Intensity and linear polarization of light scattered by irregular particles of core-mantle structure.

Abstract

Observations of cometary jets showed that the degree of linear polarization is visibly higher than in the rest of the coma and it rapidly decreases with distance from the cometary nucleus. Simultaneously, the intensity of jets depends weakly on distance. We attribute the change in polarization to sublimation of ice from cometary dust particles and examine this idea with numerical simulation of light scattering by grains of irregular shape and ice-covered agglomerates consisting of these grains. We will show the disruption of agglomerated particles due to sublimation of ice could explain qualitatively the photo- and polarimetrical features observed in cometary jets.