The low-frequency profiles of some pulsars manifest temporal broadening due to scattering, usually accompanied by flat polarization position angle (PA) curves. Assuming that the scattering works on the 4 Stokes parameters in the same way, we have simulated the effect of scattering on polarization profiles and find that the scattering can indeed flatten the PA curves. Since the higher-frequency profiles suffer less from scattering, they are convolved with scattering models to fit the observed low-frequency profiles. The calculated flat PA curves exactly reproduce the corresponding observations.
@article{arxiv.astro-ph/0308095,
title = {The Effect of Scattering on Pulsar Polarization Angle},
author = {X. H. Li and J. L. Han},
journal= {arXiv preprint arXiv:astro-ph/0308095},
year = {2008}
}