HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT # 4513
PERIOD
COVERED: UT December 21,22,23,24,25, 2007 (DOY 355,356,357,358,359)
OBSERVATIONS
SCHEDULED
NIC1/NIC2/NIC3
8795
NICMOS Post-SAA calibration - CR Persistence Part 6
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 i
mages.
Each observation will need its own CRMAP, as different SAA
passages
leave different imprints on the NICMOS detectors.
NIC1/NIC2/NIC3
11330
NICMOS
Cycle 16 Extended Dark
This
takes a series of Darks in parallel to other instruments.
ACS/SBC
11220
Mapping
the FUV Evolution of Type IIn Supernovae
We
will use the PR110L prism on the SBC of ACS to map the FUV evolution
of
Type IIn supernovae {SNe}. The main goal of this proposal is to
measure
the FUV continuum, Ly-a emission line flux, and their evolution
to
{1} quantify and interpret Type IIn SN transient event detections at
high
redshift and {2} dramatically improve current high redshift Type
IIn
selection criteria. We show that the inherent properties of Type IIn
SNe
facilitate high redshift detection. We will observe the rest-frame
FUV
of a sample of eight 0.02 < z < 0.33 Type IIn SNe to directly
measure
the survival of Ly-alpha photons in low to intermediate redshift
Type
IIn SNe environments and extrapolate the results to high redshift.
We will
calibrate relationships such as FUV luminosity vs. emission line
flux
and measure emission line evolution vs. FUV light evolution. The
intent
is to categorize and improve the utility of Type IIn SNe.
NIC2
11219
Active
Galactic Nuclei in nearby galaxies: a new view of the origin of
the
radio-loud radio- quiet dichotomy?
Using
archival HST and Chandra observations of 34 nearby early-type
galaxies
{drawn from a complete radio selected sample} we have found
evidence
that the radio-loud/radio-quiet dichotomy is directly connected
to
the structure of the inner regions of their host galaxies in the
following
sense: [1] Radio-loud AGN are associated with galaxies with
shallow
cores in their light profiles [2] Radio-quiet AGN are only
hosted
by galaxies with steep cusps. Since the brightness profile is
determined
by the galaxy's evolution, through its merger history, our
results
suggest that the same process sets the AGN flavour. This
provides
us with a novel tool to explore the co-evolution of galaxies
and
supermassive black holes, and it opens a new path to understand the
origin
of the radio-loud/radio-quiet AGN dichotomy. Currently our
analysis
is statistically incomplete as the brightness profile is not
available
for 82 of the 116 targets. Most galaxies were not observed
with
HST, while in some cases the study is obstructed by the presence of
dust
features. We here propose to perform an infrared NICMOS snapshot
survey
of these 82 galaxies. This will enable us to i} test the reality
of the
dichotomic behaviour in a substantially larger sample; ii} extend
the
comparison between radio-loud and radio-quiet AGN to a larger range
of
luminosities.
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.
NIC3
11195
Morphologies
of the Most Extreme High-Redshift Mid-IR-luminous Galaxies
II:
The `Bump' Sources
The
formative phase of some of the most massive galaxies may be
extremely
luminous, characterized by intense star- and AGN-formation.
Till
now, few such galaxies have been unambiguously identified at high
redshift,
and thus far we have been restricted to studying the
low-redshift
ultraluminous infrared galaxies as possible analogs. We
have
recently discovered a sample of objects which may indeed represent
this
early phase in galaxy formation, and are undertaking an extensive
multiwavelength
study of this population. These objects are optically
extremely
faint {R>26} but nevertheless bright at mid-infrared
wavelengths
{F[24um] > 0.5 mJy}. Mid-infrared spectroscopy with
Spitzer/IRS
reveals that they have redshifts z~2, implying luminosities
~1E13
Lsun. Their mid-IR SEDs fall into two broad, perhaps overlapping,
categories.
Sources with brighter F[24um] exhibit power-law SEDs and SiO
absorption
features in their mid-IR spectra characteristic of AGN,
whereas
those with fainter F[24um] show a "bump" characteristic of the
redshifted
1.6um peak from a stellar population, and PAH emission
characteristic
of starformation. We have begun obtaining HST images of
the
brighter sources in Cycle 15 to obtain identifications and determine
kpc-scale
morphologies for these galaxies. Here, we aim to target the
second
class {the "bump" sources} with the goal of determining if these
constitute
morphologically different objects, or simply a "low-AGN"
state
of the brighter class. The proposed observations will help us
determine
whether these objects are merging systems, massive obscured
starbursts
{with obscuration on kpc scales!} or very reddened {locally
obscured}
AGN hosted by intrinsically low-luminosity galaxies.
