Email =
distribution of the
HST Daily Report will cease on ~10/8/10. The Daily Report can now =
be
found, and will continue to appear at: http://www.stsci.edu/hst=
beneath
the heading “HST Daily Report.”
HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science =
DAILY
REPORT #5190
PERIOD
COVERED: 5am September 26 - 5am September 27, 2010 (DOY =
270/00:00z-270/23:59z)
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
13
13 =
FGS
REAcq
05
05
OBAD
with Maneuver 11
11
SIGNIFICANT=
EVENTS: (None)
OBSERVATION=
S
SCHEDULED:
ACS/WFC
11996
CCD
Daily Monitor (Part 3)
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 308 orbits (19.25 weeks) from 21 June 2010 to 1 =
November
2010.
ACS/WFC
12209
A
Strong Lensing Measurement of the Evolution of Mass Structure in =
Giant
Elliptical
Galaxies
The
structure and evolution of giant elliptical galaxies provide =
key
quantitativ=
e
tests for the theory of hierarchical galaxy formation in =
a
cold
dark matter dominated universe. Strong gravitational =
lensing
provides
the only direct means for the measurement of =
individual
elliptical
galaxy masses beyond the local universe, but there =
are
currently
no large and homogeneous samples of strong lens galaxies =
at
significant=
cosmological look-back time. Hence, an accurate =
and
unambiguous=
measurement of the evolution of the mass-density =
structure
of
elliptical galaxies has until now been impossible. =
Using
spectroscop=
ic
data from the recently initiated Baryon =
Oscillation
Spectroscop=
ic
Survey (BOSS) of luminous elliptical galaxies at =
redshifts
from
approximately 0.4 to 0.7, we have identified a large sample =
of
high-probab=
ility
strong gravitational lens candidates at =
significant
cosmologica=
l
look-back time, based on the detection of =
emission-line
features
from more distant galaxies along the same lines of sight as =
the
target
ellipticals. We propose to observe 45 of these systems with =
the
ACS-WFC
in order to confirm the incidence of lensing and to measure =
the
masses
of the lens galaxies. We will complement these lensing =
mass
measurement=
s
with stellar velocity dispersions from =
ground-based
follow-up
spectroscopy. In combination with similar data from the =
Sloan
Lens
ACS (SLACS) Survey at lower redshifts, we will directly measure =
the
cosmic
evolution of the ratio between lensing mass and dynamical =
mass,
to
reveal the structural explanation for the observed size evolution =
of
elliptical
galaxies (at high mass). We will also measure the =
evolution
of
the logarithmic mass-density profile of massive ellipticals, which =
is
sensitive
to the details of the merging histories through which they =
are
assembled.
Finally, we will use our lensing mass-to-light =
measurements
to
translate the BOSS galaxy luminosity function into a mass =
function,
and
determine its evolution in combination with data from the =
original
Sloan
Digital Sky Survey.
ACS/WFC
12210
SLACS
for the Masses: Extending Strong Lensing to Lower Masses =
and
Smaller
Radii
Strong
gravitational lensing provides the most accurate =
possible
measurement=
of mass in the central regions of early-type =
galaxies
(ETGs).
We propose to continue the highly productive Sloan Lens =
ACS
(SLACS)
Survey for strong gravitational lens galaxies by observing =
a
substantial=
fraction of 135 new ETG gravitational-lens candidates =
with
HST-ACS
WFC F814W Snapshot imaging. The proposed target sample has =
been
selected
from the seventh and final data release of the Sloan =
Digital
Sky
Survey, and is designed to complement the distribution of =
previously
confirmed
SLACS lenses in lens-galaxy mass and in the ratio of =
Einstein
radius
to optical half-light radius. The observations we propose =
will
lead
to a combined SLACS sample covering nearly two decades in =
mass,
with
dense mapping of enclosed mass as a function of radius out to =
the
half-light
radius and beyond. With this longer mass baseline, we =
will
extend
our lensing and dynamical analysis of the mass structure =
and
scaling
relations of ETGs to galaxies of significantly lower mass, =
and
directly
test for a transition in structural and dark-matter =
content
trends
at intermediate galaxy mass. The broader mass coverage will =
also
enable
us to make a direct connection to the structure of =
well-studied
nearby
ETGs as deduced from dynamical modeling of their =
line-of-sight
velocity
distribution fields. Finally, the combined sample will allow =
a
more
conclusive test of the current SLACS result that the =
intrinsic
scatter
in ETG mass-density structure is not significantly =
correlated
with
any other galaxy observables. The final SLACS sample at =
the
conclusion
of this program will comprise approximately 130 lenses =
with
known
foreground and background redshifts, and is likely to be =
the
largest
confirmed sample of strong-lens galaxies for many years to =
come.
