A 3D Hydrodynamics Study of Gravitational Instabilities in a Young Circumbinary Disc

Abstract

We present a 3D hydrodynamics study of gravitational instabilities (GIs) in a 0.14 M${}_{\odot }$ circumbinary protoplanetary disc orbiting a 1 M${}_{\odot }$ star and a 0.02 M${}_{\odot }$ brown dwarf companion. We examine the thermodynamical state of the disc and determine the strengths of GI-induced density waves, nonaxisymmetric density structures, mass inflow and outflow, and gravitational torques. Results are compared with a parallel simulation of a protoplanetary disc without the brown dwarf binary companion. Simulations are performed using CHYMERA, a radiative 3D hydrodynamics code. The onset of GIs in the circumbinary disc is much more violent due to the stimulation of a strong one-armed density wave by the brown dwarf. Despite this early difference, detailed analyses show that both discs relax to a very similar quasi-steady phase by 2,500 years after the beginning of the simulations. Similarities include the thermodynamics of the quasi-steady phase, the final surface density distribution, radial mass influx, and nonaxisymmetric power and torques for spiral arm multiplicities of two or more. Effects of binarity in the disc are evident in gravitational torque profiles, temperature profiles in the inner discs, and radial mass transport. After 3,800 years, the semimajor axis of the binary decreases by about one percentage and the eccentricity roughly doubles. The mass transport in the outer circumbinary disc associated with the one-armed wave may influence planet formation.

References in corpus (6)

• The Thermal Regulation of Gravitational Instabilities in Protoplanetary Disks III. Simulations with Radiative Cooling and Realistic Opacities
• Standing on the shoulders of giants: Trojan Earths and vortex trapping in low mass self-gravitating protoplanetary disks of gas and solids
• 3D Radiative Hydrodynamics for Disk Stability Simulations: A Proposed Testing Standard and New Results
• The fragmentation criteria in local vertically stratified self-gravitating disk simulations
• The Role of Disc Self-Gravity in Circumbinary Planet Systems: I. Disc Structure and Evolution
• Gravitational instabilities in a protosolar-like disc II: continuum emission and mass estimates

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