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arXiv 0910.0304astro-ph.GA
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湍流热电离介质中磁场强度的估算

Estimation of Magnetic Field Strength in the Turbulent Warm Ionized Medium

Qingwen Wu, Jongsoo Kim, Dongsu Ryu, Jungyeon Cho, Paul Alexander

摘要:

采用等温磁流体动力学湍流模拟方法,研究了均方根马赫数为1的湍流介质中的法拉第旋转测度。考虑了4例初始血浆β值不同的病例。我们的主要发现如下。(1)磁场强度的起伏与气体密度之间没有很强的相关性。因此,使用RM/DM(DM是分散度量)估计的磁场强度正确表示沿视线的磁场的真实平均强度。(2)RM的频率分布很好地拟合高斯分布。此外,RM/ $\bar{\rm RM}$($\bar{\rm RM}$是RM的平均值)的分布宽度与沿视线的规则场的强度之间存在良好的关系;场强越强,宽度越窄。我们讨论了我们的研究结果的影响,在温暖的电离介质中的马赫数的湍流运动是围绕1。

英文摘要:

We studied Faraday rotation measure (RM) in turbulent media with the rms Mach number of unity, using isothermal, magnetohydrodynamic turbulence simulations. Four cases with different values of initial plasma beta were considered. Our main findings are as follows. (1) There is no strong correlation between the fluctuations of magnetic field strength and gas density. So the magnetic field strength estimated with RM/DM (DM is the dispersion measure) correctly represents the true mean strength of the magnetic field along the line of sight. (2) The frequency distribution of RMs is well fitted to the Gaussian. In addition, there is a good relation between the width of the distribution of RM/$\bar{\rm RM}$ ($\bar{\rm RM}$ is the average value of RMs) and the strength of the regular field along the line of sight; the width is narrower, if the field strength is stronger. We discussed the implications of our findings in the warm ionized medium where the Mach number of turbulent motions is around unity.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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