Distant monsters: high redshift AGN predictions from a $\Lambda$CDM cosmological model

The next decade promises to revolutionise the study of the high redshift Universe: upcoming missions such as JWST, EUCLID and ATHENA will greatly advance our understanding of the early stages of galaxy formation. We use an updated model for the evolution of masses and spins of supermassive black holes (SMBHs), coupled to the latest version of the semi-analytical model of galaxy formation GALFORM using the Planck cosmology, and a new high resolution Millennium style dark matter simulation to make predictions for multiwavelength Active Galactic Nuclei (AGN) luminosity functions in the redshift range $0 6$ in the broadband filters of JWST, EUCLID and ATHENA. We predict that these three surveys will select three somewhat different samples of SMBHs, with EUCLID unveiling the more massive, high accretion rate SMBHs, JWST the less massive, lower accretion rate SMBHs and ATHENA covering objects inbetween. Overall, typical detected SMBHs will have masses, $M_{\mathrm{BH}} \sim 10^{6-7} M_{\odot}$, with dimensionless mass accretion rates, $\dot{M}/\dot{M}_{\mathrm{Edd}} \sim 1-10$, in host galaxies of stellar mass, $M_{\star} \sim 10^{8-9} M_{\odot}$. The future comparison of these predictions to observations will provide insights into our understanding of SMBHs in galaxy formation.