Candidate members of star clusters from LAMOST DR2  

作　　者：Bo Zhang Xiao-Yan Chen Chao Liu Li Chen Li-Cai Deng Jin-Liang Hou Zheng-Yi Shao Fan Yang Yue Wu Ming Yang Yong Zhang Yong-Hui Hou Yue-Fei Wang 

机构地区：[1]Key Laboratory of Optical Astronomy,National Astronomical Observatories,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences [3]Shanghai Astronomical Observatory,Chinese Academy of Sciences [4]Nanjing Institute of Astronomical Optics & Technology,National Astronomical Observatories,Chinese Academy of Sciences

出　　处：《Research in Astronomy and Astrophysics》2015年第8期1197-1208,共12页天文和天体物理学研究（英文版）

基　　金：supported by the Strategic Priority Research Program "The Emergence of Cosmological Structures" of the Chinese Academy of Sciences (Grant No. XDB09000000);the National Key Basic Research Program of China (2014CB845700);CL acknowledges the National Natural Science Foundation of China (NSFC, Grant Nos. 11373032, 11333003 and U1231119);XYC acknowledges the NSFC (Grant No. 11403036);the Youth Innovation Promotion Association of Chinese Academy of Sciences (Grant No. Y429012001);two Young Researcher Grants from National Astronomical Observatories, Chinese Academy of Sciences

摘　　要：In this work, we provide 2189 photometrically- and kinematically-selected candidate members of 24 star clusters from the LAMOST DR2 catalog. We perform two-step membership identification： selection along the stellar track in the colormagnitude diagram, i.e., photometric identification, and selection from the distribution of radial velocities, i.e. the kinematic identification. We find that the radial velocities from the LAMOST data are very helpful in the membership identification. The mean probability of membership is 40% for the sample selected with radial velocity. With these 24 star clusters, we investigate the performance of the radial velocity and metallicity estimated with the LAMOST pipeline. We find that the systematic offsets in radial velocity and metallicity are 0.85 ± 1.26 km s-1and-0.08 ± 0.04 dex, with dispersions of 5.47＋1.16-0.71 km s-1and 0.13＋0.04-0.02 dex, respectively. Finally, we propose that the photometrically-selected candidate members of the clusters covered by the LAMOST footprint should be assigned higher priority so that more candidate stars can be observed.In this work, we provide 2189 photometrically- and kinematically-selected candidate members of 24 star clusters from the LAMOST DR2 catalog. We perform two-step membership identification： selection along the stellar track in the colormagnitude diagram, i.e., photometric identification, and selection from the distribution of radial velocities, i.e. the kinematic identification. We find that the radial velocities from the LAMOST data are very helpful in the membership identification. The mean probability of membership is 40% for the sample selected with radial velocity. With these 24 star clusters, we investigate the performance of the radial velocity and metallicity estimated with the LAMOST pipeline. We find that the systematic offsets in radial velocity and metallicity are 0.85 ± 1.26 km s-1and-0.08 ± 0.04 dex, with dispersions of 5.47＋1.16-0.71 km s-1and 0.13＋0.04-0.02 dex, respectively. Finally, we propose that the photometrically-selected candidate members of the clusters covered by the LAMOST footprint should be assigned higher priority so that more candidate stars can be observed.

关 键 词：open clusters and associations： general—stars： statistics—catalogs—surveys—methods： data analysis 

分 类 号：P154.1[天文地球—天文学]