{
  "abstract": "We present a radiation-magnetohydrodynamic (RMHD) cosmological zoom-in simulation of Pop III star formation, drawing initial conditions from a Milky Way-like progenitor halo at redshift $z \\sim 21$. We follow the collapse of primordial gas over 10 orders of magnitude, through to the formation of an accretion disk that becomes gravitationally unstable $Δt \\sim -3$ kyr before the first protostar's formation. Prominent spiral arms then develop and fragment vigorously, producing $\\sim 60$ sink formation events over the first $8$ kyr post-collapse evolution, with a total stellar mass reaching $> 150\\,{\\rm M_\\odot}$ by $15$ kyr, the end of our simulation. The disk remains magnetically supercritical throughout: the mass-to-flux ratio falls from $μ_Φ\\sim 10^2$-$10^3$ to $\\sim 15$ by $15$ kyr, as the inflow brings in magnetic flux. The magnetic energy in the disk remains sub-dominant throughout, but grows by $\\sim 3.5$ orders of magnitude after the first star forms. The disk starts sub-virial and reaches virial equilibrium within $\\sim 2$ kyr. The total stellar mass of the population grows as $M_* \\propto t^2$, confirming the prediction of accelerating accretion in self-gravitating turbulent collapse, at rates of $\\dot{M} \\sim 10^{-3}$-$10^{-2}\\,{\\rm M}_\\odot {\\rm yr}^{-1}$. The star formation efficiency reaches $\\approx 90\\%$ within the disk (after $\\approx 11$ kyr; $\\approx 80\\%$ at $9.5$ kyr) and $\\sim 50\\%$ within a $0.1$ pc sphere. We find a top heavy IMF ($dN/dm \\propto m^{-α}$) with a high-mass slope $α\\approx 1$. The cosmological environment sets the boundary conditions of the disk: an envelope delivers $\\sim 3\\times 10^{-3}\\,{\\rm M}_\\odot {\\rm yr}^{-1}$ to the outer edge of a disk with a radius of $\\sim 10^{3}$ AU; the disk spreads and, in our simulation, its fragmentation sites move outward, from $\\sim 500$ to $\\sim 1350$\\,AU, until it has been depleted.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.08603",
  "author_total": 8,
  "authors": [
    {
      "name": "Vasilii Pustovoit"
    },
    {
      "name": "Shivan Khullar"
    },
    {
      "name": "Norman Murray"
    },
    {
      "name": "Yasmine J. Meziani"
    },
    {
      "name": "Claude-André Faucher-Giguère"
    },
    {
      "name": "Philip F. Hopkins"
    },
    {
      "name": "Michael Y. Grudić"
    },
    {
      "name": "J. Richard Bond"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/392190nv01gbq.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.08603",
  "fulltext_url": null,
  "id": "392190nv01gbq",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.08603",
  "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",
      "astro-ph.SR"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2611.08603",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/392190nv01gbq.ris",
  "sources": [
    {
      "first_seen": "2026-11-10T06:21:04Z",
      "native_id": "2611.08603",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.08603"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    }
  ],
  "title": "FORGE'd in Fragments: Pop III star formation in a Milky Way-like progenitor halo",
  "title_text": "FORGE'd in Fragments: Pop III star formation in a Milky Way-like progenitor halo",
  "type": "preprint",
  "updated_at": "2026-11-10T06:21:04Z",
  "url": "https://research.draconitic.com/paper/392190nv01gbq",
  "venue": "arXiv",
  "versions": []
}