Sunspot penumbral filaments intruding into a light bridge and the resultant reconnection jets
Sunspot penumbral filaments intruding into a light bridge and the resultant reconnection jets
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太阳黑子半影丝侵入光桥以及由此产生的重新连接喷流
DOI：
10.1051/0004-6361/202038668
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发表时间：
2020-08
影响因子：
6.5
通讯作者：
Y. Hou;T. Li;S. Zhong;S. Yang;Y. Guo;X. H. Li;J. Zhang;Y. Xiang
中科院分区：
文献类型：
--
作者：
Y. Hou;T. Li;S. Zhong;S. Yang;Y. Guo;X. H. Li;J. Zhang;Y. Xiang
上下文。半影细丝和光桥是太阳黑子内部的突出结构，对于理解太阳黑子磁场和下面的磁对流的性质很重要。
目标。我们调查了一个有趣的事件，几个半影细丝侵入太阳黑子光桥。通过这样做，我们的目标是进一步深入了解太阳黑子半影细丝和光桥的磁场，以及它们之间的相互作用。
方法：研究方法。结合新真空太阳望远镜、太阳动力学天文台和界面区成像光谱仪的数据，我们研究了侵入光桥的半影细丝和由此产生的喷流的发射、运动学和磁拓扑特性。
结果。在灯桥的西侧，侵入的半影细丝穿透到灯桥两侧的伞状结构中，还检测到两组急流。这些喷流与侵入的细丝具有相同的投影形态，并伴随着断断续续的足点亮化。同时的光谱成像观测提供了令人信服的证据，证明在喷流底部附近存在与磁重联有关的加热和双向流动，并有助于测量喷流的矢量速度。此外，非线性无力场外推结果显示沿侵入的半影丝的强磁场和强倾斜磁场，这与由喷流的矢量速度得出的结果高度一致。因此，我们认为这些喷流可能是由光桥内浮现的磁场和侵入细丝的近水平磁场之间的磁场重联引起的。然后，喷流沿着更强的灯丝场向外喷射。
结论。我们的研究表明，半影灯丝场和光桥内的新兴磁场之间可以发生磁重联，并沿着更强的灯丝场产生喷流。这些结果进一步补充了太阳黑子内部磁场重联和动力学活动的研究。
Context. Penumbral filaments and light bridges are prominent structures inside sunspots and are important for understanding the nature of sunspot magnetic fields and magneto-convection underneath.
Aims. We investigate an interesting event where several penumbral filaments intrude into a sunspot light bridge. In doing so we aim to gain further insight into the magnetic fields of the sunspot penumbral filament and light bridge, as well as their interaction.
Methods. Combining data from the New Vacuum Solar Telescope, Solar Dynamics Observatory, and Interface Region Imaging Spectrograph, we study the emission, kinematic, and magnetic topology characteristics of the penumbral filaments intruding into the light bridge and the resultant jets.
Results. At the west part of the light bridge, the intruding penumbral filaments penetrate into the umbrae on both sides of the light bridge, and two groups of jets are also detected. The jets share the same projected morphology with the intruding filaments and are accompanied by intermittent footpoint brightenings. Simultaneous spectral imaging observations provide convincing evidence for the presences of magnetic-reconnection-related heating and bidirectional flows near the jet bases and contribute to measuring the vector velocities of the jets. Additionally, nonlinear force-free field extrapolation results reveal strong and highly inclined magnetic fields along the intruding penumbral filaments, highly consistent with the results deduced from the vector velocities of the jets. Therefore, we propose that the jets could be caused by magnetic reconnections between emerging fields within the light bridge and the nearly horizontal fields of intruding filaments. The jets are then ejected outward along the stronger filament fields.
Conclusions. Our study indicates that magnetic reconnection could occur between the penumbral filament fields and emerging fields within the light bridge and produce jets along the stronger filament fields. These results further complement the study of magnetic reconnection and dynamic activities within the sunspot.