How disc initial conditions sculpt the atmospheric composition of giant planets
arXiv:2601.10285 · doi:10.1051/0004-6361/202556632
Abstract
Past studies have revealed the dependency of the disc parameters (mass, radius, viscosity, grain fragmentation velocity, dust-to-gas ratio) on the formation of giant planets, where more massive discs seem beneficial for giant planet formation. It is unclear how the different disc properties influence the composition of forming giant planets. The idea that the atmospheric abundances can trace directly the formation location of planets is put into question, due to the chemical evolution of the disc, caused by inward drifting and evaporating pebbles. This complicates the idea of a relation between atmospheric abundances and planet formation locations. We use planet formation simulations that include the effects of pebble drift and evaporation and investigate how the different disc parameters influence the atmospheric composition of giant planets. We focus on the atmospheric C/O, C/H, O/H and S/H ratios allowing us to probe tracers for volatiles and refractories and thus different accretion pathways of giant planets. We find that most of the disc parameters have only a limited influence on the atmospheric abundances of gas giants, except for the dust-to-gas ratio, where a larger value results in higher atmospheric abundances. However the atmospheric abundances are determined by the planetary formation location, even in the pebble drift and evaporation scenario. Our study suggests that volatile-rich giant exoplanets predominantly form in the inner disc regions, where they can accrete large fractions of vapour-enhanced gas. Our study shows that simulations that try to trace the origin of giant planets via their atmospheric abundances do not have to probe all disc parameters, as long as the disc parameters allow the formation of giant planets. Our study thus suggests that the diversity of observed planetary compositions is a direct consequence of their formation location and migration history.
Accepted by A&A, 12 pages, 4 figures, 8 pages of Appendix
References in corpus (39)
- Coagulation, fragmentation and radial motion of solid particles in protoplanetary disks
- Separating gas-giant and ice-giant planets by halting pebble accretion
- Chemical enrichment of giant planets and discs due to pebble drift
- Dust flow in gas disks in the presence of embedded planets
- Cavity opening by a giant planet in a protoplanetary disc and effects on planetary migration
- Setting the volatile composition of (exo)planet-building material. Does chemical evolution in disk midplanes matter?
- How drifting and evaporating pebbles shape giant planets I: Heavy element content and atmospheric C/O
- Planet-forming material in a protoplanetary disc: the interplay between chemical evolution and pebble drift
- Dynamical corotation torques on low-mass planets
- Where is the Water? Jupiter-like C/H ratio but strong HO depletion found on Boötis b using SPIRou
- Composition of Early Planetary Atmospheres I: Connecting Disk Astrochemistry to the Formation of Planetary Atmospheres
- Improved torque formula for low and intermediate mass planetary migration
- Five key exoplanet questions answered via the analysis of 25 hot Jupiter atmospheres in eclipse
- Connecting planet formation and astrochemistry: A main sequence for C/O in hot-exoplanetary atmospheres
- How drifting and evaporating pebbles shape giant planets II: Volatiles and refractories in atmospheres
- Influence of sub- and super-solar metallicities on the compositions of solid planetary building blocks
- Close-in ice lines and the super-stellar C/O ratio in discs around very low-mass stars
- Assessing the C/O Ratio Formation Diagnostic: A Potential Trend with Companion Mass
- Volatile-to-sulfur Ratios Can Recover a Gas Giant's Accretion History
- Growing and Trapping Pebbles with Fragile Collisions of Particles in Protoplanetary Disks
- Exploring the conditions for forming cold gas giants through planetesimal accretion
- Influence of planetary gas accretion on the shape and depth of gaps in protoplanetary discs
- Giants are bullies: how their growth influences systems of inner sub-Neptunes and super-Earths
- Influence of grain growth on the thermal structure of protoplanetary discs
- How drifting and evaporating pebbles shape giant planets III: The formation of WASP-77A b and Boötis b
- How to make giant planets via pebble accretion
- BOWIE-ALIGN: How formation and migration histories of giant planets impact atmospheric compositions
- Probing the impact of varied migration and gas accretion rates for the formation of giant planets in the pebble accretion scenario
- Enriching inner discs and giant planets with heavy elements
- Composition of giant planets: the roles of pebbles and planetesimals
- Dust crystallinity in protoplanetary disks: the effect of diffusion/viscosity ratio
- Chemical evolution in ices on drifting, planet-forming pebbles
- How does accretion of planet-forming disks influence stellar abundances?
- Exoplanet Interior Retrievals: core masses and metallicities from atmospheric abundances
- Burned to ashes: How the thermal decomposition of refractory organics in the inner protoplanetary disc impacts the gas-phase C/O ratio
- Changing disc compositions via internal photoevaporation I: Solar-mass stars
- Planet formation in chemically diverse and evolving discs -- I. Composition of planetary building blocks
- How external photo-evaporation changes the chemical composition of the inner disc
- HD 163296 and its Giant Planets: Creation of Exo-comets, Interstellar Objects and Transport of Volatile Material