• The 69 μm forsterite band in spectra of protoplanetary disks. Results from the Herschel DIGIT programme 

    Sturm, B.; Bouwman, J.; Henning, T.; Evans, N. J.; Waters, Lbfm; van Dishoeck, E. F.; Green, J. D.; Olofsson, J.; Meeus, G.; Maaskant, K.; Dominik, C.; Augereau, J. C.; Mulders, G. D.; Acke, B.; Merin, B.; Herczeg, G. J.; Digit Team (2013-05)
    Context. We have analysed far-infrared spectra of 32 circumstellar disks around Herbig Ae/Be and T Tauri stars obtained within the Herschel key programme Dust, Ice and Gas in Time (DIGIT). The spectra were taken with the ...
  • A detailed study of giants and horizontal branch stars in M68 : atmospheric parameters and chemical abundances 

    Schaeuble, Marc-Andre (2015-05)
    In this thesis, I present a detailed high-resolution spectroscopic study of post main sequence stars in the Globular Cluster M68. My sample, which covers a range of 4000 K in Teff, and 3.5 dex in log(g), is comprised of ...
  • The Absolute Magnitude Of RRc Variables From Statistical Parallax 

    Kollmeier, Juna A.; Szczygiel, Dorota M.; Burns, Christopher R.; Gould, Andrew; Thompson, Ian B.; Preston, George W.; Sneden, Christopher; Crane, Jeffrey D.; Dong, Subo; Madore, Barry F.; Morrell, Nidia; Prieto, Jose L.; Shectman, Stephen; Simon, Joshua D.; Villanueva, Edward (2013-09)
    We present the first definitive measurement of the absolute magnitude of RR Lyrae c-type variable stars (RRc) determined purely from statistical parallax. We use a sample of 242 RRc variables selected from the All Sky ...
  • The Abundance Of Boron In Diffuse Interstellar Clouds 

    Ritchey, A. M.; Federman, S. R.; Sheffer, Y.; Lambert, David L. (2011-02)
    We present a comprehensive survey of boron abundances in diffuse interstellar clouds from observations made with the Space Telescope Imaging Spectrograph (STIS) of the Hubble Space Telescope. Our sample of 56 Galactic sight ...
  • Abundances Of Light Elements In Metal-Poor Stars IV. Fe/O And Fe/Mg Ratios And The History Of Star Formation In The Solar Neighborhood 

    Gratton, Raffaele Gratton; Carretta, Eugenio; Matteucci, Francesca; Sneden, Christopher (2000-06)
    The accurate O, Mg and Fe abundances derived in previous papers of this series from a homogeneous reanalysis of high quality data for a large sample of stars are combined with stellar kinematics in order to discuss the ...
  • Abundances Of Light Elements In Metal-Poor Stars IV. Fe/O And Fe/Mg Ratios And The History Of Star Formation In The Solar Neighborhood 

    Gratton, Raffaele Gratton; Carretta, Eugenio; Matteucci, Francesca; Sneden, Christopher (2000-06)
    The accurate O, Mg and Fe abundances derived in previous papers of this series from a homogeneous reanalysis of high quality data for a large sample of stars are combined with stellar kinematics in order to discuss the ...
  • Abundances Of Neutron-Capture Elements In Metal-Poor Stars 

    Gratton, Raffaele Gratton; Sneden, Christopher (1994-06)
    We use a large set of high S/N, high resolution spectra of 19 stars with -2.8 <[Fe/H]< 0 to study the abundances of neutron-rich elements in metal-poor stars. Basic data (atmospheric parameters, iron abundances, abundance ...
  • The Abundances Of Neutron-Capture Species In The Very Metal-Poor Globular Cluster M15: A Uniform Analysis Of Red Giant Branch And Red Horizontal Branch Stars 

