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Record-breaking fast radio burst is most distant ever detected
from Contact 14
BY MACQUARIE UNIVERSITY AND THE SKAO
Scientists have discovered an eight-billion-year-old fast radio burst (FRB) – the most ancient and distant located to date.
In a paper published in Science, a global team led by Macquarie University’s Dr Stuart Ryder and Swinburne University of Technology’s A/Prof. Ryan Shannon, report on their discovery, which smashes the team’s previous record by 50%.
FRBs are a key science interest for the SKA Observatory, and authors of the paper include SKAO Postdoctoral Fellow Dr Hao Qiu and several members of the SKAO’s Science Working Groups.
The discovery was made using CSIRO’s ASKAP radio telescope in Western Australia and ESO’s optical Very Large Telescope (VLT) in Chile.
The source of the burst was shown to be a group of two or three galaxies that are merging, supporting current theories on the cause of fast radio bursts. The team also showed that eight billion years is about as far back as we can expect to see and pinpoint fast radio bursts with current telescopes.
ASKAP detected the burst, named FRB 20220610A, on 10 June 2022. It was created in a cosmic event that released, in milliseconds, the equivalent of our Sun’s total emission over 30 years. ASKAP was used to determine precisely where the burst originated, and the VLT enabled the team to search for the host galaxy.
The study is a prime example of the new era of multiwavelength astronomy, where facilities observing different types of light are used together to reveal more than they could do individually. (Read more on page 16)
“Radio observations give us key information that allows us to measure the turbulent magnetised interstellar and intergalactic medium between us and the host galaxy. Optical observations play a complementary role by enabling us to identify the distance of the host galaxy and learn more about the host and foreground environment along the line of sight,” Dr Qiu said.
“Comparing the radio and optical data allows us to test cosmological models of the intergalactic medium and better understand what could create these bursts.”
The paper confirms that FRBs are common events in the cosmos and can be used to measure the “missing” matter between galaxies, to better understand the structure of the Universe.
“If we count up the amount of normal matter in the Universe – the atoms that we are all made of – we find that more than half of what should be there today is missing. We think that the missing matter is hiding in the space between galaxies, but it may just be so hot and diffuse that it’s impossible to see using normal techniques,” Dr Shannon said.
“Fast radio bursts sense this ionised material. Even in space that is nearly perfectly empty they can ‘see’ all the electrons, and that allows us to measure how much stuff is between the galaxies.”
ASKAP is currently the best radio telescope to detect and locate FRBs, until the SKA telescopes (currently under construction in Australia and South Africa) come online.
