论文标题
冲击和飞溅：lambdacdm Galaxy簇周围的气和暗物质光环界限
Shock and Splash: Gas and Dark Matter Halo Boundaries around LambdaCDM Galaxy Clusters
论文作者
论文摘要
银河簇的模拟和观察结果的最新进展表明，存在大规模群集大小的暗物质光环的物理外界。在这项工作中，我们通过分析从Omega500变焦流体动力学宇宙学模拟中提取的65个大规模暗物质光环的样本，研究了暗物质和气体周围的暗物质和气体外部边界的位置。我们表明，与自相似模型的预测相反，吸积冲击的位置远离了暗物质飞溅半径。吸积冲击半径比文献中飞溅半径的所有定义都要大20-100％。使用熵压力曲线中最陡峭的跌落定义的吸积冲击半径大约是暗物质密度曲线中最陡峭坡度定义的飞溅半径大约2倍，并且比暗物质相位空间结构的边缘大约1.2倍。我们讨论结果对星系簇多波长研究的含义。
Recent advances in simulations and observations of galaxy clusters suggest that there exists a physical outer boundary of massive cluster-size dark matter haloes. In this work, we investigate the locations of the outer boundaries of dark matter and gas around cluster-size dark matter haloes, by analyzing a sample of 65 massive dark matter halos extracted from the Omega500 zoom-in hydrodynamical cosmological simulations. We show that the location of accretion shock is offset from that of the dark matter splashback radius, contrary to the prediction of the self-similar models. The accretion shock radius is larger than all definitions of the splashback radius in the literature by 20-100%. The accretion shock radius defined using the steepest drop in the entropy pressure profiles is approximately 2 times larger than the splashback radius defined by the steepest slope in the dark matter density profile, and it is ~1.2 times larger than the edge of the dark matter phase-space structure. We discuss implications of our results for multi-wavelength studies of galaxy clusters.
