Panel a: projected 2-d posterior of the GRAVITY+GPI fit with petitRADTRANS (spectrum shown in Fig. 5), described in Sect. 4.3. See the text in Appendix B for a description of the parameters. Panel b: pressure-temperature envelopes obtained for the same retrieval. At every pressure, we plot the 16 to 84-percentile envelopes in dark blue, and the 2.5 to 97.5 percentile envelopes in light blue. If the temperature values were following a Gauss distribution, this would correspond to the 1 and 2 σ envelopes, respectively.