By Margherita Bassi Published January 23, 2025 | Comments (0) | The CHIME telescopes that detected the February 2024 FRB. CHIME, Andre Renard, Dunlap Institute for Astronomy & Astrophysics, University of Toronto The energy flare came from an old galaxy, upending prevailing theories about the source of fast radio bursts. In February 2024, scientists on Earth detected a powerful radio blast from outer space. Seeking to discover where it had come from, they traced the brief flash of energy back to its extraterrestrial sourceand discovered something unexpected. Scientists led by Northwestern University and McGill University have traced a fast radio burst (FRB) to the edges of an ancient elliptical galaxy. Scientists had previously thought that these quick radio blasts, which generate more energy in a single flare than our Sun generates in an entire year, are exclusively produced by young galaxies that steadily churn out new stars. The recent investigations, however, detailed in two sister studies published on January 21st in The Astrophysical Journal Letters, are prompting astronomers to reconsider the potential diversity of FRB sources. Dubbed FRB 20240209A, the February 2024 FRB wasnt just a one-and-done. Between February and July 2024, the same source flared 21 times.The prevailing theory is that FRBs come from magnetars formed through core-collapse supernovae, Tarraneh Eftekhari of Northwestern University, who participated in both studies, said in a university statement. Magnetars are neutron stars with very powerful magnetic fieldsand neutron stars are extremely small and dense celestial objects thought to form in the wake of some large stars explosive deaths, that is, supernovae. That doesnt appear to be the case here, Eftekhari continued. While young, massive stars end their lives as core-collapse supernovae, we dont see any evidence of young stars in this galaxy. Thanks to this new discovery, a picture is emerging that shows not all FRBs come from young stars. Maybe there is a subpopulation of FRBs that are associated with older systems.The old galaxy in question is 11.3 billion years old, and 2 billion lightyears away from us. Using computer simulations, Eftekhari and her colleagues discovered that the galaxy is extremely bright, and 100 billion times more massive than our Sun. It seems to be the most massive FRB host galaxy to date, Eftekhari said. Its among some of the most massive galaxies out there. Not only did the unusual FRB originate from an old galaxy, it also came from that galaxys edgespecifically, 130,000 lightyears from its center.The February FRB, marked with the oval outlines, is far from its home galaxy, the big yellow splotch. Gemini Observatory Among the FRB population, this FRB is located the [farthest] from the center of its host galaxy, said Vishwangi Shah of McGill, who participated in both studies. This is both surprising and exciting, as FRBs are expected to originate inside galaxies, often in star-forming regions. The location of this FRB so far outside its host galaxy raises questions as to how such energetic events can occur in regions where no new stars are forming. But FRB 20240209A is not the first FRB to be detected far away from regions of active star formationits the second. In 2022, astronomers traced M81 FRB, which is located 12 million light years from Earth, to a cluster of stars on the edge of galaxy Messier 81. FRB 20240209A could be a twin of the M81 event [M81 FRB]. It is far from its home galaxy (far away from where any stars are being born), and the population of stars in its home galaxy is extremely old. Its had its hey-day and is now coasting into retirement, said Wen-fai Fong of Northwestern University, who participated in both studies. At the same time, this type of old environment is making us rethink our standard FRB progenitor models and turning to more exotic formation channels, which is exciting.One of the studies suggests that, like M81 FRB, the new FRB might have also originated from a cluster of stars, called a globular cluster. A globular cluster origin for this repeating FRB is the most likely scenario to explain why this FRB is located outside its host galaxy, Shah explained. We do not know for a fact if there is a globular cluster present at the FRB position and have submitted a proposal to use the James Webb Space Telescope for follow-up observations of the FRB location. If yes, it would make this FRB only the second FRB known to reside in a globular cluster. If not, we would have to consider alternative exotic scenarios for the FRBs origin.In other words: back to the drawing board!Daily NewsletterYou May Also Like By Passant Rabie Published January 21, 2025 By Margherita Bassi Published January 19, 2025 By Isaac Schultz Published January 18, 2025 By Isaac Schultz Published January 14, 2025 By Passant Rabie Published January 10, 2025 By Margherita Bassi Published January 10, 2025