The Orientation of the Magnetic Field in Radio Sources

Recent data on the polarization of extragalactic radio sources are used to investigate the distribution of ∆, the angle between the major axis of a source and the intrinsic position angle of the E vector of linear polarization. Previous work on this subject has led to widely divergent conclusions. We find that sources of high radio luminosity usually have ∆ near 90°, implying that the magnetic fields in such sources are oriented along the major axis. For radio galaxies with low luminosity, on the other hand, ∆ tends to lie nearer 0°.