Exoplanetology: Exoplanets & Exomoons

POSEIDON: A Multidimensional Atmospheric Retrieval Code for Exoplanet Spectra

By Keith Cowing

Status Report

astro-ph.IM

October 29, 2024

Filed under astro-ph.IM, astronomy, atmosphere, exoplanet, habitability, Hubble Space Telescope, JWST, POSEIDON, Spectroscopy, telescope

POSEIDON: A Multidimensional Atmospheric Retrieval Code for Exoplanet Spectra — Schematic architecture of the POSEIDON atmospheric retrieval code. Users can call POSEIDON in two main ways: (i) to generate a model exoplanet spectrum for a specified planet atmosphere (green arrows); or (ii) to fit an observed exoplanet spectrum by statistical sampling of a model’s atmospheric properties (purple arrows). The diagram highlights code inputs (circles), algorithm steps (rectangles), and code outputs (bottom green or purple boxes). — astro-ph.IM

Spectroscopic observations of exoplanet atmospheres can reveal the chemical composition, temperature, cloud properties, and (potentially) the habitability of these distant worlds. The inference of such properties is generally enabled by Bayesian atmospheric retrieval algorithms.

However, until recently, many retrieval codes have not been publicly available. Here, we describe the open source release of the POSEIDON exoplanet radiative transfer and retrieval code. POSEIDON is a Python package for the 1D, 2D, or 3D modelling and analysis of exoplanet spectra, which is frequently used to interpret Hubble and JWST observations of exoplanet atmospheres.

We provide extensive tutorials on both forward modelling and retrievals in POSEIDON’s online documentation, which we hope will serve as a helpful resource for the exoplanet atmosphere community.

Ryan J. MacDonald
Comments: 6 pages, 1 figure, published in JOSS in 2023. Tutorials available at this https URL
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2410.18181 [astro-ph.IM] (or arXiv:2410.18181v1 [astro-ph.IM] for this version)
https://doi.org/10.48550/arXiv.2410.18181
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Journal reference: Journal of Open Source Software (2023): 8(81), 4873
Related DOI:
https://doi.org/10.21105/joss.04873
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Submission history
From: Ryan MacDonald
[v1] Wed, 23 Oct 2024 18:00:03 UTC (2,818 KB)
https://arxiv.org/abs/2410.18181
Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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