论文标题
合并星系群集Abell 2034的模拟：什么决定了气体与暗物质之间的分离水平
Simulations of the merging galaxy cluster Abell 2034: what determines the level of separation between gas and dark matter
论文作者
论文摘要
聚类合并是研究暗物质（DM）和簇内气体行为的重要实验室。有分离的碰撞可以将簇内气体与DM分开。 Abell 2034提出了通过X射线和重力镜头观察到的清晰分离特征。该集群为$ z $ = 0.114，由两个子结构组成，质量比约为1：2.2，分别为$ \ sim $ 720 kpc。 X射线排放峰从South DM Peak偏离了$ \ sim $ 350 kpc。使用N体流体动力学模拟，我们旨在重建碰撞的动态历史，再现观察到的特征，并探索导致解离的条件。假设碰撞靠近天空平面，带有较小的冲击参数，中央通道后观察到0.26 GYR，则重现了该群集的观察到的特征，例如X射线和DM峰之间的偏移，X射线形态和重演。我们使用不同的气体和DM浓度为每个群集探索了几种变化。解离水平是通过X射线和DM峰之间的距离以及集群核心中的气体保留来量化的。我们发现，中央气体密度比中央DM密度比确定解离水平的比率更重要。
Cluster mergers are an important laboratory for studying the behaviour of dark matter (DM) and intracluster gas. There are dissociative collisions that can separate the intracluster gas from the DM. Abell 2034 presents clear dissociative features observed by X-rays and gravitational lensing. The cluster, at $z$ = 0.114, consists of two substructures with mass ratio of about 1:2.2, separated by $\sim$720 kpc. The X-ray emission peak is offcentred from the south DM peak by $\sim$350 kpc. Using N-body hydrodynamical simulations, we aim to reconstruct the dynamic history of the collision, reproducing the observed features, and also to explore the conditions that led to the dissociation. Our best model assuming that the collision is close to the plane of the sky, with a small impact parameter, observed 0.26 Gyr after central passage, reproduces the observed features of this cluster, such as the offset between X-ray and DM peaks, X-ray morphology and temperatures. We explored several variations using different gas and DM concentrations for each cluster. The level of dissociation was quantified by the distances between X-ray and DM peaks, and also by the gas retention in the cluster cores. We found that the ratio of central gas densities is more important than the ratio of central DM densities in determining the level of dissociation.
