Both accurate and precise gf-values for Fe II lines*
Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal e-mail: firstname.lastname@example.org
2 Universidade de São Paulo, IAG, Rua do Matão 1226, Cidade Universitária, São Paulo 05508-900, Brazil
Accepted: 28 January 2009
We present a new set of oscillator strengths for 142 lines in the wavelength range 4000–8000 Å. 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 (), high-S/N (≈700–900) Keck+HIRES spectra of the metal-poor stars HD 148816 and HD 140283, for which line-to-line scatter (σ) in the iron abundances from 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 lines is negligible ( dex). The mean solar iron abundance obtained using our gf-values and different model atmospheres is ).
Key words: Sun: abundances / Sun: photosphere / stars: abundances / atomic data
© ESO, 2009