NLTE ANALYSIS OF HIGH-RESOLUTION H-BAND SPECTRA. I. NEUTRAL SILICON**Based on observations collected with the 2.16 m telescope at Xinglong station, National Astronomical Observatories, Chinese Academy of Sciences, the 2.2 m telescope at the Calar Alto Observatory, the 1.88 m reflector at the Okayama Astrophysical Observatory, the Kitt Peak coudé feed telescope, and the McMath-Pierce solar telescope and the coudé focus of the Mayall 4 m reflector at Kitt Peak.

doi:10.3847/1538-4357/833/2/137

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	NLTE ANALYSIS OF HIGH-RESOLUTION H-BAND SPECTRA. I. NEUTRAL SILICON**Based on observations collected with the 2.16 m telescope at Xinglong station, National Astronomical Observatories, Chinese Academy of Sciences, the 2.2 m telescope at the Calar Alto Observatory, the 1.88 m reflector at the Okayama Astrophysical Observatory, the Kitt Peak coudé feed telescope, and the McMath-Pierce solar telescope and the coudé focus of the Mayall 4 m reflector at Kitt Peak.
	Zhang,Junbo 1,2; Shi,Jianrong 1,2; Pan,Kaike 3; Prieto,Carlos Allende 4,5; Liu,Chao 1
刊名	The Astrophysical Journal
	2016-12-13
卷号	833 期号:2
关键词	line: formation line: profiles stars: abundances stars: atmospheres
ISSN号	0004-637X
DOI	10.3847/1538-4357/833/2/137
英文摘要	ABSTRACT We investigated the reliability of our silicon atomic model and the influence of non-local thermodynamical equilibrium (NLTE) on the formation of neutral silicon (Si i) lines in the near-infrared (near-IR) H-band. We derived the differential Si abundances for 13 sample stars with high-resolution H-band spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE), as well as from optical spectra, both under local thermodynamical equilibrium (LTE) and NLTE conditions. We found that the differences between the Si abundances derived from the H-band and from optical lines for the same stars are less than 0.1 dex when the NLTE effects are included, and that NLTE reduces the line-to-line scatter in the H-band spectra for most sample stars. These results suggest that our Si atomic model is appropriate for studying the formation of H-band Si lines. Our calculations show that the NLTE corrections of the Si i H-band lines are negative, i.e., the final Si abundances will be overestimated in LTE. The corrections for strong lines depend on surface gravity, and tend to be larger for giants, reaching ～?0.2 dex in our sample, and up to ～?0.4 dex in extreme cases of APOGEE targets. Thus, the NLTE effects should be included in deriving silicon abundances from H-band Si i lines, especially for the cases where only strong lines are available.
语种	英语
出版者	The American Astronomical Society
WOS记录号	IOP:0004-637X-833-2-137
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/36216]
专题	中国科学院国家天文台
作者单位	1.Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, A20 Datun Road, Chaoyang District, Beijing 100012, China 2.School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing 100049, China; sjr@bao.ac.cn 3.Apache Point Observatory and New Mexico State University, P.O. Box 59, Sunspot, NM, 88349-0059, USA 4.Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife, Spain 5.Departamento de Astrofísica, Universidad de La Laguna, E-38206 La Laguna, Tenerife, Spain
推荐引用方式 GB/T 7714	Zhang,Junbo,Shi,Jianrong,Pan,Kaike,et al. NLTE ANALYSIS OF HIGH-RESOLUTION H-BAND SPECTRA. I. NEUTRAL SILICON**Based on observations collected with the 2.16 m telescope at Xinglong station, National Astronomical Observatories, Chinese Academy of Sciences, the 2.2 m telescope at the Calar Alto Observatory, the 1.88 m reflector at the Okayama Astrophysical Observatory, the Kitt Peak coudé feed telescope, and the McMath-Pierce solar telescope and the coudé focus of the Mayall 4 m reflector at Kitt Peak.[J]. The Astrophysical Journal,2016,833(2).
APA	Zhang,Junbo,Shi,Jianrong,Pan,Kaike,Prieto,Carlos Allende,&Liu,Chao.(2016).NLTE ANALYSIS OF HIGH-RESOLUTION H-BAND SPECTRA. I. NEUTRAL SILICON**Based on observations collected with the 2.16 m telescope at Xinglong station, National Astronomical Observatories, Chinese Academy of Sciences, the 2.2 m telescope at the Calar Alto Observatory, the 1.88 m reflector at the Okayama Astrophysical Observatory, the Kitt Peak coudé feed telescope, and the McMath-Pierce solar telescope and the coudé focus of the Mayall 4 m reflector at Kitt Peak..The Astrophysical Journal,833(2).
MLA	Zhang,Junbo,et al."NLTE ANALYSIS OF HIGH-RESOLUTION H-BAND SPECTRA. I. NEUTRAL SILICON**Based on observations collected with the 2.16 m telescope at Xinglong station, National Astronomical Observatories, Chinese Academy of Sciences, the 2.2 m telescope at the Calar Alto Observatory, the 1.88 m reflector at the Okayama Astrophysical Observatory, the Kitt Peak coudé feed telescope, and the McMath-Pierce solar telescope and the coudé focus of the Mayall 4 m reflector at Kitt Peak.".The Astrophysical Journal 833.2(2016).