The X-ray structure of the 3C 295 cluster - A cooling flow at a redshift of 0.5

The authors describe the X-ray morphology of the 3C 295 cluster. All X-ray and optical data are consistent with an isothermal hydrostatic equilibrium model with parameters similar to nearby clusters. There is evidence for a cooling flow of approximately 145 M_sun;yr⁻¹ onto 3C 295 itself. From a comparison of the cooling times of low-redshift clusters with the 3C 295 cluster, the authors determine that the Hubble constant is H₀ ≤ 20 (+27,-9) km s⁻¹Mpc⁻¹. The on-orbit performance characteristics of the high-resolution imager of the Einstein Observatory is also presented.