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 # 4458
PERIOD
COVERED: UT September 271,272,273, 2007 (DOY 28,29,30)
OBSERVATIONS
SCHEDULED
NIC1/NIC2/NIC3
8795
NICMOS Post-SAA calibration - CR Persistence Part 6
A
new procedure proposed to alleviate the CR-persistence problem of
NICMOS.
Dark frames will be obtained immediately upon exiting the SAA
contour
23, and every time a NICMOS exposure is scheduled within 50
minutes
of coming out of the SAA. The darks will be obtained in parallel
in
all three NICMOS Cameras. The POST-SAA darks will be non- standard
reference
files available to users with a USEAFTER date/time mark. The
keyword
'USEAFTER=date/time' will also be added to the header of each
POST-SAA
DARK frame. The keyword must be populated with the time, in
addition
to the date, because HST crosses the SAA ~8 times per day so
each
POST-SAA DARK will need to have the appropriate time specified, for
users
to identify the ones they need. Both the raw and processed images
will
be archived as POST-SAA DARKSs. Generally we expect that all NICMOS
science/calibration
observations started within 50 minutes of leaving an
SAA
will need such maps to remove the CR persistence from the science i
mages.
Each observation will need its own CRMAP, as different SAA
passages
leave different imprints on the NICMOS detectors.
WFPC2
11312
The
Local Cluster Substructure Survey {LoCuSS}: Deep Strong Lensing
Observations
with WFPC2
LoCuSS
is a systematic and detailed investigation of the mass,
substructure,
and thermodynamics of 100 X-ray luminous galaxy clusters
at
0.15<z<0.3. The primary goal is to test our recent suggestion that
this
population is dominated by dynamically immature disturbed clusters,
and
that the observed mass-temperature relation suffers strong
structural
segregation. If confirmed, this would represent a paradigm
shift
in our observational understanding of clusters, that were hitherto
believed
to be dominated by mature, undisturbed systems. We propose to
complete
our successful Cycle 15 program {SNAP:10881} which prior to
premature
termination had delivered robust weak-lensing detections in 17
clusters,
and candidate strongly-lensed arcs in 11 of these 17. These
strong
and weak lensing signals will give an accurate measure of the
total
mass and structure of the dark matter distribution that we will
subsequently
compare with X-ray and Sunyaev Zeldovich Effect
observables.
The broader applications of our project include 1} the
calibration
of mass-temperature and mass-SZE scaling relations which
will
be critical for the calibration of proposed dark energy
experiments,
and 2} the low redshift baseline study of the demographics
of
massive clusters to aid interpretation of future high redshift {z>1}
cluster
samples. To complete the all-important high resolution imaging
component
of our survey, we request deep WFPC2 observations of 20
clusters
through the F606W filter, for which wide-field weak-lensing
data
are already available from our Subaru imaging program. The
combination
of deep WFPC2 and Subaru data for these 20 clusters will
enable
us to achieve the science program approved by the Cycle 15 TAC.
WFPC2
11292
The
Ring Plane Crossings of Uranus in 2007
The
rings of Uranus turn edge-on to Earth in May and August 2007. In
between,
we will have a rare opportunity to see the unlit face of the
rings.
With the nine optically thick rings essentially invisible, we
will
observe features and phenomena that are normally lost in their
glare.
We will use this opportunity to search thoroughly for the
embedded
"shepherd" moons long believed to confine the edges of the
rings,
setting a mass limit roughly 10 times smaller than that of the
smallest
shepherd currently known, Cordelia. We will measure the
vertical
thicknesses of the rings and study the faint dust belts only
known
to exist from a single Voyager image. We will also study the
colors
of the newly-discovered faint, outer rings; recent evidence
suggests
that one ring is red and the other blue, implying that each
ring
is dominated by a different set of physical processes. We will
employ
near- edge-on photometry from 2006 and 2007 to derive the
particle
filling factor within the rings, to observe how ring epsilon
responds
to the "traffic jam" as particles pass through its narrowest
point,
and to test the latest models for preserving eccentricities and
apse
alignment within the rings. Moreover, this data set will allow us
to
continue monitoring the motions of the inner moons, which have been
found
to show possibly chaotic orbital variations; by nearly doubling
the
time span of the existing Hubble astrometry, the details of the
variations
will become much clearer.
NIC2
11219
Active
Galactic Nuclei in nearby galaxies: a new view of the origin of
the
radio-loud radio- quiet dichotomy?
