P85	December 2003

¹ Institut d'Astrophysique et de Géophysique - Université de Liège, Allée du 6 Août, 17 - Bât B5c, B-4000 Liège (Sart Tilman), Belgium

^* Research Associate FNRS, Belgium

Abstract

     In this chapter, I review the properties of high-energy particles in the stellar winds of hot early-type stars. Relativistic electrons are responsible for the synchrotron radio emission observed from a subsample of these stars. Most of the objects in the latter category are found to be binaries and the collision between the stellar winds of the binary components is thought to play a crucial role in the acceleration of the relativistic electrons. The interplay between these high-energy electrons and the intense stellar radiation field could produce a substantial non-thermal emission at X-ray and -ray energies through inverse Compton scattering. Other mechanisms, such as ⁰ decay might also contribute to the production of non-thermal emission from hot stars. These various effects could possibly account for some of the yet unidentified EGRET sources found to be correlated with OB associations in our Galaxy. Finally, I review recent results from XMM-Newton observations and discuss the prospects of forthcoming -ray observations with INTEGRAL and GLAST.