Through a unique combination of observations made by the largest telescopes in the world, an international collaboration led by researchers from the Astrophysics Department- AIM Laboratory of CEA-IRFU has detected the most distant galaxy cluster ever discovered in the Universe . Back 11.5 billion years in the past of the Universe, the snapshot of this cluster shows 17 galaxies in a strong starburst activity, a period of intense star formation. This is the first time such a structure, captured at the time of its formation, is detected as far away, when the universe was "only" 2.5 billion years. These results, achieved with the CEA skills associated in particular with the Institute for Radio Astronomy Millimeter (Iram), CNRS, and Université Paris Diderot, open a new window in our understanding about how the universe is structured in his youth . The work is published in the Astrophysical Journal on August 30th, 2016.
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Detection of the most distant cluster of galaxies ever observed. The left image shows the X-rays emission ((purple) captured by the Chandra satellite, radiated by the gas located between the galaxies and heated to millions of degrees by the tremendous gravity of the cluster. Each point on the image is a galaxy with hundreds of billions of stars. The right image shows a zoom on the heart of the galaxy cluster galaxies with 17 galaxies showing strong star formation identified by the radiation of their interstellar matter (via the detection of molecules with IRAM-NOEMA and dust with ALMA). The ALMA emission is shown by contours and the dotted lines shows the contour of the X-ray emission with galaxy redshift indicated. © Chandra/IRAM/ALMA
"Discovery of a galaxy cluster with a violently starbursting core at z=2.506"
Tao Wang, David Elbaz, Emanuele Daddi, et al., in press in The Astrophysical Journal
for the electronic version
See also : : Discovery of an extremely young stellar clump in the distant Universe (7 May 2015)
See also : - Les clés de l'évolution des galaxies (in French, Point Presse - 7 juin 2013)