Advanced Modeling of Pulsar Emissions at Radiowaves

forthcoming

Magnetospheres of neutron stars (NSs) represent unique plasma-physics labs of extreme environments characterized by ultra-high magnetic field strengths, relativistic processes, and the presence of quantum electrodynamic effects – parameters far unreachable on the Earth. Detailed information on these processes comes to us via coherent radio emissions of pulsars and possibly fast radio bursts (FRBs), being observed by fast-developing sophisticated instruments of radio astronomy like FAST, CHIME, ALMA, and in near future, SKA. However, no agreement has been reached on their exact coherent radio emission mechanism that can interpret the observations, mainly because the modeling of the radio emissions requires operation of the extreme-physical processes and simultaneous consideration of the wave coherency at plasma kinetic micro-scales. This project addresses the question of which specific mechanisms are responsible for coherent radio emissions of NSs; in detail, which qualitative radio emission properties of pulsar pair-creation events and propagating kinetic Alfvén waves in the magnetospheres of NSs can lead to the interpretation of pulsars and transient events like fast radio bursts. The mechanisms will be investigated by combination of my expertise in first-principle particle-in-cell simulations of the micro-kinetic instabilities with the long-term experience in advanced dispersion and coherency analyses of radio waves in the simulations at the host institute. This combination of skills will allow me to make predictions on coherent properties of radio waves in terms of their total power, luminosity spectrum, its directivity and polarization as they escape the emission sources. I will distinguish, for the first time, how the extreme plasma instabilities lead to the coherent and incoherent radio emissions of pulsars and FRBs. After the project, the obtained properties can be utilized in radiative transfer codes to get specific predictions on NS radio observables.