7 Jul 2026
A new Argonne- und LMU led analysis based on five years of South Pole Telescope data detects tiny shadows imprinted on the afterglow of the Big Bang: more than 7,000 galaxy clusters found
Only infrared observations (right) clearly reveal the galaxies that make up the cluster.
Around 1,800 galaxy clusters in the new catalog are so distant that their light has traveled for more than 8 billion years to reach us. A research team led by Argonne and LMU Munich has now published one of the deepest censuses of massive, distant galaxy clusters to date.
The catalog is based on five years of observations from the SPT-3G experiment at the Amundsen–Scott South Pole Station in Antarctica. Using highly sensitive measurements of the cosmic microwave background—the faint afterglow of the Big Bang—the international team identified 8,892 galaxy cluster candidates and confirmed 7,190 of them using optical and infrared data. Researchers from institutions around the world contributed to the project, including LMU Munich.