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 # 4417
PERIOD COVERED: UT August 1, 2007 (DOY 213)
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 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 11208
The co-evolution of spheroids and black holes in the last
six billion
years
The masses of giant black holes are correlated with the
luminosities,
masses, and velocity dispersions of the bulges of their
host galaxies.
This empirical correlation of phenomena on widely
different scales {from
pcs to kpcs} suggests that the formation and evolution of
galaxies and
central black holes are closely linked. In Cycle 13, we
have started a
campaign to map directly the co-evolution of spheroids and
black-holes
by measuring in observationally favorable redshift windows
the empirical
correlations connecting their properties. By focusing on
Seyfert 1s,
where the nucleus and the stars contribute comparable
fractions of total
light, black hole mass and bulge dispersion are obtained
from Keck
spectroscopy. HST is required for accurate measurement of
the non
stellar AGN continuum, the morphology of the galaxy, and
the structural
parameters of the bulge. The results at z=0.36 indicate a
surprisingly
fast evolution of bulges in the past 4 Gyrs {significant
at the 95%CL},
in the sense that bulges were significantly smaller for a
given black
hole mass. Also, the large fraction of mergers and
disturbed galaxies
{4+2 out of 20} identifies gas-rich mergers as the
mechanisms
responsible for bulge-growth. Going to higher redshift --
where
evolutionary trends should be stronger -- is needed to
confirm these
tantalizing results. We propose therefore to push our
investigation to
the next suitable redshift window z=0.57 {lookback-time 6
Gyrs}. Fifteen
objects are the minimum number required to map the
evolution of the
empirical correlations between bulge properties and
black-hole mass, and
to achieve a conclusive detection of evolution
{>99%CL}.
WFPC2 11027
Visible Earth Flats
This proposal monitors flatfield stability. This proposal
obtains
sequences of Earth streak flats to construct high quality
flat fields
for the WFPC2 filter set. These flat fields will allow
mapping of the
OTA illumination pattern and will be used in conjuction
with previous
internal and external flats to generate new pipeline
superflats. These
Earth flats will complement the Earth flat data obtained
during cycles
4-14.
WFPC2 11029
WFPC2 CYCLE 15 Intflat Linearity Check and Filter Rotation
Anomaly
Monitor
Intflat observations will be taken to provide a linearity
check: the
linearity test consists of a series of intflats in F555W,
in each gain
and each shutter. A combination of intflats, visflats, and
earthflats
will be used to check the repeatability of filter wheel
motions.
{Intflat sequences tied to decons, visits 1-18 in prop
10363, have been
moved to the cycle 15 decon proposal xxxx for easier
scheduling.} Note:
long-exposure WFPC2 intflats must be scheduled during ACS
anneals to
prevent stray light from the WFPC2 lamps from
contaminating long ACS
external exposures.
WFPC2 11084
Probing the Least Luminous Galaxies in the Local Universe
We propose to obtain deep color-magnitude data of eight
new Local Group
galaxies which we recently discovered: Andromeda XI,
Andromeda XII, and
Andromeda XIII {satellites of M31}; Canes Venatici I,
Canes Venatici II,
Hercules, and Leo IV {satellites of the Milky Way}; and
Leo T, a new
"free-floating" Local Group dwarf spheroidal
with evidence for recent
star formation and associated H I gas. These represent the
least
luminous galaxies known at *any* redshift, and are the
only accessible
laboratories for studying this extreme regime of galaxy
formation. With
deep WFPC-2 F606W and F814W pointings at their centers, we
will
determine whether these objects contain single or multiple
age stellar
populations, as well as whether these objects display a
range of
metallicities.
