Scattering Cross Sections of Magnetized Particles within Intense Electromagnetic Waves: Application to Fast Radio Bursts

TL;DR

This paper compares scattering cross sections of magnetized particles under intense electromagnetic waves in different modes, revealing that O-mode waves are more transparent than X-mode waves in magnetar magnetospheres, impacting FRB propagation.

Contribution

It provides a detailed comparison of scattering cross sections for O-mode and X-mode waves, highlighting their different effects on FRB transparency in magnetar environments.

Findings

O-mode waves have significantly smaller scattering cross sections than X-mode waves.

O-mode waves are more transparent than X-mode waves within magnetar magnetospheres.

Implications for the propagation and observation of fast radio bursts (FRBs).

Abstract

Recently, Beloborodov suggested that there exists a resonance phenomenon between an extremely intense electromagnetic wave and internal magnetized particles. The particles exchange energy with the wave at frequent resonance events and then reach the radiation reaction limit immediately. This process greatly enhances the scattering cross section of the particles. Note that these results only involve an extraordinary (X) mode wave. In this paper, we focus on an intense ordinary (O) mode wave propagating through magnetized particles and compare it with the case of the X-mode wave. Our result shows that the scattering cross section of the particles in the O-mode wave is significantly smaller than that in the X-mode wave. This has important implications for the transparency of a fast radio burst (FRB) inside the magnetosphere of a magnetar. We argue that there is a strong scattering region in the stellar magnetosphere, within which an O-mode wave is more transparent than an X-mode wave for an FRB.