The cosmic web formed very early in the history of the universe, starting with small initial fluctuations in the primordial universe. ~ American astrophysicist Behnam Darvish
Galaxies are not isolated. They are instead interactively distributed via a cosmic web of gravitational filaments.
The filaments are like bridges connecting the denser regions in the cosmic web. ~ Behnam Darvish
Where intergalactic gravitational filaments meet are dense galactic clusters of galaxies, which began as modest fluctuations away from homogeneity. Galaxy distribution ultimately reflects subtle variations in the early universe.
These galactic filaments are themselves dynamic gyres, growing as tendrils, sprouting new galaxies in a variety of formations and with different growth patterns. By this, galaxies are organized in a hierarchy of associations.
Filaments engender interaction between galaxies, thereby enhancing star formation. This dynamic began early and continues today.
Galaxies flow in currents, swirl in eddies and collect in pools. ~ German cosmologist Noam Libeskind & Canadian astronomer Brent Tully
Clusters of galaxies form superclusters comprising tens of thousands of individual galaxies. Superclusters fit into galactic sheets and filaments that fly through the immense voids that comprise 90% of the volume of the universe.
Galactic superclusters are the largest known arrangements in the universe. Even larger structures are suspected.
The Milky Way lies within the Laniakea supercluster, which encompasses 100,000 galaxies stretched out over 160 megaparsecs (520 million light-years). Laniakea weighs roughly 1017 (a hundred quadrillion) solar masses; 100,000 times that of the Milky Way.
Laniakea is an elaborately organized gyre. Within it, galaxies flow inwards toward a gravitational valley called the Great Attractor. Laniakea is Hawaiian for “immeasurable heaven”; an oddly inapt name in that the supercluster has an approximate measure and is a relatively small part of a much larger universe.
Large Quasar Groups
As quasars are the bright half of galactic formation (black holes being the shadowy opposite), astronomers refer to an oversized galactic cluster as a large quasar group. Owing to the dynamics of black hole affiliation, quasars tend to clump together.