The Generation and Dissipation of Interstellar Turbulence: Results from Large-Scale High-Resolution Simulations
The Generation and Dissipation of Interstellar Turbulence: Results from Large-Scale High-Resolution Simulations
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星际湍流的产生和消散：大规模高分辨率模拟的结果
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
D. Breitschwerdt
中科院分区：
文献类型：
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作者：
M. D. de Avillez;D. Breitschwerdt
我们研究，通过自适应网格细化水和磁流体动力学模拟，涵盖了广泛的尺度（从千秒差距到亚秒差距），最耗散结构的尺寸和注入尺度的湍流星际气体，我们发现是约75 pc，与观测一致。然而，这是小于超级气泡的平均尺寸，但与ISM中的显著密度和压力变化一致，这导致气泡局部破裂，从而导致湍流的注入。结构函数的标度与超音速湍流的对数泊松统计一致，能量主要通过激波耗散。我们的模拟与其他作者以前的模拟不同，因为（1）我们不假设等温气体，但温度变化有几个数量级，（2）我们没有人为的强迫流体与一些特设傅立叶谱，但驱动湍流恒星爆炸银河系的速度，自我调节的密度和温度阈值施加在ISM气体。
We study, by means of adaptive mesh refinement hydro- and magnetohydrodynamic simulations that cover a wide range of scales (from kiloparsec to subparsec), the dimension of the most dissipative structures and the injection scale of turbulent interstellar gas, which we find to be about 75 pc, in agreement with observations. This is, however, smaller than the average size of superbubbles but consistent with significant density and pressure changes in the ISM, which leads to the breakup of bubbles locally and hence to the injection of turbulence. The scalings of the structure functions are consistent with log-Poisson statistics of supersonic turbulence, where energy is dissipated mainly through shocks. Our simulations are different from previous ones by other authors, since (1) we do not assume an isothermal gas but have temperature variations of several orders of magnitude, and (2) we have no artificial forcing of the fluid with some ad hoc Fourier spectrum but drive turbulence by stellar explosions at the Galactic rate, self-regulated by density and temperature thresholds imposed on the ISM gas.