Studying the Structure of the Stellar Wind in LS 5039

The binary LS 5039 is a non-thermal X-ray emitter that presents jet-like radio structures, and is also one of the most misterious TeV sources in our Galaxy. The presence of an O-type star in LS 5039 implies that the non-thermal emitter must be embedded in a strong stellar wind, and the role of the latter could be relevant for the understanding of the high-energy behavior of the source. In this work, we show that the lack of absorption features in the soft X-ray spectrum of LS 5039 can constrain strongly the parameters that describe the wind, and ultimately the location of the non-thermal emitter.
Comment: 6 pages, 2 figures, submitted, proceedings of High energy phenomena in massive stars, Jaen, Spain, 2-5/2/09, ASPCS