Daily #3982
- From: Joe Cooper <jcooper@xxxxxxxxxxxx>
- Date: Tue, 8 Nov 2005 15:40:31 +0000 (UTC)
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3982
PERIOD COVERED: UT November 04,05,06, 2005 (DOY 308,309,310)
OBSERVATIONS SCHEDULED
ACS/HRC 9973
Intensive Coverage of the Eta Carinae Event in 2003
For a variety of reasons, HST can provide a very special and unique data
set when Eta Car experiences its next spectroscopic event in mid-2003.
Explaining the phenomenon is only part of the motivation. This star and
its ejecta have unique characteristics that make them important for
several branches of astrophysics; and when a spectroscopic event occurs,
it's like varying the parameters in an experiment {or rather, set of
experiments}. The 2003 event may be the only chance in the forseeable
future to obtain such a data set, especially with HST. Eta Carinae has
extreme parameters; it is mysterious in surprisingly basic ways; and
HST/ACS/HRC can gather useful data on it at a terrific rate. As we
explain below, the proposed data set will be valuable in several
independent ways: It will help solve a specific set of current problems,
it will constitute a large and unique archival data base for both
stellar and nebular astrophysics, and it will be well- suited for
educational uses.
FGS 9335
Masses of Pre-Main Sequence Binaries
We propose to continue to map the orbits of young star binaries in the
Taurus and Ophiuchus star forming regions. Our goal is to measure their
masses dynamically. This is important because there are still no low
mass young stars with reliably known masses so calculations of their
evolution to the main sequence are uncalibrated.
NIC1/NIC2/NIC3 8793
NICMOS Post-SAA calibration - CR Persistence Part 4
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.
FGS 10756
Monitoring FGS1r Stability in Position Mode
This proposal gathers the data needed to monitor the FGS1r distortions
and scale across its FOV. An astrometric field in M35 is observed 3
times per year, from Aug to December. Earlier versions of this proposal
contained additional observartions from Jan to May. However, the ORIENT
associated with those observations is not available under two-gyro
operations. The particular field being observed in this proposal is from
"orbit 1" of the FGS1r OFAD {proposal 8469}.
ACS/HRC 10752
Cycle 14 Focus Monitor
The focus of HST is measured primarily with ACS/HRC over full CVZ orbits
to obtain accurate mean focus values via a well sampled breathing curve.
Coma and astigmatism are also determined from the same data in order to
further understand orbital effects on image quality and optical
alignments. To monitor the stability of ACS to WFPC2 relative focii,
we've carried over from previous focus monitor programs parallel
observations taken with the two cameras at suitable orientations of
previously observed targets, and interspersed them with the HRC CVZ
visits.
ACS/SBC 10739
Internal Flat Field Stability
The stability of the CCD flat fields will be monitored using the
calibration lamps and a sub-sample of the filter set. For the SBC
imaging filters, differences in the low-frequency flat field structure
with wavelength will be assessed. New high signal P-flats will be
obtained for the SBC prisms.
ACS/HRC/WFC 10733
CCD Hot Pixel Annealing
Hot pixel annealing will continue to be performed once every 4 weeks.
The CCD TECs will be turned off and heaters will be activated to bring
the detector temperatures to about +20C. This state will be held for
approximately 6 hours, after which the heaters are turned off, the TECs
turned on, and the CCDs returned to normal operating condition. To
assess the effectiveness of the annealing, a bias and four dark images
will be taken before and after the annealing procedure for both WFC and
HRC. The HRC darks are taken in parallel with the WFC darks. The charge
transfer efficiency {CTE} of the ACS CCD detectors declines as damage
due to on-orbit radiation exposure accumulates. This degradation has
been closely monitored at regular intervals, because it is likely to
determine the useful lifetime of the CCDs. We combine the annealling
activity with the charge transfer efficiency monitoring and also merge
into the routine dark image collection. To this end, the CTE monitoring
exposures have been moved into this proposal . All the data for this
program is acquired using internal targets {lamps} only, so all of the
exposures should be taken during Earth occultation time {but not during
SAA passages}. This program emulates the ACS pre-flight ground
calibration and post-launch SMOV testing {program 8948}, so that results
from each epoch can be directly compared. Extended Pixel Edge Response
{EPER} and First Pixel Response {FPR} data will be obtained over a range
of signal levels for both the Wide Field Channel {WFC}, and the High
Resolution Channel {HRC}.