    Sobeck, Jennifer S.; Kraft, Robert P.; Sneden, Christopher; Preston, George W.; Cowan, John J.; Smith, Graeme H.; Thompson, Ian B.; Shectman, Stephen A.; Burley, Gregory S. (2011-06)
    The globular cluster M15 is unique in its display of star-to-star variations in the neutron-capture elements. Comprehensive abundance surveys have been previously conducted for handfuls of M15 red giant branch (RGB) and ...
  • Accretion Disk Temperatures Of QSOs: Constraints From The Emission Lines 

    Bonning, E. W.; Shields, Gregory A.; Stevens, A. C.; Salviander, Sarah (2013-06)
    We compare QSO emission-line spectra to predictions based on theoretical ionizing continua of accretion disks. The observed line intensities do not show the expected trend of higher ionization with theoretical accretion ...
  • Accretion disks in low-mass X-ray binaries in ultraviolet and optical wavelengths 

    Bayless, Amanda Jo (2010-08)
    We present new models for two low-mass X-ray binaries (LMXB), 4U 1822-371 and V1408 Aql (= 4U 1957+115). The eclipsing LMXB 4U 1822-371 is the prototypical accretion disk corona (ADC) system. We have obtained new time-resolved ...
  • Accretion Onto "Seed" Black Holes In The First Galaxies 

    Milosavljevic, Milos; Bromm, Volker; Couch, Sean M.; Oh, S. Peng (2009-06)
    The validity of the hypothesis that the massive black holes in high redshift quasars grew from stellar-sized "seeds" is contingent on a seed's ability to double its mass every few 10 million years. This requires that the ...
  • The ACS Nearby Galaxy Survey Treasury. III. Cepheids In The Outer Disk Of M81 

    McCommas, Les P.; Yoachim, Peter; Williams, Benjamin F.; Dalcanton, Julianne J.; Davis, Matthew R.; Dolphin, Andrew E. (2009-06)
    The ACS Nearby Galaxy Survey Treasury (ANGST) has acquired deep ACS imaging of a field in the outer disk of the large spiral galaxy M81. These data were obtained over a total of 20 Hubble Space Telescope orbits, providing ...
  • The ACS Survey Of Galactic Globular Clusters. VI. NGC 6366: A Heavily Stripped Galactic Globular Cluster 

    Paust, Nathaniel E. Q.; Aparicio, Antonio; Piotto, Giampaolo; Reid, I. Neill; Anderson, Jay; Sarajedini, Ata; Bedin, Luigi R.; Chaboyer, Brian; Dotter, Aaron; Hempel, Maren; Majewski, Steven; Marin-Franch, A.; Milone, Antonio; Rosenberg, Alfred; Siegel, Michael (2009-01)
    We have used observations obtained as part of the Hubble Space Telescope/ACS Survey of Galactic globular clusters (GCs) to construct a color-magnitude diagram for the bulge cluster, NGC 6366. The luminosity function derived ...
  • The ACS Survey Of Galactic Globular Clusters. VIII. Effects Of Environment On Globular Cluster Global Mass Functions 

    Paust, Nathaniel EQ; I. Neill Reid; Giampaolo Piotto; Antonio Aparicio; Jay Anderson; Ata Sarajedini; Luigi R. Bedin; Chaboyer, Brian; Dotter, Aaron; Hempel, Maren; Majewski, Steven; Marin-Franch, A.; Milone, Antonio; Rosenberg, Alfred; Siegel, Michael (2010-02)
    We have used observations obtained as part of the Hubble Space Telescope/ACS Survey of Galactic Globular Clusters to construct global present-day mass functions for 17 globular clusters utilizing multi-mass King models to ...
  • The ACS Survey Of Globular Clusters. V. Generating A Comprehensive Star Catalog For Each Cluster 

    Anderson, Jay; Ata Sarajedini; Luigi R. Bedin; Ivan R. King; Giampaolo Piotto; I. Neill Reid; Michael Siegel; Majewski, Steven R.; Paust, Nathaniel E. Q.; Aparicio, Antonio; Milone, Antonio P.; Chaboyer, Brian; Rosenberg, Alfred (2008-06)
    The ACS Survey of Globular Clusters has used Hubble Space Telescope's Wide-Field Channel to obtain uniform imaging of 65 of the nearest globular clusters to provide an extensive homogeneous data set for a broad range of ...
  • Adaptive Optics Imaging Of Quasi-Stellar Objects With Double-Peaked Narrow Lines: Are They Dual Active Galactic Nuclei? 

