A long time ago, a mysterious object sent a seriously shiny burst of radio waves into space. They travelled across the universe, past galaxies and clouds of gas and who knows what else. The radio source was first detected on the Arecibo radio telescope when astronomers happened to be watching. A team of astronomers announced on Wednesday (04.01.17) at the 229th meeting of the American Astronomical Society that, for the first time, they’d pinpointed the mysterious origin of an intergalactic fast radio burst on the cosmic map.
“Nine pulses captured with two telescopes — now we have enormous resolution,” Cornell astronomer Shami Chatterjee said. “We’ve pinpointed a speck, to a 10th of an arcsecond [a unit of angular measurement] … where the burst is coming from.”
Courtesy:- (Danielle Futselaar)
In November 2, 2012, in an event that placed it in a class of so-called fast radio bursts, known as FRB 121102, discovered with the 305-meter radio telescope in Arecibo, Puerto Rico: ultrabrief, ultrabright bursts of radio emissions with mysterious origins. They’d never seen anything like it before, and didn’t know where it came from or what could cause it. The flashes and the persistent source must be within 100 light-years of each other, and scientists think they are likely to be either the same object or physically associated with one another.
“This really is the first ironclad association of a fast radio burst with another astronomical source, so it’s a pretty huge result,” said Duncan Lorimer, an astronomer at West Virginia University who reported the first detection of a fast radio burst (FRB) in 2007.
All FRBs were found using single-dish radio telescopes that are unable to narrow down the sources’ locations with enough precision to further characterise the flashes.
They kept hunting that same spot in the sky. In 2015, they found 16 another additional flashes then, the VLA (a multi-antenna radio telescope called the Karl G Jansky Very Large Array) in New Mexico detected nine more bursts in 23 August and 18 September 2016 (In 83 hours of observing time over six months). And this week, using the optical 8.1-meter Gemini North telescope on Mauna Kea in Hawaii, astronomers have identified the source of mysterious ultrabright flashes of cosmic radio emissions known as fast radio bursts (FRBs): a dim dwarf galaxy three billion light-years away from earth.
“We now know that this particular burst comes from a dwarf galaxy more than three billion light-years from Earth,” said Cornell astronomer Shami Chatterjee, the lead author of the new Nature paper. That’s a staggering distance from Earth, underlining just how energetic these flashes are.
That radio burst news made headlines last year. But now, those reiterations have supported astronomers finally tie the fast radio burst to its home galaxy which is also detailed in articles in Nature and the Astrophysical Journal Letters, where found a new origin of persistent, weaker radio emissions nearby; probably the two are related but it’s not sure.
The first FRB have been a hot subject since 2007, in archived data from the 64-meter radio telescope in Parkes, Australia. Accidentally, the team led by radio astronomer Duncan Lorimer of West Virginia University in Morgantown found the first FRB by old observations of the Parkes Radio Telescope. Since then, astronomers were searching for new examples of magnetised neutron stars called pulsars and gamma-ray bursts, astronomers have stumbled upon 18 more FRBs – also referred to as “flashes” or “sizzles.”
FRBs are probably not directly related to long gamma ray bursts (another type of explosive event that preferentially occurs in dwarf galaxies), because there are just too many FRBs and too few gamma ray bursts. Alternative explanations, maybe it’s a magnetic kind of neutron star orbiting a black hole (matter falling into black holes), cannot yet be ruled out.
Many astronomers had thought that FRBs come from one-off, cataclysmic events—for instance the formation of a black hole by the merger of two neutron stars, the compact remains of supernova explosions or a collision of two stars. But the repeating nature of FRB 121102 reveals that whatever is producing the bursts cannot be destroyed in the process.
“This detection has really broken open the gates of a new realm of science and discovery,” said Sarah Burke-Spolaor, an astronomer at West Virginia University and co-author of the new study.
