Analyzing the multiwavelength spectrum of BL Lacertae during the 1997 July outburst

The multiwavelength spectrum of BL Lacertae during its July 1997 outburst is analyzed in terms of different variations of the homogeneous leptonic jet model for the production of high-energy radiation from blazers. We find that a two-component gamma-ray spectrum, consisting of a synchrotron self-Compton and an external Compton component, is required in order to yield an acceptable fit to the broadband spectrum. Our analysis indicates that in BL Lac, unlike other BL Lac objects, the broad emission-line region plays an important role for the high-energy emission. Several alternative blazar jet models are briefly discussed. In the Appendix, we describe the formalism in which this latter process is treated in the previously developed blazar jet simulation code which we use.