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============================================================================== TOPIC: Daily Report #5098
== 1 of 2 == Date: Tues, May 18 2010 6:08 am From: "Cooper, Joe"
HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY REPORT #5098
PERIOD COVERED: 5am May 17 - 5am May 18, 2010 (DOY 137/09:00z-138/09:00z)
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 11 11 FGS REAcq 5 5 OBAD with Maneuver 6 6
SIGNIFICANT EVENTS: (None)
OBSERVATIONS SCHEDULED: 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/WFC3/UVI 11536
COS-GTO: Sleuthing the Source of Distant Cometary Activity
Distant comets and Centaurs often show cometary activity and outbursts well beyond 3 AU, the boundary of the sublimation zone of water Super-volatiles (most likely CO, but possibly CH4, N2, or S2) are suspected to be responsible, but have never been detected in distant comets in the UV We will obtain FUV spectra of active bodies to cover important CO emission bands We plan two sets of observations: comet 29P/Schwassmann-Wachmann at 6 AU, whose outbursts are too short to capture as a Target of Opportunity, but which also shows persistent cometary activity in quiescence; and Target of Opportunity observations of the Centaur 2060 Chiron (at ~15 5 AU) in outburst
COS/NUV 11894
NUV Detector Dark Monitor
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
S/C 12046
COS FUV DCE Memory Dump
Whenever the FUV detector high voltage is on, count rate and current draw information is collected, monitored, and saved to DCE memory Every 10 msec the detector samples the currents from the HV power supplies (HVIA, HVIB) and the AUX power supply (AUXI) The last 1000 samples are saved in memory, along with a histogram of the number of occurrences of each current value
In the case of a HV transient (known as a "crackle" on FUSE), where one of these currents exceeds a preset threshold for a persistence time, the HV will shut down, and the DCE memory will be dumped and examined as part of the recovery procedure However, if the current exceeds the threshold for less than the persistence time (a "mini-crackle" in FUSE parlance), there is no way to know without dumping DCE memory By dumping and examining the histograms regularly, we will be able to monitor any changes in the rate of "mini-crackles" and thus learn something about the state of the detector
S/C/WFC3/IR 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)
STIS 11849
STIS CCD Hot Pixel Annealing
This purpose of this activity is to repair radiation induced hot pixel damage to the STIS CCD by warming the CCD to the ambient instrument temperature and annealing radiation damaged pixels Radiation damage creates hot pixels in the STIS CCD Detector Many of these hot pixels can be repaired by warming the CCD from its normal operating temperature near -83 C to the ambient instrument temperature (~ +5 C) for several hours The number of hot pixels repaired is a function of annealing temperature The effectiveness of the CCD hot pixel annealing process is assessed by measuring the dark current behavior before and after annealing and by searching for any window contamination effects
STIS/CCD 11567
Boron Abundances in Rapidly Rotating Early-B Stars
Models of rotation in early-B stars predict that rotationally driven mixing should deplete surface boron abundances during the main-sequence lifetime of many stars However, recent work has shown that many boron depleted stars are intrinsically slow rotators for which models predict no depletion should have occurred, while observations of nitrogen in some more rapidly rotating stars show less mixing than the models predict Boron can provide unique information on the earliest stages of mixing in B stars, but previous surveys have been biased towards narrow-lined stars because of the difficulty in measuring boron abundances in rapidly rotating stars The two targets observed as part of our Cycle 13 SNAP program 10175, just before STIS failed, demonstrate that it is possible to make useful boron abundance measurements for early-B stars with Vsin(i) above 100 km/s We propose to extend that survey to a large enough sample of stars to allow statistically significant tests of models of rotational mixing in early-B stars
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=1, and 1x1 at gain = 4, to build up high-S/N superbiases and track the evolution of hot columns
STIS/CCD 11849
STIS CCD Hot Pixel Annealing
This purpose of this activity is to repair radiation induced hot pixel damage to the STIS CCD by warming the CCD to the ambient instrument temperature and annealing radiation damaged pixels Radiation damage creates hot pixels in the STIS CCD Detector Many of these hot pixels can be repaired by warming the CCD from its normal operating temperature near -83 C to the ambient instrument temperature (~ +5 C) for several hours The number of hot pixels repaired is a function of annealing temperature The effectiveness of the CCD hot pixel annealing process is assessed by measuring the dark current behavior before and after annealing and by searching for any window contamination effects
STIS/CCD/STIS/MA1 11737
The Distance Dependence of the Interstellar N/O Abundance Ratio: A Gould Belt Influence?
