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Precursors of gamma-ray bursts: a clue to the burster's nature

Maxim Lyutikov·Vladimir Usov
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Abstract

In relativistic strongly magnetized winds outflowing from the fast-rotating compact progenitors of gamma-ray bursts (GRBs) there are three regions where powerful high-frequency emission may be generated: (i) the thermal photosphere, (ii) the region of the internal wind instability and (iii) the region of the wind interaction with an ambient gas. This results in a multicomponent structure of GRBs. The emission from the thermal photosphere may be observed as a weak precursor to the main burst. The precursor should have a blackbody-like spectrum with the mean energy of photons of $\sim 1$ MeV, and its intensity should be tens to hundreds of times smaller than that of the main GRB emission. Observations of such precursors with future $γ$-ray missions like GLAST can clarify the nature of bursters.

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Maxim Lyutikov, Vladimir Usov. 2000-07-27. Precursors of gamma-ray bursts: a clue to the burster's nature. https://doi.org/10.1086/317278

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