On the Black Hole Mass-Bulge Mass Relation

We have reexamined the relation between the mass of the central black holes in nearby galaxies, Mbh, and the stellar mass of the surrounding spheroid or bulge, Mbulge. For a total of 30 galaxies bulge masses were derived through Jeans equation modeling or adopted from dynamical models in the literature. In stellar mass-to-light ratios, the spheroids and bulges span a range of a factor of 8. The bulge masses were related to well-determined black hole masses taken from the literature. With these improved values for Mbh, compared to Magorrian et al., and our redetermination of Mbulge, we find that the Mbh-Mbulge relation becomes very tight. We find Mbh ~ M with an observed scatter of ≲0.30 dex, a fraction of…