Spectral synthesis of the oxygen line at 6158 Å in HD 22879 (upper panel) and [OI]6300 in HD 25704 (lower panel). The observed spectra (dots) with the 1σ photometric noise (rms) is compared with the synthetic spectra, computed for the corresponding [Fe/H] and [O/H] abundances obtained from our EW measurements (solid line). Dashed lines represent the synthetic spectra for the ± 1σ error abundances, which are δ [Fe/H] = ± 0.03 dex, dex and dex (propagated from the provided EW error). Also shown are the stellar parameters, nominal S/N, abundances, EW and residual intensities (observed - predicted).