Galaxies, intergalactic absorption lines, and feedback at high redshift

The galaxy-IGM part of the Lyman-break survey currently consists of measured redshifts for more than 1000 galaxies with redshift $1.5\lesssim z\lesssim 3.5$ along the sight-lines to 25 background QSOs. One of the goals of the survey was to measure the influence on the intergalactic medium of energetic feedback from star and black-hole formation. This talk begins with a description of the observed correlations between galaxies and intergalactic absorption lines and ends with a discussion of whether any of the observations provide clear evidence for Mpc-scale superwinds. Although our own observations remain fairly ambiguous, other observations strongly disfavour a very high redshift ($z\sim 10$) for the creation of intergalactic metals.