An European research provides new data on cosmic collisions

An international research partially funded with European funds has shed new light on the history of a cosmic crash - Abell 2744 - that emerged millions of years ago. The study, funded in part by the DARKMATTERDARKENERGY project, can help to reveal how structures form in the universe, and how different types of matter interact with each other when they are smashed together.

The research, funded in part by the DARKMATTERDARKENERGY ('Understanding the dark universe with 3D (three-dimensional) weak gravitational lensing') project, which has clinched a €100,000 Marie Curie Actions: 'International Reintegration Grant' under the EU's Seventh Framework Programme (FP7), helps elucidate the influence of structures on the formation of the universe. The researchers can use observations of these cosmic pile-ups to reconstruct events that happened over a period of hundreds of millions of years, like a crash investigator piecing together the cause of an accident. 

Researchers from the Institute of Theoretical Astrophysics at the University of Heidelberg in Germany highlighted that this findings can reveal how structures form in the universe and how different types of matter interact with each other when they are smashed together. The study has combined data generated from the NASA/ESA (European Space Agency) Hubble Space Telescope, the European Southern Observatory's (ESO) Very Large Telescope (VLT) and the Japanese Subaru telescope and NASA's Chandra X-ray Observatory.

Galaxies may be bright but they account for less than 5% of the mass, because the rest is dark matter and gas, which is invisible. For that reason, the researchers used gravitational lensing, which is the bending of light rays from distant galaxies as they pass through the gravitational field found in the cluster.

These observations are important both for determining where the gas is but also for revealing the angles and speeds at which various components of the cluster came together. Astronomers from Brazil, Israel, Italy, Taiwan, the United Kingdom and the United States contributed to this study.