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Daily Report #5112



 
 
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Old June 8th 10, 05:23 PM posted to sci.astro.hubble
Cooper, Joe
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Default Daily Report #5112

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 z3 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 z5.3 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 (4d21 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 (z5) 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.

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