Fig. 6: Observation of electron acceleration around the X-line region.

a Three components of the magnetic field. The yellow and gray bars represent the further localized enhancements of energetic electron fluxes. b Energetic electron (47–300 KeV) omnidirectional differential flux. c Electron pitch angle distribution during 10–30 KeV. d Electron pitch angle distribution during 50–300 KeV; e The total disturbed magnetic energy below the ions scale (the frequency great than fci), |δB|2, and the total flux during 30–300 KeV (pink curve). The blue bar corresponds to an isolated 3D vortex structure. The area between two vertical black dashed lines at 03:58:07 and 03:58:43 UT represents the X-line region.