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arXiv · 1207.2451

NLTE analysis of Sr lines in spectra of late-type stars with new R-matrix atomic data

M. Bergemann·C. J. Hansen·M. Bautista·G. Ruchti
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Abstract

We investigate 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 Sr I and Sr II 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 0.5 dex. The solar Sr abundance is log A = 2.93 \pm 0.04 dex, in agreement with the meteorites. A grid of NLTE abundance corrections for Sr I and Sr II lines covering a large range of stellar parameters is presented.

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M. Bergemann, C. J. Hansen, M. Bautista, G. Ruchti. 2012-07-10. NLTE analysis of Sr lines in spectra of late-type stars with new R-matrix atomic data. https://doi.org/10.1051/0004-6361%2F201219406

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