Compact radio emission indicates a structured jet was produced by a binary neutron star merger

• DOI: 10.1126/science.aau8815
• Publication Date: 2019-02-22T00:15:39Z
• Authors: G. Ghirlanda; O. S. Salafia; Z. Paragi; M. Giroletti; J. Yang; B. Marcote; J. Blanchard; I. Agudo; T. An; M. G. Bernardini; R. Beswick; M. Branchesi; S. Campana; C. Casadio; E. Chassande-Mottin; M. Colpi; S. Covino; P. D’Avanzo; V. D’Elia; S. Frey; M. Gawronski; G. Ghisellini; L. I. Gurvits; P. G. Jonker; H. J. van Langevelde; A. Melandri; J. Moldon; L. Nava; A. Perego; M. A. Perez-Torres; C. Reynolds; R. Salvaterra; G. Tagliaferri; T. Venturi; S. D. Vergani; M. Zhang
• Keywords: radiation: electromagnetic; neutron star: binary; Astronomy; FOS: Physical sciences; gravitational radiation: direct detection; Astrophysics / csillagászat; 530; 01 natural sciences; 7. Clean energy; electromagnetic field: production; jet: relativistic; 0103 physical sciences; QB Astronomy; detector: resolution; High Energy Astrophysical Phenomena (astro-ph.HE); gravitational radiation; 520; gravitational radiation detector; asztrofizika; 13. Climate action; gravitational radiation: emission; [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph]; [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]; Astrophysics - High Energy Astrophysical Phenomena

Merging produced a structured jet

The binary neutron star merger event GW170817 was observed with gravitational waves and across the electromagnetic spectrum. However, the physical processes that produced that emission remain poorly understood, particularly the late-time x-ray and radio emission. Ghirlanda et al. observed the radio afterglow with an interferometric array of 32 radio telescopes spread across the globe. The size and position of the radio source are not compatible with a uniformly expanding cocoon, as some have suggested. Instead, the data indicate that GW170817 produced a structured jet of material that escaped the surrounding ejecta and is now expanding into the interstellar medium at relativistic speeds.

Science , this issue p. 968