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Projeto Observacional para 2018A - SO2018A-023
Autor: Hektor S. Monteiro
Título: Investigating abundance discrepancies in LMC planetary nebula
Resumo: The discrepancies of estimated abundances obtained from optical recombination lines (ORLs) when compared to the ones obtained from collisionally excited lines (CELs) is a well established fact for Galactic planetary nebulae (PNe). The discrepancy values for Galactic PNe average around 5.0 but can be as high as 700 and it is one of the major unresolved problems in nebular astrophysics affecting also HII regions. Recent results indicate that different gas phases coexisting may be the reason for the discrepancy. PNe in the LMC have less of the bias factors that affect Galactic PNe such as high extinction and unknown distances and are also formed in an enviroment with different chemical history than our Galaxy, making them interesting objects to investigate the origins of the discrepancy. Spatially resolved spectroscopy has been used recently to investigate the issue in Galactic PNe and we propose here to do the same for PNe in the Large Magellanic Cloud (LMC) for which this kind of investigation has not been carried out.