WFPC2
11187
A
Deep Search for Martian Dust Rings
It
has been long suspected that Mars is encircled by two faint rings of
dust,
one originating from each of its moons Phobos and Deimos. Similar
dust
rings are associated with many of the small, inner moons orbiting
Jupiter,
Saturn, Uranus and Neptune. On December 31, 2007, Earth will
pass
through Mars' equatorial plane just a week after its December 24
opposition,
providing an exceedingly rare opportunity to image the rings
under
nearly ideal viewing geometry. The next equivalent viewing
opportunity
occurs in 2022. Using the Wide Fields of WFPC2 and a highly
optimized
observing plan, we expect to be able to detect rings with
edge-on
reflectivities of ~ 10^-8, which is at or below the level where
most
dynamicists expect rings to be visible. This is a factor of 10-30
more
sensitive than the detection limit we achieved during a slightly
inferior
viewing opportunity in 2001. The rings have been predicted to
show
some interesting dynamical properties, including large asymmetries
and
inclinations. A positive detection will test these predictions,
serving
as an effective test of dynamical models developed to account
for
the properties of other faint planetary rings as well. With such a
stringent
limit, even a negative result will be of considerable
interest,
challenging dynamicists to explain the remarkably low density
of
dust within the Martian system.
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
11176
Location
and the Origin of Short Gamma-Ray Bursts
During
the past decade extraordinary progress has been made in
determining
the origin of long-duration gamma-ray bursts. It has been
conclusively
shown that these objects derive from the deaths of massive
stars.
Nonetheless, the origin of their observational cousins,
short-duration
gamma-ray bursts {SGRBs} remains a mystery. While SGRBs
are
widely thought to result from the inspiral of compact binaries, this
is
a conjecture. A number of hosts of SGRBs have been identified, and
have
been used by some to argue that SGRBs derive primarily from an
ancient
population {~ 5 Gyr}; however, it is not known whether this
conclusion
more accurately reflects selection biases or astrophysics.
Here
we propose to employ a variant of a technique that we pioneered and
used
to great effect in elucidating the origins of long-duration bursts.
We
will examine the degree to which SGRB locations trace the red or blue
light
of their hosts, and thus old or young stellar populations. This
approach
will allow us to study the demographics of the SGRB population
in
a manner largely free of the distance dependent selection effects
which
have so far bedeviled this field, and should give direct insight
into
the age of the SGRB progenitor population.
NC3
11165
The
Radius of the "Super-Neptune" HD 149026b
Current
measurements suggest that the transiting exoplanet HD 149026b is
a
"super-
of
such a planet is a major challenge to planet formation theories. We
propose
to place the radius measurement on much firmer footing, by
obtaining
a NICMOS light curve with 0.4 mmag precision and 13 sec
cadence.
We will improve the radius measurement by a factor of 2.3, and
more
importantly, the result will be more robust because we will
determine
the stellar radius directly from the data. Numerous attempts
to
do this from the ground have failed.
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.
WFPC2/NIC3
11144
Building
on the Significant NICMOS Investment in GOODS: A Bright,
Wide-Area
Search for z>=7 Galaxies
One
of the most exciting frontiers in observational cosmology has been
to trace
the buildup and evolution of galaxies from very early times.
While
hierarchical theory teaches us that the star formation rate in
galaxies
likely starts out small and builds up gradually, only recently
has
it been possible to see evidence for this observationally through
the
evolution of the LF from z~6 to z~3. Establishing that this build up
occurs
from even earlier times {z~7-8} has been difficult, however, due
to
the small size of current high-redshift z~7-8 samples -- now
numbering
in the range of ~4-10 sources. Expanding the size of these
samples
is absolutely essential, if we are to push current studies of
galaxy
buildup back to even earlier times. Fortunately, we should soon
be
able to do so, thanks to ~50 arcmin**2 of deep {26.9 AB mag at 5
sigma}
NICMOS 1.6 micron data that will be available over the two ACS
GOODS
fields as a result of one recent 180-orbit ACS backup program and
a
smaller program. These data will nearly triple the deep near-IR
imaging
currently available and represent a significant resource for
finding
and characterizing the brightest high-redshift sources -- since
high-redshift
candidates can be easily identified in these data from
their
red z-H colours. Unfortunately, the red z-H colours of these
candidates
are not sufficient to determine that these sources are at
z>=7,
and it is important also to have deep photometry at 1.1 microns.
