Guillaume Drouart

Guillaume Drouart Colloquium - Rapidly growing black holes and host galaxies in the distant Universe

Marsfield Lecture Theatre

Abstract

Powerful high redshift radio galaxies (HzRGs) exihibit strong AGN and star formation activities making them ideal candidates to gain insights in the so called AGN-SF connection. Thanks to the HeRGE project, a comprehensive survey of 70 HzRGs covering the 3-870um range, we are able to disentangle the IR SED into a AGN and a starburst (SB) component. This suggests that the supermassive black holes may be out growing or have outgrown their host galaxies when compare to the local M_BH-M_Gal relation. Extending the SED to the optical for a subsample of 12 HzRGs and making use of a AGN torus model and the PEGASE evolutionary code, we show that three components are necessary to reproduce the observed SED: a AGN, an evolved stellar population and a starburst. If HzRGs have formed the bulk of their stars at very high redshift (evolved component), they are still experiencing intense star forming episodes representing a significant fraction of the total mass of the system.