Powerful Radio Galaxies with Simbol‐X: the Nuclear Environment

Fanaroff & Riley type II radio galaxies (FRII) are complex objects. In particular FRII Narrow Line Radio Galaxies (NLRG), optically classified as High Excitation Galaxies (HEG) show X‐ray spectra very similar to their radio‐quiet counterparts, the Seyfert 2 galaxies. They show 2–10 keV continua heavily obscured $(NH∼1023–24 cm−2)$ and intense $FeKα$ lines, typical cold matter reprocessing features. Moreover recent Chandra and XMM‐Newton observations suggest that the soft X‐ray emission of HEG and Seyfert 2 have a common origin from photoionized gas, reinforcing the idea that not only their nuclear engine but also the circumnuclear gas (at least the warm phase) are similar. On the contrary, our knowledge of NLRG HEG above 10 keV is very poor when compared to brighter Seyfert 2. As a consequence, the physical properties of the cold phase of the circumnuclear gas (possibly linked to a dusty torus) are largely unknown. Thanks to its high sensitivity up to 80 keV, Simbol‐X will provide very accurate spectra and will allow a direct comparison between the NLRG and Seyfert 2 cold environments.