Résumé
Star-forming galaxies (SFGs) are unique gamma-ray emitters. The observed correlation between their non-thermal luminosity and their star-formation rate (SFR) strongly suggests that these gamma rays result from the interactions of cosmic rays (CRs) injected by phenomena connected with the SFR, such as supernova remnants and massive star winds. These correlations provide insight into how global the physical properties of galaxies like magnetic, velocity or density fields scale with the SFR, which is also a key to understanding the origin of this field.Here we investigate the effect of gamma-ray absorption processes and cosmic-ray transport footprints in SFGs at very high energies (VHE) in terms of the luminosity--SFR correlations.With this purpose we extend an existing model that reproduces the non-thermal emission in SFGs from radio to GeV, by including gamma-gamma absorption process.We build the correlation between the integrated luminosity in the upcoming Cherenkov Telescope Array (CTA) energy range and explore how proton maximum energy and the absorption inside galaxies and en route to Earth impact this correlation.