To
obtain this crucial information, we propose to follow up each of
these
z- H dropouts with NICMOS at 1.1 microns to determine which are at
high
redshift and thus significantly expand our sample of luminous, z>=7
galaxies.
Since preliminary studies indicate that these candidates occur
in
only 30% of the NIC3 fields, our follow-up strategy is ~3 times as
efficient
as without this preselection and 9 times as efficient as a
search
in a field with no pre-existing data. In total, we expect to
identify
~8 luminous z-dropouts and possibly ~2 z~10 J-dropouts as a
result
of this program, more than tripling the number currently known.
The
increased sample sizes are important if we are to solidify current
conclusions
about galaxy buildup and the evolution of the LF from z~8.
In
addition to the high redshift science, these deep 1.1 micron data
would
have significant value for many diverse endeavors, including {1}
improving
our constraints on the stellar mass density at z~7-10 and {2}
doubling
the number of galaxies at z~6 for which we can estimate dust
obscuration.
WFPC2
11130
AGNs
with Intermediate-mass Black Holes: Testing the Black Hole-Bulge
Paradigm,
Part II
The
recent progress in the study of central black holes in galactic
nuclei
has led to a general consensus that supermassive {10^6-10^9 solar
mass}
black holes are closely connected with the formation and
evolutionary
history of large galaxies, especially their bulge
component.
Two outstanding issues, however, remain unresolved. Can
central
black holes form in the absence of a bulge? And does the mass
function
of central black holes extend below 10^6 solar masses?
Intermediate-mass
black holes {<10^6 solar masses}, if they exist, may
offer
important clues to the nature of the seeds of supermassive black
holes.
Using the SDSS, our group has successfully uncovered a new
population
of AGNs with intermediate-mass black holes that reside in
low-luminosity
galaxies. However, very little is known about the
detailed
morphologies or structural parameters of the host galaxies
themselves,
including the crucial question of whether they have bulges
or
not. Surprisingly, the majority of the targets of our Cycle 14 pilot
program
have structural properties similar to dwarf elliptical galaxies.
The
statistics from this initial study, however, are really too sparse
to
reach definitive conclusions on this important new class of black
holes.
We wish to extend this study to a larger sample, by using the
Snapshot
mode to obtain WFPC2 F814W images from a parent sample of 175
AGNs
with intermediate-mass black holes selected from our final SDSS
search.
We are particularly keen to determine whether the hosts contain
bulges,
and if so, how the fundamental plane properties of the host
depend
on the mass of their central black holes. We will also
investigate
the environment of this unique class of AGNs.
WFPC2
11113
Binaries
in the Kuiper Belt: Probes of Solar System Formation and
Evolution
The
discovery of binaries in the Kuiper Belt and related small body
populations
is powering a revolutionary step forward in the study of
this
remote region. Three quarters of the known binaries in the Kuiper
Belt
have been discovered with HST, most by our snapshot surveys. The
statistics
derived from this work are beginning to yield surprising and
unexpected
results. We have found a strong concentration of binaries
among
low-inclination Classicals, a possible size cutoff to binaries
among
the Centaurs, an apparent preference for nearly equal mass
binaries,
and a strong increase in the number of binaries at small
separations.
We propose to continue this successful program in Cycle 16;
we
expect to discover at least 13 new binary systems, targeted to
subgroups
where these discoveries can have the greatest impact.
NIC3
11107
Imaging
of Local Lyman Break Galaxy Analogs: New Clues to Galaxy
Formation
in the Early Universe
We have
used the ultraviolet all-sky imaging survey currently being
conducted
by the Galaxy Evolution Explorer {GALEX} to identify for the
first
time a rare population of low- redshift starbursts with properties
remarkably
similar to high-redshift Lyman Break Galaxies {LBGs}. These
"compact
UV luminous galaxies" {UVLGs} resemble LBGs in terms of size,
SFR,
surface brightness, mass, metallicity, kinematics, dust, and color.
