Thursday, September 04, 2014

The Great Attraction

Our Galaxy is known to have a peculiar velocity of some 600 km/s with respect to the cosmic microwave background. It's long been rather unclear what the nature of "the Great Attractor" responsible for this velocity has been. A new study seems to clarify that question and to establish our position in a newly identified supercluster of galaxies being called Laniakea.

Within the boundaries of the Laniakea Supercluster, galaxy motions are directed inward, in the same way that water streams follow descending paths toward a valley. The Great Attractor region is a large flat bottom gravitational valley with a sphere of attraction that extends across the Laniakea Supercluster.

The name Laniakea was suggested by Nawa'a Napoleon, an associate professor of Hawaiian Language and chair of the Department of Languages, Linguistics, and Literature at Kapiolani Community College, a part of the University of Hawaii system. The name honors Polynesian navigators who used knowledge of the heavens to voyage across the immensity of the Pacific Ocean.

Read more at:

The name seems to mean "immeasurable heaven", which is a bit ironic, since the supercluster was traced by careful measurements of the peculiar velocities of the constituents.

I recommend that you go to the linked sight and watch the Nature video. It's very good, and the reader's accent is lovely.