Comparisons of the effective radii of the [C II] line and the continuum emission. (Left) Effective radius of [C II] line emission compared to the rest-frame UV continuum emission (HST/WFC3 F160W). Symbols are the same as in Figure 4. The dashed black line indicates the one-to-one relation between R_e, [CII] and R_e, UV, and three dashed gray lines above this line represent R_e, [CII]/R_e, UV = 2,  4,  8. (Right) Same as the left panel, but [C II] line radius is compared to the rest-frame FIR emission, measured from the ALMA Band-7 continuum images (Mitsuhashi et al. 2024). On average, the [C II] sizes are larger than the rest-frame UV sizes by a factor of 2.90; compared to the rest-frame FIR sizes, they tend to be larger by a factor of 1.54 although with large uncertainties.