HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5072
PERIOD
COVERED: 5am April 9 - 5am April 12, 2010 (DOY 099/09:00z-102/09:00z)
OBSERVATIONS
SCHEDULED
ACS/WFC
11995
CCD
Daily Monitor (Part 2)
This
program comprises basic tests for measuring the read noise and dark
current
of the ACS WFC and for tracking the growth of hot pixels. The
recorded
frames are used to create bias and dark reference images for
science
data reduction and calibration. This program will be executed
four
days per week (Mon, Wed, Fri, Sun) for the duration of Cycle 17. To
facilitate
scheduling, this program is split into three proposals. This
proposal
covers 320 orbits (20 weeks) from 1 February 2010 to 20 June
2010.
WFC3/IR/S/C
11929
IR
Dark Current Monitor
Analyses
of ground test data showed that dark current signals are more
reliably
removed from science data using darks taken with the same
exposure
sequences as the science data, than with a single dark current
image
scaled by desired exposure time. Therefore, dark current images
must
be collected using all sample sequences that will be used in
science
observations. These observations will be used to monitor changes
in
the dark current of the WFC3-IR channel on a day-to-day basis, and to
build
calibration dark current ramps for each of the sample sequences to
be
used by Gos in Cycle 17. For each sample sequence/array size
combination,
a median ramp will be created and delivered to the
calibration
database system (CDBS).
WFC3/UVIS
11908
Cycle
17: UVIS Bowtie Monitor
Ground
testing revealed an intermittent hysteresis type effect in the
UVIS
detector (both CCDs) at the level of ~1%, lasting hours to days.
Initially
found via an unexpected bowtie-shaped feature in flatfield
ratios,
subsequent lab tests on similar e2v devices have since shown
that
it is also present as simply an overall offset across the entire
CCD,
i.e., a QE offset without any discernable pattern. These lab tests
have
further revealed that overexposing the detector to count levels
several
times full well fills the traps and effectively neutralizes the
bowtie.
Each visit in this proposal acquires a set of three 3x3 binned
internal
flatfields: the first unsaturated image will be used to detect
any
bowtie, the second, highly exposed image will neutralize the bowtie
if
it is present, and the final image will allow for verification that
the
bowtie is gone.
WFC3/UVIS
11905
WFC3
UVIS CCD Daily Monitor
The
behavior of the WFC3 UVIS CCD will be monitored daily with a set of
full-frame,
four-amp bias and dark frames. A smaller set of 2Kx4K
subarray
biases are acquired at less frequent intervals throughout the
cycle
to support subarray science observations. The internals from this
proposal,
along with those from the anneal procedure (Proposal 11909),
will
be used to generate the necessary superbias and superdark reference
files
for the calibration pipeline (CDBS).
STIS/MA1/MA2
11857
STIS
Cycle 17 MAMA Dark Monitor
This
proposal monitors the behavior of the dark current in each of the
MAMA
detectors.
The
basic monitor takes two 1380s ACCUM darks each week with each
detector.
However, starting Oct 5, pairs are only included for weeks
that
the LRP has external MAMA observations planned. The weekly pairs of
exposures
for each detector are linked so that they are taken at
opposite
ends of the same SAA free interval. This pairing of exposures
will
make it easier to separate long and short term temporal variability
from
temperature dependent changes.
For
both detectors, additional blocks of exposures are taken once every
six
months. These are groups of five 1314s FUV-MAMA Time-Tag darks or
five
3x315s NUV ACCUM darks distributed over a single SAA-free interval.
This
will give more information on the brightness of the FUV MAMA dark
current
as a function of the amount of time that the HV has been on, and
for
the NUV MAMA will give a better measure of the short term
temperature
dependence.
STIS/CC
11847
CCD
Bias Monitor-Part 2
Monitor
the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1,
and
1x1 at gain = 4, to build up high-S/N superbiases and track the
evolution
of hot columns.
STIS/CC
11845
CCD
Dark Monitor Part 2
Monitor
the darks for the STIS CCD.