ACS/HRC/WFC 10729
ACS CCDs daily monitor
This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise in
ACS CCD detectors. The files, biases and dark will be used to create
reference files for science calibration. This programme will be for the
entire lifetime of ACS. Changes from cycle 13:- The default gain for WFC
is 2 e-/DN. As before bias frames will be collected for both gain 1 and
gain 2. Dark frames are acquired using the default gain {2}. This
program cover the period Oct, 2 2005- May, 29-2006. The second half of
the program has a different proposal number: 10758.
ACS/WFC 10635
Galaxy Transformation as probed by Morphology and Velocity Fields of
Distant Cluster Galaxies
We seek to obtain ACS imaging of four distant {0.3<z<0.6} clusters of
galaxies within a 6'x6' field covered by a 2x2 mosaic to determine
morphological and structural parameters of late-type galaxies. We
specifically concentrate on peculiarities indicative of past or ongoing
interaction processes. The ~90 target galaxies have been {Period74} or
will be {P75} observed with 3D- spectroscopy at ESO-VLT yielding
2D-velocity fields with unprecedented spatial coverage and sampling. The
good spatial resolution of the ground-based data will be further
enhanced by a deconvolution method based on the proposed ACS images. The
velocity field and the morphology in restframe-UV light will reveal
possible transformation mechanisms affecting not only the stellar
populations but also the mass distribution of the galaxies.
Additionally, it will be possible to pin down the nature of the
interaction {e.g. tidally or ram-pressure induced}. This assessment gets
supported by our N-body/SPH simulations {including star formation} of
different interaction processes that allow the direct comparison of
structural and kinematical characteristics at each time step with the
observations on an individual basis taking into account all
observational constraints for a given galaxy. All together, we will be
able to explore the relative efficiency of the various proposed
transformation phenomena. In the case of non-disturbed spirals, a
rotation curve can be extracted from the full 2D velocity field with
unprecedented quality, from which the maximum rotation speed can be
derived with high confidence. In combination with accurate size and
luminosity determinations from the ACS images, we will be able to
establish the Tully-Fisher and Fundamental Plane relations of cluster
spiral members at cosmological epochs. At these distances cluster
assembly is predicted to peak and we can probe the galaxies' luminosity,
size and mass evolution with robust methods. Together with our already
existing sample of ~200 distant {z<=1} spiral galaxies in the field, we
will put strong constraints on current theories of galaxy formation and
evolution in different environments.
ACS/WFC 10626
A Snapshot Survey of Brightest Cluster Galaxies and Strong Lensing to z
= 0.9
We propose an ACS/WFC snapshot survey of the cores of 150 rich galaxy
clusters at 0.3 < z < 0.9 from the Red Sequence Cluster Survey {RCS}. An
examination of the galaxian light in the brightest cluster galaxies,
coupled with a statistical analysis of the strong-lensing properties of
the sample, will allow us to contrain the evolution of both the baryonic
and dark mass in cluster cores, over an unprecedented redshift range and
sample size. In detail, we will use the high- resolution ACS images to
measure the metric {10 kpc/h} luminosity and morphological disturbances
around the brightest clusters galaxies, in order to calibrate their
accretion history in comparison to recent detailed simulations of
structure formation in cluster cores. These images will also yield a
well-defined sample of arcs formed by strong lensing by these clusters;
the frequency and detailed distribution {size, multiplicity, redshifts}
of these strong lens systems sets strong constraints on the total mass
content {and its structure} in the centers of the clusters. These data
will also be invaluable in the study of the morphological evolution and
properties of cluster galaxies over a significant redshift range. These
analyses will be supported by extensive ongoing optical and
near-infrared imaging, and optical spectroscopy at Magellan, VLT and
Gemini telescopes, as well as host of smaller facilities.
