About the project
This project aims at contributing to the still largely unsolved questions in astrophysics. How do supermassive black holes form and evolve? What are the formation channels for their seeds? How much do black-black hole mergers and gas accretion contribute to their mass growth throughout the history of the Universe?
Supermassive black holes, extreme singularities of spacetime, of the order of a million to a billion solar masses, are lurking today in the cores of most galaxies, including our own Milky Way. The masses of supermassive black holes seem to correlate with their host galaxy and dark matter halo properties, in particular to the characteristic random motions (velocity dispersion) of stars. Observations of the deep Universe are showing that supermassive black holes as massive as a billion times the mass of the sun are already present at early epochs, providing extremely stringent constraints to the viable formation channels of these monsters.
With the use of advanced semi-empirical models, which make use of sub-halo abundance matching, coupled to the outputs of high-resolution N-body simulations, this project aims at determining the relative roles of quasar feedback and galaxy mergers in setting the scaling relations with velocity dispersion. In turn, the project aims at constraining the radiative efficiency (and thus the spin) of black holes. The project will also make extensive use of a large hydrodynamic simulation run in Southampton, on IRIDIS5, which for the first time includes the dynamical evolution of stellar mass black holes in protogalaxies as a promising route to form the seeds of supermassive black holes in the early Universe.
This project will also set very stringent constraints on the gravitational wave background from supermassive black hole binaries, of capital importance for the next gravitational wave detectors (LISA). The student will contribute to the next-generation European space galaxy missions, Euclid, LSST, SKA and Athena.