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 multiwavelength 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.

Oganesyan, G., Ascenzi, S., Branchesi, M., Salafia, O., Dall'Osso, S., Ghirlanda, G. (2020). Structured jets and x-ray plateaus in gamma-ray burst phenomena. THE ASTROPHYSICAL JOURNAL, 893(2) [10.3847/1538-4357/ab8221].

Structured jets and x-ray plateaus in gamma-ray burst phenomena

Salafia O. S.;Ghirlanda G.
2020

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 multiwavelength 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.
Articolo in rivista - Articolo scientifico
Gamma Ray Burst; Afterglow; Star Formation
English
2020
893
2
88
none
Oganesyan, G., Ascenzi, S., Branchesi, M., Salafia, O., Dall'Osso, S., Ghirlanda, G. (2020). Structured jets and x-ray plateaus in gamma-ray burst phenomena. THE ASTROPHYSICAL JOURNAL, 893(2) [10.3847/1538-4357/ab8221].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/526188
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