NASA Hubble Space Telescope Daily Report #4246

HUBBLE SPACE TELESCOPE DAILY REPORT # 4246

– Continuing to collect World Class Science

PERIOD COVERED: UT November 22,23,24,25,26, 2006 (DOY 326,327,328,329,330)

OBSERVATIONS SCHEDULED

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration – CR Persistence Part 4

A new procedure proposed to alleviate the CR-persistence problem of NICMOS. Dark frames will be obtained immediately upon exiting the SAA contour 23, and every time a NICMOS exposure is scheduled within 50 minutes of coming out of the SAA. The darks will be obtained in parallel in all three NICMOS Cameras. The POST-SAA darks will be non-standard reference files available to users with a USEAFTER date/time mark. The keyword ‘USEAFTER=date/time’ will also be added to the header of each POST-SAA DARK frame. The keyword must be populated with the time, in addition to the date, because HST crosses the SAA ~8 times per day so each POST-SAA DARK will need to have the appropriate time specified, for users to identify the ones they need. Both the raw and processed images will be archived as POST-SAA DARKSs. Generally we expect that all NICMOS science/calibration observations started within 50 minutes of leaving an SAA will need such maps to remove the CR persistence from the science images. Each observation will need its own CRMAP, as different SAA passages leave different imprints on the NICMOS detectors.

NIC3 11064

CYCLE 15 NICMOS SPECTROPHOTOMETRY CALIBRATION PROGRAM

Now that the spectrophotometric capabilities of the NICMOS grism have been established, cycle 15 observations are needed to refine the sensitivity estimates, to check for sensitivity loss with time, to improve the accuracy of the linearity correction, to improve the secondary flux standards by re-observation, and to expand the G206 data set now that the sky subtraction technique has been shown to produce useful fluxes for some of the fainter secondary standards. These faint secondary IR standards will be a significant step towards establishing flux standards for JWST, as well as for SNAP, Spitzer, and SOFIA. 1.Re-observe the 3 primary WDs GD71, G191B2b, & GD153 twice each, once at the beginning and once near the end of the 18 month cycle. To date, we have only 2 observation of each star, while the corresponding STIS data set for these primary standards ranges from 6 to 23 obs. No observations exist for GD71 or GD153 with G206, so that the current G206 sensitivity is defined solely by G191B2B. Purposes: Refine sensitivities, measure sens losses. Orbits: 2 for each of 6 visits = 12 2. Re-observe WD1057 & WD1657 plus another P041C lamp-on visit to improve the scatter in the non-lin measurements per Fig. 8 of NIC ISR 2006-02. The WD stars require 2 orbits each, while the lamp-on test is done in one. The very faintest and most crucial standard WD1657 has 2 good visits already, so to substantially improve the S/N, two visits of two orbits are needed. Include G206 for P041C in the lamp-off baseline part of that orbit. Orbits: WD1057-2, WD1657-4, P041C-1 –> 7 3. Re-observe 9 secondary standards to improve S/N of the faint ones and to include G206 for all 9. BD+17 {3 obs} is not repeated in this cycle. Four are bright enough to do in one orbit: VB8, 2M0036+18, P330E, and P177D. Orbits:2*5+4=14 Grand Total orbits over 18 month cycle 15 is 12+6+14=32 {Roelof will submit the P041C lamp-on visit in a separate program.}

ACS/WFC 11045

ACS internal CTE monitor

The charge transfer efficiency {CTE} of the ACS CCD detectors will decline as damage due to on-orbit radiation exposure accumulates. This degradation will be closely monitored at regular intervals, because it is likely to determine the useful lifetime of the CCDs. All the data for this program is acquired using internal targets {lamps} only, so all of the exposures should be taken during Earth occultation time {but not during SAA passages}. This program emulates the ACS pre-flight ground calibration and post-launch SMOV testing {program 8948}, so that results from each epoch can be directly compared. Extended Pixel Edge Response {EPER} and First Pixel Response {FPR} data will be obtained over a range of signal levels for both the Wide Field Channel {WFC}, and the High Resolution Channel {HRC}.

