VLBI Observations of an Expanding Jet in Cygnus X-3

Abstract

The X-ray binary Cyg X-3 offers a rare opportunity to study the physical conditions of the formation of a relativistic jet. While the central engines of extragalactic jets are generally poorly understood, the infrared and X-ray data on Cyg X-3 allow detailed modelling of the conditions in the inner disk and corona, the source of the jet energy. Study of the periodic nature of particle injection into the jet may yield an important clue to the nature of the particle injection mechanism. And the time scale of jet evolution is much shorter than for extragalactic sources, allowing the possibility of observing a large number of flares to determine general characteristics.