MCMC posterior distribution of the single particle laminar model (lami-1p). The 16%, 50%, and 84% confidence levels are indicated above each histogram. The runs cluster around the line of constant τ_sσ³, which indicates a mass scale above which pebble accretion operates (panel b). High-velocity solutions, as in a smooth disk (σ = η_irr), have difficulty fitting the data (panel a). The mass of the accreted pebbles is lower than the mass of the initial popluation by around 0.4 dex (panel n).