Astronomer Royal Puts The Case For
When the Astronomer Royal, Professor Sir Martin Rees of Cambridge University, launches the 1997 National Astronomy Meeting at the University of Southampton as the first invited speaker on Tuesday morning (8th April), he will share with his audience his personal conviction that supermassive black holes do exist in the universe. He will explain how observations over the last two years have transformed astronomers' understanding of these fascinating objects.
'Though theorists have predicted for three decades that black holes should exist, the evidence has, until recently, been substantial but not overwhelming' Rees admits. But he goes on, 'The case has, however, greatly strengthened in the last two years. The most convincing evidence pertains to huge dark masses, millions (or even as much as a billion) times heavier than the Sun, that lurk in the centres of most big galaxies. The mass at the centre of our own Milky Way Galaxy amounts to two and a half million Suns. These 'dark objects' are the outcome of catastrophic gravitational collapse when the Universe was 10 to 20 percent of its present age, and the galaxies themselves were young.'
'The formation of these central black holes, and its immediate aftermath, was signalled by the violent events that we call 'quasars'. We can now directly observe galaxies so remote we are looking back that far in cosmic history, because of the great period of time it has taken the light to travel to us. In so doing, we can study the population of quasars and black holes in our Universe.'
'According to Einstein's general theory of relativity, the properties of black holes depend only on their mass and their spin. The drastic distortions of space and time close to a black hole, predicted by Einstein's theory, are now being directly observed: such measurements offer the first test of Einstein's theory under circumstances where the effects are truly dramatic, rather than mere small deviations from Newton's theory, as in our solar system. An even more interesting prospect is that we may sometime observe two black holes in collision.'
Future prospects for learning more about supermassive black holes depend on ever better optical and radio observations from the ground, as well as data from x-ray telescopes in space.
The 1997 National Astronomy Meeting runs from 9.00 a.m. on Tuesday 8th April to 12.30 p.m. on Friday 11th April in the Physics Department of the University of Southampton. Press room facilities are available and media representatives are welcome to attend. Press Room phone nos. for the duration of the meeting are (0)1703 593173 and (0)1703 593174.
Dr Jacqueline Mitton, RAS Public Relations Officer
Phone: Cambridge ((0)1223) 564914
FAX: Cambridge ((0)1223) 572892