Gamma-Ray Emissions from Pulsars: Spectra of the TEV Fluxes from Outer-Gap Accelerators

We study the gamma-ray emissions from an outer-magnetospheric potential gap around a rotating neutron star. Migratory electrons and positrons are accelerated by the electric field in the gap to radiate copious gamma-rays via curvature process. Some of these gamma-rays materialize as pairs by colliding with the X-rays in the gap, leading to a pair production cascade. Imposing the closure condition that a single pair produces one pair in the gap on average, we explicitly solve the strength of the acceleration field and demonstrate how the peak energy and the luminosity of the curvature-radiated, GeV photons depend on the strength of the surface blackbody and the power-law emissions. Some predictions on the GeV emission from twelve rotation-powered pulsars are presented. We further demonstrate that the expected pulsed TeV fluxes are consistent with their observational upper limits. An implication of high-energy pulse phase width versus pulsar age, spin, and magnetic moment is discussed.Comment: Revised to compute absolute TeV spectra (22 pages, 9 figures

On the connection between gamma and radio radiation spectra in pulsars

The model of pulsar radio emission is discussed in which a coherent radio emis-sion is excited in a vacuum gap above polar cap of neutron star. Pulsar X and gamma radiation are considered as the result of low-frequency radio emission inverse Comp-ton scattering on ultra relativistic electrons accelerated in the gap. The influence of the pulsar magnetic field on Compton scattering is taken into account. The relation of radio and gamma radiation spectra has been found in the framework of the model.Comment: 15 pages, 3 figures, Russian version accepted to JETP, partly published in JETP Letters, Vol. 85, #6 (2007