An extremely powerful radio wave signal that originated more than 10 billion years ago has reached Earth, offering scientists an unprecedented glimpse into the early universe. Designated FRB 20240304B, it is the most distant localized fast radio burst (FRB) ever recorded. According to researchers, the burst occurred when the universe was about 3 billion years old, during a period known as "cosmic noon," characterized by rapid star formation.
Discovery and Observation
The discovery was made using the MeerKAT radio telescope in South Africa by an international team, including astronomers from the University of Sydney. The findings were published on the preprint website arXiv in August 2025. FRB 20240304B was first detected on March 4, 2024, by a Transient User Supplied Equipment system connected to MeerKAT. It exhibited an exceptionally high "dispersion measure," indicating the vast amount of material the radio wave traversed through space.
Scientists measured the burst's redshift at 2.148 ± 0.001, which allowed them to determine its distance and travel time. The signal traveled for more than 11 billion years before being observed on Earth, as reported by Phys.org.
Significance of the Discovery
Most previously detected FRBs originated from much closer regions, typically with redshifts below 0.5. High-redshift bursts like FRB 20240304B are invaluable for studying the early universe and the distribution of matter across the cosmos. The research paper states that this discovery "underscores the potential of FRBs as powerful probes of the cosmic web"—the vast network of matter and gas between galaxies. The burst's radio signals are altered as they pass through matter, providing insights into cosmic structure.
Moreover, this discovery doubles the highest redshift reached by localized FRBs.
Host Galaxy Identification
After detecting the burst, scientists used the James Webb Space Telescope (JWST) to trace its origin. The host galaxy is a clumpy, star-forming galaxy with a stellar mass about 10 million times that of the Sun. Its star formation rate is roughly 0.2 solar masses per year. JWST's NIRCam and NIRSpec instruments established the galaxy's spectroscopic redshift. The galaxy has low metallicity, approximately 0 to 20 percent of the Sun's metallicity.
Polarization and Magnetic Fields
FRB 20240304B displayed unusual polarization characteristics: a linear polarization fraction of 49 percent and a circular polarization fraction of only 3 percent. Scientists suggest this may indicate weak or complex magnetic fields along the signal's path. Such studies could help unravel mysteries of galaxy formation, matter distribution, and the origins of FRBs.
About the Author
This article is from the TOI Science Desk, a team of journalists dedicated to curating captivating science news for The Times of India. They cover topics from genetic engineering to space exploration, making science accessible to all readers.
