SDSS-IV MaNGA: Variations in the N/O-O/H Relation Bias Metallicity Gradient Measurements
Abstract
In this Letter we use strong line calibrations of the N/O and O/H in Mapping Galaxies at Apache Point Observatory (MaNGA) galaxy survey spaxel data to explore the systematics introduced by variations in N/O on various strong-line metallicity diagnostics. We find radial variations in N/O at fixed O/H that correlate with total galaxy stellar mass and that can induce ∼40% systematic uncertainties in oxygen abundance gradients when nitrogen-dependent abundance calibrations are used. Empirically, we find that departures from the expected N/O are associated with variation in the local star formation efficiency, as predicted by recent chemical evolution models for galaxies, but we cannot rule out other processes such as radial migration also playing a role.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2020
- DOI:
- 10.3847/2041-8213/ab6f06
- arXiv:
- arXiv:1911.00581
- Bibcode:
- 2020ApJ...890L...3S
- Keywords:
-
- Metallicity;
- Chemical abundances;
- Abundance ratios;
- Galaxy chemical evolution;
- Chemical enrichment;
- 1031;
- 224;
- 11;
- 580;
- 225;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 8 pages, 4 figures. Submitted to ApJL. All comments are welcome