The evolution of a quasar population based on a simple source model

The cosmological evolution of a population of quasars and AGNs is considered. The applied source model provides that the star collisions in the central stellar system should be the principal mechanism of supply of the gas falling on to the black hole. The continuity equation for the assumed population is solved for the zero birth function as well as for its special type. The solutions obtained depend on the distribution of two parameters characterizing a single source: the radius of stellar core and the number of stars in the system. All these solutions allow to describe practically whole evolutionary track of the considered source population, and to relate the evolution to some features of a single source.