Numerical Study of a Propagating Nonthermal Microwave Feature in a Solar Flare Loop
Numerical Study of a Propagating Nonthermal Microwave Feature in a Solar Flare Loop
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DOI：
10.1086/591268
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发表时间：
2008-06
期刊：
影响因子：
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通讯作者：
T. Minoshima;T. Yokoyama
中科院分区：
文献类型：
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作者：
T. Minoshima;T. Yokoyama
我们用解析和数值方法研究了电子沿磁环的运动，并与Yokyama等人报道的1999年8月28日太阳耀斑中非热微波源的传播特性进行了比较。我们用Fokker-Planck方程模拟了电子的运动，计算了回旋同步辐射的空间分布。我们发现，微波传播特性并不对应于具有特定初始俯仰角的电子的运动。这种明显的传播特征是具有不同初始俯仰角的电子系综运动的结果，这些电子具有不同的时间和位置，在环路中产生强烈的辐射。我们得出的结论是，1999年8月28日耀斑中的非热电子是各向同性加速的，然后被注入到环中。
We study the motion of electrons along a magnetic loop analytically and numerically, and compare the results with observations of the propagating feature of the nonthermal microwave source in the 1999 August 28 solar flare reported by Yokoyama et al. We model the electron motion with the Fokker-Planck equation and calculate the spatial distribution of the gyrosynchrotron radiation. We find that the microwave-propagating feature does not correspond to the motion of electrons with a specific initial pitch angle. This apparent propagating feature is a consequence of the motion of an ensemble of electrons with different initial pitch angles, which have different times and positions, producing strong radiation in the loop. We conclude that the nonthermal electrons in the 1999 August 28 flare were isotropically accelerated and then were injected into the loop.