2019/09/13 by Gwenael Giacinti, Giacinti, Gwenael, J. G. Kirk +1
Engineering · Physics and Astronomy · #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Particle accelerators and beam dynamics #Solar and Space Plasma Dynamics
paper · pdf · doi:10.48550/arxiv.1909.06230
openalex publication_date 2019/09/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study electron and positron acceleration at the termination shock of a striped pulsar wind. Drift motion along the shock surface keeps either electrons or positrons -but not both, close to the equatorial plane of the pulsar, where they are accelerated by the first-order Fermi process. Their energy spectrum is a power law, and both the X-ray flux and photon index of the Crab Nebula, as measured by NuSTAR, can be reproduced for sufficiently large downstream turbulence levels. The implication that one sign of charge is preferentially accelerated in pulsar wind nebulae is potentially important for the interpretation of the positron fraction in cosmic-rays.