A Model for the Dynamical and Ionization Structure of Planetary Nebula IC 418

The interacting two winds model and a spherical density distribution function are introduced to study the dynamical and ionization structure of the planetary nebula IC 418. A fast wind with a mechanical luminousity 2/34×1034erg.s-1 of interacts with a super wind with a mass-loss rate of 2×10-5M(°)yr-1 and a velocity of 10 , and produces a dense and luminous medium. In this model, the expansion velocities of OI and HI lines are predicted to be 11 and 10.5kms-1 , respectively. The calculated dynamical time-scale 1033yr for the nebula is in good agreement with the evolution time of the central star after the interaction of the two winds. Our calculations give a luminosity 0.05M(°)of for the central sta