Coloquio:19 de octubre 2020 – 11:00 horas

Expositor: Pol Bordas, Universidad de Barcelona

Resumen: The detection of two sources of gamma rays towards the microquasar SS 433 has been recently reported by the Fermi-LAT collaboration. The first source can be associated with SS 433’s eastern jet lobe, whereas the second source is variable and displays significant periodicity that is compatible with the precession period of the binary system, of about 160 days. The location of this variable component is not
compatible with the location/extrapolation of SS 433 jets. To explain
the observed phenomenology, a scenario based on the illumination of
dense gas clouds by relativistic protons accelerated at the interface
of the accretion disk envelope has been proposed. Energetic arguments
strongly constrain this scenario, however, as it requires an unknown
mechanism capable to periodically channel a large fraction of SS 433’s
kinetic energy towards an emitter located 35 parsec away from the
central binary system.