MAUVE–MUSE: When Metallicity Follows or Fights Star Formation—A Mass-Dependent Inversion in Virgo Galaxies

Abstract Although globally-integrated studies often find that, at fixed stellar mass, high star formation rate (SFR) galaxies are relatively metal-poor while lower-SFR systems are more metal-rich, the corresponding coupling between gas-phase metallicity (Zgas) and star formation on sub-galactic scales remains poorly constrained. In this study, we analyse 14 Virgo spiral galaxies from the MAUVE–MUSE survey to revisit the resolved mass–metallicity relation (rMZR) and its secondary dependence on SFR surface density (ΣSFR) at ~100 pc scales. We construct co-spatial maps of stellar mass surface density (Σ*), ΣSFR and gas-phase oxygen abundance. MAUVE–MUSE galaxies follow a standard rMZR, but once binned in Σ*, we find a clear mass-dependent inversion in the Zgas–ΣSFR relation with O3N2-based metallicity calibrations: the commonly reported anti-correlation is confined to low-Σ* bins, whereas high-Σ* regions show a positive correlation, with an inversion point at log10(Σ*/M⊙ kpc−2) ≃ 7.5–8.0. Both correlated and anti-correlated H ii regions can coexist within the same discs, and the observed mass dependence emerges only when grouping H ii spaxels by Σ*. We develop a spatially resolved gas–regulator model and show that the observed correlation and anti-correlation between Zgas and ΣSFR arise from the competition between star-formation-driven and gas-supply-driven variability: the sign of the local Zgas–ΣSFR relation is set by which of these dominates. This framework can be naturally extrapolated to the integrated scenario, providing a unified explanation for both the resolved and global Zgas–SFR relations. However, the presence and strength of the Zgas–ΣSFR (anti-)correlation depend strongly on the metallicity indicator used, highlighting the challenge of disentangling physical secondary trends within metallicity scaling relations.