The Metallicity of the Redshift 4.16 Quasar BR 2248−1242

We estimate the metallicity in the broad emission-line region of the redshiftz=4.16 quasar, BR2248-1242, by comparing line ratios involving nitrogen totheoretical predictions. BR2248-1242 has unusually narrow emission lines withlarge equivalent widths, thus providing a rare opportunity to measure severalline-ratio abundance diagnostics. The combined diagnostics indicate ametallicity of ~2 times solar. This result suggests that an episode of vigorousstar formation occurred near BR2248-1242 prior to the observed z=4.16 epoch.The time available for this enrichment episode is only ~1.5 Gyr at z=4.16 (forH_{0}=65 km s^-1 Mpc^-1, Omega_{m}=0.3 and Omega_Lambda ~< 1). This evidencefor high metallicities and rapid star formation is consistent with the expectedearly-epoch evolution of dense galactic nuclei.Comment: 8 pages, 3 figures. Prepared in AAStex. Submitted to the Astrophysical Journal Revised version: added 1 referenc