Birth of a galaxy cluster challenges early universe theories.

Astronomers using ALMA have observed the formation of vast clouds of hot gas during the birth of a distant galaxy cluster for the first time. The hot gas, known as the intra-cluster medium (ICM), contains more mass than all the galaxies in the cluster and is an important component of galaxy clusters. ALMA detected the hot gas of the ICM through the Sunyaev-Zeldovich effect, which allowed the researchers to discern how much hot gas there is and how it is distributed through the cluster. The findings were published in the journal Nature.