HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5033
PERIOD
COVERED: 5am February 12 - 5am February 16, 2010 (DOY 043/10:00z-047/10:00z)
OBSERVATIONS
SCHEDULED
COS/FUV
11997
FUV
Internal/External Wavelength Scale Monitor
This
program monitors the offsets between the wavelength scale set by
the
internal wavecal versus that defined by absorption lines in external
targets.
This is accomplished by observing two external targets in the
SMC:
SK191 with G130M and G160M and Cl* NGC 330 ROB B37 with G140L
(SK191
is too bright to be observed with G140L). The cenwaves observed
in
this program are a subset of the ones used during Cycle 17. Observing
all
cenwaves would require a considerably larger number of orbits.
Constraints
on scheduling of each target are placed so that each target
is
observed once every ~2-3 months. Observing the two targets every
month
would also require a considerably larger number of orbits.
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
11924
WFC3/UVIS
External and Internal CTE Monitor
CCD
detector Charge Transfer Inefficiency (CTI)-induced losses in
photometry
and astrometry will be measured using observations of the
rich
open cluster NGC6791 and with the EPER (Extended Pixel Edge
Response)
method using tungsten lamp flat field exposures. Although we
do
not expect to see CTE effects at the outset of Cycle 17, this CTE
monitoring
program is the first of a multi-cycle program to monitor and
establish
CTE-induced losses with time. We expect to measure CTE effects
with
a precision comparable to the ACS measurements.
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/UV
11906
WFC3
UVIS CCD Gain
The
absolute gain of each quadrant of the WFC3 UVIS detector will be
measured
for the nominal detector readout configuration and at the
on-orbit
operating temperature.
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).
COS/NUV
11900
NUV
Internal/External Wavelength Scale Monitor
This
program monitors the offsets between the wavelength scale set by
the
internal wavecal versus that defined by absorption lines in external
targets.
This is accomplished by observing two external radial velocity
standard
targets: HD187691 with G225M and G285M and HD6655 with G285M
and
G230L. The two standard targets have little flux in the wavelength
range
covered by G185M and so Feige 48 (sdO) is observed with this
grating.
Both Feige 48 and HD6655 are also observed in SMOV. The
cenwaves
observed in this program are a subset of the ones used during
Cycle
17. Observing all cenwaves would require a considerably larger
number
of orbits. Constraints on scheduling of each target are placed so
that
each target is observed once every ~2-3 months. Observing the three
targets
every month would also require a considerably larger number of
orbits.
COS/FUV
11895
FUV
Detector Dark Monitor
The
purpose of this proposal is to monitor the FUV detector dark rate by
taking
long science exposures without illuminating the detector. The
detector
dark rate and spatial distribution of counts will be compared
to
pre-launch and SMOV data in order to verify the nominal operation of
the
detector. Variations of count rate as a function of orbital position
will
be analyzed to find dependence of dark rate on proximity to the
SAA.
Dependence of dark rate as function of time will also be tracked.
COS/NUV
11894
NUV
Detector Dark Monitor
The
purpose of this proposal is to measure the NUV detector dark rate by
taking
long science exposures with no light on the detector. The
detector
dark rate and spatial distribution of counts will be compared
to
pre-launch and SMOV data in order to verify the nominal operation of
the
detector. Variations of count rate as a function of orbital position
will
be analyzed to find dependence of dark rate on proximity to the
SAA.
Dependence of dark rate as function of time will also be tracked.
STIS/CCD
11853
Cycle
17 STIS CCD Imaging Flats
This
program periodically monitors the STIS CCD imaging mode flat fields
by
using the tungsten lamps.
STIS/CCD
11846
CCD
Bias Monitor-Part 1
The
purpose of this proposal is to 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/CCD
11844
CCD
Dark Monitor Part 1
The
purpose of this proposal is to monitor the darks for the STIS CCD.
WFC3/ACS/UVIS
11803
Observing
Cluster Assembly Around the Massive Cluster RXJ0152-13
We
request ACS imaging for groups and filaments in the outskirts of two
z=0.8
forming clusters of galaxies. These images will be combined with
an
unparalleled dataset of wide-field spectroscopy from Magellan, with
~2200
confirmed members (~3200 by the summer) of the superstructures
surrounding
the two clusters. We will estimate merger rates and
determine
the morphological composition of the galaxy populations within
the
infalling groups and filaments identified in our spectroscopic
dataset.
