论文标题
使用模拟X研究星系群集形态指标
Studying galaxy cluster morphological metrics with Mock-X
论文作者
论文摘要
动态放松的星系簇长期以来一直在星系集群研究中发挥了作用，因为人们认为它们的性质可以更精确地重建，并且系统学较少。由于需要放松的簇，因此存在许多标准，可以将星系群体分类为放松。在这项工作中，我们研究了$ 9 $常用的观察性和理论形态指标，这些指标从$ 54,000 $ MOCK-X合成X射线图像中提取的星系簇的图像从Illarteristng，Bahamas和MacSis模拟套件中获取。我们发现模拟标准分布与观察到的分布是合理的一致性。许多标准分布都会随红移，簇质量，数值分辨率和亚根机理的函数而演变，从而限制了单个弛豫阈值的有效性。所有标准彼此正相关，但是，相关的强度对红移，质量和数值选择敏感。在所有形态指标固有的固有散布和松弛阈值阈值值的任意性质的驱动下，我们发现由不同指标定义的放松子集的一致性相对较差。因此，使用松弛的集群子集的使用引入了明显的选择效应，这些效应是不乏味的。
Dynamically relaxed galaxy clusters have long played a role in galaxy cluster studies because it is thought their properties can be reconstructed more precisely and with less systematics. As relaxed clusters are desirable, there exist a plethora of criteria for classifying a galaxy cluster as relaxed. In this work, we examine $9$ commonly used observational and theoretical morphological metrics extracted from $54,000$ Mock-X synthetic X-ray images of galaxy clusters taken from the IllustrisTNG, BAHAMAS and MACSIS simulation suites. We find that the simulated criteria distributions are in reasonable agreement with the observed distributions. Many criteria distributions evolve as a function of redshift, cluster mass, numerical resolution and subgrid physics, limiting the effectiveness of a single relaxation threshold value. All criteria are positively correlated with each other, however, the strength of the correlation is sensitive to redshift, mass and numerical choices. Driven by the intrinsic scatter inherent to all morphological metrics and the arbitrary nature of relaxation threshold values, we find the consistency of relaxed subsets defined by the different metrics to be relatively poor. Therefore, the use of relaxed cluster subsets introduces significant selection effects that are non-trivial to resolve.
