2017ApJ...851..144L

Black holes, anywhere in the stellar-mass to supermassive range, are often associated with relativistic jets. Models suggest that jet production may be a universal process common in all black hole systems regardless of their mass. Although in many cases observations support such hypotheses for microquasars and Seyfert galaxies, little is known regarding whether boosted blazar jets also comply with such universal scaling laws. We use uniquely rich multi-wavelength radio light curves from the F-GAMMA program and the most accurate Doppler factors available to date to probe blazar jets in their emission rest frame with unprecedented accuracy. We identify for the first time a strong correlation between the blazar intrinsic broadband radio luminosity and black hole mass, which extends over ∼9 orders of magnitude down to microquasar scales. Our results reveal the presence of a universal scaling law that bridges the observing and emission rest frames in beamed sources and allows us to effectively constrain jet models. They consequently provide an independent method for estimating the Doppler factor and for predicting expected radio luminosities of boosted jets operating in systems of intermediate or tens of solar mass black holes, which are immediately applicable to cases such as those recently observed by LIGO.