Astronomers are closer to understanding the source of one of the great mysteries of space – ‘fast radio bursts’ detected by telescopes on Earth.
Fast radio bursts are bright pulses of radio emission which are just milliseconds in duration, but incredibly energetic, and thought to originate from distant galaxies.
Theories of what causes the bursts range from neutron stars blasted by a nearby supermassive black hole to signatures of technology developed by advanced civilisations.
Now scientists have analysed the source of some bursts and ruled out others, including the supermassive black holes at the heart of galaxies like our own Milky Way.
They also believe that the signals come from galaxies not dissimilar to ours.
Shivani Bhandari, of the Commonwealth Scientific and Industrial Research Organisation (CSIRO), told Science Alert: "Just like doing video calls with colleagues shows you their homes and gives you a bit of an insight into their lives, looking into the host galaxies of fast radio bursts gives us insights to their origins."
"These precisely localised fast radio bursts came from the outskirts of their home galaxies, removing the possibility that they have anything to do with supermassive black holes."
The galaxies pinpointed by Bhandari and her team are similar to the Milky Way in that they are relatively large and are forming stars fairly slowly.
The researchers say that other possible sources could include the mergers of small, compact objects such as white dwarfs or neutron stars.
The researchers wrote: “The Australian SKA Pathfinder (ASKAP) telescope has started to localise fast radio bursts (FRBs) to arcsecond accuracy from the detection of a single pulse, allowing their host galaxies to be reliably identified.”
“The FRBs localised by ASKAP typically lie in the outskirts of their host galaxies, which appears to rule out FRB progenitor models that invoke active galactic nuclei.”
Scientists say that whatever the source, it must involve incredible energy, equivalent to the amount released by the sun in 80 years.
They have been difficult to detect as astronomers don’t know when and where to look for them.
The fast radio bursts were monitored using a detector within using ASKAP (Australian Square Kilometre Array Pathfinder), which is located at the Murchison Radio-astronomy Observatory in outback Western Australia.
ASKAP is a precursor for the future Square Kilometre Array (SKA) telescope.
The SKA could observe large numbers of fast radio bursts, giving astronomers greater capability to study the previously invisible structure in the universe.