Dust Traffic Jams in Inclined Circumbinary Protoplanetary Discs I. Morphology and Formation Theory

TL;DR

This paper investigates how inclined circumbinary discs develop long-lived dust density enhancements, called 'dust traffic jams', due to differential precession of gas and dust, with implications for planetesimal formation.

Contribution

It introduces a combined approach of 3D hydrodynamical simulations and analytical modeling to understand dust traffic jams in inclined circumbinary discs, a novel insight into disc morphology and evolution.

Findings

Dust traffic jams cause significant, long-lived dust density enhancements.

Precession differences between gas and dust lead to the formation of these traffic jams.

The study provides a new theoretical framework for understanding dust accumulation in inclined discs.

Abstract

Gas and dust in inclined orbits around binaries experience precession induced by the binary gravitational torque. The difference in precession between gas and dust alters the radial drift of weakly coupled dust and leads to density enhancements where the radial drift is minimised. We explore this phenomenon using 3D hydrodynamical simulations to investigate the prominence of these `dust traffic jams' and the evolution of the resulting dust sub-structures at different disc inclinations and binary eccentricities. We then derive evolution equations for the angular momentum of warped dust discs and implement them in a 1D code and present calculations to further explain these traffic jams. We find that dust traffic jams in inclined circumbinary discs provide significant dust density enhancements that are long lived and can have important consequences for planetesimal formation.