Related papers: Minimum Dust Abundances for Planetesimal Formation…
Recently it is proposed that porous icy dust aggregates are formed by pairwise accretion of dust aggregates beyond the snowline. We calculate the equilibrium random velocity of porous dust aggregates taking into account mutual gravitational…
We have conducted the first comprehensive numerical investigation of the relative velocity distribution of dust particles in self-gravitating protoplanetary discs with a view to assessing the viability of planetesimal formation via direct…
We show that the planetesimal formation due to the gravitational fragmentation of a dust layer in a protoplanetary disk is possible. The dust density distribution in the dust layer would approach the constant Richardson number distribution…
Interpenetrating streams of solids and gas in a Keplerian disk produce a local, linear instability. The two components mutually interact via aerodynamic drag, which generates radial drift and triggers unstable modes. The secular instability…
Aims. Dust plays a crucial role in the evolution of protoplanetary disks. We study the dynamics and growth of initially sub-$\mu m$ dust particles in self-gravitating young protoplanetary disks with various strengths of turbulent viscosity.…
We investigate the conditions required for planet formation via gravitational instability (GI) and protoplanetary disk (PPD) fragmentation around M-dwarfs. Using a suite of 64 SPH simulations with $10^6$ particles, the parameter space of…
Instabilities of the dust layer in a protoplanetary disk are investigated. It is known that the streaming instability develops and dust density concentration occurs in a situation where the initial dust density is uniform. This work…
Recent observations show that planet formation is already underway in young systems, when the protostar is still embedded into the molecular cloud and the accretion disc is massive. In such environments, the role of self gravity (SG) and…
Planet formation may begin much earlier than previously expected, when the protoplanetary disk is still massive and gravitationally unstable. It has been proposed that solid grains can concentrate in the spiral arms of self-gravitating…
We study how the interaction between the streaming instability and intrinsic gas-phase turbulence affects planetesimal formation via gravitational collapse in protoplanetary disks. Turbulence impedes the formation of particle clumps by…
In our previous work (Paper I), we demonstrated that coagulation instability results in dust concentration against depletion due to the radial drift and accelerates dust growth locally. In this work (Paper II), we perform numerical…
Context: The streaming instability (SI) is a leading candidate for reaching solid densities sufficient to trigger the gravitational collapse needed for the formation of planetesimals. However, dust growth barriers appear to impede the…
A critical phase in the standard model for planet formation is the runaway growth phase. During runaway growth bodies in the 0.1--100 km size range (planetesimals) quickly produce a number of much larger seeds. The runaway growth phase is…
The streaming instability, a promising mechanism to drive planetesimal formation in dusty protoplanetary discs, relies on aerodynamic drag naturally induced by the background radial pressure gradient. This gradient should vary in disks, but…
Enhancing the local dust-to-gas ratio in protoplanetary discs is a necessary first step to planetesimal formation. In laminar discs, dust settling is an efficient mechanism to raise the dust-to-gas ratio at the disc midplane. However,…
We report the finding of a new, local diffusion instability in a protoplanetary disk, which can operate in a dust fluid, subject to mass diffusion, shear viscosity, and dust-gas drag, provided diffusivity, viscosity, or both decrease…
The streaming instability is a fundamental process that can drive dust-gas dynamics and ultimately planetesimal formation in protoplanetary discs. As a linear instability, it has been shown that its growth with a distribution of dust sizes…
Streaming instability is considered to be one of the dominant processes to promote planetesimal formation by gravitational collapse of dust clumps. The development of streaming instability is expected to form dust clumps in which the local…
We analyze the gravitational collapse of solids subject to gas drag in a protoplanetary disk. We also study the stirring of solids by turbulent fluctuations to determine the velocity dispersion and thickness of the midplane particle layer.…
Damping of the previously discovered resonant drag instability (RDI) of dust streaming in protoplanetary disc is studied using the local approach to dynamics of gas-dust perturbations in the limit of the small dust fraction. Turbulence in a…