On the Abundance of Potassium in Metal-Poor Stars
Abstract
Based on extensive statistical-equilibrium calculations, we performed a non-LTE analysis of the K I 7699 equivalent-width data of metal-deficient stars for the purpose of clarifying the behavior of the photospheric potassium abundance in disk/halo stars. While the resulting non-LTE abundance corrections turned out to be considerably large, amounting to 0.2-0.7dex, their effect on the [K/Fe] vs. [Fe/H] relation is not very important, since these corrections do not show any significant dependence on the metallicity. Hence, we again confirmed the results of previous LTE studies, that [K/Fe] shows a gradual systematic increase toward a lowered metallicity up to [K/Fe] ~ 0.3 - 0.5 at [Fe/H]} ~ -1 to -2, such as in the case of αelements.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- April 2002
- DOI:
- 10.1093/pasj/54.2.275
- arXiv:
- arXiv:astro-ph/0110165
- Bibcode:
- 2002PASJ...54..275T
- Keywords:
-
- Galaxy: evolution;
- line: formation;
- stars: abundances;
- stars: atmospheres;
- stars: late-type;
- Astrophysics
- E-Print:
- 16 pages (including 2 tables and 4 figures), to appear in PASJ, Vol.54, No.2 (using the style file pasj00.cls)