S E M I N A R IDepartament d'Astronomia i Astrofísica
Universitat de València
Radiative jet models for low-mass X-ray binaries
Instituto Argentino de Radioastronomia
Seminari del departament d'Astronomia i Astrofisica
Divendres 21 març 2014
X-ray binaries (XRBs) are systems formed by a compact object (a neutron star or a stellar-mass black hole) accreting from a non-collapsed companion. In some X-ray binaries, a fraction of the accretion flow is ejected from the surroundings of the compact object as two collimated jets that may reach velocities close to the speed of light. Such XRBs with jets are called microquasars. Microquasars emit electromagnetic radiation almost along the whole spectrum, from radio to X-rays. A few of them have also been detected at high and very high-energy gamma rays. It is usually accepted that the gamma rays are produced by relativistic particles accelerated in situ in the jets. In this talk, I will present the main features and results of a lepto-hadronic model for the electromagnetic radiation of jets in microquasars with low-mass companion stars. I will describe the channels of interaction of relativistic particles with matter, radiation, and magnetic field that are relevant under the physical conditions in the jets. The output of these processes is a complex broadband radiative spectrum. I will show the results of the model for some generic scenarios and specific applications to two well-studied X-ray transients. Motivated by the growing volume and quality of the data available at high and very high energies, I will focus on the predictions for the gamma-ray band and the chances of detecting these sources in the near future. Finally, I will briefly comment on the neutrino emission from microquasar jets.