Exploring the distribution of matter across the universe is a pivotal endeavor in the fields of cosmology and astrophysics. Researchers are grappling with the interplay between the universe’s accelerating expansion and the gravitational forces that aim to maintain cohesion. Among the significant cosmic structures identified in the distant cosmos, there are also colossal formations much closer to home. Introducing Quipu.

Quipu is an enormous structure that stretches an impressive 1.3 billion light-years. To put that into perspective, it can accommodate approximately 13,000 galaxies similar in size to our Milky Way lined up in succession. Boasting a total mass of 2×10¹⁷ solar masses, equivalent to about 130,000 Milky Ways, these figures indicate that it cannot simply be a series of galaxies. Instead, it features a primary strand of galaxy clusters with numerous branches extending outward.

The discoverer likened this structure to the Incan Quipu, a system traditionally utilized for counting and record-keeping. Some theories even propose that this ancient system holds more linguistic significance than we realize. It consists of color-coded cords attached to a larger supporting strand, with knots tied at specific intervals to convey numerical data. In a similar fashion, the cosmic Quipu showcases over-densities of galaxy clusters along its strands.

Quipu is among five major cosmic formations discovered within a distance range of 424 million to 815 million light-years from Earth. Collectively, these structures encompass 45% of all galaxy clusters, 30% of all galaxies, and account for a quarter of all matter in this segment of the nearby universe, despite only occupying 13% of its total volume. This notable concentration marks them as clear over-densities compared to the broader cosmic landscape.

It comes as no surprise that certain areas of the universe are densely populated with galaxies, while others are relatively sparse. The universe is structured in what is known as the cosmic web, where galaxies and clusters form interconnected strands and nodes, separated by vast expanses of emptiness referred to as voids.

Quipu is recognized as the largest of these formations in the nearby universe. While even larger cosmic structures have been detected in more distant realms, creating challenges for existing astrophysical models, Quipu fits neatly within current theoretical expectations. Simulations of the universe indicate that structures like Quipu are anticipated to exist in the cosmic landscape.

The identification of such a massive structure could potentially influence measurements in cosmology. This may provide insights into the ongoing Hubble tension, which refers to the discrepancies among various methods used to gauge the universe’s expansion rate. Although the research team sought to uncover this effect in existing data, they concluded that the statistical confidence in their findings remains insufficient.

The research has been accepted for publication in the journal Astronomy & Astrophysics and is available for viewing on the arXiv preprint server.