WP1 probed the first phases of growth of SMBHs believed to occur in the early, dust-enshrouded growth phases of the host galaxies. We catalogued samples of AGN from IR/radio/X-ray at different redshifts, with some of them specifically selected to be dust-enshrouded quasars, in their early growth phase, the so-called “red quasars”. We used high-resolution ALMA observations to show that the obscured AGN are often hosted in extreme compact starburst galaxies, with large obscuration levels around the central growing black hole, in tension with canonical pure orientation models for AGN obscuration. We adopted a Bayesian-based multi-wavelength methodology to characterize the level of obscuration in deep Chandra COSMOS-legacy field data. We found that the obscured quasars have both higher star-formation IR luminosity and excess radio emission when compared to unobscured quasars. We also found an overall fraction of obscured AGN which is steadily decreasing with cosmic time, from ~60% at z~3, to ~20% in the local Universe.
WP2 probed the phase in which the SMBH is mature enough to eject energetic winds and jets with a potential to impact the host galaxy. This process is dubbed “AGN feedback”. We analysed the incidence of AGN feedback features in multiwavelength AGN samples and assessed the energetics associated with AGN outflows. We integrated ML techniques to enhance the completeness and efficiency of identifying AGN with outflows, resulting in a more than a five-fold increase in sample size compared with standard techniques. We selected ~1200 candidates AGN in the feedback phase out of a parent sample of ~14500 AGN at z>0.5. We performed a parametric analysis of the [OIII] emission lines with the aim of searching for outflows and studied the outflow properties. We analysed Type-2 quasars in the nearby Universe along with the MEGARA datacubes to characterise the emission line kinematics. We found that the kinetic power represents 0.1% of the quasar bolometric luminosity.
WP3 focused on AGN host galaxies and their environment. Via the use of Convolutional Neural Networks trained on simulated mergers and applied real time data from the Sloan Digital Sky Survey (SDSS), we found that while galaxy mergers do not cause black hole accretion overall, there is a correlation between mergers and AGN activity in galaxies with ongoing star formation. Via semi-empirical models, we found that the enhancement of AGN activity at high redshift in dense structures appears associated with galaxies that are located on the outskirts of galaxy clusters. We enhanced the SED-fitting code CIGALE for modeling low accretion rate AGN and found that black hole nuclear activity impacts both the global and radial star formation rate profiles in X-ray-selected AGN within the miniJPAS field.
WP4 aimed to provide a robust theoretical background to all observational projects developed in WP1-3, using phenomenological/data-driven models, semi-analytic models, and hydrodynamic simulations. Starting from the growth of massive “seed” BHs in high-redshift, dust-enshrouded galaxies, we built a full-scale BH mass function, from stellar mass BHs to supermassive BHs at different cosmic epochs. We included state-of-the-art subgrid models of BH growth and feedback from supernovae and AGN in the COLBRE hydrodynamic simulations, which allowed us to investigate the effects of the AGN feedback in galaxies in detail and for a large sample of galaxies. We used ML techniques to calibrate the strength of AGN and supernova feedback in the COLIBRE model. We developed a cutting-edge SMBH spin evolution model which will be coupled to a prescription for energy injection aimed at reproducing the interaction of jets from AGN with the surrounding medium. We developed DECODE, the Discrete statistical semiempirical model, specifically designed to predict rapidly and efficiently, in a full ΛCDM cosmological context, galaxy and SMBH assembly and merger histories for any given input stellar mass-halo mass and SMBH-galaxy mass relations. Via DECODE we have built a holistic and self-consistent view among several galactic-related properties, such as the galaxystar formation histories, merger histories, satellite abundances, intracluster light and probed galaxystar formation shutdown via halo and SMBH quenching. We predicted in semi-analytic and semi-empirical models the roles of both evolutionary and orientation models in shaping obscuration in AGN. We found that a central torus component seems to be a key component in many highly Compton-thick sources at any stage of their evolution.
