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A γ-ray burst at a redshift of z ≈ 8.2


Long-duration γ-ray bursts (GRBs) are thought to result from the explosions of certain massive stars1, and some are bright enough that they should be observable out to redshifts of z > 20 using current technology2,3,4. Hitherto, the highest redshift measured for any object was z = 6.96, for a Lyman-α emitting galaxy5. Here we report that GRB 090423 lies at a redshift of z ≈ 8.2, implying that massive stars were being produced and dying as GRBs 630 Myr after the Big Bang. The burst also pinpoints the location of its host galaxy.

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Figure 1: Multiband images of the afterglow of GRB 090423.
Figure 2: The composite infrared spectrum of the GRB 090423 afterglow.
Figure 3: The X-ray and infrared light curves of GRB 090423.


  1. Woosley, S. E. & Bloom, J. S. The supernova gamma-ray burst connection. Annu. Rev. Astron. Astrophys. 44, 507–556 (2006)

    Article  CAS  ADS  Google Scholar 

  2. Lamb, D. Q. & Reichart, D. E. Gamma-ray bursts as a probe of the very high redshift universe. Astrophys. J. 536, 1–18 (2000)

    Article  ADS  Google Scholar 

  3. Racusin, J. L. et al. Broadband observations of the naked-eye γ -ray burst GRB 080319B. Nature 455, 183–188 (2008)

    Article  CAS  ADS  Google Scholar 

  4. Bloom, J. S. et al. Observations of the naked-eye GRB080319B: implications of nature’s brightest explosion. Astrophys. J. 691, 723–737 (2009)

    Article  ADS  Google Scholar 

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

    Article  CAS  ADS  Google Scholar 

  6. Gehrels, N. et al. The Swift Gamma-Ray Burst Mission. Astrophys. J. 611, 1005–1020 (2004)

    Article  CAS  ADS  Google Scholar 

  7. Jakobsson, P. et al. H I column densities of z > 2 Swift gamma-ray bursts. Astron. Astrophys. 460, L13–L17 (2006)

    Article  CAS  ADS  Google Scholar 

  8. Chen, H.-W., Prochaska, J. X. & Gnedin, N. Y. A new constraint on the escape fraction in distant galaxies using γ-ray burst afterglow spectroscopy. Astrophys. J. 667, L125–L128 (2007)

    Article  CAS  ADS  Google Scholar 

  9. Fynbo, J. P. U. et al. Low-resolution spectroscopy of gamma-ray burst optical afterglows: biases in the Swift sample and characterization of the absorbers. Preprint at 〈〉 (2009)

  10. Salvaterra, R. et al. GRB 090423 at a redshift of z ≈ 8.1. Nature 10.1038/nature08459 (this issue)

  11. von Kienlin, A. et al. GRB 090423: Fermi GBM observation (correction of isotropic equivalent energy). GCN Circ. 9251, (2009)

  12. Bromm, V. & Loeb, A. High-redshift gamma-ray bursts from population III progenitors. Astrophys. J. 642, 382–388 (2006)

    Article  ADS  Google Scholar 

  13. Zhang, B. et al. Physical classification scheme of cosmological gamma-ray bursts and their observational characteristics: on the nature of z = 6.7 GRB 080913 and some short/hard GRBs. Astrophys J. (in the press); preprint at 〈〉 (2009)

  14. Zhang, B.-B. & Zhang, B. GRB 090423: pseudo burst at z = 1 and its relation to GRB 080913. GCN Circ. 9279, (2009)

  15. Wijers, R. A. M. J. et al. Gamma-ray bursts from stellar remnants - probing the universe at high redshift. Mon. Not. R. Astron. Soc. 294, L13–L17 (1998)

    Article  ADS  Google Scholar 

  16. Miralda-Escude, J. Reionization of the intergalactic medium and the damping wing of the Gunn-Peterson Trough. Astrophys. J. 501, 15–22 (1998)

    Article  CAS  ADS  Google Scholar 

  17. Barkana, R. & Loeb, A. Gamma-ray bursts versus quasars: Lyα signatures of reionization versus cosmological infall. Astrophys. J. 601, 64–77 (2004)

    Article  CAS  ADS  Google Scholar 

  18. Totani, T. et al. Implications for cosmic reionization from the optical afterglow spectrum of the gamma-ray burst 050904 at z = 6.3. Publ. Astron. Soc. Jpn 58, 485–498 (2009)

