Cosmic neighborhood may be vastly larger than previously thought

Cosmic neighborhood may be vastly larger than previously thought
by Clarence Oxford
Los Angeles CA (SPX) Sep 30, 2024

Astronomers at the University of Hawaii Institute for Astronomy, in collaboration with international researchers, have unveiled findings that suggest our cosmic neighborhood may be significantly larger than previously understood. The Cosmicflows team has been examining the movements of 56,000 galaxies, uncovering a possible expansion in the scale of our galactic basin of attraction.

A decade ago, the team identified the Milky Way as residing within a massive structure known as the Laniakea Supercluster, spanning 500 million light-years. However, new evidence indicates that this may only represent a fraction of a much larger structure. The team estimates there is a 60% probability that our galaxy is part of an even larger system, possibly 10 times greater in volume, centered around the Shapley concentration - a dense region with immense gravitational forces. These findings have been published in 'Nature Astronomy'.

"Our universe is like a giant web, with galaxies lying along filaments and clustering at nodes where gravitational forces pull them together," explained UH Astronomer R. Brent Tully, one of the lead researchers. "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."

The evolution of the universe, which began over 13 billion years ago with small density fluctuations, has led to the large-scale structures seen today. However, if our galaxy is indeed part of a larger basin of attraction beyond Laniakea, it suggests that the processes that shaped the cosmos may have extended beyond current models.

"This discovery presents a challenge: our cosmic surveys may not yet be large enough to map the full extent of these immense basins," commented UH astronomer and co-author Ehsan Kourkchi. "We are still gazing through giant eyes, but even these eyes may not be big enough to capture the full picture of our universe."

The researchers analyze the motions of galaxies to identify these large-scale structures, noting that galaxies between such structures experience gravitational forces pulling them in different directions. By mapping these galaxy velocities, the team can determine the boundaries of each supercluster's gravitational influence.

The team plans to continue mapping these expansive cosmic structures, motivated by the possibility that our place in the universe is part of a far larger and interconnected system than previously imagined.

Research Report:Identification of Basins of Attraction in the Local Universe