HIGH-RESOLUTION ABUNDANCE ANALYSIS OF VERY METAL-RICH STARS IN THE SOLAR NEIGHBORHOOD

Citation
S. Castro et al., HIGH-RESOLUTION ABUNDANCE ANALYSIS OF VERY METAL-RICH STARS IN THE SOLAR NEIGHBORHOOD, The Astronomical journal, 114(1), 1997, pp. 376-387
Citations number
40
Categorie Soggetti
Astronomy & Astrophysics
Journal title
ISSN journal
00046256
Volume
114
Issue
1
Year of publication
1997
Pages
376 - 387
Database
ISI
SICI code
0004-6256(1997)114:1<376:HAAOVM>2.0.ZU;2-D
Abstract
We report detailed analysis of high-resolution spectra of nine high ve locity metal-rich dwarfs in the solar neighborhood, selected from the proper motion samples of Grenon. The stars are super metal-rich, and 5 of them have [Fe/H]greater than or equal to+0.4, making them the most metal-rich stars currently known, We find that alpha-elements decreas e with increasing metallicity; s-elements are underabundant by about [ s-elements/Fe] approximate to-0.3; the Eu II line was measurable for 6 stars, showing [Eu/Fe]approximate to 0.0, except for G161-29 where [E u/Fe]=+0.50, All calculations followed the same methods used by Castro et al. [1996, AJ, 111, 2439] for the analysis of the well-known metal -rich prototype mu Leo and the very strong-lined bulge star BW IV-167, for which [Fe/H]=+0.36 and +0.17 were found, respectively. While exce eding the [Fe/H] of current bulge samples, the chemistry of these star s has important similarities and differences, The near-solar abundance s of the alpha-capture elements places these stars on the metal-rich e xtension of McWilliam & Rich [1994, ApJS, 91, 749], but their s-proces s abundances are much lower than those of the bulge giants, These low s-process values have been interpreted as the hallmark of an ancient s tellar population, We are unable to convincingly assign these stars to a known Galactic population and Lye urge further studies of larger sa mples. (C) 1997 American Astronomical Society.