Physics and fate of jet related emission line regions

TL;DR

This paper uses hydrodynamic simulations to study how extragalactic jets at high redshift interact with their environment, producing emission line regions and affecting galaxy evolution.

Contribution

It provides new insights into the energy transfer from jets to emission line gas and the origin of the gas, with implications for galaxy properties and jet power estimates.

Findings

Jet powers must exceed 10^47 erg/s based on emission line energy.

Most emission line gas originates from within the galaxy, not expelled material.

Expelled gas remains outside the galaxy for extended periods.

Abstract

At high redshift, extragalactic jets are associated with extended emission line regions. We present global and local hydrodynamic simulations of the interaction of jets with their environment relevant to this phenomenon. We determine the fraction of kinetic energy and momentum of the jet that should appear in the emission line gas. From momentum considerations, we argue that the gas seen in outward motion in many examples must to a large part originate from within the galaxy. The host galaxies should have been massive, gas rich and heavily star forming galaxies. The expelled gas is not expected to return to the galaxy quickly. The observed kinetic energy in the emission line gas constrains the jet powers to be greater than 10^47 erg/s.