A group of global researchers led by astronomers from the University of Hawai’i Institute for Astronomy is revolutionizing our perception of the universe with remarkable discoveries. Their work on the Cosmicflows project, which involves tracking the movements of 56,000 galaxies, indicates that our galactic neighborhood might be significantly larger than we had previously understood.
Ten years ago, this team determined that the Milky Way resides within a vast basin of attraction known as Laniākea, which spans 500 million light-years. However, fresh evidence now suggests that this view may be merely the beginning. There is a 60% chance that we are actually part of an even larger structure, potentially ten times greater in volume, which is centered on the Shapley concentration — an area rich in mass and gravitational influence. This research has recently been shared in the journal Nature Astronomy.
“Our universe resembles a massive web, with galaxies positioned along strands and clustering at junctions where gravitational pulls draw them together,” explained UH Astronomer R. Brent Tully, a leading researcher on the study. “Just like water flows within watersheds, galaxies navigate within cosmic basins of attraction. This identification of larger basins may fundamentally alter our comprehension of cosmic structures.”
Immense universe
The roots of the universe begin around 13 billion years ago, when slight variations in density began shaping the cosmos, gradually evolving into the vast formations we observe today, influenced by gravity. If our galaxy is indeed part of a much larger basin of attraction, far exceeding Laniākea — which translates to ‘immense heaven’ in Hawaiian — it would imply that the foundational elements of cosmic structure expanded well beyond our current models.
“This revelation poses a particular challenge: our cosmic surveys might not yet encompass the full scale of these immense basins,” commented UH astronomer and co-author Ehsan Kourkchi. “Although we are observing through powerful tools, even these instruments may not be adequate to capture the complete image of our universe.”
Gravitational dynamics
The researchers analyze these large-scale configurations by studying their influence on galaxy movements. A galaxy located between two such structures experiences a gravitational tug-of-war, where the gravitational pull from the surrounding large-scale formations dictates the galaxy’s trajectory. By charting the speeds of galaxies throughout our local universe, the team can delineate the spatial area dominated by each supercluster.
The team intends to persist in their efforts to chart the most significant formations of the cosmos, fueled by the potential that our position in the universe is part of a much broader and interconnected framework than we ever envisioned.
This international collaboration includes UH astronomers Tully and Kourkchi, as well as Aurelien Valade, Noam Libeskind, and Simon Pfeifer (from Leibniz Institut für Astrophysik Potsdam), Daniel Pomarede (University of Paris-Saclay), and Yehuda Hoffman (Hebrew University).
