The Shaw Prize in Astronomy for 2008 is awarded to Professor Reinhard Genzel, Director of the Max Planck Institute for Extraterrestrial Physics (MPE), in recognition of his outstanding contribution in demonstrating that the Milky Way contains a supermassive black hole at its centre, a result largely obtained with the help of ESO's telescopes.
The Shaw Prize is awarded annually by the Shaw Prize Foundation in Hong Kong in the Life Sciences, Mathematical Sciences and Astronomy, each of the three prizes bearing a monetary award of one million US dollars.
"I warmly congratulate Professor Genzel for this well-deserved award which highlights some of the best science produced with ESO's telescopes," says Tim de Zeeuw, ESO's Director General. "Professor Genzel and his team have made a dedicated, long-term effort, using our telescopes and co-developing instruments, to study the Centre of our Galaxy, and as such, he has allowed us to enter an era of observational black hole physics."
In 1969, Donald Lynden-Bell and Martin Rees suggested that the Milky Way might contain a supermassive black hole at its centre. But evidence for such an object was lacking at the time because the centre of the Milky Way is obscured by interstellar dust, and was detected only as a relatively faint radio source.
Reinhard Genzel and his collaborators obtained compelling evidence for this black hole by developing state-of-the-art astronomical instruments to be used on ESO's telescopes and carrying out a persistent programme of observing the Galactic Centre and its surrounding stars for many years, which ultimately led to the discovery of a black hole with a mass of about three million times that of the Sun.
Genzel's group has in particular followed since 1992, the motion of several stars, around the Galactic Centre. These observations were first done with the MPE-built near-infrared speckle imaging camera SHARP on ESO's New Technology Telescope at La Silla, later with the adaptive optics NACO and SINFONI instruments on the Very Large Telescope (VLT) at Paranal.
NACO observations in 2002 (ESO 17/02) showed one star approaching the central black hole to within 17 light-hours - only three times the distance between the Sun and dwarf planet Pluto - while travelling at no less than 5000 km/s. The orbital period of the star is just over 15 years, and in 2007, the team had followed a complete orbit.
Subsequent adaptive optics observations revealed powerful infrared flares coming from the supermassive black hole, strongly suggesting that the Galactic Centre black hole rotates rapidly (ESO 26/03). SINFONI also enabled the astronomers to register for the first time the infrared spectrum of a flare (ESO 21/04).
The centre of our Milky Way galaxy is located in the southern constellation Sagittarius ("The Archer") and its study, together with that of the Magellanic Clouds, were the main reasons for Europe to install major telescopes in the Southern Hemisphere.