{
  "abstract": "We report the serendipitous discovery of a dense, metal-enriched circumgalactic medium (CGM) absorber at z=7.03, together with its host galaxy, identified along the sightline toward a red quasar. The absorber exhibits the largest rest-frame equivalent widths and column densities observed to date at z>5, tracing a metal-enriched gaseous halo. Using deep JWST/NIRSpec and NOEMA observations, we characterize the absorber's physical properties and identify its host, ND1, as a vigorously star-forming galaxy at an exceptionally close impact parameter of ~16kpc, so heavily dust-obscured that it is detected only in the longest-wavelength NIRCam bands. Detections of [OIII]$λ$5007, H$α$, and [CII]$λ158\\,μ$m emission anchor the systemic redshift to z~7.0321, revealing a coherent ~50km/s blueshift of the absorbing gas relative to the host, suggesting outflow-driven metal transport into the halo. The outflow velocity, combined with the measured column density, implies an outflow rate of $\\dot{M}_{\\rm out}=64 M_\\odot\\,yr^{-1}$ and a mass loading factor $η=3$, indicating an energetic, chemically-enriched wind launched from a dust-obscured starburst. While the overall ionization state and [Mg/Fe] ratio align with empirical cosmic evolutionary trends, the absorber displays an enhanced carbon-to-oxygen ([C/O]) ratio. This abundance pattern suggests the nucleosynthetic yields of Population~III stellar explosions, and aligns with the host's star-formation history extending to $z \\gtrsim 8$, potentially offering a rare fossil record of primordial metal enrichment. Our findings demonstrate that intense star-formation feedback can rapidly and efficiently pollute the CGM/IGM well into the Epoch of Reionization. The NIR-dark nature of the host further implies that rest-UV surveys may systematically miss the dusty sources that drive CGM- and IGM-scale metal enrichment in the early Universe.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.17680",
  "author_total": 25,
  "authors": [
    {
      "name": "Qinyue Fei"
    },
    {
      "name": "Seiji Fujimoto"
    },
    {
      "name": "Gabriel Brammer"
    },
    {
      "name": "Lise Christensen"
    },
    {
      "name": "Marianne Vestergaard"
    },
    {
      "name": "Rohan P. Naidu"
    },
    {
      "name": "Robert A. Simcoe"
    },
    {
      "name": "Norman Murray"
    },
    {
      "name": "Luis C. Ho"
    },
    {
      "name": "Ruancun Li"
    },
    {
      "name": "Volker Bromm"
    },
    {
      "name": "Javier Álvarez-Márquez"
    },
    {
      "name": "Hollis B. Akins"
    },
    {
      "name": "Yoshihisa Asada"
    },
    {
      "name": "Simona Di Stefano"
    },
    {
      "name": "Kohei Inayoshi"
    },
    {
      "name": "Vasily Kokorev"
    },
    {
      "name": "Jorryt Matthee"
    },
    {
      "name": "Romain A. Meyer"
    },
    {
      "name": "Ava Polzin"
    },
    {
      "name": "Francesco Valentino"
    },
    {
      "name": "Fabian Walter"
    },
    {
      "name": "Marcel Neeleman"
    },
    {
      "name": "Yunjing Wu"
    },
    {
      "name": "Mengyuan Xiao"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/egpdvyb4zrmnv.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.17680",
  "fulltext_url": null,
  "id": "egpdvyb4zrmnv",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.17680",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7213520998",
  "pdf_url": "https://arxiv.org/pdf/2609.17680",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-11",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/egpdvyb4zrmnv.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:06Z",
      "native_id": "2609.17680",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.17680"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "A dense, metal-rich absorber driven by a heavily dust-obscured galaxy: The direct evidence of CGM enrichment at $z\\sim7$",
  "title_text": "A dense, metal-rich absorber driven by a heavily dust-obscured galaxy: The direct evidence of CGM enrichment at z∼7",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:06Z",
  "url": "https://research.draconitic.com/paper/egpdvyb4zrmnv",
  "venue": "arXiv",
  "versions": []
}