Notice:
Due to the conversion of some ACS WFC or HRC observations into
WFPC2,
or NICMOS observations after the loss of ACS CCD science
capability
in January, there may be an occasional discrepancy between a
proposal's
listed (and correct) instrument usage and the abstract that
follows
it.
HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT # 4467
PERIOD
COVERED: UT October 12,13,14, 2007 (DOY 285,286,287)
OBSERVATIONS
SCHEDULED
NIC1/NIC2/NIC3
8794
NICMOS Post-SAA calibration - CR Persistence Part 5
A
new procedure proposed to alleviate the CR-persistence problem of
NICMOS.
Dark frames will be obtained immediately upon exiting the SAA
contour
23, and every time a NICMOS exposure is scheduled within 50
minutes
of coming out of the SAA. The darks will be obtained in parallel
in
all three NICMOS Cameras. The POST-SAA darks will be non- standard
reference
files available to users with a USEAFTER date/time mark. The
keyword
'USEAFTER=date/time' will also be added to the header of each
POST-SAA
DARK frame. The keyword must be populated with the time, in
addition
to the date, because HST crosses the SAA ~8 times per day so
each
POST-SAA DARK will need to have the appropriate time specified, for
users
to identify the ones they need. Both the raw and processed images
will
be archived as POST-SAA DARKs. Generally we expect that all NICMOS
science/calibration
observations started within 50 minutes of leaving an
SAA
will need such maps to remove the CR persistence from the science
images.
Each observation will need its own CRMAP, as different SAA
passages
leave different imprints on the NICMOS detectors.
NIC1/NIC2/NIC3
8793
NICMOS
Post-SAA calibration - CR Persistence Part 4
A
new procedure proposed to alleviate the CR-persistence problem of
NICMOS.
Dark frames will be obtained immediately upon exiting the SAA
contour
23, and every time a NICMOS exposure is scheduled within 50
minutes
of coming out of the SAA. The darks will be obtained in parallel
in
all three NICMOS Cameras. The POST-SAA darks will be non- standard
reference
files available to users with a USEAFTER date/time mark. The
keyword
'USEAFTER=date/time' will also be added to the header of each
POST-SAA
DARK frame. The keyword must be populated with the time, in
addition
to the date, because HST crosses the SAA ~8 times per day so
each
POST-SAA DARK will need to have the appropriate time specified, for
users
to identify the ones they need. Both the raw and processed images
will
be archived as POST-SAA DARKSs. Generally we expect that all NICMOS
science/calibration
observations started within 50 minutes of leaving an
SAA
will need such maps to remove the CR persistence from the science
images.
Each observation will need its own CRMAP, as different SAA
passages
leave different imprints on the NICMOS detectors.
WFPC2
11289
SL2S:
The Strong Lensing Legacy Survey
Recent
systematic surveys of strong galaxy-galaxy lenses {CLASS, SLACS,
GOODS,
etc.} are producing spectacular results for galaxy masses roughly
below
a transition mass M~10^13 Mo. The observed lens properties and
their
evolution up to z~0.2, consistent with numerical simulations, can
be
described by isothermal elliptical potentials. In contrast, modeling
of
giant arcs in X-ray luminous clusters {halo masses M >~10^13 Mo}
favors
NFW mass profiles, suggesting that dark matter halos are not
significantly
affected by baryon cooling. Until recently, lensing
surveys
were neither deep nor extended enough to probe the intermediate
mass
density regime, which is fundamental for understanding the assembly
of
structures. The CFHT Legacy Survey now covers 125 square degrees, and
thus
offers a large reservoir of strong lenses probing a large range of
mass
densities up to z~1. We have extracted a list of 150 strong lenses
using
the most recent CFHTLS data release via automated procedures.
Following
our first SNAPSHOT proposal in cycle 15, we propose to
continue
the Hubble follow-up targeting a larger list of 130 lensing
candidates.
These are intermediate mass range candidates {between
galaxies
and clusters} that are selected in the redshift range of 0.2-1
with
no a priori X-ray selection. The HST resolution is necessary for
confirming
the lensing candidates, accurate modeling of the lenses, and
probing
the total mass concentration in galaxy groups up to z~1 with the
largest
unbiased sample available to date.
