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arXiv · 1603.06305

A non-LTE study of silicon abundances in giant stars from the Si I infrared lines in the zJ-band

Kefeng Tan·Jianrong Shi·Masahide Takada-Hidai·Yoichi Takeda·Gang Zhao
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Abstract

We investigate the feasibility of the Si I infrared (IR) lines as Si abundance indicators for giant stars. We find that Si abundances obtained from the Si I IR lines based on the local thermodynamic equilibrium (LTE) analysis show large line-to-line scatter (mean value of 0.13dex), and are higher than those from the optical lines. However, when the non-LTE effects are taken into account, the line-to-line scatter reduces significantly (mean value of 0.06dex), and the Si abundances are consistent with those from the optical lines. The typical average non-LTE correction of [Si/Fe] for our sample stars is about $-$0.35dex. Our results demonstrate that the Si I IR lines could be reliable abundance indicators provided that the non-LTE effects are properly taken into account.

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Kefeng Tan, Jianrong Shi, Masahide Takada-Hidai, Yoichi Takeda, Gang Zhao. 2016-03-21. A non-LTE study of silicon abundances in giant stars from the Si I infrared lines in the zJ-band. https://doi.org/10.3847/0004-637x%2F823%2F1%2F36

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