How do supermassive black holes affect their host galaxies?

Supermassive black holes, which reside in the centres of most massive galaxies, are capable of injecting vast amounts of energy into their surrounding environments via relativistic jets and radiation-driven winds. This so-called 'feedback' can result in the ejection of significant quantities of gas from the host galaxy, affecting subsequent galaxy formation which ultimately impact the distribution of matter on large scales.

Models of galaxy formation and large-scale structure tests of the standard model of cosmology therefore need to carefully assess the role of energetic feedback from supermassive black holes: this is the main aim of this PhD project.

For this research, we will first use weak gravitational lensing data (from the Dark Energy Survey (Sevilla-Noarbe et al., 2021)) and data that maps the hot ionised gas component (from cosmic microwave background (CMB) surveys, including the Planck (Planck Collaboration et al., 2013), SPT (Bleem et al., 2022), and ACT (Hand et al., 2012) facilities) to directly measure the impact of supermassive black holes on galaxies over a wide range of redshifts and mass scales. We will then compare these measurements to state-of-the-art cosmological hydrodynamical simulations from the FLAMINGO and BAHAMAS projects (developed in collaboration with the Virgo Consortium).

Finally, we will perform an assessment of the realism of black hole feedback in current simulations along with its impact on galaxy formation and cosmology.