The
UVLG sample offers the unique opportunity of investigating some very
important
properties of LBGs that have remained virtually inaccessible
at
high redshift: their morphology and the mechanism that drives their
star
formation. Therefore, in Cycle 15 we have imaged 7 UVLGs using ACS
in
order to 1} characterize their morphology and look for signs of
interactions
and mergers, and 2} probe their star formation histories
over
a variety of timescales. The images show a striking trend of
small-scale
mergers turning large amounts of gas into vigorous
starbursts
{a process referred to as dissipational or "wet" merging}.
Here,
we propose to complete our sample of 31 LBG analogs using the
ACS/SBC
F150LP {FUV} and WFPC2 F606W {R} filters in order to create a
statistical
sample to study the mechanism that triggers star formation
in
UVLGs and its implications for the nature of LBGs. Specifically, we
will
1} study the trend between galaxy merging and SFR in UVLGs, 2}
artificially
redshift the FUV images to z=1-4 and compare morphologies
with
those in similarly sized samples of LBGs at the same rest-frame
wavelengths
in e.g. GOODS, UDF, and COSMOS, 3} determine the presence
and
morphology of significant stellar mass in "pre-burst" stars, and 4}
study
their immediate environment. Together with our Spitzer
{IRAC+MIPS},
GALEX, SDSS and radio data, the HST observations will form
a
unique union of data that may for the first time shed light on how the
earliest
major episodes of star formation in high redshift galaxies came
about.
This proposal was adapted from an ACS HRC+WFC proposal to meet
the
new Cycle 16 observing constraints, and can be carried out using the
ACS/SBC
and WFPC2 without compromising our original science goals.
NIC3
11080
Exploring
the Scaling Laws of Star Formation
As
a variety of surveys of the local and distant Universe are
approaching
a full census of galaxy populations, our attention needs to
turn
towards understanding and quantifying the physical mechanisms that
trigger
and regulate the large-scale star formation rates {SFRs} in
galaxies.
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.
WFPC2
11070
WFPC2
CYCLE 15 Standard Darks - part II
This
dark calibration program obtains dark frames every week in order to
provide
data for the ongoing calibration of the CCD dark current rate,
and
to monitor and characterize the evolution of hot pixels. Over an
extended
period these data will also provide a monitor of radiation
damage
to the CCDs.
WFPC2
11040
Geometric
Distortion / Astrometry Closeout
These
observations will serve as a final characterization of the
geometric
distortion and astrometric calibration. The Omega-Cen inner
calibration
field is used. Filters F300W, F555W, and F814W are observed
at
5 roll angles spanning 180 degrees; F218W is observed at a single
roll
angle.
WFPC2
11024
WFPC2
CYCLE 15 INTERNAL MONITOR
This
calibration proposal is the Cycle 15 routine internal monitor for
WFPC2,
to be run weekly to monitor the health of the cameras. A variety
of
internal exposures are obtained in order to provide a monitor of the
integrity
of the CCD camera electronics in both bays {both gain 7 and
gain
15 -- to test stability of gains and bias levels}, a test for
quantum
efficiency in the CCDs, and a monitor for possible buildup of
contaminants
on the CCD windows. These also provide raw data for
generating
annual super-bias reference files for the calibration
pipeline.
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
stability of the cross
filter calibration.
FGS
10928
Calibrating
Cosmological Chronometers: White Dwarf Masses
We
propose to use HST/FGS1R to determine White Dwarf {WD} masses. The
unmatched
resolving power of HST/FGS1R will be utilized to follow up
four
selected WD binary pairs. This high precision obtained with
HST/FGS1R
simply cannot be equaled by any ground based technique. This
proposed
effort complements that done by CoI Nelan in which a sample of
WDs
is being observed with HST/FGS1R. This proposal will dramatically
increase
the number of WDs for which dynamical mass measurements are
possible,
enabling a better calibration of the WD mass-radius relation,
cooling
curves, initial to final mass relations, and ultimately giving
important
clues to the star formation history of our Galaxy and the age
of
its disk as well as in other galaxies.
