Abstract Pawsey was born in rural Victoria (Australia) and graduated from the University of Melbourne in 1929 with his first degree in physics. He obtained a Ph. D degree in physics from the Cavendish Laboratory, University of Cambridge (UK) in 1934 having worked with J.A. Ratcliffe on ionosphere research. In 1939 he was one of the first scientific staff at the newly founded secret Radiophysics Laboratory in Sydney, Australia, working on radars that were to be used successfully in the Pacific war against the Japanese from 1941-1945.
In 1944, Pawsey and Ruby Payne-Scott carried out the first radio astronomy observations in Australia, observing at 10 cm using a small antenna. Many of the concepts of the calibration of radio telescope systems were derived for the first time. In October 1945, Pawsey lead the first successful “solar noise” observations using an airforce radar antenna as a passive radio telescope. The following January, Pawsey and Payne-Scott carried out the first radio interferometry in radio astronomy, using the former Australian Army coastal radar at 200 MHz at Dover Heights Sydney. Fringes from the massive Type I bursts were detected, indicating a non-thermal origin for the time variable radio sources associated with a massive sunspot on 26 January 1946 (Australia Day). In the publication of these results the principles of aperture synthesis (called Fourier synthesis) were described for the first time.
Pawsey stimulated the growth of radio astronomy by recruiting a number of physicists and electrical engineers who had worked on radar in WWII: Payne-Scott, Bernie Mills, Chris Christiansen, Paul Wild, Ron Bracewell, John Bolton and Frank Kerr plus numerous others. None of these scientists had any astronomical experience. All of these scientists were to play major roles in the growth of radio astronomy in the mid 20th century in both the US and Australia. Pawsey also became an international leader of radio astronomy with many contacts which were initially made during the war and in a one year overseas trip to the US (including Harvard) and Europe in 1947-1948. Pawsey became a leader of the new radio astronomers in the IAU and URSI; he invented the term “radio astronomy” in January 1948.
Pawsey was the scientific leader of the early “solar noise “and “cosmic noise” research in Sydney. He stimulated collaborative HI 21 cm research with colleagues in the Netherlands and the US after the discovery of the HI line by Ewen and Purcell at Harvard on March 25 1951. Pawsey and Jan Oort from the Leiden Sterrewacht were close associates for many years. In the 1950s, he and E.G. (“Taffy”) Bowen planed and raised the funds (partly from the Carnegie and Rockefeller Foundations) for the construction of the 210 foot Parkes radio telescope. Later in the decade a major conflict arose within the Sydney group over future plans: would single dish cm astronomy – with the Giant Radio Telescope or GRT- dominate or would a new “Mills Cross” – the SuperCross be also constructed? (The Parkes Telescope was opened on 31 October 1961.) This conflict lead to a schism with two groups(Mills and Christiansen) leaving for Sydney University and Pawsey recruited by I.I. Rabi (AUI) as the second Director of the National Radio Astronomy Observatory in Green Bank West Virginia. Tragically, just after arriving in the US, Joe Pawsey contracted a serious form of brain cancer; major surgery followed at Mass. General Hospital on 16 May 1962 with a return home to Sydney on 29 July. He died 30 November 1962 at age 54 in Sydney. One of the last visitors in the hospital from outside the family was David Heeschen (1926-2012) of NRAO, who became the new NRAO Director after Pawsey’s death. At this time, Fred Hoyle also visited Pawsey in the hospital to present the Hughes Medal of the Royal Society.
Claire Hooker (Sydney University), Ron Ekers (CSIRO) and I are writing a biography of Joe Pawsey and John Bolton. |
