Top panel: physical model of CrA 151 obtained from the Herschel data. The green curve (left y-axis) shows the total volume density n(H₂), whilst the red curve (right y-axis) shows the dust temperature. The bumps in both profiles are due to a double Plummer-like structure. Bottom panel: velocity profile used for the MCMC modelling. In both panels, the vertical dashed and solid lines show the minimum and maximum resolution of the observations, from 13^′′(N₂H⁺ 5 − 4) to 37^′′ (Herschel data).