The Great Wall of Galaxies

Click on the galaxy cluster for finder charts and observing notes

Sheets and Voids

For an Overview: Observing Galaxy Clusters
How It All Fits Together: Large Scale Structure

Maps of the galaxy distribution in the nearby universe reveal large coherent structures. The extent of the largest features is limited only by the size of the survey. Voids are present in every survey large enough to contain them. Many galaxies lie in thin sheet-like structures. The largest sheet detected so far is the Great Wall. The frequent occurrence of these structures is one of several serious challenges to our current understanding of the origin and evolution of the large-scale distribution of matter in the universe. - Margaret Geller & John Huchra

Geller and Huchra discovered the Great Wall on the first three sections of the CfA (Center for Astrophysics) redshift survey, which covered the region from eight to 16 hours of right ascension and from 26.5 to 42.5 degrees of (north) declination. Although the Leo and Hercules Clusters lie slightly south of this region, the authors make it clear that the same structure extends south of the survey boundaries. The wall of galaxies is skewed to our line of sight, with a mean redshift distance that varies from Z = 0.023 (~350 million light years) in Leo to Z = 0.033 (~500 million light years) in Hercules.

AGC1367 Leo Cluster LEO NGC 3842 13.5 .022 1145 +19.8
AGC 1656 Coma Cluster COM NGC 4874 13.5 .023 1300 +28.0
AGC 2147 na HER IC 1165 13.8 .038 1602 +15.9
AGC 2151 Hercules Cluster HER NGC 6040 13.8 .036 1605 +17.8
AGC 2197 na HER NGC 6146 13.9 .030 1628 +40.9
AGC 2199 na HER NGC 6166 13.9 .031 1629 +39.5