z=0.1 and z=2. We propose to measure
the
fraction of escaping Lyman continuum radiation from 15 luminous
z~1.2
galaxies in the GOODS fields. Using the tremendous sensitivity of
the
ACS Solar- blind Channel, we will reach AB=30 mag., allowing us to
detect
an escape fraction of 1%. We will correlate the amount of
escaping
radiation with the photometric and morphological properties of
the
galaxies. A non-detection in all sources would imply that QSOs
provide
the overwhelming majority of ionizing radiation at z=1.3, and it
would
strongly indicate that the properties of galaxies at higher
redshift
have to be significantly different for galaxies to dominate
reionization.
The deep FUV images will also be useful for extending the
FUV
study of other galaxies in the GOODS fields.
WFPC2
10766
A
Deep X-ray Survey of the Small Magellanic Cloud
We
request deep observations of 2 representative fields in the Small
Magellanic
Cloud with Chandra and HST, with the primary goal of measuring
the
luminosity function and space density of X-ray binaries and other
sources
down to an unprecedented faint luminosity limit of 2x10E32
erg/s.
This will be the faintest XLF ever obtained for any galaxy,
including
our own. HST photometry to 24th magnitude in V and I filters
will
identify the sources and provide Fx/Fopt, which will be vital in
quantifying
the LMXB population and in measuring the properties of the
first
coronally active stars ever detected in an external galaxy.
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
21
21
FGS
REacq
18
18
OBAD
with Maneuver
78
78
SIGNIFICANT
EVENTS: (None)