High-Resolution Abundance Analysis of Very Metal-rich Stars in the Solar Neighborhood
Abstract
We report detailed analysis of high-resolution spectra of nine high velocity 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 >= +0.4, making them the most metal-rich stars currently known. We find that alpha -elements decrease with increasing metallicity; s-elements are underabundant by about [s-elements/Fe] ~ -0.3; the ion{Eu}{2} line was measurable for 6 stars, showing [Eu/Fe] ~ 0.0, except for G161-29 where [Eu/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 mul and the very strong-lined bulge star bww, for which fe =+0.46 and +0.47 were found respectively. While exceeding the [Fe/H] of current bulge samples, the chemistry of these stars has important similarities and differences. The near-solar abundances of the alpha-capture elements places these stars on the metal-rich extension of McWilliam & Rich (1994) [ApJS, 91, 749], but their s-process abundances are much lower than those of the bulge giants. These low s-process values have been interpreted as the hallmark of an ancient stellar population. We are unable to convincingly assign these stars to a known Galactic population and we urge further studies of larger samples.
- Publication:
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The Astronomical Journal
- Pub Date:
- July 1997
- DOI:
- arXiv:
- arXiv:astro-ph/9704220
- Bibcode:
- 1997AJ....114..376C
- Keywords:
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- Astrophysics
- E-Print:
- 19 pages (Latex), 4 Tables (Latex), 11 postscript figures. Tables 2a and 2b are available upon request. Accepted for publication in The Astronomical Journal