NASA Hubble Space Telescope Daily Report # 4608

Status Report From: Space Telescope Science Institute
Posted: Monday, May 12, 2008


Continuing to collect World Class Science

PERIOD COVERED: 5am May 09 - 5am May 12, 2008 (DOY 130/0900z-133/0900z)


NIC1/NIC2/NIC3 8795

NICMOS Post-SAA calibration - CR Persistence Part 6

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=3Ddate/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 i mages. Each observation will need its own CRMAP, as different SAA passages leave different imprints on the NICMOS detectors.

WFPC2 11513

The afterglow and host galaxy of GRB 080319: the first "naked eye" burst

The optical flash from GRB 080319 reached a magnitude of about 5.5 within a few seconds of the start of the burst, making it the first "naked eye" GRB. It's redshift has been determined as z=3D0.94 (about 7 billion light years distance) and hence it is by far the most distant naked eye source known.

HST has a key role to play in helping study this event, by providing the late time monitoring of the light curve and colour of the afterglow. This will allow us to constrain any breaks which may indicate a collimated outflow, to search for an underlying supernova component and to reveal the nature of the host galaxy, and the location of the burst within it.

Not surprisingly this object is attracting considerable attention both in the professional astrophysical community and also in the general public. We believe that HST observations of this GRB would be welcomed by both of these communities.

NIC2 11341

Lower Luminosity AGNs at Cosmologically Interesting Redshifts: SEDs and Accretion Rates of z~0.36 Seyferts

We propose a multiwavelength campaign to constrain the SEDs of Seyferts at z~0.36. This epoch, corresponding to a look back time of 4 Gyrs, is cosmologically interesting for studies of the coeval development of black holes and their host galaxy bulges. Our sample, comprising 24 Seyferts, has unprecedented high quality Keck spectroscopy and HST imaging already invested to extract host galaxy bulge properties, estimate black hole masses, and separate nuclear and host optical luminosities. To supplement and extend this successful program, we request 93 ks of Chandra time (to measure the shape and power of the AGN-only X-ray continuum), 11 hrs each of Spitzer and Gemini (to constrain the dust temperature), and 7 orbits of HST (to determine the nuclear luminosity for the final 7 objects).

NIC3 11334

NICMOS Cycle 16 Spectrophotometry

Observation of the three primary WD flux standards must be repeated to refine the NICMOS absolute calibration and monitor for sensitivity degradation. So far, NICMOS grism spectrophotometry is available for only ~16 stars with good STIS spectra at shorter wavelengths. There are more in the HST CALSPEC standard star data base with good STIS spectra that would also become precise IR standards with NICMOS absolute SED measurements. Monitoring the crucial three very red stars (M, L, T) for variability and better S/N in the IR. Apparent variability was discovered at shorter wavelengths during the ACS cross-calibration work that revealed a ~2% discrepancy of the cool star fluxes with respect to the hot primary WD standards. About a third of these stars are bright enough to do in one orbit, the rest require 2 orbits.

NIC3 11331

NICMOS Cycle 16 Grism Calibration

A series of pointed NICMOS observations of the spectroscopic flux calibrator P330E and two wavelength calibrators VY2-2 and HB12.

NIC1/NIC2/NIC3 11318

NICMOS Cycle 16 Multiaccum Darks

The purpose of this proposal is to monitor the dark current, read noise, and shading profile for all three NICMOS detectors throughout the duration of Cycle 16. This proposal is a slightly modified version of proposal 10380 of cycle 13 and 9993 of cycle12 and is the same as Cycle 15. Covers the period from April 08 to November 08 (inclusive)

WFPC2 11312

The Local Cluster Substructure Survey {LoCuSS}: Deep Strong Lensing Observations with WFPC2

LoCuSS is a systematic and detailed investigation of the mass, substructure, and thermodynamics of 100 X-ray luminous galaxy clusters at 0.151} cluster samples. To complete the all-important high resolution imaging component of our survey, we request deep WFPC2 observations of 20 clusters through the F606W filter, for which wide-field weak-lensing data are already available from our Subaru imaging program. The combination of deep WFPC2 and Subaru data for these 20 clusters will enable us to achieve the science program approved by the Cycle 15 TAC.

