Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

An origin for short γ-ray bursts unassociated with current star formation

Abstract

Two short (< 2 s) γ-ray bursts (GRBs) have recently been localized1,2,3,4 and fading afterglow counterparts detected2,3,4. The combination of these two results left unclear the nature of the host galaxies of the bursts, because one was a star-forming dwarf, while the other was probably an elliptical galaxy. Here we report the X-ray localization of a short burst (GRB 050724) with unusual γ-ray and X-ray properties. The X-ray afterglow lies off the centre of an elliptical galaxy at a redshift of z = 0.258 (ref. 5), coincident with the position determined by ground-based optical and radio observations6,7,8. The low level of star formation typical for elliptical galaxies makes it unlikely that the burst originated in a supernova explosion. A supernova origin was also ruled out for GRB 050709 (refs 3, 31), even though that burst took place in a galaxy with current star formation. The isotropic energy for the short bursts is 2–3 orders of magnitude lower than that for the long bursts. Our results therefore suggest that an alternative source of bursts—the coalescence of binary systems of neutron stars or a neutron star-black hole pair—are the progenitors of short bursts.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: BAT lightcurves for GRB 050724 showing the short duration of this GRB and the long softer emission.
Figure 2: VLT optical image 17 showing the association of GRB 050724 with the galaxy.
Figure 3: The smooth transition of the GRB phase into the X-ray phase.

Similar content being viewed by others

References

  1. Gehrels, N. et al. A short γ-ray burst apparently associated with an elliptical galaxy at redshift z = 0.225. Nature 437, 851–854 (2005)

    Article  ADS  CAS  Google Scholar 

  2. Villasenor, J. S. et al. Discovery of the short γ-ray burst GRB 050709. Nature 437, 855–858 (2005)

    Article  ADS  CAS  Google Scholar 

  3. Fox, D. B. et al. The afterglow of GRB 050709 and the nature of short-hard γ-ray bursts. Nature 437, 845–850 (2005)

    Article  ADS  CAS  Google Scholar 

  4. Covino, S. et al. Optical emission from GRB 050709: a short/hard GRB in a star-forming galaxy. Astron. Astrophys (submitted)

  5. Prochaska, J. X. et al. GRB 050724: Secure host redshift from Keck. GRB Circ. Netw. 3700 (2005)

  6. Krimm, H. et al. GRB050724: Refined analysis of the Swift-BAT possible short burst. GCN Circ. 3667 (2005)

  7. Berger, E. et al. The afterglow and elliptical host galaxy of the short γ-ray burst GRB 050724. Nature doi:10.1038/nature04238 (this issue)

  8. Burrows, D. N. et al. GRB 050724: Chandra observations of the X-ray afterglow. GCN Circ. 3697 (2005)

  9. Gehrels, N. et al. The Swift γ ray burst mission. Astrophys. J. 611, 1005–1020 (2004)

    Article  ADS  CAS  Google Scholar 

  10. Kouveliotou, C. et al. Identification of two classes of γ-ray bursts. Astrophys. J. 413, L101–L104 (1993)

    Article  ADS  CAS  Google Scholar 

  11. Boer, M. et al. GRB 050709: refined spectral and temporal properties. GCN Circ. 3653 (2005)

  12. Connaughton, V. BATSE observations of γ-ray burst tails. Astrophys. J. 567, 1028–1036 (2002)

    Article  ADS  Google Scholar 

  13. Lazzati, D., Ramirez-Ruiz, E. & Ghisellini, G. Possible detection of hard X-ray afterglows of short γ-ray bursts. Astron. Astrophys. 379, L39–L43 (2001)

    Article  ADS  Google Scholar 

  14. Covino, S. et al. GRB 050724: a short burst detected by Swift. GCN Circ. 3665 (2005)

  15. Antonelli, L. A. et al. GRB 050724: Swift XRT refined position. GCN Circ. 3678 (2005)

  16. Gal-Yam, A. et al. GRB 050724: Optical variability in a nearby galaxy. GCN Circ. 3681 (2005)

  17. D'Avanzo, P. et al. GRB050724: VLT observations of the variable source. GCN Circ. 3690 (2005)

  18. Bloom, J. S. et al. GRB 050724: Optical imaging/astrometry. GCN Circ. 3672 (2005)

  19. Kochanek, C. S. et al. The K-band galaxy luminosity function. Astrophys. J. 560, 566–579 (2001)

    Article  ADS  Google Scholar 

  20. Castro-Tirado, A. J. et al. GRB 050724: Optical and near-IR observations. GCN Circ. 3673 (2005)

  21. Le Floc'h, E. et al. Are the hosts of γ-ray bursts sub-luminous and blue galaxies? Astron. Astrophys 400, 499–510 (2003)

    Article  ADS  Google Scholar 

  22. Woosley, S. E. γ-ray bursts from stellar mass accretion disks around black holes. Astrophys. J. 405, 273–277 (1993)

    Article  ADS  CAS  Google Scholar 

  23. Hurley, K. et al. An exceptionally bright flare from SGR 1806–20 and the origin of short duration γ-ray bursts. Nature 434, 1098–1103 (2005)

    Article  ADS  CAS  Google Scholar 

  24. Palmer, D. M. et al. A giant γ-ray flare from the magnetar SGR 1806–20. Nature 434, 1107–1109 (2005)

    Article  ADS  CAS  Google Scholar 

  25. Frail, D. A. et al. Beaming in γ-ray bursts: Evidence for a standard energy reservoir. Astrophys. J. 562, L55–L58 (2001)

    Article  ADS  Google Scholar 

  26. Kumar, P. & Panaitescu, A. Afterglow emission from naked γ-ray bursts. Astrophys. J. 541, L51–L54 (2000)

    Article  ADS  Google Scholar 

  27. Burrows, D. N. et al. Bright X-ray flares in γ-ray burst afterglows. Science 309, 1833–1855 (2005)

    Article  ADS  CAS  Google Scholar 

  28. Rosswog, S., Ramirez-Ruiz, E., & Davies, M. B. High-resolution calculations of merging neutron stars—III. γ-ray bursts. Mon. Not. R. Astron. Soc. 345, 1077–1090 (2003)

    Article  ADS  Google Scholar 

  29. Lee, W. H., Ramirez-Ruiz, E. & Granot, J. A compact binary merger model for the short, hard GRB 050509b. Preprint at http://arXiv.org/astro-ph0504104 (2005).

  30. Davies, M. B., Levan, A. & King, A. The ultimate outcome of black hole—neutron star mergers. Mon. Not. R. Astron. Soc. 356, 54–58 (2005)

    Article  ADS  Google Scholar 

  31. Hjorth, J. et al. The optical afterglow of the short γ-ray burst GRB 050709. Nature 437, 859–861 (2005)

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

We acknowledge support from ASI, NASA and PPARC, and acknowledge benefits from collaboration within the EU FP5 Research Training Network ‘γ-Ray Bursts: An Enigma and a Tool’.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to S. D. Barthelmy.

Ethics declarations

Competing interests

Reprints and permissions information is available at npg.nature.com/reprintsandpermissions. The authors declare no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Barthelmy, S., Chincarini, G., Burrows, D. et al. An origin for short γ-ray bursts unassociated with current star formation. Nature 438, 994–996 (2005). https://doi.org/10.1038/nature04392

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature04392

This article is cited by

Comments

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.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing