OGANESYAN, GORGOROGANESYANASCENZI, STEFANOSTEFANOASCENZIBranchesi, MaricaMaricaBranchesiSALAFIA, Om SharanOm SharanSALAFIADall’Osso, SimoneSimoneDall’OssoGHIRLANDA, GiancarloGiancarloGHIRLANDA2025-03-052025-03-0520200004-637Xhttp://hdl.handle.net/20.500.12386/36429The 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.STAMPAenArticle10.3847/1538-4357/ab82212-s2.0-85085064816https://iopscience.iop.org/article/10.3847/1538-4357/ab8221FIS/05 - ASTRONOMIA E ASTROFISICA