A model for gamma-ray binaries, based on the effect of pair production feedback in shocked pulsar winds

TL;DR

This paper presents a model for gamma-ray binaries where pair production feedback in the pulsar wind influences the wind's Lorentz factor and generates energetic pairs, potentially explaining observed gamma-ray emissions.

Contribution

It introduces a novel feedback mechanism involving pair production that limits pulsar wind Lorentz factors and accounts for gamma-ray observations.

Findings

Pair feedback constrains pulsar wind Lorentz factor.

Energetic pairs produced may explain gamma-ray signals.

Model offers new insights into pulsar wind dynamics.

Abstract

We analyze the model of gamma-ray binaries, consisting of a massive star and a pulsar with ultrarelativistic wind. We consider radiation from energetic particles, accelerated at the pulsar wind termination shock, and feedback of this radiation on the wind through production of secondary electron-positron pairs. We show that the pair feedback limits the Lorentz factor of the pulsar wind and creates a population of very energetic pairs, whose radiation may be responsible for the observed gamma-ray signal.