A detailed look at chemical abundances in the Magellanic Clouds

Shaw, Richard A.; Lee, Ting-Hui; Stanghellini, Letizia; Davies, James E.; García-Hernández, D. Anibal; García-Lario, Pedro; Perea-Calderón, Jose-Vicente; Villaver, Eva; Manchado, A.; Palen, Stacy; Balick, Bruce
Referencia bibliográfica

Planetary Nebulae: An Eye to the Future, Proceedings of the International Astronomical Union, IAU Symposium, Volume 283, p. 502-503

Fecha de publicación:
Número de autores
Número de autores del IAC
Número de citas
Número de citas referidas
We determine elemental abundances of He, N, O, Ne, S, and Ar in Magellanic Cloud planetary nebulae (PNe) using direct methods and a large set of observed ions, minimizing the need for ionization correction factors. In contrast to prior studies, we find a clear separation between Type I and non-Type I PNe in these low-metallicity environments, and no evidence that the O-N nucleosynthesis cycle is active in low-mass progenitors. We find that the S/O abundance ratio is anomalously low compared to H ii regions, confirming the ``sulfur anomaly'' found for Galactic PNe. We also found that Ne/O is elevated in some cases, raising the possibility that Ne yields in low-mass AGB stars may be enhanced at low metallicity.