Has the hidden matter of the Universe been discovered?

Simulated image of the X-ray emission from gas in the cosmic web filaments. Astrophysicists consider that around 40% of the ordinary matter that makes up stars, planets and galaxies remains undetected, concealed in the form of a hot gas in the complexe cosmic web. Today, scientists at the Institut d'Astrophysique Spatiale (CNRS/Université Paris-Saclay) may have detected, for the first time, this hidden matter through an innovative statistical analysis of 20-year-old data. Their findings are published on November 6, 2020 in Astronomy & Astrophysics . Galaxies are distributed throughout the Universe in the form of a complex network of nodes connected by filaments, which are in turn separated by voids. This is known as the cosmic web. The filaments are thought to contain almost all of the ordinary (so-called baryonic) matter of the Universe in the form of a diffuse, hot gas.