3D Hydrodynamic Simulations of Large-Scale Precessing Jets: Radio Morphology

TL;DR

This study uses 3D hydrodynamic simulations to explore how relativistic jet precession affects radio morphology, revealing characteristic shapes like X-sources and tools for identifying precession with high accuracy.

Contribution

It introduces a comprehensive simulation framework for precessing jets and develops diagnostic tools to identify precession indicators in radio observations.

Findings

Precessing jets can produce X-shaped radio sources.

Indicators like point symmetry and jet misalignment are highly predictive of precession.

Precession signatures are detectable with 98% accuracy in simulated data.

Abstract

The prospect of relativistic jets exhibiting complex morphologies as a consequence of geodetic precession has long been hypothesised. We have carried out a 3D hydrodynamics simulation study varying the precession cone angle, jet injection speed and number of turns per simulation time. Using proxies for the radio emission we project the sources with different inclinations to the line of sight to the observer. We find that a number of different precession combinations result in characteristic `X' shaped sources which are frequently observed in radio data, and some precessing jet morphologies may mimic the morphological signatures of restarting radio sources. We look at jets ranging in scale from tens to hundreds of kiloparsecs and develop tools for identifying known precession indicators of point symmetry, curvature and jet misalignment from the lobe axis and show that, based on our simulation sample of precessing and non-precessing jets, a radio source that displays any of these indicators has a 98% chance of being a precessing source.