EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

The Energy Spectrum of Solar Energetic Electron Events

Linghua Wang1, Zixuan Liu1, Haobo Fu1, and Sam Krucker2
Linghua Wang et al.
  • 1Peking University, Institute of Space Physics and Applied Technology, School of Earth and Space Sciences, Beijing, China (
  • 2Space Sciences Lab, University of California, Berkeley, USA

Solar energetic electron events (SEEs) are one of the most common particle acceleration phenomena occurring at the Sun, and their energy spectrum likely reflects the crucial information on the acceleration. Here we present a statistical survey of the energy spectrum of 160 SEEs measured by Wind/3DP with a clear velocity dispersion at energies of ~1-200 keV from January 1995 through December 2016, utilizing a general spectrum formula proposed by Liu et al. (2000). We find that among these 160 SEEs, 144 (90%) have a power-law (or power-law-like) spectrum bending down at high energies, including 108 (67.5%) double-power-law events, 24 (15%) Ellison-Ramaty-like events and 12 (7.5%) log-parabola events, while 16 (10%) have a power-law spectrum extending to high energies. The average power-law spectral index βis 2.1±0.4 for double-power-law events, 1.7±0.8 for Ellison-Ramaty-like events, and 2.8±0.11 for single-power-law events. For the 108 double-power-law events, the spectral break energy Eranges from 2 keV to 165 keV, with an average of 71±79 keV, while the average spectral index βat energies above E0is 4.4±2.3. Eshows a positive correlation with the electron peak flux at energies above ~40 keV, while βhas a negative correlation with the electron peak flux at energies above ~15 keV.  

How to cite: Wang, L., Liu, Z., Fu, H., and Krucker, S.: The Energy Spectrum of Solar Energetic Electron Events, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1944,, 2020