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Non-LTE neutral carbon spectral line formation in late-type stars

Damian Fabbian·Martin Asplund·Mats Carlsson·Dan Kiselman
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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.

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Damian Fabbian, Martin Asplund, Mats Carlsson, Dan Kiselman. 2005-08-03. Non-LTE neutral carbon spectral line formation in late-type stars. https://doi.org/10.1017/s1743921305005703

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