Relations between Central Black Hole Mass and Total Galaxy Stellar Mass in the Local Universe

International audienceScaling relations between central black hole (BH) mass and host galaxy properties are of fundamental importance to studies of BH and galaxy evolution throughout cosmic time. Here we investigate the relationship between BH mass and host galaxy total stellar mass using a sample of 262 broad-line active galactic nuclei (AGNs) in the nearby universe (z stellar ≲ 109.5 M⊙ and a subsample of the reverberation-mapped AGNs. Total stellar masses of all 341 galaxies are calculated in the most consistent manner feasible using color-dependent mass-to-light ratios. We find a clear correlation between BH mass and total stellar mass for the AGN host galaxies, with MBH ∝ Mstellar, similar to that of early-type galaxies with dynamically detected BHs. However, the relation defined by the AGNs has a normalization that is lower by more than an order of magnitude, with a BH-to-total stellar mass fraction of MBH/Mstellar ∼ 0.025% across the stellar mass range 108 ≤ Mstellar/M⊙ ≤ 1012. This result has significant implications for studies at high redshift and cosmological simulations in which stellar bulges cannot be resolved