The Evolution of Cocoons Surrounding Light, Extragalactic Jets
Abstract
If the mass density of supersonic, collimated material is less than that of the surrounding medium, a so-called light jet will be enveloped by a cocoon of overpressured shocked gas. Hydrodynamical simulations are used to understand the evolution of the cocoon. The cocoon's evolution is also compared to a simple analytic theory. To reconcile the theory with the simulations, the growth of the jet head must be taken into account. The overpressured cocoon stage exists for a relatively short astronomical time, after which only the region of the cocoon near the jet head remains overpressured. The spatial distribution of the optical emission often observed in distant extragalactic jet systems can be explained with this improved understanding of cocoon evolution.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1992
- DOI:
- 10.1086/171445
- Bibcode:
- 1992ApJ...392..458C
- Keywords:
-
- Computational Astrophysics;
- Digital Simulation;
- Hydrodynamic Equations;
- Intergalactic Media;
- Radio Jets (Astronomy);
- Galactic Evolution;
- Star Formation;
- Astrophysics;
- GALAXIES: JETS;
- HYDRODYNAMICS