{
  "abstract": "We investigate UV absorption lines tracing cool gas in eight bright (−21.9 < M UV < − 20.5) galaxies at z = 7.2–10.6 using deep archival JWST/NIRSpec medium-resolution spectra. The eight galaxies were homogeneously selected based on wavelength coverage and data quality from 362 galaxies at z > 7 available to date, and all eight were observed as part of the SPURS program. We identify multiple absorption lines of low-ionization species (LIS) in five galaxies, while the remaining three show only one or no significant detections. The average LIS equivalent widths EW LIS indicate weaker absorption lines in compact ( r e ≲ 100 pc) galaxies with high L H β / L UV and Σ SFR , suggestive of absorption-line suppression due to intense star formation or nuclear activity. We simultaneously fit multiple LIS lines, accounting for both covering fraction C f and column density N , and find that the five galaxies follow the local C f – N relation. Through the LIS-line fitting, we derive chemical abundance ratios. The five galaxies have abundance ratios similar to those of damped Ly α (DLA) systems at z ∼ 5–7 in the [Si/O]–[C/O] and [Fe/Si]–[Al/Si] planes, suggesting that their absorbing gas is similar to that of DLAs. We find that two galaxies at z ∼ 7 are already highly Fe-enriched, with [Fe/Si] ≃ −0.2, near the solar abundance ratio. While the high Fe enrichment may originate from early type Ia supernovae (SNe Ia) or pair-instability supernovae (PISNe), these two galaxies also show [Al/Si] ∼ 0, with no signature of the strong odd–even effect expected from PISNe, in which odd- Z elements are suppressed relative to even- Z elements, favoring SNe Ia.",
  "abstract_shown": true,
  "affiliations": [
    "The University of Tokyo",
    "National Astronomical Observatory of Japan",
    "SOKENDAI (The Graduate University for Advanced Studies)"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 2,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Minami Nakane",
      "orcid": "0009-0000-1999-5472"
    },
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Masami Ouchi",
      "orcid": "0000-0002-1049-6658"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2zvyja4r8ftx7.bib",
  "cited_by": 0,
  "doi": "10.3847/1538-4357/aea6cc",
  "fulltext_url": null,
  "id": "2zvyja4r8ftx7",
  "issns": [
    "0004-637X",
    "1538-4357"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea6cc",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7223115060",
  "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea6cc/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-21",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/2zvyja4r8ftx7.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:11Z",
      "native_id": "10.3847/1538-4357/aea6cc",
      "source": "crossref",
      "url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea6cc"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena",
      "subfield": "galaxies"
    }
  ],
  "title": "JWST Absorption-line Analysis of UV-bright Galaxies at z = 7.2–10.6: Early Chemical Enrichment Traced by C, O, Mg, Al, Si, and Fe",
  "title_text": "JWST Absorption-line Analysis of UV-bright Galaxies at z = 7.2–10.6: Early Chemical Enrichment Traced by C, O, Mg, Al, Si, and Fe",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:11Z",
  "url": "https://research.draconitic.com/paper/2zvyja4r8ftx7",
  "venue": "The Astrophysical Journal",
  "versions": []
}