{
  "abstract": "We investigate size evolution and disk formation with a new suite of eleven cosmological zoom-in simulations, Massive Assembly of Galaxies in the Early universe (MAGE), run with RAMSES at $\\sim10\\,\\mathrm{pc}$ resolution until $z\\simeq9$. The target galaxies span stellar masses of $M_\\star\\simeq2\\times10^8$-$3\\times10^{10}\\,M_\\odot$ at $z=9$. The stellar half-mass radius grows steeply with stellar mass at low masses, turns over near $M_\\star\\simeq5\\times10^9\\,M_\\odot$, and evolves weakly with redshift. The intrinsic UV sizes in MAGE overlap the compact end of observed distributions, including the compact strong-line systems, but not the more extended population at $z>9$. Dust, PSF-limited size measurements, and our overdense environments may contribute to this offset. In the simulations, stars dominate the mass within the half-mass radius above $M_\\star\\simeq5\\times10^8\\,M_\\odot$, where the central circular speed exceeds a characteristic stellar-feedback scale. Outflows are then increasingly retained within the galaxy, consistent with gas recycling on galactic rather than halo scales, which sustains central gas supply and drives a compaction-like central buildup. The turnover in size at $M_\\star\\simeq5\\times10^9\\,M_\\odot$ coincides with rapid growth of rotational support to $v/σ\\simeq1.5$-$3$ in star-forming gas and stars younger than 10Myr, as the central circular speed exceeds the halo virial speed, which the star-forming gas velocity dispersion tracks. The subsequent low central gas fraction, declining central star formation, and younger outskirts suggest the onset of inside-out quenching.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.29070",
  "author_total": 8,
  "authors": [
    {
      "name": "Zhiyuan Yao"
    },
    {
      "name": "Avishai Dekel"
    },
    {
      "name": "Romain Teyssier"
    },
    {
      "name": "Rachel Somerville"
    },
    {
      "name": "Nir Mandelker"
    },
    {
      "name": "Zachary Andalman"
    },
    {
      "name": "Ulrich Steinwandel"
    },
    {
      "name": "Zhaozhou Li"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/857e4bj62gbh7.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.29070",
  "fulltext_url": null,
  "id": "857e4bj62gbh7",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.29070",
  "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"
    ],
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7223225326",
  "pdf_url": "https://arxiv.org/pdf/2610.29070",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/857e4bj62gbh7.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:36:22Z",
      "native_id": "2610.29070",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.29070"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "The MAGE Project: Size Evolution and Disk Formation in Massive Galaxies at Cosmic Dawn",
  "title_text": "The MAGE Project: Size Evolution and Disk Formation in Massive Galaxies at Cosmic Dawn",
  "type": "preprint",
  "updated_at": "2026-11-01T12:20:44Z",
  "url": "https://research.draconitic.com/paper/857e4bj62gbh7",
  "venue": "arXiv",
  "versions": []
}