Quasars are the most luminous non-transient objects known and as a result they enable studies of the Universe at the earliest cosmic epochs. Despite extensive efforts, however, the quasar ULAS J1120 + 0641 at redshift z = 7.09 has remained the only one known at z > 7 for more than half a decade1. Here we report observations of the quasar ULAS J134208.10 + 092838.61 (hereafter J1342 + 0928) at redshift z = 7.54. This quasar has a bolometric luminosity of 4 × 1013 times the luminosity of the Sun and a black-hole mass of 8 × 108 solar masses. The existence of this supermassive black hole when the Universe was only 690 million years old—just five per cent of its current age—reinforces models of early black-hole growth that allow black holes with initial masses of more than about 104 solar masses2,3 or episodic hyper-Eddington accretion4,5. We see strong evidence of absorption of the spectrum of the quasar redwards of the Lyman α emission line (the Gunn–Peterson damping wing), as would be expected if a significant amount (more than 10 per cent) of the hydrogen in the intergalactic medium surrounding J1342 + 0928 is neutral. We derive such a significant fraction of neutral hydrogen, although the exact fraction depends on the modelling. However, even in our most conservative analysis we find a fraction of more than 0.33 (0.11) at 68 per cent (95 per cent) probability, indicating that we are probing well within the reionization epoch of the Universe.

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We thank D. Ossip for support with the FIRE echellette observations and A. Stephens for help preparing the GNIRS observations. This work is based on data collected with the Magellan Baade telescope, the Gemini North telescope (programme GN-2017A-DD-4), the Large Binocular Telescope and the IRAM/NOEMA interferometer. We are grateful for the support provided by the staff of these observatories. We acknowledge the use of the UKIDSS, WISE and DECaLS surveys.

Author information


  1. The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, California 91101, USA

    • Eduardo Bañados
    • , Daniel D. Kelson
    •  & Gwen C. Rudie
  2. Max Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany

    • Bram P. Venemans
    • , Chiara Mazzucchelli
    • , Emanuele P. Farina
    • , Fabian Walter
    • , Roberto Decarli
    •  & Hans-Walter Rix
  3. Department of Astronomy, School of Physics, Peking University, Beijing 100871, China

    • Feige Wang
    •  & Jinyi Yang
  4. Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China

    • Feige Wang
    •  & Jinyi Yang
  5. INAF—Osservatorio Astronomico di Bologna, via Gobetti 93/3, 40129 Bologna, Italy

    • Roberto Decarli
  6. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, USA

    • Daniel Stern
  7. Steward Observatory, The University of Arizona, 933 North Cherry Avenue, Tucson, Arizona 85721-0065, USA

    • Xiaohui Fan
  8. Department of Physics, Broida Hall, University of California, Santa Barbara, California 93106-9530, USA

    • Frederick B. Davies
    •  & Joseph F. Hennawi
  9. MIT-Kavli Center for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA

    • Robert A. Simcoe
    •  & Monica L. Turner
  10. Las Cumbres Observatory, 6740 Cortona Drive, Goleta, California 93117, USA

    • Monica L. Turner
  11. Institut de Radioastronomie Millimétrique (IRAM), 300 rue de la Piscine, 38406 Saint Martin d’Hères, France

    • Jan Martin Winters


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E.B., R.D., X.F., E.P.F., C.M., H.-W.R., D.S., B.P.V., F. Walter, F. Wang and J.Y. discussed and planned the candidate selection and observing strategy, and analysed the data. E.B. selected the quasar and with D.S. obtained and analysed the discovery spectrum. R.A.S. provided the final FIRE data reduction. J.F.H. provided the final GNIRS data reduction. G.C.R. carried out the follow-up Fourstar observations for this quasar. D.D.K. reduced the follow-up Fourstar data. J.M.W., B.P.V. and F. Walter contributed to the observations and analysis of the IRAM/NOEMA data. The damping-wing analyses were carried out by E.B. (model A), F.B.D. and J.F.H. (model B), and R.A.S. and M.L.T. (model C). F.B.D. and J.F.H. performed the PCA continuum modelling. R.A.S. performed the analysis to find the characteristics of a single absorber that could cause the absorption profile of the quasar. E.B. led the team and prepared the manuscript. All co-authors discussed the results and provided input to the paper and data analysis.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Eduardo Bañados.

Reviewer Information Nature thanks D. Mortlock and the other anonymous reviewer(s) for their contribution to the peer review of this work.

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