Turbulence, plasma instabilities, transport and magnetogenesis in galaxy clusters

星系团是宇宙中最大的结构物体。星团中包含的大部分发光物质以电离气体或等离子体（称为星团内介质，简称ICM）的形式存在。这种等离子体被认为处于湍流状态，也就是说，它以一种无序的方式运动。它也被纠缠的磁场所渗透，这赋予了等离子体运动一定的弹性，也改变了单个粒子的运动。星系团中的所有大规模过程——例如，波和冲击的传播，星系团核心活跃星系吹出的“气泡”的形成和运动等——都发生在这种湍流磁化介质中，并受到它的深刻影响。这个提议是为了研究ICM的基本物理性质：其中存在什么样的湍流运动和电磁波动？ICM运动的能量是如何耗散成热量的？热量是如何在星团间传递的？团簇中磁场的起源和结构是什么？所有这些问题都必须面对，以便我们能够理解（通过射电望远镜和x射线卫星天文台获得的）数量迅速增加的观测证据，并建立正确的星团数值模型。更广泛地说，湍流问题是本研究的核心，是一个令人兴奋和艰巨的智力挑战，有时被称为经典物理学中最后一个未解决的大问题。它与磁发生（宇宙磁性的起源）问题交织在一起，继续激励着理论物理学家和天文学家。

The clusters of galaxies are the largest structured objects in the Universe. Most of the luminous matter contained in clusters is in the form of ionised gas, or plasma (called the intracluster medium, or ICM). This plasma is believed to be in a turbulent state, i.e., it is moving in a disordered fashion. It is also permeated by tangled magnetic fields, which impart a certain elasticity to the plasma motions and also alter the motion of individual particles. All large scale processes in clusters - such as, for example, the propagation of waves and shocks, formation and movement of 'bubbles' blown by the active galaxies in cluster cores etc. - occur in this turbulent magnetised medium and are profoundly affected by it. This proposal is for an investigation of the fundamental physical properties of the ICM: what kind of turbulent motions and electromagnetic fluctuations exist in it? how is the energy of ICM motions dissipated into heat? how is heat trnasported across clusters? what is the origin and structure of magnetic fields in clusters? All these questions must be faced in order for us to be able to make sense of the rapidly increasing amount of observational evidence (obtained with radiotelescopes and with X-ray satellite observatories) and also to develop correct numerical models of clusters. More broadly, the problem of turbulence, which is at the centre of this research, is an exciting and formidable intellectual challenge, sometimes referred to as the last great unsolvedx problem of classical physics. Intertwined with the problem of magnetogenesis (the origin of cosmic magnetism), it continues to inspire both theoretical physicists and astronomers.