FGS
11228
Extrasolar
Planet XO-2b
We
propose observations of the newly discovered extrasolar planet XO-2b
and
its twin star XO-2. When combined with the transit light curve, the
FGS-derived
parallax will constrain the stellar mass of the host star
XO-2.
From the high signal-to-noise near-IR time series resulting from
NICMOS
grism spectroscopy, we will refine the system parameters, in
particular
radii of the star and planet. From the same data, we will
search
for evidence of water vapor in the atmosphere via transmission
spectroscopy.
Differential observations with NICMOS in the spectroscopic
mode
will be used to search for the small spectral changes that occur
during
planetary transits resulting from absorption of stellar light as
it
passes through the planetary atmosphere. Water is an important
constituent,
the detection of which would provide information on Oxygen,
and
it has a convenient strong band well- positioned for NICMOS.
WFPC2
11202
The
Structure of Early-type Galaxies: 0.1-100 Effective Radii
The
structure, formation and evolution of early-type galaxies is still
largely
an open problem in cosmology: how does the Universe evolve from
large
linear scales dominated by dark matter to the highly non-linear
scales
of galaxies, where baryons and dark matter both play important,
interacting,
roles? To understand the complex physical processes
involved
in their formation scenario, and why they have the tight
scaling
relations that we observe today {e.g. the Fundamental Plane}, it
is
critically important not only to understand their stellar structure,
but
also their dark-matter distribution from the smallest to the largest
scales.
Over the last three years the SLACS collaboration has developed
a
toolbox to tackle these issues in a unique and encompassing way by
combining
new non-parametric strong lensing techniques, stellar
dynamics,
and most recently weak gravitational lensing, with
high-quality
Hubble Space Telescope imaging and VLT/Keck spectroscopic
data
of early-type lens systems. This allows us to break degeneracies
that
are inherent to each of these techniques separately and probe the
mass
structure of early-type galaxies from 0.1 to 100 effective radii.
The
large dynamic range to which lensing is sensitive allows us both to
probe
the clumpy substructure of these galaxies, as well as their
low-density
outer haloes. These methods have convincingly been
demonstrated,
by our team, using smaller pilot-samples of SLACS lens
systems
with HST data. In this proposal, we request observing time with
WFPC2
and NICMOS to observe 53 strong lens systems from SLACS, to obtain
complete
multi-color imaging for each system. This would bring the total
number
of SLACS lens systems to 87 with completed HST imaging and
effectively
doubles the known number of galaxy-scale strong lenses. The
deep
HST images enable us to fully exploit our new techniques, beat down
low-number
statistics, and probe the structure and evolution of
early-type
galaxies, not only with a uniform data-set an order of
magnitude
larger than what is available now, but also with a fully
coherent
and self-consistent methodological approach!
ACS/SBC
WFPC2 11175
UV
Imaging to Determine the Location of Residual Star Formation in
Galaxies
Recently Arrived on the Red Sequence
We
have identified a sample of low-redshift {z = 0.04 - 0.10} galaxies
that
are candidates for recent arrival on the red sequence. They have
red
optical colors indicative of old stellar populations, but blue
UV-optical
colors that could indicate the presence of a small quantity
of
continuing or very recent star formation. However, their spectra lack
the
emission lines that characterize star-forming galaxies. We propose
to
use ACS/SBC to obtain high- resolution imaging of the UV flux in
these
galaxies, in order to determine the spatial distribution of the
last
episode of star formation. WFPC2 imaging will provide B, V, and I
photometry
to measure the main stellar light distribution of the galaxy
for
comparison with the UV imaging, as well as to measure color
gradients
and the distribution of interstellar dust. This detailed
morphological
information will allow us to investigate the hypothesis
that
these galaxies have recently stopped forming stars and to compare
the
observed distribution of the last star formation with predictions
for
several different mechanisms that may quench star formation in
galaxies.