The degree of elemental abundance homogeneity in the interstellar medium is a function of the enrichment and mixing processes that govern Galactic chemical evolution Observations of young stars and the interstellar gas within ~500 pc of the Sun have revealed a local ISM that is so well-mixed it is having an impact on ideas regarding the formation of extrasolar planets However, the situation just beyond the local ISM is not so clear Sensitive UV absorption line measurements have recently revealed a pattern of inhomogeneities in the interstellar O, N, and Kr gas-phase abundances at distances of ~500 pc and beyond that appear nucleosynthetic in origin rather than due to dust depletion In particular, based on a sample of 13 sightlines, Knauth et al (2006) have found that the nearby stars (d < 500 pc) exhibit a mean interstellar N/O abundance ratio that is significantly higher (0 18 dex) than that toward the more distant stars Interestingly, all of their sightlines lie in the sky vicinity of the Gould Belt of OB associations, molecular clouds, and diffuse gas encircling the Sun at a distance of ~400 pc Is it possible that mixing processes have not yet smoothed out the recent ISM enrichment by massive stars in the young Belt region? By measuring the interstellar N/O ratios in a strategic new sample of sightlines with STIS, we propose to test the apparent N/O homogeneity inside the Gould Belt and determine if the apparent decline in the N/O ratio with distance is robust and associated with the Belt region
WFC3/IR 11153
The Physical Nature and Age of Lyman Alpha Galaxies
In the simplest scenario, strong Lyman alpha emission from high redshift galaxies would indicate that stellar populations younger than 10 Myrs dominate the UV This does not, however, constrain the stellar populations older than 100 Myrs, which do not contribute to UV light Also, the Lyman alpha line can be boosted if the interstellar medium is both clumpy and dusty Different studies with small samples have reached different conclusions about the presence of dust and old stellar populations in Lyman alpha emitters
We propose HST-NICMOS and Spitzer-IRAC photometry of 35 Lyman-alpha
galaxies at redshift 4
5
Taken together, these two quantities will yield the star-formation histories of Lyman alpha galaxies, which form fully half of the known galaxies at z=4-6 They will tell us whether these are young or old galaxies by straddling the 4000A break Data from NICMOS is essential for these compact and faint (i=25-26th magnitude AB) high redshift galaxies, which are too faint for good near-IR photometry from the ground
WFC3/IR 11838
Completing a Flux-limited Survey for X-ray Emission from Radio Jets
We will measure the changing flow speeds, magnetic fields, and energy fluxes in well-resolved quasar jets found in our short-exposure Chandra survey by combining new, deep Chandra data with radio and optical imaging We will image each jet with sufficient sensitivity to estimate beaming factors and magnetic fields in several distinct regions, and so map the variations in these parameters down the jets HST observations will help diagnose the role of synchrotron emission in the overall SED, and may reveal condensations on scales less than 0 1 arcsec
WFC3/UVI 11360
Star Formation in Nearby Galaxies
Star formation is a fundamental astrophysical process; it controls phenomena ranging from the evolution of galaxies and nucleosynthesis to the origins of planetary systems and abodes for life The WFC3, optimized at both UV and IR wavelengths and equipped with an extensive array of narrow-band filters, brings unique capabilities to this area of study The WFC3 Scientific Oversight Committee (SOC) proposes an integrated program on star formation in the nearby universe which will fully exploit these new abilities Our targets range from the well-resolved R136 in 30 Dor in the LMC (the nearest super star cluster) and M82 (the nearest starbursting galaxy) to about half a dozen other nearby galaxies that sample a wide range of star-formation rates and environments Our program consists of broad-band multiwavelength imaging over the entire range from the UV to the near-IR, aimed at studying the ages and metallicities of stellar populations, revealing young stars that are still hidden by dust at optical wavelengths, and showing the integrated properties of star clusters Narrow-band imaging of the same environments will allow us to measure star-formation rates, gas pressure, chemical abundances, extinction, and shock morphologies The primary scientific issues to be addressed are: (1) What triggers star formation? (2) How do the properties of star-forming regions vary among different types of galaxies and environments of different gas densities and compositions? (3) How do these different environments affect the history of star formation? (4) Is the stellar initial mass function universal or determined by local conditions?
