Using the biggest telescopes in the world, including the Very Large Telescope facility in Chile, the group has made detailed 3D maps of the galaxies, using the movement of their stars to "trace" the impression of the dark matter among them and weigh it very precisely.
With the aid of 7,000 separate measurements, the researchers have been able to establish that the galaxies contain about 400 times the amount of dark matter as they do normal matter.
"The distribution of dark matter bears no relationship to anything you will have read in the literature up to now," explained Professor Gilmore.
"It comes in a 'magic volume' which happens to correspond to an amount which is 30 million times the mass of the Sun.
"It looks like you cannot ever pack it smaller than about 300 parsecs - 1,000 light-years; this stuff will not let you. That tells you a speed actually - about 9km/s - at which the dark matter particles are moving because they are moving too fast to be compressed into a smaller scale.9km/s is very fast indeed - to put it in terrestrial terms it is something like 25 times the speed of sound (~0.34 km/s) . and it completely changes a number of assumptions about dark matter, which, hitherto, had been considered to move at speeds of millimetres/second (a million times slower).