Confirmation of high deuterium abundance in QSO absorbers

Abstract

We present a new analysis of a Keck spectrum of Q0014+813, with a new model of the $z=3.32$ absorbing cloud. We fit Lyman series absorption of the dominant HI components, including components identified with hydrogen and associated deuterium at two discrete velocities, with thermal line broadening of each species. The deuterium features are too narrow to be interlopers, and the good agreement in temperature and redshift with their hydrogen counterparts confirms the identification as deuterium. The abundance is measured to be $D/H$ $ = 1.9 \pm 0.5$ and $1.9 \pm 0.4 \times 10^{-4}$ in the two components, with an independent lower limit of D/H $> 1.3 \times 10^{-4}$ for the sum, derived from the Lyman Limit opacity. The impact on cosmological theory is briefly discussed.