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Daily 3602
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3602 PERIOD COVERED: DOY 120 OBSERVATIONS SCHEDULED 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/WFC 9765 The Dusty ISM Substructure in Nearby Spiral Galaxies We propose an ACS V&I imaging snapshot survey of all nearby edge-on spiral galaxies in order to measure the small scale structures in their dust extinction down to the 10pc scale. Dust and molecular gas are tightly coupled and therefore HST high resolution reddening maps can reveal information about the cold ISM phase on a scale inaccessible from the groundby any other means. We have recently discovered a sudden change in dust lane properties using ground-based data; all galaxies with rotation speeds in access of 120km/s show dust lanes, but none of the slower rotators does. This transition may be caused by a sudden change in the state of the multiphase ISM, and HST resolution imaging is needed to fully quantify this effect. Analysis will consist of full radiative transfer modeling of dust extinction with realistic, fractal like substructure and power spectrum analysis of the structure from the global to the 10pc scale. By observing a sample of galaxies with a range in structural parameters we can quantify how the cold ISM structure changes as function of radius, rotation speed, local surface density, et cetera. This information is duly needed with SIRTF soon providing a wealth of information on dust absorption, but lacking the resolution to determine the small scale distribution of the dust. ACS/WFC/HRC 9771 The local Hubble flow and the density field within 6 Mpc Great progress has been made recently in accurate distance measurements of nearby galaxies beyond the Local Group based on the luminosity of the tip of the red giant branch {TRGB}. Over the last three years, snapshot surveys with HST have provided us with the TRGB distances for more than a hundred nearby galaxies obtained with an accuracy of about 10%. The local velocity field within 5 Mpc exhibits a significant anisotropy which disagrees with a spherical Virgo-centric flow. The local Hubble flow is very cold, with 1-D rms deviations of ~30 km/s. Cosmological simulations with Cold Dark Matter can only realize such low dispersions with a combination of a low mean density of matter and a substantial component with negative pressure. There may be a constraint on the equation of state w=-p/rho. Our observations will concentrate on 116 galaxies whose expected distances lie within 4 - 6 Mpc, allowing us to trace a Dark Matter distribution in the Local Volume with twice the information currently available. The program is a good one for SNAP mode because the order and rate that the observations are made are not very important, as long as there is good completion over several years. SNAP/STIS 9434 A SNAPSHOT Survey of the Hot Interstellar Medium We propose to obtain SNAPSHOT STIS echelle observations of key tracers of hot interstellar gas {CIV, NV and SiIV} for selected FUSE Team OVI survey targets with known UV fluxes. By taking advantage of the SNAPSHOT observing mode we will efficiently obtain a large number of spectra suitable for the study of the highly ionized hot component of the interstellar medium {ISM}. Our goals are to explore the physical conditions in and distribution of such gas, as well as to explore the nature of the interfaces between the hot ISM and the other interstellar gas phases. Using inter--comparisons of the various ionic ratios for CIV, NV, OVI and SiIV, we will be able to discriminate between the various models for the production of the highly ionized gas in the Galactic ISM. The survey will also enable detailed studies of regions already known to contain hot gas through X-ray emission measurements {e.g., SNRs and radio loops}. The proposed SNAPSHOT observations will extend our previous Cycle 9 survey {which was compromised by the STIS side 1 failure}, and should roughly double the number of stars for which high quality STIS observations of the important hot gas tracers are available, enabling us to derive a truly global view of the hot ISM. STIS 9506 A SNAPSHOT SURVEY OF HIGH COLUMN DENSITY, LOW-Z LyAlpha ABSORBERS We propose a STIS G140L spectroscopic Snapshot program of bright {V=16.5} AGN not previously observed in the UV to discover new high-column density {N_H = 10^15 cm^-2} LyAlpha absorbers in the local Universe {z = 0.45}. Many more of these high column density systems are needed because: {1} They contribute most of the baryons to the local IGM; {2} They include many of the ``warm-hot'' absorbers, thought to be a large baryon reservoir in the local Universe; and {3} They are most likely to be ``associated'' with galaxy halos. Because of their low-z, many of these absorbers can be located relative to galaxies of known redshifts, allowing an immediate scientific return from these snapshots. Using these snapshots to select the best targets, we will obtain COS R~22, 000 spectra to determine the D/H and metallicity of absorbers in galaxy halos, groups, and voids. We will use pairs and ``constellations'' of AGN to determine absorber sizes, shapes, and covering factors. 