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Concept
Filament galactique
Résumé
In cosmology, galaxy filaments are the largest known structures in the universe, consisting of walls of gravitationally bound galactic superclusters. These massive, thread-like formations can reach 80 megaparsecs h−1 (or of the order of 160 to 260 million light-years) and form the boundaries between voids. Galaxy filaments form the cosmic web and define the overall structure of the observable universe.
Discovery of structures larger than superclusters began in the late-1980s. In 1987, astronomer R. Brent Tully of the University of Hawaii's Institute of Astronomy identified what he called the Pisces–Cetus Supercluster Complex. In 1989, the CfA2 Great Wall was discovered, followed by the Sloan Great Wall in 2003.
In January 2013, researchers led by Roger Clowes of the University of Central Lancashire announced the discovery of a large quasar group, the Huge-LQG, which dwarfs previously discovered galaxy filaments in size. In November 2013, using gamma-ray bursts as reference points, astronomers discovered the Hercules–Corona Borealis Great Wall, an extremely large filament measuring more than 10 billion light-years across.
The filament subtype of filaments have roughly similar major and minor axes in cross-section, along the lengthwise axis.
A short filament was proposed by Adi Zitrin and Noah Brosch—detected by identifying an alignment of star-forming galaxies—in the neighborhood of the Milky Way and the Local Group. The proposal of this filament, and of a similar but shorter filament, were the result of a study by McQuinn et al. (2014) based on distance measurements using the TRGB method.
The galaxy wall subtype of filaments have a significantly greater major axis than minor axis in cross-section, along the lengthwise axis.
A "Centaurus Great Wall" (or "Fornax Great Wall" or "Virgo Great Wall") has been proposed, which would include the Fornax Wall as a portion of it (visually created by the Zone of Avoidance) along with the Centaurus Supercluster and the Virgo Supercluster also known as our Local Supercluster within which the Milky Way galaxy is located (implying this to be the Local Great Wall).
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