J/A+A/546/A90       NLTE analysis of Sr lines                (Bergemann+, 2012)

NLTE analysis of Sr lines in spectra of late-type stars with new R-matrix atomic data. Bergemann M., Hansen C.J., Bautista M., Ruchti G. <Astron. Astrophys. 546, A90 (2012)> =2012A&A...546A..90B 2012A&A...546A..90B (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics Keywords: atomic data - line: formation - radiative transfer - Sun: abundances - stars: abundances - stars: atmospheres Abstract: We investigate the statistical equilibrium of neutral and singly-ionized strontium in late-type stellar atmospheres. Particular attention is given to the completeness of the model atom, which includes new energy levels, transition probabilities, photoionization and electron-impact excitation cross-sections computed with the R-matrix method. The NLTE model is applied to the analysis of SrI and SrII lines in the spectra of the Sun, Procyon, Arcturus, and HD 122563, showing a significant improvement in the ionization balance compared to LTE line formation calculations, which predict abundance discrepancies of up to 0.5dex. The solar Sr abundance is log(epsilon)=2.93±0.04dex, in agreement with the meteorites. We present the grid of NLTE abundance corrections for SrI and SrII lines that covers a wide range of stellar parameters. ************************************************************************** * * * The publication of the data will only be postponed until the * * accompanying paper is published * * * ************************************************************************** File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file -------------------------------------------------------------------------------- Author's address: M. Bergemann, mbergema(at)mpa-garching.mpg.de
(End) Patricia Vannier [CDS] 12-Oct-2012
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