Abstract

The Ly? forest frequently exhibits associated metal absorption lines, but the source of metal enrichment is not fully understood yet. We present unique high-resolution spectra of gravitationally-lensed background quasars that has allowed us to study the kpc-scale structure of this highly ionized gas. The sizes of the absorbers derived from our data constrain both the ionization conditions and the CNO relative abundances at z-2. These indicate that the gas has been processed in galaxies and recently before the absorption occured, rather than in a very early epoch (z > 6) by Population III stars. © 2006: Instituto de Astronomía, UNAM.