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Prompt and afterglow emission from the X-ray rich GRB981226 observed with BeppoSAX

F. Frontera·L. A. Antonelli·L. Amati·E. Montanari·E. Costa·D. Dal Fiume·P. Giommi·M. Feroci·G. Gennaro·J. Heise·N. Masetti·J. M. Muller·L. Nicastro·M. Orlandini·E. Palazzi·E. Pian·L. Piro·P. Soffitta·M. Stornelli·J. J. M. in 't Zand·D. A. Frail·S. R. Kulkarni·M. Vietri
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Abstract

We discuss observations of the prompt X and gamma-ray emission and X-ray afterglow from GRB981226. This event has the weakest gamma-ray peak flux detected with the Gamma-Ray Burst Monitor. It shows an isolated X-ray precursor and the highest X-ray to gamma-ray fluence ratio measured thus far with the Wide Field Cameras. The event was followed up with the Narrow Field Instruments, and the X-ray afterglow was detected up to 10 keV. The afterglow flux is observed to rise from a level below the sensitivity of the MECS/LECS telescopes up to a peak flux of (5 +/-1) * 10^(-13) erg cm-2 s-1, in the 2-10 keV energy band. This rise is followed by a decline according to a power law with index of 1.31 (+0.44,-0.39). We discuss these results in the light of the current GRB models.

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F. Frontera, L. A. Antonelli, L. Amati, E. Montanari, E. Costa, D. Dal Fiume, P. Giommi, M. Feroci, G. Gennaro, J. Heise, N. Masetti, J. M. Muller, L. Nicastro, M. Orlandini, E. Palazzi, E. Pian, L. Piro, P. Soffitta, M. Stornelli, J. J. M. in 't Zand, D. A. Frail, S. R. Kulkarni, M. Vietri. 2000-02-29. Prompt and afterglow emission from the X-ray rich GRB981226 observed with BeppoSAX. https://doi.org/10.1086/309369

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