On planet formation in HL Tau

TL;DR

This paper models the HL Tau protoplanetary disc with embedded planets to explain observed gaps, using 3D simulations that match ALMA observations and suggest multiple planets influence the disc structure.

Contribution

It introduces a 3D dusty hydrodynamics model that reproduces the observed gaps in HL Tau by simulating multiple embedded planets.

Findings

Three planets with specific masses explain the main gaps.

Simulations successfully reproduce most observed disc structures.

Uncertainties remain in precise planet mass estimates.

Abstract

We explain the axisymmetric gaps seen in recent long-baseline observations of the HL Tau protoplanetary disc with the Atacama Large Millimetre/Submillimetre Array (ALMA) as being due to the different response of gas and dust to embedded planets in protoplanetary discs. We perform global, three dimensional dusty smoothed particle hydrodynamics calculations of multiple planets embedded in dust/gas discs which successfully reproduce most of the structures seen in the ALMA image. We find a best match to the observations using three embedded planets with masses of 0.2, 0.27 and 0.55 $M_{\rm J}$ in the three main gaps observed by ALMA, though there remain uncertainties in the exact planet masses from the disc model.