A new measurement of zinc metallicity in a DLA at z∼3.35

We present chemical abundance measurements in the z(abs)=3.35045 Damped Lyman-alpha (DLA) system observed in the UVES spectrum of the BAL quasar BR 1117-1329. We measure a neutral hydrogen column density N(HI)=6.9+/-1.7x10(20) atoms cm(-2) and derive mean abundances relative to solar: [Si/H]= -1.26+/-0.13, [Fe/H]= -1.51+/-0.13, [Ni/H]= -1.57+/-0.13, [Cr/H]= -1.36+/-0.13, [Zn/H]= -1.18+/-0.13, [Al/H]> -1.25, [O/H]> -1.25 and [N/H]< -2.24. This is the third measurement of Zn, an element mildly depleted onto dust grain, at z(abs)>3. The iron to zinc and chromium to zinc ratios, [Fe/Zn]= -0.33 +/- 0.05 and [Cr/Zn]= -0.18 +/- 0.05 demonstrate that the absorber has a low dust content. The nitrogen ratio [N/Si]< -0.98 suggests that the 'secondary' N production process is taking place in this DLA. Finally, this absorber does not seem to present a convincing alpha-enhancement as shown by the alpha over Fe-peak element ratios: [Si/Fe]= 0.25+/-0.06, [Si/Cr]= 0.10+/-0.06 and [Si/Zn]= -0.08+/-0.06. (C) 2002 Elsevier Science B.V. All rights reserved.