Compact radio emission indicates a structured jet was produced by a binary neutron star merger
Journal article, 2019

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.

Author

G. Ghirlanda

University of Milano-Bicocca

National Institute for Nuclear Physics

Istituto nazionale di astrofisica (INAF)

O. S. Salafia

National Institute for Nuclear Physics

Istituto nazionale di astrofisica (INAF)

University of Milano-Bicocca

Z. Paragi

Joint Institute for VLBI in Europe (JIVE)

M. Giroletti

Istituto nazionale di astrofisica (INAF)

Jun Yang

Chinese Academy of Sciences

Chalmers, Space, Earth and Environment, Onsala Space Observatory

B. Marcote

Joint Institute for VLBI in Europe (JIVE)

J. Blanchard

Joint Institute for VLBI in Europe (JIVE)

I. Agudo

Institute of Astrophysics of Andalusia (IAA)

T. An

Shanghai Astronomical Observatory

M. G. Bernardini

Laboratoire Univers et Particules de Montpellier

R. J. Beswick

University of Manchester

M. Branchesi

National Institute for Nuclear Physics

Gran Sasso Science Institute (GSSI)

S. Campana

Istituto nazionale di astrofisica (INAF)

C. Casadio

Max Planck Society

E. Chassande-Mottin

Paris Diderot University

M. Colpi

University of Milano-Bicocca

National Institute for Nuclear Physics

S. Covino

Istituto nazionale di astrofisica (INAF)

P. D'Avanzo

Istituto nazionale di astrofisica (INAF)

V. D'Elia

Agenzia Spaziale Italiana

S. Frey

Hungarian Academy of Sciences

M. P. Gawroński

Nicolaus Copernicus University

G. Ghisellini

Istituto nazionale di astrofisica (INAF)

L. I. Gurvits

Joint Institute for VLBI in Europe (JIVE)

Delft University of Technology

P. G. Jonker

Radboud University

Netherlands Institute for Space Research (SRON)

H. J. van Langevelde

Leiden University

Joint Institute for VLBI in Europe (JIVE)

A. Melandri

Istituto nazionale di astrofisica (INAF)

J. Moldon

University of Manchester

L. Nava

Istituto nazionale di astrofisica (INAF)

A. Perego

National Institute for Nuclear Physics

M.A. Pérez-Torres

Institute of Astrophysics of Andalusia (IAA)

University of Zaragoza

C. Reynolds

Commonwealth Scientific and Industrial Research Organisation (CSIRO)

R. Salvaterra

Istituto nazionale di astrofisica (INAF)

G. Tagliaferri

Istituto nazionale di astrofisica (INAF)

T. Venturi

Istituto nazionale di astrofisica (INAF)

S. D. Vergani

Observatoire de Paris-Meudon

M. Zhang

Chinese Academy of Sciences

Science

0036-8075 (ISSN) 1095-9203 (eISSN)

Vol. 363 6430 968-971

Subject Categories

Astronomy, Astrophysics and Cosmology

DOI

10.1126/science.aau8815

PubMed

30792360

More information

Latest update

9/15/2023