Evidence of Increased UV FeII Emission in Quasars in Candidate Overdense Regions

Abstract

We present evidence for a skewed distribution of UV FeII emission in quasars within candidate overdense regions spanning spatial scales of ~ 50 Mpc at 1.11 < z < 1.67, compared to quasars in field environments at comparable redshifts. The overdense regions have an excess of high equivalent width sources (W2400 > 42 \AA), and a dearth of low equivalent width sources. There are various possible explanations for this effect, including dust, Ly\alpha fluorescence, microturbulence, and iron abundance. We find that the most plausible of these is enhanced iron abundance in the overdense regions, consistent with an enhanced star formation rate in the overdense regions compared to the field.