Galactic metallicity gradients with PNe

The radial chemical gradient of the Galactic Disk is traced by PNe with available chemical abundances and distances, and kinematic data of the CSs are employed to identify the Halo PN population.We date PN progenitors based both on abundances and on kinematic properties, finding a confirmation of the first method with the second. For all PNe with at least one oxygen determination in the literature, we find a slope of the radial oxygen gradient equal to {DELTA}log(O/H)/{DELTA}RG=-0.0144+/-0.00385 [dex/kpc].

Furthermore, we estimate radial oxygen gradients for the PNe with old (>7.5Gyr) and young (<1Gyr) progenitors to be respectively {DELTA}log(O/H)/{DELTA}RG=-0.0121+/-0.00465 and -0.022+/-0.00758 [dex/kpc], thus disclosing a mild steepening of the gradient since Galaxy formation, with a slope change of 0.01dex. The time evolution is slightly higher (~0.015dex) if we select the best available abundances in the literature.

This result is in broad agreement with previous PN results, but now based on DR3 Gaia analysis, and also in agreement with what traced by most other Galactic probes. We also find a moderate oxygen enrichment when comparing the PNe with young and old progenitors.