Rapid magnetic reconnection dominated by magnetic islands was first found in solar flares

Science and Technology Daily News (reporter Zhao Hanbin correspondent Chen Yan) reporter recently learned from the Yunnan Astronomical Observatory of the Chinese Academy of Sciences that the Fuxian Lake Solar Observation and Research Base of the station cooperated with domestic and foreign research institutions to find for the first time a rapid magnetic reconnection with a twisted structure magnetic island in a solar flare, which means that important progress has been made in magnetic reconnection research. The results were published online in Nature Communications.

Magnetic reconnection is the physical process of two sets of magnetic field lines with inverse components approaching each other and reconnecting. In this process, the magnetic field lines will be annihilated at the current sheet, so that the magnetic energy is converted into kinetic energy, thermal energy, radiation energy and so on of the plasma. Magnetic reconnection is a basic process of rapid release of magnetic energy in the plasmas prevalent in the universe, and plays an extremely important role in astrophysics, space physics, and laboratory plasma physics.

Yunnan Astronomical Observatory cooperates with Harbin Institute of Technology Shenzhen Campus, the University of Potsdam in Germany, St. Drujans University in the United Kingdom, the National Astronomical Observatory of the Chinese Academy of Sciences and the National Space Science Center, etc., mainly using the high time and high spatial resolution data of the one-meter new vacuum solar telescope at the Fuxian Lake Solar Observatory of Yunnan Observatory, combined with multi-band observations of the Solar Dynamics Observatory, as well as X-ray data such as the Ramadi high-energy solar spectroscope imaging satellite and the geostationary environment service satellite in the United States. Using self-developed high-precision numerical simulations, the magnetic reconnection process between the dark strip with a winding magnetic field structure and the magnetic ring rooted in the surrounding chromosphere fibers that occurred in the activity zone 11967 on February 2, 2014 was studied in detail.

In this event, the one-meter new vacuum telescope observed the most complete magnetic reconnection feature to date. The relevant spectral data also revealed that there is very strong non-thermal radiation in the reconnected current film, and high-resolution extreme ultraviolet observations have found that a large number of plasma groups, i.e., magnetic islands, form in the reconnected current film. Through data-driven, high-resolution numerical simulations, the research team also reproduced the formation process of magnetic islands in the current film and confirmed that the magnetic islands are small magnetic ropes with strong winding structures.

The study reveals the fine physical process of rapid magnetic reconnection in solar flares, further deepens the understanding of the basic physical process of magnetic reconnection, is of great significance for the study of the physical characteristics and activity laws of solar activity, and also provides an important reference for the study of the flare phenomenon of other celestial bodies such as solar stars, neutron stars, black holes and other celestial bodies and the study of magnetic energy dissipation, space physics and laboratory plasma physics.

Source: Science and Technology Daily