太阳耀斑调制的I型太阳射电暴

中文摘要 AI 辅助

I型太阳射电暴（又称噪声风暴）是活跃区上方持续存在的米波非热辐射，其发生及特性与局地磁场结构和非热电子加速密切相关。本研究分析了2023年12月24日的一次I型噪声风暴及其与耀斑活动的关联。该噪声风暴源与AR 3529活跃区共空间，呈现出频率相关的空间色散。关联的M2.9级耀斑对该辐射产生了强烈调制：风暴强度在耀斑开始时下降，随后恢复，并向更高频率偏移。基于多波段观测，研究认为耀斑前的小规模重联为上方闭合磁场结构提供非热电子并维持风暴；耀斑期间，活跃区上方的磁重联产生双向等离子体抛射和具有双向频率漂移的III型射电暴，这些射电暴起始频率逐渐降低，可能表明重联位置向上移动。由此产生的磁场重构破坏了电子捕获并抑制了风暴，而耀斑后的磁场恢复使辐射得以恢复。这些结果表明耀斑可通过磁场重构调制I型噪声风暴，并为噪声风暴的产生机制提供了见解。

英文摘要

Type I solar radio bursts (noise storms) are persistent meter-wave nonthermal emissions above active regions, with their occurrence and proper?ties closely related to the local magnetic configuration and nonthermal electron acceleration. This study examines a type I noise storm on 24 December 2023 and its relation to flare activity. The noise-storm source was co-spatial with active region AR 3529 and showed frequency-dependent spatial dispersion. The associated M2.9 flare strongly modulated the emission, with the storm intensity decreasing at flare onset, recovering afterward, and shifting to higher frequencies. Based on multiwavelength observations, we suggest that pre-flare small-scale reconnection supplied nonthermal electrons to overlying closed magnetic struc?tures and maintained the storm. During the flare, magnetic reconnection above the active region produced bidirectional plasma ejections and type III bursts with bidirectional frequency drifts; the gradually decreasing starting frequency of these bursts may indicate an upward-moving reconnection site. The resulting magnetic reconfiguration disrupted electron trapping and suppressed the storm, whereas post-flare magnetic recovery allowed the emission to resume. These results show that flares can modulate type I noise storms through magnetic restructuring and provide insight into the generation mechanism of noise storms.

发表机构

• Dezhou University（德州学院）
• Purple Mountain Observatory & Key Lab. of Radio Astronomy, Chinese Academy of Sciences（中国科学院紫金山天文台射电天文重点实验室）

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