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Multiple Sub-Jet Model of Gamma Ray Bursts and Possible Origin of X-ray Precursors and Post-cursors

Takashi Nakamura
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Abstract

We assume that internal shocks of Gamma Ray Bursts (GRBs) consist of multiple sub-jets with a collimation half-angle $\sim {\rm several }\timesγ_i^{-1}$, where $γ_i$ is the Lorenz factor of each sub-jet. If by chance a sub-jet is first emitted off-axis from the line of sight, the observed peak energy can be in the X-ray region. Next if by chance a subsequent sub-jet is emitted along the line of sight, then the peak energy will be in the gamma ray region and the gamma ray may arrive after the X-ray precursor from the former sub-jet depending on parameters. This model predicts a new class of GRBs with extremely weak and short gamma ray emission but X-ray precursor and/or post-cursor as well as an afterglow.

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Takashi Nakamura. 2000-04-03. Multiple Sub-Jet Model of Gamma Ray Bursts and Possible Origin of X-ray Precursors and Post-cursors. https://doi.org/10.1086/312663

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