HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5112
PERIOD
COVERED: 5am June 7 - 5am June 8, 2010 (DOY 158/09:00z-159/09:00z)
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
12297
- REAcq(1,2,1) at 159/07:28:29z failed, FGS Sequential Attitude update failed
at
159/07:31z. Initial GSACQ(1,2,1) at 159/06:02:27z was successful.
Observations affected: WFC3 49 - 52, proposal ID#11926.
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS
GSAcq 13
13
FGS
REAcq 4
3
OBAD
with Maneuver 8
8
SIGNIFICANT
EVENTS: (None)
OBSERVATIONS
SCHEDULED:
ACS/WFC
11995
CCD
Daily Monitor (Part 2)
This
program comprises basic tests for measuring the read noise and dark
current
of the ACS WFC and for tracking the growth of hot pixels. The
recorded
frames are used to create bias and dark reference images for
science
data reduction and calibration. This program will be executed
four
days per week (Mon, Wed, Fri, Sun) for the duration of Cycle 17. To
facilitate
scheduling, this program is split into three proposals. This
proposal
covers 320 orbits (20 weeks) from 1 February 2010 to 20 June
2010.
ACS/WFC3
11735
The
LSD Project: Dynamics, Merging and Stellar Populations of a Sample
of
Well-Studied LBGs at z~3
A
large observational effort with the ground-based ESO/VLT telescopes
allowed
us to obtain deep, spatially-resolved, near-IR spectra of
complete
sample of 11 Lyman-Break Galaxies at z~3.1. These observations
were
used to obtain, for the first time, the metallicity and the
dynamical
properties of a sample of objects that, albeit small, is
representative
of the total population of the LBGs. We propose to use
HST
to obtain high-resolution optical and near-IR images of this sample
of
LBGs in order to study the broad-band morphology and the stellar
light
distribution of these galaxies. These images, exploiting the
superior
spatial resolution of HST images and the low-background : 1-
will
allow a precise measure of the dynamical mass from the velocity
field
derived with spectroscopy; 2- will permit a comparison of the
distribution
of star formation (from the line emission) with the
underlying
stellar population, and, 3- will be used to check if the
complex
velocity field and the multiple line-emitting regions detected
in
most targets can be ascribed to on-going mergers. This accurate study
will
shed light on a number of unsolved problems still affecting the
knowledge
of the LBGs.
COS/FUV
11687
SNAPing
Coronal Iron
This
is a Snapshot Survey to explore two forbidden lines of highly
ionized
iron in late-type coronal sources. Fe XII 1349 (T~ 2 MK) and Fe
XXI
1354 (T~ 10 MK) -- well known to Solar Physics -- have been detected
in
about a dozen cool stars, mainly with HST/STIS. The UV coronal
forbidden
lines are important because they can be observed with velocity
resolution
of better than 15 km/s, whereas even the state-of-the-art
X-ray
spectrometers on Chandra can manage only 300 km/s in the kilovolt
band
where lines of highly ionized iron more commonly are found. The
kinematic
properties of hot coronal plasmas, which are of great interest
to
theorists and modelers, thus only are accessible in the UV at
present.
The bad news is that the UV coronal forbidden lines are faint,
and
were captured only in very deep observations with STIS. The good
news
is that 3rd-generation Cosmic Origins Spectrograph, slated for
installation
in HST by SM4, in a mere 25 minute exposure with its G130M
mode
can duplicate the sensitivity of a landmark 25-orbit STIS E140M
observation
of AD Leo, easily the deepest such exposure of a late-type
star
so far. Our goal is to build up understanding of the properties of
Fe
XII and Fe XXI in additional objects beyond the current limited
sample:
how the lineshapes depend on activity, whether large scale
velocity
shifts can be detected, and whether the dynamical content of
the
lines can be inverted to map the spatial morphology of the stellar
corona
(as in "Doppler Imaging''). In other words, we want to bring to
bear
in the coronal venue all the powerful tricks of spectroscopic
remote
sensing, well in advance of the time that this will be possible
exploiting
the corona's native X-ray radiation. The 1290-1430 band
captured
by side A of G130M also contains a wide range of key plasma
diagnostics
that form at temperatures from below 10, 000 K (neutral
lines
of CNO), to above 200, 000 K (semi-permitted O V 1371), including
the
important bright multiplets of C II at 1335 and Si IV at 1400;
yielding
a diagnostic gold mine for the subcoronal atmosphere. Because
of
the broad value of the SNAP spectra, beyond the coronal iron project,
we
waive the normal proprietary rights.