ACS/WFC 11003

Mixing It Up : Gas, Stars, Starbirth, and AGN in a Supercluster at z = 0.9

We propose a joint Spitzer/HST program to map the best-studied large scale structure at high redshift — a massive twelve-cluster supercluster at z = 0.9 which extends 15 Mpc x 100 Mpc. Because clusters are actively forming at this redshift, and significant evolution has already been observed in their galaxy populations, this survey will provide the crucial link between large scale structure and galaxy-scale physics. The supercluster is already the subject of a multi-faceted program including {1} deep r’i’z’K imaging from the Palomar 5-m to measure optical/near-IR colors, {2} spectroscopy with DEIMOS on the Keck 10-m to measure stellar content, [OII] equivalent widths, and internal velocities for over 330 supercluster members, {3} high-angular-resolution Chandra and VLA observations to study the starburst and AGN populations, and {4} an 80 ksec XMM observation to quantify the cluster gas properties and the amount of diffuse emission from the low-density filaments. The proposed 3.6-24 micron mapping is an essential complement to this program because it provides more accurate measures of stellar mass, star formation rate, and nuclear/starburst activity across the entire structure. The ACS observations will provide equal detail on galaxy structural properties and morphology. Together, the deep mid-infrared observations and the high-angular-resolution HST imagery {along with our coordinated ground and space-based data} will allow us to measure the stellar mass function, stellar population ages, and star formation rates over the full range of environmental densities; use galaxy morphology to determine what type of galaxies host AGN and which physical processes are responsible for gas-fueling events; quantify the IR/radio/X-ray correlations at z = 0.9; and determine the effect of large scale structure on the stellar and gas content of galaxies in the high-redshift Universe.

FGS 10989

Astrometric Masses of Extrasolar Planets and Brown Dwarfs

We propose observations with HST/FGS to estimate the astrometric elements {perturbation orbit semi-major axis and inclination} of extra-solar planets orbiting six stars. These companions were originally detected by radial velocity techniques. We have demonstrated that FGS astrometry of even a short segment of reflex motion, when combined with extensive radial velocity information, can yield useful inclination information {McArthur et al. 2004}, allowing us to determine companion masses. Extrasolar planet masses assist in two ongoing research frontiers. First, they provide useful boundary conditions for models of planetary formation and evolution of planetary systems. Second, knowing that a star in fact has a plantary mass companion, increases the value of that system to future extrasolar planet observation missions such as SIM PlanetQuest, TPF, and GAIA.

FGS 10929

Calibrating the Mass-Luminosity Relation at the End of the Main Sequence

We propose to use HST-FGS1R to finish calibrating the mass-luminosity relation for stars less massive than 0.5 Msun, with special emphasis on objects near the stellar/substellar border. Our goals are to determine Mv values to 0.05 magnitude and masses to 5%, and thereby build the fundamental database of stellar masses that we will use to test theoretical models as never before. This program uses the combination of HST-FGS3/FGS1R at optical wavelengths, historical infrared speckle data, ground-based parallax work, metallicity studies, and radial velocity monitoring to examine nearby, subarcsecond binary systems. The high precision separation and position angle measurements with HST-FGS3/FGS1R {to 1 mas in the separations} for these faint {V = 10-15} targets simply cannot be equaled by any ground-based technique. As a result of these measurements, we are deriving high quality luminosities and masses for the components in the systems, and characterizing their spectral energy distributions from 0.5 to 2.2 microns. One of the objects, GJ 1245 C with mass 0.074 +/- 0.002 Msun, is the only object known with an accurate dynamical mass less than 0.10 Msun. The payoff of this proposal is high because the six systems selected for final observations in Cycles 15 and 16 have already been resolved during Cycles 5-13 with HST FGS3/FGS1R and contain most of the reddest objects for which accurate dynamical masses can be determined.

NIC3/ACS/WFC 10921

Tangential Velocities of Objects in the Orion Nebula and Locating the Embedded Outflow Sources.

The Orion Nebula is arguably the Rosetta Stone for studying a very young star cluster and how the radiation and outflowing plasma from its stars interact with ambient material. It has been the subject of numerous HST imaging studies, which means that there is good opportunity for determining tangential velocities by obtaining second epoch images during Cycle 15, which may be the last cycle for which the WFPC2 is available. These velocities in the plane-of-the-sky will allow us to determine the patterns of outflow from micro-jets smaller than the Solar System to jet driven shocks more than a parsec from their sources. Combined with radial velocities, we’ll obtain spatial velocities, which are critical to determining where the embedded sources are located that produce the numerous HH objects coming from the Orion-S and BN-KL regions. We’ll also be able to determine the physics that is operating in the LL Ori type of outflows {where a bipolar jet is being distorted by a slow wind coming from the nebula}. We will also be able to search for runaway stars caused by the disintegration of young multiple-star systems. All of this is possible because the long-time base of the WFPC2 and ACS observations allow a new level of astrometric precision to be obtained and to be done efficiently by making coordinated parallel observations with all images.

