Recurrent microblazar activity in Cygnus X-1?

G. E. ROMERO; M. M. KAUFMAN BERNADÓ; I. F. MIRABEL

ASTRONOMY AND ASTROPHYSICS

EDP Sciences

Lugar: Les Ulis Cedex A; Año: 2002 vol. 393 p. 61 - 64

0004-6361

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.