Probing O-enrichment in C-rich dust planetary nebulae
Abstract
The abundance of O in planetary nebulae (PNe) has been historically used as a metallicity indicator of the interstellar medium (ISM) where they originated; e.g., it has been widely used to study metallicity gradients in our Galaxy and beyond. However, clear observational evidence for O self enrichment in low-metallicity Galactic PNe with C-rich dust has been recently reported. Here we report asymptotic giant branch (AGB) nucleosynthesis predictions for the abundances of the CNO elements and helium in the metallicity range Zsun/4 < Z < 2Zsun. Our AGB models, with diffusive overshooting from all the convective borders, predict that O is overproduced in low-Z low-mass (~1-3 Msun) AGB stars and nicely reproduce the recent O overabundances observed in C-rich dust PNe. This confirms that O is not always a good proxy of the original ISM metallicity and another chemical elements such as Cl or Ar should be used instead. The production of oxygen by low-mass stars should be thus considered in galactic-evolution models.
Keywords
Cite
@article{arxiv.1602.05346,
title = {Probing O-enrichment in C-rich dust planetary nebulae},
author = {D. A. Garcia-Hernandez and P. Ventura and G. Delgado-Inglada and F. Dell'Agli and M. Di Criscienzo and A. Yagüe},
journal= {arXiv preprint arXiv:1602.05346},
year = {2016}
}
Comments
Accepted for publication in MNRAS Letters (5 pages, 1 figure, and 1 table)