Radio Core-Dominance of Fermi-Blazars: Implication for Blazar Unification

Abstract

...The distribution of radio core-dominance is consistent with average projection angles of 13.5, 14.8, 16.8, 20.4, and 28.2 for ISPs, LSPs, FSRQs, HSPs, and radio galaxies, respectively. Linear regression analyses of our data yield significant anti-correlation r greater than 0.60 between core-dominance parameter and extended luminosity in each individual subsample, the correlation is significant only when individual subsamples are considered. There is a systematic sequence of the distribution of the different subclasses on the Core-dominance parameter-extended luminosity plane. Nevertheless, little or no correlation between Core-dominance parameter and core luminosity or between Core dominance parameter and gamma-ray luminosity r, less than 0.50 was observed. There is a clear dichotomy between high synchrotron-peaking BL Lacs and other BL Lac subclasses. The results are consistent with a unified view for blazars and can be understood in terms of relativistic beaming persisting at the largest scales.