MEAYIN and its Observational Simulation Grid: Advancing the Search for Habitable Exoplanets and Biosignature Characterization

Abstract

The search for habitable exoplanets and the characterization of potential biosignatures via atmospheric spectrum represent the forefront of exoplanetary research. Given the faint signals from distant exoplanets, identifying such exoplanets requires next generation observatories with high sensitivity and high resolution. Recently proposed space telescope concepts, such as Habitable-Worlds-Observatory (HWO) and Large Interferometer For Exoplanets (LIFE) aim to meet these requirements, promising to enhance the discovery and characterization of habitable exoplanets. We present the Multi-spacecraft Exoplanet Aperture sYnthetic INterferometer (MEAYIN) program from China. MEAYIN utilizes nulling interferometry for direct imaging of potential habitable planets orbiting nearby solar-type stars, aiming to capture their thermal emission spectrum in the mid-infrared (MIR) band to identify biosignatures. In alignment with mission concept and scientific objectives, we report on the development of the observational simulation grid for MEAYIN. This grid, based on exoplanetary atmosphere model, simulates observational spectrum of targets under various conditions (e.g., signal-to-noise ratio, spectral resolution, and wavelength range). Furthermore, by using atmospheric retrieval analysis, we could infer the atmospheric characteristics from simulated spectrum and evaluated whether observational conditions meet observational requirements, thereby informing the instrument design for MEAYIN. We aim to enhance the observational simulation grid to cover different terrestrial planets, different planetary evolutionary stages, and the effects of biological activities on atmospheres. By integrating these simulations with observational data and laboratory experiments on biosignature production mechanisms, we will deepen our understanding of potentially habitable exoplanet properties. This integrative approach will also guide the mission design and instrumentation requirements for MEAYIN and other next generation observatories.