ACS/SBC
11158
HST
Imaging of UV emission in Quiescent Early-type Galaxies
We
have constructed a sample of early type galaxies at z~0.1 that have
blue
UV-optical colors, yet also show no signs of optical emission, or
extended
blue light. We have cross- correlated the SDSS catalog and the
Galaxy
Evolution Explorer Medium Imaging Survey to select a sample of
galaxies
where this UV emission is strongest. The origin of the UV
rising
flux in these galaxies continues to be debated, and the
possibility
that some fraction of these galaxies may be experiencing low
levels
of star formation cannot be excluded. There is also a possibility
that
low level AGN activity {as evidenced by a point source} is
responsible
We propose to image the UV emission using the HST/SBC and to
explore
the morphology of the UV emission relative to the optical light.
NIC2
11157
NICMOS
Imaging Survey of Dusty Debris Around Nearby Stars Across the
Stellar
Mass Spectrum
Association
of planetary systems with dusty debris disks is now quite
secure,
and advances in our understanding of planet formation and
evolution
can be achieved by the identification and characterization of
an
ensemble of debris disks orbiting a range of central stars with
different
masses and ages. Imaging debris disks in starlight scattered
by
dust grains remains technically challenging so that only about a
dozen
systems have thus far been imaged. A further advance in this field
needs
an increased number of imaged debris disks. However, the technical
challege
of such observations, even with the superb combination of HST
and
NICMOS, requires the best targets. Recent HST imaging investigations
of
debris disks were sample-limited not limited by the technology used.
We
performed a search for debris disks from a IRAS/Hipparcos cross
correlation
which involved an exhaustive background contamination check
to
weed out false excess stars. Out of ~140 identified debris disks, we
selected
22 best targets in terms of dust optical depth and disk angular
size.
Our target sample represents the best currently available target
set
in terms of both disk brightness and resolvability. For example, our
targets
have higher dust optical depth, in general, than newly
identified
Spitzer disks. Also, our targets cover a wider range of
central
star ages and masses than previous debris disk surveys. This
will
help us to investigate planetary system formation and evolution
across
the stellar mass spectrum. The technical feasibility of this
program
in two-gyro mode guiding has been proven with on- orbit
calibration
and science observations during HST cycles 13, 14, and 15.
NIC2
11143
NICMOS
imaging of submillimeter galaxies with CO and PAH redshifts
We
propose to obtain F110W and F160W imaging of 10 z~2.4 submillimeter
galaxies
{SMGs} whose optical redshifts have been confirmed by the
detection
of millimeter CO and/or mid-infrared PAH emission. With the
4000A
break falling within/between the two imaging filters, we will be
able
to study these sources' spatially resolved stellar populations
{modulo
extinction} in the rest-frame optical. SMGs' large luminosities
appear
to be due largely to merger-triggered starbursts; high-resolution
NICMOS
imaging will help us understand the stellar masses, mass ratios,
and
other properties of the merger progenitors, valuable information in
the
effort to model the mass assembly history of the universe.
WFPC2
11134
WFPC2
Tidal Tail Survey: Probing Star Cluster Formation on the Edge
The
spectacular HST images of the interiors of merging galaxies such as
the
Antennae and NGC 7252 have revealed rich and diverse populations of
star
clusters created over the course of the interaction. Intriguingly,
our
WFPC2 study of tidal tails in these and other interacting pairs has
shown
that star cluster birth in the tails does not follow a similarly
straightforward
evolution. In fact, cluster formation in these
relatively
sparse environments is not guaranteed -- only one of six
tails
in our initial study showed evidence for a significant population
of
young star clusters. The tail environment thus offers the opportunity
to
probe star cluster formation on the edge of the physical parameter
space
{e.g., of stellar and gas mass, density, and pressure} that
permits
it to occur. We propose to significantly extend our pilot sample
of
optically bright, gas-rich tidal tails by a factor of 4 in number to
include
a more diverse population of tails, encompassing major and minor
mergers,
gas-rich and gas-poor tails, as well as early, late, and merged
interaction
stages. With 21 orbits of HST WFPC2 imaging in the F606W and
F814W
filters, we can identify, roughly age-date, and measure sizes of
star
clusters to determine what physical parameters affect star cluster
formation.