The HST data are critical to understand how the early-type
galaxy
fraction remains constant in cluster centers, while clusters
double
in mass through the steady accretion of lower mass groups. One
possibility
is that the galaxies in the filaments and infalling groups
already
have predominantly early-type morphologies, while another is
that
galaxies transform during, and possibly even in connection with,
the
process of infall. Our unique dataset of spectroscopic membership,
when
combined with the exquisite high- resolution imaging of ACS and
WF3,
will enable us to witness the accretion of galaxies unto massive
clusters
and how this process affects their properties.
COS/NUV/FUV
11741
Probing
Warm-Hot Intergalactic Gas at 0.5 < z < 1.3 with a Blind Survey
for
O VI, Ne VIII, Mg X, and Si XII Absorption Systems
Currently
we can only account for half of the baryons (or less) expected
to
be found in the nearby universe based on D/H and CMB observations.
This
"missing baryons problem" is one of the highest-priority challenges
in
observational extragalatic astronomy. Cosmological simulations
suggest
that the baryons are hidden in low-density, shock-heated
intergalactic
gas in the log T = 5 - 7 range, but intensive UV and X-ray
surveys
using O VI, O VII, and O VIII absorption lines have not yet
confirmed
this prediction. We propose to use COS to carry out a
sensitive
survey for Ne VIII and Mg X absorption in the spectra of nine
QSOs
at z(QSO) > 0.89. For the three highest-redshift QSOs, we will also
search
for Si XII. This survey will provide more robust constraints on
the
quantity of baryons in warm-hot intergalactic gas at 0.5 < z < 1.3,
and
the data will provide rich constraints on the metal enrichment,
physical
conditions, and nature of a wide variety of QSO absorbers in
addition
to the warm-hot systems. By comparing the results to other
surveys
at lower redshifts (with STIS, FUSE, and from the COS GTO
programs),
the project will also enable the first study of how these
absorbers
evolve with redshift at z < 1. By combining the program with
follow-up
galaxy redshift surveys, we will also push the study of
galaxy-absorber
relationships to higher redshifts, with an emphasis on
the
distribution of the WHIM with respect to the large-scale matter
distribution
of the universe.
WFC3/IR
11738
SPIDERWEBS
AND FLIES: OBSERVING MASSIVE GALAXY FORMATION IN ACTION
Distant
luminous radio galaxies are among the brightest known galaxies
in
the early Universe, pinpoint likely progenitors of dominant cluster
galaxies
and are unique laboratories for studying massive galaxy
formation.
Spectacular images with the ACS and NICMOS of one such
object,
the "Spiderweb Galaxy" at z = 2.2, show in exquisite detail,
hierarchical
merging occurring 11 Gyr ago. By imaging 3 additional
Spiderweb-like
galaxies we wish to study this potentially crucial phase
of
massive galaxy evolution, when hierarchical merging, galaxy
downsizing
and AGN feedback are all likely to be occurring. Properties
of
the complete sample of Spiderweb galaxies will be used to (i)
constrain
models for the formation and evolution of the most massive
galaxies
that dominate rich clusters and (ii) investigate the nature of
chain
and tadpole galaxies, a fundamental but poorly understood
constituent
of the early Universe.
We
shall image rest-frame UV and optical continuum emission from 3 radio
galaxies
with 2.4 < z < 3.8 that appear clumpy and large in shallow
WFPC/PC
observations. The new observations will typically reach ~2
magnitudes
fainter over 20-40 times larger area than previously.
Photometric
and morphological parameters will be measured for satellite
galaxies
("flies") in the clumpy massive hosts and for galaxies in ~ 1.5
Mpc
x 1.5 Mpc regions of surrounding protoclusters. Locations, sizes,
elongations,
clumpiness, masses, and star formation rates of the merging
satellite
and protocluster galaxies will be compared with new state of
the
art simulations. Combination of ACS and WFC3 images will help
disentangle
the properties of the young and old populations.
Specific
goals include: (i) investigating star formation histories of
the
satellite galaxies and the extended emission,
(ii)
studying "downsizing" and merging scenarios and (iii) measuring the
statistics
of linear galaxies and relating them to models for the
formation
of massive galaxies and to the properties of the important but
enigmatic
class of chain/tadpole galaxies in the HUDF.
