{
  "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, we measure a stellar velocity dispersion of $\\sigma = 15.8 \\pm 2.0$ km s$^{-1}$ within the half-light radius ($R_\\mathrm{e}$). We derive a dynamical mass within the 3D half-light radius of $M_\\mathrm{dyn}({\\lt} r_{1/2}) = (1.5 \\pm 0.4) \\times 10^8\\, \\mathrm{ M}_\\odot$, a factor of ${\\sim} 3$ larger than the enclosed stellar mass, implying a dark matter (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": [
    "Centre for Astrophysics and Supercomputing, Swinburne University of Technology , Hawthorn, VIC 3122 ,",
    "Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas , P-4150-762 Porto ,",
    "Department of Physics and Astronomy, San José State University, One Washington Square , San Jose, CA 95192 ,",
    "Department of Astronomy and Astrophysics, University of California Santa Cruz , 1156 High Street, Santa Cruz, CA 95064 ,",
    "Department of Astronomy & Astrophysics, University of Toronto , 50 St. George Street, Toronto, ON M5S 3H4 ,",
    "International Centre for Radio Astronomy Research (ICRAR), M468, The University of Western Australia , 35 Stirling Hwy, Crawley, WA 6009 ,"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Daniel Vaz",
      "orcid": "0000-0002-8119-6812"
    },
    {
      "affs": [
        0
      ],
      "name": "Arsen Levitskiy"
    },
    {
      "affs": [
        0
      ],
      "name": "Duncan Forbes"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Aaron J Romanowsky",
      "orcid": "0000-0003-2473-0369"
    },
    {
      "affs": [
        0,
        4
      ],
      "name": "Jonah Gannon"
    },
    {
      "affs": [
        0
      ],
      "name": "Jean P Brodie"
    },
    {
      "affs": [
        3
      ],
      "name": "Yimeng Tang",
      "orcid": "0000-0003-2876-577X"
    },
    {
      "affs": [
        5
      ],
      "name": "Kenji Bekki"
    },
    {
      "affs": [
        0
      ],
      "name": "Warrick J Couch"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/24qks2djjs0jy.bib",
  "cited_by": 0,
  "doi": "10.1093/mnras/stag1895",
  "fulltext_url": null,
  "id": "24qks2djjs0jy",
  "issns": [
    "0035-8711",
    "1365-2966"
  ],
  "landing_url": "https://academic.oup.com/mnras/article/doi/10.1093/mnras/stag1895/8875684",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7220851335",
  "pdf_url": "https://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/stag1895/71665329/stag1895.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-07",
  "publisher": "Oxford University Press (OUP)",
  "ris": "https://research.draconitic.com/paper/24qks2djjs0jy.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:17Z",
      "native_id": "10.1093/mnras/stag1895",
      "source": "crossref",
      "url": "https://academic.oup.com/mnras/article/doi/10.1093/mnras/stag1895/8875684"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena",
      "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": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:17Z",
  "url": "https://research.draconitic.com/paper/24qks2djjs0jy",
  "venue": "Monthly Notices of the Royal Astronomical Society",
  "versions": []
}