Both accurate and precise gf-values for Fe II lines

Author(s)

Melendez, J. ^[1] ; Barbuy, B. ^[2]

Affiliation

^[1] Univ Porto, Ctr Astrofis, P-4150762 Oporto - Portugal

^[2] Univ Sao Paulo, IAG, BR-05508900 Sao Paulo - Brazil

• Document type: Journal article
• Source: Astronomy & Astrophysics; v. 497, n. 2, p. 611-617, APR 2009.
• Web of Science Citations: 104

Abstract

We present a new set of oscillator strengths for 142 Fe II lines in the wavelength range 4000-8000 angstrom. Our gf-values are both accurate and precise, because each multiplet was globally normalized using laboratory data ( accuracy), while the relative gf-values of individual lines within a given multiplet were obtained from theoretical calculations ( precision). Our line list was tested with the Sun and high-resolution (R approximate to 10(5)), high-S/N (approximate to 700-900) Keck+HIRES spectra of the metal-poor stars HD 148816 and HD 140283, for which line-to-line scatter (sigma) in the iron abundances from Fe II lines as low as 0.03, 0.04, and 0.05 dex are found, respectively. For these three stars the standard error in the mean iron abundance from Fe II lines is negligible (sigma(mean) <= 0.01 dex). The mean solar iron abundance obtained using our gf-values and different model atmospheres is A(Fe) = 7.45(sigma = 0.02). (AU)

• FAPESP's process: 05/00397-1 - Chemical evolution and galactic and extragalactic stellar populations by spectroscopy and imaging
• Grantee: Beatriz Leonor Silveira Barbuy
• Support Opportunities: Research Projects - Thematic Grants