Clustering of Absorbers

Abstract

The observed clustering of Lyman-$α$ lines is reviewed and compared with the clustering of CIV systems. We argue that a continuity of properties exists between Lyman-$α$ and metal systems and show that the small-scale clustering of the absorbers is consistent with a scenario of gravitationally induced correlations. At large scales statistically significant over and under-densities (including voids) are found on scales of tens of Mpc.

8 pages Latex, with 2 PostScript figures, using conf_iap.sty. To appear in the Proceedings of the 13th IAP (Paris) Colloquium (July 1-5, 1997) Structure and Evolution of the IGM from QSO Absorption Line Systems, eds. P.Petitjean, S.Charlot