Brian John Robinson: 1930 – 2004

Brian Robinson
© CSIRO

Former ATNF staff member Brian Robinson died peacefully in his sleep on 22 July 2004. He was 73.

Brian was born on 4 November 1930 in Melbourne, where his father, Ray Robinson, was a journalist with the Melbourne Herald. When he was eight, the family moved to Sydney. "I went to Waverley School on the edge of Paddington, then a slum and notorious for the razor and acid gangs," Brian recalled. "As a kid from Melbourne I was treated just like the refugee kids arriving from Europe. I wore glasses and got beaten up every day but I made some great friends among the European Jewish kids."¹

Brian's father was a libertarian and would take his son along to parties of the Sydney Push, a group of bohemian writers, artists, musicians and academics. These were often held at the home of journalist Cyril Pearl near the Figtree Bridge. Here, Brian recalls, he witnessed some rather `adult' behaviour, but "but at my age [I] was actually keener to …take Cyril's canoe out on the river and explore". When the family later moved to Lane Cove, "I lived a kind of Huck Finn existence".²

Brian's hobbies now included chemistry and crystal-set radios. But he was not obviously a future physicist: he was consistently under-achieving at school, scoring about 45% in exams. This may have been a result of ill health: scarlet fever had left him deaf in one ear and prone to constant infections. When these problems were cured, he began to show a real gift for mathematics: "It was as if I already knew [it]". He didn't get on with his physics master, who wrote, "[He] should never take up physics".³ But that didn't stop Brian scoring a scholarship to the University of Sydney. He entered engineering, topped all six subjects in his first year, and did it again in his second year. To do Honours in engineering he had to study science, and he ended up switching to physics, largely because of his interest in electronics. In 1952 he graduated with First Class BSc Honours in Physics and the University Medal, then followed up with an MSc, also at the University of Sydney.

As a 21-year-old Honours student Brian attended the 1952 URSI Congress, held in Sydney. This event brought many of the world's radio astronomers together for the first time. Writing in 2001, Brian recalled Sir Edward Appleton's address to the first plenary session. Appleton announced that funding had been granted for what was to become the Lovell telescope at Jodrell Bank, and added that "that those of us who follow this subject … would much like to see … a similar instrument at the disposal of your radio-astronomers here in the Southern Hemisphere." Appleton also spoke of the discovery of the 21-cm hydrogen line, the possible observations it opened up, and the need to protect that frequency band for the benefit of astronomers.⁴ These developments were to loom large in the careers of many Australian radio astronomers of the day, Brian among them.

On 4 May 1953 Brian began at CSIRO's Division of Radiophysics as a fixed-term Research Officer, working at the Potts Hill field station with Frank Kerr and Jim Hindman. They were building a new 12-m (36-ft) dish with which to map the southern sky at 21 cm for neutral hydrogen. By late 1953 they had observed the Magellanic Clouds at this wavelength. This was the first observation of 21-cm radiation from an extragalactic source.⁵

In 1954 Brian sailed to the UK, to take up a Royal Society Rutherford Memorial Fellowship at Trinity College, Cambridge. For his PhD thesis he tackled an ionospheric project, rather than an astronomical one per se: this may have been because relations between the Sydney and Cambridge radio astronomers were rather strained at the time.

In January 1958 he was reappointed by Radiophysics as a temporary Research Officer and sent to work at Leiden Observatory. Planning for the Parkes telescope was now well under way and Radiophysics staff were preparing for its future 21-cm observations. Brian spent four years in The Netherlands working with others to bring the receiver-noise temperature at 21 cm down from 3000 to 150 K.⁶

On his return to Australia, Brian began to use the newly commissioned Parkes telescope to observe galaxies in the Sculptor group and the Virgo cluster at 21 cm. But he was soon diverted onto another path. Astronomers thought that the hydrogen line was not the only cosmic spectral line, but the frequencies of the others were not known with any accuracy. The first of these other lines was found in1963 by a group at MIT, which discovered two absorption lines of OH at 1665 and 1667 MHz in the direction of Cassiopeia A. "On hearing this news, it occurred to John Bolton (the director of Parkes) that it should be possible to confirm and extend the discovery by looking at the strong source Sagittarius in the direction of the Galactic nucleus," Brian later recalled.⁷ To do this, the Radiophysics team modified a 21-cm parametric receiver that Brian had brought from The Netherlands. The two strong OH absorption lines were easily detected. Two further lines had been predicted, originally at 1632 and 1700 MHz. They could not be found at these frequencies. However, D.W. Posener from the CSIRO Division of Electrotechnology produced new predictions of 1612 and 1720 MHz: these lines the Radiophysics team searched for, and found.⁸

Brian Robinson and Dick McGee then set out to investigate the distribution of OH near the Galactic Centre. "I remember measuring one set of the four OH lines in the direction of Sagittarius B2," Brian later recalled. "For the 1665-MHz line absorption, there was a curious spike which virtually went up to the zero line. We didn't wake up to what was going on since, shortly before, John Murray … [had] been on the lower floor of the telescope tower pulling the multi-channel filter-bank apart while we were observing. So, when Sagittarius B2 showed a peculiar lack of absorption, we assumed that John had pulled a filter out again. How wrong we were! A year later, we learned that we what we had seen in Sgr B2 was maser emission by OH." Harold Weaver at Berkeley was the first to announce the new phenomenon in print, in 1965.⁹

Despite this missed opportunity, at this time Bowen regarded Brian as "… undoubtedly one of our outstanding younger research men …", and successfully recommended his promotion to Senior Research Officer. In 1965 he became a Principal Research Scientist, and in 1968 a Senior Principal Research Scientist. In 1971 – 1972 he spent a period as Visiting Professor at the Max Planck Institut für Radioastronomie in Bonn. When the Division of Radiophysics was restructured he took up the leadership of the Cosmic Group. In 1975 he was promoted to Chief Research Scientist.

