Mapping how matter spreads across the universe is a key goal in cosmology and astrophysics. It’s a complex dance between the universe’s rapid expansion and the pull of gravity trying to hold everything together. Among the fascinating structures out there is one called Quipu.
Quipu is an enormous cosmic structure that stretches 1.3 billion light-years. To put that into perspective, it could line up 13,000 Milky Ways in a row! Its mass is equally staggering—about 130,000 times that of our own galaxy. This suggests that Quipu isn’t just a string of galaxies lined up. Instead, it has one main strand with clusters of galaxies connected by smaller strands.
The discoverer named it Quipu after a counting system used by the Incas. This ancient method used color-coded cords attached to a primary strand, with knots tied in specific places to convey numerical information. Like the Incan system, Quipu in space has clusters concentrated along its strands, revealing patterns in the universe’s layout.
Quipu is part of a group of five massive structures found between 424 million and 815 million light-years from Earth. Together, these structures hold 45% of all galaxy clusters, 30% of all galaxies, and a quarter of the matter in that area of the universe, even though they take up just 13% of the volume. This makes them significant over-densities compared to their surroundings.
It’s interesting how the universe isn’t evenly filled with galaxies. Instead, it forms a cosmic web, with galaxies and clusters connected by strands, leaving large empty spaces in between, known as voids.
While Quipu is the largest known structure nearby, even bigger formations exist far away, raising questions about our understanding of cosmic models. However, Quipu fits snugly within these models. Simulations suggest that structures like it should exist.
The significance of Quipu could extend to our understanding of cosmic measurements. Some scientists believe it might provide insights into the Hubble tension, the ongoing debate about the universe’s expansion rate. Researchers are analyzing the data, but they believe the statistical confidence of their findings needs to improve.
The research on Quipu has been accepted for publication in the journal Astronomy & Astrophysics and is available for reading on the arXiv preprint server.
