A Search For Stars Of Very Low Metal Abundance. VI. Detailed Abundances Of 313 Metal-Poor Stars

dc.contributor.utaustinauthorSneden, Christopheren_US
dc.creatorRoederer, Ian U.en_US
dc.creatorPreston, George W.en_US
dc.creatorThompson, Ian B.en_US
dc.creatorShectman, Stephen A.en_US
dc.creatorSneden, Christopheren_US
dc.creatorBurley, Gregory S.en_US
dc.creatorKelson, Daniel D.en_US
dc.description.abstractWe present radial velocities, equivalent widths, model atmosphere parameters, and abundances or upper limits for 53 species of 48 elements derived from high resolution optical spectroscopy of 313 metal-poor stars. A majority of these stars were selected from the metal-poor candidates of the HK Survey of Beers, Preston, and Shectman. We derive detailed abundances for 61% of these stars for the first time. Spectra were obtained during a 10 yr observing campaign using the Magellan Inamori Kyocera Echelle spectrograph on the Magellan Telescopes at Las Campanas Observatory, the Robert G. Tull Coude Spectrograph on the Harlan J. Smith Telescope at McDonald Observatory, and the High Resolution Spectrograph on the Hobby-Eberly Telescope at McDonald Observatory. We perform a standard LTE abundance analysis using MARCS model atmospheres, and we apply line-by-line statistical corrections to minimize systematic abundance differences arising when different sets of lines are available for analysis. We identify several abundance correlations with effective temperature. A comparison with previous abundance analyses reveals significant differences in stellar parameters, which we investigate in detail. Our metallicities are, on average, lower by approximate to 0.25 dex for red giants and approximate to 0.04 dex for subgiants. Our sample contains 19 stars with [Fe/H] <= -3.5, 84 stars with [Fe/H] <= -3.0, and 210 stars with [Fe/H] <= -2.5. Detailed abundances are presented here or elsewhere for 91% of the 209 stars with [Fe/H] <= -2.5 as estimated from medium resolution spectroscopy by Beers, Preston, and Shectman. We will discuss the interpretation of these abundances in subsequent papers.en_US
dc.description.sponsorshipNational Aeronautics and Space Administrationen_US
dc.description.sponsorshipNational Science Foundationen_US
dc.description.sponsorshipBarbara McClintock Fellowship from the Carnegie Institution for Scienceen_US
dc.description.sponsorshipU.S. National Science Foundation AST 06-07708, AST 09-08978, AST 12-11585en_US
dc.identifier.citationRoederer, Ian U., George W. Preston, Ian B. Thompson, Stephen A. Shectman, Christopher Sneden, Gregory S. Burley, and Daniel D. Kelson. >A Search for Stars of Very Low Metal Abundance. VI. Detailed Abundances of 313 Metal-Poor Stars.> The Astronomical Journal, Vol. 147, No. 6 (Jun., 2014): 136.en_US
dc.relation.ispartofserialAstronomical Journalen_US
dc.rightsAdministrative deposit of works to Texas ScholarWorks: This works author(s) is or was a University faculty member, student or staff member; this article is already available through open access or the publisher allows a PDF version of the article to be freely posted online. The library makes the deposit as a matter of fair use (for scholarly, educational, and research purposes), and to preserve the work and further secure public access to the works of the University.en_US
dc.subjectgalaxy: haloen_US
dc.subjectnuclear reactions, nucleosynthesis, abundancesen_US
dc.subjectstars: atmospheresen_US
dc.subjectstars: population iien_US
dc.subjectlaboratory transition-probabilitiesen_US
dc.subjectneutron-capture elementsen_US
dc.subjecthorizontal-branch starsen_US
dc.subjectexperimental oscillator-strengthsen_US
dc.subjecteffective temperature scaleen_US
dc.subjectdeficient red giantsen_US
dc.subjectproper-motion starsen_US
dc.subjectastronomy & astrophysicsen_US
dc.titleA Search For Stars Of Very Low Metal Abundance. VI. Detailed Abundances Of 313 Metal-Poor Starsen_US

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