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Daily #4034
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT #4034 PERIOD COVERED: UT January 23, 2006 (DOY 023) OBSERVATIONS SCHEDULED ACS/HRC/WFC 10570 Hosts of Quasars with Opaque Partial Covering A few quasars are known to exhibit associated absorption lines with opaque partial covering. These are the lines which are clearly saturated but not completely dark, so that these absorbing clouds are opaquely and partially covering the quasar light. In some cases, ionization parameter and density arguments indicate that the absorbers are on kpc scale. This implies that at least in some cases, the residual, unabsorbed optical {rest-UV} continuum component originates from ~kpc scales, rather than microscopic scales {such as ~100 Schwarzschild radii}. This could be a superluminous host galaxy or starbursting core, and could be resolved by HST. We address the nature of these opaquely and partially covered quasars with a simple and robust ACS imaging. ACS/HRC/WFC 10729 ACS CCDs daily monitor 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. Changes from cycle 13:- The default gain for WFC is 2 e-/DN. As before bias frames will be collected for both gain 1 and gain 2. Dark frames are acquired using the default gain {2}. This program cover the period Oct, 2 2005- May, 29-2006. The second half of the program has a different proposal number: 10758. ACS/WFC 10494 Imaging the mass structure of distant lens galaxies The surface brightness distribution of extended gravitationally lensed arcs and Einstein rings contains super-resolved information about the lensed object, and, more excitingly, about the smooth and clumpy mass distribution of the lens galaxies. The source and lens information can non-parametrically be separated, resulting in a direct "gravitational-mass image" of the inner mass-distribution of cosmologically-distant galaxies {Koopmans 2005}. With this goal in mind, we propose deep HST ACS-F555W/F814W and NICMOS-F160W imaging of 15 gravitational-lens systems with spatially resolved lensed sources, selected from the 17 new lens systems discovered by the Sloan Lens ACS Survey {Bolton et al. 2004}. Each system has been selected from the SDSS and confirmed in a time-efficient HST-ACS snapshot program {cycle-13}; they show highly-magnified arcs or Einstein rings, lensed by a massive early-type lens galaxy. High- fidelity multi-color HST images are required {not delivered by the 420-sec snapshot images} to isolate these lensed images {properly cleaned, dithered and extinction-corrected} from the lens galaxy surface brightness distribution, and apply our "gravitational-mass imaging" technique. The sample of galaxy mass distributions - determined through this method from the arcs and Einstein ring HST images - will be studied to: {i} measure the smooth mass distribution of the lens galaxies {Dark and luminous mass are separated using the HST images and the stellar M/L values derived from a joint stellar-dynamical analysis of each system}; {ii} quantify statistically and individually the incidence of mass-substructure {with or without obvious luminous counter- parts such as dwarf galaxies}. Since dark-matter substructure should be considerably more prevalent at higher redshift, both results provide a direct test of this prediction of the CDM hierarchical structure-formation model. ACS/WFC 10496 Decelerating and Dustfree: Efficient Dark Energy Studies with Supernovae and Clusters We propose a novel HST approach to obtain a dramatically more useful "dust free" Type Ia supernovae {SNe Ia} dataset than available with the previous GOODS searches. Moreover, this approach provides a strikingly more efficient search-and-follow-up that is primarily pre- scheduled. The resulting dark energy measurements do not share the major systematic uncertainty at these redshifts, that of the extinction correction with a prior. By targeting massive galaxy clusters at z 1 we obtain a five-times higher efficiency in detection of Type Ia supernovae in ellipticals, providing a well-understood host galaxy environment. These same deep cluster images then also yield fundamental calibrations required for future weak lensing and Sunyaev-Zel'dovich measurements of dark energy, as well as an entire program of cluster studies. The data will make possible a factor of two improvement on supernova constraints on dark energy time variation, and much larger improvement in systematic uncertainty. They will provide both a cluster dataset and a SN Ia dataset that will be a longstanding scientific resource. ACS/WFC 10515 The Unique Star Cluster System of M85 Even with its long history as one of the pillars of modern astronomy, the study of star clusters has continued to reveal new and surprising things. Over the past decade, numerous programs with HST have shown that extragalactic star clusters powerfully probe the processes of galactic formation, evolution, and destruction. The diversity of star cluster systems is a testament to the rich variation in galaxy properties. During the course of the ACS Virgo Cluster Survey, we have discovered that the early-type