  We study the innermost regions of bulges with surface brightness data derived
from combined HST/NICMOS and ground-based NIR profiles. Bulge profiles to 1-2
kpc may be fit with Sersic laws, and show a trend with bulge-to-disk ratio:
low-B/D bulges are roughly exponential, whereas higher-B/D bulges show
increasing Sersic shape index $n$, indicating higher peak central densities and
more extended brightness tails. N-body models of accretion of satellites onto
disk-bulge-halo galaxies show that satellite accretion contributes to the
increase of the shape index $n$ as the bulge grows by accretion. The N-body
results demonstrate that exponential profiles are fragile to merging, hence
bulges with exponential surface brightness profiles cannot have experienced
significant growth by accretion of dense satellites.

Astrophysics