Letter to the Editor
Recurrent microblazar activity in Cygnus X-1?
Instituto Argentino de Radioastronomía, C.C.5, (1894) Villa Elisa, Buenos Aires, Argentina
2 CEA/DMS/DAPNIA/Service d'Astrophysique, Centre d'Études de Saclay, 91191 Gif-sur-Yvette, France
3 Instituto de Astronomía y Física del Espacio/CONICET, C.C. 67, Suc. 28, Buenos Aires, Argentina
Corresponding author: G. E. Romero, firstname.lastname@example.org
Accepted: 20 August 2002
Recurrent flaring events at X- and soft gamma-ray energies have been recently reported for the galactic black hole candidate Cygnus X-1. The observed fluxes during these transient outbursts are far higher than what is observed in “normal” episodes. Here we suggest that the origin of this radiation is non-thermal and produced by inverse Compton interactions between relativistic electrons in the jet and external photon fields, with a dominant contribution from the companion star field. The recurrent and relatively rapid variability could be explained by the precession of the jet, which results in a variable Doppler amplification.
Key words: X-ray binaries / stars: individual: Cyg X-1 / gamma-rays: observations / gamma-rays: theory
© ESO, 2002