Aug 5, 2021 10:06 PM
https://theconversation.com/dancing-ghos...ers-165239
INTRO: Scanning through data fresh off the telescope, we saw two ghosts dancing deep in the cosmos. We had never seen anything like it before, and we had no idea what they were.
Several weeks later, we had figured out we 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? We still don’t understand the details of what is going on here, and it will probably take many more observations and modelling before we do.
We are getting used to surprises as we 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. When you boldly go where no telescope has gone before, you are likely to make new discoveries.
The Dancing Ghosts were just one of several surprises found in our first deep search of the sky using ASKAP. This search, called the EMU Pilot Survey, is described in detail in a paper soon to appear in the Publications of the Astronomical Society of Australia.
The first big surprise from the EMU Pilot Survey was the discovery of mysterious Odd Radio Circles (ORCs), which seem to be giant rings of radio emission, nearly a million light years across, surrounding distant galaxies. These had never been seen before, because they are so rare and faint. We still don’t know what they are, but we are working furiously to find out... (MORE)
INTRO: Scanning through data fresh off the telescope, we saw two ghosts dancing deep in the cosmos. We had never seen anything like it before, and we had no idea what they were.
Several weeks later, we had figured out we 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? We still don’t understand the details of what is going on here, and it will probably take many more observations and modelling before we do.
We are getting used to surprises as we 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. When you boldly go where no telescope has gone before, you are likely to make new discoveries.
The Dancing Ghosts were just one of several surprises found in our first deep search of the sky using ASKAP. This search, called the EMU Pilot Survey, is described in detail in a paper soon to appear in the Publications of the Astronomical Society of Australia.
The first big surprise from the EMU Pilot Survey was the discovery of mysterious Odd Radio Circles (ORCs), which seem to be giant rings of radio emission, nearly a million light years across, surrounding distant galaxies. These had never been seen before, because they are so rare and faint. We still don’t know what they are, but we are working furiously to find out... (MORE)