标题： 在硬X射线、无线电和极紫外波长中的准周期脉动观测 显示英文标题

标题： Observation of a Quasi-periodic Pulsation in Hard X-ray, Radio and Extreme-ultraviolet Wavelengths

摘要： 我们对2011年9月23-24日发生的M1.9耀斑中在硬X射线、射电和极紫外（EUV）通道中观测到的准周期脉动（QPP）进行了多波长分析。 RHESSI观测到的25-50 keV非热硬X射线辐射显示出五个衰减振幅的明显脉冲峰，周期约为三分钟。 类似QPP在由Nobeyama Radioheliograph和Polarimeter记录的8.8、15、17 GHz通道的微波辐射中也被观测到。 有趣的是，在米波和分米波射电频率（25-180、245、610 MHz）中也观测到了3分钟的QPP，表现为重复的III型爆发。 来自SDO/AIA、Hinode/SOT和STEREO/SECCHI的多波长观测表明，在爆发位置存在扇形-脊状拓扑结构，与耀斑期间准圆形条带的形成有关。 在耀斑开始之前，在扇形环下方观测到一个小的暗条。 该暗条缓慢上升并与周围磁场相互作用。 随后发生了暗条的解缠运动。 暗条的两种不同结构在顺时针和逆时针方向上表现出$\sim$3分钟周期的交替旋转。 发现3分钟的QPP与附近太阳黑子中的3分钟振荡高度相关。 我们认为，在磁零点处的周期性重新连接（可能由太阳黑子慢模式波调制或由解缠暗条调制）最有可能导致了粒子的重复加速，从而产生了在硬X射线、微波和III型射电爆发中观测到的QPP。 显示英文摘要

摘要： We present multi-wavelength analysis of a quasi-periodic pulsation (QPP) observed in the hard X-ray, radio, and extreme-ultraviolet (EUV) channels during an M1.9 flare occurred on 23-24 September 2011. The non-thermal hard X-ray emission in 25-50 keV observed by RHESSI shows five distinct impulsive peaks of decaying amplitude with a period of about three minutes. Similar QPP was observed in the microwave emission recorded by the Nobeyama Radioheliograph and Polarimeter in the 8.8, 15, 17 GHz channels. Interestingly, the 3-min QPP was also observed in the metric and decimetric radio frequencies (25-180, 245, 610 MHz) as repetitive type III bursts. Multi-wavelength observations from the SDO/AIA, Hinode/SOT, and STEREO/SECCHI suggest a fan-spine topology at the eruption site, associated with the formation of a quasi-circular ribbon during the flare. A small filament was observed below the fan-loops before the flare onset. The filament rose slowly and interacted with the ambient field. This behaviour was followed by an untwisting motion of the filament. Two different structures of the filament showed $\sim$3-min periodic alternate rotation in the clockwise and counterclockwise directions. The 3-min QPP was found to highly correlate with 3-min oscillations in a nearby sunspot. We suggest that the periodic reconnection (modulated either by sunspot slow-mode wave or by untwisting filament) at a magnetic null-point most likely causes the repetitive particle acceleration, generating the QPP observed in hard X-ray, microwave and type III radio bursts.