Collaborative Research: Fast Dynamos in the Computer, the Galaxy, and the Laboratory

本研究项目旨在了解天体物理磁场的产生和演化。磁场在许多天体物理过程中起着决定性的作用，从调节恒星的形成和在无处不在的吸积盘中传输角动量到影响星系团内的加热和冷却。在所有这些情况下，流动的大磁雷诺数需要通过快速重联来实现磁场拓扑的任何改变，而磁场的产生需要快速发电机。该项目利用最近在数值能力方面的进展来测试最近先进的快速重联和快速发电机理论。它还建议进一步发展重联理论，将理论和数值结果与液态钠测量结果进行比较，并对银河发电机进行模拟。这项工作的另一个非常重要的成果将是开发出一个并行的AMR MI-ID代码Riemann，用于模拟旋转天体物理系统中的MHD现象。这将是一个通用的实用程序，将广泛提供给社区。该项目的资金由NSF河外天文与宇宙学计划(AST/EXC)提供。*

AST 0125544LazarianThis research program is aimed at understanding the generation and evolution of astrophysical magnetic fields. Magnetic fields play decisive role in many astrophysical processes from mediating star formation and transporting angular momentum in ubiquitous accretion disks to influencing heating/cooling within clusters of galaxies. In all these situations, the large magnetic Reynolds numbers of the flows require that any changes of magnetic field topology be implemented through fast reconnection, while magnetic field generation requires fast dynamo.The project makes use of recent advances in numerical capabilities to test recently advanced theories of fast reconnection and fast dynamos. It also proposes further development of reconnection theory, comparisons of theoretical and numerical results with liquid sodium measurements, and simulations of the galactic dynamo. Another very important outcome of this effort will be the development of a parallel AMR MI-ID code, RIEMANN, for simulating MHD phenomena in rotating astrophysical systems. This will be a general-purpose utility that will be made widely available to the community. Funding for this project was provided by the NSF program for Extragalactic Astronomy & Cosmology (AST/EXC).***