Line fluxes and luminosities from the central star versus effective temperature for the Spitzer 12.407 μm blend. The blue dots are the line fluxes of the models for the different central stars. The stars indicate the luminosities in the different wavelength bands. Detection limits for Spitzer IRS observations towards the same central star disks are plotted as thick green dashes (see Appendix A). Light green curve shows a fit to the sensitivity limits. The central stars are labelled with the name reported in Col. 1 of Table 2.