2000AJ....120.1648C

We report on high-resolution observations (R≃45,000) of the Hubble Deep Field South QSO J2233-606 obtained with the VLT UV-Visual Echelle Spectrograph. We present spectral data for the wavelength region 3050 Å<λ<10000 Å. The signal-to-noise ratio of the final spectrum is about 50 per resolution element at 4000 Å, 90 at 5000 Å, 80 at 6000 Å, and 40 at 8000 Å. Redshifts, column densities, and Doppler widths of the absorption features have been determined with Voigt profile fitting. A total of 621 lines have been measured. In particular, 270 Lyα lines, 41 Lyβ lines, and 24 systems containing metal lines have been identified. Together with other data in the literature, the present spectrum confirms that the evolution of the number density of Lyα lines with logN(H I)>14 has an upturn at z∼1.4-1.6.