galaxy M85 has a system of star clusters unlike any other galaxy studied to date. Hundreds of star clusters in M85 are fainter and more extended than typical globular clusters, and have no local analog. We propose deep optical- infrared imaging with ACS and NICMOS to obtain ages, metallicities, luminosities, and sizes of unprecedented precision to characterize these new star clusters and unravel the evolutionary state of M85 that gave rise to them. ACS/WFC 10543 Microlensing in M87 and the Virgo Cluster Resolving the nature of dark matter is an urgent problem. The results of the MACHO survey of the Milky Way dark halo toward the LMC indicate that a significant fraction of the halo consists of stellar mass objects. The VATT/Columbia survey of M31 finds a similar lens fraction in the M31 dark halo. We propose a series of observations with ACS that will provide the most thorough search for microlensing toward M87, the central elliptical galaxy of the Virgo cluster. This program is optimized for lenses in the mass range from 0.01 to 1.0 solar masses. By comparing with archival data, we can detect lenses as massive as 100 solar masses, such as the remnants of the first stars. These observations will have at least 15 times more sensitivity to microlensing than any previous survey, e.g. using WFPC2. This is due to the factor of 2 larger area, factor of more than 4 more sensitivity in the I-band, superior pixel scale and longer baseline of observations. Based on the halo microlensing results in the Milky Way and M31, we might expect that galaxy collisions and stripping would populate the overall cluster halo with a large number of stellar mass objects. This program would determine definitively if such objects compose the cluster dark matter at the level seen in the Milky Way. A negative result would indicate that such objects do not populate the intracluster medium, and may indicate that galaxy harassment is not as vigorous as expected. We can measure the level of events due to the M87 halo: this would be the best exploration to date of such a lens population in an elliptical galaxy. Star-star lensing should also be detectable. About 20 erupting classical novae will be seen, allowing to determine the definitive nova rate for this giant elliptical galaxy. We will determine if our recent HST detection of an M87 globular cluster nova was a fluke, or indicative of a 100x higher rate of incidence of cataclysmic variables and nova eruptions in globulars than previously believed. We will examine the populations of variable stars, and will be able to cleanly separate them from microlensing. ACS/WFC 10740 Absolute Photometric & Spectrophometric Calibration This program has several goals: 1.}Verify repeatability of the ACS instrumentation on a single bright star to +/-0.2%. 2.}Determine any shift in the filter bandpasses since the preflight lab measurements. 3.}Determine the relative magnitude of the 3 primary WD calibrators to 0.1%. 4.}Refine the sensitivity calibration of the CCD prism and grisms at field center and determine the repeatability accuracy of this calibration. 5.}Determine the level of variability of the three HST red standard stars: VB-8 {M7}, 2M0038+18 {L3.5} and 2M0559-14 {T5}, and also measure their short wavelength {7000A} fluxes. 6.}Cross calibrate with a faint STIS and NICMOS standard WD and solar analog star. NICMOS 8790 NICMOS Post-SAA calibration - CR Persistence Part 1. 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. WFPC2 10748 WFPC2 CYCLE 14 Standard Darks This dark calibration program obtains dark frames every week in order to provide data for the ongoing calibration of the CCD dark current rate, and to monitor and characterize the evolution of hot pixels. Over an extended period these data will also provide a monitor of radiation damage to the CCDs. WFPC2 10778 WFPC2 WF4 Supplemental Darks These darks are to supplement those in program 10748 to ensure sufficient dark frames for routine calibration. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTARS: 10100 - REAcq (2,1,2) failed due to search radius limit exceeded on FGS 2 @ 024/0301z At AOS (024/03:11:30) REAcq (2,1,2) scheduled @ 024/03:01:23 indicated failed due to search radius limit exceeded. ESB "a05", Exceeded SRL was received. No OBADs prior to REAcq. Prior OBAD MAP showed the following errors: V1 6.83, V2 0.46, V3 -1.60, RSS 7.03. Following OBAD MAP showed the following errors: V1 -741.22, V2 530.18, V3 -355.15, RSS 978.07 COMPLETED OPS REQUEST: SCHEDULED SUCCESSFUL FAILURE TIMES FGS GSacq 08 08 FGS REacq 05 04 024/0301z (HSTAR 10100) OBAD with Maneuver 24 24 COMPLETED OPS NOTES: (None) SIGNIFICANT EVENTS: FLASH REPORT: VTFE Curve Adjustment K1L4 Equivalent On DOY 2006/023 at 14:52 GMT, the VTFE curves were increased from K1L4-100mv to K1L4 in an effort to take advantage of the low battery temperatures. The system was monitored for one orbit and nominal performance was observed with the benchmark reset threshold satisfied and the maximum system SOC increased from 246 Ah to 253 Ah. Peak battery temperatures are still below -1 degC. |
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