General Physical Properties of CGRaBS Blazars

Abstract

We present the results of a multi-frequency, time-averaged analysis of blazars included in the Candidate Gamma-ray Blazar Survey catalog. Our sample consists of 324 γ -ray detected ( γ -ray loud) and 191 γ -ray undetected ( γ -ray quiet) blazars; we consider all the data up to 2016 April 1. We find that both the γ -ray loud and γ -ray quiet blazar populations occupy similar regions in the WISE color–color diagram, and γ -ray loud sources are brighter in the radio and X-ray bands. A simple one-zone synchrotron inverse-Compton emission model is applied to derive the physical properties of both populations. We find that the central black hole mass and accretion disk luminosity ( L disk ) computed from the modeling of the optical-UV emission with a Shakura–Sunyaev disk reasonably matches that estimated from the optical spectroscopic emission-line information. A significantly larger Doppler boosting in the γ -ray loud blazars is noted, and their jets are more radiatively efficient. On the other hand, the γ -ray quiet objects are more MeV-peaked and thus could be potential targets for next-generation MeV missions. Our results confirm earlier findings about the accretion-jet connection in blazars; however, many of the γ -ray quiet blazars tend to deviate from the recent claim that the jet power exceeds L disk in blazars. A broadband study, considering a larger set of γ -ray quiet objects and also including BL Lacs, will be needed to confirm/reject this hypothesis as well as to verify the evolution of the powerful high-redshift blazars into their low-power nearby counterparts.