It is therefore a unique opportunity for astronomers to have been able to observe this cluster in formation thanks to the ALMA (Atacama Large Millimeter/submillimeter Array). A big part of the physics of galaxy clusters is well understood, but observations of the early stages of ICM formation remain rare.
“Cosmological simulations have predicted the presence of hot gas in galaxy clusters for more than a decade, but observations have failed to confirm it“, explains Elena Rasia, researcher at the Italian National Institute of Astrophysics (INAF) in Trieste, Italy, and co-author of the study. The discovery of a large reservoir of hot gas in the Spider’s Web proto-cluster (here studied by astronomers) would indicate that the system might become a veritable cluster of long-lived galaxies rather than dispersing into the Universe.