COS/NUV/FUV
11728
The
Impact of Starbursts on the Gaseous Halos of Galaxies
Perhaps
the most important (yet uncertain) aspects of galaxy evolution
are
the processes by which galaxies accrete gas and by which the
resulting
star formation and black hole growth affects this accreting
gas.
It is believed that both the form of the accretion and the nature
of
the feedback change as a function of the galaxy mass. At low mass the
gas
comes in cold and the feedback is provided by massive stars. At high
mass,
the gas comes in hot, and the feedback is from an AGN. The
changeover
occurs near the mass where the galaxy population transitions
from
star-forming galaxies to red and dead ones. The population of red
and
dead galaxies is building with cosmic time, and it is believed that
feedback
plays an important role in this process: shutting down star
formation
by heating and/or expelling the reservoir of cold halo gas. To
investigate
these ideas, we propose to use COS far-UV spectra of
background
QSOs to measure the properties of the halo gas in a sample of
galaxies
near the transition mass that have undergone starbursts within
the
past 100 Myr to 1 Gyr. The galactic wind associated with the
starburst
is predicted to have affected the properties of the gaseous
halo.
To test this, we will compare the properties of the halos of the
post-starburst
galaxies to those of a control sample of galaxies matched
in
mass and QSO impact parameter. Do the halos of the post-starburst
galaxies
show a higher incidence rate of Ly-Alpha and metal
absorption-lines?
Are the kinematics of the halo gas more disturbed in
the
post-starbursts? Has the wind affected the ionization state and/or
the
metallicity of the halo? These data will provide fresh new insights
into
the role of feedback from massive stars on the evolution of
galaxies,
and may also offer clues about the properties of the QSO metal
absorption-line
systems at high-redshift .
ACS/WFC
11715
The
Luminous Galactic Cepheid RS Puppis: A Geometric Distance from its
Nested
Light Echoes
RS
Puppis is one of the most luminous Cepheids in the Milky Way (P =
41.4
days) and an analog of the bright Cepheids used to measure
extragalactic
distances. An accurate distance would help anchor the
zero-point
of the bright end of the period-luminosity relation, but at a
distance
of about 2 kpc it is too far away for a trigonometric parallax
with
existing instrumentation.
RS
Pup is unique in being surrounded by a reflection nebula, whose
brightness
varies as pulses of light from the Cepheid propagate
outwards.
Members of our team have used ground-based imaging of the
nebula
to derive phase lags in the light variations of individual
features
in the nebula, and have inferred a seemingly very precise
geometric
distance to the star. However, there is an unavoidable
ambiguity
involving the cycle counts, which was resolved by assuming
that
the features lie in the plane of the sky. If this assumption is
incorrect,
a large systematic error would be introduced into the
distance
measurement.
We
show that polarimetric imaging using the high spatial resolution of
ACS/WFC
and its ability to image close to the star can resolve this
ambiguity
and yield a reliable geometric distance to RS Pup. We will
also
obtain a wide-field multicolor image of the nebula, in order to
study
its morphology and the mass-loss history of the Cepheid.
WFC3/UV/IR
11709
Stretching
the Diversity of Cosmic Explosions: The Supernovae of
Gamma-ray
Bursts
While
the association between gamma-ray bursts (GRBs) and massive stars
is
robust, there is a large diversity of properties among supernovae
(SNe)
associated with GRBs. The converse is also true: Several recent
events
show that there is a large brightness range among high energy
transients
associated with SNe. As part of a comprehensive program, we
propose
to use HST in order to search for and characterize the SNe
associated
with GRB.
HST
offers the means to cleanly separate the light curve of the GRB
afterglow
from the supernova, and to remove the contamination from the
host
galaxy, opening a clear path to the fundamental parameters of the
SN,
and thence to the progenitor. From these observations, we will
determine
the absolute magnitude at maximum, the shape of the spectral
energy
distribution, and any change over time of the energy
distribution.
We will also measure the rate of decay of the exponential
tail.
