Particle acceleration at ultrarelativistic, perpendicular shock fronts. Issue 1 (9th December 2022)

• Record Type: Journal Article
• Authors: Kirk, John G; Reville, Brian; Huang, Zhi-Qiu
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 519:Issue 1(2023)
• Page Start: 1022
• Page End: 1029
• Publication Date: 2022-12-09
• Subjects: acceleration of particles -- radiation mechanisms: non-thermal -- transients: gamma-ray bursts; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac3589
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Using an eigenfunction expansion to solve the transport equation, complemented by Monte Carlo simulations, we show that ultrarelativistic shocks can be effective particle accelerators even when they fail to produce large amplitude turbulence in the downstream plasma. This finding contradicts the widely held belief that a uniform downstream magnetic field perpendicular to the shock normal inhibits acceleration by the first-order Fermi process. In the ultrarelativistic limit, we find a stationary power-law particle spectrum of index s = 4.17 for these shocks, close to that predicted for a strictly parallel shock.