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 9906 Volatile Abundances and the D/H Ratio in Long-Period Comets Comet NEAT {C/2001 Q4} is predicted to reach naked-eye visibility in the spring of 2004, under excellent conditions for observations with HST. Although predicting cometary magnitudes more than 1 year in advance is notoriously risky, C/NEAT seems likely to be exceptionally active, allowing us for the first time to perform sensitive measurements of the D/H and OD/OH ratios. Accurate measurements of the deuterium abundance in comets, which can vary in different species, are crucial for determining if comets retain a signature of their possible interstellar origin and if they supplied a significant fraction of the water on Earth. HST observations of C/NEAT will additionally provide accurate abundances for highly volatile ices in the nucleus, such as CO, CO2 {via Cameron band emission}, and S2, which also provide important insights on the comet's origin and evolution. This opportunity in cycle 12 is unique in the history of HST and is unlikely to be repeated during its remaining lifetime. STIS/CCD/MA1 9724 Towards a global understanding of accretion physics - Clues from an UV spectroscopic survey of cataclysmic variables Accretion inflows and outflows are fundamental phenomena in a wide variety of astrophysical environments, such as Young Stellar Objects, galactic binaries, and AGN. Observationally, cataclysmic variables {CVs} are particularly well suited for the study of accretion processes. We are currently carrying out a Cycle 11 STIS UV spectroscopic snapshot survey of CVs to fully exploit the diagnostic potential of these objects for our understanding of accretion physics. While the data obtained so far are of excellent quality, the number of targets that will be observed in Cycle 11 is too small for a statistically significant analysis {only 19 objects out of our 149 accepted Cycle 11 snapshot targets have been observed at the time of writing}. We propose here to extend this survey into Cycle 12, building a homogenous database of accretion disc and wind outflow spectra covering a wide range of mass transfer rates and binary inclinations. We will analyze these spectra with state-of-the-art accretion disc model spectra {SYNDISK}, testing our current knowledge of the accretion disc structure, and, thereby, providing new insight into the so far not well understood process of viscous dissipation. We will use our parameterised wind model PYTHON for the analysis of the radiation driven accretion disc wind spectra, assessing the fundamental question whether the mass loss rate correlates with the disc luminosity. In addition, our survey data will identify a number of systems in which the white dwarf significantly contributes to the UV flux, permitting an analysis of the impact of mass accretion on the evolution of these compact stars. This survey will triple the number of currently available high-quality accretion disc / wind outflow / accreting white dwarf spectra, and we waive our proprietary rights to permit a timely use of this database. 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: 17146-1 Battery 6 Capacity test scrip (Steps 32-45) @ 120/13:03z 17161-0 Dump ACS Error Log @ 120/18:54z OPS NOTES EXECUTED: 1229-0 Change Limits MAMA2 Threshold Voltage @ 120/19:45z 1230-0 PRD Updated with new Tables @ 120/20:17z SCHEDULED SUCCESSFUL FAILURE TIMES FGS GSacq 15 15 FGS REacq 01 01 FHST Update 20 20 LOSS of LOCK SIGNIFICANT EVENTS: Final FLASH Report for Battery 6 Capacity Test Battery 6 has sufficiently recovered from its discharge to 23.688 volts. It's voltage, pressure, and loadshare, are in family with the other batteries. At 120/1255 GMT, Battery 6 was placed back on-line in flight software. The SOC-1 safing test was successfully modified to represent a 6-battery system and the BM SOC was reset to 305 A-h. The K2 SPA Trim relay was un-masked at this time and the proper charge optimization scheme was reinstated. The EPS system is now back to its nominal configuration in both FSW and Hardware. |
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