WFPC2 imaging has been used effectively in our initial study
of
four mergers, and it will be possible in this program to reach
similar
limits of Mv=-8.5 for each of 16 more tails. With the much
larger
sample we expect to isolate which factors, such as merger stage,
HI
content, and merger mass ratio, drive the formation of star clusters.
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.
WFPC2
11103
A
Snapshot Survey of The Most Massive Clusters of Galaxies
We
propose the continuation of our highly successful SNAPshot survey of
a
sample of 125 very X-ray luminous clusters in the redshift range
0.3-0.7.
As demonstrated by the 25 snapshots obtained so far in Cycle14
and
Cycle15 these systems frequently exhibit strong gravitational
lensing
as well as spectacular examples of violent galaxy interactions.
The
proposed observations will provide important constraints on the
cluster
mass distributions, the physical nature of galaxy-galaxy and
galaxy-gas
interactions in cluster cores, and a set of optically bright,
lensed
galaxies for further 8-10m spectroscopy. All of our primary
science
goals require only the detection and characterization of
high-surface-brightness
features and are thus achievable even at the
reduced
sensitivity of WFPC2. Because of their high redshift and thus
compact
angular scale our target clusters are less adversely affected by
the
smaller field of view of WFPC2 than more nearby systems.
Acknowledging
the broad community interest in this sample we waive our
data
rights for these observations. Due to a clerical error at STScI our
approved
Cycle15 SNAP program was barred from execution for 3 months and
only
6 observations have been performed to date - reinstating this SNAP
at
Cycle16 priority is of paramount importance to reach meaningful
statistics.
NIC3
11082
NICMOS
Imaging of GOODS: Probing the Evolution of the Earliest Massive
Galaxies,
Galaxies Beyond Reionization, and the High Redshift Obscured
Universe
(uses
ACS/SBC and WFPC2)
Deep
near-infrared imaging provides the only avenue towards
understanding
a host of astrophysical problems, including: finding
galaxies
and AGN at z > 7, the evolution of the most massive galaxies,
the
triggering of star formation in dusty galaxies, and revealing
properties
of obscured AGN. As such, we propose to observe 60 selected
areas
of the GOODS North and South fields with NICMOS Camera 3 in the
F160W
band pointed at known massive M > 10^11 M_0 galaxies at z > 2
discovered
through deep Spitzer imaging. The depth we will reach {26.5
AB
at 5 sigma} in H_160 allows us to study the internal properties of
these
galaxies, including their sizes and morphologies, and to
understand
how scaling relations such as the Kormendy relationship
evolved.
Although NIC3 is out of focus and undersampled, it is currently
our
best opportunity to study these galaxies, while also sampling enough
area
to perform a general NIR survey 1/3 the size of an ACS GOODS field.
These
data will be a significant resource, invaluable for many other
science
goals, including discovering high redshift galaxies at z > 7,
the
evolution of galaxies onto the Hubble sequence, as well as examining
obscured
AGN and dusty star formation at z > 1.5. The GOODS fields are
the
natural location for HST to perform a deep NICMOS imaging program,
as
extensive data from space and ground based observatories such as
Chandra,
GALEX, Spitzer, NOAO, Keck, Subaru, VLT, JCMT, and the VLA are
currently
available for these regions. Deep high-resolution
near-infrared
observations are the one missing ingredient to this
survey,
filling in an important gap to create the deepest, largest, and
most
uniform data set for studying the faint and distant universe. The
importance
of these images will increase with time as new facilities
come
on line, most notably WFC3 and ALMA, and for the planning of future
JWST
observations.
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
11039
Polarizers
Closeout
Observations
of standard stars and a highly polarized reflection nebula
are
made as a final calibration for the WFPC2 polarizers. VISFLATS are
also
obtained.
