Dark matter comes out of the cold
By Jonathan Amos
BBC News science reporter
“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.”