Rotation and toroidal magnetic field effects on the stability of two-component jets

Abstract

Several observations of astrophysical jets show evidence of a structure in the direction perpendicular to the jet axis, leading to the development of "spine & sheath" models of jets. Most studies focus on a two-component jet consisting of a highly relativistic inner jet and a slower - but still relativistic - outer jet surrounded by an unmagnetized environment. These jets are believed to be susceptible to a relativistic Rayleigh-Taylor-type instability, depending on the effective inertia ratio of the two components. We extend previous studies by taking into account the presence of a non-zero toroidal magnetic field. Different values of magnetization are examined, to detect possible differences in the evolution and stability of the jet. We find that the toroidal field, above a certain level of magnetization $\sigma$, roughly equal to 0.01, can stabilize the jet against the previously mentioned instabilities and that there is a clear trend in the behaviour of the average Lorentz factor and the effective radius of the jet when we continuously increase the magnetization. The simulations are performed using the relativistic MHD module from the open source, parallel, grid adaptive, MPI-AMRVAC code.

15 pages, 17 figures

References in corpus (10)

• Magnetic acceleration of relativistic AGN jets
• MPI-AMRVAC for Solar and Astrophysics
• Kinematics of the jet in M87 on scales of 100 -- 1000 Schwarzschild radii
• Semi-implicit scheme for treating radiation under M1 closure in general relativistic conservative fluid dynamics codes
• Formation of dynamical structures in relativistic jets: the FRI case
• Are Spine--Sheath Polarization Structures in the Jets of Active Galactic Nuclei Associated with Helical Magnetic Fields?
• Transverse Faraday-Rotation Gradients Across the Jets of 15 Active Galactic Nuclei
• Two-component jet simulations: I. Topological stability of analytical MHD outflow solutions
• Transverse stability of relativistic two-component jets
• Faranoff-Riley type I jet deceleration at density discontinuities "Relativistic hydrodynamics with realistic equation of state"

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• Linear Theory of the Rayleigh-Taylor Instability at a Discontinuous Surface of a Relativistic Flow
• Triggering mixing and deceleration in FRI jets: a solution
• The different flavors of extragalactic jets: the role of relativistic flow deceleration
• Are Low-Frequency Quasi-Periodic Oscillations seen in accretion flows the disk response to a jet instability?