The dynamics of the giant radio galaxy 3C 457

TL;DR

This study combines radio and X-ray observations to analyze the structure, emission mechanisms, and physical conditions of the giant radio galaxy 3C 457, revealing insights into its lobes, core, and environment.

Contribution

It provides the first detailed multi-frequency radio and X-ray analysis of 3C 457, including measurements of magnetic fields and pressure balance, and clarifies the origin of X-ray emission.

Findings

X-ray emission from lobes is due to inverse-Compton scattering of CMB photons.

Lobes' magnetic field strength is close to equipartition.

Lobes are in pressure balance near hotspots and under-pressured towards the core.

Abstract

We present multi-frequency radio observations with the Giant Metrewave Radio Telescope and Very Large Array, and X-ray observations with the X-ray Multi-Mirror Mission ({\it XMM-Newton}) telescope of the giant radio source (GRS) 3C 457. We have detected the core, lobes and the environment of the GRS in X-ray. We examine the relationships between the radio and X-ray emission, determine the radio spectrum over a large frequency range and attribute the X-ray emission from the lobes to the inverse-Compton scattering of cosmic microwave background (CMB) photons. The magnetic field strength of the lobes is very close to the equipartition value. Both the lobes are in pressure balance near the hotspots and apparently under-pressured towards the core. The X-ray spectrum of the core of the GRS consists of an unabsorbed soft power-law component and a heavily absorbed hard power-law component. The soft unabsorbed component is likely to be related to the radio jets. There is no strong evidence of Fe K$\alpha$ emission line in our data.