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

Abstract

Correlations between black holes and their host galaxies provide insight into what drives black hole-host co-evolution. We use the Meraxes semi-analytic model to investigate the growth of black holes and their host galaxies from high redshift to the present day. Our modelling finds no significant evolution in the black hole-bulge and black hole-total stellar mass relations out to a redshift of 8. The black hole-total stellar mass relation has similar but slightly larger scatter than the black hole-bulge relation, with the scatter in both decreasing with increasing redshift. In our modelling the growth of galaxies, bulges and black holes are all tightly related, even at the highest redshifts. We find that black hole growth is dominated by instability-driven or secular quasar-mode growth and not by merger-driven growth at all redshifts. Our model also predicts that disc-dominated galaxies lie on the black hole-total stellar mass relation, but lie offset from the black hole-bulge mass relation, in agreement with recent observations and hydrodynamical simulations.

Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). XII. Extended [C ii] Structure (Merger or Outflow) in a z = 6.72 Red Quasar

“…Indeed, some works have found companions (e.g., Decarli et al 2017;Trakhtenbrot et al 2017;Willott et al 2017;Neeleman et al 2019), or very close, likely merging galaxies (Bañados et al 2019;Decarli et al 2019;Venemans et al 2019), to optically luminous (M 1450  −26 mag) quasars, which would support the triggering of quasars by gas-rich major mergers. In contrast to this, no overdensity of submillimeter continuum emitters has been reported for the case of optically less luminous (M 1450  −25 mag) quasars (Izumi et al 2019), implying that rather secular processes (e.g., Shirakata et al 2019;Marshall et al 2020) may also be capable of triggering z  6 quasars.…”

A Physical Model for the Quasar Luminosity Function Evolution between Cosmic Dawn and High Noon

“…In fact, the SMBH -host galaxy mass relation is broadly expected to follow the evolution in L c (M h ) since neither the stellar efficiency parameter (Behroozi et al 2012) or the Eddington ratio distribution (Kollmeier et al 2006) show strong evidence of redshift evolution up to z ∼ 4. Both observations (Decarli et al 2010) and simulations (Volonteri et al 2016;Marshall et al 2020) support only a mild evolution in the SMBH -host galaxy mass relation. However, our modeling finds that any evolution can be largely suppressed by assuming a lower intrinsic duty cycle ε DC ≤ 0.1, which yields a lower k. On the other hand, assuming k << 1 also leads to difficulties in reproducing the observed QLF at z = 1 under fiducial model assumptions, due to an over-representation of fainter quasars.…”

“…Since the only redshift dependent terms in Equation 3 are the HMF and the halo assembly times, our model therefore suggests that the evolution of the overall quasar density is driven by the HMF, with some possible contribution from R A (M h ) and its associated power index k, depending on ε DC . One interpretation for R A (M h ) is to associate this quantity as a proxy for the contribution of merger-driven growth to the SMBH, which can be expected to account for some part in the SMBH growth history (Marshall et al 2020). We see in Equation 5 that the effect of R A (M h ) is to provide a boost in L c (M h ).…”

“…a description of the quasar population, can yield information on the joint evolution of black holes, galaxies and their halos. Indeed, the QLF has been utilised in numerous studies to inform and constrain both models of black hole growth (Hirschmann et al 2014;Sijacki et al 2015) and galaxy formation (Qin et al 2017;Marshall et al 2020). Observations of the QLF have been enabled by large wide-area surveys across visible and infrared wavelengths, such as the Sloan Digital Sky Survey (SDSS; York et al 2000), the VISTA Kilo-degree Infrared Galaxy Survey (VIKINGS; Peth et al 2011), and the Panoramic Survey Telescope and Rapid Response System 1 (Pan-STARRS1; Morganson et al 2012).…”

It is feasible to directly measure black hole masses in the first galaxies

“…Vertical dashed lines in each panel indicate R inf , the radius of influence at which influence on the circular velocity profiles of galaxies at high redshift. A couple of caveats to this conclusion, however, are worth noting: it has been pointed out in the literature that the evolution in the black hole -bulge mass relation may be a selection effect [e.g., [18][19][20][21], whereas some simulation papers do not find much evolution [e.g., [22][23][24]. In the following section, we quantify the magnitude of this effect and its observational consequences for current and future generation experiments.…”