Astronomers have finally located the universe’s “missing” matter, a vast tendril of hot gas stretching out for 23 million light-years across four galaxy clusters. This discovery confirms that our best models of the universe were right all along and sheds new light on the Cosmic Web, the vast structure along which entire galaxies grew and gathered during the earlier epochs of our 13.8 billion-year-old universe.
The “missing” matter is not dark matter, but rather ordinary matter made up of atoms, composed of electrons, protons, and neutrons. A third of the baryonic matter in the cosmos is believed to be missing, but scientists have now confirmed that this matter is indeed present in vast filaments stretching between densest pockets of space.
The newly observed filament stretches diagonally through the Shapley Supercluster, a gathering of over 8,000 galaxies forming one of the most massive structures in the nearby cosmos. It has a temperature of around 18 million degrees Fahrenheit, making it 1,800 times hotter than the surface of the sun.
A team of astronomers used X-ray data from XMM-Newton and Suzaku to characterize this filamentary structure. By combining these observations with optical data from various telescopes, they were able to remove “cosmic contaminants” that had been affecting their measurements. The results show that the filament is exactly as expected from large-scale simulations of the universe.
This discovery has significant implications for our understanding of the Cosmic Web and how galaxies are connected across vast cosmic distances. It also validates decades of simulations and reinforces our standard model of the cosmos.
Source: https://www.space.com/astronomy/astronomers-turn-up-missing-matter-in-the-largest-structures-in-the-cosmos-the-models-were-right