Line luminosities for [O i] 630.03 and [O i] 557.79 are plotted as functions of the stellar luminosity (left panels) and of the accretion luminosity (right panels). Red filled dots are the Lupus objects, blue filled squares are objects in σ Ori, arrows show 3σ upper limits. The black crosses show the same quantities for the strongly accreting TTS DR Tau at different epochs (Banzatti et al. 2014). Black diamonds are values for Taurus very low-mass objects from Herczeg & Hillenbrand (2008, 2014, see text); green open squares denote Taurus TTS from Gullbring et al. (1998) and Hartigan et al. (1995), as described in the text. A few objects discussed in Sect. 6.2 are only labeled in some panels, to avoid confusion. Black lines show the relations derived in Eqs.(1)–(4) for the GTO sample.