2020/01/31 by Patrick Kilian, Xiaocan Li, Fan Guo +1
Physics and Astronomy · #Acceleration #Astrophysics and Cosmic Phenomena #Classical mechanics #Computational physics #Electric field #Electron #Gamma-ray bursts and supernovae #Ionosphere and magnetosphere dynamics #Kinetic energy #Magnetic energy #Magnetic field #Magnetic reconnection #Magnetization #Particle acceleration #Physics #Plasma #Power law #Quantum electrodynamics #Quantum mechanics #astro-ph.HE #physics.plasm-ph
paper · pdf · doi:10.3847/1538-4357/aba1e9
20 pages, 21 figures; Accepted for publication in The Astrophysical Journal
openalex created_date 2020/01/23 · arxiv created 2020/07/02 · openalex publication_date 2020/08/01 · arxiv updated 2020/09/02 · openalex updated_date 2026/08/06
Abstract Magnetic reconnection in the relativistic and transrelativistic regimes is able to accelerate particles to hard power-law energy spectra f ∝ γ − p (approaching p = 1). The underlying acceleration mechanism that determines the spectral shape is currently a topic of intense investigation. By means of fully kinetic plasma simulations, we carry out a study of particle acceleration during magnetic reconnection in the transrelativistic regime of a proton–electron plasma. While earlier work in this parameter regime has focused on the effects of electric field parallel to the local magnetic field on the particle injection (from thermal energy to the lower-energy bound of the power-law spectrum), here we examine the roles of both parallel and perpendicular electric fields to gain a more complete understanding on the injection process and further development of a power-law spectrum. We show that the parallel electric field does contribute significantly to particle injection, and is more important in the initial phase of magnetic reconnection. However, as the simulation proceeds, the acceleration by the perpendicular electric field becomes more important for particle injection and completely dominates the acceleration responsible for the high-energy power-law spectrum. This holds robustly, in particular for longer reconnection times and larger systems, i.e., in simulations that are more indicative of the processes in astrophysical sources.