Radiative damping and emission signatures of strong superluminal waves in pulsar winds

TL;DR

This paper investigates how strong superluminal electromagnetic waves in pulsar winds are damped by radiation reaction and Compton drag, and links these processes to observed gamma-ray flares in binary systems like PSR B1259-63.

Contribution

It provides a detailed analysis of the damping mechanisms of superluminal waves and connects these effects to observable gamma-ray signatures in pulsar binary systems.

Findings

Gamma-ray flares can be explained by inverse Compton scattering in pulsar winds.

The wind's mass-loading factor is constrained to about 6×10^4.

Superluminal waves may form roughly 30 days after periastron in PSR B1259-63.

Abstract

We analyse the damping by radiation reaction and by Compton drag of strong, superluminal electromagnetic waves in the context of pulsar winds. The associated radiation signature is found by estimating the efficiency and the characteristic radiation frequencies. Applying these estimates to the gamma-ray binary containing PSR B1259-63, we show that the GeV flare observed by Fermi-LAT can be understood as inverse Compton emission by particles scattering photons from the companion star, if the pulsar wind termination shock acquires a precursor of superluminal waves roughly 30 days after periastron. This constrains the mass-loading factor of the wind $\mu=L/\dot{N}mc^2$ (where $L$ is the luminosity and $\dot{N}$ the rate of loss of electrons and positrons) to be roughly $6\times 10^4$.