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Daily 3702
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3702 PERIOD COVERED: DOY 267 OBSERVATIONS SCHEDULED ACS/HRC 10198 Probing the Dynamics of the Galactic Bar through the Kinematics of Microlensed Stars The observed optical depths to microlensing of stars in the Galactic bulge are difficult to reconcile with our present understanding of Galactic dynamics. The main source of uncertainty in those comparisons is now shifting from microlensing measurements to the dynamical models of the Galactic bar. We propose to constrain the Galactic bar models with proper motion observations of Bulge stars that underwent microlensing by determining both the kinematic identity of the microlensed sources and the importance of streaming motions. The lensed stars are typically farther than randomly selected stars. Therefore, our proper motion determinations for 36 targeted MACHO events will provide valuable constraints on the dynamics of bulge stars as a function of distance. The first epoch data for our proposed events is already available in the HST archive so the project can be completed within a single HST cycle. The exceptional spatial resolution of HST is essential for completion of the project. Constraints on the total mass in the bulge will ultimately lead to the determination of the amount of dark matter in inner Galaxy. ACS/HRC 9733 Direct imaging of the progenitors of massive, core-collapse supernovae Modern supernovae searches in the nearby Universe are discovering large numbers of SNe which have massive star progenitors {Types II, Ib and Ic}. The extensive HST {and ground-based} image archives of galaxies within ~20Mpc enables their individual bright stellar content to be resolved. As massive, evolved stars are the most luminous single objects in a galaxy, the progenitors of core-collapse SNe should be directly detectable on pre-explosion images. Within the last two cycles we have set direct mass-limits on three type II-P supernovae using HST images, and already these can be used to constrain theoretical models of pre-supernova stellar evolution which predict which stars cause which of the supernovae types. We request time to continue this successful project, and require ACS observations of future SNe which are discovered in galaxies closer than 20Mpc which have pre-explosion HST archive images available. These ToO observations will allow the SNe to be precisely positioned on the pre-explosion frames with the required astrometric accuracy of around 0.05", and allow 3-colour photometry of the surrounding stellar populations for reddening estimations. The goal of this project is to directly identify the progenitor stars of core-collapse supernovae. We will compare the progenitor detections or luminosity limits to our own stellar evolutionary tracks in order to determine masses or restrictive mass-limits for the progenitors. ACS/HRC/WFC 10061 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 10166 ACS and WFPC2 Stellar Photometry in the Kepler Mission Target Field We will observe three regions at the Galactic Equator {GE} to determine the number of stars in the magnitude range from 18 to 25 in the target field of the NASA Kepler mission. This mission will search for Earth-size planets orbiting other stars. The field is a twelve by twelve degree square in Cygnus. It abuts the GE. The detection technique is to search photometrically for planetary transits. Faint eclipsing binaries that are not spatially resolved from the target star by Kepler may cause confusion, leading to false positive detections. The HST is uniquely capable of determining the potential magnitude of the issue in the region of the GE, where stellar densities are extremely high. ACS/WFC 10178 Imaging Polarimetry of Young Stellar Objects with ACS and NICMOS: A study in dust grain evolution The formation of planetary systems is intimately linked to the dust population in circumstellar disks, thus understanding dust grain evolution is essential to advancing our understanding of how planets form. By combining {1} the high resolution polarimetric capabilities of ACS and NICMOS, {2} powerful 3-D radiative transfer codes, and {3} observations of objects known to span the earliest stellar evolutionary phases, we will gain crucial insight into the initial phases of dust grain growth: evolution away from an ISM distribution. Fractional polarization is a strong function of wavelength, therefore by comparing polarimetric images in the optical and infrared, we can sensitively constrain not only the geometry and optical depth of the scattering medium, but also the grain size distribution. By observing objects representative of the earliest evolutionary sequence of YSOs, we will be able to investigate how the dust population evolves in size and distribution during the crucial transition from a disk+envelope system to a disk+star system. The proposed study will help to establish the fundamental time scales for the initial depletion of ISM-like grains: the first step in understanding the transformation from small submicron sized dust grains, to large millimeter sized grains, and untimely to planetary bodies. ACS/WFC 10207 Star Formation in Damped Lya Galaxies: Testing the Connection with the Lyman Break Population The principal challenge of damped Lya {DLA} research is to identify and study the stellar components of these galaxies. Although two decades of absorption-line research has yielded the HI gas content, metallicity, velocity fields, molecular and dust content of these galaxies only a handful have been studied in emission. Therefore, it has been very difficult to compare the DLA galaxies with the successful surveys of high z galaxies discovered in emission {e.g. Lyman break galaxies; LBG}. This is particularly important given that DLA systems are the probable precursors to galaxies like the Milky Way. Because the DLA systems are identified toward bright background quasars, deep observations at high spatial resolution with astable PSF are essential and only HST provides the observing capability. Recently, two major advances have greatly enhanced the prospects for measuring emission from DLA host galaxies: {1} we have