1999/11/09 by Miguel-Angel Aloy, M. Á. Aloy, José L. Gómez +7
Engineering · Physics and Astronomy · #Active galactic nucleus #Aerodynamics and Acoustics in Jet Flows #Astrophysical jet #Astrophysics #Astrophysics and Cosmic Phenomena #Asymmetry #Blazar #Galaxy #Jet (fluid) #Magnetic field #Mechanics #Physics #Radio Astronomy Observations and Technology #Radio galaxy #Stratification (seeds) #astro-ph
paper · pdf · doi:10.1086/312436
6 pages, 5 figures, 1 latex style file, ApJL accepted
arxiv created 1999/11/09 · openalex publication_date 2000/01/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present the first radio emission simulations from high-resolution three-dimensional relativistic hydrodynamic jets; these simulations allow us to study the observational implications of the interaction between the jet and the external medium. This interaction gives rise to a stratification of the jet in which a fast spine is surrounded by a slow high-energy shear layer. The stratification (in particular, the large specific internal energy and slow flow in the shear layer) largely determines the emission from the jet. If the magnetic field in the shear layer becomes helical (e.g., resulting from an initial toroidal field and an aligned field component generated by shear), the emission shows a cross section asymmetry, in which either the top or the bottom of the jet dominates the emission. This, as well as limb or spine brightening, is a function of the viewing angle and flow velocity, and the top/bottom jet emission predominance can be reversed if the jet changes direction with respect to the observer or if it presents a change in velocity. The asymmetry is more prominent in the polarized flux because of field cancellation (or amplification) along the line of sight. Recent observations of jet cross section emission asymmetries in the blazar 1055+018 can be explained by assuming the existence of a shear layer with a helical magnetic field.