The Efficiency of the Magnetic Acceleration in Relativistic Jets
Author: Vlahakis, Nektarios
Source: Astrophysics and Space Science, Volume 293, Numbers 1-2, September 2004 , pp. 67-74(8)
Abstract:Using steady, axisymmetric, ideal magnetohydrodynamics (MHD) we analyze relativistic outflows by means of examining the momentum equation along the flow and in the transfield direction. We argue that the asymptotic Lorentz factor is ∞∼− M , and the asymptotic value of the Poynting-to-matter energy flux ratio—the so-called function—is given by ∞/(1 +∞) ∼ M /, where M is the Michel’s magnetization parameter and c 2 the total energy-to-mass flux ratio. We discuss how these values depend on the conditions near the origin of the flow. By employing self-similar solutions we verify the above result, and show that a Poynting-dominated flow near the source reaches equipartition between Poynting and matter energy fluxes, or even becomes matter-dominated, depending on the value of M /.
Document Type: Research Article
Affiliations: Section of Astrophysics, Astronomy and Mechanics, Department of Physics, University of Athens, Panepistimiopolis, GR-15784, Zografos Athens, Greece, Email: email@example.com
Publication date: September 2004