WFC3/UVIS
11697
Proper
Motion Survey of Classical and SDSS Local Group Dwarf Galaxies
Using
the superior resolution of HST, we propose to continue our proper
motion
survey of Galactic dwarf galaxies. The target galaxies include
one
classical dwarf, Leo II, and six that were recently identified in
the
Sloan Digital Sky Survey data: Bootes I, Canes Venatici I, Canes
Venatici
II, Coma Berenices, Leo IV, and Ursa Major II. We will observe
a
total of 16 fields, each centered on a spectroscopically-confirmed
QSO.
Using QSOs as standards of rest in measuring absolute proper
motions
has proven to be the most accurate and most efficient method.
HST
is our only option to quickly determine the space motions of the
SDSS
dwarfs because suitable ground-based imaging is only a few years
old
and such data need several decades to produce a proper motion. The
two
most distant galaxies in our sample will require time baselines of
four
years to achieve our goal of a 30-50 km/s uncertainty in the
tangential
velocity; given this and the finite lifetime of HST, it is
imperative
that first-epoch observations be taken in this cycle. The
SDSS
dwarfs have dramatically lower surface brightnesses and
luminosities
than the classical dwarfs. Proper motions are crucial for
determining
orbits of the galaxies and knowing the orbits will allow us
to
test theories for the formation and evolution of these galaxies and,
more
generally, for the formation of the Local Group.
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 possiblity 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.
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.
ACS/WFC3
11670
The
Host Environments of Type Ia Supernovae in the SDSS Survey
The
Sloan Digital Sky Survey Supernova Survey has discovered nearly 500
type
Ia supernovae and created a large, unique, and uniform sample of
these
cosmological tools. As part of a comprehensive study of the
supernova
hosts, we propose to obtain Hubble ACS images of a large
fraction
of these galaxies. Integrated colors and spectra will be
measured
from the ground, but we require high-resolution HST imaging to
provide
accurate morphologies and color information at the site of the
explosion.
This information is essential in determining the systematic
effects
of population age on type Ia supernova luminosities and
improving
their reliability in measuring dark energy. Recent studies
suggest
two populations of type Ia supernovae: a class that explodes
promptly
after star-formation and one that is delayed by billions of
years.
Measuring the star-formation rate at the site of the supernova
from
colors in the HST images may be the best way to differentiate
between
these classes.
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.
S/C/STIS/CC/MA/FUV
11621
SDSS
J1507: The First Halo CV or the First CV Born With a Brown Dwarf
Donor?
The
eclipsing cataclysmic variable (CV) SDSS J1507 has an orbital period
well
below the period minimum obeyed by other CVs. Furthermore, it
contains
a cool, pulsating primary white dwarf (WD) and a sub-stellar
brown-dwarf
(BD) companion. We have now discovered that J1507 is also a
high
proper motion star, with a transverse velocity much higher than
other
CVs. These characteristics can all be reconciled if the system is
the
first Galactic halo CV to be discovered. However, there is one
possible
alternative explanation, according to which the system formed
only
recently from a detached WD-BD binary system. Here, we propose a
definitive
test of these two scenarios by using time-resolved, FUV + NUV
spectroscopy
to determine the metallicity of the system. The outcome of
this
test will have an immediate impact on our understanding of the
Galactic
CV population and of close binary evolution more generally. We
will
also measure the wavelength-dependence of the WD pulsation
amplitudes
in J1507 and determine high precision binary parameters based
on
a combination of spectroscopic modeling and eclipse analysis. As a
result,
J1507 will become the benchmark for theoretical studies of CV
evolution
and the first proper calibrator for models of pulsations in
accreting
WDs.
