Structural Features and Scattering Properties of Dust Particles

Abstract

The theory of the scattering of light by ensembles of particles with irregular shape is of interest in the context of interstellar and interplanetary dust grains and particles associated with comets or observed in aerosols and hydrosols. The scattering properties of homogeneous particles are determined by both, geometrical features and chemical composition as represented by the complex frequency dependent index of refraction. We have performed a systematic investigation on the former aspect, namely the influence of structural features of the surface of large dielectric particles on their light scattering properties.* The formal equivalent of these properties is the frequency dependent differential scattering cross section or, as it is often taken, the scattering function and the polarization curve for certain regions of wave length. From the observation of these quantities one wishes to draw conclusions on the geometrical, structural properties as well as on the chemical composition of the dust grains.