P08

Presentation Title:	Hard X-ray imaging of slipping reconnection and quasi-periodic pulsations in a solar flare
Author(s):	Changxue Chen, Yang Su, Yang Guo, Dong Li, Wei Chen, Fu Yu, Yu Huang, Zhe Zhang , Jian Wu, Xiankai Jiang, Fanxiaoyu Xia, Zhentong Li, Wei Liu, Dengyi Chen, Yan Zhang, Yiming Hu, Yongqiang Zhang, Astrid Veronig, Zhao Wu, Julia Shamsutdinova, Larisa Kashapova, Hui Li1, Li Feng, Hui Liu, Ying Li, Youping Li and Weiqun Gan

Abstract:

Quasi-periodic pulsations (QPPs) widely exist in solar and stellar flares and other celestial activities. They are deeply related to the basic physical processes behind and therefore have attracted great attentions. However, the physical mechanism responsible for QPPs remains a controversial topic. Here we present observation and simulation evidence of spatially resolved hard X-ray (HXR) QPPs associated with slipping magnetic reconnection during an M6.5-class solar flare. The high cadence HXR images reconstructed by ASO-S/HXI revealed two clearly separated footpoints sources in 30–50 keV that show significant slipping motion along the flare ribbons. The locations and motion of HXR sources are in good line with the sequential brightening along the same ribbons seen in the UV images. The fluxes of the two sources change synchronously and quasi-periodically with a period of approximately 23 seconds, and the same period is simultaneously identified in full-disk microwave emissions. Moreover, the magnetic field strength and flux along the path of the footpoint sources follow a spatial quasi-periodic distribution that has almost the same period of 26 seconds when the variations are converted from space to time. In addition, the flare process was successfully reproduced and represented by our magnetohydrodynamic simulation, where the overall evolution and the slipping motion of magnetic field along the ribbons are found to be consistent with the observations. Based on these findings we propose a new QPP mechanism that is associated with energetic electrons accelerated by quasi-periodic energy release from a slipping reconnection process with quasi-periodic magnetic flux input.

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