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Explanation: What is the largest structure known? The answer might depend on how one defines "structure." A grouping of galaxies known as the Sloan Great Wall was discovered in the Sloan Digital Sky Survey and is a leading candidate. The Sloan Great Wall can be seen in this digitally recast contour map of galaxies in the Two Degree Field galaxy survey. Galaxies within one billion light years, a redshift of about 0.1, are depicted. The labeled Sloan Great Wall spans over one billion light years, longer than any structure ever measured. Critics worry that the Sloan Great Wall should not itself be characterized as a coherent structure because it is not currently gravitationally bound together and parts of it might never become gravitationally bound. Regardless, the beauty of the local universe of galaxies is evident in the image where several huge superclusters of galaxies -- clusters of galaxy clusters -- can also be seen. These include the Shapley Supercluster of galaxies, part of the Pisces-Cetus Supercluster, and part of the Horologium-Reticulum Supercluster.
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NASA Official: Jay Norris. Specific rights apply.
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Based on Astronomy Picture
Of the Day
Publications with keywords: galaxies - universe
Publications with words: galaxies - universe
See also:
- APOD: 2024 December 18 Á NGC 660: Polar Ring Galaxy
- APOD: 2024 December 1 Á Cosmic Latte: The Average Color of the Universe
- APOD: 2024 October 20 Á Dark Matter in a Simulated Universe
- Stellar Streams in the Local Universe
- APOD: 2024 July 1 Á Time Spiral
- APOD: 2024 April 15 Á The Cigar Galaxy from Hubble and Webb
- APOD: 2024 March 20 Á The Eyes in Markarians Galaxy Chain