Merged
with the ground-based data that we will obtain for each event, we
will
be able to compare our data set to models and constrain the energy
of
the explosion, the mass of the ejecta and the mass of Nickel
synthesized
during the explosion. These results will shed light on the
apparent
variety of supernovae associated with gamma-ray bursts and
X-ray
flashes, and on the relation between these SNe and other, more
common,
types of core-collapse explosions.
STIS/CCD
11703
The
Nature of the Black Hole in a NGC 4472 Globular Cluster and the
Origin
of Its Broad [OIII] Emission
We
propose to use STIS to obtain optical spectroscopy at high spatial
resolution
of the black hole-hosting globular cluster RZ2109 in the
Virgo
elliptical NGC 4472. This is motivated by our very recent
discovery
broad [OIII] 4959, 5007 emission with a width of several
thousand
km/s in this globular cluster. The STIS spectroscopy will
enable
us to determine if the very broad [OIII] emission is due to
material
driven at high velocity from the central accreting black hole
across
the globular cluster, or if the velocity widths are due to
gravitational
motions very close to the central black hole. In the
former
case, the [OIII] emission should extend over a few-tenths of an
arcsecond
and be spatially resolved by HST and STIS, while in the latter
case,
the emission lines will be unresolved. Distinguishing between
these
two possibilities will allow us to - 1) determine whether the
black
hole is of intermediate mass or a stellar mass, and thereby
whether
the black hole mass - sigma relation extends to globular cluster
masses,
2) test models of black hole formation and evolution in dense
stellar
systems, and 3) address the nature of accretion in the high
luminosity
black-hole X-ray source, and constrain the feedback processes
from
luminous black holes into their surrounding medium in dense stellar
systems.
COS/FUV
11699
On
the Evolutionary Status of Extremely Hot Helium Stars - are the O(He)
Stars
Successors of the R CrB Stars?
We
propose UV spectroscopy of the four unique post-AGB stars of spectral
type
O(He) in order to understand the origin of their peculiar surface
abundances.
These stars are the only known amongst the hottest post-AGB
stars
(effective temperatures > 100, 000 K) whose atmospheres are
composed
of almost pure helium. This chemistry markedly differs from
that
of the hydrogen-deficient post-AGB evolutionary sequence with
objects
which have carbon dominated atmospheres (PG1159 stars and
Wolf-Rayet
central stars).
While
PG1159 and Wolf-Rayet stars are the result of a late helium-shell
flash,
this scenario cannot explain the O(He) stars. Instead, they are
possibly
double-degenerate mergers. We speculate that the four O(He)
stars
represent evolved RCrB stars, which also have helium-dominated
atmospheres.
We aim to determine the C, N, O, and Si abundances
precisely,
in order to proof this evolutionary link.
WFC3/IR
11696
Infrared
Survey of Star Formation Across Cosmic Time
We
propose to use the unique power of WFC3 slitless spectroscopy to
measure
the evolution of cosmic star formation from the end of the
reionization
epoch at z>6 to the close of the galaxy- building era at
z~0.3.Pure
parallel observations with the grisms have proven to be
efficient
for identifying line emission from galaxies across a broad
range
of redshifts. The G102 grism on WFC3 was designed to extend this
capability
to search for Ly-alpha emission from the first galaxies.
Using
up to 250 orbits of pure parallel WFC3 spectroscopy, we will
observe
about 40 deep (4-5 orbit) fields with the combination of G102
and
G141, and about 20 shallow (2-3 orbit) fields with G141 alone.
Our
primary science goals at the highest redshifts are: (1) Detect Lya
in
~100 galaxies with z>5.6 and measure the evolution of the Lya
luminosity
function, independent of of cosmic variance; 2) Determine the
connection
between emission line selected and continuum-break selected
galaxies
at these high redshifts, and 3) Search for the proposed
signature
of neutral hydrogen absorption at re-ionization. At
intermediate
redshifts we will (4) Detect more than 1000 galaxies in
Halpha
at 0.5<z<1.8 to measure the evolution of the extinction-corrected
star
formation density across the peak epoch of star formation. This is
over
an order-of-magnitude improvement in the current statistics, from
the
NICMOS Parallel grism survey. (5) Trace ``cosmic downsizing" from
0.5<z<2.2;
and (6) Estimate the evolution in reddening and metallicty in
star-
forming galaxies and measure the evolution of the Seyfert
population.