ACS/HRC 10609
Sizes, Shapes, and SEDs: Searching for Mass Segregation in the Super
Star Clusters of Nearby Starburst
We propose to investigate mass segregation and star cluster evolution
and dissolution processes in Super Star Cluster {SSC} populations in a
small sample of nearby starburst galaxies. ACS/HRC and NICMOS images of
these nearby {d < 10 Mpc} starbursts can reveal evidence for mass
segregation in the form of variations in size, shape, and color of the
SSCs as a function of wavelength. The compactness of the cluster light
profiles, and hence the stellar mass distributions, is a critical
indicator of the likely fate of an SSC: long life and eventual evolution
into a globular-like cluster, or dissolution. These observations will
allow us to generate spectral energy distributions {SEDs} for a large
sample of the SSCs at all ages and extinctions in each system. We will
combine the SEDs with population synthesis models and existing ground-
based spectra and Spitzer images to estimate ages, reddenings, and
masses thus derive a more complete picture of the star-formation
histories of the galaxies. For the brightest and most likely virialized
among the SSCs we will also constrain their initial mass functions
{IMFs} using high- resolution spectroscopy. Conclusions about IMFs from
this technique require detailed information about the SSC concentration,
light profiles, and virial status, which are only possible via ACS data.
The proposed observations will provide an extensive and comprehensive
data set for a large number of SSCs. By addressing the issues of mass
segregation, evaporation, and destruction of SSC populations, the
proposed observations will provide strong constraints on theories
regarding the processes involved in the formation and evolution of SSCs
and globular clusters. Given the dire predictions for the lifetime of
HST, and its tremendous impact on the study of SSCs, we feel that the
proposed observations not only are necessary and timely {even urgent}
but will also be a fitting { and possibly final} addition to HST's
legacy in the study of starburst SSCs.
ACS/HRC 10602
A Complete Multiplicity Survey of Galactic O2/O3/O3.5 Stars with ACS
Massive stars are preferentially formed in compact multiple systems and
clusters and many of them remain spatially unresolved to date, even in
our Galaxy. This has hindered the determination of the stellar upper
mass limit. The lack of an accurate knowledge of the multiplicity of
massive stars can also introduce biases in the calculation of the IMF at
its high-mass end. We have recently used ACS/HRC to resolve HD 93129 A,
the earliest O-type star known in the Galaxy, into a 55 mas binary. We
propose here to extend that work into a complete multi-filter ACS
imaging survey of all {20} known O2/O3/O3.5 Galactic stars to
characterize the multiplicity of the most massive stars. The data will
be combined with existing FGS observations to explore as large a
parameter range as possible and to check for consistency. We will also
derive the IMF of each system using a crowded-field photometry package
and processing the data with CHORIZOS, a code that can derive stellar
temperatures, extinctions, and extinction laws from multicolor
photometry.
ACS/WFC 10596
AGNs with Intermediate-mass Black Holes: A Test of the Black Hole-Bulge
Paradigm
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 {10^4-10^6 solar masses}, if they exist,
may offer important clues to the nature of the seeds of supermassive
black holes. In a first systematic search using the Sloan Digital Sky
Survey, we have recently discovered 19 Type 1 AGNs with candidate
intermediate-mass black holes that reside in low-luminosity, presumably
late-type host galaxies. Follow-up observations with Keck indicate that
these objects obey the low-mass extension of the well-known correlation
between black hole mass and bulge stellar velocity dispersion. However,
very little is known about the host galaxies themselves, including the
crucial question of whether they have bulges or not. We propose to
obtain ACS/WFC images of this unique sample of AGNs in order to
investigate the detailed structural properties of the host galaxies. We
are particularly keen to determine whether the hosts contain bulges, and
if so, where they lie on the fundamental plane of spheroids compared to
the bulges of supermassive black holes. We will also be able to measure
an accurate optical luminosity for the AGN, which is an essential
ingredient to improve the current mass estimates.
