{
  "abstract": "Context. Recent James Webb Space Telescope (JWST) observations have revealed a small number of galaxies with UV spectra exhibiting intense nitrogen emission lines, which are not typically detected in galaxy spectra. The observations indicate super-solar N/O abundances at low metallicity, a phenomenon whose nature is currently intensely debated. Aims. To better understand these enigmatic objects and provide new constraints on proposed scenarios, we did a systematic search for galaxies with UV nitrogen emission lines (N IV ] λ 1486 and/or N III ] λ 1750). Methods. Using public JWST NIRSpec data, we identified 45 N-emitters with robust N III ] or N IV ] detections, including four previously known objects. We then classified these objects, determined relative C, N, O, and H chemical abundance ratios, determined other properties, and carried out a statistical analysis of the N-emitter population. Results. We find N-emitters at redshifts z ∼ 3 − 11 spanning a broad diversity of galaxies in terms of morphology, UV magnitude, stellar mass, star formation rate, metallicity, and rest-optical emission line strengths. The UV nitrogen lines show typical equivalent widths (EW) between ∼5 Å and up to ∼100 Å in a few cases. Diverse ionisation conditions, as traced by N IV ] λ 1486/N III ] λ 1750, are observed. The carbon lines (C IV λ 1550 and C III ] λ 1909) are generally fainter than the N lines. Using strong line calibrations established at high-redshift, we find metallicities 12 + log(O/H)∼7.15 − 8.5, spanning up to high metallicity values. The H β EW of N-emitters varies strongly, and sources with low EWs show clear signs of a Balmer break, indicative of composite stellar populations combining both young (≲10 Myr) stars responsible for the UV emission lines and an older population contributing to the rest-optical spectrum. Super-solar N/O ratios are found in all N-emitters. C/O abundances are comparable to those of galaxies at the same metallicity, and all N-emitters show either high N/C ratios or lower limits (log(N/C) ≳ 0.5), regardless of metallicity. The observed abundance ratios are compatible with ejecta from H-burning and show no signs of carbon enhancements, even at higher metallicities. Finally, we find that the fraction of N-emitters increases with redshift, and we quantify this evolution. Conclusions. Our study increases the sample of known N-emitters by a factor of ∼3, reveals a diversity of properties among N-emitters, and provides new constraints on their nature.",
  "abstract_shown": true,
  "affiliations": [
    "Observatoire de Genève, Université de Genève",
    "CNRS, IRAP",
    "Institut d’Astrophysique de Paris, UMR 7095 CNRS, Sorbonne Université",
    "Cosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "I. Morel",
      "orcid": "0009-0002-8287-7406"
    },
    {
      "affs": [
        1,
        0
      ],
      "name": "D. Schaerer",
      "orcid": "0000-0001-7144-7182"
    },
    {
      "affs": [
        0
      ],
      "name": "R. Marques-Chaves",
      "orcid": "0000-0001-8442-1846"
    },
    {
      "affs": [
        2
      ],
      "name": "Nikos Prantzos",
      "orcid": "0000-0002-4591-6253"
    },
    {
      "affs": [
        1,
        0
      ],
      "name": "Corinne Charbonnel",
      "orcid": "0000-0002-6449-6194"
    },
    {
      "affs": [
        3
      ],
      "name": "G. Brammer",
      "orcid": "0000-0003-2680-005X"
    },
    {
      "affs": [
        0
      ],
      "name": "Mengyuan Xiao",
      "orcid": "0000-0003-1207-5344"
    },
    {
      "affs": [
        0
      ],
      "name": "Miroslava Dessauges-Zavadsky",
      "orcid": "0000-0003-0348-2917"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3981k57hcv274.bib",
  "cited_by": 25,
  "doi": "10.1051/0004-6361/202558256",
  "fulltext_url": null,
  "id": "3981k57hcv274",
  "issns": [
    "0004-6361",
    "1432-0746"
  ],
  "landing_url": "https://doi.org/10.1051/0004-6361/202558256",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7160944741",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-05-12",
  "publisher": "EDP Sciences",
  "ris": "https://research.draconitic.com/paper/3981k57hcv274.ris",
  "sources": [
    {
      "first_seen": "2026-11-07T13:20:45Z",
      "native_id": "W7160944741",
      "source": "openalex",
      "url": "https://doi.org/10.1051/0004-6361/202558256"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena",
      "subfield": "galaxies"
    }
  ],
  "title": "Discovery of new N-emitters over a wide redshift range",
  "title_text": "Discovery of new N-emitters over a wide redshift range",
  "type": "peer-reviewed",
  "updated_at": "2026-11-08T13:20:38Z",
  "url": "https://research.draconitic.com/paper/3981k57hcv274",
  "venue": "Astronomy and Astrophysics",
  "versions": []
}