Radio Galaxies near and far:
what can learn from these spectacular active galactic nuclei?
Marco Chiaberge
Space Telescope Science Institute

Radio galaxies are a spectacular class of Active Galactic Nuclei (AGN). They are powered by accretion of matter onto the most massive black holes and they are hosted by the largest galaxies in the Universe. I will focus on results from our studies of radio galaxies at all distances, from the closest objects to high redshifts, when the Universe was less than a quarter of the age it is now. I will show how low-redshift radio galaxies observed with HST and other instruments allowed us a better understanding of the innermost regions of AGNs and of their black holes. While we still don’t know the details of the physics of the jet launch, we learned that the nuclei of lower power objects are fundamentally different from all other AGNs. In recent years, we focused on the cosmological evolution of these sources. I will show the first results of the analysis of a new sample of high redshift (11, which will allow a detailed comparison of the properties of the environment of these sources over more than four decades in radio power.

Location: Physics Bldg., Room 401