For hundreds of spectra we will be able to measure one or
even
two line pair ratios -- in particular, the Balmer decrement and
[OII]/[OIII]
are sensitive to gas reddening and metallicity. As a bonus,
the
G102 grism offers the possibility of detecting Lya emission at
z=7-8.8.
To
identify single-line Lya emitters, we will exploit the wide
0.8--1.9um
wavelength coverage of the combined G102+G141 spectra. All
[OII]
and [OIII] interlopers detected in G102 will be reliably separated
from
true LAEs by the detection of at least one strong line in the G141
spectrum,
without the need for any ancillary data. We waive all
proprietary
rights to our data and will make high-level data products
available
through the ST/ECF.
COS/FUV
11686
The
Cosmological Impact of AGN Outflows: Measuring Absolute Abundances
and
Kinetic Luminosities
AGN
outflows are increasingly invoked as a major contributor to the
formation
and evolution of supermassive black holes, their host
galaxies,
the surrounding IGM, and cluster cooling flows. Our HST/COS
proposal
will determine reliable absolute chemical abundances in six AGN
outflows,
which influences several of the processes mentioned above. To
date
there is only one such determination, done by our team on Mrk 279
using
16 HST/STIS orbits and 100 ksec of FUSE time. The advent of COS
and
its high sensitivity allows us to choose among fainter objects at
redshifts
high enough to preclude the need for FUSE. This will allow us
to
determine the absolute abundances for six AGN (all fainter than Mrk
279)
using only 40 HST COS orbits. This will put abundances studies in
AGN
on a firm footing, an elusive goal for the past four decades. In
addition,
prior FUSE observations of four of these targets indicate that
it
is probable that the COS observations will detect troughs from
excited
levels of C III. These will allow us to measure the distances of
the
outflows and thereby determine their kinetic luminosity, a major
goal
in AGN feedback research.
11686( 7) - 25-Sep-2009 13:44:14 - [ 2]
We
will use our state of the art column density extraction methods and
velocity-dependent
photoionization models to determine the abundances
and
kinetic luminosity. Previous AGN outflow projects suffered from the
constraints
of deciding what science we could do using ONE of the
handful
of bright targets that were observable. With COS we can choose
the
best sample for our experiment. As an added bonus, most of the
spectral
range of our targets has not been observed previously, greatly
increasing
the discovery phase space.
WFC3/ACS/IR
11677
Is
47 Tuc Young? Measuring its White Dwarf Cooling Age and Completing a
Hubble
Legacy
With
this proposal we will firmly establish the age of 47 Tuc from its
cooling
white dwarfs. 47 Tuc is the nearest and least reddened of the
metal-rich
disk globular clusters. It is also the template used for
studying
the giant branches of nearby resolved galaxies. In addition,
the
age sensitive magnitude spread between the main sequence turnoff and
horizontal
branch is identical for 47 Tuc, two bulge globular clusters
and
the bulge field population. A precise relative age constraint for 47
Tuc,
compared to the halo clusters M4 and NGC 6397, both of which we
recently
dated via white dwarf cooling, would therefore constrain when
the
bulge formed relative to the old halo globular clusters. Of
particular
interest is that with the higher quality ACS data on NGC
6397,
we are now capable with the technique of white dwarf cooling of
determining
ages to an accuracy of +/-0.4 Gyrs at the 95% confidence
level.
Ages derived from the cluster turnoff are not currently capable
of
reaching this precision. The important role that 47 Tuc plays in
galaxy
formation studies, and as the metal-rich template for the
globular
clusters, makes the case for a white dwarf cooling age for this
metal-rich
cluster compelling.
Several
recent analyses have suggested that 47 Tuc is more than 2 Gyrs
younger
than the Galactic halo. Others have suggested an age similar to
that
of the most metal poor globular clusters. The current situation is
clearly
uncertain and obviously a new approach to age dating this
important
cluster is required.
