1.The end point of the collapse and relaxation of a protogalaxy is a dark matter halo, inside of which the baryonic gas is in hydrostatic equilibrium at a temperature of typically a few million degrees.
9.Applying general relativity to this expanding model universe, and comparing it to the latest observational data, scientists realised that the particles we could see – known as baryonic matter – made up only 5% of the universe.