By Yerong Xu

We perform flux-resolved X-ray spectroscopy on a narrow-line Seyfert 1 AGN 1H 0707-495, using all archival XMM-Newton EPIC and RGS data to study the structure of the ultra-fast outflow (UFO). The most important discovery is that UFO velocity decreases with the source X-ray luminosity, explained by the scenario where the strong radiation field extends the launching radius outwards.

Simulations with an exposure of 10 ks show that Athena/X-IFU can provide seven times better statistics with one order of magnitude shorter exposure time than XMM-Newton. To obtain a similar significance of the UFO detection in XMM-Newton, Athena only needs 1 ks exposure time. Athena will enable investigation of the UFO within the variability timescales, which is necessary to understand their response and origin.

Access to the manuscript in ADS.