Growing dust grains in protoplanetary discs - II. the radial-drift barrier problem

The author acknowledges the Australian Research Council for funding via Discovery project grant DP1094585 and acknowledges funding from the European Research Council for the FP7 ERC advanced grant project ECOGAL.We aim to study the migration of growing dust grains in protoplanetary discs, where growth and migration are tightly coupled. This includes the crucial issue of the radial-drift barrier for growing dust grains. We therefore extend the study performed in Paper I, considering models for grain growth and grain dynamics where both the migration and growth rate depend on the grain size and the location in the disc. The parameter space of disc profiles and growth models is exhaustively explored. In doing so, interpretations for the grain motion found in numerical simulations are also provided. We find that a large number of cases is required to characterize entirely the grains radial motion, providing a large number of possible outcomes. Some of them lead dust particles to be accreted on to the central star and some of them do not. We find then that q