Coevolution of black holes and host galaxies

One of the most important astronomical discoveries of the last 20 years is that most local massive galaxies host a supermassive black hole (hereafter BH), with mass of ∼ 10^6 − 10^10 solar masses , in their centre. The most relevant discovery supporting a connection between a BH and its host galaxy is the tight correlation between the BH mass and the velocity dispersion of the stars in the bulge, which corresponds to the whole galaxy for the elliptical ones. Together with similar correlations with bulge luminosity and mass, this led to the belief that BHs and bulges coevolve by regulating each other’s growth. However, the difference of nine orders of magnitude between the typical spatial scales of BHs and bulges seems to preclude a direct casual connection.The goal of this thesis is a comprehensive investigation of the BH-galaxy coevolution over cosmic time and, in particular, of the main processes connecting a BH to its host galaxy. To analyse the evolution of star-forming galaxies over the cosmic history, we made use of data obtained at different wavelength ranges thanks to the new generation telescopes, such as the astronomical interferometry Atacama Large Millimetre/submillimetre Array (ALMA).