ACS/WFC/HRC 10920

High-Resolution Imaging of Nearby Lyman Break Galaxy Analogs in the GALEX All-Sky Survey

We have used the ultraviolet all-sky imaging survey currently being conducted by the Galaxy Evolution Explorer {GALEX} to identify for the first time a rare population of low-redshift starbursts with properties remarkably similar to high-redshift Lyman Break Galaxies. These compact UV luminous galaxies {UVLGs} resemble Lyman Break Galaxies in terms of size, UV luminosity, star-formation rate, surface brightness, mass, metallicity, kinematics, dust content, and color. They have characteristic “ages” {stellar mass/SFR} of only a few hundred Myr. This population of galaxies is thus worthy of study in its own right and as a sample of local analogs of Lyman Break Galaxies. We propose to image a sample of the 9 nearest and brightest compact UVLGs in the near-ultraviolet, near-infrared, and H-alpha using ACS. With these images we will 1} characterize their structure and morphology, 2} look for signs of interactions and mergers, 3} investigate the distribution and propogation of star formation over varying time scales, and 4} quantify the stellar populations and star formation history, in order to determine whether a previous generation of stars formed long before the current burst. These data will perfectly complement our existing Spitzer, GALEX, and SDSS data, and will provide important information on star-formation in the present-day universe as well as shed light on the earliest major episodes of star formation in high-redshift galaxies.

WFPC2 10915

ACS Nearby Galaxy Survey

Existing HST observations of nearby galaxies comprise a sparse and highly non-uniform archive, making comprehensive comparative studies among galaxies essentially impossible. We propose to secure HST’s lasting impact on the study of nearby galaxies by undertaking a systematic, complete, and carefully crafted imaging survey of ALL galaxies in the Local Universe outside the Local Group. The resulting images will allow unprecedented measurements of: {1} the star formation history {SFH} of a >100 Mpc^3 volume of the Universe with a time resolution of Delta[log{t}]=0.25; {2} correlations between spatially resolved SFHs and environment; {3} the structure and properties of thick disks and stellar halos; and {4} the color distributions, sizes, and specific frequencies of globular and disk clusters as a function of galaxy mass and environment. To reach these goals, we will use a combination of wide-field tiling and pointed deep imaging to obtain uniform data on all 72 galaxies within a volume-limited sample extending to ~3.5 Mpc, with an extension to the M81 group. For each galaxy, the wide-field imaging will cover out to ~1.5 times the optical radius and will reach photometric depths of at least 2 magnitudes below the tip of the red giant branch throughout the limits of the survey volume. One additional deep pointing per galaxy will reach SNR~10 for red clump stars, sufficient to recover the ancient SFH from the color-magnitude diagram. This proposal will produce photometric information for ~100 million stars {comparable to the number in the SDSS survey} and uniform multi-color images of half a square degree of sky. The resulting archive will establish the fundamental optical database for nearby galaxies, in preparation for the shift of high-resolution imaging to the near-infrared.

ACS/WFC/WFPC2 10890

Morphologies of the Most Extreme High-Redshift Mid-IR-Luminous Galaxies

The formative phase of the most massive galaxies may be extremely luminous, characterized by intense star- and AGN-formation. Till now, few such galaxies have been unambiguously identified at high redshift, restricting us to the study of low-redshift ultraluminous infrared galaxies as possible analogs. We have recently discovered a sample of objects which may indeed represent this early phase in galaxy formation, and are undertaking an extensive multiwavelength study of this population. These objects are bright at mid-IR wavelengths {F[24um]>0.8mJy}, but deep ground based imaging suggests extremely faint {and in some cases extended} optical counterparts {R~24-27}. Deep K-band images show barely resolved galaxies. Mid-infrared spectroscopy with Spitzer/IRS reveals that they have redshifts z ~ 2-2.5, suggesting bolometric luminosities ~10^{13-14}Lsun! We propose to obtain deep ACS F814W and NIC2 F160W images of these sources and their environs in order to determine kpc-scale morphologies and surface photometry for these galaxies. The proposed observations will help us determine whether these extreme objects are merging systems, massive obscured starbursts {with obscuration on kpc scales!} or very reddened {locally obscured} AGN hosted by intrinsically low-luminosity galaxies.