FGS 11212

Filling the Period Gap for Massive Binaries

The current census of binaries among the massive O-type stars is seriously incomplete for systems in the period range from years to millennia because the radial velocity variations are too small and the angular separations too close for easy detection. Here we propose to discover binaries in this observational gap through a Faint Guidance Sensor SNAP survey of relatively bright targets listed in the Galactic O Star Catalog. Our primary goal is to determine the binary frequency among those in the cluster/association, field, and runaway groups. The results will help us assess the role of binaries in massive star formation and in the processes that lead to the ejection of massive stars from their natal clusters. The program will also lead to the identification of new, close binaries that will be targets of long term spectroscopic and high angular resolution observations to determine their masses and distances. The results will also be important for the interpretation of the spectra of suspected and newly identified binary and multiple systems.

FGS 11210

The Architecture of Exoplanetary Systems

Are all planetary systems coplanar? Concordance cosmogony makes that prediction. It is, however, a prediction of extrasolar planetary system architecture as yet untested by direct observation for main sequence stars other than the Sun. To provide such a test, we propose to carry out FGS astrometric studies on four stars hosting seven companions. Our understanding of the planet formation process will grow as we match not only system architecture, but formed planet mass and true distance from the primary with host star characteristics for a wide variety of host stars and exoplanet masses. We propose that a series of FGS astrometric observations with demonstrated 1 millisecond of arc per-observation precision can establish the degree of coplanarity and component true masses for four extrasolar systems: HD 202206 {brown dwarf+planet}; HD 128311 {planet+planet}, HD 160691 =3D mu Arae {planet+planet}, and HD 222404AB =3D gamma Cephei {planet+star}. In each case the companion is identified as such by assuming that the minimum mass is the actual mass. For the last target, a known stellar binary system, the companion orbit is stable only if coplanar with the AB binary orbit.

NIC2 11208

The co-evolution of spheroids and black holes in the last six billion years

The masses of giant black holes are correlated with the luminosities, masses, and velocity dispersions of the bulges of their host galaxies. This empirical correlation of phenomena on widely different scales {from pcs to kpcs} suggests that the formation and evolution of galaxies and central black holes are closely linked. In Cycle 13, we have started a campaign to map directly the co-evolution of spheroids and black-holes by measuring in observationally favorable redshift windows the empirical correlations connecting their properties. By focusing on Seyfert 1s, where the nucleus and the stars contribute comparable fractions of total light, black hole mass and bulge dispersion are obtained from Keck spectroscopy. HST is required for accurate measurement of the non stellar AGN continuum, the morphology of the galaxy, and the structural parameters of the bulge. The results at z=3D0.36 indicate a surprisingly fast evolution of bulges in the past 4 Gyrs {significant at the 95%CL}, in the sense that bulges were significantly smaller for a given black hole mass. Also, the large fraction of mergers and disturbed galaxies {4+2 out of 20} identifies gas-rich mergers as the mechanisms responsible for bulge-growth. Going to higher redshift -- where evolutionary trends should be stronger -- is needed to confirm these tantalizing results. We propose therefore to push our investigation to the next suitable redshift window z=3D0.57 {lookback-time 6 Gyrs}. = Fifteen objects are the minimum number required to map the evolution of the empirical correlations between bulge properties and black- hole mass, and to achieve a conclusive detection of evolution {>99%CL}.

