Speaker
Description
First Name: Linghua
Last Name: Wang
Affiliation: Peking University
All Authors: Linghua Wang, Wenyan Li, R. F. Wimmer-Schweingruber, and Säm Krucker
Abstract: Solar energetic electron (SEE) events are one of the most common solar particle acceleration phenomena detected in the interplanetary space. Here we present a comprehensive study of three SEE events observed by SolO/EPD at 0.5 AU and one SEE event by Wind/3DP at 1 AU on March 6, 2022 when the two spacecraft were separated by 1 degree in longitude. According to the velocity dispersion analysis, the solar release start-time (peak-time) of SolO event #1 (#3) agrees with the solar release start-time (peak-time) of the Wind event within uncertainties. Moreover, the three SolO SEE events exhibit, respectively, a single-power-law (SPL) energy spectrum with a spectral index of 3.340.11, a double-power-law (DPL) spectrum with a spectral index of 4.020.32 (5.711.53) at energies below (above) a break energy of 22.7 10.3 keV, and a DPL spectrum with a spectral index of 2.880.85 (5.51 2.44) at energies below (above) a break energy of 9.33.4 keV. The Wind/3DP SEE event shows an SPL energy spectrum with a spectral index of 3.410.17. During the event peak, the electron pitch angle width at half maximum is about 13-20 degrees at 7.4 keV for the three SolO events, while it is about 47 degrees at 4.2 keV for the Wind event. On the other hand, SolO event #1 and #3 are accompanied by two HXR microflares measured by SolO/STIX, while event #3 is also associated with multiple EUV jects measured by SDO/AIA. All these microflares/jets, as well as the magnetic field lines that connect to SolO and Wind, originate from the same active region (AR12957). These results suggest that the three events detected by SolO likely arise from different sources/processes at the Sun, and then they merge to one event during the propagation from 0.5 AU to 1 AU.