Shoulder of Dust Rings Formed by Planet-disk Interactions

TL;DR

This paper explains the formation of dust shoulders in protoplanetary disks as a result of 3D planet-disk interactions, using simulations and radiative transfer to match observations and reveal the underlying mechanisms.

Contribution

It introduces a novel explanation for dust shoulders based on 3D hydrodynamic simulations showing how massive planets create pressure maxima that trap dust.

Findings

Dust shoulders are caused by planet-driven gas flows and pressure maxima.

3D effects are crucial for understanding dust ring structures.

The model explains observed dust shoulders in ALMA data.

Abstract

Recent analyses of mm-wavelength protoplanetary disk observations have revealed several emission excesses on the previously identified dust rings, referred to as dust shoulders. The prevalence of dust shoulders suggests that they trace a common but unclear mechanism. In this work, we combine 3D, multifluid hydrodynamic simulations with radiative transfer calculations to explain the formation of dust shoulders. We find that the ring-shoulder pairs can result from the 3D planet-disk interactions with massive, gap-opening planets. The key driver is the dust filtration effect at the local pressure maximum due to planet-driven outward gas flows. Our work provides a possible explanation for the outer dust shoulders in recent super-resolution analyses of ALMA observations. It also provides insights into the formation of the inner dust shoulder in the PDS 70 disk and highlights the role of 3D effects in planet-disk interaction studies.