ACS/WFC 10592
An ACS Survey of a Complete Sample of Luminous Infrared Galaxies in the
Local Universe
At luminosities above 10^11.4 L_sun, the space density of far-infrared
selected galaxies exceeds that of optically selected galaxies. These
`luminous infrared galaxies' {LIRGs} are primarily interacting or
merging disk galaxies undergoing enhanced star formation and Active
Galactic Nuclei {AGN} activity, possibly triggered as the objects
transform into massive S0 and elliptical merger remnants. We propose
ACS/WFC imaging of a complete sample of 88 L_IR > 10^11.4 L_sun luminous
infrared galaxies in the IRAS Revised Bright Galaxy Sample {RBGS: i.e.,
60 micron flux density > 5.24 Jy}. This sample is ideal not only in its
completeness and sample size, but also in the proximity and brightness
of the galaxies. The superb sensitivity, resolution, and field of view
of ACS/WFC on HST enables a unique opportunity to study the detailed
structure of galaxies that sample all stages of the merger process.
Imaging will be done with the F439W and F814W filters {B and I-band} to
examine as a function of both luminosity and merger state {i} the
evidence at optical wavelengths of star formation and AGN activity and
the manner in which instabilities {bars and bridges} in the galaxies may
funnel material to these active regions, {ii} the relationship between
star formation and AGN activity, and {iii} the structural properties
{AGN, bulge, and disk components} and fundamental parameters {effective
radius and surface brightness} of LIRGs and their similarity with
putative evolutionary byproducts {elliptical, S0 and classical AGN host
galaxies}. This HST survey will also bridge the wavelength gap between a
Spitzer imaging survey {covering seven bands in the 3.6-160 micron
range} and a GALEX UV imaging survey of these galaxies, but will resolve
complexes of star clusters and multiple nuclei at resolutions well
beyond the capabilities of either Spitzer or GALEX. The combined
datasets will result in the most comprehensive multiwavelength study of
interacting and merging galaxies to date.
ACS/WFC 10586
The Rosetta Stone without a Distance: Hunting for Cepheids in the
Primordial Galaxy I Zw 18
The Blue Compact Dwarf galaxy I Zw 18 is one of the most intriguing
objects in the Local Universe. It has the lowest nebular metallicity of
all known galaxies {Z=1/32 solar}. It has long been regarded as a
possible example of a galaxy undergoing its first burst of star
formation. However, its real evolutionary state continues to be
controversial. The WFPC2 and NICMOS detection of AGB stars by our group
and others suggested the presence of an underlying older population.
However, deeper ACS observations by Izotov & Thuan {2004} recently
failed to detect the signature of RGB stars. This was interpreted as
confirmation that I Zw 18 is in fact a galaxy "in formation", a local
analog of primordial galaxies in the distant Universe. This result was
widely reported in the international news media. However, an alternative
possibility is that I Zw 18 is somewhat further away than previously
believed, so that Red Giant Branch stars were too faint to detect.
Quoted distances in the literature have ranged from 10 to 20 Mpc. We
intend to resolve this controversy by direct determination of the
distance to 1 Mpc accuracy using Cepheids. For this we request 12 visits
of two orbits each, to execute at carefully planned intervals. We will
obtain V and I band ACS/WFC photometry in each visit. The new data will
be combined with archival data, but we show that the archival data by
themselves are insufficient to achieve our science goals. The distance
will allow us to place I Zw 18 into its proper place in the evolutionary
sequence of galaxy formation.
ACS/HRC 10556
Neutral Gas at Redshift z=0.5
Damped Lyman-alpha systems {DLAs} are used to track the bulk of the
neutral hydrogen gas in the Universe. Prior to HST UV spectroscopy, they
could only be studied from the ground at redshifts z>1.65. However, HST
has now permitted us to discover 41 DLAs at z<1.65 in our previous
surveys. Followup studies of these systems are providing a wealth of
information about the evolution of the neutral gas phase component of
the Universe. But one problem is that these 41 low-redshift systems are
spread over a wide range of redshifts spanning nearly 70% of the age of
the Universe. Consequently, past surveys for low-redshift DLAs have not
been able to offer very good precision in any small redshift regime.
Here we propose an ACS-HRC- PR200L spectroscopic survey in the redshift
interval z=[0.37, 0.7] which we estimate will permit us to discover
another 41 DLAs. This will not only allow us to double the number of
low-redshift DLAs, but it will also provide a relatively high-precision
regime in the low-redshift Universe that can be used to anchor
evolutionary studies. Fortunately DLAs have high absorption equivalent
width, so ACS-HRC-PR200L has high-enough resoultion to perform this
proposed MgII-selected DLA survey.
