A new view of matter accretion and plasma ejection in Radio Galaxies

It is generally thought that powerful FRII radio galaxies host efficient cold accretion (Sakura-Sunyaev) disks, while powerless FRI radio sources have hot inefficient accretion flows (ADAF). Recently, the study down to mJy fluxes has cast doubts on this picture. This contribution provides an overview of the current state of research on this topic, presenting recent results based on a statistical multifrequency study of more than 14000 SDSS/FIRST radio galaxies with solid optical and radio classification. In particular, we show that the accretion flow is the main driver for the radio galaxies segregation in different optical-radio classes and that the one-to-one accretion-jet power correspondence is not valid anymore. As similar accretion regimes can produce a large variety of jets, we speculate that different black hole properties (spin and magnetic field) can explain the observed spread.