With
the observations of 47 Tuc, this project will complete a legacy for
HST.
It will be the third globular cluster observed for white dwarf
cooling;
the three covering almost the full metallicity range of the
cluster
system. Unless JWST has its proposed bluer filters (700 and 900
nm)
this science will not be possible perhaps for decades until a large
optical
telescope is again in space. Ages for globular clusters from the
main
sequence turnoff are less precise than those from white dwarf
cooling
making the science with the current proposal truly urgent.
WFC3/UVIS/IR
11662
Improving
the Radius-Luminosity Relationship for Broad-Lined AGNs with a
New
Reverberation Sample
The
radius-luminosity (R-L) relationship is currently the fundamental
basis
for all techniques used to estimate black hole masses in AGNs, in
both
the nearby and distant universe. However, the current R-L
relationship
is based on 34 objects that cover a limited range in black
hole
mass and luminosity. To improve our understanding of black hole
growth
and evolution, the R-L relationship must be extended to cover a
broader
range of black hole masses using the technique known as
reverberation
mapping. To this end, we have been awarded an
unprecedented
64 nights on the Lick Observatory 3-m telescope between
March
24 and May 31, 2008, to spectroscopically monitor 12 AGNs in order
to
measure their black hole masses. To properly determine the
luminosities
of these 12 AGNs, we must correct them for their
host-galaxy
starlight contributions using high-resolution images.
Previous
work by Bentz et al. (2006) has shown that the starlight
correction
to AGN luminosity measurements is an essential component to
interpreting
the R-L relationship. The correction will be substantial
for
each of the 12 sources we will monitor, as the AGNs are relatively
faint
and embedded in nearby, bright galaxies. Starlight corrections are
not
possible with ground-based images, as the PSF and bulge
contributions
become indistinguishable under typical seeing conditions,
and
adaptive optics are not yet operational in the spectral range where
the
corrections are needed. In addition, spectral decompositions are
very
model-dependent and are limited by the degree of accuracy to which
we
understand emission processes and stellar populations in galaxies.
Without
correcting for starlight, we will be unable to apply the results
of
our Spring 2008 campaign to the body of knowledge from previous
reverberation
mapping work. Therefore, we propose to obtain high
resolution,
high dynamic range images of the host galaxies of the 12
AGNs
in our ground-based monitoring sample, as well as one white dwarf
which
will be used as a PSF model.
WFC3/UVIS/IR
11644
A
Dynamical-Compositional Survey of the Kuiper Belt: A New Window Into
the
Formation of the Outer Solar System
The
eight planets overwhelmingly dominate the solar system by mass, but
their
small numbers, coupled with their stochastic pasts, make it
impossible
to construct a unique formation history from the dynamical or
compositional
characteristics of them alone. In contrast, the huge
numbers
of small bodies scattered throughout and even beyond the
planets,
while insignificant by mass, provide an almost unlimited number
of
probes of the statistical conditions, history, and interactions in
the
solar system. To date, attempts to understand the formation and
evolution
of the Kuiper Belt have largely been dynamical simulations
where
a hypothesized starting condition is evolved under the
gravitational
influence of the early giant planets and an attempt is
made
to reproduce the current observed populations. With little
compositional
information known for the real Kuiper Belt, the test
particles
in the simulation are free to have any formation location and
history
as long as they end at the correct point. Allowing compositional
information
to guide and constrain the formation, thermal, and
collisional
histories of these objects would add an entire new dimension
to
our understanding of the evolution of the outer solar system. While
ground
based compositional studies have hit their flux limits already
with
only a few objects sampled, we propose to exploit the new
capabilities
of WFC3 to perform the first ever large-scale
dynamical-compositional
study of Kuiper Belt Objects (KBOs) and their
progeny
to study the chemical, dynamical, and collisional history of the
region
of the giant planets. The sensitivity of the WFC3 observations
will
allow us to go up to two magnitudes deeper than our ground based
studies,
allowing us the capability of optimally selecting a target list
for
a large survey rather than simply taking the few objects that can be
measured,
as we have had to do to date. We have carefully constructed a
sample
of 120 objects which provides both overall breadth, for a general
understanding
of these objects, plus a large enough number of objects in
the
individual dynamical subclass to allow detailed comparison between
and
within these groups. These objects will likely define the core
Kuiper
Belt compositional sample for years to come. While we have many
specific
results anticipated to come from this survey, as with any
project
where the field is rich, our current knowledge level is low, and
a
new instrument suddenly appears which can exploit vastly larger
segments
of the population, the potential for discovery -- both
anticipated
and not -- is extraordinary.
