{
  "abstract": "A $10^6\\,M_\\odot$ object has recently been inferred from gravitational imaging of the strong-lensing system JVAS B1938+666, exhibiting an unusually dense inner region embedded within an extended envelope, far exceeding expectations for cold dark matter (CDM) halos. Using gravothermal fluid simulations, we show that such a structure arises naturally in self-interacting dark matter (SIDM) halos evolving into a deep core-collapse phase, where a secondary dense central core forms within an extended profile. The resulting density structure closely matches the inferred properties of the lensing object. We also demonstrate that a similar profile could be reproduced in CDM in the presence of an intermediate-mass black hole, but this requires an early-forming progenitor that subsequently loses $5$ orders of magnitude in mass through tidal stripping by the lens galaxy. Whether such a scenario can be realized in realistic cosmological environments remains an open question.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.12909",
  "author_total": 2,
  "authors": [
    {
      "name": "Xingyu Zhang"
    },
    {
      "name": "Hai-Bo Yu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/55a0ewvybgar0.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.12909",
  "fulltext_url": null,
  "id": "55a0ewvybgar0",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.12909",
  "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"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7164511696",
  "pdf_url": "https://arxiv.org/pdf/2606.12909",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-24",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/55a0ewvybgar0.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:24:52Z",
      "native_id": "2606.12909",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.12909"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "SIDM and CDM interpretations of the million-solar-mass lensing perturber JVAS B1938+666-$\\mathcal{V}$",
  "title_text": "SIDM and CDM interpretations of the million-solar-mass lensing perturber JVAS B1938+666-𝒱",
  "type": "preprint",
  "updated_at": "2026-10-30T12:24:52Z",
  "url": "https://research.draconitic.com/paper/55a0ewvybgar0",
  "venue": "arXiv",
  "versions": []
}