It may not be stamped in your passport, but everyone on Earth is now officially a citizen of Laniakea.
That is the name scientists have given the gigantic super-cluster of galaxies that contains our own Milky Way, which is revealed in a stunning new 3D animation.
The word means 'immeasurable heaven' in Hawaiian - an appropriate description for a structure 500 million light years across that contains 100,000 galaxies and the mass of a hundred quadrillion suns.
Scientists have long-known that galaxies are not distributed randomly but congregate together in clusters.
On the largest scales, galaxies are strung out like pearls, forming glowing 'filaments'.
Where these intersect they produce enormous 'superclusters' of galaxies whose motion is affected by gravity.
The Milky Way sits near the edge of one such supercluster, the first to have its size mapped by astronomers.
Within Laniakea, galaxies flow inwards towards a region called the Great Attractor, the equivalent of a large gravitational valley.
Around Laniakea are four neighbouring superclusters known as Shapley, Hercules, Coma and Perseus-Pisces.
Dr Brent Tully, from the University of Hawaii in Honolulu, led the team of scientists that mapped Laniakea's boundaries from measurements of the velocities of local galaxies.
The researchers compared the galactic flow with that of water in a landscape of hills and valleys, tracing the outer surface of a region where the net-motion of galaxies was inward.
They wrote in the journal Nature: 'We define a supercluster to be the volume within such a surface, and so we are defining the extent of our home supercluster, which we call Laniakea.'
No comments:
Post a Comment