ACS/HRC 10555
A Search for Satellites Around Kuiper Belt Objects Which Exhibit High
Angular Momentum
We propose to use the HST to search for satellites around Kuiper Belt
Objects which have large amplitude, fast rotational light curves. Large
main belt asteroids with similar light curve characteristics have been
found to have near an 80 percent companion rate. This is over an order
of magnitude more than the companion rate of main belt asteroids in
general. The satellites were probably formed during the process which
imparted the high angular momentum on the primary object. To date five
Kuiper Belt objects exhibit high angular momentum through their
rotational light curves. Two of them have been observed with STIS on the
HST and one was found to be a binary. We request three orbits with
HST/ACS in order to obtain deep high resolution images of the other
three Kuiper Belt objects that have large amplitudes and fast rotations.
In addition, we request one orbit to reobserve the other KBO which
didn't have a satellite detection in order to obtain deeper and better
resolution images than the first observations. Finding binaries is
important not only to understand the processes which created the high
angular momentum of the primary but also in determining the bulk
densities and collisional histories of the objects.
ACS/HRC 10547
A SNAP Program to Obtain Complete Wavelength Coverage of Interstellar
Extinction
We propose a SNAP program to obtain ACS/HRC spectra in the near-UV
{PR200L} and near-IR {G800L} for a set of main sequence B stars with
available IUE UV spectrophotometry, optical photometry, and 2MASS IR
photometry. Together with these existing data, the new observations will
provide complete photometric and spectrophotometric coverage from 1150
to 11000 A and enable us to produce complete extinction curves from the
far-UV to the near-IR, with well- determined values of R{V}. The
proposed set of 50 program sight lines includes the full range of
interstellar extinction curve types and a wide range of color excesses.
The new data will allow us to examine variability in the near-UV through
near-IR spectral regions, including the UV-optical "knee" and the "Very
Broad Structure." We will examine the response of these features to
different interstellar environments and their relationship to other
curve features. These are largely unexplored aspects of extinction
curves which will provide additional constraints on the properties of
interstellar grains. The curves will be derived using stellar atmosphere
models to represent the intrinsic spectral energy distributions of the
program stars, eliminating the need to observe unreddened "standard
stars." This approach virtually eliminates "mismatch error", allowing us
to derive extinction curves with much higher precision than previously
possible. In addition, the new spectra will provide higher S/N data for
the peak of the 2175 A bump than previously available.
WFPC2 10537
Caught in the Act with HST -- Active Jet Sculpting in the Young
Preplanetary Nebulae IRAS 22036+5306
We have discovered an extended, highly-structured and bipolar nebula
surrounding the post- AGB object IRAS22036+5306 {I22036}, in a Cycle 10
WFPC2 imaging survey of very young pre- planetary nebulae {PPNs}. Young
PPNs like I22036, objects in rapid transition between the AGB and
Planetary Nebulae {PN} phases, retain direct signatures, in the spatial
character of their outflows, of the physical mechanisms which transform
slowly expanding, round circumstellar AGB envelopes into highly
aspherical PNs with fast-expanding elongated lobes along one or more
axes. I22036 shows intriguing evidence for the presence of jets in the
HST images, and VLA A-array maps show OH maser emission in a linear
structure along the nebular axis. Our ground-based echelle H-alpha
spectra show high-velocity blue-shifted absorption in a very broad
{~2000 km/s} line profile, and mm-wave CO J=1-0 interferometric data
show a bipolar molecular outflow. There are very few young PPNs like
I22036 which show clear morphological & kinematical evidence of the
presence of jets and their working surfaces, making it unquestionably a
key object for understanding how jets can sculpt out bipolar lobes in a
progenitor AGB star wind. Using ground-based long-slit spectroscopy with
the Keck/ESI, we have partially spatially resolved the H-alpha emission
in this object. We now propose to image I22036 in F658N, F631N, F606W
and F814W in order to identify accurately the location and structure of
the shocked gas, and its relation to the jets and their working
surfaces. An important goal is to determine whether we can characterise
the forward and reverse shocks near the heads of the knotty jets. The
proposed HST imaging will help us to understand the spatio- kinematic
structure of the outflowing gas in the bipolar lobes, and allow us to
study the relationships between the important dynamical components of
this nebula. Supporting ground- based observations such as Zeeman
measurements of polarised OH masers with the VLBA to search for magnetic
fields in I22036 are being pursued for testing magnetic-collimation
models for jets in PPNs.
