TY - JOUR
T1 - Small-scale variations in the radiating surface of the GRB 011211 jet
AU - Jakobsson, Pall
AU - Hjorth, Jens
AU - Ramirez-Ruiz, Enrico
AU - Kouveliotou, Chryssa
AU - Pedersen, Kristian
AU - Fynbo, Johan P.U.
AU - Gorosabel, Javier
AU - Watson, Darach
AU - Jensen, Brian L.
AU - Grav, Tommy
AU - Hansen, Morten W.
AU - Michelsen, Rene
AU - Andersen, Michael I.
AU - Weidinger, Michael
AU - Pedersen, Holger
N1 - Funding Information: It is a pleasure to thank Sir M. Rees, S.E. Woosley, G. Björnsson, E.H. Gudmundsson, A. Loeb, S.T. Holland and E. Nakar for helpful comments and suggestions. We are grateful to the anonymous referee for stimulating remarks which have improved the paper. Our results are based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. We acknowledge the availability of DSS-2 exposures used in this work. P.J. gratefully acknowledges support from The Icelandic Research Fund for Graduate Students, and a Special Grant from the Icelandic Research Council. E.R. thanks CONACyT and the ORS for sponsorship. J.P.U.F. and K.P. acknowledge support from the Carlsberg foundation. This work was supported by the Danish Natural Science Research Council (SNF). The authors acknowledge benefits from collaboration within the EU FP5 Research Training Network “Gamma-Ray Bursts: an Enigma and a Tool”.
PY - 2004/7
Y1 - 2004/7
N2 - We report the discovery of the afterglow of the X-ray rich, long-duration γ-ray burst GRB 011211 and present evidence for oscillatory behaviour in its early optical light curve. The time-scale of the fluctuations, ∼1 h, is much smaller than the time of the observations, ∼12 h from the onset of the γ-ray burst. The character and strength of the fluctuations are unprecedented and are inconsistent with causally connected variations in the emission of a symmetric, relativistic blast wave, i.e. flux variations which are produced uniformly throughout the shell surface are ruled out. Therefore, the wiggles are the result of spherically asymmetric density or energy variations. Additionally, there is evidence for fluctuations in the X-ray afterglow light curve. If real, the resulting difference in the observed time of the peaks of the short-term variations at X-ray and optical frequencies, would demonstrate that the energy content across the jet-emitting surface is not uniform.
AB - We report the discovery of the afterglow of the X-ray rich, long-duration γ-ray burst GRB 011211 and present evidence for oscillatory behaviour in its early optical light curve. The time-scale of the fluctuations, ∼1 h, is much smaller than the time of the observations, ∼12 h from the onset of the γ-ray burst. The character and strength of the fluctuations are unprecedented and are inconsistent with causally connected variations in the emission of a symmetric, relativistic blast wave, i.e. flux variations which are produced uniformly throughout the shell surface are ruled out. Therefore, the wiggles are the result of spherically asymmetric density or energy variations. Additionally, there is evidence for fluctuations in the X-ray afterglow light curve. If real, the resulting difference in the observed time of the peaks of the short-term variations at X-ray and optical frequencies, would demonstrate that the energy content across the jet-emitting surface is not uniform.
KW - Gamma rays: bursts
KW - X-rays: general
UR - https://www.scopus.com/pages/publications/11144358327
U2 - 10.1016/j.newast.2004.01.007
DO - 10.1016/j.newast.2004.01.007
M3 - Article
SN - 1384-1076
VL - 9
SP - 435
EP - 442
JO - New Astronomy
JF - New Astronomy
IS - 6
ER -