STIS/CCD/MA1/MA2
11616
The
Disks, Accretion, and Outflows (DAO) of T Tau Stars
Classical
T Tauri stars undergo magnetospheric accretion, power
outflows,
and possess the physical and chemical conditions in their
disks
to give rise to planet formation. Existing high resolution FUV
spectra
verify that this spectral region offers unique diagnostics of
these
processes, which have the potential to significantly advance our
understanding
of the interaction of a star and its accretion disk. To
date
the limited results are intriguing, with dramatic differences in
kinematic
structure in lines ranging from C IV to H2 among the few stars
that
have been observed. We propose to use HST/COS to survey the disks,
outflows,
and accretion (the DAO) of 26 CTTS and 6 WTTS in the FUV at
high
spectral resolution. A survey of this size is essential to
establish
how properties of accretion shocks, winds and disk irradiation
depend
on disk accretion rate. Specifically, our goals are to (1)
measure
the radiation from and understand the physical properties of the
gas
very near the accretion shock as a function of accretion rate using
emission
line profiles of hot lines (C IV, Si IV, N V, and He II); (2)
measure
the opacity, velocity, and temperature at the base of the
outflow
to constrain outflow models using wind absorption features; and
(3)
characterize the radiation incident on disks and protoplanetary
atmospheres
using H2 line and continuum emission and reconstructed
bright
Ly-alpha line emission.
WFC3/ACS/IR
11597
Spectroscopy
of IR-Selected Galaxy Clusters at 1 < z < 1.5
We
propose to obtain WFC3 G141 and G102 slitless spectroscopy of galaxy
clusters
at 1 < z < 1.5 that were selected from the IRAC survey of the
Bootes
NDWFS field. Our IRAC survey contains the largest sample of
spectroscopically
confirmed clusters at z > 1. The WFC3 grism data will
measure
H-alpha to determine SFR, and fit models to the low resolution
continua
to determine stellar population histories for the brighter
cluster
members, and redshifts for the red galaxies too faint for
ground-based
optical spectroscopy.
WFC3/UVIS
11595
Turning
Out the Light: A WFC3 Program to Image z>2 Damped Lyman Alpha
Systems
We
propose to directly image the star-forming regions of z>2 damped Lya
systems
(DLAs) using the WFC3/UVIS camera on the Hubble Space Telescope.
In
contrast to all previous attempts to detect the galaxies giving rise
to
high redshift DLAs, we will use a novel technique that completely
removes
the glare of the background quasar. Specifically, we will target
quasar
sightlines with multiple DLAs and use the higher redshift DLA as
a
``blocking filter'' (via Lyman limit absorption) to eliminate all FUV
emission
from the quasar. This will allow us to carry out a deep search
for
FUV emission from the lower redshift DLA, shortward of the Lyman
limit
of the higher redshift absorber. The unique filter set and high
spatial
resolution afforded by WFC3/UVIS will then enable us to directly
image
the lower redshift DLA and thus estimate its size, star- formation
rate
and impact parameter from the QSO sightline. We propose to observe
a
sample of 20 sightlines, selected primarily from the SDSS database,
requiring
a total of 40 HST orbits. The observations will allow us to
determine
the first FUV luminosity function of high redshift DLA
galaxies
and to correlate the DLA galaxy properties with the ISM
characteristics
inferred from standard absorption-line analysis to
significantly
improve our understanding of the general DLA population.
WFC3/ACS/IR
11563
Galaxies
at z~7-10 in the Reionization Epoch: Luminosity Functions to
<0.2L*
from Deep IR Imaging of the HUDF and HUDF05 Fields
The
first generations of galaxies were assembled around redshifts
z~7-10+,
just 500-800 Myr after recombination, in the heart of the
reionization
of the universe. We know very little about galaxies in this
period.
Despite great effort with HST and other telescopes, less than
~15
galaxies have been reliably detected so far at z>7, contrasting with
the
~1000 galaxies detected to date at z~6, just 200-400 Myr later, near
the
end of the reionization epoch. WFC3 IR can dramatically change this
situation,
enabling derivation of the galaxy luminosity function and its
shape
at z~7-8 to well below L*, measurement of the UV luminosity
density
at z~7-8 and z~8-9, and estimates of the contribution of
galaxies
to reionization at these epochs, as well as characterization of
their
properties (sizes, structure, colors). A quantitative leap in our
understanding
of early galaxies, and the timescales of their buildup,
requires
a total sample of ~100 galaxies at z~7-8 to ~29 AB mag. We can
achieve
this with 192 WFC3 IR orbits on three disjoint fields
(minimizing
cosmic variance): the HUDF and the two nearby deep fields of
the
HUDF05. Our program uses three WFC3 IR filters, and leverages over
600
orbits of existing ACS data, to identify, with low contamination, a
large
sample of over 100 objects at z~7-8, a very useful sample of ~23
at
z~8-9, and limits at z~10. By careful placement of the WFC3 IR and
parallel
ACS pointings, we also enhance the optical ACS imaging on the
HUDF
and a HUDF05 field. We stress (1) the need to go deep, which is
paramount
to define L*, the shape, and the slope alpha of the luminosity
function
(LF) at these high redshifts; and (2) the far superior
performance
of our strategy, compared with the use of strong lensing
clusters,
in detecting significant samples of faint z~7-8 galaxies to
derive
their luminosity function and UV ionizing flux. Our recent z~7.4
NICMOS
results show that wide-area IR surveys, even of GOODS-like depth,
simply
do not reach faint enough at z~7-9 to meet the LF and UV flux
objectives.
