N-enhancement in GN-z11: First evidence for supermassive stars nucleosynthesis in proto-globular clusters-like conditions at high redshift ?

Unusually high N/O abundance ratios were recently reported for a very compact, intensively star-forming object GN-z11 at \(z=10.6\) from JWST/NIRSpec observations. We present an empirical comparison with the C, N, and O abundance ratios in Galactic globular clusters (GCs) over a large metallicity ra...

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Bibliographic Details
Published inarXiv.org
Main Authors Charbonnel, C, Schaerer, D, Prantzos, N, Ramírez-Galeano, L, Fragos, T, Kuruvandothi, A, Marques-Chaves, R, Gieles, M
Format Paper Journal Article
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 17.04.2023
Subjects
Abundance
Galactic clusters
Globular clusters
Metallicity
Nuclear fusion
Physics - Astrophysics of Galaxies
Ratios
Red shift
Star formation
Supermassive stars
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Summary:Unusually high N/O abundance ratios were recently reported for a very compact, intensively star-forming object GN-z11 at \(z=10.6\) from JWST/NIRSpec observations. We present an empirical comparison with the C, N, and O abundance ratios in Galactic globular clusters (GCs) over a large metallicity range. We show that hot hydrogen-burning nucleosynthesis within supermassive stars (SMS) formed through runaway collisions can consistently explain the observed abundances ratio in GN-z11 and in GCs. This suggests that a proto-globular cluster hosting a SMS could be at the origin of the strong N-enrichment in GN-z11. Our model predicts the behavior of N/O, C/O, and Ne/O ratios as a function of metallicity, which can be tested if high-\(z\) objects similar to GN-z11 are detected with JWST in the future. Further studies and statistics will help differentiate the proto-GC scenario from the Wolf-Rayet scenario that we quantify with a population synthesis model, and shed more light on this peculiar object.
ISSN:2331-8422
DOI:10.48550/arxiv.2303.07955