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   PR # 11071
    Abstract for the 'observation of irregular shape SNRs'.We propose to
    observe three SNRs in irregular shape in X-ray region.  They are
    3C391, 3C396 and 3C397.  If the SNe occur in the average density
    medium, they will evolve as typical shell structure. Whereas, if they
    occur in the low density region like the hot bubble,they will be left
    unseen for a long time, particulary in the energy range of the
    Einstein.  Assuming that the hot bubble occupies a large fraction of
    the Galaxy,the typical SNRs will be those occurred in the low density
    region.  We believe that the shape irregularity of the SNRs are due
    to the density variation in the surrounding medium.  Our observation
    will reveal the evolution of the SNR occurred in the hot bubble.

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