Astronomers Expand the Knowledge of Repeating Fast Radio Bursts

An illustration presents the detection of fast radio bursts by the CHIME telescope throughout the year. Credit: CHIME/FRB Collaboration, with artistic additions by Luka Vlajić

According to a study published in The Astrophysical Journal, researchers from the MIT Kavli Institute and other institutions have effectively doubled the number of known repeating Fast Radio Burst (FRB) sources to 50. By utilizing advanced statistical tools and the CHIME telescope, the scientists propose that all FRBs have the potential to repeat, each with distinct burst durations and frequency ranges, indicating diverse origins. This research significantly contributes to our comprehension of explosive stellar deaths and their aftermaths.

Fast radio bursts (FRBs) are recurrent bursts of radio waves originating from sources outside the Milky Way, remaining enigmatic to astronomers. While it is known that FRBs likely arise from the remnants of dying stars, the occurrence of multiple bursts has raised questions about their nature and origin.

A collaborative team of astronomers, including members from the MIT Kavli Institute for Astrophysics and Space Research and the MIT Department of Physics, has made strides in unraveling the mysteries surrounding FRBs. Their recent publication in The Astrophysical Journal, freely accessible to the public, unveils the discovery of 25 new repeating FRB sources, doubling the previously known count to 50. Additionally, the team observed that many repeating FRBs exhibit inactivity, producing fewer than one burst per week of observation time.

The Canadian-led Canadian Hydrogen Intensity Mapping Experiment (CHIME) has played a crucial role in detecting thousands of FRBs while surveying the entire northern sky. Thus, astronomers from the CHIME/FRB Collaboration developed a new suite of statistical tools to sift through vast amounts of data and identify all detected repeating sources to date. This breakthrough allowed astronomers to study the same source using different telescopes and examine the diversity of emissions. Ziggy Pleunis, a Dunlap Postdoctoral Fellow at the Dunlap Institute for Astronomy and Astrophysics and the corresponding author of the study, elaborates, “We can now accurately calculate the probability that two or more bursts coming from similar locations are not just a coincidence.”

The researchers also concluded that all FRBs have the potential to repeat. They observed distinguishing characteristics between radio waves that burst only once and those that burst multiple times, including variations in burst duration and emitted frequency range, solidifying the notion of distinct origins for these radio bursts.

Daniele Michilli, a postdoctoral researcher at MIT, and Kaitlyn Shin, a Ph.D. student, both members of MIT Assistant Professor Kiyoshi Masui’s Synoptic Radio Lab, meticulously analyzed signals from the CHIME telescope’s 1,024 antennae. Michilli explains that their work “enabled us to unequivocally identify some of the sources as repeaters and provide other observatories with accurate coordinates for follow-up studies.”

“With a much larger sample of repeating FRBs, we are better equipped to understand why some FRBs are repeaters while others appear non-repeating, and how this knowledge contributes to a better understanding of their origins,” adds Shin.

Pleunis further emphasizes, “FRBs are most likely produced by the remnants of explosive stellar deaths. By examining repeating FRB sources in detail, we can investigate the environments where these explosions occur and gain a better understanding of the final stages of a star’s life. Additionally, we can learn more about the materials expelled before and during the star’s demise, which are subsequently reintegrated into the galaxies housing the FRBs.”

For more information on this research, please refer to the article “Doubling the Number of Repeating Fast Radio Burst Sources.”

Reference: “CHIME/FRB Discovery of 25 Repeating Fast Radio Burst Sources” by Bridget C. Andersen, Kevin Bandura, Mohit Bhardwaj, P. J. Boyle, Charanjot Brar, Tomas Cassanelli, S. Chatterjee, Pragya Chawla, Amanda M. Cook, Alice P. Curtin, Matt Dobbs, Fengqiu Adam Dong, Jakob T. Faber, Mateus Fandino, Emmanuel Fonseca, B. M. Gaensler, Utkarsh Giri, Antonio Herrera-Martin, Alex S. Hill, Adaeze Ibik, Alexander Josephy, Jane F. Kaczmarek, Zarif Kader, Victoria Kaspi, T. L. Landecker, Adam E. Lanman, Mattias Lazda, Calvin Leung, Hsiu-Hsien Lin, Kiyoshi W. Masui, Ryan Mckinven, Juan Mena-Parra, Bradley W. Meyers, D. Michilli, Cherry Ng, Ayush Pandhi, Aaron B. Pearlman, Ue-Li Pen,, Emily Petroff, Ziggy Pleunis, Masoud Rafiei-Ravandi, Mubdi Rahman, Scott M. Ransom, Andre Renard, Ketan R. Sand, Pranav Sanghavi, Paul Scholz, Vishwangi Shah, Kaitlyn Shin, Seth Siegel, Kendrick Smith, Ingrid Stairs, Jianing Su, Shriharsh P. Tendulkar, Keith Vanderlinde, Haochen Wang, Dallas Wulf, Andrew Zwaniga, and The CHIME/FRB Collaboration, 26 April 2023, The Astrophysical Journal.
DOI: 10.3847/1538-4357/acc6c1

Apart from Michilli, Shin, and Masui, MIT contributors to the study include physics graduate students Calvin Leung and Haochen Wang.

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More about Fast Radio Bursts

• The Astrophysical Journal
• CHIME/FRB Discovery of 25 Repeating Fast Radio Burst Sources
• MIT Kavli Institute for Astrophysics and Space Research
• MIT Department of Physics
• Canadian Hydrogen Intensity Mapping Experiment (CHIME)