WFC3/UVI 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 (11909), will be used to generate the
necessary superbias
and superdark reference files for the
calibration pipeline (CDBS)
WFC3/UVI 12018
Ultra-Luminous x-Ray Sources in the Most Metal-Poor Galaxies
There is growing observational and theoretical evidence to suggest that Ultra-Luminous X-ray sources (ULX) form preferentially in low metallicity environments Here we propose a survey of 27 nearby (< 30Mpc) star-forming Extremely Metal Poor Galaxies (Z<5% solar) There are almost no X-ray observations of such low abundance galaxies (3 in the Chandra archive) These are the most metal-deficient galaxies known, and a logical place to find ULX if they favor metal-poor systems We plan to test recent population synthesis models which predict that ULX should be very numerous in metal-poor galaxies We will also test the hypothesis that ULX form in massive young star clusters, and ask for HST time to obtain the necessay imaging data
== 2 of 2 == Date: Wed, May 19 2010 6:52 am From: "Cooper, Joe"
HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY REPORT #5098
PERIOD COVERED: 5am May 17 - 5am May 18, 2010 (DOY 137/09:00z-138/09:00z)
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated )
HSTARS:
12283 - GSAcq(1,2,1) at 138/19:26:04z acquired fine lock backup on FGS 2 due to scan step limit exceeded on FGS 1
Observations possibly affected: STIS 22 to 23, proposal ID#11740
REAcq(1,2,1) scheduled at 138/22:36:56z and at 139/00:12:48z acquired fine lock backup on FGS 2 with scan step limit exceeded on FGS 1
Observations possibly affected: STIS 24-29 Proposal ID#11740; STIS 30 Proposal ID#11845; WFC3 80 and 84 Proposal ID#11914; WFC3 82 Proposal ID#11908; WFC3 85 Proposal ID#11905; ACS 13-18 Proposal ID#11995
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS GSAcq 10 10 FGS REAcq 7 7 OBAD with Maneuver 8 8
SIGNIFICANT EVENTS: (None)
OBSERVATIONS SCHEDULED:
ACS/WFC 11564
Optical and Ultraviolet Photometry of Isolated Neutron Stars
We propose ultraviolet and B-band observations of 5 nearby, thermally emitting neutron stars These data will measure the Rayleigh-Jeans tails of their spectra, providing a vital complement to X-ray spectroscopy and helping to constrain atmospheric models, working toward the ultimate goal of unraveling the physics of neutron stars With these data we will have good-quality optical and UV data for the full sample of these objects, allowing detailed comparisons between them Finally, the data should allow us to measure proper motions for one or two objects, and will serve as the reference data for the remaining objects; such proper motions allow ages to be determined for these objects by tracing them back to likely birth locations
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/WFC/WFC3/IR 11663
Formation and Evolution of Massive Galaxies in the Richest Environments at 1 5 < z < 2 0
We propose to image seven 1
5 COS/FUV/COS/NUV 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 along a significant
total pathlength through the IGM (Delta z ~ 20)
COS/NUV 11894 NUV Detector Dark Monitor 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
STIS/CCD 11637 A Closeup View of a Twin of SN 1987A Before Explosion Last year we reported the discovery of a ring nebula called SBW1
around a blue supergiant star in our Galaxy
In almost every respect,
it is a true "twin" of the equatorial ring nebula around SN 1987A: it
has an identical physical radius of 0
2pc, a similar expansion speed
and age, it is located in a massive HII region, the central star is an
early B supergiant with the same luminosity as SN1987A's progenitor,
and the ring's structure in our ground-based H-alpha images looks
almost identical to early HST images of SN1987A's ring
The detailed
density structure of SN1987A's ring on scales smaller than the
limiting resolution of HST has become a pressing question, because the
forward shock of the supernova is now colliding with that ring,
causing it to brighten by 3 orders of magnitude and giving rise to a
series of "hotspots" around the ring
HST/WFC3 images of SBW1 will
provide a snapshot of an SN1987A-like ring before the supernova
explodes, and will provide a detailed view of the important density
inhomogeneities in the ring with a physical spatial resolution 10
times better than HST images of SN1987A (because SBW1 is 10 times
closer to us)
STIS spectra will allow us to directly measure the
radial density structure of the ring
Both the overall radial density
