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

S. D. Barthelmy, G. Chincarini, D. N. Burrows, N. Gehrels, S. Covino, A. Moretti, P. Romano, P. T. O'Brien, C. L. Sarazin, C. Kouveliotou, M. Goad, S. Vaughan, G. Tagliaferri, B. Zhang, L. A. Antonelli, S. Campana, J. R. Cummings, P. D'Avanzo, M. B. Davies, P. GiommiD. Grupe, Y. Kaneko, J. A. Kennea, A. King, S. Kobayashi, A. Melandri, P. Meszaros, J. A. Nousek, S. Patel, T. Sakamoto, R. A.M.J. Wijers

Research output: Contribution to journalArticlepeer-review

320 Scopus citations


Two short (<2 s) γ-ray bursts (GRBs) have recently been localized1-4 and fading afterglow counterparts detected 2-4. 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 observations6-8. 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.

Original languageEnglish (US)
Pages (from-to)994-996
Number of pages3
Issue number7070
StatePublished - Dec 15 2005

All Science Journal Classification (ASJC) codes

  • General


Dive into the research topics of 'An origin for short γ-ray bursts unassociated with current star formation'. Together they form a unique fingerprint.

Cite this