For J0657 (blue) and J1317 (green), we show the 1σ confidence region distribution in luminosity and emission radius space, as it can be derived from the best-fit BB model depicted in Table 3. The rectangles indicate the 1σ confidence region at certain distances. For the computation via the Stefan-Boltzmann law, we assumed varying test distances ranging from 0.1–5 kpc. The radius-luminosity positions of thermal emission components observed in archival INSs are marked as well. The values and object descriptions were taken from Potekhin et al. (2020).