Magnetic fields, non-thermal radiation and particle acceleration in colliding winds of WR-O stars

TL;DR

This paper reviews recent MHD simulations of wind-wind collision regions in WR-O star binaries, focusing on magnetic fields and particle acceleration mechanisms responsible for observed non-thermal emissions.

Contribution

It provides new insights into magnetic field configurations and particle acceleration processes through advanced numerical simulations of colliding stellar winds.

Findings

Magnetic fields are amplified at shock regions.

Relativistic particles are efficiently accelerated via Fermi processes.

Magnetic field geometry influences non-thermal emission characteristics.

Abstract

Non-thermal emission has been detected in WR-stars for many years at long wavelengths spectral range, in general attributed to synchrotron emission. Two key ingredients are needed to explain such emissions, namely magnetic fields and relativistic particles. Particles can be accelerated to relativistic speeds by Fermi processes at strong shocks. Therefore, strong synchrotron emission is usually attributed to WR binarity. The magnetic field may also be amplified at shocks, however the actual picture of the magnetic field geometry, intensity, and its role on the acceleration of particles at WR binary systems is still unclear. In this work we discuss the recent developments in MHD modelling of wind-wind collision regions by means of numerical simulations, and the coupled particle acceleration processes related.