$L_{\rm syn}-E_{\rm syn, p}-\delta$ relation in Active Galactic Nucleus Jets and Implication for the physical origin of the $L_{\rm p}-E_{\rm p,z}-\Gamma_0$ relation of Gamma-Ray Bursts

Abstract

High energy photon radiations of gamma-ray bursts (GRBs) and active galactic nuclei (AGNs) are dominated by their jet radiations. We examine wether the synchrotron radiations of jets in BL Lacs, flat spectrum radio quasars (FSRQs), and Narrow Line Seyfert 1 galaxies (NLS1s) follow the relation between the prompt gamma-ray emission and the initial Lorentz factor ($\Gamma_0$) of GRBs. It is showed that the AGNs sample does not agree with the $L_{\rm p}-E_{\rm p,z}-\Gamma_{0}$ of GRBs. In addition, we obtain a tight relation of $L_{\rm syn}\propto E^{0.45\pm0.15}_{\rm syn,p}\delta^{3.50\pm0.25}$ for FSRQs and NLS1 galaxies, where $L_{\rm syn}$ is the luminosity at peak photon energy $E_{\rm syn, p}$ of the synchrotron radiations. This relation is different from the $L_{\rm p}-E_{\rm p,z}-\Gamma_{0}$ relation of GRBs. The dependence of $L_{\rm syn}$ to $\delta$ is consistent with the expectation of the Doppler boosting effect for the FSRQs and NLS1 galaxies, but it is not for GBRs. We argue that $\Gamma_0$ may be a representative of the kinetic power of the radiating region and the tight $L_{\rm p}-E_{\rm p, z}-\Gamma_0$ relation is shaped by the radiation physics and the jet power together.