N/O in spiral discs: a new algorithm for abundance determinations
Abstract
We obtain nitrogen abundances in the HII regions of selected spiral galaxies by using a new algorithm developed from grids of photoionization models. The new method requires only the observation of optical [NII], [OII] and [OIII] lines. We show the self-consistency of the new method, and also the agreement with more detailed modelling of individual HII regions. Gradients in [N/O] against effective radius and [O/H] are presented for a well-observed subset of galaxies from the Vila-Costas & Edmunds sample.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- December 1996
- DOI:
- 10.1093/mnras/283.3..990
- Bibcode:
- 1996MNRAS.283..990T
- Keywords:
-
- HII REGIONS;
- GALAXIES: ABUNDANCES;
- GALAXIES: SPIRAL