Flux evolution and kinematics of superluminal components in blazar 3C345

TL;DR

This paper models the kinematics and flux evolution of superluminal components in blazar 3C345 using a precessing jet-nozzle scenario, validating the physical nature of these components and their Doppler-boosted emission.

Contribution

It introduces a detailed precessing nozzle model to explain the kinematics and flux evolution of superluminal jet components in blazar 3C345, linking their motion to Doppler boosting effects.

Findings

The model accurately reproduces the observed flux and kinematic properties.

The Doppler boosting effect explains the flux evolution of superluminal components.

The derived Lorentz factor and viewing angle vary continuously over time.

Abstract

The precessing jet-nozzle scenario previously proposed was applied to model-fit the kinematics of five superluminal components (C19,C20,C21,B5 and B7) of jet-B in blazar 3C345. Based on a specific pattern for the the precessing common trajectory of jet-B, the kinematic properties (including trajectory,coordinates, core separation and apparent velocity) were model-fitted and their flux evolution could be studied. Through model-simulation of their kinematic behavior, the bulk Lorentz factor, viewing angle and Doppler factor were derived as continuous functions of time and the association of their flux evolution with their Doppler-boosting effect was investigated. The 43GHz light-curves of the five superluminal components can be well interpreted in terms of their Doppler effect. The close association of their flux evolution with the Doppler-boosting effect firmly validates our precessing nozzle scenario and supports the traditional point-view that superluminal components are physical entities (traveling shocks or plasmoids) participating relativistic motion toward us at small angles. The model-simulation of kinematic behavior of superluminal components by using our precessing nozzle scenario with specific patterns (helical or ballistic) assumed for the precessing common trajectories yields the model-derived bulk Lorentz factor, apparent velocity, viewing angle and Doppler factor as continuous functions of time, which are most applicable to study the connection of flux evolution with Doppler boosting effect for the superluminal components.