What do we know about radio-loud Active Galactic Nuclei at the beginning of the "Fermi era"?, Giovanni Fossati (Rice University)

The formation and evolution of relativistic jets in Active Galactic Nuclei (AGN) remains one of the unsolved fundamental problems in astrophysics. This problem has become increasingly relevant because of the evidence that AGN jets can have a profound influence on the formation and evolutions of galaxies.

Blazars comprise a large class of AGN with relativistic jets. The study of their properties is one the principal avenues for investigating how jets form and grow, how the black hole powers them, and the connection with the accretion disk.

Observations suggest a physical thread connecting all the properties of jets in blazars, seemingly revealing that the true dimensionality of blazars parameter space is reduced to just one or two key physical properties, and that it may be possible to organize blazars in a H-R like diagram.  We have previously proposed a unifying model positing the existence of a "blazar sequence".

I will review our work on a large survey of candidate blazars, that is going to enable us to investigate the "big picture" context of their phenomenology, and also the complementary side of very detailed studies of individual bright objects, whose variability provides clues as to what are the physical conditions in blazar jets.