Observing Formation of Flux Rope by Tether-cutting Reconnection in the Sun
Observing Formation of Flux Rope by Tether-cutting Reconnection in the Sun
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在阳光下观察绳索切断重连形成的磁绳
DOI：
10.3847/2041-8213/aa7066
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发表时间：
2017
影响因子：
7.9
通讯作者：
Zhao Li
中科院分区：
文献类型：
--
作者：
Xue Zhike;Yan Xiaoli;Yang Liheng;Wang Jincheng;Zhao Li
绳索切断重新连接被认为是形成磁通绳的一种机制。它已被提出30多年；然而，迄今为止，对其进行直接观察的情况非常罕见。在这封信中，我们结合新真空太阳望远镜和太阳动力观测站的观测结果，展示了 2014 年 2 月 2 日在 NOAA AR 11967 中通过系绳切断重连形成磁通绳的观测结果。绳索切断重新连接发生在两组高度剪切的磁拱之间。重联的综合观测证据如下：拱廊之间连接的变化、重联处的增亮、热流出、磁绳的形成、磁绳的缓慢上升运动和磁通抵消。流出沿从重连点到足点的三个方向，速度从 24 ± 1 km s−1 到 69 ± 5 km s−1 。另外，发现新形成的磁绳连接较远的足点，具有左旋绞合结构，细丝较多，中间呈凹形结构。所有观察结果都与系绳切割模型一致，并提供了系绳切割重新连接导致与磁通剪切流和抵消相关的磁绳形成的证据。
Tether-cutting reconnection is considered as one mechanism for the formation of a flux rope. It has been proposed for more than 30 years; however, so far, direct observations of it are very rare. In this Letter, we present observations of the formation of a flux rope via tether-cutting reconnection in NOAA AR 11967 on 2014 February 2 by combining observations with the New Vacuum Solar Telescope and the Solar Dynamic Observatory. The tether-cutting reconnection occurs between two sets of highly sheared magnetic arcades. Comprehensive observational evidence of the reconnection is as follows: changes of the connections between the arcades, brightenings at the reconnection site, hot outflows, formation of a flux rope, slow-rise motion of the flux rope, and flux cancelation. The outflows are along three directions from the reconnection site to the footpoints with the velocities from 24 ± 1 km s−1 to 69 ± 5 km s−1. Additionally, it is found that the newly formed flux rope connects far footpoints and has a left-handed twisted structure with many fine threads and a concave-up-shape structure in the middle. All the observations are in agreement with the tether-cutting model and provide evidence that tether-cutting reconnection leads to the formation of the flux rope associated with flux shear flow and cancelation.