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Daily 3735
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3735 PERIOD COVERED: DOYs 315-316 OBSERVATIONS SCHEDULED ACS/WFC 9727 Exploration of the SN Ia Hubble Diagram at z 1.2 In the spirit of a Treasury proposal, we propose to organize, and deliver to the astronomical community, non-proprietary follow-up observations of ~10 Type Ia supernovae at 1z1.7 that are expected to be discovered in a Cycle 12 Treasury proposal. Together with the currently available sample, this would provide a Hubble diagram with over 20 SNe Ia in this redshift range, where it is possible to test the current cosmological model in the epoch of deceleration: If z ~ 0.5 SNe Ia are fainter due to evolution rather than an accelerating expansion, they should continue to get fainter at even higher redshifts. This size sample will show trends and outliers, and permit a more rigorous treatment of the asymmetric amplification distribution from gravitational lensing. This is a key redshift range for the studies of dark energy that will be done with future surveys {and future instruments now being designed}; this dataset will lay the ground-work for these studies by establishing the simple properties of the supernovae in this redshift range, including magnitudes, colors, and timescales. If considered more appropriate, this proposal could be treated as a part of a Treasury or Director's Discretionary program, since the data would be available to everybody immediately, and we would welcome others who would want to work with us on it. NIC1/NIC2/NIC3 8794 NICMOS Post-SAA calibration - CR Persistence Part 5 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. ACS/HRC 10377 ACS Earth Flats High signal sky flats will be obtained by observing the bright Earth with the HRC and WFC. These observations will be used to verify the accuracy of the flats currently used by the pipeline and will provide a comparison with flats derived via other techniques: L-flats from stellar observations, sky flats from stacked GO observations, and internal flats using the calibration lamps. Weekly coronagraphic monitoring is required to assess the changing position of the spots. ACS/HRC/WFC 10367 ACS CCDs daily monitor- cycle 13 - part 1 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. ACS/HRC 10253 A UV Survey of Quiescent Black Holes and Neutron Stars Existing STIS observations of quiescent Galactic black hole and neutron star binaries suggest a striking difference between them. The spectra of black holes appear to drop off steeply in the near-UV, whereas those of neutron stars continue to rise, at least down to 1700A. This difference has been interpreted in terms of advective accretion models, and may indicate a fundamental signature of the two types of object. The existing data do not include enough objects to form a representative sample, however. We will exploit the faint source sensitivity of ACS to perform a survey of the UV spectral shapes across a larger sample containing both black holes and neutron stars. This survey will test the assertion that their UV spectra are strikingly different; allow modelling of the broad band spectral energy distribution; test for variability in the UV flux; and identify suitable targets for subsequent spectroscopic follow-up.. NIC/NIC3 10226 The NICMOS Grism Parallel Survey We propose to continue managing the NICMOS pure parallel program. Based on our experience, we are well prepared to make optimal use of the parallel opportunities. The improved sensitivity and efficiency of our observations will substantially increase the number of line-emitting galaxies detected. As our previous work has demonstrated, the most frequently detected line is Halpha at 0.7z1.9, which provides an excellent measure of current star formation rate. We will also detect star- forming and active galaxies in other redshift ranges using other emission lines. The grism observations will produce by far the best available Halpha luminosity functions over the crucial--but poorly observed--redshift range where galaxies appear to have assembled most of their stellar mass. This key process of galaxy evolution needs to be studied with IR data; we found that observations at shorter wavelengths appear to have missed a large fraction of the star-formation in galaxies, due to dust reddening. We will also obtain deep F110W and F160W images, to examine the space densities and morphologies of faint red galaxies. In addition to carrying out the public parallels, we will make the fully reduced and calibrated images and spectra available on-line, with some ground-based data for the deepest parallel fields included. ACS/WFC 10217 The ACS Fornax Cluster Survey The two rich clusters nearest to the Milky Way, and the only large collections of early- type galaxies within ~ 25 Mpc, are the Virgo and Fornax Clusters. We propose to exploit the exceptional imaging capabilities of the ACS/WFC to carry out the most comprehensive imaging survey to date of early-type galaxies in Fornax: