Evidence for collisionless conduction fronts in impulsive solar flares
Evidence for collisionless conduction fronts in impulsive solar flares
复制标题
脉冲太阳耀斑中无碰撞传导前沿的证据
DOI：
--
复制
发表时间：
1985
期刊：
影响因子：
--
通讯作者：
A. Magun
中科院分区：
文献类型：
--
作者：
D. Batchelor;C. Crannell;H. Wiehl;A. Magun
在大多数太阳耀斑期间都可以观察到硬X射线和微波的脉冲爆发，这两种发射都可以归因于能量从大约10 keV到几百keV的源电子的共同分布。电子分布的演化的详细说明是至关重要的一个完整的描述耀斑的能量过程。本文对Brown提出的热耀斑模型作了新的分析。梅尔罗斯和斯派塞;史密斯和利列奎斯特。他们认为，在这个模型中假设的源不能解释同时发生的脉冲微波发射。相比之下，这里提出的新结果表明，该模型导致了电子准麦克斯韦分布的发展，从而解释了硬X射线和微波发射。这意味着，源的大小可以确定的光学厚portios的微波光谱和相关的硬X射线观测获得的温度的观测。在这个模型中，脉冲串发射将在时间t/sub r/近似等于L/c/sub s/的时间内上升到最大值，其中L是拱的半长，c/sub s/ =（kT/sub e///m/sub i/）/sup 1/2/是离子声速。本文分析了这些脉冲耀斑发射的新观测结果，以检验模型的预测。«少
Impulsive bursts of hard x-rays and microwaves are observed during most solar flares, and both emissions can be attributed to a common distribution of source electrons with energies from approximately 10 keV to several hundred keV. A detailed account of the evolution of the electron distribution is crucial to a complete description of the energy process in flares. In this paper, a new analysis is made of a thermal flare model proposed by Brown. Melrose, and Spicer; and Smith and Lilliequist. They argued that the source assumed in this model would not explain the simultaneous impulsive microwavve emissio. In contrast, the new results presented here show that this model leads to the development of a quasi-Maxwellian distribution of electrons that explains both the hard x-ray and microwave emissions. This implies that the source sizes can be determined from observations of the optically thick portios of microwave spectra and the temperatures obtained from associated hard x-ray observations. In this model, the burst emission would rise to a maximum in a time t/sub r/ approximately equal to L/c/sub s/, where L is the half-length of the arch, and c/sub s/ = (kT/sub e//m/sub i/)/sup 1/2/ is the ion-sound speed. New observations ofmore » these impulsive flare emissions are analyzed herein to test this prediction of the model.« less