Magnetic Reconnection during the Post-impulsive Phase of a Long-duration Solar Flare: Bidirectional Outflows as a Cause of Microwave and X-Ray Bursts

Magnetic reconnection plays a crucial role in powering solar flares, production of energetic particles, and plasma heating. However, where the magnetic reconnections occur, how and where the released magnetic energy is transported, and how it is converted to other forms remain unclear. Here we report recurring bidirectional plasma outflows located within a large-scale plasma sheet observed in extreme-ultraviolet emission and scattered white light during the post-impulsive gradual phase of the X8.2 solar flare on 2017 September 10. Each of the bidirectional outflows originates in the plasma sheet from a discrete site, identified as a magnetic reconnection site. These reconnection sites reside at very low altitudes (

磁重联在为太阳耀斑提供能量、产生高能粒子以及等离子体加热方面起着至关重要的作用。然而，磁重联在何处发生，释放的磁能如何以及在何处传输，以及它如何转化为其他形式，这些问题仍然不清楚。在此我们报道在2017年9月10日X8.2级太阳耀斑的脉冲后渐变阶段，在极紫外辐射和散射白光中观测到的位于一个大尺度等离子体片中反复出现的双向等离子体喷流。每一个双向喷流都从等离子体片中一个离散的位置产生，该位置被确定为一个磁重联位置。这些磁重联位置位于非常低的高度（