Changing disc compositions via internal photoevaporation I: Solar-mass stars

Abstract

The chemical evolution of protoplanetary discs is not fully understood, several factors influence the final distribution of disc material. One such factor are inward drifting and evaporating pebbles that enrich the inner disc with vapour. In particular, it is first enriched with water vapour, resulting in a low C/O ratio, before carbon-rich gas from the outer disc is transported inwards elevating the C/O ratio again. However, it is unclear how internal photoevaporation, which carries away gas and opens gaps that block inward drifting pebbles, affects the chemical composition of the disc. We aim to study these effects in discs around solar-like stars, where we especially focus on the C/O ratio and the water content. The simulations are carried out using a semi-analytical 1D disc model. Our code chemcomp includes viscous evolution and heating, pebble growth and drift, pebble evaporation and condensation, and a simple chemical partitioning model. We show that internal photoevaporation plays a major role in the (chemical) evolution of protoplanetary discs: As it opens a gap, inward drifting pebbles are stopped and cannot contribute to the volatile content any more. In addition, gas from the outer disc is carried away by photoevaporative winds. Consequently, the C/O ratio in the inner disc is low. In contrast, gaps opened by giant planets allow the gas to pass, resulting in an elevated C/O ratio, similar to viscous discs without internal photoevaporation. This will enable us to distinguish observationally between these two scenarios when measuring the C/O ratio, implying that we can infer the cause of gap structures in disc observations. In the case of a photoevaporative disc, we additionally find an elevated water content in the inner disc as the water vapour and ice undergo a cycle of evaporation/re-condensation, preventing its inward accretion onto the star.

References in corpus (27)

• Coagulation, fragmentation and radial motion of solid particles in protoplanetary disks
• X-Shooter spectroscopy of young stellar objects in Lupus: Accretion properties of class II and transitional objects
• Separating gas-giant and ice-giant planets by halting pebble accretion
• The imprint of exoplanet formation history on observable present-day spectra of hot Jupiters
• The stickiness of micrometer-sized water-ice particles
• Chemical enrichment of giant planets and discs due to pebble drift
• Dust flow in gas disks in the presence of embedded planets
• Contacts of Water Ice in Protoplanetary Disks - Laboratory Experiments
• A solar C/O and sub-solar metallicity in a hot Jupiter atmosphere
• Formation of planetary systems by pebble accretion and migration: Growth of gas giants
• Dust retention in protoplanetary disks
• Planet-forming material in a protoplanetary disc: the interplay between chemical evolution and pebble drift
• MINDS. The detection of ${}^{13}$CO${}_2$ with JWST-MIRI indicates abundant CO${}_2$ in a protoplanetary disk
• Planet population synthesis driven by pebble accretion in cluster environments
• Water in the terrestrial planet-forming zone of the PDS 70 disk
• 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
• The dispersal of protoplanetary discs. II: Photoevaporation models with observationally derived irradiating spectra
• MINDS. Abundant water and varying C/O across the disk of Sz 98 as seen by JWST/MIRI
• Close-in ice lines and the super-stellar C/O ratio in discs around very low-mass stars
• Exploring the conditions for forming cold gas giants through planetesimal accretion
• How drifting and evaporating pebbles shape giant planets III: The formation of WASP-77A b and $\tau$ Boötis b
• Enriching inner discs and giant planets with heavy elements
• Chemical evolution in ices on drifting, planet-forming pebbles
• Forming super-Mercuries: The role of stellar abundances
• How the origin of stars in the Galaxy impacts the composition of planetary building blocks
• Influence of grain sizes and composition on the contraction rates of planetary envelopes and on planetary migration

Cited by in corpus (10)

• CO2-rich protoplanetary discs as a probe of dust radial drift & trapping
• Burned to ashes: How the thermal decomposition of refractory organics in the inner protoplanetary disc impacts the gas-phase C/O ratio
• MINDS. JWST-MIRI reveals a peculiar CO${}_2$-rich chemistry in the drift-dominated disk CX Tau
• Chemical transformation of CO in evolving protoplanetary discs across stellar masses: a route to C-rich inner regions
• There is no disk mass budget problem of planet formation
• How external photo-evaporation changes the chemical composition of the inner disc
• Changing disc compositions via internal photoevaporation II: M dwarf systems
• How disc initial conditions sculpt the atmospheric composition of giant planets
• Timescales diagnostics for saving viscous and MHD-driven dusty discs from external photoevaporation
• How leaky? A large parameter study of leaky dust traps to quantify the transport of pebbles and ice in protoplanetary discs