Filament eruptions and the impulsive phase of solar flares. Report for 18 May 1987-17 May 1988
Filament eruptions and the impulsive phase of solar flares. Report for 18 May 1987-17 May 1988
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DOI：
10.1086/166340
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发表时间：
1988-05
期刊：
影响因子：
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通讯作者：
S. Kahler;R. Moore;S. Kane;H. Zirin
中科院分区：
文献类型：
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作者：
S. Kahler;R. Moore;S. Kane;H. Zirin
我们研究所观察到的发展的灯丝喷发的冲动阶段的耀斑的证据是如何驱动的喷发。一种可能性有时被采纳为工作假说是暗条喷发和伴随的日冕物质抛射是耀斑脉冲阶段能量释放的结果;它们被认为是耀斑等离子体加热产生的压力脉冲导致的爆炸中的抛射物。反对这一观点的证据是从四个耀斑，其中，在H-α电影，观察到一个灯丝喷发期间的耀斑脉冲阶段定义的E =约。30 keV硬X射线发射与U。的Calif。ISEE 3号宇宙飞船上的伯克利探测器。在每一种情况下，我们发现：（1）暗条爆发在脉冲相开始之前就已经开始了：（2）爆发运动与脉冲相的平滑演化相一致，加速，但没有表现出新的可归因于脉冲相的加速;（三）在致密区，脉冲相H α耀斑带的增亮远小于爆发暗条的总跨度;以及（4）在脉冲阶段的开始处，观测到的投影速度在阿特莫尔的数量级上为100 km/s。这些特征表明，暗条喷发不是由耀斑等离子体压力驱动的，而是标志着由耀斑区域场位形的全球MHD不稳定性驱动的磁场喷发。看来暗条爆发和脉冲能量释放是协调的，并由一个共同的原因驱动，整个场结构的不稳定性。当爆发运动超过100 km/s量级的速度极限时，可能会启动一种新的能量释放模式，即脉冲阶段。«少
We examine the observed development of filament eruptions in the impulsive phase of flares for evidence of how the eruption is driven. A possibility sometimes adopted as working hypothesis is that the filament eruption and accompanying coronal mass ejection are consequences of energy release in the flare impulsive phase; they are taken to be ejecta in the explosion resulting from the pressure pulse from plasma heating in the flare. Evidence against this view is from four flares in which, in H-alpha movies, a filament eruption was observed during the flare impulsive phase defined by the E = approx. 30 keV hard x-ray emission observed with the U. of Calif. at Berkely detector on the ISEE 3 spacecraft. In each case it was found find that: (1) filament eruption began before onset of the impulsive phase; (2) eruptive motion is consistent with a smooth evolution through the impulsive phase, accelerating, but showing no new acceleration attributable to the impulsive phase; (3) brightening of the H alpha flare ribbons in the impulsive phase occurring in compact areas is much smaller than the overall span of the erupting filament; and (4) the observed projected speed is on the order of 100 km/s atmore » the onset of the impulsive phase. These characteristics indicate that filament eruption is not driven by flare plasma pressure, but instead marks an eruption of magnetic field driven by a global MHD instability of the field configuration in the flare region. It appears that filament eruption and impulsive energy release are coordinated and driven by a common cause, the instability of the whole field configuration. A new mode of energy release, that of the impulsive phase, may be initiated when the eruptive motion surpasses some speed limit of order 100 km/s.« less