Morphology and kinematics of planetary nebulae. I. A new modeling tool

We present a new modeling tool for planetary nebulae, based on three-dimens ional photoionization calculations. Our goal is to show that all the inform ation provided by observations regarding kinematics and morphology has to b e consistently accounted for in order to achieve real insight into the obje ct. Only three-dimensional simulations offer this possibility. From models for two theoretical planetary nebulae (PNe), we show that the enhancement i n the equatorial zone observed in several PNe is not necessarily due to a d ensity gradient, as usually interpreted. It is also shown that asymmetric v elocity profiles often observed (e.g., Gesicki et al.) can be easily reprod uced. Observations providing better insight into the morphology of PNe are discussed.