Planetary-mass-limit VLT/SINFONI library

We modeled them using ForMoSA, a Bayesian forward modeling tool for spectral analysis, and we explored four families of self-consistent atmospheric models: ATMO, BT-Settl, Exo-REM, and Sonora Diamondback. Here, we present the spectra of our targets and the derived parameters from the atmospheric modeling process. We confirm a drop in Teff as a function of the spectral type of more than 500 K at the M/L transition.

In addition, we report C/O measurements for three companions, 2M 0103 AB b, AB Pic b, and CD-35 2722 b, thereby adding to the growing list of exoplanets with measured C/O ratios. The VLT/SINFONI Library highlights two key points. First, there is a critical need to further investigate the discrepancies among grids of spectra generated by self-consistent models, as these models yield varying results and do not uniformly explore the parameter space.

Second, we do not observe any obvious discrepancies in the K-band spectra between companions and isolated brown dwarfs, which suggests that these super-Jupiter objects might have formed through a similar process; however, this possibility warrants further investigation.