arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1301.7149astro-ph.CO
收藏

邻近星暴星系M82中的星团系统

The Star Cluster System in the Nearby Starburst Galaxy M82

Sungsoon Lim, Narae Hwang, Myung Gyoon Lee

摘要:

利用UBVI、YJ和H波段哈勃空间望远镜的观测资料,对邻近星暴星系M82的星团进行了光度学研究。我们发现了1105个V<23等的星团,其中1070个位于盘区,35个星团位于晕区。星盘中的星团主要由蓝色星族和较弱的红色星族组成,蓝色星族的色峰在(B-V)0 ~ 0.45之间。光度函数呈幂律分布,指数α =-2.04+-0.03,标度高度h_z=9”.64+-0“.40(164 +-7 pc),与M82薄盘相似。利用UBVI(YJ)H波段测光数据和简单的恒星星族模型,用光谱能量分布拟合方法计算了~630个星团的年龄。盘状星团的年龄分布表明,最具优势的星团人口的年龄范围从1亿年到1亿年,峰值约为5亿年。这表明M82在大约5亿年前经历了一个盘状的恒星形成过程,可能是通过与M81的相互作用。核区域最亮的星团比其他区域的星团要亮得多,这表明在密度更大的环境中形成了更大质量的星团。另一方面,晕状星团的颜色与银河系中的球状星团相似,它们的年龄估计大于1 Gyr。这些可能是M82中真正古老的球状星团。

英文摘要:

We present a photometric study of star clusters in the nearby starburst galaxy M82 based on the UBVI, YJ and H band Hubble Space Telescope images. We find 1105 star clusters with V<23 mag. 1070 of them are located in the disk region, while 35 star clusters are in the halo region. The star clusters in the disk are composed of a dominant blue population with a color peak at (B-V)0 ~ 0.45, and a weaker red population. The luminosity function of the disk clusters shows a power-law distribution with a power law index alpha=-2.04+-0.03, and the scale height of their distribution is h_z=9".64+-0".40 (164 +- 7 pc), similar to that of the stellar thin disk of M82. We have derived the ages of ~630 star clusters using the spectral energy distribution fit method by comparing UBVI(YJ)H band photometric data with the simple stellar population models. The age distribution of the disk clusters shows that the most dominant cluster population has ages ranging from 100 Myr to 1 Gyr, with a peak at about 500 Myr. This suggests that M82 has undergone a disk-wide star formation about 500 Myr ago, probably through the interaction with M81. The brightest star clusters in the nuclear region are much brighter than those in other regions, indicating that more massive star clusters are formed in the denser environments. On the other hand, the colors of the halo clusters are similar to those of globular clusters in the Milky Way Galaxy, and their ages are estimated to be older than 1 Gyr. These are probably genuine old globular clusters in M82.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