SFB 963: Astrophysical Flow Instabilities and Turbulence

在天体物理学和宇宙学中，流体流动发生在大范围的尺度上，并且在非常不同的条件下发生，从恒星和行星的密集内部到高度稀薄的星际介质。这些流动都有一个共同的事实，那就是它们通常是湍流的，即在空间和时间上都高度无序。大多数天体物理流动发生在驱动力产生速度和压力的巨大波动，从而对能量和质量的传输产生重要影响的条件下。湍流是各种地球和天体物理系统结构和演化的关键过程之一。天体物理上的湍流和不稳定性与旋转、对流和磁场有关。天体物理湍流的普遍性将行星或恒星内部的物理与原行星或星系盘，以及星系外的星际气体联系在一起。例如，湍流的角动量传输是一个核心问题，必须回答这个问题，才能理解星系或恒星是如何形成的，原行星盘是如何演化的，金属在星际和星际介质中是如何混合的，或者恒星和行星中的差异旋转是如何建立的。通过湍急的发电机过程放大磁场在行星、恒星和星系中无处不在。由尘埃颗粒或原行星盘中新形成的行星引起的不稳定性的开始控制着不断演变的结构的性质。我们可以观察到恒星、行星和星系与它们的环境之间的各种相互作用，从而导致能量和(角动量)的交换。这一汇编突出了合作努力调查共同的潜在物理过程的巨大潜力和前景。我们的项目组合将使我们能够了解湍流磁场放大、旋转流体的湍流和不稳定，以及湍流和不稳定与辐射、引力或尘埃粒子的相互作用，从而回答关于星系、恒星和行星的形成和演化的基本问题。

In astrophysics and cosmology, fluid flow occurs on a large range of scales and under very different conditions, from the dense interior of stars and planets to the highly rarefied intergalactic medium. These flows share the fact that they are generally turbulent, i.e. highly disordered both in space and time. Most astrophysical flows occur under conditions where the driving forces generate large fluctuations in velocity and pressure with important consequences for the transport of energy and mass. Turbulence is one of the key processes for the structure and evolution of a large variety of geo- and astrophysical systems. Astrophysical turbulence and instabilities occur in connection with rotation, convection and magnetic fields. The universality of astrophysical turbulence interlinks the physics of the interior of planets or stars with protoplanetary or galactic disks, as well as the intergalactic gas outside of galaxies. For example, angular momentum transport by turbulence is a central question that must be answered to understand how galaxies or stars form, how protoplanetary disks evolve, how metals are mixed in the interstellar and intergalactic medium, or how differential rotation is established in stars and planets. Magnetic field amplification through turbulent dynamo processes is ubiquitous in planets, stars and galaxies. The onset of instabilities due to dust particles or newly formed planets in protoplanetary disks controls the properties of the evolving structures. We can observe a variety of interactions between stars, planets and galaxies with their environment leading to the exchange of energy and (angular-)momentum. This compilation highlights the enormous potential and perspective of a collaborative effort to investigate the common underlying physical processes. Our combination of projects will enable us to understand aspects of turbulent magnetic field amplification, turbulence and instabilities of rotating fluids, and in the interaction of turbulence and instabilities with radiation, gravitation or dust particles and hence answer fundamental questions about the formation and evolution of galaxies, stars and planets.