AGN feedback

In the past decades the so-called "AGN feedback" became a central topic in galaxy evolution studies.  It has become a fundamental component of most semi-analytical models and hydrodynamical cosmological simulations to regulate the efficiency of star formation, especially at high stellar masses, and reproduce the observed properties of galaxies. 

AGN feedback is a problem of many scales over multiple orders of magnitudes in temporal, temperature and spatial scales. I use a vairiety of observational probes to understand the physics of ou the energy and momentum from the SMBH couple with the surrounding medium on multiple scales. I lead the SINFONI 280 hour large programme  SUPER, whcih provided the first statistical investigation of AGN outflows at Cosmic Noon.  I have used ALMA to trace the cold molecular phase  and JWST MIRI/MRS (Cycle-1 and Cycle-2)  to trace the hot molecular phase.

I am part of the Quasar Feedback Survey with the primary goal to understand how low-power jets can have an impact on the interstellar-medium of their host galaxies and drive galaxy scale outflows. Looking ahead, this is an area where SKAO has a transformational potential as we described in this article (Maccagni & Mainieri 2026),

In numerical simulations, the impact of AGN feedback on the properties of the gas  on hundreds of kpc scales surrounding a galaxy (CGM)  strongly depends on the efficiency of the feedback recipe adopted. Costa et al. (2022) explore the link between AGN-driven outflows and the formation of Lyα nebulae and found that AGN-driven outflows, beside modifying the temperature and density of the gas in the halo, cause a dramatic drop in the HI and dust optical depths in the host galaxy, facilitating the escape of Lyα photons from the galactic nucleus. Without AGN feedback, their simulations cannot reproduce the observed Lyα nebulae. I have led the first observational test of this scenario, observing with ERIS/VLT a sample of AGN at z~2 with previously detected Lyα nebulae. In Rueda Vargas, Mainieri et al. (2026) we found indeed a correlation between the properties of the detected AGN-driven outflows (i.e. outflow power) and those of the surrounding nebulae (i.e. nebulae size).