Pawsey, Joseph Lade

Abstract

Pawsey’s achievements during his short career included a legacy that influenced science in Australia and throughout the astronomy world. During World War II (WWII) (1939–1945) he was a leader of radar research in Australia at the CSIRO Laboratory, Division of Radiophysics. Immediately after the war Pawsey led his colleagues in applying radar techniques to understand extraterrestrial sources of radio emission, creating what would become the field of radio astronomy. In October 1945, they used sea-cliff interferometry to detect bursts (fraction of a second to minutes) of 200 MHz radiation from the sun and correlated this with the presence of a strong sunspot (Fig.1). Pawsey also determined that the steady 200 MHz radiation he detected was free-free optically thick radiation from a million-degree plasma – the discovery of the hot solar corona. In the 1950s, he provided the scientific leadership for the iconic Parkes 64 m radio telescope, which is still active 61 years later (Robertson 1992). He recognized the importance of higher frequency investigation of linear polarization of the Galaxy and radio sources. In a prescient prediction, he stressed the importance of using Faraday rotation of linearly polarized sources in order to determine the properties of the [Galactic] magnetic field.