English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

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

The Metallicity of the Redshift 4.16 Quasar BR 2248−1242