    Rosario, D. J.; McGurk, R. C.; Max, C. E.; Shields, Gregory A.; Smith, K. L.; Ammons, S. M. (2011-09)
    Active galaxies hosting two accreting and merging supermassive black holes (SMBHs)-dual active galactic nuclei (AGNs)-are predicted by many current and popular models of black-hole-galaxy co-evolution. We present here the ...
  • The Afterglows Of Swift-Era Gamma-Ray Bursts. I. Comparing Pre-Swift And Swift-Era Long/Soft (Type II) Grb Optical Afterglows 

    Kann, D. A.; Klose, S.; Zhang, B.; Malesani, D.; Nakar, E.; Pozanenko, A.; Wilson, A. C.; Butler, N. R.; Jakobsson, Pall; Schulze, S.; Andreev, M.; Antonelli, L. A.; Bikmaev, I. F.; Biryukov, V.; Bottcher, M.; Burenin, R. A.; Ceron, J. M. C.; Castro-Tirado, A. J.; Chincarini, G.; Cobb, B. E.; Covino, S.; D'Avanzo, P.; D'Elia, V.; Della Valle, M.; Postigo, A. D.; Efimov, Y.; Ferrero, P.; Fugazza, D.; Fynbo, Johan P. U.; Galfalk, M.; Grundahl, F.; Gorosabel, J.; Gupta, S.; Guziy, S.; Hafizov, B.; Hjorth, J.; Holhjem, K.; Ibrahimov, M.; Im, M.; Israel, G. L.; Jelinek, M.; Jensen, B. L.; Karimov, R.; Khamitov, I. M.; Kiziloglu, U.; Klunko, E.; Kubanek, P.; Kutyrev, A. S.; Laursen, P.; Levan, A. J.; Mannucci, F.; Martin, C. M.; Mescheryakov, A.; Mirabal, N.; Norris, J. P.; Ovaldsen, J. E.; Paraficz, D.; Pavlenko, E.; Piranomonte, S.; Rossi, A.; Rumyantsev, V.; Salinas, R.; Sergeev, A.; Sharapov, D.; Sollerman, Jesper; Stecklum, B.; Stella, L.; Tagliaferri, G.; Tanvir, N. R.; Telting, J.; Testa, V.; Updike, A. C.; Volnova, A.; Watson, D.; Wiersema, K.; Xu, D. (2010-09)
    We have gathered optical photometry data from the literature on a large sample of Swift-era gamma-ray burst (GRB) afterglows including GRBs up to 2009 September, for a total of 76 GRBs, and present an additional three ...
  • The Afterglows Of Swift-Era Gamma-Ray Bursts. II. Type I GRB Versus Type II GRB Optical Afterglows 

    Kann, D. A.; Klose, S.; Zhang, B.; Covino, S.; Butler, N. R.; Malesani, D.; Nakar, E.; Wilson, A. C.; Antonelli, L. A.; Chincarini, G.; Cobb, B. E.; D'Avanzo, P.; D'Elia, V.; Della Valle, M.; Ferrero, P.; Fugazza, D.; Gorosabel, J.; Israel, G. L.; Mannucci, F.; Piranomonte, S.; Schulze, S.; Stella, L.; Tagliaferri, G.; Wiersema, K. (2011-06)
    Gamma-ray bursts (GRBs) have been separated into two classes, originally along the lines of duration and spectral properties, called "short/hard" and "long/soft." The latter have been conclusively linked to the explosive ...