Supermassive Black Hole Binaries as Galactic Blenders

This paper focuses on the dynamical implications of close supermassive blackhole binaries both as an example of resonant phase mixing and as a potentialexplanation of inversions and other anomalous features observed in theluminosity profiles of some elliptical galaxies. The presence of a binarycomprised of black holes executing nearly periodic orbits leads to thepossibility of a broad resonant coupling between the black holes and variousstars in the galaxy. This can result in efficient chaotic phase mixing and, inmany cases, systematic increases in the energies of stars and their consequenttransport towards larger radii. Allowing for the presence of a supermassiveblack hole binary with plausible parameter values near the center of aspherical, or nearly spherical, galaxy characterised initially by a Nukerdensity profile enables one to reproduce in considerable detail the centralsurface brightness distributions of such galaxies as NGC 3706.Comment: 14 pages plus 15 figures, revised and condensed version to appear in Astrophysical Journa