星系团并合和活动星系核反馈效应的研究

Mergers of galaxy clusters are one of the fundamental and important processes of the formation and evolution of galaxy clusters. Feedback from active galactic nuclei (AGN) has also become one fundamental and important physical process in understanding the thermal dynamics in the intracluster medium (ICM) and the coevolution of galaxies and massive black holes in recent years. By using numerical simulations and semi-analytical methods, we plan to involve AGN feedback into the merging processes of galaxy clusters, and study the statistics of the difference in the distributions of different kinds of matter within galaxy clusters as a probe to cosmology and the physical processes occurred in the ICM. We plan to study how the baryonic effect on the merger timescales of galaxy clusters depends on the gas distribution in galaxy clusters and how it affects the results obtained from previous dark matter-only cosmological simulations (e.g., on cluster mass function and the distribution of cluster substructures). We also plan to use the baryonic effect as a new way to determine the cosmology parameter on the baryonic fraction Ωb. In the study, we will include the feedback from multiple massive black holes/AGNs housed in thousands of the galaxies in a rich cluster, not limited to the feedback only from its central biggest one. We will also explore the kinetic Sunyaev-Zel’dovich (SZ) effect in the galaxy cluster “El Gordo” and the contribution of the thermal SZ effect to the cosmic microwave radiation background. This proposed research will deepen our understanding of the formation and evolution of the large-scale structure, cosmic velocity fields, the rate of galaxy cluster mergers and even the rate of galaxy mergers and black hole mergers, and the relation of the physical processes occurred in the vicinity of a massive black hole with the large-scale structure of the universe.

星系团的并合是星系团的形成和演化的一个基本和重要的过程。活动星系核反馈在近年来已成为研究星系团内介质热力学和星系与黑洞协同演化的一个基本和重要的物理过程。我们计划利用数值模拟和半解析的方法在星系团并合过程中结合活动星系核反馈效应，研究和预期星系团中不同物质偏离的统计分布和如何利用其作为宇宙学和星系团内物理过程的探针。我们将研究重子物质对星系团并合时标的影响以及该重子物质效应对过去只含暗物质的宇宙学模拟所获得的星系团质量函数等结果的影响。我们将利用该重子物质效应从另一角度确定宇宙学参数Ωb。我们在研究中将考虑富星系团内众多星系内大质量黑洞和多活动星系核反馈的贡献。我们将探索胖子星系团的运动学SZ效应和微波背景辐射中热SZ效应的贡献。本研究将帮助我们加深理解宇宙大尺度结构的形成和演化、宇宙速度场、星系团并合率乃至星系和黑洞并合率、以及大质量黑洞附近物理过程与宇宙大尺度结构之间演化的关系。