SCANNING through data fresh off the telescope, Australian scientists saw two ghosts dancing deep in the cosmos. Scientists said that they had never seen anything like it before, and had no idea what they were. Several weeks later, they had figured out that they were seeing two radio galaxies, about a billion light years away. In the centre of each one is a supermassive black hole, squirting out jets of electrons that are bent into grotesque shapes by an intergalactic wind. But where does the intergalactic wind come from?

 

Why is it so tangled? And what is causing the streams of radio emission? Scientists still don’t understand the details of what is going on here, and it will probably take many more observations and modelling. They said they are getting used to surprises as they scan the skies in the Evolutionary Map of the Universe (EMU) project, using CSIRO’s new Australian Square Kilometre Array Pathfinder (ASKAP), a radio telescope that probes deeper into the Universe than any other.