TEA: A Code for Calculating Thermochemical Equilibrium Abundances

Abstract

We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. (1958) and Eriksson (1971). It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature-pressure pairs. We tested the code against the method of Burrows & Sharp (1999), the free thermochemical equilibrium code CEA (Chemical Equilibrium with Applications), and the example given by White et al. (1958). Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

14 pages, 8 figures, article is submitted to ApJS, posted on arXiv for public commentary, please send comments to the lead author

References in corpus (8)

• Thermal structure of an exoplanet atmosphere from phase-resolved emission spectroscopy
• Atomic and Molecular Opacities for Brown Dwarf and Giant Planet Atmospheres
• Atmospheric Sulfur Photochemistry on Hot Jupiters
• A chemical model for the atmosphere of hot Jupiters
• A Systematic Study of Departures from Chemical Equilibrium in the Atmospheres of Substellar Mass Objects
• Re-Evaluating WASP-12b: Strong Emission at 2.315 micron, Deeper Occultations, and an Isothermal Atmosphere
• Deciphering the Atmospheric Composition of WASP-12b: A Comprehensive Analysis of its Dayside Emission
• Ks band secondary eclipses of WASP-19b and WASP-43b with the Anglo-Australian Telescope

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