On June 9, 2021, my colleagues and I announced the discovery of 535 rapid radio bursts, which we discovered using the Canadian Hydrogen Intensity Mapping Experiment Telescope (CHIME). These radio waves, discovered in 2018 and 2019, last only milliseconds, come far from the entire universe and are enormously powerful – a typical event releases as much energy in a millisecond as the sun does for many days.
Fast radio bursts are the subject of a young and growing field in astrophysics, where only about 150 were found before the release of our new catalog. Much work has been done to understand these events, but these cosmic radio eruptions remain as mysterious as when they were first discovered in 2007. In short: no one knows what exactly produces them.
Each newly captured event allows astrophysicists like me to learn more about these strange cosmic phenomena. And as this happens, some astronomers have begun using fast radio bursts as incredibly powerful tools to study the universe itself.
What is a fast radio burst?
The name “fast radio burst” is beautiful on the nose. These signals are bursts of radiation in radio frequencies that last for just milliseconds. A defining property of these bursts is their scattering: the bursts produce a spectrum of radio waves, and as the waves move through matter, they scatter – or scatter – with bursts at higher radio frequencies arriving at telescopes earlier than those at lower frequencies.
This spread allows researchers to learn about two important things. First, telescopes like CHIME can measure this spread to learn about the things that radio bursts pass through as they move toward Earth. For example, some of my colleagues were able to solve a long-standing mystery about the lack of matter scattered across the universe.
Second, by measuring scattering, astronomers can indirectly determine one of the most important pieces of information in all astronomy: how far things are apart. The larger the dispersion target, the more material the signal encountered. So presumably, passing through several things means that burst traveled further across the universe.
The dispersal measures for rapid radio eruptions are so large that astronomers know that the signals must come from outside the Milky Way galaxy, but these estimates may be inaccurate due to the uneven distribution of matter in the universe. We therefore needed a different way of finding distances to the sources of rapid radio outbursts to avoid assumptions about how the case is distributed and thus unlock a large amount of information and opportunities.
A striking solution to this problem came in 2017, when my colleagues were able to locate the exact location of the source of a recurring fast radio burst in the sky. By taking pictures of repeated eruptions in the sky, they found the specific galaxy from which the eruptions came. Then, using optical telescopes, they determined the distance to this galaxy – about 3 billion light-years away from Earth.
Repetition of rapid radio eruptions makes it much easier to locate host galaxies from their sources by giving scientists more chances to capture them. While astronomers are working to answer important questions about rapid radio eruptions – What are they? Are repeated bursts different from single bursts? Are they all caused by the same thing? – these lingering mysteries do not prevent us from using them in the meantime.
Using fast radio bursts to study the cosmos
The unique properties of fast radio explosions and their host galaxies – combined with recent technological advances such as the CHIME telescope – have given scientists hope that these phenomena can be used to answer some long-standing questions about the universe.
For example, some theorists have suggested that fast radio bursts can be used to study the three-dimensional structure of matter in the universe. Others have shown that the most distant bursts can be used to learn about poorly understood early moments in the evolution of the universe. But to answer these and other questions, astronomers need a large number of rapid radio eruptions and their dispersal measures, forces, and locations in the sky.
And this is where our new catalog from CHIME comes in. By releasing information on 535 new fast radio bursts – including 61 bursts from 18 repeat sources – our team doubles more than the total number of known events and pushes the field into an era of big data. With a large and growing number of measurements, all sorts of questions can finally be addressed.
Recently, student members of the CHIME Collaboration began releasing studies using this catalog. A study showed that the rapid radio failures detected by CHIME come from all directions – a fact that had previously been under debate. Another team examined the shapes and sizes of bursts in the catalog and confirmed that recurring events behave differently than single bursts, pointing to several causes of rapid radio bursts. And a third team for the first time confirmed that fast radio bursts are strongly associated with known galaxies. This means that astronomers can use events to map the structure of the universe.
An adventurous future lies ahead of us
CHIME and other telescopes detect faster radio bursts every day, but scientists are just scratching the surface of what can be learned about – and done with – these mysterious and powerful cosmic events.
My colleagues recently claimed that attributing thousands of events to their individual host galaxies is “the most pressing observation priority for [fast radio burst] science. “However, finding host galaxies is very challenging – only 14 galaxies hosting fast radio bursts have been found so far. But other telescopes, such as the Australian square kilometer Array Pathfinder, have successfully detected and located a small number of non-repeat bursts to their host galaxies Next-generation telescopes are designed to combine high-detection CHIME with high-resolution images of the Australian telescope.
The field of fast radio burst astronomy is still in its infancy and it is difficult to predict what discoveries will be made thereafter. But I expect the future of the field to be like these deep cosmic events: bright and fast.[[[[Understand new developments in science, health and technology every week. Subscribe to the conversation’s science newsletter.]
This article is republished from The Conversation, a nonprofit news site dedicated to sharing ideas from academic experts. It was written by: Emmanuel Fonseca, West Virginia University.
Emmanuel Fonseca does not work for, consult, own shares in or receive funding from any company or organization that will benefit from this article, and has not disclosed any relevant affiliations other than their academic appointment.