Direct Pathway to the Early Supermassive Black Holes: A Red Super-Eddington Quasar in a Massive Starburst Host at z = 7.2
Year: 2026
Type: article
Abstract: We present a panchromatic optical-millimeter characterization of GNz7q, a recently identified X-ray-weak, rapidly growing red quasar embedded within a dusty starburst galaxy at z = 7.1899, using the full suite of JWST/NIRCam, NIRSpec, Mid-Infrared Instrument (MIRI), and archival NOEMA observations. Our deep NIRSpec/G395M spectroscopy reveals unambiguous broad Balmer emission (FWHM = 2221 ± 20 km s −1 ), confirming a super-Eddington accreting black hole (BH) ( λ Edd = 2.7 ± 0.4) with a mass of log ( M BH / M ⊙ ) = 7.55 ± 0.34 , using accretion-rate-corrected BH mass estimators. After subtracting the point source, we robustly detect stellar emission from the host galaxy across multiple NIRCam and MIRI filters. Our joint morphological-spectral analysis yields a stellar mass of log ( M * / M ⊙ ) = 10.5 ± 0.4 and an intense star formation rate of SFR = 330 ± 97 M ⊙ yr −1 , confirming the host as a massive, dusty starburst galaxy. We find that GNz7q lies on the local M BH – M * relation ( M BH / M * ≃ 0.001) and is well positioned to evolve into the locus of massive Sloan Digital Sky Survey (SDSS) quasars with log ( M BH / M ⊙ ) ≈ 9 and M * ≈ 10 11 M ⊙ at z ∼ 6, owing to its remarkably rapid growth in both the BH and its host galaxy. This stands in stark contrast to many recently reported JWST active galactic nucleus populations at similar redshifts, including the little red dots, whose weak or undetected star formation makes it difficult for them to grow into the massive galaxies hosting SDSS-like quasars. These results suggest that GNz7q marks a rare, pivotal phase of early BH–galaxy coevolution, plausibly providing a crucial direct pathway to the supermassive BH systems within the first billion years of the Universe.
Source: The Astrophysical Journal
Authors: Qinyue Fei, Seiji Fujimoto, Gabriel Brammer, Ruancun Li, Luis C. Ho, Volker Bromm, Javier Álvarez-Márquez, Yoshihisa Asada, Guillermo Barro, Luis Colina, Pratika Dayal, Steven L. Finkelstein, Johan P. U. Fynbo, Michele Ginolfi, Kohei Inayoshi, Vasily Kokorev, Gene C. K. Leung, Jorryt Matthee, Romain A. Meyer, Rohan P. Naidu, Masafusa Onoue, Pablo G. Pérez-González, Charles L. Steinhardt, Francesco Valentino, Fabian Walter, Mengyuan Xiao, Haowen Zhang
Institutions: University of Toronto, University of Copenhagen, Max Planck Institute for Extraterrestrial Physics, Peking University, The University of Texas at Austin, Centro de Astrobiología, University of the Pacific, Arcetri Astrophysical Observatory, University of Florence, National Institute for Astrophysics, Massachusetts Institute of Technology, Institute of Science and Technology Austria, University of Geneva, Waseda University, The University of Tokyo, University of Missouri, Technical University of Denmark, California Institute of Technology, National Radio Astronomy Observatory, Max Planck Institute for Astronomy
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Awards: G103270039, G103507813, G1105844351, G121809054, G1611291055, G1622782223, G1638893853, G1855990336, G2019505627, G2237791728, G2309174360, G256731684, G2660406951, G279363373, G3518538256, G3823816291, G410571670, G4212894969, G423104186, G430777504, G451917667, G491712853, G5404395142, G5421974903, G5539308778, G5568641063, G5635532810, G579566091, G5967599077, G624877701, G6871265517, G717256432, G7328853082, G7709247530, G7805626310, G7863371703, G8497050386, G8920660035, G897484643, G929308097, G99296377
OpenAlex ID: W7221139887