Demonstration of crystalline forsterite grain formation due to coalescence growth of Mg and SiO smoke particles

Abstract

Experimental studies of coalescence between Mg grains and SiO grains in smoke reveal the direct production of crystalline forsterite grains. The present results also show that different materials can be produced by grain­grain collisions, which have been considered one of the models of grain formation in the interstellar medium. The fundamentals of coalescence growth in smoke, which have been developed in our series of experiments, are presented in this paper. Mg2Si polyhedral grains were obtained in a Mg grain-rich atmosphere. Mg2SiO4 polyhedral grains were obtained in a SiO grain-rich atmosphere. The IR spectra of the resultant grains showed the characteristics of crystalline forsterite.