Steven Balbus, Savilian Professor of Astronomy in Oxford University's Department of Physics, has won The Shaw Prize in Astronomy 2013, sharing a $1m award for work that explains how astronomical objects form.
The Shaw Prize is an annual international award to honour individuals who are currently active in their respective fields and who have recently achieved distinguished and significant advances. The Shaw Prize, established under the auspices of Mr Run Run Shaw in November 2002, is managed and administered by The Shaw Prize Foundation based in Hong Kong.
This year's Shaw Prize in Astronomy, worth $1m, recognises the contribution the research of Professor Balbus and Professor John Hawley of the University of Virginia has made to our understanding of the accretion of matter in the Universe: the process in which planets, black holes, and stars, form.
In space as gas is drawn together the small amount of rotation that is always present means that as the gas contracts it rotates faster and faster – rather like figure skaters spinning by drawing in their arms. This forms a gaseous accretion disc. However, a longstanding problem was how this spinning gas ever made it into the centre of such a disc to build an object like a planet or black hole.
Professors Balbus and Hawley showed that if magnetic forces are properly included in the analysis the rotating gas in the disc becomes turbulent and the flow complex, even if the magnetism is very weak. This breakdown process is called the 'magnetorotational instability'. The gas continues to rotate as a disc when the magnetorotational instability is present, but it is also mixed by turbulence. In this process, the inner part of the disc loses its angular momentum to the outer part. Eventually, almost all the gas spirals in to the centre where it belongs whilst almost all the disc's angular momentum has been transferred to the outermost region, which now contains relatively little gas. The work of Professors Balbus and Hawley demonstrated that magnetorotational instability is a key process in understanding how many of the objects in the Universe are able to form and evolve.
Professor Balbus said: 'I am delighted to have been selected for the Shaw Prize in Astronomy. There are so many worthy candidates for an award of this nature, that to have been chosen from such a field is an indication that one's work has been important to many people. This is very gratifying to a scientist, to know that all that effort will have a lasting impact. It is a marvellous feeling.'
The presentation ceremony for the three annual prizes that make up The Shaw Prize – Astronomy, Life Science and Medicine, and Mathematical Sciences – is due to be held on 23 September 2013.