Metals in the intergalactic medium

Abstract

The enrichment of the intergalactic medium (IGM) with heavy elements provides us with a record of past star formation and with an opportunity to study the interactions between galaxies and their environments. We discuss what future observations with extremely large telescopes could do for this field. We conclude that a further increase in the quality of the spectra of bright, $z\sim 3$ quasars will be useful, but may not lead to dramatic progress. In contrast, the ability to obtain high-quality spectra of $z>5$ quasars will be extremely exciting because they will allow us to extend studies of the distribution of metals to early times and to lower density contrasts, and because they may enable us to study the end of reionization. Spectacular progress in our understanding of the interactions between galaxies and the IGM can be made at $z\sim 3$, by obtaining accurate redshifts for large numbers of faint galaxies in the fields of bright quasars, and by obtaining low and intermediate resolution absorption spectra of some of the brighter galaxies.