Astronomers have unveiled an awe-inspiring find: a cosmic superstructure nicknamed “Quipu”, which they identify as the largest coherent structure in the universe ever observed. Quipu is an immense chain of galaxies and galaxy clusters intertwined in the cosmic web, spanning over 400 megaparsecs in length – that’s more than 1.3 billion light-years from end to end. For perspective, this single structure stretches across a distance roughly ten thousand times the diameter of our Milky Way, and it contains an estimated mass of ~2×10^17 times the mass of our Sun (about 200 quadrillion solar masses). This discovery, reported in a new study, far surpasses previous cosmic record-holders in scale, making Quipu a landmark in our understanding of the universe’s grandest features.
- Record-Breaking Scale: Quipu is the largest known structure in the universe, stretching over 1.3 billion light-years and containing approximately 200 quadrillion solar masses.
- Significant Cosmic Impact: This colossal structure comprises about 45% of galaxy clusters, 30% of galaxies, and 25% of the matter in the universe, while occupying only 13% of its volume.
- Implications for Cosmology: The discovery of Quipu has important implications for cosmology, including possible modifications of the cosmic microwave background through the integrated Sachs-Wolfe effect and influences on measurements of the Hubble constant.
Quipu gets its name from the Incan “quipu” – a knotted cord used for record-keeping – and with good reason. Observations show Quipu as a long filament with smaller side filaments, resembling a cord with many knots. In fact, the structure was so prominent in the sky map of galaxies that the researchers could spot it “by eye” even before running advanced detection algorithms. This vivid image of a cord with dangling threads captures Quipu’s essence: it is essentially a gigantic strand of the cosmic web, where densely packed galaxy clusters act like knots tied along filamentary strings of galaxies.
Unveiling a Cosmic Giant: How Quipu Was Discovered
The discovery of Quipu emerged from an all-sky survey of galaxy clusters designed to map the universe’s largest structures within about 130 to 250 Mpc (roughly 425–815 million light-years) of Earth. The research team used data from the CLASSIX survey (COSmic Large-Scale Structure In X-rays), which catalogs galaxy clusters detected in X-ray light. Massive galaxy clusters contain hot gas that glows in X-rays, making them beacons of mass concentration and excellent tracers of where matter is clustered in the universe. By plotting the positions of hundreds of these X-ray luminous clusters across the sky, the team effectively mapped the densest knots of the cosmic web. Patterns quickly emerged. Among them, Quipu stood out dramatically: a contiguous chain of dozens of clusters forming one enormous structure.
In total, the survey identified five immense superstructures in this local volume of the universe. Quipu is the largest and most striking of the five. The others include the well-known Shapley Supercluster, plus newly recognized structures named for the constellations or regions they occupy: Serpens–Corona Borealis, Hercules, and Sculptor–Pegasus. Each of these structures is an enormous collection of galaxy clusters and groups, but Quipu tops them all in sheer scale. According to the study, these five superstructures together contain a staggering 45% of all galaxy clusters, 30% of the galaxies, and about 25% of all matter in our local universe, while occupying only about 13% of the volume. In other words, a huge fraction of everything in our cosmic neighborhood lies within just a few gigantic filaments and cluster complexes – a striking confirmation of how clumpy the large-scale structure of the universe can be.
How Big Is Quipu? Size and Significance
Just how big is Quipu? In terms of length, Quipu extends over ~400 Mpc, which is on the order of a billion light-years. By comparison, our own Laniakea Supercluster (the region of galaxies that includes the Milky Way) spans “only” a few hundred million light-years across. Quipu is several times larger, making it a record-breaker in size. Its mass (~2×10^17 suns) is equally mind-bending – roughly equivalent to 200,000 Milky Way galaxies’ worth of mass all linked together. Even in the realm of astronomy, where enormous numbers are routine, Quipu’s mass and size are extreme outliers.
What makes Quipu especially significant is not just its record length, but its influence on the cosmic landscape. Such a concentration of matter in one region means that the universe is far from uniform on these scales. In the Quipu superstructure and the other top five, matter is densely packed, while other regions are relatively emptier voids. This uneven distribution on scales of hundreds of millions of light-years has important consequences. Galaxies near Quipu live in a markedly different environment than galaxies in quieter, more isolated parts of space. The study found that galaxy densities are enhanced out to great distances around each superstructure compared to the outskirts of lone clusters in the “field.” Essentially, if a galaxy cluster resides in one of these superstructures, it’s embedded in an extended envelope of galaxies and filaments, whereas an isolated cluster has a much sparser surroundings. This hints that environment matters even on colossal scales, possibly affecting how galaxies grow and evolve within these titanic structures.
Moreover, Quipu being the largest cosmic structure ever identified means it sets a new benchmark for cosmologists. It is a vivid demonstration of the upper end of structure formation in the universe: a product of billions of years of cosmic history, where gravity has woven galaxies and clusters into one immense pattern. Finding Quipu shows that the cosmic web’s “threads” can bundle together into truly gargantuan strands, much larger than many scientists would have expected a few decades ago.
Looking Ahead: A New Era of Cosmic Cartography
The identification of the Quipu superstructure opens up many new questions and avenues for research. One immediate next step is to study Quipu in greater detail: now that we know where this massive structure is, astronomers can target it for further observations across different wavelengths. Mapping the galaxies and gas within Quipu in optical and radio surveys could reveal the fine-scale structure of its filaments, the star-forming activity in its galaxies, and how the clusters within it might be connected by faint bridges of intergalactic gas. Each cluster “knot” along Quipu could be studied to measure its mass and motion. In fact, the authors note that superstructures like this are probably transient features on cosmic timescales – over the next several billion years, cosmic expansion will pull them apart into smaller pieces, or gravity will cause parts of them to collapse into tighter clusters.
The discovery of Quipu highlights the power of modern observational astronomy to reveal ever-larger cosmic structures, reshaping our understanding of the universe’s large-scale architecture. Future telescopes and surveys will likely continue to push the boundaries of cosmic cartography, potentially uncovering even larger structures lurking in the depths of space.
Authors of the study: Hans Boehringer, Gayoung Chon, Joachim Truemper, Renee C. Kraan-Korteweg, and Norbert Schartel.
Original Research Paper: “Unveiling the largest structures in the nearby Universe: Discovery of the Quipu superstructure”
Available at: https://arxiv.org/abs/2501.19236
