Jury report for prof. dr. M.B.M. (Michiel) van der Klis

Professor of astronomy at Universiteit van Amsterdam

Professor Michiel van der Klis receives the NWO Spinoza prize 2004 for, amongst other things, his pioneering research into X-ray radiation from binary stars.

Michiel van der Klis (The Hague, 9 June 1953) has been professor of astronomy at the Astronomical Institute 'Anton Pannekoek', Universiteit van Amsterdam since 1993. Van der Klis gained his doctorate in 1983 from the Universiteit van Amsterdam for his observations of X-ray stars. After his Ph.D. he held various positions, including a period at the European Space Research and Technology Centre in Noordwijk. In 1989, Van der Klis returned to the Universitiet van Amsterdam as a senior lecturer and he became a professor there in 1993. In 1987, Van der Klis received the Bruno Rossi Prize, the highest international award in high-energy astrophysics. In 1991 he received a Pioneer subsidy from NWO to set up a research group.

Van der Klis investigates the X-ray radiation from binary stars. Binary stars consist of two stars which rotate around each other. A small percentage of such binary stars contain a neutron star or a black hole. These are the two most extreme objects in the universe. Van der Klis studies how material moves in the strong gravitational field of such objects. This not only provides data about the mass, radius and rotational speed of the stars and black holes, but it also provides insights into the general theory of relativity.

Twenty years ago, Van der Klis opened up a new research field and he is still the world's leading expert in it. In 1985 he clarified why X-ray radiation emitted by binary stars does not consist of stable pulses but instead of quasi-periodic oscillations. And in the 1990s his group hit the world headlines, when they discovered the first X-ray star which rotated at 400 times per second around its axis. The existence of such a star had been predicted 16 years previously, but had not yet been proved.

The research methods of Van der Klis and his manner of processing data have been a gold standard within his subject area and beyond, for the past 20 years. He gives many lectures and holds several important board positions. But above all Van der Klis is a prolific researcher. For example, in recent years he has published more than 20 articles per year, many of which have appeared in top journals such as Science and Nature. In a nutshell, Van der Klis is a scientist with a considerable international reputation, a pioneer and an inspirer. In view of his drive and creativity, it is expected that over the next ten years he will continue to make considerable contributions to worldwide astrophysical research.

Further information for the press available from:

prof. dr. M.B.M. (Michiel) van der Klis (Astronomical Institute 'Anton Pannekoek', Universiteit van Amsterdam)

t: +31 (0)20 525 74 91 / 98, michiel@science.uva.nl

http://zon.astro.uva.nl/cgi-bin/astroweb/person.cgi?name=Klis

This jury report served as the basis for the speech given by Prof. R. Prins at the announcement ceremony for the NWO Spinoza prizes 2004 on 7 June.