Astronomers discover an arc of galaxies 3,000 million light-years long

Posted:

Jun 11, 2021 22:42 GMT

If its existence is confirmed, it would pose a major problem for one of the basic tenets of cosmology.

British astronomers have discovered an arc of galaxies spanning 3.3 billion light-years, or about 3.5% of the visible universe. If the structure turns out to be real, it would challenge one of the basic tenets of cosmology: that on a large scale, matter in the universe is distributed evenly no matter where you look. new world.

“It would overturn cosmology as we know it,” confirmed Cosmologist Alexia López of the University of Central Lancashire (UK) at a virtual press conference for the American Astronomical Society. “Our standard modelnot to say much, fail“.

López and his colleagues discovered the alleged structure, which they simply call the Giant Arch, by studying the light of about 40,000 quasars captured by the Sloan Digital Sky Survey research project.

The “signatures” of atoms

Quasars are the luminous cores of giant galaxies so far away that they appear to be points of light. As they head toward Earth, atoms in and around foreground galaxies absorb some of this light, leaving specific “signals” in the light that eventually reach astronomers’ telescopes.

The “signature” of the giant arc is in the magnesium atoms that have lost an electron. The quasar light absorbed by these atoms traces a roughly symmetrical curve to dozens of galaxies that extend roughly One-fifteenth of the radius of the visible universe, detailed Lopez.

The team ran three statistical tests to calculate the odds of galaxies aligning in a giant arc by chance. All three indicate that the structure is real, with a less than 0.00003 percent probability of being statistical chance.