The Hot and Energetic Universe: The close environments of supermassive black holes

Understand

Most of the action in Active Galactic Nuclei (AGN) occurs within a few tens of gravitational radii from the supermassive black hole, where matter in the accretion disk may lose up to almost half of its energy with a copious production of X-rays, emitted via Comptonization of the disk photons by hot electrons in a corona and partly reflected by the accretion disk.

• Thanks to its large effective area and excellent energy resolution, Athena+ contributions in the understanding of the physics of accretion in AGN will be fundamental - and unique - in many respects.
• It will allow us to map the disk-corona system - which is crucial to understand the mechanism of energy extraction and the relation of the corona with winds and jets - by studying the time lags between reflected and primary photons.
• These lags have been recently discovered by XMM-Newton, but only Athena+ will have the sensitivity required to fully exploit this technique.