Similar to Figure 3, but showing the variation of UV spectral flux as a function of log g. The synthetic spectra were calculated for fixed parameters (T_eff=4500 K,[Fe/H]=−1.0). Upper row: variation for the [O/Fe] ratios of −0.2,+0.2,+0.6, and +0.8. Lower row: same as the upper row but for [Mg/Fe] ratios. As the log g increases, the depth of the OH molecular band becomes deeper. The intensity of the Mg I line increases with increasing log g, while the Mg II line weakens.