Jet break candidates in the X-ray and optical afterglow lightcurves

Enwei Liang, Judith L. Racusin, Bing Zhang, Bin Bin Zhang, David N. Burrows

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

1 Scopus citations


The Swift/XRT data for 179 GRBs (050124 to 070129) and the optical afterglow data for 57 pre-and post-Swift GRBs are analyzed to explore whether the breaks in the afterglow light curves can be interpreted as jet breaks and their implications for jet energetics. We find that no textbook version of jet break is found, in which the data fully satisfy jet break criteria. By relaxing one or more requirements, candidates to various degrees are identified. The break time in the X-ray band is earlier than that in the optical bands. Among thirteen bursts having both the optical and X-ray light curves, only seven have an achromatic break, and even in these cases only one band data satisfies the closure relations. These raise concerns about interpreting the breaks as jet breaks and further inferring GRB energetics. Assuming that the candidates are jet breaks, we find that the geometrically-corrected kinetic energy (E k) distribution is much more scattered than the pre-Swift sample, but a tentative anti-correlation between jet opening angle θj and EK,iso is found, indicating that the EK could still be quasi-universal.

Original languageEnglish (US)
Title of host publicationGamma-Ray Bursts 2007 - Proceedings of the Santa Fe Conference
Number of pages4
StatePublished - 2008
EventSanta Fe Conference on Gamma-Ray Bursts 2007, GRB 2007 - Santa Fe, NM, United States
Duration: Nov 5 2007Nov 9 2007

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


OtherSanta Fe Conference on Gamma-Ray Bursts 2007, GRB 2007
Country/TerritoryUnited States
CitySanta Fe, NM

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


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