E. TrojaB. O'ConnorG. RyanPIRO, LUIGILUIGIPIRORICCI, ROBERTOROBERTORICCIB. ZhangT. PiranBruni, GabrieleGabrieleBruniS. B. CenkoH. van Eerten2022-03-282022-03-2820220035-8711http://hdl.handle.net/20.500.12386/31985X-ray emission from the gravitational wave transient GW170817 is well described as non-thermal afterglow radiation produced by a structured relativistic jet viewed off-axis. We show that the X-ray counterpart continues to be detected at 3.3 years after the merger. Such long-lasting signal is not a prediction of the earlier jet models characterized by a narrow jet core and a viewing angle of about 20 deg, and is spurring a renewed interest in the origin of the X-ray emission. We present a comprehensive analysis of the X-ray dataset aimed at clarifying existing discrepancies in the literature, and in particular the presence of an X-ray rebrightening at late times. Our analysis does not find evidence for an increase in the X-ray flux, but confirms a growing tension between the observations and the jet model. Further observations at radio and X-ray wavelengths would be critical to break the degeneracy between models.STAMPAenArticle10.1093/mnras/stab35332-s2.0-85125869004http://arxiv.org/abs/2104.13378v1https://academic.oup.com/mnras/article/510/2/1902/6449400?login=trueFIS/05 - ASTRONOMIA E ASTROFISICA