Energetic Nonthermal Electrons within the Above-the-looptop Regions in Solar Flares: Acceleration, Feedback, and Quasi-Periodic Pulsations
Abstract
Solar flares are among the most dramatic events in the solar system, releasing substantial magnetic energy and accelerating a large number of electrons to high energies. Notably, in certain events, the above-the-looptop region may contain a significant population of nonthermal electrons, both in number and energy. For the first time, we adopt a novel numerical method that combines magnetohydrodynamics with energetic particles incorporating feedback from nonthermal electrons to investigate electron acceleration and transport in solar flares. We find that a large fraction of energetic electrons are accelerated via the current sheet and termination shock regions. Most energetic electrons are concentrated in the above-the-looptop region, carrying a sizable amount of the released energy. We observe that greater feedback of nonthermal electrons leads to steeper energy spectra. The energy density of the nonthermal electrons oscillates due to the periodic impact of magnetic islands into the above-the-looptop, which may help explain the observed quasi-periodic pulsations (QPPs). Our simulations provide new insights into the origin of nonthermal electrons and associated emissions in the above-the-looptop region.
Versions
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BibTeX
@misc{seo2026energetic,
title = {{Energetic Nonthermal Electrons within the Above-the-looptop Regions in Solar Flares: Acceleration, Feedback, and Quasi-Periodic Pulsations}},
author = {Jeongbhin Seo and Fan Guo and Xiaocan Li and Bin Chen and Chengcai Shen and Hui Li},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.06763},
eprint = {2611.06763},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.06763},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Energetic Nonthermal Electrons within the Above-the-looptop Regions in Solar Flares: Acceleration, Feedback, and Quasi-Periodic Pulsations
AU - Jeongbhin Seo
AU - Fan Guo
AU - Xiaocan Li
AU - Bin Chen
AU - Chengcai Shen
AU - Hui Li
PY - 2026
DA - 2026/11/04
PB - arXiv
DO - 10.48550/arxiv.2611.06763
UR - https://arxiv.org/abs/2611.06763
AB - Solar flares are among the most dramatic events in the solar system, releasing substantial magnetic energy and accelerating a large number of electrons to high energies. Notably, in certain events, the above-the-looptop region may contain a significant population of nonthermal electrons, both in number and energy. For the first time, we adopt a novel numerical method that combines magnetohydrodynamics with energetic particles incorporating feedback from nonthermal electrons to investigate electron acceleration and transport in solar flares. We find that a large fraction of energetic electrons are accelerated via the current sheet and termination shock regions. Most energetic electrons are concentrated in the above-the-looptop region, carrying a sizable amount of the released energy. We observe that greater feedback of nonthermal electrons leads to steeper energy spectra. The energy density of the nonthermal electrons oscillates due to the periodic impact of magnetic islands into the above-the-looptop, which may help explain the observed quasi-periodic pulsations (QPPs). Our simulations provide new insights into the origin of nonthermal electrons and associated emissions in the above-the-looptop region.
ER -