{
  "abstract": "Hot coronae are key regulators in Milky Way (MW)-type galaxy formation and are thought to emerge once a galaxy’s dark matter halo crosses a critical mass threshold, $M_{\\rm vir}\\sim 10^{12}\\, {\\rm M}_\\odot$, so that accretion shocks can heat infalling gas to virial temperatures, $T_{\\rm vir}$. Here, we investigate the roles of stellar feedback and accretion shocks in establishing the circumgalactic medium (CGM) around MW-mass galaxies using the vintergatan cosmological simulation suite. We find that stellar feedback drives the early formation of a hot CGM, with $T_{\\rm CGM}\\sim T_{\\rm vir}$. By contrast, in feedback-free simulations, accretion shocks alone do not produce a CGM with comparably high average temperatures at early epochs ($z\\gt 2$), independent of gas metallicity. We show that CGM virialization (defined when halo-gas cooling time exceeds the free-fall time) begins with the emergence of a hot corona ($T\\gt 10^5$ K) that can appear as early as $z\\approx 3$ at virial radius, $R_{\\rm vir}$, when feedback is included. This is much earlier than predicted by accretion-shock theory or feedback-free models ($z\\lesssim 1$). While accretion shocks alone produce an inside-out virialization pattern, feedback can alter this behaviour, driving a rapid transition (${\\lesssim} 0.5$ Gyr) that is either outside-in or nearly simultaneous throughout the halo. Finally, these early-forming coronae are largely stable from formation through to the present day, but can appear to evolve simply because the definition of $R_{\\rm vir}$ grows with time. This ‘CGM pseudo-evolution’ is analogous to the pseudo-evolution of dark matter haloes and should be taken into account when interpreting the evolution of hot coronae.",
  "abstract_shown": true,
  "affiliations": [
    "Lund Observatory, Division of Astrophysics, Department of Physics, Lund University , Box 118, SE-221 00 Lund ,",
    "Department of Physics, University of Bath , Claverton Down, Bath BA2 7AY ,",
    "Sydney Institute for Astronomy, School of Physics, University of Sydney , Sydney, NSW 2006 ,",
    "Department of Physics, University of Surrey , Guildford GU2 7XH ,",
    "Institut d’Astrophysique de Paris, Sorbonne Université, CNRS , UMR 7095, 98 bis bd Arago, F-75014 Paris ,",
    "Sub-department of Astrophysics, University of Oxford , DWB, Keble Road, Oxford OX1 3RH ,"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Víctor Rufo-Pastor",
      "orcid": "0000-0003-3259-9890"
    },
    {
      "affs": [
        0
      ],
      "name": "Oscar Agertz",
      "orcid": "0000-0002-4287-1088"
    },
    {
      "affs": [
        0
      ],
      "name": "Santi Roca-Fábrega",
      "orcid": "0000-0002-6299-152X"
    },
    {
      "affs": [
        1
      ],
      "name": "Martin P Rey",
      "orcid": "0000-0002-1515-995X"
    },
    {
      "affs": [
        2
      ],
      "name": "Joss Bland-Hawthorn",
      "orcid": "0000-0001-7516-4016"
    },
    {
      "affs": [
        3
      ],
      "name": "Justin I Read",
      "orcid": "0000-0002-1164-9302"
    },
    {
      "affs": [
        2
      ],
      "name": "Thor Tepper-García",
      "orcid": "0000-0002-1081-883X"
    },
    {
      "affs": [
        4
      ],
      "name": "Corentin Cadiou",
      "orcid": "0000-0003-2285-0332"
    },
    {
      "affs": [
        5
      ],
      "name": "Anatole Storck",
      "orcid": "0009-0000-3245-7951"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7qtanz7dyne0a.bib",
  "cited_by": 0,
  "doi": "10.1093/mnras/stag1931",
  "fulltext_url": null,
  "id": "7qtanz7dyne0a",
  "issns": [
    "0035-8711",
    "1365-2966"
  ],
  "landing_url": "https://academic.oup.com/mnras/article/doi/10.1093/mnras/stag1931/8907361",
  "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": "W7220899642",
  "pdf_url": "https://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/stag1931/71838609/stag1931.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-10",
  "publisher": "Oxford University Press (OUP)",
  "ris": "https://research.draconitic.com/paper/7qtanz7dyne0a.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:17Z",
      "native_id": "10.1093/mnras/stag1931",
      "source": "crossref",
      "url": "https://academic.oup.com/mnras/article/doi/10.1093/mnras/stag1931/8907361"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena",
      "subfield": "galaxies"
    }
  ],
  "title": "Early onset of the hot circumgalactic medium around Milky Way galaxies",
  "title_text": "Early onset of the hot circumgalactic medium around Milky Way galaxies",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:17Z",
  "url": "https://research.draconitic.com/paper/7qtanz7dyne0a",
  "venue": "Monthly Notices of the Royal Astronomical Society",
  "versions": []
}