A Pattern in the Large-scale Distribution of Galactic Polarized Radio Emission

Abstract

THE initial discovery by the Dutch¹ and Cambridge² groups of a linearly polarized component of galactic radio emission was followed by a large-scale survey^3,4 of the polarization at 408 Mc/s using the Dwingeloo radio telescope (aerial beam-width 2°). In 1963, a polarization survey was made, using the 210-ft. steerable reflector at Parkes at 408 Mc/s (aerial beam-width 0.8°), of that part of the sky not covered by the Dutch survey; the detailed results of this will be published elsewhere. This communication concerns an outstanding feature of the large-scale distribution of the polarized radio emission which is seen when the results of both surveys are combined. It appears that more than 90 per cent of the polarized radio emission at this frequency comes from regions which lie inside a band about 50° wide that contains the great circle which passes through the galactic poles and cuts the plane at lII = 340° and 160°.