Comparison between X‐ray surface brightness (gray tones plus 3 σ‐above‐background contour level), 6 cm radio‐continuum sources (marked "R," from Hummel & van der Hulst 1986), and regions of CO emission (marked "CO," from Stanford et al. 1990). Note spatial correlation between X‐ray emission and radio sources. Two CO sources coincide with nuclei of NGC 4038/39, while third CO source plus three radio sources lie in region of low X‐ray emissivity associated with presumed contact region between the two disks.