Correlation between VLBI Radio Flux and Gamma-Ray Flux of EGRET Active Galactic Nuclei

Abstract
Through the correlation analysis of the VLBI radio flux and the γ-ray flux of EGRET active galactic nuclei (AGNs), a significant correlation has been established that tends to be an upper bound relationship. This correlation not only shows that the γ-ray emission mechanism is likely to be the synchrotron self-Compton model or the inverse Compton model, which directly links the γ-ray emission with the extreme relativistic electron distribution, but it also shows that the γ-ray emission may come from the region within the order of 1 pc (the latter being consistent with the results given by the luminosity variation). Furthermore, there is a significant correlation between the luminosities (L100 MeVL). The upper bound relationship implies that the contribution of AGNs to the diffuse γ-ray background is smaller than that predicted before.