2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/13244HST observations show that the surface brightness profiles of early-type galaxies have central cusps. I summarize here the results of van der Marel (1999), which show that the observed characteristics of these cusps are consistent with the hypothesis that all early-type galaxies have central black holes (BHs) that grew adiabatically in homogeneous isothermal cores. The models suggest a roughly linear correlation between BH mass and V-band galaxy luminosity, log M_BH = -1.83 + log L in solar units, similar to the relation suggested by kinematical BH detections in nearby galaxies.4 pages, LaTeX, with 3 PostScript figures. Contributed paper to `Galaxy Dynamics', ASP Conference Series, 1999Astrophysicstext