WFC3/UV
11635
In
Search of SNIb/Ic Wolf-Rayet Progenitors and Comparison with Red
Supergiants
(SNII Progenitors) in the Giant ScI Spiral M101
We
propose to test two of the clearest predictions of the theory of
evolution
of massive-star evolution: 1) The formation of Wolf-Rayet
stars
depends strongly on these stars' metallicity (Z), with relatively
fewer
WR stars forming at lower Z, and 2) Wolf-Rayet stars die as Type
Ib
or Ic supernovae. To carry out these tests we propose a deep,
narrowband
imaging survey of the massive star populations in the ScI
spiral
galaxy M101. Just as important, we will test the hypothesis that
Superclusters
like 30 Doradus are always richly populated with WR stars,
and
by implication that these complexes are responsible for the spectral
signatures
of starburst galaxies.
Our
previous HST survey of the HII regions in the ScIII galaxy NGC 2403
suggested
that the distribution of WR stars and RSG is a sensitive
diagnostic
of the recent star-forming history of these large complexes:
young
cores of O and WR stars are surrounded by older halos containing
RSG.
Theory predicts that this must change with metallicity; relatively
fewer
WR stars form at lower Z. A key goal of our proposal is to
directly
test this paradigm in a single galaxy, M101 being the ideal
target.
The abundance gradient across M101 (a factor of 20) suggests
that
relatively many more WR will be found in the inner parts of this
galaxy
than in the outer "suburbs". Second, we note that WR stars are
predicted
to end their lives as core-collapse or pair-instability
supernovae.
The WR population in M101 may be abundant enough for one to
erupt
as a Type Ib or Ic supernova within a generation. The clear a
priori
identification of a WR progenitor would be a major legacy of HST.
Third,
we will also determine if "superclusters", heavily populated by
WR
stars, are common in M101. It is widely claimed that such
Superclusters
produce the integrated spectral signatures of Starburst
galaxies.
We will be able to directly measure the numbers and
emission-line
luminosities of thousands of Wolf Rayet stars located in
hundreds
of M101 Superclusters, and correlate those numbers against the
Supercluster
sizes and luminosities. It is likely (but far from certain)
that
Supercluster sizes and emission-line luminosities are driven by
their
Wolf-Rayet star content. Our sample will be the largest and
best-ever
Supercluster/Wolf Rayet sample, an excellent local proxy for
characterizing
starburst galaxies' Superclusters.
COS/FUV
11625
Beyond
the Classical Paradigm of Stellar Winds: Investigating Clumping,
Rotation
and the Weak Wind Problem in SMC O Stars
SMC
O stars provide an unrivaled opportunity to probe star formation,
evolution,
and the feedback of massive stars in an environment similar
to
the epoch of the peak in star formation history. Two recent
breakthroughs
in the study of hot, massive stars have important
consequences
for understanding the chemical enrichment and buildup of
stellar
mass in the Universe. The first is the realization that rotation
plays
a major role in influencing the evolution of massive stars and
their
feedback on the surrounding environment. The second is a drastic
downward
revision of the mass loss rates of massive stars coming from an
improved
description of their winds. STIS spectroscopy of SMC O stars
combined
with state-of-the-art NLTE analyses has shed new light on these
two
topics. A majority of SMC O stars reveal CNO- cycle processed
material
brought at their surface by rotational mixing. Secondly, the
FUV
wind lines of early O stars provide strong indications of the
clumped
nature of their wind. Moreover, we first drew attention to some
late-O
dwarfs showing extremely weak wind signatures. Consequently, we
have
derived mass loss rates from STIS spectroscopy that are
significantly
lower than the current theoretical predictions used in
evolutionary
models. Because of the limited size of the current sample
(and
some clear bias toward stars with sharp-lined spectra), these
results
must however be viewed as tentative. Thanks to the high
efficiency
of COS in the FUV range, we propose now to obtain
high-resolution
FUV spectra with COS of a larger sample of SMC O stars
to
study systematically rotation and wind properties of massive stars at
low
metallicity. The analysis of the FUV wind lines will be based on our
2D
extension of CMFGEN to model axi-symmetric rotating winds.
