Polarization Properties of Weakly Relativistic Cylindrical Jets

Abstract

Jets can be not only ultrarelativistic, but also relativistic but with velocities appreciably lower than the speed of light. They can be launched not only by supermassive black holes in active galactic nuclei, but also by young, rapidly rotating stars (Herbig-Haro objects) and microquasars, which are binary systems displaying supercritical accretion onto a black hole (e.g., the SS 433 system) [1]. It is believed that the mechanisms for the launching of jets in these systems are related. The polarization properties of weakly relativistic cylindrical jets in an inhomogeneous magnetic field are studied in the geometrical optics approximation for the cases of isotropic and anisotropic distribution functions for the radiating particles. Various configurations for a helical magnetic field satisfying the force-free approximation are considered. In addition, the PLUTO code is used to model a jet with an inhomogeneous magnetic field. The intensity, spectrum, and polarization of gyrosynchrotron radiation of the jets are computed.