High-energy radiation from pulsars: a challenge to polar-cap models

Abstract

Spectacular results of pulsar observations in X-ray and gamma-ray domains gave a new boost to theoretical models of pulsar magnetospheric activity. A challenging aspect of these efforts is that lightcurves and broadband energy spectra of the brightest HE sources exhibit unexpected richness of features, making each object almost a unique case to be interpreted with a custom-made model. This review offers our subjective account of how the models of high-energy radiation used within the framework of SCLF polar-cap scenarios tackle these challenges. We describe major characteristics of all radiative processes relevant for modeling the observed features. Then we address successes as well as noticeable disadvantages of these models upon their confrontation with the available data.