The precise location of a fast radio burst almost 4 billion light years away highlights the power of Australia's Square Kilometre Array Pathfinder radio telescope (ASKAP).
The ASKAP facility is the world’s fastest survey radio telescope, and may be one of the most enticing scientific investments ever made in Australia. Built with a budget of $160 million at the Murchison Radio-astronomy Observatory, it consists of an array of 36 ‘dish’ antennas that are spread across an area of 6 kilometres in diameter.
What sets ASKAP apart from traditional radio telescopes is that it allows astronomers to study large volumes of space at once, as each antenna provides a scan of the sky, which are then bundled together to produce a large singe image.
It makes space surveys incredibly fast, leading to discoveries that were previously not possible. This was recently highlighted in a research paper published in Science in which ASKAP was used to determine the precise location of a powerful one-off burst of cosmic radio waves.
The CSIRO-led work is a breakthrough that astronomers have hoped for since the first fast radio burst was discovered in 2007, according to lead author Dr Keith Bannister.
To date, 85 of theses events have been recorded, and most have been ‘one-offs’ lasting less than a millisecond. To precisely locate such ‘non-repeaters’ has presented an enormous challenge.
Dr Bannister's group at CSIRO developed a new technology to freeze and save ASKAP data less than a second after a burst arrives at the telescope. This now allowed the researchers to pinpoint the location of the one-off fast burst to the outskirts of a massive Milky Way-sized galaxy around 3.6 billion light-years away.
The international team, including from several Australian universities*, then imaged the galaxy with the European Southern Observatory's Very Large Telescope in Chile and measured its distance with the Keck telescope in Hawaii and the Gemini South telescope in Chile.
Previously, there has only been one successful attempt to locate a burst, a ‘repeater’ that came from a very tiny galaxy forming lots of stars.
By contrast, the now localised 'non-repeater' burst was from a massive galaxy forming relatively few stars, which suggests fast radio bursts can be produced in a variety of environments, or be generated by different mechanisms.
The discovery provides new opportunities for astronomers, as fast radio bursts are affected by the matter they encounter in space. With their precise location researchers may be able to reveal and measure the amount of matter in the intergalactic space through which the radio waves travel on their way to Earth. This is something astronomers have struggled with for decades.