Cycle 17 Abstract Catalog (Based on Phase I Submissions) Generated On: Fri May 30 08:50:52 EDT 2008
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Cycle 17 Abstract catalog (based on Phase I submissions) Generated on: Fri May 30 08:50:52 EDT 2008 Proposal Category: GO Scientific Category: UNRESOLVED STELLAR POPULATIONS AND GALAXY STRUCTURE ID: 11554 Title: Luminosity Profiles of Extremely Massive Clusters in NGC 7252 PI: Nate Bastian PI Institution: University of Cambridge The galactic merger remnant NGC 7252 represents one of the most extreme post- starburst environments in the local universe. During the disk-disk merger (~400 Myr ago) this galaxy produced the largest young massive star cluster population known, including two clusters above 10^7 Msun, a factor of 100 more massive than typical globular clusters in the Milky Way. We propose ACS-HRC observations of 3 fields in NGC 7252 in order to explore the detailed properties, i.e. luminosity profiles, of these massive star clusters. These observations will be able to test massive cluster formation mechanisms (e.g. the cluster merger scenario) as well as the possible tidal erosion and truncation of the outer regions of the clusters by the galactic tidal field. These observations will compliment our large on-going study using archival HST data, of star cluster profiles outside the Local Group. The cluster population in NGC 7252 will extend our sample in cluster mass by an order of magnitude. ====================================================================== Proposal Category: GO Scientific Category: COOL STARS ID: 11555 Title: Transition Region and Chromospheric Activity on Low Metallicity Arcturus Moving Group "Alien" Dwarfs PI: Alexander Brown PI Institution: University of Colorado at Boulder How does low metallicity affect the heating and resultant temperature structure of the chromospheres, transition regions, and coronae of old solar- like dwarf stars? The Arcturus Moving Group is very likely a remnant of the merger of a dwarf galaxy with the Milky Way Galaxy in the distant (~ 7- 8 Gyr) past. This kinematically distinct group has members that are located very close to the Sun, allowing study of stellar activity on very old, low metallicity stars that typically would not be possible. We propose to obtain COS G140L spectra of four dwarf star members of the Arcturus Moving Group to measure the fluxes of their transition region and upper chromospheric emission lines and to investigate the effects of low metallicity on the outer atmospheric radiative losses and temperature structure. Our targets have metallicities of ~ 20% solar or less, spectral types F9 - M4, and are at distances less than 25 pc from the Sun. COS is the only UV spectrograph that is capable of registering the FUV spectra of these stars in a reasonable number of HST orbits. ====================================================================== Proposal Category: GO Scientific Category: SOLAR SYSTEM ID: 11556 Title: Investigations of the Pluto System PI: Marc Buie PI Institution: Southwest Research Institute We propose a set of high SNR observations of the Pluto system that will provide improved lightcurves, orbits, and photometric properties of Nix and Hydra. The key photometric result for Nix and Hydra will be a vastly improved lightcurve shape and rotation period to test if the objects are in synchronous rotation or not. A second goal of this program will be to retrieve a new epoch of albedo map for the surface of Pluto. These observations will also improve masses and in some case densities for the bodies in the Pluto system. ====================================================================== Proposal Category: GO Scientific Category: AGN/QUASARS ID: 11557 Title: The Nature of low-ionization BAL QSOs PI: Gabriela Canalizo PI Institution: University of California - Riverside The rare subclass of optically-selected QSOs known as low-ionization broad absorption line (LoBAL) QSOs show signs of high-velocity gas outflows and reddened continua indicative of dust obscuration. Recent studies show that galaxies hosting LoBAL QSOs tend to be ultraluminous infrared systems that are undergoing mergers, and that have dominant young (< 100 Myr) stellar populations. Such studies support the idea that LoBAL QSOs represent a short-lived phase early in the life of QSOs, when powerful AGN-driven winds are blowing away the dust and gas surrounding the QSO. If so, understanding LoBALs would be critical in the study of phenomena regulating black hole and galaxy evolution, such as AGN feedback and the early stages of nuclear accretion. These results, however, come from very small samples that may have serious selection biases. We are therefore taking a more aggressive approach by conducting a systematic multiwavelength study of a volume limited sample of LoBAL QSOs at 0.5 < z < 