IMPROVING THE DETERMINATION OF CHEMICAL ABUNDANCES IN PLANETARY NEBULAE
O. Cavichia, R. D. D Costa, W. J. Maciel, M.Mollá
Workshop Chemical abundances in gaseous nebulae, AAA Workshop Series, , ed. G. Hägele et al.,
10, 173-178 (2018)
Planetary nebulae are the products of the evolution of low and intermediate mass stars. The chemical
property studies of these objects give important information about the elemental abundances as He, O,
Ne, Ar, S and their modifications associated with the evolution of the progenitor stars. The determination
of accurate abundances in planetary nebulae is important from the perspective of the stellar evolution as
well as the formation and chemical evolution of galaxies. Recently, new HeI emissivities and ionization
correction factors (ICFs) were published in the literature. In this work, these new parameters are used
in a code for the determination of chemical abundances in photoionized nebulae. This code is used for
the recompilation of the chemical abundances of planetary nebulae from the Galactic bulge observed
previously by our group and also for the determination of new chemical abundances of a sample of planetary
nebulae located near the Galactic centre. The new emissivities and ICFs slightly modified the elemental
abundances of He, N, O, Ar and Ne. On the other hand, S abundances are higher than previous determinations.
The new ICFs can contribute to solve partially the sulphur anomaly.
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