Galaxies metallicity gradients

We find that the T[OII]~T[SII]~T[OII], as expected since these ions all trace the low-ionization zone of nebulae. The [OIII] temperatures become substantially larger than those of other ions at high metallicity, indicating potentially unaccounted for spectral contamination or additional physics. In light of this uncertainty we base our abundance calculation on the temperatures of [SIII] and the low-ionization ions.

We recover a mass-metallicity relation (MZR) similar to that obtained with different empirical calibrations. We do not find evidence, however, for a secondary dependence on SFR using direct metallicities. Finally, we derive metallicity gradients that becomes steeper with stellar mass for log(M_star_/M_{sun}_)<10.5.

At higher masses, the gradients flatten again, confirming with auroral line determinations the trends previously defined with strong-line calibrators.