对N体数值模拟中暗物质晕的卫星星系空间分布的研究  

A Study on the Spatial Distribution of Satellite Galaxies within Dark Matter Halos in an N-Body Numerical Simulation

作　　者：骆初嘉 

机构地区：[1]中国科学院紫金山天文台南京210008 [2]中国科学院大学北京100049

出　　处：《天文学报》2015年第6期554-563,共10页Acta Astronomica Sinica

基　　金：江苏省杰出青年科学基金项目(BK20140050);科技部973项目(2015CM857003,2013CB834900);国家自然科学基金项目(11333008,11173056);中国科学院B类先导项目(XDB09010403)资助

摘　　要：对N体数值模拟中暗物质晕的卫星星系的空间分布进行三轴椭球拟合,以拟合椭球的轴比来衡量该分布的扁平程度,通过比较不同条件下的轴比分布分析样本数量、样本选取方式以及对样本径向分布的归一化对计算结果的影响,并考察了暗晕所在的大尺度结构的空间方向与拟合椭球的空间取向之间的关系.发现对样本径向分布的归一化对计算结果具有较大影响,同时发现大尺度丝状结构中的暗晕的拟合椭球的短轴更趋于与丝状结构的方向垂直,而大尺度片状结构中的暗晕的拟合椭球的短轴则更趋于与片状结构的法线方向平行.We fitted the spatial distribution of satellite galaxies of the dark matter halos in N-body numerical simulation to a tri-axial ellipsoid, and then used the axial ratio of the fitting ellipsoid to measure the flatness of that distribution. By comparing the axial ratio distribution under different conditions, we analyzed how the number of samples, the way in which the samples are chosen, and whether the samples are normalized affect the result, then we analyzed the correlation between the minor axis of the fitting ellipsoid and the orientation of the large scale structure. We found that whether the sample were normalized will have a great impact on the result, the minor axes of the fitting ellipsoid of the halos in filament tend to be perpendicular to the filament, and the minor axes of the fitting ellipsoid of the halos in sheet tend to be parallel to the normal vector of sheet.

关 键 词：星系:群:普通 暗物质 方法:数值 

分 类 号：P157[天文地球—天文学]