A deep X-ray view of the bare nucleus Seyfert Ark120: unveiling the core of AGN

International audienceThe physical characteristics of the matter around supermassive black hole (SMBH) are currently determined thanks to X-ray observations. However, the origins of the main X-ray spectral components such as the soft X-ray excess, the FeK line complex and the hard X-ray excess are still hotly debated. This is difficult to investigate in AGN which show a significant warm absorber that severely distort the continuum. Therefore, AGN which show no (or very weak) warm absorption on the line-of-sight, so-called "bare AGN'' are the best targets to probe the processes at work very close to the SMBH. We will present the first results from an extensive observation campaign (XMM-Newton Large Program, Chandra/HETG, NuSTAR) of Ark120 that is the brightest and cleanest bare AGN known so far. We will focus on the analysis of the deep RGS spectrum, as well as on the X-ray broad band spectrum