标题： 星团的初始大小：对星系演化过程中星团瓦解的影响 显示英文标题

标题： Initial sizes of star clusters: implications for cluster dissolution during galaxy evolution

摘要： 大质量星团常被用作星系形成和组装的示踪剂。为了做到这一点，我们必须了解它们在形成时的属性，以及这些属性如何随时间、星系环境和星系组装历史而变化。控制恒星集群演化的两个最重要的固有属性是质量和半径。 在这篇文章中，我们研究了10种理论上和观测上启发的恒星集群初始大小-质量关系，并通过星系形成模型演化集群群体。我们将我们的结果与其他结果进行比较，并与M83、M31和银河系中的集群群体观测结果进行对比。我们发现，在6到10亿年的演化后，我们的所有大小-质量关系都不符合观测结果。我们可以成功地用具有小范围初始半径的模型来重现集群的质量函数，并且这些模型不允许集群半径随时间变化。然而，这些模型不符合我们对集群演化的理解（这确实涉及半径演化），并且不能匹配观测到的半径分布。我们注意到存在一个参数空间区域，在这个区域内，集群受到潮汐冲击和由于二体松弛导致蒸发的最佳保护。允许集群演变成这个参数空间的集群很可能能够存活下来。为了恰当地将当前集群属性与其作为星系形成和组装示踪剂的用途联系起来，有必要对真实、时变星系势场中恒星集群的质量和半径演化有更深入的理解。 显示英文摘要

摘要： Massive star clusters are often used as tracers of galaxy formation and assembly. In order to do so, we must understand their properties at formation, and how those properties change with time, galactic environment, and galaxy assembly history. The two most important intrinsic properties that govern star cluster evolution are mass and radius. In this paper, we investigate 10 theoretically and observationally motivated initial size-mass relations for star clusters, and evolve populations of clusters through galaxy formation models. We compare our results to each other and to observations of cluster populations in M83, M31, and the Milky Way. We find that none of our size-mass relations agree with the observations after 6-10 Gyr of evolution. We can successfully reproduce the cluster mass functions with models that have a small range of initial radii, and which do not allow cluster radii to change with time. However, these models do not agree with our understanding of cluster evolution, which does involve radius evolution, and do not match the observed distributions of radii. We note that there is a region of parameter space where clusters are optimally protected from both tidal shocks and evaporation due to two-body relaxation. Clusters which are allowed to evolve into this parameter space will likely survive. An improved understanding of both mass and radius evolution of star clusters in realistic, time-varying galactic potentials is necessary to appropriately make the connection between present-day cluster properties and their use as tracers of galaxy formation and assembly.