A geostatistical analysis of multiscale metallicity variations in galaxies – II. Predicting the metallicities of H <scp>ii</scp> and diffuse ionized gas regions via universal kriging

ABSTRACT The metallicity of diffuse ionized gas (DIG) cannot be determined using strong emission line diagnostics, which are calibrated to calculate the H ii regions. Because this, resolved maps from integral field spectroscopy (IFS) data remain largely incomplete. In this paper (the second a series), we introduce geostatistical technique universal kriging, allows complete 2D distribution galaxy reconstructed metallicities measured at regions, accounting for spatial correlations between nearby points. We apply method construct high-fidelity local spiral NGC 5236 TYPHOON/PrISM survey. find significant correlation in regions separated by up 0.4–1.2 kpc. Predictions constructed were tested cross-validation and show that they outperform significantly interpolation based on gradients. Furthermore, kriging predict dominated DIG emission, considering seven additional galaxies with high resolution (≲100 pc) maps. compare computed novel ionization corrections, such corrections systematic offset ±0.1 dex any individual galaxy, scatter 0.02–0.07 sample. Overall recommend together model, as superior inferring DIG-dominated galaxies, demonstrating further potential applying methods spatially observations.