A_FUV − M_star diagram at z ∼ 4.5 (left) and z ∼ 5.5 (right). The gray areas correspond to the expected relation at z = 4.5 and 5.5 from Bogdanoska & Burgarella (2020). This relation was formed by a broken line, which is flat at log₁₀M_star ≤ 9.8 and rises at log₁₀ (M_star) > 9.8. The ALPINE data are very dispersed at z ∼ 4.5, while this flatness is supported by the data at z ∼ 5.5. The conversion from IRX to A_FUV is from Burgarella et al. (2005): A_FUV = −0.028[log₁₀ (IRX)]³ + 0.392 [log₁₀ (IRX)]² + 1.094 [log₁₀ (IRX)] + 0.5.