Astronomer Ron Allen passed away on Aug. 8

Ronald J. Allen came to Groningen in January 1969 as a postdoctoral researcher after a PhD from the Massachusetts Institute of Technology and a a National Research Council of Canada Fellowship at Meudon Radio Observatory near Paris. He was attracted by the almost-completed Westerbork Synthesis Radio Telescope. After a short spell at the Institute of Astronomy at Cambridge, Ron joined the permanent staff of the Kapteyn Institute in 1972.

His interest was to a great extent in the techniques of radio astronomy. He was instrumental in getting the WSRT continuum backend adapted to observe the 21-cm line of neutral atomic hydrogen (HI). With this '80-channel line receiver' the first HI images of galaxies were made, notably of Messier 101 and NGC 891, showing the presence of spiral structure and the overall extent of the HI. In hindsight this initiative to turn the WSRT into a spectral line machine was fundamental for the Kapteyn Institute's international reputation in galaxy research covering a wide range of topics: spiral structure, dark matter distribution in galaxies, galaxy interactions, etc.

He had a keen interest in the structure of galaxies, but was also an important driving force in setting up effective and interactive reduction procedures for 21-cm line observations from Westerbork. To this end Ron supervised the provision of a dedicated state-of-the-art reduction and visualization facility with I^2S equipment and the development of the Groningen Image Processing SYstem GIPSY. Together these provided the most sophisticated spectral line visualization and reduction facility in the world. To help train students in the use of synthesis radio techniques he was also one of the initiators of a small two-element radio interferometer built on the Groningen campus for educational purposes, the Paddepoel Quasi Radio Sterrenwacht (PQRS, also known as the Toad Puddle Radio Observatory, TPRO).

Ron was chairman of the astronomy department in 1983 when the Kapteyn Laboratory (now the Kapteyn Astronomical Institute) moved to the Zernike Building. He saw to it that astronomers in Groningen were among the first to use e-mail, stimulated the introduction of personal computers and arranged to have a Local Area Network installed in the institute, one of the first at the University.

In 1985 he returned to the USA (Ron was Canadian, but his wife Janice American), first to the University of Illinois and since 1989 at the Space Telescope Science Institute in Baltimore. He supervised a number of important PhD theses. Even after he moved to Baltimore, Ron remained a frequent visitor to Kapteyn and worked with Piet van der Kruit in exchanging students, which in three cases resulted in a University of Groningen PhD thesis of which he was one of the supervisors.