For immediate release Click here to jump to photo. Surprisingly, the total mass of NGC 1399 found from these new measurements is about ten times as large as the combined mass of the stars and nebulae seen in this galaxy. These new results also have important implications for the current ideas about the formation of giant galaxies. Some look like spinning spirals, like our own Milky Way galaxy, with its several hundreds of billions of stars in a flat, rotating disk.
Some galaxies lead a comparatively quiet life, others are violent and explosive.
But perhaps the most enigmatic of them all are the largest ones, the giant elliptical galaxies. The giant galaxies are mostly found at the centres of vast clusters of hundreds or thousands of smaller galaxies, like swarms of bees about the central hive. Astronomers who make computer simulations of the early Universe believe they know the answer. In their simulations, they see these giant galaxies forming by gradual aggregation of small clumps of matter falling towards the centre, thereby making larger and larger bodies as time progresses. It turns out that a crucial test is to measure how the matter now moves in the outskirts of these huge galaxies, at distances of 100,000 light-years or more from their centres.