Universe Today by Carolyn Collins Petersen October 5, 2024
If you want to pinpoint your place in the Universe, start with your cosmic address. You live on Earth->Solar System->Milky Way Galaxy->Local Cluster->Virgo Cluster->Virgo Supercluster->Laniakea. Thanks to new deep sky surveys, astronomers now think all those places are part of an even bigger cosmic structure in the “neighborhood” called The Shapley Concentration.
Astronomers refer to the Shapley Concentration as a “basin of attraction”. That’s a region loaded with mass that acts as an “attractor”. It’s a region containing many clusters and groups of galaxies and comprises the greatest concentration of matter in the local Universe. All those galaxies, plus dark matter, lend their gravitational influence to the Concentration. There are many of these basins in the Universe, including Laniakea. Astronomers are working to survey them more precisely, which should help provide a more precise map of the largest structures in the Universe.
A data visualization of the motions of galaxies in structures called basins of attraction. The Milky Way is the
red dot. Courtesy of the University of Hawai'i.
One group, led by astronomer R. Brent Tully of the University of Hawai’i measured the motions of some 56,000 galaxies to understand these basins and their distribution in space. “Our universe is like a giant web, with galaxies lying along filaments and clustering at nodes where gravitational forces pull them together,” said Tully. “Just as water flows within watersheds, galaxies flow within cosmic basins of attraction. The discovery of these larger basins could fundamentally change our understanding of cosmic structure.”
Cosmic Flows and Mapping Structures
Tully’s team is called CosmicFlows and they study the motions through space of those distant galaxies. The team’s “redshift” surveys revealed a possible shift in the size and scale of our local galactic basin of attraction. We already know that we “live” in Laniakea, which is about 500 million light-years across. However, the motions of other clusters indicate there’s a larger “attractor” directing the cluster flow. The CosmicFlows data suggest that we could be part of the Shapley Concentration, which could be 10 times the volume of Laniakea. It’s about half the volume of the largest structure in space, known as “the Great Wall”, which is a string of galaxies stretching across 1.4 billion light-years.
More:
https://www.universetoday.com/168816/the-milky-way-might-be-part-of-an-even-larger-structure-than-laniakea/
