Further Models of Planetary Nebula Spectral Evolution

Abstract

Four new calculations of planetary nebulae spectral evolution are presented, as in Volk (1992). These models use the 0.64 M_⊙ central star evolution track of Schönberner (1983) but with the rate of evolution accelerated by a factor of 2, as the original models evolve to the planetary nebula phase too slowly to match the observations. Models were calculated for mass-loss rates of 2.1 × 10⁻⁵ and 5.2 × 10⁻⁵ MM_⊙ yr⁻¹ using solar composition and silicate dust, and using the average observed planetary nebula composition and graphite dust. An interacting winds shell was assumed to form. The model results were combined with an assumed Galactic distribution of 25000 planetary nebula to simulate a variety of observables including V magnitudes, Hβ fluxes, the IRAS colours, the 5 GHz radio flux densities, and the nebular radii.