The New Vacuum Solar Telescope (NVST) observed the release of magnetic twist by magnetic reconnection for the first time.
A related research article “Observing the Release of Twist by Magnetic Reconnection in a Solar Filament Eruption”, finished jointly by researchers from Yunnan Observatories, National Astronomical Observatories and other institutions was published online in Nature Communications on June 16, 2016.
Magnetic reconnection is a very important process of energy release in Astrophysics. It is widely accepted that the energy on the Sun is released by the magnetic reconnection. However, observational evidence has been relatively rare and partial. Mainly using high temporal and spatial resolution Hα observations from NVST, and supplemented by ultraviolet, extreme ultraviolet images and vector magnetograms observed by Solar Dynamics Observatory, the X-ray data from Hinode and Geostationary Operational Environmental Satellite, the researchers study in detail the process of the magnetic reconnection in the active region 12178 on October 03, 2014.
The magnetic reconnection occurs between the filament threads and the ambient chromospheric fibrils. For the first time, researchers report that the twist in the filament is released quickly by the magnetic reconnection. In this event, an unprecedented comprehensive set of observational evidences are detected, including reconnection inflows and outflows, current sheet, two hot cusp-shaped structures, newly formed magnetic loops, shrinking of the loops and so on. The estimated reconnection rate is consistent with the values of the theoretical expectations. In addition, the change of magnetic structures is supported by the change in the structure of the extrapolated nonlinear force-free field and by a magnetohydrodynamic simulation. These results further confirm the occurrence of the magnetic reconnection during the filament eruption and the release process of the twist in the filament by the magnetic reconnection.
Information regarding the paper: ZhikeXue, Xiaoli Yan, Xin Cheng, Liheng Yang, Yingna Su, Bernhard Kliem, Jun Zhang, Zhong Liu, Yi Bi, Yongyuan Xiang, Kai Yang and Li Zhao. “Observing the Release of Twist by Magnetic Reconnection in a Solar Filament Eruption” at http://www.nature.com/ncomms/2016/160616/ncomms11837/full/ncomms11837.html.
Contact the authors at yanxl@ynao.ac.cn.
This work is funded by the following projects: National Science Foundation of China, 973 Program, CAS “Light of West China” program, Youth Innovation Promotion Association of CAS and other projects.
The filament threads and chromospheric fibrils are indicated by red and white arrows respectively in panels (a) and (b). The current sheet forming in magnetic reconnection is marked by the cyan arrows in panels (c)-(f). The results of magnetohydrodynamic simulation reproducing the magnetic reconnection during the filament eruption are presented in panels (g)-(i).
(Provided by Yunnan Observatories)
