Quasars and Galactic Nuclei,a Half-Century Agitated Story

Abstract

I recall how the discovery of quasars occurred more than forty years ago, and the strong debates marking out their story. It led to the discovery of Massive Black Holes, which are now known to be present in almost all galaxies, and it opened on a coherent physical model and on a new vision of galaxy evolution.Comment: 14 pages, 4 figures, talk given at the Albert Einstein Century International Conference, held in Paris, France, July 18-22, 2005, submitted to publication in AIP, Eds J.-M. Alimi and A. Fuzfa, replaced to add few references and to correct a mistak