Washington: Astronomers using the Karl G. Jansky Very Large Array (VLA) and the Chandra X-Ray Observatory have produced a spectacular image that reveals new details of violent collisions involving at least four clusters of galaxies.
Combined with an earlier image from NASA`s Hubble Space Telescope (HST), the new observations show a complex region more than 5 billion light-years from Earth where the collisions are triggering a host of phenomena that scientists still are working to understand.
The HST image forms the background of this composite, with the X-ray emission detected by Chandra in blue and radio emission seen by the VLA in red. The X-rays indicate hot, tenuous gas that pervades the region containing the galaxy clusters.
The large, oddly-shaped red feature at the center probably is a region where shocks caused by the collisions are accelerating particles that then interact with magnetic fields and emit the radio waves.
Reinout van Weeren , an Einstein Fellow at the Harvard-Smithsonian Center for Astrophysics, said the complex shape of this region is unique; we`ve never spotted anything like this before, adding that the shape probably is the result of the multiple ongoing collisions.
The new radio and X-ray observations are much more sensitive than previous ones, the scientists said. The combination of these images will make this region one of the best-studied examples of cluster-cluster collisions yet known, and can yield new insights on the complex interactions during cluster mergers. Together, the merging clusters are called MACS J0717+3745, which also is one of the HST Frontier Fields for which HST will produce the deepest observations ever.