Relative growth of black holes and the stellar components of galaxies

Abstract

Recent observations indicate that the mass of supermassive black holes (SMBHs) correlate differently with different galaxy stellar components. Comparing such observations with the results of "ab initio" galaxy formation models can provide insight on the mechanisms leading to the growth of SMBHs. Here we use a state-of-the-art semi-analytic model of galaxy formation to investigate the correlation of the different galaxy stellar components with the mass of the central SMBH. The stellar mass in the disc, in the bulge, and in the pseudo-bulge of galaxies is related to quiescent star formation, to galaxy interactions, and to the loss of angular momentum following disc instabilities, respectively. Consistently with recent findings, we find that while the predicted bulge masses are tightly correlated with the SMBH masses, the correlation between the latter and the galactic discs shows a much larger scatter, in particular when bulgeless galaxies are considered. In addition, we obtain that the predicted masses of pseudo-bulges shows little or no-correlation with the masses of SMBHs. We track the histories of merging, star formation, and SMBH accretion to investigate the physical processes at the origin of such findings within the context of cosmological models of galaxy formation. Finally, we discuss the effects of variations of our assumed fiducial model on the results.

A local baseline of the black hole mass scaling relations for active galaxies. IV. Correlations between $M_{\rm BH}$ and host galaxy $σ$, stellar mass, and luminosity

“…For none of the scaling relations do we find a significant difference between pseudo-and classical bulges in terms of correlations with M BH . This is in line with some studies (e.g., Davis et al 2018), but contrary to many others (e.g., Hu 2008;Greene et al 2010;Sani et al 2011;Läsker et al 2016;Saglia et al 2016;Menci et al 2016;de Nicola et al 2019). For example, Kormendy & Ho (2013) went so far to conclude that "any M BH correlations with the properties of diskgrown pseudobulges [...] are weak enough to imply no close coevolution" (see also, Kormendy et al 2011).…”

“…Secular evolution may have a synchronizing effect, growing BHs and bulges simultaneously at a small but steady rate for late-type galaxies, and keeping them on tight relations over time. Comparison with semi-analytical models for galaxy formation including secular evolution (such as e.g., Menci et al 2016, who, however, find little or no correlation of pseudo-bulge mass with M BH ) can further shed light on such a scenario, but is beyond the scope of this paper.…”

Testing the fidelity of simulations of black hole - galaxy co-evolution at z ~ 1.5 with observations

“…While high-resolution Nbody simulations can describe specific galaxy systems, an understanding of the physical mechanisms influencing the scaling relations require an analytical description of such processes to be implemented into existing semianalytic models including the SAM. In previous works, MBII (Huang et al 2018;DeGraf et al 2015;Khandai et al 2015a;Bhowmick et al 2019) and SAM (Menci et al 2014(Menci et al , 2016 have made highly successful predictions. In the following two sections, we present detailed information on the two simulation projects.…”

“…Several other works have investigated scaling relations using large-volume simulations, resulting in good agreement with the local relation and some redshift evolution, including the Magneticum Pathfinder SPH Simulations (Steinborn et al 2015), the Evolution and Assembly of GaLaxies and their Environments (EAGLE) suite of SPH simulations (Schaye et al 2015), Illustris moving mesh simulation (Sijacki et al 2015;Vogelsberger et al 2014;Li et al 2019) and SIMBA simulation (Thomas et al 2019). Besides hydrodynamic simulations, semi-analytic models (e.g., Menci et al 2014Menci et al , 2016 have also made remarkable progress and recovered the local scaling relations (Kormendy & Ho 2013). These comparisons between simulations and the observed scaling relations, based on high-resolution HST imaging, have been carried out mainly at z < 1 due to prior limitations of the availability of observational data.…”

“…In this scenario, AGN activity heats and unbinds a significant fraction of the gas and inhibits star formation. An alternative and more indirect connection is one where AGN accretion and star formation are fed through a common gas supply (Cen 2015;Menci et al 2016). A completely different view holds that the statistical convergence from galaxy assembly alone (i.e., dry mergers) may reproduce the observed correlations without any direct physical mechanisms (Peng 2007;Jahnke & Macciò 2011;Hirschmann et al 2010).…”