Title: An INTEGRAL investigation of non-thermal phenomena in the stellar

Title: An INTEGRAL investigation of non-thermal phenomena in the stellar winds of early-type stars

Proposal ID: 0120067
Subject category: Others
Principal investigator: Rauw
Institute: Institut d'Astrophysique & Geophysique, Universite de Liege

Abstract

We propose to use the instruments on board the INTEGRAL observatory for a detailed study of the non-thermal processes in the winds of early-type stars. For this purpose, we focus on the rich OB associations Cyg OB2 and IC 1805 that contain at least four O-stars displaying a clear non-thermal radio emission. INTEGRAL observations of these associations will allow us to collect data of unprecedented quality and with a sufficient angular and spectral resolution to unambiguously identify the origin of the gamma-ray emission predicted by theoretical models. The results of this study will shed new light on the acceleration and cooling processes of relativistic particles in the stellar winds and will allow us to constrain the so-far undetermined magnetic field strengths of these stars. Finally, we also expect that these results will have important implications on our understanding of the interaction between the early-type stars and their ambient interstellar medium.