Vertically integrated dust density distribution after 1 Myr of evolution without radial drift. Case of R_out = 30 AU and v_f = 30 m s^-1 and different values of the gas density slope p = 0 (top panels), p = 0.5 (middle panels) and p = 1.0 (bottom panels); with the turbulence parameter α_turb = 10^-3 (left panels), α_turb = 10^-4 (center panels) and α_turb = 10^-5 (right panels). The solid white line represents the particle size corresponding to St = 1 (Eq. (3)) and reflects the shape of the gas density.