Emission Beam Geometry of Selected Pulsars Derived from Average Pulse Polarization Data

Abstract

By fitting the classical Rotating Vector Model (RVM) to high quality polarization data for selected radio pulsars, we find the inclination of the magnetic axis to the spin axis, alpha, as well as the minimum angle between the line of sight and the magnetic axis, beta, for ten objects. We give a full treatment of statistical errors in the fitting process. We also present a dictionary and conversion table of various investigators' geometric definitions to facilitate future comparisons. We compare our results with other RVM fits and with empirical/geometrical (E/G) approaches, and we examine the strengths and weaknesses of RVM fits and E/G investigations for the determination of pulsar emission beam geometry. Our fits to B0950+08 show that it is an orthogonal rotator, contrary to previous findings. Finally, we find that RVM fits are easily perturbed by systematic effects in polarized position angles, and that the formal uncertainties significantly underestimate the actual errors.