Detecting Biosignatures in Nearby Rocky Exoplanets using High-Contrast Imaging and Medium-Resolution Spectroscopy with Extremely Large Telescope

Abstract

In the upcoming decades, one of the primary objectives in exoplanet science is to search for habitable planets and signs of extraterrestrial life in the universe. Signs of life can be indicated by thermal-dynamical imbalance in terrestrial planet atmospheres. O${}_2$ and CH${}_4$ in the modern Earth's atmosphere are such signs, commonly termed biosignatures. These biosignatures in exoplanetary atmospheres can potentially be detectable through high-contrast imaging instruments on future extremely large telescopes (ELTs). To quantify the signal-to-noise ($S/N$) ratio with ELTs, we select up to 10 nearby rocky planets and simulate medium resolution (R $\sim$ 1000) direct imaging of these planets using the Mid-infrared ELT Imager and Spectrograph (ELT/METIS, 3-5.6 $\mu$m) and the High Angular Resolution Monolithic Optical and Near-infrared Integral field spectrograph (ELT/HARMONI, 0.5-2.45 $\mu$m). We calculate the $S/N$ for the detection of biosignatures including CH${}_4$, O${}_2$, H${}_2$O, and CO${}_2$. Our results show that GJ 887~b has the highest detection $S/N$ for biosignatures and Proxima Cen b exhibits the only detectable CO${}_2$ among the targets for ELT/METIS direct imaging. We also investigate the TRAPPIST-1 system, the archetype of nearby transiting rocky planet systems, and compare the biosignature detection $S/N$ of transit spectroscopy with JWST versus direct spectroscopy with ELT/HARMONI. Our findings indicate JWST is more suitable for detecting and characterizing the atmospheres of transiting planet systems such as TRAPPIST-1 that are relatively further away and have smaller angular separations than more nearby non-transiting planets.

arXiv comment19 pages, 5 figures; Accepted to The Astronomical Journal

References in corpus (49)

• The SIMBAD astronomical database
• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• Detection of an Extrasolar Planet Atmosphere
• Images of a fourth planet orbiting HR 8799
• A giant planet imaged in the disk of the young star Beta Pictoris
• The evaporation valley in the Kepler planets
• Probabilistic Forecasting of the Masses and Radii of Other Worlds
• Discovery and spectroscopy of the young Jovian planet 51 Eri b with the Gemini Planet Imager
• Habitable planets around the star Gl 581?
• Infrared Transmission Spectroscopy of the Exoplanets HD209458b and XO-1b Using the Wide Field Camera-3 on the Hubble Space Telescope
• Exoplanet Biosignatures: A Review of Remotely Detectable Signs of Life
• Core-powered mass loss and the radius distribution of small exoplanets
• Sculpting the Valley in the Radius Distribution of Small Exoplanets as a by-product of Planet Formation: The Core-Powered Mass-Loss Mechanism
• Characterizing transiting exoplanet atmospheres with JWST
• PandExo: A Community Tool for Transiting Exoplanet Science with JWST & HST
• An atmospheric radiation model for Cerro Paranal. I. The optical spectral range
• Super-Earth Atmospheres: Self-Consistent Gas Accretion and Retention
• Photochemistry in Terrestrial Exoplanet Atmospheres I: Photochemistry Model and Benchmark Cases
• Synthetic Spectra and Colors of Young Giant Planet Atmospheres: Effects of Initial Conditions and Atmospheric Metallicity
• The Atmospheric Signatures of Super-Earths: How to Distinguish Between Hydrogen-Rich and Hydrogen-Poor Atmospheres
• The Detectability and Characterization of the TRAPPIST-1 Exoplanet Atmospheres with JWST
• An advanced scattered moonlight model for Cerro Paranal
• Discovery of a warm, dusty giant planet around HIP65426
• Identification of carbon dioxide in an exoplanet atmosphere
• Exoplanet Reflected Light Spectroscopy with PICASO
• Photochemistry in Terrestrial Exoplanet Atmospheres III: Photochemistry and Thermochemistry in Thick Atmospheres on Super Earths and Mini Neptunes
• Disequilibrium biosignatures over Earth history and implications for detecting exoplanet life
• Photochemistry in Terrestrial Exoplanet Atmospheres II: H2S and SO2 Photochemistry in Anoxic Atmospheres
• Observing Exoplanets with High Dispersion Coronagraphy. I. The scientific potential of current and next-generation large ground and space telescopes
• Theoretical Spectra of Terrestrial Exoplanet Surfaces
• Confirmation of the planet around HD 95086 by direct imaging
• Direct detection of exoplanets in the 3 -- 10 micron range with E-ELT/METIS
• MICADO: the E-ELT Adaptive Optics Imaging Camera
• Information Content Analysis for Selection of Optimal JWST Observing Modes for Transiting Exoplanet Atmospheres
• Abundant atmospheric methane from volcanism on terrestrial planets is unlikely and strengthens the case for methane as a biosignature
• Bioverse: A Comprehensive Assessment of the Capabilities of Extremely Large Telescopes to Probe Earth-like O${}_2$ Levels in Nearby Transiting Habitable Zone Exoplanets
• A multiple planet system of super-Earths orbiting the brightest red dwarf star GJ887
• Characterizing Atmospheres of Transiting Earth-like Exoplanets Orbiting M Dwarfs with James Webb Space Telescope
• Direct imaging and spectroscopy of exoplanets with the ELT/HARMONI high-contrast module
• Testing the Detectability of Extraterrestrial ${\mathrm{O}}_2$ with the ELTs using Real Data with Real Noise
• Exoplanets with ELT-METIS I: Estimating the direct imaging exoplanet yield around stars within 6.5 parsecs
• Detecting the proposed CH4-CO2 biosignature pair with the James Webb Space Telescope: TRAPPIST-1e and the effect of cloud/haze
• The Formation and Dynamics of Super-Earth Planets
• Properties of the radius valley around low mass stars: Predictions from the core-powered mass-loss mechanism
• METIS - the Mid-infrared E-ELT Imager and Spectrograph
• Simulated performance of the molecular mapping for young giant exoplanets with the Medium Resolution Spectrometer of JWST/MIRI
• Detecting Biosignatures in the Atmospheres of Gas Dwarf Planets with the James Webb Space Telescope
• The Direct Mid-Infrared Detectability of Habitable-zone Exoplanets Around Nearby Stars
• Exoplanets Sciences with Nulling Interferometers and a Single-Mode Fiber-Fed Spectrograph

Cited by in corpus (3)

• Vertical structure of an exoplanet's atmospheric jet stream
• JWST COMPASS: NIRSpec/G395H Transmission Observations of the Super-Earth TOI-776b
• Bioverse: Potentially Observable Exoplanet Biosignature Patterns Under the UV Threshold Hypothesis for the Origin of Life