2025/01/01 by S. C. Gupta, Navin Sridhar, Gupta, Sanya +3 · 3 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.2501.00979
openalex publication_date 2025/01/01 · openalex created_date 2025/01/04 · openalex updated_date 2026/08/01
Magnetic reconnection in relativistic plasmas -- where the magnetization σ≫1 -- is regarded as an efficient particle accelerator, capable of explaining the most dramatic astrophysical flares. We employ two-dimensional (2D) particle-in-cell simulations of relativistic pair-plasma reconnection with vanishing guide field and outflow boundaries to quantify the impact of the energy gain occurring in regions of electric dominance (E>B) for the early stages of particle acceleration (i.e., the ``injection'' stage). We calculate the mean fractional contribution ζ(ε^∗,ε\rm T) by E>B fields to particle energization up to the injection threshold energy, ε^∗=σ/4; here, ε\rm T is the particle energy at time T. We find that ζ monotonically increases with σ and ε\rm T; for σ\gtrsim 50 and ε\rm T/σ\gtrsim 8, we find that \gtrsim 80% of the energy gain obtained before reaching ε^∗=σ/4 occurs in E>B regions. We find that ζ is independent of simulation box size Lx, as long as ε\rm T is normalized to the maximum particle energy, which scales as ε\rm max∝ L\rm x1/2 in 2D. The distribution of energy gains εχ acquired in E>B regions can be modeled as dN/dεχ∝εχ-0.35exp[-(εχ/0.06 σ)0.5]. Our results help assess the role of electric dominance in relativistic reconnection with vanishing guide fields, which may be realized in the magnetospheres of black holes and neutron stars.