Zwicky 3146 : the most massive cooling flow ?

In this Letter we present a deep ROSAT HRI image of Zwicky 3146 (or Zw 37-19), a distant cluster with high X-ray luminosity. The X-ray data show that the cluster contains the most massive known cooling flow at 1250 M_sun_ yr^-1^, the existence of which has important implications for the formation and evolution of the cluster. The central galaxy in the cluster shows strong optical line emission and a blue continuum, and is also aligned with the X-ray emission.