The radius spectrum of solid grains settling in gaseous giant protoplanets

Abstract

Growth of grains having different initial sizes (10−3 cm ≤ r0 ≤ 1 cm) has been investigated by coagulation processes inside gas giant protoplanets, formed by disk instability, in the mass range 0.3 to 10 Jovian masses. In doing so, we have determined distribution of thermodynamic variables inside the protoplanets and using the results we have determined growth of the grains having assumed initial sizes. Regarding the transference of heat inside the protoplanets, we have considered the possible two cases of interest, namely convection and conduction-radiation. The results of our calculation show that growth of the grains depends on protoplanetary masses and on initial states of the protoplanets and eventually all the grains having assumed different initial sizes acquire almost the same distribution in the central regions of respective protoplanets in the respective cases.