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Daily 3585
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3585 PERIOD COVERED: DOY 96 OBSERVATIONS SCHEDULED ACS/HRC 9747 An Imaging Survey of the Statistical Frequency of Binaries Among Exceptionally-Young Dynamical Families in the Main Asteroid Belt We propose an ambitious SNAPSHOT program to determine the frequency of binaries among two very young asteroid families in the Main Belt, with potentially profound implications. These families {of C- and S-type} have recently been discovered {Nesvorny et al. 2002, Nature 417, 720}, through dynamical modeling, to have been formed at 5.8 MY and 8.3 MY ago in catastrophic impact events. This is the first time such precise and young ages have been assigned to a family. Main-belt binaries are almost certainly produced by collisions, and we would expect a young family to have a significantly higher frequency of binaries than the background, because they may not yet have been destroyed by impact or longer-term gravitational instabilities. In fact, one of the prime observables from such an event should be the propensity for satellites. This is the best way that new numerical models for binary production by collisions {motivated largely by our ground-based discoveries of satellites among larger asteroids}, can be validated and calibrated. We will also measure two control clusters, one being an "old" family, and the other a collection of background asteroids that do not have a family association, and further compare with our determined value for the frequency of large main-belt binaries {2%}. We request visits to 180 targets, using ACS/HRC. ACS/HRC 9869 X-ray-Bright, Optically Normal Galaxies: The Hidden Truth Chandra has resolved most of the 2 keV X-ray background {XRB} into discrete sources. Ground-based optical studies of these sources have revealed a substantial population of apparently normal galaxies at modest redshift, not the Seyfert 2 galaxies predicted by models for the origin of the XRB. These objects have X-ray spectral properties and luminosities similar to Seyfert 2s, but emission lines are weak or absent in their starlight-dominated optical spectra, suggesting the emergence of a new class of obscured or gas-poor AGNs at moderate redshifts. However, most of the galaxies in question are distant enough that their angular sizes are comparable to the slit widths used in ground-based spectroscopic observations. Thus, it is possible that these "normal" galaxies are classical Seyfert 2s whose nuclear spectral features have been overwhelmed {"hidden"} by host galaxy light. The high angular resolution of HST/STIS offers a unique opportunity to isolate the nuclei of these objects spatially. STIS spectra of a small, carefully selected sample of optically "normal" X-ray galaxies will help clarify the origin of the XRB, which is vital for understanding the growth of supermassive black holes in galactic nuclei. ACS/HRC/WFC 10060 CCD Daily Monitor This program consists of basic tests to monitor, the read noise, the development of hot pixels and test for any source of noise in ACS CCD detectors. This programme will be executed once a day for the entire lifetime of ACS. ACS/HRC/WFC 9884 Dwarf Elliptical Galaxies in Nearby Groups: Stellar Populations and Abundances The M81 group is of the nearest galaxy groups, but its properties are quite different from the Local Group, providing a different evolutionary environment for its member galaxies. This team has been studying M81-group analogs to Local Group dwarf elliptical {dE} galaxies. We observed two M81-group dEs with WFPC2: the results were published in Caldwell et al. {1998}. These observations revealed the upper two magnitudes of the red giant branch, yielding distance via the luminosity of the red giant branch tip, mean abundance via the mean giant branch color and first assessment of the star formation history via the frequency of occurrence of upper-AGB stars. Despite the different environment, the two M81-group dEs follow the Local Group {absolute magnitude, mean abundance} relation. But without data for additional dEs in nearby groups, particularly at higher luminosities, we can't definitely say whether this relation is universal or not. Establishing the answer to this question is vital because the relation is fundamental to theories of dE formation within dark matter halos, and the general applicability of these theories requires demonstration that the relation isn't strongly influenced by environment. This proposal requests ACS/WFC observations of five M81-group dEs to resolve this question. ACS/WFC/WFPC2 9822 The COSMOS 2-Degree ACS Survey We will undertake a 2 square degree imaging survey {Cosmic Evolution Survey -- COSMOS} with ACS in the I {F814W} band of the VIMOS equatorial field. This wide field survey is essential to understand the interplay between Large Scale Structure {LSS} evolution and the formation of galaxies, dark matter and AGNs and is the one region of parameter space completely unexplored at present by HST. The equatorial field was selected for its accessibility to all ground-based telescopes and low IR background and