EXTINCTION IN FAR ULTRAVIOLET

The model of interstellar grains consisting of an appropriate size distribution of elongated dielectric particles represented by infinite circular cylinders is shown to reproduce the observed interstellar extinction through the spectral range from the infrared to the far ultraviolet. It is shown that this model gives at least as good a match with observation as any which have been obtained with graphite core-dielectric mantle particles. It is also shown that if the dielectric material in either model is optically like dirty ice" then there is a drop in the theoretical extinction curves at wavelengths longward of {double barred pipe}-1= 5-6 μ-1. © 1969."