Modeling X-ray emission in radiation-rich magnetar magnetospheres

          @misc{ pirsa_PIRSA:25030149,
            doi = {10.48660/25030149},
            url = {https://pirsa.org/25030149},
            author = {Mahlmann, Jens},
            keywords = {Strong Gravity},
            language = {en},
            title = {Modeling X-ray emission in radiation-rich magnetar magnetospheres},
            publisher = {Perimeter Institute},
            year = {2025},
            month = {mar},
            note = {PIRSA:25030149 see, \url{https://pirsa.org}}
          }
          

Abstract

Neutron star magnetospheres are a source of abundant X-ray activity. They have transients observed in different bands, like the fast radio burst (FRB) and associated hard X-ray flare from the Galactic magnetar SGR 1935+2154. We present global models for magnetar X-ray emission, including a landmark first-principle radiative particle-in-cell simulation of the twisted magnetar magnetosphere with the GPU-PIC code Entity. In one scenario, plasma particles accelerated by surface-motion-induced discharges interact resonantly with thermal background photons. Our GPU-accelerated particle-in-cell simulations track up-scattered high-energy photons that drive secondary pair production and ignite a magnetospheric circuit that persistently generates X-rays. We divulge the plasma properties of such a magnetospheric circuit, including densities and velocities, and give an outlook on alternative ignition scenarios for persistent magnetar X-ray emission.