THE RADIO AND X-RAY-PROPERTIES OF ABELL-2255

New radio and X-ray data are reported for the rich cluster Abell 2255. The cluster radio emission is characterized by the presence of a diff use halo source, located at the cluster center, and a more peripheral ridge of radio emission which could be a relic. In addition, 6 tailed radio sources and a small double are found to be associated with clust er galaxies. At Xray wavelengths, the cluster shows elongated emission in the center, indicating an ongoing cluster merger, with the axis in the east-west to southeast-northwest direction. The overall cluster t emperature is found from the ROSAT observation to be kT = 3.5(+/-1.5) keV, while the temperature determined from the Einstein MPC data was r eported to be 7.3 keV. We interpret this difference as due to the exis tence in the cluster of several coexisting temperature components. The merger process can provide energy to maintain the radio halo, but we stress the need for tailed radio galaxies orbiting at the cluster cent er to provide the halo relativistic electrons.