A&A 433, 313-322 (2005)
A layered model for non-thermal radio emission from single O starsS. Van Loo, M. C. Runacres and R. Blomme
Royal Observatory of Belgium, Ringlaan 3, 1180 Brussel, Belgium
(Received 7 September 2004 / Accepted 29 November 2004 )
We present a model for the non-thermal radio emission from bright O stars, in terms of synchrotron emission from wind-embedded shocks. The model is an extension of an earlier one, with an improved treatment of the cooling of relativistic electrons. This improvement limits the synchrotron-emitting volume to a series of fairly narrow layers behind the shocks. We show that the width of these layers increases with increasing wavelength, which has important consequences for the shape of the spectrum. We also show that the strongest shocks produce the bulk of the emission, so that the emergent radio flux can be adequately described as coming from a small number of shocks, or even from a single shock.
Key words: stars: early-type -- stars: mass-loss -- stars: winds, outflows -- radio continuum: stars -- radiation mechanisms: non-thermal
© ESO 2005