Constraining viewing geometries of pulsars with single-peaked γ-ray profiles using a multiwavelength approach

Abstract

Since the launch of the Large Area Telescope (LAT) on board the Fermi spacecraft in June 2008, the number of observed γ-ray pulsars has increased dramatically. A large number of these are also observed at radio frequencies. Constraints on the viewing geometries of 6 γ-ray pulsars exhibiting single-peaked γ-ray profiles were derived using high-quality radio polarization data [14]. We obtain independent constraints on the viewing geometries by using a geometric emission code to model the Fermi LAT and radio light curves (LCs). We find fits for the magnetic inclination and observer angles by searching the solution space by eye. Our results are generally consistent with those previously obtained [14], although we do find differences in some cases. We will indicate how the γ-ray and radio pulse shapes as well as their relative phase lags lead to constraints in the solution space. Values for the flux correction factor (fΩ) corresponding to the fits are also derived (with errors).