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

Simple item page
dc.contributor.utaustinauthorSneden, Christopheren_US
dc.creatorSobeck, Jennifer S.en_US
dc.creatorKraft, Robert P.en_US
dc.creatorSneden, Christopheren_US
dc.creatorPreston, George W.en_US
dc.creatorCowan, John J.en_US
dc.creatorSmith, Graeme H.en_US
dc.creatorThompson, Ian B.en_US
dc.creatorShectman, Stephen A.en_US
dc.creatorBurley, Gregory S.en_US
dc.date.accessioned2016-04-22T19:47:27Z
dc.date.available2016-04-22T19:47:27Z
dc.date.issued2011-06en
dc.description.abstractThe 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 red horizontal branch (RHB) stars. No attempt has been made to perform a single, self-consistent analysis of these stars, which exhibit a wide range in atmospheric parameters. In the current effort, a new comparative abundance derivation is presented for three RGB and six RHB members of the cluster. The analysis employs an updated version of the line transfer code MOOG, which now appropriately treats coherent, isotropic scattering. The apparent discrepancy in the previously reported values for the metallicity of M15 RGB and RHB stars is addressed and a resolute disparity of Delta(RHB-RGB) approximate to 0.1 dex in the iron abundance was found. The anti-correlative behavior of the light neutron-capture elements (Sr, Y, Zr) is clearly demonstrated with both Ba and Eu, standard markers of the s- and r-process, respectively. No conclusive detection of Pb was made in the RGB targets. Consequently for the M15 cluster, this suggests that the main component of the s-process has made a negligible contribution to those elements normally dominated by this process in solar system material. Additionally for the M15 sample, a large Eu abundance spread is confirmed, which is comparable to that of the halo field at the same metallicity. These abundance results are considered in the discussion of the chemical inhomogeneity and nucleosynthetic history of M15.en_US
dc.description.departmentAstronomyen_US
dc.description.sponsorshipNational Science Foundation AST 07-07447, AST 09-08978en_US
dc.identifierdoi:10.15781/T2350Q
dc.identifier.citationSobeck, Jennifer S., Robert P. Kraft, Christopher Sneden, George W. Preston, John J. Cowan, Graeme H. Smith, Ian B. Thompson, Stephen A. Shectman, and Gregory S. Burley. >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.> The Astronomical Journal, Vol. 141 No. 6 (Jun., 2011)en_US
dc.identifier.doi10.1088/0004-6256/141/6/175en_US
dc.identifier.issn0004-6256en_US
dc.identifier.urihttp://hdl.handle.net/2152/34493
dc.language.isoEnglishen_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.subjectglobular clusters: individual (m15)en_US
dc.subjectradiative transferen_US
dc.subjectstars:en_US
dc.subjectabundancesen_US
dc.subjectstars: horizontal-branchen_US
dc.subjectstars: late-typeen_US
dc.subjectlaboratory transition-probabilitiesen_US
dc.subjectrelative oscillator-strengthsen_US
dc.subjectr-process-richen_US
dc.subjecthubble-space-telescopeen_US
dc.subject2-dimensionalen_US
dc.subjectradiative-transferen_US
dc.subjectlaser-induced-fluorescenceen_US
dc.subjectsingly ionized vanadiumen_US
dc.subjecta1d2 0.90 even_US
dc.subjectchemical-compositionen_US
dc.subjectsolar abundanceen_US
dc.subjectastronomy & astrophysicsen_US
dc.titleThe Abundances Of Neutron-Capture Species In The Very Metal-Poor Globular Cluster M15: A Uniform Analysis Of Red Giant Branch And Red Horizontal Branch Starsen_US
dc.typeArticleen_US

Access full-text files

Original bundle

Now showing 1 - 1 of 1
Thumbnail Image
Name:
neutroncapturespecies.pdf
Size:
1.01 MB
Format:
Adobe Portable Document Format
Download

Collections

UT Faculty/Researcher Works