Large Interferometer For Exoplanets (LIFE): V. Diagnostic potential of a mid-infrared space-interferometer for studying Earth analogs

Abstract

An important future goal in exoplanetology is to detect and characterize potentially habitable planets. Using nulling interferometry, LIFE will allow us to constrain the radius and effective temperature of (terrestrial) exoplanets, as well as provide unique information about their atmospheric structure and composition. We explore the potential of LIFE in characterizing emission spectra of Earth at various stages of its evolution. We perform Bayesian retrievals on simulated spectra of 8 different scenarios, which correspond to cloud-free and cloudy spectra of four different epochs of the evolution of the Earth. Assuming a distance of 10 pc and a Sun-like host star, we simulate observations obtained with LIFE using its simulator LIFEsim, considering all major astrophysical noise sources. With the nominal spectral resolution (R=50) and signal-to-noise ratio (assumed to be S/N=10 at 11.2 $\mu$m), we can identify the main spectral features of all the analyzed scenarios (most notably CO${}_2$, H${}_2$O, O${}_3$, CH${}_4$). This allows us to distinguish between inhabited and lifeless scenarios. Results suggest that particularly O${}_3$ and CH${}_4$ yield an improved abundance estimate by doubling the S/N from 10 to 20. We conclude that the baseline requirements for R and S/N are sufficient for LIFE to detect O${}_3$ and CH${}_4$ in the atmosphere of an Earth-like planet with an abundance of O${}_2$ of around 2% in volume mixing ratio. This information is relevant in terms of the LIFE mission planning. We also conclude that cloud-free retrievals of cloudy planets can be used to characterize the atmospheric composition of terrestrial habitable planets, but not the thermal structure of the atmosphere. From the inter-model comparison performed, we deduce that differences in the opacity tables (caused by e.g. a different line wing treatment) may be an important source of systematic errors.

arXiv comment18 pages (main text, incl. 11 figures) + appendix; submitted to A&A; comments are very welcome! Fifth paper of LIFE telescope series. First: arXiv:2101.07500v4, Second: arXiv:2203.00471, Third: arXiv:2112.02054, Sixth: arXiv:2201.04891

References in corpus (41)

• Astropy: A Community Python Package for Astronomy
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• X-ray spectral modelling of the AGN obscuring region in the CDFS: Bayesian model selection and catalogue
• Probabilistic Forecasting of the Masses and Radii of Other Worlds
• petitRADTRANS: a Python radiative transfer package for exoplanet characterization and retrieval
• ExoMol line lists IV: The rotation-vibration spectrum of methane up to 1500 K
• Atomic and Molecular Opacities for Brown Dwarf and Giant Planet Atmospheres
• The faint young Sun problem
• Exoplanet Biosignatures: Understanding Oxygen as a Biosignature in the Context of Its Environment
• The Pale Orange Dot: The Spectrum and Habitability of Hazy Archean Earth
• Transits of Earth-Like Planets
• Spectral Evolution of an Earth-Like Planet
• Model atmospheres of irradiated exoplanets: The influence of stellar parameters, metallicity, and the C/O ratio
• Retrieving scattering clouds and disequilibrium chemistry in the atmosphere of HR 8799e
• Exoplanet Biosignatures: A Framework for Their Assessment
• Observing transiting planets with JWST -- Prime targets and their synthetic spectral observations
• Large Interferometer For Exoplanets (LIFE): I. Improved exoplanet detection yield estimates for a large mid-infrared space-interferometer mission
• The Occurrence of Rocky Habitable Zone Planets Around Solar-Like Stars from Kepler Data
• The ExoMolOP Database: Cross-sections and k-tables for Molecules of Interest in High-Temperature Exoplanet Atmospheres
• The Habitable Exoplanet Observatory (HabEx) Mission Concept Study Final Report
• Spectral Fingerprints of Earth-like Planets Around FGK Stars
• Exoplanet Biosignatures: Future Directions
• The HOSTS survey for exozodiacal dust: Observational results from the complete survey
• Characterizing Earth Analogs in Reflected Light: Atmospheric Retrieval Studies for Future Space Telescopes
• Toward the analysis of JWST exoplanet spectra: Identifying troublesome model parameters
• A comparison of exoplanet spectroscopic retrieval tools
• Spectra of Earth-like Planets Through Geological Evolution Around FGKM Stars
• Atmospheric Retrieval of Exoplanets
• An Ensemble of Bayesian Neural Networks for Exoplanetary Atmospheric Retrieval
• Large Interferometer For Exoplanets (LIFE): III. Spectral resolution, wavelength range and sensitivity requirements based on atmospheric retrieval analyses of an exo-Earth
• Call for a Framework for Reporting Evidence for Life Beyond Earth
• Large Interferometer For Exoplanets (LIFE): II. Signal simulation, signal extraction and fundamental exoplanet parameters from single epoch observations
• Dreaming of atmospheres
• The Influence of H2O Pressure Broadening in High Metallicity Exoplanet Atmospheres
• Understanding planetary context to enable life detection on exoplanets and test the Copernican principle
• Theoretical Reflectance Spectra of Earth-Like Planets through Their Evolutions: Impact of Clouds on the Detectability of Oxygen, Water, and Methane with Future Direct Imaging Missions
• Exoplanetary Monte Carlo Radiative Transfer with Correlated-k I. Benchmarking Transit and Emission Observables
• Habitability of the early Earth: Liquid water under a faint young Sun facilitated by strong tidal heating due to a closer Moon
• High pCO${}_2$ reduces sensitivity to CO${}_2$ perturbations on temperate, Earth-like planets throughout most of habitable zone
• Earth: Atmospheric Evolution of a Habitable Planet

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• Earth as an Exoplanet. III. Using Empirical Thermal Emission Spectra as an Input for Atmospheric Retrieval of an Earth-twin Exoplanet
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• Is Ozone a Reliable Proxy for Molecular Oxygen? II. The impact of N${}_2$O on the O${}_2$-O${}_3$ relationship for Earth-like atmospheres
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• Photobombing for the Large Interferometer For Exoplanets (LIFE). A new criterion for target confusion and application to a MIR rotating nulling interferometer
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