Using
archival HST and Chandra observations of 34 nearby early-type
galaxies
{drawn from a complete radio selected sample} we have found
evidence
that the radio-loud/radio-quiet dichotomy is directly connected
to
the structure of the inner regions of their host galaxies in the
following
sense: [1] Radio-loud AGN are associated with galaxies with
shallow
cores in their light profiles [2] Radio-quiet AGN are only
hosted
by galaxies with steep cusps. Since the brightness profile is
determined
by the galaxy's evolution, through its merger history, our
results
suggest that the same process sets the AGN flavour. This
provides
us with a novel tool to explore the co-evolution of galaxies
and
supermassive black holes, and it opens a new path to understand the
origin
of the radio-loud/radio-quiet AGN dichotomy. Currently our
analysis
is statistically incomplete as the brightness profile is not
available
for 82 of the 116 targets. Most galaxies were not observed
with
HST, while in some cases the study is obstructed by the presence of
dust
features. We here propose to perform an infrared NICMOS snapshot
survey
of these 82 galaxies. This will enable us to i} test the reality
of
the dichotomic behaviour in a substantially larger sample; ii} extend
the
comparison between radio-loud and radio-quiet AGN to a larger range
of
luminosities.
WFPC2
11218
Snapshot
Survey for Planetary Nebulae in Globular Clusters of the Local
Group
Planetary
nebulae {PNe} in globular clusters {GCs} raise a number of
interesting
issues related to stellar and galactic evolution. The number
of
PNe known in Milky Way GCs, 4, is surprisingly low if one assumes
that
all stars pass through a PN stage. However, it is likely that the
remnants
of stars now evolving in Galactic GCs leave the AGB so slowly
that
any ejected nebula dissipates long before the star becomes hot
enough
to ionize it. Thus there should not be ANY PNe in Milky Way
GCs--but
there are four! It has been suggested that these PNe are the
result
of mergers of binary stars within GCs, i.e., that they are
descendants
of blue stragglers. The frequency of occurrence of PNe in
external
galaxies poses more questions, because it shows a range of
almost
an order of magnitude. I propose a Snapshot survey aimed at
discovering
PNe in the GC systems of Local Group galaxies more distant
than
the Magellanic Clouds. These clusters, some of which may be much
younger
than their counterparts in the Milky Way, might contain many
more
PNe than those of our own galaxy. I will use the standard technique
of
emission-line and continuum imaging, which easily discloses PNe.
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.
NIC2
11101
The
Relevance of Mergers for Fueling AGNs: Answers from QSO Host
Galaxies
The
majority of QSOs are known to reside in centers of galaxies that
look
like ellipticals. Numerical simulations have shown that remnants of
galaxy
mergers often closely resemble elliptical galaxies. However, it
is
still strongly debated whether the majority of QSO host galaxies are
indeed
the result of relatively recent mergers or whether they are
completely
analogous to inactive ellipticals to which nothing
interesting
has happened recently. To address this question, we recently
obtained
deep HST ACS images for five QSO host galaxies that were
classified
morphologically as ellipticals {GO-10421}. This pilot study
revealed
striking signs of tidal interactions such as ripples, tidal
tails,
and warped disks that were not detected in previous studies. Our
observations
show that at least some "elliptical" QSO host galaxies are
the
products of relatively recent merger events rather than old galaxies
formed
at high redshift. However, the question remains whether the host
galaxies
of classical QSOs are truly distinct from inactive ellipticals
and
whether there is a connection between the merger events we detect
and
the current nuclear activity. We must therefore place our results
into
a larger statistical context. We are currently conducting an HST
archival
study of inactive elliptical galaxies {AR-10941} to form a
control
sample. We now propose to obtain deep HST/WFPC2 images of 13
QSOs
whose host galaxies are classified as normal ellipticals. Comparing
the
results for both samples will help us determine whether classical
QSOs
reside in normal elliptical galaxies or not. Our recent pilot study
of
five QSOs indicates that we can expect exciting results and deep
insights
into the host galaxy morphology also for this larger sample of
QSOs.
A statistically meaningful sample will help us determine the true
fraction
of QSO hosts that suffered strong tidal interactions and thus,
whether
a merger is indeed a requirement to trigger nuclear activity in
the
most luminous AGNs. In addition to our primary science observations
with
WFPC2, we will obtain NICMOS3 parallel observations with the
overall
goal to select and characterize galaxy populations at high
redshifts.
The imaging will be among the deepest NICMOS images: These
NICMOS
images are expected to go to a limit a little over 1 magnitude
brighter
than HUDF-NICMOS data, but over 13 widely separated fields,
with
a total area about 1.5 times larger than HUDF-NICMOS. This
separation
means that the survey will tend to average out effects of
cosmic
variance. The NICMOS3 images will have sufficient resolution for
an
initial characterization of galaxy morphologies, which is currently
one
of the most active and promising areas in approaching the problem of
the
formation of the first massive galaxies. The depth and area coverage
of
our proposed NICMOS observations will also allow a careful study of
the
mass function of galaxies at these redshifts. This provides a large
and
unbiased sample, selected in terms of stellar mass and unaffected by
cosmic
variance, to study the on-going star formation activity as a
function
of mass {i.e. integrated star formation} at this very important
epoch.
