Norris et al. 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 ASKAP covering 270 square degrees. The catalogue will be used 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, the team 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.

In the majority of DRAGNs, the two jets/lobes and the host galaxy are roughly in a straight line. In a significant minority, the two jets are bent, presumably by their interaction with the intergalactic medium.  In this paper the team tag any DRAGN where the jet is bent by more than 10 degrees (i.e., so the angle between the jets must be less than 170 degrees) as a “Bent-tail” (BT) source.  Examples of bent-tail sources are given above. The red crosses denote the tentative position of the host galaxies.