A single burst of radio emission of unknown origin was detected outside our Galaxy about six years ago but no one was certain what it was or even if it was real, so astronomers have spent the last four years searching for more of these explosive, short-duration bursts.
The international research team, writing in the journal Science, ruled out terrestrial sources for the four fast radio bursts and say their brightness and distance suggest they come from cosmological distances when the Universe was just half its current age. The burst energetics indicate that they originate from an extreme astrophysical event involving relativistic objects such as neutron stars or black holes.
Study lead Dan Thornton, a PhD student at England's University of Manchester and Australia's Commonwealth Scientific and Industrial Research Organisation, said the findings pointed to some extreme events involving large amounts of mass or energy as the source of the radio bursts.
The paper describes four more bursts, removing any doubt that they are real. The radio bursts last for just a few milliseconds and the furthest one that we detected was 11 billion light years away."
Astonishingly, the findings -- taken from a tiny fraction of the sky -- also suggest that there should be one of these signals going off every 10 seconds. "The bursts last only a tenth of the blink of an eye," explained Max-Planck Institute Director and Manchester professor, Michael Kramer. "With current telescopes we need to be lucky to look at the right spot at the right time. But if we could view the sky with 'radio eyes' there would be flashes going off all over the sky every day."
The team, which included researchers from the UK, Germany, Italy, Australia and the US, used the CSIRO Parkes 64metre radio telescope in Australia to obtain their results.
Co-author Professor Matthew Bailes, from the Swinburne University of Technology in Melbourne, thinks the origin of these explosive bursts may be from magnetic neutron stars, known as 'magnetars'. He said: "Magnetars can give off more energy in a millisecond than our Sun does in 300,000 years and are a leading candidate for the burst."
Journal Reference: D. Thornton, B. Stappers, M. Bailes, B. Barsdell, S. Bates, N. D. R. Bhat, M. Burgay, S. Burke-Spolaor, D. J. Champion, P. Coster, N. D'Amico, A. Jameson, S. Johnston, M. Keith, M. Kramer, L. Levin, S. Milia, C. Ng, A. Possenti, W. van Straten. A Population of Fast Radio Bursts at Cosmological Distances. Science, 2013; 341 (6141): 53 DOI: 10.1126/science.1236789
The Daily Galaxy via University of Manchester.