{
  "abstract": "We revisit EBG-1, a gravitationally lensed galaxy at $z = 9.244$, using newly obtained deep (14 hr) JWST/NIRSpec G235M ($R \\sim 1000$) spectroscopy. EBG-1 is one of the bluest galaxies observed at $z > 9$. Along with its remarkably blue continuum of $β= -2.99 \\pm 0.15$, we find very weak nebular emission from EBG-1. We obtain a $3σ$ upper limit of EW $< 8.4$ Angstrom for C III], a marginal H$β$ measurement (EW $= 256.2 \\pm 122.2$ Angstrom), and a $5σ$ detection of [O III] $λ5007$ (EW $= 882.8 \\pm 180.6$ Angstrom). These lines suggest an oxygen abundance of $12 + \\log(\\mathrm{O/H}) = 7.16 \\pm 0.25$ ($\\simeq 3\\% Z_{\\odot}$) and $\\log(\\mathrm{C/O}) < -0.88$ ($3σ$), placing EBG-1 on the C/O-metallicity sequence traced by lower-redshift galaxies. To constrain the escape fraction ($f_{\\rm esc}$), we compare the observed UV slope and emission-line equivalent widths with synthetic spectra generated using BEAGLE. The models favor $f_{\\rm esc} \\gtrsim 0.75$, with $f_{\\rm esc} \\approx 0.85$ providing the best overall agreement with the observations. These results suggest that relatively UV-bright galaxies like EBG-1 can achieve the exceptionally high ionizing efficiencies supported by late reionization scenarios.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.24092",
  "author_total": 31,
  "authors": [
    {
      "name": "Yunjing Wu"
    },
    {
      "name": "Sijia Cai"
    },
    {
      "name": "Yongda Zhu"
    },
    {
      "name": "Masami Ouchi"
    },
    {
      "name": "Yuichi Harikane"
    },
    {
      "name": "Zheng Cai"
    },
    {
      "name": "Mengtao Tang"
    },
    {
      "name": "Khee-Gan Lee"
    },
    {
      "name": "John D. Silverman"
    },
    {
      "name": "Fengwu Sun"
    },
    {
      "name": "Xiaohui Fan"
    },
    {
      "name": "Zuyi Chen"
    },
    {
      "name": "Minami Nakane"
    },
    {
      "name": "Hiroto Yanagisawa"
    },
    {
      "name": "Angela Adamo"
    },
    {
      "name": "Fuyan Bian"
    },
    {
      "name": "Jaclyn B. Champagne"
    },
    {
      "name": "Dan Coe"
    },
    {
      "name": "Seiji Fujimoto"
    },
    {
      "name": "Enrico Garaldi"
    },
    {
      "name": "Tiger Yu-Yang Hsiao"
    },
    {
      "name": "Xiangyu Jin"
    },
    {
      "name": "Mingyu Li"
    },
    {
      "name": "Yongming Liang"
    },
    {
      "name": "Xiaojing Lin"
    },
    {
      "name": "Guan-Fu Liu"
    },
    {
      "name": "Junjie Mao"
    },
    {
      "name": "Masamune Oguri"
    },
    {
      "name": "Takafumi Tsukui"
    },
    {
      "name": "Feige Wang"
    },
    {
      "name": "Jinyi Yang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cwshvb90vaky6.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.24092",
  "fulltext_url": null,
  "id": "cwshvb90vaky6",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.24092",
  "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.CO"
    ],
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7223004791",
  "pdf_url": "https://arxiv.org/pdf/2610.24092",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-16",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cwshvb90vaky6.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:30:52Z",
      "native_id": "2610.24092",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.24092"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "Can Blue UV-Bright Galaxies Drive Reionization at Cosmic Dawn? An $M_{\\rm UV}=-19.6$ Galaxy with $f_{\\rm esc}\\approx0.85$ at $z=9.244$",
  "title_text": "Can Blue UV-Bright Galaxies Drive Reionization at Cosmic Dawn? An M_UV=−19.6 Galaxy with f_esc≈0.85 at z=9.244",
  "type": "preprint",
  "updated_at": "2026-10-30T12:33:41Z",
  "url": "https://research.draconitic.com/paper/cwshvb90vaky6",
  "venue": "arXiv",
  "versions": []
}