Dynamics and Evolution of Young Dense Star Clusters

AST-0708299 McMillan稠密恒星系统（如星系核和致密星星团）中的物理相互作用和碰撞可能会显著改变恒星、双星系统和这些系统中致密天体的性质。 该项目将对致密恒星系统的动力学和演化进行逼真的高分辨率N体模拟，将星团中所有恒星的直接积分与外部潮汐场和动力学摩擦的自洽处理相结合。 核心的计算挑战是模块化软件工具的设计和实现，结合许多独立的物理模块，在专用硬件加速的并行平台上高效运行。 初始条件将被选择用于模拟特定的系统，包括银河系的中心秒差距，以及银河系中心几十秒差距内的拱和五重星系团。初始质量函数和质量分离，原始双星和多重双星的种群，白矮星双星和X射线源的形成，以及恒星残余物和合并产物向银河系中心的向内输送，是特别强调的主题。 结果将直接与真实的星团的光学、红外和X射线观测结果进行比较。 这项工作将在天体物理学和计算物理学的前沿问题上取得重大进展，并阐明我们银河系中心的动力学，演化和物理特性。项目团队结合了高性能科学计算，理论天体物理学以及复杂模拟和分布式数据分析软件包开发方面的专业知识。 本科生和研究生将参与该项目。 该主题以及数据分析所需的实际操作可视化技术，共同使这项研究成为向广泛的非科学受众展示的自然主题。

AST-0708299McMillanPhysical interactions and collisions in dense stellar systems, such as galactic nuclei and compact star clusters, may significantly alter the properties of the stars, binary systems, and compact objects these systems contain. This project will perform realistic, high-resolution N-body simulations of the dynamics and evolution of dense stellar systems, combining direct integration of all stars in the cluster with self-consistent treatments of external tidal fields and dynamical friction. The central computational challenge is the design and implementation of modular software tools, combining many independent physics modules, that run efficiently on parallel platforms accelerated by special-purpose hardware. Initial conditions will be chosen to model specific systems, including the central parsec of our Galaxy, and the Arches and Quintuplet clusters within a few tens of parsecs of the Galactic center.The initial mass function and mass segregation, the population of primordial binaries and multiples, the formation of white-dwarf binaries and X-ray sources, and the inward transport of stellar remnants and merger products to the Galactic center, are topics of special emphasis. Results will be compared directly with optical, infrared, and X-ray observations of real clusters. This work should make significant inroads into forefront problems in astrophysics and computational physics, and elucidate the dynamics, evolution, and physical properties of the center of our Galaxy.The project team combines expertise in high-performance scientific computing, theoretical astrophysics, and development of sophisticated simulation and distributed data-analysis packages. Undergraduate and graduate students will be working on the project. The subject matter, and the hands-on visualization techniques needed for the data analysis, together make this research a natural topic for presentations to broad, non-scientific audiences.