论文标题
速度质心各向异性和湍流ISM中不同MHD模式的特征
Velocity Centroids Anisotropy and the Signature of different MHD Modes in the Turbulent ISM
论文作者
论文摘要
磁性湍流是各向异性的，因为运动方向受到磁场的约束。可以在从光谱观测的速度质心中观察到这种各向异性。我们使用磁水动力学（MHD）模拟来产生合成光谱观测（位置位置 - 速度数据），并研究速度质心图的结构功能的各向异性。我们将模拟中的速度分解为Alfvén，缓慢和快速模型，并研究了它们中的每个速度如何有助于观察到的各向异性。我们发现，当视线和平均磁场之间的角度很大时，Alfvén模式主导了观察到的各向异性，而对于较小的角度，各向异性不足以用于探测培养基的磁化，并且由慢模式主导。我们的结果与Kandel等人（2016,2017）中的理论预测公平吻合。
Magnetic turbulence is anisotropic as the directions of motion are constrained by the magnetic field. Such anisotropy can be observed in velocity centroids obtained from spectroscopic observations. We use magnetohydrodynamics (MHD) simulations to produce synthetic spectroscopic observations (position-position-velocity data) and study the anisotropy in the structure function of velocity centroid maps. We decomposed the velocity in the simulations into Alfvén, slow and fast-modes and studied how each of them contribute to the observed anisotropy. We found that when the angle between the line of sight and the mean magnetic field is large the Alfvén-mode dominates the observed anisotropy, while for smaller angles the anisotropy is not large enough to be used to probe the magnetization of the media, and it is dominated by the slow-mode. Our results are in fair agreement with the theoretical predictions in Kandel et al.(2016,2017).
