Born in the Czech Republic and educated at Wadham College, Oxford and Manchester University in England, he adopted Australian nationality some 37 years ago. He became a Professor of Astronomy at the Mount Stromlo Observatory, now the Research School of Astronomy & Astrophysics at the Australian National University in 1994. Elected Fellow of the Australian Academy of Science in 1996, was Treasurer (2007-13) & Council Member of that body. He was President of Division VI of the International Astronomical Union (1997-2000). 

An expert on galaxy formation and evolution, the physics of the interstellar medium, plasma diagnostics and spectral synthesis, star formation and the feeding and the galactic environment of black holes, he is author of over 630 publications (360 refereed) and invited speaker at over 50 conferences. His research work has been cited over 21000 times, and his H-Index is 75. In 2002, with his long-time colleague Ralph Sutherland, he published a major text book in the field, Diffuse Matter in the Universe. He is ISI Citation Laureate (2001), was awarded the Australian Centenary Medal (2003), Member of the Order of Australia (AM) (2013) and an inaugural Australian Federation Fellow (2002-06). He was Editor-in-Chief for Astrophysics & Space Science (2007-14). He has either served upon or chaired a number of HST and Spitzer Space Observatory peer review panels and international visiting committees. 

He has won over $15M in research funding, including a $5.6M Systemic Infrastructure Initiative grant which enabled the world-beating technologically advanced Wide Field Spectrograph instrument to be built, and has been involved in several other instrumental projects which include the FUSE and the Endeavour UV Space Telescopes. He provided policy advice to NASA though service on the Science Oversight Committee for the successful and productive Hubble Space Telescope Wide Field Camera 3, and also served on ARENA, the Franco-Italian Policy advice committee for the conduct of Antarctic Astronomy at Dome C.