ACS/WFC/HRC 10536
What Are Stalled Preplanetary Nebulae? An ACS SNAPshot Survey
Essentially all planetary nebulae {PNs} are aspherical, whereas the
mass-loss envelopes of AGB stars are strikingly spherical. Our previous
SNAPshot surveys of a morphologically unbiased sample of pre-planetary
nebulae {PPNs} -- objects in transition between the AGB and PN
evolutionary phases -- show that roughly half our observed targets are
resolved, with bipolar or multipolar morphologies. Spectroscopic
observations of our sample confirm that these objects have not yet
evolved into planetary nebulae. Thus, the transformation from spherical
to aspherical geometries has already fully developed by the time these
dying stars have become PPNs. Although our current studies have yielded
exciting results, they are limited in two important ways -- {1} the
number of well-resolved objects is still small {18}, and the variety of
morphologies observed relatively multitudinous, hence no clear trends
can yet be established between morphology and other source properties
{e.g., near-IR, far-IR colors, stellar spectral type, envelope mass},
and {2} the current samples are strongly biased towards small PPNs, as
inferred from their low 60-to-25 micron flux ratios [R{60/25}<1].
However, the prototype of objects with R{60/25}>1, the Frosty Leo
Nebula, has a puzzlingly large post-AGB age {almost 10^4 yr} and a
fairly cool central star, very different from the expectations of
single-star stellar evolutionary models. A proposed, but still
speculative, hypothesis for such objects is that the slow evolution of
the central star is due to backflow of material onto the mass-losing
star, retarding its evolution towards the PN phase. This hypothesis has
significant consequences for both stellar and nebular evolution. We
therefore propose a survey of PPNs with R{60/25}>1 which is heavily
weighted towards the discovery of such "stalled PPNs". Supporting
kinematic observations using long-slit optical spectroscopy {with the
Keck}, millimeter and radio interferometric observations {with OVRO, VLA
& VLBA} are being undertaken. The results from this survey {together
with our previous work} will allow us to draw general conclusions about
the complex mass-outflow processes affecting late stellar evolution, and
will provide crucial input for theories of post-AGB stellar evolution.
Our survey will produce an archival legacy of long-standing value for
future studies of dying stars.
ACS/WFC 10523
The Halo Shape and Metallicity of Massive Spiral Galaxies
We propose to resolve the stellar populations of the halos of seven
nearby, massive disk galaxies using a SNAP survey with WFC/ACS. These
observations will provide star counts and color-magnitude diagrams 2-3
magnitudes below the tip of the Red Giant Branch along the two principal
axes and one intermediate axis of each galaxy. We will measure the
metallicity distribution functions and stellar density profiles from
star counts down to very low average surface brightnesses, equivalent to
~31 V-mag per square arcsec. This proposal will create a unique sampling
of galaxy halo properties, as our targets cover a range in galaxy mass,
luminosity, inclination, and morphology. As function of these galaxy
properties this survey will provide:- the first systematic measurement
of radial light profiles and axial ratios of the diffuse stellar halos
and outer disks of spiral galaxies- a comprehensive analysis of halo
metallicity distributions as function of galaxy type and position within
the galaxy- an unprecedented study of the stellar metallicity and age
distribution in the outer disk regions where the disk truncations occur-
the first comparative study of globular clusters and their field stellar
populations We will use these fossil records of the galaxy assembly
process to test halo formation models within the hierarchical galaxy
formation scheme.
