Speaker
Description
First Name: Yifeng
Last Name: Li
Affiliation: Peking University
All Authors: Yifeng Li, Linghua Wang, Junqi Jia, Wenyan Li, Yang Su, R. F. Wimmer-Schweingruber
Abstract: We investigate two solar energetic electron (SEE) events observed by Solar Orbiter/EPD around 04:00 UT on December 24, 2022, at a heliocentric distance of 0.93 AU. The symmetric peaks in their temporal profiles, strongly beamed pitch-angle distributions (PADs), and narrow longitudinal distributions suggest scatter-free propagation in the interplanetary medium (IPM). Using the pan-spectrum fitting method, we self-consistently determine the spectral shape of the background-subtracted peak flux. The first event exhibits a higher peak flux and a harder spectral shape above 25 keV. By accounting for the energy bandwidth response and propagation effects, we forward-fit the in-situ temporal profiles to infer the injection profiles at the Sun. Electrons in both events behave similarly below 25 keV, whereas in the first event, electrons above 25 keV show delayed release times and longer durations. Other associated phenomena - including coronal jets, X-ray flares, and radio bursts - reflect similar disparities between two events.. We suppose that the acceleration process is likely similar in both events at low energies, while the first event may have undergone further or more efficient acceleration at higher energies.