On the interaction of jet plasma with dark matter subhaloes in active galaxies

► The interaction of fragmented AGN jets with galactic haloes is studied. ► The lensing of jet radiation by halo masses is negligible. ► Jet widens as its plasma fragments are deflected by gravitation of subhaloes. ► Gravitational scattering results in specific profiles of jet radiation. The interaction of fragmented plasma of active galactic nuclei jets with galactic haloes via gravitational scattering and lensing by dark matter subhaloes is studied using analytical calculations and numerical Monte-Carlo method. The lensing of jet radiation by halo masses is found to be negligible and unobservable. Moving through a galactic halo jet plasma fragments are sequentially deflected on hyperbolic orbits by gravitational field of subhaloes and deviates at some angles when leaving halo, causing widening of the jet. Based on this model jet opening angles are calculated numerically for various values of jet and halo characteristics. Though these angles are very small, gravitational scattering by halo masses results in specific radial profile of jet radiation intensity, that does not depend on halo mass distribution and jet properties. The intensity of jet radiation, obeying the derived profile, decreases by reasonable observable factors giving possibility to probe the presence of dark matter subhaloes.