******************************************************
   PR # 22165
    The discovery of Gamma-ray emission from blazars provides strong     
    model-independent evidence for relativistic beaming. For most blazars
    the Gamma-ray luminosity dominates the bolometric luminosity and is  
    probably due to Compton scattering of lower energy photons. Measuring
    correlated X- and Gamma-ray variations is the key to verifying the   
    Compton scattering model and identifying the seed photons. We propose
    to observe three blazars that will be pointed at with GRO/EGRET      
    during ASCA AO2, including the most Gamma-ray luminous, the X-ray-   
    brightest, and the only BL Lac.                                      
 ******************************************************