The Hubble Deep Field provides one of the deepest multiwavelength views of the distant Universe and has led to the detection of thousands of galaxies seen throughout cosmic time1. An early map of the Hubble Deep Field at a wavelength of 850 micrometres, which is sensitive to dust emission powered by star formation, revealed the brightest source in the field, dubbed HDF 850.1 (ref. 2). For more than a decade, and despite significant efforts, no counterpart was found at shorter wavelengths, and it was not possible to determine its redshift, size or mass3,4,5,6,7. Here we report a redshift of z = 5.183 for HDF 850.1, from a millimetre-wave molecular line scan. This places HDF 850.1 in a galaxy overdensity at z ≈ 5.2, corresponding to a cosmic age of only 1.1 billion years after the Big Bang. This redshift is significantly higher than earlier estimates3,4,6,8 and higher than those of most of the hundreds of submillimetre-bright galaxies identified so far. The source has a star-formation rate of 850 solar masses per year and is spatially resolved on scales of 5 kiloparsecs, with an implied dynamical mass of about 1.3 × 1011 solar masses, a significant fraction of which is present in the form of molecular gas. Despite our accurate determination of redshift and position, a counterpart emitting starlight remains elusive.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    et al. The Hubble Deep Field: observations, data reduction, and galaxy photometry. Astron. J. 112, 1335–1389 (1996)

  2. 2.

    et al. A submillimetre survey of the Hubble Deep Field: unveiling dust-enshrouded star formation in the Early Universe. Nature 394, 241–247 (1998)

  3. 3.

    et al. Proposed identification of Hubble Deep Field submillimeter source HDF 850.1. Astron. Astrophys. 347, 809–820 (1999)

  4. 4.

    et al. Discovery of the galaxy counterpart of HDF 850.1, the brightest submillimetre source in the Hubble Deep Field. Mon. Not. R. Astron. Soc. 350, 769–784 (2004)

  5. 5.

    et al. A broad-band spectroscopic search for CO line emission in HDF850.1: the brightest submillimetre object in the Hubble Deep Field-north. Mon. Not. R. Astron. Soc. 375, 745–752 (2007)

  6. 6.

    , , & An accurate position for HDF 850.1: the brightest submillimeter source in the Hubble Deep Field-north. Astrophys. J. 697, L122–L126 (2009)

  7. 7.

    & The radio-to-submillimeter spectral index as a redshift indicator. Astrophys. J. 513, L13–L16 (1999)

  8. 8.

    Radio Identification of Submillimeter Sources in the Hubble Deep Field. Astrophys. J. 513, L9–L12 (1999)

  9. 9.

    & Molecular Gas at High Redshift. Annu. Rev. Astron. Astrophys. 43, 677–725 (2005)

  10. 10.

    et al. A kiloparsec-scale hyper-starburst in a quasar host less than 1 gigayear after the Big Bang. Nature 457, 699–701 (2009)

  11. 11.

    et al. The Chandra Deep Field North survey. XIII. 2 ms point-source catalogs. Astron. J. 126, 539–574 (2003)

  12. 12.

    et al. Excitation of the molecular gas in the nuclear region of M 82. Astron. Astrophys. 521, L2 (2010)

  13. 13.

    & Rotating nuclear rings and extreme starbursts in ultraluminous galaxies. Astrophys. J. 507, 615–654 (1998)

  14. 14.

    et al. Submillimeter galaxies at z 2: evidence for major mergers and constraints on lifetimes, IMF, and CO-H2 conversion factor. Astrophys. J. 680, 246–262 (2008)

  15. 15.

    et al. Tracing the molecular gas in distant submillimetre galaxies via CO(1–0) imaging with the Expanded Very Large Array. Mon. Not. R. Astron. Soc. 412, 1913–1925 (2011)

  16. 16.

    , & A universal, local star formation law in galactic clouds, nearby galaxies, high-redshift disks, and starbursts. Astrophys. J. 745, 69 (2012)

  17. 17.

    et al. A 158 μm [C II] line survey of galaxies at z 1–2: an indicator of star formation in the early Universe. Astrophys. J. 724, 957–974 (2010)

  18. 18.

    et al. X-ray, optical, and infrared imaging and spectral properties of the 1Ms Chandra Deep Field North sources. Astron. J. 124, 1839–1885 (2002)

  19. 19.

    et al. A massive protocluster of galaxies at a redshift of z ≈ 5.3. Nature 470, 233–235 (2011)

  20. 20.

    , & A highly complete spectroscopic survey of the GOODS-N field. Astrophys. J. 689, 687–708 (2008)

  21. 21.

    , , , & A candidate gravitational lens in the Hubble Deep Field. Astrophys. J. 467, L73–L75 (1996)

  22. 22.

    et al. A massive molecular gas reservoir in the z = 5.3 submillimeter galaxy AzTEC-3. Astrophys. J. 720, L131–L136 (2010)

  23. 23.

    et al. Two bright submillimeter galaxies in a z = 4.05 protocluster in Goods-North, and accurate radio-infrared photometric redshifts. Astrophys. J. 694, 1517–1538 (2009)

  24. 24.

    et al. Molecular gas in a submillimeter galaxy at z = 4.5: evidence for a major merger at 1 billion years after the Big Bang. Astrophys. J. 689, L5–L8 (2008)

  25. 25.

    et al. A bright z = 5.2 lensed submillimeter galaxy in the field of Abell 773. HLSJ091828.6+514223. Astron. Astrophys. 538, L4 (2012)

