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A galaxy rapidly forming stars 700 million years after the Big Bang at redshift 7.51


Of several dozen galaxies observed spectroscopically that are candidates for having a redshift (z) in excess of seven, only five have had their redshifts confirmed via Lyman α emission, at z = 7.008, 7.045, 7.109, 7.213 and 7.215 (refs 1, 2, 3, 4). The small fraction of confirmed galaxies may indicate that the neutral fraction in the intergalactic medium rises quickly at z > 6.5, given that Lyman α is resonantly scattered by neutral gas3,5,6,7,8. The small samples and limited depth of previous observations, however, makes these conclusions tentative. Here we report a deep near-infrared spectroscopic survey of 43 photometrically-selected galaxies with z > 6.5. We detect a near-infrared emission line from only a single galaxy, confirming that some process is making Lyman α difficult to detect. The detected emission line at a wavelength of 1.0343 micrometres is likely to be Lyman α emission, placing this galaxy at a redshift z = 7.51, an epoch 700 million years after the Big Bang. This galaxy’s colours are consistent with significant metal content, implying that galaxies become enriched rapidly. We calculate a surprisingly high star-formation rate of about 330 solar masses per year, which is more than a factor of 100 greater than that seen in the Milky Way. Such a galaxy is unexpected in a survey of our size9, suggesting that the early Universe may harbour a larger number of intense sites of star formation than expected.

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Figure 1: The observed NIR spectrum of the galaxy z8_GND_5296.
Figure 2: Images of z8_GND_5296.
Figure 3: Spectral energy distribution fitting of z8_GND_5296.


  1. Vanzella, E. et al. Spectroscopic confirmation of two Lyman break galaxies at redshift beyond 7. Astrophys. J. 730, L35 (2011)

    ADS  Article  Google Scholar 

  2. Schenker, M. A. et al. Keck spectroscopy of faint 3 < z < 8 Lyman break galaxies: evidence for a declining fraction of emission line sources in the redshift range 6 < z < 8. Astrophys. J. 744, 179 (2012)

    ADS  Article  Google Scholar 

  3. Ono, Y. et al. Spectroscopic confirmation of three z-dropout galaxies at z = 6.844–7.213: demographics of Lyα emission in z 7 galaxies. Astrophys. J. 744, 83 (2012)

    ADS  Article  Google Scholar 

  4. Shibuya, T. et al. The first systematic survey for Lyα emitters at z = 7.3 with red-sensitive Subaru/Suprime-Cam. Astrophys. J. 752, 114 (2012)

    ADS  Article  Google Scholar 

  5. Kashikawa, N. et al. The end of the reionization epoch probed by Lyα emitters at z = 6.5 in the Subaru deep field. Astrophys. J. 648, 7–22 (2006)

    ADS  CAS  Article  Google Scholar 

  6. Iye, M. et al. A galaxy at a redshift z = 6.96. Nature 443, 186–188 (2006)

    ADS  CAS  Article  Google Scholar 

  7. Ouchi, M. et al. Statistics of 207 Lyα emitters at a redshift near 7: constraints on reionization and galaxy formation models. Astrophys. J. 723, 869–894 (2010)

    ADS  CAS  Article  Google Scholar 

  8. Pentericci, L. et al. Spectroscopic confirmation of z 7 Lyman break galaxies: probing the earliest galaxies and the epoch of reionization. Astrophys. J. 743, 132 (2011)

    ADS  Article  Google Scholar 

  9. Smit, R. et al. The star formation rate function for redshift z 4–7 galaxies: evidence for a uniform buildup of star-forming galaxies during the first 3 Gyr of cosmic time. Astrophys. J. 756, 14 (2012)

    ADS  Article  Google Scholar 

  10. Grogin, N. A. et al. CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. Astrophys. J. 197 (Supp.). 35 (2011)

    Article  Google Scholar 

  11. Koekemoer, A. M. et al. CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey – The Hubble Space Telescope observations, imaging data products, and mosaics. Astrophys. J. 197 (Supp.). 36 (2011)

    Article  Google Scholar 

  12. McLean, I. S. et al. MOSFIRE, the multi-object spectrometer for infra-red exploration at the Keck Observatory. Proc. SPIE 8446, J84460–1-15 (2012)

    Article  Google Scholar 

  13. Finkelstein, S. L. et al. On the stellar populations and evolution of star-forming galaxies at 6.3 ≤ z ≤ 8.6. Astrophys. J. 719, 1250–1273 (2010)

    ADS  Article  Google Scholar 

  14. McLure, R. J. et al. Galaxies at z = 6–9 from the WFC3/IR imaging of the Hubble Ultra Deep Field. Mon. Not. R. Astron. Soc. 403, 960–983 (2010)

