The Timing Revolution of Accreting Black Holes

Accreting black holes are unique sources of some of the most extreme physics in the universe. These objects also have a profound effect on their galactic environments and play a vital role in shaping the cosmos from its origins to how it appears today. When matter approaches a black hole in an ‘active galaxy’, energy is released from the conversion of gravitational potential energy. The radiation emitted by this material before it plunges through the event horizon provides a unique probe of the strongly distorted spacetime. The energetic processes involved in the accretion of matter also produce powerful outflows in the form of winds and jets. These play a powerful role in regulating the growth and evolution of the host galaxy over cosmic time. The accretion and subsequent ejection of matter onto black holes is not a static process, so the application of ‘time-series analysis’ methods provides important insight that spectra or spatial information cannot achieve alone. To answer these important questions, I am leading key areas in the development and application of novel time-series analysis methods to astronomical data. This program will enable us to make crucial progress in answering key contemporary astrophysics questions. In part 1 we will develop the most up-to-date models for spatially echo-mapping the inner regions of black holes, providing a database of independent measurements of mass and spin. These measurements from local galaxies will be used as a calibrator for other methods as well as preparing for when future missions allow us to perform this test at higher redshifts. This modelling will also reveal the physical process involved in accretion and launching of outflows as a function mass accretion rate. In part 2 we will perform deep analysis and modelling of a unique active galaxy which shows a periodic modulation of X-rays coming from immediately outside the event horizon. This serves as unique probe of the strongly distorted spacetime, allowing us to perform new tests of general relativity (GR) in the strongest limit. This work couples the accretion history of the universe with the black hole merger population seen through gravitational wave events.