GRB 011121: A collimated outflow into wind-blown surroundings

J. Greiner; S. Klose; M. Salvato; A. Zeh; R. Schwarz; D. H. Hartmann; N. Masetti; B. Stecklum; G. Lamer; N. Lodieu; R. D. Scholz; C. Sterken; J. Gorosabel; I. Burud; J. Rhoads; I. Mitrofanov; M. Litvak; A. Sanin; V. Grinkov; M. I. Andersen; J. M. Castro Cerón; A. J. Castro-Tirado; A. Fruchter; J. U. Fynbo; J. Hjorth; L. Kaper; C. Kouveliotou; E. Palazzi; E. Pian; E. Rol; N. R. Tanvir; P. M. Vreeswijk; R. A. M. J. Wijers; E. van den Heuvel

doi:10.1086/379606

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arXiv · astro-ph/0309733

GRB 011121: A collimated outflow into wind-blown surroundings

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Abstract

We discover a break in the GRB 011121 afterglow light curve after 1.3 days, which implies an initial jet opening angle of about 9 deg. The SED during the first four days is achromatic, and supports the jet origin of this break. The SED during the supernova bump can be best represented by a black body with a temperature of 6000 K. The deduced parameters for the decay slope as well as the spectral index favor a wind scenario, i.e. an outflow into a circum-burst environment shaped by the stellar wind of a massive GRB progenitor. Due to its low redshift of z=0.36, GRB 011121 has been the best example for the GRB-supernova connection until GRB 030329, and provides compelling evidence for a circum-burster wind region expected to exist if the progenitor was a massive star.

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J. Greiner, S. Klose, M. Salvato, A. Zeh, R. Schwarz, D. H. Hartmann, N. Masetti, B. Stecklum, G. Lamer, N. Lodieu, R. D. Scholz, C. Sterken, J. Gorosabel, I. Burud, J. Rhoads, I. Mitrofanov, M. Litvak, A. Sanin, V. Grinkov, M. I. Andersen, J. M. Castro Cerón, A. J. Castro-Tirado, A. Fruchter, J. U. Fynbo, J. Hjorth, L. Kaper, C. Kouveliotou, E. Palazzi, E. Pian, E. Rol, N. R. Tanvir, P. M. Vreeswijk, R. A. M. J. Wijers, E. van den Heuvel. 2003-09-26. GRB 011121: A collimated outflow into wind-blown surroundings. https://doi.org/10.1086/379606

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