Spectral Diagnostics of Blazar Central Engines. III. Submillimeter Flares in Blazars

This article investigates the difference in submillimeter flares in BL Lac objects and flat-spectrum radio quasars. It is shown that a strong distinction can be found in the low-frequency emission at centimeter wavelengths. This is ascribed to a mildly varying centimeter-peaked background spectral component that is far more powerful in quasar radio cores than in BL Lac objects. There is also a highly variable millimeter peaked component, the flaring component, which is similar in quasars and BL Lac objects. This analysis is supportive of the two-component spectral model discussed in Papers I and II of this series.