In 1968 Brian had a brief flirtation with the newly discovered pulsars: one of his 1968 chart records was reproduced on the previous Australian $50 bank note. But his major research interest was now Galactic molecules, including water and hydroxyl. In 1968 the Radiophysics group began to collaborate with chemists from Monash University, led by Ron Brown, to investigate Galactic chemistry. The chemists would suggest probable cosmic molecules, and establish their spectra in the laboratory; the astronomers would then try to find their counterparts with the Parkes telescope. The first success was thioformaldehyde (H₂CS) in 1973, followed by five more up to 1975. In 1977, in an attempt to improve Parkes' performance in this field, the original panels over the innermost 17-m diameter of the dish were replaced with panels that could operate down to 7-mm wavelengths, which was sufficient for observing silicon monoxide and ethanonitrile (CH₃CN). Then with a new receiver and an improved spectrograph the telescope's range was pushed to 3.5 mm, and spectral lines for hydrogen cyanide (HCN) and the formyl radical (HCO+) were confirmed. However, at far southern declinations the pointing accuracy was too poor for effective spectral line searches at 3.5 mm.¹⁰

During the early 1970s Brian led a team that investigated the siting of a new millimetre facility in Australia. "It would have been a great leap in Southern Hemisphere millimetre-wavelength research, and was years ahead of competitors anywhere in the world," says John Whiteoak, former ATNF Deputy Director. "The problem was that the plans for this coincided with plans to build the Australian Synthesis Telescope, the Compact Array forerunner. Paul Wild (the then Chief of Radiophysics) got the Astro people together for a vote and just about everyone voted for the interferometer. … After this, Brian threw in his lot with the AST project." When Bob Frater replaced Paul Wild, and took on leadership of the Australia Telescope project, Brian offered him advice on some of the political aspects of the enterprise. It was his idea, for instance, that the building of the ATCA should be designated as a Bicentennial project, which gave it greater symbolic importance.

Meanwhile, however, Brian did not abandon his interest in millimetre-wavelength astronomy, and money was found to build a 4-m millimetre-wave dish at Marsfield. This operated at up to 115 GHz. The backend was an acousto-optical spectrograph, with a bandwidth of a few hundred megahertz: by the standards of the day, this was large. Brian and his colleagues used this instrument to study the millimetre-wave transitions of interstellar molecules, and to make the first survey of CO in the Southern Hemisphere, which gave details of the Galaxy's spiral structure.

From the mid `70s Brian was involved in seeking national and international protection for the frequency bands used by radio astronomers. "In this area Brian was an unsung hero," John Whiteoak says. He was a Council Member of URSI during 1975 – 80; Chairman of the IAU Working Group on Protection of Molecular Line Frequencies 1976 – 1994; he served on the Organising Committees of the IAU Radio Astronomy and Interstellar Medium Commissions; and he was also Chairman of the Inter-Union Commission on Allocation of Frequencies (IUCAF) 1987 – 1995. "As IUCAF Chairman he was very active in obtaining the protection of the 18-cm OH spectral bands from interference from first the Russian satellite system GLONASS and then the US system IRIDIUM," says John Whiteoak. "I would say that these protection successes, and not his science, are his most important legacy to the successful future of radio astronomy, even more so than his involvement in the development of the Australia Telescope."

Brian became a Fellow of the Royal Astronomical Society in 1964, and a Fellow of the Australian Institute of Physics in 1967. In 1974 he was elected Fellow of the Australian Academy of Science: in the same year he was also awarded the Walter Burfitt Prize by the Royal Society of New South Wales for his contributions to the field of radio physics.

Brian retired from CSIRO in 1992, but remained an ATNF Fellow. For several years he and his wife Jill spent their winters on Magnetic Island, Queensland. Here Brian pursued his lifelong love of writing, penning a "Found in Space" space column for the local paper. Brian and Jill were also both interested in jazz and the visual arts: Brian played the clarinet, and in retirement he and Jill took up drawing and sculpture. In recent years Brian became a friend and supporter of Sydney installation artist Joan Brassil, helping her to incorporate pulsar sounds and references to radio astronomy into installations she created for the Art Gallery of NSW and Mount Stromlo Observatory.

Brian is survived by his wife Jill, his son Anthony, and his stepchildren Peter and Mandy.

Helen Sim, Wayne Orchiston
(Helen.Sim@csiro.au) (Wayne.Orchiston@csiro.au)

¹ "Vale Brian Robinson: A great Australian", Magnetic Times, 31 July 2004, p.1.
² Ibid.
³ Ibid.
⁴ www.drao-ofr.hia-iha.nrc-cnrc.gc.ca/~kerton/graphics /appleton.html
⁵ Kerr, F. J., Hindman, J. F., Robinson, B. J. Australian Journal of Physics 7 (1954), 297, and Kerr, F. J., Hindman, J. V. Astronomical Journal 58 (1953), 218
⁶ Brian Robinson, "Spectral Line Astronomy at Parkes" in Parkes: Thirty Years of Radio Astronomy, ed. D.E. Goddard and D.K. Milne, p. 106
⁷ Raymond Haynes, Roslynn Haynes, David Malin and Richard McGee, Explorers of the Southern Sky (CUP 1996) p. 261
⁸ Gardner, F.F., Robinson, B.J., Bolton, J.G., van Demme, K.J. 1964, Physical Review Letters, 13, 3.
⁹ Brian Robinson, "Spectral Line Astronomy at Parkes", op. cit., p. 108
¹⁰ Explorers of the Southern Sky, op. cit., p. 264.