Great wall (astronomy)

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The Great Wall includes the Hercules, Coma, and Leo clusters on the right side of this view of the local universe.

In astronomy, the Great Wall is the name of a cosmic structure, consisting of a denser arrangement of galaxies compared to the surrounding space, in the form of a so-called filament . It forms - after U1.27 and the Sloan Great Wall - the third largest known coherent structure in the universe. The center of the Great Wall is the Coma supercluster .

This structure is the boundary of a void and was discovered in 1989 by Margaret Geller and John Huchra through lengthy, systematic measurement of the redshift of the spectral lines . It lies 200 million light years away in the direction of the constellation Virgo , is 500 million ly. Long - roughly parallel to the northern edge of the galactic disk of the Milky Way - only 15 million ly. Thick and at least 300 million ly. High. The elevation may possibly be greater, but visibility is limited by the extinction of the Milky Way to the south. In contrast, the Sloan Great Wall is almost three times as large with a length of around 1.4 billion light years.

The galaxy clusters Abell 2151 ( Hercules galaxy clusters ), 1656 ( Coma galaxy clusters ) and 1367 ( Leo galaxy clusters ) are located in the Great Wall . Like the Virgo supercluster , to which our local group also belongs, it moves at approx. 600 km / s in the direction of the Hydra-Centaurus supercluster , and all together move at a similar speed to the large attractor in 200 million, which was only discovered in 1990 . Ly. Distance, in the direction of the Norma galaxy cluster in the constellation Winkel Maß , south of Scorpio .

The gravity of normal ( baryonic ) matter would be too weak to explain the formation of such large structures. But if dark matter is included , which according to the lambda CDM model , the standard model of cosmology , makes up over 80% of the total matter , there is a good agreement with the theory. Computer simulations of the structure formation result in similar large structures as the Great Wall.

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