Date: May 21st 2010

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Today's topics:

  • Daily Report #5098 - 2 messages, 1 author http://groups google com/group/sci astro hubble/t/9eb4bfac6f463531?hl=en
  • Daily Report #5100 - 1 messages, 1 author http://groups google com/group/sci astro hubble/t/7bdb7b152b1e5dba?hl=en

============================================================================== TOPIC: Daily Report #5098

http://groups google com/group/sci astro hubble/t/9eb4bfac6f463531?hl=en

== 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 8) not easily probed by any other means (2) The dust extinction in the rest-frame UV, and therefore a correction to their present star-formation rates

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
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 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

http://groups google com/group/sci astro hubble/t/7bdb7b152b1e5dba?hl=en

== 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)

                  SCHEDULED  SUCCESSFUL

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 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)

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