STELLAR and BLACK HOLE MASS DENSITIES AS EMPIRICAL TRACERS of CO-EVOLUTION SHOW LOCK-STEP GROWTH since Z ∼ 3

At redshifts beyond z ∼ 1, measuring the black hole (BH) galaxy relations proves to be a difficult task. The bright light of the active galactic nuclei aggravates the deconvolution of BH and galaxy properties. However, highredshift data on these relations are vital to understand the ways in which galaxies and BHs co-evolve and the ways in which they do not. In this work we use BH and stellar mass densities (BHMDs and SMDs) to constrain the possible co-evolution of BHs with their host galaxies since z ∼ 5. The BHMDs are calculated from quasar luminosity functions using the Soltan argument, while we use integrals over stellar mass functions or the starformation rate density to obtain values for the SMD. We find that both quantities grow in lock-step below redshifts of z ∼ 3 with a non-evolving BHMD to SMD ratio. A fit to the data assuming a power-law relation between the BHMD and the SMD yields exponents around unity (1.0-1.5). Up to z ∼ 5 the BHMD to SMD ratio does not show a strong evolution given the larger uncertainty in the completeness of high-redshift data sets. Our results, always applying the same analysis technique, seem to be consistent across all adopted data sets.