  We present the first comprehensive analysis of the AU Mic debris disk
properties since the system was discovered by Kalas et al. (2004), and we
explore whether the dynamical model, successful to reproduce the Beta Pic
brightness profile could apply to AU Mic. We calculate the surface density
profile of the AU Mic disk by performing the inversion of the near-IR and
visible scattered light brightness profiles measured by Liu (2004a) and Krist
et al. (2005), respectively. We discuss the grain properties by analysing the
blue color of the disk in the visible (Krist et al. 2005) and by fitting the
disk spectral energy distribution. We show that irrespective of the mean
scattering asymmetry factor of the grains, most of the emission arises from an
asymmetric, collisionally-dominated region that peaks close to the surface
brightness break around 35 AU. The elementary scatterers at visible wavelengths
are found to be sub-micronic, but the inferred size distribution underestimates
the amount of large grains, resulting in too low sub-millimeter emissions
compared to the observations. From our inversion procedure, we find that the V-
to H-band scattering cross sections ratio increases outside 40 AU, in line with
the observed color gradient of the disk. We show that a standard, solar-like
stellar wind generates a pressure force onto the dust particles that behaves
much like a radiation pressure force. With an assumed Mdot ~ 300 Mdot_sun, the
wind pressure overcomes the radiation pressure and this effect is enhanced by
the stellar flares. This explains the similarity between the Beta Pic and AU
Mic brightness profiles. In both cases, the color gradient beyond 120 AU for
Beta Pic and 35 AU for AU Mic, is believed to be a direct consequence of the
dust dynamics.
