Joint Astrophysical Colloquium
Self-Consistently building Galaxy-Supermassive Black Hole Co-Evolution via data-driven, self-consistent cosmological models
Francesco Shankar (University of Southampton)
Tuesday 02/12/2025 @ 14:00, Sala Antonio Sollima (IV piano Battiferro)
The co-evolution of supermassive black holes (SMBHs) and galaxies remains one of the most highly debated topics in present-day extra-galactic astrophysics and cosmology. Some of the open issues focus around the relative importance between star formation and mergers in shaping galaxies and growth of SMBHs, as well as the drivers behind galaxy quenching and the SMBH-galaxy scaling relations. In this talk, I present a new, flexible, and rapid approach, to tackle all these open questions in a self-consistent and data-driven manner, which naturally reduces the number of assumptions and free parameters. In our model, galaxy growth is associated with the assembly of their host dark matter haloes through abundance matching between the specific halo accretion rate and the specific star formation rate. Central SMBHs within these galaxies are then evolved by sampling the observed Eddington ratio distribution functions and integrating the accretion rates over cosmic time. Galaxy/SMBH mergers are self-consistently incorporated using the dark matter halo merger trees, with the stellar and SMBH masses assigned at infall via the scaling relations characterizing their central counterparts at that epoch and environment. The model also explores relevant star formation quenching mechanisms induced by active SMBHs or halo quenching. I will present results on: 1) galaxy growth histories against observed star formation histories; 2) SMBH growth, scaling relations, and mass functions; 3) the impact of the new JWST-driven SMBH scaling relations at z~5; 4) results on galaxy quenching via haloes and SMBHs.