A NON-LTE STUDY OF SILICON ABUNDANCES IN GIANT STARS FROM THE Si i INFRARED LINES IN THE zJ -BAND
- Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)
- Liberal Arts Education Center, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan)
- National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
We investigate the feasibility of 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 0.13 dex), and are higher than those from the optical lines. However, when non-LTE effects are taken into account, the line-to-line scatter reduces significantly (mean value of 0.06 dex), 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 −0.35 dex. 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.
- OSTI ID:
- 22666264
- Journal Information:
- Astrophysical Journal, Vol. 823, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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