'Radio burst' came from a distant galaxy, Swedish researchers conclude

Sarah Burke-Spolaor, assistant professor in the physics and astronomy department of the Eberly College of Arts and Sciences, and Maura McLaughlin, Eberly Distinguished Professor of Physics and Astronomy, are leading members of a team that has pinpointed the location in the sky of one of these bursts for the first time, allowing scientists to determine the distance and home galaxy of one of these pulses of radio waves. This turned out to be roughly 3 billion light-years away in a small dwarf galaxy which holds just a hundredth or so of the Milky Way's mass.

Fast radio bursts, which are highly energetic but last just a few thousandths of a second, have puzzled astrophysicists since their discovery a decade ago.

Fast radio bursts appear to come from beyond the Milky Way and crop up seemingly at random across the sky. "Identifying more burst hosts will allow us to uniquely explore the host galaxies themselves, the space between galaxies, and other material that fast radio bursts travel through on their path to our telescopes".

Although an explanation of an extraterrestrial origin would be a more exciting prospect, it turns out in this case the FRB in question - of which we have now found 18 since 2007 - comes from a dwarf galaxy three billion light-years away from Earth. "Later on in life, it looks like the magnetars we see in our galaxy, which have extremely strong magnetic fields but rotate more like ordinary pulsars".

"We think that the bursts and the continuous source are likely to be either the same object or that they are somehow physically associated with each other", said Benito Marcote, of the Joint Institute for VLBI ERIC, Dwingeloo, Netherlands.

"This is the only known fast radio burst from which repeated bursts have been detected, and it is not yet clear whether this object is representative of the broader population. This dwarf galaxy has fewer stars but is forming stars at a high rate, which may suggest that FRBs are linked to young neutron stars", Tendulkar said in an official statement from the McGill University in Montreal released this Wednesday. Spinning neutron stars that radiate beams of light are known as pulsars, and they appear to flicker on and off because of a lighthouse effect: The beam sweeps across Earth as the pulsar spins, moving in and out of view with a regular frequency. These solid structures are formed from the explosion of large stars, and as the gravity pressures the body of the object, both protons and electrons combine to make neutrons, hence the name "neutron star".

FRBs flash only for an micro-instant, and can emit as much energy in a millisecond as the Sun does in 10,000 years.

Since then 17 more FRBs have been identified but only one, spotted in 2012 by astronomers at the Arecibo Observatory in Puerto Rico, has recurred repeatedly. Since then, more than a dozen have been detected in telescope data. Also, the astronomers can't alert other telescopes for them to see the mentioned event.

Still, the scientists cautioned, this is still just a single data source. Astronomers are now studying FRB 121102 with radio, optical, X-ray and gamma-ray telescopes to search for clues.

Shami Chatterjee, Senior Research Associate at Cornell and one of the astronomers that helped with the discovery of the origin of the mysterious phenomenon, explained that the FRB 121102 was capable of repetition as a cataclysmic event didn't produce it. But astronomers are still uncertain about exactly what is creating these bursts.

As well as pinpointing the location, astronomers also observed weaker bursts nearby.

As for other FRBs, if they're similar to this one, we'll need precise measurements with powerful arrays like the Very Large Array to nail down their location. In that time, they added up 83 hours of observations. They were able to catch FRB 121102 a total of nine times. This definition was made after the analysis made by the astronomers from Hawaii's research center where there is the 8-feet Gemini North Telescope.

"When we reported previous 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".



Other news