Abstract
The study of planetary nebulae (PNe) is extremely important in order to understand the evolution of low- and intermediate-mass stars. Photoionization codes intent to reproduce the interactions of the central star's radiation with the nebular gas. By using this tool, we are able to determine the physical properties of both: nebula and central star. About 70% of the PNe are ellipticals and bipolars and 20% have round morphologies. The reason why the PNe present so different morphological types is not well understood yet. A well accepted suggestion is that the binary central stars could be partially responsible for the bipolar shapes. Considering that there is only one 3D modeling of a bipolar PN (NGC 6302; Wright et al. 2011, MNRAS, 418, 370) and also because NGC 2346 has a binary system as central star, this PN seems to be an excellent candidate for a 3D detailed modeling. The code used for the modeling process was MOCASSIN (Ercolano, B. et al. 2003, MNRAS, 340, 1136). The density distribution we assumed for NGC 2346 has two components: torus and lobes. We considered the density constant in the torus (n_{T}) and three different cases in the lobes (n_{L}): (i) n_{L}= constant; (ii) n_{L} ∝ r^{-1}; and (iii) n_{L} ∝ r^{-2}. In our models we have observed that density stratification is essential in order to reproduce the higher ionization stages observed in this nebula. So far, the n_{L} ∝r^{-1} distribution has given the best agreement between the observed and modeled spectrum.
