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   PR # 21174
     HCG51 (Hickson's compact group No.51) is a group of galaxies  contai
    ning 7 members under a close gravitational interaction. Tidal force  
    among the galaxies is expected to enhance the  starbutst activity and
    to produce a large quantity of hot plasmas. By observing this object,
    we expect to measure temperature,  spatial extent, luminosity of the 
    X-ray emission, as well as metal abundance of the plasma responsible 
    for the X-ray emission.                                              
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