Relativistic radiative jets confined by a disk corona

We examine steady relativistic jets, emanating from an inner accretion disk, driven by disk radiation fields, and confined by an isothermal corona. In order to describe the radiation fields produced by the standard accretion disk, we derive bridging formulae which approximately represent the components of the radiation fields from a near-disk regime to a distant regime. We use a streamline approach, where the dynamical equations are expressed by the streamline coordinates, and a cold approximation, where the pressure-gradient force is ignored. When the effect of a corona is ignored, the jet streamlines widen due to the centrifugal force, since the jet gas emanating from the disk has angular momentum. When the corona is considered, on the other hand, the jet flow is remarkably collimated by the corona gas. As a result, radiative winds from an inner disk forms hollow cylindrical jets. The present radiative jets have a terminal speed, where the radiation force is balanced by the gravitational and radiation drag forces. The terminal speed nu(infinity) is not sensitive to the corona properties, but depends on the disk luminosity L-d normalized by the Eddington one L-E. The terminal speed nu(infinity) of the present model is approximately expressed as nu(infinity)/c similar to (0.5/Gamma(d))(0.9) (Gamma(d) - 0.5), where Gamma(d) = L-d/L-E For the Eddington luminosity (Gamma(d) = 1), the terminal speed is about 0.27 c, which is very close to the speed of SS 433 jets.