Star-forming [O/Fe] versus sSFR relation for simulated galaxies from the EAGLE cosmological simulations (turquoise contours) and TNG 100 cosmological simulations (brown contours). The contours enclose 50, 68, and 95 % of all central galaxies with log₁₀(M_*/M_⊙) = 9–10.5 at redshifts between 0 and 8. The solid turquoise line shows the fit to the relation in EAGLE from Matthee & Schaye (2018), while the dashed brown line shows our fit to the relation in TNG 100. The black dotted line shows the relation obtained by Kashino et al. (2022) for MS galaxies modeled within the gas-regulator framework.