Informazioni sull’evento

02/09/2018

Joint Astrophysical Colloquium

What drives the non-linear growth of supermassive black holes in galaxies?

Ivan Delvecchio (CEA-Saclay, Department of Astrophysics - Paris (France))

Thursday 07/05/2020 @ 11:30, Google Hangouts Meet

Supermassive black holes (SMBHs) are tightly correlated with their hosts, but the origin of such connection remains elusive. However, recent observations are providing first quantitative constraints on the "typical" SMBH accretion rate in low- and high-mass galaxies and at different cosmic epochs. Based on these studies, we built an empirically-motivated model that tracks galaxy and SMBH growth since z~10 down to z=0. An intriguing result of our modeling is that SMBHs and galaxies do not seem to evolve in lockstep at all times, contrary to the common idea of co-evolution. Nevertheless, this study is well supported by recent observations and simulations. Moreover, our modeling naturally explains the anti-hierarchical behaviour of galaxy and SMBHs, the dearth of BHs in low-mass galaxies and the assembly of local scaling relations at z~0. We speculate that the observed non-linear BH-galaxy buildup is reflected in a twofold behavior with dark matter halo mass (M_DM), displaying a clear turnover at M_DM ~ 2*10^12 Msun. While supernovae-driven feedback suppresses BH growth in smaller halos, above that M_DM threshold cold gas inflows might provide the fuel to sustain both BH accretion and star formation in a similar fashion.

Scarica le slides (pdf)