The log of the deuterium abundances (), and their uncertainties, inferred from 12 low, high QSOALS. In (a) is shown as a function of the redshift. In (b) is shown as a function of the metallicity (squares for silicon and triangles for oxygen). In (c) is shown as a function of the neutral hydrogen column density. The filled symbols reflect a subjective determination of the more robust determinations of D/H compared to the open symbols. The blue solar symbol in (b) is the solar system (presolar nebula) D abundance [23].