NIC1 10517
Imaging Astrometrically-Discovered Brown Dwarfs
We propose to image the astrometrically discovered companions of three
M-dwarfs with NICMOS to more tightly constrain their masses and
determine their stellar or sub-stellar natures. Each of these systems
has been observed with a sensitive ground-based adaptive optics system
and no companions have been detected. NICMOS results will eliminate an
ambiguity in the astrometric mass measurements that arises because a
companion that contributes significantly to the visible light reduces
the motion of the center of light and mimics a small motion of the
center of mass. In addition the astrometric measurements made with
NICMOS will fix the scale of the system, distinguishing among possible
orbits. Finally the color photometry will constrain the spectral types
to within a couple of subtypes. When we measure the masses of
astrophysical objects, we test and assist the development of the
theoretical mass models. Models are based upon parameters such as age
and metallicity. Determining the correct mass thus deepens our
understanding of the fundamental physics of stars and substellar objects
ACS/HRC/WFC 10514
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 a
Snapshot program using the ACS/HRC that has a potential discovery
efficiency an order of magnitude higher than the HST observations that
have already discovered the majority of known transneptunian binaries.
By more than doubling the number of observed objects in dynamically hot
and cold subpopulations we will be able to answer, with statistical
significance, the question of whether these groups differ in the
abundance of binaries as a result 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 10496
Decelerating and Dustfree: Efficient Dark Energy Studies with Supernovae
and Clusters
We propose a novel HST approach to obtain a dramatically more useful
"dust free" Type Ia supernovae {SNe Ia} dataset than available with the
previous GOODS searches. Moreover, this approach provides a strikingly
more efficient search-and-follow-up that is primarily pre- scheduled.
The resulting dark energy measurements do not share the major systematic
uncertainty at these redshifts, that of the extinction correction with a
prior. By targeting massive galaxy clusters at z > 1 we obtain a
five-times higher efficiency in detection of Type Ia supernovae in
ellipticals, providing a well-understood host galaxy environment. These
same deep cluster images then also yield fundamental calibrations
required for future weak lensing and Sunyaev-Zel'dovich measurements of
dark energy, as well as an entire program of cluster studies. The data
will make possible a factor of two improvement on supernova constraints
on dark energy time variation, and much larger improvement in systematic
uncertainty. They will provide both a cluster dataset and a SN Ia
dataset that will be a longstanding scientific resource.
ACS/WFC 10494
Imaging the mass structure of distant lens galaxies
The surface brightness distribution of extended gravitationally lensed
arcs and Einstein rings contains super-resolved information about the
lensed object, and, more excitingly, about the smooth and clumpy mass
distribution of the lens galaxies. The source and lens information can
non-parametrically be separated, resulting in a direct
"gravitational-mass image" of the inner mass-distribution of
cosmologically-distant galaxies {Koopmans 2005}. With this goal in mind,
we propose deep HST ACS-F555W/F814W and NICMOS-F160W imaging of 15
gravitational-lens systems with spatially resolved lensed sources,
selected from the 17 new lens systems discovered by the Sloan Lens ACS
Survey {Bolton et al. 2004}. Each system has been selected from the SDSS
and confirmed in a time-efficient HST-ACS snapshot program {cycle-13};
they show highly-magnified arcs or Einstein rings, lensed by a massive
early-type lens galaxy. High- fidelity multi-color HST images are
required {not delivered by the 420-sec snapshot images} to isolate these
lensed images {properly cleaned, dithered and extinction-corrected} from
the lens galaxy surface brightness distribution, and apply our
"gravitational-mass imaging" technique. The sample of galaxy mass
distributions - determined through this method from the arcs and
Einstein ring HST images - will be studied to: {i} measure the smooth
mass distribution of the lens galaxies {Dark and luminous mass are
separated using the HST images and the stellar M/L values derived from a
joint stellar-dynamical analysis of each system}; {ii} quantify
statistically and individually the incidence of mass-substructure {with
or without obvious luminous counter- parts such as dwarf galaxies}.
Since dark-matter substructure should be considerably more prevalent at
higher redshift, both results provide a direct test of this prediction
of the CDM hierarchical structure-formation model.
ACS/WFC 10491
A Snapshot Survey of the most massive clusters of galaxies
We propose a snapshot survey of a sample of 124 high X-ray luminosity
clusters in the redshift range 0.3-0.7. Similarly luminous clusters at
these redshifts frequently exhibit strong gravitational lensing. The
proposed observations will provide important constraints on the nature
of the cluster mass distributions and a set of optically bright, lensed
galaxies for further 8-10m spectroscopy. We acknowledge the broad
community interest in this sample and waive our data rights for these
observations.
