A search for Mg-poor stars using LAMOST survey data

作     者：Qian-Fan Xing Gang Zhao Yong Zhang Yong-Hui Hou Yue-Fei Wang Yue Wu 

作者机构：Key Laboratory of Optical AstronomyNational Astronomical ObservatoriesChinese Academy of Sciences University of Chinese Academy of Sciences Nanjing Institute of Astronomical Optics & TechnologyNational Astronomical ObservatoriesChinese Academy of Sciences 

出 版 物：《Research in Astronomy and Astrophysics》 (天文和天体物理学研究（英文版）)

年 卷 期：2015年第15卷第8期

页      面：1275-1281页

核心收录：

学科分类：07[理学] 08[工学] 080401[工学-精密仪器及机械] 070401[理学-天体物理] 0804[工学-仪器科学与技术] 0704[理学-天文学] 081102[工学-检测技术与自动化装置] 0811[工学-控制科学与工程] 

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 11390371  11233004  11303040 and U1431106) 

主　　题：methods: data analysis—stars: abundance—stars: atmospheres 

摘      要：Most Galactic metal-poor stars exhibit enhanced α-abundances（e.g.[Mg/Fe] ～ ＋0.4） according to previous studies of stellar chemical ***, a handful of metal-poor stars with large deficiencies in Mg（e.g. [Mg/Fe]～-0.2） show severe departures from this α-enhancement trend. The sub-solar[Mg/Fe] ratios of these anomalous stars indicate that they possess different chemical enrichment histories than the majority of Galactic metal-poor stars. In previous work,we presented a method to select Mg-poor metal-poor stars from low-resolution SDSS spectra based on a spectral matching technique. In this paper, a similar method is applied to low-resolution（R ～ 1800） LAMOST spectra. Stellar [Mg/Fe] abundances are determined by using stellar parameters delivered by the LAMOST Data Release2 catalog. From a sample of ～ 60 000 stars with atmospheric parameters in the range Teff = [5500, 6500] K and [Fe/H] = [-2.4, ＋0.5], we select 15 candidate Mg-poor metal-poor stars.