Interaction of supernova remnants with interstellar clouds

外界冲击对云的压缩被认为是星际介质中恒星形成的重要触发机制。然而，对激波云相互作用的物理学还远未完全了解。过去对这个问题的研究往往忽略了关键的物理过程，或者依赖于过于严格的几何设置假设。例如，迄今为止还没有研究在三维模型中探索辐射冷却、磁场和（各向异性）热传导之间复杂的相互作用。在这个项目中，我们打算通过在大规模并行模式下应用NIRVANA代码执行如此复杂的模拟来弥合这一差距。自适应网格细化技术的使用将是一个关键因素，以便充分解决冲击波锋面和由冲击冲击产生的云结构的细节。我们认为，由球形超新星残骸撞击的云，是一种比平面激波场景更真实地模拟由附近爆炸恒星引起的激波诱导恒星形成的前期阶段的尝试。我们研究了上述物理过程在离爆炸波原点不同的云距离上的重要性，这些距离对应于残骸与云碰撞时的不同演化阶段。通过这项研究，我们希望能更好地了解在什么样的条件下激波触发的恒星形成是可能的。

Cloud compression by external shocks is believed to be an important triggering mechanism for star formation in the interstellar medium. Yet, the physics of shockcloud interactions is still far from being completely understood. Past work on the problem often ignored crucial physical processes or relied on too restrictive assumptions concerning the geometric setup. For instance, there is no research to date which explores the complex interplay between radiative cooling, magnetic fields, and (anisotropic) thermal conduction in a three-dimensional model. In this project we intend to bridge this gap by performing such sophisticated simulations applying our NIRVANA code in massively-parallel mode. The use of adaptive mesh refinement techniques will be a key ingredient in order to adequately resolve both the shock front and details of the cloud structure emanating from the shock impact. We consider clouds struck by a spherical supernova remnant as an attempt to model more realistically the pre-stage of shock-induced star formation by a nearby exploding star than planar shock scenarios can do. We investigate the importance of the mentioned physical processes for different cloud distances from the blast wave origin corresponding to different evolutionary stages of the remnant at the time it collides with the cloud. With this study, we expect to gain improved insight under which conditions shock-triggered star formation may become possible.