#1
|
|||
|
|||
Daily 3546
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3546 PERIOD COVERED: DOY 36 OBSERVATIONS SCHEDULED ACS 9984 Cosmic Shear With ACS Pure Parallels Small distortions in the shapes of background galaxies by foreground mass provide a powerful method of directly measuring the amount and distribution of dark matter. Several groups have recently detected this weak lensing by large-scale structure, also called cosmic shear. The high resolution and sensitivity of HST/ACS provide a unique opportunity to measure cosmic shear accurately on small scales. Using 260 parallel orbits in Sloan textiti {F775W} we will measure for the first time: beginlistosetlength sep0cm setlengthemsep0cm setlength opsep0cm em the cosmic shear variance on scales 0.7 arcmin, em the skewness of the shear distribution, and em the magnification effect. endlist Our measurements will determine the amplitude of the mass power spectrum sigma_8Omega_m^0.5, with signal-to-noise {s/n} ~ 20, and the mass density Omega_m with s/n=4. They will be done at small angular scales where non-linear effects dominate the power spectrum, providing a test of the gravitational instability paradigm for structure formation. Measurements on these scales are not possible from the ground, because of the systematic effects induced by PSF smearing from seeing. Having many independent lines of sight reduces the uncertainty due to cosmic variance, making parallel observations ideal. ACS/HRC/WFC 10059 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 9722 Life in the fast lane: The dark-matter distribution in the most massive galaxy clusters in the Universe at z0.5 We propose two-filter ACS observations of a complete sample of 12 very X-ray luminous galaxy clusters at 0.5z0.7 as a cornerstone of a comprehensive multi-wavelength study of the properties of the most massive clusters in the universe. Our sample includes the famous systems Cl0016+16 and MS0451-03; all other clusters are new discoveries from the MACS survey. Being the counterparts of the best-studied systems at lower and higher redshift and comprising ALL massive clusters at 0.5z0.7 observable from Mauna Kea this sample will become the ultimate reference for cluster studies at z0.5. HST's unique capabilities will allow us to: 1} measure accurately the clusters' dark matter distribution on scales from tens to more than 500/h_50 kpc from observations of strong and weak gravitational lensing, 2} use galaxy-galaxy lensing to measure the shape, extent, and mass content of the dark-matter halos of both cluster and field galaxies, and 3} study the color morphology of mergers and the star formation history of galaxies in a high-density environment. The proposed observations are complemented by Chandra observations of all our targets {all 12 awarded, 11 executed to date} which provide independent constraints on the dark matter and gas distribution in the cluster cores, as well a by extensive groundbased observations of weak lensing on yet larger scales, galaxy dynamics, and the SZ effect. ACS/WFC 9744 HST Imaging of Gravitational Lenses Gravitational lenses offer unique opportunities to study cosmology, dark matter, galactic structure, galaxy evolution and quasar host galaxies. They are also the only sample of galaxies selected based on their mass rather than their luminosity or surface brightness. While gravitational lenses can be discovered with ground-based optical and radio observations, converting them into astrophysical tools requires HST. HST has demonstrated that it is the only telescope that can in each case precisely locate the lens galaxy, measure its luminosity, color and structure, and search for lensed images of the source host galaxy given the typical image separations of ~1''. We will obtain ACS/WFC V and I images and NICMOS H images of 21 new lenses never observed by HST and NICMOS H images of 16 lenses never observed by HST in the IR. As in previous cycles, we request that the data be made public immediately. HST 9382 A Large Targeted Survey for z 1.6 Damped Lyman Alpha Lines in SDSS QSO MgII-FeII Systems. We have searched the first public release of SDSS QSO spectra for low-z {z1.65} metal absorption lines and found over 200 large rest equivalent width MgII-FeII systems. Previously, we empirically showed that such systems are good tracers of large neutral gas columns, with ~50% being classical damped Lyman alpha {DLA} systems {N_HI=2*10^20 cm^-2}. Here we propose to follow up a well-defined subset of 79 of them to search for DLAs with 0.47z1.60. Only QSOs brighter than g'=19 were selected. The QSO emission and DLA absorption redshifts were constrained to virtually eliminate data loss due to intervening Lyman limit absorption. Consequently, we expect to discover ~40 new DLAs, which is a three-fold increase in this redshift interval. This will significantly improve our earlier low-z DLA statistical results on their incidence, cosmological mass density, and N_HI distribution. The results will also allow us to better quantify the empirical DLA -- metal-line correlation. With this improved understanding, the need for follow-up UV spectroscopy will lessen and, with the release of the final database of SDSS QSO spectra {an ~25-fold increase}, the number of low-z DLAs could be increased arbitrarily. Thus, the power of the large and statistically-sound SDSS database in combination with a proven technique for finding low-z DLAs will, over the next few years, essentially solve the problem of making an accurate determination of the cosmic evolution of the neutral gas component down to z~0.4. NIC/NIC3 9865 The NICMOS Parallel Observing Program 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. NIC1 9833 T Dwarf Companions: Searching for the Coldest Brown Dwarfs Faint companions to known stars have historically led to the discovery of new classes of stellar and substellar objects. Because these discoveries are typically limited by the flux ratio of the components in the system, the intrinsically faintest