An article accepted for publication in the journal “Publications of the Astronomical Society of Australia” reports the first results of the EMU (Evolutionary Map of the Universe) survey, which allowed to discover several objects and phenomena. One of those phenomena is made by strange clouds of electrons surrounding two galaxies about a billion light-years from Earth. This survey was conducted using the ASKAP radio telescope and led to the cataloging of about 220,000 sources including the electron clouds that were compared to dancing ghosts due to their curious shape.

The ASKAP (Australian Square Kilometer Array Pathfinder) radio telescope is one of the precursors of the next generation radio telescope SKA and the technologies developed in its construction are already providing interesting results. In recent years, it was also used to conduct the EMU survey, which serves various purposes and has now led to the publication of the first results.

Professor Ray Norris, an astronomer at Western Sydney University and CSIRO (Commonwealth Scientific and Industrial Research Organization), lead researcher on the EMU survey, stated that he and his colleagues are getting used to surprises as they scan the sky. What were nicknamed dancing ghosts are one of the surprises.

Initially, the astronomers had no idea what these electron clouds that surround two galaxies about a billion light-years from Earth were. It took weeks of work to figure out that they were looking at two galaxies that host at their center two supermassive black holes that emit jets of electrons that get tangled in grotesque shapes by an intergalactic wind.

The image (Courtesy Jayanne English/EMU/Dark Energy Survey) shows the jets of electrons nicknamed dancing ghosts with the two galaxies likely emitting them at the top, between the two clouds, and at the bottom, at the base of the left jet.

The conclusion still poses some questions regarding the electron clouds. Where does the intergalactic wind that generates the strange shapes observed come from? Why is it so tangled that it generates those strange shapes? What’s causing the radio emission streams? Basically, the astronomers understood the nature of the electron clouds but according to Professor Ray Norris, it will still take many observations and modeling before they can get all the answers.

This and other discoveries that astronomers are making with the ASKAP radio telescope can give an idea of ​​what is in the cosmos that we are only now beginning to see. In a few years, with the activation of the SKA radio telescope, this type of discovery could expand considerably.