H.B. and St.K. thank the Verbundforschung for support under grant No. 50 OR 93065. J.P.H. acknowledges support from the Smithsonian Institution and NASA grant NAGW-201. We thank Andreas Vogler for providing the software to plot the overlay contours of Fig. 2. The ROSAT project has been supported by the German Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie (BMBF/DLR) and the Max-Planck-Society. This research has made use of the NASA/IPAC extragalactic database (NED) which is operated by the Jet Propulsion Laboratory, Caltech, under contract with the National Aeronautics and Space Administration. The optical images shown are based on photographic data of the National Geographic Society - Palomar Observatory Sky Survey (NGS-POSS) obtained using the Oschin telescope on Palomar Mountain.
© European Southern Observatory (ESO) 1999
Online publication: August 25, 1999