companions are most effectively identified around the intrinsically faintest primaries. We propose to use NICMOS to image a sample of 22 of the coolest known {T-type} brown dwarfs in the Solar Neighborhood in order to search for fainter and cooler brown dwarf companions. The high spatial resolution of the NIC 1 detector enables us to distinguish binary systems with apparent separations greater than 0"08, or physical separations greater than 1.2 AU at the nominal distances of the objects in our sample. Furthermore, the substantial sensitivity of NICMOS imaging allows us to probe companion masses of 5-50 Jupiter masses and companion effective temperatures of 250-1300 K in a maximally efficient manner. Based on work to date, we expect that roughly 20% of the objects in our sample will be binary, and that one or two of these will likely harbor a significantly fainter secondary. Hence, we expect to find a companion cooler than any currently known brown dwarf, a potential prototype for the next spectral class. In addition, our investigation will add substantially to the sample of known binary brown dwarfs, allowing improved statistical analyses of the binary fraction, separation distribution, and mass ratio distribution of these systems, key quantities for probing brown dwarf formation. We will also identify optimal substellar systems for astrometric mass measurements, a critical check for theoretical models of brown dwarfs and extrasolar planets. NIC2 9834 Finding Planets in the Stellar Graveyard: A Faint Companion Search of White Dwarfs with NICMOS We propose to do a deep search for substellar objects in orbit around white dwarfs with the newly refurbished NICMOS camera as part of the PI's doctoral thesis work. Direct imaging of planets around main sequence stars is difficult due to the large contrast ratio, a problem which is much less severe for companions to white dwarfs. White dwarfs are not usually considered in planet searches but recent theoretical work and observations are motivating new searches for planetary systems and dust disks around DAZ white dwarfs. We propose to conduct the search with the NIC2 coronagraph to find resolved companions and do photometry to search for unresolved companions through Near-IR excesses. We estimate that the survey will be sensitive to brown dwarfs, high mass jovian planets, and dust disks. By probing a wide range of orbital separations and companion masses, this survey will help to answer questions about the brown dwarf desert, common envelope evolution, and planet formation. HST and NICMOS provide a unique capability to do this search, as no ground based observatory with AO can adequately search for faint companions as close and with such high contrast. NICMOS 8791 NICMOS Post-SAA calibration - CR Persistence Part 2 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. STIS/CCD 10017 CCD Dark Monitor-Part 1 Monitor the darks for the STIS CCD. STIS/CCD 10019 CCD Bias Monitor - Part 1 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 10085 STIS Pure Parallel Imaging Program: Cycle 12 This is the default archival pure parallel program for STIS during cycle 12. STIS/CCD/MA1 9769 STIS Observations of Orbital and Rotational Variations in the Unique Post-Common Envelope System HS1136+6646 HS1136+6646 is a recently discovered close-binary system consisting of a hot {Teff ~ 120, 000 K} DAO white dwarf and a K7V main sequence companion. It is unique in being a relatively bright, nearby example of both a very young post-common envelope system and a pre-cataclysmic variable system. Although the K star component of HS1136+6646 has now been well studied from the ground, the white dwarf can only be effectively studied at UV wavelengths from space. We propose STIS observations of HS1136+6646 which focus specifically on the nature of the white dwarf, i.e., its mass, temperature, age, photospheric composition and possible magnetic field. High-dispersion echelle spectra, taken at quadrature of the 0.83607 day orbital period of the system will provide an accurate determination of the gravitational redshift of the white dwarf. STIS/MA1/MA1 10031 STIS MAMA Cycle 12 Deep Wavecals This program will obtain deep wavecals for the STIS Echelle modes in order to produce improved dispersions solutions. The new wavelength solution is based on a physical model of the instrument's optical elements and will supercede the empirical polynomial fit. This work is part of the STIS Calibration Enhancement project conducted at the ST-ECF. Deep wavecals are required in order to take full advantage of the new line list from the ESA -funded Pt/Cr-Ne calibration lamp project and to test the predictive power of physical instrument model of STIS. A second epoch of observations will investigate the issue of MSM repeatability. 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. WFPC2 10082 POMS Test Proposal: WFII backup parallel archive proposal This is a POMS test proposal designed to simulate scientific plans WFPC2 10084 WFII parallel archive proposal This is the generic target version of the WFPC2 Archival Pure Parallel program. The program will be used to take parallel images of random areas of the sky, following the recommendations of the 2002 Parallels Working Group. 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: 1194-0 Adjust Recharge Ratio Limits for High Sun DOY 2004/036-046 @ 036/12:01z SCHEDULED SUCCESSFUL FAILURE TIMES FGS GSacq 09 09 FGS REacq 10 10 FHST Update 07 07 LOSS of LOCK SIGNIFICANT EVENTS: None |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Monitoring NASA Daily ISS Report | JimO | Space Station | 2 | June 1st 04 10:33 PM |
JimO Speaks on 'Daily Planet' re Hubble | JimO | Policy | 0 | February 11th 04 10:53 PM |
Spirit's daily activities schedule? | Matti Anttila | Policy | 0 | January 15th 04 08:39 AM |
best site for daily schedule of rover activity? | bob | History | 2 | January 5th 04 12:16 PM |
Investor's Business Daily: Rethinking NASA | dougk | Policy | 1 | August 28th 03 12:07 AM |