High-energy processes in starburst-driven winds

TL;DR

This paper explores how starburst-driven galactic winds accelerate particles and produce non-thermal radiation, contributing significantly to gamma-ray emission and X-ray sources outside galactic disks.

Contribution

It presents a detailed analysis of relativistic particle acceleration and non-thermal radiation production in bowshocks around clouds formed by starburst winds, highlighting their observational signatures.

Findings

Cosmic rays at bowshocks do not reach the highest energies.

Up to ~10% of gamma-ray emission in starbursts may originate from these sources.

Discrete X-ray sources with power-law spectra are expected.

Abstract

Starburst galaxies generate large-scale winds powered by the activity in the star-forming regions located in the galactic disks. Fragmentation of the disk produced by the outbreak of the wind results in the formation of clouds. Bowshocks caused by the supersonic outflow appear around such clouds. In this paper we discuss the acceleration of relativistic particles and the production of non-thermal radiation in such scenario. Cosmic rays accelerated at the bowshocks do not reach the highest energies, although the high-energy luminosity generated is significant. We show that up to ~10% of the gamma-ray emission in starbursts might come from these sources outside the galactic disks. Discrete X-ray sources with a power-law component are also expected.