WFPC2 11202

The Structure of Early-type Galaxies: 0.1-100 Effective Radii

The structure, formation and evolution of early-type galaxies is still largely an open problem in cosmology: how does the Universe evolve from large linear scales dominated by dark matter to the highly non-linear scales of galaxies, where baryons and dark matter both play important, interacting, roles? To understand the complex physical processes involved in their formation scenario, and why they have the tight scaling relations that we observe today {e.g. the Fundamental Plane}, it is critically important not only to understand their stellar structure, but also their dark-matter distribution from the smallest to the largest scales. Over the last three years the SLACS collaboration has developed a toolbox to tackle these issues in a unique and encompassing way by combining new non-parametric strong lensing techniques, stellar dynamics, and most recently weak gravitational lensing, with high-quality Hubble Space Telescope imaging and VLT/Keck spectroscopic data of early-type lens systems. This allows us to break degeneracies that are inherent to each of these techniques separately and probe the mass structure of early-type galaxies from 0.1 to 100 effective radii. The large dynamic range to which lensing is sensitive allows us both to probe the clumpy substructure of these galaxies, as well as their low-density outer haloes. These methods have convincingly been demonstrated, by our team, using smaller pilot-samples of SLACS lens systems with HST data. In this proposal, we request observing time with WFPC2 and NICMOS to observe 53 strong lens systems from SLACS, to obtain complete multi-color imaging for each system. This would bring the total number of SLACS lens systems to 87 with completed HST imaging and effectively doubles the known number of galaxy-scale strong lenses. The deep HST images enable us to fully exploit our new techniques, beat down low-number statistics, and probe the structure and evolution of early-type galaxies, not only with a uniform data-set an order of magnitude larger than what is available now, but also with a fully coherent and self-consistent methodological approach!

NIC3 11195

Morphologies of the Most Extreme High-Redshift Mid-IR-luminous Galaxies II: The `Bump' Sources

The formative phase of some 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, and thus far we have been restricted to studying the 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 optically extremely faint {R>26} but nevertheless bright at mid-infrared wavelengths {F[24um] > 0.5 mJy}. Mid-infrared spectroscopy with Spitzer/IRS reveals that they have redshifts z~2, implying luminosities ~1E13 Lsun. Their mid-IR SEDs fall into two broad, perhaps overlapping, categories. Sources with brighter F[24um] exhibit power-law SEDs and SiO absorption features in their mid-IR spectra characteristic of AGN, whereas those with fainter F[24um] show a "bump" characteristic of the redshifted 1.6um peak from a stellar population, and PAH emission characteristic of starformation. We have begun obtaining HST images of the brighter sources in Cycle 15 to obtain identifications and determine kpc-scale morphologies for these galaxies. Here, we aim to target the second class {the "bump" sources} with the goal of determining if these constitute morphologically different objects, or simply a "low-AGN" state of the brighter class. The proposed observations will help us determine whether these objects are merging systems, massive obscured starbursts {with obscuration on kpc scales!} or very reddened {locally obscured} AGN hosted by intrinsically low-luminosity galaxies.

NIC3 11174

A Spitzer/X-ray candidate cluster at z>2: NICMOS imaging

We propose deep H-band imaging with NICMOS of a remarkable z>2 cluster of galaxy candidate. Over a 1000 arcmin^2 field imaged with Spitzer's IRAC and MIPS we have discovered a compact (<30'' diameter) concentration of extremely red galaxies with a factor of >40 overdensity over the adjacent field. Among these galaxies for which we can derive meaningful photometric redshifts, 17 are consistent with zphot=3D2-2.5, making very likely that the concentrationis is a real cluster at such high redshift. This is further supported by a 3.5 sigma detection of extended X-Ray emission on Newton-XMM data, by a likely color-magnitude sequence of red galaxies, and by the presence of a giant galaxy consistent with a BCG at the cluster redshift. While spectroscopic confirmation of the cluster might result prohibitive with current facilities, HST high resolution imaging will allow us to gain crucial information for the study and scientific exploitation of this hot gas hosting, record high-z cluster of galaxies. The HST high resolution observations will allow us to unveil the rest frame optical morphologies of the galaxies and confirm the presence of ellipticals in the structure, detect and characterize the color-magnitude relation, measure their effective radii and construct their Kormendy relation for the passively evolving subsample, improve the photometric redshift estimates to confirm the real cluster nature of the structure, estimate stellar masses and check for possible deviations from the local mass-size relation, search for mergers and AGNs, and establish a cluster benchmark for cluster-field comparisons at this highest redshift.

