Collimated light

Routing (electronic design automation)

Quantum mechanics

Context (archaeology)

Magnetic field

Engineering

Viewing angle

Gamma-ray burst

Biology

Galaxy

Magnetohydrodynamics

Computational physics

Nuclear physics

Compact star

Astrophysics

Plasma

Afterglow

Computer science

Jet (fluid)

Transverse plane

Computer network

Paleontology

Routing protocol

Laser

Physics

Mathematics

Active galactic nucleus

Optics

Magnetohydrodynamic drive

Link-state routing protocol

Geometry

Astrophysical jet

Structural engineering

Neutron star

Black hole (networking)

Mechanics

Liquid-crystal display

Accretion (finance)

Torus

Monthly Notices of the Royal Astronomical Society Letters

ABSTRACT GW170817/GRB170817A has offered unprecedented insight into binary neutron star post-merger systems. Its Prompt and afterglow emission imply the presence of a tightly collimated relativistic jet with a smooth transverse structure. However, it remains unclear whether and how the central engine can produce such structured jets. Here, we utilize 3D general relativistic magnetohydrodynamic simulations starting with a black hole surrounded by a magnetized torus with properties typically expected of a post-merger system. We follow the jet, as it is self-consistently launched, from the scale of the compact object out to more than three orders of magnitude in distance. We find that this naturally results in a structured jet, which is collimated by the disc wind into a half-opening angle of roughly 10°; its emission can explain features of both the prompt and afterglow emission of GRB170817A for a 30° observing angle. Our work is the first to compute the afterglow, in the context of a binary merger, from a relativistic magnetized jet self-consistently generated by an accreting black hole, with the jet’s transverse structure determined by the accretion physics and not prescribed at any point.

EM counterparts of structured jets from 3D GRMHD simulations