UVES observations of a damped Lyα system at zabs=4.466 towards the quasar APM BR J0307-4945

We present the first high-resolution (6.2 to 7.7 km s(-1) FWHM) spectra of the APM BR J0307-4945 quasar at z(em) = 4.73 obtained with UVES on the 8.2 m VLT Kueyen telescope. We focus our analysis on a damped Ly alpha (DLA) system at z(abs) = 4.466 with a neutral hydrogen column density N(H1) = (4.68 +/- 0.97) 10(20) cm(-2) It is the most distant DLA system known to the present date, observed when the age of the universe was only 1.3 Gyr. It shows complex low- and high-ionization line profiles spanning approximate to 240 and 300 km s(-1) in velocity space respectively. We derive accurate abundances for N, O, Al, Si and Fe, and place a lower limit on C and an upper limit on Ni: [N/H] = -3.07 +/- 0.15, [O/H] = -1.63 +/- 0.19, [Al/H] = -1.79 +/- 0.11, [Si/H] = -1.54 +/- 0.11, [Fe/H] = -1.97 +/- 0.19, [C/H] > -1.63 and [Ni/H] < -2.35. The derived high metallicity, <similar to>1/90 solar, shows that this very young absorber (<1.3 Gyr) has already experienced a significant metal enrichment. The [O/Si] ratio is nearly solar suggesting a limited amount of dust, the relative [Si. O/Fe] abundance ratios show a similar enhancement as observed in the Milky Way stars with comparable metallicities, and the [N/O] ratio is very low. All these results point to an enrichment pattern dominated by type II supernovae which suggests a Milky Way type evolutionary model.