论文标题
宇宙射线光环的形成：非线性Landau阻尼的作用
Formation of the cosmic-ray halo: The role of nonlinear Landau damping
论文作者
论文摘要
我们提出了一个自洽的银河光环的非线性模型，其中包括宇宙射线（CR）传播和MHD波的激发/阻尼的过程。防止CR从星系中逃脱的MHD扰动完全由共振流不稳定性产生。控制光晕尺寸的关键机制是非线性Landau（NL）阻尼，它抑制了MHD波动的幅度，因此使光环更大。平衡湍流光谱取决于CR激发和NL阻尼的平衡，该平衡设置了CRS的扩散和对流传播区域。两个区域之间的边界$ z_ {cr}（e）$是光环大小，它随着能量而缓慢增加。对于$ \ sim 1〜μg $的垂直磁场，我们估计$ z_ {cr} \ sim 1 $ kpc用于GEV质子。派生的质子光谱与观察数据非常一致。
We present a nonlinear model of self-consistent Galactic halo, where the processes of cosmic ray (CR) propagation and excitation/damping of MHD waves are included. The MHD-turbulence, which prevents CR escape from the Galaxy, is entirely generated by the resonant streaming instability. The key mechanism controlling the halo size is the nonlinear Landau (NL) damping, which suppresses the amplitude of MHD fluctuations and, thus, makes the halo larger. The equilibrium turbulence spectrum is determined by a balance of CR excitation and NL damping, which sets the regions of diffusive and advective propagation of CRs. The boundary $z_{cr}(E)$ between the two regions is the halo size, which slowly increases with the energy. For the vertical magnetic field of $\sim 1~μG$, we estimate $z_{cr} \sim 1$ kpc for GeV protons. The derived proton spectrum is in a good agreement with observational data.
