Hot gas falling on to a supermassive black hole can produce more than enough energy to completely unbind the galaxy in which it resides. Thus only a fraction of this accretion energy needs to couple to large scales in the galaxy in order to affect the galaxy’s evolution and growth through the quenching of star formation. Most of the power output from an Active Galactic Nucleus is released close to the black hole, and therefore studying the inner accretion flow–at the intersection of inflow and outflow–is essential for understanding how black holes grow and how they affect their surrounding environments.

My group studies several aspects of black hole accretion starting from how gas flows towards the black hole via an accretion disc, and how energy is released through electromagnetic radiation and the production of relativistic jets and winds. We use a range of X-ray telescopes to peer into the hearts of quasars and other accreting compact objects.