{
  "abstract": "We present the first measurement of the stellar velocity dispersion of LEDA 4014647, a compact dwarf galaxy spatially aligned with the NGC 1052 trail, a linear chain of dark matter-deficient galaxies (DMDGs) proposed to have formed in a single high-speed dwarf$-$dwarf collision $\\sim 8$ Gyr ago. Using integral-field spectroscopy obtained with the Keck Cosmic Web Imager (KCWI), we measure a stellar velocity dispersion of $σ= 15.8 \\pm 2.0$ km s$^{-1}$ within the half-light radius ($R_\\mathrm{e}$). We derive a dynamical mass within the 3D half-light radius of $M_\\mathrm{dyn}(<r_{1/2}) = (1.5 \\pm 0.4) \\times 10^8\\,M_\\odot$, a factor of $\\sim 3$ larger than the enclosed stellar mass, implying a DM fraction of $f_\\mathrm{DM} = 0.7 \\pm 0.1$ at $r_{1/2}$. Full-spectrum stellar population fitting yields an old ($t \\approx 13$ Gyr) and metal-poor ($[\\mathrm{M/H}] \\approx -1.2$ dex) stellar population, consistent with independent photometric estimates and predating the proposed collision epoch. LEDA 4014647 is therefore a DM-dominated system, and cannot have formed from the DM-free, shock-compressed gas that produced the proposed trail DMDGs DF2, DF4, and DF9. Its nature, however, remains an open question: while a chance-projection along the trail axis is a possible explanation, its old stellar population, compact morphology, and DM content are also consistent with the surviving collisionless remnant of one of the progenitor dwarfs of the dwarf$-$dwarf collision. Distinguishing between these two scenarios will ultimately require deeper spectroscopy to tighten the stellar population and DM halo constraints, and targeted $N$-body and hydrodynamical simulations tracking the post-encounter fate of the progenitors.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.07467",
  "author_total": 9,
  "authors": [
    {
      "name": "Daniel Vaz"
    },
    {
      "name": "Arsen Levitskiy"
    },
    {
      "name": "Duncan Forbes"
    },
    {
      "name": "Aaron J. Romanowsky"
    },
    {
      "name": "Jonah Gannon"
    },
    {
      "name": "Jean P. Brodie"
    },
    {
      "name": "Yimeng Tang"
    },
    {
      "name": "Kenji Bekki"
    },
    {
      "name": "Warrick J. Couch"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1thceqxg1x11m.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.07467",
  "fulltext_url": null,
  "id": "1thceqxg1x11m",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.07467",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.GA"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2610.07467",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/1thceqxg1x11m.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:22Z",
      "native_id": "2610.07467",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.07467"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "The Rogue One: A Dark Matter-Dominated Dwarf in the Trail of Dark Matter-Deficient Galaxies",
  "title_text": "The Rogue One: A Dark Matter-Dominated Dwarf in the Trail of Dark Matter-Deficient Galaxies",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:22Z",
  "url": "https://research.draconitic.com/paper/1thceqxg1x11m",
  "venue": "arXiv",
  "versions": []
}