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 # 4419
PERIOD COVERED: UT August 3,4,5 2007 (DOY 215,216,217)
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.
FGS 11295
Trigonometric Calibration of the Distance Scale for
Classical Novae
The distance scale for classical novae is important for
understanding
the stellar physics of their thermonuclear runaways, their
contribution
to Galactic nucleosynthesis, and their use as
extragalactic standard
candles. Although it is known that there is a relationship
between their
absolute magnitudes at maximum light and their subsequent
rates of
decline--the well-known maximum-magnitude rate-of-decline
{MMRD}
relation--it is difficult to set the zero-point for the
MMRD because of
the very uncertain distances of Galactic novae. We propose
to measure
precise trigonometric parallaxes for the quiescent
remnants of the four
nearest classical novae. We will use the Fine Guidance
Sensors, which
are proven to be capable of measuring parallaxes with
errors of ~0.2
mas, well below what is possible from the ground.
WFPC2 11292
The Ring Plane Crossings of Uranus in 2007
The rings of Uranus turn edge-on to Earth in May and
August 2007. In
between, we will have a rare opportunity to see the unlit
face of the
rings. With the nine optically thick rings essentially invisible, we will
observe features and phenomena that are normally lost in
their glare. We
will use this opportunity to search thoroughly for the
embedded
"shepherd" moons long believed to confine the
edges of the rings,
setting a mass limit roughly 10 times smaller than that of
the smallest
shepherd currently known, Cordelia. We will measure the
vertical
thicknesses of the rings and study the faint dust belts
only known to
exist from a single Voyager image. We will also study the
colors of the
newly-discovered faint, outer rings; recent evidence
suggests that one
ring is red and the other blue, implying that each ring is
dominated by
a different set of physical processes. We will employ near-edge-on
photometry from 2006 and 2007 to derive the particle
filling factor
within the rings, to observe how ring epsilon responds to
the "traffic
jam" as particles pass through its narrowest point,
and to test the
latest models for preserving eccentricities and apse
alignment within
the rings. Moreover, this data set will allow us to
continue monitoring
the motions of the inner moons, which have been found to
show possibly
chaotic orbital variations; by nearly doubling the time
span of the
existing Hubble astrometry, the details of the variations
will become
much clearer.
FGS 11210
The Architecture of Exoplanetary Systems
Are all planetary systems coplanar? Concordance cosmogony
makes that
prediction. It is, however, a prediction of extrasolar
planetary system
architecture as yet untested by direct observation for
main sequence
stars other than the Sun. To provide such a test, we
propose to carry
out FGS astrometric studies on four stars hosting seven
companions. Our
understanding of the planet formation process will grow as
we match not
only system architecture, but formed planet mass and true
distance from
the primary with host star characteristics for a wide
variety of host
stars and exoplanet masses. We propose that a series of
FGS astrometric
observations with demonstrated 1 millisecond of arc
per-observation
precision can establish the degree of coplanarity and
component true
masses for four extrasolar systems: HD 202206 {brown
dwarf+planet}; HD
128311 {planet+planet}, HD 160691 = mu Arae {planet+planet},
and HD
222404AB = gamma Cephei {planet+star}. In each case the
companion is
identified as such by assuming that the minimum mass is
the actual mass.
For the last target, a known stellar binary system, the
companion orbit
is stable only if coplanar with the AB binary orbit.
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!
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.
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 Monte Carlo technique to
optimally schedule our observations.
WFPC2 11169
Collisions in the Kuiper belt
For most of the 15 year history of observations of Kuiper
belt objects,
it has been speculated that impacts must have played a major
role in
shaping the physical and chemical characteristics of these
objects, yet
little direct evidence of the effects of such impacts has
been seen. The
past 18 months, however, have seen an explosion of major
new discoveries
giving some of the first insights into the influence of
this critical
process. From a diversity of observations we have been led
to the
hypotheses that: {1} satellite-forming impacts must have
been common in
the Kuiper belt; {2} such impacts led to significant
chemical
modification; and {3} the outcomes of these impacts are
sufficiently
predictable that we can now find and study these
impact-derived systems
by the chemical and physical attributes of both the
satellites and the
primaries. If our picture is correct, we now have in hand
for the first
time a set of incredibly powerful tools to study the
frequency and
outcome of collisions in the outer solar system. Here we
propose three
linked projects that would answer questions critical to
the multiple
prongs of our hypothesis. In these projects we will study
the chemical
effects of collisions through spectrophotometric
observations of
collisionally formed satellites and through the search for
additional
satellites around primaries with potential impact signatures,
and we
will study the physical effects of impacts through the
examination of
tidal evolution in proposed impact systems. The intensive
HST program
that we propose here will allow us to fully test our new
hypotheses and
will provide the ability to obtain the first extensive
insights into
outer solar system impact processes.