0.6 drawn from SDSS. We propose to image their host galaxies in two bands using WFC3/UVIS and WFC3/IR to study the morphologies for signs of recent tidal interactions and to map their interaction and star forming histories. We will thus determine whether LoBAL QSOs are truly exclusively found in young merging systems that are likely to be in the early stages of nuclear accretion. ====================================================================== Proposal Category: GO Scientific Category: ISM AND CIRCUMSTELLAR MATTER ID: 11558 Title: Planetary Nebulae, Globular Clusters and Binary Mergers PI: Orsola De Marco PI Institution: American Museum of Natural History Four planetary nebulae (PNe) have been found within 130 of the 150 globular clusters (GCs) of our Galaxy. This might not seem like many, but stellar evolution predicts that the old populations of these clusters should contain no PN at all ====================================================================== Proposal Category: GO Scientific Category: SOLAR SYSTEM ID: 11559 Title: Jovian Upheaval and its Impact on Vortices PI: Imke de Pater PI Institution: University of California - Berkeley We propose observations of Jupiter with global coverage at high resolution to quantify changes in its atmosphere during and following the global upheaval. Only HST has the capability to obtain images with enough spatial resolution and contrast to extract velocity fields (we will use our newly developed technique to accomplish this), and with WFC3 we can image Jupiter in its entirety in a single exposure. We are in particular interested in the Red Oval BA: Will the Oval be long-lived, remain red, or turn white again, disappear? Both the merger of its precursors, and change in color has never before been witnessed. The Great Red Spot: This storm system appears to decrease in size and has become rounder, both as derived from its associated cloud deck, but also from its potential vorticity, a more powerful dynamical quantity. How will the GRS evolve? Will it swallow the new vortices detected in amateur images at this same latitude band? How will this effect the potential vorticity? In addition, we hope to understand Disturbances and stagnation points, both of which were detected during the present global upheaval: are these cyclonic regions, can they spawn anticyclones (as suggested by amateur images)? ====================================================================== Proposal Category: GO Scientific Category: COSMOLOGY ID: 11560 Title: Cl0016+1609: the first (and the last) massive cluster of galaxies at z>0.5 PI: Harald Ebeling PI Institution: University of Hawaii We propose two-filter (F555W, F814W) ACS observations of the core of Cl0016+1609, arguably the most famous massive cluster at z>0.5. The most- studied such system at all wavelengths from X-ray to radio, Cl0016+1609 has no useful multi-passband ACS images to date. Complementing the only existing ACS data (a 2x2 mosaic in the F606W passband and a snapshot of the core in the F775W passband), the observations proposed here will provide resolved color information on both lensed background objects and cluster galaxies, thereby allowing us to measure accurately the cluster's dark-matter distribution on scales from tens to more than 500/h_50 kpc using both strong- and weak- gravitational lensing, and to study the color morphology of mergers and the star-formation history of galaxies in a high-density environment. Supported by an extensive groundbased imaging and spectroscopic campaign, as well as by deep Chandra X-ray observations, this observation completes our HST/ACS survey of the 12 most distant galaxy clusters detected in the MACS X-ray survey. ====================================================================== Proposal Category: GO Scientific Category: EXTRA-SOLAR PLANETS ID: 11561 Title: An intensive COS spectroscopic study of the planetary debris disks around two warm white dwarfs PI: Boris Gaensicke PI Institution: The University of Warwick It is very likely that the gas giants in our Solar system will survive the evolution of the Sun into a white dwarf, and the same is thought to be generally true for Jovian planets around solar-like stars if their initial orbits are wider than ~3AU. Despite this prediction, no unambiguous detection of a planet around a white dwarf has been announced so far. However, over the past few years, about a dozen white dwarfs have been identified which host metal-rich debris disks that are thought to stem from the tidal disruption of asteroids. In most cases the debris disks are observed in the form of an infrared flux excess, and offer relatively little diagnostic potential for the study of their structure. We have discovered three warm (T~20000K) white dwarfs with metal-rich debris disks in a gaseous phase which display strong double-peaked CaII emission