Stellar and Black Hole Mass Densities as Empirical Tracers of Co-Evolution Show Lock-Step Growth Since Z ∼ 3

Abstract

At redshifts beyondz 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 sincez 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 ofz 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 toz 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.

Linking black hole growth with host galaxies: the accretion–stellar mass relation and its cosmic evolution

“…At z 0.8, the BHAR/SFR does not have strong redshift dependence at a given M . The weak redshift dependence of the M BH -M relation is consistent with the observations of Schindler et al (2016) which show that the ratio between SMBH and stellar mass densities is flat as a function of redshift since z ≈ 5. Based on observations of BL AGNs, Sun et al (2015) also found a redshift-independent M BH -M relation (but also see Merloni et al 2010).…”

Dark-ages reionization and galaxy formation simulation – XVIII. The high-redshift evolution of black holes and their host galaxies

“…DeGraf et al (2015, on the other hand, found that the relation evolves slightly for z ≥ 1 for the highest mass black holes, with a steeper slope at the high-mass end at higher redshifts, making selection effects important. The more statistical study of Schindler et al (2016) found that the ratio of the black hole to stellar mass density is constant within the uncertainties from z = 0 to 5, with a slight decrease in the ratio at 3 ≤ z ≤ 5; this is also consistent with no cosmological evolution in the M BH -M * relation.…”

Recoiling supermassive black hole escape velocities from dark matter haloes

“…SMBH masses correlate with host galaxy properties such as velocity dispersion, luminosity, and bulge mass (Häring & Rix 2004;Heckman & Kauffmann 2011;McConnell & Ma 2013). Additionally, as far as z = 6 there is strong similarity between both the cosmic star formation rate and total AGN luminosity and the black hole and stellar mass densities (Madau & Dickinson 2014;Schindler et al 2016). Many authors interpret these correlations as evidence for the coevolution of SMBHs and their hosts.…”