Shape of pulsar beams revisited

Abstract

Using a carefully selected subset of the recently published multifrequency polarimetric observations of 301 radio pulsas (Gould & Lyne 1997), we have attempted modeling the shape of pulsar beams. From the 6-frequency data selected on conal triple and multiple component profiles, we find that there are three distinct cones of emission and that the pulsar beam shape changes from circular (for an aligned rotator) to latitudinally compressed form (for an orthogonal rotator). We see no evidence in support of the evolution of the pulsar beam shape as a function of period, while as expected the overall size scales as P to the power -0.5, where p is the pulsar period.