A structure and energy dissipation efficiency of relativistic reconfinement shocks

TL;DR

This paper develops a semi-analytical model for relativistic jet reconfinement shocks, accurately predicting shock structure and energy dissipation efficiency, with implications for understanding astrophysical jet interactions.

Contribution

It introduces a refined hydrodynamical model that incorporates exact conservation laws and angular relations, improving upon previous approximate formulas for shock size and energy dissipation.

Findings

Shock size is approximately twice larger when including transverse pressure gradients.

Energy dissipation efficiency strongly depends on jet Lorentz factor and opening angle.

Model confirms accuracy of earlier approximate formulas with added precision.

Abstract

We present a semi-analytical hydrodynamical model for the structure of reconfinement shocks formed in astrophysical relativistic jets interacting with external medium. We take into account exact conservation laws, both across the shock front and in the zone of the shocked matter, and exact angular relations. Our results confirm a good accuracy of the approximate formulae derived by Komissarov & Falle (1997). However, including the transverse pressure gradient in the shocked jet, we predict an absolute size of the shock to be about about twice larger. We calculate the efficiency of the kinetic energy dissipation in the shock and show a strong dependence on both the bulk Lorentz factor and opening angle of the jet.