1.4-GHz observations of extended giant radio galaxies

TL;DR

This study uses combined single-dish and interferometric 1.4-GHz observations to produce high-quality images of 15 extended giant radio galaxies, revealing detailed structures and enabling physical parameter estimation.

Contribution

It introduces a method of combining Effelsberg single-dish data with NVSS interferometric maps to accurately image and analyze very extended radio galaxies.

Findings

Revealed extended low surface-brightness cocoons in many sources.

Produced reliable spectral index patterns across giant radio galaxy structures.

Enabled estimation of physical parameters of the radio sources.

Abstract

This paper presents 1.4-GHz radio continuum observations of 15 very extended radio galaxies. These sources are so large that most interferometers lose partly their structure and total flux density. Therefore, single-dish detections are required to fill in the central (u,v) gap of interferometric data and obtain reliable spectral index patterns across the structures, and thus also an integrated radio continuum spectrum. We have obtained such 1.4-GHz maps with the 100-m Effelsberg telescope and combined them with the corresponding maps available from the NVSS. The aggregated data allow us to produce high-quality images, which can be used to obtain physical parameters of the mapped sources. The combined images reveal in many cases extended low surface-brightness cocoons.