Effects of refraction on transmission spectra of gas giants: decrease of the Rayleigh scattering slope and breaking of retrieval degeneracies

摘要: Detection of the signature Rayleigh scattering in transmission spectrum an exoplanet is increasingly becoming target observational campaigns because spectral slope continuum enables one to determine scaleheight its atmosphere absence hazes. However, this only true when ignores refractive effects exoplanet's atmosphere. I illustrate with a suite simple isothermal clear Jovian H2-He models various abundances water that refraction can decrease significantly and it becomes flat infrared. This mimics surface, or optically thick cloud deck, at much smaller pressures than probe non-refractive case. The relative impact on decreases atmospheric temperatures increases stellar temperature. Refraction quite important from retrieval's perspective for Jovian-like planets even highest (1200 K) considered paper, all types. Indeed, breaks large part retrieval degeneracy between chemical species planet's radius size features abundances, stark contrast case which simply shifts them larger effective radius. Abundances inferred assuming cloud-free are lower limits. These results show how include algorithms interpret spectra gas giants accurately.