  26. 26.

    et al. Gas and dust in a submillimeter galaxy at z = 4.24 from the Herschel atlas. Astrophys. J. 740, 63 (2011)

  27. 27.

    et al. A robust sample of submillimetre galaxies: constraints on the prevalence of dusty, high-redshift starbursts. Mon. Not. R. Astron. Soc. 364, 1025–1040 (2005)

  28. 28.

    et al. A population of massive and evolved galaxies at z>5. Astrophys. J. 676, 781–806 (2008)

  29. 29.

    et al. The unusual infrared object HDF-N J123656.3+621322. Astrophys. J. 531, 624–634 (2000)

  30. 30.

    et al. Very high gas fractions and extended gas reservoirs in z = 1.5 disk galaxies. Astrophys. J. 713, 686–707 (2010)

Download references


This work is based on observations carried out with the IRAM Plateau de Bure Interferometer. IRAM is supported by MPG (Germany), INSU/CNRS (France) and IGN (Spain). The Jansky Very Large Array of NRAO is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. D.A.R. acknowledges support from NASA through a Spitzer Space Telescope grant. R.D. acknowledges funding through DLR project FKZ 50OR1004.

Author information


  1. Max-Planck Institut für Astronomie, Königstuhl 17, D-69117, Heidelberg, Germany

    • Fabian Walter
    • , Roberto Decarli
    • , Elisabete Da Cunha
    • , Jacqueline Hodge
    •  & Hans-Walter Rix
  2. National Radio Astronomy Observatory, Pete V. Domenici Array Science Center, PO Box O, Socorro, New Mexico 87801, USA

    • Fabian Walter
    •  & Chris Carilli
  3. Cavendish Laboratory, University of Cambridge, 19 J J Thomson Avenue, Cambridge CB3 0HE, UK

    • Chris Carilli
    • , Lindley Lentati
    •  & Roberto Maiolino
  4. Argelander Institute for Astronomy, University of Bonn, Auf dem Hügel 71, 53121 Bonn, Germany

    • Frank Bertoldi
  5. IRAM, 300 rue de la Piscine, F-38406 Saint-Martin d'Hères, France

    • Pierre Cox
    • , Dennis Downes
    • , Roberto Neri
    •  & Melanie Krips
  6. Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot, Irfu/Service d’Astrophysique, CEA Saclay, Orme des Merisiers, 91191 Gif-sur-Yvette cedex, France

    • Emanuele Daddi
    •  & David Elbaz
  7. National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, Arizona 85719, USA

    • Mark Dickinson
  8. Astronomy Department, California Institute of Technology, MC105-24, Pasadena, California 91125, USA

    • Richard Ellis
    •  & Dominik A. Riechers
  9. Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany

    • Axel Weiss
    •  & Karl Menten
  10. Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, Michigan 48109, USA

    • Eric Bell
  11. Universität Wien, Institut für Astronomie, Türkenschanzstraße 17, 1080 Wien, Austria

    • Helmut Dannerbauer
  12. Department of Astronomy and Astrophysics, University of California, Santa Cruz, California 95064, USA

    • Mark Krumholz
  13. INAF-Osservatorio Astronomico di Roma, via di Frascati 33, 00040 Monte Porzio Catone, Italy

    • Roberto Maiolino
  14. Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, Arizona 85721, USA

    • Brant Robertson
    •  & Dan P. Stark
  15. Department of Astronomy, University of California at Berkeley, Berkeley, California 94720, USA

    • Hyron Spinrad
  16. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, USA

    • Daniel Stern


  1. Search for Fabian Walter in:

  2. Search for Roberto Decarli in:

  3. Search for Chris Carilli in:

  4. Search for Frank Bertoldi in:

  5. Search for Pierre Cox in:

  6. Search for Elisabete Da Cunha in:

  7. Search for Emanuele Daddi in:

  8. Search for Mark Dickinson in:

  9. Search for Dennis Downes in:

  10. Search for David Elbaz in:

  11. Search for Richard Ellis in:

  12. Search for Jacqueline Hodge in:

  13. Search for Roberto Neri in:

  14. Search for Dominik A. Riechers in:

  15. Search for Axel Weiss in:

  16. Search for Eric Bell in:

  17. Search for Helmut Dannerbauer in:

  18. Search for Melanie Krips in:

  19. Search for Mark Krumholz in:

  20. Search for Lindley Lentati in:

  21. Search for Roberto Maiolino in:

  22. Search for Karl Menten in:

  23. Search for Hans-Walter Rix in:

  24. Search for Brant Robertson in:

  25. Search for Hyron Spinrad in:

  26. Search for Dan P. Stark in:

  27. Search for Daniel Stern in:


F.W. had the overall lead of the project. The Plateau de Bure Interferometer data were analysed by R.D., F.W., P.C., R.N., M.K. and D.D. The Jansky Very Large Array data reduction was performed by C.C., J.H. and L.L. The molecular gas excitation was led by A.W. Spectroscopic redshift information was provided by M.D., R.E., H.S., D.S. and D.P.S. The spectral energy distribution analysis, including new Herschel data, was led by E.D.C, D.E. and E.D. An updated lensing model was provided by D.D. All authors helped with the proposal, data analysis and interpretation.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Fabian Walter.

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    This file contains Supplementary Text and Data 1-3, Supplementary Table 1, Supplementary Figures 1-2 and additional references.

About this article

Publication history







By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.