Comparison of $r_{90,[\mathrm{C}\mathrm{I}\mathrm{I}]}$ and r_90,  SFR for simulated galaxies at redshifts z = 5 (left) and 4 (right). The galaxies are colour-coded by their multicomponent extent parameter ℰ defined as the ratio of the r₉₀ and r₇₀ values of the [C II] surface brightness profile. The shape of the symbol reflects the 𝒮 parameter that quantifies the satellite contribution to the total [C II] emission (see text for details). We use ‘low 𝒮’ and ‘high 𝒮’, respectively to denote galaxies with < 10% and ≥10% satellite contribution. The $r_{90,[\mathrm{C}\mathrm{I}\mathrm{I}]}$ versus r_90,  SFR values of observed galaxies are shown as red open circles (Fujimoto et al. 2020), a yellow plus (Lambert et al. 2023), a green pentagon (Herrera-Camus et al. 2021), and a blue diamond (Posses et al. 2024). The black dashed line indicates a 1:1 relation, while the top and bottom grey dashed lines indicate 2:1 and 1:2 relations, respectively. Note that the error bars are not shown for Fujimoto et al. (2020) galaxies for the sake of clarity.