WFPC2 11100
Two new `bullets' for MOND: revealing the properties of
dark matter in
massive merging clusters
The principal objective of this proposal is to study the
physical nature
of dark matter by using two, massive, newly-identified
merging clusters
of galaxies. As shown by the pioneering example of the
``bullet
cluster'' {1E0657-56}, such systems are ideal laboratories
for detecting
dark matter and distinguishing between cold dark matter
{CDM} and other
scenarios {e.g. self- interacting dark matter}. Our limit
on the
self-interaction cross-section of dark matter relies on
the assumption
of a normal pre-merger mass-to-light ratios, and a small
impact
parameter during the collision of the two clusters. In
order to mitigate
any possible systematic effects, it is vital to extend
this work to
other, similar systems. With detailed observations of new
systems, the
systematic uncertainties in the dark matter cross section
calculations
can be improved substantially, allowing us to move from
rough order of
magnitude estimates to measurements with quantifiable
uncertainties that
can be compared usefully with the predictions from
numerical
simulations. Our targets are two extraordinary,
high-redshift, merging
galaxy clusters recently discovered by the Massive Cluster
Survey
{MACS}. This survey is by far the best matched to this
study, since it
selects medium redshift {optimal for gravitational lensing
studies} and
X-ray luminous {hence massive} objects. We have selected
the best
candidates with clear evidence for considerable offsets
between the hot
X-ray emitting gas and optically luminous stellar
material. The two most
striking examples are the targets of this proposal. To pin
down the
position of the dark matter component we require high
resolution,
absolutely calibrated mass maps. The combination of weak
and strong
lensing measurements is needed to attain this goal. This
can only be
achieved with the excellent resolving power of the HST {in
combination
with wide-field, multicolor Subaru data already in hand}.
We therefore
request multicolor HST/WFPC2 observations of the two merging
clusters.
The combination of constraints from multiply lensed images
{identified
via morphology and color information} and high-resolution
weak lensing
data will allow us to construct, self-consistently, their
mass
distribution from the very centers to the outskirts.
Gravitational
lensing thus provides a unique tool transforming these
clusters into
dark matter laboratories. They will supply us with answers
as to the
nature and properties of dark matter, and how it shapes
galaxies and
galaxy clusters and their evolution through cosmic time.
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.
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 undertstand 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 seperately
and probe the
mass structure of early-type galaxies from 0.1 to 100 effective
radii.
The large dynamic range to which lensing is sentive 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!
WFPC2/NIC3 11188
First Resolved Imaging of Escaping Lyman Continuum
The emission from star-forming galaxies appears to be
responsible for
reionization of the universe at z>6. However, the
models that attempt to
describe the detailed impact of high- redshift galaxies on
the
surrounding inter-galactic medium {IGM} are strongly
dependent upon
several uncertain parameters. Perhaps the most uncertain
is the fraction
of HI-ionizing photons produced by young stars which
escape into the
IGM. Most attempts to measure this "escape
fraction" {f_esc} have
produced null results. Recently, a small subset of z~3
Lyman Break
Galaxies {LBGs} has been found exhibiting large escape
fractions. It
remains unclear however, what differentiates them from
other LBGs.
Several models attempt to explain how such a large
fraction of ionizing
continuum can escape through the HI and dust in the ISM
{eg. "chimneys"
created by SNe winds, globular cluster formation, etc.},
each producing
unique signatures which can be observed with resolved
imaging of the
escaping Lyman continuum. We propose a deep, high
resolution WFPC2 image
of the ionizing continuum {F336W} and the rest-frame 1500
Angstrom
continuum {F606W} of five of the six known LBGs with large
escape
fractions. These LBGs all fit within a single WFPC2
pointing, yielding
high observing efficiency. Additionally, they all have
z~3.1 or higher,
the optimal redshift range for probing the Lyman Continuum
region with
available WFPC2 filters. These factors make our proposed
sample
especially suitable for follow- up. With these data we
will discern the
mechanisms responsible for producing large escape
fractions, and
therefore gain insight into the process of reionization.
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 07 07
FGS REacq 08 08
OBAD with Maneuver 30 30
SIGNIFICANT EVENTS: (None)