Assembly of the most massive black holes in the universe

The most massive black holes, with up to 10 billion solar masses, are found at the centres of massive, red elliptical galaxies in the nearby universe. Our project will focus on understanding how and when these extreme black holes assembled their mass. We will start by considering their host galaxies, diagnosing how these galaxies have evolved and identifying their progenitors in the more distant universe. We will then use deep X-ray survey data to assess when such galaxies hosted luminous AGN and track the growth of their black holes back in time. Using SDSS-V data, we will directly identify the most massive black holes over cosmic time as they grow, constrain their incidence, extract the properties of their host galaxies and the determine how such objects can produce the massive black holes in the nearby universe.