    ADS  Article  Google Scholar 

  15. Finkelstein, S. L. et al. CANDELS: The evolution of galaxy rest-frame ultraviolet colors from z = 8 to 4. Astrophys. J. 756, 164 (2012)

    ADS  Article  Google Scholar 

  16. McLure, R. J. et al. A new multifield determination of the galaxy luminosity function at z = 7–9 incorporating the 2012 Hubble Ultra-Deep Field imaging. Mon. Not. R. Astron. Soc. 432, 2696–2716 (2013)

    ADS  Article  Google Scholar 

  17. Stark, D. P. et al. Keck spectroscopy of 3 < z < 7 faint Lyman break galaxies: the importance of nebular emission in understanding the specific star formation rate and stellar mass density. Astrophys. J. 763, 129 (2013)

    ADS  Article  Google Scholar 

  18. Riechers, D. A. et al. A dust-obscured massive maximum-starburst galaxy at a redshift of 6.34. Nature 496, 329–333 (2013)

    ADS  CAS  Article  Google Scholar 

  19. Stark, D. P., Ellis, R. S. & Ouchi, M. Keck spectroscopy of faint 3>z>7 Lyman break galaxies: a high fraction of line emitters at redshift six. Astrophys. J. 728, L2 (2011)

    ADS  Article  Google Scholar 

  20. Fan, X. et al. Constraining the evolution of the ionizing background and the epoch of reionization with z6 quasars. II. A sample of 19 quasars. Astron. J. 132, 117–136 (2006)

    ADS  CAS  Article  Google Scholar 

  21. Bolton, J. S. et al. How neutral is the intergalactic medium surrounding the redshift z = 7.085 quasar ULAS J1120+0641? Mon. Not. R. Astron. Soc. 416, L70–L74 (2011)

    ADS  Article  Google Scholar 

  22. Finkelstein, S. L. et al. CANDELS: the contribution of the observed galaxy population to cosmic reionization. Astrophys. J. 758, 93 (2012)

    ADS  Article  Google Scholar 

  23. Dekel, A. et al. Toy models for galaxy formation versus simulations. Mon. Not. R. Astron. Soc. 435, 999–1019 (2013)

    ADS  Article  Google Scholar 

  24. Kennicutt, R. C. & Evans, N. J. Star formation in the Milky Way and nearby galaxies. Annu. Rev. Astron. Astrophys. 50, 531–608 (2012)

    ADS  CAS  Article  Google Scholar 

  25. Krumholz, M. R. & Dekel, A. Metallicity-dependent quenching of star formation at high redshift in small galaxies. Astrophys. J. 753, 16 (2012)

    ADS  Article  Google Scholar 

  26. Riechers, D. A. et al. A dust-obscured massive maximum-starburst galaxy at a redshift of 6.34. Nature 496, 329–333 (2013)

    ADS  CAS  Article  Google Scholar 

  27. Kennicutt, R. C., Jr Star formation in galaxies along the Hubble sequence. Annu. Rev. Astron. Astrophys. 36, 189–231 (1998)

    ADS  CAS  Article  Google Scholar 

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We thank M. Dijkstra, J. Rhoads and S. Malhotra for conversations, as well as N. Konidaris and C. Steidel for assistance with the MOSFIRE data reduction pipeline. We also thank our Keck Support Astronomer G. Wirth for assistance during our observing run. S.L.F. acknowledges support from the University of Texas at Austin, the McDonald Observatory and NASA through a NASA Keck PI Data Award, administered by the NASA Exoplanet Science Institute. Data presented here were obtained at the W. M. Keck Observatory from telescope time allocated to NASA through the agency’s scientific partnership with the California Institute of Technology and the University of California. The Observatory was made possible by the financial support of the W. M. Keck Foundation. We recognize and acknowledge the cultural role and reverence that the summit of Mauna Kea has within the indigenous Hawaiian community. This work is also based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555, as well as the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA.

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Authors and Affiliations



S.L.F. wrote the text, obtained and reduced the data and led the initial observing proposal. C.P. and M.D. assisted with the analysis of the data. M.S. and V.T. assisted with the observation planning and implementation. K.D.F. performed the Spitzer/IRAC photometry. A.M.K. was responsible for the reduction of the optical and NIR imaging data used to select the sample. G.G.F., M.L.N.A. and S.P.W. obtained and reduced the mid-infrared data. B.J.W. provided grism spectroscopic information. B.M., H.C.F., M.G., N.R., A.D., A.F., N.A.G., J.-S.H., D.K. and M.R. have contributed in their roles as members of the CANDELS and S-CANDELS teams, and assisted with the planning and interpretation of the observations.

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Correspondence to S. L. Finkelstein.

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The authors declare no competing financial interests.

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Finkelstein, S., Papovich, C., Dickinson, M. et al. A galaxy rapidly forming stars 700 million years after the Big Bang at redshift 7.51. Nature 502, 524–527 (2013).

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