Relativistic accretion disk models for Active Galactic Nuclei: mass and spin of Supermassive black holes

Active Galactic Nuclei are among the brightest and most energetic objects in the Universe and determining their mass M and spin a is crucial for understanding their physical nature, the link with the host galaxy, and their possible evolution in time. The commonly accepted scenario describes them with a supermassive black hole of 10^6 − 10^10 solar masses at their center along with an accretion disk of hot rotating matter. The surrounding environment (e.g., dusty torus, Broad and Narrow Line Region) is thought to be shaped by both the strong gravitational field of the black hole and the disk radiation. Uncertainties on their mass and spin are still too large and new methods have to be used to set more stringent constraints. In this thesis, I used different accretion disk models to predict the main black hole features (i.e., mass and spin), comparing them with different independent measurements, and to study the surrounding environment (i.e., the dusty torus), shaped by the relativistic disk radiation pattern.