ENHANCED DISSIPATION RATE OF MAGNETIC FIELD IN STRIPED PULSAR WINDS BY THE EFFECT OF TURBULENCE
ENHANCED DISSIPATION RATE OF MAGNETIC FIELD IN STRIPED PULSAR WINDS BY THE EFFECT OF TURBULENCE
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DOI：
10.1088/0004-637x/755/1/76
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发表时间：
2012-06
期刊：
影响因子：
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通讯作者：
M. Takamoto;T. Inoue;S. Inutsuka
中科院分区：
文献类型：
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作者：
M. Takamoto;T. Inoue;S. Inutsuka
本文报道了波音庭通量主导流，如蟹状脉冲星风星云激波后区域磁场耗散的湍流加速。我们对脉冲风中Pointing通量占优流动激波前沿Richtmyer-Meshkov不稳定性驱动的亚音速湍流进行了二维阻性相对论磁流体动力学模拟。我们发现，湍流拉长了电流片，这大大增强了磁场的耗散，并且大部分初始磁场能量在几个涡旋翻转时间内耗散。我们还发展了一个简单的磁场湍流耗散的解析模型，该模型与我们的模拟结果很好地吻合。分析模型表明，即使在小的电阻率极限下，耗散率也不依赖于电阻率。我们的发现可能会缓解蟹状脉冲星风星云中的σ问题。
In this paper, we report on turbulent acceleration of the dissipation of the magnetic field in the post-shock region of a Poynting flux-dominated flow, such as the Crab pulsar wind nebula. We have performed two-dimensional resistive relativistic magnetohydrodynamics simulations of subsonic turbulence driven by the Richtmyer–Meshkov instability at the shock fronts of the Poynting flux-dominated flows in pulsar winds. We find that turbulence stretches current sheets which substantially enhances the dissipation of the magnetic field, and that most of the initial magnetic field energy is dissipated within a few eddy-turnover times. We also develop a simple analytical model for turbulent dissipation of the magnetic field that agrees well with our simulations. The analytical model indicates that the dissipation rate does not depend on resistivity even in the small resistivity limit. Our findings can possibly alleviate the σ-problem in the Crab pulsar wind nebulae.