The radio signals are called Fast Radio Bursts. These take the form of short-lived, although powerful, pulses of radio waves and they take the form of bright, unresolved, broadband, millisecond flashes found in parts of the sky outside the Milky Way. The point of origin is deep within the cosmos. Due to the short duration, as well as the intensity, has resulted in the source of the radio waves proving impossible to pinpoint.
The first Fast Radio Burst was detected by the Parkes Radio Telescope in Australia back in 2007. The discovery came about by accident when scientists were researching pulsars (a type of neutron star). To date some 18 bursts have been recorded. The frequencies of each burst are delayed by different amounts of time depending on the wavelength.
This has now changed with one group of astronomers identifying the origin of the radio bursts and they relate to a different galaxy to our own. Previous theories included the more grounded (black holes) to the more wishful (extra-terrestrial life). The confirmed origin is a dwarf galaxy more than three billion light-years from Earth.
The connection to another galaxy has come from a team led by Dr. Shami Chatterjee, who is based at Cornell University, New York. The discovery has come about due to data gathered by the Very Large Array telescope. This comprises 27 linked 25-meter radio telescopes in a Y-shaped array. Astronomers have used the array to probe the Universe’s cosmological parameters.
The attention of the astronomers was sparked when one of the radio bursts began repeating unexpectedly (a burst coded FRB121102). Speaking with the BBC, Dr Chatterjee adds: “When we reported last year that one of these objects was repeating, that – in one go – knocked out about half of those models, because for this one source, at least, we knew it couldn’t be explosive. It had to be something where the engine that produced this survived for the next flash.”
The research will shortly be published in the journal Nature. Interested readers will note that Digital Journal discussed such radio bursts last month, describing how a different science group had attributed radio bursts to pulsars. For two contradictory research articles to emerge within the space of a few weeks shows how the mystery of these intergalactic signals continues and a scientific consensus has yet to be reached.