NIC2 10173
Infrared Snapshots of 3CR Radio Galaxies
Radio galaxies are an important class of extragalactic objects: they are
one of the most energetic astrophysical phenomena and they provide an
exceptional probe of the evolving Universe, lying typically in high
density regions but well-represented across a wide redshift range. In
earlier Cycles we carried out extensive HST observations of the 3CR
sources in order to acquire a complete and quantitative inventory of the
structure, contents and evolution of these important objects. Amongst
the results, we discovered new optical jets, dust lanes, face-on disks
with optical jets, and revealed point-like nuclei whose properties
support FR-I/BL Lac unified schemes. Here, we propose to obtain NICMOS
infrared images of 3CR sources with z<0.3 as a major enhancement to an
already superb dataset. We aim to deshroud dusty galaxies, study the
underlying host galaxy free from the distorting effects of dust, locate
hidden regions of star formation and establish the physical
characteristics of the dust itself. We will measure frequency and
spectral energy distributions of point-like nuclei, expected to be
stronger and more prevalent in the IR, seek spectral turnovers in known
synchrotron jets and find new jets. We will strongly test unified AGN
schemes and merge these data with existing X-ray to radio observations.
The resulting database will be an incredibly valuable resource to the
astronomical community for years to come.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports
of potential non-nominal performance that will be investigated.)
HSTARS:
10005 - GSACQ(2,1,2) fails, search radius limit exceeded @308/2048z
GSACQ(2,1,2) at 308/20:44:21 failed due to Search Radius Limit Exceeded
on FGS 1 at 20:48:07. One 486 status buffer message A07 (CT timed out
waiting for data valid) was received.
OBAD prior to GSACQ had total RSS attitude error correction of 7.17
arcseconds, within the search radius.
10006 - GSACQ(1,2,1) fine lock backup, scan step exceeded on FGS2 @309/0006z
GSACQ(1,2,1) at 309/00:02:44 ended in fine lock backup on FGS 1 due to
scan step limit exceeded on FGS 2 at 00:06:05.
10007 - REacq(2,1,1) faileddue to search radius limit exceeded on FGS2@309/0928z
REacq(2,1,1) scheduled at 309/09:20:29 failed due to search radius limit
exceeded on FGS 2 at 09:27:40. A ESB A05 (FGS Coarse Track failed -
Search Radius Limit exceeded)was received.
OBAD1 showed errors of: V1=-17.55, V2=-2931.24, V3= -22.72, RSS=2931.38
OBAD2 showed errors of V1=-4.32, V2=-14.82, V3=-5.94, RSS=16.54
The Map at 09:27:55 showed errors of: V1=-1.13, V2=154.53, V3=-0.34,
RSS=154.53
10008 - GSAcq(2,1,1) failed, search radius limit exceeded on FGS 2 @309/1237z
GSAcq (2,1,1) scheduled @ 309/12:32:27 failed due to search radius limit
exceeded.
OBAD #1 - V1 -801.53, V2 -5795.11, V3 474.84, RSS 5869.51
OBAD #2 - V1 5.46, V2 0.25, V3 -0.73, RSS 5.52
10009 - REAcq(1,2,2) was not attempted @310/0124z
The OBAD at 310/01:06:02 failed. ESB 1902 (OBAD Failed Identification)
was received at 01:08:51. The OBAD showed errors of V1=-31166.14,
V2=-5346.01, V3=-47158.95, RSS=56779.18.
10010 - OBAD Failed Identification @310/0108z
The OBAD at 310/01:06:02 failed. ESB 1902 (OBAD Failed Identification)
was received at 01:08:51. The OBAD showed errors of V1=-31166.14,
V2=-5346.01, V3=-47158.95, RSS=56779.18.
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 36 34 308/2048z(HSTAR 10005)
309/1237z(HSTAR10008)
FGS REacq 08 06 309/0928z(HSTAR 10007)
310/0124z(HSTAR10009)
OBAD with Maneuver 84 83 310/0108z(HSTAR 10010)
SIGNIFICANT EVENTS: (None)
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