The Fate of Cold Clouds in Galaxy Outflows

在这个方案中，我们研究了超音速星系风中冷气体的命运。星系外流在星系形成的历史上扮演着重要的角色，将多相物质从星系最密集区域的深处驱赶到环星系介质稀有的边缘。即使这种冷气和快速气的存在也是令人惊讶的，因为简单的理论估计，在它加速到显著速度之前，它应该会被与热风的相互作用破坏。在这种情况下，关键问题是热风在破坏冷物质之前加速冷物质的能力。我们确定了这一提议的三个目标，这三个目标对于回答这个提议的一个核心问题是至关重要的：磁化外流中的各向异性传导能否防止冷云的破坏？1.在AMR MHD代码Flash中开发一个隐式各向异性传导模块。2.对磁化流出冷云进行参数研究，测量云的寿命。3.找出寿命的解析表达式，并将模拟结果放在星系物质循环的背景下。

In this proposal, we study the fate of cold gas in supersonic galactic winds. Galaxy outflows play a key role in the history of galaxy formation, driving multiphase material from deep within the densest regions of galaxies out into the rarified fringes of the circumgalactic medium. Even the presence of this cold and fast gas is surprising, as simple theoretical estimates predict that it should be disrupted by interactions with the hot wind well before it is accelerated to significant velocities. The key issue in this case is the ability for the hot wind to accelerate cold material, before it disrupts it.We identify three objectives of this proposal that are essential to answer the one central question of this proposal: Can anisotropic conduction in magnetised outflows prevent the disruption of cold clouds? 1. Develop a module for implicit anisotropic conduction in the AMR MHD code FLASH. 2. Perform parameter study of cold clouds in magnetised outflow and measure the lifetime of clouds. 3. Find analytic expressions for lifetimes and put the results of the simulations into the context of the cycle of matter in galaxies.