A SIGNATURE OF RELATIVISTIC ELECTRON-POSITRON BEAMS IN BL LACERTAE OBJECTS

BL Lacertae objects have been observed to vary in all wavebands on various timescales ranging from years to hours. Compton Gamma Ray Observatory (CGRO) observations have revealed intense gamma-ray emission from several BL Lac Objects. We show here that there is a significant correlation between the Doppler-corrected minimal X-ray luminosity and the equivalent timescale of X-ray variability extrapolated from the observed optical variability for BL Lac objects. We interpret this as evidence for relativistic electron-positron beams in BL Lac objects.