The evolution of AGN across cosmic time: what is downsizing?

Understand

We use a coupled model of the formation and evolution of galaxies and black holes (BH) to study the evolution of active galactic nuclei (AGN) in a cold dark matter universe.

• The model predicts the BH mass, spin and mass accretion history.
• BH mass grows via accretion triggered by discs becoming dynamically unstable or galaxy mergers (called the starburst mode) and accretion from quasi-hydrostatic hot gas haloes (called the hot-halo mode).
• By taking into account AGN obscuration, we obtain a very good fit to the observed luminosity functions (LF) of AGN (optical, soft and hard X-ray, and bolometric) for a wide range of redshifts (0<z<6).