Position-velocity diagrams derived for the cuts along the observed velocity gradient in Fig. 13. The offset refers to the distance along the cut from the dust continuum peak. The contour levels are from 3σ in steps of 1σ in both panels (1σ = 60 mJy beam^-1). The full line in the C¹⁸O panel shows a Keplerian rotation curve with a central mass of 28 M_⊙, which is the mass of the whole continuum structure in S255IR. The negative features are shown by dashed lines.