Chief Scientist for CASS, CSIRO

My astrophysics research has focused on the interstellar and intergalactic medium of our own, nearby and distant galaxies. A primary tool in this endeavour has been the 21cm line of neutral hydrogen (HI), but insight into the evolving star formation rate in galactic disks has also come from the radio continuum and infrared portions of the electromagnetic spectrum.

Recent contributions have included elucidation of the interaction history (over the past 5 billion years) of one of the nearest external galaxies, Messier 31, via extremely sensitive HI imaging of its extended environment. Faint gaseous filaments, which likely have only a microscopic neutral fraction, trace the ancient interaction of Messier 31 and it’s smaller companion, Messier 33.


  • –present
    Chief Scientist, CSIRO Astronomy and Space Science


  • 1985 
    Leiden University, PhD