A MYSTERIOUS type of radio wave from deep space called fast radio bursts (FRBs) was discovered 10 years ago. In 2007, the Parks radio-telescope (Australia) observed a single intense radio pulse.
According to the standard analysis techniques, this pulse comes from a source at a distance of 1.5 billion light-years, well beyond the local group of galaxies. FRBs flash only for a micro-instant, and can emit as much energy in a millisecond as the Sun does in 10,000 years.
What causes split-second blasts of radio waves that appear in the sky from billions of light years away is one of the most perplexing mysteries in astronomy and remains the subject of intense debate.
Several theories have been proposed. Some scientists assert that they could result from cataclysmic events like the merging of two white dwarfs, or of two neutron stars, or from the implosion of a massive and unstable neutron star into a black hole. Others say that they could be giant flares from stars in our galaxy. Other astronomers propose FRB could come from bodies orbiting a pulsar.
There have been 18 fast radio bursts registered since 2007, but only one – observed in 2012 at the Arecibo Observatory in Puerto Rico, and dubbed FRB121101 – recurred numerous times. A team of scientists from Cornell University prepared in case it happened again. The idea paid off. In 83 hours of observation over six months, the Karl G. Jansky multi antenna array of radio telescopes – more powerful than any to have spotted a FRB in the past – detected nine distinct pulses. The team reported in the Journal Nature that they traced the particular burst from a dwarf galaxy more than three billion light years from Earth. This new discovery will not settle the issue, but it definitively eliminates several theories that have been in the running, scientists said.