On 23 July 2016 after 05:00\,UTC, the first 48-antenna stage of the Siberian Radioheliograph detected two flares of M7.6 and M5.5 GOES importance that occurred within half an hour in the same active region. Their multi-instrument analysis reveals the following. The microwave spectra were flattened at low frequencies and the spectrum of the stronger burst had a lower turnover frequency. Each flare was eruptive, emitted hard X-rays and gamma-rays exceeding 800\,keV, and had a rare three-ribbon configuration. An extended hard X-ray source associated with a longest middle ribbon was observed in the second flare. The unusual properties of the microwave spectra are accounted for by a distributed multi-loop system in an asymmetric magnetic configuration that our modeling confirms. Microwave images did not to resolve compact configurations in these flares that may also be revealed incompletely in hard X-ray images because of their limited dynamic range. Being apparently simple and compact, non-thermal sources corresponded to the structures observed in the extreme ultraviolet. In the scenario proposed for two successive three-ribbon eruptive flares in a configuration with a coronal-null region, the first eruption causes a flare and facilitates the second eruption that also results in a flare.

中文翻译：

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具有不寻常微波光谱的双零点相关主要爆发性三带耀斑

2016 年 7 月 23 日 05:00\,UTC 之后，西伯利亚射电日光仪的第一个 48 天线级检测到在同一活动区域半小时内发生的两个 M7.6 和 M5.5 GOES 重要性的耀斑。他们的多仪器分析揭示了以下内容。微波频谱在低频处变平，而较强的爆发的频谱具有较低的周转频率。每个耀斑都是爆发性的，发射出超过 800 keV 的硬 X 射线和伽马射线，并且具有罕见的三带结构。在第二次耀斑中观察到与最长的中间带相关的扩展硬 X 射线源。微波光谱的不寻常特性是由我们的模型证实的非对称磁性配置中的分布式多回路系统引起的。微波图像无法解析这些耀斑中的紧凑配置，由于其动态范围有限，硬 X 射线图像中也可能无法完全显示这些耀斑。非热源显然简单而紧凑，对应于在极紫外线中观察到的结构。在为具有日冕无效区域的配置中的两次连续三带状喷发耀斑提出的情景中，第一次喷发引起耀斑并促进第二次喷发，第二次喷发也导致耀斑。