Relativistic spectroscopy of the extreme NLS1 IRAS 13224-3809

The narrow line Seyfert 1 (NLS1) IRAS 13224-3809 is the most X-ray variable active galactic nucleus (AGN), exhibiting 0.3–10 keV flux changes of over an order of magnitude within an hour. We report on the results of the 1.5 Ms 2016 XMM-Newton/NuSTAR observing campaign, which revealed the presence of a 0.24c ultra-fast outflow in addition to the well-known strong relativistic reflection. We also summarise other key results of the campaign, such as the first detection of a non-linear RMS-flux relation in an accreting source, correlations between outflow absorption strength/velocity and source flux, and a disconnect between the X-ray and UV emission. Our results are consistent with a scenario where a disk wind is launched close to the black hole, imprinting absorption features into the spectrum and variability.