标题： 晕浓度和星系团的基本平面 显示英文标题

标题： Halo Concentrations and the Fundamental Plane of Galaxy Clusters

摘要： 根据标准的冷暗物质（CDM）宇宙学，包括星系团在内的暗晕结构反映了它们的质量积累历史。 较老的星系团通常比年轻的星系团更加集中。 它们的结构，由Navarro--Frenk--White（NFW）密度分布的特征半径$r_s$和质量$M_s$表示，与它们的形成时间有关。 在本研究中，我们表明$r_s$、$M_s$以及星系团内介质（ICM）的X射线温度$T_X$在$(\log r_s, \log M_s, \log T_X)$的空间中形成一个薄平面。 这一紧密的相关性表明，ICM温度也由单个星系团的形成时间决定。 数值模拟显示，随着演化，星系团沿着基本平面移动。 该平面以及平面内的星系团演化可以通过宇宙结构形成的相似解来解释。 该平面的角度表明，从某种意义上说，星系团尚未达到“动力学平衡”，因为质量和尺寸的增长以及边界处的压力不能被忽略。 平面上星系团的分布与暗晕浓度-质量关系中的固有离散性有关，这种离散性来源于星系团年龄的多样性。 众所周知的星系团质量-温度关系（$M_\Delta\propto T_X^{3/2}$）可以通过基本平面以及暗晕浓度的质量依赖性来解释，而无需假设动力学平衡。 基本平面还可以用于校准星系团的质量。 显示英文摘要

摘要： According to the standard cold dark matter (CDM) cosmology, the structure of dark halos including those of galaxy clusters reflects their mass accretion history. Older clusters tend to be more concentrated than younger clusters. Their structure, represented by the characteristic radius $r_s$ and mass $M_s$ of the Navarro--Frenk--White (NFW) density profile, is related to their formation time. In~this study, we showed that $r_s$, $M_s$, and the X-ray temperature of the intracluster medium (ICM), $T_X$, form a thin plane in the space of $(\log r_s, \log M_s, \log T_X)$. This tight correlation indicates that the ICM temperature is also determined by the formation time of individual clusters. Numerical simulations showed that clusters move along the fundamental plane as they evolve. The plane and the cluster evolution within the plane could be explained by a similarity solution of structure formation of the universe. The angle of the plane shows that clusters have not achieved "virial equilibrium" in the sense that mass/size growth and pressure at the boundaries cannot be ignored. The distribution of clusters on the plane was related to the intrinsic scatter in the halo concentration--mass relation, which originated from the variety of cluster ages. The well-known mass--temperature relation of clusters ($M_\Delta\propto T_X^{3/2}$) can be explained by the fundamental plane and the mass dependence of the halo concentration without the assumption of virial equilibrium. The fundamental plane could also be used for calibration of cluster masses.