Astronomers Detect Repeating Radio Signals from a Remote ‘Dead’ Galaxy

Astronomers have detected fast-repeating radio bursts (FRBs) emanating from a distant “dead” galaxy that lacks the energy typically required to produce such signals, according to a recent study published in The Astrophysical Journal Letters.

FRBs—brief, intense flashes of radio waves lasting mere milliseconds—are often linked to young, highly magnetized neutron stars expelling large amounts of energy during their formation. However, the ancient elliptical galaxy associated with these bursts contains only old, inactive stars, making this discovery an unexpected anomaly.

The specific FRBs, labeled FRB 20240209A, originate from a region outside the massive galaxy, which is about 2 billion light-years from Earth and estimated to be 11.3 billion years old. “This discovery was really surprising and exciting,” said Vishwangi Shah, a PhD student at McGill University’s Department of Physics and Trottier Space Institute.

Using the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope, Shah and her team identified multiple bursts from the same location. To pinpoint the exact source, they combined CHIME data with observations from a smaller CHIME-like telescope. Subsequent imaging with the Gemini North telescope in Hawaii confirmed the absence of any nearby galaxies, solidifying the connection between the FRBs and the dormant galaxy.

“There’s no other galaxy there,” Shah explained.

Since their initial discovery in 2007, thousands of FRBs have been recorded, but precise locations have been determined for only about 100, all typically near star-forming regions. The uniqueness of FRB 20240209A challenges existing theories about the origins of FRBs.

Astronomers hypothesize that these FRBs could be produced by the merging or collapsing of two neutron stars within supernova remnants. Shah emphasized the importance of studying such outliers to better understand cosmic phenomena and the vast regions of space between their origins and Earth.

“This particular FRB is an outlier and challenges our theories about what is producing FRBs,” Shah said. “Continuing to study them will help us learn more about distant regions of space and the universe as a whole.”