Abstract

Astrophysical black holes are described by two properties: their mass and their spin. While the mass evolution of massive black holes in the context of their host galaxies has been the subject of many detailed studies, comparatively little is understood about the spin of massive black holes. Much like the mass, the spin of black holes is thought to evolve as the black hole coevolves with its host galaxy. Black hole spin has important consequences for the inner structure of the accretion disc, which in affects the radiative efficiency of black hole feedback, i.e. how much of the accreted mass is converted to energy and released by the black hole. Black hole spin is also thought to power black hole jets via the Blandford-Znajek mechanism. In this talk, I will share insights into the long-term spin evolution of massive black holes as their host galaxies form and evolve, using the NewHorizon simulation.