同等质量下盘状星系的颜色-尺度关系  

Color-size Relations of Disc Galaxies with Similar Stellar Masses

作　　者：付炜[1,2,3] 常瑞香[2,3] 沈世银[2,3] 张波[1] 

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]中国科学院上海天文台星系与宇宙学重点实验室,上海200030 [3]上海市星系与宇宙学半解析研究重点实验室,上海200234

出　　处：《天文学报》2011年第1期25-33,共9页Acta Astronomica Sinica

基　　金：国家自然科学基金项目(10803016和10833005)资助

摘　　要：挑选Sloan数字巡天第7次释放数据(SDSS DR7)的主星系样本中近邻的、面向的盘状星系作为星系样本,统计研究了在恒星总质量相等的情况下盘状星系的颜色和尺度之间的相关性,并对相关性的真实性进行了检验.发现对于同等质量的盘状星系,u-r颜色与尺度相关性很弱,而g-r、r-i、r-z颜色与尺度负相关,即星系的尺度越大,颜色越蓝.该结果意味着盘状星系的质量分布对其恒星形成历史影响很大,物质分布越延展的星系,其演化越慢.To investigate the correlations between colors and sizes of disc galaxies with similar stellar masses, a sample of 7959 local face-on disc galaxies is collected from the main galaxy sample of the Seventh Data Release of Sloan Digital Sky Survey （SDSS DR7）. Our results show that, under the condition that the stellar masses of disc galaxies are similar, the relation between u-r and size is weak, while g-r, r-i and r-z colors decrease with disk size. This means that the color-size relations of disc galaxies with similar stellar masses do exist, i.e., the more extended disc galaxies with similar stellar masses tend to have bluer col- ors. An artificial sample is constructed to confirm that this correlation is not driven by the color-stellar mass relations and size-stellar mass relation of disc galaxies. Our results suggest that the mass distribution of disk galaxies may have an important influence on their stellar formation history, i.e., the galaxies with more extended mass distribution evolve more slowly.

关 键 词：演化 星系旋涡 星系 统计 

分 类 号：P157[天文地球—天文学]