Astronomers have found the farthest galaxy cluster till date – 10 billion light years from earth. Four unknown galaxy clusters each potentially containing thousands of individual galaxies have been discovered. Galaxy clusters are the most massive objects in the universe, containing hundreds to thousands of galaxies, bound together by gravity. In common parlance, this means that the light from the most distant of the four new clusters identified by the team has taken over 10 billion years to reach us. Up to now, the most distant clusters found by astronomers date back to when the universe was 4.5 billion years old.
This equates to around nine billion light years away. While astronomers have identified many nearby clusters, they need to go further back in time to understand how these structures are formed. This means finding clusters at greater distances from the Earth. An international team of astronomers, led by Imperial College London, used a new way of combining data from the two European Space Agency satellites, Planck and Herschel, to identify more distant galaxy clusters than has previously been possible.
The Planck satellite scanned the whole sky while the Herschel satellite surveyed certain sections in greater detail. The researchers from the UK, Spain, USA, Canada, Italy and South Africa believe up to 2000 further clusters could be identified using this technique, helping to build a more detailed timeline of how clusters are formed. Lead researcher Dr David Clements, from the department of physics at Imperial College London, explains “The clusters can be identified at such distances because they contain galaxies in which huge amounts of dust and gas are being formed into stars. This process emits light that can be picked up by the satellite surveys.”