Refractive indices of photochemical haze analogs for Solar System and exoplanet applications : a cross-laboratory comparative study between the PAMPRE and COSmIC experimental set-ups

Abstract

Previous observations of Titan, Pluto and Solar System gas giants along with recent observations of exoplanet atmospheres with the James Webb Space Telescope taught us that photochemical hazes are ubiquitous and form in a variety of temperature, gas composition and irradiation environments. Despite being crucial to understand their impact on observations and on the planetary radiative budget, the refractive indices of these haze particles are unknown and strongly influenced by changes in the gas phase chemistry. In this study, we perform a cross-laboratory investigation to assess the effect of the experimental set-up and gas composition on the refractive indices of Titan, Pluto and exoplanet haze analogs. We report new data in a broad spectral range from UV to far-IR (up to 200 microns) for future use in climate models and retrieval frameworks.