An international team of astronomers has detected the most distant fast radio burst (FRB) ever recorded, FRB 20240304B. This fleeting cosmic signal was captured by South Africa's MeerKAT radio telescope on March 4, 2024. The burst originates from an era when the universe was approximately three billion years old, about 11 billion years ago, during the "cosmic dawn" period when star formation was at its peak.
The red-shift of FRB 20240304B is approximately 2.148. The James Webb Space Telescope (JWST) was crucial in pinpointing the source of this ancient burst, identifying it within a small, active galaxy with a stellar mass of about 10 million solar masses. This galaxy is characterized by low metal content and a vigorous rate of new star formation. The signal itself exhibited a high degree of linear polarization (49%) and low circular polarization (3%), with a significant dispersion measure of approximately 2,330 parsecs per cubic centimeter, indicating its immense journey through intergalactic space. This discovery effectively doubles the redshift reach of localized FRBs, allowing astronomers to probe ionized baryons across approximately 80% of the universe's history. The characteristics of FRB 20240304B, particularly its occurrence in a young, actively star-forming galaxy, support theories that FRBs originate from highly magnetized neutron stars known as magnetars.