supercluster

(redirected from Galaxy superclusters)
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supercluster

(soo -per-klus-ter) A loosely bound aggregate of several clusters of galaxies, about 100 megaparsecs in extent. As seen in the sky, different superclusters overlap; their members can be distinguished only after the distances of the constituent galaxies have been determined from a redshift survey. Over a dozen superclusters have been identified, the nearest of which include the Local Supercluster, the Pisces–Perseus supercluster, the Shapley supercluster, and Hydra–Centaurus. Superclusters contain between 2 and 15 rich clusters and have total masses of up to 1016 solar masses. Although the galaxies within each cluster are tightly bound, the clusters' gravitational effect on each other is not sufficient to overcome the expansion of the Universe. Each supercluster is thus growing in extent, although more slowly than the space between the superclusters. The larger superclusters appear to be elongated with no central concentration or axial symmetry, and form parts of filaments that surround empty voids (see large-scale structure).

supercluster

[′sü·pər‚kləs·tər]
(astronomy)
An association of galaxy clusters and groups, typically composed of a few rich clusters and many poorer groups and isolated galaxies.
References in periodicals archive ?
Connolly says that photons from the microwave background do show dark energy's effect after passing through specific galaxy superclusters that have been cataloged by the Sloan survey.
According to the mind-boggling standard theory, these irregularities began as microscopic, random quantum fluctuations as small as elementary particles and ballooned so vastly during inflation that they spawned the galaxy superclusters we see today.
A faint-object camera and spectrograph will soon enable cosmologists to construct "Subaru Deep Field" images and three- dimensional maps of galaxy superclusters.
As such, Bahcall says, it will allow astronomers to see the distribution of numerous galaxy superclusters and voids in unprecedented detail.