A Kinematical Detection of Two Embedded Jupiter Mass Planets in HD 163296

TL;DR

This paper introduces a novel kinematic method to detect and characterize embedded Jupiter-mass planets in protoplanetary disks by analyzing deviations in gas rotation curves, demonstrated on ALMA observations of HD 163296.

Contribution

The study presents the first kinematic detection of embedded planets in a disk and a new technique to measure gas surface density profiles without relying on gas-to-dust ratios.

Findings

Detected two Jupiter-mass planets at 83 au and 137 au in HD 163296.

Rotation curve deviations match hydrodynamic simulations with embedded planets.

Method offers a new way to probe gas pressure profiles and planet masses in disks.

Abstract

We present the first kinematical detection of embedded protoplanets within a protoplanetary disk. Using archival ALMA observations of HD 163296, we demonstrate a new technique to measure the rotation curves of CO isotopologue emission to sub-percent precision relative to the Keplerian rotation. These rotation curves betray substantial deviations caused by local perturbations in the radial pressure gradient, likely driven by gaps carved in the gas surface density by Jupiter-mass planets. Comparison with hydrodynamic simulations shows excellent agreement with the gas rotation profile when the disk surface density is perturbed by two Jupiter mass planets at 83 au and 137 au. As the rotation of the gas is dependent on the pressure of the total gas component, this method provides a unique probe of the gas surface density profile without incurring significant uncertainties due to gas-to-dust ratios or local chemical abundances which plague other methods. Future analyses combining both methods promise to provide the most accurate and robust measures of embedded planetary mass. Furthermore, this method provides a unique opportunity to explore wide-separation planets beyond the mm continuum edge and to trace the gas pressure profile essential in modelling grain evolution in disks.