Evaluating Helium Variations By Modeling Red Giant Branch Bump of Large Magellanic Cluster NGC 1978

作     者：Xin Ji Cheng-Yuan Li Li-Cai Deng Xin Ji;Cheng-Yuan Li;Li-Cai Deng

作者机构：Key Laboratory for Optical AstronomyNational Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space ScienceUniversity of Chinese Academy of SciencesBeijing 100049China School of Physics and AstronomySun Yat-sen UniversityZhuhai 519082China Department of AstronomySchool of Physics and AstronomyChina-West Normal UniversityNanchong 637002China 

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

年 卷 期：2022年第22卷第3期

页      面：72-79页

核心收录：

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：support through Grant Nos.11633005 and 12073090 the National Key R&D Program of China(Grant No.2020YFC2201400)。 

主　　题：globular clusters:general globular clusters:individual(NGC 1978) stars:abundances stars:Hertzsprung-Russell and C-M diagrams stars:luminosity function 

摘      要：Many evidences show that the Multiple Population(MP)features exist not only in old clusters but also in intermediate-age clusters in the Megallanic Clouds(MCs),which are characterized by star-to-star abundance scatter of several elements,including helium(He).The red giant branch bump(RGBB)’s photometric properties are proved to be related to the variation in helium abundances of the member stars in star clusters.We use theModules for Experiments in Stellar Astrophysics(MESA)stellar evolution code to calculate the evolution sequences of stars along the red giant branch(RGB)with changing helium content.Following the RGB sequences,we then generate a luminosity function of the RGB stars within the grid of input helium abundances,which are compared with the observational data of an intermediate-age MC cluster NGC 1978.