Dynamics of multiple protoplanets embedded in gas/pebble disks and its dependence on $\Sigma$ and $\nu$ parameters

Abstract

Protoplanets of Super-Earth sizes may get trapped in convergence zones for planetary migration and form gas giants there. These growing planets undergo accretion heating, which triggers a hot-trail effect that can reverse migration directions, increase eccentricities and prevent resonant captures (Chrenko et al. 2017). We study populations of embryos accreting pebbles using Fargo-Thorin 2D hydrocode. We find that embryos in a disk with high surface density (${\Sigma }_0=990\mathrm{g}{\mathrm{cm}}^{-2}$) undergo `unsuccessful' two-body encounters which do not lead to a merger. Only when a 3rd protoplanet arrives to the convergence zone, three-body encounters lead to mergers. For a low-viscosity disk ($\nu =5\times 10^{13}{\mathrm{cm}}^2{\mathrm{s}}^{-1}$) a massive coorbital is a possible outcome, for which a pebble isolation develops and the coorbital is stabilised. For more massive protoplanets ($5M_{\oplus }$), the convergence radius is located further out, in the ice-giant zone. After a series of encounters, there is an evolution driven by a dynamical torque of a tadpole region, which is systematically repeated several times, until the coorbital configuration is disrupted and planets merge. This may be a pathway how to solve the problem that coorbitals often form in simulations but they are not observed in nature. In contrast, the joint evolution of 120 low-mass protoplanets ($0.1M_{\oplus }$) reveals completely different dynamics. The evolution is no longer smooth, but rather a random walk. This is because the spiral arms, developed in the gas disk due to Lindblad resonances, overlap with each other and affect not only a single protoplanet but several in the surroundings. Our hydrodynamical simulations may have important implications for N-body simulations of planetary migration that use simplified torque prescriptions and are thus unable to capture protoplanet dynamics in its full glory.

arXiv comment15 pages, 25 figures, Astronomy & Astrophysics, accepted

References in corpus (40)

• Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions
• Spectral Energy Distributions of T Tauri Stars With Passive Circumstellar Disks
• Using FU Orionis Outbursts to Constrain Self-Regulated Protostellar Disk Models
• Rapid growth of gas-giant cores by pebble accretion
• IAS15: A fast, adaptive, high-order integrator for gravitational dynamics, accurate to machine precision over a billion orbits
• The effect of gas drag on the growth of protoplanets -- Analytical expressions for the accretion of small bodies in laminar disks
• FARGO: a fast eulerian transport algorithm for differentially rotating disks
• A torque formula for non-isothermal Type I planetary migration - II. Effects of diffusion
• Forming the cores of giant planets from the radial pebble flux in protoplanetary discs
• Linear and nonlinear evolution of the vertical shear instability in accretion discs
• Turbulence in Accretion Disks. Vorticity Generation and Angular Momentum Transport via the Global Baroclinic Instability
• Breaking the Chains: Hot Super-Earth systems from migration and disruption of compact resonant chains
• Mass Flow and Accretion through gaps in Accretion Discs
• Pebble isolation mass --- scaling law and implications for the formation of super-Earths and gas giants
• Protoplanetary disc evolution and dispersal: the implications of X-ray photoevaportion
• Growing the gas-giant planets by the gradual accumulation of pebbles
• Disk eccentricity and embedded planets
• Accretion Rates for T Tauri Stars Using Nearly Simultaneous Ultraviolet and Optical Spectra
• Evolution of Protoplanetary Discs with Magnetically Driven Disc Winds
• The minimum mass of detectable planets in protoplanetary discs and the derivation of planetary masses from high resolution observations
• Cavity opening by a giant planet in a protoplanetary disc and effects on planetary migration
• Planet heating prevents inward migration of planetary cores
• Stellar irradiated discs and implications on migration of embedded planets I: equilibrium discs
• The radial dependence of pebble accretion rates: A source of diversity in planetary systems I. Analytical formulation
• Reduced gas accretion on super-Earths and ice giants
• 3D-radiation hydro simulations of disk-planet interactions: I. Numerical algorithm and test cases
• Treating gravity in thin disk simulations
• On the formation of compact planetary systems via concurrent core accretion and migration
• Accretion of Uranus and Neptune from inward-migrating planetary embryos blocked by Jupiter and Saturn
• The Structure of Magnetocentrifugal Winds I. Steady Mass Loading
• Torques Induced by Scattered Pebble-flow in Protoplanetary Disks
• Stellar irradiated discs and implications on migration of embedded planets III: viscosity transitions
• Evolution of eccentricity and inclination of hot protoplanets embedded in radiative discs
• Runaway gas accretion and gap opening versus type~I migration
• Fast migration of low-mass planets in radiative discs
• Eccentricity excitation and merging of planetary embryos heated by pebble accretion
• The Spiral Wave Instability Induced by a Giant Planet: I. Particle Stirring in the Inner Regions of Protoplanetary Disks
• Transit timing variations for planets coorbiting in the horseshoe regime
• Migration of accreting planets in radiative discs from dynamical torques
• Accretion, winds and outflows in young stars

Cited by in corpus (8)

• Formation and Evolution of Compact Object Binaries in AGN Disks
• Mass-gap Mergers in Active Galactic Nuclei
• Spin Evolution of Stellar-mass Black Hole Binaries in Active Galactic Nuclei
• Pebbles versus Planetesimals: The case of Trappist-1
• Oscillatory migration of accreting protoplanets driven by a 3D distortion of the gas flow
• Stability of the co-orbital resonance under dissipation: Application to its evolution in protoplanetary discs
• Transit-Timing Variation Signature of Planet Migration: The Case of K2-24
• Substructures in protoplanetary disks imprinted by compact planetary systems