Vertical density profiles in the vortices (r/r₀ = 3) after 3 rotations for three different population of dust: , 0.01 and for the gas in each of theses cases. As the ranges of density vary a lot between populations, different colour tables are used to avoid misunderstandings. The position of the vortices is not the same in the 5 cm grain simulation due to the back reaction of the dust on the gas as explained in Sect. 4.4. A colour version of this figure is accessible in the electronic version of this paper.