On Gas-Drag Induced Rapid Migration of Solids in a Non-Uniform Solar Nebula

We study the motions of small solids, ranging from micron-sized dust grains to meter-sized objects, in the vicinity of local pressure enhancements of a gaseous nebula. Integrating numerically, we show that as a result of the combined effect of gas drag and pressure gradients, solids tend to accumulate at the locations where the pressure of the gas maximizes. The rate of migration of solids varies with their sizes and densities and also with the physical properties of the gas. The results of our numerical simulations indicate that such migrations are most rapid for meter-sized objects. The applicability of the results to the enhancement of the collision and coagulation of solids and also to the growth-rate of planetesimals is discussed.