Luminosity function and cosmological evolution of X-ray selected quasarsThe preliminary analysis of a complete sample of 55 X-ray sources is presented as part of the Medium Sensitivity Survey of the Einstein Observatory. A pure luminosity evolutionary law is derived in order to determine the uniform distribution of the sources and the rates of evolution for Active Galactic Nuclei (AGNs) observed by X-ray and optical techniques are compared. A nonparametric representation of the luminosity function is fitted to the observational data. On the basis of the reduced data, it is determined that: (1) AGNs evolve cosmologically; (2) less evolution is required to explain the X-ray data than the optical data; (3) the high-luminosity portion of the X-ray luminosity can be described by a power-law with a slope of gamma = 3.6; and (4) the X-ray luminosity function flattens at low luminosities. Some of the implications of the results for conventional theoretical models of the evolution of quasars and Seyfert galaxies are discussed.
Document ID
19850031180
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Maccacaro, T. (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Gioia, I. M. (CNR Istituto di Radioastronomia, Bologna, Italy)