Speaker
Description
Atmospheric boundary conditions play a critical role in interior modeling, as they define the interior adiabat and strongly influence the inferred planetary radius for a given interior structure. For hot Jupiters, their extended and highly irradiated atmospheres enable detailed observational constraints on atmospheric composition, now reaching unprecedented quality with JWST and ground-based instruments. While previous interior structure retrievals have incorporated simplified atmospheric constraints, such as metal enrichment, they rarely include the richer chemical information that is now becoming available. In this talk, we show how atmospheric composition, specifically the metal enrichment ([M/H]) and C/O ratio, affects interior properties of hot Jupiters. We also illustrate how assuming simplified atmospheric compositions, such as a solar C/O ratio, can bias inferred interior properties. We couple a grid of self-consistent 1D radiative-chemical equilibrium models to a static interior structure model. This framework allows atmospheric composition to be used both as an atmospheric boundary condition and as a chemically informed constraint on envelope metallicity. Consistent with previous works, we find that the planetary radius predicted for a given interior structure depends strongly on atmospheric metallicity because of its direct coupling to the envelope metallicity. In addition, we observe a systematic effect from varying the C/O ratio: for a fixed interior structure, higher C/O ratios generally lead to smaller planetary radii. This effect is most pronounced for hotter interiors and therefore particularly relevant for hot Jupiters. By retrieving the interior structure of WASP-19b with different atmospheric boundary conditions, we show that assumptions about atmospheric composition can alter inferred interior properties, highlighting the importance of using chemically informed atmospheric boundary conditions when available.
| Talk category | NOVA Network 2 |
|---|---|
| PhD relevance | 2nd |
