{
  "id": "2505.01499",
  "version": "v1",
  "published": "2025-05-02T18:00:01.000Z",
  "updated": "2025-05-02T18:00:01.000Z",
  "title": "An extremely metal-poor Lyman-$α$ emitter candidate at $z=6$ revealed through absorption spectroscopy",
  "authors": [
    "Dominika Ďurovčíková",
    "Anna-Christina Eilers",
    "Robert A. Simcoe",
    "Louise Welsh",
    "Romain A. Meyer",
    "Jorryt Matthee",
    "Emma V. Ryan-Weber",
    "Minghao Yue",
    "Harley Katz",
    "Sindhu Satyavolu",
    "George Becker",
    "Frederick B. Davies",
    "Emanuele Paolo Farina"
  ],
  "comment": "10 pages, 4 figures",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We report the discovery of a Lyman $\\alpha$ emitter (LAE) candidate in the immediate foreground of the quasar PSO J158-14 at $z_{\\rm QSO}=6.0685$ at a projected distance $\\sim29\\ {\\rm pkpc}$ that is associated with an extremely metal-poor absorption system. This system was found in archival observations of the quasar field with the Very Large Telescope/Multi-Unit Spectroscopic Explorer (VLT/MUSE) and was previously missed in searches of absorption systems using quasar absorption line spectroscopy as it imparts no detectable metal absorption lines on the background quasar spectrum. The detected Ly$\\alpha$ emission line at a redshift of $z_{\\rm LAE}=6.0323$ is well aligned with the outer edge of the quasar's proximity zone and can plausibly cause its observed damping wing if it is associated with a proximate sub-damped Ly$\\alpha$ absorption system with a column density of $\\log {N_{\\rm HI} / {\\rm cm}^{-2}} \\approx 19.8$. A $>10$ hour medium-resolution spectrum of the quasar observed with the Magellan/Folded-port InfraRed Echellette (FIRE) and VLT/X-Shooter spectrographs reveals a metallicity constraint of ${\\rm [Z/H]} < -3$. Such low metallicity makes this system an extremely metal-poor galaxy candidate and provides an exciting site to study possible signatures of Population III stars.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2025-05-02T18:00:01.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "emitter candidate",
      "absorption spectroscopy",
      "quasar absorption line spectroscopy",
      "large telescope/multi-unit spectroscopic explorer",
      "detectable metal absorption lines"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}