Excerpt from cnet.com
The distribution of galaxies throughout the universe is not
more-or-less even; instead, galaxies tend to cluster together, bound
together by the pull of each other’s gravity. These groups can be a
variety of sizes. The Milky Way Galaxy, for instance, is part of what is
called the Local Group, which contains upwards of 54 galaxies, covering
a diameter of 10 megalight-years (10 million light-years).
But
this Local Group is just a small part of a much, much bigger structure,
which researchers at the University of Hawai’i Mānoa have now mapped in
detail. Coming in at over 100,000 galaxies, the massive supercluster has
been given the name Laniakea — “immense heaven” in Hawaiian.
The new 3D map was
created by examining the positions and movements of the 8000 closest
galaxies to the Milky Way. After calculating which galaxies were being
pulled away from us and which were being pulled towards us — accounting
for the universe’s expansion — the team, led by astronomer R. Brent
Tully, was able to map the paths of galactic migration — and define the
boundaries of Laniakea.
Traditionally, the borders of galactic
superclusters have been difficult to map, but studying the gravitational
force acting on our neighbouring galaxies has provided some important
clues. All objects inside Laniakea are being slowly but surely drawn to a
single point — a force known as the Great Attractor, a gravitational anomaly with a mass tens of thousands of times the mass of the Milky Way.
Everything that is
being pulled towards the Great Attractor is part of Laniakea — although
it’s possible that Laniakea itself might in turn be part of a structure
that is larger still.
“We probably need to measure to another
factor of three in distance to explain our local motion,” Tully said.
“We might find that we have to come up with another name for something
larger than we’re a part of — we’re entertaining that as a real
possibility.”
The full paper, “The Laniakea supercluster of galaxies”, can be read online in the journal Nature.
Source Article from http://feedproxy.google.com/~r/AscensionEarth2012/~3/Ny8FFjUKD1g/earths-address-within-massive.html
Earth's address within a massive supercluster of 100,000 galaxies ~ Video
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