X-ray & Optical Images of Coma Cluster
Enormous arms of hot gas have been revealed in the Coma galaxy cluster in data from NASA's Chandra X-ray Observatory and ESA's XMM-Newton. A specially processed Chandra image is shown with optical data from the Sloan Digital Sky Survey to highlight these spectacular arms. Researchers think that these arms -- which span at least a half million light years -- were most likely formed when smaller galaxy clusters had their gas stripped away by the head wind created by the motion of the clusters through the hot gas.
(Credit:X-ray: NASA/CXC/MPE/J.Sanders et al, Optical: SDSS)