STRONG CLUSTERING OF HIGH-REDSHIFT LY-ALPHA FOREST ABSORPTION SYSTEMS

We use new observations of very weak C IV absorption lines associated with high-redshift Ly alpha absorption systems to measure the high-red shift Ly alpha line two-point correlation function (TPCF). These very weak C IV absorption lines trace small-scale velocity structure that c annot be resolved by Ly alpha absorption lines. We find that (1) high- redshift Ly alpha absorption systems with N(H I)> 3 x 10(13) cm(-2) ar e strongly clustered in redshift, (2) previous measurements of the Ly alpha line TPCF underestimated the actual clustering of the absorbers due to unresolved blending of overlapping velocity components, (3) the present observations are consistent with the hypothesis that clusteri ng of Ly alpha absorption systems extends to lower column densities, b ut maybe with smaller amplitude in the correlation function, and (4) t he observed clustering is broadly compatible with that expected for ga laxies at z similar to 2-3. We interpret these results as suggesting t hat many or most Ly alpha absorbers may arise in galaxies even at high redshifts, and, therefore, that the Ly alpha forest probes processes of galaxy formation and evolution for redshifts z less than or similar to 5.