In a recent study published in Monthly Notices of the Royal Astronomical Society, Dr. MEI Zhixing from Yunnan Observatories of the Chinese Academy of Sciences and his colleagues presented a high-resolution 3D magnetohydrodynamics (MHD) numerical simulation to investigate bimodality nature of the extreme ultraviolet (EUV) disturbances in the corona during eruption of the solar prominence/filament.

Research on EUV disturbances during the solar eruption has been going on for more than two decades. At present, the researchers tend to accept a so-called bimodality interpretation that the EUV disturbances have both wave and non-wave components. The wave component is fast magneto-acoustic shock (FS) in front of the eruptive magnetic structure, and the non-wave component is associated with the coronal mass ejection (CME) bubble structure.

The 3D MHD numerical simulation carried out in this study was based on the flux-rope model of the prominence/filament eruption. The corresponding synthetic image of Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO / AIA) of the numerical results was obtained, so that the researchers can directly compare their numerical results with the observation datum. The results enrich the bimodality interpretation.

In the synthetic AIA image, the researchers observed the heating of the bright fast-mode shock (FS) hemispherical front and the behind prominence/filament material. Between the prominence and the FS, a dark dimming region appeared. During the evolution process, the magnetic structure of the prominence continued to expand, its brightness continued to decay, and eventually disappeared in the dark area.

When observing this process from the edge of the solar surface, the synthetic image of the EUV disturbance supports the bimodality interpretation of the EUV disturbances. However, when observing the above process near the center of the sun, the synthetic image does not support this interpretation, because the shape of the bright prominence does not have the typical quasi-circular features.

In addition, looking from the side of the CME, they also identified the slow mode shock, velocity vortex and echo of the fast mode shock in the velocity distribution. Among them, the slow mode shock is related to a three-dimensional velocity separatrix.

However, these details in velocity distribution belong to the fine structure of the magnetic field configuration during the solar eruption, so that solar physicists cannot recognize them in the current observational datum, because the technical level and resolution of the observations are not enough.

The researchers are looking forward to high-resolution observations that can help verify these details.