Numerical Simulation of Bent Jets: Propogation into an Oblique Magnetic Field

We have investigated the propagation of a fluid jet through an oblique uniform magnetic field using a three-dimensional ideal magnetohydrodynamic model. The numerical experiments show that the jet is bent by the oblique magnetic field. We found that the bending scale depends on the jet velocity and jet-magnetic field angle. The high magnetic Mach number jet goes straight compared with the slow jet. The magnetic field with the angle between the jet and magnetic field 45^deg^ bends the jet most quickly. The plasma and the perpendicular component of the magnetic field are compressed at the head of the jet. We found also that the oblique magnetic field decelerates the speed of the jet head. These numerical results are explained by a simple analytical model. We apply these results to explain the peculiarities of BL Lacertae objects among active galactic nuclei (AGNs) from a unified point of view: interaction between the jet from AGNs and the extragalactic magnetic field.