A Baryonic Effect on the Merger Timescale of Galaxy Clusters
A Baryonic Effect on the Merger Timescale of Galaxy Clusters
复制标题
星系团合并时间尺度的重子效应
DOI：
10.3847/0004-637x/820/2/85
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
You Jun Lu
中科院分区：
文献类型：
--
作者：
Congyao Zhang;Qingjuan Yu;You Jun Lu
准确估计星系团的合并时间尺度对于理解星系团合并过程和进一步理解宇宙大尺度结构的形成和演化具有重要意义。在本文中，我们探讨了重子效应对星系团合并时标的流体动力学模拟。我们发现重子在加速并合过程中起着重要的作用。星系团的气体比例越大，合并时间越短。例如，合并的时间尺度缩短了高达3倍的气体分数为0.15的合并集群，与0气体分数获得的时间尺度相比。重子效应对于大范围的合并参数是显著的，并且对于近迎头合并和高合并速度是特别显著的。星系团合并时间尺度上的重子效应将对宇宙中的结构形成产生影响，如星系团质量函数和星系团中的质量子结构等，而仅暗物质的宇宙学模拟结果可能存在“无气体”的偏差。
Accurate estimation of the merger timescales of galaxy clusters is important for understanding the cluster merger process and further understanding the formation and evolution of the large-scale structure of the universe. In this paper, we explore a baryonic effect on the merger timescale of galaxy clusters by using hydrodynamical simulations. We find that the baryons play an important role in accelerating the merger process. The merger timescale decreases upon increasing the gas fraction of galaxy clusters. For example, the merger timescale is shortened by a factor of up to 3 for merging clusters with gas fractions of 0.15, compared with the timescale obtained with 0 gas fractions. The baryonic effect is significant for a wide range of merger parameters and is particularly more significant for nearly head-on mergers and high merging velocities. The baryonic effect on the merger timescale of galaxy clusters is expected to have an impact on the structure formation in the universe, such as the cluster mass function and massive substructures in galaxy clusters, and a bias of “no-gas” may exist in the results obtained from the dark matter-only cosmological simulations.