Investigation of jet break features in Swift gamma-ray bursts

G. Sato, R. Yamazaki, K. Ioka, T. Sakamoto, T. Takahashi, K. Nakazawa, T. Nakamura, K. Toma, D. Hullinger, M. Tashiro, A. M. Parsons, H. A. Krimm, S. D. Barthelmy, N. Gehrels, D. N. Burrows, P. T. O'Brien, J. P. Osborne, G. Chincarini, D. Q. Lamb

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We analyze Swift gamma-ray bursts (GRBs) and X-ray afterglows for three GRBs with spectroscopic redshift determinations - GRB 050401, XRF 050416a, and GRB 050525a. We find that the relation between spectral peak energy and isotropic energy of prompt emissions (the Amati relation) is consistent with that for the bursts observed in pre-Swift era. However, we find that the X-ray afterglow lightcurves, which extend up to 10-70 days, show no sign of the jet break that is expected in the standard framework of collimated outflows. We do so by showing that none of the X-ray afterglow lightcurves in our sample satisfies the relation between the spectral and temporal indices that is predicted for the phase after jet break. The jet break time can be predicted by inverting the tight empirical relation between the peak energy of the spectrum and the collimation-corrected energy of the prompt emission (the Ghirlanda relation). We find that there are no temporal breaks within the predicted time intervals in X-ray band. This requires either that the Ghirlanda relation has a larger scatter than previously thought, that the temporal break in X-rays is masked by some additional source of X-ray emission, or that it does not happen because of some unknown reason.

Original languageEnglish
Title of host publication11th Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Gravitation and Relativistic Field Theories - Proc. of the MG11 Meeting on General Relativity
Pages2033-2035
Number of pages3
Publication statusPublished - 2008
Event11th Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Gravitation and Relativistic Field Theories, MG 2006 - Berlin
Duration: 2006 Jul 232006 Jul 29

Other

Other11th Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Gravitation and Relativistic Field Theories, MG 2006
CityBerlin
Period06/7/2306/7/29

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Fingerprint

Dive into the research topics of 'Investigation of jet break features in Swift gamma-ray bursts'. Together they form a unique fingerprint.

Cite this