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
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/FUV/STIS/CCD/MA1
11592
Testing
the Origin(s) of the Highly Ionized High-Velocity Clouds: A
Survey
of Galactic Halo Stars at z>3 kpc
Cosmological
simulation predicts that highly ionized gas plays an
important
role in the formation and evolution of galaxies and their
interplay
with the intergalactic medium. The NASA HST and FUSE missions
have
revealed high-velocity CIV and OVI absorption along extragalactic
sightlines
through the Galactic halo. These highly ionized high-velocity
clouds
(HVCs) could cover 85% of the sky and have a detection rate
higher
than the HI HVCs. Two competing, equally exciting, theories may
explain
the origin of these highly ionized HVCs: 1) the "Galactic"
theory,
where the HVCs are the result of feedback processes and trace
the
disk-halo mass exchange, perhaps including the accretion of matter
condensing
from an extended corona; 2) the "Local Group" theory, where
they
are part of the local warm-hot intergalactic medium, representing
some
of the missing baryonic matter of the Universe. Only direct
distance
determinations can discriminate between these models. Our group
has
found that some of these highly ionized HVCs have a Galactic origin,
based
on STIS observations of one star at z<5.3 kpc. We propose an HST
FUV
spectral survey to search for and characterize the high velocity NV,
CIV,
and SiIV interstellar absorption toward 24 stars at much larger
distances
than any previous searches (4<d<21 kpc, 3<|z|<13 kpc). COS
will
provide atomic to highly ionized species (e.g.,OI, CII, CIV, SiIV)
that
can be observed at sufficient resolution (R~22, 000) to not only
detect
these highly ionized HVCs but also to model their properties and
understand
their physics and origins. This survey is only possible
because
of the high sensitivity of COS in the FUV spectral range.
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/FUV
11598
How
Galaxies Acquire their Gas: A Map of Multiphase Accretion and
Feedback
in Gaseous Galaxy Halos
We
propose to address two of the biggest open questions in galaxy
formation
- how galaxies acquire their gas and how they return it to the
IGM
- with a concentrated COS survey of diffuse multiphase gas in the
halos
of SDSS galaxies at z = 0.15 - 0.35. Our chief science goal is to
establish
a basic set of observational facts about the physical state,
metallicity,
and kinematics of halo gas, including the sky covering
fraction
of hot and cold material, the metallicity of infall and
outflow,
and correlations with galaxy stellar mass, type, and color -
all
as a function of impact parameter from 10 - 150 kpc. Theory suggests
that
the bimodality of galaxy colors, the shape of the luminosity
function,
and the mass-metallicity relation are all influenced at a
fundamental
level by accretion and feedback, yet these gas processes are
poorly
understood and cannot be predicted robustly from first
principles.
We lack even a basic observational assessment of the
multiphase
gaseous content of galaxy halos on 100 kpc scales, and we do
not
know how these processes vary with galaxy properties. This ignorance
is
presently one of the key impediments to understanding galaxy
formation
in general. We propose to use the high-resolution gratings
G130M
and G160M on the Cosmic Origins Spectrograph to obtain sensitive
column
density measurements of a comprehensive suite of multiphase ions
in
the spectra of 43 z < 1 QSOs lying behind 43 galaxies selected from
the
Sloan Digital Sky Survey. In aggregate, these sightlines will
constitute
a statistically sound map of the physical state and
metallicity
of gaseous halos, and subsets of the data with cuts on
galaxy
mass, color, and SFR will seek out predicted variations of gas
properties
with galaxy properties. Our interpretation of these data will
be
aided by state-of-the-art hydrodynamic simulations of accretion and
feedback,
in turn providing information to refine and test such models.
We
will also use Keck, MMT, and Magellan (as needed) to obtain optical
spectra
of the QSOs to measure cold gas with Mg II, and optical spectra
of
the galaxies to measure SFRs and to look for outflows. In addition to
our
other science goals, these observations will help place the Milky
Way's
population of multiphase, accreting High Velocity Clouds (HVCs)
into
a global context by identifying analogous structures around other
galaxies.
Our program is designed to make optimal use of the unique
capabilities
of COS to address our science goals and also generate a
rich
dataset of other absorption-line systems
STIS/CC
11845
CCD
Dark Monitor Part 2
Monitor
the darks for the STIS CCD.
