A cosmic radio burst — a split-second burst of mysterious radio - TopicsExpress



          

A cosmic radio burst — a split-second burst of mysterious radio waves from light years away — has been seen for the first time in real time by an Australian scientist. Emily Petroff, an astrophysicist who is undertaking her PhD at Swinburne University in Melbourne, spotted the fast radio burst (FRB) using the Parkes Telescope in New South Wales on May 14. An international team of 12 watched the aftermath from various locations. See also: Atmospheres may be the key to day and night for alien planets It is the first time the cosmic action has been spotted in real time by a human, and with so little known about the source of the activity, it is a dramatic breakthrough. Astronomers across the globe have been vying to explain the phenomenon — which produces as much energy as the sun in a single day Astronomers across the globe have been vying to explain the phenomenon — which produces as much energy as the sun in a single day. These bursts were generally discovered weeks, months or even more than a decade after they happened, Petroff said in a statement. We are the first to catch one in real time. Whatever causes the burst is massive, cataclysmic and may be 5.5 billion light years away from Earth. It is possible the collapse of a neutron star or a flare from a neutron star with an intense magnetic field could be behind the mysterious radio bursts, though nothing is definite. We know that we see them with radio telescopes, that they appear to come from distant galaxies, and that they only last for a very short amount of time — about a millisecond, Petroff told Mashable. We still dont know the exact distances to these bursts or what is producing them. Since 2007, when the bursts were first discovered, eight have been witnessed — but until now, always after the fact, never as they occurred. This new discovery helped the team rule out some theoretical models and proves real-time detections are a possibility. This is a major breakthrough, Duncan Lorimer, an astronomer at West Virginia University in the U.S., told New Scientist. Petroff said by observing the burst in real time, scientists hope to answer questions about its origins. If the source can be found, the density of the burst can be measured to see how it has changed over time and the distance the source is from Earth. This discovery will also allow the research team to react quickly to a FRB next time, securing more information about these secretive beasts. We can rule out some ideas because no counterparts were seen in the optical, infrared, ultraviolet or X-ray, said Dr Simon Johnston, head of astrophysics at CSIRO, Australias national science agency. However, the neat idea that we are seeing a neutron star imploding into a black hole remains a possibility, he said in a statement. The teams remarkable discovery, near the constellation Aquarius, did reveal an unknown element of the bursts — the waves seem circularly polarised, rather than linearly polarised; therefore, they vibrate in two planes instead of one. Our real-time detection system allows us to capture the polarisation information, which wasnt possible before, Petroff said. We are also able to alert telescopes observing at other wavelengths that can point at the same spot to look for an afterglow. This study is also the first time a burst has been viewed by telescopes at multiple locations — in Australia, California, the Canary Islands, Chile, Germany, Hawaii, and India as well as from space — to watch for the aftereffect. With this burst no afterglow was spotted, which rules out a nearby supernovae and long gamma ray bursts. Weve set the trap. Now we just have to wait for another burst to fall into it, Petroff added in a statement.
Posted on: Fri, 23 Jan 2015 12:22:27 +0000

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