Key points are not available for this paper at this time.
The masses of supermassive black holes correlate almost perfectly with the velocity dispersions of their host bulges, M (BH) ~ sigmaᵃlpha, where alpha =4. 8 +/- 0. 5. The relation is much tighter than the relation between M (BH) and bulge luminosity, with a scatter no larger than expected on the basis of measurement error alone. Black hole masses estimated by Magorrian et al. (1998) lie systematically above the M (BH) -sigma relation defined by more accurate mass estimates, some by as much as two orders of magnitude. The tightness of the M (BH) -sigma relation implies a strong link between black hole formation and the properties of the stellar bulge.
Ferrarese et al. (Thu,) studied this question.