WFPC2
11079
Treasury
Imaging of Star Forming Regions in the Local Group:
Complementing
the GALEX and NOAO Surveys
We
propose to use WFPC2 to image the most interesting star-forming
regions
in the Local Group galaxies, to resolve their young stellar
populations.
We will use a set of filters including F170W, which is
critical
to detect and characterize the most massive stars, to whose hot
temperatures
colors at longer wavelengths are not sensitive. WFPC2's
field
of view ideally matches the typical size of the star-forming
regions,
and its spatial resolution allows us to measure individual
stars,
given the proximity of these galaxies. The resulting H-R diagrams
will
enable studies of star-formation properties in these regions, which
cover
largely differing metallicities {a factor of 17, compared to the
factor
of 4 explored so far} and characteristics. The results will
further
our understanding of the star-formation process, of the
interplay
between massive stars and environment, the properties of dust,
and
will provide the key to interpret integrated measurements of
star-formation
indicators {UV, IR, Halpha} available for several
hundreds
more distant galaxies. Our recent deep surveys of these
galaxies
with GALEX {FUV, NUV} and ground-based imaging {UBVRI, Halpha,
[OIII]
and [SII]} provided the identification of the most relevant SF
sites.
In addition to our scientific analysis, we will provide catalogs
of
HST photometry in 6 bands, matched corollary ground-based data, and
UV,
Halpha and IR integrated measurements of the associations, for
comparison
of integrated star-formation indices to the resolved
populations.
We envisage an EPO component.
WFPC2
11033
Full
Moon Earth Flats Closeout
Flat
field exposures will be obtained by observing the moonlit Earth
with
the broadband WFPC2 filters F606W and F814W, which saturate in the
minimum
exposure time on the sunlit Earth. These observations will be
used
to improve the flats currently in the pipeline and are part of the
WFPC2
closeout operations. Because CTE effects are large for star flats
and
small for full field illumination, Earth flats are the superior
technique.
FGS
10930
Mass
and Radius of a Near-Chandrasekhar-limit magnetic white dwarf
REJ0317-853
is a unique object. According to our analyses it is the most
massive
white dwarf ever found, with a mass of 1.35 solar masses,
approaching
the Chandrasekhar limit. With a period of just 725 seconds
it
is the most rapidly rotating isolated white dwarf ever found.
Moreover,
RE J0317-853 is the hottest magnetic white dwarf discovered so
far
and has a strong magnetic field varying from about 180 to more than
700
MG over the stellar surface. Due to its strong polarization and high
mass
it has been used to test gravitational theories predicting
gravitational
birefringence. However, the existing mass and radius
determination
is indirect and still uncertain and would greatly profit
from
a high-precision parallax determination with the HST FGS.
NIC3
10909
Exploring
the diversity of cosmic explosions: The supernovae of
gamma-ray
bursts
While
the connection between gamma-ray bursts {GRBs} and supernovae
{SNe}
is now clearly established, there is a large variety of
observational
properties among these SNe and the physical parameters of
these
explosions are poorly known. As part of a comprehensive program,
we
propose to use HST in order to obtain basic information about the
supernovae
associated with gamma-ray bursts. HST offers the means to
cleanly
separate the light curves of the GRB afterglow from the
supernova,
and to remove the contamination from the host galaxy, opening
a
clear route to the fundamental parameters of the SN. 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 varieties of core-collapse explosions.
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.
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:
11005
- FHST OBAD Failure
GSACQ(1,3,3) at 269/04:44:27 acquired in fine lock backup on FGS 1 only,
with QF3STOPF and QSTOP flags set on FGS 3 at 04:50:02. No other flags
were seen.
REACQ(1,3,3) at 06:17:50 also acquired on FGS 1 only.
11008
- GSAcq (1,2,1) failed to RGA Hold (Gyro Control) @ 272/1319z
At
AOS 272/13:19:35 observed that GSAcq (1,2,1) scheduled from
272/12:32:14-12:39:44 had failed to RGA Hold (Gyro Control). This was
due to QSTOP flag on FGS 1.
OBAD #1 V1 93.63, V2 845.44, V3 557.62 RSS 1017.09
OBAD #2 V1 -2.31, V2 -10.12, V3 6.90, RSS 12.46
OBAD MAP: V1 -553.72, V2 -828.30, V3 342.81, RSS 1053.66
REAcq (1,2,1) scheduled from 272/14:06:47-14:14:17 failed to RGA Hold
(Gyro Control) due to QSTOP flag on FGS 1. There were no OBAD's
scheduled prior to the re-acquisition.
OBAD MAP: V1 350.57, V2 583.31, V3 -38.95, RSS 681.67
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq 21
20
FGS
REacq 19
18
OBAD
with Maneuver
76
75
SIGNIFICANT
EVENTS: (None)