Simulation of Turbulence and Magnetic Field Evolution in Astrophysical Plasmas

Abstract

Galaxy clusters, the largest gravitationally bound systems in the universe, are composed of hundreds to thousands galaxies, and are a few megaparsecs, or ~1023 meters, in size. These massive bodies are characterized by a hot diffuse gas within the cluster, called the intra-cluster medium (ICM). The study of the ICM is important to understanding the evolutionary process of clusters themselves. With a given set of initial conditions, computational models of the ICM observe its evolution to extract its properties at a given point in time. It is understood that the ICM is tumultuous and dynamic, which leads to turbulence that interacts with weak magnetic fields in the gas. In this project, our models of these systems seek to calculate the evolution of a diffuse turbulent gas with various initial conditions of the weak magnetic field. The primary focus is on the effects of the presence of various random magnetic fields whose vector components average to zero over the entire system. These fields, stretched and pulled by the turbulent medium, grow in magnitude until the system reaches equilibrium. The growth of the magnetic field strength and the final equilibrium states are compared to more commonly made simulations containing a uniform initial magnetic field. These simulations and comparisons give better insight into the evolution and properties of the ICM.