Christophe Morisset (Instituto de Astronomia-UNAM, Mexico)
In this talk I will present a review on the determination of oxygen abundance from photoionization models of nebulae. I will first describe the way models are performed using photoionization codes, explaining the necessary ingredients (inputs) and results (outputs), and the hidden but fundamental atomic data. I will also compare the results (especially the abundances, but also the temperature and density) obtained by photoionization models to the ones obtained by direct methods. I will illustrate the talk showing examples of models, focusing on the convergence process and on some limits of the method.
Invited talk given at the meeting Mapping Oxygen in the Universe, Tenerife, Spain (14-18 May 2012)

