2021MNRAS.507.4274M

We study the relations between the mass of the central black hole (BH) M_BH, the dark matter halo mass M_h, and the stellar-to-halo mass fraction f_*∝M_*/M_h in a sample of 55 nearby galaxies with dynamically measured M_ BH_> 10⁶ M_☉ and M_ h_> 5×10¹¹ M_☉. The main improvement with respect to previous studies is that we consider both early- and late-type systems for which M_h is determined either from globular cluster dynamics or from spatially resolved rotation curves. Independently of their structural properties, galaxies in our sample build a well defined sequence in the M_BH-M_h-f_* space. We find that: (i) M_h and M_BH strongly correlate with each other and anticorrelate with f_*; (ii) there is a break in the slope of the M_BH-M_h relation at M_h of 10¹² M_☉, and in the f_*-M_BH relation at M_BH of ∼10⁷-10⁸ M_☉; (iii) at a fixed M_BH, galaxies with a larger f_* tend to occupy lighter haloes and to have later morphological types. We show that the observed trends can be reproduced by a simple equilibrium model in the ΛCDM framework where galaxies smoothly accrete dark and baryonic matter at a cosmological rate, having their stellar and BH build-up regulated both by the cooling of the available gas reservoir and by the negative feedback from star formation and active galactic nuclei (AGNs). Feature (ii) arises as the BH population transits from a rapidly accreting phase to a more gentle and self-regulated growth, while scatter in the AGN feedback efficiency can account for feature (iii).