The 3D structure of disc-instability protoplanets

Abstract

Context. The model of disc fragmentation due to gravitational instabilities offers an alternate formation mechanism for gas giant planets, especially those on wide orbits. Aims. Our goal is to determine the 3D structure of disc-instability protoplanets and to examine how this relates to the thermal physics of the fragmentation process. Methods. We modelled the fragmentation of gravitationally unstable discs using the SPH code PHANTOM, and followed the evolution of the protoplanets formed through the first and second-hydrostatic core phases (up to densities 1e-3 g/cm3). Results. We find that the 3D structure of disc-instability protoplanets is affected by the disc environment and the formation history of each protoplanet (e.g. interactions with spiral arms, mergers). The large majority of the protoplanets that form in the simulations are oblate spheroids rather than spherical, and they accrete faster from their poles. Conclusions. The 3D structure of disc-instability protoplanets is expected to affect their observed properties and should be taken into account when interpreting observations of protoplanets embedded in their parent discs.

Accepted in Astronomy & Astrophysics Letters

References in corpus (17)

• SPLASH: An interactive visualisation tool for Smoothed Particle Hydrodynamics simulations
• Two accreting protoplanets around the young star PDS 70
• The properties of brown dwarfs and low-mass hydrogen-burning stars formed by disc fragmentation
• The Two Modes of Gas Giant Planet Formation
• A Circumplanetary Disk Around PDS70c
• Brown dwarf formation by gravitational fragmentation of massive, extended protostellar discs
• Accreting Circumplanetary Disks: Observational Signatures
• The minimum mass for star formation, and the origin of binary brown dwarfs
• Images of Embedded Jovian Planet Formation At A Wide Separation Around AB Aurigae
• Radiative transfer and the energy equation in SPH simulations of star formation
• The role of magnetic fields in the formation of protostellar discs
• Planet formation around M dwarfs via disc instability: Fragmentation conditions and protoplanet properties
• The effect of radiative feedback on disc fragmentation
• Formation of intermediate-mass planets via magnetically-controlled disk fragmentation
• On the fragmentation boundary in magnetised self-gravitating discs
• Giant planets and brown dwarfs on wide orbits: a code comparison project
• On the survivability of a population of gas giant planets on wide orbits