Non-LTE neutral carbon spectral line formation in late-type stars
Abstract
We present non-Local Thermodynamic Equilibrium (non-LTE) calculations for neutral carbon spectral line formation, carried out for a grid of model atmospheres covering the range of late-type stars. The results of our detailed calculations suggest that the carbon non-LTE corrections in these stars are higher than usually adopted, remaining substantial even at low metallicity. For the most metal-poor stars in the sample of Akerman et al. (2004), the non-LTE abundance corrections are of the order of -0.35...-0.45 dex (when neglecting H collisions). Applying our results to those observations, the apparent [C/O] upturn seen in their LTE analysis is no longer present, thus revealing no need to invoke contributions from Pop. III stars to the carbon nucleosynthesis.
Cite
@article{arxiv.astro-ph/0508063,
title = {Non-LTE neutral carbon spectral line formation in late-type stars},
author = {Damian Fabbian and Martin Asplund and Mats Carlsson and Dan Kiselman},
journal= {arXiv preprint arXiv:astro-ph/0508063},
year = {2015}
}
Comments
2 pages, 1 figure. To appear in the Proceedings of IAU Symposium 228 "From Li to U: Elemental Tracers of Early Cosmic Evolution", eds. V. Hill, P. Francois and F. Primas, Cambridge University Press. Replacement with minor textual corrections