M-subdwarf Research. II. Atmospheric Parameters and Kinematics
文献类型:期刊论文
作者 | Zhang,Shuo1,2,4,7; Luo,A-Li1,2,3,5; Comte,Georges6; Wang,Rui1,2; Li,Yin-Bi2; Du,Bing2; Hou,Wen2; Qin,Li2,3; Gizis,John5; Chen,Jian-Jun2 |
刊名 | The Astrophysical Journal
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出版日期 | 2021-02-01 |
卷号 | 908期号:2 |
关键词 | M subdwarf stars |
ISSN号 | 0004-637X |
DOI | 10.3847/1538-4357/abcfc5 |
英文摘要 | Abstract We applied the revised M subdwarf classification criteria discussed in Zhang et al. to Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) DR7 and combined the result with the M subdwarf sample from Savcheva et al. to construct a new M subdwarf sample for further study. The atmospheric parameters for each object were derived from fitting to the PHOENIX grid, and the sources with available astrometry and photometry from Gaia DR2 were combined for further analysis. The relationship between the gravity and metallicity was explored according to the locus both in the color–absolute magnitude diagram and the reduced proper motion diagram. Objects that have both the largest gravity and the lowest metallicity are located away from the main-sequence cloud and may be considered as the intrinsic M subdwarfs, which can be classified as luminosity class VI. Another group of objects whose spectra show typical M subdwarf characteristics have lower gravity and relatively moderate metal deficiency and occupy part of the ordinary M dwarf region in both diagrams. The Galactic U, V, W space velocity components and their dispersion show that the local Galactic halo population sampled in the solar neighborhood is represented by objects of high gravity and an inconspicuous bimodal metallicity distribution, with a fraction of prograde orbits. The other M subdwarfs seem to belong in part to the thick disk component, with a significant fraction of thin disk, moderately metal-poor objects intricately mixed with them. However, selection effects, especially the favored anticenter direction of investigation in the LAMOST subsample, as well as contamination by multiplicity and parameter coupling, could play important roles and need to be investigated further. |
语种 | 英语 |
WOS记录号 | IOP:0004-637X-908-2-ABCFC5 |
出版者 | The American Astronomical Society |
源URL | [http://ir.bao.ac.cn/handle/114a11/60598] ![]() |
专题 | 中国科学院国家天文台 |
通讯作者 | Luo,A-Li |
作者单位 | 1.University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China 2.CAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Beijing 100101, People's Republic of China; lal@nao.cas.cn 3.School of Information Management & Institute for Astronomical Science, Dezhou University, Dezhou 253023, People's Republic of China 4.Kavli institute of Astronomy and Astrophysics, Peking University, Beijing 100871, People's Republic of China 5.Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA 6.Aix-Marseille Université, CNRS, CNES, LAM, Laboratoire d’Astrophysique de Marseille, Marseille, France; georges.comte@lam.fr 7.Department of Astronomy, School of Physics, Peking University, Beijing 100871, People's Republic of China |
推荐引用方式 GB/T 7714 | Zhang,Shuo,Luo,A-Li,Comte,Georges,et al. M-subdwarf Research. II. Atmospheric Parameters and Kinematics[J]. The Astrophysical Journal,2021,908(2). |
APA | Zhang,Shuo.,Luo,A-Li.,Comte,Georges.,Wang,Rui.,Li,Yin-Bi.,...&Zuo,Fang.(2021).M-subdwarf Research. II. Atmospheric Parameters and Kinematics.The Astrophysical Journal,908(2). |
MLA | Zhang,Shuo,et al."M-subdwarf Research. II. Atmospheric Parameters and Kinematics".The Astrophysical Journal 908.2(2021). |
入库方式: OAI收割
来源:国家天文台
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