ACS/SBC 11158

HST Imaging of UV emission in Quiescent Early-type Galaxies

We have constructed a sample of early type galaxies at z~0.1 that have blue UV-optical colors, yet also show no signs of optical emission, or extended blue light. We have cross-correlated the SDSS catalog and the Galaxy Evolution Explorer Medium Imaging Survey to select a sample of galaxies where this UV emission is strongest. The origin of the UV rising flux in these galaxies continues to be debated, and the possibility that some fraction of these galaxies may be experiencing low levels of star formation cannot be excluded. There is also a possibility that low level AGN activity {as evidenced by a point source} is responsible We propose to image the UV emission using the HST/SBC and to explore the morphology of the UV emission relative to the optical light.

NIC2/WFPC2 11142

Revealing the Physical Nature of Infrared Luminous Galaxies at 0.3We aim to determine physical properties of IR luminous galaxies at 0.3 0.8mJy and their mid-IR spectra have already provided the majority targets with spectroscopic redshifts {0.31 ULIRGs, as in the local Universe. {2} study the co-evolution of star formation and blackhole accretion by investigating the relations between the fraction of starburst/AGN measured from mid-IR spectra vs. HST morphologies, L{bol} and z. {3} obtain the current best estimates of the far-IR emission, thus L{bol} for this sample, and establish if the relative contribution of mid-to-far IR dust emission is correlated with morphology {resolved vs. unresolved}.

WFPC2 11113

Binaries in the Kuiper Belt: Probes of Solar System Formation and Evolution

The discovery of binaries in the Kuiper Belt and related small body populations is powering a revolutionary step forward in the study of this remote region. Three quarters of the known binaries in the Kuiper Belt have been discovered with HST, most by our snapshot surveys. The statistics derived from this work are beginning to yield surprising and unexpected results. We have found a strong concentration of binaries among low-inclination Classicals, a possible size cutoff to binaries among the Centaurs, an apparent preference for nearly equal mass binaries, and a strong increase in the number of binaries at small separations. We propose to continue this successful program in Cycle 16; we expect to discover at least 13 new binary systems, targeted to subgroups where these discoveries can have the greatest impact.

NIC3 11107

Imaging of Local Lyman Break Galaxy Analogs: New Clues to Galaxy Formation in the Early Universe

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 {LBGs}. These "compact UV luminous galaxies" {UVLGs} resemble LBGs in terms of size, SFR, surface brightness, mass, metallicity, kinematics, dust, and color. The UVLG sample offers the unique opportunity of investigating some very important properties of LBGs that have remained virtually inaccessible at high redshift: their morphology and the mechanism that drives their star formation. Therefore, in Cycle 15 we have imaged 7 UVLGs using ACS in order to 1} characterize their morphology and look for signs of interactions and mergers, and 2} probe their star formation histories over a variety of timescales. The images show a striking trend of small- scale mergers turning large amounts of gas into vigorous starbursts {a process referred to as dissipational or "wet" merging}. Here, we propose to complete our sample of 31 LBG analogs using the ACS/SBC F150LP {FUV} and WFPC2 F606W {R} filters in order to create a statistical sample to study the mechanism that triggers star formation in UVLGs and its implications for the nature of LBGs. Specifically, we will 1} study the trend between galaxy merging and SFR in UVLGs, 2} artificially redshift the FUV images to z=3D1-4 and compare morphologies with those in = similarly sized samples of LBGs at the same rest-frame wavelengths in e.g. GOODS, UDF, and COSMOS, 3} determine the presence and morphology of significant stellar mass in "pre- burst" stars, and 4} study their immediate environment. Together with our Spitzer {IRAC+MIPS}, GALEX, SDSS and radio data, the HST observations will form a unique union of data that may for the first time shed light on how the earliest major episodes of star formation in high redshift galaxies came about. This proposal was adapted from an ACS HRC+WFC proposal to meet the new Cycle 16 observing constraints, and can be carried out using the ACS/SBC and WFPC2 without compromising our original science goals.

