A Non-Parametric Estimate of Mass 'Scoured' in Galaxy Cores
  We present a simple estimate of the mass 'deficits' in cored spheroids, as a
function of galaxy mass and radius within the galaxy. Previous attempts to
measure such deficits depended on fitting some functional form to the profile
at large radii and extrapolating inwards; this is sensitive to the assumed
functional form and does not allow for variation in nuclear profile shapes. We
take advantage of larger data sets to directly construct stellar mass profiles
of observed systems and measure the stellar mass enclosed in a series of
physical radii (M(<R)), for samples of cusp and core spheroids at the same
stellar mass. There is a significant bimodality in this distribution at small
radii, and we non-parametrically measure the median offset between core and
cusp populations (the deficit Delta_M(<R)). We construct the scoured mass
profile as a function of radius, without reference to any assumed functional
form. The mass deficit rises in power-law fashion (Delta_M(<R) R^{1.3-1.8})
from a significant but small mass at R<10pc, to asymptote to a maximum ~0.5-2
M_BH at ~100pc. At larger radii there is no statistically significant
separation between populations; the upper limit to the cumulative scoured mass
at ~kpc is ~2-4 M_BH. This does not depend strongly on stellar mass. The
dispersion in M(<R) appears larger in the core population, possibly reflecting
the fact that scouring increases the scatter in profile shapes. These results
are in good agreement with models of scouring from BH binary systems.
