论文标题
关于可压缩磁流体动力湍流中快速模式的存在
On the Existence of Fast Modes in Compressible Magnetohydrodynamic Turbulence
论文作者
论文摘要
我们通过进行许多具有可压缩且不可压缩的驱动条件的模拟来研究3D可压缩MHD湍流中快速磁性模式的存在和特性。我们使用两种方法来确定快速模式的存在：仅基于空间变化的模式分解以及所有波动的时空4D-FFT分析。后一种方法使我们能够量化满足以有限频率的快速模式的分散关系的波动。总体而言，我们发现，通过时空4D FFT方法在总波动功率中识别的快速模式的比例很小，几乎无法压缩驾驶，或者〜2％，而高度可压缩的驾驶。我们讨论了我们的结果对理解空间和天体物理等离子体中可压缩波动的含义。
We study the existence and property of Fast magnetosonic modes in 3D compressible MHD turbulence by carrying out a number of simulations with compressible and incompressible driving conditions. We use two approaches to determine the presence of Fast modes: mode decomposition based on spatial variations only and spatio-temporal 4D-FFT analysis of all fluctuations. The latter method enables us to quantify fluctuations that satisfy the dispersion relation of Fast modes with finite frequency. Overall, we find that the fraction of Fast modes identified via spatio-temporal 4D FFT approach in total fluctuation power is either tiny with nearly incompressible driving or ~2% with highly compressible driving. We discuss the implications of our results for understanding the compressible fluctuations in space and astrophysics plasmas.
