At 340 million light years from Earth, in a cluster of galaxies called Abell 2877, a curious specimen produces radio waves at the lowest frequencies. Covering an area of 1.2 million light years, it is an immense space “jellyfish” – and scientists are eyeing this cosmic “creature” with the expectation that it will reveal truly ancient Universe mysteries.
Such signals have gone unnoticed by equipment in the past 40 years, explains Melanie Johnston-Hollitt, an astrophysicist at Curtin University, Australia, and suggest that intergalactic gases in the region accelerated electrons expelled from monumental black holes a long time ago. “It was an invisible source [of data] for most radio telescopes,” she says.
From the moment the analyzed frequency rises, complements the researcher, the visible records disappear and present the biggest falls detected so far. In short, the waves are more than a meter long and correspond to photons, particles of light; surprisingly, they are 30 times brighter at 87.5 MHz – similar to that of an FM station – than at 185.5 MHz.
“This is spectacular,” said Reinout van Weeren, an astronomer at the University of Leiden in the Netherlands, regarding the discovery of the phenomenon, led by Torrance Hodgson, graduating who was dedicated to his research at the Murchison Widefield Array complex. “It is a very good result, because it is really extreme”, she defends, even though she did not participate in the study.
Speculations in full swing
One of the most interesting characteristics about the “jellyfish” galaxies is that, although they also inhabit clusters, they are individual and pass through the hot gas of their neighborhoods, which tears up their materials and creates what would be the tentacles of their animal equivalent.
Still, the USS Jellyfish, the given name of the personality of the time, hides a secret: it seems to have been formed precisely by such interaction, not before.
Haunted by the finding, Hodgson and his colleagues then noticed that two galaxies in the Abell 2877 cluster coincide with the brightest patches of radio waves on the bug’s head – and speculate on the presence of supermassive black holes in their centers, which, as simulations point out, they would have been accumulating elements for about 2 billion years.
In the process, hot gas disks formed around each of them, sending huge jets of material into the surrounding galaxy cluster. The unrest, of course, had its consequences.
Almost at the speed of light, the material supposedly had electrons that revolved around magnetic fields and thus emitted radio waves. By losing energy over time, however, the more powerful particles would have weakened, but the gas waves scattered around the cluster have accelerated the elements around the two galaxies.
“It is a very smooth process,” says Johnston-Hollitt. “Electrons do not receive as much energy, which means that they do not light up at high frequencies”, concludes the researcher, who, with the theory, published in Astrophysical Journal, brings to light an answer to the bizarre behavior of something that, it seems, we know very little about.