Linear polarization observations of galactic radio emission at 620 and 408 Mc/s

Abstract

Observations at 620 and 408 Mc/s have been used to determine the intrinsic polarization of galactic radio emission in the strong extended regions of the band of polarization discovered at 408 Mc/s. Many of the intrinsic polarization angles lie nearly parallel to the approximate midline of the band, i.e. the great circle passing through the galactic poles and intersecting the plane at zn = 340° and 160°. This new observational evidence supports the explanation proposed by Mathewson and Milne in 1965 for the existence of the band, namely, that the emission is synchrotron radiation from regions in the local spiral arm that are pervaded by a fairly uniform magnetic field parallel to the galactic plane and directed towards zn = 70° or 250°.