{
  "abstract": "Early James Webb Space Telescope (JWST) observations are providing growing evidence for a ubiquitous population of accreting supermassive black holes (BHs) at high redshift, many of which appear overmassive compared to the empirically derived local scaling relation between BH mass and host galaxy stellar mass. In this study, we leverage predictions from the semi-analytical Cosmic Archaeology Tool (CAT) to reconstruct the evolutionary pathways for this overmassive BH population, investigating how they assemble over cosmic time and interact with their host galaxies. We find that the large $\\rm {\\it M}_{BH}{\\!-\\!}{\\it M}_{star}$ ratios can be explained if light and heavy BH seeds grow by short, repeated episodes of super-Eddington accretion, triggered by major galaxy mergers. On average, we find that BH-galaxy co-evolution starts in earnest only at $z \\lt 8$, when $\\simeq 30{{\\ \\rm per\\ cent}}$ of the final galaxy stellar mass has formed outside the massive BH host. Our model suggests that super-Eddington bursts of accretion last between $0.5\\,\\text{and}\\,3$ Myr, resulting in a duty cycle of $1{\\!-\\!}4{{\\ \\rm per\\ cent}}$ for the target BH sample. The boost in luminosity of BHs undergoing super-Eddington accretion helps to explain the luminosity function of active galactic nuclei observed by JWST. At the same time, a large population of these overmassive BHs is predicted to be inactive, with Eddington ratios $\\lambda _{\\rm Edd} \\lt 0.05$, in agreement with recent observations.",
  "abstract_shown": true,
  "affiliations": [
    "Como Lake Center for Astrophysics, DiSAT, Università degli Studi dell’Insubria , Via Valleggio 11, I-22100 Como ,",
    "INAF/Osservatorio Astronomico di Roma , Via Frascati 33, 00040 Monte Porzio Catone ,",
    "INFN, Sezione Roma1, Dipartimento di Fisica, ‘Sapienza’ Università di Roma , Piazzale Aldo Moro 2, I-00185 Roma ,",
    "Institute for Astronomy, University of Edinburgh, Royal Observatory , Blackford Hill, Edinburgh EH9 3HJ ,",
    "Dipartimento di Fisica, ‘Sapienza’ Università di Roma , Piazzale Aldo Moro 2, I-00185 Roma ,",
    "Sapienza School for Advanced Studies , Viale Regina Elena 291, I-00161 Roma ,",
    "Kavli Institute for Cosmology, University of Cambridge , Madingley Road, Cambridge CB3 0HA ,",
    "Cavendish Laboratory, University of Cambridge , 19 JJ Thomson Avenue, Cambridge CB3 0HE ,",
    "INFN, Sezione di Milano-Bicocca , Piazza della Scienza 3, I-20126 Milano ,",
    "Department of Astronomy, Yale University , New Haven, CT 06511 ,",
    "Department of Physics, Yale University , New Haven, CT 06511 ,",
    "Yale Center for Astronomy & Astrophysics, Yale University , New Haven, CT 06520 ,",
    "Institut d’Astrophysique de Paris, Sorbonne Université, CNRS , UMR 7095, 98 bis bd Arago, F-75014 Paris ,"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 10,
  "authors": [
    {
      "affs": [
        0,
        1,
        2,
        3
      ],
      "name": "Alessandro Trinca",
      "orcid": "0000-0002-1899-4360"
    },
    {
      "affs": [
        1
      ],
      "name": "Rosa Valiante",
      "orcid": "0000-0003-3050-1765"
    },
    {
      "affs": [
        4,
        1,
        2,
        5
      ],
      "name": "Raffaella Schneider",
      "orcid": "0000-0001-9317-2888"
    },
    {
      "affs": [
        6
      ],
      "name": "Ignas Juodžbalis",
      "orcid": "0009-0003-7423-8660"
    },
    {
      "affs": [
        7,
        6
      ],
      "name": "R. Maiolino",
      "orcid": "0000-0002-4985-3819"
    },
    {
      "affs": [
        4,
        1,
        2
      ],
      "name": "Luca Graziani",
      "orcid": "0000-0002-9231-1505"
    },
    {
      "affs": [
        0,
        8
      ],
      "name": "Alessandro Lupi",
      "orcid": "0000-0001-6106-7821"
    },
    {
      "affs": [
        9,
        10,
        11
      ],
      "name": "Priyamvada Natarajan",
      "orcid": "0000-0002-5554-8896"
    },
    {
      "affs": [
        12
      ],
      "name": "Marta Volonteri",
      "orcid": "0000-0002-3216-1322"
    },
    {
      "affs": [
        4,
        1,
        2
      ],
      "name": "Tommaso Zana",
      "orcid": "0000-0003-4244-8527"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/024dx8a87tmqw.bib",
  "cited_by": 24,
  "doi": "10.1093/mnras/stag1608",
  "fulltext_url": null,
  "id": "024dx8a87tmqw",
  "issns": [
    "0035-8711",
    "1365-2966",
    "1365-8711"
  ],
  "landing_url": "https://doi.org/10.1093/mnras/stag1608",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W4405627267",
  "pdf_url": "https://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/stag1608/70818559/stag1608.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-27",
  "publisher": "Oxford University Press",
  "ris": "https://research.draconitic.com/paper/024dx8a87tmqw.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:18Z",
      "native_id": "W4405627267",
      "source": "openalex",
      "url": "https://doi.org/10.1093/mnras/stag1608"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena",
      "subfield": "galaxies"
    }
  ],
  "title": "Episodic super-Eddington accretion as a clue to overmassive black holes in the early Universe",
  "title_text": "Episodic super-Eddington accretion as a clue to overmassive black holes in the early Universe",
  "type": "peer-reviewed",
  "updated_at": "2026-11-05T13:20:42Z",
  "url": "https://research.draconitic.com/paper/024dx8a87tmqw",
  "venue": "Monthly Notices of the Royal Astronomical Society",
  "versions": []
}