Block-induced Complex Structures Building the Flare-productive Solar Active Region 12673
Block-induced Complex Structures Building the Flare-productive Solar Active Region 12673
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DOI：
10.3847/2041-8213/aa9476
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发表时间：
2017-10
期刊：
影响因子：
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通讯作者：
Shuhong Yang;Jun Zhang;Xiaoshuai Zhu;Q. Song
中科院分区：
文献类型：
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作者：
Shuhong Yang;Jun Zhang;Xiaoshuai Zhu;Q. Song
2017年9月，太阳活动区（AR） 12673在穿越可见太阳圆盘时产生了4个x级、27个m级和许多低级别耀斑。我们的研究是为了回答为什么这个AR会产生如此多的耀斑，以及过去十年中最大的X9.3耀斑是如何发生的。我们发现最初几天有一个太阳黑子，然后在它附近先后出现了两个两极区。由于已存在的黑子的存在，双极子的运动被阻断，而已存在的黑子仅保持其准圆形本影，半影部分消失。因此，双极斑块明显扭曲，相反的极性形成两个半圆形结构。之后，在狭窄的半圆形区域内出现了两个新的双极区序列，双极斑块沿着弯曲的通道分离。新的双极与之前的双极发生剪切和相互作用，形成了一个复杂的拓扑系统，其间发生了多次耀斑。在高剪切区，积累了大量的自由能。9月6日，靠近极性倒转线的一个负磁场开始与周围正磁场快速旋转和切变，X9.3耀斑爆发。我们的研究结果表明，块诱导的复杂结构构建了产生耀斑的AR， X9.3耀斑是由扭结不稳定性引起的爆发灯丝触发的。为了更好地说明这一过程，首次提出了块体诱发喷发模型。
Solar active region (AR) 12673 produced 4 X-class, 27 M-class, and numerous lower-class flares during its passage across the visible solar disk in 2017 September. Our study is to answer the questions why this AR was so flare-productive and how the X9.3 flare, the largest one of the past decade, took place. We find that there was a sunspot in the initial several days, and then two bipolar regions emerged nearby it successively. Due to the standing of the pre-existing sunspot, the movement of the bipoles was blocked, while the pre-existing sunspot maintained its quasi-circular shaped umbra only with the disappearance of a part of penumbra. Thus, the bipolar patches were significantly distorted, and the opposite polarities formed two semi-circular shaped structures. After that, two sequences of new bipolar regions emerged within the narrow semi-circular zone, and the bipolar patches separated along the curved channel. The new bipoles sheared and interacted with the previous ones, forming a complex topological system, during which numerous flares occurred. At the highly sheared region, a great deal of free energy was accumulated. On September 6, one negative patch near the polarity inversion line began to rapidly rotate and shear with the surrounding positive fields, and consequently the X9.3 flare erupted. Our results reveal that the block-induced complex structures built the flare-productive AR and the X9.3 flare was triggered by an erupting filament due to the kink instability. To better illustrate this process, a block-induced eruption model is proposed for the first time.