Potential Atmospheric Compositions of TRAPPIST-1 c Constrained by JWST/MIRI Observations at 15 μm
| Autor: | Andrew P. Lincowski, Victoria S. Meadows, Sebastian Zieba, Laura Kreidberg, Caroline Morley, Michaël Gillon, Franck Selsis, Eric Agol, Emeline Bolmont, Elsa Ducrot, Renyu Hu, Daniel D. B. Koll, Xintong Lyu, Avi Mandell, Gabrielle Suissa, Patrick Tamburo |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | The Astrophysical Journal Letters, Vol 955, Iss 1, p L7 (2023) |
| Druh dokumentu: | article |
| ISSN: | 2041-8213 2041-8205 |
| DOI: | 10.3847/2041-8213/acee02 |
| Popis: | The first James Webb Space Telescope observations of TRAPPIST-1 c showed a secondary eclipse depth of 421 ± 94 ppm at 15 μ m, which is consistent with a bare rock surface or a thin, O _2 -dominated, low-CO _2 atmosphere. Here we further explore potential atmospheres for TRAPPIST-1 c by comparing the observed secondary eclipse depth to synthetic spectra of a broader range of plausible environments. To self-consistently incorporate the impact of photochemistry and atmospheric composition on atmospheric thermal structure and predicted eclipse depth, we use a two-column climate model coupled to a photochemical model and simulate O _2 -dominated, Venus-like, and steam atmospheres. We find that a broader suite of plausible atmospheric compositions are also consistent with the data. For lower-pressure atmospheres (0.1 bar), our O _2 –CO _2 atmospheres produce eclipse depths within 1 σ of the data, consistent with the modeling results of Zieba et al. However, for higher-pressure atmospheres, our models produce different temperature–pressure profiles and are less pessimistic, with 1–10 bar O _2 , 100 ppm CO _2 models within 2.0 σ –2.2 σ of the measured secondary eclipse depth and up to 0.5% CO _2 within 2.9 σ . Venus-like atmospheres are still unlikely. For thin O _2 atmospheres of 0.1 bar with a low abundance of CO _2 (∼100 ppm), up to 10% water vapor can be present and still provide an eclipse depth within 1 σ of the data. We compared the TRAPPIST-1 c data to modeled steam atmospheres of ≤3 bars, which are 1.7 σ –1.8 σ from the data and not conclusively ruled out. More data will be required to discriminate between possible atmospheres or more definitively support the bare rock hypothesis. |
| Databáze: | Directory of Open Access Journals |
| Externí odkaz: |
|