WFPC2 11102

HST as a Jovian Climate Satellite

In the past year, there have been striking changes in Jupiter's atmosphere. Among these are the Oval BA's change from white to red, two new dark Disturbances in the southern hemisphere, and a 30% change (since 1997) in the aspect ratio of the potential vorticity anomaly of the GRS (not just its associated clouds), as we determined from high-accuracy velocities extracted from HST images. The determination of high-accuracy velocities requires both high-resolution imaging by HST (or flybys), and our novel adaptation of Correlation Image Velocimetry (CIV), a technique that has far greater accuracy than the traditional method (of identifying velocity tie-points by hand). Our proposed observations will test the hypothesis that these changes in Jupiter validate our 2004 prediction: that the merger of the 3 White Ovals in 1998-2000 would lead to climate change on Jupiter. The key is to determine, by indirect means, the temperature at the base of the weather layer, a quantity that cannot be observed directly at any wavelength. The new Red Oval BA's velocities will be used to test our finding that the color change is due to global temperature changes. The change in the GRS's aspect ratio suggests a large (at least 20%) change in the shear of the local velocity since 1997. The latter can be investigated only by determining Jupiter's current zonal winds.

WFPC2 11029

WFPC2 CYCLE 15 Intflat Linearity Check and Filter Rotation Anomaly Monitor

Intflat observations will be taken to provide a linearity check: the linearity test consists of a series of intflats in F555W, in each gain and each shutter. A combination of intflats, visflats, and earthflats will be used to check the repeatability of filter wheel motions. {Intflat sequences tied to decons, visits 1-18 in prop 10363, have been moved to the cycle 15 decon proposal xxxx for easier scheduling.} Note: long-exposure WFPC2 intflats must be scheduled during ACS anneals to prevent stray light from the WFPC2 lamps from contaminating long ACS external exposures.

WFPC2 10896

An Efficient ACS Coronagraphic Survey for Debris Disks around Nearby Stars

We propose to finish our Cycle 11 optical survey for nearby debris disks using the ACS/HRC coronagraph. Out of 43 orbits originally proposed for the survey, 23 orbits were allocated, leading to a survey of 22 stars, from which two new debris disks were imaged for the first time. Our analysis of the initial survey gives an empirical estimate for the detection rate of debris disks relative to heliocentric distance and dust optical depth. Our target list for Cycle 15 is now optimized to yield more frequent disk detections. Likewise our observing strategy is improved to maximize sensitivity per telescope orbit allocated. Therefore we present the most efficient survey possible. The scientific motivation is to obtain scattered light images of previously unresolved debris disks to determine their viewing geometry and physical architecture, both of which may characterize the underlying planetary system. We choose 25 debris disk targets for which we predict a detection rate of 25% ? 5%. Four targets have extrasolar planets from which the viewing geometry revealed by a disk detection will resolve the v sin{i} ambiguity in the planet masses. These targets present the remarkable opportunity of finally seeing a debris disk in system with known planets.


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

HSTARS: 11299 - GSACQ (1,2,1) failed while LOS

GSACQ(1,2,1) at 133/05:45:25 failed to RGA control with QF2STOPF and QSTOP flags set. No other flags were seen. Vehicle was LOS at time of failure. #44 commands did change since previous acquisition. 486 ESB message "1808" (TxG FHST Sanity Check Failed) was observed at AOS. OBAD prior to acquisition had RSS error of 14.12 arcseconds. Further information after engineering recorder dump.



                       SCHEDULED      SUCCESSFUL

FGS GSacq               29                  28
FGS REacq               13                  13
OBAD with Maneuver      84                  83

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