In cosmology, galaxy filaments are the largest known structures in the universe, consisting of walls of galactic superclusters. These massive, thread-like formations can commonly reach 50/h to 80/h Megaparsecs (160 to 260 megalight-years)—with the largest found to date being the Hercules-Corona Borealis Great Wall at around 3 gigaparsecs (9.8 Gly) in length—and form the boundaries between voids.[1] Due to the accelerating expansion of the universe, the individual clusters of gravitationally bound galaxies that make up galaxy filaments are moving away from each other at an accelerated rate; in the far future they will dissolve.[2]
Galaxy filaments form the cosmic web and define the overall structure of the observable universe.[3][4][5]
^R. G. Clowes; "Large Quasar Groups – A Short Review"; The New Era of Wide Field Astronomy, ASP Conference Series, vol. 232.; 2001; Astronomical Society of the Pacific; ISBN1-58381-065-X; Bibcode:2001ASPC..232..108C