Metallicity [Z] (as defined in Eq. (5)), helium mass fraction Y, and α-enhancement [Mg/Fe] of the ejected gas from a dying star (or supernova event) as a function of the stellar initial metal mass fraction Z and the stellar initial mass M_*, initial (or the initial mass of the possible SNIa progenitor, i.e. 3 to 8 M_⊙ shown by the dashed line). The thin dotted lines indicate the solar value (the solar value of Y = 0.273 is adopted from Serenelli & Basu 2010). The relation is interpolated from the stellar total yield table given by Marigo (2001) and Portinari et al. (1998) where a solar value stellar initial helium abundance is assumed for the stellar evolution model. The values are different from those in the original paper because of the difference between the “net yield” and the “total yield” (see text). The colour-coding is the same as in Figs. 5 and A.1.