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

The binary neutron star merger event GW170817 was detected through both electromagnetic radiation and gravitational waves. Its afterglow emission may have been produced by either a narrow relativistic jet or an isotropic outflow. High-spatial-resolution measurements of the source size and displaceme...

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Bibliographic Details
Authors: Ghirlanda, G.; Salafia, O.S.; Paragi, Z.; Giroletti, M.; Yang, J.; Marcote, B.; Blanchard, J.; Agudo, I.; An, T.; Bernardini, M.G.; Beswick, R.; Branchesi, M.; Campana, S.; Casadio, C.; Chassande-Mottin, E.; Colpi, M.; Covino, S.; D''Avanzo, P.; D''Elia, V.; Frey, S.; Gawronski, M.; Ghisellini, G.; Gurvits, L.I.; Jonker, P.G.; Van Langevelde, H.J.; Melandri, A.; Moldon, J.; Nava, L.; Perego, A.; Perez-Torres, M.A.; Reynolds, C.; Salvaterra, R.; Tagliaferri, G.; Venturi, T.; Vergani, S.D.; Zhang, M.
Format: Article
Status:Accepted version
Publication date:2019
Country:España
Institution:Universidad de Zaragoza
Repository:Zaguán. Repositorio Digital de la Universidad de Zaragoza
OAI Identifier:oai:zaguan.unizar.es:78946
Online Access:http://zaguan.unizar.es/record/78946
Access Level:Open access
Description
Summary:The binary neutron star merger event GW170817 was detected through both electromagnetic radiation and gravitational waves. Its afterglow emission may have been produced by either a narrow relativistic jet or an isotropic outflow. High-spatial-resolution measurements of the source size and displacement can discriminate between these scenarios. We present very-long-baseline interferometry observations, performed 207.4 days after the merger by using a global network of 32 radio telescopes. The apparent source size is constrained to be smaller than 2.5 milli-arc seconds at the 90% confidence level. This excludes the isotropic outflow scenario, which would have produced a larger apparent size, indicating that GW170817 produced a structured relativistic jet. Our rate calculations show that at least 10% of neutron star mergers produce such a jet.