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A novel explosive process is required for the γ-ray burst GRB 060614


Over the past decade, our physical understanding of γ-ray bursts (GRBs) has progressed rapidly, thanks to the discovery and observation of their long-lived afterglow emission. Long-duration (2 s) GRBs are associated with the explosive deaths of massive stars (‘collapsars’, ref. 1), which produce accompanying supernovae2,3,4,5; the short-duration (2 s) GRBs have a different origin, which has been argued to be the merger of two compact objects6,7,8,9. Here we report optical observations of GRB 060614 (duration 100 s, ref. 10) that rule out the presence of an associated supernova. This would seem to require a new explosive process: either a massive collapsar that powers a GRB without any associated supernova, or a new type of ‘engine’, as long-lived as the collapsar but without a massive star. We also show that the properties of the host galaxy (redshift z = 0.125) distinguish it from other long-duration GRB hosts and suggest that an entirely new type of GRB progenitor may be required.

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Figure 1: Temporal evolution of the optical transient associated with GRB 060614.
Figure 2: HST observations of the location of GRB 060614.


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A.G. and E.B. acknowledge support by NASA through Hubble Fellowships. S.R.K. is supported by NSF and NASA. The HST campaign combined resources from our approved programmes (principal investigators S.R.K. and D.B.F.).

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Correspondence to A. Gal-Yam.

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Supplementary Notes

This file contains Supplementary Notes describing the association of GRB 060614 with the proposed z=0.125 host galaxy and host properties and GRB environment; Supplementary Figures 1-3 with legends and Supplementary Data.

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Gal-Yam, A., Fox, D., Price, P. et al. A novel explosive process is required for the γ-ray burst GRB 060614. Nature 444, 1053–1055 (2006).

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