论文标题
径向各向异性速度分布的星形簇中原始二进制的质量分离和动力学
Mass segregation and dynamics of primordial binaries in star clusters with a radially anisotropic velocity distribution
论文作者
论文摘要
本文是通过$ n $ body模拟进行的系列研究中的第三篇，这是初始径向各向异性速度分布对恒星簇动力学的影响。这种速度分布可能在集群的早期进化阶段印记，几项观察性研究发现了旧球状簇的例子，其中径向各向异性仍然存在于当前速度分布中。在这里，我们关注其对质量分离的影响和原始二进制恒星的动力学（破坏，弹射和组件交换）。在各向异性簇的外部区域的径向/高度偏心轨道上的恒星较大的比例会导致内恒星和外部恒星之间的动力相互作用的增强，从而影响质量分离的过程和原始二进制物的演变。我们的模拟结果表明，与最初的各向同性系统相比，最初各向异性簇的质量分离时间尺度在核心中更长，并且在外部区域更短。原始二进制文件的演变也受到初始速度分布的显着影响，我们发现影响各向异性簇中原始二进制的破坏，弹性和交换事件的速度高于各向同性的二进制。
This paper is the third in a series investigating, by means of $N$-body simulations, the implications of an initial radially anisotropic velocity distribution on the dynamics of star clusters. Such a velocity distribution may be imprinted during a cluster's early evolutionary stages and several observational studies have found examples of old globular clusters in which radial anisotropy is still present in the current velocity distribution. Here we focus on its influence on mass segregation and the dynamics of primordial binary stars (disruptions, ejections, and component exchanges). The larger fraction of stars on radial/highly eccentric orbits in the outer regions of anisotropic clusters lead to an enhancement in the dynamical interactions between inner and outer stars that affects both the process of mass segregation and the evolution of primordial binaries. The results of our simulations show that the time scale of mass segregation of the initially anisotropic cluster is longer in the core and shorter in the outer regions, when compared to the initially isotropic system. The evolution of primordial binaries is also significantly affected by the initial velocity distribution and we find that the rate of disruptions, ejections and exchange events affecting the primordial binaries in the anisotropic clusters is higher than in the isotropic ones.
