{
  "abstract": "We reassess the direct collapse black hole (DCBH) interpretation of UHZ1 (UNCOVER-26185), a gravitationally lensed galaxy at z spec = 10.054. That interpretation rests on a hard (2–7 keV) X-ray excess detected with Chandra, attributed to a Compton-thick AGN with an inferred 2–10 keV luminosity of L X,int ∼ 10 ⁴⁶ erg s ⁻¹ (Á. Bogdán et al. 2024). The resulting extreme X-ray to rest-frame optical–IR ratio was taken as the hallmark signature of an “outsize black hole galaxy” at cosmic dawn. We analyze the full 2.2 Ms Chandra imaging dataset—including 0.95 Ms of unpublished observations—and present new JWST/MIRI photometry at λ obs > 5 μ m. Across the full range of plausible Chandra data reductions, the 2–7 keV excess at the position of UHZ1 reaches a significance of only 2.0–2.9 σ ; the originally reported 4.2–4.4 σ detection is sensitive to the specific astrometric alignment adopted and is not robustly reproducible. Moreover, the hard X-ray signal does not grow with the additional exposure, contrary to expectations for a steady source, indicating that any excess is not persistent. UHZ1 is also undetected in all nine MIRI imaging bands. Fitting red/obscured AGN SED templates to the tightest MIRI upper limit, we constrain the bolometric luminosity of any buried AGN to L bol < 1.3 × 10 ⁴⁵ erg s ⁻¹ . These conclusions are further supported by independent JWST spectroscopy, which reveals no AGN signatures in the rest-frame UV or optical. Taken together, the multiwavelength data paint a consistent picture of UHZ1 as a low-mass, metal-poor, star-forming galaxy in the early Universe, with no compelling evidence for a luminous obscured AGN, regardless of its proposed formation channel.",
  "abstract_shown": true,
  "affiliations": [
    "University of Michigan",
    "X-ray Astrophysics Laboratory",
    "University College London",
    "University of California",
    "Universitá degli Studi di Milano-Bicocca",
    "Center for Astrophysics",
    "Harvard University",
    "University of Utah",
    "Peking University"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 11,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Fan Zou",
      "orcid": "0000-0002-4436-6923"
    },
    {
      "affs": [
        0
      ],
      "name": "Elena Gallo",
      "orcid": "0000-0001-5802-6041"
    },
    {
      "affs": [
        0
      ],
      "name": "Zihao Zuo",
      "orcid": "0009-0000-8524-8344"
    },
    {
      "affs": [
        1
      ],
      "name": "Edmund Hodges-Kluck",
      "orcid": "0000-0002-2397-206X"
    },
    {
      "affs": [
        0
      ],
      "name": "Dieu D. Nguyen",
      "orcid": "0000-0002-5678-1008"
    },
    {
      "affs": [
        2
      ],
      "name": "Guido Roberts-Borsani",
      "orcid": "0000-0002-4140-1367"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Piero Madau",
      "orcid": "0000-0002-6336-3293"
    },
    {
      "affs": [
        5,
        6
      ],
      "name": "Fabio Pacucci",
      "orcid": "0000-0001-9879-7780"
    },
    {
      "affs": [
        7
      ],
      "name": "Anil C. Seth",
      "orcid": "0000-0003-0248-5470"
    },
    {
      "affs": [
        3
      ],
      "name": "Tommaso Treu",
      "orcid": "0000-0002-8460-0390"
    },
    {
      "affs": [
        8
      ],
      "name": "Shouyi Wang",
      "orcid": "0009-0003-1260-4143"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/55ztnh6ekr68r.bib",
  "cited_by": 0,
  "doi": "10.3847/1538-4357/aea0cc",
  "fulltext_url": null,
  "id": "55ztnh6ekr68r",
  "issns": [
    "0004-637X",
    "1538-4357"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea0cc",
  "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": "W7221752215",
  "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea0cc/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-14",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/55ztnh6ekr68r.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:11Z",
      "native_id": "10.3847/1538-4357/aea0cc",
      "source": "crossref",
      "url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea0cc"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena",
      "subfield": "galaxies"
    }
  ],
  "title": "Revisiting the Claim for a Direct-collapse Black Hole in UHZ1 at z = 10.05",
  "title_text": "Revisiting the Claim for a Direct-collapse Black Hole in UHZ1 at z = 10.05",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:11Z",
  "url": "https://research.draconitic.com/paper/55ztnh6ekr68r",
  "venue": "The Astrophysical Journal",
  "versions": []
}