Our Galaxy Appears To Be Part Of Structure So Large It Challenges Our Models Of Cosmology
Wednesday, October 09, 2024As we study the universe more, we have found ourselves to be part of much larger structures, formed by gravitational interactions. We orbit the Sun, the Sun is part of the Milky Way, and the Milky Way is part of the Local Group, which includes several small galaxies as well as Andromeda, of "it may collide with us" fame.
But it doesn't stop there. The Local Group is on the outer edge of the Virgo Supercluster, which is itself part of a giant basin known as Laniakea. According to the new study, Laniakea too resides within a larger "basin of attraction" (BoA) potentially 10 times its volume.
"The entire Universe can be considered a patchwork of abutting BoA, just as the terrestrial landscape is separated into watersheds," the team explains in their paper. "A BoA is generally not gravitationally bound because the relative motion of distant points within it is usually dominated by cosmic expansion."