0000000000854995
AUTHOR
J. Ma. Martí
Relativistic Numerical Simulations of Superluminal Sources
AbstractWe study the generation and evolution of superluminal components in relativistic jets through relativistic hydrodynamical and emission simulations of a square-wave perturbation in the jet velocity.
VLBA Observations of 3C 120
AbstractWe present 1.3 cm and 7 mm VLBA observations of the radio galaxy 3C 120 at epochs November 11 and December 22, 1996. The 7 mm maps, with linear resolution of ~0.1 pc, show a very rich structure consisting of up to eight superluminal (~ 7 c) components.
Riemann solvers in relativistic astrophysics
AbstractOur contribution reviews High Resolution Shock Capturing methods (HRSC) in the field of relativistic hydrodynamics with special emphasis on Riemann solvers. HRSC techniques achieve highly accurate numerical approximations (formally second order or better) in smooth regions of the flow, and capture the motion of unresolved steep gradients without creating spurious oscillations. One objective of our contribution is to show how these techniques have been extended to relativistic hydrodynamics, making it possible to explore some challenging astrophysical scenarios. We will review recent literature concerning the main properties of different special relativistic Riemann solvers, and disc…
Morphology and Dynamics of Relativistic Jets
We present a comprehensive analysis of the morphology and dynamics of relativistic pressure-matched axisymmetric jets. The numerical simulations have been carried out with a high-resolution shock-capturing hydrocode based on an approximate relativistic Riemann solver derived from the spectral decomposition of the Jacobian matrices of relativistic hydrodynamics. We discuss the dependence of the jet morphology on several parameters, paying special attention to the relativistic effects caused by high Lorentz factors and large internal energies of the beam flow. The parameter space of our analysis is spanned by the ratio of the beam and ambient medium rest mass density (η), the beam Mach number…