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A quick introduction to BOND: Bayesian Oxygen and Nitrogen abundance Determinations in giant HII regions – Natalia Vale Asari (UFSC)
11 de abril de 2018: 12:30 - 13:30
The abundances of chemical elements other than hydrogen and helium in a galaxy are the fossil record of its star formation history. Empirical relations such as mass–metallicity relation are thus seen as guides for studies on the history and chemical evolution of galaxies. Those relations usually rely on nebular metallicities measured with strong-line methods, which assume that HII regions are a one- (or at most two-) parameter family where the oxygen abundance is the driving quantity. Nature is however much more complex than that, and metallicities from strong lines may be strongly biased. We have developed the method BOND (Bayesian Oxygen and Nitrogen abundance Determinations) to simultaneously derive oxygen and nitrogen abundances in giant HII regions by comparing strong and semi-strong observed emission lines to a carefully-defined, finely-meshed grid of photoionization models. Our code and results are public and available at http://bond.ufsc.br.