STIS/CCD
11606
Dynamical
Hypermassive Black Hole Masses
We
will use STIS spectra to derive the masses of 5 hypermassive black
holes
(HMBHs). From the observed scaling relations defined by less
massive
spheroids, these objects are expected to reside at the nuclei of
host
galaxies with stellar velocity dispersions greater than 320 km/s.
These
5 targets have confirmed regular gas distributions on the scales
of
the black hole sphere of influence. It is essential that the sphere
of
influence is resolved for accurate determinations of black hole mass
(0.1").
These scales cannot be effectively observed from the ground.
Only
two HMBHs have had their masses modeled so far; it is impossible to
draw
any general conclusions about the connections between HMBH mass and
their
massive host galaxies. With these 5 targets we will determine
whether
these HMBHs deviate from the scaling relations defined by less
massive
spheroids. A larger sample will allow us to firmly anchor the
high
mass end of the correlation between black hole mass and stellar
velocity
dispersion, and other scaling relations. Therefore we are also
conducting
a SNAPshot program with which we expect to detect a further
24
HMBH candidates for STIS observation in future cycles. At the
completion
of this project we will have populated the high mass end of
the
scaling relations with the sample sizes enjoyed by less massive
spheroids.
WFC3/ACS/IR
11600
Star
Formation, Extinction, and Metallicity at 0.7<z<1.5: H-Alpha Fluxes
and
Sizes from a Grism Survey of GOODS-N
The
global star formation rate (SFR) is ~10x higher at z=1 than today.
This
could be due to drastically elevated SFR in some fraction of
galaxies,
such as mergers with central bursts, or a higher SFR across
the
board. Either means that the conditions in z=1 star forming galaxies
could
be quite different from local objects. The next step beyond
measuring
the global SFR is to determine the dependence of SFR,
obscuration,
metallicity, and size of the star-forming region on galaxy
mass
and redshift. However, SFR indicators at z=1 typically apply local
calibrations
for UV, [O II] and far-IR, and do not agree with each other
on
a galaxy-by-galaxy basis. Extinction, metallicity, and dust
properties
cause uncontrolled offsets in SFR calibrations. The great
missing
link is Balmer H-alpha, the most sensitive probe of SFR. We
propose
a slitless WFC3/G141 IR grism survey of GOODS-N, at 2
orbits/pointing.
It will detect Ha+[N II] emission from 0.7<z<1.5, to
L(Ha)
= 1.7 x 10^41 erg/sec at z=1, measuring H-alpha fluxes and sizes
for
> 600 galaxies, and a small number of higher-redshift emitters. This
will
produce: an emission-line redshift survey unbiased by magnitude and
color
selection; star formation rates as a function of galaxy
properties,
e.g. stellar mass and morphology/mergers measured by ACS;
comparisons
of SFRs from H-alpha to UV and far-IR indicators;
calibrations
of line ratios of H-alpha to important nebular lines such
as
[O II] and H-beta, measuring variations in metallicity and extinction
and
their effect on SFR estimates; and the first measurement of scale
lengths
of the H-alpha emitting, star- forming region in a large sample
of
z~1 sources.
WFC3/ACS/UVIS/IR
11570
Narrowing
in on the Hubble Constant and Dark Energy
A
measurement of the Hubble constant to a precision of a few percent
would
be a powerful aid to the investigation of the nature of dark
energy
and a potent "end-to end" test of the present cosmological model.
