{ "abstract": "JWST has revealed an abundance of supermassive black holes (BHs) in the early Universe, and yet the lowest mass seed BHs that gave rise to these populations remain elusive. Here, we present a systematic search for broad-line active galactic nuclei (AGNs) in some of the faintest high- z galaxies surveyed yet by combining ultra-deep JWST/NIRSpec G395M spectroscopy with the strong lensing aid in AS1063. By employing the profile of the [O iii ] λ 5007 emission lines as a template for narrow-line components and carefully cross-validating with mock observations, we identify a sample of 10 broad-line AGNs at 4.5 < z < 7.0 (eight secure, two tentative). The inferred BH masses from the broad H α line explore the intermediate BH mass regime down to ∼10 5.5 M ⊙ . The stellar mass ( M * ) is estimated with a galaxy+AGN composite model, and we find the BH to stellar mass ratio spans down to M BH / M * ≲ 0.1%, unveiling populations on the empirical M BH – M * relation observed in the local Universe. We also derive the BH mass function and investigate its low-mass end at this epoch. While we confirm the agreement of our results with previous studies at M BH ≳ 10 6.5 M ⊙ , we find the mass range of ∼10 5.5 M ⊙ features an enhanced abundance with respect to the extrapolated best-fit Schechter function. Comparison with theoretical models suggests that a possible origin for this enhanced abundance is the direct-collapse BH formation, supporting the scenario that the direct collapse of massive gas clouds is a significant pathway for the earliest supermassive BHs.", "abstract_shown": true, "affiliations": [ "University of Toronto", "Dunlap Institute for Astronomy and Astrophysics", "MIT Kavli Institute for Astrophysics and Space Research", "The University of Texas at Austin", "Sorbonne Université", "IAP - Institut d'Astrophysique de Paris (98bis, bd Arago - 75014 Paris France - France)", "University of Copenhagen", "Waseda University", "Ben-Gurion University of the Negev", "Princeton University", "Institute of Science and Technology Austria (ISTA)", "Harvard University", "Yale University", "Tufts University", "Univ Lyon", "CRAL - Centre de Recherche Astrophysique de Lyon (9 Avenue Charles André 69561 ST GENIS LAVAL CEDEX - France)", "Stockholm University", "CNRS", "Université de Genève", "IRAP - Institut de recherche en astrophysique et planétologie (9 avenue Colonel Roche 31028 Toulouse - France)" ], "article_type": null, "arxiv": null, "author_total": 22, "authors": [ { "affs": [ 0 ], "name": "Qinyue Fei", "orcid": "0000-0001-7232-5355" }, { "affs": [ 1, 0 ], "name": "Seiji Fujimoto", "orcid": "0000-0001-7201-5066" }, { "affs": [ 2 ], "name": "Rohan P. Naidu", "orcid": "0000-0003-3997-5705" }, { "affs": [ 3 ], "name": "John Chisholm", "orcid": "0000-0002-0302-2577" }, { "affs": [ 4, 5 ], "name": "Hakim Atek", "orcid": "0000-0002-7570-0824" }, { "affs": [ 6 ], "name": "Gabriel Brammer", "orcid": "0000-0003-2680-005X" }, { "affs": [ 1, 0, 7 ], "name": "Yoshihisa Asada", "orcid": "0000-0003-3983-5438" }, { "affs": [ 3 ], "name": "Danielle A. Berg", "orcid": "0000-0002-4153-053X" }, { "affs": [ 3 ], "name": "Volker Bromm", "orcid": "0000-0003-0212-2979" }, { "affs": [ 8 ], "name": "Lukas J. Furtak", "orcid": "0000-0001-6278-032X" }, { "affs": [ 9 ], "name": "Jenny E. Greene", "orcid": "0000-0002-5612-3427" }, { "affs": [ 3 ], "name": "Tiger Yu-Yang Hsiao", "orcid": "0000-0003-4512-8705" }, { "affs": [ 3 ], "name": "Junehyoung Jeon", "orcid": "0000-0002-6038-5016" }, { "affs": [ 3 ], "name": "Vasily Kokorev", "orcid": "0000-0002-5588-9156" }, { "affs": [ 10 ], "name": "Jorryt Matthee", "orcid": "0000-0003-2871-127X" }, { "affs": [ 11, 12 ], "name": "Priyamvada Natarajan", "orcid": "0000-0002-5554-8896" }, { "affs": [ 13 ], "name": "Richard Pan", "orcid": "0000-0002-9651-5716" }, { "affs": [ 14, 15 ], "name": "Johan Richard", "orcid": "0000-0001-5492-1049" }, { "affs": [ 16 ], "name": "Alberto Saldana-Lopez", "orcid": "0000-0001-8419-3062" }, { "affs": [ 17, 18, 19 ], "name": "D. Schaerer", "orcid": "0000-0001-7144-7182" }, { "affs": [ 4, 5 ], "name": "Marta Volonteri", "orcid": "0000-0002-3216-1322" }, { "affs": [ 8 ], "name": "Adi Zitrin", "orcid": "0000-0002-0350-4488" } ], "bibtex": "https://research.draconitic.com/paper/1er2k0zcvaynx.bib", "cited_by": 23, "doi": "10.3847/1538-4357/ae6248", "fulltext_url": null, "id": "1er2k0zcvaynx", "issns": [ "0004-637X", "1538-4357" ], "landing_url": "https://doi.org/10.3847/1538-4357/ae6248", "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": "W4416763258", "pdf_url": null, "pmcid": null, "pmid": null, "published": "2026-05-28", "publisher": "IOP Publishing", "ris": "https://research.draconitic.com/paper/1er2k0zcvaynx.ris", "sources": [ { "first_seen": "2026-10-30T13:26:43Z", "native_id": "W4416763258", "source": "openalex", "url": "https://doi.org/10.3847/1538-4357/ae6248" } ], "subjects": [ { "field": "astronomy", "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena", "subfield": "galaxies" } ], "title": "A GLIMPSE of Intermediate Mass Black Holes in the Epoch of Reionization: Witnessing the Descendants of Direct Collapse?", "title_text": "A GLIMPSE of Intermediate Mass Black Holes in the Epoch of Reionization: Witnessing the Descendants of Direct Collapse?", "type": "peer-reviewed", "updated_at": "2026-11-09T13:21:02Z", "url": "https://research.draconitic.com/paper/1er2k0zcvaynx", "venue": "The Astrophysical Journal", "versions": [] }