profile and the detailed structures of the clumps that give rise to
the "hotspots" are critical factors in modeling the rapid evolution of
SN1987A, and our proposed study of SBW1 will provide extremely
valuable input for those models
STIS/CCD 11740 A Complete Optical and NIR Atmospheric Transmission Spectrum of the
Exoplanet HD189733b The hot Jupiter HD189733b offers the best exoplanet in which to
perform atmospheric studies through transit spectroscopy
Here we
propose STIS and Nicmos spectra to help construct a full exoplanetary
transit transmission spectrum that extends over the entire optical and
near-infrared range
Such a spectrum will link existing observed
atmospheric features such as haze, water, and methane, providing a
coherent understanding of all these reported features
With a spectrum
covering many observed absorption features, the absolute pressure
scale and abundances can be determined linking observed features to
the actual atmospheric properties of the exoplanet
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=1,
and 1x1 at gain = 4, to build up high-S/N superbiases and track the
evolution of hot columns
STIS/CCD/STIS/MA2 11568 A SNAPSHOT Survey of the Local Interstellar Medium: New NUV
Observations of Stars with Archived FUV Observations We propose to obtain high-resolution STIS E230H SNAP observations of
MgII and FeII interstellar absorption lines toward stars within 100
parsecs that already have moderate or high-resolution far-UV (FUV),
900-1700 A, observations available in the MAST Archive
Fundamental
properties, such as temperature, turbulence, ionization, abundances,
and depletions of gas in the local interstellar medium (LISM) can be
measured by coupling such observations
Due to the wide spectral range
of STIS, observations to study nearby stars also contain important
data about the LISM embedded within their spectra
However, unlocking
this information from the intrinsically broad and often saturated FUV
absorption lines of low-mass ions, (DI, CII, NI, OI), requires first
understanding the kinematic structure of the gas along the line of
sight
This can be achieved with high resolution spectra of high-mass
ions, (FeII, MgII), which have narrow absorption lines, and can
resolve each individual velocity component (interstellar cloud)
By
obtaining short (~10 minute) E230H observations of FeII and MgII, for
stars that already have moderate or high-resolution FUV spectra, we
can increase the sample of LISM measurements, and thereby expand our
knowledge of the physical properties of the gas in our galactic
neighborhood
STIS is the only instrument capable of obtaining the
required high resolution data now or in the foreseeable future
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 11696 Infrared Survey of Star Formation Across Cosmic Time We propose to use the unique power of WFC3 slitless spectroscopy to
measure the evolution of cosmic star formation from the end of the
reionization epoch at z>6 to the close of the galaxy-building era at
z~0
3
Pure parallel observations with the grisms have proven to be
efficient for identifying line emission from galaxies across a broad
range of redshifts
The G102 grism on WFC3 was designed to extend this
capability to search for Ly-alpha emission from the first galaxies
Using up to 250 orbits of pure parallel WFC3 spectroscopy, we will
observe about 40 deep (4-5 orbit) fields with the combination of G102
and G141, and about 20 shallow (2-3 orbit) fields with G141 alone
Our primary science goals at the highest redshifts are: (1) Detect
Lya in ~100 galaxies with z>5
6 and measure the evolution of the Lya
luminosity function, independent of of cosmic variance; 2) Determine
the connection between emission-line selected and continuum-break
selected galaxies at these high redshifts, and 3) Search for the
proposed signature of neutral hydrogen absorption at re-ionization
At
intermediate redshifts we will (4) Detect more than 1000 galaxies in
Halpha at 0
5 To identify single-line Lya emitters, we will exploit the wide
0
8--1
9um wavelength coverage of the combined G102+G141 spectra
All
[OII] and [OIII] interlopers detected in G102 will be reliably
separated from true LAEs by the detection of at least one strong line
in the G141 spectrum, without the need for any ancillary data
We
waive all proprietary rights to our data and will make high-level data
products available through the ST/ECF
WFC3/IR 11719 A Calibration Database for Stellar Models of Asymptotic Giant Branch
