The mode-separated pulse profiles of pulsar radio emission

Two modes of orthogonal polarization are generally observed in the radio emission from pulsars. Essentially all attempts to calculate the average profiles of the individual modes have assumed that the modes occur separately. We have presented evidence, however, that the modes occur simultaneously. Therefore, we believe that "mode-separated" pulse profiles that have been published to date reveal little about the polarization properties of the individual modes. Calculating mode-separated pulse profiles for superposed orthogonal modes is complicated by the unknown polarization properties of the individual modes. However, the simplest model of pulsar radio emission that can explain the wide variety in the emission's polarization is one in which the individual modes are completely polarized. We argue that the orthogonal modes in PSR B0525+21 and PSR B2020+28 are highly polarized and use our simple model to compute the average profiles of their orthogonal modes. For both pulsars, the total intensity of the two mode profiles resembles the overall pulse profile, and each profile is highly linearly polarized.