http://arxiv.org/abs/1903.02496
Binary systems formed by early-type stars with strong winds are known to display variable non-thermal radio emission, thermal X-rays, and, at least in one case (Eta Carina), $\gamma$ rays. Some of these systems are quite eccentric and the conditions for efficient particle acceleration and $\gamma$-ray production might manifest only occasionally. In this paper I briefly review the physics of colliding wind binaries with emphasis on the observational signatures of non-thermal particle acceleration. I discuss, in particular, the case of the system HD 93129A which is made up by an O2 If* star (the primary) and an O3.5 V star (the secondary). The primary is among the earliest, hottest, most massive, luminous, and windy O stars in the Galaxy. The periastron passage during 2018 will offer an outstanding observational window that will be exploited by an international multi-wavelength campaign.
G. Romero
Thu, 7 Mar 19
52/82
Comments: 7 pages, 2 figures. Solicited review published in Rendiconti Lincei. Scienze Fisiche e Naturali, DOI: 10.1007/s12210-019-00763-2