EMU and the DRAGNs I: A Catalogue of DRAGNs

TL;DR

This paper presents a new catalogue of 3557 DRAGNs observed with ASKAP, revealing more complex structures and rare types, which will aid in understanding their physical processes and improve detection algorithms.

Contribution

The paper provides the first large, detailed catalogue of DRAGNs from EMU, including morphological classifications and parameters, enabling advanced analysis and machine learning applications.

Findings

Discovery of more diffuse and complex structures compared to earlier catalogues.

Identification of rare radio source types such as Hybrid Morphology and one-sided jets.

Detection of a wide variety of bent-tail and head-tail sources.

Abstract

We present a catalogue of 3557 Double Radio sources associated with Active Galactic Nuclei (DRAGNs) from the First Pilot Survey of the Evolutionary Map of the Universe (EMU), observed at 944 MHz with the Australian Square Kilometre Array Pathfinder (ASKAP) telescope, covering 270 deg^2. We have extracted and identified each source by eye, tagged it with a morphological type and measured its parameters. The resulting catalogue will be used in subsequent papers to explore the properties of these sources, to train machine-learning algorithms for the detection of these sources in larger fields, and to compare with the results of Citizen Science projects, with the ultimate goal of understanding the physical processes that drive DRAGNs. Compared with earlier, lower sensitivity, catalogues, we find more diffuse structure and a plethora of more complex structures, ranging from wings of radio emission on the side of the jets, to types of object which have not been seen in earlier observations. As well as the well-known FR1 and FR2 sources, we find significant numbers of rare types of radio source such as Hybrid Morphology Radio Sources and one-sided jets, as well as a wide range of bent-tail and head-tail sources.