Through technology, ordinarily incompatible wavelengths of radiation can be combined to reveal the Virgo ClusterΓÇÖs structure. This image is a composite of high-energy x-rays and low-energy radio waves. (X-rays are represented as blue and radio waves as red.) The x-rays are from the clusterΓÇÖs center and are probably emitted by a halo of emissions around the giant elliptical galaxy M87, which is the gravitationally dominant object in the cluster. The radio emissions are from the clusterΓÇÖs ten brightest spiral galaxies and trace their clouds of un-ionized neutral hydrogen. Spiral galaxies are usually rich in hydrogen gas, but these appear to contain very little. X-ray emissions here are associated with the absence of radio waves, so astronomers