Stars Studies of galaxy formation and evolution rely increasingly on the
interpretation and modeling of near-infrared observations
At these
wavelengths, the brightest stars are intermediate mass asymptotic
giant branch (AGB) stars
These stars can contribute nearly 50% of the
integrated luminosity at near infrared and even optical wavelengths,
particularly for the younger stellar populations characteristic of
high-redshift galaxies (z>1)
AGB stars are also significant sources
of dust and heavy elements
Accurate modeling of AGB stars is
therefore of the utmost importance
The primary limitation facing current models is the lack of useful
calibration data
Current models are tuned to match the properties of
the AGB population in the Magellanic Clouds, and thus have only been
calibrated in a very narrow range of sub-solar metallicities
Preliminary observations already suggest that the models are
overestimating AGB lifetimes by factors of 2-3 at lower metallicities
At higher (solar) metallicities, there are no appropriate observations
for calibrating the models
We propose a WFC3/IR SNAP survey of nearby galaxies to create a large
database of AGB populations spanning the full range of metallicities
and star formation histories
Because of their intrinsically red
colors and dusty circumstellar envelopes, tracking the numbers and
bolometric fluxes of AGB stars requires the NIR observations we
propose here
The resulting observations of nearby galaxies with deep
ACS imaging offer the opportunity to obtain large (100-1000's)
complete samples of AGB stars at a single distance, in systems with
well-constrained star formation histories and metallicities
WFC3/IR/WFC3/UVI 11644 A dynamical-compositional survey of the Kuiper belt: a new window into
the formation of the outer solar system The eight planets overwhelmingly dominate the solar system by mass,
but their small numbers, coupled with their stochastic pasts, make it
impossible to construct a unique formation history from the dynamical
or compositional characteristics of them alone
In contrast, the huge
numbers of small bodies scattered throughout and even beyond the
planets, while insignificant by mass, provide an almost unlimited
number of probes of the statistical conditions, history, and
interactions in the solar system
To date, attempts to understand the
formation and evolution of the Kuiper belt have largely been dynamical
simulations where a hypothesized starting condition is evolved under
the gravitational influence of the early giant planets and an attempt
is made to reproduce the current observed populations
With little
compositional information known for the real Kuiper belt, the test
particles in the simulation are free to have any formation location
and history as long as they end at the correct point
Allowing
compositional information to guide and constrain the formation,
thermal, and collisional histories of these objects would add an
entire new dimension to our understanding of the evolution of the
outer solar system
While ground based compositional studies have hit
their flux limits already with only a few objects sampled, we propose
to exploit the new capabilities of WFC3 to perform the first ever
large-scale dynamical-compositional study of Kuiper belt objects
(KBOs) and their progeny to study the the chemical, dynamical, and
collisional history of the region of the giant planets
The
sensitivity of the WFC3 observations will allow us to go up to two
magnitudes deeper than our ground based studies, allowing us the
capability of optimally selecting a target list for a large survey
rather than simply taking the few objects that can be measured, as we
have had to do to date
We have carefully constructed a sample of 120
objects which provides both overall breadth, for a general
understanding of these objects, plus a large enough number of objects
in the individual dynamical subclass to allow detailed comparison
between and within these groups
These objects will likely define the
core Kuiper belt compositional sample for years to come
While we have
many specific results anticipated to come from this survey, as with
any project where the field is rich, our current knowledge level is
low, and a new instrument suddenly appears which can exploit vastly
larger segments of the population, the potential for discovery -- both
anticipated and not -- is extraordinary
WFC3/UVI 11657 The population of compact planetary nebulae in the Galactic Disk We propose to secure narrow- and broad-band images of compact
