Introduction to Reverberation Mapping of Active Galactic Nuclei

During my presentation I will describe main concepts, observational results and open questions of Active Galactic Nuclei (AGN) reverberation mapping. Angular size of vast majority of active galaxy centers is way to small to be spatially resolved by modern instruments and thus cannot be directly observed via traditional methods. The reverberation mapping method allows to use variability properties of AGN to swap spatial resolution to time resolution and directly test vicinity of supermassive black holes in the centers of galaxies. Rapid development of  reverberation mapping studies in the past two decades makes it a very promising tool for galaxy evolution and observational cosmology.