Temporal evolution of MHD shocks in the interstellar medium
Temporal evolution of MHD shocks in the interstellar medium
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星际介质中 MHD 激波的时间演化
DOI：
10.1046/j.1365-8711.1998.01391.x
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发表时间：
1998
影响因子：
4.8
通讯作者：
D. Flower
中科院分区：
文献类型：
--
作者：
J. Chièze;G. P. des Forêts;D. Flower
我们进行计算的冲击波在黑暗和弥漫的星际云传播的时间依赖性结构。的时间依赖性模型的结果进行了比较，通过一个独立的稳态代码，并发现同意在足够晚的时间。中性流体流动中的不连续性通过引入伪粘度来处理。为了不扭曲非弹性碰撞过程的作用，采用特殊的程序来校正相关的不连续性的扩大。我们发现，在乌云中，C冲击往往占主导地位，但不太可能在云的寿命达到稳定状态。另一方面，在扩散云中，可以达到稳定状态，但中性流体流动的不连续性仍然存在。我们没有发现C* 激波存在的证据，其中中性流体经历了从超音速到亚音速流的连续过渡（在激波的参考系中）。注意这些结果的可能的重要性的解释H2振转谱线强度。
We undertake calculations of the time-dependent structure of shock waves propagating in dark and diffuse interstellar clouds. The results of the timedependent model are compared with those obtained by means of an independent steady-state code and found to agree well at sufficiently late times. Discontinuities in the flow of the neutral fluid are handled by introducing a pseudo-viscosity. Special procedures are adopted to correct for the associated widening of the discontinuity, in order not to distort the role of inelastic collision processes. We find that, in dark clouds, C shocks will tend to predominate, but are unlikely to have attained steady state in the cloud lifetime. On the other hand, in diffuse clouds, steady state may be reached but the discontinuity in the flow of the neutral fluid remains. We find no evidence for the existence of C* shocks, in which the neutral fluid undergoes a continuous transition from supersonic to subsonic flow (in the reference frame of the shock wave). Attention is drawn to the possible importance of these results for the interpretation of H 2 rovibrational line intensities.