学术文献库

Aims. Dust plays a crucial role in the evolution of protoplanetary disks. We study the dynamics and growth of initially sub-$μm$ dust particles in self-gravitating young protoplanetary disks with various strengths of turbulent viscosity. We aim to understand the physical conditions that determine the formation and spatial distribution of pebbles when both disk self-gravity and turbulent viscosity can be concurrently at work. Methods. We perform the thin-disk hydrodynamics simulations of self-gravitating protoplanetary disks over an initial time period of 0.5 Myr using the FEOSAD code. Turbulent viscosity is parameterized in terms of the spatially and temporally constant $α$-parameter, while the effects of gravitational instability on dust growth is accounted for by calculating the effective parameter $α_{\rm GI}$. We consider the evolution of dust component including momentum exchange with gas, dust self-gravity, and also a simplified model of dust growth. Results. We find that the level of turbulent viscosity strongly affects the spatial distribution and total mass of pebbles in the disk. The $α=10^{-2}$ model is viscosity-dominated, pebbles are completely absent, and dust-to-gas mass ratio deviates from the reference 1:100 value no more than by 30\% throughout the disk extent. On the contrary, the $α=10^{-3}$ model and, especially, the $α=10^{-4}$ model are dominated by gravitational instability. The effective parameter $α+α_{\rm GI}$ is now a strongly varying function of radial distance. As a consequence, a bottle neck effect develops in the innermost disk regions, which makes gas and dust accumulate in a ring-like structure. Abridged.