High-energy neutrino emission from X-ray binaries

We show that high-energy neutrinos can be efficiently produced in X-ray binaries with relativistic jets and high-mass primary stars. We consider a system where the star presents a dense equatorial wind and the jet has a small content of relativistic protons. In this scenario, neutrinos and correlated gamma-rays result from pp interactions and the subsequent pion decays. As a particular example we consider the microquasar LSI +61 303. Above 1 TeV, we obtain a mean-orbital ν-luminosity of ∼ 4 1034 erg/s which can be related to an event rate of 3–5 muon-type neutrinos per kilometer-squared per year if we take into account neutrino oscillations. The upper limit of integration in energy depends on the orbital position and is a function of the largest magnetic gyro-radius compatible with the jet dimensions. As a consequence, the maximal neutrino energies here considered will range between 8 and 25 TeV along the orbit. The local infrared photon-field is responsible for opacity effects on the associated gamma radiation. PACS: 95.85.Ry; 98.70.Sa; 13.85.Tp 13.85-t Submitted for publication on 12th August 2005