ACS/WFC 10886

The Sloan Lens ACS Survey: Towards 100 New Strong Lenses

As a continuation of the highly successful Sloan Lens ACS {SLACS} Survey for new strong gravitational lenses, we propose one orbit of ACS-WFC F814W imaging for each of 50 high- probability strong galaxy-galaxy lens candidates. These observations will confirm new lens systems and permit immediate and accurate photometry, shape measurement, and mass modeling of the lens galaxies. The lenses delivered by the SLACS Survey all show extended source structure, furnishing more constraints on the projected lens potential than lensed-quasar image positions. In addition, SLACS lenses have lens galaxies that are much brighter than their lensed sources, facilitating detailed photometric and dynamical observation of the former. When confirmed lenses from this proposal are combined with lenses discovered by SLACS in Cycles 13 and 14, we expect the final SLACS lens sample to number 80–100: an approximate doubling of the number of known galaxy-scale strong gravitational lenses and an order-of-magnitude increase in the number of optical Einstein rings. By virtue of its homogeneous selection and sheer size, the SLACS sample will allow an unprecedented exploration of the mass structure of the early-type galaxy population as a function of all other observable quantities. This new sample will be a valuable resource to the astronomical community by enabling qualitatively new strong lensing science, and as such we will waive all but a short {3-month} proprietary period on the observations.

NIC3 10874

Search for Extremely Faint z>7 Galaxy Population with Cosmic Lenses

Deep UDF/NICMOS observations find a significant decrease in the number of galaxy candidates between redshift z=6 and 7, but the sample at z>7 is too small to draw conclusions. From our observations of 15 clusters we have found a number of bright z-dropouts, aided by the lensing amplification. We propose deep NICMOS observations of the best cases of cluster centers where a rare combination of a significant lensing effect and the richness in z-band dropouts in background may dramatically increase the discovery rate. The NICMOS images will reach an unprecendented depth of AB~27.8, or AB~30 in nonlensed intrinsic magnitude, and may find many faint {~0.05L*} galaxies at z=7-10, at a level that the UDF reaches for z~6 objects. We produce precision mass distribution maps from weak-lensing models, which enable us to derive the candidates’ intrinsic magnitudes and their luminosity function. The knowledge of such faint galaxy population at z>7 will facilitate the models of the IGM reionization and future JWST planning.

ACS/HRC 10860

The largest Kuiper belt object

The past year has seen an explosion in the discoveries of Pluto-sized objects in the Kuiper belt. With the discoveries of the methane-covered 2003 UB313 and 2005 FY9, the multiple satellite system of 2003 EL61, and the Pluto-Charon analog system of Orcus and its satellite, it is finally apparent that Pluto is not a unique oddball at the edge of the solar system, but rather one of a family of similarly large objects in the Kuiper belt and beyond. HST observations over the past decade have been critical for understanding the interior, surface, and atmosphere of Pluto and Charon. We propose here a comprehensive series of observations designed to similarly expand our knowledge of these recently discovered Pluto-sized and near-Pluto-sized Kuiper belt objects. These observations will measure objects’ sizes and densities, explore the outcome of collisions in the outer solar system, and allow the first ever look at the interior structure of a Kuiper belt object. Our wide field survey that discovered all of these objects is nearly finished, so after five years of continuous searching we are finally almost complete in our tally of these near-Pluto-sized objects. This large HST request is the culmination of this half-decade search for new planetary-sized objects. As has been demonstrated repeatedly by the approximately 100 previous orbits devoted to the study of Pluto, only HST has the resolution and sensitivity for detailed study of these distant objects.

NIC2 10852

Coronagraphic Polarimetry with NICMOS: Dust grain evolution in T Tauri stars

The formation of planetary systems is intimately linked to the dust population in circumstellar disks, thus understanding dust grain evolution is essential to advancing our understanding of how planets form. By combining {1} the coronagraphic polarimetry capabilities of NICMOS, {2} powerful 3-D radiative transfer codes, and {3} observations of objects known to span the Class II-III stellar evolutionary phases, we will gain crucial insight into dust grain growth. By observing objects representative of a known evolutionary sequence of YSOs, we will be able to investigate how the dust population evolves in size and distribution during the crucial transition from a star+disk system to a system containing planetesimals. When combine with our previous study on dust grain evolution in the Class I-II phase, the proposed study will help to establish the fundamental time scales for the depletion of ISM-like grains: the first step in understanding the transformation from small submicron sized dust grains, to large millimeter sized grains, and untimely to planetary bodies.

