论文标题
比较簇内轻质和暗物质的空间分布
Comparison of spatial distributions of Intracluster light and Dark Matter
论文作者
论文摘要
在星系群中,暗物质,构件星系,气体和簇内光(ICL)的相对空间分布可能意味着它们在簇演化上的相互作用。但是,为两个多维标量分布之间的形状匹配提供定量度量是一个具有挑战性的问题。我们提出了一种新的方法,称为{\ em加权重叠系数(WOC)},以量化二维空间分布的相似性。我们将WOC与称为修饰的Hausdorff距离(MHD)的标准方法进行比较。我们发现我们的方法是强大的,即使存在多个子结构,也可以表现良好。我们将我们的方法论用于搜索一个可见的组件,其空间分布与暗物质相似。如果发现这样的组件可以以高忠诚度追踪暗物质分布以获得更轻松的星系簇,则分布的相似性也可以用作群集的动力阶段估计器。我们将该方法应用于在GRT模拟中模拟的不同动态阶段的六个星系簇,这是使用Galaxy替换技术的N体模拟。在各种组件(恒星颗粒,星系,ICL)中,ICL+最亮的簇星系(BCG)组件最忠实地追踪暗物质分布。在样品星系簇中,放松的簇在暗物质和ICL+BCG的空间分布中比动态的年轻簇显示出更强的相似性。尽管MHD结果通过动态阶段显示出较弱的趋势。
In a galaxy cluster, the relative spatial distributions of dark matter, member galaxies, gas, and intracluster light (ICL) may connote their mutual interactions over the cluster evolution. However, it is a challenging problem to provide a quantitative measure for the shape matching between two multi-dimensional scalar distributions. We present a novel methodology, named the {\em Weighted Overlap Coefficient (WOC)}, to quantify the similarity of 2-dimensional spatial distributions. We compare the WOC with a standard method known as the Modified Hausdorff Distance (MHD). We find that our method is robust, and performs well even with the existence of multiple sub-structures. We apply our methodology to search for a visible component whose spatial distribution resembled with that of dark matter. If such a component could be found to trace the dark matter distribution with high fidelity for more relaxed galaxy clusters, then the similarity of the distributions could also be used as a dynamical stage estimator of the cluster. We apply the method to six galaxy clusters at different dynamical stages simulated within the GRT simulation, which is an N-body simulation using the galaxy replacement technique. Among the various components (stellar particles, galaxies, ICL), the ICL+ brightest cluster galaxy (BCG) component most faithfully trace the dark matter distribution. Among the sample galaxy clusters, the relaxed clusters show stronger similarity in the spatial distribution of the dark matter and ICL+BCG than the dynamically young clusters. While the MHD results show weaker trend with the dynamical stages.