Temperature of the Source Plasma for Impulsive Solar Energetic Particles
Temperature of the Source Plasma for Impulsive Solar Energetic Particles
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DOI：
10.1007/s11207-015-0711-2
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发表时间：
2015-05
期刊：
影响因子：
2.8
通讯作者：
D. Reames;E. Cliver;S. Kahler
中科院分区：
文献类型：
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作者：
D. Reames;E. Cliver;S. Kahler
在脉冲太阳高能粒子（SEP）事件中，元素丰度的增强与离子的质荷比[]呈陡峭的幂律关系，这使得这些增强反映了源等离子体中离子的温度依赖模式。我们搜索SEP事件的日冕等离子体是热或冷比有限的区域2.5 - 3.2 MK以前发现占主导地位的111脉冲SEP事件。发现了15个新事件，其中4（3）个源自2-MK（4-MK）等离子体，但没有一个来自该温度范围之外。虽然脉冲SEP事件与耀斑密切相关，但这一结果表明，这些离子不会从耀斑加热的等离子体中加速，而耀斑加热的等离子体通常会超过10 MK。显然，我们在太空中观测到的离子是从耀斑附近的开放磁场线上的活动区等离子体加速的，而不是从耀斑的闭合环加速的。从磁重联区域加速的理论模型中，预计离子丰度增强对离子丰度的幂律依赖性。
The steep power-law dependence of element abundance enhancements on the mass-to-charge ratios [] of the ions in impulsive solar energetic-particle (SEP) events causes these enhancements to reflect the temperature-dependent pattern ofof the ions in the source plasma. We searched for SEP events from coronal plasma that is hotter or cooler than the limited region of 2.5 – 3.2 MK previously found to dominate 111 impulsive SEP events. Fifteen new events were found, four (three) originating in 2-MK (4-MK) plasma, but none from outside this temperature range. Although the impulsive SEP events are strongly associated with flares, this result indicates that these ions are not accelerated from flare-heated plasma, which can often exceed 10 MK. Evidently the ions ofthat we observe in space are accelerated from active-region plasma on open magnetic-field lines near the flare, but not from the closed loops of the flare. The power-law dependence of the abundance enhancements onof the ions is expected from theoretical models of acceleration from regions of magnetic reconnection.