Speaker
Description
We model curvature radiation from primary particles accelerated in a dissipative magnetosphere, within an extended separatrix region leading into the current sheet outside the light cylinder, using the azimuthally-dependent electric field from global magnetospheric simulations. This serves as a step towards a full synchro-curvature treatment of the Vela pulsar's high-energy emission observed by H.E.S.S. II (up to ~100 GeV) and the Fermi Large Area Telescope. Unlike synchro-curvature radiation, curvature radiation assumes particles move strictly along field lines, neglecting the additional pitch-angle (synchrotron-like) component that develops in the current sheet (Harding et al. 2021). We compute energy-dependent light curves and phase-resolved spectra, and assess how well this curvature-only model reproduces the observed trends, i.e., the decreasing flux of the first peak relative to the second, the evolving bridge emission, the near-constant peak phases, and the narrowing of pulses with energy. We are extending our model to include synchro-curvature radiation, using this curvature-only treatment as a baseline against which the impact of the additional synchrotron-like component can be assessed.