Radio Jellyfish

 Brandon Specktor LIVE SCIENCE...

Galaxy clusters are the largest structures in the universe bound together by gravity. They can contain thousands of galaxies, enormous oceans of hot gas, invisible islands of dark matter and — sometimes — the glowing ghost of a jellyfish or two.

In the galaxy cluster Abell 2877, located in the southern sky about 300 million light-years from Earth, astronomers have discovered one such jellyfish. Visible only in a narrow band of radio light, the cosmic jelly is more than 1 million light-years wide and includes a large lobe of supercharged plasma, dripping with tentacles of hot gas.

The structure's jelly-like appearance is both "ghostly" and "uncanny," according to the authors of a new paper published March 17 in the Astrophysical Journal. However, even more astonishing than the space jelly's shape is how quickly the structure vanishes from view, the authors said.

"This radio jellyfish holds a world record of sorts," lead study author Torrance Hodgson, of the International Centre for Radio Astronomy Research (ICRAR) in Perth, Australia, said in a statement. "Whilst it's bright at regular FM radio frequencies, at 200 megahertz the emission all but disappears. No other extragalactic emission like this has been observed to disappear anywhere near so rapidly."  READ MORE