疏散星团的空间分布  

The space distribution of open clusters

作　　者：孙一鸣[1] 束成钢[2] 

机构地区：[1]上海师范大学数理学院,上海200234 [2]上海师范大学上海市星系与宇宙学重点实验室,上海200234

出　　处：《上海师范大学学报（自然科学版）》2009年第4期376-382,共7页Journal of Shanghai Normal University(Natural Sciences)

基　　金：国家自然科学基金(10878003);国家973基金项目(2007CB815402);上海市科委基金项目(08240514100)

摘　　要：基于最新版本的“疏散星团及其候选者表”，对银河系疏散星团的空间分布进行了讨论，特别是利用蒙特卡罗方法得到了未知距离疏散星团的模拟距离．结果表明：已知距离星团和未知距离星团样本在天空的投影分布是一致的，未知距离星团距离较远，与观测的选择效应一致：观测所得星团样本沿银盘方向并不满足指数分布，特别是朝着银心方向，由于严重的消光，使得完备性大大降低；疏散星团在太阳附近垂直银道面的分布可以用指数分布予以描述，所得的标高为～150pc．Based on the newest version of open cluster catalog provided by Dias, et al （2008）, 1622 clusters with 1008 known distances and 622 unknown distances are selected to investigate their space distributions statistically. It is found that the distributions of clusters with and without known distances are similar in Galactic longitude and latitude. The fraction with larger apparent diameters is larger for clusters with known distances, which implies that the fraction of clusters with unknown distances is biased to be more distant. The simulated distances for clusters with unknown distances are obtained by Monte Carlo simulation assuming that their diameter distribution is the same as those with known distances. The distribution of clusters along the Galactic plane can not be described exponentially because the dust extinction is serious in the disk, especially the direction to the Galactic Center. The distribution of open clusters perpendicular to the Galactic plane can be well fitting exponentially with the scale height is about 150pc.

关 键 词：疏散星团 银盘 银河系 

分 类 号：P154.1[天文地球—天文学]