High energy phenomena in the Cartwheel's ring
  We present the first X-ray detection of the Cartwheel's ring. The impact that created the characteristic optical structure is responsible also for an enhanced level of star formation to which we can ascribe the relatively high level of X-ray emission observed. Deeper images and spectroscopic information are needed to confirm or disprove the hypothesis that High Mass X-ray Binaries contribute most of the radiation in this band. 
Anna Wolter, Ginevra Trinchieri and Angela Iovino (Osservatorio   Astronomico di Brera, Milano)