Planet migration, resonant locking and accretion streams in PDS70: Comparing models and data

TL;DR

This study uses 3D simulations to model the PDS 70 system, demonstrating that planet-disc interactions and accretion streams can explain observed features without invoking circumplanetary discs.

Contribution

The paper presents the first detailed 3D hydrodynamical simulations showing resonant locking and accretion streams in PDS 70, matching observations without requiring circumplanetary discs.

Findings

Resonant locking of planets in PDS 70 is dynamically stable.

Accretion streams explain observed infrared and millimetre features.

Planet-disc interactions alone reproduce observational data.

Abstract

The disc surrounding PDS 70, with two directly imaged embedded giant planets, is an ideal laboratory to study planet-disc interaction. We present three-dimensional smoothed particle hydrodynamics simulations of the system. In our simulations, planets, which are free to migrate and accrete mass, end up in a locked resonant configuration that is dynamically stable. We show that features observed at infrared (scattered light) and millimetre (thermal continuum) wavelengths are naturally explained by the accretion stream onto the outer planet, without requiring a circumplanetary disc around planet c. We post-processed our near-infrared synthetic images in order to account for observational biases known to affect high-contrast images. Our successful reproduction of the observations indicates that planet-disc dynamical interactions alone are sufficient to explain the observations of PDS 70.