Hot Jupiter formation in dense stellar clusters: A Monte Carlo model applied to 47 Tucanae

Abstract

We study the efficiency of high-e migration as a pathway for Hot Jupiter formation in the dense globular cluster 47 Tuc. Gravitational N-body simulations are performed to investigate the orbital evolution of star-planet systems due to dynamical stellar perturbations. Planetary systems that have been scattered into orbits of sufficiently high eccentricity can undergo tidal circularisation, with Hot Jupiter formation being one possible stopping condition. We also account for the possibility of (i) ionisation due to high-energy encounters, (ii) tidal disruption of the planet by tidal forces inside the Roche limit and (iii) Warm Jupiter formation. The orbital evolution of a population of cold Jupiter progenitors, with initial semi-major axes between 1-30 au, is simulated over 12 Gyr using a simplified dynamical model of 47 Tuc. Our computational treatment of dynamical encounters yields an overall HJ occurrence rate of F_HJ = 5.9 x 10^-4 per cluster star (a 51 per cent enhancement relative to the analytic baseline). The probability of Hot Jupiter formation is highest in the core and falls off steeply beyond a few parsecs from the centre of the cluster, where the stellar density is too low to drive efficient eccentricity diffusion. The code can be found here: https://github.com/James-Wirth/HotJupiter.

References in corpus (35)

• REBOUND: An open-source multi-purpose N-body code for collisional dynamics
• The Keck Planet Search: Detectability and the Minimum Mass and Orbital Period Distribution of Extrasolar Planets
• IAS15: A fast, adaptive, high-order integrator for gravitational dynamics, accurate to machine precision over a billion orbits
• Giant Planet Occurrence in the Stellar Mass-Metallicity Plane
• Planet Migration and Binary Companions: the case of HD 80606b
• Dynamical Origin of Extrasolar Planet Eccentricity Distribution
• The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics From 10-100 AU
• Can giant planets form by direct gravitational instability?
• Tidal Evolution of Close-in Extra-Solar Planets
• Unresolved stellar companions with Gaia DR2 astrometry
• The Equilibrium-Tide Model for Tidal Friction
• Friends of Hot Jupiters I: A Radial Velocity Search for Massive, Long-Period Companions to Close-In Gas Giant Planets
• The Frequency of Hot Jupiters Orbiting Nearby Solar-Type Stars
• Stellar Collisions During Binary-Binary and Binary-Single Star Interactions
• No large population of unbound or wide-orbit Jupiter-mass planets
• Hints for a Turnover at the Snow Line in the Giant Planet Occurrence Rate
• Consequences of the Ejection and Disruption of Giant Planets
• Friends of Hot Jupiters. IV. Stellar companions beyond 50 AU might facilitate giant planet formation, but most are unlikely to cause Kozai-Lidov migration
• The Effect of Encounters on the Eccentricity of Binaries in Clusters
• Formation of close in Super-Earths \& Mini-Neptunes: Required Disk Masses \& Their Implications
• The destruction of inner planetary systems during high-eccentricity migration of gas giants
• Halo globular clusters observed with AAOmega: dark matter content, metallicity and tidal heating
• Stellar clustering shapes the architectures of planetary systems
• Monte Carlo Simulations of Star Clusters - VII. The globular cluster 47 Tuc
• Planet-planet scattering as the source of the highest eccentricity exoplanets
• Search for giant planets in M67 III: excess of hot Jupiters in dense open clusters
• Exploring the Dependence of Hot Jupiter Occurrence Rates on Stellar Mass with TESS
• In Search of the Thermal Eccentricity Distribution
• Hot Jupiters driven by high-eccentricity migration in globular clusters
• Reassessment of the Null Result of the HST Search for Planets in 47 Tucanae
• Photochemical-dynamical models of externally FUV irradiated protoplanetary discs
• Formation of hot Jupiters through disk migration and evolving stellar tides
• Binary properties of the globular cluster 47 Tuc (NGC 104). A dearth of short-period binaries
• Hot Jupiter engulfment by a red giant in 3D hydrodynamics
• Forming short period sub-stellar companions in 47 Tucanae -- II. Analytic expressions for the orbital evolution of planets in dense environments