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Daily #3925
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3925 PERIOD COVERED: UT August 16, 2005 (DOY 228) OBSERVATIONS SCHEDULED ACS/HRC 10431 A Search for Faint Companions of Altair We propose to use the innovative new technique of spectral deconvolution {Sparks & Ford 2002} to search for very faint companions, possibly extrasolar planets shining by reflected light, around Altair, the nearest bright, single star to the Sun. The technique offers a Poisson-limited detection capability that brings Jovian-class planets into the realm of feasibility for a select few stars. We turn the wavelength dependence of the coronagraphic PSF to advantage and use it to eliminate stray light from the host star. As part of the detection process, we obtain a spectrum over the wavelength range, 750 nm to 1 micron, with 9% resolution. The search will be orders of magnitude more sensitive than all previous efforts and should take us to within about an order of magnitude of the Jovian luminosity flux limit. ACS/HRC 10525 Characterizing the Near-UV Environment of M Dwarfs: Implications for Extrasolar Planetary Searches and Astrobiology We propose SNAP observations with the ACS HRC PR200L prism, designed to measure the near ultraviolet emission in a sample of 107 nearby M dwarfs. The sample spans the mass range from 0.1 - 0.6 solar masses {temperature range 2200K - 4000K} where the UV energy distributions vary widely between active and inactive stars. The strength and distribution of this UV emission can have critical consequences for the atmospheres of attendant planets. Our proposed observations will provide desperately needed constraints on models of the habitability zone and the atmospheres of possible terrestrial planets orbiting M dwarf hosts, and will be used to sharpen TPF target selection. In addition, the NUV data will be used in conjunction with existing optical, FUV and X-ray data to constrain a new generation of M dwarf atmospheric models, and to explore unanswered questions regarding the dynamo generation and magnetic heating in these low-mass stars. ACS/HRC/NIC3 10182 Towards a Comprehensive Understanding of Type Ia Supernovae: The Necessity of UV Observations Type Ia supernovae {SNe Ia} are very important to many diverse areas of astrophysics, from the chemical evolution of galaxies to observational cosmology which led to the discovery of dark energy and the accelerating Universe. However, the utility of SNe Ia as cosmological probes depends on the degree of our understanding of SN Ia physics, and various systematic effects such as cosmic chemical evolution. At present, the progenitors of SNe Ia and the exact explosion mechanisms are still poorly understood, as are evolutionary effects on SN Ia peak luminosities. Since early-time UV spectra and light curves of nearby SNe Ia can directly address these questions, we propose an approach consisting of two observational components: {1} Detailed studies of two very bright, young, nearby SNe Ia with HST UV spectroscopy at 13 epochs within the first 1.5 months after discovery; and {2} studies of correlations with luminosity for five somewhat more distant Hubble-flow SNe Ia, for which relative luminosities can be determined with precision, using 8 epochs of HST UV spectroscopy and/or broad-band imaging. The HST data, along with extensive ground-based optical to near-IR observations, will be analyzed with state-of-the-art models to probe SN Ia explosion physics and constrain the nature of the progenitors. The results will form the basis for the next phase of precision cosmology measurements using SNe Ia, allowing us to more fully capitalize on the substantial past {and future} investments of time made with HST in observations of high-redshift SNe Ia. ACS/WFC 10626 A Snapshot Survey of Brightest Cluster Galaxies and Strong Lensing to z = 0.9 We propose an ACS/WFC snapshot survey of the cores of 150 rich galaxy clusters at 0.3 z 0.9 from the Red Sequence Cluster Survey {RCS}. An examination of the galaxian light in the brightest cluster galaxies, coupled with a statistical analysis of the strong-lensing properties of the sample, will allow us to contrain the evolution of both the baryonic and dark mass in cluster cores, over an unprecedented redshift range and sample size. In detail, we will use the high- resolution ACS images to measure the metric {10 kpc/h} luminosity and morphological disturbances around the brightest clusters galaxies, in order to calibrate their accretion history in comparison to recent detailed simulations of structure formation in cluster cores. These images will also yield a well-defined sample of arcs formed by strong lensing by these clusters; the frequency and detailed distribution {size, multiplicity, redshifts} of these strong lens systems sets strong constraints on the total mass content {and its structure} in the centers of the clusters. These data will also be invaluable in the study of the morphological evolution and properties of cluster galaxies over a significant redshift range. These analyses will be supported by extensive ongoing optical and near-infrared imaging, and optical spectroscopy at Magellan, VLT and Gemini telescopes, as well as host of smaller facilities. ACS/WFC/NIC3 10405 