Radio Halos in Galaxy Clusters




WSRT image of the COMA Cluster at 90 cm.



The radio halo in COMA. Contours represent the radio emission (previous image), colours refer to the X-ray emission (from White, Briel and Henry 1993).




The radio halo in A 2319. Contours represent the radio emission, colours refer to the X-ray emission




The cluster A 2255: colour represents the X-Ray emission, the contours are the radio galaxies (mostly with tailed structure)




The cluster A 2255: grey-scale represents the X-Ray emission, the contours refer to the extended radio halo emission (after subtraction of discrete sources)