NIC2 10849

Imaging Scattered Light from Debris Disks Discovered by the Spitzer Space Telescope around 21 Sun-like Stars

We propose to use the high-contrast capability of the NICMOS coronagraph to image a sample of newly discovered circumstellar disks associated with Sun-like stars. These systems were identified by their strong thermal infrared {IR} emission with the Spitzer Space Telescope as part of the Spitzer Legacy Science program titled “The Formation and Evolution of Planetary Systems” {FEPS, P.I.: M.Meyer}. Modeling of the thermal excess emission from the spectral energy distributions alone cannot distinguish between narrowly confined high-opacity disks and broadly distributed, low-opacity disks. By resolving light scattered by the circumstellar material, our proposed NICMOS observations can break this degeneracy, thus revealing the conditions under which planet formation processes are occuring or have occured. For three of our IR-excess stars that have known radial-velocity planets, resolved imaging of the circumstellar debris disks may further offer an unprecedented view of planet-disk interactions in an extrasolar planetary system. Even non-detections of the light scattered by the circumstellar material will place strong constraints on the disk geometries, ruling out disk models with high optical depth. Unlike previous disk imaging programs, our program contains a well-defined sample of ~1 solar mass stars covering a range of ages from 3 Myr to 3 Gyr, thus allowing us to study the evolution of disks from primordial to debris for the first time. The results from our program will greatly improve our understanding of the architecture of debris disks around Sun-like stars, and will create a morphological context for the existence of our own solar system. This proposal is for a continuation of an approved Cycle 14 program {GO/10527, P.I.: D. Hines}.

ACS/WFC 10817

Unveiling Starburst Morphology of Distant Damped Ly-alpha Galaxies Hosting Gamma-Ray Bursts

The damped Lya systems {DLAs}, `clouds’ with high columns of neutral hydrogen, dominate the neutral gas mass at z>2 and are believed to be the building blocks of galaxies like the Milky Way. At present, high resolution spectroscopy of the DLAs provide the only detailed study of the ISM of young galaxies during early epochs. Yet by the very nature of their discovery – along bright quasar sightlines – direct imaging of the stellar counterparts presents a major obstacle. The use of gamma-ray bursts {GRBs} presents a novel new alternative: GRB afterglows are temporarily as bright as quasars, allowing for high-quality spectroscopy to identify and study new DLAs out to redshifts comparable to those probed by quasars. Afterglows then disappear after a few weeks, affording a direct and unimpeded view of the faint DLAs free from a glaring background source. Through an extensive ground-based program in 2005, we have now obtained early-time high-resolution echelle spectra of several NASA/Swift GRB afterglows. These data reveal that nearly all GRB host galaxies produce a DLA feature. Furthermore, the associated metal absorption lines indicate an ISM environment around the GRB progenitors — extremely dense gas and warm temperature — that has never been seen beyond the local universe. We request ACS late-time imaging of fields surrounding nine GRBs, all of which exhibit a strong DLA signature or strong metal absorption lines that indicate a DLA at the redshift of the host. In concert with our afterglow absorption line studies and stellar properties of both the GRB host galaxies and galaxies that give rise to strong intervening absorbers, these proposed observations will provide an unprecedented glimpse into the nature of DLAs beyong redshift of unity. As a complete sample, this study will provide robust measurements of the morphology and luminosity of DLA galaxies in a manner inaccessible to QSO lines of sight.

NIC2, ACS/WFC 10802

SHOES-Supernovae, HO, for the Equation of State of Dark energy

The present uncertainty in the value of the Hubble constant {resulting in an uncertainty in Omega_M} and the paucity of Type Ia supernovae at redshifts exceeding 1 are now the leading obstacles to determining the nature of dark energy. We propose a single, integrated set of observations for Cycle 15 that will provide a 40% improvement in constraints on dark energy. This program will observe known Cepheids in six reliable hosts of Type Ia supernovae with NICMOS, reducing the uncertainty in H_0 by a factor of two because of the smaller dispersion along the instability strip, the diminished extinction, and the weaker metallicity dependence in the infrared. In parallel with ACS, at the same time the NICMOS observations are underway, we will discover and follow a sample of Type Ia supernovae at z > 1. Together, these measurements, along with prior constraints from WMAP, will provide a great improvement in HST’s ability to distinguish between a static, cosmological constant and dynamical dark energy. The Hubble Space Telescope is the only instrument in the world that can make these IR measurements of Cepheids beyond the Local Group, and it is the only telescope in the world that can be used to find and follow supernovae at z > 1. Our program exploits both of these unique capabilities of HST to learn more about one of the greatest mysteries in science.