Probing the establishment of galaxy morphologies in the best-studied high-redshift structure We propose deep ACS I-band imaging of arguably the best-studied high-redshift proto-cluster environment, a high-contrast structure in the SSA22 field at z=3.1. Our on-going study of this region has identified over 400 probable members of this structure across a 16-arcmin-square field, selected through narrow-band Lyman-alpha emission, Lyman-break photometric criteria and far-infrared/radio emission. Our proposed high-resolution imaging of galaxies in the z=3.1 structure and in the nearby field, will provide morphological information on galaxies over nearly two-orders of magnitude in local density at this early epoch. This will allow us for the first time to test whether galaxy morphology is defined at the formation of a galaxy or reflects processes acting on it during its lifetime. FGS 10386 Long Term Monitoring of FGS1r in Position Mode It is known from our experience with FGS3, and later with FGS1r, that an FGS on orbit experiences long term evolution, presumably due to disorption of water from the instrument's graphite epoxy composits. This manifests principly as a change in the plate scale and secondarily as a change in the geometric distortions. These effects are well modeled by adjustments to the rhoA and kA parameters which are used to transform the star selector servo angles into FGS {x, y} detector space coordinates. By observing the relative positions of selected stars in a standard cluster at a fixed telescope pointing and orientation, the evolution of rhoA and kA can be monitored and calibrated to preserve the astrometric performance of FGS1r. NIC1/NIC2/NIC3 10721 NICMOS dark current tests for newly implemented SPARS sequences On June 12, 2005, 4 new NICMOS multiaccum sequences {SPARS4, SPARS16, SPARS32, SPARS128} were implemented. The purpose of this observation is to measure the dark currents for these new multiaccum sequences for all three NICMOS detectors. NIC1/NIC2/NIC3 8793 NICMOS Post-SAA calibration - CR Persistence Part 4 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. NIC2 10176 Coronagraphic Survey for Giant Planets Around Nearby Young Stars 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. S/C ACS/HRC 10719 A Coordinated NICMOS and XMM Experiment to Observe the Variability of Sgr A* The massive black hole Sgr A* at the Galactic center has recently shown not only quiescent emission at near-IR wavelengths, but also flare activity with quasi-periodicity of 17 minutes. Our research group has been granted two blocks of observing time with XMM-Newton to monitor the spectral and temporal properties of Sgr A*. Simultaneously with these X-ray observations, we will also monitor Sgr A* at radio, submillimeter, near-IR, and gamma-ray wavelengths. We propose to use NICMOS in parallel with the XMM observations to provide evidence of a well- defined minimum periodicity in the spectrum of flare periodicities. This, combined with periodicity in the near-IR line emission, would strengthen the claim that the emitting gas resides at the innermost stable circular orbit around the GC black hole, thus measuring the spin parameter of a massive black hole. Current groundbased near-IR data suggest a spin parameter of ~0.5. In addition, the correlation pattern of emission over a wide spectrum would elucidate a key issue of how to explain the low luminosity of Sgr A*. The NICMOS on HST is the only instrument that can accurately measure the 17 minute quasi-periodic variability of Sgr A* because of the long time baseline over which HST can observe Sgr A* in parallel with XMM-Newton. WFPC2 10360 WFPC2 CYCLE 13 INTERNAL MONITOR This calibration proposal is the Cycle 13 routine internal monitor for WFPC2, to be run weekly to monitor the health of the cameras. A variety of internal exposures are obtained in order to provide a monitor of the integrity of the CCD camera electronics in both bays {gain 7 and gain 15}, a test for quantum efficiency in the CCDs, and a monitor for possible buildup of contaminants on the CCD windows. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTARS: 9917 - OBAD Failed During Lunar Observation @228/2300z OBADS failed at 228/23:00 during OR#17498-0 Lunar Observation Viewing 1 OBAD 1. Mnemonic QT2GMST showed MapFail. COMPLETED OPS REQUEST: 17502-1 - Lunar Ob Viewing 1 Zero Observer @228/2245z 17498-0 - Lunar Observation Viewing 1 OBAD 1 @228/2302z 17506-0 - Lunar Observation Viewing 1 MAP 1 @229/0036z 17507-0 - Lunar Observation Viewing 1 MAP 2 @229/0212z 17508-1 - Lunar Observation Viewing 1 MAP 3 @229/0346z COMPLETED OPS NOTES: (None) SCHEDULED SUCCESSFUL FGS Gsacq 06 06 FGS Reacq 06 06 FHST Update 12 12 LOSS of LOCK SIGNIFICANT: Lunar Observation Map Summary: PCS evaluated data taken for gyro bias update at 228/2054 and determined that the observer data used was consistent with predictions, indicating that V2 attitude drift resulting from the AOA would be small. Map data collected during the visit indicated accumulating errors were consistent with estimates based on maneuver angles and gyro bias errors The Lunar Observations were transmitted to the Science Institute and evaluated @229/0500z , with final analysis still in progress. |
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