The Self-Similar Secondary Infall Model (SSIM) is modified to simulate a
merger event. The model encompass spherical versions of tidal stripping and
dynamical friction that agrees with the Syer & White merger paradigm's
behaviour. The SSIM shows robustness in absorbing even comparable mass
perturbations and returning to its original state. It suggests the approach to
be invertible and allows to consider accretion as smooth mass inflow merging
and mergers as intermittent mass inflow accretion.Comment: letter accepted by A&A 29/09/08, 4 pages, colour figure