银盘恒星的年龄-金属丰度关系研究  

Study on the Age-metallicity Relation of Disk Stars of the Galaxy

作　　者：梁波[1] 李冀[1] 曹藏文[1] 范纬世[1] 赵刚[2] 

机构地区：[1]河北师范大学,物理科学与信息工程学院,石家庄050016 [2]中国科学院国家天文台,北京100012

出　　处：《天文学进展》2008年第3期244-256,共13页Progress In Astronomy

基　　金：国家自然科学基金(10778616;10433010;10673002)

摘　　要：该文回顾了恒星的AMR(年龄-金属丰度关系)研究的历史,评述了研究的现状;介绍和比较了确定恒星年龄和金属丰度的有关方法;分析和讨论了最近有关AMR研究的4个大样本工作,分别利用每两样本之间的共同样本星,详细比较了它们分别给出的恒星年龄、金属丰度和AMR;结果表明样本的选择效应以及确定恒星年龄和金属丰度的方法或采用参数的不同都会影响AMR。通过比较选取了恒星年龄比较一致且金属丰度精度相对较高的2个样本,分别包括4007和1042颗恒星,用纯运动学标准确定了各自的星族成分,分别讨论了薄盘和厚盘恒星的AMR,结果显示厚盘恒星的存在明显的AMR,而薄盘恒星的AMR不如厚盘那么明显.也提出了进一步研究AMR需要开展的几项工作。The age-metallicity relation（AMR）of the Galactic disk stars is a fundamental issue to study the formation and evolution of the Galaxy.However,whether is there a relation between ages and metallicities for stars in the solar neighbourhood is still in debated.Some works support the existence of AMR,some others think that the AMR is a false trend.In the study presented here we will address the question of a relation between ages and metallicities for stars that are kinematically belong to the thin disk and thick disk.At first,we reviewd the history of studies on AMR.Then we introduced the methods of determining the ages and metallicities of stars.Thirdly,we choose four large sample works,which includes 552,5828,1658,and 14000 stars respectively,to investigate the AMRs of common stars between these samples.At last,we selecte two subsamples A and B by means of presenting consistent ages for common stars from two samples of three large sample works,and the stellar population membership of each star is identified using pure kinematics criterions.As a result,subsample A includes 3856 thin disk stars and 146 thick disk stars,subsample B includes 970 thin disk stars and 70 thick disk stars. Our results confirm the correlation between ages and metallicities for thick disk stars,but this correlation is very weak for thin disk stars due to the scatter of metallicities along the AMR, and this scatter seems to be substantially larger than that can be explained by observational errors.Our results also show that the stellar AMR is affected by many factors,such as the sample selection effect and the stellar population effect as well as the uncertainties of stellar ages and metallecities.So that to derive more truethful age-metallicity relations,an unbiased stellar sample with more accurate ages and metallicities are required in future studies.

关 键 词：天体物理学 年龄-金属丰度关系 银河系 薄盘 厚盘 恒星 

分 类 号：P144.1[天文地球—天体物理]