    Article  ADS  Google Scholar 

  19. Greiner, J. et al. GRB 080913 at redshift 6.7. Astrophys. J. 693, 1610–1620 (2009)

    Article  CAS  ADS  Google Scholar 

  20. Faucher-Giguere, C.-A., Lidz, A., Hernquist, L. & Zaldarriaga, M. Evolution of the intergalactic opacity: implications for the ionizing background, cosmic star formation, and quasar activity. Astrophys. J. 688, 85–107 (2008)

    Article  ADS  Google Scholar 

  21. McQuinn, M. et al. Probing the neutral fraction of the IGM with GRBs during the epoch of reionization. Mon. Not. R. Astron. Soc. 388, 1101–1110 (2008)

    CAS  ADS  Google Scholar 

  22. Grindlay, J. in Gamma-Ray Burst: Sixth Huntsville Symposium (eds Meegan, C., Kouveliotou, C. & Gehrels, N.) 18–24 (AIP Conf. Ser. 1113, American Institute of Physics, 2009)

    Google Scholar 

  23. Tanvir, N. R. & Jakobsson, P. Observations of GRBs at high redshift. Phil. Trans. R. Soc. A 365, 1377–1384 (2007)

    Article  CAS  ADS  Google Scholar 

  24. Berger, E. et al. Hubble Space Telescope and Spitzer observations of the afterglow and host galaxy of GRB 050904 at z = 6.295. Astrophys. J. 665, 102–106 (2007)

    Article  ADS  Google Scholar 

  25. Komatsu, E. et al. Five-year Wilkinson Microwave Anisotropy Probe observations: cosmological interpretation. Astrophys. J. 180 (suppl.). 330–376 (2009)

    Article  Google Scholar 

  26. Malhotra, S. & Rhoads, J. E. Luminosity functions of Lyα emitters at redshifts z = 6.5 and z = 5.7: evidence against reionization at z≤6.5. Astrophys. J. 617, L5–L8 (2004)

    Article  CAS  ADS  Google Scholar 

  27. Becker, G. D., Rauch, M. & Sargent, W. L. W. The evolution of optical depth in the Lyα forest: evidence against reionization at z6. Astrophys. J. 662, 72–93 (2007)

    Article  CAS  ADS  Google Scholar 

  28. Willingale, R. et al. Testing the standard fireball model of gamma-ray bursts using late X-ray afterglows measured by Swift. Astrophys. J. 662, 1093–1110 (2007)

    Article  CAS  ADS  Google Scholar 

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We thank Ph. Yock, B. Allen, P. Kubanek, M. Jelinek and S. Guziy for their assistance with the BOOTES-3 YA telescope observations (Supplementary Information). This work was partly based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the US National Science Foundation on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), the Ministério da Ciência e Tecnologia (Brazil) and SECYT (Argentina). This work was also partly based on observations made using ESO telescopes at the La Silla or Paranal observatories by G. Carraro, L. Schmidtobreick, G. Marconi, J. Smoker, V. Ivanov, E. Mason and M. Huertas-Company. The UKIRT is operated by the Joint Astronomy Centre on behalf of the UK Science and Technology Facilities Council. R.J.F. acknowledges a Clay Fellowship.

Author Contributions Triggering observations: N.R.T., D.B.F., A.J.L., E.B., J.S.B., D.P., J. Greiner, A.J.C.-T., A.d.U.P.; analysis of ground-based data: N.R.T., D.B.F., A.J.L., E.B., K.W., J.P.U.F., A.C., J.S.B., J.F., J.D., J. Gorosabel, B.C., D.P., J.R.M., T. Krühler, A.J.C.-T., A.d.U.P., C.G.M.; Swift analysis: P.A.E., R.L.C.S., K.P., R.W., A.J.L., N.R.T., N.G., D.W., P.S., T.S.; observations at various observatories and their automation to accept GRB overrides: A.J.A., A.A., T. Kerr, T.N., A.W.S., K.R., T.W. All authors made contributions through their involvement in the programmes from which the data derive, and contributed to the interpretation, content and discussion presented here. Writing was led by N.R.T., A.J.L., D.B.F. and E.B.

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Correspondence to N. R. Tanvir.

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This file contains Supplementary Methods and Notes, Supplementary Data, Supplementary Tables S1-S3, Supplementary Figures S01-S06 with Legends and Supplementary References. (PDF 1507 kb)

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Tanvir, N., Fox, D., Levan, A. et al. A γ-ray burst at a redshift of z ≈ 8.2. Nature 461, 1254–1257 (2009).

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