the ACS Fornax Cluster Survey. Deep ACS/WFC images -- in the F475W {g'} and F850LP {z'} bands -- will be acquired for 44 E, S0, dE, dE, N and dS0 cluster members. In Cycle 11, we initiated a similar program targeting early-type galaxies in the Virgo Cluster {the ACS Virgo Cluster Survey; GO-9401}. Our proposed survey of Fornax would yield an extraordinary dataset which would complement that already in hand for Virgo, and allow a definitive study of the role played by environment in the structure, formation and evolution of early-type galaxies and their globular cluster systems, nuclei, stellar populations, dust content, nuclear morphologies and merger histories. It would also be a community resource for years to come and, together with the ACS Virgo Cluster Survey, constitute one of the lasting legacies of HST. ACS/HRC/NIC1/WFC 10190 The Star Formation History and Metallicity Evolution of M33: A Comprehensive Study of Disk Evolution We will obtain deep, panchromatic imaging photometry of stellar populations in four fields ranging from 0.5 to 4 scale lengths across the disk of the Local Group spiral M33. The observations are designed to detect the oldest main-sequence turnoffs in three outer disk fields, and to reach the crowding limit in the innermost field. We will combine the photometry data with information we already have in-hand on abundances from stars and H II regions in M33 to derive the star formation history and metallicity evolution of the M33 disk. The information from our four fields will allow us to obtain {1} the ages of the oldest disk stars and the radial variation of their ages; {2} the radial variation of the star formation history and its nature {e.g., constant, declining, or bursting}; and {3} the metallicity distribution in each field and the time evolution of the metallicity gradient. Our team, an experienced mix of photometrists, spectroscopists, and galaxy evolution theorists, will use the results from this program to construct a comprehensive chemo-dynamical model for the M33 disk. This detailed study of M33 will be a key in developing an understanding of the formation and evolution of disks that can be applied to studies of disks at both low and high redshift, and will also yield a wealth of information on stellar populations, chemical evolution, and star clusters that will be of great value to future investigators. NIC2 10176 Coronagraphic Survey for Giant Planets Around Nearby Young Star A systematic imaging search for extra-solar Jovian planets is now possible thanks to recent progress in identifying "young stars near Earth". For most of the proposed young {~ 30 Myrs} and nearby {~ 60 pc} targets, we can detect a few Jupiter-mass planets as close as a few tens of AUs from the primary stars. This represents the first time that potential analogs of our solar system - that is planetary systems with giant planets having semi-major axes comparable to those of the four giant planets of the Solar System - come within the grasp of existing instrumentation. Our proposed targets have not been observed for planets with the Hubble Space Telescope previously. Considering the very successful earlier NICMOS observations of low mass brown dwarfs and planetary disks among members of the TW Hydrae Association, a fair fraction of our targets should also turn out to posses low mass brown dwarfs, giant planets, or dusty planetary disks because our targets are similar to {or even better than} the TW Hydrae stars in terms of youth and proximity to Earth. Should HST time be awarded and planetary mass candidates be found, proper motion follow-up of candidate planets will be done with ground-based AOs. NIC2 10173 Infrared Snapshots of 3CR Radio Galaxies Radio galaxies are an important class of extragalactic objects: they are one of the most energetic astrophysical phenomena and they provide an exceptional probe of the evolving Universe, lying typically in high density regions but well-represented across a wide redshift range. In earlier Cycles we carried out extensive HST observations of the 3CR sources in order to acquire a complete and quantitative inventory of the structure, contents and evolution of these important objects. Amongst the results, we discovered new optical jets, dust lanes, face-on disks with optical jets, and revealed point-like nuclei whose properties support FR-I/BL Lac unified schemes. Here, we propose to obtain NICMOS infrared images of 3CR sources with z0.3 as a major enhancement to an already superb dataset. We aim to deshroud dusty galaxies, study the underlying host galaxy free from the distorting effects of dust, locate hidden regions of star formation and establish the physical characteristics of the dust itself. We will measure frequency and spectral energy distributions of point- like nuclei, expected to be stronger and more prevalent in the IR, seek spectral turnovers in known synchrotron jets and find new jets. We will strongly test unified AGN schemes and merge these data with existing X-ray to radio observations. The resulting