The shape of pulsar radio beams

Using all available multicomponent radio pulse profiles for pulsars with me dium to long periods and good polarization data, we have constructed a two- dimensional image of the mean radio beam shape. This shows a peak near the centre of the beam but is otherwise relatively uniform with only mild enhan cements in a few regions. This result supports the patchy beam model for em ission beams, in which the mean beam shape represents the properties of the emission mechanism and observed pulse components result from emission sour ces distributed randomly across the beam.