Into the Heart of the AGN IRAS 13224-3809

September 3, 2020 Prof. Andrew Fabian, Institute of Astronomy, Cambridge CfA Colloquium Abstract: The redshift 0.06 narrow-line Seyfert 1 galaxy IRAS13224 probably has the highest level of persistent variability yet seen, with an X-ray flux varying by a factor ranging up to 100. Following a long campaign of XMM observations in 2016, the total exposure is now about 2 Ms. Strong X-ray reflection signatures are observed in its spectrum, enabling us to use both reflection and reverberation techniques to determine that the mass and spin of the black hole are 2±0.2 Million Msun and more than 0.98, respectively. The height of the illuminating lamppost corona varies between 5 and 12 gravitational radii above the black hole. Deep, 0.24c blueshifted, iron K absorption is seen when the flux is low, suggesting either an ultrafast outflow or a thin, lower density, absorbing layer over the inner parts of the accretion disc, which is viewed at an inclination of 70 deg. New reflection models that yield the disc surface density will also be presented and discussed. They confirm the low coronal height when combined with the observed ionization parameter in a disc illumination model that includes the expected (large) effects of strong light bending and energy shifts.