“Not only are the galaxies spinning, but also the stars within the galaxies, and the Earth is spinning, and the Earth around the sun and the moon around the Earth. Pretty much the whole universe is spinning,” says Noam Libeskind at the Leibniz Institute for Astrophysics. “We don’t really know why, and one way to try to answer that is to figure out where the spinning stops.”
Intergalactic filaments harbor half of all matter in our Universe
In December of 2020, astronomers at the University of Bonn discovered a primordial gas filament stretching more than 50 million light years across. These unfathomably large threads of hot gas surround and connect galaxies and galaxy clusters, forming an immense cosmic web. The intergalactic filaments contain nearly half of all baryonic matter in our universe –matter of which stars, planets, homo sapiens are composed.
Largest structures in the Universe are Rotating
Now, it appears that our local pocket of the universe is spinning — rapidly. Using data from the Sloan Digital Sky Survey, scientists have discovered that some of the largest structures in the universe — filaments of galaxies that stretch between galaxy clusters forming the cosmic web– appear to be rotating. At present, scientists are baffled about this mystery of why galaxies and everything else in space rotates.
“The rotation we find is surprising because we don’t really know what can generate rotation on such scales” wrote Noam Libeskind in an email to The Daily Galaxy. “It could be due to tidal forces but the interplay between gravitational collapse and tidal torques is unclear on these scales.”
Researchers are looking for patterns: when most of the galaxies on one side of these gigantic filaments were moving away from us and most on the other were coming towards us, that indicated that the whole filament was spinning –some at nearly 100 kilometers per second.
“These galaxies are moving on these corkscrew-like, helical orbits,” says Libeskind, with the filaments that end at more massive clumps of galaxies seeming to rotate faster, but it is not clear why. The net rotation of the largest structures in our universe were likely imprinted during the formation of the first galaxies and galaxy clusters before universal expansion stretched them out. The rotation of the filaments provides important clues and diagnostics for cosmologists to understand the physical processes that created the cosmic web.
Image credit top of page: The 2MASS Redshift Survey (2MRS) 3-D map pushes the envelope of the Galactic Plane out to 380 million light-years – encompassing more than 500 million stars and resolving more than 1.5 million galaxies. The 2MRS has logged what’s been previously hidden behind our Milky Way.