NIC3/WFPC2
10921
Tangential
Velocities of Objects in the Orion Nebula and Locating the
Embedded
Outflow Sources.
The
Orion Nebula is arguably the Rosetta Stone for studying a very young
star
cluster and how the radiation and outflowing plasma from its stars
interact
with ambient material. It has been the subject of numerous HST
imaging
studies, which means that there is good opportunity for
determining
tangential velocities by obtaining second epoch images
during
Cycle 15, which may be the last cycle for which the WFPC2 is
available.
These velocities in the plane-of-the-sky will allow us to
determine
the patterns of outflow from micro-jets smaller than the Solar
System
to jet driven shocks more than a parsec from their sources.
Combined
with radial velocities, we'll obtain spatial velocities, which
are
critical to determining where the embedded sources are located that
produce
the numerous HH objects coming from the Orion-S and BN-KL
regions.
We'll also be able to determine the physics that is operating
in
the LL Ori type of outflows {where a bipolar jet is being distorted
by
a slow wind coming from the nebula}. We will also be able to search
for
runaway stars caused by the disintegration of young multiple-star
systems.
All of this is possible because the long-time base of the WFPC2
and
ACS observations allow a new level of astrometric precision to be
obtained
and to be done efficiently by making coordinated parallel
observations
with all images.
WFPC2
10915
ACS
Nearby Galaxy Survey
Existing
HST observations of nearby galaxies comprise a sparse and
highly
non-uniform archive, making comprehensive comparative studies
among
galaxies essentially impossible. We propose to secure HST's
lasting
impact on the study of nearby galaxies by undertaking a
systematic,
complete, and carefully crafted imaging survey of ALL
galaxies
in the Local Universe outside the Local Group. The resulting
images
will allow unprecedented measurements of: {1} the star formation
history
{SFH} of a >100 Mpc^3 volume of the Universe with a time
resolution
of Delta[log{t}]=0.25; {2} correlations between spatially
resolved
SFHs and environment; {3} the structure and properties of thick
disks
and stellar halos; and {4} the color distributions, sizes, and
specific
frequencies of globular and disk clusters as a function of
galaxy
mass and environment. To reach these goals, we will use a
combination
of wide-field tiling and pointed deep imaging to obtain
uniform
data on all 72 galaxies within a volume-limited sample extending
to
~3.5 Mpc, with an extension to the M81 group. For each galaxy, the
wide-field
imaging will cover out to ~1.5 times the optical radius and
will
reach photometric depths of at least 2 magnitudes below the tip of
the
red giant branch throughout the limits of the survey volume. One
additional
deep pointing per galaxy will reach SNR~10 for red clump
stars,
sufficient to recover the ancient SFH from the color-magnitude
diagram.
This proposal will produce photometric information for ~100
million
stars {comparable to the number in the SDSS survey} and uniform
multi-
color images of half a square degree of sky. The resulting
archive
will establish the fundamental optical database for nearby
galaxies,
in preparation for the shift of high- resolution imaging to
the
near-infrared.
WFPC2
10873
The
Radio-quiet Jet Flow in Markarian 34
The
properties of AGN jet flows are notoriously difficult to ascertain.
We
are currently studying jets in Seyferts by combining emission-line
diagnostics
with radio observations. We have devised a method of
analysis
which -- with only modest and reasonable assumptions -- leads
to
a physical description of the jet flow: its mass, momentum and energy
flux,
along with its density, velocity and Mach number. We have applied
this
method to a rich dataset on Markarian 78 and discovered that its
jet
is very weak, slow, and dense relative to the kind of jets found in
radio
loud AGN {Whittle \& Wilson 2004, Whittle et al 2005, 2006}. Such
a
difference between radio quiet and radio loud jet flows would be a
major
result -- if it were found to be generally true. We have more
modest
observations of a further six Seyferts with jets, but only one of
these
-- Mkn 34 -- approaches Mkn 78 as a clean enough case to allow our
full
analysis. Our existing VLA and STIS data are excellent, but the HST
archive
emission-line and continuum images are of poor quality and low
resolution.
We are requesting just 3 orbits to obtain higher S/N images
at
high resolution {ACS/HRC} in [OIII] 5007, [OII] 3727, green and red
continuum,
bringing the total dataset up to a par with that of Mkn 78.
We
will then be able to apply our full analysis to determine the nature
of
the jet flow in this second radio quiet AGN.
