The relation between nuclear obscuration, galaxy interactions and accretion properties of AGN
Abstract
Most of the accretion onto supermassive black holes (SMBHs) happens during a phase in which the AGN is obscured. However, to date it is not clear what is the mechanism regulating the amount of obscuration around supermassive black holes, and how obscuration is related to the host galaxy and to the accretion properties of the SMBH. Our group has carried out the multi-wavelength study of a large sample of local AGN selected in the hard X-ray band (14-195 KeV), where obscuration does not play a strong role. This includes detailed broad-band X-ray spectroscopy for ∼830 sources, and optical and near-IR spectroscopy for ∼640 AGN. This allowed us to measure, for the first time, black hole masses and Eddington ratios of a large number of obscured AGN. In my talk I will show how obscuration is related to the Eddington ratio and black hole mass of the accreting system, and discuss our results in the frame of an evolutionary scenario for the growth of supermassive black holes. I will also discuss some recent results obtained with NuSTAR, showing the relation between galaxy mergers and nuclear obscuration.
- Publication:
-
The X-ray Universe 2017
- Pub Date:
- October 2017
- Bibcode:
- 2017xru..conf..190R