{
  "abstract": "We present an analysis of 23 Spitzer/IRAC excess galaxies at $5.66 < z < 7.64$, observed as part of the NIRSpec Wide GTO survey. With NIRSpec PRISM spectroscopy, we measure a median rest-frame [OIII]$+\\rm{H}β$ EW $=1583$~Å, consistent with predictions from the pre-JWST selection and we identify $17/23$ $(\\sim74\\%)$ of our sample as extreme emission line galaxies (EELGs), based on a selection of [OIII]$+\\rm{H}β$ EW $\\geq1000$~Å. The typical EELG is powered by star-formation rather than active galactic nuclei (AGN) based on their line widths, line ratios and absence of high-ionization lines, though we cannot exclude an AGN contribution in a few individual sources. We find that our luminous ($\\langle M_\\mathrm{UV}\\rangle=-20.7$) EELG sample is characterised by sub-solar metallicities $(7.38 < \\rm 12 + \\log(O/H) < 8.12)$, young stellar populations ($t_\\star \\sim 20$ Myr), and enhanced ionizing photon production efficiencies, with median $\\log_{10}(ξ_\\mathrm{ion}/\\mathrm{erg}^{-1}~\\mathrm{Hz}) = 25.62$. We find that more UV luminous ($\\sim L_\\mathrm{UV, z=7}^\\ast$) EELGs exhibit systematically lower O32 ratios than fainter ($\\sim 0.1\\times L_\\mathrm{UV}^\\ast$) EELGs at fixed [OIII]$+\\rm{H}β$ EW, indicating less extreme radiation fields and/or lower gas densities than their fainter counterparts. Furthermore, bright EELGs exhibit low neutral hydrogen column densities, consistent with a scenario in which they have largely ionized their circumgalactic medium (CGM). Despite this, we find very low Lyman-$α$ escape fractions ($<2$\\%), suggesting these systems reside in relatively small ($\\lesssim 0.25$~pMpc) ionized regions of the intergalactic medium (IGM), possibly suggesting that bright galaxies have a minor contribution to reionization.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.20332",
  "author_total": 7,
  "authors": [
    {
      "name": "Katherine Ormerod"
    },
    {
      "name": "Renske Smit"
    },
    {
      "name": "Joris Witstok"
    },
    {
      "name": "Anna de Graaff"
    },
    {
      "name": "Michael V. Maseda"
    },
    {
      "name": "Andrew J. Bunker"
    },
    {
      "name": "Chris Willott"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/29g643p6zxzkb.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.20332",
  "fulltext_url": null,
  "id": "29g643p6zxzkb",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.20332",
  "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": "W7222358088",
  "pdf_url": "https://arxiv.org/pdf/2610.20332",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-14",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/29g643p6zxzkb.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:31Z",
      "native_id": "2610.20332",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.20332"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "IRAC-Excess Galaxies in the NIRSpec Wide Survey: physical properties of bright EELGs at $z\\sim7$ and implications for Reionization",
  "title_text": "IRAC-Excess Galaxies in the NIRSpec Wide Survey: physical properties of bright EELGs at z∼7 and implications for Reionization",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:31Z",
  "url": "https://research.draconitic.com/paper/29g643p6zxzkb",
  "venue": "arXiv",
  "versions": []
}