Plotted in black, profiles of 30 absorption features of the spectrum of Vega from different species. Superimposed on the observed lines are the results of the spectral synthesis described in Sect. 4, and the spectral single-T, single-log g synthesis carried out with the values of $T_{\mathrm{e}\mathrm{f}\mathrm{f}}^{\mathrm{a}\mathrm{v}\mathrm{e}\mathrm{r}}$ and log $g_{\mathrm{e}\mathrm{f}\mathrm{f}}^{\text{aver }}$, listed in Table 1, plotted in red and light blue, respectively (see the text for further details).