  New measurements of the stellar-mass deficits at the centers of luminous
elliptical galaxies are presented. These were derived considering the following
observational facts. Firstly, ``core'' galaxies, which are thought to have had
their inner region depleted from the coalesence of supermassive black holes,
show an abrupt downward deviation of their inner light-profile relative to
their outer Sersic profile. Second, ``power-law'' galaxies, having undisturbed
profiles and no partially depleted core, have inner light-profiles that display
no departure from the inward extrapolation of their outer Sersic profile. The
central stellar deficits have therefore been derived from the difference in
flux between the HST-observed galaxy light-profiles and the inward
extrapolation of each galaxy's outer Sersic profile. This approach gives flux
deficits ~0.1% of the total galaxy light, and mass deficits that are ~2 times
each galaxy's central supermassive black hole mass. These results are in
agreement with the theoretical expectations of mass ejection from binary black
hole mergers and also with popular LCDM models of hierarchical galaxy
formation. It is also explained why this result is some 10 times smaller than
current observational estimates of the central mass deficit, and therefore
implies a merger history for giant elliptical galaxies that is one order of
magnitude less violent than previously suggested.
