KMS National Astronomical Observatories, CAS
Evaluation of Stellar Parameters and Calibrating the Surface Gravity log g for LAMOST-II Median Resolution Survey | |
Chen,Xiang-Lei1,2; Luo,A-Li1,2,3,4; Chen,Jian-Jun1,2; Du,Bing1![]() ![]() | |
2021-03-26 | |
Source Publication | Publications of the Astronomical Society of the Pacific
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ISSN | 0004-6280 |
Volume | 133Issue:1022 |
Abstract | Abstract The LAMOST II survey began in the fall of 2018, and LAMOST formally released the obtained medium-resolution spectra (MRS) as well as catalogs of stellar parameters and radial velocities (RV) derived from the MRS in the seventh LAMOST data release (DR7). Compared with the RVs and parameters from high-resolution SDSS14/APOGEE spectra, nearly no RV discrepancy was found, with only dispersion around one km s?1. The Teff of MRS was 27.79 K systematically lower than that of APOGEE, and the 1σ difference was approximately 60.40 K. For metallicity, the [Fe/H] of the MRS was 0.11 dex poorer than that of APOGEE, with a dispersion of 0.07 dex. More apparently, the offset of log g was 0.14 dex, and the scatter was 0.23 dex. The gravities of APOGEE have been corrected through seismological data. Similarly, in this study, we tried to calibrate LAMOST MRS log g with the Kepler data for red clump stars and red giant branch stars based on two fitted calibration relations. In addition, we found log g of a small fraction late-K type giants mistakenly measured as dwarfs, and vice versa, on the HR diagram generated with LAMOST Teff and Gaia absolute magnitudes. This was because the MRS parameters were measured from blue band spectra only. The measurements of log g for late-K stars can be significantly improved by adding red spectra. |
Keyword | Surveys Radial velocity Stellar atmospheres |
DOI | 10.1088/1538-3873/abe0ac |
Language | 英语 |
WOS ID | IOP:0004-6280-133-1022-abe0ac |
Publisher | The Astronomical Society of the Pacific |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://ir.bao.ac.cn/handle/114a11/59036 |
Collection | 中国科学院国家天文台 |
Corresponding Author | Luo,A-Li |
Affiliation | 1.Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, People's Republic of China lal@nao.cas.cn, jjchen@nao.cas.cn 2.University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China 3.School of Information Management & Institute for Astronomical Science, Dezhou University, Dezhou 253023, People's Republic of China 4.Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA 5.Department of Astronomy, Peking University, Beijing 100871, People's Republic of China |
First Author Affilication | National Astronomical Observatories, Chinese Academy of Sciences |
Corresponding Author Affilication | National Astronomical Observatories, Chinese Academy of Sciences |
Recommended Citation GB/T 7714 | Chen,Xiang-Lei,Luo,A-Li,Chen,Jian-Jun,et al. Evaluation of Stellar Parameters and Calibrating the Surface Gravity log g for LAMOST-II Median Resolution Survey[J]. Publications of the Astronomical Society of the Pacific,2021,133(1022). |
APA | Chen,Xiang-Lei.,Luo,A-Li.,Chen,Jian-Jun.,Du,Bing.,Wang,Rui.,...&Qu,Caixia.(2021).Evaluation of Stellar Parameters and Calibrating the Surface Gravity log g for LAMOST-II Median Resolution Survey.Publications of the Astronomical Society of the Pacific,133(1022). |
MLA | Chen,Xiang-Lei,et al."Evaluation of Stellar Parameters and Calibrating the Surface Gravity log g for LAMOST-II Median Resolution Survey".Publications of the Astronomical Society of the Pacific 133.1022(2021). |
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