High energy gamma-rays from massive binary systems

TL;DR

This paper reviews models explaining TeV gamma-ray emissions from massive binary systems, focusing on anisotropic inverse Compton pair cascades as a key mechanism, considering various particle acceleration scenarios within these systems.

Contribution

It summarizes the anisotropic IC e-p pair cascade model as a plausible explanation for observed gamma-ray modulations in massive binaries, incorporating different particle acceleration scenarios.

Findings

Gamma-ray emission modulated with orbital periods suggests origin inside the binary.

Anisotropic IC e-p pair cascade model explains observed gamma-ray features.

Multiple scenarios for particle acceleration are considered, including pulsars, accretion, and stellar wind collisions.

Abstract

During last years a few massive binary systems have been detected in the TeV gamma-rays. This gamma-ray emission is clearly modulated with the orbital periods of these binaries suggesting its origin inside the binary system. In this paper we summarize the anisotropic IC e-p pair cascade model as likely explanation of these observations. We consider scenarios in which particles are accelerated to relativistic energies, either due to the presence of an energetic pulsar inside the binary, or as a result of accretion process onto the compact object during which the jet is launched from the inner part of the accretion disk, or in collisions of stellar winds from the massive companions.