EM counterparts of structured jets from 3D GRMHD simulations

Journal Article · Wed Jan 23 00:00:00 EST 2019 · Monthly Notices of the Royal Astronomical Society: Letters

DOI:https://doi.org/10.1093/mnrasl/slz012· OSTI ID:1493567

Kathirgamaraju, Adithan ; Tchekhovskoy, Alexander; Giannios, Dimitrios; Barniol Duran, Rodolfo

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.

• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1493567
• Journal Information: Monthly Notices of the Royal Astronomical Society: Letters, Journal Name: Monthly Notices of the Royal Astronomical Society: Letters Vol. 484 Journal Issue: 1; ISSN 1745-3925
• Publisher: Oxford University Press
• Country of Publication: United Kingdom
• Language: English