Drifting Pulsation Structure at the Very Beginning of the 2017 September 10 Limb Flare
Drifting Pulsation Structure at the Very Beginning of the 2017 September 10 Limb Flare
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DOI：
10.3847/1538-4357/ab63d0
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发表时间：
2019-12
期刊：
影响因子：
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通讯作者：
M. Karlický;Bin Chen;D. Gary;J. Kašparová;J. Rybák
中科院分区：
文献类型：
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作者：
M. Karlický;Bin Chen;D. Gary;J. Kašparová;J. Rybák
漂移脉动结构（DPSs）是在太阳耀斑爆发初期观测到的重要射电精细结构。有人认为，DPS携带的重要信息的能量释放过程中的太阳耀斑。我们研究了2017年9月10日在微波，EUV和X射线观测提供的空间和光谱诊断背景下在X8.2级耀斑中观察到的DPS。我们描述了DPS和它的子结构，首次观察到。我们使用一种新的小波技术来揭示DPS的特征周期及其频带。比较这个DPS中发现的脉动周期与以前的DPS中发现的脉动周期，我们发现新的非常短的周期在0.09-0.15秒的范围内。我们目前扩大欧文斯谷太阳能电池阵列的图像和光谱的微波源在DPS期间观察到的。这种DPS在其最开始时具有两个频带（1000-1300 MHz和1600-1800 MHz）中的脉动，这两个频带通过快速漂移突发相互连接。我们表明，这些双带脉动开始的时刻，当喷出的灯丝分裂在撕裂运动的位置，其中一个签名的耀斑电流片后来出现。使用标准耀斑模型和以前的观测DPS，我们解释这些双波段脉动的超热电子被困在上升的磁绳和耀斑拱廊的时刻，耀斑磁重联开始的无线电签名。结果进行了讨论的情况下，在上升的磁绳的等离子体团。
Drifting pulsation structures (DPSs) are important radio fine structures usually observed at the beginning of eruptive solar flares. It has been suggested that DPSs carry important information on the energy release processes in solar flares. We study DPS observed in an X8.2-class flare on 2017 September 10 in the context of spatial and spectral diagnostics provided by microwave, EUV, and X-ray observations. We describe DPS and its substructures that were observed for the first time. We use a new wavelet technique to reveal characteristic periods in DPS and their frequency bands. Comparing the periods of pulsations found in this DPS with those in previous DPSs, we found new very short periods in the 0.09–0.15 s range. We present Expanded Owens Valley Solar Array images and spectra of microwave sources observed during the DPS. This DPS at its very beginning has pulsations in two frequency bands (1000–1300 MHz and 1600–1800 MHz), which are interconnected by fast drifting bursts. We show that these double-band pulsations started just at the moment when the ejected filament splits apart in a tearing motion at the location where a signature of the flare current sheet later appeared. Using the standard flare model and previous observations of DPSs, we interpret these double-band pulsations as a radio signature of superthermal electrons trapped in the rising magnetic rope and flare arcade at the moment when the flare magnetic reconnection starts. The results are discussed in a scenario with the plasmoid in the rising magnetic rope.