Seminar: "A tale of two components: Revealing the origin of the high energy gamma-ray emission from LS 5039"

Speaker: Dr. Victor Zabalza Torres
(Instituto Max-Planck-Institut für Kernphysik, Heidelberg, Alemanya).

Site: Seminari del DAM (Dept. Astronomia i Meteorologia, planta 7)
Data: Dilluns dia 12, de març de 2012
Time: 10:45 hores

Gamma-ray binaries are systems composed of a young massive star and a compact object, either a black hole or a neutron star. They exhibit broadband non-thermal emission from radio to TeV gamma-rays which is typically modulated with the orbital period in the four systems known to date. Recent Fermi/LAT observations in the GeV band indicate that it is unlikely that the GeV and TeV emission components arise from a single emitter location in the system. In this talk I will review our current understanding of these systems and propose a new model, based on the binary pulsar scenario, to account for the puzzling two-component high-energy emission of the binary LS 5039. The interaction of the stellar and pulsar winds in short orbital period system such as LS 5039 provides two natural candidates for the emitters: the shock inside the orbit, and the location where the Coriolis force overpowers the pulsar wind, creating a termination shock farther away from the star.


Monday, March 5, 2012