JADES NIRSpec Spectroscopy of GN-z11: Evidence for Wolf-Rayet contribution to stellar populations at 430 Myr after Big Bang?

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We investigate the unusual emission line luminosity ratios observed in the JADES NIRSpec spectroscopy of GN-z11, which reveal exceptionally strong emission lines and a significant detection of the rarely observed N III] $\lambda1748-1753$\r{A} multiplet.

• These features suggest an elevated N/O abundance, challenging existing models of stellar populations and nebular emission.
• To assess whether Wolf-Rayet (WR) stars can account for the observed line ratios, we construct a suite of stellar and nebular models incorporating high-resolution stellar spectral libraries, enabling a more accurate treatment of WR evolution and its influence on the ionising radiation field.
• We find that the inclusion of WR stars is essential for reproducing the observed position of GN-z11 in the C III]/He II versus C III]/C iv diagnostic plane, resolving discrepancies from previous studies.