The spectral structure and energetics of powerful radio sources

TL;DR

This paper investigates the detailed spectral structure of powerful FR-II radio galaxies using advanced broadband observations, revealing small-scale features and implications for their energy content and overall population energetics.

Contribution

It introduces high-resolution broadband spectral analysis of FR-II radio galaxies, addressing previous analysis limitations and providing new insights into their energetics.

Findings

Detection of small-scale spectral structures in radio galaxies

Potential increase in total energy content of radio lobes

Implications for the energetics of the radio galaxy population

Abstract

Determining the energy spectrum of an electron population can give key insights into the underlying physics of a radio source; however, the lack of high resolution, broad-bandwidth observations has left many ambiguities in our understanding of radio galaxies. The improved capabilities of telescopes such as the JVLA and LOFAR mean that within the bandwidth of any given observation, a detailed spectral shape can now be produced. We present recent investigations of powerful FR-II radio galaxies at GHz and MHz frequencies and show for the first time their small-scale spectral structure. We highlight problems in traditional methods of analysis and demonstrate how these issues can now be addressed. We present the latest results from low frequency studies which suggest a potential increase in the total energy content of radio galaxy lobes with possible implications for the energetics of the population as a whole.