Spectral energy distribution, radio maps and polarization of Cygnus X-1: a lepto-hadronic model

VILA, GABRIELA SOLEDAD; PEPE, CAROLINA; ROMERO, GUSTAVO ESTEBAN

La Plata

Congreso; 58 Reunión Anual de la Asociación Argentina de Astronomía; 2015

The microquasar Cygnus X-1 is one of the most studied astrophysical sources. Several radiativemodels for the non-thermal broadband emission of Cygnus X-1 are available. For the jet emission in particular,only leptonic models have been considered despite the observational evidence of the presence of hadrons in the jetsof other microquasars. In this work, we present an inhomogeneous, lepto-hadronic jet model for the non-thermalbroadband emission of Cygnus X-1. We calculate the contribution to the spectrum of both relativistic electronsand protons, taking into account their interaction with the magnetic field, matter and photon fields internal andexternal to the jet We obtain best-fit models for the spectrum that reproduce the observations from radio togamma rays, including the MeV tail whose origin is still disputed. We also produce synthetic radio maps of thejet and compare them to actual interferometric observations of the source. Finally, we present preliminary resultsof calculations of the degree of polarization of the synchrotron radiation in the jet in the MeV band.