Collaborative Research: Stellar Collisions and Mergers

AST 0205991PI LombardiClose相互作用经常发生在密集的恒星系统中，例如球状星团的核心，其中恒星的密度可能非常高，甚至可能发生恒星之间的物理碰撞。它们也可能发生在近距离双星的演化过程中，在那里它们经常导致两个组成部分的合并。密切的恒星相互作用在决定致密星团的长期动力学演化和最终命运方面起着至关重要的作用。此外，这些星系团中的动力相互作用被认为是产生大量奇异天体的原因，如X射线源、双星射电脉冲星和蓝散射电。理解致密恒星系统的长期动力学演化和它们所包含的特殊源的形成机制是理论天体物理学中的两个长期问题。这个项目将集中在一些理论和计算研究上，这些研究涉及致密星团和双星系统中这些流体动力学恒星相互作用的各个方面。流体力学和恒星演化过程的大规模数值模拟将在并行超级计算机上进行，提供可以直接与观测进行比较的定量准确的理论预测。大部分工作将由本科生完成。

AST 0205991PI LombardiClose interactions happen frequently in dense stellar systems, such as the cores of globular star clusters, where the density of stars can be so high that even physical collisions between stars can occur. They can also happen during the evolution of close binary stars, where they often lead tomergers of the two components. Close stellar interactions play a crucial role in determining the long-term dynamical evolution and final fate of dense star clusters. In addition, dynamical interactions in these clusters are thought to be responsible for the production of large numbers of exotic objects such as X-ray sources, binary radio pulsars, and blue stragglers. Understanding the long-term dynamical evolution of dense stellar systems and the formation mechanisms for the peculiar sources they contain are two long-standing problems in theoretical astrophysics. This project will focus on a number of theoretical and computational studies dealing with various aspects of these hydrodynamic stellar interactions in dense star clusters and in binary star systems. Large-scale numerical simulations of the hydrodynamic and stellar evolution processes will be performed on parallel supercomputers, providing quantitatively accurate theoretical predictions that can be compared directly to observations. Much of the work will be carried out by undergraduate students.***