ACS/HRC 10800

Kuiper Belt Binaries: Probes of Early Solar System Evolution

Binaries in the Kuiper Belt are a scientific windfall: in them we have relatively fragile test particles which can be used as tracers of the early dynamical evolution of the outer Solar System. We propose to continue a Snapshot program using the ACS/HRC that has a demonstrated discovery potential an order of magnitude higher than the HST observations that have already discovered the majority of known transneptunian binaries. With this continuation we seek to reach the original goals of this project: to accumulate a sufficiently large sample in each of the distinct populations collected in the Kuiper Belt to be able to measure, with statistical significance, how the fraction of binaries varies as a function of their particular dynamical paths into the Kuiper Belt. Today’s Kuiper Belt bears the imprints of the final stages of giant-planet building and migration; binaries may offer some of the best preserved evidence of that long-ago era.

ACS/HRC/WFC 10758

ACS CCDs daily monitor

This program consists of a set of basic tests to monitor, the read noise, the development of hot pixels and test for any source of noise in ACS CCD detectors. The files, biases and dark will be used to create reference files for science calibration. This programme will be for the entire lifetime of ACS. Changes from cycle 13:- The default gain for WFC is 2 e-/DN. As before bias frames will be collected for both gain 1 and gain 2. Dark frames are acquired using the default gain {2}. This program cover the period May, 31 2006- Oct, 1-2006. The first half of the program has a different proposal number: 10729.

FGS 10614

Internal Structure and Figures of Binary Asteroids

The goal of this proposal is to obtain very important information on the internal structure of a number of asteroids, and insight on the gravitational reaccumulation-process after a catastrophic disruptive collision. High resolutions observations with the HST/FGS interferometer are proposed to obtain high precision data for the topographic shape and size of a number of selected asteroids. Here we focus on objects with satellites, hence with known masses, so that the bulk density and porosity will be derived in the most accurate manner. This will yield plausible estimates on the internal properties of the objects, test wether they are close or not to figures of equilibrium {in terms of shape and adimensional rotational frequency}, and provide estimates of their relative density. The HST/FGS in interferometric mode is an ideal facility to carry out this program.

ACS/HRC 10556

Neutral Gas at Redshift z=0.5

Damped Lyman-alpha systems {DLAs} are used to track the bulk of the neutral hydrogen gas in the Universe. Prior to HST UV spectroscopy, they could only be studied from the ground at redshifts z>1.65. However, HST has now permitted us to discover 41 DLAs at z<1.65 in our previous surveys. Followup studies of these systems are providing a wealth of information about the evolution of the neutral gas phase component of the Universe. But one problem is that these 41 low-redshift systems are spread over a wide range of redshifts spanning nearly 70% of the age of the Universe. Consequently, past surveys for low-redshift DLAs have not been able to offer very good precision in any small redshift regime. Here we propose an ACS-HRC- PR200L spectroscopic survey in the redshift interval z=[0.37, 0.7] which we estimate will permit us to discover another 41 DLAs. This will not only allow us to double the number of low-redshift DLAs, but it will also provide a relatively high-precision regime in the low-redshift Universe that can be used to anchor evolutionary studies. Fortunately DLAs have high absorption equivalent width, so ACS-HRC-PR200L has high-enough resoultion to perform this proposed MgII-selected DLA survey.

