Credit: X-ray (NASA/CXC/INAF/G.Brunetti et al.); Radio (NRAO/NSF/INAF/G.Brunetti et al.)
This composite image shows the galaxy cluster Abell 521, located about 2.9 billion light years from Earth. A Chandra X-ray Observatory image, in blue, shows hot gas in the cluster, and an image from the Giant Meterwave Radio Telescope in India shows radio emission in orange.
A team of scientists, including astronomers from the Naval Research Laboratory (NRL), have detected long wavelength radio emission from a colliding, massive galaxy cluster which, surprisingly, is not detected at the shorter wavelengths typically seen in these objects. The discovery implies that existing radio telescopes have missed a large population of these colliding objects. It also provides an important confirmation of the theoretical prediction that colliding galaxy clusters accelerate electrons and other particles to very high energies through the process of turbulent waves. The team revealed their findings in the October 16, 2008 edition of Nature. Source: Naval Research Laboratory