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Investigating Non-LTE Abundances of Neodymium in Metal-poor FGK Stars

文献类型：期刊论文

作者Dixon, John D.1,6; Ezzeddine, Rana6; Li, Yangyang6; Merle, Thibault2,3; Bautista, Manuel4; Guo YJ(郭彦君)5
刊名ASTROPHYSICAL JOURNAL
出版日期2025-11-20
卷号994期号:1
ISSN号0004-637X
DOI10.3847/1538-4357/ae0b59
产权排序第6完成单位
文献子类Article
英文摘要The dominant site(s) of the r-process are a subject of current debate. Ejecta from r-process-enrichment events like kilonovae are difficult to directly measure, so we must instead probe abundances in metal-poor stars to constrain r-process models. This requires state-of-the-art non-LTE (NLTE) modeling, as LTE is a poor approximation for the low-opacity atmospheres of metal-poor giants. Neodymium (Nd) is a prominent r-process element detected in both near-infrared kilonova spectra and the spectra of metal-poor stars, so precise Nd stellar abundances are particularly needed to model kilonovae and constrain r-process sites. We thus constructed an Nd i/Nd ii model atom to compute NLTE abundances in FGK metal-poor stars. We obtain A(Nd)circle dot = 1.44 +/- 0.05, in agreement with the meteoritic value, when calibrating the model atom with a Drawin hydrogen collision factor of SH = 0.1. For a sample of metal-poor r-process-enhanced stars with observed optical and near-infrared Nd ii lines, we find NLTE Nd corrections in the range -0.3 to 0.3 dex. Optical and UV lines have positive NLTE corrections, whereas H-band lines have negative corrections. Additionally, we compute a large grid of NLTE corrections for 122 Nd ii spectral lines ranging from the UV to the H band, for stellar parameters of typical metal-poor FGK dwarfs and giants with -3 <= [Fe/H] <= -1 and -2 <= A(Nd) <= 2. Within this grid, we find NLTE corrections ranging from -0.3 to +0.5 dex. Deviations from LTE are found to be strongest for blue lines with low excitation potentials in the most metal-poor giants.
学科主题天文学 ; 恒星与银河系
URL标识查看原文
出版地No.2 The Distillery, Glassfields, Avon Street, Bristol, ENGLAND
WOS关键词R-PROCESS ALLIANCE ; PROCESS-ENHANCED STARS ; NEUTRON-CAPTURE ELEMENTS ; IRON ABUNDANCES ; SOUTHERN SEARCH ; LINE FORMATION ; DATA RELEASE ; 1ST RELEASE ; COOL STARS ; ND-II
资助项目National Aeronautics and Space Administration (NASA)[80NSSC24K0899]; National Science Foundation (NSF)[AST-2206263]; Joint Institute for Nuclear Astrophysics - Center for the Evolution of the Elements (JINA-CEE)[PHY-1430152]
WOS研究方向Astronomy & Astrophysics
语种英语
WOS记录号WOS:001614025200001
出版者IOP Publishing Ltd
资助机构National Aeronautics and Space Administration (NASA)[80NSSC24K0899] ; National Science Foundation (NSF)[AST-2206263] ; Joint Institute for Nuclear Astrophysics - Center for the Evolution of the Elements (JINA-CEE)[PHY-1430152]
版本出版稿
源URL[http://ir.ynao.ac.cn/handle/114a53/28727]  
专题云南天文台_大样本恒星演化研究组
通讯作者Dixon, John D.
作者单位1.Department of Physics and Astronomy, Texas A&M University, College Station, TX 77843, USA; johndixon@tamu.edu;
2.Institut d’Astronomie et d’Astrophysique and Brussels Laboratory of the Universe (BLU-ULB), Université Libre de Bruxelles, CP 226, 1050 Brussels, Belgium;
3.Royal Observatory of Belgium, Avenue Circulaire 3, 1180 Brussels, Belgium;
4.United States Department of Energy, Washington, DC 20585, USA;
5.Yunnan Observatories, Chinese Academy of Sciences (CAS), Kunming 650216, Yunnan, People’s Republic of China
6.Department of Astronomy, University of Florida, Gainesville, FL 32601, USA;
推荐引用方式
GB/T 7714		 Dixon, John D.,Ezzeddine, Rana,Li, Yangyang,et al. Investigating Non-LTE Abundances of Neodymium in Metal-poor FGK Stars[J]. ASTROPHYSICAL JOURNAL,2025,994(1).
APA Dixon, John D.,Ezzeddine, Rana,Li, Yangyang,Merle, Thibault,Bautista, Manuel,&郭彦君.(2025).Investigating Non-LTE Abundances of Neodymium in Metal-poor FGK Stars.ASTROPHYSICAL JOURNAL,994(1).
MLA Dixon, John D.,et al."Investigating Non-LTE Abundances of Neodymium in Metal-poor FGK Stars".ASTROPHYSICAL JOURNAL 994.1(2025).

入库方式： OAI收割

来源：云南天文台

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