As a major cooling line of the interstellar gas, the far-IR 158 μm line from singly ionised carbon [C II] is an important tracer of various components of the interstellar medium in galaxies across all spatial and morphological scales. Yet, we still do not have a strong constraint on the origins of [C II] emission. In this work, we derive the resolved [C II]-star formation rate relation, and aim to unravel the complexity of the origin of [C II]. We use the Field-Imaging Far-Infrared Line Spectrometer onboard the Stratospheric Observatory for Infrared Astronomy to map [C II] in 3 nearby, star-forming galaxies at sub-kpc scales: NGC 3627, NGC 4321, and NGC 6946, and compare them to the galactic properties derived from complementary data from the literature. We find that the relationship between the [C II] fine structure line and star formation rate shows variations between the galaxies, as well as between different environments within each galaxy. Further studies will require a larger sample and additional observational tracers, obtained on spatial scales within galaxies, to accurately disentangle the origin of [C II] and calibrate its use as a star formation tracer
