If you could zoom in to look at the universe at its greatest scale, you would see it consist of a gigantic cosmic web. Now astronomers have detected shock waves traveling through this network, providing new insights into large-scale magnetic fields. When the universe was young it was more or less homogeneous, with matter and magnetic fields basically the same in all directions. But over time, the scattering of dark matter engulfed the matter, forming a giant web of dense filaments containing galaxies and clusters passing through the vast voids.

This cosmic web was first proposed theoretically in the 1960s, and its structure has been modeled in simulations since the 1980s. Recently, astronomers have been able to map it and observe the glow of its filaments.

In a new study, scientists from ICRAR and CSIRO were able to observe radio emissions from shock waves rolling in the cosmic web. This was not easy to do, because the signals are extremely weak and difficult to distinguish from all the other radio emissions that are constantly buzzing in the universe.

Therefore, the team focused instead on a less common option: polarized radio signals produced as the result of a series of processes in the space network. Areas of the web containing more matter will attract even more matter through gravity. When matter enters these areas, it heats the gases that are emitted outwardly in the form of shock waves. When these shock waves reach extremely cold spaces, this interaction creates polarized radio light.

The team used data from various projects and observatories, including the Global Magneto-Ionic Medium Survey, the Planck Legacy Archive, the Owens Valley Longwavelength Array, and the Murchison Widefield Array. This allowed them to stack their data of detected polarized radio emissions onto known clusters and bands of the cosmic web, showing that the detections did indeed come from the web.

“Since there are very few sources emitting polarized radio light, our research was less prone to contamination, and we were able to provide much more convincing evidence that we see emissions from shock waves in the largest structures in the universe, which helps validate our models. The growth of this large-scale structure.” , lead author of the study, Dr. said Tessa Wernstrom. The team says these new observations will help astronomers understand how magnetism works at the largest scales in the universe.