HIGH-REDSHIFT SUPERCLUSTERING OF QUASI-STELLAR OBJECT ABSORPTION-LINESYSTEMS ON 100-H(-1) MPC SCALES

We have analyzed the clustering of C IV absorption-line systems in an extensive new catalog of heavy-element quasi-stellar object (QSO) abso rbers. The catalog permits exploration of clustering over a large rang e in both scale (from about 1 to 300 h(-1) Mpc) and redshift (z from 1 .2 to 4.5). We find significant evidence (5.0 sigma; Q = 2.9 X 10(-7)) that C IV absorbers are clustered on comoving scales of 100 h(-1) Mpc (q(0) = 0.5) and less-similar to the size of voids and walls found in galaxy redshift surveys of the local universe (z < 0.2)-with a mean c orrelation function [xi(aa)] = 0.42 +/- 0.10 over these scales. We fin d, on these scales, that the mean correlation function at low ([z](low ) = 1.7), medium ([z](med) = 2.4), and high redshift ([z](high) = 3.0) is [xi(aa)] = 0.40 +/- 0.17, 0.32 +/- 0.14, and 0.72 +/- 0.25, respec tively. Thus, the superclustering is present even at high redshift; fu rthermore, it does not appear that the superclustering scale, in comov ing coordinates, has changed significantly since then. We find seven Q SOs with rich groups of absorbers (potential superclusters) that accou nt for a significant portion of the clustering signal, with two at red shift z similar to 2.8. We find that the superclustering is just as ev ident if we take q(0) = 0.1 instead of 0.5; however, the inferred scal e of clustering is then 240 h(-1) Mpc, which is larger than the larges t scales of clustering known at present. This discrepancy may be indic ative of a larger value of q(0) and hence Omega(0). The evolution of t he correlation function on 50 h(-1) Mpc scales is consistent with that expected in cosmologies with density parameter ranging from Omega(0) = 0.1 to 1. Finally, we find no evidence for clustering on scales grea ter than 100 h(-1) Mpc (q(0) = 0.5) or 240 h(-1) Mpc (q(0) = 0.1).