Fast bursts of radio waves were first detected in 2007, and since then they have been recorded 18 times, but only one of these signals is repeated several times.
After the first signal detected by the Parker telescope in Australia, scientists analyzed a repeat signal to discover its origin.
The exposures are extremely strong even though they last very short, between 30 microseconds and 9 milliseconds, and release a fairly large amount of energy, equivalent to what our sun releases in a day.
As their source, a dwarf galaxy three billion light-years away was detected last year, and scientists have now discovered some of the unusual conditions in which these explosions are created.
“The bursts are highly polarized and come from an environment that contains a very strong magnetic field. We also detected signals with a higher frequency so far. When radio waves pass through the magnetic field, they come into rotation, a phenomenon known as the Faraday effect or rotation. The rotation is stronger than the magnetic field, but these are the strongest explosions ever measured. This indicates that the signals come from the vicinity of a massive black hole or from powerful nebulae, interstellar nebulae or clouds filled with hydrogen, helium and other ionizing gases in which stars are born,” says the study published in the journal Nature.
But this opens new questions, because if it is a source close to the black hole, says Jason Hessels from the University of Amsterdam. According to him, it is unclear how such a black hole ever existed inside a dwarf galaxy.
“As for the direct source, we think it’s a pulsar, a neutron star that emits electromagnetic radiation,” Hessels said.
“We try to follow how the explosions change over time, to find out which hypothesis is correct – whether it is a neutron star near the black hole, or a neutron star inside the nebula,” he adds.