ACS/WFC3
11882
CCD
Hot Pixel Annealing
This
program continues the monthly anneal that has taken place =
every
four
weeks for the last three cycles. We now obtain WFC biases and =
darks
before
and after the anneal in the same sequence as is done for the =
ACS
daily
monitor (now done 4 times per week). So the anneal =
observation
supplements=
the monitor observation sets during the appropriate =
week.
Extended
Pixel Edge Response (EPER) and First Pixel Response (FPR) =
data
will
be obtained over a range of signal levels for the Wide =
Field
Channel
(WFC). This program emulates the ACS pre-flight =
ground
calibration=
and post-launch SMOV testing (program 8948), so that =
results
from
each epoch can be directly compared. The High Resolution =
Channel
(HRC)
visits have been removed since it could not be repaired =
during
SM4.
This
program also assesses the read noise, bias structure, and =
amplifier
cross-talk
of ACS/WFC using the GAIN=3D1.4 A/D conversion setting. =
This
investigati=
on
serves as a precursor to a more comprehensive study of =
WFC
performance=
using GAIN=3D1.4.
COS/FUV
11895
FUV
Detector Dark Monitor
Monitor
the FUV detector dark rate by taking long science =
exposures
without
illuminating the detector. The detector dark rate and =
spatial
distributio=
n
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/FUV
11897
FUV
Spectroscopic Sensitivity Monitoring
The
purpose of this proposal is to monitor sensitivity in each =
FUV
grating
mode to detect any changes due to contamination or other =
causes.
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. =
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. =
COS/NUV
11896
NUV
Spectroscopic Sensitivity Monitoring
The
purpose of this proposal is to monitor sensitivity of each =
NUV
grating
mode to detect any changes due to contamination or other =
causes.
COS/NUV
12041
COS-GTO:
Io Atmosphere/STIS
We
will use six HST orbits with COS to observe the =
disk-integrated
longitudina=
l
distribution of Io's atmosphere, and ten HST orbits =
with
STIS
to provide complementary disk-resolved information at =
key
locations.
We wil use the COS G225M grating to observe four =
SO2
absorption
bands, which can be used to determine SO2 =
atmospheric
density.
Disk-integrated 19 micron observations of the =
atmosphere
indicate
that the anti-Jupiter hemisphere of Io has an =
atmospheric
density
roughly ten times greater than the Jupiter-facing side =
(Spencer
et
al. 2005), and mm-wave observations suggest a similar =
pattern.
However
the infrared and mm-wave observations cannot easily =
separate
atmospheric=
density from atmospheric temperature, so these results =
are
model-depen=
dent.
Sparse 2100 2300 disk-resolved =
observations
(McGrath
et al. 2000, Jessup et al. 2004) tell a consistent story, =
but
do
not cover enough of Io's surface to provide full confirmation of =
the
long-wavele=
ngth
result. We will therefore observe Io's =
disk-integrated
atmospheric=
density at six longitudes, roughly 30, 90, 150, 210, =
270,
and
330 W, to confirm the 19 micron results and improve our ability =
to
model
the 19-micron data. With STIS, we plan disk-resolved 2000-3200 =
spectroscop=
y
of Io's SO2 atmosphere. Our observations will =
target
low-latitud=
e
regions away from active plumes (in contrast to our =
Cycle
10
observations (Jessup et al. 2004) which targeted the =
Prometheus
plume),
to look for the effect of plumes on the atmosphere. We will =
also
look
at the variation of low-latitude atmospheric abundance with =
terrain
type,
to look for explanations for the large longitudinal variations =
in
atmospheric=
pressure to be studied with COS. Finally, we will look at =
a
variety
of regions at two different times of day to determine the =
extent
of
diurnal variations in the atmosphere, which are expected if =
the
atmosphere
is dominantly supported by frost sublimation.
COS/NUV/FUV=
/WFC3/UV
12248
How
Dwarf Galaxies Got That Way: Mapping Multiphase Gaseous Halos =
and
Galactic
Winds Below L*
One
of the most vexing problems in galaxy formation concerns how =
gas
accretion
and feedback influence the evolution of galaxies. In high =
mass
galaxies,
numerical simulations predict the initial fuel is =
accreted
through
'cold' streams, after which AGN suppress star formation to =
leave
galaxies
red and gas-poor. In the shallow potential wells that =
host
dwarf
galaxies, gas accretion can be very efficient, and =
"superwinds"
driven
either by hot gas expelled by SNe or momentum imparted by SNe =
and
hot-star
radiation are regarded as the likely source(s) of =
feedback.
However,
major doubts persist about the physics of gas accretion, =
and
particularl=
y
about SN-driven feedback, including their scalings =
with
halo
mass and their influence on the evolution of the galaxies. =
While
"super=
winds"
are visible in X-rays near the point of their =
departure,
they
generally drop below detectable surface-brightness limits at ~ =
10
kpc.
