Hawking - How supermassive black holes shape our Universe: at the interface of galaxy formation, cosmology and multi-messenger astronomy

Our home galaxy, the Milky Way, plays host to a super-massive black hole (SMBH) at its centre, dubbed Sagittarius A*, with a mass more than 4 million times that of the sun. SMBHs reside in the centres of most (if not all) galaxies, from low-mass dwarf galaxies to giant ellipticals in vast galaxy clusters. Despite their small sizes compared to the galaxies that host them, SMBH and galaxy properties are intimately linked through co-evolution. SMBHs represent some of the most extreme objects in the Universe and act as incredibly efficient engines that can convert a large fraction of the rest mass energy (remember Einstein's famous equation E=mc^2) of material that falls under their gravitational spell into energy, known as feedback, in the form of radiation, winds and jets. These processes give the SMBH its voice, allowing it to communicate across a vast range of scales, from the black hole event horizon to far beyond the host galaxy.

Over the coming decade and beyond, many missions (e.g. SKA, Athena, Euclid, JWST and LISA) will provide observations of the Universe not only in light but with LISA also in gravitational waves, and hence revolutionise multi-messenger astronomy of SMBHs. Systems ranging from SMBH binaries to individual galaxies, up to vast clusters that represent the most massive objects in the Universe and contain thousands of galaxies, will be observed in the local Universe and out to when it was less than a quarter of its current age. We will receive more data than ever before providing insights into the co-evolution of SMBHs and their galaxies over cosmic time.

To help to interpret the plethora of new observational data, it is vital to have robust and realistic theoretical models to compare to. The vast array of complex physical processes that shape the properties of SMBHs and their cosmic environment and the huge range of scales involved presents a formidable challenge. Using powerful supercomputers, I will perform state-of-the-art simulations...