[OI] λ6300 LVC luminosities of σ-Orionis sources in both datasets (MIKE and X-shooter) as a function of FUV field strength. Expected luminosities from external photoevaporation models (Ballabio et al. 2023) for disks with different initial sizes (solid lines) are shown. Disks exposed to FUV field strength >10³ G₀ (within 0.8 pc from σ-Ori) are labeled. The range of luminosities found in other low-mass SFRs is also shown for comparison (Fang et al. 2018, 2023). The location of proplyd 182–413 is taken from (Ballabio et al. 2023) which assumes an accretion luminosity estimated using the empirical relations from Nisini et al. (2018) for the stellar mass of the object.