Proton Acceleration in Low-β Magnetic Reconnection with Energetic Particle Feedback
Year: 2024
Type: article
Abstract: Magnetic reconnection regions in space and astrophysics are known as active particle acceleration sites. There is ample evidence showing that energetic particles can take a substantial amount of converted energy during magnetic reconnection. However, there has been a lack of studies understanding the backreaction of energetic particles at magnetohydrodynamical scales in magnetic reconnection. To address this, we have developed a new computational method to explore the feedback by nonthermal energetic particles. This approach considers the backreaction from these energetic particles by incorporating their pressure into magnetohydrodynamics (MHD) equations. The pressure of the energetic particles is evaluated from their distribution evolved through Parker’s transport equation, solved using stochastic differential equations (SDEs), so we coin the name MHD-SDE. Applying this method to low-β magnetic reconnection simulations, we find that reconnection is capable of accelerating a large fraction of energetic particles that contain a substantial amount of energy. When the feedback from these particles is included, their pressure suppresses the compression structures generated by magnetic reconnection, thereby mediating particle energization. Consequently, the feedback from energetic particles results in a steeper power-law energy spectrum. These findings suggest that feedback from nonthermal energetic particles plays a crucial role in magnetic reconnection and particle acceleration.
Source: The Astrophysical Journal
Authors: Jeongbhin Seo, Fan Guo, Xiaocan Li, Hui Li
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, Smithsonian Institution, U.S. Department of Energy, National Aeronautics and Space Administration, National Energy Research Scientific Computing Center, Nuclear Safety and Security Commission, Smithsonian Astrophysical Observatory, Laboratory Directed Research and Development, Los Alamos National Laboratory
Awards: G1405629206, G3284530418, G3443673831, G3890645960, G5395596559, G66958357, G6871336836, Collaborative Research: Achieving a New Understanding of Solar Flare Termination Shocks, Collaborative Research: WoU-MMA: Understanding the Physics and Electromagnetic Counterparts of Neutrino Blazars with Numerical Simulations, G8665951991, G8762421008
OpenAlex ID: W4405213899