# An X-ray survey of the 2Jy sample. II: X-ray emission from extended structures

## TL;DR

This study investigates X-ray emissions from extended structures in a sample of radio galaxies, revealing that hotspots and jet knots are common in FRII sources, with magnetic fields and emission mechanisms differing from traditional models.

## Contribution

It provides new insights into the X-ray emission mechanisms and magnetic field properties of extended structures in radio galaxies, especially in FRII sources.

## Key findings

- Hotspots and jet knots are common in FRII sources.
- Inverse-Compton models under-predict observed X-ray emission.
- Lobes exhibit magnetic fields lower than equipartition estimates.

## Abstract

The 2Jy sample is a survey of radio galaxies with flux densities above 2 Jy at 2.7 GHz. As part of our ongoing work on the southern subset of 2Jy sources, in paper I of this series we analysed the X-ray cores of the complete 2Jy sample with redshifts 0.05<z<0.7. For this work we focus on the X-ray emission associated with the extended structures (jets, lobes, and environments) of the complete subset of 2Jy sources with 0.05<z<0.2, that we have observed with Chandra. We find that hotspots and jet knots are ubiquitous in FRII sources, which also inhabit systematically poorer environments than the FRI sources in our sample. Spectral fits of the hotspots with good X-ray statistics invariably show properties consistent with synchrotron emission, and we show that inverse-Compton mechanisms under-predict the X-ray emission we observe by 1-2 orders of magnitude. Inverse-Compton emission is detected from many of the lobes in our sample, and we find that the lobes of the FRII sources show magnetic fields lower by up to an order of magnitude than expected from equipartition extrapolations. This is consistent with previous results, which show that most FRII sources have electron energy densities higher than minimum energy requirements.