Fujimoto, S.S.FujimotoBrammer, G. B.G. B.BrammerWatson, D.D.WatsonMagdis, G. E.G. E.MagdisKokorev, V.V.KokorevGreve, T. R.T. R.GreveToft, S.S.ToftWalter, F.F.WalterVALIANTE, RosaRosaVALIANTEGinolfi, M.M.GinolfiSchneider, R.R.SchneiderValentino, F.F.ValentinoColina, L.L.ColinaVestergaard, M.M.VestergaardMarques-Chaves, R.R.Marques-ChavesFynbo, J. P. U.J. P. U.FynboKrips, M.M.KripsSteinhardt, C. L.C. L.SteinhardtCortzen, I.I.CortzenRIZZO, FedericoFedericoRIZZOOesch, P. A.P. A.Oesch2025-03-132025-03-1320220028-0836http://hdl.handle.net/20.500.12386/36767Understanding how super-massive black holes form and grow in the early Universe has become a major challenge<SUP>1,2</SUP> since it was discovered that luminous quasars existed only 700 million years after the Big Bang<SUP>3,4</SUP>. Simulations indicate an evolutionary sequence of dust-reddened quasars emerging from heavily dust-obscured starbursts that then transition to unobscured luminous quasars by expelling gas and dust<SUP>5</SUP>. Although the last phase has been identified out to a redshift of 7.6 (ref. <SUP>6</SUP>), a transitioning quasar has not been found at similar redshifts owing to their faintness at optical and near-infrared wavelengths. Here we report observations of an ultraviolet compact object, GNz7q, associated with a dust-enshrouded starburst at a redshift of 7.1899 ± 0.0005. The host galaxy is more luminous in dust emission than any other known object at this epoch, forming 1,600 solar masses of stars per year within a central radius of 480 parsec. A red point source in the far-ultraviolet is identified in deep, high-resolution imaging and slitless spectroscopy. GNz7q is extremely faint in X-rays, which indicates the emergence of a uniquely ultraviolet compact star-forming region or a Compton-thick super-Eddington black-hole accretion disk at the dusty starburst core. In the latter case, the observed properties are consistent with predictions from cosmological simulations<SUP>7</SUP> and suggest that GNz7q is an antecedent to unobscured luminous quasars at later epochs.STAMPAenArticle10.1038/s41586-022-04454-12-s2.0-85128315745https://www.nature.com/articles/s41586-022-04454-1https://api.elsevier.com/content/abstract/scopus_id/851283157452022Natur.604..261FFIS/05 - ASTRONOMIA E ASTROFISICA