The impact of cosmic rays on the multi-phase structure of the turbulent interstellar medium

宇宙线（CR）是星际介质（ISM）不可分割的（非热）部分。它们很可能在超新星爆炸产生的强烈冲击中被加速，并沿着沿着磁力线传播到ISM中。由于低能量损失率，它们可以在长距离上运输，并且可以是热ISM气体的重要能量和动量源（如果它们可以耦合），也可以在低密度区域中。分析和一维计算表明，显着的影响，CR的ISM属性与潜在的驱动大规模外流。这是由近似星系尺度的模拟所表明的。然而，没有详细的磁流体动力学（MHD）模拟的动力学影响的CRs上的湍流ISM已经执行到目前为止。我们建议进行这样的高分辨率模拟与联合开发的新版本的AMR网格代码FLASH扩展的CR（十个能源箱）沿着磁场线的能量依赖各向异性运输，并考虑到绝热损失。我们建议扩展代码的一个模块，允许自洽注射CR在强冲击率来自计算效率和良好的测试半分析模型的非线性扩散冲击加速。有了这些强大的工具和两个博士职位，我们申请在这个建议，我们的目标是解决以下问题与三维MHD模拟的第一次：什么是全球动力学的影响，宇宙射线产生的超新星上的湍流多相结构的ISM？不同能量的宇宙射线是如何通过湍流磁化ISM扩散的？宇宙射线能支持在现实结构的ISM中发射银河风吗？CR加速如何改变冲击结构？CR如何从冲击扩散到ISM？SN前身的电离和恒星风如何改变激波结构和CR注入？对于时间和空间耦合的SNe，CR加速度如何变化？根据这项研究的结果，我们很可能证明CR在塑造ISM属性方面发挥的作用比以前认为的更重要。如果我们能够证实，CR实际上可以驱动大规模的星系外流从一个现实结构的ISM，他们将成为一个全球性的球员，塑造ISM和调节星星形成星系的形成效率在所有质量和宇宙时代的主要作用。

Cosmic rays (CR) are an integral (non-thermal) part of the interstellar medium (ISM). They are most likely accelerated in strong shocks generated by supernova explosions and propagate into the ISM along magnetic field lines. Due to the low energy loss rates they can be transported over large distances and can be a significant energy and momentum source for the thermal ISM gas (provided they can couple), also in regions of low density. Analytical and one-dimensional calculations have indicated a significant impact of CRs on the ISM properties with the potential of driving large scale outflows. This was indicated by approximate galaxy scale simulations. However, no detailed magneto-hydrodynamical (MHD) simulations of the dynamical impact of CRs on the turbulent ISM have been performed so far. We propose to perform such high-resolution simulations with a jointly developed novel version of the AMR grid code FLASH extended for the energy dependent anisotropic transport of CRs (ten energy bins) along magnetic field lines and taking into account adiabatic losses. We propose to extend the code with a module that allows for the self-consistent injection of CRs in strong shocks at rates derived from a computationally efficient and well tested semi-analytical model for non-linear diffuse shock acceleration. With these powerful tools and the two PhD positions that we apply for in this proposal we aim at addressing the following questions with three-dimensional MHD simulations for the first time: What is the global dynamical impact of cosmic rays generated in supernovae on the turbulent multi-phase structure of the ISM? How do cosmic rays at different energies diffuse through the turbulent magnetized ISM? Can cosmic rays support the launching of galactic winds in a realistically structured ISM? How does CR acceleration change the shock structure? How do the CRs diffuse away from shocks into the ISM? How do ionization and stellar winds of the SN progenitor change the shock structure and the CR injection? How does the CR acceleration vary for temporally and spatially coupled SNe? With the results of the proposed study we might very well prove that CRs do play a more significant role in shaping the ISM properties than previously thought. If we can confirm that CRs can actually drive large scale galactic outflows from a realistically structured ISM they will become a global player with a major role for shaping the ISM and regulating the formation efficiency of star forming galaxies at all masses and cosmic epochs.