Upper row: Relation between beam (blue circles) and global (red dots) α_CO(1–0) measurements on gas-phase metallicity (12+log(O/H), left panel) and stellar mass surface density (Σ_* right panel) calculated within the same regions. Bottom row: Distributions of metallicity and stellar mass surface density. The histograms show median metallicity and integrated Σ_* calculated across the full maps (global, empty black histograms) and tapered maps (beam, grey histograms). The red (blue) dashed lines indicate the median of the global (beam) quantities, while the green dash-dotted line (left panel) shows the solar metallicity (8.69 by Allende Prieto et al. 2001).