Gamma-ray pulsars: The pulse profiles and phase-resolved spectra of Geminga

Abstract

We present a calculation of a three-dimensional pulsar magnetosphere model to explain high energy emission from the Geminga pulsar with a thick outer gap. High-energy γ-rays are produced by primary accelerated particles with a power-law energy distribution through curvature radiation inside the outer gap. We also calculate the emission pattern, pulse profile and phase-resolved spectra of high-energy γ-rays of the Geminga pulsar, and find that its pulse profile is consistent with the observed one if the magnetic inclination and viewing angle are ∼50° and ∼86° respectively. We describe the relative phases among soft (thermal) X-rays hard (non-thermal) X-rays, and γ-rays. Our results indicate that X-ray and γ-ray emission from the Geminga pulsar may be explained by the single thick outer gap model. Finally, we discuss the implications of the radio and optical emission of the Geminga pulsar.