Clumping effects on non-thermal particle spectra in massive star systems

摘要

Observational evidence exists that winds of massive stars are clumped. Manymassive star systems are known as non-thermal particle production sites, asindicated by their synchrotron emission in the radio band. As a consequencethey are also considered as candidate sites for non-thermal high-energy photonproduction up to gamma-ray energies. The present work considers the effects ofwind clumpiness expected on the emitting relativistic particle spectrum incolliding wind systems, built up from the pool of thermal wind particlesthrough diffusive particle acceleration, and taking into account inverseCompton and synchrotron losses. In comparison to a homogeneous wind, a clumpywind causes flux variations of the emitting particle spectrum when the clumpenters the wind collision region. It is found that the spectral featuresassociated with this variability moves temporally from low to high energy bandswith the time shift between any two spectral bands being dependent on clumpsize, filling factor, and the energy-dependence of particle energy gains andlosses.