SEARCH FOR CORRELATIONS OF LYMAN-ALPHA CLOUDS AND METAL SYSTEMS ON CLOSELY SPACED LINES OF SIGHT

摘要

Spectra of four quasars projected within 2.8° on the sky with emission redshifts near 1.9 were analyzed for correlations of metal-line and Lyα absorbers. The group of bright quasars LB 9601, LB 9605, LB 9612, and LB 9615 probes scales on the sky of clusters and superclusters of galaxies. No significant correlation signal was detected in any of the three pairs of sight lines tested out to a velocity separation of 10,000 km s~(-1). One common pair of Lyα absorbers was newly detected, with velocities identical to within 10 km s~(-1). Four new heavy-element absorption systems are reported. Three C IV systems, one along each of three of the lines of sight, agree in velocity to within 4% of the accessible velocity range, which may indicate that the absorbers are associated. No evidence is found that intervening hydrogen clouds are correlated on the scale of super-clusters of galaxies.