ACS/WFC 10494

Imaging the mass structure of distant lens galaxies

The surface brightness distribution of extended gravitationally lensed arcs and Einstein rings contains super-resolved information about the lensed object, and, more excitingly, about the smooth and clumpy mass distribution of the lens galaxies. The source and lens information can non-parametrically be separated, resulting in a direct “gravitational-mass image” of the inner mass-distribution of cosmologically-distant galaxies {Koopmans 2005}. With this goal in mind, we propose deep HST ACS-F555W/F814W and NICMOS-F160W imaging of 15 gravitational-lens systems with spatially resolved lensed sources, selected from the 17 new lens systems discovered by the Sloan Lens ACS Survey {Bolton et al. 2004}. Each system has been selected from the SDSS and confirmed in a time-efficient HST-ACS snapshot program {cycle-13}; they show highly-magnified arcs or Einstein rings, lensed by a massive early-type lens galaxy. High- fidelity multi-color HST images are required {not delivered by the 420-sec snapshot images} to isolate these lensed images {properly cleaned, dithered and extinction-corrected} from the lens galaxy surface brightness distribution, and apply our “gravitational-mass imaging” technique. The sample of galaxy mass distributions – determined through this method from the arcs and Einstein ring HST images – will be studied to: {i} measure the smooth mass distribution of the lens galaxies {Dark and luminous mass are separated using the HST images and the stellar M/L values derived from a joint stellar-dynamical analysis of each system}; {ii} quantify statistically and individually the incidence of mass-substructure {with or without obvious luminous counter- parts such as dwarf galaxies}. Since dark-matter substructure should be considerably more prevalent at higher redshift, both results provide a direct test of this prediction of the CDM hierarchical structure-formation model.

ACS/WFC 10475

An ACS H-alpha Survey of the Carina Nebula

We propose an H-alpha ACS imaging survey covering 540 square arcminutes of the Carina Nebula, including an unbiased survey of the bright core, and several prominent dust pillars in the rich southern region of the nebula. Carina provides an important link between well-studied nearby H II regions like Orion, and more distant mini-starbusts like 30 Doradus. CVZ orbits will allow extremely efficient use of HST to map a large area of this complex and important region — more than 95 percent of the proposed survey will be observed by HST for the first time. This survey will provide a complete census of microjets, proplyds, and silhouette disks with diameters as small as 200 AU, enough to spatially resolve disks like those in Orion, and will provide the first catalog of outflows {jets} from embedded low-mass stars, thin filamentary shocks, and wind-wind collisions in Carina. An accurate census of these phenomena is needed to characterize the star formation activity and gas dynamics as a function of position in the nebula, and to determine if models for protoplanetary disk evaporation from Orion are applicable in more extreme regions. Our previous ground-based optical and IR surveys have already revealed dozens of candidates for this type of activity — but this is just the tip of the iceberg. Our proposed HST/ACS survey promises to be a bonanza for understanding ongoing low-mass star formation influenced by extremely high-mass stars.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)

HSTARS:

10523 – GSAcq (1,2,1) failed due to Search Radius Limit Exceeded on FGS 1 GSAcq (1,2,1) failed due to Search Radius Limit Exceeded on FGS 1. At AOS 327/08:47:35 received 12 486 ESB messages “1805” (FHST Moving Target Detected). At 327/08:55:09 received 4 486 ESB messages “1805” (FHST Moving Target Detected). OBAD #1 unavailable due to LOS. OBAD #2 RSS = 179.17. OBAD MAP RSS = 153.54

10526 – GSacq(2,1,1) failed to RGA control

GSacq (2,1,1) scheduled at 328/14:00:30 failed due to search radius limit exceeded on FGS 1 at 14:04:06. Before the acquisition an ESB 1806(T2G Moving Target Detected) was received at 328/13:57:38. The OBAD success flag GCHACL09 did not increment to 3 although mnemonic QT2GMST indicated MapCompl. Also ESB a05 was received at 14:04:14. OBAD1 showed errors of V1=176.71, V2= -4756.95, V3= 371.09, and RSS= 4774.67. OBAD2 showed errors of V1=-5.32, V2=-0.53, V3=10.26, and RSS= 11.57

10527 – Reacq(2.3.2) failed to RGA hold @ 329/0541z

This occurred during an MA reduction period. All data after 1st OBAD was retrieved using an engineering dump.

486 STB Error message “A0E” (FGS Sequential Attitude update failed because error was too large to correct) occurred at 05:45:35 and was received at AOS.

1st OBAD at 05:27:57 V1 -34.70, V2 -1382.87, V3 -22.66, RSS 1383.49

2nd OBAD at 05:35:52 V1 -1.32, V2 17.69, V3 6.2, RSS 18.80 MAP at 05:48:26 V1 899.06, V2 -2962.28, V3 377.21, RSS 3118.61

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                         SCHEDULED      SUCCESSFUL
FGS GSacq               39                     37
FGS 
REacq                35                    34
OBAD with Maneuver 146                   146

SIGNIFICANT EVENTS: (None)