The σ-diameters relationship of clumps in high-redshift galaxies and in H II regions in nearby galaxies (upper panel). The position of the clumps selected on the A2 2D spectrum of the 8 o’clock arc (bottom left) and on the A3 2D spectrum of the SMILE arc (bottom right) fall on the relation obtained by Wisnioski et al. (2012; solid black line in the upper panel), but covers a range of clump sizes and velocity dispersion smaller than those reported in other high-redshift surveys and close to those followed by giant H II regions in the local Universe. Uncertainties for the velocity dispersion are overplotted denoting the Gaussian fit error in combination with the spectral resolution of the observation, i.e. 20 km s⁻¹.