Coherent radio emission from relativistic reconnection in neutron star magnetospheres
Coherent emission from merging plasmoids in relativistic reconnection is the leading model for radio emission originating in the outer magnetospheres of pulsars such as the Crab, and a candidate emission mechanism for fast radio bursts. Previous studies of this mechanism were limited to 2D, and whether it survives in 3D, where the dynamics of structures in the reconnection layer can differ substantially, had remained an open question. In this talk, I will present the first study of coherent wave generation from flux rope mergers in 3D relativistic reconnection, showing that its efficiency is remarkably robust to 3D dynamics and the presence of a moderate guide field. I will also discuss the polarization of the escaping waves and implications for observations of the Crab and fast radio bursts. Finally, I will discuss the potential for this same emission mechanism to produce electromagnetic precursors to binary neutron star mergers. Global kinetic simulations reveal periodic magnetic eruptions in the interacting magnetospheres of these binaries. The reconnecting current sheets trailing these eruptions could produce FRB-like radio transients shortly before merger, potentially detectable by upcoming radio facilities.
