Abstract :
Radio-loud active galactic nuclei (AGN) are among the most captivating sources in the Universe, with their high luminosity (up to 10^48 erg/s) and spectacular extended radio emission (up to Mpc distances from the radio galaxy core).
It has been established that a connection between the central supermassive black hole and its host galaxy exists, but it is still debated how the large-scale environment in which AGN reside affects their evolution. The study of the so-called AGN feedback gave some answers on how the AGN interact with the surrounding medium, but some questions still need to be addressed. Radio and X-ray observations are a key tool to investigate the feedback process in AGN because they reveal different components (synchrotron radio lobe non-thermal and bremmstrahlung ICM thermal) and allow to study the interplay between these components.
In this talk I will present multifrequency data of the so-called "unidentified" sources from the Third Cambridge Catalog (3C), the high radio frequency follow-up of the giant radio galaxy 3CR 403.1 and the follow-up study of the high-redshift (z=1.408) radio-loud quasar 3C 297. In all cases I will show how complementing radio, optical and X-ray data is crucial to obtain an insight on the environment inhabited by radio-loud AGN and offers a chance to study how these sources interact with it through feedback processes.