developed a new spectroscopic technique for inferring the star formation rates {SFR} of the DLA which enables one to pre-select the brightest candidates; {2} the high spatial resolution and sensitivity of the ACS represents a major improvement over previous capabilities. We will obtain deep V-band images with the ACS of 5 high z DLA with the highest inferred apparent optical magnitudes. The complete survey will offer a robust statistical analysis of: {a} the extent and morphology of the DLA star forming regions; {b} the likelihood that the DLA and LBG correspond to the same population of protogalaxies; {c} a test of the protogalactic clump models favored by CDM cosmology. We emphasize this program will offer a major advance over all previous studies. Finally, we will complement these HST observations with an extensive observing campaign {IFU spectroscopy and deep IR imaging} on the Keck, VLT, and Magellan telescopes to provide the most extensive dataset yet on the physical properties of high z DLA. ACS/WFC 10217 The ACS Fornax Cluster Survey The two rich clusters nearest to the Milky Way, and the only large collections of early-type galaxies within ~ 25 Mpc, are the Virgo and Fornax Clusters. We propose to exploit the exceptional imaging capabilities of the ACS/WFC to carry out the most comprehensive imaging survey to date of early-type galaxies in Fornax: the ACS Fornax Cluster Survey. Deep ACS/WFC images -- in the F475W {g'} and F850LP {z'} bands -- will be acquired for 44 E, S0, dE, dE, N and dS0 cluster members. In Cycle 11, we initiated a similar program targeting early-type galaxies in the Virgo Cluster {the ACS Virgo Cluster Survey; GO-9401}. Our proposed survey of Fornax would yield an extraordinary dataset which would complement that already in hand for Virgo, and allow a definitive study of the role played by environment in the structure, formation and evolution of early-type galaxies and their globular cluster systems, nuclei, stellar populations, dust content, nuclear morphologies and merger histories. It would also be a community resource for years to come and, together with the ACS Virgo Cluster Survey, constitute one of the lasting legacies of HST. ACS/WFC 10342 Hubble Heritage Observations of NGC 1300 Observing NGC1300 in four bands for Hubble Heritage project. 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 10169 Star Formation in Luminous Infrared Galaxies: giant HII Regions and Super Star Clusters Luminous Infrared Galaxies {LIRGs, LIR = 10^11-10^12Lsol} and Ultraluminous Infrared Galaxies {LIR10^12Lsol} account for approximately 75% of all the galaxies detected in the mid-infrared in the redshift range z=0-1.5. In the local universe it is found that LIRGs are predominantly powered by intense star formation {SF}. However, the physical conditions and processes governing such dramatic activity over scales of tens to a few hundred parsecs are poorly known. In the last decade HST has been playing a significant role, mainly with the discovery of super star cluters {SSCs}, and more recently, giant HII regions. Based on observations of a few LIRGs, we found that these giant HII regions and associated SSCs appear to be more common in LIRGs than in normal galaxies, and may dominate the star formation activity in LIRGs. A larger sample is required to address fundamental questions. We propose an HST/NICMOS targeted campaign of a volume limited sample {v5200km/s} of 24 LIRGs. This proposal will probe the role of giant HII regions in the overall energetics of the current star formation, their relation to SSCs, and the dependence of star formation properties on other parameters of LIRGs. Such detailed knowledge of the SF properties of LIRGs in the local universe is essential for understanding galaxies at high redshift. NIC2 10177 Solar Systems In Formation: A NICMOS Coronagraphic Survey of Protoplanetary and Debris Disks Until recently, despite decades of concerted effort applied to understanding the formation processes that gave birth to our solar system, the detailed morphology of circumstellar material that must eventually form planets has been virtually impossible to discern. The advent of high contrast, coronagraphic imaging as implemented with the instruments aboard HST has dramatically enhanced our understanding of natal planetary system formation. Even so, only a handful of evolved disks {~ 1 Myr and older} have been imaged and spatially resolved in light scattered from their constituent grains. To elucidate the physical processes and properties in potentially planet-forming circumstellar disks, and to understand the nature and evolution of their grains, a larger spatially resolved and photometrically reliable sample of such systems must be observed. Thus, we propose a highly sensitive circumstellar disk imaging survey of a well-defined and carefully selected sample of YSOs {1-10 Myr T Tau and HAeBe stars} and { app 10 Myr} main sequence stars, to probe the posited epoch of planetary system formation, and to provide this critically needed imagery. Our resolved images will shed light on the spatial distributions of the dust in these thermally emissive disks. In combination with their long wavelength SEDs the physical properties of the grains will be discerned, or constrained by our photometrically accurate surface brightness sensitivity limits for faint disks which elude detection. Our sample builds on the success of the exploratory GTO 7233 program, using two-roll per orbit PSF-subtracted NICMOS coronagraphy to provide the highest detection sensitivity to the smallest disks around bright stars which can be imaged with HST. Our sample will discriminate between proposed evolutionary scenarios while providing a legacy of cataloged morphologies for interpreting mid- and far-IR SEDs that the recently launched Spitzer Space Telescope will deliver. WFPC2 10071 WFPC2 CYCLE 12 Supplemental Darks Part 3/3 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 Executed Ops Note 1271: Battery Pressure Limit Updates after 2004 Capacity Testing @ 267/22:10Z. SCHEDULED SUCCESSFUL FAILURE TIMES FGS GSacq 11 11 FGS REacq 5 5 FHST Update 15 15 LOSS of LOCK SIGNIFICANT EVENTS: None |
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