2006ApJ...637..506M

X-ray spectroscopy of several OB stars with massive winds has revealed that many X-ray line profiles exhibit unexpectedly small blueshifts and are almost symmetric. Moreover, the hottest X-ray lines appear to originate closest to the star. These properties appear to be inconsistent with the standard model of X-rays originating in shocked material in line-driven spherically symmetric winds. Here we raise the question, can the X-ray line data be understood in terms of a two-component wind? We consider a scenario in which one component of the wind is a standard line-driven wind that emerges from a broad range of latitudes centered on the equator. The second component of the wind emerges from magnetically active regions in extensive polar caps. The existence of such polar caps is suggested by a recent model of dynamo action in massive stars. We describe how the two-component model is consistent with a variety of observational properties of OB star winds.