Photospheric Metals in the Far Ultraviolet Spectroscopic Explorer Spectrum of the Subdwarf B Star PG 0749+658
Abstract
We present an abundance analysis of the far-ultraviolet (905-1187 Å) spectrum of the subdwarf B star PG 0749+658 obtained by the Far Ultraviolet Spectroscopic Explorer. The data have a resolution of about R=λ/Δλ=12000-15000 Å (20-25 km s-1). We determine C, N, Si, P, S, Cr, Mn, Fe, Co, and Ni abundances, and upper limits on the abundance of Cl and V, using a grid of synthetic spectra based on an LTE stellar atmosphere model. He, C, N, Si, and Cl are depleted by a factor of >~10 with respect to the solar abundance, while P, S, and Fe are diminished by less than a factor of 10. We measure a solar abundance of Cr, Mn, and Co and a Ni enhancement of ~0.6 dex. We compare these values with predictions based on radiative levitation theory.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2000
- DOI:
- 10.1086/312802
- Bibcode:
- 2000ApJ...538L..95O
- Keywords:
-
- Stars: Abundances;
- Stars: Horizontal-Branch;
- Stars: Individual: Alphanumeric: PG 0749+658