planetary nebulae (PNe) in the Galactic Disk to study the missing link
of the early phases of post-AGB evolution
Ejected AGB envelopes
become PNe when the gas is ionized
PNe expand, and, when large
enough, can be studied in detail from the ground
In the interim, only
the HST capabilities can resolve their size, morphology, and central
stars
Our proposed observations will be the basis for a systematic
study of the onset of morphology
Dust properties of the proposed
targets will be available through approved Spitzer/IRS spectra, and so
will the abundances of the alpha-elements
We will be able thus to
explore the interconnection of morphology, dust grains, stellar
evolution, and populations
The target selection is suitable to
explore the nebular and stellar properties across the Galactic Disk,
and to set constraints on the Galactic evolutionary models through the
analysis of metallicity and population gradients
WFC3/UVI 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 WFC3/UVI 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
WFC3/UVI 11914 UVIS Earth Flats This program is an experimental path finder for Cycle 18 calibration
Visible-wavelength flat fields will be obtained by observing the dark
side of the Earth during periods of full moon illumination
The
observations will consist of full-frame streaked WFC3 UVIS imagery:
per 22-min total exposure time in a single "dark-sky" orbit, we
anticipate collecting 7000 e/pix in F606W or 4500 e/pix in F814W
To
achieve Poisson S/N > 100 per pixel, we requires at least 2 orbits of
F606W and 3 orbits of F814W
For UVIS narrowband filters, exposures of 1 sec typically do not
saturate on the sunlit Earth, so we will take sunlit Earth flats for
three of the more-commonly used narrowband filters in Cycle 17 plus
the also-popular long-wavelength quad filters, for which we get four
filters at once
Why not use the Sunlit Earth for the wideband visible-light filters?
It is too bright in the visible for WFC3 UVIS minimum exposure time of
0
5 sec
Similarly, for NICMOS the sunlit-Earth is too bright which
saturates the detector too quickly and/or induces abnormal behaviors
such as super-shading (Gilmore 1998, NIC 098-011)
In the narrowband
visible and broadband near-UV its not too bright (predictions in Cox
et al
1987 "Standard Astronomical Sources for HST: 6
Spatially Flat
Fields
" and observations in ACS Program 10050)
Other possibilities? Cox et al
's Section II
D addresses many other
possible sources for flat fields, rejecting them for a variety of
reasons
A remaining possibility would be the totally eclipsed moon
Such eclipses provide approximately 2 hours (1 HST orbit) of
opportunity per year, so they are too rare to be generically useful
An advantage of the moon over the Earth is that the moon subtends less
than 0
25 square degree, whereas the Earth subtends a steradian or
more, so scattered light and light potentially leaking around the
shutter presents additional problems for the Earth
Also, we're unsure
if HST can point 180 deg from the Sun
==============================================================================
TOPIC: Daily Report #5100 == 1 of 1 ==
Date: Thurs, May 20 2010 12:20 pm
From: "Bassford, Lynn" HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science DAILY REPORT #5100 PERIOD COVERED: 5am May 19 - 5am May 20, 2010 (DOY 139/09:00z-140/09:00z) FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated
) HSTARS: For DOY (136) 12284 - GSAcq(1,2,1) at 136/17:23:21z required 10 attempts to achieve
CT-DV on FGS2
The acquisition was successful
COMPLETED OPS REQUEST: (None) COMPLETED OPS NOTES: (None) FGS GSAcq 8 8
FGS REAcq 9 9
OBAD with Maneuver 4 4 SIGNIFICANT EVENTS: (None) OBSERVATIONS SCHEDULED: ACS/WFC 11564 Optical and Ultraviolet Photometry of Isolated Neutron Stars We propose ultraviolet and B-band observations of 5 nearby, thermally
emitting neutron stars
These data will measure the Rayleigh-Jeans
tails of their spectra, providing a vital complement to X-ray
spectroscopy and helping to constrain atmospheric models, working
toward the ultimate goal of unraveling the physics of neutron stars
With these data we will have good-quality optical and UV data for the
full sample of these objects, allowing detailed comparisons between
them
Finally, the data should allow us to measure proper motions for
one or two objects, and will serve as the reference data for the
remaining objects; such proper motions allow ages to be determined for
these objects by tracing them back to likely birth locations
