Presentation #106.58 in the session “AGN (Poster)”.
Accreting black holes are unique sources of some of the most extreme physics in the universe. They are a testbed for our understanding of general relativity and high-energy physics, and play a vital role in shaping the cosmos from its origins to how it appears today. The accretion process is not static, so the application of time-series analysis methods provides important insight that spectra or spatial information cannot achieve alone. X-ray reverberation echoes are subtle time-delay signatures observed in active galaxies, which allow us to spatially map the unresolved accretion geometry. They provide an independent estimate on black hole mass and spin, as well as revealing the detailed physics involved when matter is accreted. In this talk I will present our recent X-ray reverberation mapping campaign on the highly-variable Seyfert galaxy, IRAS 13224-3809, using the longest XMM-Newton observation to date. This revealed a dynamic corona, turning our static picture of the accretion flow into a movie. I will show how this provides black hole mass estimates with better accuracy than the leading optical based measurements, and discuss the future potential of this technique.