Local galaxies scaling relations

We also test different models and priors. We estimate light-weighted mean stellar ages for 354977 galaxies (SNR>=10) and metallicities for 89,852 galaxies (SNR>=20) and study their dependence on stellar mass. Key findings include: i) A revised bimodal distribution in the mass-age plane, with a young sequence (dominant at low masses) and an old sequence (dominant at high masses), partly overlapping in mass and transitioning at M_tr_=10^10.80^M_{sun}_. ii) A Mass-Metallicity Relation (MZR) shifted ~0.2dex higher than previous studies.

Our aperture corrections produce mass-dependent reductions in masses, ages, and metallicities, enhancing the young sequence and steepening the MZR at low masses. iii) Using Halpha-based SFR classification, we found that while star-forming/young and quiescent/old correspondences generally hold, exceptions exist for many galaxies. Quiescent galaxies show flatter, less scattered MZR than star-forming ones, converging at high masses. iv) Different SPS modelling assumptions significantly impact results, with star formation and chemical enrichment histories having the strongest effects.

These revised relations provide new benchmarks for galaxy evolution studies and simulations. Systematic effects of 0.1-0.2dex can arise from uncorrected aperture biases and different SPS modelling choices. Consistent assumptions should be used when comparing observations and models.