ACS/WFC 12012 Binary Formation in the Sparse Galactic Globular Cluster NGC 3201 Bright X-ray sources in globular clusters, X-ray binaries, cataclysmic
variables, active binaries, and millisecond pulsars, are all binary
systems or thought to be the products of such systems
Studies of
X-ray sources in GCs thus probe binary formation
Most past
observations have concentrated on dense GCs; these systems show clear
evidence for strong dynamical formation of binaries; however, sparse
clusters seem to fall off this pattern
Potential explanantions
include, among others, primordial binary formation and a
misunderstanding of the dynamical state of some GCs
We propose an 85
ks ACIS-S observation of NGC~3201, the nearest sparse GC unobserved by
Chandra to test these explanations
We request 1 orbit of HST to
discriminate CVs from ABs, and 1 hour of GBT time to search for MSPs
ACS/WFC/WFC3/UVI 11233 Multiple Generations of Stars in Massive Galactic Globular Clusters This is a follow-up to recent HST imaging of NGC 2808, which
discovered that its main sequence is triple, with three well-separated
parallel branches (Fig
~1)
Along with the double MS of Omega
Centauri, this challenges the long-held paradigm that globular
clusters are simple, single stellar populations
The cause of this
main sequence multiplicity in both clusters is likely to be
differences in helium abundance, which could play a fundamental role
in the understanding of stellar populations
We propose to image seven
more of the most massive globular clusters, to examine their main
sequences for indications of splitting
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=1,
and 1x1 at gain = 4, to build up high-S/N superbiases and track the
evolution of hot columns
STIS/MA1 11861 MAMA FUV Flats This program will obtain FUV-MAMA observations of the STIS internal
Krypton lamp to construct an FUV flat applicable to all FUV modes
STIS/MA2 11857 STIS Cycle 17 MAMA Dark Monitor This proposal monitors the behavior of the dark current in each of the
MAMA detectors
The basic monitor takes two 1380s ACCUM darks each week with each
detector
However, starting Oct 5, pairs are only included for weeks
that the LRP has external MAMA observations planned
The weekly pairs
of exposures for each detector are linked so that they are taken at
opposite ends of the same SAA free interval
This pairing of exposures
will make it easier to separate long and short term temporal
variability from temperature dependent changes
For both detectors, additional blocks of exposures are taken once
every six months
These are groups of five 1314 s FUV-MAMA TIME-TAG
darks or five 3x315 s NUV ACCUM darks distributed over a single SAA
free interval
This will give more information on the brightness of
the FUV MAMA dark current as a function of the amount of time that the
HV has been on, and for the NUV MAMA will give a better measure of the
short term temperature dependence
WFC3/IR 11664 The WFC3 Galactic Bulge Treasury Program: Populations, Formation
History, and Planets Exploiting the full power of the Wide Field Camera 3 (WFC3), we
propose deep panchromatic imaging of four fields in the Galactic
bulge
These data will enable a sensitive dissection of its stellar
populations, using a new set of reddening-free photometric indices we
have constructed from broad-band filters across UV, optical, and
near-IR wavelengths
These indices will provide accurate temperatures
and metallicities for hundreds of thousands of individual bulge stars
Proper motions of these stars derived from multi-epoch observations
will allow separation of pure bulge samples from foreground disk
contamination
Our catalogs of proper motions and panchromatic
photometry will support a wide range of bulge studies
Using these photometric and astrometric tools, we will reconstruct
the detailed star-formation history as a function of position within
the bulge, and thus differentiate between rapid- and
extended-formation scenarios
We will also measure the dependence of
the stellar mass function on metallicity, revealing how the
characteristic mass of star formation varies with chemistry
Our
sample of bulge stars with accurate metallicities will include 12
candidate hosts of extrasolar planets
Planet frequency is correlated
with metallicity in the solar neighborhood; our measurements will
extend this knowledge to a remote environment with a very distinct
chemistry
Our proposal also includes observations of six well-studied globular
