Gamma-ray halos around pulsars as the key to understanding cosmic ray transport in the Galaxy

Abstract

Pulsars are factories of relativistic electrons and positrons that propagate away from the pulsar, permeating later our Galaxy. The acceleration and propagation of these particles are a matter of intense debate. In the last few years, we had the opportunity to directly observing the injection of these particles into the interstellar medium through the discovery of gamma-ray halos around pulsars. This new type of gamma-ray source is produced by electrons and positrons diffusing out of the pulsar wind nebula and scattering ambient photon fields to produce gamma rays. This new field of study comes with a number of observations and

American Musicals: Stage and screen / L’écran et la scène. Anne Martina & Julie Vatain-Corfdir (dir.). Paris : Sorbonne Université Presses. Paris, 2019, 254 p.

“…The transport of high-energy charged particles in magnetized, collisionless turbulence is central to many topics of high-energy astrophysics and space plasma physics, e.g. it governs the phenomenology of cosmic rays of all energies and on all scales (Berezinskii et al 1990;Zweibel 2017;Amato & Blasi 2018), just as it controls the acceleration rate of particles in Fermi-type processes (Fermi 1949;Blandford & Eichler 1987) or dictates the spatial profile of high-energy radiation around powerful sources (HESS Collaboration et al 2016;López-Coto et al 2022;Liu 2022). Most of the phenomenology in those fields has relied on the use of a quasilinear (QLT) description of wave-particle interactions (Jokipii 1966;Hall & Sturrock 1967;Kulsrud & Pearce 1969;Schlickeiser 2002) and its extensions, e.g.…”