Planet population synthesis: The role of stellar encounters
arXiv:2202.11935 · doi:10.1093/mnras/stac569
Abstract
Depending on the stellar densities, protoplanetary discs in stellar clusters undergo background heating, disc truncation-driven by stellar encounter, and photo-evaporation. Disc truncation leads to reduced characteristic sizes and disc masses that eventually halts gas giant planet formation. We investigate how disc truncation impacts planet formation via pebble-based core accretion paradigm, where pebble sizes were derived from the full grain-size distribution within the disc lifetimes. We make the best-case assumption of one embryo and one stellar encounter per disc. Using planet population syntheses techniques, we find that disc truncation shifts the disc mass distributions to the lower margins. This consequently lowered the gas giant occurrence rates. Despite the reduced gas giant formation rates in clustered discs, the encounter models mostly show as in the isolated field; the cold Jupiters are more frequent than the hot Jupiters, consistent with observation. Moreover, the ratio of hot to cold Jupiters depend on the periastron distribution of the perturbers with linear distribution in periastron ratio showing enhanced hot to cold Jupiters ratio in comparison to the remaining models. Our results are valid in the best-case scenario corresponding to our assumptions of: only one disc encounter with a perturber, ambient background heating and less rampant photo-evaporation. It is not known exactly of how much gas giant planet formation would be affected should disc encounter, background heating and photo-evaporation act in a concert. Thus, our study will hopefully serve as motivation for quantitative investigations of the detailed impact of stellar cluster environments on planet formations.
13 pages, 8 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society
References in corpus (42)
- Coagulation, fragmentation and radial motion of solid particles in protoplanetary disks
- Photoevaporation of protoplanetary discs II: evolutionary models and observable properties
- Separating gas-giant and ice-giant planets by halting pebble accretion
- The stickiness of micrometer-sized water-ice particles
- The structure of protoplanetary discs around evolving young stars
- The Exoplanet Mass-Ratio Function from the MOA-II Survey: Discovery of a Break and Likely Peak at a Neptune Mass
- Dust size distributions in coagulation/fragmentation equilibrium: Numerical solutions and analytical fits
- On the formation of planetary systems via oligarchic growth in thermally evolving viscous discs
- Global Models of Planet Formation and Evolution
- Dynamical corotation torques on low-mass planets
- Radiation Feedback and Fragmentation in Massive Protostellar Cores
- Grain opacity and the bulk composition of extrasolar planets. II. An analytical model for the grain opacity in protoplanetary atmospheres
- Planet population synthesis driven by pebble accretion in cluster environments
- Microlensing Results Challenge the Core Accretion Runaway Growth Scenario for Gas Giants
- The opacity of grains in protoplanetary atmospheres
- How drifting and evaporating pebbles shape giant planets II: Volatiles and refractories in atmospheres
- Stability of Multiplanetary Systems in Star Clusters
- Tidally induced brown dwarf and planet formation in circumstellar discs
- Planet formation by pebble accretion in ringed disks
- Protoplanetary disc evolution affected by star-disc interactions in young stellar clusters
- Sizes of protoplanetary discs after star-disc encounters
- Can habitable planets form in clustered environments?
- Flybys in protoplanetary discs: II. Observational signatures
- Strong effect of the cluster environment on the size of protoplanetary discs?
- Planet formation and migration near the silicate sublimation front in protoplanetary disks
- Survivability of planetary systems in young and dense star clusters
- How dust fragmentation may be beneficial to planetary growth by pebble accretion
- Cluster dynamics largely shapes protoplanetary disc sizes
- Runaway gas accretion and gap opening versus type~I migration
- Influence of planetary gas accretion on the shape and depth of gaps in protoplanetary discs
- Hot Jupiters driven by high-eccentricity migration in globular clusters
- Influence of grain growth on the thermal structure of protoplanetary discs
- Are the observed gaps in protoplanetary discs caused by growing planets?
- Highly inclined and eccentric massive planets. II. Planet-planet interactions during the disc phase
- Probing the impact of varied migration and gas accretion rates for the formation of giant planets in the pebble accretion scenario
- A Near-coplanar Stellar Flyby of the Planet Host Star HD 106906
- Gravitational Instabilities induced by Cluster Environment? - The encounter-induced angular momentum transfer in discs
- The imprint of X-ray photoevaporation of planet-forming discs on the orbital distribution of giant planets
- Influence of grain sizes and composition on the contraction rates of planetary envelopes and on planetary migration
- Does the mass distribution in discs influence encounter-induced losses in young star clusters?
- 8 in 10 Stars in the Milky Way Bulge Experience Stellar Encounters Within 1000 AU in a Gigayear
- How the planetary eccentricity influences the pebble isolation mass