and open star clusters; these observations will serve to calibrate our
photometric indices, provide empirical population templates, and
transform the theoretical isochrone libraries into the WFC3 filter
system
Besides enabling our own program, these products will provide
powerful new tools for a host of other stellar-population
investigations with HST/WFC3
We will deliver all of the products from
this Treasury Program to the community in a timely fashion
WFC3/IR 11696 Infrared Survey of Star Formation Across Cosmic Time We propose to use the unique power of WFC3 slitless spectroscopy to
measure the evolution of cosmic star formation from the end of the
reionization epoch at z>6 to the close of the galaxy-building era at
z~0
3
Pure parallel observations with the grisms have proven to be
efficient for identifying line emission from galaxies across a broad
range of redshifts
The G102 grism on WFC3 was designed to extend this
capability to search for Ly-alpha emission from the first galaxies
Using up to 250 orbits of pure parallel WFC3 spectroscopy, we will
observe about 40 deep (4-5 orbit) fields with the combination of G102
and G141, and about 20 shallow (2-3 orbit) fields with G141 alone
Our primary science goals at the highest redshifts are: (1) Detect
Lya in ~100 galaxies with z>5
6 and measure the evolution of the Lya
luminosity function, independent of of cosmic variance; 2) Determine
the connection between emission-line selected and continuum-break
selected galaxies at these high redshifts, and 3) Search for the
proposed signature of neutral hydrogen absorption at re-ionization
At
intermediate redshifts we will (4) Detect more than 1000 galaxies in
Halpha at 0
5 To identify single-line Lya emitters, we will exploit the wide
0
8--1
9um wavelength coverage of the combined G102+G141 spectra
All
[OII] and [OIII] interlopers detected in G102 will be reliably
separated from true LAEs by the detection of at least one strong line
in the G141 spectrum, without the need for any ancillary data
We
waive all proprietary rights to our data and will make high-level data
products available through the ST/ECF
WFC3/IR/WFC3/UVI 11360 Star Formation in Nearby Galaxies Star formation is a fundamental astrophysical process; it controls
phenomena ranging from the evolution of galaxies and nucleosynthesis
to the origins of planetary systems and abodes for life
The WFC3,
optimized at both UV and IR wavelengths and equipped with an extensive
array of narrow-band filters, brings unique capabilities to this area
of study
The WFC3 Scientific Oversight Committee (SOC) proposes an
integrated program on star formation in the nearby universe which will
fully exploit these new abilities
Our targets range from the
well-resolved R136 in 30 Dor in the LMC (the nearest super star
cluster) and M82 (the nearest starbursting galaxy) to about half a
dozen other nearby galaxies that sample a wide range of star-formation
rates and environments
Our program consists of broad-band
multiwavelength imaging over the entire range from the UV to the
near-IR, aimed at studying the ages and metallicities of stellar
populations, revealing young stars that are still hidden by dust at
optical wavelengths, and showing the integrated properties of star
clusters
Narrow-band imaging of the same environments will allow us
to measure star-formation rates, gas pressure, chemical abundances,
extinction, and shock morphologies
The primary scientific issues to
be addressed are: (1) What triggers star formation? (2) How do the
properties of star-forming regions vary among different types of
galaxies and environments of different gas densities and compositions?
(3) How do these different environments affect the history of star
formation? (4) Is the stellar initial mass function universal or
determined by local conditions? WFC3/UVI 11905 WFC3 UVIS CCD Daily Monitor The behavior of the WFC3 UVIS CCD will be monitored daily with a set
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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 (11909), will be used to generate the
necessary superbias
and superdark reference files for the
calibration pipeline (CDBS)
http://groups
google
com/group/sci
astro
hubble/t/7bdb7b152b1e5dba?hl=en
SCHEDULED SUCCESSFUL
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 (11909), will be used to generate the
necessary superbias
and superdark reference files for the
calibration pipeline (CDBS)
<mailto:[list_owner_email]>
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