STIS/CC
11847
CCD
Bias Monitor-Part 2
Monitor
the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1,
and
1x1 at gain = 4, to build up high-S/N superbiases and track the
evolution
of hot columns.
STIS/CCD
11721
Verifying
the Utility of Type Ia Supernovae as Cosmological Probes:
Evolution
and Dispersion in the Ultraviolet Spectra
The
study of distant type Ia supernova (SNe Ia) offers the most
practical
and immediate discriminator between popular models of dark
energy.
Yet fundamental questions remain over possible
redshift-dependent
trends in their observed and intrinsic properties.
High-quality
Keck spectroscopy of a representative sample of 36
intermediate
redshift SNe Ia has revealed a surprising, and unexplained,
diversity
in their rest-frame UV fluxes. One possible explanation is
hitherto
undiscovered variations in the progenitor metallicity.
Unfortunately,
this result cannot be compared to local UV data as only
two
representative SNe Ia have been studied near maximum light. Taking
advantage
of two new `rolling searches' and the restoration of STIS, we
propose
a non-disruptive TOO campaign to create an equivalent comparison
local
sample. This will allow us to address possible evolution in the
mean
UV spectrum and its diversity, an essential precursor to the study
of
SNe beyond z~1.
WFC3/ACS/UVIS
11603
A
Comprehensive Study of Dust Formation in Type II Supernovae with HST,
Spitzer,
and Gemini
The
recent discovery of three extremely bright Type II SNe, (2007it,
2007oc,
2007od) gives us a unique opportunity to combine observations
with
HST, Spitzer, and Gemini to study the little understood dust
formation
process in Type II Sne. Priority 1 Spitzer Cycle 5 and band 1
Gemini
2008A time has already been approved for this project. Since
late-time
Type II Sne are faint and tend to be in crowded fields, we
need
the high sensitivity and high spatial resolution of ACS and
NICMOS/NIC2
for these observations. This project is motivated by the
recent
detection of large amounts of dust in high redshift galaxies. The
dust
in these high-z galaxies must come from young, massive stars so
Type
II Sne could be potential sources. The mechanism and the efficiency
of
dust condensation in Type II SN ejecta are not well understood,
largely
due to the lack of observational data. We plan to produce a
unique
dataset, combining spectroscopy and imaging in the visible, near-
and
mid-IR covering the key phase, 400-700 days after maximum when dust
is
known to form in the SN ejecta. Therefore, we are proposing for
coordinated
HST/NOAO observations (HST ACS, NICMOS/NIC2 & Gemini/GMOS
and
TReCS) which will be combined with our Spitzer Cycle 5 data to study
these
new bright Sne. The results of this program will place strong
constraints
on the formation of dust seen in young high redshift (z>5)
galaxies.
WFC3/IR
11666
Chilly
Pairs: A Search for the Latest-type Brown Dwarf Binaries and the
Prototype
Y Dwarf
We
propose to use HST/NICMOS to image a sample of 27 of the nearest (<
20
pc) and lowest luminosity T-type brown dwarfs in order to identify
and
characterize new very low mass binary systems. Only 3 late-type T
dwarf
binaries have been found to date, despite that fact that these
systems
are critical benchmarks for evolutionary and atmospheric models
at
the lowest masses. They are also the most likely systems to harbor Y
dwarf
companions, an as yet unpopulated putative class of very cold (T <
600
K) brown dwarfs. Our proposed program will more than double the
number
of T5-T9 dwarfs imaged at high resolution, with an anticipated
yield
of ~5 new binaries with initial characterization of component
spectral
types. We will be able to probe separations sufficient to
identify
systems suitable for astrometric orbit and dynamical mass
measurements.
We also expect one of our discoveries to contain the first
Y-type
brown dwarf. Our proposed program complements and augments
ongoing
ground-based adaptive optics surveys and provides pathway
science
for JWST.
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/IR
11926
IR
Zero Points
We
will measure and monitor the zeropoints through the IR filters using
observations
of the white dwarf standard stars, GD153, GD71 and GD191B2B
and
the solar analog standard star, P330E. Data will be taken monthly
during
Cycle 17. Observations of the star cluster, NGC 104, are made
twice
to check color transformations. We expect an accuracy of 2% in the
wide
filter zeropoints relative to the HST photometric system, and 5% in
the
medium- and narrow-band filters.
