Modeling Dense Star Clusters in the Milky Way and beyond with the Cluster Monte Carlo Code
Modeling Dense Star Clusters in the Milky Way and beyond with the Cluster Monte Carlo Code
复制标题
DOI：
10.3847/1538-4365/ac2edf
复制
发表时间：
2021-06
期刊：
影响因子：
--
通讯作者：
C. Rodriguez;Newlin C. Weatherford;S. Coughlin;P. A. Seoane;K. Breivik;S. Chatterjee;Fulya Kirouglu-Fulya-Kiroug
中科院分区：
文献类型：
--
作者：
C. Rodriguez;Newlin C. Weatherford;S. Coughlin;P. A. Seoane;K. Breivik;S. Chatterjee;Fulya Kirouglu-Fulya-Kiroug
我们描述了 Cluster Monte Carlo (CMC) 代码的公开发布，这是一种并行的逐星 N 体代码，用于建模密集星团。 CMC 使用 Hénon 方法处理碰撞恒星动力学，其中许多两体相遇的累积效应在统计上再现为弛豫时间尺度上最近邻粒子之间的单次有效相遇。逐星方法允许包含额外的物理学，包括强引力三体和四体相遇、二体潮汐和引力波捕获、任意银河潮汐场中的质量损失以及单星和双星的恒星演化。 CMC 的公开发布直接固定到 COSMIC 族群合成代码，允许使用关于恒星物理和初始条件的相同假设来执行动态星团模拟和族群合成研究。作为演示，我们提出了两个星团建模示例：首先，我们对演化为核心塌缩的普卢默球体进行最大（N = 108）逐星 N 体模拟，再现了超过 15 个数量级的预期自相似密度分布；其次，我们为典型的球状星团生成了真实的模型，并且表明它们的动态演化可以产生大量的黑洞合并，其质量大于孤立双星演化产生的质量（例如GW190521，最近报道的与脉动对不稳定质量间隙中的组成质量的合并）。
We describe the public release of the Cluster Monte Carlo (CMC) code, a parallel, star-by-star N-body code for modeling dense star clusters. CMC treats collisional stellar dynamics using Hénon’s method, where the cumulative effect of many two-body encounters is statistically reproduced as a single effective encounter between nearest-neighbor particles on a relaxation timescale. The star-by-star approach allows for the inclusion of additional physics, including strong gravitational three- and four-body encounters, two-body tidal and gravitational-wave captures, mass loss in arbitrary galactic tidal fields, and stellar evolution for both single and binary stars. The public release of CMC is pinned directly to the COSMIC population synthesis code, allowing dynamical star cluster simulations and population synthesis studies to be performed using identical assumptions about the stellar physics and initial conditions. As a demonstration, we present two examples of star cluster modeling: first, we perform the largest (N = 108) star-by-star N-body simulation of a Plummer sphere evolving to core collapse, reproducing the expected self-similar density profile over more than 15 orders of magnitude; second, we generate realistic models for typical globular clusters, and we show that their dynamical evolution can produce significant numbers of black hole mergers with masses greater than those produced from isolated binary evolution (such as GW190521, a recently reported merger with component masses in the pulsational pair-instability mass gap).