Heavy Elements in the Lyman-$\alpha$\ Forest: Abundances and Clustering at z=3

Abstract

For the purpose of studying the properties of heavy-elements associated with the Lyman-$\alpha$\ forest, we observed the gravitational lens Q1422+2309. We used the HIRES instrument on the W.M. Keck telescope to obtain a high-resolution, very high signal-to-noise spectrum of this z=3.63 quasar; the spectrum covers wavelengths from below Lyman-$\beta$\ up to the C IV emission line. Consistent with previous estimates, we find that a moderate fraction of the Ly-$\alpha$\ forest clouds have been enriched with heavy elements at a level significantly below solar abundance. However, unlike the fairly uniform distribution of Ly-$\alpha$\ forest lines, we show that the C IV absorption lines are clustered on large velocity scales.