In
Cycle 15 we constructed a new streamlined distance ladder utilizing
high-
quality type Ia supernova data and observations of Cepheids with
HST
in the near-IR to minimize the dominant sources of systematic
uncertainty
in past measurements of the Hubble constant and reduce its
total
uncertainty to a little under 5%. Here we propose to exploit this
new
route to reduce the remaining uncertainty by more than 30%,
translating
into an equal reduction in the uncertainty of the equation
of
state of dark energy. We propose three sets of observations to reach
this
goal: a mosaic of NGC 4258 with WFC3 in F160W to triple its sample
of
long period Cepheids, WFC3/F160W observations of the 6 ideal SN Ia
hosts
to triple their samples of Cepheids, and observations of NGC 5584
the
host of a new SN Ia, SN 2007af, to discover and measure its Cepheids
and
begin expanding the small set of SN Ia luminosity calibrations.
These
observations would provide the bulk of a coordinated program aimed
at
making the measurement of the Hubble constant one of the leading
constraints
on dark energy.
WFC3/UVI/IR
11557
The
Nature of Low-Ionization BAL QSOs
The
rare subclass of optically-selected QSOs known as low-ionization
broad
absorption line (LoBAL) QSOs show signs of high-velocity gas
outflows
and reddened continua indicative of dust obscuration. Recent
studies
show that galaxies hosting LoBAL QSOs tend to be ultraluminous
infrared
systems that are undergoing mergers, and that have dominant
young
(< 100 Myr) stellar populations. Such studies support the idea
that
LoBAL QSOs represent a short- lived phase early in the life of
QSOs,
when powerful AGN-driven winds are blowing away the dust and gas
surrounding
the QSO. If so, understanding LoBALs would be critical in
the
study of phenomena regulating black hole and galaxy evolution, such
as
AGN feedback and the early stages of nuclear accretion. These
results,
however, come from very small samples that may have serious
selection
biases. We are therefore taking a more aggressive approach by
conducting
a systematic multiwavelength study of a volume limited sample
of
LoBAL QSOs at 0.5 < z < 0.6 drawn from SDSS. We propose to image
their
host galaxies in two bands using WFC3/UVIS and WFC3/IR to study
the
morphologies for signs of recent tidal interactions and to map their
interaction
and star forming histories. We will thus determine whether
LoBAL
QSOs are truly exclusively found in young merging systems that are
likely
to be in the early stages of nuclear accretion.
WFC3/ACS/IR
11142
Revealing
the Physical Nature of Infrared Luminous Galaxies at 0.3<z<2.7
Using
HST and Spitzer
We
aim to determine physical properties of IR luminous galaxies at
0.3<z<2.7
by requesting coordinated HST/NIC2 and MIPS 70um observations
of
a unique, 24um flux-limited sample with complete Spitzer mid-IR
spectroscopy.
The 150 sources investigated in this program have S(24um)
>
0.8mJy and their mid-IR spectra have already provided the majority
targets
with spectroscopic redshifts (0.3<z<2.7). The proposed
150~orbits
of NIC2 and 66~hours of MIPS 70um will provide the physical
measurements
of the light distribution at the rest-frame ~8000A and
better
estimates of the bolometric luminosity. Combining these
parameters
together with the rich suite of spectral diagnostics from the
mid-IR
spectra, we will (1) measure how common mergers are among LIRGs
and
ULIRGs at 0.3<z<2.7, and establish if major mergers are the drivers
of
z>1 ULIRGs, as in the local Universe, (2) study the co-evolution of
star
formation and blackhole accretion by investigating the relations
between
the fraction of starburst/AGN measured from mid-IR spectra vs.
HST
morphologies, L(bol) and z, and (3) obtain the current best
estimates
of the far-IR emission, thus L(bol) for this sample, and
establish
if the relative contribution of mid-to-far IR dust emission is
correlated
with morphology (resolved vs. unresolved).
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
23
23
OBAD
with Maneuver 17 17
SIGNIFICANT
EVENTS: (None)