because it will eventually contain ~100, 000 galaxy spectra from the VLT-VIMOS instrument. The imaging will detect over 2 million objects with I 27 mag {AB, 10 sigma}, over 35, 000 Lyman Break Galaxies {LBGs} and extremely red galaxies out to z ~ 5. COSMOS is the only HST project specifically designed to probe the formation and evolution of structures ranging from galaxies up to Coma-size clusters in the epoch of peak galaxy, AGN, star and cluster formation {z ~0.5 to 3}. The size of the largest structures necessitate the 2 degree field. Our team is committed to the assembly of several public ancillary datasets including the optical spectra, deep XMM and VLA imaging, ground-based optical/IR imaging, UV imaging from GALEX and IR data from SIRTF. Combining the full-spectrum multiwavelength imaging and spectroscopic coverage with ACS sub-kpc resolution, COSMOS will be Hubble's ultimate legacy for understanding the evolution of both the visible and dark universe. FGS 9879 An Astrometric Calibration of the Cepheid Period-Luminosity Relation We propose to measure the parallaxes of 10 Galactic Cepheid variables. When these parallaxes {with 1-sigma precisions of 10% or better} are added to our recent HST FGS parallax determination of delta Cep {Benedict et al 2002}, we anticipate determining the Period-Luminosity relation zero point with a 0.03 mag precision. In addition to permitting the test of assumptions that enter into other Cepheid distance determination techniques, this calibration will reintroduce Galactic Cepheids as a fundamental step in the extragalactic distance scale ladder. A Period-Luminosity relation derived from solar metallicity Cepheids can be applied directly to extragalactic solar metallicity Cepheids, removing the need to bridge with the Large Magellanic Cloud and its associated metallicity complications. S/C/STIS/MA1/MA2 10035 MAMA Fold Distribution The performance of MAMA microchannel plates can be monitored using a MAMA fold analysis procedure. The fold analysis provides a measurement of the distribution of charge cloud sizes incident upon the anode giving some measure of changes in the pulse-height distribution of the MCP and, therefore, MCP gain. This proposal executes the same steps as the STIS MAMA Fold Analysis {8860} during Cycle 9. STIS 9786 The Next Generation Spectral Library We propose to continue the Cycle 10 snapshot program to produce a Next Generation Spectral Library of 600 stars for use in modeling the integrated light of galaxies and clusters. This program is using the low dispersion UV and optical gratings of STIS. The library will be roughly equally divided among four metallicities, very low {[Fe/H] lt -1.5}, low {[Fe/H] -1.5 to -0.5}, near-solar {[Fe/H] -0.3 to 0.1}, and super-solar {[Fe/H] gt 0.2}, well-sampling the entire HR-diagram in each bin. Such a library will surpass all extant compilations and have lasting archival value, well into the Next Generation Space Telescope era. Because of the universal utility and community-broad nature of this venture, we waive the entire proprietary period. STIS/CCD 10018 CCD Dark Monitor-Part 2 Monitor the darks for the STIS CCD. STIS/CCD 10020 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 10026 STIS Sparse Field CTE test-internal {Cycle 12} CTE measurements are made using the "internal sparse field test", along the parallel axis. The "POS=" optional parameter, introduced during cycle 11, is used to provide off-center MSM positionings of some slits. All exposures are internals. STIS/MA1 10034 Cycle 12 MAMA Dark Monitor This test performs the routine monitoring of the MAMA detector dark noise. This proposal will provide the primary means of checking on health of the MAMA detectors systems through frequent monitoring of the background count rate. The purpose is to look for evidence of change in dark indicative of detector problem developing. WFPC2 10067 WFPC2 Cycle 12 Decontaminations and Associated Observations This proposal is for the monthly WFPC2 decons. Also included are instrument monitors tied to decons: photometric stability check, focus monitor, pre- and post-decon internals {bias, intflats, kspots, & darks}, UV throughput check, VISFLAT sweep, and internal UV flat check. WFPC2 10070 WFPC2 CYCLE 12 Supplemental Darks Part 2/3 This dark calibration program obtains 3 dark frames every day to provide data for monitoring and characterizing the evolution of hot pixels. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) None COMPLETED OPS REQs: NONE OPS NOTES EXECUTED: 1160-2 Default Configuration for TMDIAG's @ 096/14 SCHEDULED SUCCESSFUL FAILURE TIMES FGS GSacq 05 05 FGS REacq 04 04 FHST Update 16 16 LOSS of LOCK SIGNIFICANT EVENTS: Set-up and Execution of HST FSW 2.5b OAT for RAM Installation, Back-out, and EEPROM Installation scheduled 097/10:00Z 098/04:00Z with GDOC, HITT SE, and VEST using CCS F and D Strings with CCS Release 5.0.3.1 and PRD O06300ST and CCS B and C Strings with CCS Release 4.0.3.1 and PRD O06300T. The purpose of this testing is to verify installation and backout procedures for RAM version of FSW 2.5b in an operational scenario. |
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