Issue |
A&A
Volume 546, October 2012
|
|
---|---|---|
Article Number | A90 | |
Number of page(s) | 12 | |
Section | Stellar atmospheres | |
DOI | https://doi.org/10.1051/0004-6361/201219406 | |
Published online | 12 October 2012 |
NLTE analysis of Sr lines in spectra of late-type stars with new R-matrix atomic data⋆,⋆⋆
1
Max-Planck Institute for Astrophysics,
Karl-Schwarzschild Str. 1,
85741
Garching,
Germany
e-mail: mbergema@mpa-garching.mpg.de
2
Landessternwarte, Königstuhl 12, 69117
Heidelberg,
Germany
3
Department of Physics, Western Michigan University,
Kalamazoo, MI
49008,
USA
Received:
13
April
2012
Accepted:
5
July
2012
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 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 ϵ = 2.93 ± 0.04 dex, in agreement with the meteorites. We present the grid of NLTE abundance corrections for Sr I and Sr II lines that covers a wide range of stellar parameters.
Key words: atomic data / line: formation / radiative transfer / Sun: abundances / stars: abundances / stars: atmospheres
Tables 3–5 are available in electronic form at http://www.aanda.org
The atomic data is available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/546/A90
© ESO, 2012
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