MULTIFREQUENCY OBSERVATIONS OF BLAZARS .5. LONG-TERM MILLIMETER, SUBMILLIMETER, AND INFRARED MONITORING

Multifrequency monitoring data are presented for 17 blazars between 37 5 and 22 GHz. These data are used to study the overall flaring behavio r of blazars and, in particular, to test predictions of shock models f or the early phases of flare evolution. It is shown that time delays b etween light curves and flare amplitudes at different frequencies are in good agreement with existing shock models. Evidence is found for th e flares in BL Lac objects to reach maximal development at lower frequ ency than those of optically violent variable quasars. On short timesc ales the variability behavior is complex, with ''flickering'' over a r ange of amplitudes. Most objects that underwent a large outburst durin g the monitoring period show a flattening of the 375-150 GHz spectral slope with increasing 270 GHz flux.