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    PR # 31166                                                                   
     We propose the BL Lacertae objects RXJ10131+5053 to observe with ASCA       
      The source indicated the `concave' X-ray spectra during the ROSAT  p       
     revious observatoin. According to the report the spectrum was well  f       
     itted with a broken power-law model whose lower and higher energy  in       
     dices are 2.4 and 0.94, respectively, and the breaking energy was  at       
      0.7 keV. It suggests that it is to be regard as the bridge object  b       
     etween X-ray synchrotron sources, such as the most of BL Lacs, and  S       
     SC sources often seen in the OVV quasars. Thus the source could be a        
      clear evidence of the unified model of Blazars. Here we propose to         
     observe the object with ASCA in order to exam the two component model       
      and their emission mechanisms.                                             
                                                                                 
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