Massive Rotating Galaxy Structure Detected

A Gargantuan Discovery in the Cosmic Web

Scientists have made a remarkable observation of the largest-known rotating structure in the cosmos—a massive, thread-like assembly of hundreds of galaxies, gas, and dark matter. This filament is part of the cosmic web, an intricate network that forms the large-scale structure of the universe.

The filament, located approximately 140 million light-years from Earth, was primarily observed using the MeerKAT radio telescope in South Africa. This powerful array consists of 64 interconnected satellite dishes, allowing researchers to gather detailed data about distant cosmic structures.

This rotating filament stretches an astonishing 50 million light-years in length and is 117,000 light-years wide. To put this into perspective, a light-year is the distance light travels in a year—about 5.9 trillion miles (9.5 trillion kilometers). For comparison, our Milky Way galaxy, which is also part of a filament in the cosmic web, has a diameter of roughly 100,000 light-years.

Madalina Tudorache, an astrophysicist at the University of Cambridge and co-lead author of the study published in the journal Monthly Notices of the Royal Astronomical Society, explained the significance of this discovery. She described the universe as being composed of a network-like distribution of galaxies, gas, and dark matter, known as the cosmic web.

"The cosmic web is formed of clusters, which are dense regions of matter often containing multiple groups of galaxies; voids, which are nearly empty regions of space; and filaments, which are strand-like structures connecting the dense regions and surrounding the voids," she said.

The newly discovered rotating filament contains nearly 300 galaxies of varying sizes, along with gas and dark matter. Dark matter, a mysterious and invisible substance, is estimated to make up 27% of the universe. In contrast, ordinary matter—comprising everything visible such as stars, planets, and moons—accounts for only about 5% of the universe.

Dark matter does not emit, absorb, or reflect light, but its presence can be inferred through its gravitational effects on large scales. The researchers determined that the filament is spinning by observing that galaxies on either side of its central axis are moving in opposite directions. The entire structure rotates at a speed of about 246,000 miles (396,000 km) per hour.

Lyla Jung, an astrophysicist at the University of Oxford and another co-lead author of the study, noted that while this is the largest spinning structure detected so far, there may be even larger ones yet to be discovered. "We believe there are other spinning structures, some of which could be larger. However, we have not been able to detect them directly with our current data and telescopes," she said.

To help visualize the unique spinning motion of the filament, the researchers compared it to a teacup ride. "First, each galaxy in the filament spins on its own. The gas and stars in each galaxy orbit around the galaxy center, like each teacup on the ride spins individually. Second, the entire cosmic filament also rotates. The filament is made of many galaxies, and this study demonstrates that the entire structure is rotating, like the teacup platform spins as a whole," Jung explained.

Astrophysicists study the universe at various scales, from the tiniest particles like neutrinos to vast structures such as galaxies, clusters, and filaments. This study focuses on the largest end of these structures, offering new insights into the formation and behavior of the cosmic web.

Tudorache emphasized the excitement surrounding this field of research. "This is a very exciting time to work in this field, as our capacity for discovering such structures is increasing with the advent of better radio and optical surveys. It will deepen our understanding of the universe," she said.