3 - Radio Galaxies

Summary

After radio surveys of the sky uncovered a variety of discrete radio sources, there was an intense debate as to whether the radio emission originated in nearby “radio stars,” or were powerful sources located in distant galaxies? In Australia, John Bolton and Gordon Stanley discovered radio emission from two known galaxies. However, unwilling to accept the implied powerful radio emission if the sources were so distant, they instead erroneously reported that the optical counterparts to the radio sources were nearby Galactic nebulosities and not remote galaxies. Later, another Australian scientist identified the bright Cygnus A radio source with a faint galaxy and drew this identification to the attention of Mt. Wilson and Palomar astronomers, who initially either ignored or rejected the identification as being unrealistic. But, a few years later, they independently reidentified the Cygnus A radio sources, firmly establishing the nature of powerful radio galaxies and leading to wide-ranging speculation about the source of the apparent huge energy needed to power the giant radio lobes that typically extended hundreds of thousands of light years from the host galaxy.