database will be an incredibly valuable resource to the astronomical community for years to come. ACS/WFC 10159 Characterizing the Sources Responsible for Cosmic Reionization Our group has demonstrated the role that massive clusters of galaxies, acting as powerful cosmic lenses, can play in locating sources with modest mass and star formation rate beyond redshifts z~5-6 likely to be representative of those responsible for cosmic reionization. The large magnifications, possible in the critical regions of well-constrained clusters, bring sources into view that would lie at or beyond the limits of conventional exposures such as the UDF. Recently, using deep ACS and NICMOS imaging, we have located a low mass source at z=7.05 whose UV continuum slope is apparently steeper than for normal star-forming galaxies. We propose a deep ACS grism exposure to confirm the nature of this source and further ACS and NICMOS imaging of well-studied clusters to locate further examples. The grism spectroscopy will conclusively determine the UV SED of this source and our 3- color survey will constrain the redshift, star-formation rate, and SED of additional 6z8 sources. Over the strongly-lensed {unlensed} area of 2.5 arcmin^2, we expect to detect 10 more sources at z6.5, with more than 2.5 Msun/yr of star formation {our survey limit}. Before the advent of the next generation of observational facilities, our search technique may represent the only way to reliably select and characterize the likely population of galaxies during the epoch of reionization. NIC1 10143 Ultracool companions to the nearest L dwarfs We propose to conduct the most sensitive survey to date for low mass companions to nearby L dwarfs. We will use NICMOS to image targets drawn from a volume- complete sample of 70 L dwarfs within 20 parsecs. The combination of infrared imaging and proximity will allow us to search for T dwarf companions at separations as small as 1.6 AU. This is crucial, since no ultracool binaries are currently known with separations exceeding 15 AU. Only 10 dwarfs in this sample have previous HST observations primarily at optical wavelengths. With the increased sensitivity of our survey, we will provide the most stringent test to date of brown dwarf models which envisage formation as ejected stellar embryos. In addition, our observations will be capable of detecting binaries with mass ratios as low as 0.3, and will therefore also test the apparent preference for equal-mass ultracool binaries. Finally, our observations offer the best prospect to date of detecting companions significantly cooler than the coolest t dwarf currently known. WFPC2 10112 HST Observations of Astrophysically Important Visual Binaries This is a continuation of a project begun in Cycle 7 and continued up through Cycle 11. The program consists of annual or biannual WFPC2 or FGS observations of three visual binary stars that will ultimately yield fundamental astrophysical results, once their orbits and masses are determined. Our targets are the following: {1} Procyon {P = 41 yr}, for which our first WFPC2 images yielded an extremely accurate angular separation of the bright F star and its much fainter white-dwarf companion. Combined with ground-based astrometry of the bright star, our observation significantly revised downward the derived masses, and brought Procyon A into excellent agreement with theoretical evolutionary tracks for the first time. With the continued monitoring proposed here, we will obtain masses to an accuracy of better than 1%, providing a testbed for theories of both Sun-like stars and white dwarfs. {2} G 107-70, a close double white dwarf {P = 19 yr} that promises to add two accurate masses to the tiny handful of white-dwarf masses that are directly known from dynamical measurements. {3} Mu Cas {P = 21 yr}, a famous metal-deficient G dwarf for which accurate masses will lead to the stars' helium contents, with cosmological implications. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTAR 9594- GSAcq(2,1,1) Loss of Lock. OTA SE review of PTAS processing revealed GSAcq(2,1,1) required two attempts to successfully achieve fine lock. HSTAR 9595 GSAcq(1,2,2) Loss of Lock. OTA SE review of PTAS processing revealed GSAcq(1,2,2) required two attempts to successfully achieve fine lock. HSTAR 9596 GSACQ(1,3,1) fine lock backup, scan step limit exceeded on FGS 1. GSACQ(1,3,1) at 315/18:28:38 ended in fine lock backup on FGS 1 due to scan step limit exceeded on FGS 1 at 18:31:59. Observations affected: ACS 135, 136, NICMOS 44. Under investigation. COMPLETED OPS REQs: 17301-0 FSW 2.6C EEPROM Installation @ 316/02:01 17304-0 Clear ACS Event Flag # 2 @ 316/18:26z 17303-0 Genslew for proposal 10253 - Slot-14 @ 316/18:28z OPS NOTES EXECUTED: 1286-0 HST486 Full RAM Memory Dump @ 316/01:44z 1288-0 Transfer FSW load QSTARCAT1.FSL to Command Queue @ 316/22:15z SCHEDULED SUCCESSFUL FAILURE TIMES FGS Gsacq 19 19 FGS Reacq 14 14 FHST Update 33 33 LOSS of LOCK SIGNIFICANT EVENTS: None |
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