The New Generation Planetary Population Synthesis (NGPPS) VIII. Impact of host star metallicity on planet occurrence rates, orbital periods, eccentricities, and radius valley morphology

Abstract

The dust-to-gas ratio in the protoplanetary disk, which is likely imprinted into the host star metallicity, is a property that plays a crucial role during planet formation. We aim at constraining planet formation and evolution processes by statistically analysing planetary systems generated by the Generation III Bern model, comparing with the correlations derived from observational samples. Using synthetic planets biased to observational completeness, we find that (1) the occurrence rates of large giant planets and Neptune-size planets are positively correlated with [Fe/H], while small sub-Earths exhibit an anti-correlation. In between, for sub-Neptune and super-Earth, the occurrence rate first increases and then decreases with increasing [Fe/H] with an inflection point at 0.1 dex. (2) Planets with orbital periods shorter than ten days are more likely to be found around stars with higher metallicity, and this tendency weakens with increasing planet radius. (3) Both giant planets and small planets exhibit a positive correlation between the eccentricity and [Fe/H], which could be explained by the self-excitation and perturbation of outer giant planets. (4) The radius valley deepens and becomes more prominent with increasing [Fe/H], accompanied by a lower super-Earth-to-sub-Neptune ratio. Furthermore, the average radius of the planets above the valley increases with [Fe/H]. Our nominal model successfully reproduces many observed correlations with stellar metallicity, supporting the description of physical processes and parameters included in the Bern model. However, the dependences of orbital eccentricity and period on [Fe/H] predicted by the synthetic population is however significantly weaker than observed. This discrepancy suggests that long-term dynamical interactions between planets, along with the impact of binaries/companions, can drive the system towards a dynamically hotter state.

20 Pages, 23 figures, 1 Table, Accepted for publication on A&A

References in corpus (38)

• The Transiting Exoplanet Survey Satellite
• Tidal Evolution of Close-in Extra-Solar Planets
• Models of the in situ formation of detected extrasolar giant planets
• Planetary population synthesis coupled with atmospheric escape: a statistical view of evaporation
• Three regimes of extrasolar planets inferred from host star metallicities
• Density, not radius, separates rocky and water-rich small planets orbiting M dwarf stars
• Tidal friction in close-in satellites and exoplanets. The Darwin theory re-visited
• Exoplanet Orbital Eccentricities Derived From LAMOST-Kepler Analysis
• The New Generation Planetary Population Synthesis (NGPPS). IV. Planetary systems around low-mass stars
• On the formation of planetary systems via oligarchic growth in thermally evolving viscous discs
• Post-Oligarchic Evolution of Protoplanetary Embryos and the Stability of Planetary Systems
• The Gaia-Kepler Stellar Properties Catalog. II. Planet Radius Demographics as a Function of Stellar Mass and Age
• A new equation of state for dense hydrogen-helium mixtures
• AQUA: A Collection of H${}_2$O Equations of State for Planetary Models
• Global Models of Planet Formation and Evolution
• A Spectroscopic Analysis of the California-Kepler Survey Sample: I. Stellar Parameters, Planetary Radii and a Slope in the Radius Gap
• CSI 2264: Investigating rotation and its connection with disk accretion in the young open cluster NGC 2264
• Superabundance of Exoplanet Sub-Neptunes Explained by Fugacity Crisis
• LAMOST telescope reveals that Neptunian cousins of hot Jupiters are mostly single offspring of stars that are rich in heavy elements
• A Super-Solar Metallicity For Stars With Hot Rocky Exoplanets
• From stellar nebula to planetesimals
• The origin of the high metallicity of close-in giant exoplanets: Combined effect of the resonant and aerodynamic shepherding
• CKS VIII: Eccentricities of Kepler Planets and Tentative Evidence of a High Metallicity Preference for Small Eccentric Planets
• A deep radius valley revealed by Kepler short cadence observations
• Hydrodynamic escape of water vapor atmospheres near very active stars
• A fading radius valley towards M-dwarfs, a persistent density valley across stellar types
• A Joint Mass-Radius-Period Distribution of Exoplanets
• The metallicity distribution and hot Jupiter rate of the Kepler field: Hectochelle High-resolution spectroscopy for 776 Kepler target stars
• The New Generation Planetary Population Synthesis (NGPPS). VI. Introducing KOBE: Kepler Observes Bern Exoplanets. Theoretical perspectives on the architecture of planetary systems: Peas in a pod
• Shallower radius valley around low-mass hosts: Evidence for icy planets, collisions or high-energy radiation scatter
• Planetary Population Synthesis and the Emergence of Four Classes of Planetary System Architectures
• Planets Across Space and Time (PAST). V. The evolution of hot Jupiters revealed by the age distribution of their host stars
• Planets Across Space and Time (PAST). III. Morphology of the Planetary Radius Valley as a Function of Stellar Age and Metallicity in the Galactic Context Revealed by the LAMOST-Gaia-Kepler Sample
• The Period Distribution of Hot Jupiters is Not Dependent on Host Star Metallicity
• A Distinct Population of Small Planets: Sub-Earths
• Planetary Orbit Eccentricity Trends (POET). I. The Eccentricity-Metallicity Trend for Small Planets Revealed by the LAMOST-Gaia-Kepler Sample
• On the origin of the eccentricity dichotomy displayed by compact super-Earths: dynamical heating by cold giants
• The New Generation Planetary Population Synthesis (NGPPS). VII. Statistical comparison with the HARPS/Coralie survey

Cited by in corpus (3)

• Exploring the conditions for forming planetesimals by the streaming instability and planetary systems by pebble accretion
• A break in planet occurrence near the pebble isolation mass should be observable by the Roman microlensing survey
• Sub-Neptunes Show a Stronger Correlation with Cold Jupiters than Super-Earths Especially in Metal-rich Systems