In the spirit of the HDF and the HUDF, we will waive any
proprietary
period, and will also deliver the reduced data to STScI. The
proposed
data will provide a Legacy resource of great value for a wide
range
of archival science investigations of galaxies at redshifts z~2-9.
The
data are likely to remain the deepest IR/optical images until JWST
is
launched, and will provide sources for spectroscopic followup by
JWST,
ALMA and EVLA.
NIC2/WFC3/IR
11548
Infrared
Imaging of Protostars in the Orion A Cloud: The Role of
Environment
in Star Formation
We
propose NICMOS and WFC3/IR observations of a sample of 252 protostars
identified
in the Orion A cloud with the Spitzer Space Telescope. These
observations
will image the scattered light escaping the protostellar
envelopes,
providing information on the shapes of outflow cavities, the
inclinations
of the protostars, and the overall morphologies of the
envelopes.
In addition, we ask for Spitzer time to obtain 55-95 micron
spectra
of 75 of the protostars. Combining these new data with existing
3.6
to 70 micron photometry and forthcoming 5-40 micron spectra measured
with
the Spitzer Space Telescope, we will determine the physical
properties
of the protostars such as envelope density, luminosity,
infall
rate, and outflow cavity opening angle. By examining how these
properties
vary with stellar density (i.e. clusters vs. groups vs.
isolation)
and the properties of the surrounding molecular cloud; we can
directly
measure how the surrounding environment influences protostellar
evolution,
and consequently, the formation of stars and planetary
systems.
Ultimately, this data will guide the development of a theory of
protostellar
evolution.
NIC1/WFC3/IR
11205
The
Effects of Multiplicity on the Evolution of Young Stellar Objects: A
NICMOS
Imaging Study
We
propose to use NICMOS to investigate the multiplicity of young
stellar
objects (YSOs) in the Orion B molecular cloud. Previous
observations
with the Spitzer Space Telescope have revealed a remarkable
star
forming filament near the NGC 2068 reflection nebula. The
population
of YSOs associated with the filament exhibit a surprisingly
wide
range of circumstellar evolutionary states, from deeply embedded
protostars
to T Tauri accretion disks. Many of the circumstellar disks
themselves
show evidence for significant dust evolution, including grain
growth
and settling and cleared inner holes, apparently in spite of the
very
young age of these stars. We will estimate the binary fraction of a
representative
sample of objects in these various stages of evolution in
order
to test whether companions may play a significant role in that
evolution.
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
12189
- GSAcq(1,2,1) at 044/07:19z failed to RGA control with, Search Radius Limit
exceeded on FGS 1.
Observations affected: WFC3 174-178 Proposal ID# 11548.
12190
- GSAcq(2,0,2) at 045/00:02z failed to RGA control due to Scan Step Limit on
FGS 2.
Observations affected: ACS 107-110 Proposal ID# 11995,
STIS 37-41 Proposal ID# 11844 & 11846, WFC3 207-210 Proposal
ID# 11548.
12192
- GSAcq(2,1,1) at 046/07:01z, REAcq(2,1,1) 046/07:41z and REAcq(2,1,1) at
046/08:30z
failed with search radius limit on FGS 1 and FGS 2.
Observations affected: COS 5-13 Proposal ID#11997, WFC3 10-13
Proposal ID# 11906.
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS
GSAcq
30
27
FGS
REAcq
36
34
OBAD
with Maneuver 18
18
SIGNIFICANT
EVENTS: (None)