WFC3/UV
12119
Rapid
Response: Unexpected Jupiter Impact
On
3 June 2010, amateur astronomers A. Wesley and C. Go independently
captured
observations of an impact on Jupiter: the bright flash of an
impact
itself, not the dark aftermath as seen in 2009. This event was
completely
unexpected given the recent impact in 2009, and contradicts
recently
revised predictions of jovian impact rates. Three circumstances
make
this 2009 event unique: first, the event was captured on video;
second,
it was on the jovian day-side and hence fully visible from
Earth;
and third, it was at low latitude (i.e., favorably placed on the
planet).
These factors will permit a lightcurve to be extracted, which
is
critical for determining the energy of the explosion and hence the
size
of the impacting body (not available for the 2009 event and
available
for only a few 1994 events by Galileo). As of this writing, no
dark
impact site has been detected with telescopes of any aperture,
including
the Gemini North telescope. Hubble may be the only facility
with
high enough spatial resolution to detect the 2010 impact site. If
Hubble
images show a site, then the body's trajectory might be
obtainable.
If no site is detected, then Hubble will confirm that this
is
the first observation of a meteor on another atmosphere-bearing
planet.
If an event of this size occurred on Earth, it would be likely
be
termed a Type 1 Low-Altitude Airburst, like Tunguska or larger. Thus,
this
new event could become the best-observed analogue of a terrestrial
airburst
of the size that dominates the impact threat to humans. The
observations
we propose should provide independent constraints on
penetration
depth and atmospheric effects. This data will strongly
inform
our understanding of terrestrial airbursts and allow better
quantification
of the associated threat. We request a single orbit to
image
the impact latitude on the planet's central meridian. Of critical
importance
are Hubble's unique UV sensitivity (critical for assessing
aspects
of the 2009 impact, and not obtainable from any ground-based
facility)
and Hubble's high spatial resolution (also not obtainable in
the
visible form any ground-based telescope).
WFC3/UVIS
11707
Detecting
Isolated Black Holes through Astrometric Microlensing
This
proposal aims to make the first detection of isolated stellar-mass
black
holes (BHs) in the Milky Way, and to determine their masses. Until
now,
the only directly measured BH masses have come from radial-velocity
measurements
of X-ray binaries. Our proposed method uses the astrometric
shifts
that occur when a galactic-bulge microlensing event is caused by
a
BH lens. Out of the hundreds of bulge microlensing events found
annually
by the OGLE and MOA surveys, a few are found to have very long
durations
(>200 days). It is generally believed that the majority of
these
long-duration events are caused by lenses that are isolated BHs.
To
test this hypothesis, we will carry out high-precision astrometry of
5
long-duration events, using the ACS/HRC camera. The expected
astrometric
signal from a BH lens is >1.4 mas, at least 7 times the
demonstrated
astrometric precision attainable with the HRC.
This
proposal will thus potentially lead to the first unambiguous
detection
of isolated stellar-mass BHs, and the first direct mass
measurement
for isolated stellar-mass BHs through any technique.
Detection
of several BHs will provide information on the frequency of
BHs
in the galaxy, with implications for the slope of the IMF at high
masses,
the minimum mass of progenitors that produce BHs, and
constraints
on theoretical models of BH formation.
WFC3/UVIS
11732
The
Temperature Profiles of Quasar Accretion Disks
We
can now routinely measure the size of quasar accretion disks using
gravitational
microlensing of lensed quasars. At optical wavelengths we
observe
a size and scaling with black hole mass roughly consistent with
thin
disk theory but the sizes are larger than expected from the
observed
optical fluxes. One solution would be to use a flatter
temperature
profile, which we can study by measuring the wavelength
dependence
of the disk size over the largest possible wavelength
baseline.
Thus, to understand the size discrepancy and to probe closer
to
the inner edge of the disk we need to extend our measurements to UV
wavelengths,
and this can only be done with HST. For example, in the UV
we
should see significant changes in the optical/UV size ratio with
black
hole mass. We propose monitoring 5 lenses spanning a broad range
of
black hole masses with well-sampled ground based light curves,
optical
disk size measurements and known GALEX UV fluxes during Cycles
17
and 18 to expand from our current sample of two lenses. We would
obtain
5 observations of each target in each Cycle, similar to our
successful
strategy for the first two targets.
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).
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.