China News Service, Beijing, November 4 (Reporter Sun Zifa) The National Astronomical Observatory of the Chinese Academy of Sciences announced to the media on November 4 that based on the observation data of the Mid-Infrared Observation System (English abbreviation AIMS) telescope independently developed by China for accurate measurement of the solar magnetic field, a joint research team led by researcher Deng Yuanyong of the station found that during the outbreak of solar flares, the magnetic field of the sun's lower atmosphere is significantly weakened.
This important astronomical discovery will help build a more complete solar flare model and deepen our understanding of the dynamic process mechanism of flares. Relevant research papers were recently published online in the international professional academic journal "Nature-Astronomy".
Measurement accuracy improved by an order of magnitude
According to the research team, the solar atmosphere is a huge magnetic plasma environment dominated by magnetic fields, and all phenomena and processes in it are dominated by magnetic fields and their interactions. Flares are the most violent and rapid release of energy in the solar atmosphere driven by the magnetic field, and are the main driving source of disastrous space weather. There have been many observations and theories describing the physical images of the flare process for a long time. However, there is still no clear physical image of how the magnetic field in the sun's lower atmosphere, which is an important carrier of the accumulation, transmission and release of flare energy, changes during the flare process.
The main reason for this situation is that flares will affect the solar spectrum profile used for magnetic field measurement. The traditional measurement method based on spectral polarization to diagnose the magnetic field cannot give accurate results or even fails. In addition, the flare evolution process is fast and requires high time resolution measurements to match. The short single measurement time results in a low signal-to-noise ratio and low magnetic field measurement accuracy, which cannot be used to study the rapid evolution of the magnetic field during the flare.
As a major national scientific research instrument development project that will be completed and accepted in China in 2025, the AIMS telescope adopts a targeted special design in its research and development design, which can improve the measurement accuracy of magnetic field intensity from the traditional hundred gauss level to a level better than ten gauss.
Based on this internationally unique observation feature, AIMS observed the spectral evolution during an X1.5-level flare for the first time. The analysis results showed that the magnetic field strength below the flare belt weakened significantly. The research team also used the flare dynamics atmospheric model to simulate the spectral evolution during the flare and tested the above results.
This is the first time special observation has been achieved
Regarding the important observational findings of the AIMS telescope, one journal reviewer commented that "the author used numerical simulation tools to conduct a very detailed and comprehensive study"; another reviewer said that "this type of special observation has been achieved for the first time."
This research work has also attracted the attention of experts in the same field: Researcher Shen Jinhua of the Xinjiang Observatory of the Chinese Academy of Sciences believes that accurate magnetic field measurements are of great significance in solving problems such as chromosphere and corona heating, and magnetic energy accumulation and release mechanisms; Researcher Zhou Guiping of the National Astronomical Observatory of the Chinese Academy of Sciences believes that magnetic field diagnosis during flares provides new observational constraints and physical revelations for establishing a flare model that couples magnetic field reconstruction, energy deposition and radiation response, and for revealing the dynamic feedback mechanism between the corona and the lower atmosphere.
Deng Yuanyong said that the unique observation capabilities of AIMS design benefit from independent breakthroughs in a series of key core technologies. The spectral data used in this study were obtained from the infrared Fourier spectrometer scientific terminal. It is independently developed by the AIMS team and is the world's first infrared Fourier spectrometer with both high spectral resolution and imaging capabilities. "The publication of this scientific research result perfectly illustrates the complementarity of independent technological innovation and original research results."
It is reported that the joint research team is composed of researchers from the National Key Laboratory of Solar Activity and Space Weather of the National Observatory of the Chinese Academy of Sciences, Stockholm University in Sweden, Yunnan Observatory of the Chinese Academy of Sciences, Hunan Institute of Engineering, Shanghai Institute of Technical Physics of the Chinese Academy of Sciences, Xi'an Institute of Optics and Precision Mechanics of the Chinese Academy of Sciences, and Kunming University of Science and Technology.
