PANCHROMATIC VIEW OF THE LIFE-CYCLE OF AGN

In the last two decades, the unified models of active galactic nuclei (AGN) have been able to explain several of their observational properties. Whereas the simple orientation-based unification model works as a first-degree approximation, the reality is more complicated, and there is a host of different parameters at play. Statistical methods, aimed at simplifying multidimensional data, and in particular the so-called eigenvector 1 (EV1), have proven to be a useful tool in studying AGN grand unification. The position of a source on the EV1 is believed to be a combination of observational (mainly inclination) and physical properties, with the Eddington ratio acting as the main driver. However, different stages of AGN evolution can also appear as different classes of sources. Indeed, mounting evidence shows that the AGN life-cycle, that is, how AGN are born, how they grow, and how they interact with their closest environment, likely plays an essential role in this grand unification scenario. The main purpose of this workshop is to present the current status of the research on the life-cycle of active galactic nuclei, to discuss its future direction, and prepare for the advent of the new space- and ground-based observational facilities (e.g., JWST, Athena, ELT, Euclid).

Topics: Narrow-line Seyfert 1 galaxies, early-stage AGN, intermittent activity, duty cycle of AGN, quasar main sequence, multifrequency observations