Abstract
The gravitational arc observed by Holden in 2001 at z = 3.356 reveals strong emission lines of N IV]λ1485, C IV λλ1549, O III]λ1665 but no NV λ1240. We consider the possibility that the ionizing source consisting of a partially absorbed powerlaw. We compare the line ratios from a low metallicity nebula ( Z[total] = 0.05 ZM_⊙) photoionized by such filtered continuum with those produced by a zero-metallicity star of T[eff] = 80000 K. Whether using a thermal or an absorbed AGN continuum, all models result in very weak [O II]λ3727.
