Lee and his colleagues studied 445 galaxies within 400 million light years of Earth, and noticed that many of the ones rotating in a direction toward Earth had neighbors that were moving toward Earth, while those that were rotating in the opposite direction had neighbors moving away from Earth.
“The observed coherence must have some relationship with large-scale structures, because it is impossible that the galaxies separated by six megaparsecs [roughly 20 million light years] directly interact with each other,” Lee said.
Lee and his colleagues suggest that the synchronized galaxies may be embedded along the same large-scale structure, which is very slowly rotating in a counter-clockwise direction. That underlying dynamic could cause the kind of coherence between the rotation of the studied galaxies and the motions of their neighbors, though he cautioned that it will take a lot more research to corroborate his team’s findings and conclusions.
While this particular iteration of weirdly synced up galaxies is novel, scientists have observed odd coherences between galaxies at even more mind-boggling distances. In 2014, a team observed curious alignments of supermassive black holes at the cores of quasars, which are ancient ultra-luminous galaxies, that stretch across billions of light years.
@physicists, what is your best guess at the explanation of these sorts of observations?