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
follow
up 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.
WFPC2
10812
Space
Motions for the Draco and Sextans Dwarf Spheroidal Galaxies
We
will use the powerful astrometric capabilities of HST to measure
proper
motions for the Draco and Sextans dwarf spheroidal galaxies that
will
yield tangential velocities accurate to about 30 km/s. These two
galaxies
are the last inside a galactocentric radius of 200~kpc without
measured
proper motions. Knowing their orbits is critical for our
understanding
of the low-luminosity satellites of the Milky Way. In
particular
they are critical for understanding why Ursa Minor has
survived
tidal disruption on its plunging orbit and how Carina formed a
large
intermediate-age stellar population despite its small mass.
WFPC2
10787
Modes
of Star Formation and Nuclear Activity in an Early Universe
Laboratory
Nearby
compact galaxy groups are uniquely suited to exploring the
mechanisms
of star formation amid repeated and ongoing gravitational
encounters,
conditions similar to those of the high redshift universe.
These
dense groups host a variety of modes of star formation, and they
enable
fresh insights into the role of gas in galaxy evolution. With
Spitzer
mid-IR observations in hand, we have begun to obtain high
quality,
multi-wavelength data for a well- defined sample of 12 nearby
{<4500km/s}
compact groups covering the full range of evolutionary
stages.
Here we propose to obtain sensitive BVI images with the ACS/WFC,
deep
enough to reach the turnover of the globular cluster luminosity
function,
and WFPC2 U-band and ACS H-alpha images of Spitzer-identified
regions
hosting the most recent star formation. In total, we expect to
detect
over 1000 young star clusters forming inside and outside
galaxies,
more than 4000 old globular clusters in >40 giant galaxies
{including
16 early-type galaxies}, over 20 tidal features,
approximately
15 AGNs, and intragroup gas in most of the 12 groups.
Combining
the proposed ACS images with Chandra observations, UV GALEX
observations,
ground-based H-alpha imaging, and HI data, we will conduct
a
detailed study of stellar nurseries, dust, gas kinematics, and AGN.
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
11113
- Loss of Lock while LOS
HST lost fine lock on FGS 1 and 2 at 356/00:27:52. P4TAKDAT (Take
Data
Flag) went down at that time, causing four ACS 779 Status Buffer
Messages ("Fold Mechanism Move Was Blocked") to occur at
00:28:00,
00:37:54, 00:47:50 and 00:57:44. Upon acquisition of signal at
00:43:00
QF1STOPF was observed to be flagging.
11114
- GSacq (1,3,3) resulted in Fine Lock Back-up (1,0,1) using FGS 1
At 356/13:00:39, GSAcq (1,3,3) scheduled from 356/12:57:09 -
13:04:24
had failed to Fine Lock Back-up (1,0,1) using FGS 1, due to stop
flags
QF3STOPF and QSTOP on FGS 3. Pre-acquisition OBAD #1 had an RSS
value of
472.38 arc seconds. Pre-acquisition OBAD #2 had an RSS value of
24.87
arc seconds. Post-acquisition OBAD Map had an RSS value of 11.01
arc
seconds.
11116
- REacq (1,3,1) fine lock backup on FGS 1
REACQ(1,3,1) at 357/06:26:02 acquired in fine lock backup on FGS 1
only,
with QF3STOPF and QSTOP flags set on FGS 3. No other flags were
seen.
Initial GSACQ(1,3,1) at 03:15:01 and REACQ at 04:50:03 were
successful.
11117
- GSacq (1,2,2) failed, Search Radius Limit exceeded on FGS 1 @ 358/0320z
GSACQ(1,2,2) at 03:20:53 failed with search radius limit exceeded
on FGS
1 at 03:26:40. One "A05" ESB message (FGS Coarse Track
failed- search
Radius Limit exceeded) was received at 03:26:50.
OBADs prior to GSACQ had RSS errors of 1653.05 and 27.31
arcseconds,
OBAD map following GSACQ at 03:28:57 had RSS error of 572.46
arcseconds.
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL FAILURE TIMES
FGS
GSacq
40
39
FGS
REacq
30
30
OBAD
with Maneuver 140
139
LOSS
of
LOCK
@
356/0027z
SIGNIFICANT
EVENTS: (None)