[Russian version]

 

M a i n    p a g e

Future  seminars

P a s t  seminars

Seminar council

 

"Radiation-driven winds from stars and Active Galactic Nucle"

A. V. Dorodnitsyn (IKI)

Abstract:

It is now clearly understood that the problem of mass loss is crucially important both from the point of view of it’s influence on the evolution  of stars and for the explanation of physical processes and observational data in active galactic nuclei (AGN). Evolution of massive stars is accompanied by mass loss as strong as 10-4 -10-6  M_sun/yr. Absorption of the radiation by continuum opacity is responsible for such an evolutionary significant mass loss in cold massive stars. Massive hot stars may have winds as fast as v_{inf}=2000 km/s that is three orders of magnitude faster then that of the massive evolved stars. The momentum is transferred from the radiation to outflowing plasma due to absorption in different line transitions. This mechanism of radiation acceleration is probably responsible for the acceleration of winds from accretion discs in AGN as well. It was recently recognized (Dorodnitsyn A., 2003) that if the wind is accelerated from the vicinity of the black hole, Sobolev mechanism should be revisited considerably in order to take into account  influence of the strong gravitational field on the radiation. Detailed analytical and numerical analysis had revealed a significant difference between a wind form AGN that is predicted by a standard line-driven wind theory and a developed approach.