Retrieval results of the joint transmission spectra of CoRoT-1b using different model assumptions. The orange lines are the posteriors of the retrieved models. The yellow dots are models downsampled to the data passbands. The Bayesian evidence for each hypothesis is denoted as ln 𝒵. The median offsets of the NIR spectra in the retrievals have been added to the error bars in each panel, which are -92 ppm (upper left), 10 ppm (upper right), −54 ppm (lower left), and −146 ppm (lower right).