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arXiv · 1904.08786

Structured Jets and X-ray Plateaus in Gamma-Ray Burst Phenomena

Gor Oganesyan·Stefano Ascenzi·Marica Branchesi·Om Sharan Salafia·Simone Dall'Osso·Giancarlo Ghirlanda
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Abstract

The first multi-messenger detection of a binary neutron star merger, GW170817, brought to the forefront the structured jet model as a way to explain multi-wavelength observations taken more than a year after the event. Here we show that the high-latitude emission from a structured jet can naturally produce an X-ray plateau in gamma-ray burst (GRB) light curves, independent of the radiation from an external shock. We calculate the radiation from a switched-off shell featuring an angular structure in both its relativistic bulk motion and intrinsic brightness. Our model is able to explain the shallow decay phase (plateau) often observed in GRB X-ray light curves. We discuss the possible contribution of the structured jet high-latitude emission to other distinctive features of GRB X-ray light curves, and its capability to explain the chromatic optical/X-ray light curve properties.

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Gor Oganesyan, Stefano Ascenzi, Marica Branchesi, Om Sharan Salafia, Simone Dall'Osso, Giancarlo Ghirlanda. 2020-03-20. Structured Jets and X-ray Plateaus in Gamma-Ray Burst Phenomena. https://doi.org/10.3847/1538-4357%2Fab8221

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