Research on the physical mechanism of the formation of solar jets in the Yunnan Observatory

[ Instrument Network Instrument Development ] The Shenyuan Light and its collaborators of the Yunnan Astronomical Observatory of the Chinese Academy of Sciences found that the two-way jet phenomenon of the sun is driven by a micro-dark burst and undergoes two magnetic reconnection processes. This is consistent with the physical mechanism of the formation of collimated jets of another type of solar jet phenomenon that they discovered earlier. These studies unify and improve the understanding of different types of jet formation processes. The research results were recently published in the American Astrophysical Journal.

The phenomenon of solar jet activity is one of the processes of energy and material release that occur in the solar atmosphere. Long-term studies have shown that solar jets are likely to play an important role in solar physics and solar wind acceleration. However, people's understanding of its basic formation process is still not clear. Shen Yuandeng et al. used high-resolution multi-band stereoscopic data from satellites such as the Solar Dynamic Observatory and the Solar Terrestrial Relations Observatory to study the phenomenon of jet activity. Whether the collimated jet or the bidirectional jet is formed by the burst of the micro-dark strip, and a new interpretation of the jet formation is proposed based on the observation results. They believe that the micro-dark strip usually loses stability under the action of the magnetic ball's magnetic cancellation or instability, and starts to rise or burst. The bound magnetic field above the dark strip first recombines with the surrounding open or horizontal magnetic field to form a hot plasma. Body flow, and then, due to the rise of the dark strip, magnetic field reconnection occurs below it to accelerate the burst of the dark strip.

"The formation process of two different types of jet flow activities is basically the same, both contain micro-dark bursts and undergo two magnetic reconnection processes. However, due to different magnetic field configurations, the results are slightly different. In the case of direct jet flow, since it contains a dark strip burst, and the jet is formed to move along the open magnetic field line, a wide and narrow two-day birthday 冕 substance ejection is usually formed in the corona meter; and for the two-way jet, the formed jet is formed. The flow of the plasma usually moves along the closed magnetic field line, and usually does not form a coronal mass ejection." Shen Yuan said, "This research has promoted the understanding of the process of jet formation on the one hand, and the small-scale sun spray on the other hand. The outbreak activity is highly similar to the outbreaks of large-scale dark bars and coronal mass ejections."

The research work was supported by the National Natural Science Foundation of China Excellent Young Scientists Fund Project, the Surface Project, the Western Academy of Young Scholars Program of the Chinese Academy of Sciences, the Yunnan Provincial Ten Thousand Talents Program and the Yunnan Basic Research Project.

Schematic diagram of two types of jet formation processes. The upper row is the formation process of the collimated jet, and the lower row is the formation process of the bidirectional jet. The red dotted line in the figure is the position where the magnetic field reconnection occurs, the orange circle structure represents the micro dark bar, the black line represents the unreconnected magnetic lines of force, and the blue line represents the magnetic lines of force after the reconnection. The + and - signs represent the positive and negative magnetic fields, respectively.