ACS/SBC
10872
Lyman
Continuum Emission in Galaxies at z=1.2
Lyman
continuum photons produced in massive starbursts may have played a
dominant
role in the reionization of the Universe. Starbursts are
important
contributors to the ionizing metagalactic background at lower
redshifts
as well. However, their contribution to the background depends
upon
the fraction of ionizing radiation that escapes from the intrinsic
opacity
of galaxies below the Lyman limit. Current surveys suggest
escape
fractions of a few percent, up to 10%, with very few detections
{as
opposed to upper limits} having been reported. No detections have
been
reported in the epochs between z=0.1 and z=2. We propose to measure
the
fraction of escaping Lyman continuum radiation from 15 luminous
z~1.2
galaxies in the GOODS fields. Using the tremendous sensitivity of
the
ACS Solar- blind Channel, we will reach AB=30 mag., allowing us to
detect
an escape fraction of 1%. We will correlate the amount of
escaping
radiation with the photometric and morphological properties of
the
galaxies. A non-detection in all sources would imply that QSOs
provide
the overwhelming majority of ionizing radiation at z=1.3, and it
would
strongly indicate that the properties of galaxies at higher
redshift
have to be significantly different for galaxies to dominate
reionization.
The deep FUV images will also be useful for extending the
FUV
study of other galaxies in the GOODS fields.
NIC2
10852
Coronagraphic
Polarimetry with NICMOS: Dust grain evolution in T Tauri
stars
The
formation of planetary systems is intimately linked to the dust
population
in circumstellar disks, thus understanding dust grain
evolution
is essential to advancing our understanding of how planets
form.
By combining {1} the coronagraphic polarimetry capabilities of
NICMOS,
{2} powerful 3-D radiative transfer codes, and {3} observations
of
objects known to span the Class II-III stellar evolutionary phases,
we
will gain crucial insight into dust grain growth. By observing
objects
representative of a known evolutionary sequence of YSOs, we will
be
able to investigate how the dust population evolves in size and
distribution
during the crucial transition from a star+disk system to a
system
containing planetesimals. When combine with our previous study on
dust
grain evolution in the Class I-II phase, the proposed study will
help
to establish the fundamental time scales for the depletion of
ISM-like
grains: the first step in understanding the transformation from
small
submicron sized dust grains, to large millimeter sized grains, and
untimely
to planetary bodies.
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:
11021
- GSacq(1,3,3) fails to RGA control while LOS
Upon acquisition of signal at 285/18:23:42, QF1STOPF (FGS 1 stop
flag)
was set and #44 commands did not update from their values prior to
LOS,
indicating that GSACQ(1,3,3) at 17:13:47 did not succeed.
Four ACS 779 NSSC-1 status buffer messages were received at AOS,
indicating that take data flag was down. OBAD prior to GSACQ at
17:09:27
had RSS error of 12.54 arcseconds.
11022
- REacq(2,1,1) failed to RGAHold (Gyro Control)
Upon acquisition of signal (AOS) at 286/03:51:30, the
REacq(2,1,1,)
scheduled at 286/03:21:00 - 03:29:04 had failed to RGA Hold due to
a
Search Radius Limit Exceeded Error on FGS-2. 486 Status Buffer
(ESB)
Dump completed at 286/04:10:35 showed one 486 ESB "a05"
(FGS Coarse
Track failed-Search Radius Limit Exceeded) was received at
286/03:26:27.
Additional ESB 1805(x3) (T2G_MOVING_TARGET_DETECTED) were
received.
Pre-acquisition OBAD1 attitude correction (RSS) value not
available due
to LOS. Pre-acq OBAD2 had (RSS) value of 78.22 arcseconds.
Post-acq
OBAD/MAP had (RSS) value of 562.45 arcseconds.
11023
- GSacq(2,1,2) results in fine lock backup
During LOS GSacq(2,1,2) scheduled at 287/14:04:07 resulted in fine
lock
backup (2,0,2). Stop flags were received for FGS 1. The map at
14:11:40
showed erros of V1= -13.04, V2= -6.38, V3= -8.12, and RSS = 16.64.
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
22
21
FGS
REacq
17
16
OBAD
with Maneuver 77
77
SIGNIFICANT
EVENTS: (None)