Abstract
Millimeter-sized, spherical silicate grains abundant in chondritic meteorites, which are called as chondrules, are considered to be a strong evidence of the melting event of the dust particles in the protoplanetary disk. Compound chondrules are composed of two or more chondrules fused together. In this study, we propose a new scenario for compound chondrule formation in framework of the shock-wave heating model. We model the disruption of molten cm-sized parent dust particle exposed to high-velocity gas flow in order to estimate the efficiency of mutual collisions between small fragments. The predicted collision frequency was ~0.1 - 1 or more, which is about one order of magnitude larger than the observational compound fraction. We find that the predictions of our model are consistent with other observational data. We conclude that this new model can account for compound chondrule formation.
