{
  "abstract": "Aims. We investigate the mass-metallicity relation (MZR) from z = 1 to z = 9 using electron-temperature based gas-phase metallici-ties. We explore how auroral-line selection effects, SFHs, and secondary abundances impact its interpretation in the early Universe. Methods. We compiled a homogeneous sample of 286 star-forming galaxies observed with JWST/NIRSpec medium-resolution spectroscopy, selected through detections of the [O III] λ4363 auroral line from the public DAWN JWST Archive (DJA). We derived the electron densities, temperatures, and oxygen abundances using the direct Te method, along with relative N/O and He/H abundances. Stellar masses are obtained via SED fitting and star formation rates from reddening-corrected Balmer emission lines. To quantify any auroral-line selection biases, we additionally stacked sets of galaxy spectra with and without auroral-line detections, extending the MZR into regimes that are inaccessible with respect to individual measurements. Results. The auroral line-detected sample spans stellar masses of log(M★/M⊙) = 6.77-10.5, star formation rates of log(SFR[M⊙ yr−1]) = −0.24 to 2.38, and low metallicities of 12 + log(O/H) = 6.9-8.4, with electron temperatures of T[OIII] = 10 030 K to 37 400 K and electron densities ranging from 100 to 990 cm−3. A linear fit to the individually detected sample yields a MZR slope of γ = 0.38 ± 0.09. Stacked galaxies without individual auroral-line detections define a relation with a similar slope, but a systematically higher metallicity by 0.2–0.3 dex at a fixed stellar mass. These two sequences differ markedly in their star-formation properties: galaxies with individual auroral-line detections exhibit higher SFRs, larger emission-line equivalent widths, and larger deviations from the fundamental metallicity relation (FMR). In contrast, stacked non-detections appear more chemically evolved and closer to the FMR. In several stacked bins, we also found enhanced N/O and He/H ratios, suggesting rapid enrichment channels such as Wolf–Rayet stars or supermassive stars. Conclusions. The MZR of high-z galaxies traced by JWST at low stellar masses is shaped both by recent SFH and auroral-line selection effects. Auroral lines preferentially identify high-EW and high-sSFR galaxies in the low-metallicity envelope of the relation, where the effects of dilution due to inflows of pristine gas are greater; whereas non-detections reveal a more enriched sequence closer to the metallicity predicted by the FMR.",
  "abstract_shown": true,
  "affiliations": [
    "Instituto de Astrofísica de Andalucía (IAA-CSIC)"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Giménez-Alcázar A.",
      "orcid": "0000-0001-5891-1083"
    },
    {
      "affs": [
        0
      ],
      "name": "Amorín R.",
      "orcid": "0000-0001-5758-1000"
    },
    {
      "affs": [
        0
      ],
      "name": "Vilchez J. M.",
      "orcid": "0000-0001-7299-8373"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6w6k2fcv6m6t9.bib",
  "cited_by": 0,
  "doi": "10.1051/0004-6361/202660477",
  "fulltext_url": "https://www.aanda.org/articles/aa/full_html/2026/11/aa60477-26/aa60477-26.html",
  "id": "6w6k2fcv6m6t9",
  "issns": [
    "0004-6361",
    "1432-0746"
  ],
  "landing_url": "https://doi.org/10.1051/0004-6361/202660477",
  "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": [
    [
      "lcc",
      "QB1-991"
    ],
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7160666226",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": "EDP Sciences",
  "ris": "https://research.draconitic.com/paper/6w6k2fcv6m6t9.ris",
  "sources": [
    {
      "first_seen": "2026-11-05T14:21:10Z",
      "native_id": "11ed671f2b634f7fa152105d2a7be906",
      "source": "doaj",
      "url": "https://doi.org/10.1051/0004-6361/202660477"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena",
      "subfield": "galaxies"
    }
  ],
  "title": "Shape of the direct-method mass-metallicity relation with JWST",
  "title_text": "Shape of the direct-method mass-metallicity relation with JWST",
  "type": "peer-reviewed",
  "updated_at": "2026-11-06T14:20:38Z",
  "url": "https://research.draconitic.com/paper/6w6k2fcv6m6t9",
  "venue": "Astronomy & Astrophysics",
  "versions": []
}