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A spectroscopic survey of FHB stars near the south galactic pole†

Published online by Cambridge University Press:  13 April 2010

Silvia Rossi ,
Roberto Ortiz ,
Ronald Wilhelm ,
Roberto Costa  and
Timothy C. Beers
Silvia Rossi
Affiliation:
Departamento de Astronomia, IAG/USP, Rua do Matão 1226 Cidade Universitaria, 05508-900, São Paulo, SP, Brazil
Roberto Ortiz
Affiliation:
Escola de Artes, Ciencias e Humanidades, USP, Av. Arlindo Bettio, 1000 03828-000, São Paulo, SP, Brazil
Ronald Wilhelm
Affiliation:
Department of Physics, Campus Box 41051, Texas Tech University Lubbock, TX 79409, USA
Roberto Costa
Affiliation:
Departamento de Astronomia, IAG/USP, Rua do Matão 1226 Cidade Universitaria, 05508-900, São Paulo, SP, Brazil
Timothy C. Beers
Affiliation:
Department of Physics and Astronomy, CSCE: Center for the Study of Cosmic Evolution, and JINA: Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824-1116, USA
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Abstract

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We present the results of a medium-resolution spectroscopic survey of 43 field horizontal-branch (FHB) candidates carried out near the south galactic pole, selected from the original list of FHB candidates compiled by Beers et al. (2007). The observation list includes only stars classified as “high-probability” candidates, according to their 2MASS infrared colours. Atmospheric parameters of some stars have been obtained by comparing some spectral features with theoretical models provided by Kurucz (1993). A comparison between the grid of model atmospheres with some parameters of the Hδ line allowed the determination of log g, whilst [Fe/H] was estimated by the equivalent widths of the MgII 4481 and Caii lines. About 77% of the sample have been classified as FHB stars, 10% as subdwarfs, whilst the remaining 13% are probably main-sequence A-type stars far from the Galactic plane.

Keywords

stars: horizontal-branchGalaxy: haloGalaxy: stellar content
Type
Poster Papers
Information
Proceedings of the International Astronomical Union , Volume 5 , Symposium S262: Stellar Populations – Planning for the Next Decade , August 2009 , pp. 422 - 423
Copyright
Copyright © International Astronomical Union 2010

References

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