Keck Spectra of Q 0014 + 813 : annulling the case for high deuterium abundances

The spectrum of quasar 0014+813 was the first in which deuterium was claimed to be observed, at first as a probable detection, and later " confirmed ". It is important because it is the only case in which there is a serious likelihood of a high D/H ratio, since the others are more ambiguous and admit a wide range of D/H including zero. We present new high-resolution spectra with higher quality than those published. Deuterium has been reported in two Lyman limit systems (z abs = 3.32, 2.80) along the line of sight. In both we find that the absorption is readily explained by H alone and that deuterium absorption is neither required nor suggested by the spectra. The three previous models with high D/H values (D/H ≈ 20 × 10 −5) are not compatible with the new data, and in some cases the differences are surprisingly large. Since the spectrum is compatible with all values of D/H from zero up to large upper limits, neither absorption system can be used to measure D/H, and previously cited values should be disregarded. There is now no case in which a high value of D/H has been established, and all data are compatible with low D/H. Deuterium has been seen and measured in only two QSOs (Q1937–1009 and Q1009+2956), both of which give low D/H. Several other QSOs give upper limits which are about ten times less sensitive.