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.
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 undersampled,
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 11079
Treasury Imaging of Star Forming Regions in the Local
Group:
Complementing the GALEX and NOAO Surveys
We propose to use WFPC2 to image the most interesting
star-forming
regions in the Local Group galaxies, to resolve their
young stellar
populations. We will use a set of filters including F170W,
which is
critical to detect and characterize the most massive
stars, to whose hot
temperatures colors at longer wavelengths are not
sensitive. WFPC2's
field of view ideally matches the typical size of the
star-forming
regions, and its spatial resolution allows us to measure individual
stars, given the proximity of these galaxies. The
resulting H-R diagrams
will enable studies of star- formation properties in these
regions,
which cover largely differing metallicities {a factor of
17, compared to
the factor of 4 explored so far} and characteristics. The
results will
further our understanding of the star-formation process,
of the
interplay between massive stars and environment, the
properties of dust,
and will provide the key to interpret integrated
measurements of
star-formation indicators {UV, IR, Halpha} available for
several
hundreds more distant galaxies. Our recent deep surveys of
these
galaxies with GALEX {FUV, NUV} and ground-based imaging
{UBVRI, Halpha,
[OIII] and [SII]} provided the identification of the most
relevant SF
sites. In addition to our scientific analysis, we will
provide catalogs
of HST photometry in 6 bands, matched corollary
ground-based data, and
UV, Halpha and IR integrated measurements of the
associations, for
comparison of integrated star-formation indices to the
resolved
populations. We envisage an EPO component.
FGS 11019
Monitoring FGS1r's Interferometric Response as a Function
of Spectral
Color
This proposal
uses FGS1r in Transfer mode to observe standard single
stars of a variety of spectral types to obtain point
source
interferograms for the Transfer mode calibration library.
In specific
cases, the calibration star will also be observed in POS
mode multiple
times with the F583W and F5ND elements to provide the data
to verify the
stabiligy of the cross filter calibration.
NIC2 10854
Coronagraphic Imaging of Bright New Spitzer Debris Disks
II.
Fifteen percent of bright main sequence stars possess
dusty
circumstellar debris disks revealed by far-infrared
photometry. These
disks are signposts of planetary systems: collisions among
larger,
unseen parent bodies maintain the observed dust population
against
losses to radiation pressure and P-R drag. Images of
debris disks at
optical, infrared, and millimeter wavelengths have shown
central holes,
rings, radial gaps, warps, and azimuthal asymmetries which
indicate the
presence of planetary mass perturbers. Such images provide
unique
insights into the structure and dynamics of exoplanetary
systems.
Relatively few debris disks have been spatially resolved.
Only thirteen
have ever been resolved at any wavelength, and at
wavelengths < 10
microns {where subarcsec resolution is available}, only
ten. Imaging of
many other debris disk targets has been attempted with
various HST
cameras/coronagraphs and adaptive optics, but without
success. The key
property which renders a debris disk observable in
scattered light is
its dust optical depth. The ten disks imaged so far all
have a dust
excess luminosity >~ 0.01% that of the central star; no
disks with
smaller optical depths have been detected. Most main
sequence stars
known to meet this requirement have already been observed,
so future
progress in debris disk imaging depends on discovering
additional stars
with large infrared excess. The Spitzer Space Telescope
offers the best
opportunity in 20 years to identify new examples of high
optical depth
debris disk systems. We propose to complete ACS
coronagraphic imaging
followup of bright, new debris disks discovered during the
first two
years of the Spitzer mission, by observing three additional
targets in
Cycle 15. Our goal is to obtain the first resolved images
of these disks
at ~3 AU resolution, define the disk sizes and
orientations, and uncover
disk substructures indicative of planetary perturbations.
The results
will open wider a window into the structure of planetary
systems.
NIC3 10839
The NICMOS Polarimetric Calibration
Recently, it has been shown that NICMOS possesses an
instrumental
polarization at a level of 1.2%. This completely inhibits
the data
reduction in a number of previous GO programs, and hampers
the ability
of the instrument to perform high accuracy polarimetry. In
all, 90
orbits of HST data are affected, with potentially many
more in Cycle 15.
We propose to obtain high signal to noise observations of
three
polarimetric standards at the cardinal roll angles of the
NICMOS
polarizers for both NIC1 and NIC2. These observations are
designed to
fully characterize the instrumental polarization in order
for NICMOS to
reach its full potential by enabling high accuracy
polarimetry of
sources with polarizations around 1%. The residual
polarization will
also be determined as a function of position and spectral
energy
distribution. Our group will rapidly turn around the
required data
products and produce reports and software for the accurate
representation of the instrumental polarization. These
items will be
presented to STScI and for dissemination among the wider
astronomical
community.
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
19
19
OBAD with Maneuver
82
82
SIGNIFICANT EVENTS: (None)