Cold clumps in winds can be detected as blue-shifted =
absorption
against
the galaxy's own starlight, but the radial extent of these =
winds
are
difficult to constrain, leaving their energy, momentum, and =
ultimate
fate
uncertain. Wind prescriptions in hydrodynamical simulations =
are
uncertain
and at present are constrained only by indirect =
observations,
e.g.
by their influence on the stellar masses of galaxies and =
IGM
metallicity=
.
All these doubts lead to one conclusion: we do not
understand
gas accretion and feedback because we generally do =
not
observe
the infall and winds directly, in the extended gaseous halos =
of
galaxies,
when it is happening. To do this effectively, we must =
harness
the
power of absorption-line spectroscopy to measure the =
density,
temperature=
,
metallicity, and kinematics of small quantities of =
diffuse
gas
in galaxy halos. The most important physical diagnostics lie in =
the
FUV,
so this is uniquely a problem for HST and COS. We propose new =
COS
G130M
and G160M observations of 41 QSOs that probe the gaseous halos =
of
44
SDSS dwarf galaxies well inside their virial radii. Using =
sensitive
absorption-=
line
measurements of the multiphase gas diagnostics =
Lya,
CII/IV,
Si II/III/IV, and other species, supplemented by optical =
data
from
SDSS and Keck, we will map the halos of galaxies with L =3D 0.02 =
-
0.3
L*, stellar masses M* =3D 10^(8-10) Msun, over impact parameter =
from
15
- 150 kpc. These observations will directly constrain the content =
and
kinematics
of accreting and outflowing material, provide a =
concrete
target
for simulations to hit, and statistically test proposed =
galactic
superwind
models. These observations will also inform the study =
of
galaxies
at high z, where the shallow halo potentials that host =
dwarf
galaxies
today were the norm. These observations are low-risk =
and
routine
for COS, easily schedulable, and promise a major advance in =
our
understandi=
ng
of how dwarf galaxies came to be.
STIS/CCD
11845
CCD
Dark Monitor Part 2
Monitor
the darks for the STIS CCD.
STIS/CCD
11847
CCD
Bias Monitor-Part 2
Monitor
the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at =
gain=3D1,
and
1x1 at gain =3D 4, to build up high-S/N superbiases and track =
the
evolution
of hot columns.
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/U
12015
Rapid
Follow-Up Observations of Tidal Disruption Events Discovered =
by
Pan-STARRS1=
We
propose for rapid follow-up Chandra TOO ACIS-S observations =
and
HST/COS
NUV imaging and FUV low-resolution spectroscopy of 5 flares =
from
the
tidal disruption of stars by supermassive black holes discovered =
in
the
Pan-STARRS1 Medium Deep Survey. With TOO observations =
obtained
within
a month of the peak of the flare, and 5 months later, we aim =
to
1)
constrain the flare's broadband SED and bolometric luminosity, =
2)
follow
the decay of the flare and look for spectral evolution, and =
3)
place
strong limits on the presence of a persistent AGN nucleus. =
Tidal
disruption
events provide a cosmic laboratory to study the physics =
of
accretion
onto black holes, and are a unique probe of the mass of =
black
holes
in the nuclei of distant galaxies.
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
Supercluste=
rs
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
Supercluste=
rs
produce the integrated spectral signatures of =
Starburst
galaxies.
We will be able to directly measure the numbers =
and
emission-li=
ne
luminosities of thousands of Wolf Rayet stars located =
in
hundreds
of M101 Superclusters, and correlate those numbers against =
the
Supercluste=
r
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
characteriz=
ing
starburst galaxies' Superclusters.
WFC3/UV
12237
Orbits,
Masses, Densities, and Colors of Two Transneptunian Binaries =
Binaries
are the key to learning many crucial bulk properties =
of
transneptun=
ian
objects (TNOs) including their masses. Perhaps the =
most
interesting=
mass-dependent property of a TNO is its bulk density, =
which
provides
unique information about its bulk composition and =
interior
structure.
Densities have so far only been measured for a handful =
of
binary
TNO systems. This proposal seeks to determine orbits and =
thus
masses
of two more binary TNOs, both of which are also to be observed =
at
thermal
infrared wavelengths by the Herschel spacecraft. Combining =
the
masses
from Hubble with the sizes from Herschel will enable us =
to
compute
their densities. We will also obtain =
multi-wavelength
photometric=
colors of the individual components of each binary =
system.
It
is imperative to link colors to the physical properties measurable =
in
binary
systems in order to use the remnant planetesimals in =
today's
Kuiper
belt to learn more about the early history of our own =
solar
system,
and more generally about how planetesimals form in nebular =
disks
and
subsequently evolve.
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).