Zhou Xinping, Shen Yuandeng, Yuan Ding, Keppens Rony, Zhao Xiaozhou, Fu Libo, Tang Zehao, Wang Jiaoyang, Zhou Chengrui
College of Physics and Electronic Engineering, Sichuan Normal University, Chengdu, 610068, People's Republic of China.
Yunnan Observatories, Chinese Academy of Sciences, Kunming, 650216, People's Republic of China.
Nat Commun. 2024 Apr 16;15(1):3281. doi: 10.1038/s41467-024-46846-z.
Electromagnetic wave lensing, a common physical phenomenon recognized in visible light for centuries, finds extensive applications in manipulating light in optical systems such as telescopes and cameras. Magnetohydrodynamic wave is a common perturbation phenomenon in the corona. By using high spatio-temporal resolution observations from the Solar Dynamics Observatory, here, we report the observation of a magnetohydrodynamic wave lensing in the highly ionized and magnetized coronal plasma, where quasi-periodic wavefronts emanated from a flare converged at a specific point after traversing a coronal hole. The entire process resembles an electromagnetic wave lensing from the source to the focus. Meanwhile, the magnetohydrodynamic wave lensing is well reproduced through a magnetohydrodynamic numerical simulation with full spatio-temporal resolution. We further investigate potential applications for coronal seismology, as the lensing process encodes information on the Alfvén speed, in conjunction with favorable geometric and density variations.
电磁波透镜效应是数百年来在可见光领域为人熟知的一种常见物理现象,在诸如望远镜和相机等光学系统中操控光线方面有着广泛应用。磁流体动力学波是日冕中一种常见的扰动现象。在此,通过利用太阳动力学天文台的高时空分辨率观测数据,我们报告了在高度电离和磁化的日冕等离子体中观测到的磁流体动力学波透镜效应,其中耀斑产生的准周期波前在穿过一个冕洞后在特定点汇聚。整个过程类似于从源到焦点的电磁波透镜效应。同时,通过具有全时空分辨率的磁流体动力学数值模拟很好地再现了磁流体动力学波透镜效应。我们进一步研究了日冕地震学的潜在应用,因为透镜效应过程结合有利的几何和密度变化,编码了关于阿尔文速度的信息。