Cosmic Origin of Radiation at Radio Frequencies

Abstract

THE recent identification by W. Baade and R. Minkowski of the intense discrete radio source in Cygnus as being an emission from two colliding galaxies¹ raises a number of interesting theoretical questions. In the first place, the only material likely to be seriously disturbed by such a collision is the diffuse interstellar material lying between the stars in these galaxies. Consequently, it would seem profitable to seek a process of generation of radio waves that takes place in extremely diffuse gas clouds. Secondly, processes of magnetic resonance requiring field intensities of many gauss, such as the Larmor precession, would seem to be excluded, since fields of this intensity could scarcely be maintained throughout regions of galactic dimensions.