New advances in pulsar magnetosphere modelling
Abstract
The wealth of high-energy (E &50MeV) and very-high-energy (E >100 GeV) data accumulated
over the past few years have provided unprecedented opportunities to probe pulsar emission models.
The Fermi Large Area Telescope (LAT) has now detected over 200 g -ray pulsars of vastly
different ages, providing an extensive dataset of spectra and light curves compared to a mere
decade ago. Ground-based Cherenkov telescopes deepened our appreciation of the mysterious
richness of the pulsar mechanism by a surprise detection of pulsed emission up to 1 TeV from the
Crab pulsar. These discoveries position us to make real progress in pulsar theory. A number of
studies have developed new and enhanced existing dissipative magnetohydrodynamical (MHD)
and particle-in-cell (PIC) codes to solve the global electrodynamics and pursue fundamental questions
about magnetospheric particle injection, acceleration, and radiation. While MHD models
capture the global aspects of pulsar magnetospheres, the microphysics need to be probed selfconsistently
by PIC simulations. Some dissipative MHD models consider the current sheet (CS)
as an important site for high-energy curvature radiation (CR), while early PIC results point to
energy dissipation taking place in the CS, where particles are accelerated by magnetic reconnection
and may possibly emit g rays via synchrotron radiation (SR). This is in marked contrast to
some older local emission models that studied CR g rays produced in gaps nearer to the spinning
neutron star. The universality of these results should become clearer as current computational
restrictions are overcome and boundary conditions are refined. Continued and combined polarimetric,
spectral, and temporal measurements should aid us in scrutinising these new emission
models in our persistent pursuit of a deeper understanding of the pulsar marvel
URI
http://hdl.handle.net/10394/26003https://pos.sissa.it/275/040/pdf
https://doi.org/10.22323/1.275.0040